Vacuum pump for acidic conditions
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Dear seniors, I would like to ask for advice: for acidic working conditions involving hydrochloric acid vapor, what type of vacuum pump should be chosen? It would be ideal if it can reach 600 Pa; if not, a vacuum level of 97 kPa is also an acceptable alternative (Without considering water jet pumps) Can it undergo alkaline adsorption treatment before entering the pump? (Ignoring cryoprocessing) Has anyone **implemented a similar approach before
Screw or reciprocating vacuum pump.
The acidic hydrochloric acid gas operating condition is not very suitable
Ignoring the water-jet pump, it won’t be able to achieve the vacuum level you need. I think I’ll use a glass-lined disc condenser followed by a Roots vacuum pump; I’ll also add alkali to the water tank of the water ring pump.
Your approach is rather crude, but we have also considered it; there are mainly several issues: 1. The condensation efficiency of the condenser under negative pressure is not very good, and for certain key areas we use liquid nitrogen cooling wells； 2. Adding alkali to the water tank results in excessive water viscosity as well as severe scaling ； 3. The main problem is that, for new projects these days, environmental experts and similar authorities do not allow the use of pumps of the water-ring or water-jet type. Helpless ╮(╯▽╰)╭
600 Pa – that’s a very high level of vacuum. What you are worried about is the corrosion of the subsequent vacuum pump by acidic gases; that is the core issue. Screw pumps can achieve the vacuum level you need, but they will corrode the rotor. I’m also troubled by the same issue: the gas before the pump is not clean, which corrodes the pump.
We also have such operating conditions on site, using a water ring + Roots system. Efforts are made in terms of materials, adopting a structure of a duplex steel pump body + graphite heat exchanger + RPP gas-liquid separation tank.
I am facing the same operating conditions; I am currently using an anti-corrosion coating made from new materials, along with a dry, oil-free vacuum pump. The customer is located in Ningxia, and the system has been in operation for almost a year now without any problems – the vacuum level is satisfactory. If you are interested, please call 18653370285