BOILERSPREPARED BY:- MASOOD-UR-REHMANTECHNICAL TRAINING CENTER

COURSE INTENTIONSTHIS COURSE HAS BEEN PREPARED TO INTRODUCE THE MECHANICAL MAINTENANCE PERSONNEL, INVOLVED IN MAINTENANCE OF BOILERS, ABOUT THE BOILER BASICS, CONSTRUCTION AND THEIR WORKINGSPECIAL CONSIDERATION HAS BEEN GIVEN TO B-605 AND B-601/B-602

COURSE OUTLINESINTRODUCTION TO BOILERSAUXILIARY BOILER B-605WASTE HEAT BOILER B-601/B-602AUXILIARY BOILER B-4601FIRE TUBE BOILERSTERMINOLOGIES USEDMAIN COMPONENTSBOILER MAINTENANCE HISTORYWATER TREATMENT TECHNIQUES

INTRODUCTION TO BOILERS

WHAT IS A BOILER ?THE BOILER IS A CLOSED HIGH PRESSURE VESSEL IN WHICH HEAT CHANGES WATER INTO STEAM.BOILERS ARE WIDELY USED IN INDUSTRY FOR PRODUCTION OF HOT WATER AND STEAM

WHY WE USE WATER IN A BOILER ?THE REASON BEING:NON-TOXIC, HAZARDOUS OR COMBUSTIBLEWATER IS A CHEAP MEDIUMAVAILABLE EVERYWHEREBOILS AT RELATIVELY LOW TEMPERATUREON BOILING IT VOLUME INCREASES ABOUT 1600 TIMES

CLASSIFICATION OF BOILERSTHERE ARE TWO MAJOR CLASSIFICATION OF BOILERSFIRE TUBE BOILERSWATER TUBE BOILERS

FIRE TUBE BOILERSWHEN BOILER WATER IS ON THE SHELL SIDE OF THE BOILER IT IS CALLED FIRE TUBE BOILER

ADVANTAGES OF FIRE TUBE BOILERLOW INITIAL COSTFUEL EFFICIENTEASIER TO OPERATELOW PRESSURE AND TEMPERATURE UNITSLOW CAPACITYLOW INITIAL COSTDISADVANTAGESPACKAGED DESIGN

LIMITATIONSHIGH PRESSURES ARE DANGEROUSPOOR CIRCULATIONTUBE LEAKAGES AT HIGH TEMPERATURES

WATER TUBE BOILERSWHEN BOILER WATER IS ON THE TUBE SIDE OF THE BOILER IT IS CALLED WATER TUBE BOILER

TYPICAL WATER TUBE BOILER

ADVANTAGES OF WATER TUBE BOILERHIGH CAPACITYHIGH PRESSURES AND TEMPERATURESGOOD EFFICIENCYHIGH MAINTENANCE COSTSHIGH INITIAL COSTOPERATIONAL DIFFICULTIESDISADVANTAGES

OTHER CLASSIFICATION CRITERIAFUEL USED COAL, OIL OR GASPRESSURE HIGH, MEDIUM AND LOW PRESSURE BOILERSFIRING METHOD FIRED OR UNFIRED BOILERSFURNACE TYPE NATURAL, INDUCED OR FORCED DRAUGHT WATER CIRCULATION NATURAL OR FORCED CIRCULATION

BASIC TERMINOLOGIES CONDUCTIONCONVECTIONTHERMO-SIPHONRADIATIONHEATING SURFACEBOILER CAPACITYBOILER BLOW DOWNDE-AERATIONCONVECTION SECTION

CONDUCTION

A METHOD OF HEAT TRANSFER IN WHICH HEAT IS TRANSFERRED FROM ONE POINT TO ANOTHER WITHOUT ACTUAL MOVEMENT OF MOLECULES

CONVECTION

CONVECTION IS THE MODE OF HEAT TRANSFER IN WHICH HEAT IS TRANSFERRED FROM ONE LOCATION TO THE OTHER THROUGH MOVEMENT OF MOLECULES

RADIATION

A METHOD OF HEAT TRANSFER THAT DOES NOT REQUIRE ANY MEDIUM OR MOLECULES FOR HEAT TRANSFER

THERMO-SIPHON

THE FLOW OF WATER (OR ANY LIQUID) FROM A LOWER ELEVATION TO A HIGHER ELEVATION DUE TO DIFFERENCE IN TEMPERATURE AT TWO LOCATIONS

BOILER CAPACITY

IS THE QUANTITY OF STEAM PRODUCED PER HOUR AND IT SHOWS IT SIZE. IT IS ALSO THE QUANTITY OF WATER EVAPORATED IN ONE HOUR. IT IS REPRESENTED IN TONNES PER HOUR

HEATING SURFACE AREA

REFERS TO THE TOTAL AREA EXPOSED TO HOT COMBUSTION GASES

CONVECTION SECTION

IS THE SECTION OF THE BOILER WHERE HEAT IS TRANSFERRED TO THE MEDIUM THRU CONVECTION

BLOW DOWN

IS THE DRAINAGE OF WATER FROM A BOILER TO REDUCE THE LEVEL OF IMPURITIES AND REPLACING IT WITH BETTER QUALITY WATER

DE-AERATION

DE-AERATION IS THE REMOVAL OF DISSOLVED GASES ESPECIALLY OXYGEN FROM THE DEMIN. WATER. THESE GASES (ESPECIALLY OXYGEN) CAUSE CORROSION INSIDE THE BOILERS AT HIGH TEMPERATURES

MAIN PARTS OF A BOILERBOILER FURNACEBURNERSSTEAM DRUMBOILER BANK TUBESSUPERHEATERECONOMIZERFURNACE DRAUGHT SYSTEM

BOILER FURNACE

THE SECTION OF THE BOILER WHERE FUEL IS BURNED TO GENERATE HEAT. HEAT IS TRANSFERRED TO MEDIUM THRU RADIATION IN THIS SECTION

BURNERS

THEY ARE LOCATED IN THE VERTICAL WALL OF THE COMBUSTION CHAMBER AND BURN FUEL.BURNERS ARE DESIGNED FOR EFFICIENT BURNING OF THE FUEL AND MAINTAIN HIGH EFFICIENCY.

STEAM DRUM

STEAM DRUM IS A HIGH PRESSURE VESSEL WHICH SERVES MANY FUNCTIONS IN A BOILER SUCH AS A LARGE RESERVOIR FOR BOILER FEED WATER, CENTER FOR WATER DISTRIBUTION AND SATURATED STEAM COLLECTING AND SUPPLY TO SUPERHEATER.

BOILER BANK TUBES

THIS IS A BUNCH OF TUBES CONNECTED TO STEAM DRUM (AND LOWER DRUM) AND FALLS IN THE CONVECTION ZONE OF THE BOILER.THE WATER PARTIALLY EVAPORATES IN THE BOILER BANK TUBES. IT CONTAINS RISERS AND DOWN-COMERS.

SATURATED STEAM FROM THE STEAM DRUM RISES THRU DEMISTER PADS AND ENTERS INTO A SERIES OF TUBES WHICH ARE LOCATED IN THE BOILER FURNACE RADIANT SECTION OR IN CONVECTION SECTION BEFORE ENTERING BOILER SECTION.SUPERHEATER

ECONOMIZER IS A STEEL TUBE BANK PLACED AT THE OUTLET OF THE BOILER SECTION IN THE WAY OF FLUE GASES BEFORE THEY EXIT. ECONOMIZER

FURNACE DRAUGHT SYSTEMIT REGULATES THE FLOW OF AIR TO AND FROM THE BURNER AND PROVIDES ENOUGH AMOUNT OF OXYGEN REQUIRED FOR COMBUSTION IT ALSO FORCES OUT COMBUSTION GASES OUT OF THE FURNACE TO THE EXHAUST DUCT.A FORCED DRAFT SYSTEM USES A FAN TO FORCE (OR PUSH) AIR THROUGH THE FURNACEAN INDUCED DRAFT SYSTEM USES A FAN TO DRAW (OR PULL) AIR THROUGH THE FURNACE.BALANCED DRAFT SYSTEM IS SOMETIMES USED WHICH UTILIZES BOTH FORCED AND INDUCED DRAFT FANS.