Explosion-proof dust collectors are mainly used to deal with dust that poses a risk of combustion or explosion. The explosion-proof capability of the equipment is not determined by a single component, but is composed of multiple measures such as structural design, filter materials, electrical configuration, explosion venting and explosion-proofing, static electricity control and daily management.

1. Explosion-proof design of the overall structure

During the structural design stage of the explosion-proof dust collector, the accumulation of dust inside the equipment should be minimized to avoid the formation of dead corners where dust easily accumulates. The ash hopper, baffle, box connection and internal diversion structure should be reasonably arranged so that dust can smoothly fall into the ash hopper and be discharged in time.

For locations prone to dust accumulation, long-term dust deposition can be reduced by optimizing the baffle angle, adding deflectors, or adopting a smooth transition structure. The volume of the ash hopper, the ash discharge method and the air locking device should also be designed according to the nature of the dust and the air volume of the treatment.

2. Selection of antistatic filter bags

Ordinary filter materials are not necessarily suitable for handling dust with explosion risks. Explosion-proof bag dust collectors usually need to select filter bags with antistatic properties based on dust characteristics, and ensure a reliable electrostatic conduction path between the filter bag, keel, flower board and equipment shell.

It should be noted that anti-static filter bags are only one measure in the explosion-proof system and cannot alone replace the overall safety design such as grounding, explosion venting, explosion-proof and explosion-proof electrical.

3. Explosion-proof pulse solenoid valves and electrical components

For the solenoid valves, electromagnetic coils, control boxes, motors and other electrical components in the pulse cleaning system, corresponding explosion-proof products should be selected based on the level of hazardous areas on site and the use environment.

The working voltage, control mode and explosion-proof level of the solenoid valve should be determined based on the equipment’s electrical system and on-site working conditions. It should not be selected directly based on conventional equipment parameters alone.

IV. Explosion venting, explosion-proofing and explosion suppression measures

In order to reduce the harm caused by dust explosions, explosion-proof dust collectors can be equipped with explosion-proof discs, explosion-proof doors, flameless explosion-proof devices, explosion-proof valves or explosion suppression systems based on risk assessment.

1. Explosion relief device: releases the pressure when the internal pressure of the equipment rises rapidly, reducing the risk of box damage.

2. Explosion-proof device: used to prevent flames and explosion pressure from propagating through pipelines to front and rear equipment.

3. Flameless explosion venting: suitable for some installation scenarios where the explosion vent cannot directly lead to a safe outdoor area.

4. Explosion suppression system: Reduce the development of explosions by quickly detecting and releasing explosion suppression media.

The explosion vent area, installation location and vent direction should be professionally designed. The explosion vent must not face personnel passages, operating areas or other dangerous locations.

5. Equipment grounding and static electricity control

Dust-containing airflow may generate static electricity when it moves inside pipes, filter bags and equipment. The dust collector box, air duct, ash hopper, filter bag frame and other metal parts should be reliably grounded and connected to equipotential to avoid static electricity accumulation from forming an ignition source.

If there is a risk of static electricity in soft connections and non-metallic pipe sections, bridging or other static conduction removal measures should also be taken according to the working conditions, and the grounding connection should be regularly checked for looseness, corrosion or failure.

6. Control the entry of high-temperature particles and sparks

For working conditions that may contain high-temperature particles, sparks or open flames, a spark detection, spark extinguishing, cooling or pre-separation device should be installed at the front of the dust collector to prevent ignition sources from entering the filter bag area.

The so-called “fire section” should not be set up around the dust collector to continue burning dust. Instead, process isolation, spark control and standardized ash discharge should be used to prevent unextinguished particles from entering or leaving the equipment and causing secondary accidents.

7. Timely discharge ash and prevent dust accumulation

Long-term accumulation of dust in the ash hopper will increase the risk of equipment operation. The ash discharge system should be kept in normal operation and a reasonable ash discharge cycle should be established based on the amount of dust generated.

The ash discharge valve, screw conveyor or ash discharge device should maintain sealing and continuous operation capabilities to prevent air backflow, dust blockage or large amounts of dust accumulation inside the equipment.

8. Safety requirements before maintenance

Before overhauling the explosion-proof dust collector, the operation of the equipment should be stopped, the relevant power supply and air source should be cut off and locked, the residual dust inside the equipment should be removed, and the internal temperature, oxygen content and harmful gas concentration should be confirmed to meet the entry conditions.

Before entering the box, maintenance personnel should be fully ventilated, and undergo approval, testing and monitoring in accordance with the requirements for limited space operations. Do not enter the dust collector directly without confirming safety.

1. Cut off and lock the energy of fans, motors, ash cleaning and ash discharge systems.

2. Bleed the residual pressure in the compressed air system.

3. Clean the dust inside and around the equipment.

4. Use explosion-proof tools, lighting and detection equipment that meet on-site requirements.

5. During the maintenance process, special personnel should be arranged for supervision and reliable communication should be maintained.

9. Operation management and regular inspection

After the explosion-proof dust collector is put into operation, equipment files and inspection records should be established, and filter bags, pulse valves, explosion relief devices, explosion-proof devices, grounding systems, ash discharge systems and electrical equipment should be inspected regularly.

Operators should also pay attention to equipment resistance, air volume, temperature and abnormal sounds. If an abnormal increase in temperature, increase in exhaust dust, equipment vibration or abnormal pressure difference is found, the machine should be shut down for inspection in time.

The explosion-proof dust removal system should be specially designed according to the dust explosion characteristics, processing air volume, equipment installation location and on-site hazardous areas. Explosion venting, explosion-proof, explosion-suppression and explosion-proof electrical configurations should be determined by professionals with corresponding capabilities. Overall explosion-proofing cannot be achieved by relying solely on anti-static filter bags or single components.