SINO Testing Services| 2020-09-28|Return
1、 Explosion hazards of combustible dust
When it comes to explosions, people naturally think of explosives or combustible gases with oxygen（Or air）The earth shattering roar during the explosion. Little did they know that the swirling dust suspended in the air could also cause a powerful explosion. Dust explosion accidents are not uncommon both domestically and internationally, such as the recent Kunshan metal dust explosion incident and the Taiwan amusement park flour explosion case.
Why does dust explode? In a certain enclosed space, when combustible dust is suspended in the air and reaches a certain concentration, it forms an explosive mixture. Once encountering Mars, it may cause rapid combustion and explosion. Common dust explosions include pulverized coal, flour, wood flour, sugar powder, corn flour, potato flour, dried milk powder, aluminum powder, zinc powder, magnesium powder, sulfur powder, etc. But as long as we strengthen our preventive measures, such explosions can still be completely avoided. If effective ventilation and dust removal measures are adopted, smoking and open flame operations are strictly prohibited. Install pressure relief valves or other devices on the equipment casing, and use explosion suppression systems, etc. Below, we will briefly introduce how polishing wet dust removal equipment is implemented in places with combustible dustExplosion proof technologyof
2、 Application of polishing wet dust removal equipment in explosive dust environments
Polishing wet dust removal equipment is generally used in processing places for polishing magnesium alloys, aluminum, zinc, iron, and other materials. Due to the large amount of metal dust generated during the processing in such places, the combination of dust and air forms an explosive environment. Once it encounters an ignition source, it is easy to produce an explosion. So, it is required that the dust removal equipment itself must haveExplosion proof certificationof
Polishing wet dust removal equipment is a pump free pneumatic dust collector that does not require the use of any filtering materials throughout the entire water cycle process. The overall structure of the dust removal bin and water gas separation bin has no dead corners of dust accumulation, is observable, can be cleaned at any time, and has good air circulation safety performance.
The main structure of the dust collector is composed of a box, a centrifugal fan, an electrical control box, a lighting lamp, an explosion-proof motor, a silencer, and a pressure differential gauge.
Its working principle: It is a device that closely contacts dusty gases with liquids (usually water), uses the inertia collision of water droplets and particles, or uses the full mixing effect of water and dust and other effects to capture particles, or increases or leaves particles in a fixed container to achieve the separation effect of water and dust.
The wet dust collector produced combines two forms: water bath and spray. Firstly, by utilizing the suction force of a high-pressure centrifugal fan, the dusty gas is compressed into a water tank filled with a certain height of water. The water bath will adsorb some of the dust in the water. After uniform distribution and diversion, the gas flows from bottom to top, while the high-pressure nozzle sprays water mist from top to bottom, capturing the remaining dust particles. Its filtration efficiency can reach85%Above.
3、 Technical requirements for explosion-proof certification of polishing wet dust removal equipment
In such dust explosion areas, polishing wet dust removal equipment is often relatively large and may have many components combined. The explosion-proof of dust removal equipment first requires all electrical components to be explosion-proof, such as purchasing motors with explosion-proof certificates, as well as lighting fixtures, electrical control boxes, etc. It should be noted that the hazardous source involved in the dust collector is explosive dust, so the purchased components must also beDust explosion-proofOr gas and dust. Some manufacturers often overlook this point when purchasing components, and use lighting that is only suitable for explosive gas environments.
In addition, due to the particularity of dust collectors, in addition to meeting the requirements ofExplosion proof standardGB12476To meet industry standardsAQ 4273-2016Safety technical specifications for dust removal systems used in dust explosion hazardous areas. Including structural inspection of the dust collector, abnormal operation alarm, alarm requiring simultaneous activation of interlocking devices, etc.
4、 How to apply for explosion-proof certification for polishing wet dust removal equipment?
1. List of materials provided: copies of valid explosion-proof certificates, final assembly drawings, schematic diagrams for each live componentBOMTables, product manuals, enterprise standards, copies of business licenses, application authorization letters, etc.
2. Certification method: on-site evaluation and evidence collection. Due to the large size of the equipment, and considering the inconvenience of sending samples to customers, we directly dispatched engineers to the customer's site for product testing and evaluation. We raised and assisted in rectifying non-conforming items on site, greatly reducing the time for customer certification and saving costs.
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