Contract maintenance workers often will not replace the tray manways unless the tray manway is adjacent to a tower external manway. They reason that once…
Category: Tower Pressure
The downcomer from the bottom tray is submerged in a seal pan (see Fig. 8.3), to preserve its downcomer seal. I always set the horizontal…
If a tower has a history of tray deck damage due to pressure surge or high liquid level, the mechanical integrity of the trays should…
At a Gulf Coast refinery, the reboiler thermosyphon circulation could not be reestablished after a turnaround. The tower was reopened and a lessthan-alive contract employee…
Most trays have outlet weirs devoted to maintaining the downcomer seal. But some trays have inlet weirs too, or inlet weirs, but no outlet weirs.…
The bottom edge of the downcomer from the tray above should be 0.25 to 0.5 in below the top edge of the weir of the…
The vertical edges to the downcomers are bolted to bars welded to the vessel wall. These are called, “downcomer bolting bars.” Gaskets are often used…
For smaller diameter towers a visual check of tray deck levelness is sufficient. For two-pass trays, a small diameter tower is less than 8 ft.…
The tray temperatures in our preflash tower, shown in Fig. 6.4, drop as the gas flows up the tower. Most of the reduced sensible-heat content…
When we raise the top reflux rate to our preflash tower, the tower-top temperature goes down. This is a sign that we are washing out…