The setting of gas in the problem of pure particle flow heat transfer

Hi,bro.I plan to simulate the falling process of a particle.In this process, the particles will come into contact with the outer wall of the tube to achieve heat exchange(show in picture). I plan to use pure particle flow. However, I found that the initial gas temperature set by default in the background affects the heat transfer. So, I want to know how to eliminate the heat transfer effect of gas, in other words, make gas not participate in heat transfer. Thank you so much!

For pure granular flow the heat transfer between gas and solids should be turned off. The only effect you may see at the wall is particle-fluid-wall component in the heat transfer at the wall. You can turn it off by setting a zero gas conductivity (set k_g0=0.0). From You will need to enable the fluid solver go go into the fluid pane, set a constant gas thermal conductivity equal to zero and turn off the fluid solver again.

Thank you so much!
This is very helpful for me.