Reasons for tower flooding in polyester process towers
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I would like to ask experts about the reasons for tower flooding in polyester processing towers, the early signs of such issues, and what precautions should be taken during operation
Pressure! Liquid level! ! ! ! Temperature!
Please explain the specific steps; you mentioned it’s basic
Take a look, as shown in the image! First, during the driving phase, residual acetaldehyde leads to an explosion and tower collapse during hot-state simulation! Second, older models typically have 16 trays, while newer models usually have 18 trays; or the top two sets are combined trays. The lowest tray, the first one, is equipped with an ethylene glycol backflow pipe to prevent the trays from getting clogged, and this pipe should be switched on and off frequently! If the tray gets blocked and pressure builds up in the vapor phase, with a loud \"bang\", it breaks through! Third, the esterification process fails, resulting in a large volume of vapor flowing into the process tower and excessive pressure! Fourth, a fault in the process tower results in an excessively high liquid level, which pushes up against the tray! (Flooded tower) Fifth, generally, a high-pressure alarm interlock is installed to stop the esterification process as well as the heating system of the process tower! Prevent tower collision! Six, temperature faults: the actual temperature is too high, resulting in an evaporation rate that exceeds the design capacity of the process tower. Seven, during inspection and maintenance, the tray must be secured! 8. It occurs more easily during the start-up and shutdown phases; it’s fine under normal circumstances. Remember, never cancel the chain reactions randomly!
In polyester production, there are occasional issues where the EG content in the water at the bottom of the process tower is high, as well as a high EG content in the process water at the top of the tower. What could be the reasons for this?
From time to time? ? Unstable! How many trays do you have? What should the reflux ratio and tray temperature be, as well as the bottom of the tower temperature? Was it designed by East China University of Science and Technology or somewhere else?
18 trays, 176 degrees at the bottom of the tower, 120 degrees at the sensitive tray
18 trays should be fine; the EG content can be kept below 0.2%, and with good performance it can reach 0.1%； Do you use shell-and-tube exchangers or air coolers for the condensation of exhaust gases from your process tower, or do you have an external lithium bromide chiller? What should the temperature at the top of the tower be? Is there any pressure buildup, with a high pressure at the tower top? ； The reflux ratio is also crucial; too low a value can lead to high concentrations. Is the temperature of the recycled stream stable?
18 trays should be fine; the EG content can be kept below 0.2%, and with good performance it can reach 0.1%； Do you use shell-and-tube exchangers or air coolers for the condensation of exhaust gases from your process tower, or do you have an external lithium bromide chiller? What should the temperature at the top of the tower be? Is there any pressure buildup, with a high pressure at the tower top? ； The reflux ratio is also crucial; too low a value can lead to high concentrations. Is the temperature of the recycled stream stable?
The exhaust gas from the process tower is cooled using an air cooler; the temperature at the top of the tower is maintained around 101 degrees, while the temperature of the recycled water is around 45 degrees