| 摘要 |
An inductively operated apparatus for heating plastic materials in extruders or for other purposes has a heat-transmitting housing with one or more passages for the material or materials to be heated, and an arrangement for heating the housing. The heating arrangement employs a laminated core with two legs which are magnetically coupled to the housing with the interposition of distancing elements of heat insulating material. The core is surrounded by an exciting coil. In order to prevent overheating of the coil, the heating arrangement further comprises at least one barrier which is interposed between the core and the core and is cooled by one or more streams of a gaseous or liquid coolant, such as water. The barrier can be constituted by a flat tube which is convoluted around the core and supports the coil. A second barrier can be placed around the coil so that the latter is received between two barriers. Alternatively, the barrier can employ a vessel which confines the coil, and a fluid-conveying conduit which draws heat from the vessel. |
