Functional Designs

Using cohesive strength, wall friction, compressibility, internal friction, and permeability test results, and in some cases, DEM (discrete element method) modeling, functional design recommendations including dimensions, angles, materials of construction, and feeder details are provided.

Test Equipment Design

Rotary testers do a poor job of measuring wall friction, and permeability testers are difficult to find.  I have drawings and parts lists for wall friction and permeability testers that can be fabricated from readily available, inexpensive components or I can recommend testers that are commercially available.

DEM (Discrete Element Method)

I have access to Rocky DEM modeling tools to design transfer chutes and other equipment and testers to calibrate DEM inputs.  


Caking problems are challenging because unwanted agglomeration is not always immediately evident.  I can find causes and propose remedies.  The adjacent photograph shows modifications to a 30-gal drum that reduces the compaction pressure inside.

Low-throughput Gravimetric Feeder

 Gravimetric feeders are often unreliable because during the refill stage when new powder is added, stress is transmitted to the material in the feeder, increasing its bulk density.  This causes the the discharge rate to increase.  Once the controller returns to gravimetric mode, it recognizes the error and compensates, often overshooting due to outdated tuning parameters.  My design  ensures  that the solids stress in the feeder remains nearly constant during filling and emptying, allowing a constant bulk density and steady discharge rate.