Dry flue gas desulfurization technology refers to the desulfurization absorption and product treatment are carried out in the dry state. The process of initial investment costs and operating costs lower than the wet method, and the desulfurization products were dry, easy to handle.
Dry flue gas desulfurization process
When the flue gas (temperature is generally 150 ℃) coming out of the air preheater of the boiler or so, remove most of the dust through the pre-dust collector (when desulfurization ash and fly ash need to be separately collected, a pre-precipitator is provided, Otherwise, the flue gas can directly enter the absorption tower) and enter the absorption tower from the bottom. The flue gas then enters the circulating fluidized bed through the acceleration of the venturi at the bottom of the absorption tower. In Venturi tube outlet diffusion section set sprinkler device for cooling flue gas humidification, thus creating a good desulfurization reaction conditions. Desulfurizer and circulating material in the circulating fluidized bed, the gas-solid two-phase due to the role of airflow, resulting in intense turbulence and mixing, full contact, in the process of rising, the continuous formation of floc returns down, and flocculent In the intense turbulent motion, it is continuously disintegrated and then re-airflow is increased, making the gas-solid sliding speed up to several times the single particle sliding speed; through the intense turbulence of particles leading to continuous collision between particles, the desulfurization agent is hydrogenated The surface of calcium particles are continuously updated and the desulphurization ash is continuously recycled so as to greatly increase the utilization rate of calcium hydroxide desulfurizing agent. The top structure of the absorption tower is optimized to further strengthen the return of flocs, The bed density of the granules gives an instantaneous Ca / S ratio of up to 50 in the bed. Such circulating fluidized bed gas-solid two-phase flow mechanism, greatly enhanced the gas-solid mass transfer and heat transfer, in order to achieve high desulfurization rate provides a fundamental guarantee. After absorption tower desulfurization reaction of flue gas discharged from the top, into the two precipitator (electrostatic or bag filter) dust removal standards and then through the induced draft fan into the chimney emissions.
Introduction of Dry Flue Gas Desulfurization System Device
The absorbent preparation system mainly includes a raw lime silo, a hydrated lime silo, a digester and its accompanying bag dust remover, a weighing screw and an electric air lock feeder. In the preparation process, quick lime and water react to emit heat, the water in the hydrated lime evaporates, and the hydrated lime turns into a powder.
Dusting and humidifying system mainly includes dusting fan, process water pump, water tank and nozzle. Its function is to cool and humidify flue gas and provide moisture for the reaction.
Flue gas system mainly includes flue, electric baffle door, induced draft fan, the role of the flue gas access and transport.
The net flue gas recirculation absorption system mainly consists of a recirculation flue and an electric baffle door, which serves to maintain the bed fluidization speed and ensure the stability of the fluidized bed.
The ash conveying system mainly includes the external discharge ash electric locking gas feeder, the ash conveying chute, the flow control valve, the bin pump and the humidifying mixer, etc. The purpose of the ash conveying system is to provide a stable outer circulating ash for the absorption tower.
Electronic control systems include electrical cabinets, DCS or PLC control cabinets, UPS, CEMS, electric actuators, flow meters and pressure transmitters. The role is to provide power for the device and automatic control, detection alarm.
Dry flue gas desulfurization technology features
1. Desulfurization efficiency, up to 90%;
2 process system is simple, easy to operate, stable and reliable operation;
3 flue gas without heating;
4 small footprint, investment, low maintenance costs;
5. Desulfurization by-products for dry, easy to handle, no waste water and secondary pollution;
6. Beautiful system, clean running environment, clean;
7. System operation plant low power consumption, low operating costs;
8. System to adapt to a wide range, while effectively out of flue gas SO3 and other pollutants, the chimney without corrosion.