repairing and protecting
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,the main pipeline and
equipment of desulfurization system,such as absorption tower,mist eliminator and pumps etc all need to take measures of corrosion resistant,
for the existent corrosion problem inside of desulfurization tower,it has already had much more mature anti abrasion corrosion resistant meatures,
we use the Xiangyang Hundred Shield desulfurization tower ceramic lining coating material and pass the actual application,and achieve ideal anti
wear abrasion corrosion resistant effect.
Desulfuration tower is the core equipment of the wet desulfurization system(FGD).Flue gas contacts with the slurry here in the desulfurization tower
and mix to complete desulfurization reaction,this area mainly has corrosion together with abrasion,choosing BD7058 desulfuration tower ceramic lining
coating material can effectively solve its internal abrasion and corrosion problem,since 2008 we researched and developed this ceramic liner coating
material,it has already been used in many power plants,the use effect is very good,it got customers’ consistent good reputation,this ceramic liner
material is a kind of special anti wear corrosion resistant coating which is developed for the desulfurization tower anti abrasion corrosion resistant
protection by Xiangyang City Hundred Shield Coating.It is the high performance,high temperature resistant,abrasion resistant and corrosion resistant
polymeric ceramic material which compounded by high performance wear resistant and corrosion resistant material and modified toughening heat
resistant resin and special curing agent.
This ceramic lining material has the below features:
1.Wigh good performance of wear resistant and corrosion resistant,do not crack for long-terms hot-water soak,it can sustained and effective protect
desulfurization tower(absorption tower) from erosive wear and lose efficacy,only in this way it can make the equipment long-term reliable running.
2.With high bonding strength to metal substrates.
3.With good toughness,do not crack,with long working life
4.Suitable for the protection of high temperature erosive wear and corrosion working condition
5.Hot water resistant,steam resistant,acid & alkali resistant(especially for chloridion corrosion resistant)
6.Do not flow and slip,the construction is convenient,the coating after curing has smooth surface.
This ceramic liner coating material is used for protecting anti corrosion resistant coating from erosive wear and cause losing efficacy,and provide
continuous protection for the workpiece,its service life is depends on the coating thickness,according to the feedback data,the desulfuration tower
which is repaired by using BD7058 ceramic lining coating material,every 4mm coating thickness can provide about 3 years’ protection for the
desulfurization tower.
The construction technology 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 coating be brush coating on the pending-construction area of desulfurization tower uniformly,
and brush coating for at least 2 times with corrosion resistant protective coating,the whole coating thickness is about 1.3mm.
Third:The curing and detection of anti corrosion protection 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.
The preparation of desulfuration tower ceramic liner coating material:
Before the BD7058 desulfurization tower ceramic lining material construction,we should confirm that the previous used anti corrosion resistant protective
coating has already been complete curing,should pay attention to doing the protection for already cured corrosion resistant protective coating during
abrasion resistant ceramic liner material,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 BD7058 high performance abrasion resistant ceramic lining 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 desulfurization tower ceramic lining 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 ceramic liner material,according to the different temperature,we should place it for about 24 hours to do the curing.
Fourth:Brush coating the topcoat,brush coating the topcoat on the surface of ceramic lining material 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.
