| 摘要 |
1393472 Bell-type furnaces ISOMAX INGENIOR-OG HANDELSAKTIESELSKAB 6 June 1973 [8 June 1972] 27024/73 Heading F4B An exhaust duct 6 extends through a bed of pebbles 4 forming the hearth of a bell-type furnace and is provided at one end with an exhaust fan 13 and, at the other end, with a valve 15 controlling the flow of secondary air. The duct 6 consists of channels 7, 8 separated by exhaust gaps 9. The valve 15 is controlled by a pressure sensor 18 which closes the valve when the pressure increases, and the fan is controlled by a thermostat 20 whereby the suction is increased when the exhaust temperature falls. Oil burners 10 are built into the hearth. In a modification, Fig. 3 (not shown), secondary air enters the hearth through holes in a duct arranged around the hearth. (For Figures see next column.) |
