摘要 |
A small heat exchanger can efficiently exchange heat, and can be produced at low cost in comparison with a conventional heat exchanger. In the heat exchanger, a heat-transfer tube can be easily replaced so that the heat exchanger can be used for a treatment which requires a low flow rate. A heat-transfer tube produced in the form of a coil is attached to, for example, a lower closing portion and an inner tube, which are integrally produced. The heat-transfer tube is pulled in the U-direction to reduce the diameter of the coiled portions and, thus, is closely bonded or welded to the inner tube. An outer tube and an upper closing portion are attached so that there is a slight gap between the outer tube and the outer diameter of the heat-transfer tube.
|