GB533015A - Improvements in or relating to reducing or grinding material - Google Patents

Abstract

533,015. Cellulose-ester and synthetic-resin articles. KIDWELL, C. H. July 3, 1939, No. 19370. [Classes 2 (ii) and 2 (iii)] [Also in Group II] In apparatus wherein solid material is reduced by attrition as it is carried by a fluid along a curved pipe or through a curved chamber, the pipe or chamber is constructed of, or lined with, material of high di-electric strength and low conductivity, for example, cellulose derivatives, such as cellulose acetate, or synthetic plastics, such as phenol-formaldehyde urea-formaldehyde, vinyl, methyl-methacrylate, or glycerylphthalate resins. Adhesion of material to the wall of the pipe or chamber is thus prevented. Fig. 1 shows simple form of apparatus comprising a curved pipe 30. The fluid enters through an injector 39 drawing in the material under treatment from a hopper 41 and passing through a nozzle 37 to the pipe 30. Auxiliary jets of fluid are supplied through nozzles 34, 35. Coarser solid matter tends to remain on the outer side of the curve and the reduced matter is carried away by the fluid through the outlet 33. A second curved section may be provided in continuation of the section 30, this section being either in the plane of the section 30 or at right angles thereto. Fig. 5 shows a closed chamber confining two curved sections 47, 49. The fluid and material enter at an inlet 46. After passing round the chamber reduced material is carried off through an outlet 51 directed backwards on the inner side of the curve and coarser material joins that freshly supplied and is carried round the chamber a second time. Fig. 9 shows the attrition chamber in the form of a spiral with inlet 62 and outlet 70. A pipe 66 connects the outer side of the curve to the inlet end of the chamber and serves to pass unreduced material back for further treatment. A form of apparatus is also shown in which the chamber takes the form of a helical coil. As shown in Fig. 12, the attrition chamber 76 has the form of a toroid with inlet 77 and auxiliary jet nozzles 82. The reduced matter is carried off through passages 79 to a central chamber 78. As shown in Fig. 14, the inlet 97 is connected to an inner feed tube 100 with apertures 101 through which the fluid and material enter the attrition chamber 100.