Boiler blowdown will be a really essential aspect of almost any water treatment application. Boiler blowdown has function to control content level of impurities in boiler water. Determination amount of boiler blowdown is crucial: very much will leads to high cost of chemical water treatment and energy loss; very little will leads to too much content level of impurities. There are not specific rules to regulate amount of boiler blowdown due to variation in quality of water may differ from one location to other location. It may range from 1% until 25% according to the flow of feedwater.
Blowdown could be performed intermittently or continuously. Boiler blowdown can be performed either from the bottom of steam drum, header, or mud drum, or it could be performed from the base of steam boiler. The following are several principles to assist determine an efficient boiler blowdown application:
- For boiler with fire tube type, blowdown may be done either intermittently or continuously. It could be blown down through the base of boiler. Timeframe, rate of recurrence, and type be determined by operating conditions, design boiler, and the kind of water treatment system.
- For steam boiler which has drum type, the content level of water must be regulated through blowdown via steam drum. Continuous boiler blowdown is definitely recommended.
- Likewise in steam boiler with drum type, blowdown through bottom header or mud drum will perform removal of suspended solids in steam boiler. Attempting to manage the content level of impurities through blowdown from this place could result in a serious interruption of water circulation and leading to deterioration to steam boiler. If bottom blowdown is performed, it must be in quick timeframe or intermittent. This condition is established by operating conditions, design boiler, and also the deposition rate of suspended solids.