Hello,everyone!
I am having problems with the fluidisation properties of fluid beds, I want to achieve the results shown in Figure 3. As shown in Figure 1, this is a particle motion process for the following case to shut down the chemical reaction, no bubbles are generated and it is far from Figure 3. When I added the two chemical reactions R1:2C+O2=2CO; R2:2CO+O2=2CO2, the particle motion became as shown in Figure 2.
I tried to adjust the drag model and particle friction coefficient of the case still can’t achieve the effect of figure 3. Can anyone suggest me what modifications to make to create bubbles in the fluid bed?
24.1.1.mfx (30.6 KB)
usr_rates.f (3.9 KB)
usr_rates_des.f (6.1 KB)
Does Figure 3 have reactions turned on? How did you adjust the drag? If you know the minimum fluidization velocity, you can use Syamlal-O’Brien drag and calibrate its two coefficients.
Thanks for your reply!Figure 3 opened the reaction, and I adjusted these two friction coefficients.
![image](//discourse-attachments.s3.dualstack.us-west-2.amazonaws.com/original/2X/4/4b5dc975107b73d0a81a1299d9d9572f4a4d4dd0.png)
How to calibrate these two coefficients of the Syamlal O’Brien model through minimum fluidization velocity?
You can use the spreadsheet on the documentation page to calibrate the Syamlal O’Brien drag law:
https://mfix.netl.doe.gov/doc/mfix-archive/umf_spreadsheets/umf.xls
I changed the parameters of Syamlal O’Brien drag law according to this document, but at 0.22s the particles are almost immobile and the carbon particles (yellow colour) stay in the freeboard, why is this?
![12b60fc1eda173a50e4567af8d04cb1](//discourse-attachments.s3.dualstack.us-west-2.amazonaws.com/original/2X/7/7b02c5f349dcda487f5f47d132b06691a23398fa.png)