Users who have high requirements for vacuum must be familiar with Roots pumps. Roots pumps are often combined with mechanical pumps to form a pump group to achieve a higher vacuum. In a pump group, the pumping speed of a Roots pump is faster than that of a mechanical pump. For example, a mechanical vacuum pump with a pumping speed of 70 L/s needs to be matched with a Roots pump with a pumping speed of 300L/s. Why? This involves the operation of the pump group.
In the pump group, the mechanical vacuum pump firstly evacuate, and then it's turn of the Roots pump to evacuate. During the vacuuming process, the air in the cavity will become thinner and thinner, and it will become increasingly difficult for the vacuum pump to evacuate. After the mechanical pump has evacuated to a certain extent, it will not be able to continue evacuating, and a higher vacuum cannot be achieved. At this time, the Roots pump with a faster pumping speed begins to evacuate, thereby achieving a higher vacuum. A high fineness filter element will reduce the pumping rate of the pump group and may even make the vacuum level substandard. Because a high fineness element means that the pore size of the filter material is smaller, it is more difficult for the gas to pass through the filter element. Therefore, the filter element used for the pump group is generally made of stainless steel.
How to solve the filtration problem if there are tiny impurities in the working condition? We recommend using polyester filter element and increasing the size of the filter. This will increase the filtering area. The larger contact surface means that more air can pass through the filter element at the same time, thereby reducing the impact on the pumping rate of the pump group.
I think through this article, you have learned why high fineness filter elements are not suitable for pump group, and also know how to choose filters for pump groups.
Post time: Jan-10-2025
