| 摘要 |
An electric heating element comprises a plurality of electrically non-conducting support segments 23, each segment being moveably connected 25,26 to two neighbouring segments and capable of one dimensional motion in respect thereto, the outer surface of each segment including a helical ridge 27, the ridges of neighbouring segments co-operating together to form a helical channel. A resistance wire 21 comprises a first electrically resistive wire heating portion helically wound about the support within said helical channel, the segments defining a further channel 28 along the axis of the helix, said further channel retaining a second electrically resistive wire heating portion spatially separated from the first resistive wire portion and acting as the return path. The segments may be ceramic and the assembled element may be inserted into a curved tube (fig5,6) which mounts into an immersion heated tank. |
