Patent GB-654144-A (GB)
Title: Improved methods of and means for the production of acetylene by the interaction of water and metal carbides
IPC: C10H13/00
Filed: 1947-01-18
Abstract: Acetylene is prepared by reacting carbide in the ingot form with water in a generating chamber.  By carbide in ingot form is meant a mass of metal carbide, capable of yielding acetylene when treated with water, solidified from the molten material in one or more layers either in the receptacle in which it is prepared or in which it is teemed from the furnace; the term is also intended to cover broken ingots exceeding 120 mm. screen mesh size.  The metal carbide in ingot form, e.g. calcium carbide, may be substantially wholly immersed in a body of water, or the ingot may be mounted in juxtaposition to a body of water and movement is effected between the ingot and water so that the ingot progressively reacts with the water.  At least one ingot may be mounted in a generating chamber and one or more jets of water or steam or water as vapour entrained in a fluid medium are directed on the ingot or ingots. The ingot may be crushed within the generating chamber.  An apparatus for generating acetylene from carbide in the ingot form comprises in combination a generating chamber supplied with water and means for receiving the carbide ingot and guiding it into the generating chamber wherein the means for receiving the carbide ingot is so shaped and dimensioned that the ingot makes a sliding fit.  The <PICT:0654144/IV (b)/1> <PICT:0654144/IV (b)/2> <PICT:0654144/IV (b)/3> <PICT:0654144/IV (b)/4> <PICT:0654144/IV (b)/5> <PICT:0654144/IV (b)/6> <PICT:0654144/IV (b)/7> means for receiving the carbid and guiding it into the generating chamber may comprise a shoot down which the carbide ingot is projected.  In Figs. 1 to 6, the receptacle or receptacles 21 for one or more ingots 22 are attached to the generating chamber 20 in which there is a support 23 for the ingot or ingots.  The water delivery pipe 24 delivers water in the form of liquid, steam or vapour to produce acetylene which is drawn off at 26, if necessary, through non-return valve 30, while sludge is removed at 27.  Excess water is removed through the overflow device 25.  In Figs. 1 and 2, the generation of acetylene is commenced by operating the ingot-retaining device 28.  In Fig. 3 the formation of acetylene is controlled by operating piston 34 connected to the ingot support 23 with rod 35 by means of compressed air in cylinder 32.  In Fig. 4, the carbide ingot 22 is held rigid while support 23 is rotated by shaft 36; a scraper blade or scraper blades 39 project slightly above support 23 and are mounted eccentrically with respect to shaft 36 and rotate with support 23 to remove lime layer from the ingot.  In Fig. 5, lime is removed from the ingot with revolving brushes 41; the ingot is preferably cylindrical to revolve on support 23 operated by shaft 36.  Fig. 6 illustrates an apparatus in which thermo-circulation of the water takes place.  The hopper 21 is mounted upon an inner chamber 42 fitted with an ingot holder 43 extending downwardly therethrough in axial continuity with the hopper 21, and terminating in a flared portion 44 located in the lower part of the main generating chamber 20.  Circulation down-take pipes 45 are connected respectively to return pipes 46 through the sludge settling tank 47.  Water heated by reaction with the carbide rises in the ingot holder 43, flows outwardly through ports 48 into chamber 42, down through pipes 45 to tanks 47 and returns to the ingot holder 43 through pipes 46.  Gas ports 49 allow acetylene to pass out of 43 to take-off 26.  The water seal 30 may be short-circuited with byepass 50 to operate under pressure.  In an alternative system, acetylene may be obtained by causing one or more jets of water to impinge on the ingot surface, e.g. under sufficient pressure to remove lime.  Water used for reaction with the carbide may contain lime and may be filtered to extract free lime.  The lime residue may be obtained in a substantially dry form by limiting the amount of water in any form to that amount <PICT:0654144/IV (b)/8> <PICT:0654144/IV (b)/9> required to decompose the carbide wholly into hydroxide.  The hydroxide may be removed by ingot, e.g. as in Fig. 7. The ingots 22 are tumbled in basket 23 operated by shaft 52 and water, steam or vapour is supplied through 24 while lime is removed by means of screw 55.  Ports 20, 21, 26, 30 and 50 are as previously indicated.  Alternatively the chamber may be filled with water. Fig. 8 illustrates an apparatus of the water-recession type, water rising and falling in tank 58 according to the demand. Ports 20, 21, 22, 26 and 27 are as previously indicated.  The apparatus in Fig. 9 incorporates a crushing device with movable jaw 66 operated by rod 68 and cam 69 Ports 20 to 28, inclusive, and 30 are as previously indicated.  The Provisional Specification refers to using carbide ingots which have been enclosed in a sheath of any non-hygroscopic material by painting, extruding, spraying, dipping, spreading or wrapping.  The envelope is completely removed or partly removed before inserting the ingot in the generator, alternatively, a solvent for the envelope may be included with the water in the generator. Any of the means given above for removing lime from carbide in the generator may be used to remove the envelope.  Materials from which the envelopes are prepared include cellulose esters, pitch, varnish, lacquer, bitumen, rubber, resins, metals, metal foil and clay rendered impervious by glazing.ALSO:The Provisional Specification refers to enclosing metal carbide ingots formed from molten carbide either in the receptacle in which it is prepared or in a receptacle in which it is teemed from the furnace, said metal carbide forming acetylene when treated with water, in an envelope impervious to water.  The envelope may consist of a coating applied to the solidified carbide by painting, spraying, dipping or extrusion, or the envelope may be made from metal sheet or foil, or paper or textile material coated with a water-repellent substance.  Cellulose esters, pitch, varnish, lacquer, bitumen, rubber and resins are specific materials mentioned.  The molten metal carbide may be cast into an unfired clay container so that the heat of the carbide renders the clay impervious to water by firing or glazing.