If you had good experience with your pneumatic system, a simple replacement of components is in order. However, if your maintenance and operating costs were high, you should consider either an enclosed drag type conveyor, as you described, or an enclosed belt system such as a pipe belt, the Enerka belt system, or Imperial's Multi-Fold belt system (described by the previous poster).
Imperial can be reached at (330) 305-2100 or via e-mail at email@example.com
The Enerka system is being marketed in the US by Fairfield Engineering (visit their web site).
If you require assistance, please feel free to contact me.
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