WHAT IS A BOILER?WHAT IS A BOILER?
Boiler is an apparatus to produce Boiler is an apparatus to produce steam .Thermal released by steam .Thermal released by combustion of fuel is transferred combustion of fuel is transferred to water which vaporizes and gets to water which vaporizes and gets converted into steam at a desired converted into steam at a desired pressure and temperature.pressure and temperature.
FEATURES OF A FEATURES OF A BOILERBOILER
1.1. SAFETYSAFETY
2.2. ACCESSIBILITYACCESSIBILITY
3.3. CAPACITYCAPACITY
4.4. EFFICIENCYEFFICIENCY
5.5. COSTCOST
6.6. CONSTRUCTIONCONSTRUCTION
TYPES OF BOILERSTYPES OF BOILERS
ACCORDING TOACCORDING TO FLOW OF WATER AND HOT GASESFLOW OF WATER AND HOT GASES POSITION OF FURNACEPOSITION OF FURNACE POSITION OF PRINCIPAL AXISPOSITION OF PRINCIPAL AXIS APPLICATIONAPPLICATION CIRCULATING WATERCIRCULATING WATER STEAM PRESSURESTEAM PRESSURE
FLOW OF WATER AND FLOW OF WATER AND HOT GASESHOT GASES
1.1.WATER TUBE BOILER WATER TUBE BOILER Water circulates through tubes . Water circulates through tubes .
Hot products of combustion flow Hot products of combustion flow over these tubes.over these tubes.
2.FIRE TUBE BOILER2.FIRE TUBE BOILER Hot combustion gases flow through Hot combustion gases flow through
the tubes . Water surrounds the the tubes . Water surrounds the tubes.tubes.
BABCOCK AND WILCOX BABCOCK AND WILCOX BOILERBOILER
It’s a water tube It’s a water tube boiler . It consists boiler . It consists of a drum , super of a drum , super heater ,headers , heater ,headers , tubes etc.tubes etc.
COCHRAN BOILERCOCHRAN BOILER
It’s a fire tube boiler . Its a It’s a fire tube boiler . Its a vertical boiler, has a lesser vertical boiler, has a lesser space . Flue gases escape to space . Flue gases escape to atmosphere after passing through atmosphere after passing through smoke box and stack.smoke box and stack.
POSITION OF FURNACEPOSITION OF FURNACE
INTERNALLY FIREDINTERNALLY FIRED EXTERNALLY FIREDEXTERNALLY FIRED
Internally fired boilers the grate Internally fired boilers the grate combustion the grate combustion combustion the grate combustion chamber are enclosed within chamber are enclosed within boiler shell.boiler shell.
POSITION OF PRINCIPAL POSITION OF PRINCIPAL AXISAXIS
VERTICALVERTICAL HORIZONTALHORIZONTAL INCLINEDINCLINED
SCOTCH MARINE SCOTCH MARINE BOILERBOILER
It’s a fire tube It’s a fire tube boiler . It is of 2 boiler . It is of 2 types:types:
1.Single ended 1.Single ended
2.Double ended2.Double ended
CIRCULATION OF WATERCIRCULATION OF WATER
Natural circulationNatural circulation Forced circulationForced circulation
STEAM PRESSURESTEAM PRESSURE
Low pressureLow pressure Medium pressureMedium pressure High pressureHigh pressure
HIGH PRESSURE HIGH PRESSURE BOILERBOILER
Boiler pressure is 250 kg per sq . Boiler pressure is 250 kg per sq . CmCm
And steam temperature is 550 And steam temperature is 550 degree centigrade. It is a water degree centigrade. It is a water tube boiler.tube boiler.
BOILER MOUNTINGS BOILER MOUNTINGS AND ACCESSORIESAND ACCESSORIES
Mountings are the Mountings are the components used components used for the safety of for the safety of the boiler.the boiler.
Ex-feed pump , Ex-feed pump , speed check speed check valve etc.valve etc.
THERMAL EFFICIENCY THERMAL EFFICIENCY OF BOILEROF BOILER
It is defined as the ratio of heat It is defined as the ratio of heat actually utilized be water in actually utilized be water in generation of steam to the heat generation of steam to the heat supplied during the combustion of supplied during the combustion of fuel.fuel.
Efficiency=W(H2-H1)/W1*CVEfficiency=W(H2-H1)/W1*CV
BOILER MAINTENANCEBOILER MAINTENANCE
Regular Regular maintenance and maintenance and careful careful supervision of supervision of working of working of various various components components result in efficient result in efficient operationoperation