7CFM Vacuum Pump Rotary vane double stage vacuum pump 110V, 3L

  

The rotary vane vacuum pump is the basic equipment used to extract gas from the airtight container. It can be used alone or as the pre-pumping pump of booster pump, diffusion pump, molecular pump, maintenance pump and titanium pump. It can be used for the manufacture of electric vacuum devices, vacuum welding, printing, plastic absorption, refrigeration equipment repair and instrument matching. The dual-stage vacuum pump is small in size and light in weight, and has a large oil window for easy observation of oil volume even when adding oil. The oil mist catcher has the advantages of five-layer filtration, effective prevention of oil smoke splashing and noise reduction.

17.78.112.2(4520.531cm). Check the oil level and fill the oil to the center of the oil pointer when the pump is stopped. If it is too low, it will not seal the exhaust valve and affect the vacuum degree. If it is too high, it may cause fuel injection during atmospheric starting. It is normal for the oil level to rise during operation. Oil is added from the oil filling hole, and the screw plug shall be screwed on after filling. The oil should be filtered to prevent sundries from entering and blocking the oil hole. The pump can be started at one time under atmospheric or any vacuum. If a solenoid valve is installed at the pump port, it should act simultaneously with the pump. When the ambient temperature is too high, the temperature of the oil will increase, the viscosity will decrease, and the saturated vapor pressure will increase, which will cause the limit vacuum to decrease, especially the total pressure measured by the thermocouple. If the ventilation and heat dissipation are strengthened or the pump oil performance is improved, the limit vacuum can be improved. Check the limit vacuum of the pump based on the compressed mercury vacuum gauge. If the vacuum gauge has been fully pre-pumped and calibrated, the pump temperature is stable, the pump port is directly connected with the gauge, and the limit vacuum will be reached within 30 minutes of operation.

The value measured by the total pressure gauge is related to the pump oil, vacuum gauge and gauge error, sometimes the error can be even large, and can only be used as a reference. If the relative temperature is high, or the extracted gas contains more condensable steam, open the gas ballast valve after connecting the extracted container, and close the gas ballast valve after 20-40 minutes of operation. Before stopping the pump, the gas ballast valve can be opened for 30 minutes without load to extend the service life of the pump oil.

Oil selection: the viscosity of the pump oil affects the starting power and the limit vacuum of the pump. When the viscosity is high, it is beneficial to the vacuum degree, while the starting power is higher.

The saturated vapor pressure of oil at pump temperature will affect the ultimate total pressure of the pump, the lower the better. The viscosity of high-speed vacuum pump oil and 3 # diffusion pump oil is higher than that of 1 # vacuum pump oil, and the saturated vapor pressure is lower than that of 1 # vacuum pump oil, but the price of 3 # diffusion pump oil is higher. The specific oil to be selected can be selected according to the above introduction and the specific use requirements. (1) In general, the high-speed vacuum pump oil made in Shanghai should be used where the total pressure is expected to be more than 6X10-2. Small pumps below 4L/s can also be replaced by 1 # vacuum pump, and direct-connected pumps above 8L/s can be replaced by 3 # diffusion pump.

(2) If the requirements for vacuum degree are not high, and the oil is polluted and replaced frequently, and the vacuum pump oil supply is difficult, No. 50 machine oil can be used instead. (3) If the ambient temperature is low, it is difficult to start, and the limit vacuum requirement is not high, the real pump oil or mechanical oil with lower viscosity can be used.