Is coking in the riser particularly severe? Why?
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Coking in the riser is particularly severe; operations were halted for maintenance a few days ago due to issues with the slide valve. Why is coking so serious inside the riser?
This topic is a bit too broad to answer properly. There are many reasons for coking in the riser, which are related to factors such as the properties of the feed oil, the riser nozzles, reaction time, and the amount of atomizing steam.
How long has it been since work started? Which part is coking? Common causes include: insufficient amount of vapor for atomization, too low oil-to-agent ratio, excessive amount of slurry recycled, high residual carbon in the feedstock, excessively low reaction temperature for a period of time, issues with nozzle design or installation. A decrease in catalyst activity over time, as well as delayed shutdown of the feed supply, can also lead to coking in the lift pipe.
First, check whether the settings of the operating parameters are appropriate – whether coking occurs gradually during the production process, or as a result of improper handling under abnormal operating conditions
Could the poster tell me the preheating temperature of the raw materials and the range of fluctuations in the reaction temperature?
The main influencing factors are as follows: 1. The reaction time in the lift tube, which is related to the number of lines; 2. The atomization effect of the nozzle, which depends on the preheating temperature of the raw material, the amount of atomizing steam, and the properties of the raw material; 3. Emergency handling, which relates to whether the supply of material can be stopped in a timely manner. 4 Others, such as an excessively low oil-to-agent ratio, insufficient contact with crude oil, and uneven distribution.
How long is the continuous operating time? What are the properties of the raw materials used for processing? What are the preheating temperature of the raw materials and the amount of atomizing steam? Was there frequent interruption of feeding during this period? Was coking in the riser only observed during this cycle? Have there been any recent indications of significant changes in temperature or oil-to-fuel ratio?
The atomization effect is poor; in many cases, this is caused by worn nozzles
I was being lazy, but I happened to have relevant text in the materials I had on hand!