tbaygen
Chemical
- Nov 8, 2013
- 11
Hey all,
I am working on a maintenance replacement of a graphite shell and tube heat exchanger. The primary use of this exchanger is to condense phosgene and methylene chloride.
The issues im running into is the service life on the shells of the exchangers is poor on average 15 years, well before tube life. Ideally the most expensive component of these exchangers it the tubes and I want to maximize the shells to the tube life.
We completed an RCA and concluded low fluid velocity to be the root cause (with other contributing factors). With that being said, I am working on a design to remove tubes from the window, and decrease baffle spacing with increased baffle cut to increase velocity with the manufacture. One question I have though is that with graphite, are there velocity limitations outside of normal practice. We are severely limited on flow with the current configuration and the best I may acheive is 3 ft/s.
Is vibration an issue? I specified NTIW and I think we can get to 3ft/s with baffles and cut (single segmented). I dont care about pressure drop in this case.
Any other thoughts on graphite exchangers I should know? This is alien to me.
I am working on a maintenance replacement of a graphite shell and tube heat exchanger. The primary use of this exchanger is to condense phosgene and methylene chloride.
The issues im running into is the service life on the shells of the exchangers is poor on average 15 years, well before tube life. Ideally the most expensive component of these exchangers it the tubes and I want to maximize the shells to the tube life.
We completed an RCA and concluded low fluid velocity to be the root cause (with other contributing factors). With that being said, I am working on a design to remove tubes from the window, and decrease baffle spacing with increased baffle cut to increase velocity with the manufacture. One question I have though is that with graphite, are there velocity limitations outside of normal practice. We are severely limited on flow with the current configuration and the best I may acheive is 3 ft/s.
Is vibration an issue? I specified NTIW and I think we can get to 3ft/s with baffles and cut (single segmented). I dont care about pressure drop in this case.
Any other thoughts on graphite exchangers I should know? This is alien to me.
