The dust pollution of foundry mainly comes from smelting, sand treatment, unpacking, vibration shakeout, cleaning and other production links.

The dust removal equipment of the foundry is basically a filter type bag dust collector. The filter type dust removal device includes bag type dust collector and particle layer dust collector, the former usually uses the filter bag made of organic fiber or inorganic fiber fabric as the filter layer, and the filter layer of the latter is mostly composed of particles of different sizes, such as quartz sand, river sand, ceramic particles, slag and so on. With the powder repeatedly attached to the outer surface of the filter bag, the powder layer continues to thicken, and the resistance value of the bag dust collector also increases: the pulse valve diaphragm gives instructions, the pulse valve is opened when the flood is left and right, the compressed air in the high pressure air bag is passed, if there is no dust or small to a certain degree, the mechanical cleaning work will stop working.

The working principle of the bag dust collector is that after the dust-containing gas enters the ash hopper from the tuyere, a part of the coarser dust particles and condensed dust masses fall directly due to the inertia effect and play the role of pre-collecting dust. The air flow into the hopper is turned upward into the box, and when it passes through the filter bag with a metal skeleton inside, the dust is blocked on the outside surface of the filter bag. The purified gas enters the cleaning chamber at the upper part of the filter bag and is collected and discharged into the outlet duct. The dust removal of the dust collector is carried out in turn by room, and its program is adjusted by the controller according to the process conditions. Reasonable cleaning procedure and cleaning cycle ensure the cleaning effect and filter bag life of this type of dust collector. The cleaning controller has two kinds of cleaning functions: timing and fixed resistance. Timing cleaning is suitable for the occasions where the working conditions are more stable. If the working conditions change frequently, the fixed resistance cleaning is used.