Power plant desulfurization process:
Periods of power plant coal desulfurization desulfurization process has, can be divided into combustion, burning and after burning three categories. Formerly known as the burning of coal desulfurization mainly coal cleaning, chemical desulfurization of coal conversion; called burning furnace desulfurization circulating fluidized bed furnace with burning desulfurization; desulfurization after combustion, also known as flue gas desulfurization, according to the desulfurization medium temperature can be divided into wet, dry and semidry. The current the mainstream desulfurization method used by the thermal power plant flue gas desulfurization.
The flue gas desulfurization process are the following:
• double-loop wet washing desulphurization technology (DLWS wet)
Process characteristics: pH value of the upper and lower loop control on the loop pH (5.8 to 6.5) higher SO2 removal efficiency of the maximum, the next loop pH (5) lower limestone easy to dissolve, absorbent improved utilization, cost reduction.
• spray dry desulfurization process (SDA semidry)
The SDA desulfurization process with Ca (OH) 2 slurry as the desulfurization absorbent to absorb Qi atomization in the spray drying absorber, centrifugal rotary atomizer or air-atomizing nozzle. The hot flue gas entering the absorber and atomization absorption contact at the same time …
• LIFAC dry flue gas desulfurization
Process characteristics: a combination of furnace I and the advantages of spray disabilities dry desulfurization process is relatively simple, and easy maintenance. Lime needs to be processed into 40μm below the powder, higher operating costs.
The purpose of the power plant desulfurization:
With the rapid development of economic construction in the world, air pollution control has become a prominent problem. In sulfur dioxide emissions from power plant flue gas emissions account for about half. Since the beginning of 2000, China formulated the Tenth Five-Year Plan “of the” two control’s area of acid rain and sulfur dioxide pollution control, acid rain control areas and sulfur dioxide control area (two control’s area), will focus on the reduction of sulfur dioxide emissions control fire power plant pollution, and a series of measures.
China’s electric power energy mix of thermal power accounted for 75.6%, among which coal-fired electricity-based. Annual thermal coal consumption reached 400 million tons of coal in primary energy consumption accounted for 78%, is the world’s largest coal and coal country, according to constitute the economic foundation of our resources, the next 50 years, China’s primary energy consumption pattern is difficult to change is dominated by coal burning emissions of SO2, NOx and CO2 generated environmental pollution has drawn worldwide attention this desulfurization based clean coal technology should be transported to the unfamiliar. The development of desulfurization and other clean energy production technology, has become a must in today’s world energy industry until the entire economy of sustainable development.
The power plant desulfurization milling equipment:
A. LM vertical roller mill furnace spray calcium tail humidifier in the flue gas desulfurization
Limestone injection and flue gas humidification activation desulfurization process is in the rear of the boiler limestone injection desulfurization process based on the addition of a humidifier section, in order to improve the desulfurization efficiency. The process and more absorbent, limestone powder, limestone powder is injected into the pneumatic chamber 850 to 1150 ℃ temperature zones, limestone thermal decomposition of calcium oxide and carbon dioxide, calcium oxide and the reaction of sulfur dioxide in the flue gas to produce calcium sulfite. Reactions in the gas-solid between the mass transfer process, the response speed, low absorbent utilization. In the reactor tail humidifier activation, the humidifier water to mist sprayed into contact with the unreacted calcium oxide to calcium hydroxide and then reaction with sulfur dioxide in flue gas. When the calcium sulfur ratio control in the 2.0 to 2.5, the system desulfurization rate can reach 65 ~ 80%. Humidifier water, flue gas temperature decreased, the general control of exports of flue gas temperature is higher than dew point temperature 10 ~~ 15 ℃, the humidification water temperature of the smoke heating by rapid evaporation, the unreacted absorbent, the reaction product was dried state with flue gas discharged by the dust collection down. stone crusher
MTW European version of the mill in the limestone desulfurization in power plants part of the application
Wet flue gas desulfurization using a low cost of limestone or lime as a desulfurization absorbent, limestone is crushed and pulverized into powder mixed with water and stir made to suck the slurry. When using limestone as the absorbent into lime powder by digestion after treatment with mixing with water made of the absorption slurry. Slurry to mixing contact with the flue gas in the absorber, absorption, oxidation of sulfur dioxide in the flue gas and slurry of calcium carbonate as well as drum into the air for chemical reaction, the final reaction product is gypsum. Removal of part of its flue gas pollutants such as dust, HCI, of HF, of SO3. Desulfurization of flue gas and in addition to the device through the heat exchanger heating are removed with a small droplet, discharged into the chimney. FGD gypsum dewatering by the dewatering device recovery.
The technology uses a round robin spray empty tower structure, with a mature technology, a wide range of applications, high desulfurization efficiency, high reliability, high availability, reduce the project cost in the magnitude of possibilities.
Overpressure trapezoid Mill flue gas circulating fluidized bed desulfurization
CFB desulfurization process by the absorbent preparation, absorption desulfurization recycling of ash, dust collector and control system and other components. The process is generally dry hydrated lime powder as an absorbent, can be applied to sulfur dioxide absorption reaction capacity of the dry powder or slurry as absorbent. Untreated flue gas discharged from the boiler from the bottom of the absorber (ie, fluidized bed) to enter. Absorber at the bottom of a venturi device, flue gas flows through the Venturi tube faster, and with very thin absorbent powder mixed with each other, between the particles, the intense friction between the gas and particles to form a fluidized bed in injected into a uniform mist to reduce the temperature of the smoke conditions, the reaction of sulfur dioxide in the absorbent in the flue gas to generate CaSO3 and of CaSO4. Carry large amounts of solid particles in the flue gas desulfurization after discharge from the absorber at the top to enter the recycling precipitators, particles are separated out by the middle gray position to return to the absorber, due to solid particles, repeated cycle of up to one hundred times, so the use of absorbent higher. A byproduct of this process was a dry powder, its chemical composition is similar to spray drying FGD process, the absorbent mainly by fly ash, CaSO3, CaSO4 and unreacted after Ca (OH) 2 and other components, suitable for void mine backfill road infrastructure
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