Kamengo Technology Inc. - Reliable Flow with the Moving Hole

Biomass Materials
Flow Problems
Feeder Problems
Biomass R & D

Biomass R & D

Development of the "Moving Hole" Feeder

An extensive research project funded by the Canadian Government department of Natural Resources, Alternative Energy Division, was carried out at the British Columbia Research Corporation in Vancouver, BC, in the eighties.

Objective of the project was to derive guidelines for improved designs of storage bins and discharge feeders.

The project involved laboratory evaluations of the flow characteristics of different samples of hog fuel, wood chips sawdust and shavings, followed by tests on a pilot-scale experimental bin with a conventional "live bottom" type multiple screw feeder as well as a belt feeder.

The research showed that fibrous materials have enormous resistance to "funnel flow", that is "material on material" flow. Hence, bin geometry or feeder design that leads to funnel flow is likely to cause flow problems.

Laboratory flow test results, confirmed on a large test bin, showed that flow through a positive slope hopper was possible, and in fact very practical, provided that the hopper is designed for mass flow.

This contradicted a widely held view that the storage bin for fibrous materials must be negatively tapered. The "negative taper" bin tends to concentrate the load of the stored material on the feeder, and compacts material in this area, increasing the possibility of "hang-ups".

A positive taper bin results in better distribution of load as majority of the load is taken by the walls. Properly designed, this approach can provide reliable flow, and is especially advantageous when a large storage volume is required.

Results showed that the discharge feeder is a major cause of the flow problems. The "Moving Hole" feeder was developed to overcome problems and limitations identified by the R. & D.

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