A common type of cooling for Roots vacuum pumps is called air cooling or aircooling. In addition, another type of cooling is often used. In addition, water cooling is also often used, so, together with the following to understand how to cool the device of Roots vacuum pump!
1. Air cooling
Roots vacuum pump generates heat through gas transportation and compression, and this heat needs to be transferred from the rotor to the casing for heat dissipation. However, at low pressure, due to the poor performance of gas heat conduction and convection, the heat absorbed by the rotor is difficult to distribute, and the temperature of the rotor is always higher than the temperature of the shell.
Thermal expansion of the rotor causes the clearance between the rotor and the rotor and between the rotor and the pump casing to decrease, especially when the differential pressure is high, it will become particularly serious, and sometimes the rotor will stick, resulting in damage to the pump. In order to make the Roots pump work under high differential pressure, expand the range of use and improve the reliability of the pump, you need to try to discharge the heat generated by the rotor, that is, to cool the rotor.
Roots vacuum pump In order to understand the nature of air cooling, let's take a look at the gas flow on the exhaust side of a Roots vacuum pump. In a Roots vacuum pump, the suction gas is compressed not continuously, but abruptly. The suction gas is enclosed within the chamber as the rotor rotates. In addition, as the rotor rotates, the gas within the chamber is suddenly connected to the exhaust port.
2. Cooling inside the rotor
In order to make the Roots vacuum pump work under a higher pressure difference, you can use circulating oil to cool the rotor, the pump shaft at each end of the installation of oil holes, the oil diameter of the shaft head to play, through the inner wall of the rotor from the other end of the discharge of a more effective cooling method. Cooling oil in addition to cooling the rotor, but also lubricate gears and bearings. The cooling effect is good, the pump in operation when the rotor temperature is lower than the shell temperature, large pumps are mostly used in this way.
3. Rotor oil film cooling
The cooling method is to connect the pipeline to the inlet of the Roots vacuum pump and absorb the heat of the rotor with the cooling oil dripping evenly. The oil passes through the filter and cooler, and is transported to the inlet of the pump through the pipeline through the closed oil pump. After dripping oil into the rotor, it flattens out on the rotor surface as the rotor rotates.
This not only takes away the heat from the rotor, but also forms an oil film on both rotor surfaces, preventing backflow of gas, and also takes away fine dust adhering to the rotor surfaces. An oil tank is set up at the outlet of the pump to collect waste oil, filter it, cool it and recirculate it.
4. Water cooling
Wet Roots vacuum pump refers to the intermediate stage or double-stage pump inhalation of air compression, with the comprehensive absorption of a phase difference between the combination of silencer delivery. Injecting a tiny amount of water into the pump removes the heat generated by the compressed air. The suction hose is mounted at the inlet end of the single- or two-stage pump unit and is connected to the inlet of the vacuum pump.
The water is drawn in by the vacuum generated by the vacuum pump; the greater the vacuum, the higher the amount of water drawn in. A simple regulating valve should ensure good suction, and the temperature of the suction water should be kept at about 20 degrees, clean and free of calcium.
The above introduction is how to cool the device of Roots vacuum pump, if you need to know more, feel free to contact us!
