sshep
Chemical
- Feb 3, 2003
- 761
Friends,
I had a previous post (now archived thread124-117403 ) getting advice on a reboiler return line. I wanted a 28" return nozzle installed, my project manager said it would cost too much and wished to pipe the return to two existing 20" nozzles located 180deg apart, with the exchanger centered between the nozzles. I was reluctant to do this because of "unforeseen problems". "Like what", he asks (several times). "If I knew they wouldn't be unforseen", I reply (sometime throwing in a lame "like instability"). I finally agreed that if we could get an exchanger vendor to guarentee the design then I would go for it.
We went for 3 bids, but one refused to bid on the design outright as too risky. Later I nearly choked when the piping designers asked if it was ok to put 55 feet of pipe in each branch for an expansion loop (at least they asked!). Thankfully we got a mechanical engineer to design for expansion at the exchanger and supporting structure.
Today I am happy to report that this tower refit started up as smooth as they ever do, and my anxiety about this unusual configuration was unfounded. Did we save money with all the extra piping, supports, bottom nozzle revisions, and skirt penetration? I think not, but that is a future question best asked after my project manager has been loosened up with a few beers.
Anyway, best wishes as always,
sshep
I had a previous post (now archived thread124-117403 ) getting advice on a reboiler return line. I wanted a 28" return nozzle installed, my project manager said it would cost too much and wished to pipe the return to two existing 20" nozzles located 180deg apart, with the exchanger centered between the nozzles. I was reluctant to do this because of "unforeseen problems". "Like what", he asks (several times). "If I knew they wouldn't be unforseen", I reply (sometime throwing in a lame "like instability"). I finally agreed that if we could get an exchanger vendor to guarentee the design then I would go for it.
We went for 3 bids, but one refused to bid on the design outright as too risky. Later I nearly choked when the piping designers asked if it was ok to put 55 feet of pipe in each branch for an expansion loop (at least they asked!). Thankfully we got a mechanical engineer to design for expansion at the exchanger and supporting structure.
Today I am happy to report that this tower refit started up as smooth as they ever do, and my anxiety about this unusual configuration was unfounded. Did we save money with all the extra piping, supports, bottom nozzle revisions, and skirt penetration? I think not, but that is a future question best asked after my project manager has been loosened up with a few beers.
Anyway, best wishes as always,
sshep
