The outer rotor centrifugal fan has a long history. In 1862, the British Guibell invents centrifuge air, the impeller, the casing is concentric circular, the casing brick, the wooden impeller adopts the backward straight blade, the efficiency is only about 40%, mainly used for the mine ventilation. In 1880, people designed a worm housing for mines, and the centrifugal fan of the rear curved blade, the structure is complete. The outer rotor centrifuge fan is a high-energy-consuming device, the proportion of power resources is large in stone processing, with the increasing shortage of energy in my country, the promotion and application of high-yield, energy-saving reduction has become stone The problem of universal concern, many stone production enterprises reduce the power consumption of the fan as the current important work.
The outer rotor centrifugal fan needs to regulate the flow in accordance with the host load. Currently, the energy-saving adjustment method of Compact Fan Heater the fan processing enterprise fan is more old, generally adopting throttle adjustment. When the throttle is used, the flow of the fan is mainly adjusted by adjusting the valve or throttle baffle. The throttle of the fan is large, and even when the low load is more than 50%, there is a throttling loss and deviation from the high-efficiency area. Energy waste is very serious. If the speed of the fan is adjusted, the exterior is to remove the throttle loss, but also ensure that the fan is always running in the high-efficiency area, so energy can be greatly saved. It can be said that the speed of the regulator is to run the fan is an effective energy-saving method, which reflects the current new trend in the production of building materials industry.
The pressure generated by the outer rotor centrifugal fan is affected by the change in intake temperature or density. For a given intake, the pressure is lowered at the time of the highest intake temperature (the air density). For a given pressure and flow characteristic curve, there is a power and flow characteristic curve. When the blower operates constant speed For a given flow, the required power is raised as the air temperature is lowered. The essence of the centrifugal fan is a variable flow constant voltage device. When the speed is constant, the pressure-flow theory curve of the centrifugal fan should be a straight line. Due to internal losses, the actual characteristic curve is curved.
Contemporary Western countries use a high-molecular composite repair method for the above problems, and more applications are the United States, the United States, which has superior adhesion, excellent compressive strength, etc., free of disassembly Processing. The wear of the centrifugal fan transmission is often the equipment problem, including the winding machine bearing, bearing chamber wear, blower shaft bearing wear. For the above failure of the centrifugal fan, the traditional maintenance method has a surfacing, thermal spraying, electrical brush, etc., but there is a certain drawback: the thermal stress generated by the soldering high temperature cannot be completely eliminated, which is easy to cause material damage, resulting in bending or fracture of the components; The brush-plating is limited by the thickness of the coating, and it is easy to peel off, and the above two methods are metal repair metal, which cannot change the cooperation of "hard to hard". Under the integration of all force, it will still cause incluscal rollers. Wear again.