Before answering the question, shall we better understand the context of a filter element?
When it comes to equipment, machinery and engines, what is expected is adequate productivity, as well as the least possible wear on parts. However, for this to happen, it is necessary that the entire system is functioning correctly, starting with the filtering process.
Filtration is the technology responsible for eliminating the contamination present in the oil. Briefly, it is the process of forcing the passage of a liquid or gas through a porous material in order to remove suspended particles (solid or water). These particles, in turn, cause great damage on a daily basis when not eliminated, such as:
- Slow performance;
- Low productivity;
- Difficulty of operation;
- Increased maintenance expenses;
- Need for spare parts;
- Accelerated wear of equipment;
- Stopped machines;
However, for filtering to be efficient, it is essential to ensure that the filter element is in proper condition.
What is the filter element?
Also known as a cartridge or refill, the filter element plays a fundamental role in removing water and solid particles from the oil. It is the mobile part of the filter, which acts on the retention of particles up to 2 microns.
The filter element prevents dirt from circulating and damages hydraulic, lubricating and combustion systems of machines and vehicles. That is, the solid and water particles are prevented from returning to the pipeline.
What are the types of filter elements?
There are 2 types of filter element, the surface and the depth. Both work to remove water and solid particles from the oil.
Surface filter element:
If the thickness of the filter medium is similar to the particle size of the particles to be extracted, the process is called surface filtration. This is because the material is trapped on the filter surface. The filtering mechanisms are collision or sieving. It is very common to find air filters of this model.
Depth filter element:
A depth filter element is made of pure long fiber cellulose. The fibers are organized and enveloped specifically in an industrial process, the final appearance of which resembles highly dense paper rolls. Such “coils” are manufactured in specific sizes to fit properly in the structures and hulls of the filters. The filtering element is made up of a random network of microfibers of very small granulometry, to the point of retaining microscopic particles.
VIDEO – Filtration equipment with depth filter element
How the filter element acts in the filtration
How the filter element acts in the filtration The long cellulose fibers attack the water formed in the system by combustion or condensation, and absorb it as if it were a sponge. At the same time, they allow oil molecules and additives to pass through the densely packed fibers in the narrow filter galleries.
As professionals from the POC Filters, the oil passes through the filter element, while tiny carbon particles, wear metals and silicon particles are extracted. The “dirt” is absorbed by the filter’s extensive contact surface, which also removes the water present in the oil. The filter element also:
- Inhibits the production of acids, which degrade the oil and cause excessive wear on the mechanical parts;
- Simultaneously removes contaminants at the exact moment they appear, which allows an increase in the time of oil use within the original conditions of use of the equipment;
Filter element and removal of solid particles
Solid particles are invariably present in combustion, hydraulic and lubricant systems. This is due to problems with oil storage, contaminated air entering, contaminated mechanical components, or even burning residues. Within systems, these particles flow through high pressure and blast their components, such as: pumps, valves, cylinders and seals.
With the use of a depth filter element, the problem with oil contamination, even by microparticles, is solved. Particles of up to 2 microns are trapped in the galleries of the filter element.
Filter element and moisture removal
The natural moisture formed in the reservoir, or even condensed water from the equipment’s temperature variations, causes damage to the tank walls. This generates rust, fungi and bacteria, contaminants which are captured by the pump and distributed throughout the system.
In modern machines, the tolerances for the moisture content are so small that the expansion of condensed water causes “explosions” against the contact areas of the parts. The event, in turn, produces new wear particles and, consequently, the contact areas lose the lubricating film.
That is, the condensed water attacks the metal surfaces through corrosion and slowly penetrates the microscopic pores. This causes fatigue wear.
Again, to solve this type of problem, the use of a depth filter element is recommended. The action causes moisture to be absorbed by the element’s fibers, eliminating contamination from the system.
The advantages of the depth filter element
- Prevention of mechanical failures and increase the useful life of the equipment;
- Reduction of maintenance costs;
- Decrease in the level of contamination by particles suspended in the oil;
- Increase of the useful life of the machinery and prevention of possible component failures;
- Extension of oil change periods, which means increased equipment availability and financial gain;
- Prevents oxidation and wear of oil additives
Also read our case studies:
Find out more: how a depth filter element is made
– A bed of coarser grains (for example, 0.3 mm to 5 mm deep layer of sand);
– A granular support layer to the main filter (pre-coating layer, for example); They can be wire cartridges, fiber agglomerates, porous plastic and sintered metals.
Therefore, depth filters are constituted by a random network of microfibers of very small granulometry, to the point of retaining microscopic particles. This is what ensures that filtration does not occur only on the surface, but in depth through the entire filter medium. The filter, in turn, can consist of polymers, cellulose or fiberglass, separated or composed.
Maze: the depth filtration process means that contaminants have to pass through a kind of “labyrinth” inside the device. In this way, solid particles and water become entangled in the interwoven microfibers that make up the filtering network. Many depth filters are papers folded in various thicknesses, thus creating a larger filter surface in the same space, when compared to surface filters of equal size.
Filter element for hydraulic, industrial and diesel oils
The filtering element is essential to guarantee the quality of hydraulic, industrial and diesel oils. This is because it increases productivity and extends the useful life of equipment, machines and engines. This is because it increases productivity and extends the useful life of equipment, machines and engines.
The oil filter element can be found with different compositions, such as:
- Paper matrix (cellulose): it has a high particle retention capacity, being recommended for the filtration of mineral oils, emulsions, and most synthetic oils. It is a low cost filter element and ideal for low pressures;
- Fiberglass: performs depth filtration and offers great particle absorption capacity (absolute filters). Also intended for mineral oils, emulsions, and most synthetic oils, the glass fiber filter element has uniform fiber size, in addition to a smaller diameter than cellulose fibers. That means smaller, more controlled passes.
How to choose filter element right?
The choice of the filter will depend on its purpose. However, the most important features when choosing elements are:
Efficiency: nominal x absolute filtration;
Beta filtering ratio;
Type of oil flow: full flow or independent circuit?
Specific resistance of the porous filtration medium;
Volume of oil to be filtered;
Degree of contamination;
Ease of maintenance, cleaning and removal of the pie formed;
Below we explain a little more about the first two items in the previous list.
Efficiency: nominal filter element x absolute filter element
Pay attention to the beta ratio of the filter element
At POC Filters, we consider that analyzing the Beta Ratio of a filter element is one of the best methodologies for comparing filter performance. Performed according to standardized procedures, its application allows to measure the filter capacity to remove particles of a given size in the fluid stream, evaluating its efficiency.
See a comparative table
See a comparative table
|Beta reason (x = particle size in microns)||Efficiency|
|ßx = 2||50%|
|ßx = 10||90%|
|ßx = 20||95%|
|ßx = 75||98,7%|
|ßx = 200||99,5%|
|ßx = 1.000||99,9%|
Read too: Find out what the beta filter ratio is
Rated filter element absorption power
The unit of measurement used by the nominal filter element is the micron (µm). The measurement determines the particle size that the filter is capable of retaining, for example, 5 microns.
However, the nominal filter element ends up allowing a percentage of particles above 5 microns to end up going through the filtering process. This even with a performance that can vary between 90% to 98% of oil cleaning.
This even with a performance that can vary between 90% to 98% of oil cleaning.
This even with a performance that can vary between 90% to 98% of oil cleaning.
The absolute filter element works with the maximum particle diameter that can pass through the system, such as “up to” 5 microns. That is, nothing equal to or above 5 microns will remain in the oil, as can happen with the nominal filter element. The beta degree of filtration efficiency generally ranges from 99% to 99.99%.
The beta degree of filtration efficiency generally ranges from 99% to 99.99%.
The beta degree of filtration efficiency generally ranges from 99% to 99.99%. the great villains of the lubricating and hydraulic systems. The action of contaminants generates damage to pumps, valves, cylinders and seals.
However, thanks to the filter element, such problems can be prevented, which guarantees the quality of the oil.
The table and video demonstrations throughout this post highlight that the best filter element is “depth” or ABSOLUTE. The depth filter element carried out the so-called “microfiltration”Of oil and fluids. The predictive maintenance technique prevents moisture and solid particles, such as metals (which originate from friction events in the system), to accelerate the process of oil oxidation and wear of oil additives.
The importance of installing the oil filter
In addition to increasing the service life of the equipment, the oil filtration system is crucial to the reliability of any hydraulic or combustion installation, which ultimately depends on the cleanliness of the system. This is equivalent to saying that the quality of the machines, engines and equipment, as well as the final products, will depend on filtration.
Fundamentally, oil filters must be able to retain all contaminants that may cause damage, failures or breakdowns in the engine or equipment. At the same time, it also aims to maintain the structural characteristics of the oil, as well as the uniformity of circulation of the lubricant inside the machine and efficiency while it is being used.
For this reason, it is very important that filters and filtration systems are designed with the production objective in mind. It is also necessary to take into consideration the cost-benefit ratio, the performance of the filter, the ease of use and maintenance, the environmental standards and the environmental management system adopted by your company.
In addition, following the filter change recommendations offered by manufacturers in the instruction manuals is essential.
Do you want to know more about the filter element or need specialized help? Then get in touch with professionals POC Filters, who are always on hand to assist in the search for the best solutions for your equipment.