The DCC regeneration inclined tube tray with degassing tank experiences significant vibration
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As the title suggests, I have adjusted many things; various methods were tried but with little improvement. There is significant vibration in the expansion joint at the bottom of the degassing tank, as well as large fluctuations in the pressure drop across the regeneration slide valve and the thrust force applied by the inclined tubes. What causes these vibrations? What are the reasons for the large pressure drop fluctuations? How can this be resolved?
The gas between the catalyst particles in the inclined tubes gathers into bubbles, and as these bubbles rise and burst, vibrations are generated. Good inclined tube conveying requires the catalyst to be fluidized without bubbles forming. Dare you try turning off the loosening air from the degassing tank?
Some plants indeed see improved fluidization after turning off the loosening air
In fact, many organizations do indeed do this!
Continue to reduce the loosening gas. Is the gas escaping from the inclined tubes steam or air?
The original poster needs to clarify a few points: 1. How long has this situation been going on? 2. Under the current operating conditions, is the catalyst circulation rate, in particular, within the designed range? I believe there are mainly the following possible reasons for the large vibration of the inclined tubes: 1. The operating conditions deviate from normal ones, and the catalyst circulation rate is not at the normal level ； The catalyst circulation rate has reached a critical point, resulting in severe vibration. 2. Poor degassing in the inclined tubes results in a non-continuous flow of the catalyst; large bubbles exist within these tubes, and the continuity of catalyst fluidization is poor. This is likely due to overly frequent installation of loose points in the inclined tubes, or an excessive flow rate of air/steam used for loosening them ； Poor defoaming in the feed hopper ； In my opinion, whether the looseness of the inclined tubes is too large or too small is not conducive to catalyst fluidization, and vibrations can occur in either case. 3. The catalyst has poor fluidity; its fluidity is reduced when the temperature is too low. The temperature of the catalyst inside the regeneration inclined tube is monitored using thermocouples, and if it is too low, the superheated steam supply can be increased as appropriate. 4. The distributor section at the feed port of the regenerative inclined tube is partially blocked; this issue can be identified through data analysis. Please point out any mistakes above.
Strongly agree! Could you provide a particle size analysis of the balanced catalyst?