| 摘要 |
<p>1,205,277. Automatic pressure control. SARTORIUS-WERKE G.m.b.H. April 9, 1968 [April 12, 1967], No.17112/68. Heading G3R. A desired pressure is maintained in a chamber supplied with gas through a series arrangement of reducing valve, solenoid valve and control valve, and exhausted through a series arrangement of control valve and solenoid valve by electrical means, responsive to the pressure, controlling the solenoid valves and a motor-operating one of the control valves. As shown, nitrogen from a high-pressure source 1 is supplied to a receiver 5 through a pressure reducing valve 2, solenoidoperated valves 3, 3 and differently adjusted throttle valves 4, 4. Gas is withdrawn from the receiver by a pump 11 through a solenoid-operated valve 10 and a motor-operated valve 8. A gauge 6 produces an electrical signal, corresponding to receiver pressure, which is compared with a reference signal so that any error is effective to operate a galvanometer 7. Light responsive pickoffs associated with the pointer of galvanometer 7 maintain receiver pressure between predetermined limits. At the upper limit valve 10 is opened and the opening of valve 8 gradually increased. At one lower limit one valve 3 is opened and at a still lower limit both valves 3, 3 are opened. The pressure datum may be varied with time by a timer 12 causing step by step adjustment of resistances which determine the value of the reference signal. Use of only one set of valves 3 and 4 and location of motor -operated valve 8 on the input side of the receiver are referred to.</p> |
