HG/T 20570.19-1995 Flame Arrester Settings HG/T20570.19-1995 Standard download decompression password: www.bzxz.net

Setting of flame arrester
HG/T20570.19—95
Compiled by:
China Huanqiu Chemical Engineering Corporation
Process System Design Technology Center Station of Ministry of Chemical Industry Approved by: Ministry of Chemical Industry
Implementation date September 1, 1996
Compiled by:
Shang Changyou of China Huanqiu Chemical Engineering Corporation
Gong Renwei
Process System Design Technology Center Station of Ministry of Chemical Industry Audited by:
Yang Yi of China Huanqiu Chemical Engineering Corporation
Zhou Lizhen of Shanghai Chemical Engineering Design Institute
Zhou Zhaolin
1.0.1 Function
Function and noun
A flame arrester is composed of a material with many tiny channels or gaps through which gas can pass. When the flame enters the flame arrester, it is divided into many small flame streams by the flame arrester element. Due to the heat transfer effect (gas is cooled) and the wall effect, the flame stream is quenched.
1.0.2 Nouns
1.0.2.1 Explosion and explosive mixed gas
Any phenomenon that can undergo drastic chemical changes in a very short period of time and cause a sharp increase in pressure due to external forces such as high heat, friction, impact or other substances, accompanied by a loud noise and the release of a large amount of heat, is called an explosion. This regulation refers to the explosion of a combustible mixed gas, and this gas mixture is called an explosive mixed gas.
1.0.2.2 Deflagration
The combustion process in which the flame wave of an explosive mixed gas propagates in a pipeline at a speed lower than the speed of sound is called deflagration.
1.0.2.3 Detonation
The combustion process in which the flame wave of the explosive gas mixture propagates in the pipeline at a speed higher than the speed of sound is called detonation (deto-nation). www.bzxz.net
1.0.2.4 The maximum experimental safety gap (MESG) refers to the width of the slit (the length of the slit is 25mm) that just prevents the flame from passing through under standard test conditions (1 bar, 20°C). The definition of MESG (MAXIMUM EXPERIMETAL SAFE GAP) is internationally unified: its data must be taken from a standard MESG test device. 501
2.0.1 Classification by performance
2 Classification of flame arresters
2.0.1.1 Anti-deflagration flame arrester: used to prevent the spread of flames propagating at subsonic speeds. 2.0.1.2 Anti-detonation flame arrester: used to prevent the spread of flames propagating at sonic and supersonic speeds. 2.0.2 Classification by place of use
2.0.2.1 Vent flame arrester: installed on the vent pipe of the storage tank (or tank truck) to prevent external flames from entering the storage tank (or tank truck), divided into pipe end type and ordinary type. Pipe end type: one end is connected to the atmosphere. To prevent dust and rain from entering the flame arrester, a wind and rain cap opened by temperature control is installed on the top. The pipe end type vent flame arrester is a deflagration type. Ordinary type: both ends are connected to the pipeline and connected to the atmosphere through the downstream pipeline. It is divided into deflagration type and detonation type. 2.0.2.2 Pipeline flame arrester is installed in a closed pipeline system to prevent the flame at one end of the pipeline system from spreading to the other end of the pipeline system. It is divided into deflagration type and detonation type. 2.0.3 Classification by structure
2.0.3.1 Filling type flame arrester
Filling type flame arrester is also called filler type flame arrester. 2.0.3.2 Plate-type flame arrester
Plate-type flame arrester has two types: parallel plate type and porous plate type. 2.0.3.3 Metal mesh-type flame arrester
This type of flame arrester has limited ability to extinguish flames and is rarely used nowadays. 2.0.3.4 Liquid-sealed flame arrester
This type of flame arrester is characterized by being able to be used in material systems containing a small amount of solid powder particles. 2.0.3.5 Corrugated flame arrester
Among the above five types of flame arresters, corrugated flame arresters are widely used in industrial practice due to their stable performance. This regulation uses corrugated flame arresters as an example to illustrate the selection, installation and maintenance of flame arresters. 502
3.0.1 Setting of vent flame arrester
3 Setting of flame arrester
3.0.1.1 Setting of flame arrester for petroleum oil storage tanks shall be carried out in accordance with the "Petroleum Depot Design Code" (GBJ74-84).
3.0.1.2 For storage tanks (and tank trucks) with a flash point of chemical oil <43°C, flame arresters shall be installed on their direct vent pipes (including vent pipes with breathing valves).
3.0.1.3 When the maximum operating temperature of the material in the storage tank (and tank truck) is greater than or equal to the flash point of the material, flame arresters shall be installed on their direct vent pipes (including vent pipes with breathing valves). The maximum operating temperature shall take into account factors such as ambient temperature changes, sunlight exposure, and loss of control of heating pipes. 3.0.1.4 Flame arresters shall be installed on the vent collection pipes of the online analysis equipment of combustible gas. 3.0.1.5 Flame arresters shall be installed on the exhaust pipes of internal combustion engines entering explosion-hazardous areas. 3.0.1.6 Other occasions where it is necessary to install flame arresters. 3.0.2 Installation of pipeline flame arresters
3.0.2.1 For pipelines that transport explosive mixed gases that may produce deflagration or detonation (possible accident conditions should be considered), pipeline flame arresters shall be installed at the entrance of the receiving equipment. 3.0.2.2 For pipelines that transport gas materials that can decompose and explode by themselves and cause flame spread (such as acetylene), pipeline flame arresters shall be installed at the entrance of the receiving equipment or at the best position to prevent explosion determined by experiments. 3.0.2.3 Flame arresters or flame arresting devices shall be installed before the flare exhaust gas enters the flare head. 3.0.2.4 Other occasions where pipeline flame arresters should be installed. 503
4.0.1 Steps for selecting flame arresters
Selection of flame arresters
4.0.1.1 Decide whether to use a venting flame arrester or a pipeline flame arrester based on the place of use. 4.0.1.2 Determine whether to use an anti-deflagration type flame arrester or a detonation type flame arrester. The propagation speed of the flame wave in the pipeline is not only related to the type of medium, the temperature and pressure of the pipeline, but also to the distance between the flame arrester and the ignition source, the installation position, and the shape of the pipeline between the flame arrester and the ignition source. Therefore, the channel diameter of the flame arrester element of the selected flame arrester must be able to prevent the spread of flames in this case. This requires determining whether to use an anti-deflagration type or a detonation type flame arrester, which is usually determined by experiments or based on experience. 4.0.1.3 Select a flame arrester of appropriate specifications based on the MESG value of the medium under actual working conditions. (1) In the national standard "General requirements for explosion-proof electrical equipment for explosive atmospheres" (GB3836.1-83), explosive gas mixtures are divided into different technical safety levels according to the maximum test safety gap (MESG), see Table 4.0.1. MESG classification table
Maximum test safety gap (MESG)
MESG ≥ 0.9
0.5
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