What factors should be noticed in the manufacture of vacuum pumps
Vacuum pump is a kind of equipment or equipment which can obtain vacuum by mechanical, physical, chemical or physical chemical methods. Following the development of vacuum applications, many varieties have been developed, and their pumping speed has increased from a few minutes per second to hundreds of thousands or millions of liters per second. According to the working principle of vacuum pump, it can be divided into two types, namely, gas transmission pump and gas trapping pump. With the application of vacuum technology in the field of production and scientific research, the demand for its application pressure scale becomes wider and wider. Most of them need several vacuum pumps to form a vacuum gas extraction system to satisfy the demand of production and scientific research process. Because the vacuum application part touches on a wide range of operating pressure, so any type of liquid ring vacuum pump can not be used. Completely applicable to all operating pressure scale, can only be based on different operating pressure scale and different operating requirements, the use of different types of vacuum pumps. In order to use conveniently and meet the needs of various vacuum technology processes, various vacuum pumps are sometimes combined according to their functional requirements for unit type application.
Vacuum pump function:
1. Limit pressure of vacuum pump: The unit of limit pressure of pump is Pa, which means that the pump is equipped with standard test cover at the inlet and operates under regular conditions, and tends to the lowest stable pressure without introducing normal gas.
2. Vacuum pump pumping rate: the unit of pumping rate is m3/s or l/s. It refers to the ratio of the flow rate of gas flowing through the experimental cover to the equilibrium pressure measured at the specified azimuth of the experimental cover when the pump is equipped with a standard experimental cover and operates under regular conditions. Pump pumping speed for short.
3. Vacuum pump pumping capacity: Vacuum pump pumping capacity unit is Pam3/s or Pal/s. It refers to the gas flow rate at the inlet of the pump.
4. Starting pressure of vacuum pump: The starting pressure unit of vacuum pump is Pa. It refers to the pressure when the pump starts without damage and has the effect of pumping.
5. Pressure of the front stage of the pump: The unit of pressure of the front stage of the vacuum pump is Pa, which refers to the outlet pressure of the vacuum pump whose exhaust pressure is lower than that of an atmospheric pressure.
6. Maximum front-stage pressure of vacuum pump: The maximum front-stage pressure unit of the vacuum pump mouth is Pa, which means that it exceeds the front-stage pressure that can damage the pump.
7. Maximum operating pressure of vacuum pump: The maximum operating pressure unit of vacuum pump is Pa, which refers to the inlet pressure corresponding to the maximum pumping volume. Under this pressure, the pump can work continuously without deterioration or damage.
8. Compression ratio: Compression ratio refers to the ratio of the outlet pressure of a pump to the inlet pressure of a given gas.
9. Ho's coefficient: the ratio of the actual pumping speed on the area of the pumping passage to the theoretical pumping speed calculated by molecular slurry.
10. Pumping speed coefficient: the ratio of the actual pumping speed of the pump to the theoretical pumping speed calculated by molecular slurry at the inlet of the pump.
11. Reflux rate: The unit of reflux rate of pump is g/cm2.s. It refers to the mass flow rate of the pump flow passing through the unit area of the pump inlet when the pump operates under regular conditions.
12. Water vapor allowance: The allowance unit of water vapor is kg/h. It refers to the mass flow rate of water vapor that can be pumped out by gas-ballast pumps in continuous operation under normal environmental conditions.
13. Maximum allowable steam inlet pressure: The maximum allowable steam inlet pressure unit is Pa. It refers to the maximum inlet pressure of water vapor that can be pumped out by air ballast pumps in continuous operation under normal environmental conditions.