| 摘要 |
1,182,786. Automatic control. IMPERIAL CHEMICAL INDUSTRIES Ltd. Oct.30, 1967 [Nov.18, 1966], No.51841/66. Heading G3R. To prevent explosive conditions in a chemical reactor, the flow of gas to the reactor is measured and compared with a lagged signal representing a previous measurement so that a reduction in the flow-rate is demanded if the difference exceeds a predetermined value. As shown, electrical signals dependent the rate of flow of gas to a reactor, measured at 1, are applied to a D.C. summing amplifier 8 directly through a resistor 7 and indirectly in the opposite sense through a resistor 6 after delay in a unit A formed by a D. C. amplifier 2 with capacitive feedback. The two signals cancel under steady conditions but changes exceeding a predetermined rate produce a difference between the signals which is effective, if above a predetermined value, to operate an alarm and/or modify the rate of flow at 10. |
