Abstract: The invention features a control system for controlling the supply of bodyfeed to a filter for removing solids from a beer stream is described. By applying the bodyfeed at an appropriate rate and hence achieving appropriate effective bed voidage it is possible to maintain beer clarity while minimizing filter aid usage. The control system includes a means for determining turbidity of the liquid stream upstream of the filter, a means for determining the rate of pressure drop change across the filter, and a controller for altering the supply of bodyfeed to the filter in accordance with a calculated dose change.

Abstract: Method of inhibiting the precipitation of calcium carbonate from an aqueous system, comprises adding to the aqueous system a scale precipitation inhibiting amount of bis(phosphonomethylene) aminomethylene carboxylic acid.Typical aqueous systems usefully treated by the new method are water- or oil well systems, cooling water systems, steam generating systems, sea-water evaporators, hydrostatic cookers, gas-scrubbing systems, closed circuit heating systems, reverse-osmosis systems and aqueous-based refrigeration systems.

Abstract: The invention provides particulate calcium carbonate having incorporated therein from 0.1 to 10% by weight, based on the weight of calcium carbonate, of polymaleic acid or a water-soluble salt thereof.