| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve the problem that useless heat discharge is caused because water supplied in a supply water preheater is likely to be overheated at closed drain recovery in a small one-through boiler and closed drain recovery is made difficult. <P>SOLUTION: Closed drain recovery is enabled, wherein the pumpless closed drain recovery device prevents supply water in a supply water preheater from being overheated by continuously supplying steam drain when each electromagnetic valve opens during constant pressure supply based on a water level difference, low combustion, and high combustion. <P>COPYRIGHT: (C)2013,JPO&INPIT |
