Patent GB-1467333-A (GB)
Title: Open hearth fireplaces
IPC: F23J15/02
Filed: 1974-02-22
Abstract: 1467333 Purifying waste gases CHEMINEES RICHARD LE DROFF SA 22 Feb 1974 [23 Feb 1973 18 Dec 1973] 8285/74 Headings B1L. BIT and B1W [Also in Divisions C1 and F4] An open-hearth fire place comprises an outer casing housing purifying means for removing the gases and solid particles produced by combustion, a suction device within the housing for creating a flow through the purifying means of the combustion gases and particles, and a duct coupled to an outlet of the purifying means for returning the residual gases to the hearth. In the embodiment shown in Fig. 1, an ejector 12 is supplied with compressed air by a compressor 14 for drawing combustion products upwards through removavble cylindrical purifying devices 20, 30 which comprise a mattress 23 of wires, silica or alumina to retain solid particles, a layer 24 of activated carbon to remove gases such as H 2 S, a layer 25 of silica gel to dry the gases, a molecular seive 26 to remove molecules of gas produced by combustion of plastics material or alternatively ammonia, acetylene or ethylene a layer 27 of metallic oxides such as the oxides of manganese, copper, cobalt, silver for the catalytic oxidation of CO to CO 2 , an annular element 32 formed of superimposed corrugated bands of blotting paper, immersed at its lower, end in an alkaline solution e.g. caustic soda or caustic potash, to retain CO 2  by formation of carbonates, and a mattress 36 similar to mattress 23 to retain water droplets. A hollow hemispherical deflector 17 with a liquid outlet 17b is screw-threadedly mounted on a dehector 16 to define an adjustable annular opening to create turbulence in the space defined by element 32. The element 32 is replaced in other embodiments by wicks or strips (42, Fig. 3) of blotting paper immersed at their lower ends in the alkaline solution; strips (53, Fig. 4) hanging from and communicating with the interior of a tank of the alkaline solution; a tank for the solution having a conduit (63, Fig. 5) connected to the nozzle 12 for atomisation of the solution by the gaseous flow through the 'nozzle, superimposed tanks (72, Fig. 6) for the solution having central gas passages (74) and hoods (75) thereover to force the gases to bubble through the solution in successive tanks; or a tank (82, Fig. 7) for the solution having at its lower end non-return ball valves (84) for inlet of the gases, and containing an agitator (85). The casing 3 of the fireplace may be brick-built or made of sheet steel, with a removable top 5. A heat exchanger (91, Fig. 8) may be located upstream of purifying device 20 to heat room air drawn through a filter (93) by a venturi nozzle (92) connected to the compressor 14, and returned to the room through a filter (95) at floor level. Alternatively the heat exchanger (91) may heat water for supply to radiators. In the embodiment shown in Fig. 9, the fireplace includes a solid particles filter 103, a heat exchanger 105, a filter 108 comprising activated carbon and metallic oxides, a condensate collector 109, a venturi nozzle 111 connected to a compressor 112 and a tank 113 containing alkaline solution or ethyl alcohol and a rotatable wire-mesh cylinder 115.