rwells
Jr. Member
A while back I had an idea about building a 3' long trommel with 4 to 5 tubes inside each other. This was meant to be a compact classification system, light weight made of aluminum. The center tube was 10in diameter and 3' long and had 1/2" holes in it. The next tube was 14" in diameter and had 3/8 holes in it. The next 2 or 3 tubes followed the same idea with the holes getting smaller. I was going to take material out of each tube and run it through a sluice box. I believed in classification was the key to good recovery percentages. I thought each sluice box could be tailored for a certain size of material. A grizzly at the start of the 9" tube would filter out anything larger than 1".
My trommel idea is not going well. I have some friends in the design department at the college. We built a computer model of what my plan was. Plan was to run the rocks down the tube and anything smaller than 1/2 inch fall through to the next tubes and so on. Rocks 1 inch to 1/2 inch plus went on out the center tube. This was all straight forward like trommel designs I saw on the web.
Problem: When the rocks smaller than 1/2 in fell through, most of them were over half way down the center tube. This only gave about half the second tube to sort for the next one. By the third tube almost all the material was exiting with out any further sort. I lost most of the 3 foot distance I wanted the material to travel for a good sort. I varied the speed of rotation and tilt angle with no success. Capacity was not a goal, but I wanted a complete sort (classification). We kicked around a lot of ideas on how to make sure each tube sorted the material for the entire 3 foot. I (we) started looking at a reverse helix that I saw on the web. If we used the helix in every other tube, we could bring the material back up and over the entire tube length. I still like the idea of a compact classification system and not stretching the tubes end over end for 20 feet. This is the current direction that holds the most promise at this time.
Another problem I have is I have no first hand experience at classifying rock. I need to see the terrain really get out and visit with people prospecting, mainly get my hands dirty. All the books and computer models don’t replace that.
If anyone has any comments or suggestions they are welcome. This summer I plan some road trips to some claims and get some first hand experience. At the end of the summer I plan to sort through all the ideas and models and maybe get a working prototype.
If this idea ever works, the idea is freely available to anyone who wants to build one. All the research is public.
My trommel idea is not going well. I have some friends in the design department at the college. We built a computer model of what my plan was. Plan was to run the rocks down the tube and anything smaller than 1/2 inch fall through to the next tubes and so on. Rocks 1 inch to 1/2 inch plus went on out the center tube. This was all straight forward like trommel designs I saw on the web.
Problem: When the rocks smaller than 1/2 in fell through, most of them were over half way down the center tube. This only gave about half the second tube to sort for the next one. By the third tube almost all the material was exiting with out any further sort. I lost most of the 3 foot distance I wanted the material to travel for a good sort. I varied the speed of rotation and tilt angle with no success. Capacity was not a goal, but I wanted a complete sort (classification). We kicked around a lot of ideas on how to make sure each tube sorted the material for the entire 3 foot. I (we) started looking at a reverse helix that I saw on the web. If we used the helix in every other tube, we could bring the material back up and over the entire tube length. I still like the idea of a compact classification system and not stretching the tubes end over end for 20 feet. This is the current direction that holds the most promise at this time.
Another problem I have is I have no first hand experience at classifying rock. I need to see the terrain really get out and visit with people prospecting, mainly get my hands dirty. All the books and computer models don’t replace that.
If anyone has any comments or suggestions they are welcome. This summer I plan some road trips to some claims and get some first hand experience. At the end of the summer I plan to sort through all the ideas and models and maybe get a working prototype.
If this idea ever works, the idea is freely available to anyone who wants to build one. All the research is public.
GETTN' CLOSE CGDJ TO EXODUS BUD 
