The corrosion abrasion of fan impeller is mainly caused by corrosive gas and fine grain particle from the draught fan transport medium,
when the fan impeller carries the dusty gas conveying,the dust particles in the gas such as coal dust,sand grains and rocks etc should impact
the surface of the fan impeller,the blade suffers erosion and corrosion etc. multiple action from abrasive (material) and gas,and cause surface abrasion.
The consequence is that the impeller's balance is damaged,causes the unbalanced vibration of the draught fan,result in the draught fan can’t be normal
running,it is necessary to replace the impeller when serious,when you found the abrasion of the fan impeller,the measures should be taken to protect it
in time,to avoid affecting normal production operations,the usual method is to build up welding the abrasion position,spray welding (spray coating) or apply coating/spray coating on the surface of the impeller.
Nov.2017,during the overhauling of a steel company in hebei province,it was found that the fan impeller is abrasion perforation,they choose the
BD7091 fan impeller special anti wear corrosion resistant coating of Xiangyang City Hundred Shield Coating Material Co.,Ltd to repair it,the blade
surface of fan impeller is inspected on site,it is found that the most serious worn parts of the area have become gouge (local wear out),the slight
severe parts have been worn thin blade shape,the surfaces of other parts wear into minuteness grooves,so it is necessary to take corresponding
protective measures.
construction technology process:
First: impeller surface treatment:
1. Make the pending-repair surface be clean with sand blasting treatment,or use electric wire brush to polish and expose fresh metal substrate,the degree
of processing meets the technical standard requirements.
2. Clean it with special cleaning agent,or wipe the dust to be clean from the surface of machine parts with dry duster cloth,the substrate surface after
treatment should be coarse,dry and clean.
Second: The preparation and brush coating of corrosion resistant coating.
Make the Part A and Part B of BD407 anti corrosion coating mix uniformly according to the specified mixing weight ratio,then brush coating it on the
surface of pending-repair parts,the suitable coating thickness can be 1 to 2mm.
Third: Coating of special wear resistant prime coat.
After the corrosion resistant prime coat curing,make the Part A and Part B of BD4261 prime coat mix uniformly according to the special mixing weight ratio,
then brush coating it on the surface of anti corrosion coating uniformly,the coating thickness shoud not be too large,it is suitable with the dosage of 1.2 kgs
per square meter.
Fourth:The preparation and blade coating of fan impeller special wear resistant coating.
Before the abrasion resistant prime coat curing,weigh the weight of Part A and part B of BD7091 coating accurately according to the specified weight ratio
strictly and mix the two components uniformly,then blade coating it on the surface of prime coat.Repair the surface to be smooth after the coating is in
the suitable size.
Fifth:the curing of the coating.
It can be put into using after curing for 24 hours at room temperature 25 deg C,if the temperature is low,should heat it up or prolong the curing time to
promote the curing.
