Patent GB-359220-A (GB)
Title: Improvements in heating systems for buildings
IPC: F24D1/00
Filed: 1930-10-29
Abstract: 359,220. Heating buildings. DUNHAM, C. A. and DUNHAM, A. R., 150, Maple Hill Road, Glencoe, Illinois, U.S.A. Oct. 29, 1930, No. 32482. [Classes 64 (ii) and 123 (ii).] In a heating system for buildings, fuel is burned in the presence of water, and the mixed combustion gas and steam are circulated through the system at a pressure below atmospheric. The apparatus comprises a generator A, burner control mechanism B, remote control and thermostatic controls, radiators E, and exhauster F. The generator, Fig. 2, comprises a combustion chamber 11, supported in a housing 1 below a mixing chamber 27. Combustion products are directed from a burner 17 tangentially into the chamber 11 and pass upward through chamber 27 against water which overflows from the space 33 on to trays 30, 28, so that it is vaporized by the hot gases. The mixed products pass through pipe 21 into the heating system. Any surplus water passes out through pipe 43 and seal 5. The heating medium passes to the radiators through pipe 44, each radiator being provided with a cut-off valve 45, Fig. 10, associated with an orifice plate 47. Discharge pipes 50 are connected to a return main 34 to which an electrically-driven exhauster 52 is also connected. Fuel gas is supplied through pipe 56, Fig. 8, to a sleeve valve 57, Figs. 7 and 8, communicating through pipe 60 with a thermostatic valve 61. A full or restricted supply of gas is obtained through port 63 or 66, Fig. 8, the latter port being regulable by a screw 67. From the closed end of the sleeve 57 a spindle 68, Figs. 6, 7, and 9, projects into a contact box 69. A disc 71 carries four similar pins 73, and a lever 74, Fig. 6, pivoted at 75 is provided at one end with a pawl 79 to engage the pins 73, and is connected at the other end to the core 77 of an electromagnet 78. Current is supplied from mains 86, 87, Fig. 9, through a transformer 88 to a normally open pushbutton 92 and electromagnet 78, which are in series, so that when the pushbutton is pressed the pawl 79 is actuated to rotate the spindle 68 through 90‹. The spindle 68 carries a pair of contact pins 100, 101, spaced 180‹ apart, and another pair of contact pins 104, 105, spaced 90‹ apart. These are connected to signal lights 96, 97. A coiled spring 101, Fig. 6, carries a pendulum 112 and an electric contact 113, and a finger 116 on the spindle 68 is adapted when turned through 90‹ to snap past the pendulum 112 and cause it to oscillate, thereby intermittently closing the contacts 113, 114. This energizes a spark coil 117, the secondary of which is connected to a sparking plug 122. The spindle 68 carries an insulating disc 123 having a flat 124, which controls the contacts 125, 126 and thereby the circuit of the motor 53 driving the exhauster 52. When the apparatus is at rest, the spindle 68 is turned 90‹ in a counter-clockwise direction from the position shown in Figs. 6 and 8, so that the valve 57 is closed, contacts 125, 126 are open, and the exhauster is at rest, none of the contact pins 100, 101 104, 105, is engaged and the lamps 96, 97 are not lit. If the pushbutton 92 is then actuated, solenoid 78 is energized, and the pawl 79 actuated to rotate the spindle 68 through 90‹. The valve 57 is then in the fully-open position, and the pendulum 112 is also actuated to cause the plug 122 to spark and ignite the pilot lights described later. The contacts 125, 126 are also closed and the exhauster is actuated. The contact fingers 100, 104 are engaged with their corresponding spring contacts and the circuits of the lamps 96, 97 completed. If it is desired to restrict the flow of gas to the burner, the pushbutton 92 is pressed a second time to move the spindle 68 another 90‹. The smaller port 66, Fig. 8, is then operative and less gas flows to the burner. The contact fingers 100, 104 are disengaged, but contact finger 105 is engaged, and the lamp 96 only remains illuminated. The exhauster continues to operate. A third operation of the pushbutton moves the spindle 68 and the valve 57 another 90‹, so that the gas is cut off. Contact finger 101 only is engaged and the lamp 97 only is illuminated. The exhauster continues to operate, so that any remaining hot gas is drawn through the radiators. A fourth operation of the pushbutton restores all parts to the inoperative position. A pipe 137 from the inlet chamber of the valve 61 leads to a pilot jet 138, and a small flame is ignited by the plug 122. This ignites a larger pilot flame 141 which in turn ignites the main burner 17. The inlet chamber of the valve 61 is also connected by a pipe 142 to a thermostatic temperature control D, and thence by a pipe 145 to a pilot jet 146 at the base of a chimney 139. The pipe 145 terminates close to a diaphragm 148, Fig. 5, and is adapted to be more or less closed by a plunger 149 actuated by a bimetallic strip 150 adjustable to a desired temperature by a lever 151. Normally, the jet 146 is ignited from the jet 138 and continues to burn until the predetermined temperature is reached at the location of the thermostat D. The chimney 139 contains a bimetallic strip 152 which, when heated, actuates a link 153 and lever 154 which close the main gas valve 156. A spring 157 moves the valve with a snap action when the lever 154 is moved past its mid point. The main gas valve is opened only after the pilot jets are ignited and the strip 152 deflected, and remains open until the thermostat D cuts off the gas supply to the jet 146; the jet 138 remains ignited. The thermostat D is placed near the outlet port for the exhaust gases, but may be placed at D<1> in a room, and a thermostat D<11> may be placed in or on the exhaust pipe 34. The contact 203 of this thermostat is connected to a contact 210 associated with a spring arm 208 resting on an insulated cam disc 207. This circuit is completed only when the spindle 68 is in its third position, i.e. when the gas is cut off but the exhauster is still in operation. The completion of the circuit by the thermostat D<11> due to cold air being drawn through the system energizes the solenoid 78, turns the spindle 68 to its fourth position and stops the exhauster. Contacts 216, 218 are provided adjacent to the spring 157, by which, if the main valve 156 is open when the control mechanism is in its fourth or inoperative position, the transformer circuits cannot be completed and the cycle cannot be initiated while a large volume of gas is flowing to the main burner. To avoid the occurrence of pressures above atmospheric in the system, flap valves such as 164, Fig. 2, may be provided in the supply and return sides of the system.