For many years, the majority of vibratory separators had a rectangular or square design and employed a simple reciprocating movement to classify the powder.
During the early 1930's, machines that used gyratory motion, i.e. small circular orbital movements, were introduced. This then led to the use of circular screens, which offered a much better usage of screen area, and therefore an increased capacity per unit mesh area. Since then, in addition to the outward appearance of sieves evolving, there have been major advances in their component parts and in developing machines for specific applications and/or industries.
Most machines vibrate at 1400 rpm, but by separating the motor from the rubber suspension in this type of design, it became possible to increase the operating speed of the machines up to 2800 rpm with high out-of-balance forces.
This development led to increased efficiency of sieves, enabling smaller diameter machines to be used without adversely affecting performance. For example, a 22' diameter machine operating at 2800 rpm can significantly out-perform a 48' diameter machine operating at 1400 rpm on materials which are traditionally difficult to screen.
These smaller sized sieves are now one of the most widely used screening solutions across numerous industries. Companies appreciate having units with a small footprint as space requirements are often limited, but capacity levels must remain high to ensure there are not bottlenecks in the process which would compromise profitability. For example, many food manufacturers experience difficulty safely sieving bagged...