Boiler and Steam Technology

A boiler is primarily used for

• Generating hot air for heating purposes.

• • Producing steam or hot water for various applications.  

• Cooling down liquids in industrial processes.

• Storing large quantities of water.

Which of the following statements is TRUE regarding the design and classification of boilers?

• Fire-tube boilers are suitable for superheated steam applications.

• Water-tube boilers have their heat source inside the tubes and are cheaper to build.

• Fire-tube boilers have mechanical constraints that limit capacity to 30 T/hr and pressure to 15-20 barg.

• Water-tube boilers are mechanically constrained in terms of capacity.

What happens if steam and water separation fail in a boiler?

• There will be no impact on the boiler system.

• Harmful chemical deposits, erosion, or mechanical damage can occur.

• The boiler will produce more steam.

• Only fire-tube boilers are affected by separation failure.

Which statement about boiler components is TRUE?

• Superheaters are always used in fire-tube boilers

• Re-heaters are used to heat steam again after it goes through a power turbine.

• Economizers reduce the efficiency of the boiler.

• Re-heaters and superheaters are completely different.

What affects the water quality standards for boilers?

• Only the operating pressure matters for setting water quality standards.

• Fire-tube boilers require stricter water quality standards than water-tube boilers.

• Higher pressure and heat flux demand purer water in boilers.

• Non-fired boilers have stricter water standards than fired boilers.

Which of the following is TRUE about feedwater quality for boilers?

• Softeners remove 99% of impurities from water.

• Reverse osmosis water has residual dissolved solids 2 to 9 mg/l

• Mixed bed water removes over 99.9% of ions from water.

• Condensate water is always pure and never contaminated.

What is important when designing a boiler for reliability?

• Superheater design has no impact on reliability.

• Applying generous water quality standards, circulation and separation help reliability.

• Careful insulation isn't necessary for reliable boiler design.

• Small design margins on furnace size improve reliability

What is combustion?

• Combustion is a slow chemical reaction with oxygen that releases energy.

• Combustion is the reaction of carbon and hydrogen in their pure forms.

• Combustion is a fast chemical reaction of fuel with oxygen that releases energy as heat.

• The only final product of combustion is carbon dioxide.

Which type of premix gas burner is most widely used due to its reliability and ability to maintain a consistent gas-to-air ratio across its turndown range?

• Fan mixers

• Aspirators

• Inspirators

Which of the following is TRUE about nozzle mix gas burners?

• Nozzle mix burners mix gas and air inside the burner body.

• The flame from a nozzle mix burner is short and wide.

• Silicon carbide tubes offer good resistance to thermal shock and a longer service life.

• Nozzle mix burners do not use any kind of tube or tile for flame stabilization.