Over the past few decades, our parent company SSI has built numerous aggregate processing facilities focusing on a variety of finished stone products. Some of these plants screen and size stone dry and then rinse the products as required, while others use multi-deck wash screens to produce clean and sized products. Utilizing dry screening and then rinsing individual products is our preferred method because it allows for washed or dry production of each individual product, and the process uses less water than wet screening. Compared to traditional eccentric shaft machines, the Mule screen has the advantage of a slim-elliptical motion which can convey material across the vibrating surface at an appropriate bed depth for rinsing or washing while resisting pegging.

The Mule’s compact design also minimizes overall investment for a processing station which makes it practical to utilize multiple mule screens to rinse individual coarse products in lieu of a multi-deck rinse screen. Rinsing coarse aggregate was the first application tackled by Mule screens because we felt that most vibratory screens focus on sizing and carry too high of a bed depth on the feed end of the machine for the spray system to be fully effective. Additionally, eccentric shaft machines required too much investment in machine and support structure for rinsing to be competitive with wet sizing and processing.

Along with product rinsing, Mule screens have also proven themselves effective in wet sizing of aggregate or sand materials. Wet applications often call for a shallower deck angle to increase the materials exposure to the spray system. The Mule screen is typically installed on a slight incline (+/- 10 degrees) and runs with a 7/16” x 1/8” elliptical stroke at 900 RPM. This allows the Mule to convey the material at an appropriate travel rate for the application while maximizing the materials’ exposure to the spray system. Combined with the low maintenance overhead drive mechanism, this makes the Mule the perfect candidate for single and double deck wash applications.