Abstract: Used in RH vacuum equipment of dry mechanical pump is gradually extended, compared with the traditional steam pump, there are many advantages. Based on the using effects of vacuum pumps in the hotrolled plant and the stainless steel company of Hesteel Tangsteel, the differences of operating characteristics, process effects, cost and environmental impact between steam jet pump and dry mechanical pumps were compared adequately. It was found that the dry mechanical pump running consumption savings of 70 % more than the traditional steam jet pump, and the minimum vacuum degree was 67 Pa, the dehydrogenation capacity was 55 %-80 %,and the denitrification capacity was 10 %-50 %, in the decarburization of vacuum control, cost control and environmental protection was better than three aspects of steam jet pump, compared with the steam jet pump, the effect of degassing and decarbonization was same or even better. By fully excavating the similarities and differences between these two types of vacuum pumps, guidance of choosing vacuum pump is provided for followup production lines.

Key words: RH, roots pump, steam jet pump, vacuum, cost