Recommended Hopper Design for Feeders

Proper hopper design plays an important role in obtaining the rated capacity of a feeder.  Proper transition design is also critical to controlling the material "headload" on the feeder and avoiding possible resulting damage to the feeder.

Recommended Hopper Configuration
 
The rear wall should be at a slope of approximately 60° to ensure flow of material from the rear of the hopper. The slope of the front wall should be 5° – 10° less than that of the rear wall (50° – 55°).

Hopper Dimensions

Generally speaking, the gate height (H) should be a minimum of twice the largest particle size for material with normal size distribution. The hopper throat dimension (T) should be approximately 1/2 the gate height (H), otherwise the material flow patterns could be distorted and feed rate could be significantly reduced. In addition, it could also create an excessive “headload” of material to the hopper that could overpower the ability of the feeder to convey material and cause feeder damage.  The hopper width dimension should allow for approximately 1/2" clearance on each side.  The hopper width should also be a minimum of 2.5 times the largest particle size for random size material and five times the largest particle size for near-size particles.

Skirting Installation

Skirts should be tapered slightly away from the bottom of the feeder deck and have 1/2" clearance from each sidewall of the feeder.

Feeder Length

A safety factor of 6" – 12" (E) of extra length is recommended to prevent the possibility of free flow.