Questions and answers related to Boilers

What is the function of the economizer? Economizer economizes the power plant operation.

What are the functions of steam drum? (a) steam separation, (b) steam-water circulation and (c) purifying steam.

What is the function of super-heater? Super-heater is used to super heat the steam and get higher thermal Efficiency of the plant.

Why large boilers are top supported? (a) avoid buckling of furnace walls, (b) allow thermal expansion and (c) reduce thermal loads.

Why steel structures (avoiding concrete) are used for boiler structures? Steel structures are used are used for speeding - up the construction schedule and facilitate changes.

What is resonance? When the natural frequency and the induced frequency matches Resonance takes place.

Why resonance should be avoided? During resonance, high vibration and stress will occur. Hence, resonance Should be avoided.

What is the life of a power plant? Life of the power plant is about 50 years. But, many components need Replacement and repair.

What is safety requirement for boiler, in India? The Indian Boiler Regulations, 1950 (with amendments).

What are the materials used for boiler pressure parts? Carbon steel, low alloy steel, medium alloy steel and stainless steel.

What are the materials  used for boiler structures? Mild steel as per IS2062 is used. For fasteners, IS1367 is used.

What is the material used for boiler insulation? Slag wool, mineral wool and glass wool are used.

What is the material used for boiler foundation? Reinforced Cement Concrete (RCC) with a specification "M20" is used.

What are the types of bolted connections used for boiler structures? Bearing type connection and Friction type connections are used. Bearing type is popularly used.

What is a shear key? Shear key are flat plates welded at the bottom of the structure base plates to transfer shear forces.

What are the types of chimneys? Rcc chimney and steel chimney are used.

What are the types of steel chimneys? Self supporting type and guyed chimney are used.

Why conical chimneys are preferred? Conical chimneys are economical.

What is the corrosion allowance used for steel chimney? Corrosion allowance = 3.0 mm (typical).

Which boiler code is governing in India? The Indian Boiler Regulations, 1950 (with amendments)is governing in India.

Who is the authorized inspector in India? The Chief Inspector of Boiler (CIB) is the authorized inspector for the Respective states.

Which body is empowered to amend The Indian Boiler Regulation? The Central Boiler Board (CBB) is authorized to amend the IBR.

Why steel is used for boiler pressure parts? The cost to weight ratio is favorable for steel. Hence, steel is used.

What is the purpose of refractory? Refractory is provided where the flue gas temperature is high (above 800 Degree C).

What is the purpose of refractory retainers? Retainers are embed within the refractory and they retain the refractory to the surfaces.

What are the steps in design? Design, engineering, process analysis, stress analysis, detailing, drafting, Documentation and document approval.

What is DAS? Data Acquisition System (DAS) is used record readings.

What is VLH? Variable Load Hangers (CLH) are used for support, permiting limited Support load variation.

What is CLH? Constant Load Hangers(CLH) are used for support,permitting small load variations.

Why water quality is control of in boilers? Water quality is controlled to avoid corrosion of boiler parts.

Why paints are required? Paints are required to protect the surface of boiler.

Why rockers are used for boiler hanger supports? Rockers reduce the induced bending load. This leads to economic design.