Division of application fields of explosion-proof cameras

Definition of explosive material area China standard North America standard

Under normal circumstances, when the mixture of gas (class I) and explosive gas exists continuously or for a long time, zone 0 (Zone 0) div. 1.

The area where explosive gas mixture may appear under normal circumstances 1.

Div.2, Area 2, explosive gas mixture is impossible under normal circumstances, but occasionally or for a short time under abnormal circumstances.

Dust or fiber (Grade II/III) In general, explosive dust or a mixture of combustible fiber and air may appear continuously, frequently in a short time or exist for a long time. Area 10 partition 1.

Under normal circumstances, there will be no explosive dust or mixture of combustible fiber and air, and only under abnormal circumstances, the place where it appears occasionally or for a short time is Div.2 in 1 1.

③ bit coding

Ⅰ —— Electrical Equipment for Coal Mine and Underground Mine

Ⅱ —— Electrical Equipment for Factory Use

④ bit coding

Classification of Class Ⅱ explosive gas environment

Working condition category level Representative gas Minimum ignition spark energy Maximum experimental safety gap MESG(mm) Minimum ignition current ratio MICR

Methane under mine I is 0.280mJ

Ii a propane 0.180mj mesg ≥ 0.9mcr > 0.8

Ⅱ b ethylene 0.060mj0.9 & gt mesg > 0.5 0.8≥MICR≥0.45

ⅱ c hydrogen 0.019mj0.5 ≥ mesg0.45 > Magnetic ink character recognition magnetic ink character recognition

Fifth bit coding

Temperature Group of Electrical Equipment in Class Ⅱ Explosive Gas Environment

Temperature group natural temperature T(℃) Allowable surface temperature of common explosive gas equipment (℃)

T 1 T≥450 46 kinds of hydrogen, acrylonitrile and so on.

T2 450 & gt； T≥300 Acetylene, ethylene and other 47 kinds of 300

T3 300 >T≥200 36 kinds of gasoline, crotonaldehyde, etc.

T4 200 & gt； T≥ 135 six kinds of acetaldehyde, tetrafluoroethylene, etc. 135.

T5 135 >T≥ 100 carbon disulfide 100

T6 100 >T≥85 ethyl nitrate and ethyl nitrite 85 divide dangerous places into different areas according to the frequency and duration of explosion environment. The gas field is divided into three zones: Zone 0, 1 and Zone 2. The dust field is divided into three areas: area 20, area 2 1 and area 22.

Flammable gas, steam and mist gas places

Zone 0 (red part)

A place where explosive mixture appears continuously or exists for a long time in the form of gas, steam or fog in an explosive environment.

The electrical equipment used in Zone 0 shall be designed, tested and marked according to the relevant provisions of EN50284 and IEC60079-26 on д type (gas) electrical equipment.

1 area (orange part)

In normal operation, an explosive mixture in the form of gas, steam or mist may appear in an explosive environment. 1 area is a typical application place of explosion-proof electrical equipment. Standard EN500 14~

-7,-1 1,-18, -25 specify the electrical equipment used in 1 area.

Zone 2 (yellow part)

In normal operation, explosive mixture in the form of gas, steam or mist is unlikely to appear in explosive environment, even if it does, it only happens occasionally and exists for a short time.

Usually, "short time" means that the duration does not exceed 2 hours.

The standards EN5002 1 and IEC60079- 15 stipulate the electrical equipment used in Zone 2, and must also meet the general requirements of insulation resistance, impact energy and dissipation power.

Dust place

Area 20

The standard EN 50281-1-1specifies the structure and design of electrical equipment enclosures used in Zone 20. C6024 1- 1 1 put forward supplementary requirements for electrical equipment used in Area 20, including intrinsic safety protection.

Explosion and other aspects. Area 20 application 1 (dust) electrical equipment.

2 1 region

Mills, coal, grain depots, packaging production lines and their surrounding areas are typical places in 2 1 area. In 2 1 area, explosive dust mixture may appear due to dust leakage and other reasons. In addition,

Dust on the surface of electrical equipment is also a hidden danger in factory safety production, which should be paid enough attention to.

2 1 area must use Class 2 (dust) explosion-proof electrical equipment.

Area 22

In normal operation, it is impossible to have explosive dust mixture, which only happens in fault state. Class 3 (dust) explosion-proof electrical equipment should be used in Area 22. If it's explosive

If the dust in the environment is conductive dust, according to the provisions of EN5028 1- 1-2, Class 2 (dust) explosion-proof electrical equipment must be used. The division of dangerous places is related to many factors on the spot. Generally speaking, it is difficult to give a clear standard and definition for the division of dangerous places. The following factors are closely related to the classification of dangerous places:

1. Physical properties of combustible materials

2. The quantity of gas, steam, mist and liquid in the environment.

3. The status of the publishing source

4. Ventilation status

5. Measures to prevent the diffusion of gas, steam and fog

6. Factors affecting the volatility of combustible gas, steam and water mist.

7. Safety records at the production site

8. Structure and configuration of equipment and devices