The dust pollution in foundries mainly comes from production processes such as smelting, sand treatment, unpacking, vibration sand falling, and cleaning.
The dust removal equipment in the foundry is basically a filter type bag filter. The filter type dust remover includes bag type dust remover and particle layer dust remover. The former usually uses the filter bag made of organic fiber or inorganic fiber fabric as the filter layer, while the latter mostly uses particles with different particle sizes, such as quartz sand, river sand, ceramsite, slag, etc. As the powder repeatedly adheres to the outer surface of the filter bag, the powder layer continuously thickens, and the resistance value of the bag dust collector also increases: the pulse valve diaphragm sends a command, and when the left and right sides are submerged, the pulse valve opens, and the compressed air inside the high-pressure air bag passes. If there is no dust or it is too small to a certain extent, the mechanical dust cleaning work will stop working.
The working principle of a bag dust collector is to introduce dust containing gas from the air outlet into the ash hopper, and a portion of coarse dust particles and agglomerated dust clusters will fall directly due to inertia, playing a role in pre collection of dust. The airflow entering the ash hopper twists upwards and flows into the box. When passing through the filter bag with a metal skeleton inside, the dust is blocked from staying on the outer surface of the filter bag. The purified gas enters the cleaning room on the upper part of the filter bag and is collected and discharged into the air outlet duct. The dust removal of the dust collector is carried out in turns from room to room, and its program is determined by the controller according to the process conditions. A reasonable cleaning procedure and cleaning cycle ensure the cleaning effect and filter bag life of this type of dust collector. The dust cleaning controller has two types of dust cleaning functions: timed and fixed resistance. Timed dust cleaning is suitable for situations with relatively stable working conditions. If the working conditions change frequently, a fixed resistance type dust cleaning is used.