PP defogger

Demister (mist eliminator) is mainly composed of fixtures waveform blades, sheet, strip cards, etc., in the wet desulfurization absorber during operation, easy to produce a particle size of 10 - 60 microns, "fog" "Fog" is not only contains water, it dissolved sulfate, sulfate, sulfur dioxide, etc., but also resulted in fans, heat exchangers and flue tarnished and severe corrosion, so the wet FGD technology absorption equipment made defogging request, before the purified gas leaving the absorption column to the demister. Demister system consists demister body and flushing system. Specifically two demister body wash water pipes, nozzles, cage, support beams and associated connections, fixed, seals and other components. Demister for separating entrained liquid droplets gas tower to ensure that there is mass transfer efficiency and reduce the loss of valuable materials and improve the operation of the compressor after the tower, and more generally at the top of the tower is set defogger. Can effectively remove ≥26μ droplets between trays if set defogger, not only to ensure the efficiency of the mass transfer tray, plate spacing can also be reduced. So demister mainly for gas-liquid separation. Also for the air filter for gas separation. Wet FGD, it dissolved sulfate, sulfate, sulfur dioxide. If not properly addressed, any incoming chimney "fog" is in fact the sulfur dioxide emissions into the atmosphere, but also result in fans, heat exchangers and flue tarnished and severe corrosion. Therefore, the absorption of the wet FGD technology defogging equipment proposed requirements were purified gas before leaving the absorber must demisting. FGD systems defogger is the key equipment, its performance directly affects the wet FGD system can run continuously and reliably. Defogger failure will not only cause outage desulfurization system, and may even cause the entire unit (system down). The most common arrangement in the form of mist eliminator style layout and has a flat roof style layout. Demister demister mainly by the sheet supporting means. Plates are usually made of two major categories of material from polymer materials (such as polypropylene PP, FRP, etc.) or stainless steel (eg, 316L, 317L, etc.). Generally divided into streamlined and mansard. When the principle when mist containing gas flows through the demister to a certain speed, due to the effect of inertial impaction gas, mist and wave plates collide and large droplets were clustered to produce its own gravitational force over rising gas and When the liquid surface tension force, the droplets are separated from the surface of the plate down on the waveform. Defogger wave plates to structure multi-fold increase in the chance of trapped mist, mist is not removed at the next turn through the same action is captured, so that repeated action, thus greatly improving the efficiency demisting . After the gas passes through the wave plate demister, substantially free of mist. Flue gas through the curved path of the defogger, under the action of inertial force and gravity of the gas stream to separate entrained liquid droplets: FGD constant speed after passing through the demister, the flue gas is rapidly, continuously change the direction of movement, due to centrifugal force and inertia effects, droplets impinging on smoke within the demister vanes trapped down, the water droplet collection formation, due to the action of gravity, fall to the slurry pool, to achieve a gas-liquid separator, After making the flue gas flowing through the demister demisting achieve discharge requirements. Demisting efficiency demister with increasing gas velocity increases, which is due to the high flow rate, inertial forces acting on the droplets, is conducive to the gas-liquid separation. However, increasing the flow rate of the system will result in increased resistance, but also the increase in energy consumption. And increase the flow rate of a certain limit, the flow rate is too high will cause secondary with water, thereby reducing the demisting efficiency. The flue gas velocity is usually defined by the highest section of the demister and because water is not a secondary zone for the critical velocity, the velocity structure and the defogger system with water load, air flow direction, demister layout and other factors . Design flow is generally selected at 3.5-5.5m / s. In usual chemical operations encountered gas dispersed droplets of a diameter of about 0.1 ~ 5000μm. General particle size above 100μm particles due to rapid sedimentation rate, the separation problem is easily solved. Typically droplet diameter greater than 50μm, and be isolated by gravity settling; 5μm or more droplets available inertial impaction and centrifugation; for smaller fine mist will have to be managed to aggregate to form larger particles, or fiber filter and Electrostatic defogger. Arranged in the form of mist eliminators are usually arranged in the form of: horizontal, human-shaped, V-shaped, the combination of desulfurization absorber other large multi-use herringbone layout, V-shaped arrangement or combination-type arrangement (such as diamond, X-type ). Absorber on export levels using horizontal section. Performance Guarantee (1) defogging efficiency: In normal operating conditions, the demister outlet flue gas droplet concentrations below 75mg / Nm3; (2) the pressure drop: front and rear defogger does not consider interference, ensuring 100% flue gas load, the pressure drop over the defogger system is lower than 120Pa. (3) High temperature: 80--95 ℃. (4) Pressure: 0.3MPa guaranteed to withstand water pressure washing, the blade can work properly. (5) Rinse nozzle: full cone nozzle, spray rinse water for 90-120 degree angle, solid cone spray, to ensure that all the blades are covered. (Water consumption are designed maximum gas load, considering water balance requirements, if the gas load is decreased, by increasing the interval between flushing water consumption reduced by half). The installation process: Installation defogger generally divided into six steps 1, 2 ceiling, install the first layer defogger 3, install a second layer of mist eliminator 4, 5 installation flush pipes, factory inspection and installation quality 6, Acceptance into operation