Lean Phase Pneumatic Conveying for Calcined Alumina

Hello Everyone,

I have already posted this question on a different thread about Lean phase conveyors for Calcined Alumina.

I am learning how to design pneumatic conveyors. I don’t have any experience in this field (I am a new graduate mechanical engineer). I need to determine the air flow rate and the pipe diameter for the following system:

- Pressure System (not Vacuum)

- Conveying rate : 11 t/h

- Horizontal Distance : 80 m

- Vertical distance : 19 m

- Number of 90 degree bends: 6

- Material: Al2O3: Size: 15 micrometer

Density: 3900 kg/m3

Bulk Density: 1000 kg/m3

Material temperature: 120 C

I need know the solid loading ratio so i can calculate the mass flow rate of air (because i already know the conveying rate). I assume that the ratio for calcined alumina is low. So i tried to use a ratio of 5. This gave air flow rate of 24.39 m3/min and a 180 mm diameter pipe. Does this looks right to anyone?

i also need to select a blower or a fan for the system. I am assuming that an axial fan with low pressure and high volume flow rate will do the job. Does anyone have any suggestion concerning this issue?

I choose a rotary valve as a feeding device, but Teus Tuinenburg (from the previous thread) did not recommend a rotary valve for alumina because of high abrasive properties. I may have to reconsider the rotary valve then.

I hope someone can put me on the right track. Any information, equation, suggestion will be much appreciated.

Regards,

Tony ■