What is boiler blow down? why it is needed?

Blow down of the boiler is done to remove scum and bottom deposits. This means that blow down is done either for scum or for bottom blow down.

The reasons for boiler blow down are:

• In case of pollution from sea water, regular blow down is necessary to low the chloride level
• To remove excess water in case of emergency
• To remove solid particles, dirt, foam or oil molecules from the boiler water. This is mainly done by scum valve and the procedure is known as “scumming.”
• To remove the precipitates formed as a result of chemical addition to the boiler water.