• Proceedings of the KSME Conference
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• 2002.08a
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• pp.313-316
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• 2002

A grease filter is used to remove grease generated from a cooking appliance in a kitchen. This numerical study has been conducted to investigate the particle collection characteristics of a grease filter having nominal flowrate of $100m^{3}/h$. The flow field and particle trajectories in the grease filter with a flow chamber were simulated by using the commercial code of STAR-CD. The pressure drop of a grease filter rapidly increases with increasing the air flowrate. The numerical values of the pressure drop are slightly lower than the experimental values when the air flowrates are 50, 75, and $100m^{3}/h$. The particle collection efficiency of a grease filter increases with increasing the particle diameter and the air flowrate, which means that the inertial impaction is a dominant particle removal mechanism in a grease filter The cut-off diameter of the tested grease filter representing $50-{\%}$ collection efficiency is about $11.6{\mu}m$ for water droplets at $100m^{3}/h$.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.14 no.10
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• pp.792-800
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• 2002

A grease filter is used to remove grease generated from a cooking appliance in a kitchen. This numerical study has been conducted to investigate the particle collection characteristics of a grease filter having nominal flowrate of $100m^3$/h. The flow field and particle trajectories in the grease filter with a flow chamber were simulated by using the commercial code of STAR-CD. The air velocity and pressure distributions were discussed in detail. The pressure drop of a grease filter rapidly increases with increasing the air flowrate. The numerical values of the pressure drop are slightly lower than the experimental values when the air flowrates are 50, 75, and 100㎥/h. The particle collection efficiency of a grease filter increases with increasing the particle diameter, the particle density, and the air flowrate, which means that the inertial impaction is a dominant particle removal mechanism in a grease filter. The cut-off diameter of the tested grease filter representing 50-% collection efficiency is about 11.6$\mu$m for water droplets at $100m^3$/h.

• Applied Chemistry for Engineering
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• v.34 no.4
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• pp.434-443
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• 2023

We have investigated the performance improvement of grease by synthesizing calcium sulfonate grease as an alternative to lithium grease, which is widely used globally. Since the composition ratio of the grease, when manufactured, is usually 50% base oil and 50% thickener, using grease as a lubricant in a cryogenic environment is not encouraged due to its inferior low-temperature performance. In this study, we have synthesized three types of calcium sulfonate grease with paraffin oil and PAO-based base oil and thickener. Furthermore, lithium grease was synthesized via saponification with PAO-based base oil, lithium hydroxide, 12-hydroxystearic acid, and sebacic acid. We have measured low-temperature characteristics using a rheometer and low-temperature torque meter, and tribology characteristics were obtained using a four-ball lubricant tester and schwingung reibung verschleiß (SRV). As a result, the flow point of the calcium sulfonate grease synthesized with a PAO-based base oil and thickener was found to be -40℃, overcoming the existing calcium sulfonate grease's low-temperature limitation. Moreover, the synthesized calcium sulfonate grease showed low-temperature performance similar to that of lithium grease synthesized with PAO base oil, but superior anti-wear, extreme pressure, coefficient of friction, heat resistance, adhesion, and corrosion resistance. It is thus expected to commercially replace the existing lithium grease.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.15 no.8
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• pp.619-629
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• 2003

A grease filter is used to remove grease generated from a cooking appliance in a kitchen. Since the inertial impaction is a dominant particle removal mechanism of the grease filter, the performance of the filter is greatly affected by the geometry. This numerical study has been conducted to investigate the effect of geometry on the performance of grease filters for four models having nominal flowrate of 100 m$^3$/h. Four models were designed by changing the shape of impaction surface, the length of eyelid, and the number of eyelids of the grease filter. The flow field and particle trajectories in the grease filter with a flow chamber were simulated using the commercial code of STAR-CD. The difference of air velocity and pressure distributions among four models was discussed in detail. The collection efficiency curves and the pressure drops of four models were also compared. It was found that the grease filter model with flat top surfaces shows highest performance among four models, having high particle collection efficiency and relatively low pressure drop. The cutoff diameter of this model representing 50-% collection efficiency is about 7.1 ${\mu}{\textrm}{m}$ for water droplets at 100 m$^3$/h.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1998.10a
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• pp.306-312
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• 1998

This paper describes syntheses of thickener for di-urea grease using constant velocity joint. The thickeners of di-urea grease were synthesized by reaction of diisocyanate with various alkylamines, hexylamine, octylamine, stearylamine and cyclohexylamine at high temperatxire. The synthesized thickener were analyzed by FT-IR spectroscopy and two kinds of Mass spectroscopy (EI & FAB). Dropping point and Consistency of synthesized di-urea grease were determined.

• Journal of the Korean Society for Precision Engineering
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• v.33 no.1
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• pp.37-43
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• 2016

Friction of mechanical components affects the life and reliability of various machines. In order to improve the wear resistance of mechanical components, grease has been used as a lubricant. However, depending on the operating condition of the machine, the grease may be contaminated with water, which lowers the its lubricating ability. In this work, the effect of the water content on the lubricating ability of grease was investigated. Friction tests using grease were performed between a stainless steel ball and an acrylic plate. Water content in the grease was varied (0, 5, 10 wt.%). It was found that the contact angle varied due to the addition of water in the grease. The friction and wear of the specimens were assessed with respect to amount of water content. Wear of the specimens was relatively severe when water was added. A water content of 10 wt.% resulted in significant lubricant degradation.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.7 no.4
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• pp.121-127
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• 2008

Automatic grease lubricator is an equipment that provides adequate amount of fresh grease constantly to the shaft and bearings of machines. It minimizes the friction heat and reduces the friction loss of machines to the least. This paper is developing an automatic grease lubricator using a mode of the gas generation type from galvanic electricity. The ultimate goal of this equipment is to lubricate an adequate amount of grease with galvanic corrosion. In an electrolyte, combining anode(Mo) with cathode(Zn) is pressing out hydrogen gas of an galvanic element with galvanic reaction. The characteristics of this method is continuous flowing small hydrogen gas and controling the usage of the amount of the generation of hydrogen gas. The exterior body of grease lubricator was analyzed by Digital Mock-up of CATIA V5 and finite element analysis. The maximum stress is distributed over the outlet part where the grease lubricator suddenly narrowly contracts. The outlet part is analyzed with different constructed angle due to the different loading and setting angles. Using the analyzed design, RP trial products were producted and tested.

• Tribology and Lubricants
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• v.38 no.3
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• pp.115-119
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• 2022

This paper selected three kinds of grease with the same type but different consistency for the experiment. The purpose of the experiment is tested the effect of different consistency of grease on the wear of the gear surface. Different torque test groups were selected in the test, and the lubrication effect of different greases was tested in the test groups with the same torque. After each set of tests, the wear of the gear surfaces was observed and recorded. The data recorded in the experiment included the area of the wear area on the gear surface, the type of wear and the volume of wear. After the test, the gear surface roughness was measured. By calculating the wear volume, the effects of different concentrations of grease on the gear surface wear were compared. The experimental results show that under different stress conditions, the consistency of the grease has a great influence on the lubricating effect of the gear surface and the gear wear. Under the condition with low speed and high torque, different grease consistency affect the gear surface wear, the high consistency grease can reduce the wear of the gear surface, so that the gear can get better lubrication effect during the work.

• Tribology and Lubricants
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• v.18 no.4
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• pp.273-278
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• 2002

Grease deterioration of mineral oil type grease was investigated using sealed deep groove ball bearings (6203) and bearing life test rig. The bearing test was performed under 3,000 rpm and 245 N radial load at 120。C. Grease taken ken tested bearings was checked in using certain evaluation methods, for example, oxidation induction time (OIT), FT-IR peak intensity, leakage .ate, bleeding .ate, total acid number. (TAN) and bearing noise increase. Within these test conditions, OIT, TAN, bleeding rate were changed gradually in accordance with bearing operating time and showed useful indices for deterioration of grease.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.2 s.179
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• pp.199-206
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• 2006

Automatic grease lubricator is equipment that provides adequate amount of fresh grease constantly to the shaft and the bearings of machines. It minimizes the friction heat and reduces the friction loss of machines to the least. This research is to develop automatic grease lubricator by gear driven mechanism with controlled operation time. The ultimate design of this equipment is to lubricate an adequate amount of grease by a simple switch clicking according to the advanced set cycle. The backlash of the gear was minimized to increase the output power. To increase the power of gear mechanism, the binding frequency and the thickness of the coil were changed. To control the rotating cycles of the main shaft according to its set numbers, different resistance and chips were used to design the circuit to controls electrical signals with pulse. The body of the lubricator was analyzed by stress analysis with different constructed angle. The stress analysis for differing loading pressures applied to the exterior body of grease lubricator due to the setup angle, was found that the maximum stress was distributed over the outlet part where the grease lubricator suddenly narrowed contracts. Digital mock-up was analyzed and the rapid prototyping(RP) trial products were tested with PCB circuit and grease. The evaluation of the outlet capacity for RP trial products was conducted, because the friction caused by the outlet on the wall surface was an important factor in the operation of the equipment. Finally, the finishing process was applied to decrease the roughness of the surface to a comparable level and was able to test the performance examination for the product.