US 4,031,950 AGranted

Process fluid circulation and temperature control system

AssigneeApplication Engineering Corporation

InventorGilbert F. Shultz

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Abstract

A process liquid circulation and temperature control system including a pump for circulating water or other process liquid through a path including a heating unit, a cooling unit, and a process apparatus that is returned to the pump; the pump and the heating and cooling units are actuated in response to temperature/pressure variations sensed at the return from the process apparatus and at the delivery thereto. One pressure control measures the differential pressure across the pump and inhibits system operation except when the differential exceeds a predetermined magnitude in a given direction; another pressure control inhibits operation if the return pressure falls below a given threshold; a circuit that determines .DELTA.P/T prevents boiling of the process fluid. For both temperature and pressure controls, the delivery and return sensors are calibrated to match each other on system start-up.

Claims21

Dependent claims

A process fluid circulation and temperature control system comprising:

a main heat exchange means, electrically actuatable between an active heat-exchange condition and an inactive condition, for effecting a heat exchange with a process fluid;
a pump for circulating a process fluid through the heat exchange means and through an external process apparatus that utilizes the process fluid to effect a second heat exchange;
a thermal sensor for sensing the temperature of the process fluid at a given point on its circulation path;
temperature control circuit means, coupled to the thermal sensor and to the heat exchange means, for actuating the heat exchange means between its active and inactive operating conditions in response to changes in the temperature of the process fluid;
a delivery pressure sensor for sensing the pressure of the fluid delivered to the process apparatus to develop a delivery pressure signal;
a return pressure sensor for sensing the pressure of the fluid returned to the pump to develop a return pressure signal;
and pressure differential control circuit means, coupled to both pressure sensors and to the temperature control circuit means, for inhibiting actuation of the heat exchange means to its active condition except in the presence of a differential of predetermined sign and amplitude between the delivery pressure signal and the return pressure signal.

4 more elements

A temperature and pressure control for a process fluid circulation control system of the kind including a heat exchanger electrically actuatable between an active heat-exchange condition and an inactive condition, for effecting a heat exchange with a process fluid, and a pump for circulating a process fluid through the heat exchange means and through an external process apparatus that utilizes the process fluid to effect a second heat exchange, the control comprising:

a thermal sensor for sensing the temperature of the process fluid at a given point on its circulation path;
a delivery pressure sensor for sensing the pressure of the fluid delivered to the process apparatus to develop a delivery pressure signal;
a return pressure sensor for sensing the pressure of the fluid returned to the pump to develop a return pressure signal;
temperature control means, coupled to the thermal sensor and to the heat exchange means, for actuating the heat exchange means between its active and inactive operating conditions in response to changes in the temperature of the process fluid relative to a preset temperature;
and pressure differential control means, coupled to both pressure sensors and to the temperature control means, for inhibiting actuation of the heat exchange means to its active condition except in the presence of a differential of predetermined sign and amplitude between the delivery pressure signal and the return pressure signal.

2 more elements

Dependencies are inferred from the claim text.