During the crushing operation of the crusher (such as petrol concrete breaker
), a large number of fine particles will disperse in the surrounding space due to the transportation of materials and the operation of equipment, causing damage to operators and equipment (such as petrol concrete breaker). Gas - solid two-phase separation must be carried out for this dust-containing gas to purify the air.
Dust removal is mainly carried out in corresponding equipment according to the characteristics of dust particles, such as particle size, density, concentration, adhesiveness, hygroscopicity and electrostatic characteristics, etc., using various methods such as gravity, inertia, centrifugal force, washing, filtration and electric dust removal.
(1) Gravity dust removal can treat coarse particles over 100UM, and is used for pretreatment of coarse dust removal and other fine dust removal. The operation mode is to introduce dust-containing gas into a large-volume gravity settling tank, reduce the gas flow rate, and use gravity to settle particles and separate them from the gas.
(2) Inertial dust removal can be used to separate particles above 5UM from gas. The dust-containing gas impacts on the baffle plate of the inertial dust collector during directional baffle, and the particles are captured due to inertial action. In order to prevent the scattering effect during impact collision, high flow rate cannot be adopted.
(3) Centrifugal dust removal uses centrifugal force, which is hundreds to thousands of times greater than the gravity of the particles, generated when the gas rotates, to cause solid particles to settle along the peripheral wall. The equipment used is cyclone dust collector. Usually, the inlet speed is 10 - 20m / s, and the minimum particle diameter that can be trapped is 5UM or less.
(4) Washing and dedusting make gas contact with spray water to capture solid particles therein. Commonly used spray dedusting tower introduces gas from the lower part and sprays water into mist from the upper part for countercurrent washing.
(5) Electric dust removal causes solid particles in gas to be with charge and thus attracted to electrodes with opposite charges to achieve the purpose of dust removal. Electric dust collector applies a direct voltage of tens of thousands of volts between metal discharge electrodes, causing gas between the two electrodes to ionize. When the negative ionized gas collides with solid particles, the solid particles are negatively charged, attracted by the positive electrode, and settle down after neutralizing the charge. This method is suitable for fine dust removal with high requirements. However, the dust concentration should not be too high and the gas flow rate should not be too fast.