Losing $$$$ due to iron scale, silt, & debris in cooling water lines
Losing $$$$ due to iron scale, silt, & debris in cooling water lines
(OP)
I am working in an oil refinery and we have had major production losses due to reduced cooling in some shell and tube exchangers in one of our units.
After the last utilites shutdown we noticed that we were not getting enough cooling out of 4 of our shell and tube exchangers. As a result we had to cut rates until we could get some temporary cooling towers in. When winter came we got rid of the temporary cooling towers but we were still short on cooling. We cut rates and cleaned out the tube bundles and everything has been fine since.
After looking at what came out of the bundles we determined that the problem was iron scale, silt, and debris that settled out in the headers during the utilities turnaround when the water was not flowing. When the cooling water was restarted, all of the debris was swept into the unit at the end of the cooling water circuit. We have an 8" blowdown valve at the end of the 24" supply header. However this valve was not used to blowdown the collected debris. The ditch that this valve drains to is not very big and will fill in minutes.
Has anyone else encountered a similar problem? We have another shutdown coming up and we're not sure if using the 8" valve for a few minutes will prevent the problems with debris. If it doesn't it will cost us $millions. Does anyone have any other solutions to getting this debris out of the lines?
After the last utilites shutdown we noticed that we were not getting enough cooling out of 4 of our shell and tube exchangers. As a result we had to cut rates until we could get some temporary cooling towers in. When winter came we got rid of the temporary cooling towers but we were still short on cooling. We cut rates and cleaned out the tube bundles and everything has been fine since.
After looking at what came out of the bundles we determined that the problem was iron scale, silt, and debris that settled out in the headers during the utilities turnaround when the water was not flowing. When the cooling water was restarted, all of the debris was swept into the unit at the end of the cooling water circuit. We have an 8" blowdown valve at the end of the 24" supply header. However this valve was not used to blowdown the collected debris. The ditch that this valve drains to is not very big and will fill in minutes.
Has anyone else encountered a similar problem? We have another shutdown coming up and we're not sure if using the 8" valve for a few minutes will prevent the problems with debris. If it doesn't it will cost us $millions. Does anyone have any other solutions to getting this debris out of the lines?





RE: Losing $$$$ due to iron scale, silt, & debris in cooling water lines
Richard A. Cornelius, P.E.
WWW.amlinereast.com
RE: Losing $$$$ due to iron scale, silt, & debris in cooling water lines
We would like to be able to blow down the system but we have two problems. The current blowdown valve is fairly small (8" on a 24" header) and the ditch the blowdown valve drains to fills in a matter of minutes which limits the amount of time that you can blow down.
RE: Losing $$$$ due to iron scale, silt, & debris in cooling water lines
the only difference is that you need to modify the piping to accomodate a spool piece that will contain the screen or the witch-hat (for 24 inches pipe the w/h will be about 106 in long).
HTH
saludos.
a.
RE: Losing $$$$ due to iron scale, silt, & debris in cooling water lines
RE: Losing $$$$ due to iron scale, silt, & debris in cooling water lines
Richard A. Cornelius, P.E.
WWW.amlinereast.com