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1
Content available remote Used oil degradation detection sensor development
Raadnui S.
International Journal of Applied Mechanics and Engineering
|
2006
|
Vol. 11, no. 4
765-769
EN
This paper introduces an on-line condition monitoring of lubricant degradation for oil-lubricated machinery. The system detects the relative variation of lubricant degradation i.e., physical/chemical properties, generated wear particles and ingested contaminants, by using the grid capacitance sensor in an on-line installation. The system consists of grid sensing unit and a multitude of small holes (up to 2mm. in diameter) between the sensing grids. The oil enters in the top part and flows through the holes and exits at the bottom. In addition, the sensor can also detect large size "metal" particles i.e., whereas the component being monitored approaches catastrophic failure which cannot be detected by the conventional on-line "Ferrous Debris Monitoring Sensor" such as the Magnetic Chip Detector (MCD). In addition, the system can also be used to distinguish the relative variation of the dielectric constant of lubricant caused by contaminants such as water, fuel dilution, etc.
2
Content available remote The abrasive wear behaviour of a Thai silk fabric
Raadnui S.
International Journal of Applied Mechanics and Engineering
|
2006
|
Vol. 11, no. 4
755-763
EN
Friction and wear characteristics of general engineering materials have been studied extensively in the past few decades. However, just a few papers reported on tribological features of silk fabrics. In this particular work, Thai silk fabric abrasive wear behaviour characteristics were investigated. The influences of silk fabric wear factors or cause variables such as the applied load, speed, and grain size of abrasive media were evaluated.
3
Content available remote Filter debris analysis
Raadnui S.
International Journal of Applied Mechanics and Engineering
|
2006
|
Vol. 11, no. 4
751-754
EN
Due to normal friction, wear, corrosion, etc., it is not uncommon to find small amounts of debris in a used filter element. Ferrous metals may indicate wear of the steel parts. Principally, one can use a magnet to differentiate between ferrous and non-ferrous metals found in the used filter element. Further, the analyst should use microscopic examination of debris morphology characteristics such as shape, size, color, surface texture, thickness ratio and edge detail as their principal analysis technique. The wear debris morphological analysis technique has been applied for monitoring the condition of oil-lubricated machinery for quite sometimes. However, most the works reported to date have been focused on used oil debris analysis. In this particular work, systematic filter debris analysis is reported.
4
Content available remote The development of coolant recycling unit
Raadnui S., Timlerk P.
International Journal of Applied Mechanics and Engineering
|
2005
|
Vol. 10, no. spec.
279-284
EN
Ecological aspects are gaining in our society, bearing in mind that our environment is being increasingly contaminated with all kinds of pollutants, any reduction is welcome. From an environmental point of view and compared to a number of other chemical products, waste coolants have been one of the main sources of fresh and ground water contamination. Even though mineral based oil coolant products can be relatively and rapidly biodegraded by the microorganisms present in nature, these natural degrading systems are overwhelmed by the volume of the losses. Hence, the development of coolant recycling unit was proposed. The unit composes of three main subunits: Hydrocyclone, Pasteurizing and aeration unit. Preliminary performance of the unit was assessed and reported.
5
Content available remote Palm oil based coolant for metal metalworking
Raadnui S., Mahathanabodee S.
International Journal of Applied Mechanics and Engineering
|
2005
|
Vol. 10, no. spec.
273-278
EN
Cutting oils and coolants are used to reduce friction and wear when cutting or forming metal. As well, they lubricate the cutting area, remove contaminants and prevent corrosion. There are two broad categories of conventional metalworking fluids: neat and water based. Neat cutting oils can be derived from animal, petroleum, vegetable or synthetic sources; however most are petroleum based. Having achieved success in Europe, vegetable oil based metal working oils are now being introduced in other parts of the world. This because vegetable oil cutting fluids are more environmental friendly, less of a health hazard, and superior in "boundary-condition" lubrication mode, they could become the based oil of choice for coolant formation. In this work, the performance of palm oil based coolant was evaluated in comparison with the reference commercial coolants. The aim of the test was to evaluate mineral and palm oil based coolants characteristics. In addition of specific combinations of function formulae, work piece quality and tool wear were compared.
6
Content available remote Palm based oil anti-oxidation behaviour improvement: utilization of epoxidation process
Raadnui S., Narasingha M. H.
International Journal of Applied Mechanics and Engineering
|
2005
|
Vol. 10, no. spec.
291-296
EN
The pressure for increased use of vegetable oils in lubricants, due to both environmental and health & safety considerations, is likely to continue. In addition, economic trends are likely to make vegetable oils increasingly more attractive than in the past in many areas of the globe. All these factors will probably result in an increase use of vegetable oil as lubricants. In this work, systematic research on palm based oil anti-oxidation characteristic assessment was carried out. Mainly, the utilization of "epoxidation process" has been exposed. The key influencing epoxidation parameters on the response varaiable "anti-oxidation characteristic" has been asessed and reported.
7
Content available remote Minimum quantity lubrication of cast iron turning process
Raadnui S.
International Journal of Applied Mechanics and Engineering
|
2005
|
Vol. 10, no. spec.
285-290
EN
The ever-changing legislation and every increasing awareness of the environment have led to a change in the production processes used up to new and especially in the production auxiliaries such as coolants. It has been widely accepted that a considerable proportion of the process costs are caused by the application of metalworking fluids. In this aspect the costs for coolant concentrates themselves played an insignificant role. The actual cost are caused by system costs, labour costs for the care and monitoring of materials, coolant recycling and water purification system and last, but not least, the cost for disposal. Despite the trends towards "dry cutting" and low friction tool coatings, there is still a need for cutting fluids, or coolants, because of their ability to improve product quality, remove heat and swarf from the tool/workpiece interface and increase tool life. This has led to much more attention being paid to the Minimum Quantity Lubrication (MQL) system. In this particular research, turning of Cast Iron (CI) work pieces with MQL system has been carried out. The influences of MQL on tool wear mode/mechanism and surface roughness of workpiece was assesed and compared with conventional flood-type coolant system. In short, the results showed that surface finish and tool wear were all affected beneficially with all the MQL techniques compared to original flood-type coolant system.
8
Content available remote Palm oil-based cutting fluids
Raadnui S., Mahathanabodee S.
International Journal of Applied Mechanics and Engineering
|
2004
|
Vol. 9, no. spec.
129-134
EN
There are no exact figures available as to how many machining operation are carried out without using "cutting fluids" or "coolants". However, there is no doubt that wet machining is applied very much more frequently than dry machining. Also, the oil embargo of 1973 brought needed attention to alternatives for petroleum oils. In addition, the pressure for increased use of vegetable oils in lubricants, due to both environmental and health and safety considerations, specifically on cutting fluids, is likely to continue. In addition, economic trends are likely to make vegetable oils increasingly more attractive than in the past in many areas of the globe. All these factors will probably result in an increase use of vegetable oil as lubricants. In this work, systematic research on palm oil-based cutting fluids characteristics assessment will be carried out.
9
Content available remote Palm oil as hydraulic fluids
Raadnui S.
International Journal of Applied Mechanics and Engineering
|
2004
|
Vol. 9, no. spec.
135-140
EN
The used of vegetable oils and animal fats for lubrication purposes have been practices for years. With the discovery of petroleum and the availability of inexpensive oils, alternatives became unattractive and were left by the wayside. Attention was refocused on vegetable oils during wartime and oil shortage situations. For example, during World War I and II, the use of vegetable oils for fuel, lubricants, greases and energy transfer increased rapidly. Also, the oil embargo of 1973 brought needed attention to alternatives for petroleum oils. In addition, the pressure for increased use of vegetable oils in lubricants, due to both environmental and health and safety considerations, is likely to continue. In addition, economic trends are likely to make vegetable oils increasingly more attractive than in the past in many areas of the globe. All these factors will probably result in an increase use of vegetable oil as lubricants. In this work, basic research on palm oil-based hydraulic fluid properties assessment will be carried out.
10
Content available remote Multi-parameter analysis condition monitoring technique for grease-lubricated rolling element bearings
Raadnui S.
International Journal of Applied Mechanics and Engineering
|
2004
|
Vol. 9, no. spec.
87-91
EN
In order to maintain the original performance of a bearing for as long as possible, proper maintenance and inspection should be employed. Items that should be regularly checked during operation include temperature, noise, vibration and lubricants. If proper procedures are followed, most bearing problems can be avoided and the reliability, productivity, operating and maintenance cost of the equipment containing the bearing are all improved. In this particular work, those grease-lubricated rolling element bearings are of the author's interest. Performing the used grease analysis should give a more vivid picture on bearing "health" status. If any irregularity is found, the cause can then be determined and the proper corrective actions can be taken before catastrophic failure occurs.
11
Content available remote An integrated approach condition monitoring of grease-lubricated rolling element bearings
Raadnui S.
International Journal of Applied Mechanics and Engineering
|
2004
|
Vol. 9, no. spec.
93-98
EN
In this particular paper, the correlation of noise level, used grease analysis and worn surface assessment was carried out. An experimental test rig consists of tested rolling element bearing driven by an electric motor was set up to examine the correlation between the three techniques under various bearing "severity" conditions. Noise signals were collected regularly. Used grease wear debris and contaminant analysis was performed. In addition, worn surfaces were examined. Fault detection in the noise signatures were compared with the used grease debris analysis and worn surface analysis results.
12
Content available remote Palm oil-based grease tribological characteristics
Raadnui S.
International Journal of Applied Mechanics and Engineering
|
2003
|
Vol. 8, no. spec.
103-108
EN
The pressure for increased use of vegetable oils in lubricants, due to both environmental and health and safety considerations, is likely to continue. In addition, economic trends are likely to make vegetable oils increasingly more attractive than in the past in many areas of the globe. All these factors will probably result in an increase use of vegetable oil as lubricants. In this work, systematic research on palm oil-based grease tribological characteristics assessment will be carried out.
13
Content available remote Palm oil-based grease rheological properties
Raadnui S.
International Journal of Applied Mechanics and Engineering
|
2003
|
Vol. 8, no. spec.
97-102
EN
Vegetable oils have a long and continuity history of use in lubricants, even though modern lubricants are predominantly based on mineral oil owing to cost and performance considerations. However, recently there has been increased interested in extending the use of vegetable oils in lubricants, driven mostly by environmental as well as health and safety issues and also arising from changes in economic and supply factors; there is, specially in Thailand, a plentiful supply of palm oils domestically. Most of the published research works have been mainly focused on tribological characteristics of lubricating greases. In fact lubricating grease rheological property assessment is among the most complex systems studied by industrial rheologists. In this particular work some preliminary rheological properties of the palm oil-based grease will be reported.
14
Content available remote Palm oil-based grease blending: utilization of the statistical design of experiments (DOE)
Raadnui S.
International Journal of Applied Mechanics and Engineering
|
2003
|
Vol. 8, no. spec.
93-96
EN
Natural fatty oils such as palm oil, castor oil, rapeseed oil, soybean oil, sunflower oil, lard, and sperm oil have been used as lubricants for years. They are normally called triglycerides of more or less unsaturated fatty esters. This type of base is "biodegradable" and, compare to mineral oils, show excellent tribological properties (low friction coefficient and good wear protection). However, their range of use is limited by lower stability against thermal oxidative and partly inferior cold flow properties, specifically in lubricating grease. Their limits can be improved gradually either with appropriate additives or with chemically modified process. In this particular work, an optimal palm oil-based grease blending formula is proposed utilization of the statistical design of experiments (DOE). Input variables are palm oil-based grease structures (% of palm oil, % of thickener and % of additives), type and percentage of each specific additives.
15
Content available remote Machinery health monitoring and maintenance tribology research at King Mongkut's Institute of Technology North Bangkok
Raadnui S.
International Journal of Applied Mechanics and Engineering
|
2003
|
Vol. 8, no. 1
135-145
EN
The King Mongkut's Institute of Technology North Bangkok (KMITNB), founded in 1959 with the support of the government of the Federal Republic of Germany, is one of the premier higher education institutions in Thailand with a strong base in applied sciences, technology and engineering. The faculty of engineering, the largest of the four faculties of the institute, was founded with an aim to provide a range of professional engineering education service to meet the community and industry at the early phase of industrialization in Thailand. The degrees were established to fill a need for better-educated engineers in the practice of engineering as well as in research and development. The Machinery Health Monitoring and Tribology Laboratory (MHM and Tribo. Lab.) forms part of the Production Engineering Department, Faculty of Engineering. Currently, machinery health monitoring research is combined with tribology studies. In general terms, the current activities of the condition monitoring and tribology research group include: condition monitoring studies relating to oil and wear debris analysis, hydraulic failure studies as related to contaminants, routine oil, wear debris and contamination analysis for industry, developments of new and improved condition monitoring techniques, especially used oil, wear debris and contamination analysis, fundamental of friction, lubrication and wear studies, maintenance strategy studies for productivity improvement.
16
Content available remote Worn surface evaluation
Raadnui S.
International Journal of Applied Mechanics and Engineering
|
2002
|
Vol. 7, Spec. iss.
161-166
EN
Microscopic observation by human unaided eyes has greatly contributed to identify and/or classify worn surfaces of tribomaterials. Words, codes, sketches and photographs used in expressing surface characteristics by all means qualitative and depend on human a sense, which inadequately varies from time to time and from person to person. It would be, therefore, beneficial to be able to translate these "qualitative" properties into somewhat "quantitative" aspect. In this paper, an author seeks his own initiative to utilize a statistical - based mean to classify/identify the differences between worn surfaces from different wear mechanisms i.e. abrasive, adhesive, rolling and reciprocating wear in particular. The relationship between conventional quantitative surface roughness parameters and physical properties of worn surfaces are assessed. The more fundamental exploratory statistical data analysis is employed.
17
Content available remote Plain bearing used grease debris analysis
Raadnui S.
International Journal of Applied Mechanics and Engineering
|
2002
|
Vol. 7, Spec. iss.
273-276
EN
Due to normal friction and wear, even in properly lubricated moving machine elements, it is not uncommon to find small amounts of debris in used lubricants. The wear debris analysis technique has been applied for monitoring machine condition for quite sometimes. However, most of the works reported to date have been focussed for oil - lubricated machinery. Actually, very little primary material of the application of used grease analysis technique for plain bearings is to be found in the periodical literature. The identification of the cause of damage or failure in plain bearings is crucial before remedial action can be taken to prevent further damage. The first step is a visual examination of the wear debris and/or contaminants in the used grease samples. In addition, this step can then be followed up by visualization of the damaged parts, if applicable. Once failure has been initiated, the origin mechanism may lead to other failure mechanisms and it is essential to identify the original cause. In this particular work, "systematic used grease wear debris analysis" is proposed. Preliminary results are presented and discussed.
18
Content available remote Magnetic chip detector (MCD) wear particle analysis
Raadnui S.
International Journal of Applied Mechanics and Engineering
|
2002
|
Vol. 7, Spec. iss.
419-423
EN
In general, Magnetic Chip Detectors (MCD) are used to collect ("catch") ferrous debris for further analysis. The analysts should use microscopic examination of debris morphology characteristics such as shape, size, color, surface texture, thickness ratio, and edge detail as their principal analysis technique. Wear debris is also quantified and trends are plotted to support the visual examination and assist in diagnosis and corrective action. MCD ferrous wear particle analysis is a valuable diagnostic tool for condition monitoring. Samples of MCD are either submitted individually for evaluation of a special problem or over time to establish a baseline for use as a predictive maintenance tool. When trending quantitative debris analysis results over time, machinery component (s) degradation and wear rates can be monitored. Knowing these critical characteristics one can make maintenance decisions and be assured that the right steps will be taken to prevent catastrophic failures of vital machinery.
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