sshep
Chemical
- Feb 3, 2003
- 761
Dear All,
This post is follow-up to thread124-137383. The old equipment is a packed tower running under 2 stages (jets) of vacuum. This project is moving forward as a new trayed steam stripping tower- trayed for cost and tower can be designed more tolerant of solids loading and foaming.
The original designer chose a vacuum operation to reduce the steam (and feed/bottoms heat recovery) requirements, and to reduce corrosion in a carbon steel vessel. An atmospheric tower will require a lot more heat and/or heat recovery. I am considering the use of a partial vacuum (i.e. one stage) because the equipment already exists.
This are my questions:
1) This tower consists of oxygenated water at pH=6 or above. Can vacuum help reduce corrosion and allow for carbon steel construction as a result of lower stripping temperatures?
2) Are there any coatings which can reduce corrosion? Because of potentially high chlorides, we don't want to use stainless steel. Hastalloy prices are very high these days.
2) What other problems/advantages can result from vacuum vs atmospheric operation?
I realize these are general questions, but I will take any knowledgable advice.
best wishes, sshep
P.S. I checked out StoneCold's idea of a macro-polymer using the contact info provided. I got a reasonable quote for a new grass roots unit especially considering energy usage is low; but they also required a fairly pricy annual service contract. Even though we didn't go this route, it is worth considering on future applications.
This post is follow-up to thread124-137383. The old equipment is a packed tower running under 2 stages (jets) of vacuum. This project is moving forward as a new trayed steam stripping tower- trayed for cost and tower can be designed more tolerant of solids loading and foaming.
The original designer chose a vacuum operation to reduce the steam (and feed/bottoms heat recovery) requirements, and to reduce corrosion in a carbon steel vessel. An atmospheric tower will require a lot more heat and/or heat recovery. I am considering the use of a partial vacuum (i.e. one stage) because the equipment already exists.
This are my questions:
1) This tower consists of oxygenated water at pH=6 or above. Can vacuum help reduce corrosion and allow for carbon steel construction as a result of lower stripping temperatures?
2) Are there any coatings which can reduce corrosion? Because of potentially high chlorides, we don't want to use stainless steel. Hastalloy prices are very high these days.
2) What other problems/advantages can result from vacuum vs atmospheric operation?
I realize these are general questions, but I will take any knowledgable advice.
best wishes, sshep
P.S. I checked out StoneCold's idea of a macro-polymer using the contact info provided. I got a reasonable quote for a new grass roots unit especially considering energy usage is low; but they also required a fairly pricy annual service contract. Even though we didn't go this route, it is worth considering on future applications.
