Coal mill reject conveying

(not verified)
Posted in: , on 31. May. 2003 - 11:05

Respected sir

I am working on conveying coal mill reject of size approx below 40mm with a distance of 100- 130m to elevation of 12-13m.

Is it appropriate to say that coal mill reject can be conveyed in dense phase.

Would sholud be solid/air ratio,bulk mean velocity and conveying pressure for conveying mill reject.

Any literature, if avaiable,may be please be informed.

My email id :

Dennis Hauch - Freeport, TX, USA
(not verified)

Coal Conveying

Posted on 31. May. 2003 - 02:08


Particle size distribution (PSD) is key to this application. If the PSD is wide, it is possible that dense-phase conveyance may work. If the PSD is narrow and the D50 > 20 - 25 MM, neither dense-phase nor dilute-phase would represent viable solutions. I would suggest that a test program undertaken with a global supplier such as Coperion-Waeschle or Zeppelin would establish the dense-phase conveying potential.

Short of a pneumatic test program, it would seem that the coal would be an ideal candidate for a drag-disk conveyor. I would recommend Schrage Rohrkettensystem GmbH.


Dennis Hauch

Re: Coal Mill Reject Conveying

Posted on 3. Jun. 2003 - 09:52

We have dense-phase conveyed sub 50 mm crushed coal quite successfully over such distances. However, the success does depend largely on consistency of coal size and moisture (as well as required tonnage rate). If these parameters can be controlled to acceptable limits, then you can dense-phase convey such materials. The largest dense-phase coal system that we have been involed with (design/test/optimisation) involved 40 to 50 t/h over 200 m with a 60 m lift.