| 摘要 |
<p>933,932. Automatic control of water content. AMERICAN INSTRUMENT CO. Inc. Oct. 5, 1960 [Nov. 9, 1959], No. 34070/60. Class 38 (4). In a system in which the proportion of water in a liquid mixture supply varies from a desired value, a portion of the mixture is continuously vaporized and variations of a property of the vaporized liquid used to correct the water content automatically. In Fig. 1, dry-cleaning fluid containing water is circulated through a cleaning tank 11 by a pump 12. A portion of the fluid is continuously fed back to the cleaning tank through an electronic device 19 which measures the proportion of water in the mixture and, when the proportion falls below a predetermined value, opens an electromagnetically operated valve 20 to add water from a tank 21 to cleaning tank 11 so that the water content of the fluid is maintained at a predetermined value. Within the measuring device 19 fluid is by-passed through a coil type heat exchanger housed in a compartment which is heated by an electric element 30, Fig. 3. The fluid so vaporized is led to a chamber containing a variable resistance bifilar type humidity sensing device 60. When the humidity in the chamber and hence the water content of the fluid exceeds a predetermined value a thermionic valve operated relay 44 is actuated to de-energize the solenoid of valve 20 which is connected to terminals 55. Meter 46 indicates the water content and jack 48 facilitates remote indication.</p> |
