Corrosion and its Prevention

After having learnt about materials used for the fabrication of dairy equipment, it is now important to learn as to how to increase the life of machine and equipment.Metals employed for their fabrication becomes unstable and tend to react with environment within the dairy plant. Dairies have hot and humid environment and equipment come in contact with detergents and other chemicals used for their cleaning and sanitization. Corrosion is a process of electro-chemical decay. The amount of corrosion will depend on the type and composition of materials. Corrosion will be greatly affected by the presence of moisture or water, the temperature of surroundings and the chemical nature of the product in contact. Two dissimilar metals if used during construction, the corrosion will be fast. Non-metals are considered corrosion resistant. Now question is that how to prevent or reduce the corrosion. It can be done by:

Protective coating on metals/equipment: Most of the equipment are generally made from stainless steel, which does not need any protective coating. But certain frames, supports or the components of equipment are made from other metals.These could be protected by metallic coating such as hot-dipping, electroplating,metal spray coating, or cladding/ covering with soft metal like thin aluminum sheet.

Some inorganic chemicals like anodizing treatment for aluminum cans are also made. Painting the surface does involve organic coating. Synthetic resins in oil or solvent give a continuous inert film on surface.By selecting non-corrosive metal as far as possible.

By engineering design of components: Avoid in-built stress or loading during fabrication. Like no dead corners, avoid undulation or pits, self-draining slopes,rounded corners, no over hung parts/ component, inbuilt thermal expansion joints,appropriate gaskets and packing materials, etc.

Control of process environment: As already explained, avoid moisture accumulation around equipment, especially near its base and foundation. Avoid condensation, seepage, leakage, etc. Keep the surrounding dry as much as possible.Some general life giving practices to be followed: Use only soft brush (fibre brush) during manual cleaning of surfaces, remove all accumulated milk residues,use only recommended detergents and keep the surface dry whenever the equipment is not in use.

No comments:

Post a Comment

Note: Only a member of this blog may post a comment.


Most Reading