Another recent client problem we were able to troubleshoot successfully dealt with a TEG dehydration system. The lean TEG out of the regenerator (reboiler) never matched the reboiler temperature that controlled the fired heater that provided the heat for regeneration. The temperature probes were checked and double checked and calibrated and still nothing made sense. The outlet lean temperature was verified via heat balance with the Lean / Rich exchanger. Other similar checks like this verified the temperatures were correct. But how can that be?
Finally RCE engineers realized that the feed entered the reboiler approximately one foot from the overflow weir inside the reboiler. This meant that the rich TEG falling from the Still column was almost immediately overflowing the weir into the surge portion of the reboiler without truly being heated up (see picture below). The reboiler temperature probes were located back near the end where the fire-tube was and were reading correctly. The problem was they were basically in a stagnant zone and the reboiler was firing just to keep the back part of the reboiler at temperature. The feed short-circuited the reboiler and flowed out much cooler than it should.
An alternate feed nozzle was found near the back-end of the reboiler where the rich TEG can enter and properly mix and flow the length of the reboiler and then over the weir at the proper temperature.
If you have problems like this we are here to solve your problems.
