wet desulfuration system wear corrosion resistant coating

The construction application of our anti chemical corrosion abrasion wearing resistant epoxy compound ceramic coatings
used in wet desulfurization system rubber lining pipeline repairing and protecting

(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.

Itself performance of wet desulfurization (FGD) protective coating material and the selection of materials is very important,the control and testing of
the construction process is also very important.

We should pay special attention to the following details during construction:

1. The surface treatment of the substrate must be clean,dry and rough.

2. The ratio of material must be accurate,the proportion of material manufacturers provide by the equivalent response,a component of more or less
will certainly have free substance which doesn't participate in the reaction,the overall performance of the coating will certainly decrease.

3. The material must stir uniformly,uneven material certainly has the place of bad curing,affect the overall performance of the coatings.

4. We should use up the materials at the specific time or before initial curing,the material which has already initial curing can't be used again.

5. we should be careful during smearing,the material should smear uniformly and compacted,we should pay more attention to the summer-planting parts,
especially the edge corner.

6. The construction principle of combined coatings is that smear the next layer when the first layer is not complete curing,make the coatings form
an integral whole.

7.Curing,the length of curing time is not the same under the different temperature,we must put into operation after the combined coating materials
complete curing.Not complete curing material physical and mechanical properties is very low,premature starting up is likely to cause damage for
not complete curing combined coatings

8. Testing,desulfurization system protective coating projects can't judge the quality only by the naked eye,be sure to use special instrument to detect,
for the part of appearing the problem,we should do leak repairing construction,and test again until there is no problem.