A ventilator is a machine that relies on the input of mechanical energy to raise the gas pressure and send the gas side by side. It is a driven fluid machine. Exust pressure below 1.510 ^ 4 pa. Modern ventilators are widely used in factories, mines, tunnels, cooling towers, vehicles, ships, ventilation, dust removal and cooling of buildings, ventilation and air ventilation of boilers and industrial furnaces, cooling and air ventilation in air conditioning equipment and household appliances, drying and entry of grains, air tunnel air sources and inflation and propulsion of hovercraft, etc.
Centrifugal ventilator is a kind of modern power engine (Shaded Pole Motor) to drive the impeller in the worm shell, and the air is inhaled from the center of the impeller through the suction mouth. Due to the dynamic action of the blade on the gas, the gas pressure and speed are increased, and the centrifugal force is thrown along the blade path to the casing, and discharged from the exhaust port. Because the flow of gas in the impeller is mainly in the radial plane, so it is also called the radial ventilator.
The centrifugal ventilator is mainly composed of impeller and casing. The impeller of the small ventilator is directly installed on the motor, and the large ventilator is connected with the motor through the coupling or pulley. Centrifugal ventilator is generally single-side intake, with single-stage impeller; large flow can be bilateral intake, with two back-to-back impeller, also known as double suction centrifugal ventilator.
Impeller is the main component of the ventilator, and its geometry, size, blade number and manufacturing accuracy have a great influence on the performance. The impeller passes the static balance and the dynamic balance correction to ensure the smooth rotation of the ventilator. According to the different direction of the blade exit, the impeller is divided into three types: forward, radial and backward. The top of the blade of the front impeller is inclined in the rotating direction; the top of the radial impeller is radial, with straight blade and curved blade, and the top of the blade of the rear impeller is inverted.
