Patent GB-186701930-A (GB)
Title: Economising waste heat in washing, drying, burning or evaporating
Inventor: GORDON GEORGE
IPC: B01D1/14
Filed: 1867-07-02
Granted: 1867-12-31
Abstract: 1930. Gordon, G. July 2. Filtering - media, regenerating; strainers. -Relates to apparatus for washing, drying, and burning granular materials, such as animal charcoal which has been used for filtering in sugar manufacture, reference b e i n g made to Specification No. 2571, A.D. 1866. The material is conveyed on belts f<1>, Fig. 1 (Sheet 1), to a washing-vessel A divided into compartments. W i r e cloth or other perforated belts b<1>, b<2>, b<3>, supported on drums and rollers, move the material slowly forward, while jets of steam rise through the belts. Hot water enters at d, and leaves at e. The vessel A has one double side, the interior plates of which do not reach the bottom, so as to permit the removal of any material that falls from the belts. Another form of washer, shown in Fig. 1 (Sheet 2), consists of an open vessel divided into two compartments separated by an inclined partition a, and c o n t a i n i n g lifting-belts b<1>, b<2>, b<3> and shaking-plates c<1>, c<2>, c<3>. The washing- water travels in an opposite direction to the material being washed, the latter being delivered to the first lifting-belt b<1>, from which it falls on and down the shaking-plate c<1> to be lifted by the second belt, and so on through the series. The vessel has a sloping bottom, and each compartment slopes down to a well wherein any material spilled from the belts collects. More than two compartments may be similarly arranged. When an acid solution is employed for washing, the charcoal is carried on a band which is deflected by rollers and made to dip into the solution. It may be previously, and subsequently, passed through compartments containing water. The Provisional Specification states that the washing-chamber may have motion imparted to it, and that rotary apparatus similar to evaporating- apparatus described in the Specification may be used, which apparatus consists of a rotating cylinder with internal ribs and fixed inclined planes for feeding the liquid through the apparatus. From the washer the material enters the straining- apparatus B, Fig. 1 (Sheet 1), which consists of a hollow drum a divided into compartments open at the periphery. The wet material collects in the compartment d, and is enclosed, while rotating, by the porous belt e, which works over rollers and serves to rotate the drum upon the hollow shaft f. A current of air passes through this shaft and, entering the compartment, emerges through the porous belt, carrying water with it. The drained material leaves the belt at g, the belt being then washed in a tank h, and by a rotating hopper i passes to a drying-retort C with internal shaking-plates l, down which it passes, while the steam produced is carried away by the opening g and steam pipes r. The Provisional Specification states that the stepped plate may form the bottom of the retort, which may be fixed or movable ; or simple inclined retorts may be used. The retort may have rakes to move the material forward. From the retort C the material falls into the "burners" D, consisting of narrow vertical chambers or retorts set in a furnace chamber s, and, after being made red hot, it goes into coolers E. These consist of narrow water chambers t, between which the hot material falls. Heated water from the coolers is conveyed to the washer A. Below the coolers are discharging-boxes v, v, the valves of which are actuated from the shaft that rotates the hopper i, so that the feed and discharge are at the same rate. The furnace gases pass first under the drying-retort C, then around the burning-retorts D, and thence over the top of the retort C and around tubes b, b, to heat the air supply of the furnace, which is worked as a gas-producer. Air is drawn into the tubes b, b, through openings d, d, and mixes with the products of incomplete combustion at an opening c, c beneath the retort C. The steam produced in drying is led away for utilization, the Specification describing its use in the worm or steam chamber of a sugar-boiling vacuum pan. In a modified arrangement of dryer, burner, and cooler shown in transverse section in Fig. 2 (Sheet 3), the wet material is received into a hopper placed above drying-tubes G, G, which taper as they descend to the burners U, C, and below which are the coolers F, F, with water chambers and discharging-boxes as above described. Within the drying-tubes are a series of inverted funnels connected together, the top one leading into a pipe through which the steam collected passes to the apparatus for utilizing the waste heat. The series of funnels receive an up and down motion that serves to feed the damp material into the burners. This motion is derived from the same source that actuates the discharging-valves at D, thus equalizing the feed and discharge. The drying-tubes may be cylindrical, in which case a perforated tube with umbrella-like projecting rings may be used instead of the funnel chambers shown. In the case of an upright charcoal kiln of the kind described in Specification No. 2571, A.D. 1866, a hopper is placed round the top of the drying and burning tubes C, C, as shown in Fig. 4 (Sheet 3), and funnel chambers similar to those above described are fitted in the upper or drying portions of the tubes and continued in a modified form (consisting of a perforated tube as shown), down through the lower burning portions. Below are coolers F, F, as described above. The Provisional Specitication states that any of the driers described may be prolonged to form burners at their lower parts. In rotary charcoal kilns an internal cylinder fills up the space, so that the charcoal may be worked in thin strata, and the waste steam collected. The Provisional Specification describes a rotary drier consisting of a tubular chamber (horizontal or inclined) "the form of which in the central cross- " section is a series of segments of circles or other figures." The inside is formed with longitudinal ribs to carry up the material, and ribs set at any angle form a series of inclined planes along which the material slides towards the discharging end as the chamber rotates.