[ Reply | Next | Previous | Up ]
From: mendozajaj@pdsva.com
Category: Process
Date: 11 Jan 2005
I'd like to discuss with u a problem we are having in our delayed coker in amuay refinery. Historically, we've always had problems with marginal NPSH with our charge pumps. Therefore, nowadays we r controling a level of 85% in the bottom of our fractionator, which leaves a distance between the entrance to the tower of the coke drum vapors and the top level of resid of about 3 feet. This represents barely 1000 barrels to reach this entrance. From time to time, the suction temperature of the heater charge pumps suffers a sudden increase from 430 °F to 580 °F in less than 3 minutes aprox. which creates equal fluctuations in the COT of the furnace. After 2 min, the temperature returns to normal (430 °F). We believe that this creates a problem with the deposit rate of coke in our furnace coils, by increasing it. Have any of u seen sth like this in your fractionator tower? or your pump suction temperature? Thanks in advance.