How to calculate the linear speed of catalytic feed nozzle?
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How to calculate the linear speed of catalytic feed nozzle? The fine powder content of our catalyst is too high. I suspect that the current processing capacity is large and the linear speed of the feed nozzle exceeds the design value, causing violent collision and fragmentation of the catalyst, so I would like to calculate the actual linear speed of the feed nozzle. There is one thing that puzzles me. The nozzle atomized steam must be calculated according to the gas phase, but is it reasonable to calculate the nozzle raw oil according to the gas phase or the liquid phase? This has a huge impact on the calculation results. Please give me some advice, thank you very much!
According to the liquid phase calculation, I wonder if you saw the nozzle of your device when it was installed. The raw material nozzle is insulated. After the raw material is sprayed out, it enters the riser in the form of droplets, and then goes through seven processes including vaporization, adsorption reaction, and desorption. The linear velocity of the nozzle can be obtained by converting the amount of the nozzle plus the amount of steam into a volume flow rate and then calculating it.
This post was last edited by caochaohui on 2012-9-10 18:00. The nozzle outlet is a two-phase flow, and there is a velocity difference. The particle velocity cannot be calculated. Theoretically, it is a world-class problem. The particles at the nozzle exit can only be estimated based on experimental test results. The nozzle linear speed and the nozzle exit particle speed are two concepts. There is little correlation between the two, or even a negative correlation. According to the results measured with a Doppler particle analyzer in the XXX unit, the particle velocity at the nozzle outlet is 30-40m/s. A Doppler particle analyzer costs more than 2 million, and its operation is very complicated and beyond the reach of ordinary people. So we probably think that the particle velocity at the nozzle exit is about 40m/s-50m/s, and there is no need to go into details. If anyone wants to know more about it, please add me on QQ: 875351942.
Agree with you. Personally, I understand that the nozzle is not necessarily used for throttling, but may also be used for rectification. Once I calculated based on the nozzle area, the result was quite different.
Please indicate: The one I calculated at that time was BWJ. The atomization effect was mainly at the cyclone, not the throttling atomization at the nozzle. .
The calculation methods for different nozzles are different. Generally, the four gas and liquid phases are calculated at the same speed and the average speed is calculated. Based on the outermost area of the nozzle, the pressure is based on the pressure inside the riser. It can only be estimated according to one structure and one method. How much linear speed will it break? The data is relative.
According to the nozzle design of Luoyang Institute, the ejection speed at the nozzle outlet is 60 to 80m/s, which is more suitable.
It seems that if the nozzle linear speed exceeds 90m/s, the catalyst will be damaged.
First of all, because the amount of atomized steam is in the gas phase, it contributes first to the line speed. Secondly, your problem should not be that the line speed is too high. Maybe the nozzles are not aligned when installed, causing bias flow and the atomized raw materials directly hitting the wall of the container, which will cause the greatest damage to the catalyst. The solution can be to reduce the amount of atomized steam, adjust the raw oil and atomized steam of each channel, and strive to avoid biased flow. Pay attention to whether the oil pressure and steam pressure on the on-site pressure gauge are the same. As long as there is no biased flow, there should be no problem.