Nanguang vacuum

　　Vacuum pump the function of the one is from the vacuum chamber surking air molecules, reduce vacuum indoor gas pressure, so as to meet the requirements of the vacuum. To sum up from the atmosphere to the extremely high vacuum has a great range, so far haven't a vacuum system can cover the range. Therefore, in order to achieve different product process indicators, work efficiency and equipment working life requirements, different vacuum section need choice different vacuum system configuration. To achieve the optimal configuration, choose the vacuum system, should consider the following points:

　　To determine the vacuum range:

　　-must first check to make sure every requirement of process of vacuum. Because each technology has its adapt to the vacuum range, we must study the determined.

　　Sure limit vacuum

　　In determining the technological requirements-the vacuum degree of vacuum pump system on the basis of the inspection limiting vacuum, because the system limiting vacuum decided the system the best work vacuum. Generally speaking, the system than the limiting vacuum system work 20% lower than the vacuum degree, the former stage limiting vacuum pump low 50%.

　　Are pumping gas species and extraction flow

　　Check to be sure process requirements of the suction type and extraction flow. Because if are pumping gas species and pump liquid in the reaction, the pump system will be pollution. At the same time must consider the appropriate time and smoke exhaust gas generated by the process of gas.

　　Vacuum volume

　　Check to be sure to meet the requirements of the time required to vacuum, vacuum pipelines flow resistance and leakage.

　　Consider to meet the requirements in a certain process requirement after the vacuum degree under the condition of the vacuum to maintain lashing velocity.

　　The choice of the vacuum pump is calculated

　　S = 2.303 V/tLog (P1 / P2)

　　Among them:

　　S for vacuum pump suction rate (L/S)

　　V for vacuum chamber volume (L)

　　T is to meet the requirements of the time needed for vacuum (s)

　　For the initial vacuum Torr (P1)

　　P2 required for vacuum Torr ()

　　For example:

　　V = 500 L

　　T = 30 s

　　P1 = 760 Torr

　　P2 = 50 Torr

　　It, S = 2.303 V/t Log (P1 / P2)

　　= 2.303 x500/30 xLog (760/50)

　　= 35.4 L/s

　　Of course on just the theoretical calculation result of several variables, and not taken into consideration, such as pipe flow resistance, leakage, filter flow resistance, are pumping gas temperature, etc. In fact should also will take into account. Safety factor