The application of desulfurization system(slurry pipeline and absorption tower) combined protective coatings:
(the author:Xiangyang City Hundred Shield Coating Material Co.,Ltd--Mr Lee Huanxin)
The current our Chinese thermal power and metallurgy sintering desulfurization system mainly choose wet process limestone-gypsum method desulfurization (FGD) process,its process is make the slurry made-up of limestone powder and water pump into the absorption tower,make it mix and contact with the flue gas fully,the sulphur dioxide in flue gas and the calcium carbonate in slurry react to produce the calcium sulfate,calcium sulfate crystallizes to form the dihydrate gypsum,after the gypsum slurry concentrating and dewatering,and then transported to gypsum warehouse stacking,the flue gas after desulfurization removes the droplets by the demister,after heating it up by the flue gas heat exchanger (GGH) again,make it discharge into the atmosphere by chimney.
Wet desulfurization (FGD) system mainly includes the following systems and equipment:flue gas system,absorption system,slurry preparation system,gypsum processing system,process water system,waste water treatment system,control system etc.The main equipment: supercharge axis flow fan,rotary flue gas heat exchanger (GGH),absorption tower,mist eliminator,shower pipe,oxidation air blower,slurry circulating pump,crusher,ball mill,gypsum cyclone,limestone hydrocyclone,dewatering machine,rubber lining pipeline and valve etc.
Wet desulfurization (FGD) technology determines that this system equipment should run under the solid,liquid or gas three states,the equipment bear different temperature,and even the same equipment in different working conditions are not uniform temperature,the equipment at the same time bear the corrosion and wear composite working condition,the corrosion and wear of different equipment are not uniform.The operation of the equipment is always in a state of slight vibration.The current protection of the desulfurization system,slurry pipeline mainly uses lining rubber technology,for the absorption tower,we mainly choose lining glass flakes technology.But there is also insufficient places during using,such as the rubber lining will appear bulge,falling off phenomenon.Flakes coating will appear crack,falling off phenomenon,brought security hidden danger for the operation of the desulfurization system.Simple corrosion resistant or abrasion resistant can not solve the protection problem of the desulfurization system completely.The ideal performance of the desulfurization system protective coatings: the material has excellent corrosion resistance,abrasion resistance,aging resistance,resistance to hot water permeability,high temperature resistance,and can withstand the high and low temperature cycle,enough toughness to resist the vibration of the equipment and the internal stress caused by the different expansion coefficient between different materials,and the excellent adhesive strength between the substrate,high strength of material itself is not easy to crack etc.
Obviously make one kind of material have all of the above performance is not reality,Xiangyang City Hundred Shield Coating Material Co.,Ltd puts forward the concept of the desulfurization system combined protective coatings,let each kind of coatings play its biggest advantage,and then use them together,thus to achieve a perfect protection for the desulfurization system equipment.Composite coating can be divided into: corrosion resistant coatings,flakes coating, wear resistant coatings,high temperature anti corrosive coating,high temperature abrasion resistant coatings,can be processed into the silicon carbide anti abrasive coating etc.Above several kinds of coating with different combination can satisfy the protection and maintenance requirements of the wet desulfurization (FGD) equipment completely.
