| 摘要 |
<p>PURPOSE:To provide the title process for preventing the flowing water in the tubes from freezing to aviod lowering in the heat transfer efficiency, also preventing the tube damage, by heating the liquefied petroleum gas in the shell through the flowing water (a heating medium) with concurrent flow of air. CONSTITUTION:Liquefied petroleum (LP) gas is fed, through the inlet 2, to the shell of a vertical type multitubular heat exchanger 1, while the water as a heating medium is supplied, through another inlet 3, to the tubes. Air is fed, through a pipe 5, to the heat exchanger 1 in such a way as to charged to be each of the tubes 4. The LP gas is then subjected to heat exchange, through the walls of the tubes 4, with the water flowing down with air bubbles in it. The air may be fed only in the case of water flow decrease due to freezing. Even if the water should freeze, the air bubbles could offset the expansion caused by the freezing, thus protecting the tubes from damage or fracture. The air quantity required for charging to the water is only 0.09 m<3>/hr or more (in the case of a tube of 20 mm diameter)</p> |
