As an important part of the Roots blower, how much do you know about it?Roots BlowerI'll take you through it.

I. Roots fan casing design return holes
In the Roots fan casing out of the wind end not over the rotor center to open a certain U-shaped bar hole, you can reduce the outbreak of pressure at the outlet end, in the impeller and the casing, the wall plate formed by the cavity is about to enter the state of confinement, so that a small portion of high-pressure gas out of the outlet to flow back into the cavity, and the outlet gas chamber to form a certain pressure balance.
At the same time when the impeller continues to rotate, the volume of the cavity becomes smaller, the pressure increases, and can make the closed cavity in a large number of discharged gas can be pre-exhausted through the reflux holes, so that can reduce the “dead” gas eddy current noise, but also to reduce the exhaust due to the pressure is too much to release the noise caused by the impact. This is also the “countercurrent cooling” technology that is being continuously developed in China.
Inlet return hole orifice should be connected with the “dead center”, and the exit direction should be consistent with the exhaust direction, the hole size should not be too large, generally take 10 ~ 15mm, and the angle should be less than 20 °, otherwise it will be due to excessive internal leakage caused by the air volume can not meet the requirements.
Roots blower casing wall plate inspection and repair inspection content, all used casing and wall plate, should carefully check its working surface, see whether there is abrasion, corrosion, eyelets and cracks and other defects, and use the inner diameter micrometer to measure the size of the casing inner hole, to see whether it is deformed.
Second, Roots blower repair measures for various defects
1. For minor abrasions, the abrasions can be polished smooth with an oil stone. If the chassis or wall panels scratches a larger area, deeper layer, or corrosion is more serious as well as deformation of the chassis bore, can be corrected by machining. If the processing has a large impact on the size, if necessary, can be coated, sprayed and other methods to be repaired.
2, for the occurrence of the Roots blower casing, wall panels on the outer surface and the fixed bonding surface of the eyelet defects, can be filled with epoxy resin special filler goods putty. For some small holes on the working surface, you can use plugs with threads for plugging, or use nickel-iron welding rod for welding.
3, for the Roots blower shell cracks, in the case of not affecting the use of the Roots blower, can also be patch welding. Replacement welding has hot welding and cold welding two methods, hot welding is to preheat the parts to 650-700 ℃, welding operations at this temperature, cold welding without preheating. Because of the cold welding method is economical, easy to do, the repair of most of the use of this welding method.