Explosion proof fan for coal mines

The explosion-proof fan in coal mines is the core equipment of the coal mine ventilation system, commonly known as the "lung" of the mine. It is specifically designed to transport fresh air underground, discharge gas, carbon monoxide, coal dust, and cannon smoke. All models entering the mine must have the MA coal safety mark and Exd Ⅰ explosion-proof to prevent gas and coal dust explosions and meet the mandatory requirements of the "Coal Mine Safety Regulations".

1、 Three major types

1. Main ventilation fan (main fan, FBCDZ series, ground level machine room)

The overall ventilation of the mine/mining area operates continuously for 24 hours, with a dual machine configuration of one in use and one backup, dual circuit power supply, and must have anti wind function to quickly change the direction of air flow in case of fire accidents for emergency rescue.

Mainstream: Counter rotating axial flow fan, two-stage impeller rotating in reverse, high air volume, high static pressure; Adjustable blade angle, suitable for different ventilation resistances in mines

Installation: Ground return air shaft room

Supporting equipment: anti air damper, diffuser, muffler, shock absorber base, online monitoring system, explosion-proof frequency converter

2. Local ventilation fan (local fan, underground excavation face, FBD/FBCD)

Dedicated for single head excavation tunnels, connected to flame-retardant and anti-static air ducts for air supply, essential for mining.

FBD press in counter rotating fan: fresh air is sent to the front of the excavation, which is most commonly used in low gas mines

FBCD extraction type counter rotating fan: directly extracts polluted air containing gas, high gas, coal and gas outburst mines. Features: Small size, high air pressure, long-distance air supply; The regulations mandate wind power locking, gas power locking, automatic shutdown when power is cut off/gas exceeds the standard, with one in use and one as backup.

3. Auxiliary ventilation fan (auxiliary fan)

Boosting underground tunnels and balancing pipeline resistance are commonly used for long-distance tunnels and areas with uneven ventilation resistance.

2、 Core structure (mainly consisting of counter rotating axial flow)

Shell, two-stage explosion-proof motor+two sets of impellers, bearing box, inlet air damper, diffuser; The supporting parts refer to the complete set of accessories introduced earlier: inlet and outlet soft connections, mufflers, shock absorbers, couplings, shields, and explosion-proof electrical control cabinets. The impeller is mostly made of wear-resistant steel plates, and wear-resistant spraying can be used under dust erosion conditions.

3、 Hard safety requirements (emphasis)

1. MA Coal Safety Mark: Essential qualifications for underground equipment in coal mines. Without MA, it is strictly prohibited to go underground

2. Explosion proof grade Exd Ⅰ Mb: Explosion proof shell, internal explosion will not ignite external gas and coal dust

3. Main fan: dual power supply, backup fan, reverse air device, online monitoring (vibration, temperature, air volume)

4. Local fan: equipped with flame-retardant and anti-static air ducts, wind power locking, gas power locking, and it is strictly prohibited for one local fan to supply multiple excavation faces

5. The whole machine is wear-resistant and dustproof, and the explosion-proof surface is maintained for rust prevention. It is strictly prohibited to continue using the explosion-proof surface if it is damaged

4、 Key parameters for selection

1. Type: Main fan/Local fan; Press in/Pull out

2. Airflow, total pressure, and total resistance of the mine

3. Media: gas concentration, coal dust, temperature

4. Power supply voltage: 380V/6kV/10kV; Is it variable frequency speed regulation

5. Supporting facilities: noise reduction, shock absorption, online monitoring, anti wind (main fan)

5、 Common faults

1. Dust accumulation and wear on the impeller, damage to dynamic balance, and excessive vibration

2. Corrosion and collision of explosion-proof surface, explosion-proof failure, major safety hazards

3. Excessive temperature rise and poor lubrication of bearings

4. Leakage of air duct, insufficient frontal airflow, and accumulation of gas

5. The air door is stuck and the reverse air function is malfunctioning