KB Mathur describes how manufacturing plants can use Total Lubrication Management (TLM) recommended best practices to reduce their energy consumption, emissions and operating costs.
It is a simple fact: good machine lubrication can lead to energy savings and an improved mechanical maintenance, thus helping in corporate profitability. This ought to interest any plant management, people who are looking for ways to reduce operating costs; it is especially significant at a time when operating in a competitive global economy, besides energy-conservation, is a national cause.
Power utility bills of the plants are far larger than maintenance and lubrication costs. So, while controlling or reducing maintenance and lubrication costs is important, reducing electricity usage is critical. There exists tremendous opportunities for the use of an improved lubrication reliability programme to decrease plant energy costs, thereby increasing plant profitability.
Energy for work
During conversions from one form of energy to another, some useable energy is lost. These energy losses can be extremely costly. The science of physics reveals that lubrication can play a role in reducing energy losses by reducing friction. Placed between two moving surfaces, a lubricant decreases the co-efficient of friction. Naturally, this would also mean the more a lubricant decreases friction, the less energy a well- lubricated machine consumes.
Lubricant formulation
All lubricants consist of a base oil of required viscosity, blended with special chemicals called additives. These additives are carefully selected by the oil companies, keeping in view the end use application, such as engine oils, gear oils, transmission oil, hydraulic oils, compressor oils, etc. A lot of research work is done by the oil companies before the oil is approved for an application and offered to users or the market. All lubricants are approved by OEMs after field tests under stringent test conditions. However, just buying an expensive lubricant also does not ensure maximum lubricant performance and energy savings. The lubricant must be the right one for the application and must be properly maintained for its quality in order for it to provide maximum machine performance. So, how does the end-user know what to do? The answer is to adopt the Total Lubrication Management (TLM) system. Always remember that the oil in the machine is like blood in the human body, so, keep it clean and free from any contamination.
Lubrication and energy savings
It is possible to measure energy savings in a variety of ways, including production output, temperature changes or reduction in electrical energy consumption. Other measurements are maintenance costs and fuel consumption.
Production output: When using any mechanical equipment, it is possible to evaluate the equipment’s energy efficiency by recoding its production output. For example, if a machine is capable of producing a certain number of parts in a given amount of time and the lubricant is kept clean, as per recommended cleanliness standards and lubrication systems are improved, t his will result in a higher volume of production in the same amount of time, and the machine has obviously become more energy efficient and productive.
Temperature changes: Monitoring temperature changes is another way to optimise the lubrication programme performance. Increased friction in a machine’s moving parts results in higher operating temperatures. Friction is the result of metal-to-metal contact that occurs between two surfaces moving relative to one another. Asperity contact occurs even between highly machined surfaces, under microscopic view.
The greater the amount of metal-to-metal contact, the greater is the amount of friction. As a result, more energy is required to move the surfaces relative to one another. This friction results in higher electrical power costs. Lubricants and a good lubrication system can reduce that friction. When friction is reduced, less electricity is required to drive a gearbox, compressor, pump or other equipment, and this leads to energy conservation.
Electrical energy reduction: Tracking electrical consumption is a highly reliable way to evaluate improvements in plant energy use. In fact, various organisations have been able to document improvements in electrical energy efficiency after the implementation of lubrication management programmes. Companies that upgrade their lubrication and reliability practices have been able to document a 5 û 10 per cent reduction in power consumption, more than enough to pay for implementing good lubrication programme by professional service providers. Average documented savings were ten per cent in gear boxes, 12 per cent in air compressors and 4 per cent in electric motors.
Electric motors power most plant machinery like gearboxes, compressors, refrigeration systems, pumps, hydraulic systems and ball mills. The following equation can determine the amount of electricity used by an electric motor:
kW = V/1000 x A x 1.73 (where V is volts and A is amperes)
b kW = v3 VI. Cos + û corresponding Cos + at 0.9 which all the plants are meeting as per requirement of the Electricity Board.
Both are common metric measurements of electrical current measured using a voltmeter or ammeter. For a three-phase motor, 1.73 is a standard factor. Data logging equipment is available that allows one to measure and collect data for either amperes, volts or both. Yet, most electrical consumers pay for electricity by kilowatt-hour (kWh) per month. The following formula is commonly used to determine the electrical charge per month (ECM):
ECM = kW x h x EC (where h is hours of service and EC is the electrical charge.
Air compressors are an excellent source of energy savings. Compressed air is one of the most expensive uses of energy in a manufacturing plant, and approximately 70 per cent of all manufacturers have a compressed air system. These systems power a variety of equipment, including machine tools, material handling and separation equipment and spray painting equipment. According to a study, compressed air systems account for ten per cent of all electricity and roughly 16 per cent of industrial motor system energy use. This adds up to large amount of expenditure per year in energy costs. Energy audits conducted suggest that more than 50 per cent of compressed air systems at industrial facilities have significant energy conservation opportunities.
Conclusion
Energy conservation is very important to industry, as important as conserving natural resources, reducing emissions and improving profitability. Governments and corporate management in the industry alike are looking for ways to reduce energy consumption. It is possible to make dramatic gains in energy efficiency by reducing friction, and the best ways to do that is to employ good lubrication practices, use high-performance lubricants and adopt lubrication reliability best practices. Adopting Total Lubrication Management for energy conservation, manufacturing cost reduction and improving productivity and profitability, would be ideal.
RECOMMENDED PARAMETERS FOR TLM IMPLEMENTATION
- Select correct grade and viscosity of lubricants for the specific application and ensure this grade has OEM acceptance.
- Store oil in a clean environment to keep oil uncontaminated in storage. Greases should be stored indoors to avoid day/night temperature fluctuations. This can lead to soap-oil separation, making grease unfit for usage. Good housekeeping at lubricants storage is the most important and is at fulcrum of entire activity.
- Adopt colour coding to eliminate any possibility of mix-up in oils leading to contamination.
- Use good and clean lubrication equipment to ensure feeding uncontaminated lubricants to machines.
- Keep oil clean by providing `breathers on machines oil sump and inspect oil filters on machines oil systems regularly.
- Test oils regularly for oil condition and machine condition, i.e, contamination, additive depletion, wear debris and elemental analysis, etc.
- Regular training to be given lubrication staff for correct lubrication techniques. All lubrication staff should be skilled.
- Enforce excellent housekeeping at oil storage, handling and dispensing area.
- Keep oil points at machine clean to ensure that no dust or dirt particles go in the machine sump along with oil.
- Adopt target based oil management system. Ensure that at least 95% of the oil is drained out from the sump before feeding new oil into the sump.
K.B. Mathur, Director, Global Technical Services, Email: kbmathur@gtsindia.com