| 摘要 |
<p>The preheater is intended for burners whose oil flow is controllable by a thermostat in accordance with the heat demand. The preheater has a relatively short electric flow heater with inlet and outlet, whose flow tube surrounds concentrically a tubular heating element. In the element circuit is incorporated a triac as a power switch. The switch power terminals are controlled by a phase control, mounted in a common housing with the flow heater. The phase control is regulated by a temperature dependent semi- conductor resistor, coupled to the flow tube. Pref. the flow heater consists of a single flow tube of appropriate curvature, surrounding the tubular heating element. The flow heater may consist of several sections, each with its own tubular heating element section. At the open ends of the flow sections may be connected tubular members for fixing the protruding ends of the tubular heating element sections.</p> |
