A basic knowledge of oil filtration requirements, challenges, and solutions can make it easy to understand oil contamination and filtration. Oil filters are utilized in many types of hydraulic machinery to improve the quality of oil.
Oil filtration requirements
Filtration plays a key role in maintaining hydraulic equipment and fluids. The fluid contamination leads to corrosion, wear, unsatisfactory performance, and ultimately, the equipment failure. Most of the oil filters perform a simple function; trapping the particles in small holes and cleaning oil. The fluid passes through the filter while particles above a certain size are trapped. Engine oil filters have to deal with the following challenges:
- To remove or mitigate contaminants that are detrimental to the engine
- To have the ability to hold contaminants for the required service interval
- To have the capacity to allow oil to flow through the filter and be cleaned
There are many types of oil filtration products that vary in terms of performance and efficiency. Some filters offer 50% efficiency which means they remove half of the contaminants in oil at a given particle size. We can test the efficiency of an oil filter through various techniques.
Cold flow is a common term experts use to describe a condition where oil experience restrictions while passing through the filter. It happens when oil becomes thick due to high soot and sludge levels. Cold flow also happens when filtration experts put filters on high efficiency. When the unfiltered oil is allowed to circulate in the engine, it stimulates corrosion process that affects engine life. Therefore, it is important to have the filters with the right balance of efficiency, cold flow ability, and capacity.
Capacity, efficiency, and cold flow ability are three critical requirements and mandatory to ensure extended engine life and performance. Real world testing is the only way to determine an optimal balance of these three requirements.
Contamination in lubrication systems
We must first understand the issues that arise due to oil contamination in an engine. We can classify contaminants in diesel engines lubrication systems as organic and inorganic. Organic contamination or sludge is formed due to by-products of combustion and comprises more than 70% of total contaminants in diesel engines. It limits the ability of a filter to trap harmful contaminants.
Inorganic contaminant also called dust is formed due to core sand, wear metal, gasket material, and dirt. A filter’s capacity to filter out dust does not reflect its performance. High-quality oil filtration systems play effective role in holding sludge along with the dust in the oil. Controlling these organic and inorganic contaminants can effectively reduce wear in the engine and improve equipment performance.