Energy Efficiency in Manufacturing – DIY Series 002

With rapidly depleting natural resources, it becomes essential to move towards energy-efficient and cleaner methods of manufacturing. This article focuses on manufacturing technologies for Indian industries that are looking forward to implementing green practices or energy-efficient practices into their processes.

In today’s world, where the power situation has become grim and power cuts have become the norm, the availability and cost of energy have become prime concerns for the industry. To meet this gap between demand and supply, the Indian government will have to make large investments in a short period of time. Even in the machine tool industry, manufacturers are becoming increasingly aware of the higher energy costs. For instance, the machine tool builders, The Blue Competence Machine Tools committed themselves to optimize the use of energy and other resources to enable faster, better and higher quality manufacturing in end-user industries. They believed that the production technology and equipment supplied by the machine tool industry is the key enabler of resource-efficient processes in all other manufacturing industries.

India has a huge population of machines with the potential for substantial energy saving. Inverters and servo motors in hydraulic power packs help this cause by saving energy, which can then be used for industrial growth. The objective of using inverter and servo-motors in hydraulic power packs rather than conventional induction motors is to introduce end-users to lifetime benefits rather than payback period.  This helps reduce the investment in infrastructure and results in considerable socio-economic benefits.

Nearly 30% of all plastic products are produced by using the injection molding process, it is evident that energy-saving practices are needed to enter this segment. Injection molding is a manufacturing process for producing parts of thermoplastic and thermosetting plastic materials. On average, the injection molding machine comes up to 70% of the electricity. Typically this energy goes into three places, namely heating of machine’s hydraulic oil, noise, and wear and tear on the machine’s hydraulic system.

If machines always operated at full capacity, then there is no problem. However, machines rarely work at full capacity. This leaves an opportunity to save electricity if there is a way to pump the oil needed by the machine. This was difficult in the past, but with the introduction of AC inverters drives, a remedy to conserve energy can be incorporated during plastic molding.

The basic principle behind implementing a Variable Frequency Drive (VFD) and the system controller is to eliminate not only wastage of hydraulic oil but also energy associated with it. This is done by simply not pumping the oil if it is not required.

Benefits of implementing VFD:

  • Energy Savings
  • Better repeatability
  • Quieter machine
  • Lower oil temperature
  • Less wear and tear of the machine

Similarly, compressed air is widely used in foundries for a variety of tasks including blowing sand into or off moulds, pneumatic transport, spray coating or cleaning. Most foundries use rotary screw compressors (also known as positive displacement compressors) owing to its easy installation for various tasks. Air compression can be an extremely inefficient process with the fact that around 80% of electricity input can be lost as waste heat.

Rotary air compressors can be fitted with Variable Frequency Drives during operations to increase their efficiencies.

Benefits of adding VFD to Screw compressors:

  • Greater efficiency
  • Regulated speed, rotational force, torque output of electric motors
  • Prevents wastage of energy
  • Reduction in power usage
  • Less maintenance
  • Better and longer life spans

These are the few energy efficiency practices followed in the manufacturing sector in India.