Requirements for the design and operation of flare systems. general provisions. flare installations. space and facility requirements. requirements for equipment, communications, automation. Vertical Flares Serviced

SUBSTANCE: invention relates to heads of flare installations for burning emergency, permanent and periodic emissions of combustible gases, can be used in petrochemical, oil refining and other industries and improves the reliability and service life of the head by eliminating the effect of flame on the outer surface of the main burner and windshield. The head of the flare unit contains the main burner for burning the discharged gas, pilot burners, a windproof device installed coaxially and forming an annular gap with it, made in the form of a cylinder, open from above and plugged from below by the bottom, installed on the main burner, the walls of the cylinder are made in the form of a shell and a set of evenly spaced blades installed between the shell and the bottom, the blades are made in the form of cylinder sectors, and the outer parts of the blades touch the radial planes. 2 ill.

Drawings to the RF patent 2344347

SUBSTANCE: invention relates to heads of flare installations for burning emergency, permanent and periodic emissions of combustible gases and can be used in petrochemical, oil refining and other industries.

Known tip flare installation containing the main burner (cylindrical pipe), windscreen installed in the upper part of the tip coaxially with the main burner and forming an annular gap with it, pilot burners (see RF patent 2095686, IPC F23D 14/38, publ. 11.10 .1997) (analogue).

This heading works as follows. The combusted gas enters the main burner in the form of a cylindrical pipe and is ignited by pilot burners when it exits. The windscreen keeps the flame upright. However, this windshield does not protect the outer surface of the main burner from flame exposure in side winds. This is explained by the fact that with a side wind from the leeward side of the tip, a low-pressure zone is formed with a separated recirculation air flow, into which the flame is sucked down through the annular gap. As a result of the thermal effect of the flame, the reliability and service life of the flare head are reduced.

This drawback is partially eliminated in the flare units described in the catalog of the industrial organization "Generation" page 4 (see the website of the PG "Generation" www.generation.ru) (prototype).

In these installations, the head contains the main burner in the form of a cylindrical pipe, outside of which a cylindrical-conical windscreen and pilot burners are installed coaxially. The conical section of the windscreen is located in the upper part of the screen and covers the annular gap between the cylindrical pipe and the windscreen.

The principle of operation of such a head is as follows. The combusted gas enters the main cylindrical burner of the head and is ignited by the pilot burners when it exits. Cylindrical windscreen protects the outer surface of the main burner from flames in crosswinds. However, in this case, the outer surface of the cylindrical windshield is exposed to heat as a result of the lowering of the flame from the leeward side into the zone of low pressure and the recirculation flow behind the screen. This leads to a thermal effect on the screen, reduces the reliability and service life of the head, and requires periodic replacement of the windscreen.

The technical result of the invention is to increase the reliability and increase the service life of the head by eliminating the effect of the flame in a side wind on the outer surfaces of the main burner and windshield.

To achieve this goal, the head of the flare installation contains, like the prototype closest to it, the main burner with a coaxial wind protection device installed on it, forming an annular gap with it (the burner), and pilot burners.

In contrast to the well-known head, the windscreen is made in the form of a cylinder, open from above and muffled from below by a bottom mounted on the main burner, the walls of the cylinder are made in the form of a shell mounted on top and a set of evenly spaced blades installed between the shell and the bottom. The blades are made in the form of cylinder sectors, the outer parts of the blades touch the radial planes.

Figure 1 shows a longitudinal section of the head of the flare installation, figure 2 - section A-A of figure 1.

The head contains the main burner 1 and coaxially installed on it a windshield, which forms an annular gap 2 and pilot burners 3 with it. and a set of evenly spaced blades 6. The blades are made in the form of cylinder sectors, the outer parts of the blades touch the radial planes 7.

The proposed heading works as follows.

The combusted gas enters the main burner 1 of the head and, upon exiting, is ignited by the pilot burners 3. In the case of a side wind from the windward side, the wind flow enters through the gaps between the blades 6 inside the wind protection device into the annular gap 2, acquiring rotational motion. Only a small part of the incoming air can exit to the leeward side through the gap between the blades 6, because to exit the rotating air flow, it is necessary to change the direction almost to the opposite, and this is due to overcoming a large hydraulic resistance. In order to create such an air movement in the annular gap 2, the blades 6 are mounted so that their outer parts touch the radial surfaces 7, while the inner parts are directed tangentially. Deaf bottom 4 excludes the movement of air from the gap 2 down. All this leads to the movement of air upwards, which prevents the lowering of the flame and its impact on the head structure. The shell 5 protects the flame of the main burner 1 and pilot burners 3 from the effects of wind gusts.

CLAIM

The head of the flare unit, containing the main burner for burning the discharged gas, the pilot burners and the windproof device, installed coaxially and forming an annular gap with it, made in the form of a cylinder, open from above and muffled from below by the bottom, installed on the main burner, the walls of the cylinder are made in the form of a shell and a set of evenly spaced blades installed between the shell and the bottom, the blades are made in the form of cylinder sectors, and the outer parts of the blades touch the radial planes.

A 30" diameter steam flare tip is offered with a pilot burner ignition and flame control panel. The 30" tip diameter is selected based on a flare stack diameter of 800 mm, a 6" diameter tip would suffice to burn a maximum emergency discharge of 1630 kg/h.

Flaring process data

Notes:

* The steam pressure at the head inlet must be at least 7 barg.
** Steam temperature 250 °С (calculated).

Notes:

* The supply of steam will ensure completely smokeless combustion of the discharged gas.
** Noise levels include ±3 dB tolerance. Noise levels do not include negligible background noise. The background noise must be at least 10 dB less than the calculated noise levels in each frequency range.

Notes:

* The purge gas can be any gas above the dew point under ambient conditions without oxygen, without steam and without hydrogen.
** The steam pipe running along the flare shaft must be insulated without fail in order to ensure the necessary steam parameters at the flare head.

Main offer

• Flare tip with steam assist, equipped with a stabilization ring, windscreen, steam lines, pilot lines and manifold
• Aerodynamic shutter
• 3 (three) windproof pilot burners with high energy igniter. Each pilot burner is equipped with a single thermocouple
• Connection cable box for connecting thermocouple with cable
• Mating flanges with gaskets and bolts (fasteners) including 10% spare bolts and 2 gasket sets per size.
• Pilot gas control unit
• Manual/Automatic combined ignition system (high energy and flame front generator) including high energy electrodes, cables from transformer to electrodes, ignition piping from ignition unit to pilot burners.
• 140 m thermocouple extension cable
• 3x140m high energy ignition cable
• Technical documentation in Russian, GOST-R certificate.

Optional:

• Optical flame detection system for pilot burners
• Steam control unit

The Economical Steam Flare Tip is a cost-effective solution for achieving smokeless combustion. Although the headband has been used effectively for some time, our new design offers improved performance.

• Efficient smokeless combustion
• Improved sound insulation and steam consumption
• Work stability
• Wear minimization
• Flame drop reduction

Smokeless operation:

Smoke appears when gases are not completely burned, and the burnt carbon enters the atmosphere in the form of smoke. Incomplete combustion is the result of not enough mixed air in the center of the flame to ensure complete combustion. The flare head mixes the air and gas inside the flame and ensures complete combustion. The flare tip design consists of a multi-point system of steam nozzles mounted on a manifold (with O-ring) at the top of the flare tip. To achieve smokeless combustion, the flare head can only be operated using the required amount of steam, while maintaining a minimum flow rate.

Stability:

Conventional tubular flares exhibit incomplete combustion, and at high exit velocities may be extinguished due to insufficient flame stability. To eliminate this problem, the company provides a flame retention cap that creates a low pressure zone at the outlet. This low pressure zone guarantees both complete combustion of the exhaust gases and flame stability at high outlet speeds.

Lowering the flame:

When wind acts on the flare tip, a low pressure zone is created on the leeward side of the flare. This low pressure zone draws the flame down, causing the gases to act and burn on the body, as shown in the cap without the ring on the right. The ring is located along the perimeter of the flare head, which is designed to raise the flame vertically and reduce the lowering of the flame. The result of additional protection is an increase in the service life of the head. A wind guard is also provided as additional protection.

Flare head with steam supply

Manual/automatic ignition and flame control panel, combined, climate/explosion proof

Manual/Auto ignition systems for remote ignition of pilot burners.

Rolling Fire Generator and High Energy Ignition System with Control Box

Explosion-proof ignition control panel, made of die-cast aluminum, suitable for zone 2, gas group II B, TK, includes the following components:

• 1 Power on/off selector
• 1 Power on/off indicator
• 1 Running fire button "Ignition"
• 1 Ignition transformer for running fire
• 1 Indicator test button
• 1 Selector switch for manual or automatic ignition
• 3 High Energy Ignition Buttons
• 6 on/off indicators for pilot status
• Free contact for consumers
• When the thermocouple detects flame failure on its pilot burner, it will automatically start the emergency burner re-ignition sequence.

Junction boxes

The scope of delivery includes the following die-cast aluminum junction boxes:

• Qty 1 CK Top Level for Thermocouples
• Qty 1 CK stem base for thermocouples
• Qty 1 CK top level for high voltage cables
• Qty 1 CK flame base with 3 high energy ignition units

Cables

The scope of delivery includes the following cables:

• Teflon thermocouple compensating cable (3 pairs) insulated along the flare stack.
• Compensating armored PVC cable for thermocouples (3 pairs), insulated, from the flare stack to the ignition panel (length is predetermined)
• Habia high-voltage heat-resistant cable along the flare stack.
• Draka high-voltage heat-resistant cable from the base of the flare stack to the ignition panel (length is predetermined).

Windproof pilot burners

The windproof pilot burner offers the best flame detection and ignition flexibility for flare pilot burners along with proven high performance. The burner is capable of sustaining combustion in winds of 160 mph.

Powerful electrodes are used in the pilot burner nozzles. These are high-temperature ceramic electrodes, which are placed in a stainless steel protective tube.

Windproof pilot burner

The following device is a gas flow dependent device that operates on the condition that atmospheric air enters the flare system along the inner walls of the flare tip. This is a conical structure, which is located inside the flare tip. It prevents the passage of air down the inner wall and redirects its movement up and to the center. In addition, reducing the airflow increases and focuses the purge gas flow to the center of the tip, forcing any atmospheric air out of the tip.

The cost of operation increases due to the consumption of purge gas. Three identical flare stacks were built to demonstrate the effectiveness of the devices in terms of reducing purge gas volume requirements and, at the same time, in preventing oxygen from entering the flare system. One of them is equipped with a molecular gate, the other is equipped with this device, and the third does not have any device. The flare stacks were operated for 8 months, during which the oxygen content was measured 6 meters below the flare tip.

As shown in the above datasheet, this device significantly reduces the purge gas velocity. It only needs 0.012 m/s of purge gas to maintain an acceptable oxygen level for all adverse weather conditions. The minimum purge gas velocity without device is 0.06 to 0.15 m/s. If zero oxygen access or protection against potential purge gas losses is required, a molecular seal should be used.

Steam control unit

The steam supply control unit is designed for smooth regulation of steam supply to the head depending on the flow rate of the flare gas.
This block consists of a flow meter, a pressure sensor and a pneumatic control valve.
This unit must be controlled from the customer's automated process control system.
The company provides a steam supply versus flare gas flow rate curve.
The development of the control program is not included in the scope of delivery.
For the operation of this unit, information on the flow of flare gas is required.
The flare gas flow meter is not included in the scope of supply.

Optical flame detection system for pilot burners

Flare systems are designed to burn explosive gases in normal operation and in emergency situations. When the flame goes out, explosive gases can be accidentally released into the environment. Constant flame friction of the flare pilot burner is a fundamental requirement for the correct operation of the system and ensuring safety. and presently, the flame of many pilot burners is controlled by the use of thermocouples which must be mounted in the flare. This system, while effective, can be problematic if the thermocouple fails. Thermocouple failure can occur on some flares due to a combination of heat and oxidation. Access to faulty components is often difficult and expensive. When the system is disabled, no safety status is provided for the pilot burner.

APPROVED

Gosgortekhnadzor

RULES
DEVICE AND SAFE OPERATION
FLARE SYSTEMS

PB 09-12-92

Editorial team: E. A. Malov, E. S. Starodubtsev, A. A. Shatalov, R. A. Standrik, A. I. Elnatanov, A. V. Kulikov

These Rules have been prepared on the basis of the Rules for the Design and Safe Operation of Flare Systems, approved by the USSR Gospromatomnadzor on December 3, 1991, with a number of additions and changes.

When preparing the Rules, the advanced experience of domestic enterprises and foreign firms in the field of ensuring the safe operation of flare systems was taken into account.

The rules apply to enterprises and organizations of the chemical, petrochemical, oil refining industries, regardless of ownership.

With the entry into force of these Rules, the Rules for the Construction and Safe Operation of Flare Systems approved in 1984 (PU and BEF-84) shall be deemed invalid.

1. GENERAL PROVISIONS

1.1. The flare system is designed for discharge and subsequent combustion of combustible gases and vapors in the following cases:

actuation of emergency discharge devices, safety valves, hydraulic seals, manual bleed, as well as the release of process units from gases and vapors in emergency situations automatically or using remotely controlled shut-off valves, etc.;

constant blow-offs provided for by the technological regulations;

periodic discharges of gases and vapors, start-up, adjustment and shutdown of technological facilities.

The terms used in these Rules and their definitions are given in Appendix. .

1.2. The design, construction, reconstruction and operation of flare systems for fire and explosion hazardous and explosive industries controlled by the Gosgortekhnadzor of Russia must be carried out in accordance with the requirements of building codes and regulations, the General Explosion Safety Rules for fire and explosion hazardous chemical, petrochemical and oil refining industries, the Rules for the Design and Safe Operation of Vessels Operating Under pressure, the Rules for the Design and Safe Operation of Pipelines for Combustible, Toxic and Liquefied Gases, the Instructions for Arranging Lightning Protection of Buildings and Structures, and these Rules.

The procedure and terms for bringing existing flare systems in line with the requirements of these Rules are determined by the heads of enterprises in agreement with the bodies of the Gosgortekhnadzor of Russia.

1.3. Prior to bringing flare systems in line with the requirements of these Rules, enterprises, together with design organizations, must develop and approve in the prescribed manner measures to improve the safety of existing flare systems, agreed with the bodies of the Gosgortekhnadzor of Russia.

1.4. At enterprises operating flare systems, instructions for their safe operation must be drawn up and approved in accordance with the established procedure.

These instructions are subject to review every five years. If it is necessary to make additions to the instructions, as well as in case of changes in the scheme or mode of operation, they must be revised before their expiration date.

1.5. Commissioning of newly constructed flare systems with deviations from these Rules, as well as without instructions for safe operation, is prohibited.

In justified cases, deviations from the Rules are agreed with the Gosgortekhnadzor of Russia in the prescribed manner.

1.6. To control the operation of flare systems, by order (instruction) for the enterprise, production, workshop where these systems are operated, responsible persons who have passed the test of knowledge of these Rules are appointed from among the engineering and technical workers.

1.7. Electrical receivers of flare systems (flame control devices, igniters and instrumentation) are classified as consumers of the first category in terms of power supply reliability.

2. TYPES OF DISCHARGE AND REQUIREMENTS FOR THEM

2.1. When designing technological processes, if necessary, provision should be made for the block-by-block release of equipment and pipelines from explosive gases and vapors with the appropriate automatic, according to a given program, or remote control of shut-off devices that stop the flow of gases and vapors into the emergency unit.

2.2. Discharges of combustible gases and vapors, divided into permanent, periodic and emergency, for combustion or collection and subsequent use should be sent to flare systems:

general (subject to compatibility of discharges);

separate;

special.

Schematic diagrams of the discharge of gases and vapors are given in App. And .

2.3. For each source of discharge of gases and vapors directed to flare systems, their possible compositions and parameters (temperature, pressure, density, flow rate, discharge duration, as well as parameters of maximum, average and minimum total discharges from the facility) should be determined.

2.4. To prevent the formation of an explosive mixture in the flare system, it is necessary to use a purge gas - fuel or natural, inert gases, including gases produced at process plants and used as inert gases.

A schematic diagram of the purge gas supply is given in App. .

2.5. The oxygen content in purge and exhaust gases and vapors, including gases of complex composition, must not exceed 50% of the minimum explosive oxygen content in a possible mixture with fuel.

2.6. When discharging hydrogen, acetylene, ethylene and carbon monoxide and mixtures of these fast-burning gases, the oxygen content in them should not exceed 2% by volume.

2.7. It is forbidden to send substances into the flare system, the interaction of which can lead to an explosion (for example, an oxidizing agent and a reducing agent).

2.8. Gases and vapors discharged into the common and separate flare systems should not contain dropping liquid and solid particles. For these purposes, separators must be installed within the boundaries of the process plant.

In the flare header and supply pipelines, the temperature of gases and vapors must be such that the possibility of crystallization of discharge products is excluded.

2.9. For a flare system with a hydrocarbon gas and vapor collection unit, the temperature of discharged gases and vapors at the outlet of the process unit must be no higher than 200 and no lower than -30 °C, and at a distance of 150-200 m before entering the gas tank - no more than 60 °C .

2.10. It is forbidden to use as fuel discharged hydrocarbon gases and vapors with a volume content of inert gases in them of more than 5%, substances I and II hazard classes (except for benzene) - more than 1%, hydrogen sulfide - more than 8%.

Discharges, during the combustion of which harmful substances are formed or stored in the combustion products I and II hazard classes should be sent to special containers for further disposal and processing.

Deviations from the requirements of this paragraph may be allowed only with appropriate justification and in agreement with the bodies of the Gosgortekhnadzor of Russia.

2.11. Continuous and periodic discharges of gases and vapors into common flare systems into which emergency discharges are directed are not allowed if the combination of these discharges can lead to an increase in pressure in the system to a value that prevents the normal operation of safety valves and other emergency devices.

2.12. Pressure losses in flare systems at maximum discharge should not exceed:

for systems to which emergency discharges of gases and vapors are directed - 0.02 MPa at the process unit and 0.08 MPa in the section from the process unit to the exit from the flare stack head;

for systems with a hydrocarbon gas and vapor collection unit - 0.05 MPa from the process unit to the exit from the flare stack head.

For individual and special flare systems, pressure losses are not limited and are determined by the conditions for the safe operation of the devices connected to them.

2.13. Combustible gases and vapors discharged from process equipment through hydraulic seals designed for a pressure lower than the pressure in the flare header should be directed to a special flare system or through a special flare pipeline that is not connected to the header from other emergency relief safety devices, permanent and periodic discharges .

A special pipeline through a separate separator must be connected directly to the flare stack.

2.14. In justified cases, it is allowed to install shut-off valves after hydraulic seals at the place of tie-in into the common flare system (with the exception of the possibility of its accidental closing). At the same time, additional security measures are provided, including the removal of the stop valve handwheel, sealing it in the open state, installing special covers on it, and outputting a signal about the position of the valve to the control panel.

The type of stop valves is determined by the design organization.

3. DISCHARGE FROM RELIEF VALVES

3.1. Effluents from safety valves are directed to flare systems.

3.2. Discharges of gases and vapors from safety valves installed on vessels and apparatuses working with media that are not explosive and harmful substances, as well as discharges of light gases, may be directed through a discharge pipe into the atmosphere.

The arrangement of discharge pipes and discharge conditions must ensure effective dispersion of discharged gases and vapors, excluding the formation of explosive concentrations in the area of ​​technological equipment, buildings and structures. The calculation of combustible gas concentrations when discharged through a discharge pipe is given in App. . At the same time, devices should be provided to prevent liquid from entering the discharge pipes and its accumulation.

Notes.

1. Light gases include methane, natural gas and hydrogen-containing gas with a density of not more than 0.8 relative to the density of air.

2. If it is possible to change the composition of the discharged gas, leading to an increase in its density of more than 0.8 in relation to the density of air, the discharge of gas into the atmosphere is not allowed.

3. When organizing discharges into the atmosphere, one should be guided by the Methodology for calculating the concentration in the atmospheric air of harmful substances contained in the emissions of enterprises, and sanitary standards.

3.3. Discharges from safety valves of combustible gases and vapors containing substances I and II hazard classes in quantities not exceeding 1% by volume (hydrogen sulfide - up to 8% by volume), it is allowed to be directed to the common flare system.

3.4. Discharges from safety valves of gases and vapors containing substances of I and II hazard classes in quantities of more than 1% by volume must be cleaned and neutralized (neutralization, absorption, decomposition, combustion, etc.). For incineration, such discharges are sent to a separate or special flare system.

3.5. Combustible gases and vapors from safety valves installed on storage tanks intended for the storage of liquefied hydrocarbon gases and flammable liquids must be discharged into a separate or special flare system.

In justified cases, such discharges may be sent for burning into the flare stack of the common flare system.

4. COLLECTORS, PIPING, PUMPS

4.1. For individual and special flare systems, one flare collector and one flare unit should be provided.

General flare systems should have two flare headers and two flare units to ensure non-stop operation.

When discharges into the common flare system of gases, vapors and their mixtures that do not cause corrosion more than 0.1 mm per year, it is allowed to provide flare installations with one collector.

4.2. On common flare systems in places where pipelines branch, in order to disconnect technological installations, warehouses from flare systems, switch separators, collectors and flare stacks, it is possible to place locking devices in a horizontal position, sealed in the open state.

4.3. Flare collectors and pipelines should be of minimum length and have a minimum number of turns, they must be laid above the ground (on supports and overpasses).

4.4. It is forbidden to install stuffing box compensators on flare collectors and pipelines.

4.5. Thermal compensation of flare collectors and pipelines should be calculated taking into account the maximum and minimum temperatures of discharged gases and vapors, the maximum steam temperature for steaming, as well as the temperature of the heating medium for heated collectors and the average temperature of the coldest five-day period.

4.6. Collectors and pipelines of flare systems should be, if necessary, thermally insulated and (or) they should be equipped with heating traces to prevent condensation and crystallization of substances in flare systems.

4.7. In flare installations designed to burn hot gases and vapors, a separator with a permanent liquid withdrawal should be used.

4.8. Flare collectors and pipelines must be laid with a slope towards separators of at least 0.003. If it is impossible to maintain the specified slope, condensate drain devices are placed at the lowest points of the flare collectors and pipelines. The design of condensate collectors must exclude liquid entrainment and provide for their thermal insulation and external heating. Condensate collectors should be emptied automatically, and in justified cases - remotely from the control room. Centrifugal pumps are used to pump condensate from separators and collectors.

4.9. The tie-in of shop pipelines into the flare header must be made from above in order to exclude their filling with liquid.

4.10. If the content of condensate in separators at flare units intended for combustion of vapors of low-boiling liquids (including propane, propylene, ammonia and ammonia-containing gases) is insignificant, it is allowed to remove liquid from the separator by supplying steam or hot water to the external coil heating the separator, while it is necessary eliminate the possibility of increasing the pressure in the tank above the calculated one.

4.11. In the presence of solid or resinous deposits in the waste gases, two parallel separators should be installed. With a low content of impurities, the separator can be equipped with a bypass line with a system of interlocked "closed-open" valves and quick-detachable plugs that provide a constant gas flow and the possibility of cleaning the separator.

4.12. Depending on the installation location, it is necessary to use pumps manufactured in 1 or 2 placement categories in accordance with.

4.13. The installation of the flare separator and the pump in relation to each other is carried out on the basis of the condition of ensuring that the pump is filled with condensate when it enters the separator and to exclude the occurrence of cavitation during pump operation.

4.14. The suction piping must be of minimum length and slope towards the pump, and must be free of stagnant zones.

Horizontal sections of suction pipelines should be located at the bottom (at the pumps). It is necessary to avoid horizontal sections immediately after the separator, for which the outlet of the suction pipeline from the lower fitting of the separator to the pump should be placed vertically down.

4.15. The diameter of the suction pipe is determined by the maximum performance of the pump, taken from the characteristic curve.

4.16. All pipelines and pump piping fittings must be heated and insulated to prevent freezing during the cold season.

4.17. Turning on and off pumps for pumping condensate from collectors and separators must be both automatic and from their installation site (performed in accordance with the diagram of the appendix).

with constant and periodic discharges - by the sum of periodic (with a coefficient of 0.2) and permanent discharges from all connected technological installations, but not less than the sum of constant discharges and the maximum periodic discharge (with a coefficient of 1.2) from the installation with the highest value of this reset;

in case of emergency discharges - by the sum of emergency discharges (with a coefficient of 0.25) from all connected installations, but not less than by the value of the emergency discharge (with a coefficient of 1.5) from the installation with the largest value of this discharge.

Note.

It is allowed to calculate the throughput for the sum of emergency discharges from all connected process units; in case of emergency, permanent and periodic discharges - for the sum of all types of discharges calculated in accordance with the procedure established by this paragraph.

4.20. The area of ​​the passage section of valves for emergency release with manual or remote activation of the drive must correspond to the throughput of the flare collector at the outlet of the unit.

4.21. On pipelines of discharged gases and vapors, flange connections are installed only at the points of attachment of fittings, instrumentation, and for field connections - in places where welding is not feasible.

Each weld of the flare header (pipeline) and the flare stack is inspected by a non-destructive method that provides effective quality control of the weld.

4.22. The manifold before the flare stack or on the flare stack shall have a flanged connection for the installation of a plug for strength testing.

4.23. To purge process units and workshop flare pipelines with nitrogen or air during start-up or shutdown for repairs, in justified cases, a candle with shut-off valves is installed at the exit from the process unit.

4.24. To avoid the formation of an explosive mixture, it is necessary to provide for a continuous supply of purge (fuel or inert) gas to the beginning of the flare header. In the event of a fuel gas supply failure, an automatic supply of inert gas shall be provided. The amount of purge gas is determined in accordance with clause of these Rules.

5. FLARE PLANT

5.1. During the operation of the flare unit, it is necessary to ensure stable combustion in a wide range of gas and vapor flow rates, smokeless combustion of constant and periodic discharges, as well as a safe heat flux density and prevention of air ingress through the upper section of the flare stack.

5.2. The design of the flare unit should provide for the presence of a flare stack equipped with a cap and a gas seal, control and automation equipment, a remote electric ignition device, fuel gas and combustible mixture supply pipelines, pilot burners with igniters.

If necessary, the flare unit is equipped with a separator, a water seal, a flame arrester (when acetylene is discharged), pumps and a condensate drain.

Notes.

1. In justified cases, for the combustion of gases and vapors, it is allowed to use special ground-based flare installations without a flare stack.

2. In the presence of solid and resinous substances in waste gases and vapors, which, when deposited, reduce the area of ​​the flow section of the gas seal, the latter is not installed.

5.3. To ensure stable (without stall) combustion, the diameter of the upper cut of the flare head should be calculated from the maximum speed of gases and vapors, which should not exceed 0.5 of the speed of sound in the waste gas. When burning gases and vapors with a density of more than 0.8 relative to the density of air, the discharge velocity should not exceed 120 m/s.

5.4. For complete combustion of discharged hydrocarbon gases and vapors (with the exception of natural and non-smoking gases), the supply of steam, air or water should be provided. The amount of steam is determined by calculation based on the condition for ensuring smokeless combustion of permanent discharges.

If the ratio of the shedding speed to the speed of sound is greater than 0.2, no steam is required.

5.5. Pilot burners with igniters should be installed on the flare head. The number of burners is determined depending on the diameter of the flare tip in accordance with the data below

5.6. Fuel gas for pilot burners must be provided to the flare stack, and fuel gas and air for preparing the ignition mixture should be provided to the flame ignition device. To prevent condensation of water vapor and its freezing in pipelines during the cold season, fuel gas must be dried or supplied through a heated pipeline. Fuel gas must not contain mechanical impurities.

not less than 0.05 m/s - with a gas seal;

not less than 0.9 m / s - without a gas seal at a purge (fuel) gas density of 0.7 kg / m 3 or more;

not less than 0.7 m/s - without a gas seal with an inert purge gas (nitrogen).

Note.

In flare systems not equipped with gas seals, it is forbidden to use fuel gas with a density less than 0.7 kg/m 3 as a purge gas.

10.3. Before discharging of combustible gases and vapors heated to a high temperature, it is necessary to provide an additional supply of purge gas in order to prevent the formation of a vacuum in the flare system during cooling or condensation.

10.4. Before carrying out repair work, the flare system must be disconnected from the process units with standard plugs and purged with nitrogen (if necessary, steamed) until the combustible substances are completely removed, followed by air purging to a volume content of oxygen of at least 18% and a content of harmful substances not more than MPC.

Specific measures to ensure the safety of repair work should be developed in accordance with the guidance materials.

10.5. Repair of flare tips when several flare stacks are located in the common fencing area should be carried out in a heat-protective suit.

10.6. During a thunderstorm, it is forbidden to be on the site of the flare installation and touch metal parts and pipes.

10.7. Persons who are not involved in the operation of flare systems are prohibited from staying in the flare stack fencing zone.

10.8. Flare installations must be provided with primary fire extinguishing equipment in accordance with current regulations.

Annex 1

TERMS AND DEFINITIONS

EMERGENCY RESETS- combustible gases and vapors entering the flare system when operating safety valves and other emergency discharge devices operate. The value of the emergency discharge is taken equal to the maximum possible discharge from the process unit.

GAS GATE- a device to prevent air from entering the flare system through the top section of the flare stack and reduce the purge gas flow rate.

MINIMUM EXPLOSIVE OXYGEN CONTENT - the concentration of oxygen in the combustible mixture, below which ignition and combustion of the mixture become impossible at any concentration of fuel in the mixture.

THE BEGINNING OF THE TORCH SYSTEMS- sections of flare pipelines (collectors) directly adjacent to the boundary of the process unit.

TOTAL FLARE SYSTEM- a flare system that serves a group of technologically unrelated industries (installations).

INDIVIDUAL FLARE SYSTEM- a system that serves one production, one workshop, one technological installation, one warehouse or several technological blocks that are connected by a single technology into one technological thread and can be stopped simultaneously (one source of discharge).

PERIODIC RESETS- combustible gases and vapors sent to the flare system during start-up, shutdown of equipment, deviations from the technological regime.

PERMANENT RESETS - combustible gases and vapors coming continuously from process equipment and communications during their normal operation.

PERMANENT RETRACT LIQUIDS- its continuous removal from the separator by gravity without the use of pumps.

WORKING SAFETY VALVE- a valve installed in accordance with the Rules for the Design and Safe Operation of Pressure Vessels to prevent pressure build-up in the apparatus.

RESERVE WORKING VALVE- a safety valve installed parallel to the working one and put into operation by a “closed-open” blocking device.

DISCHARGE PIPE- a vertical pipe for discharging gases and vapors into the atmosphere without burning.

EMISSIONS (WASTE GASES AND COUPLES)- combustible gases and vapors escaping from the production, workshop, process plant, warehouse or other source that cannot be directly used in this technology.

CANDLE- a device for the release of purge gas into the atmosphere.

SPECIAL FLARE SYSTEM- a system for burning gases and vapors, which, due to their properties and parameters, cannot be directed to a common or separate flare system. Discharges in this case have the following features: discharged gases contain substances that are prone to decomposition with the release of heat; polymerizing products, aggressive substances, mechanical impurities that reduce the throughput of pipelines; products capable of reacting with other substances sent to the flare system; hydrogen sulfide in concentrations of more than 8%. It is also used if the pressure in the process unit does not provide discharge into the common flare system, etc.

SPECIAL FLARE PIPELINE- a pipeline for supplying waste gas to the flare unit (flare head) under special conditions that do not coincide with the conditions in the flare header.

HYDROCARBON GASES AND VAPOR GATHERING PLANT - a set of devices and structures designed to collect and short-term storage of discharged gases from the common flare system, return gas and condensate to the enterprise for further use.

FLARE MANIFOLD - a pipeline for collecting and transporting waste gases and vapors from several sources of discharge.

TORCH HEAD- a device made of heat-resistant steel with pilot burners and igniters, equipped with devices for supplying steam, atomized water and air.

FLARE TANK- a vertical pipe with a cap and a gas seal.

FLARE PIPING - a pipeline for the supply of waste gases and vapors from one source of discharge.

FLARE INSTALLATION- a set of devices, apparatus, pipelines and structures for burning discharged gases and vapors.

Annex 2
(recommended)

Schematic diagram of the discharge of gases (vapours) into the flare system from safety valves

1 - protected device; 2 - workshop separator; 3 - flare separator; 4 - flare stack; 5 - gas seal; 6 - blocking device "closed-open"; 7 - shop collector; 8 - flare collector; 9 - purge gas; 10 - manual reset line; 11 - shop boundary; 12 - discharge of gases from the PC on other devices of the shop; 13 - discharge of gases from other production shops

Appendix 3
(recommended)

Schematic diagram of the discharge of gases (vapors) into the flare system with a constant removal of condensate from the separator through a hydraulic seal

1 - flare collector; 2 - blocking device; 3 - flare stack; 4 - separator (option A); 5 - separator (option B); 6 - supply of sealing liquid; 7 - water seal; 8 - purge gas

Appendix 4
(recommended)

Schematic diagram of the purge gas supply to the flare header

1 - purge (fuel) gas supply; 2 - flare collector; 3 - discharge source, the most remote from the flare unit; 4 - nitrogen supply

Appendix 5
(recommended)

CALCULATION
combustible gas concentrations when discharged from a safety valve through a discharge pipe

The calculation was carried out for conditions when the release is carried out horizontally for a long time under the worst weather conditions (calm), and the maximum surface gas concentration does not exceed 50% of the lower limit of flame propagation (ignition). To reduce the surface concentration, it is recommended to direct the discharge pipe vertically upwards.

1. The value of the surface gas concentration at various distances from the safety valve is determined by the formula:

G/m 3 ,

Where M - amount of discharged gas, g/s;

V-second volume of discharged gas at normal pressure, m 3 /s;

d- outlet pipe diameter, m;

X -horizontal distance from the discharge pipe to the place where the concentration is determined, m;

r , r V- density of discharged gas and ambient air, kg/m 3 ;

h- height of the discharge pipe, m.

2. The value of the maximum surface gas concentration is determined by the formula:

G/m 3 .

3. The distance at which the maximum surface concentration occurs is:

4. The minimum height of the release is determined by the formula:

Where WITH npv - concentration of the lower limit of flame propagation, g / m 3.

2. The danger zone is considered to be a circle with a radius X m.

Appendix 6
(recommended)

Scheme of equipping pumps for pumping hydrocarbons with pipelines, instrumentation and automation

1 - working pump; 2 - inlet of the sealing liquid of the mechanical seal of the shaft of the working pump; 3 - valve of the return pipeline of the working pump; 4 - valve of the discharge pipeline of the working pump; 5 - the minimum level of the liquid phase in the separator; 6 - the level of the beginning of pumping out the liquid phase from the separator; 7 - maximum level of the liquid phase in the separator; 8 - perforated pipe; 9 - valve of the discharge pipeline of the reserve pump; 10 - reserve pump return line valve; 11 - backup pump; 12 - inlet of the sealing liquid of the mechanical seal of the standby pump shaft; 13 - standby pump suction pipe valve; 14 - working pump suction pipe valve

DESCRIPTION OF THE PUMPS

Situation 1

Hydrocarbon gases are not discharged into the flare system. The flare system is filled with fuel or inert gas. The flare separator and pumps are not filled with liquid. Gate valves (appendix - pos. 13 and 14), valves (pos. 3 and 10) are in the open position. Gate valves (pos. 4 and 9) are closed.

Situation 2

Hydrocarbon gases are discharged into the flare system. Condensate appears in the separator, which enters both pumps through the suction pipe and fills them. The gas phase is removed from the discharge lines of the pumps to the separator through the DN 25 pipeline through a throttling washer with an opening in it of 10 mm.

Situation 3

Fluid continues to accumulate in the flare separator. The liquid reaches the pumping level (1/4 of the separator height). The work pump turns on automatically. The discharge valve opens (appendix - pos. 4). If the level continues to rise and reaches the maximum level (1 / 2 of the separator height), a command is given to turn on the standby pump and the valve (pos. 9) on the standby pump discharge line opens.

Situation 4

As a result of pumping out, the amount of liquid in the separator is reduced to a minimum level, which is determined by the pump stop time. When this level is reached, the pump(s) are automatically switched off and the discharge gate valves are closed.

Annex 7

CALCULATION
heat flux density from the flame, minimum distance and height of the flare stack

1. Notation and definitions.

C pi, C vi- heat capacities of components, J/(mol· TO);

D-flare stack diameter, m;

k- adiabatic index,

M -molecular weight, kg/(kg/kg/mol);

N i- molar fraction i-th component in the mixture;

T - gas temperature, TO;

V-waste gas flow rate, m/s;

V V - wind speed at the level of the center of the flame, m/s,

At H + Z< 6 0,

At 60< H+ Z< 200;

V T - maximum wind speed, m/s, determined according to Appendix 4 "Construction climatology and geophysics".

V sv - speed of sound in discharged gas, m/s:

m - the ratio of the velocity of the outflow to the speed of sound in the discharged gas,m = V/ V sv.

Strelkin Aleksey Viktorovich, Head of the Department of Experts, NC LLC NTC NefteMetService

Filin Vladimir Evgenievich, Deputy General Director of Techexpertiza LLC

The article describes the requirements for various elements of flare installations, including tips, and provides calculations for the optimal size of the shaft.

Currently, at the facilities of capital construction and technical re-equipment of the flare facilities, according to the design assignment, we are designing a flare unit and its piping. A significant part of process units (BPS, UPS, UPVSN) is connected to the existing gas gathering system, thus, flare units serve only for emergency flaring of associated gas and for flaring small volumes of gas from discharges from safety spring valves (PPV).

The gas discharged by safety devices must be discharged into the system or to a torch (candle). I propose the installation of one emergency combustion flare on the existing gas collection system from a group of process units, and on the process plant we install a candle for burning small, periodic gas discharges from safety valves and when emptying process tanks.

According to the schematic diagram, well production enters the oil and gas separator pos. NGS, where gas separation is carried out at an overpressure of 0.3 MPa. The pressure is maintained by an upstream control valve, which is installed in the gas line. The gas released in the NHS is fed into the gas separator. In the GS gas separator, the condensate (droplet liquid) is separated from the gas, after which the associated petroleum gas is sent to the tie-in into the existing gas pipeline to the gas gathering system. In emergency mode (compressor house or gas processing plant does not receive gas), gas is supplied to the projected common flare unit for a group of booster pumping stations located in the BPS-10 area. The flare unit is equipped with a flare stack, a flare head with control and automation equipment. Application conditions: gas through the gas gathering system to the flare unit at BPS-10 must be transported under its own pressure (without a compressor) and the pressure at the point of connection of the gas pipeline from the process unit to the general gas gathering system should be no more than 0.3 MPa.

The gas released in the drainage tank during discharge from the safety valves and during emptying of the capacitive equipment (pos. EPn-1) is diverted to a candle for burning small, periodic gas discharges.

Ignition on the candle occurs as follows, when the safety valve on the tank is triggered, the pressure sensor installed on the outlet pipeline from the control panel gives a signal to the ignition system, it is also possible to send a signal for ignition by the position of the check valve shutter on the candle.

The composition of the candle equipment:

1. Dn80 head.

2. Barrel h=5.0m, Dу 100;

3. Check valve;

4. Automated control system for ignition and flame control ACS RKP. Typical equipment of a flare unit for a BPS group:

1. Flare installation;

2. Underground drainage tank for collecting condensate with two pumps;

3. Electrified gate valves

Features of the installation in question:

Full automation of the process "electric ignition - flame control";

Unlimited number and speed of torch launches;

The following figure shows the design diagram of a flare unit with a straight-through head. The flare unit contains a flare shaft 1, a flare head 2 and an inlet fitting 3. Often, the commonly used ratio is taken for calculations:

- flare stack height, m;

Flare stack diameter, m

In this case, the coefficient of local resistance when turning the flow after the inlet fitting 3 is taken ξ rev =1

When burning saturated light hydrocarbons: methane, ethane, propane, direct-flow type heads have proven themselves well.

When burning heavy hydrocarbons, and especially unsaturated hydrocarbons, without the use of special smoke suppression means (supply of water vapor, additional air), much less smoke is generated when special jet flare tips are used. This head differs from direct-flow ones in that the waste gas escapes into the atmosphere not through a cylindrical section of the flare head, but through a series of nozzles, while ensuring good mixing with air and, as a result, good, and often smokeless combustion.

The initial data for calculating the diameter of the flare unit are: gas composition, its density ρ and overpressure ∆:

- atmospheric pressure, Pa.

For a gas, the incompressible fluid model can be applied using simple equations:

– gas velocity, m/s;

- cross-sectional area, m 2.

is the diameter of the passage section.

Reynolds number:

is the kinematic coefficient of viscosity, Stokes.

Modern flare installations must meet the following requirements:

Smokeless or low-smoke gas combustion;

Fast and trouble-free ignition;

Ability to control from a remote location (operator room);

The possibility of transferring the parameters of the installation to the operator and to the upper level of the process control system, making automatic decisions in case the installation goes beyond the normal mode.

In accordance with the existing theory of gas combustion, the greater the molar mass of the gas, the more difficult it is to ensure smokeless combustion. Especially a lot of smoke occurs in unsaturated hydrocarbon gases. Many methods are used to achieve smokeless combustion. Basically, they are aimed at ensuring maximum mixing of the combusted gas with air. In this case, according to the experimental data, the higher the velocity of the gas emanating from the nozzle, the greater the molar mass can be smokeless to burn the gas.

An effective method of smoke suppression is to supply steam to the combustion zone, but in most cases this is not possible. The use of blowers has not found much use either, as this increases capital and operating costs.

The design of most of the heads produced today is a heat-resistant steel pipe with a kinetic gas seal inside, which serves to prevent the penetration of flame into the installation shaft, which requires the use of a purge gas.

At the end of the pipe, standby burners and a windshield are installed. The ignition device can be both on the head and the trunk, including on the base of the trunk or even behind the installation fence. In this case, pilot pipelines are suitable for the pilot burners. Flame control is carried out by thermocouples, ionization probes, optical, acoustic or gas-dynamic sensors. Each manufacturer decides in its own way how to organize the exit of gas from the head and ensure smokeless combustion of waste gas.

The blades installed in the slot provide the turbulence of the flow, during which the gas is mixed with air. The area of ​​the gap is calculated so that the gas flow velocity is in the range from 0.2 to 0.5 of the speed of sound in gas for gases with a density less than 0.8 of the density of air and from 0.2 of the speed of sound to 120 m/s for gases with greater density.

If the gas pressure at the barrel inlet is insufficient to provide such speeds, then the head is designed as a burner of a household gas stove with diffusion combustion of gas.

In such burners, propane or a propane-butane mixture, that is, a gas with a sufficiently large molar mass, burns smokelessly.

To ensure fast and trouble-free ignition, it was decided to abandon high-voltage systems in which the ignition of the combustible mixture is carried out by a spark in a spark plug, due to the difficult ignition of the cold combustible mixture in winter. After the experiments, the self-sucking “running fire” system was also rejected, in which the ignition unit with an injector that prepares a combustible mixture of gas and air is located at a significant distance from the pilot burners of the head and the pilot burners are ignited by the flame front passing through the ignition pipeline.

The main reason is the difficulty of ensuring the stoichiometric composition of the combustible mixture in the injector (each fuel gas composition requires its own gas-to-air ratio) and the high probability of flame front extinction in long ignition pipelines.

The best and practically trouble-free way turned out to be ignition with a glow plug installed inside the pilot burner at a distance of 100 mm from the combustible mixture outlet. Ignition with a glow plug has proven itself well in liquid burners, but for gas systems it has been used relatively recently.

Thermocouples were installed to control the flame (this method is used by leading foreign companies). To ensure their long-term operation, it was necessary to order a special design with an increased length and increased heat resistance of the terminal head. In order to increase the service life of the ignition system, they did not combine the pilot and pilot burners into a single pilot burner operating in pilot mode (commercially produced pilot burners are usually made of ordinary stainless steel of the 12X18H10T type, not intended for long exposure to flame). That is, only duty burners made of special heat-resistant steel are in the flame, and the ignition burners go out after ignition of the duty burners, preserving their resource.

The ignition and control system includes:

Block for preparing and supplying fuel gas to pilot and pilot burners, placed in a heat-insulated heated cabinet;

An injector that prepares a combustible mixture for pilot burners;

Pilot and pilot burner units with flame control thermocouple;

ACS system based on industrial controller.

The ACS system consists of three blocks: an ACS cabinet, a local ignition panel and an operator console. The ACS cabinet with a local ignition panel of explosion-proof versions is installed behind the installation fence, the operator's console is in the control room. Communication of the ACS cabinet with the operator's console and with the upper level of the process control system is carried out via the RS-485 interface.

Control is possible in manual and automatic mode. A feature of the ACS is that it not only ignites and controls the operation of the flare unit, but can also receive signals from the sensors of the entire flare facility: the temperature and level of condensate in the flare separator and drainage tank, the flow rate and amount of purge and waste gas with data archiving in ring buffer mode. At the same time, the cost of ACS increased slightly,

however, these additional features will allow designers and customers to significantly reduce setup costs and design time.

If the regime is violated, for example, the flame goes out, the ACS will independently ignite it. If the purge gas flow rate drops below the standard, it will give a signal to the process control system about the need to supply inert gas to the flare collector. When the drainage tank is overfilled, it will signal the need to turn on the pumping pump.

The operator console is equipped with a touch panel with a convenient and understandable mnemonic diagram, which displays the data from the sensors and the name of the current operation of the ignition process with a countdown to its completion.

The volumetric flow rate and outflow rate of associated petroleum gas flared in a flare plant is measured experimentally, or, in the absence of direct measurements, Wv is calculated by the formula:

Wv = 0.785 ∙ U d02

U is the rate of APG outflow from the outlet nozzle of the flare unit, m/s (according to the measurement results); d0 - diameter of the outlet nozzle, m (according to the design data of the flare unit).

In the absence of direct measurements, the outflow velocity is taken:

for periodic and emergency discharges:

Usv - speed of sound propagation in APG.

The mass flow rate of the gas discharged at the flare plant is calculated by the formula:

Wg = 2826U d02 ∙ pg

pr - APG density, kg/m3.

Volumetric flow rate of combustion products leaving the flare unit:

W PR \u003d W v * W ps * (___________)

WV is the volume flow (m/s) of the flared;

WPS - volume of combustion products;

Tg - combustion temperature.

References:

1. Federal Law No. 116.

2. PB 03-591-03. Rules for the design and safe operation of flare systems.

3. SAFETY GUIDE FOR FLARE SYSTEMS.

GOST R 53681-2009

Group G43

NATIONAL STANDARD OF THE RUSSIAN FEDERATION

OIL AND GAS INDUSTRY

FLARE PARTS FOR GENERAL REFINERIES OPERATIONS

General technical requirements

oil and gas industry. Flare parts for general refinery and petrochemical service. General technical requirements

OKS 75.200
OKP 36 0000

Introduction date 2011-01-01

Foreword

The goals and principles of standardization in the Russian Federation are established by the Federal Law of December 27, 2002 N 184-FZ "On Technical Regulation", and the rules for the application of national standards of the Russian Federation - GOST R 1.0-2004 "Standardization in the Russian Federation. Basic provisions"

About the standard

1 DEVELOPED BY VNIINEFTEMASH Open Joint Stock Company (VNIINEFTEMASH OJSC)

2 INTRODUCED by the Technical Committee for Standardization TC 23 "Technique and technology for the production and processing of oil and gas"

3 APPROVED AND PUT INTO EFFECT by Order of the Federal Agency for Technical Regulation and Metrology dated December 15, 2009 N 1067-st

4 This standard uses the norms of federal laws of June 21, 1997 N 116-FZ "On the industrial safety of hazardous production facilities" and of December 27, 2002 N 184-FZ "On technical regulation"

5 INTRODUCED FOR THE FIRST TIME


Information about changes to this standard is published in the annually published information index "National Standards", and the text of changes and amendments - in the monthly published information indexes "National Standards". In case of revision (replacement) or cancellation of this standard, a corresponding notice will be published in the monthly published information index "National Standards". Relevant information, notification and texts are also posted in the public information system - on the official website of the Federal Agency for Technical Regulation and Metrology on the Internet

1 area of ​​use

1 area of ​​use

This standard applies to flare installations used in the production of oil and gas processing, chemical, petrochemical industries and other hazardous production facilities associated with the handling and storage of substances capable of forming vapor and gas-air explosive mixtures.

The standard is intended for use in the design, construction, operation, technical re-equipment, conservation and liquidation of flare installations. The requirements do not apply to flare installations put into operation prior to the issuance of this standard.

The standard does not apply to flare units used on offshore floating and stationary oil and gas complexes intended for drilling, production, treatment, storage and offloading of oil, gas, gas condensate and their products, to flare units used in drilling, development of oil fields, gas and gas condensate wells.

2 Normative references

This standard uses normative references to the following standards:

GOST R 52630-2006 Steel welded vessels and apparatus. General specifications

GOST 9.014-78 Unified system of protection against corrosion and aging. Temporary anticorrosive protection of products. General requirements

GOST 12.1.003-83 Occupational safety standards system. Noise. General safety requirements

GOST 12.2.003-91 Occupational safety standards system. Production equipment. General safety requirements

GOST 380-2005 Carbon steel of ordinary quality. Stamps

GOST 1050-88 Rolled bars, calibrated, with special surface finish from quality carbon structural steel. General specifications

GOST 4543-71 Rolled products from alloyed structural steel. Specifications

GOST 5632-72 High-alloy steels and corrosion-resistant, heat-resistant and heat-resistant alloys. Stamps

GOST 8509-93 Hot-rolled steel equal-shelf angles. Assortment

GOST 8568-77 Steel sheets with rhombic and lenticular corrugation. Specifications

GOST 15150-69 Machinery, instruments and other technical products. Versions for different climatic regions. Categories, conditions of operation, storage and transportation in terms of the impact of environmental climatic factors

GOST 19281-89 High-strength rolled steel. General specifications

GOST 19903-74 Hot-rolled sheet metal. Assortment

GOST 23118-99 Steel building structures. General specifications

GOST 27751-88 Reliability of building structures and foundations. Basic provisions for the calculation

GOST 27772-88 Rolled products for building steel structures. General specifications

Note - When using this standard, it is advisable to check the validity of reference standards and classifiers in the public information system - on the official website of the Federal Agency for Technical Regulation and Metrology on the Internet or according to the annually published information index "National Standards", which was published as of January 1 of the current year, and according to the corresponding monthly published information indexes published in the current year. If the reference standard is replaced (modified), then when using this standard, you should be guided by the replacing (modified) standard. If the referenced standard is canceled without replacement, the provision in which the reference to it is given applies to the extent that this reference is not affected.

3 Terms and definitions

In this standard, the following terms are used with their respective definitions:

3.1 emergency releases: Combustible gases and vapors entering the flare system when safety valves actuate.

3.2 gas seal: A device to prevent air from entering the flare system through the tip when gas flow is reduced.

3.3 single flare head:

3.4 multi-burner flare head: A flare tip that contains a number of burners (or nozzles) that use vent gas pressure energy to inject additional air.

3.5 low smoke torch: A torch with a tip with one or more nozzles, providing a small amount of smoke. It can be used additionally when smoke-free requirements are low.

3.6 supporting tower: A metal structure that holds one or more flare stacks in a vertical position.

3.7 periodic resets: Combustible gases and vapors sent to the flare system during start-up, shutdown of equipment, deviations from the technological regime.

3.8 permanent resets: Combustible gases and vapors coming continuously from process equipment and communications during their normal operation.

3.9 flame flash: A phenomenon characterized by the escape of the flame into the body of the burner.

3.10 pilot (duty) burner: A burner that operates continuously during the entire period of use of the torch.

3.11 flameout: A phenomenon characterized by a total or partial detachment of the base of the flame above the burner openings or above the flame stabilization zone.

3.12 self-supporting structure: A shaft structure that performs its functions and does not bear vertical loads, except for its own weight and loads both from the weight of all flare stack units and from external factors (wind, snow, etc.). The flare stack is held in a vertical position by means of one or more tiers of rope guys.

3.13 flame stability: A steady state in which the flame is in a fixed position with respect to the burner outlets.

3.14 flare head: A device with pilot burners for burning waste gases.

3.15 flare stack: A vertical pipe with a head, with a shutter (gas or gas-dynamic), means of control, automation, a remote electric ignition device, supply pipelines for fuel gas and a combustible mixture, pilot burners with igniters.

3.16 flare collector: A pipeline for collecting and transporting waste gases and vapors from several sources of discharge.

3.17 flare plant: A set of devices, apparatus, pipelines and structures for the combustion of discharged vapors and gases.

3.18 flame front: The layer in which the combustion chain reaction occurs.

4 Classification

Flare installations should be made of the following types:

- flare installations with vertical shafts;

- flare installations with horizontal shafts;

- closed (ground) flare installations.

4.1 Vertical stack flares

4.1.1 Self-supporting shaft structure

In a self-supporting structure, the flare stack must bear all loads both from the weight of all flare stack units and from external factors (wind, snow, etc.).

4.1.2 Guyed shaft design

Keeping the flare stack in a vertical position must be carried out by a system of ropes located on one or more tiers. The ropes should be placed in a triangular plan to provide secure support.

The number of tiers should be determined by the project.

4.1.3 Torch stack design

4.1.3.1 The design of the flare stack with the support tower shall hold one or more flare stacks in a vertical position and ensure the mechanical stability of the support tower.

The support tower, in addition to the fixing support structures, must include devices for dismantling flare stacks intended for removing flare tips, for dismantling the stacks and lowering the sections using hoisting devices. It is allowed to lower the torch shaft to the ground (on special supports) without dismantling it.

4.1.3.2 The design of the tower shall provide for additional devices that ensure the dismantling and lowering of the flare tip to the ground for maintenance and repair.

Additional devices must be assembled in sections, which must be raised or lowered using guides and stationary winches.

4.1.3.3 Requirements for impact loads - according to SNiP 2.01.07.

4.1.3.4 Requirements for the protection of building structures from corrosion - according to SNiP 2.03.11 and GOST 9.014.

4.1.3.5 Requirements for steel load-bearing and enclosing structures - according to SNiP II-23, SNiP 3.03.01 and GOST 23118.

4.1.3.6 Requirements for the reliability of metal structures and additional devices - according to GOST 27751.

4.1.3.7 Requirements for materials used in the manufacture of structures - according to GOST 380, GOST 4543, GOST 8509, GOST 8568, GOST 1050, GOST 19281, GOST 19903, GOST 27772.

4.2 Horizontal stack flares

The flare plant with a horizontal shaft consists of a burner for burning waste gases and liquids, has a system for remote ignition and parameter control, and an emergency protection system. The burner is installed in the bunding.

4.3 Closed (ground) flares

4.3.1 Closed (ground) flare installations are designed for smokeless combustion of waste gases and liquids near the ground surface. The design of a closed flare plant should provide for a combustion chamber with lined walls that are open from above to protect the burners from wind exposure.

4.3.2 The flare unit must ensure complete combustion and the absence of visible flame, as well as the reduction of noise and heat radiation to the standards established by PB 03-591-03 *.
________________
order of Rostekhnadzor dated December 29, 2012 N 801. The Safety Guidelines for flare systems are in force, approved by order of Rostekhnadzor dated December 26, 2012 N 779

4.4 Design of flare tips

4.4.1 Single flare tips

A single flare tip is a device with a single outlet nozzle.

Single flare tips may be smokeless or limitedly smokeless.

4.4.2 Multi-burner flare tips

The design of multi-burner flare heads should include two or more burners that use the energy of the waste gas pressure to inject additional air.

4.4.3 Smokelessness must be ensured by the optimal gas / air ratio, which is achieved by creating the following conditions:

- high gas pressure;

- large surfaces of gas flows.

4.5 Tips for smokeless flares

4.5.1 Tips for smokeless flares should eliminate smoke by means of a special arrangement of waste gas and atmospheric air flows. Smokeless combustion can be achieved by forced air, steam and pressurization of the waste gas, as well as by the use of other means of increasing turbulence to better mix the combustible gas with air.

4.5.2 Combustion stability must be ensured at waste gas flow rates in the flow rate range from zero to its maximum value in accordance with PB 03-591-03 (subsection 6.1) . Smokeless combustion must be ensured with constant and periodic discharges up to ~10% of the maximum. When using fan air (or steam) this value can be increased up to 20%. Large discharges are considered emergency and smokeless combustion is not guaranteed.

4.5.3 Depending on the composition and pressure of the waste gas, the head design should be selected.

4.6 Flare heads for smokeless combustion of hydrocarbon (including unsaturated hydrocarbons) gases in the full operating range of flow rates

4.6.1 The flare tips must ensure the separation of the gas flow into a number of jets directed at an angle to the torch axis, determined by calculation, and a number of additional jets that swirl the injected air flow. In this case, the stabilization of combustion should be carried out by gas jets and stabilizers-swirlers.

4.6.2 To enhance the vortex motion of gas jets and air flows and their better mixing, it is necessary to use a system of nozzles for supplying water vapor (it is possible to supply air from a compressor unit). The flame of the torch must be wind resistant. In this case, there should be no contact between the flame and the head body.

4.7 Limited smokeless flares

4.7.1 Limited smokeless flares are designed to burn hydrocarbon gases and vapors that do not create a smoke hazard.

4.7.2 Limited smokeless flares can be used as additional ones to expand the working range of smokeless flares.

4.8 Endothermic flare (with auxiliary fuel gas supply)

4.8.1 An endothermic flare should use high calorific value fuel gas to generate additional heat from the combustion of low calorific vapors.

4.8.2 An endothermic flare should be used with high calorific value fuel gas or heavy pilot burners when the calorific value of the gas flow is below 1300-1800 kcal/nm.

5 Requirements for vertical stack flares

5.1 Flare head

5.1.1 The design of the flare head shall ensure the safe combustion of waste gas at the maximum possible flow rate.

The tip must operate on a mixture of fuel and air at speeds, turbulence and concentrations that provide proper ignition and stable combustion.

Ignition of the main waste gas flow must be carried out by the flame of pilot burners, which are ignited by the ignition system. The head may have a mechanical device or other means of establishing and maintaining a stable flame in the operating range of flow rates.

5.1.2 The noise level measured near the protection zone fence is in accordance with GOST 12.1.003. Primary flame stabilization and smokeless operation of the tip must be provided by the supply of auxiliary steam, which controls the formation of smoke when a large amount of hydrocarbon gases is discharged. The amount of steam supplied must be proportional to the amount of discharged gas and its composition.

Steam must be supplied to a manifold with nozzles at the top of the tip to inject atmospheric air into the combustion zone and protect the tip from flame exposure.

A steam injector, located in the center of the head, must be used to mitigate internal combustion and remove flames from the internal volume and reduce thermal loads.

5.2 Flare heads with internal steam/air supply

In order to more completely mix the waste gas with air, it is possible to supply a steam-air mixture to the head using devices that have injectors into which water vapor is supplied. The release of the vapor/air mixture inside the head must be carried out at high speed and to ensure an increase in the speed of the outflow of waste gas.

5.3 Flare heads with auxiliary air supply

Flame heads with auxiliary (additional) air supply are used in flares if smokeless combustion is required. In this case, auxiliary air is supplied inside the head. Thus carry out a preliminary mixing of waste gas with air. When the gas-air mixture flows out of the head, it also mixes with atmospheric air. This method must be used in the absence of a source of steam.

5.4 Flare head wind protection device

Wind deflectors are used to protect the flame from wind. It is allowed not to use these devices if during operation auxiliary steam or forced air supply is used for protection.

5.5 Flame head stabilizer

5.5.1 A flame tip stabilizer is used to prevent damage to the tip from a touching flame.

5.5.2 The stabilizer must ensure the movement of the air flow to the head, to the steam / air collectors to reduce the force of the wind.

5.6 Material requirements

5.6.1 All parts of the flame must be temperature resistant. The upper part of the flare tip must be made of heat-resistant alloys in accordance with GOST 5632. It is allowed to manufacture the lower part of the head (together with the connecting flange) from lower quality stainless steel grades.

5.6.2 High-temperature lining materials are used for large diameter heads (more than 1000 mm) to protect against internal combustion. Materials must be resistant to high temperature and its sudden changes. The design of the lining should provide:

- resistance to temperatures of the operating range, the possibility of cyclic operation and its susceptibility to moisture;

- the possibility of using various methods of fixing the refractory.

5.6.3 The inner channel of the head should have a heat-resistant lining with special fasteners. When designing, it is necessary to take into account the consequences of the destruction of the lining, including the possibility of falling dense refractory into the barrel and the difficulty in passing the flow of waste gas, and the fall of external refractory to the ground.

5.7 Installation and dismantling requirements

5.7.1 For repairs, the flare heads must be dismantled. All piping elements must be designed to facilitate disassembly.

5.7.2 Removal and replacement of the flare tip is carried out using a beam crane. In cases of high flares (in the absence of cranes of sufficient height), it is necessary to provide a retractable beam crane on the flare support tower. The beam crane must be installed below the upper platform (or below the gas seal) and be inaccessible to the effects of the creeping flame. A lifting device must be provided to place the overhead crane in the lifting position.

5.8 Requirements for the ignition system

5.8.1 The remote ignition device shall ensure the ignition of the pilot burners of the flare, the control of the presence of a flame on them and the supply of an alarm signal to the control room about the termination of the operation of the pilot burners.

5.8.2 In the event of a failure in the air supply, the ignition system must automatically return to the process of pre-mixing the gas with air.

5.8.3 If necessary, a backup set of the ignition system should be provided.

5.8.4 In justified cases, it is allowed to use direct spark ignition of the flame.

To ensure stable operation of ignition systems, it is necessary to use a reliable source of fuel. It is preferable to use natural gas.

5.8.5 The ignition system shall operate stably for the service life specified by the manufacturer.

5.9 Ignition equipment requirements

5.9.1 The following types of ignition systems are used for ignition of pilot burners:

- spark ignition system in the pilot burner tunnel;

- spark ignition system for gas/air mixture up to the pilot burner tunnel;

- burner of gas/compressed air flaring system;

- a burner with a preliminary preparation of a combustible mixture of a gas flaring system.

5.9.2 The sparking device of the gas/air spark ignition system upstream of the tunnel shall be located close to the pilot burner tunnel, but not more than 7.5 m from it. In this case, the life of the pilot burner can be reduced due to the exposure of the sparking device to the flame of the pilot burner itself or the torch. It is allowed to place the sparking device in the tunnel.

5.9.3 Spark ignition of the gas/air mixture upstream of the pilot burner may be used to ignite the combustible mixture before the flame exits the tunnel. In this case, flashover of the flame must be excluded and stable combustion must be ensured.

5.9.4 In the gas-air mixture flaring system, compressed air and fuel gas are passed through diaphragms into the mixing chamber. The gas-air mixture must be combustible and must not detonate when ignited. The flame front must flow through the pipeline into the pilot burner tunnel and ensure its ignition.

5.9.5 In a gas/air mixture spark ignition system, an electrode capable of a high-energy capacitive discharge shall be located in the ascending flow of the mixture in the pipeline to the pilot flame burner or in the bypass pipeline between the control panel located at the boundary of the protective zone and the burner outlet.

The electrode in this system should not be located in close proximity to the flame.

5.9.6 The compressed air pilot burner of the gas flaring system must be connected to the control panel. The design of the control panel must provide for the presence of an ignition device and a viewing window. The ignition device can be a spark plug or a piezoelectric electric igniter.

Fuel and air pressure sensors must be filled with liquid or be dampened to prevent damage to the sensors from pressure pulses. The channel of the spark generating device must be designed for the same pressure as the transport pipeline. A gas flaring burner may be used to ignite two or more pilot burners.

5.9.7 The pilot burners of the gas flaring system may be connected to the header by lines fitted with valves, each of which ignites one pilot burner. In this case, each pilot burner must be ignited individually. In this case, the flame front must be such that all pilot burners can be ignited with a single passage of the flame front. The arrangement of pipeline lines must comply with the requirements of regulatory documents for the safe operation of process pipelines.

5.9.8 The pilot burner of the gas flaring system is used to light one pilot burner. The length of the pipeline connecting the burner with the injector should not exceed 90 m. The system, including the pilot burner and the pipeline with the injector, is mounted on the flare shaft.

5.9.9 The minimum allowable number of ignition systems for most flare tips is determined by the manufacturer's regulations. For non-gaseous hydrocarbons or hydrocarbon/inert mixtures with a calorific value of less than 2700 kcal/nm, additional ignition systems with a higher heat output are used.

5.9.10 A direct electric igniter is installed directly on the pilot burner at the discretion of the project developer.

5.10 Flame control

5.10.1 The flame control system shall confirm that the pilot burners are ignited.

5.10.2 Thermal converters must detect the presence of a pilot burner flame and, at the same time, not be affected by it.

5.10.3 Ionization detectors should respond to a change in conductivity between the electrodes in the flame and give a signal about the presence of a flame on the pilot burner.

5.10.4 In the optical flame detection system, two types of optical sensors should be used - ultraviolet and infrared.

5.10.5 In acoustic systems, it is necessary to use detectors that control the sound characteristic of the operating burner. The requirements for the frequency range generated by the flame of the burner are specified in the manufacturer's documents.

6 Requirements for flare installations with horizontal shafts

6.1 The burner device of a flare plant with a horizontal shaft must provide fine atomization of industrial effluents supplied for fire neutralization and mixing with air and combustible gas.

6.2 Combustible gas must be supplied in quantities necessary to form a stable flame.

6.3 The design of the burner must provide sufficient atmospheric air injection for smokeless combustion.

6.4 Flare installations with horizontal shafts are equipped with a protection system that cuts off gas and industrial effluents in case of deviation from the operating values ​​of technological parameters established by the project documentation.

6.5 The burner must have a system of pilot burners to ensure stable combustion of the flame.

7 Requirements for closed (ground) flare installations

7.1 Combustion chambers in closed (ground) flare installations must have a fence made in such a way as to reduce the wind effect on the combustion process and prevent unauthorized access of air.

7.2 During the operation of closed (ground) flare installations, the quantity and quality of air supplied to the combustion chamber and the temperature of the flue gas flow leaving the chamber are monitored.

7.3 When the maximum load of the first stage is reached, the next system of burners for burning waste gas with a large flow rate should be switched on.

7.4 The dimensions of the combustion chamber must be determined by the design characteristics of the burner assembly. The dimensions of the combustion chamber are determined depending on the volumetric heat release, the average value of which should be equal to 310 kW/m.

7.5 Burners and burner control systems for energized pilot burners shall be designed for the specified gas and liquid flow rates specified in the design documentation in order to ensure smokeless combustion.

7.6 The design of the burner unit must ensure stable combustion for all conditions of the waste gas flow in the operating range, not cause combustion pulsations, which can cause resonant vibrations of the combustion chamber body.

7.7 The design of the ground flare should provide the necessary air flow into the combustion chamber and an outlet for the flow of hot flue gases from the combustion chamber. To reduce the temperature of the combustion products, it is necessary to provide for the supply of excess air. Air flow into the combustion chamber must be provided by natural or forced draft.

7.8 In the design with forced air supply, adjustment devices shall be provided to ensure draft that excludes flame distortion and vibration.

7.9 During operation, a uniform air flow to all burners should be ensured. Blinds for air inlet to the burners must ensure an even distribution of the air flow over the burners.

7.10 The design of the barrier should provide protection of personnel from flame radiation and from the outer surfaces of the combustion chamber.

7.11 The design of the air inlets in the enclosure should provide a noise level not exceeding 80 dBA at a distance of 1.0 m from the air inlets.

8 Technical requirements for flare equipment

8.1 The equipment must comply with the requirements of PB 09-540-03 *, sections: III "Requirements for ensuring the explosion safety of technological processes"; V "Hardware design of technological processes"; VI "Systems of control, management, signaling and emergency automatic protection of technological processes"; VII "Electrical supply and electrical equipment of explosive technological systems"; XI "Maintenance and repair of technological equipment and pipelines" .
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* On the territory of the Russian Federation, the document is not valid on the basis of the order of Rostekhnadzor dated March 11, 2013 N 96. The Federal norms and rules in the field of industrial safety are in force "General explosion safety rules for explosive chemical, petrochemical and oil refining industries", hereinafter in the text. - Database manufacturer's note.

8.2 General safety requirements for equipment and controls - according to GOST 12.2.003.

8.3 Requirements for the climatic version of the equipment - according to GOST 15150.

8.4 Requirements for pressure equipment - according to GOST R 52630.

8.5 Equipment during operation must exclude the formation of a gas-air mixture in the internal volume of the flare shaft. Air inflow through the flare head into the barrel and further into the flare header must be excluded. During operation, continuous purge with inert or fuel gas should be carried out. The necessary interlocks (determined by the equipment design) shall be provided to prevent the entry of atmospheric air into the flare stack when the rarefaction at the base of the flare stack is more than 1000 Pa and the supply of inert gas to the flare header when the purge gas supply is stopped.

8.6 The design of the equipment must provide for the presence of protective devices or devices that prevent the ingress of atmospheric air into the flare collector. These devices and (or) devices are located in the head or in the line of waste gas.

8.7 As protective devices, diffusion (gasostatic closures), high-speed (gasdynamic) closures, liquid closures and, if necessary, flame arresters are used.

8.8 The torch tower support must be protected from direct lightning strikes by installing a lightning rod at the top of the structure and ensuring its electrical contact with grounding (possibly through the metal structures of the supports with the implementation of appropriate design measures). Requirements for a lightning protection device - according to SO 153-343.21.122.

8.9 Daytime marking and lighting of the support must be carried out in accordance with the requirements of REGA RF-94, PB 03-591-03. When performing a lighting system on the upper platform, portable lighting devices should be installed.

8.10 The flare plant must be equipped with devices that control process parameters with constant registration and output of readings, according to PB 03-591-03.

8.11 The device for remote ignition of the torch shall be provided with automatic regulation of fuel gas and air pressure.

8.12 In operating mode, the flare unit shall be provided with automatic control of the purge gas flow to maintain its design value.

9 Safety requirements

9.1 Before each start, the flare system should be purged with nitrogen so that the oxygen content inside (at the base) of the flare stack does not exceed 1.0% vol. (requirement PB 08-624-03 *) .
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* On the territory of the Russian Federation, the document is not valid on the basis of the order of Rostekhnadzor dated March 12, 2013 N 101. The Federal norms and rules in the field of industrial safety "Safety rules in the oil and gas industry" ., hereinafter in the text. - Database manufacturer's note.


When discharging hydrogen, acetylene, ethylene and carbon monoxide, the volume content of oxygen should not exceed the standards established by PB 03-591-03.

Measurement of oxygen concentration should be carried out inside the flare stack at its base.

9.2 To prevent air penetration into the flare system, purge gas supply is provided at an intensity that ensures the flow rate in accordance with the requirements of PB 03-591-03, preventing air from entering. The flow rate of the purge gas is set by the project documentation.

9.3 When preparing and carrying out repair work, measures must be taken to ensure the safety of these works in accordance with the current regulatory documents.

9.4 The flare unit must comply with the explosion and fire safety requirements specified in PB 08-624-03. Provision of primary fire extinguishing equipment - in accordance with applicable regulations.

10 Environmental requirements

10.1 The flare plant must ensure stable combustion in the full range of waste gas flow rates, smokeless combustion of constant and periodic discharges.

10.2 The flare installation must provide a safe heat flux density in the protective zone and on the surface of the surrounding equipment.

Zones and safe levels of heat flows are determined in accordance with the requirements of PB 03-591-03.

10.3 When designing, design solutions should be used to ensure the completeness of combustion of discharged hydrocarbon gases and vapors, for which design solutions should be used to ensure the injection of atmospheric air and the necessary mixing of waste gas with air.

10.4 When designing a flare device, one should take into account the height at which the emission of harmful combustion products occurs in order to exclude possible environmental pollution.

11 Storage requirements

11.1 The equipment, apparatus and metal structures of the flare unit (without automation equipment) must be mothballed before storage.

11.2 Storage of equipment, apparatus and metal structures of the flare unit must be carried out in conditions 7 (Zh1) in accordance with GOST 15150. Instruments and automation equipment must be stored in accordance with the requirements of the manufacturers' operating instructions.

12 Disposal

The equipment of the flare plant before being sent for disposal (for recycling) must be freed from working environments according to the technology of the owner enterprise, which ensures the safe conduct of work, as well as dismantling and cutting equipment with metal sorting by type and brand.