Abstract: A sludge dewatering system that includes a reactor to apply an electric field across at least a portion of the volume of the sludge and a dewatering station to dewater the sludge. The dewatering system may include one or more bypass lines so that at a portion of volume the sludge bypasses particular stages of the system. The dewatering station may use, for example, pressing or a centrifuge.

Abstract: The invention comprises a method of treating sludges which includes the steps of applying an electric field to the sludge to effect dewatering prior to further dewatering of the sludge. Typically the sludge comprises dilute phase sludge, and the electric field is a DC electric field. The pH of the sludge may be adjusted to between substantially 5 and substantially 6 prior to applying the electric field.

Abstract: The invention comprises method of and apparatus for drying pasty materials. The pasty materials are subjected to a first drying stage (1) at a first temperature, and then subjecting the partially dried pasty material are subjected to a second drying stage (10) at a second temperature. The second temperature is lower than the first temperature. The invention also envisages a method of drying and sterilising a pasty material comprising the steps of subjecting the pasty material to a first heat sterilisation process (1) and then a second heat drying process (10).

Abstract: A rendering process in which fats and oils are rendered from fat and oil bearing raw materials. The process comprises reducing the particle size of the raw material, heating the reduced raw material in a rendering vessel to a rendering temperature without the introduction of any process water and/or steam while establishing fluidization of the raw material within tallow resident in the rendering vessel and moving a flow of the heated material to a separator.