Patent GB-572907-A (GB)
Title: Improvements in drying apparatus or dehydrating plant for the treatment of grass, peat, and other moist substances
IPC: F26B19/00
Filed: 1943-09-03
Abstract: 572,907. Drying grass &e. MCLEOD, H. N. Sept. 3, 1943, No. 14449. [Class 34 (ii)] [Also in Group I] In apparatus for drying material such as grass, peat, seaweed, fruit, vegetables &c. the material collected by or fed into the apparatus is divided up in a comminutor, is gripped in endless conveyer means which, after being pressed at one part of its travel to compress the material and squeeze moisture from it, carries the material over heated drums, and is delivered to a heating and drying chamber, heated air or hot gas and vapours being supplied to parts of the apparatus. The figure shows a mobile plant which, when in use, has its wheels b, removed so that it can be 'drawn on sled runners over ground on which material to be dried is lying. This material, after passing under the roller j, is caught up by curved lines on the plate k, and carried up by the rotating drum g. The drum may be formed to impart a traversing motion to the material, or may be formed as a rotary brush with shallow channels in its surface, or may have teeth or the like. The plate k may have sharp projections or be fitted with a wire mat with such projections. The material is thus comminuted before it is delivered to the pair of endless belt conveyers h, h<1>, which converge as they leave the drum g so that they grip the material. Rollers i, i<1> squeeze the material, the moisture from which may run or be pumped by a pump o to a receptacle at the side. The two conveyers then pass over heated drums p, p<1>, deliver the partially dried material to a trough t, and return separately to where they receive material from the comminutor. A worm conveyer, which may have serrated or shaped edges or be a spiral brush, conveys the material to one end of the trough t, and a conveyer w or flexible saddles on the worm conveyer deliver it to the drying chamber u. A rotating helical conveyer v<1>, with a shaft v which may be hollow, carries the material to the other end of this chamber, from which it is delivered by a transverse worm conveyer x, to a side outlet. On the periphery of the conveyer v<1> are small troughs for lifting the material to the top of the chamber u and dropping it. The chamber u, drums p, p<1> and, if desired, the rollers i, i<1> are heated by the exhaust from the engine 3 which drives the conveyers &c., and by combustion products from the furnace or burner 20. The exhaust from the tractor drawing the plant and waste heat from the cooling system of the engine 3 may also be used for the same purpose. The hot gases may be passed into the chamber u itself or through a surrounding jacket and through the hollow shaft v, which may contain a worm blade. If roots are to be dealt with, they are first divided up by a device comprising bladed, spiked or other rollers 1 and tines 2. If peat is to be dried, it may be broken up by a harrow or scarifier. The comminutor means which picks up the material may also be constructed to mow it. The drum g and plate k may be replaced by two travelling webs or wire mats with opposed hard points, travelling or oscillating at different speeds, by two oscillating plates with opposed blades or points,or by such a plate associated with a many-pointed wire mat. Material may be fed into the machine through a hopper f with a revoluble drum e carrying flexible beaters. Vapours from the chamber u may be collected and condensed. Other substances may be added to the material in the course of treatment.