| 摘要 |
An apparatus and method for automatically blowing down a boiler are disclosed, wherein the discharged sediment-containing water is drawn off to an intermediate receiver or holding tank for a short interval and then sent through a heat exchanger which is isolated for the boiler. The condition of the water in the boiler is continuously monitored by conductivity sensors to begin each blowdown cycle when the conductivity reaches a predetermined level. A three-way valve connected to the bottom blowdown line of the boiler is opened automatically and the blowdown water is forced out of the boiler under the steam pressure to the receiver and sent by means of the same valve to a heat exchanger. This is accomplished by allowing steam from the boiler to enter the receiver to displace the blowdown water, and sweep non-condensibles therefrom. The flow of blowdown water through the heat exchanger is strictly regulated to meet design requirements and at the same time, the receiver tank is isolated from the boiler and fresh water is introduced into the boiler to replace that which was removed by the blowdown. The method is applicable to installation on a multi-boiler system.
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