| 摘要 |
The heater comprises sheet casing(s) (2) which can be formed to tubular shape. Each sheet includes a mounting groove (3) for flexible tubular electrical heater (4). The latter has its own casing containing the heater conductor and insulant filling. This laid- or pressed in. End closures (5, 6) leave preferably axially, from one or both edges. A closure device holds the tubular casing in shape, o tensions it around the nozzle. Preferred features: The casing sheet has a greater thickness than the diameter or cross section of the heater (4), a part o which may protrude out of the groove. The groove formation is dovetailed in cross section, to accept the pressed-in heater. The casing is a good thermal conductor. The groove opens into the interior of the tubular casing. A clamping band or collar closes t cylinder, placed around the casing, bridging over the butted join. Parts forming the casing have a hinge-like connection. Each h separate heater in its mounting groove. |
