SAND CASTING EQUIPMENT.

The dust bag is made of needle-punched filter felt. The production of needle-punched filter felt abandons the traditional production process and adopts a new process of non-woven acupuncture method. To make it form a three-dimensional structure, after a series of finishing processes of hot rolling, singeing, coating or filming, and shaping, the thorned filter material is shaped and its filtration performance is improved.

The bag filter is a kind of dust collector that uses a porous fiber filter bag (film-coated needle felt) to separate the dust in the dusty gas from the air through sieving, interception, collision, diffusion and electrostatic adsorption. The cylindrical filter cartridge is fixed on the upper and lower partitions of the dust collector. The dust-laden gas enters from the air inlet of the side wall, and the dust-laden gas passes through the outer wall of the filter cartridge and is discharged through the exhaust port. The dust particles are retained by the filter cloth and accumulated. A layer of dust particles is formed on the outer wall of the filter bag. The mechanism is: the dust particles larger than the filter cloth mesh hole in the dust-laden gas are blocked by the filter cloth; the dust particles (1-10µm) smaller than the filter cloth hole diameter when the airflow passes along the tortuous fabric holes, due to the inertial effect of the dust particles. , the impact on the fiber loses kinetic energy and loses kinetic energy and adheres to the filter cloth. For extremely fine dust particles (less than 1µm), due to the diffusion and electrostatic effect of the dust particles themselves, when passing through the filter cloth pores, the pore size is smaller than the thermal motion free path of the fine dust particles, so that the dust particles collide with the filter cloth fibers and adhere. In the gap between the filter cloth, so that the fine dust particles can also be captured.
During the filtration process, due to the continuous accumulation of dust on the surface of the filter cloth and the outside, the air inlet side of the filter bag forms a dust layer with a small pore size composed of dust particles. The primary dust adhesion layer also acts as a filter interface, improving the filter performance. However, with the thickening of the dust layer and the increase in filtration resistance, it is difficult to filter. In order to ensure smooth air flow and maintain stable processing capacity and dust collection efficiency, the dust layer on the filter cloth must be cleaned regularly.