Wet flue gas desulfurization process is the most mature in technology and the most widely used in the world at present,wet flue gas desulfurization
contacts with the flue gas through circulating liquid to produce the chemical reaction to achieve desulfuration effect,the flue gas which produced by
burning is acidic,acidic material from flue gas dissolved in water to form weak acid.Wet sprinkling reduced the temperature of flue gas,when the flue
gas temperature is below acid dew point,it will appear the acid dew formation phenomenon,congealed acid liquor will absorbed on the absorption tower
inner wall and other parts accessories to cause the equipment corrosion.
Zhenzhou Xinli Electric Power Co. , Ltd has 5 sets 220 MW heat supply turbine units for business undertaking at present,absorption tower piperonyl
cyclonene is under the condition of serious corrosion and abrasion,use the Xiangyang Hundred Shield composite protective coating to do the protection,
this project tested run in successful on March,2016,go through testing run for 6 months,it has already finished performance tests of continuous 15 days
on Sep.2016,the various index all achieve the standard requirements,we can make sure the desulfuration efficiency be more than 95%,the desulfurization
equipment runs steadily,corrosion resistant condition is good
1.The construction procedure as follow:
surface treatment:Do coarsening treatment on the pending-repair area, grinding with angle grinder or sand blasting and so on, the surface after
coarsening treatment should be cleaned,the surface after this treatment should be the one coarsening,dry and fresh substrates,should be no greasy
dirt and dust.
2.The preparation of anti corrosion resistant protective coating:
First: The preparation of BD407 corrosion resistant repair coating is based on the mixing weight ratio A:B=4:1,then stir and mix them uniformly.Notice:
every time the largest preparation quantity can’t be more than 2Kg,and use it up within 30 min.
Second:Make the well mixed anti corrosion resistant protective coating be blade coating on the pending-construction area of absorption tower piperonyl
cyclonene uniformly,and blade coating for at least 2 times with corrosion resistant protection coating,the whole coating thickness is about 1.5mm.
Third:The curing and detection of anti corrosion protective coating:After the corrosion resistant coating curing,should do electric spark leak-checking detection,electric spark detector voltage should be setted between 1000V and 1500V,the detection area where has no electric discharge phenomena is
compliance region,if there is electric discharge part,we should line out obvious tagged,then do the repairing for this area,the part after repairing after
curing,should do the secondary detection,until that the whole anti corrosion resistant protective coating has no leakage point,we should do the next step
operation after the repairing part curing.
3.The preparation of anti wear abrasion resistant protection coating:
Before wear abrasion resistant protective coating construction,we should confirm that the previous used anti corrosion protective coating has already
been complete curing,should pay attention to doing the protection for already cured corrosion resistant protective coating during the wear resistant
protection coating construction,must not let the corrosion resistant coating appear damage phenomenon,the constructors could pave soft nature
protective material on the already cured corrosion resistant protective coating to do the protection,and the construction action should be tenderness.
First:The preparation of BD7053 high performance ceramic composite coating material is based on the mixing weight ratio A:B=4:1,and stir it uniformly,
notice:every time the largest preparation quantity should be 5 to 10Kg,and use it up within 30 min.
Second:Make the well mixed BD7053 ceramic composite coating material be blade coating on the surface which has already finished anti corrosion
protective coating layer by layer uniformly.We should ensure coating material surface be smooth during construction,and make sure the internal dense
and jointing part fastness.
Third:The curing of anti wear abrasion resistant protective coating,according to the different temperature,we should place it for 12-24 hours to do
the curing.
Fourth:Brush coating the topcoat:brush coating the topcoat on the surface of anti wear abrasion resistant protective coating after curing,it can close
the interspace of abrasion wear resistant coating surface based on the actual condition.
Should pay attention to the below details during construction:
1.Substrates surface treatment should be clean,dry and rough
2.The mixing ratio of materials should be accurate
3.The materials should be stirred uniformly,non-uniform materials will certainly have some parts without good curing,it will affect the coating whole
performance.
4.The materials should be used up within the specified operation time limit or before initial curing,the material which has already been initial curing can’t
be used any more.
5.The spread coating should be careful,the material should be spread coating uniformly and compacted,we should pay more attention to especially the corner
and jointing part.
6.The construction principle of composite coating is that spread coating the next layer before the upper layer has no complete curing,make the coating
form the whole.
7.Curing:the curing time is different under the different temperature,we should put it into using after the composite protective coating material complete
curing.
8.Detection:The quality of desulfurization system protective coating project can not judge only by the naked eyes,we should be sure that inspect it through
special instruments,for the part of the problem by detection,we should do the leak repairing construction,and test it again until there is no problem.
