Mobile and portable explosion-proof equipment – explosion proof flashlight, explosion proof cell phone introduction

In the production site containing explosive hazardous environments, explosion-proof cell phones, explosion-proof walkie-talkies, explosion-proof flashlights and other mobile explosion-proof electrical equipment is widely used.

Explosion-hazardous gas environment mobile equipment and portable equipment selection general requirements are different from permanently installed equipment, mobile equipment or portable equipment is only temporarily used in hazardous locations. This type of equipment may include: emergency generators, welding machines, industrial lifting vehicles (forklifts), air compressors, electric fans or blowers, portable power tools, certain detection equipment.

Equipment that may enter or be brought into a hazardous location should have an appropriate level of equipment protection. If mobile or portable equipment used in a hazardous location does not meet the routinely required EPL level, a documented hazard management procedure shall be implemented. The procedure shall include appropriate training, procedures and controls.

Depending on the requirements of use and flexibility of use, different locations may require the use of mobile equipment, portable equipment. Areas requiring higher EPL levels should not use equipment with lower EPL levels, except where otherwise protected. In practice, however, such a restriction may be difficult to enforce, especially for portable equipment. Therefore, it is recommended that all equipment complies with the requirements of the area requiring the highest EPL level. Similarly, it is desirable that the equipment category and temperature group be appropriate for all gases, vapors and dusts likely to be encountered where the equipment is used. Backup batteries should not be taken into hazardous locations unless proper precautions are taken.

For mobile or portable electrical equipment, where metallic flexible armor or shielding is used in cables, the armor or shielding should not be used as the sole protective conductor. The cable should be suitable for the circuit protection layout, e.g. when earth monitoring is used, and should include the number of conductors required. If the equipment needs to be grounded, the cable may include a grounded flexible metal shield in addition to the grounding conductor (PE).

Mobile (hand-held, portable and removable) electrical equipment is particularly susceptible to damage or misuse, so the intervals between successive supervisory inspections may be shortened as practical. Mobile electrical equipment should be inspected at least once every 12 months, and frequently opened enclosures (e.g. battery covers) should be inspected in detail. In addition, such equipment should be visually inspected before use to ensure that there is no obvious damage to the equipment.

Explosion-proof knowledge ten questions

1 flammable and explosive site inspection using a non-explosion-proof cell phone, the phone to the flight mode state to take pictures, meet the requirements?

First of all, you need to recognize whether the flammable and explosive site is an explosion-proof area. If it is in a non-explosion-proof area, theoretically you can use flight mode to take pictures. If it is in an explosion-proof area, you cannot use non-explosion-proof electrical appliances. Flammable and explosive locations pose a very high safety risk, as sparks, static electricity, etc. can cause explosions or fires. Non-explosion-proof cellular phones are not designed and manufactured with specific explosion-proof measures, and their internal circuits and batteries may still generate tiny electrical sparks or release static electricity during operation, thus becoming a potential source of ignition. Flight mode only shuts down the communication function of the cell phone, but it does not change the circuit characteristics and potential hazardous factors of the cell phone itself. In order to ensure the safety of personnel lives and the safety and stability of the premises, special equipment certified as explosion-proof should be used for operations such as taking pictures.

2 gas boiler room (Category D, open flame) of the explosion hazardous area how to divide? How to select the type of electrical equipment explosion-proof?

In the production process using open-flame equipment or baking hot surface temperature exceeds the temperature of combustible gases in the area of the ignition temperature of the equipment in the vicinity of the area. Such as boiler room, hot water furnace room. Located in other buildings, oil, gas boiler room boiler room, should be set up independent of the air supply and exhaust system, the ventilation device should be explosion-proof. Therefore, the gas boiler room may not be divided into explosion hazardous areas. Gas boiler room ventilation device should be used explosion-proof equipment.

3 hydrogen peroxide tank transfer pump motor need explosion-proof? How to determine the explosion-proof level?

Simple hydrogen peroxide storage tanks, cofferdam range does not require explosion-proof. Storage tanks can be considered according to Class A tank spacing, tanks and production equipment to maintain fire separation, tanks may not be explosion-proof electrical; such as no other gases or dust, simple hydrogen peroxide environment to choose a good corrosive level of protection can be, explosion-proof settings of little significance.

4 sodium dithionite is a combustible dust?

Sodium dithionite is not included in the “industrial and trade industry key combustible dust directory (2015 edition)”, for the dust not included in the directory and explosion-proof standards, in accordance with GB/T 3836.12-2019 “explosive environment Part 12: test methods for the characteristics of combustible dust substances” standard identification.

5 Does Class C device need to be divided into explosion hazardous areas? Which cases should be carried out in the explosive atmosphere environment of the design of electrical installations?

Class C operating temperature exceeds the flash point should also be divided into explosion-hazardous areas, electrical whether the need for explosion-proof to refer to the “explosion-hazardous environment power plant design specifications” 3.1.1 in the production, processing, handling, transit or storage process, or the possibility of one of the following explosive gas mixtures in the environment, should be the design of electrical installations for explosive gas environments:

(1) under atmospheric conditions, combustible gases mixed with air to form explosive gas mixtures;

(2) flash point lower than or equal to the ambient temperature of combustible liquid vapor or mist mixed with air to form explosive gas mixtures;

(3) in the material operating temperature is higher than the flash point of combustible liquids, when the combustible liquids may leak, combustible liquids, vapors or mists mixed with air to form explosive gas mixtures.

6 Can graphite powder be considered as combustible dust?

Graphite powder is class IIIC combustible conductive dust.

7 site inspection of gas alarms will generally exist what problems?

Generally there will be the following kinds:

(1) Missing: the area where it should be installed is not set;

(2) Location error: height or coordinates can not effectively cover the range;

(3) Selection error: explosion-proof class does not match;

(4) Configuration error: toxic and combustible at the same time, not equipped with both functions;

(5) Range error: mismatch between range and applicable gas;

(6) Range accuracy: the accuracy required by the range and the standard is not enough;

(7) Quantity problem: the quantity is too small and the coverage is insufficient;

(8) Detection problems: failure to test and calibrate or calibrate according to the cycle;

(9) Alarm problems: alarms are recorded but not disposed of;

(10) Setting problems: alarm companies install on their own, without professional design;

(11) Alarm functions: sound and light alarms, area alarms are not properly installed and used;

(12) maintenance and repair management issues: whether normal operation, whether regular inspection, maintenance, calibration.

8 there is no specification clear Class A and B plant can not be set up in the laboratory?

Laboratory, office and other equipment facing the fire hazard side of the external wall should be no windows and doors opening non-combustible material solid wall. When it is necessary to set up windows and doors, fire doors and windows should be used.

9 cable through the pipe or the use of explosion-proof hose can play a role in explosion-proof?

Can play a role in mechanical protection and energy suppression, but can not play a role in explosion-proof, explosion-proof role is the equipment body electrical interface measures.

10 gas environment explosion-proof electrical equipment can be used for dust explosion hazardous areas?

No.

(1) gas explosion-proof and dust explosion-proof double certification of explosion-proof equipment can be used both in the gas environment and dust environment; only gas explosion-proof certification of equipment can not be used in the dust environment, only dust explosion-proof certification of equipment can not be used in the gas environment.

(2) need to pay attention to the environment group and the use of explosion-proof area. For the simultaneous existence of explosive gases and dust areas, the choice of explosion-proof electrical equipment should meet both the explosive gas explosion-proof requirements, but also to meet the explosive dust explosion-proof requirements, and its explosion-proof marking at the same time, including gas and dust explosion-proof marking.