Manufacturing of automobiles and auto components involves many steps such as casting, forging, painting and electroplating and so on that require heat or steam. Original Equipment Manufacturers and larger players have in-house facilities to perform the above mentioned activities. However, some industries outsource the activities such as electroplating and painting of the auto components to smaller and unorganized sector units. The entire process requires large amount of energy in the form of both heat and electrical energy.
Some of the typical processes in the automobile manufacturing are explained in the following figure:
The use of an appropriate solar thermal technology can have a positive impact on the energy and environmental scenario of Automobile industry at a large. There are various solar thermal technologies available for Automobile industries mainly in solar concentrator systems. The steam or pressurized hot water generated by the solar thermal technologies can be used in the following processes:
- Component Cleaning (Degreasing): Hot water is sprayed on the components to remove the dust content from different engine components. The hot water to be sprayed is heated either by electric heaters or some other heating sources.
- Drying of washed components: The washed components are dried in the hot air chamber in which the hot air is blown at 200°C. The air is heated using electrical coil or gas fired burner. The heating cycle depends upon the size of the component.
- Dip Zinc Phosphating (7 tank process): A standard 7 tank DIP ZINC PHOSPHATING process is used, where good paint adhesion and corrosion resistance are required before painting. All heated tanks may be heated directly by electrical immersion heaters, closed steam coils or Thermopac.
- Mould Drying – The casted/moulded components are coated with anti-corrosion coatings for improving life and the performance. These components are dried by hot air blower.
- Tempering Furnace: Hardening and tempering are normally used to improve the wear resistance, strength and toughness of the component. Some typical application in automobile industry are low temperature tempering (150°C-200°C) of 1%C 1%Cr bearing steels; medium temperature tempering (350°C-550°C) of 0.7% carbon steel & high temperature tempering (550°C-650°C) of medium carbon low alloy steel.
- Paint baking ovens: After each coat of paint, the paint is baked in baking oven using hot air heated either by electric coils or gas burners. The temperatures required in different baking ovens ranges from 120°C to 170°C