Abstract: A method for reducing color impurities in sugar-containing syrups. First, hydrogen peroxide is added to the syrup and mixed with it. Following that, a suitable cationic surfactant is added, ahd there is further mixing. After that, a suitable defecant is added, such as a mixture of calcium chloride and sodium carbonate, which react with each other to form calcium carbonate in the sugar solution. Activated vegetable carbon and diatomaceous earth are added and mixed. Then the solids are filtered out to obtain a purified sugar solution which may be used directly or may be inverted, as by conventional acid treatment, and then used.

Abstract: The pressure of heated gases supplied by a furnace to an induced draft, rotating drum drier, through which the material being dried is moved primarily by the heated gases, is compared with the pressure of gases discharging from the drum, and the differential between these pressures is used in controlling the induced draft of the drum by decreasing the draft upon an increase in differential pressure and increasing the draft upon a decrease in differential pressure. The differential in pressure may be maintained at a value on the order of 1.2 to 1.6 inches H.sub.2 O, depending on the installation. The induced draft may be controlled at a damper between a discharge chamber for the furnace and an induced draft fan, through an electro-hydraulic actuator acting through a lever and a rod, the lever being manually settable when automatic operation is not used.