| 摘要 |
Apparatus is provided for controlling the level of steam condensate in a steam retort wherein sealed cans of food are exposed to incoming steam. The apparatus comprises a pneumatically actuated condensate drain valve which is controlled by a solenoid valve and opens to drain condensate if it reaches a dangerously high level, an alarm to indicate when the high level is reached, a recorder to provide a continuous permanent record of condensate level and drain valve status, and an electric control system for sensing condensate level and operating the solenoid valve, the alarm and the recorder in accordance therewith. The electric control system includes a condensate level sensor in the form of a one or more float-operated magnetically-responsive reed switches mounted in the retort. The sensor comprises a hollow stem in which a reed switch is potted in elastomeric non-displaceable material. In one embodiment the control system employs two reed switches and two relays and the drain valve opens when the condensate reaches an upper level and closes when it reaches a lower level. In another embodiment the control system employs one reed switch and a time-delay relay to prevent the drain valve from opening unless the condensate level remains high for a certain length of time. The apparatus is fail-safe in that the drain valve opens if its pneumatic or electric power supplies fail. A thermocouple may be mounted in the sensor to provide temperature indications to the recorder.
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