Boiler Types: Water Tube and Babcock and Wilcox

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What is the purpose of hand holes provided at the ends of cross tubes in a boiler?

To allow for efficient circulation of water

To facilitate the escape of combustion gases

To provide access for cleaning the tubes (correct)

To increase the heating surface area

In a Cochran boiler, where are the combustion gases directed after passing through the horizontal fire tubes?

Fire brick lining

Chimney (correct)

Flue tube

Smoke box

What is the advantage of a Cornish boiler design in terms of sediment contained in water?

Sediment does not affect boiler efficiency

Sediment is kept in suspension in the water

Sediment falls to the bottom away from hottest gases (correct)

Sediment is directed to the combustion chamber

What is the reason for carrying combustion gases first through side flues and then through the bottom flue in a Cornish boiler?

To prevent overheating of the bottom plates Signup and view all the answers

Which type of boiler is commonly used in sugar-mills and textile industries due to its simplicity and reliability?

Lancashire boiler Signup and view all the answers

What is located inside the cylindrical shell of a Lancashire boiler?

Large tubes Signup and view all the answers

Which mountings are common to both Cochran and Cornish boilers?

Steam stop valve and water gauge Signup and view all the answers

What is the purpose of a manhole in a boiler?

For cleaning purposes Signup and view all the answers

What advantage does a simple vertical boiler have in terms of transportation?

It is self-contained and can be easily transported Signup and view all the answers

What does the crown of a Cochran boiler provide due to its hemispherical shape?

Maximum volume of space for steam Signup and view all the answers

What is the purpose of the antipriming pipe in a boiler?

To prevent priming in the steam Signup and view all the answers

Why are metallic slings or girders used to hang the boiler?

To prevent expansion and contraction Signup and view all the answers

What distinguishes a Babcock Wilcox water tube boiler with cross drum from a longitudinal drum boiler?

Number of tubes connected to one drum Signup and view all the answers

What is the function of a baffle in a steam drum of a Stirling water tube boiler?

To deflect water downwards into the drum Signup and view all the answers

Why are manholes provided at each end of the drums in a Stirling water tube boiler?

For cleaning operation Signup and view all the answers

How does a fire brick arch contribute to combustion in a boiler?

By helping prevent chilling when fire door is opened Signup and view all the answers

What is the purpose of the chimney in a boiler system?

To discharge combustion products Signup and view all the answers

How do bent tube boilers differ from straight tube boilers?

"Bent tube boilers are more flexible but harder to clean compared to straight tube boilers" Signup and view all the answers

What is the purpose of the furnace tubes in the boiler?

To pass combustion products through them Signup and view all the answers

In a locomotive boiler, what is the function of the superheater tubes?

To return steam to the superheated steam chamber Signup and view all the answers

What is the role of the fire brick arch in a locomotive boiler?

To heat the walls of the fire box properly Signup and view all the answers

Why is natural draught not achievable in a locomotive boiler?

Requires a very high chimney Signup and view all the answers

What are some boiler mountings typically found on a locomotive boiler?

Safety valves and pressure gauge Signup and view all the answers

Why is low brickwork fire bridge placed at the back of the gate in boilers?

To prevent entry of burning coal and ashes into furnace tubes Signup and view all the answers

What is the function of the steam dome in a locomotive boiler?

Fits over the barrel to collect steam Signup and view all the answers

In a locomotive boiler, where is the ash pit located?

Below the fire box Signup and view all the answers

What is one of the demerits associated with a locomotive boiler design?

Difficult to clean some water spaces Signup and view all the answers

Why are fire tubes surrounded by water in a locomotive boiler?

To transmit heat into water Signup and view all the answers

What is the main function of pumps in high pressure boilers?

Maintain forced circulation of water Signup and view all the answers

In a Lamont boiler, what maintains the circulation of water?

Centrifugal pump Signup and view all the answers

How is the issue of salt deposition addressed in a Loeffler boiler?

By preventing water flow into the tubes Signup and view all the answers

What is the primary purpose of the economiser in a steam boiler?

To heat water before it enters the superheater Signup and view all the answers

What is the advantage of using small diameter tubes in high-pressure boilers?

Increased rate of heat release Signup and view all the answers

What is the novel principle used in a Loeffler boiler?

Evaporating feed water using superheated steam Signup and view all the answers

Why are Loeffler boilers suitable for land or sea transport power generation?

Can carry higher salt concentrations Signup and view all the answers

What is a key benefit of pressurized combustion in high-pressure boilers?

Higher rate of heat release Signup and view all the answers

In a Lamont boiler, where is the feed water drawn from?

Economiser Signup and view all the answers

What is the main purpose of using a superheater in a steam boiler?

To increase the temperature of steam Signup and view all the answers

What is the function of Sugden's superheater?

To increase the temperature of steam above its saturation value Signup and view all the answers

How many 'U' tubes of steel are generally attached to each pair of headers in Sugden's superheater?

Ten Signup and view all the answers

What happens to the steam when the valve V1 is closed and valves V2 and V3 are opened?

Steam is directed to the main steam pipe Signup and view all the answers

How is the path of gases controlled in the system described?

By operating the hand wheel Signup and view all the answers

Which component ensures that the steam available from a boiler is either wet, dry, or superheated?

The steam separator Signup and view all the answers

What happens when the steam is taken from the boiler direct to the main steam pipe according to the description?

The valves V1 and V2 are closed and V3 is opened Signup and view all the answers

What is the main difference between a single-acting pump and a double-acting pump?

Single-acting pumps have one side of the piston displace water, while double-acting pumps have both sides displace water. Signup and view all the answers

How is the reciprocating feed pump continuously operated in a steam pump system?

It is run by steam from the same boiler it feeds. Signup and view all the answers

What type of pump is commonly employed for medium-sized boilers?

Double feed pump Signup and view all the answers

What does a rotary feed pump utilize for pumping liquid?

Centrifugal force of a rotating impeller Signup and view all the answers

What is the main function of an injector in a boiler system?

To combine steam and water for increased pressure Signup and view all the answers

What are the advantages of using an injector for feeding water into a boiler?

'Low initial cost', 'simplicity', 'compactness', 'ease of operation' Signup and view all the answers

What type of device utilizes waste heat from flue gases to heat feed water in a boiler system?

'Economiser' Signup and view all the answers

What is the purpose of an economiser in a boiler system?

'To utilize waste heat from flue gases for heating feed water' Signup and view all the answers

What is the function of an economiser in a boiler system?

To increase the temperature of air before it enters the furnace Signup and view all the answers

Where is the air preheater generally placed in relation to the economiser?

After the economiser Signup and view all the answers

What is the purpose of a superheater in a boiler system?

To increase the temperature of steam above its saturation point Signup and view all the answers

Why are scrapers used in an economiser?

To prevent soot deposit on pipes Signup and view all the answers

How does an air preheater facilitate combustion in a boiler system?

By preheating the air to be supplied to the furnace Signup and view all the answers

Which type of superheater makes use of heat from flue gases?

Convective superheater Signup and view all the answers

In a superheater, where is a radiant superheater typically placed to receive heat?

In the furnace and wall tubes Signup and view all the answers

What happens to gaseous products of combustion after leaving an air preheater?

They escape to the atmosphere through a stack Signup and view all the answers

What leads to an increase in evaporative capacity of a boiler with an economiser?

Reduction of temperature range between boiler parts Signup and view all the answers

What is prevented by keeping external surfaces of pipes clean with scrapers in an economiser?

Increase in soot deposit on pipes Signup and view all the answers

What is the minimum pressure requirement for using Babcock and Wilcox water tube boiler?

10 bar Signup and view all the answers

What material are the water tubes made of in a Babcock and Wilcox water tube boiler?

Solid drawn mild steel Signup and view all the answers

What is the angle of inclination of the water tubes in a Babcock and Wilcox water tube boiler to the horizontal?

15° Signup and view all the answers

What is the function of baffle plates in a Babcock and Wilcox water tube boiler?

To direct hot gases between tubes Signup and view all the answers

How is the flow of water inside a Babcock and Wilcox water tube boiler from the drum to the shell described?

Circulatory Signup and view all the answers

Where does the steam get collected in a Babcock and Wilcox water tube boiler?

In the steam space of the drum Signup and view all the answers

What is the main advantage of shell boilers over water tube boilers?

Lower cost Signup and view all the answers

Which type of boiler is generally preferred for high pressure and high output applications?

Water tube boiler Signup and view all the answers

What is the purpose of a combustion chamber in a Scotch boiler?

To transfer heat to water Signup and view all the answers

In high pressure boilers, what method is commonly used to maintain water circulation?

Forced circulation with a pump Signup and view all the answers

What is the purpose of exposing water tubes to flue gases in high pressure boilers?

Enhancing heat transfer Signup and view all the answers

How do high pressure boilers utilize superheated steam for heating water?

Mixing superheated steam directly with water Signup and view all the answers

What distinguishes water tube boilers from shell boilers in terms of geometry?

Smaller diameter pressure parts Signup and view all the answers

"U" tube systemis employed in which part of a high-pressure boiler?

Water circulation Signup and view all the answers

Why are shell boilers generally preferred over water-tube boilers for applications below 30 bar pressure?

Cost-effectiveness Signup and view all the answers