| 摘要 |
PURPOSE:To make it easy to replace a cleaning tool and to inspect the inside of a tube, by easily detaching a stopper plate, by making the stopper plate to keep the cleaning tool from coming off, of shape memory alloy. CONSTITUTION:A tool holder 3 is built in the end of a tube 1 by inserting the end of a holder 3 into the end of the tube 1. The critical temperature of a ring 4 made of shape memory alloy is below normal ambient temperature. The ring 4 remembers the shape that is enough to expand the end of the holder 3 from inside and enable it to pressedly fit and fix to the inner diameter of the tube 1 at the room temperature. A stopper plate 5 provided at the outside end of a holder 3 keeps a cleaning tool 6 such as a brush in the position so as not to come off. The stopper plate 5 is made of shape memory alloy. It has considerablly higher critical temperature than the temperature during operating time of a heat exchanger. It remembers its reduced shape so that it is fitted and is held by the holder 3 at the operating temperature, and it becomes a reduced shape so as to come off from the holder 3 as shown by 5' in the figure, when it is heated up exceeding the critical temperature. |
