Designing Fans For Use In Corrosive Conditions
                     Designing Fans For Use In Corrosive 
Conditions
Neel Rao
Writes on Reitz India forced draft fan & Reitz 
India Industrial centrifugal fans manufacturer.
Selecting the right fan is important while dealing with corrosive environments. Further, 
for achieving optimal performance and increasing the longevity of the equipment it is 
essential to select the right fan for use in corrosive environments. The chance of 
erosion of the process fans depends on the industrial application of the fan. There are 
chances of corrosion in chemical, pulp and paper, or water treatment application, 
metal and mineral processing, petrochemical, pharmaceutical and steel processing 
industries.
Corrosive gases that exist in an industrial environment are hydrogen sulphide, chlorine, 
sulphur dioxide, ammonia, ozone, mercaptans, hydrogen fluoride or sodium 
hypochlorite. These are not gases that need to be dealt with, but these cause 
equipment corrosion.
The service life of fan constructed of carbon steel may be significantly reduced when 
corrosives are allowed to attack the surface of the metal through chemical or 
electrochemical action. Hence, it is necessary to provide protection from a variety of 
corrosives including acids, alkalis, solvents, salts, and oils. Some methods for inhibiting 
this corrosive action is by use of specialized alloys and fiberglass-reinforced plastic 
(FRP).
Remarkable resistance to corrosion is offered through stainless steel. But there are 
environments that can cause permanent breakdown of the protective chromium 
oxide passive layer on the steel, leading to corrosion on an unprotected surface. To 
improve resistance to corrosion resistance fans are manufactured using high-
performance stainless steels which are steel alloys created by adding elements like 
molybdenum and nitrogen.  Stainless steel is more corrosion resistant as compared to 
carbon steel or mild steel.
Polyvinyl chloride (PVC) fans provide good protection from corrosion. PVC fans are 
suitable for up to 140°F. When compared with fiberglass-reinforced plastic (FRP) fans, 
PVC/ polypropylene fans often are more economical.
Polypropylene fans are resistant to many acids, caustic, and inorganic saline products 
used in labs and hence they are corrosion resistive. Further, polypropylene fans can 
be operated at higher temperatures than PVC fans i.e. up to 190°F.
For corrosion resistance, one can use fans made up of fiberglass. Other than corrosion 
resistance fiberglass also provides other applications such as fume, pollution, odor, 
process control, oil mist emissions, heating or cooling and scrubbers. Some 
advantages of using fiberglass fans are it provides superior corrosion resistance to 
gases and vapors.  Also, its maintenance costs are much lower and fiberglass fans are 
more economical than stainless steel construction.
Apart from building industrial fans with different materials, there are corrosion 
resistant coatings that can be applied for fans manufactured with regular materials. 
These protective coatings act as a barrier between the corrosive and the parent 
material. Protective coating selection is critical in determining the service life of the 
equipment. The actual chemical composition of the gas stream and concentrations 
and temperatures of the chemicals present must be considered for the selection 
process. There are nearly a dozen different types of protective coatings that can be 
applied to an industrial fan including phenolic, epoxy, Epoxy-phenolic, inorganic zinc, 
vinyl, coal tar epoxy, alkyds, silicone, polyurethane, polyester and vinyl ester.
The ambient air within the area of using corrosive material will also have a 
concentration of these materials. Therefore, it is important to consider this fact when 
choosing the correct fan for your industrial application.
About REITZINDIA
Reitz India has set a benchmark to deliver high quality fans for heavy duty industries 
which can work at precise operating conditions like high temperatures and pressures. 
Reitz offer idealistic Centrifugal Fan and Centrifugal blower design that can be used in 
all large scale process industries like cement, iron & steel, power plants, fertilizers/ 
chemicals and more.
Thank you for spending your precious time in reading this article!