A. prevent the bulging of flat surfaces
B. avoid explosion in furnace
C. prevent leakage of hot flue gases
D. support furnace freely from top
E. prevent atmospheric air leaking into furnace
Related Mcqs:
- Boiler stays are used to___________________?
A. prevent flat surfaces under pressure from tearing apart
B. take care of failure in shear
C. take care of failure in compression
D. provide support for boiler
E. provide foundation of boiler - Pick up the correct statement as regards Cornish boiler and Lancashire boiler _______________?
A. cornish is fire tube and lancashire is water tube
B. cornish is water tube and lancashire is fire tube
C. cornish has two fire tubes and lancashire has one
D. lancashire has two fire tubes and cornish has one
E. both have two fire tubes - The difference between cornish boiler and lancashire boiler is that_________________?
A. former is fire tube type and latter is water tube type boiler
B. former is water tube type and latter is fire tube type
C. former contains one fire tube and latter contains two fire tubes
E. none/of the above - The size of a boiler drum in pulverised fuel fired boiler,as its size and capacity, (steam pressure and flow ratings) increase __________________?
A. increases
B. decreases
C. remains unchanged
D. increases/decreases depending on steam temperature requirements
E. unpredictable - For the same diameter and thickness of tube, a water tube boiler compared to a fire tube boiler has ____________________?
A. more heating surface
B. less heating surface
C. equal heating surface
D. heating surface depends on other parameters
E. none of the above - Latent heat of dry steam at atmospneric pressure is equal to____________________?
A. 539 kcal/kg
B. 539 BTU/lb
C. 427 kcal/kg
D. 100 kcal/kg
E. 471 kcal/kg - Tertiary air is the air used to____________________?
A. provide air around burners for obtaining optimum combustion
B. transport and dry the coal
C. cool the scanners
D. supply air for ignitors
E. convert CO (formed in lower zone of furnace) into C02 at higher zone - The function of injector used in small capacity boilers is to____________________?
A. create vacuum
B. inject chemical solution in feed pump
C. pump water, similar to boiler feed pump
D. add make up water in the system
E. none of the above - The fire tubes in, a Coarran and Scotish marine boiler are_________________?
A. horizontal
B. vertical
C. inclined
D. both horizontal and vertical
E. horizontal and inclined - In ordetjo obtain superheated steam, a superheater is added in an existing boiler. As as result, furnace vacuum will _________________?
A. remain unaffected
B. improve C. worsen
C. may improve/worsen depending on size
D. unpredictable
