Boiler Instrumentation and Controls

[seminar surveyer]

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Industrial Boilers

Steam generators
Closed vessels
made of steel and
used for generation of steam
vaporizing water
combustion of fuels
eg. coal,coke,oil,wood,saw dust and begesse etc.
Steam used for producing power,for industrial process work or for heating proposes.

Requirements of a Perfect Steam Boilers

Should be absolutely reliable,capable of producing maximum steam at required pressure for minimum of fuel consumption,with minimum attention and minimum initial cost and operating cost.
Simple constructions
Quick starting from cold
Strong enough against temp. stress & strains
Well design combustion chamber
Less floor area, space & light weight
Best gauges,safety valves and other mountings
Easily accessible for inspection,cleaning and repairs

Classification of Steam Boilers

Vertical or Horizontal
Stationary(Power plant,industrial,central heating and combined power and heating boilers.),Portable,Locomotive or Marine
Internally Fired or Externally Fired (Lancashire and Locomotive Boilers)
Solid,Liquid or Gas Fired
Fire(Smoke)Tube:Water is outside the tubes while the hot gases are inside the tubes eg.Vertical,Cochran,Lancashire,Cornish,Locomotives,etc) or Water Tube: Contain a large number of small tubes through which water circulates,the fire and hot gases being outside of the tubes.eg.Babcock and Wilcox, Stirling and High pressure Boilers etc.)

Vertical Boilers
Used in small factories,small water supply plants,cranes,excavators,winch engines in mines and on sites of temporary nature such as construction work etc.
Required minimum floor space,not required elaborate foundations,and is portable.
Cheap,easy to start but inefficient due to large wastage of fuel and less heating surface.
Vertical Boilers are:Simple(having one to three cross tubes), fire tubes and water tubes types.


for more:
http://docs.googleviewer?a=v&q=cache:Z_y...3kyZOX9RKA

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