Patent GB-172962-A (GB)
Title: Improvements in the process of, and apparatus for, treating liquids with decolorizing, purifying, and filtering agents, and for separating undissolved substances from liquids
IPC: B01D15/02
Filed: 1921-12-13
Abstract: 172,962. Naamlooze Vennootschap Algemeene Norit Maatschappij, (known as General Norit Co., Ltd.), Assignee of Sauer, J. N. A.). Dec. 13, 1920, [Convention date]. Addition to 163,505. Purifying oils, glycerine, paraffin waxes, fats, &c.-The process and apparatus described in the parent Specification are so modified that the passage of the liquid from the mixing-chamber to the separator and the passage of the solid matter separated back to the mixing-chamber take place along separate paths, the separated solid matter being mixed with the liquid to make a pasty fluid which is conveyed back to the mixing-chamber. In the apparatus shown in Fig. 3, the liquid enters the mixing-chamber 1 by pipes 18 the solid reagent being inserted through an opening 19, the vanes 15 being operated to impel the contents from the centre towards the ends of the chamber. The liquid with the reagent in suspension passes up the passage 2 to the separator 3 consisting of a series of filters 4 which may be enclosed in a casing 49, the liquid entering the casing at the top. The solid matter deposited on the filter cloths is detached by reciprocating wire scrapers 8 and falls into a collector 9, in which revolve agitators 10 to homogenize the pasty fluid, which is then withdrawn by a pump 21 through a pipe 22 and discharged into the mixing chamber 1. An agitator 24 prevents the solid matter which accumulates at the top of the filter-chamber from caking together and the pasty fluid may also be withdrawn from this point by a second pipe leading to the pump 21. In a modified form, the collector 9 and pump 21 are dispensed with and a cylinder 51, Fig. 8, fitted within the passage 2 so as to form an annular passage 52 by which the liquid passes from the mixing-chamber to the separator, and a central passage 53 through which the separated solid matter falls back to the mixing-chamber. The passage 53 may be open or may be fitted with a removable cover and bottom which may take the form of plates 54, 55 pivoted on spindles 56, 57 which can be turned by racks and pinions or other gearing to open or close either pair of plates. When the upper pair is opened and the lower closed the solid matter accumulates on the lower pair, and when these are opened, the upper pair having been closed, is thrown down into the mixing-chamber. The wire scrapers 8 are carried by a frame carried by rods 67 attached to a cross-bar 69 which is reciprocated by means of endless chains 14 or by a screw having reversing gear the clutch of which is operated by a tappet device. Contact between the wires and the filter cloths is normally prevented by iron strips 40, but the bags may be inflated with air, gas, or steam injected through inlets 42 to complete the cleaning and the scrapers may or may not be operated simultaneously, the supply of liquid being preferably shut off. The process and apparatus are suitable for use in treating liquids of high specific gravity or viscosity, such as heavy oils especially with finely divided reagents such as decolorizing carbon, or filtering or adsorption agents. When employed for separating substances in suspension such as paraffin from gasoline or petrol, the liquid is pumped into the space 2. Materials so separated may be removed and the final separation effected by evaporating or draining off the liquid, or by centrifugal apparatus.