Particle separation in discontinuous vacuum processes
Heat-sensitive products such as battery components or pharmaceutical formulations are dried at reduced process pressures. This prevents overheating and thus destruction of the usually expensive products. The process pressure is often well below 100 mbar, depending on the final moisture content to be achieved. The rising steam can entrain fine particles from the bulk material to be dried. These particles must be separated in order to prevent contamination of the downstream plant components. In addition, this enables recovery of the high-quality products. Particle separation is realized with filtering separators (often surface filters).
Currently, these are dimensioned according to the design principles for surface filters at ambient conditions. However, this leads to over- or undersized filter surfaces. This in turn can result in unstable filter operation, higher costs, and higher energy consumption.
To improve the design of surface filters at low pressures, various experiments on filtration behavior will be conducted. This includes investigations on differential pressure, particle separation and filter regeneration.