Other screens were cylindrical, making 10 revolutions per minute and performing the same function as shaking screen.
2.
The first steam-powered shaking screens were used in the U . S . 1890, and the first steam-powered coal washers installed in 1892.
3.
These flat screens were sometimes shaken back and forth ( hence the name " shaking screens " ), which not only removed dirt and sulphur from the coal but broke down larger lumps of coal into smaller sizes and sorted it for further cleaning and processing.
मोबाइल