You havnt mentioned what material it is ? some materials will stick in such small flights and will reduce the flowrate. If you give more details of the material then furhter comments could be made.

If you are lucky you might only have to change the auger. ■

The flight thickness seems excessive for the size of screw and, as the pitch is less than half the screw diameter, the screw is probably of uniform pitch construction, which begs the question of what form of hopper opening and shape feeds the screw. The compactability shown by the difference in loose and tapped bulk density implies a fine powder, which suggests that the problem could be either build-up in the small pitch space and/or flow problems in the feed hopper as any opening length greater than 30 mm will result in dead regions and an opening of 30 x 35 mm is small for the flow of a cohesive powder, particularly if the hopper has corner gullies. This seems like a classic case of a designer looking only at the dimensions for construction on a theoretical volume basis and neglecting the behavioural characteristics of fine powders. I suspect that the overall design is woefully inadequate.

Small feeders can present tough flow problems. Both experience and the lack of it have to be paid for, the latter usually being the most expensive. A detailed review of the equipment and the operation is needed to advise properly. ■