Method based on the desulfurization of coal-fired power plant desulfurization process, can be divided into before and after combustion, combustion and combustion in three broad categories. Formerly known as burning coal desulfurization main washing, chemical desulfurization of coal and coal conversion; burn known as the main circulating fluidized bed desulfurization in furnace and the furnace with burning desulfurization; after combustion desulfurization of flue gas desulfurization, according to desulfurization medium’s temperature can be divided into wet, dry and half dry. Currently using mainstream methods for flue gas desulfurization of thermal power plant desulfurization.
Flue gas desulfurization process have the following
Dual-circuit wet scrubbing desulphurization technology (DLWS wet)
1.Technical features: upper and lower pH values of the circuit can be controlled individually, our last road pH value (5.8 ∼ 6.5) a high SO2 removal efficiency reached its maximum, next road pH (4 ∼ 5) lower, easier to dissolve the limestone, absorbing agent utilization, and cost reduction.
2.Spray dry desulfurization technology (SDA process)
SDA desulfurization process in Ca (OH) 2 as desulfurization absorbent slurry through Rotary centrifugal atomization absorption line or air-atomizing nozzle atomization in spray drying absorption.
3.LIFAC flue gas desulfurization by dry process
Technical features: integrated shunt and advantages of spray dry desulfurization in furnaces, process is simple, and easy to maintain. Lime needs to processed into powder below 40 μ m, high running costs.
LM vertical roller mill in spraying calcium in furnace end application of wet flue gas desulfurization process
Furnace injection and tail flue gas humidification activated desulfurization process is injection desulfurization in furnace technology in boiler on the basis of additional conditioning, to improve the efficiency of desulfurization. The technology of limestone powder for absorbent, limestone powder pneumatic injection into the furnace 850~1150℃ temperature area, heat decomposition of limestone to calcium oxide and carbon dioxide, calcium oxide, calcium sulfite reacts with sulfur dioxide in flue gas generated. Due to the reaction between gas-solid two-phase, under the influence of mass transfer processes, reaction slow, absorbing agent utilization is low. Tail-humidifying activation in the reactor, humidifier water mist sprayed into, contact with unreacted calcium oxide produce calcium hydroxide reacts with sulfur dioxide in flue gas. When sulfur-calcium ratio control in 2.0~2.5, and system desulfurization efficiency can reach 65~80%. Because the humidifier water join the bring down the flue gas temperature, general control of outlet flue gas temperature above the dew point temperature 10~15℃, heated humidification water with flue gas temperature is rapidly evaporated, no reaction of absorbents, reaction product is a dry state with flue gas exhaust, dust collection.
MTW European mill application in power plant desulfurization with lime links
Wet flue gas desulfurization technology of desulfurization of limestone or lime as a cheap and easy absorption agent, limestone made from crushed granulated powder mixed with water mixed slurry. When using limestone as absorbent, lime after digestion and absorption made from water mixed slurry. In the absorber, absorption liquid contact with flue gas mixing, and slurry of calcium carbonate and sulfur dioxide in the flue gas bubble oxidation air for chemical reactions, final reaction product for plaster. Simultaneous removal of part of the pollutants in the flue gas, such as dust, HCI,HF,SO3. Desulfurization of flue gas after and apart from dropping out of the tiny droplets, heating by heat exchanger discharged into the chimney. Desulfurization gypsum dehydration unit recovery after dehydration.
The technology uses single cycle spray towers, with mature technology, wide range of application, high desulfurization efficiency, high operating reliability, high availability, has the possibility to reduce construction cost and so on.
Super pressure trapezium grinder in application of flue gas circulating fluidized bed desulfurization
Flue gas circulating fluidized bed desulfurization sorbents preparation, recycling, dust collector, desulfurization absorption tower ash and control systems, and other components. The process generally use dry Hydrated lime powder used as absorbent, others have the ability to absorb the reaction of sulfur dioxide can also be used as an absorbent powder or serous. Untreated flue gas of boiler exhaust from the absorber (fluidized bed) entered at the bottom. Absorb a venturi device to the bottom of the Tower, accelerated after the flue gas flow through the venturi tube, and this and the very small of absorbent powder mixed with each other, friction between particles, gases and particles between violent, form a fluidized bed, spray into a uniform spray to reduce flue gas temperature conditions, absorbent reacts with sulfur dioxide in the flue gas and CaSO4 CaSO3. Carrying large amounts of solid particles in flue gas after desulfurization absorption tower from discharges into recycled dust, ash bin by separating particles by the middle of return absorption tower, due to the repetition of solids up to as much as dust-ups, absorbers use. Of this process the byproducts of dry powder, its chemical composition is similar to spray dry desulfurization technology, mainly of fly ash, the CaSO3, CaSO4 and not complete reaction of absorbents Ca (OH) 2 and so on, and void for mine backfill, road infrastructure, etc.