GB1220931A - Improvements relating to the combustion of materials - Google Patents

Abstract

1,220,931. Combustion of waste materials; burner liquid supplies. M. E. P. HILL. 9 Feb., 1968 [9 Feb., 1967; 23 March, 1967; 2 May, 1967; 17 Nov., 1967], Nos. 6317/67, 13657/67, 20353/67 and 52380/67. Headings F4B and F4T. [Also in Division G2-G3] Solid or liquid waste materials are burnt, using minimal excess air, in a forced air stream within a refractory lined combustion chamber, partial recirculation of the combustion gases within the chamber occurring. In the embodiment of Fig. 1, a regulated stream of used engine or cutting oil with up to a further 60 % by volume of added water, is gravity fed through conduit 25 to be entrained in a combustion air stream from compressor 26 and burnt within a combustion chamber located within but spaced from brick outer casing 6, the fuel/air mixture entering the chamber at its lower end segmentally and abutting against a baffle (Fig. 2, not shown) to produce vortical gas flow within the chamber, surrounding a central core of gas at a higher temperature. Due to the restricted size of flue outlet 9 partial recirculation of gas back along the cylindrical side wall occurs, so ensuring complete combustion and also cooling the wall. A tangential air flow is induced into the space between the combustion chamber and the casing 6 to also cool the wall. The exhaust gases, and cooling air from the annular space entrained thereby, under control of valve BF pass to fan 27 to be used in a brick-drying kiln. In Fig. 9 a horizontally disposed cylindrical combustion chamber 40 for burning tyres 56 is shown, the tyres plus water if desired, being fed from endless conveyer 57 into the chamber to be burnt with air supplied from compressor 51 through segmentally directed pipes 52, 53 (and 54, Fig. 10, not shown) again to produce vortical flow and partial recirculation within the chamber, the ashes falling into ashpit 49 and the exhaust gases passing via pipe 66 over heat exchange tubes 68. Alternatively (Fig. 11, not shown), the cylindrical chamber may be vertically disposed. In a further embodiment, Fig. 12, refuse, with or without added water, from shoot 94 is fed into combustion chamber 73 through casing 93 and cowling 90 by a reciprocating charger 104, a segmentally directed forced combustion air supply to produce a like gas flow path to the previous embodiments being provided through line 80 and cowling 81. Additional liquid fuel may be supplied via funnel 89<SP>1</SP>. The apparatus may also burn tyres. The upper flue outlet aperture of the chamber of this embodiment may be varied in size by valve means in the form of a displaceable cover (Fig. 16, not shown) or by the use of replaceable refractory rings of various diameters (Fig. 15, not shown). In a further embodiment, Fig. 17, refuse from shoot 122 is burnt in the combustion chamber with a forced air supply from segmentally directed inlets 120, on a rotatable floor 123. Ash and exhaust gases exit through lower aperture 127, the ash falling into water tank 130 to be periodically removed by scraper chains 132 and the exhaust gases leaving through flue pipe 131. In Fig. 19 a waste oil combustion chamber generally similar to that of Fig. 1 is shown but having top and bottom exit flue apertures and top and bottom air/fuel segmental inlets 144, 145. A rotary table 134 is located below flue aperture 138 partly in the flue gas path, on which table stone chips 140 may be heattreated, or tyres burnt. Other fuels combustible in the chambers described include chemical sludges, coal slack and combustible fines. All the chambers previously described could be provided with top and bottom flu apertures. Liquid fuel supply.-When burning used oil to which up to 60% by volume of water may be added, the filtered mixture is pumped from reservoir 14, Fig. 1, through a circulation line 22, a regulated amount being drawn off to be burnt by partially obstructing with a pivotable knife-like member (Fig. 4, not shown) a spray from nozzle 24, the obstructed portion falling into funnel 15 and the remainder returning to the reservoir. In a modification, Fig. 5, the flow is divided using a pivotable tray 33 adjustably positioned under a fan-shaped spreader 31, or under a cone-shaped member (Fig. 7, not shown). In the latter case a plurality of separate feeds from a common source is obtainable. An extensible pipe (Fig. 8, not shown) may replace the pivotable tray.