Since you are in the conveyor industry "Belt Coveyors For Bulk Materials" would be worth looking at. It is a publication put out by the Conveyor Equipment Manufacturers Association (CEMA) and is available through thier website. It covers conveyor design in great detail.
Check out this post...
I am designing a small arbour press. I am planning on using a round rack and pinion (12 pitch). Can I rely on the tooth engagement to keep the rack from rotating or should I use another means to keep the rack from rotating.
Thanks