Patent GB-191413364-A (GB)
Title: Improved Process of and Apparatus for the Manufacture of Sugar and Chemical Substances of similar Soluble Properties.
Inventor: GRIERE JEAN CHARLES
IPC: C13B30/02
Filed: 1914-05-30
Granted: 1915-09-16
Abstract: 13,364. Griere, J. C. May 30. Saccharine solutions, crystallizing. - A continuous process for the direct conversion of a solution of sugar or similar substance or a massecuite containing crystals into a dry and friable product consists in treating a supply of hot concentrated solution with a supply of friable precipitating-substance regulated according to the quantity and concentration of the solution supplied. The precipitating-substance may be derived from the partially finished product, or it may be sugar in grains or a foreign substance such as kieselguhr, sand, alumina, or powdered boneblack. The foreign substance may be left in the finished product, or may be separated by any known method when the sugar is remelted. The hot paste so formed is then subjected to a kneading process and afterwards treated in primary and secondary drying-appliances. In the primary drying- apparatus, the mass is agitated and exposed to the action of hot air partly saturated with moisture, while in the second apparatus the mass is subjected to energetic agitating and mixing, and to the action of cold air. The mass may be sifted between the two drying operations, and may be further heated by a current of hot air before sifting. After drying, the product is treated with moist air to give it its natural amount of hygroscopic moisture, and is simultaneously cooled. This may be carried out by allowing the product to fall over refrigerating-surfaces on which moisture from hot moist air passing through the apparatus is allowed to condense. The process may be varied by compressing the paste received from the kneading apparatus, the moist blocks so formed being dried in a current of cold air or in a vacuum. The process may also be modified by introducing at any stage a decomposable solid or liquid or gaseous substance for the purpose of varying the composition, taste, or colour of the final product. The raw solution, after being treated in a concentrator supplied with heating steam under constant pressure, passes to a regulating chamber fitted with a weir so shaped that the flow is directly proportional to the height of liquid above the weir. The regulating chamber is further provided with a float adapted to operate the valve controlling the supply of solution to the concentrator and also to control the rate of delivery of the precipitating-material. The precipitating-material is stored in a receptacle o provided with hoppers n from which it is delivered by a conveying screw r to pipes s, s<1>, s<2> leading to various points in a precipitating-tank u provided with a suitable agitating - device. The conveying screw is driven by a variable-speed gearing such as coned pulleys t controlled by the float in the regulating-chamber. from the precipitating- chamber, the material in the form of a paste falls into the kneading-machine. This apparatus comprises a cylinder 1 open at the top and surrounding a rotating kneading - member, which consists of a number of helical blades 3 carried by radial iron arms 4 shaped to cut their way through the mass. The material is discharged through a valve-controlled aperture 6 into the primary drying-device shown in Fig. 3. The material is fed in through a hopper 14 by blades 15, so as to plug the inlet and prevent the escape of air. Inside the drying-apparatus are a series of horizontal or slightly inclined partitions having apertures alternately at the centre and at the circumference through which the material is caused to pass by rotating spiral blades 10. The blades are preferably inclined to the surfaces to crush the lumps, and the apertures are made progressively smaller towards the bottom of the. apparatus while the paste is passing downwards through the apparatus, a current of slightly moist warm air is passing upward. The material next passes into the secondary drying-apparatus shown in Fig. 6, where it is subjected to a counter-current of cold air. This apparatus comprises an horizontal cylinder fitted with a rotating stirring and conveying device. This consists of a rotating axle fitted with cutting-knives, with triangular shares 17 arranged obliquely to a plane passing through the axis and to a plane at right-angles thereto and with spoon-shaped members arranged about 90 degrees behind the shares. The material finally passes into the humidifying and cooling appliance shown in Fig. 9. In this device, which is supplied with warm moist air, the material absorbs the moisture condensed on a series of conical refrigerating-surfaces 50 as it is passed from one surface to another by rotary brushes 51. In a modified form of this apparatus, horizontal refrigerating- surfaces are fitted in addition to the conical surfaces. In another form of cooling-device, the refrigerating-surfaces are arranged in the form of a cylinder mounted within a second cylinder fitted with lifting-buckets and cleaning-brushes. Specification 9148/09 is referred to.