3 years ago

MDA Technologies 4/2016

MDA Technologies 4/2016


COMPRESSED AIR NEWS Author: Robert Corna, Market Manager Compressors Central Europe, Klüber Lubrication Deutschland SE & Co. KG Working with clean compressed air Robert Corna Two key factors play a major role in compressed air generation: high availability of clean compressed air and compressed air generation at reasonable cost. Newly-developed synthetic compressor oils have proven their worth in practice. Long oil lifetime, high efficiency and a very low oil content in the compressed air combine to reduce operating costs considerably. Compressed air is the fourth energy utility after electricity, gas and water. Few production lines in the world would run without it. The majority of compressed air is provided by oil-injected screw compressors and the compressor oils play a major role in generating clean compressed air in an energy-efficient way. They account for less than one percent of the cost of compressor operation; however, the right oil helps save a considerable part of the total cost. The oil has three key functions: First it ensures that the rotors and rotor bearings in the compressor are lubricated, second it dissipates the heat of the compression process and third it forms a sealing film at the seal edge between the rotor and the compressor casing. For efficient and trouble-free production, an oil with long service life and good temperature behaviour with low residual content in Saving costs and valuable resource Practical examples show that changeover to fully synthetic compressor oils made by Klüber Lubrication can be made very easily. Oil service life can be considerably extended and compressor performance increased to save costs and valuable resources. the compressed air is required. However, there are considerable differences between the performances of different compressor oils. A well-formulated synthetic product has considerable advantages over mineral oil-based products and stands out in particular for optimum oxidation protection, good adhesion and low residue formation. The newly-developed synthetic oils of the Klüber Summit SH series and the NSF H1-registered Klüber Summit FG series made by Klüber Lubrication stand out because of their considerably increased performance compared to conventional compressor oils. Benefits of synthetic compressor oils Special oxidation-resistant compressor oils ensure reduced maintenance costs, higher compressor availability, reduced total cost for oil, oil filters and oil separators as well as reduced disposal costs. Furthermore, the right compressor oil increases compressor performance with the same power input owing to its high lubricity base oil combined with the optimum additive package. During the compression process, this product will avoid decomposition, oxidation and residue formation of the oil. A compressor basically “destroys” the oil during operation, with several factors having an effect on the oil: high pressure, continual intake of fresh air, high temperatures, considerable shearing forces, particle intrusion and atmospheric humidity. All these factors cause ageing of the oil, which shows mostly as oxidation. At temperatures between 90 and 100 °C or more and under continual oxygen intake, organic acids produced by oxidation quickly decompose the oil. The concentration of such acids is expressed by the so-called neutralisation number. The lower this value, the lower the extent of oxidation. Klüber Summit products ensure a low neutralisation number through carefully selected high-quality additives. Condensate produced by air humidity is another factor leading to high maintenance costs. Unsuitable oils or low-quality additives lead to emulsification of the condensates, making it impossible to separate oil and water in a normal separator, requiring moreexpensive condensate separators, increasing cost. Particularly in the food-processing and pharmaceutical industries, the oil content MDA Technologies 4/2016

COMPRESSED AIR NEWS in the compressed air must be as low as possible and compressor oils must be registered as NSF H1. Convincing in practical operation A leading sausage manufacturer was having trouble with his NSF H1 compressor oils. Oil service life of less than 1,000 hours caused high maintenance costs and frequent downtime. Following precise analyses, Klüber Lubrication recommended on-line cleaning of the compressors with Klüber Summit Varnasolv and changeover to a Klüber Summit FG oil. After cleaning, the compressor could be operated up to 15 Kelvin cooler than before. Additionally, the cooler Modern compressor oils help save money no longer required an annual strip and clean. The operating hours increased to more than 4,000 and maintenance costs were decreased considerably while the oil price was comparable. Klüber Summit FG oils were especially developed for compressors in the food-processing and pharmaceutical industries where compressed air can have contact with the end product during the production process. With NSF H1 registration and certification according to ISO 21469, these oils support manufacturing plants in their compliance with demanding hygiene requirements. Klüber Summit FG oils show very good resistance to oxidation, which means that the presence of oxidation residues or lacquer in the compressor is minimised. Oil change intervals can be extended, e.g. up to 5,000 operating hours in oil-injected screw-type compressors. Besides reduced maintenance and operating costs, this enables higher operational reliability. Another example is a manufacturer of particle boards. Compressor oil changes were required after 2,000 operating hours. Klüber Lubrication recommended changing to a Klüber Summit SH series oil. After 8,000 operating hours, used oil analysis in the Klüber Lubrication laboratories revealed that additive degradation in the oil had started, however the oil would not have to be changed for another 2,000 hours. Hence, the oil service life is five times longer than with the previouslyused compressor oil. Summing the total costs for oil change, disposal, oil filters, oil separators and maintenance, the premium product turns out to be the most cost-efficient one. The total cost calculation in the above example reveals considerable cost savings. More compressed air can be produced with the same energy consumption. Klüber Summit SH oils were especially developed for the lubrication of heavily-loaded air compressors with projected oil change intervals of up to 10,000 operating hours (under normal operating conditions). They are neutral towards most elastomer seals used in air compressors. Special inhibitors keep compressors clean on the inside to avoid cleaning costs and unplanned compressor downtime. 01 Klüber Summit FG oils were developed specifically for compressors in the food-processing and pharmaceutical industries, where compressed air is in contact with the end product 02 Oil service life in compressors used by a manufacturer of particle boards could be quadrupled Easy compressor cleaning Mineral oil-based compressor oils can cause varnish and carbon build-up, especially in oil-injected screw compressors and rotary vane compressors, which settle in the entire oil circuit. In hydraulic systems, mineral oils can cause glueing of valves on hot surfaces, resulting in high energy consumption, clogged oil ducts and filters and high maintenance costs and downtime. Klüber Summit Varnasolv made by Klüber Lubrication is a highly effective cleaning concentrate based on ester oil with cleaning additives. It is substituted in a concentration of 10 % to the oil filling 60 hours prior to the next oil change and run normally. The cleaning concentrate dissolves residues on the surfaces while the compressor is in operation and ensures that they remain dissolved in the oil to be flushed out at the oil change. This method is much more effective than flushing the compressor with normal compressor oil. The 03 Compressed air is the fourth energy utility besides electricity, gas and water operator can easily determine if and when an oil change is necessary with the Klüber Summit TAN Kit, which uses the breakdown acids in the oil to indicate by colour the extent of oxidation of the used oil. Alternatively, Klüber Lubrication can make a full used oil analysis to determine any contamination and wear in the unit. Photographs: 01 Klüber Lubrication, 02 and 03 Fotolia MDA Technologies 4/2016