GB823568A - Improvements in or relating to the combustion of refuse - Google Patents

Abstract

823,568. Treating refuse. VAGO, P., and VASS, B. March 5, 1957, No. 7229/57. Class 111. [Also in Groups II, XII and XXX] A process for treating refuse, to render it suitable for use as fuel in a boiler furnace, comprises eliminating pieces of iron from the refuse by magnetic attraction and then effecting a pneumatic separation of combustible from incombustible parts of the refuse simultaneously with a vaporisation of the moisture content of the refuse by means of combustion gases from the boiler furnace, the temperature of the combustion gases applied to the refuse being regulated in such a manner that the heat transmitted to the refuse substantially equals the sum of the heat of vaporisation of the moisture and of the heat required for heating the refuse to about 100‹C., the mixture of combustion gases and vaporised moisture being then allowed to escape into the atmosphere. The desired amount of heat is transmitted to the refuse if the gas-vapour mixture leaving the plant has a temperature of about 110‹C. In the drawings, refuse carried on conveyer belt 9, Fig. 7, passes through magnetic device 19 for removal of iron objects and is then directed by scraper 56 through crusher 20. The crushed refuse falls on to conveyer belt 21 which delivers it on to endless conveying and drying grate 25, Fig. 6, immediately below a similar grate 26. Within grates 25, 26 are airdistributing boxes 27, 28. Box 27 is connected by pipe 29 to the blowing side of blower 30, which draws combustion gases from the combustion zone via pipe 48 and heat exchange 47. Box 28 is connected by pipe 32 to the suction side of blower 31, pipe 32 being provided with a dust separator 42. The heavy incombustible portions of the refuse fall from grate 25 into funnel 43 and are classified according to their specific gravities in hydraulic brake sieve 44. Under the influence of the horizontal stream of gases from blower 31, the lighter combustible portions of the refuse are directed into funnel 43<SP>1</SP> and are thereupon charged to the reciprocating step grate 45 in the combustion zone. Hermetically sealed receptacle 51, within classification chamber 36, is connected by way of pipe 52 to a cylinder containing a piston 54, the cylinder being closed by bellows 53. Receptacle 51, pipe 52 and the cylinder are waterfilled, and piston 54 engages air inlet valve 55. By means of this arrangement, the temperature of the combustion gases utilized for drying the refuse is controlled. The combustion gases, having effected the drying of the incoming refuse, are sucked through conduit 38, Fig. 7, by means of hydraulic exhauster 39 and discharged into the smoke exhaust channel 40, which is connected with a chimney for venting the gases to the atmosphere. Cold water mixed with a soluble disinfectant such as formalin may be introduced into exhauster 39 to disinfect the gases.