GB925772A - Improvements in and relating to heating appliances such as hot water boilers, space heating stoves and cookers - Google Patents

Abstract

925,772. Draught regulations. PERKINS BOILERS Ltd. Dec. 6, 1961 [Feb. 11, 1961], No.5166/61. Class 51 (1). [Also in Group XI] In a "balanced flue " heating appliance such as a hot-water boiler, space-heating stove or cooker having a burner and a power-driven blower delivering fresh air to the burner through a control valve at a suitable pressure, the air that is in excess of the burner requirements, as determined by the valve, is delivered by a by-pass to a flue gas outlet to create exhaust conditions which will effectively discharge the products of combustion from the appliance. The appliance has a hermeticallysealed burner chamber 10 in which an oil burner of the vaporizing type is placed. Above the said chamber is a combustion chamber 12 with an exhaust connection 10 leading to a flue box 20 and thence to a flue 21. Air is supplied to the burner by a fan 37 driven by an electric motor 36, the amount being controlled by a valve 39 which may be of any suitable type, for example, a hinged flap 39 and adjusting screw 40, as shown in Fig. 5, adjustable to supply a predetermined amount of air to the burner. The excess air which is not allowed to pass through the valve is by-passed through a pipe 42 to a flue box 20 through which it is conducted by a pipe 43 which terminates in a flue 21, the emerging stream of air drawing the combustion gases from the combustion chamber 12 through the duct 19, flue box 20 and into the flue 21. In Fig. 1, air is drawn from the exterior of a building through a duct 45 and the flue extends to an external terminal 47. The invention may be applied to a hot-water boiler, Figs. 2, 3 and 4, not shown. As shown in Fig. 5, it is applied to an air-heating stove. The stove comprises a control cabinet 60 housing the air-control equipment and also a metering device 55 for the oil supply to the vaporizing burner 11. Air from the fan 37 is delivered into an air jacket 64 which communicates with the burner chamber 10 via the valve 30 situated in one wall of the jacket adjacent to the burner chamber 10. A pipe 68 (equivalent to the pipe 43 in Fig. 1) discharges the excess air into the exhaust connection leading to the outlet terminal 47. Provision is made to encase the whole installation, and the control cabinet may be mounted in a retaining wall to draw air through louvres 62 in a cover-plate 61 of the control cabinet. In a further modification the oil burner is replaced by a gas burner, the air supply system being as hereinbefore described.