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Figure 16. A continuous liner product off-loading system that uses a continuous feed of bag liners fitted to the process outlet to isolate and contain process emissions and product (Used with permission from ILC Dover.)

3.4.3.2 Bag Dumping/Emptying

Technology used to control dusts during bag dumping has been in place for many years. The standard control—a ventilated bag dump station—consists of a hopper outfitted with an exhaust ventilation system to pull dusts away from workers as they open and dump bags of powdered materials.

This equipment eradicates the dust problems caused by manually emptying bags and the need to dispose of empty bags. This ensures a healthy environment is maintained in the process area as well as reduces maintenance and repair problems caused by powder contamination to surrounding areas. The basic equipment consists of a bag dump cabinet with a dust extraction outlet for connection to a separate dust collector or existing plant exhaust. A bag is placed on the mesh support shelf and manually slit, with the contents falling directly into the inlet of a flexible conveyor or mixing tank. A side-mounted empty bag compactor may also be included. Design examples for these devices are available from several manufacturers of industrial materials. The British HSE has developed a control approach for a ventilated station for emptying bags of solid materials [HSE 2003d]. The control includes the specification of a face velocity of 200 fpm (1.0 m/s) and includes a waste bag collection chute (Figure 17). Current Strategies for Engineering Controls in Nanomaterial Production and Downstream Handling Processes

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