Roots vacuum pump unit used in dry gas concentration unit on investigation
Through the investigation on the air tightness, load test run and operation of the two roots vacuum pump units in the dry gas concentration unit, it is found that the two units can basically meet the current consumption demand, but whether they can meet the demand of long-term operation of the unit still needs further investigation in the future
① Sealing problem.
Due to the special request of process medium, the sealing is required to have high reliability. At present, the compromise is to increase nitrogen seal. As for the applicability of roots pump, the main need is to improve the sealing mode. In order to prevent the air from being sucked into the pump or too much nitrogen being sucked into the pump, the analyzer for detecting nitrogen and oxygen is added in the following process.
② Pump body temperature.
There are many factors that affect the temperature of vacuum pump body. No matter what causes the temperature rise of the pump body, once there is a sign of accident, especially when the local temperature of the pump body rises, the temperature rises rapidly, and the temperature at the pump outlet can not be reflected in time. Therefore, the pump may have had an accident. It is suggested that temperature monitoring points should be installed on the pump body, and the corresponding shutdown interlock function should be added to avoid serious equipment accidents.
③ As for the air-cooled Roots vacuum pump, ensuring the cooling of the pump body is the key. Considering the periodic change of the load, the cooling effect of the intercooler, especially the cooling effect of the secondary cooler, can be properly increased to ensure that the temperature of the reflux cooling gas is not too high.
④ Inter stage check valve problem.
In view of the importance of the inter stage check valve, it is suggested that the valve should be changed into a program-controlled valve and controlled by PLC program. In this way, the load between the primary and secondary pumps can be adjusted in a large range, and the compliance of the pump set to the working condition can be increased. Or according to the existing process conditions, a check valve with less resistance should be replaced to reduce the load of the secondary pump.
⑤ Due to the particularity of PSA process, the maintenance of Roots vacuum pump is also put forward higher request, such as when the pump starts with the minimum load, when the switching has the minimum impact on the pump, and in the operation process, due to the large noise, how to inspect can more effectively detect problems, which are different from ordinary centrifugal pumps and fans, and need to be explored from time to time 。