Fully Contained Bulk Material Conveying
Dust Controlled Solutions

Serious environmental concerns play a central role in today’s bulk solids handling industries. The ecological, safety, and health hazards of product dust are now well-documented, and, recognizing this fact, OSHA, the EPA, MSHA and other governmental agencies vigorously regulate these industries. This is especially the case with hazardous materials, such as chemicals, cement, lime, gypsum, coal, coke, mineral ore, heavy metals, silica, and waste products.

Not surprisingly, many industry leaders are taking a hard look at their methods of conveying since conventional mechanical conveyors are dust-generating machines. No matter how well designed, conventional mechanical conveyors pose a serious environmental hazard. That hazard comes directly from the friction-intensive principles of their operation, principles that are both obsolete and ineffective. Grisley’s reliable and cost-effective air-supported conveyors are the environmentally-sound alternative. Taking the industry beyond roller conveying has introduced a number of unique environmental safety innovations that simply are not possible with conventional conveying methods.

Conventional roller conveyors, which are the most common mode of handling bulk solids, rely on rollers to carry and track the belt. The friction between the rollers and the belt agitates the material it is carrying, which produces substantial product degradation and dust. Belt sag is another contributor to degradation and dust. Due to the combined forces of gravity and product bulk, roller conveyors cause their belts to sag between rollers, which causes the belt to move like a roller coaster. The problem gets progressively worse as the speed increases, effectively turning the conveyor into a product pulverizer. The extraordinary precautions the industry takes to protect roller bearing assemblies from the destructive effects of fugitive product dust demonstrates the fundamental flaw in their operating principle. Mining and mineral companies alone spend millions of dollars annually to repair and replace damaged rollers, whose bearings are damaged from dust penetration. To address this problem, many conveyor manufacturers have gone to great lengths to build better rollers and protected bearing assemblies. But they are spending their time perfecting an inherently flawed technology. The most practical solution is to eliminate the need for roller-based conveying, not to make it better.

Grisley ASC conveyors use a low-horsepower centrifugal fan to provide the airflow that supports the belt. A single fan supports up to 600 feet of conveyor. The Grisley ASC requires substantially less horsepower to operate, saving up to 35% on horizontal applications.

The airflow completely eliminates the belt sag inherent in conventional troughing conveyors. The Grisley air supported conveyor maintains a consistent level of support throughout every square inch of the belt’s movement. The smooth belt motion keeps the product stationary, eliminating the source of product degradation. No more troughing rollers to repair and replace: Since the belt is free of roller support, the Grisley ASC conveyor is dramatically less susceptible to the hazards of dust inherent in conventional conveyors. Without rollers, the Grisley conveyor reduces maintenance to the head and tail sections, which simplifies its operation.

Due to its full enclosure, the lower horsepower of its drive, and the absence of load agitation, the Grisley Air Supported Conveyor is much quieter in normal operation. This benefit makes a positive contribution to workplace safety, since mechanical noise increases the likelihood of accidents and long-term employee hearing loss.

Reliable air support allows higher-volume, faster conveying at angles up to 25 degrees. Compare the effectiveness to conventional conveyors, which can only handle angles up to 16 degrees.

Sound plenum architecture self-supports conveyor spans up to 45 feet, reducing the amount of truss-work and structural support.

Airtight and weather-resistant covers protect delicate loads inside and prevent pollution outside the conveyor. The precisely-calibrated airflow eliminates bumps and roller friction from the conveying process, eliminating the source of dust. This method of dust prevention is so effective that the Grisley conveyor can be enclosed fully and safely with airtight and weather-resistant covers. Together with its safe dust-tight enclosure, the air-supported conveyor’s smooth belt motion sets a new standard in dust control.

With conventional conveying, on the other hand, the user must factor the costs of maintaining, cleaning up, and replacing damaged product; all costs that are incurred from the conveyor’s operation. With their superior performance, lower sales and operating costs, and professional engineering support, Grisley Air Supported Conveyors set new standards for smooth, reliable, cost-effective conveying.