ISOPur® BCA® Versus the Competition
ISOPur competes in the Industrial Fluid Filtration and Purification market. ISOPur recognizes purification as the removal of all particles larger than 0.1 microns, including sticky oxide insolubles, ferrous abrasive particles, and bacteria. Purification is not only the act of removing particles, it is also the process of improving the quality of the oil by removing water, breaking emulsions, releasing air, and restoring lubricity.
There are many old technologies in this market such as mechanical filters and centrifuges. These products were introduced over fifty (50) years ago and have more or less remained unchanged. There are a few newer technologies that have improved particle removal capabilities over incumbent technology.
Choosing the appropriate filtration and/or purification depends upon the application, the machine environment, the goals of the plant, and the budget available. The following is a factual, objective view of the current filtration and purification options. Cost comparisons are also listed. The following alternatives are reviewed:
ISOPur Versus Mechanical Filtration
Filtration is an absolute necessity for the protection of industrial machinery. In-line filtration that forms the last line of defense prior to the fluid entering the machine. In fact, ISOPur is usually quite complementary to filtration systems – making them more efficient. ISOPur does not view mechanical filtration as “competition” but as two technologies that work together to perform different functions.
One important note with fine filtration is the result of the electrostatic discharge given off into the fluid. As pore sizes shrink to capture more contaminants, contaminants are given a charge as they pass which creates an attraction to reservoir walls, bearings, pistons, valves, etc. This is the root cause of harmful sludge and varnish build-up.
Occasionally, customers in need of a purification solution on the return path to the reservoir will benchmark ISOPur versus a fine filtration solution (e.g. 3 to 5 micron filtration). Filters, while good at removing medium and large particles, are not a solution for sub-micron particle removal. Mechanical filters used for this purpose have the following problem areas:
- Removal of particles smaller than the pore size. By definition, a 3-micron filter will let most particles smaller than 3 microns pass freely through. Unfortunately, these particles are usually the most plentiful in the system and the precursor for varnish and sludge (see Sub-Micron Matters). In addition, when fine filters start plugging, backpressure behind the filter builds, and then blows holes in the filter medium. A fine filter suddenly opens up and becomes a coarse filter.
- No purification occurs. Filters are excellent at removing “sticks and stones” in oil, but do not restore the quality of the oil such as water removal, air release, and sludge removal.
- Cost. The smaller the pore size, the faster the filter will become blocked. A dirty system will require the frequent and costly replacement of filters, important man-hours and maintenance.
| Feature | ISOPur BCA | Mechanical Filtration | Comments |
|---|---|---|---|
| Large (> 30 micron) particle removal | + | + | |
| Medium (10-30 micron) particle removal | + | + | |
| Fine (3-10 micron) particle removal | + | + | Filters unable to perform below 10 microns for some applications |
| Purification (<3 micron) particle removal | + | ||
| Water removal | + | ISOPur with coalescer option | |
| Functionality in presence of water | + | + | |
| Maintenance costs | + | 3 and 5-micron filter replacement expensive | |
| Repair costs | + | + | |
| Sludge and Varnish removal | + | ||
| Remove products of oxidation | + | ||
| Flow rates | + | + | Both appropriate for off-line fluid treatment of most applications. ISOPur not appropriate for high pressure/high flow in-line purification |
ISOPur Costs:
- Upfront capital cost or monthly lease payment
- Bi-annual collection cartridge replacement and quarterly pre-filter replacement
Mechanical Filtration Costs:
- Upfront capital cost or monthly lease payment
- Weekly maintenance costs
- Replacement part and repairs costs
Situations where mechanical filtration is a better choice than ISOPur:
- Non-mission critical machinery, where purification is not necessary
- In-line high-flow, high pressure filtration
ISOPur Versus Centrifuges
A centrifuge is a drum that spins at a very high speed to impart a centrifugal force on contaminant particles. The force imparted varies by the diameter of the spinning, and particles separate from each other based on their differences in specific gravity. The force also separates particulate from the liquid. Centrifuges are usually called upon when contamination levels are very high and full of large particles, and when there is a high water content. Centrifuges are a common solution for the maintenance of turbine oil, hydraulic oil, quench oil, drawing oil, and cutting oil.
Centrifuges have three key problem areas:
- Removal of particles smaller than 30-40 microns. Centrifuges excel at removing large particles. In fact, they are a preferred solution in certain machining applications, where the quantity of large particle debris makes it the only viable solution. However, medium sized (e.g. 10-30 micron) particles are difficult, as these particles tend to stay with the oil during the separation process. Centrifuges are ineffective at fine filtration (e.g. <10 micron) and ultra- (e.g. <3 micron) purification.
- High maintenance costs. The particulate separated by a centrifuge does not exit the system easily. Instead, it tends to cake on drum surfaces. This caked sludge must be removed manually by plant maintenance workers, adding several hours per week per centrifuge.
- High repair costs. Centrifuges are metal drums spinning at high speeds and G-force. Therefore, periodic breakdown and repair is common and must be budgeted for.
| Feature | ISOPur BCA | Centrifuge Filtration | Comments |
|---|---|---|---|
| Large (> 30 micron) particle removal | + | + | |
| Medium (10-30 micron) particle removal | + | ||
| Fine (3-10 micron) particle removal | + | ||
| Purification (<3 micron) particle removal | + | ||
| Water removal | + | + | ISOPur with coalescer option |
| Functionality in presence of water | + | + | |
| Maintenance costs | + | ||
| Repair costs | + | + | |
| Very high particulate (> 0.5%) contamination | + | ||
| Sludge and Varnish removal | + | ||
| Remove products of oxidation | + | ||
| Flow rates | + | + | Both appropriate for off-line fluid treatment of most applications |
ISOPur Costs:
- Upfront capital cost or monthly lease payment
- Bi-annual collection cartridge replacement and quarterly pre-filter replacement
Centrifuge Costs:
- Upfront capital cost or monthly lease payment
- Bi-annual collection cartridge replacement and quarterly pre-filter replacement
Situations where the centrifuge is a better choice than ISOPur:
- Where there is very high concentration of particles (>0.5%), as is common in cutting and grinding applications where particulate is falling from metalwork back into the oil.
- Where centrifuges are already in place and there is no capital budget for newer technologies.
ISOPur Versus Electrostatic Precipitators
ISOPur Balanced Charge Agglomeration is often compared to and confused with Electrostatic Precipitators (EPs). This is understandable, since both BCA and EP work on the principal of using electric charge to make particle separation easier. EPs charge particles in a unipolar fashion (i.e. all the particles are charged in only one direction). The particles are then attracted to a grounding plate with the opposite polarity. Thus, the system looks like a sandwich with alternating charging electrodes and collection plates, with the fluid flowing between them.
This is in contrast to BCA, which separates the fluid into two streams and charges particles in opposite directions, thus balancing the charge. Particles are mixed and attracted to each other, growing in size. Once agglomerated, contaminants are easy to remove with ISOPur filter media.
EPs can be very effective at removing small particles, and can also boast of removing sub-micron particles. As a result, they have achieved a niche following in some markets.
However, EPs have three major issues:
- Water Sensitivity. EP units are highly sensitive to water, generally having problems when the water content exceeds a meager 0.5%. Water in the system can cause shorts between the charging electrodes and collection plates. To accommodate this problem, EPs sometimes have a bypass mode that effectively shuts down the unit when the water content increases.
- Flow Rates. For a variety of technical reasons, EPs are flow-rate limited. Most EPs operate at or below 1.0 gallon per minute, with the highest flow versions coming in at 2.8 gallons per minute.
- Cleaning Efficiency. EPs collect particulate on a polar collection plate. As the plate collects particles, the efficiency of the plate decreases over time.
| Feature | ISOPur BCA | Centrifuge Filtration | Comments |
|---|---|---|---|
| Large (> 30 micron) particle removal | + | + | |
| Medium (10-30 micron) particle removal | + | + | |
| Fine (3-10 micron) particle removal | + | + | Filters unable to perform below 10 microns for some applications |
| Purification (<3 micron) particle removal | + | + | |
| Water removal | + | ISOPur with coalescer option | |
| Functionality in presence of water | + | ISOPur functions in water content up to 20% versus 0.5% for EPs | |
| Maintenance costs | + | ||
| Repair costs | + | ||
| Very high particulate (> 0.5%) contamination | |||
| Sludge and Varnish removal | + | ||
| Remove products of oxidation | + | ||
| Flow rates | + |
ISOPur Costs:
- Upfront capital cost or monthly lease payment
- Bi-annual collection cartridge replacement and quarterly pre-filter replacement
Electrostatic Precipitator (EP) Costs:
- Upfront capital cost or monthly lease payment
- Cost of water removal equipment
- Periodic filter replacement
- Risk of equipment short or bypass operation
ISOPur Versus Ion Exchange Resin
ISOPur Balanced Charge Agglomeration has been shown to induce no chemical change to the solution it is purifying. The electrostatic charge does not cause ionization that results in chemical change.
Ion exchange is a chemical process where a group of ions are exchanged with ions held in the resin beads of the ion exchange chamber. The operation of this process is analogous to what occurs in a water softener or a water demineralizer. In a water demineralizer, minerals in an ionic state are removed from water in exchange for a loosely bound ion in the resins. In water, the product released into the water is H (Hydrogen) and OH (Hydroxyl Radical) by the two resins employed. When the resins are mixed in the correct proportion, minerals are removed from water and the pH of the water is kept neutral.
Ion Exchange has been used successfully for reducing acid in synthetic oils such as Phosphate Esters. In this case, it’s use is similar to the water example used above. Acid is reduced by absorbing the acid and releasing a base. In about 2007, the first attempts at migrating this technology to mineral oil caused destructive chemical changes to the oil.
Ion Exchange companies claim that soluble varnish is removed by their resin. There is no mention of what is exchanged for the soluble varnish, and what affect this has on the oil chemistry. The first applications of this technology destroyed some of the oils’ additives and significantly shortened the life of the oil.
If Ion Exchange does work to reduce the precursors of varnish, it could reduce varnish buildup, but may do nothing to clean the internal parts of the system. No documentation or case studies seem to be available to show long term results when this technology is used. Other than possibly reducing soluble varnish and reducing varnish potential test numbers, the ion exchange method has not been around long enough to be fully understood or trusted.
BCA does not affect the additives that protect oil from oxidation. In fact, BCA reduces submicron metals in oil which act as catalyst to increase amount of oil degradation caused by oxidation. This reduction in metal catalytized oxidation, reduces the amount of additive depletion and enhances the life of the oil. This is a major step in making hydraulic oils last the life of the machine.