In order to ensure the internal cleaning of the heating surface and to ensure the qualified steam-water quality, the scheduled blowdown to the boiler shall be conducted.

There are two kinds of blowdown devices:

1.Continuous blowdown device: installed inside the boiler drum for draining the suspended matters in the boiler water in order to maintain the rated saltness and ensuring good steam-water quality.

2.Periodic blowdown device: installed at the bottom of the lower header of the water-cooled wall for draining the sediment materials from the lower header, in order to quickly adjust the boiler water quality and to replenish the insufficiency of continuous blowdown. When the boiler water quality is poor， the numbers of times of blowdown shall be increased.

3.The continuous blowdown shall be controlled and adjusted by the chemical water treatment persons, before adjustment the stoker shall be informed. The periodic blowdown shall be operated by the operator once in a day and shall be monitored by the chemical water treatment person.