If spilled, lubricants can contaminate the environment. Therefore, most maintenance strategies today work to prevent such contamination from occurring. Gradually more and more companies are becoming aware of the effects of lubricant disposal and the impact on the environment. Within the company there should be an understanding of lubrication best practices. The use of quality lubes will go a long way in keeping equipment running longer, smoother and with greater efficiency. Good lubrication keeps equipment from ageing prematurely. Studies have shown, that well-oiled machinery consumes less electrical power, and this saving can help finance proactive maintenance.
Making good environmental lubricant choices does not have to compromise equipment reliability or functionality. In fact, appropriate environmental decisions can be part of a first-rate, cost-effective design. The design aspects include the equipment itself, maintainability, economic life span, ergonomics, operation and eventual removal. Removal does not necessarily mean disposal, because there may be some recoverable value left in the machine.
Oil in equipment should not be changed unless it has reached the end of its useful life. This is typically not the case, because the oil is often changed based on an arbitrary time criteria or because of contaminants such as water or dirt. These contaminants can normally be removed with the proper equipment.
A longer oil lifecycle not only contributes to less liquid waste, but there are other benefits as well: cost savings because labor can be used more effectively elsewhere, and fewer shutdowns for oil changes. These added costs can amount to at least five times the price of the oil alone. In addition, not having to drain the old oil, move it for disposal and bring in new oil also means less chance of spills. Spillage can often occur when a pail is knocked over or a drain valve breaks off.
The effect of lubricants on the environment is proportional to the amount used, so minimizing consumption is a major component to conserving natural resources. Therefore, anything that can be done to minimize consumption is worthwhile to your lube management program.
For a lubricant to be most effective, a number of correct decisions must be made throughout its service life, such as the following:
Selecting the proper lubricant is important to sharply reduce long-term costs. The best-fit product selection can mean longer lubricant life, reduced machine wear, reduced incipient power losses and improved safety. Suitable base stocks and additives reduce environmental impact. This is important because there will be leaks, spills and eventual disposal.
With the right lubricant, there is a greater likelihood that a product can later be used elsewhere in less demanding applications. The correct choice might be synthetic lubricants, lubricants with different additives, or biodegradable products and/or products with less environmental impact. The best product selection for each application varies, depending upon the equipment specifics.
Eliminating conditions such as hot spots and air entrainment, as well as providing a good ergonomic design, will reduce the stresses on the lubricant. Proper and effective maintenance is the key for maximum performance from both the equipment and the lubricants.
Equipment should have adequate seals to prevent the ingress of contaminants and reduce lubricant loss. Breathers should have adequate provisions for filtration to remove particulates and contact-type shaft seals should be selected based on lifecycle and durability. These kinds of features help extend the life of the lubricant and the equipment. Proper component selection and configuration can also mean lower temperatures and possibly less auxiliary equipment such as coolers or heaters.
Reducing Liquid Waste and Cost
Industrial lubricant lifecycles can be extended dramatically from typical annual lifecycles if the lubricant is managed effectively in the sump. To get maximum value from the oil-lubricated components, keep the oil cool, clean and dry. For self-contained sumps this can simply mean ensuring that make-up oil is added properly, that the breathers are adequate and operational, and that any cloudiness is corrected. For circulating oil systems, ensure that the make-up oil is not a source of contaminant. In most cases, side-stream filtration, either continuous or intermittent, can be deployed to control these factors.
Lubricant condition monitoring (oil analysis), is critical for safe lifecycle extension. Analysis serves three main purposes:
First, it ensures that the right lubricant is in place.
Viscosity, additive content and acid number are all telltale indicators of lubricant mixing. Some types of cross contamination become immediately evident.
For example, even a slight amount of combustion engine oil mixed into the turbine circulating oil will destroy the turbine oil’s ability to shed water. Extreme pressure additives may be necessary in some cases, while the same additive may be detrimental in others. Generally, they shorten service lives or present additional considerations for materials such as for the plastic cages in bearings.
Secondly, machine condition monitoring, when done in conjunction with lubricant condition monitoring, provides a long-term view into the health of the production asset. An advantage of lubricant-based analysis is that it detects machine problems in the oil before the problems are manifested in the equipment.
Other analysis methods, while certainly beneficial, measure for damage that already exists at a level which almost always requires repair. This is important, as the goal is not to save the oil, which is typically inexpensive, but rather to prevent damage to and extend lubricant component lifecycles. Even an inexpensive shaft bearing will require taking that equipment out of service to be replaced.
Lastly, oil testing determines what is required to keep it in good condition. This can be purification or additive supplement through sweetening (bleed and feed). When contamination exists, it is usually an advantage if the lubricant can be treated while still in the equipment so an outage will not be required.
From the perspective of environmental impact, managing your lubricant consumption can be a challenge!
The WinnerWheel's part 9: Environmental Control
can be downloaded here:
Machinery Lubrication – K. Brown