The main sources of pollutants in the boiler feed pump system are as follows:
(1) Contamination caused by venting of the sealing material in the pumping system. In particular, elastomer seals, seal greases, lubricants will also cause serious pollution.
(2) The backflow of the multistage pump oil vapor of the diffusion boiler feed water. This is the most important source of pollution.
(3) The backflow of the oil pump of the front oil seal mechanical pump. This problem is also very serious. When the inlet pressure is high, when the pressure in the transition zone (1~10-1Pa) is reached, the oil vapor of the boiler feedwater multistage pump can directly enter the diffusion pump and directly pollute the system. Many of the vacuum process contamination comes from mechanical pump return. When the mechanical pump is stopped, if the gas is not amplified into the pump in time, the boiler feed water multi-stage pump oil can be directly returned to the diffusion pump oil pan. The contamination of the system is more severe when the diffusion pump is started.
(4) Parts in the system are taken with oily hands during assembly. Use oily gloves to get contaminated organic molecules that can cause contamination inside the system.
(5) When the pump is amplifying the gas after the pump is stopped, the vacuum components are contaminated with water vapor, soot, etc. in the air, causing pollution to the vacuum system.
