GB1499091A - Heating apparatus - Google Patents

Abstract

1499091 Gas-fired heater E L M LEBLANC 19 July 1976 [28 July 1975 3 Oct 1975 4 Feb 1976] 29960/76 Heading F4T Heating, apparatus comprises a gas burner 11 and a waste gas duct with a forced flow/device 4, the duct having valve 1 to admit air downstream, of the burner, and a heat-sensitive valve control device 9 arranged to open and close the valve 1 in response to the heat output of the burner to adjust its output to an optimum value. In operation, air passes from a duct 5 to the burner 11 and when the latter heats a bimetallic strip 9, valve 1 is opened by a link 17, Fig. 2, so that some of the air instead of passing to the burner, is mixed-with burnt gases at 6 and, is evacuated by fan 4. The extent to which the valve opens, and therefore the amount of air passed straight to be mixed with the waste gases, is determined by the temperature reached by the burner, and the amount of useful heat generated per unit of fuel used is kept constant. The element 9 may be replaced by a thermostat bulb arranged below the burner, Fig. 3 (not shown), or two bimetallic elements (12) (18), Fig. 5 (not shown), or two bulbs (7) (20) Fig. 11 (not shown), may be used. A bimetallic element (10) Fig. 8 (not shown), is used to close valve 1 when cold. Fig. 14 shows a heat sensitive device 8 which controls valve 1 when the burner flame is small against a spring- urged diaphragm 25 which is acted upon by gas pressure supplied from the burner through a conduit 28. The membrane may be subjected to differential pressure of the waste gas on each side of a diaphragm (36) Fig. 15 (not shown). In a modification, the gas is supplied to the burner by valve 50, Fig. 17, having two closures 45, 46, actuated by solenoids 44, 41, and the air supply through valve 1 is controlled as a function of the setting of valve 50, and by an electromagnet 51.