Coking shutdown issue

This... there’s too much to write

When the processing volume reaches its limit, the cooling and cutting universal wax oil is used to replace the fractionation system and furnace tubes, after which steam is used to clean the furnace tubes. That’s roughly it; there are many details

There is no good solution other than to reduce the feed rate as much as possible once there is a problem with the coking system, and to carry out repairs promptly. When the coking layer becomes too thick and can no longer be maintained, the furnace must be shut down urgently; the radiation pump and furnace tubes should then be stopped so that the lines can be cleaned and connected to the production tower.

This reduction is inevitable. Once, when we started operating the coking unit to remove coke from the first tower, problems arose right from the start due to the fact that the equipment had been shut down for some time and the coke remover had not been properly maintained. As a result, the plant had to reduce its production significantly – to the lowest level possible. We then removed the coke remover from the other tower and replaced it (while simultaneously placing an order with the manufacturer for another coke remover). Fortunately, this did not lead to a shutdown of the plant.

The maintenance of degassing equipment is actually very important, especially in systems with one furnace and two towers; these days, more attention is paid to the production process at the front end, while little attention is given to the back end. We pay close attention to the defocusing equipment; whenever we detect any abnormalities in it, we address them before problems arise. As for spare parts, one must not be afraid to spend money on preparing them.

When there is a problem with the coking system, reduce the feed rate as much as possible immediately, carry out repairs as fast as feasible to avoid shutdowns. When the coking layer becomes too thick and cannot be maintained, adjust the temperature and feed rate according to the situation; change the connection between the top feed line and the main oil-gas line, switch to the top feed line, and establish a closed-loop circulation from the outlet of the radiation pump to the heating furnace, then to the main oil-gas line, and finally to the distillation tower. Stabilize the three-tower cycle, open the compressor’s vent valve, and shut down the compressor. There are many specifics. It is also possible to open the vent valve at the furnace outlet and introduce the hot oil into the cold tank; the oil can then be routed through the start-up circulation line to the main circulation in the feed tank, thereby preventing coking in the main oil and gas lines.