There are many kinds of vacuum equipment, but no matter what kind of vacuum equipment, there is a set of extraction system to remove the gas in the evacuated container, so as to obtain the required vacuum conditions in the vacuum container. For example, a container for vacuum treatment is connected with a vacuum pump by pipes and valves. When the vacuum pump vacuumizes the container, there must be a vacuum measuring device on the container, which constitutes the simplest vacuum pumping system (as shown in Figure 1).
The simplest vacuum system shown in Figure 1 can only obtain the vacuum degree in the low vacuum range in the pumped container. When it is necessary to obtain the vacuum degree in the high vacuum range, a high vacuum pump is usually connected in series in the vacuum system. When a high vacuum pump is connected in series, valves are usually added at the inlet and outlet of the high vacuum pump respectively, so that the high vacuum pump can keep vacuum independently. If the high vacuum pump in series is an oil diffusion pump, in order to prevent a large amount of oil vapor from flowing back into the pumped container, a water-cooled baffle is usually added at the inlet of the oil diffusion pump (as shown in Figure 2).
According to the requirements, we can also add dust remover, vacuum relay gauge head, vacuum soft connection pipe, vacuum pump inlet vent valve, etc. in the pipeline, thus forming a relatively perfect high-yield vacuum system.
For a vacuum system composed of more than two vacuum pumps in series, the low vacuum pump is usually called the front pump (or pre pump) of its upper high vacuum pump, and the highest vacuum pump is called the main pump of the vacuum system, that is, it is the main pump. The limit vacuum degree and working vacuum degree in the pumped container are determined by the main pump. The pipeline from the outlet of the pumped vessel to the inlet of the main pump is called high vacuum pipeline, and the valve at the inlet of the main pump is called the main valve.
Usually, the front pump is also used as a vacuum pump. The pipeline from the pumped container to the pre pumping pump is called the pre vacuum pipeline, and the valve on the pipeline is called the pre vacuum pipeline valve. The pipeline from the outlet of main pump to the inlet of front stage pump is called front stage pipeline, and the valve on the pipeline is called front stage pipeline valve, while the soft connection pipeline is set to isolate the vibration of front stage pump.
So, what is a high-yield vacuum system? In a word, it is a pumping system used to obtain a specific vacuum degree. The basic content of the design of high-yield vacuum system is to select the appropriate design scheme of vacuum system according to the requirements of the vacuum degree of the pumped vessel, to calculate the selection and distribution of pumps; to determine the conduit, valve, catcher, vacuum measuring elements, etc., to make a reasonable configuration, and finally draw the assembly drawing and parts drawing of the vacuum system.