| 摘要 |
A smoke generator in which a supply of smoke making fluid is caused to pass cyclically down tubing (20). In a heat exchanger, an electrical current is passed along the tubing to heat the tubing and a sensor (54) is arranged to sense the tube temperature. Electrical power is controlled to heat the tubing cyclically so that fluid in the tubing is burnt off, every cycle of the power being switched on or off, thus reducing clogging. |
