| 摘要 |
<p>A cast aluminum body has a plurality of stainless steel conduits and an electrical heating element cast therein. Water is circulated through one of the conduits, and the fluid to be heated is circulated in the remaining conduits. The electrical heating element heats the aluminum casting in response to a signal created by a heat sensor located in the fluid to be heated. As the temperature of the aluminum casting rises, the heat will be transferred from the aluminum to the conduits and then to the fluid passing through the conduits. In this regard, the casting of the conduits in the aluminum body results in a very intimate contact between the cast aluminum and stainless conduits which provides very efficient heat transfer. When the fluid to be heated attains the desired temperature, the sensor deenergizes the heating element. The water circulating through one of the conduits and the aluminum body act as a heat sink to substantially eliminate any undesirable heating of the aluminum body after the heating element is shut off.</p> |
