| 摘要 |
1, 084, 518. Automatic control. EDWIN DANKS & CO. (OLDBURY) Ltd. May 8, 1964 [May 9, 1963], No. 18475/63. Heading G3R. [Also in Division F4] A steam boiler is operated, when the output is below the modulating range of its firing means, by periodically firing and storing the firing energy by increase of water level and during the interval supplying a load through reduction in steam pressure and in water level. Below a low value of steam pressure in the boiler a pressure switch is closed to open a flue damper and light up an oil burner. As the steam pressure rises the low-pressure switch is opened and through relays a feedwater valve is opened and the water level raised to, and maintained between, limiting values of a low-water level by a float switch. Further rise in steam pressure actuates an intermediate-pressure switch to select a high-level float switch by which the water level is controlled. With further increase in steam pressure a pressure switch is operated to cause the damper to close and the oil burner to go out. |
