What should be paid attention to when vacuum unit is used in rare metal metallurgy?
The process of obtaining vacuum in a vacuum system is called vacuum pumping, also known as pumping or exhausting. The volume of gas pumped out per unit time under specified air pressure is called pumping rate, i.e. pumping speed. It can also be called pump speed, and the unit is L / s. The lowest air pressure that a pump or a vacuum system can reach after exhausting for a long time is called limit vacuum degree
High vacuum condition is required for the metal metallurgy of thin oil. Therefore, the complete set of high vacuum unit equipped with mechanical pump and diffusion pump is often used. The vacuum can be pumped up to 10-6pa by using mechanical pump and booster pump in series. To further improve the vacuum degree, adsorbent or cold trap can be installed in the working system to absorb or condense the gas not pumped out by the pump. Sometimes, one-stage mechanical booster pump and unit are added In order to improve the pumping capacity in a certain vacuum range.
In the high vacuum unit. Mechanical pump can make the air pressure from an atmospheric pressure to become smaller, called the front stage pump; diffusion pump can only pump from lower air pressure to lower pressure, called secondary pump. The air pressure at which the secondary pump starts to work is called the preparatory vacuum or the pre vacuum. The best pumping speed of each kind of vacuum pump is corresponding to a certain inlet pressure. Therefore, the best vacuum efficiency can only be obtained by reasonably matching the vacuum unit. An unreasonable configuration will not only cause waste, but also lead to the vacuum degree of the empty system not reaching the expected requirements.
The following main problems should be solved in reasonable configuration of vacuum unit
1) According to the requirements of the amount of gas produced by the vacuum equipment, the working pressure, the limit of its space and the pumping time, the type of the main pump is selected, the pipeline and the vacuum components are selected;
2) After the main pump is selected, the pumping time and pressure of the vacuum equipment are calculated;
3) Understand the relationship between the basic parameters of vacuum pump and the passing capacity of pipe