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Hydrogen Properties for Energy Research (HYPER) Lab Dr. Jacob Leachman

Sorting & Sizing



 Goal: To efficiently sort the sizes of the crushed rocks.


Team members: Bashir Hussein, Idris Alrubkhi, Mundher Alsinaidi, Sulaiman Alsiyabi


To help the women in Uganda with sorting the crushed rocks into three different sizes, we came up with three different paradigms.

  1. Sifting Machine

Description: A machine used to separate the products using flat sieves that make successive circular movements on a horizontal plane.

Pros:                          Untitled                              

  • Strength and Durability
  • Availability of Materials
  • Fast Efficient  Sifting


  • Needs electricity
  • High cost ( cost about $2000) more than 6 million Ugandan shillings.



2. Belt with Grates

Description: Machines that have belts with multiple grate sizes to separate the rocks according to their


  • Easy to transport
  • Full efficiency
  • Can be manually operated
  • More production


  • Availability of materials
  • Hard to assemble
  • Prices depend on the number of sets
  • Heavy(up to 300 kg)


3. Coins Sorting Machine

Description: Dropping the rocks through a path that contains different sized holes.


  • No power needed
  • Low cost(wood).
  • Easy to assemble
  • Support heavy loads


  • Slow
  • Needs weekly maintenance
  • inaccurate




Decision & Integration

For our final design it was imperative that the sifting mechanism would sufficiently integrate into the overall design schematic. Because of this our final design was geared for ease of assembly as well the low cost of construction and material. In our design we synthesized the ideas of the belt grater with the concept of the sifting machine in a rather low tech way such that the idea could be mimicked by the Ugandan rock crushers but also successfully accomplish the desired result. By utilizing two mesh screens attached together by a wooden frame and set at an incline, we were able to create a rock sifter capable of assorting the rocks and allowing the least amount of labor to accomplish the task.


  • We have used 1/4″ mesh to isolate the quarter inch rocks.
  • We have also used 1/2 mesh to sort the half inch rocks.
  •  The team used pine wood for framing.

Final Design:

  • The final design is 1.83m by 0.7m sifter. The mesh is attached to the frame using 2″ screws.
  • The total cost of the sifter is about $30. (about 99450 Ugandan shillings).
  • It takes about 30 minutes to assemble.



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What is next?

Integrate the sifter in the machine in a way that minimize the labor work and gives it the ability to sift more efficient.

Make sure that the angle of the incline is good enough for the sorting job. It must not be too large nor too small.

Make sure that this design works well with whole machine crusher, if not , come up with another design of the sifter.


Washington State University