| 摘要 |
<p>An in-line electric heater for heating fluids, such as paint, moving in a conduit has a thermally conductive massive body in which is formed a fluid passage having an inlet port and a outlet port. An electric heating element in the body directly heats only the upstream portion of the fluid passage and heater body. The downstream portion of the fluid passage and heater body is indirectly heated to a substantially lesser temperature by heat conduction from the upstream portion whereby the downstream portion acts as a "thermal accumulator" which damps the cycling, overshoot and undershoot of the temperature of the fluid at the outlet port of the passage. A temperature control means for controlling operation of the heating element is provided and includes a temperature sensor arranged to sense the temperature of the proximate the point in the passage wherein the fluid exhibits its greatest temperature cycling excursion, undershoot and overshoot under constant flow conditions, thereby providing optimum feedback control.</p> |
