Boiler Classification by Firing Oil- or Gas-Fired Boilers Oil — and gas-fired boilers are burner-fired and are amenable to extensive standardization because of a fair degree of uniformity of the fuel characteristics. The quick and relatively clean burning nature of the fuels makes them compact and suitable for full or part shop assembly, as in […]

Water Tube Boilers for Industry and Power Water tube boilers are made • From ~5 tph to —4500 tph capacity • At steam pressures ranging from —3.5 to 320 bar • At steam temperatures ranging from saturation to —620°C The lower end of the range up to —400 tph is employed for its process steam, […]

Water-level indicators (WLIs) or gauge glasses are installed on the boiler drums, deaerator tanks, and CBD tanks on the boiler island. Water-level indicators can be for direct or remote viewing, direct water-level indicator (DWLI) or remote water-level indicator (RWLI), respectively. As per ASME Section 8.5, the most important guidelines for WLI are: • Each boiler […]

Soot blowers are installed in most boilers for the removal of entrained soot and ash susceptible to slagging and fouling. Natural gas (or such clean fuel)-fired boilers are exceptions because there is no ash in the fuel to deposit on the HSs. Soot blowers remove. 1. Soot and ash deposits from the fire sides of […]

Valves, mountings, and fittings are the auxiliaries in the steam and water circuit. The mountings and fittings are the mandatory safety devices specified by codes for permitting a boiler to steam. These are • Main steam stop valve (MSSV) • Nonreturn valve (NRV) on steam line • Safety valves (SV) • Blow-down valves • High-low […]

The principle of dust collection in a WS is different from that of the previous three meth­ods. Instead of directly separating the dust from the flue gas, the dust is merely diverted from the flue gas to the scrubbing liquid, and thereby the gases are freed from the dust burden. Wet scrubbers use a fine […]

This method of dust collection uses the property of dust particles to acquire electrical charge, when subjected to high DC voltage. Operating Principle of an ESP An ESP is a large settling chamber in which discharge or emitting electrodes (EEs) and collecting electrodes (CEs) are suspended from the roof with high-voltage DC power (by transformer-rectifier […]

Depending on the collection process, MDCs can be classified as • Inertial separators • Centrifugal separators Inertial separators rely on a change of direction of gas flow or interception of dust or both, to effect a separation of dust particles from gas. They are simple in construction with low pressure drop and moderate collection efficiencies. […]

Dust collection in a boiler plant is mainly for the control of the particulate emissions, and the separated dust is disposed of by a suitable ash-handling system. In some cases, part (stoker, BFBC) or all (CFBC) of the dust is required to be returned to the system to enhance the combustion efficiency. In CFBC boilers, […]

Fans in Boiler Plant Fans are perhaps the most important of all the auxiliaries because they affect the boiler • Performance • Auxiliary power consumption • Dynamics Almost all boilers are provided with fans for air and flue gas movement, except for certain waste heat recovery boilers (WHRBs) and heat recovery steam generators (HRSGs), which […]