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Ashish Kumar Patel (Assistant Professor)

Mechanical Engineering DepartmentLovely Professional University

A steam boiler is a closed vessel made of steel whosefunction is to transfer heat produced by combustion of fuel towater to produce steam.

The steam so produced may be supplied:

a) To a steam engine or steam turbine

b) For industrial process work in sugar factories, cotton millsetc.

c) For heating installations.

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Ashish Kumar Patel (Assistant Professor)

Mechanical Engineering DepartmentLovely Professional University

a) Fire tube and water tube boilers

b) Horizontal, vertical and inclined

c) Externally fired and internally fired

d) Locomotive, marine, stationary and portable

e) Natural Circulation and forced circulation

8/22/2019 16776 Boileboiler pptrs

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Ashish Kumar Patel (Assistant Professor)

Mechanical Engineering DepartmentLovely Professional University

Fire Tube Boilers Water Tube Boilers

Hot gases inside the tubes and water outside the

tubes

Water inside the tubes and hot gases outside the

tubes

Generates steam up to pressure 24 bar Generates steam up to pressure 162 bar

Steam production rate= 9000 kg/hr Steam production rate= 45 x 104 kg/hr

Max Steam temperature=340 C Max Steam temperature=560 C

Poor water circulation Good water circulation

Occupies more floor area for a given power Occupies less floor area for a given power

Operating cost is less Operating cost is more

8/22/2019 16776 Boileboiler pptrs

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Ashish Kumar Patel (Assistant Professor)

Mechanical Engineering DepartmentLovely Professional University

Maximum rate of production:2500kg/hr

Pressure limit:7.5 to 10 bar

8/22/2019 16776 Boileboiler pptrs

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Ashish Kumar Patel (Assistant Professor)

Mechanical Engineering DepartmentLovely Professional University

Shell dia: 2.75 mHeight: 5.78 mEvaporative/Steam capacity:3500kg/hr(Max.4000 kg/hr)

Max. pressure:20 barEfficiency:70 to 75%

Advantages:a) Used where space is limited as it takes up small floor space.b) Boiler is self-contained.

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Ashish Kumar Patel (Assistant Professor)

Mechanical Engineering DepartmentLovely Professional University

Barrel Length: 5.21 mDiameter: 2.1 mDia of ordinary tube: 5.72 cmDia of superheating tube: 14 cmNo. of ordinary tubes:116

No. of superheating tubes:38Evaporative/Steam capacity: 9350kg/hrCoal Burnt: 1750 kg/hrMax. pressure:14.2 barEfficiency:70 %

Advantages:a) Compactnessb) High Steaming capacityc) Portabilityd) Fair economy

Disadvantages:a) Large flat surface requires sufficientsupporting

b) Corrosion in water legsc) It is difficult to clean inside

Specification of a locomotive boiler manufactured by Chittaranjan Locomotive works

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Ashish Kumar Patel (Assistant Professor)

Mechanical Engineering DepartmentLovely Professional University

No. of flue tubes: OneDiameter of shell: 1.25 to 1.75 mLength of shell: 4 to 7 mSteam capacity: 6500kg/hrPressure of steam:10.5 bar

The advantage possessed by this type of boiler is that the sedimentcontained in the water falls to the bottom, where the plates are notbrought into contact with the hottest portion of the furnace gases.

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Ashish Kumar Patel (Assistant Professor)

Mechanical Engineering DepartmentLovely Professional University

No. of flue tubes: TwoDiameter of shell: 2 to 3 mLength of shell: 8 to 9.5 mSteam capacity: 9000kg/hrPressure of steam:16 bar

This boiler is still used in industry, on account of its simplicity of design,reliability and freedom from maintainance costs for repairs and tuberenewals.

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Ashish Kumar Patel (Assistant Professor)

Mechanical Engineering DepartmentLovely Professional University

Diameter of drum: 1.22 to 1.83 mLength : 6.096 to 9.144 mSteam capacity: 40000kg/hr(max)Pressure of steam:40 bar(max)Efficiency: 60 to 80%Angle of inclination of water tubesto horizontal: 15

8/22/2019 16776 Boileboiler pptrs

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Ashish Kumar Patel (Assistant Professor)

Mechanical Engineering DepartmentLovely Professional University

8/22/2019 16776 Boileboiler pptrs

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Ashish Kumar Patel (Assistant Professor)

Mechanical Engineering DepartmentLovely Professional University

Modern high pressure boilers employed for power generationare for steam capacities 30 to 650 tonnes/hr and above witha pressure upto 160 bar and maximum steam temperature of

above 540C.Unique features of high pressure boilers:

1. Method of water circulation

2. Type of tubing

3. Improved method of heating

8/22/2019 16776 Boileboiler pptrs

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Ashish Kumar Patel (Assistant Professor)

Mechanical Engineering DepartmentLovely Professional University

Modern high pressure boilers employed for power generationare for steam capacities 30 to 650 tonnes/hr and above witha pressure upto 160 bar and maximum steam temperature of

above 540C.Unique features of high pressure boilers:

1. Method of water circulation

2. Type of tubing

3. Improved method of heating

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Ashish Kumar Patel (Assistant Professor)

Mechanical Engineering DepartmentLovely Professional University

These boilers have been built to generate 45 to 50 tonnes ofsuperheated steam at a pressure of 130 bar and at atemperature of 500C.

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Ashish Kumar Patel (Assistant Professor)

Mechanical Engineering DepartmentLovely Professional University

Steam generation capacity:100tonnes/hourOperating pressure: 140 bar

This boiler can carry higher salt concentrations than any othertype and is more compact than indirectly heated boilers havingnatural circulation. These qualities fit it for land or sea transportpower generation.

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Ashish Kumar Patel (Assistant Professor)

Mechanical Engineering DepartmentLovely Professional University

Max. working pressure:500 atmMax steam temp.: 650CSteam generationcapacity: 150 tonnes/hr

It eliminates the latent heat of water by first compressing thefeed to a pressure of 235 bar, it is then above the criticalpressure and its latent heat is zero.

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Ashish Kumar Patel (Assistant Professor)

Mechanical Engineering DepartmentLovely Professional University

The size of the velox boiler is limited to 100 tonnes/hr because600 B.H.P is required to run the air compressor at this outputas power developed by the gas turbine is not sufficient to runthe compressor.