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How to handle water in oil problems? Oil contaminated with water can come from surrounding humidity or immediate as in water jet washing or sudden seal failure. In the case of the latter, the EASZ-1 is the only reliable tool to immediately inform the user that a problem has occurred. The response time is 1 second. Immediate knowledge of a problem can save hundreds of thousands of dollars on equipment cost and downtime. Whatever the source the root cause needs to be known for corrective measures. Without knowing the cause, it may be pointless to simply replace the oil with newer oil. It may be difficult to know what the cause may be without a device that can monitor moisture build up or water contamination online. The device needs to have an immediate response time as well as an ability to measure low ppm ranges and higher percent ranges of contamination. The EASZ-1 can measure below 100ppm with a resolution of +/- 35ppm. It can also measure in percent ranges up to 25% water in oil. This places the instrument above former instruments simply used for “screening” purposes. Direct measurement of ppm values are meaningful to oil suppliers and clients, since oil is supplied to a specification which relates to its ppm level of water. Laboratory results are reported in ppm as well. Correlations can be made between the EASZ-1 online instrument and laboratory reports. Having said this, the EASZ-1 will give more meaningful results than a laboratory sample, simply because a lab sample is a small volume of the oil drawn off the line at a particular time, it has to be handled carefully and transport and handling can be a problem affecting lab results. It cannot adequately represent all of the oil contained in a system at every moment of time. The EASZ-1 samples 24 hours a day , once every second and it samples the total volume of oil so that any changes whether small or large can be monitored. There are a number of ways to remove water online. Some methods uses are gravity separation and vacuum dehydration. Each client has to decide which technology is most beneficial to his process. The final decisions will depend on the ultimate dryness level required, the volume of water that must be removed, the base oil and the required flow and processing rate. Removing water in oil using absorption methods Some types of filter cartridges have an additional wrap consisting of polymer and desiccants or similar methods. These filters are specifically designed to remove water by absorption and remove both emulsified and free water, as well as solids. However, the elements typically have a limited volume capacity and are best fitted to a portable filter cart for minor water ingression problems. In fact, when a small gearbox is being fitted with an expansion chamber type breather, it is worthwhile to filter the gearbox with a water-removing element to remove any trace elements of moisture that may condense out on surfaces within the unit when it cools. This method is a cost effective method although knowing when to perform a filter change can be a problem. This can be solved by installing an online EASZ-1 water in oil monitor that will alarm the operator when moisture or water levels in the oil could poise a threat to oil contamination A known disadvantage of absorption removal is that it has a limited capability for water removal which depends on the element’s capacity. A positive aspect is its ability to trap solids. Removing water in oil using Gravity Separation Free water in the system will usually settle to the bottom of the tank . Some oils are designed to hold water in suspension rather than to allow it to separate out, making gravity separation a less-than-effective strategy. The effectiveness of the gravity separation process can be ascertained by placing and EASZ-1 water in oil transmitter prior to separation and after separation. Currently, it is difficult to tell the immediate effectiveness of a gravity separator while it is online. Clients currently have to rely on manufacturer’s promises or specifications. A low cost but cost effective , accurate water in oil monitor will certainly test the effectiveness of the separator and give an indication on the reliability of the system in actual working conditions. Since the temperature of the oil affects its ability to hold water, the EASZ-1 is temperature compensated so that measurements are not affected by hotter or cooler oil. In most of these systems ,the major downside to this method is that it removes only free water, so elements of emulsified and dissolved water will remain. The upside is the low cost of water removal. However, the level of remaining moisture can be directly monitored by the EASZ-1. Removing water in oil using Centrifuge systems Basically , this technology removes water by spinning the oil at very fast rates. The greater the difference in specific gravity between the contaminant and the oil, the more effective the process. For this reason, centrifuges often work better on low specific gravity and low viscosity oils, like turbine oils, rather than heavier gear type oils. The great advantage of the EASZ-1 water in oil transmitter is that it is able to measure moisture or water contamination in both these types of oils. In a centrifuge, both free and emulsified water will be removed; this will depend to some extent on the type of additive package, as some water will be held in suspension in the oil. The EASZ-1 uses the principle of dielectric measurement, so it can still measure both free and emulsified water in oil even with additive packages. A possible setback to centrifuges is that only emulsified and free water will be removed - although this can be partially overcome by keeping temperatures low. Removing water in oil using Vacuum dehydrators By heating the oil, typically to approximately 65 degC the water is vaporized inside the dehydrator, without causing excessive oil degradation due to thermal and oxidative stress. In most dehydrators, the air is warmed and dried prior to being passed over the oil, encouraging the water to transfer from the oil into the air. The real benefit of this process is its ability to remove dissolved water. Dissolved water in oil will normally be in lower ppm ranges. The EASZ-1 will be able to measure the effectiveness of this process since the EASZ-1 can measure water lower than 100ppm. In reality, turbines and paper mills would like to keep water levels as low as possible but in reality these levels can sometimes exceed wished for results. In this case, the water in oil transmitter must also be able to report higher levels of contamination, so that as processes are being adjusted to meet contamination requirements, the instrument will reflect the affects of these changes i.e. if they problem has occurred, the EASZ-1 will know about it. The EASZ-1 will also know when the problem has been solved. A known fact regarding vacuum dehydrators is their cost. Since the cost can be high, many companies may chose to rent dehydrators on an “as-needed” basis rather than purchase them. Since the EASZ-1 online water in oil monitor is relatively a low cost item, the clients can benefit from purchasing their own water in oil transmitter to ascertain the effectiveness of different vacuum dehydrator systems and make sure that their investment is being covered. Removing water in oil using Dehydration /Air Stripping Air stripping can remove free and emulsified water as well as dissolved water down to less than 100 ppm. The EASZ-1 water in oil monitor can measure values of water less than 100ppm with a resolution of +/- 35ppm. It will measure free water, emulsified water or dissolved water by direct measurements of dielectric. The sensor will work in lower ranges and will not be destroyed by free water. There is also no need for continual re-calibration, however, the instrument can be tested now and again in the client’s laboratory against dry oil . The air strippers have an ability to degas. Air stripping works by drawing air or nitrogen gas into a stream of heated oil, which mixes in and absorbs the water and gasses within the oil. The oil/air is then expanded to release the air or nitrogen, which takes the impurities with it. Just like vacuum dehydrators, cost can be an issue with air stripping. However, its advantage is that it costs less to maintain than a typical vacuum dehydrator because it has fewer moving parts. Air stripping can also remove gaseous impurities, as well as dissolved water and can be considered an effective alternative to vacuum dehydration.
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