Cabinet centrifugal fan as the more common type of fan should have in the purchase of certain skills, Xiao Bian gave you specific about it: 1, a reasonable choice of blade types: at a certain speed common tank centrifugal fan, After Ψt small pressure coefficient of the impeller, the impeller diameter is large, and high efficiency; the forward impeller and vice versa. 2. Select the drive way: If the transmission mode for the A, D, F are three, the tank centrifugal blower speed and the same motor speed; and three B, C, E are variable speed, the flexibility to choose cabinet centrifugal design fan speed. General widespread adoption of small wind turbines with direct-drive motor A ,, large fan, belt drive and sometimes discomfort, and many more transmission mode D, F drive. High temperature, dusty conditions, transmission mode also consider the issue of protection and cooling motors, bearings. 3, volute dimensions selection: volute dimensions should be as small as possible. Higher than the number of revolutions of the fan, can be used to shorten the snail-shaped, lower than the number of revolutions of the fan is generally used in standard scroll. Sometimes in order to reduce the size of the volute, the choice of volute outlet tank centrifugal fan inlet velocity greater than the speed of the program, this time using the outlet diffuser to increase static pressure value. 4, blade outlet angle selected: blade exit angle is one of the main geometric parameters of the design to be selected first. In order to facilitate the application of our blades are classified as: a strong backward curved blade (pump type), after the bend arc blade, straight blade backward curved, backward curved airfoil-shaped leaves; radial vane outlet, radial straight blade; curved blade before, Strong forward curved blade (multi-blade leaf). 5. Select the number of leaves: in tank centrifugal fan, the increase in the number of impeller blades of the impeller can improve the theoretical pressure, because it can reduce the impact of the relative vortex (an increase of K value). However, an increase in the number of blades, will increase the friction loss of the impeller channels, this loss will reduce the actual pressure tank centrifugal fan and increase energy consumption. So for each impeller there is an optimum number of blades. Determine how many times a specific number of leaves to be based on the designer's experience may be. 

palabras clave: Centrifugal fan, tank centrifugal fan, ,