Boiler maintenance And inspection
Boiler maintenance And inspection Shows The quality of the water used within the boiler cycle is very important . Higher pressure boilers require higher quality water . Maintaining the recommended feed water and boiler water quality limits will insure more reliable and increase unit availability.
Typical arrangement of the pre-boiler water treatment equipment:-
1.pre-boiler water treatment:-used to remove the contaminates in the raw feed water.
2.clarification:-the addition of chemicals to assist in the setting out of suspended solids.
3.filtration:- used to kill the organics in the water and to remove the finer suspended material.
4.demineralization:-used to remove the dissolved solids (various cations and anions) in the feed water.
5.dearation:-to remove the bulk of free oxygen in the feed water.
6.addition of hydrazine:-an oxygen scavenger used for additional free oxygen removal.
7.addition of ammonia:-to increase the PH of the feed water between 8.5 and 9.5.
8.condensate treatment:-to purify the condensate returns for boiler feed water usage.
9.condensate polishing:-to remove the bulk of the contaminates such as metal oxides which have been entrained in the condensate.
You can also Read Valves, Piping and Pipelines Handbook, 3rd Edition
Chemical cleaning:-
The purpose of chemical cleaning is to remove any internal deposits within the boiler and therefore reduce the possibility of down time due to tube failures. Periodic chemical cleaning should become a part of a preventive maintenance program.
Methods of determining when chemical cleaning is necessary:-
1.Tube failure:-an analysis of the cause for the tube failure could indicate the need for chemical cleaning. This is a highly undesirable method of determination.
2.Periodic tube sample analysis:-the analysis could indicate the need for chemical cleaning prior to tube failures.
3.Chordal thermocouples:- the increase in external surface metal temperature during operation could be used to gauge the build-up of internal deposition.
Comments are closed.