NEWS & BLOG
A detailed explanation of vacuum pump knowledge—what do you already know about it?
Category: Technical Support
Time: 2021-01-18
Summary: Detailed Explanation of Vacuum Pump Knowledge 1. Vapor Capacity of a Vacuum Pump: The unit for vapor capacity is kg/h, which refers to the mass flow rate of vapor that the pump can remove under normal operating conditions when the gas ballast pump is running continuously. 2. Pumping Speed of a Vacuum Pump: The unit for pumping speed is m³/s or l/s. It represents the ratio of the gas flow rate passing through the test hood—when the pump is equipped with a standard test hood and operated under specified conditions—to the differential pressure measured at a designated location within the test hood. This is commonly referred to as the pump’s pumping rate. 3. Ultimate Pressure of a Vacuum Pump: The unit for ultimate pressure is Pa. It refers to the highest stable working pressure achieved by the pump under normal operating conditions, with a standard test hood installed at the pump outlet and operated according to prescribed procedures, without introducing any additional gases. 4. Backflow Rate of a Vacuum Pump: The unit for backflow rate is g/cm²·s. It indicates the mass flow rate of pumped gas passing through a unit area at the pump outlet when the pump is operating under specified conditions. 5. Pumping Speed Coefficient: This is the ratio of the theoretical pumping speed of the pump to its actual pumping speed calculated based on molecular effusion at the pump outlet.
A Detailed Explanation of Vacuum Pumps
1. Vapor capacity of the vacuum pump:
The unit of allowable vapor capacity is kg/h, which refers to the mass flow rate of vapor that the pump can remove when the gas ballast pump is operating continuously under normal conditions.
2. The pumping speed of the vacuum pump:
The pumping speed of a pump, expressed in units of m³/s or l/s, refers to the ratio of the gas flow rate passing through the standard test hood when the pump is equipped with the specified test hood and operated under prescribed conditions, to the differential pressure measured at the designated location within the test hood. This ratio is commonly referred to as the pump’s pumping speed.
3. Ultimate vacuum pressure of the vacuum pump:
The unit of the pump’s ultimate vacuum pressure is Pa. It refers to the maximum stable gauge pressure that the pump can achieve at its outlet when equipped with a standard test nozzle and operated under specified conditions, provided that no extraneous gases are introduced during operation.
4. Backflow rate of the vacuum pump:
The pump’s backflow rate is measured in g/cm²·s. It refers to the mass flow rate of the pumped fluid passing through a unit area at the pump outlet under specified operating conditions.
5. Pumping speed coefficient of the vacuum pump:
The ratio of the pump's theoretical pumping speed to its practical pumping speed at the pump outlet, calculated based on molecular effusion.