Lubricants cloud point

Other important diesel-fuel properties include flash point, cloud point, pour point, kinematic viscosity, and lubricity. Cloud point and pour point indicate the temperature at which the fuel tends to thicken and then gel in cold weather. In addition to providing energy, diesel fuel also serves as a lubricant for fuel pumps and injectors, which prolongs the life of the engine. Viscosity measures the tendency of a fluid to flow. In a diesel engine, viscosity indicates how well a fuel atomizes in spray injectors. It also measures its quality as a lubricant for the fuel system. Lubricity measures the fuel s ability to reduce fnction between solid surfaces in relative motion. It indicates how the engine will perform when loaded. 

Damin, B., A. Faure, J. Denis, B. Sillion, P. Claudy and J.M. Letoffe (1986), New additives for diesel fuels cloud point depressents . SAE paper No. 86-1527, International fuels and lubricants meeting and exposition, Philadelphia, PA. 

Cloud Point This is the temperature at which a cloud or haze of wax crystals appears when a fuel or lubricant is cooled under standard test conditions. 

In temperate climates, diesel fuel must remain fluid at temperatures below the minimum expected temperature for the season. Through much of North America, winter diesel fuels have low temperature flow points below —30°C. Diesel fuels with low pour points have lower viscosity and often lack lubricity (110). These fuels typically provide little lubricity. For example, Noureddini (111) reports that biodiesel fuels that are simple esters of various vegetable oils have poor flow characteristics below a temperature of —2°C. To overcome this difficulty, a solvent consisting of mixed ethers of glycerol is added to the biodiesel. The resultant fluid has a low temperature cloud point below —32°F (—36°C). The pour point of this fluid is still above that necessary to effectively add to many winter diesels, as it may be necessary to pour the fuel component at temperatures as low as —45°C. 

The cloud point (ASTM D-2500, IP 219) of lubricating oil is the temperature at which paraffinic wax, and other components that readily solidify, begin to crystallize out and separate from the oil under prescribed test conditions. It is of importance to know when narrow clearances might be restricted by accumulation of solid material (for example, oil feed lines or filters). 

Neither the cloud point nor the pour point should be confused or interchanged with the freezing point (ASTM D-D 2386, ASTM D-5901, ASTM D-5972, IP 16, IP 434, IP 435). The freezing point presents an estimate of minimum handling temperature and minimum line or storage temperature. It is not a test for an indication of purity and has limited value for lubricating oil. 

Pour point is the lowest temperature at which an oil sample will flow by gravity alone. The oil is warmed and then cooled at a specified rate. The test jar is removed from the cooling bath at intervals to see if the sample is still mobile. The procedure is repeated until movement of the oil does not occur, ASTM D97/IP 15. The pour point is the last temperature before movement ceases, not the temperature at which solidification occurs. This is an important property of diesel fuels as well as lubricant base oils. High-viscosity oils may cease to flow at low temperatures because their viscosity becomes too high rather than because of wax formation. In these cases, the pour point will be higher than the cloud point. 

Studies of diffusional phenomena have direct relevance to detergency processes. Experiments are reported which investigate the effects of changes in temperature on the dynamic phenomena, which occur when aqueous solutions of pure non-ionic surfactants contact hydrocarbons such as tetradecane and hexadecane. These oils can be considered to be models of non-polar soils such as lubricating oils. The dynamic contacting phenomena, at least immediately after contact, are representative of those which occur when a cleaner solution contacts an oily soil on a polymer surface. With Ci2E5 as non-ionic surfactant at a concentration of 1 wt.% in water, quite different phenomena were observed below, above, and well above the cloud point when tetradecane or hexadecane was carefully layered on top of the aqueous solution. Below the cloud point temperature of 31°C very slow solubilisation of oil into the one-phase micellar solution occurred. At 35°C, which is just... 

The temperature at which a cloud or haze of wax crystals appears at the bottom of a sample of lubricating oil in a test jar, when cooled under conditions prescribed by test method ASTM D 2500. Cloud point is an indicator of the tendency of the oil to plug filters or small orifices at cold operating temperatures. It is very similar to wax appearance point. 

Refers to the removal of paraffin wax from lubricating oils to improve low temperature properties, especially to lower the cloud point and pour point. 

BURCO LAF-125 is a low cloud point linear alcohol alkoxylate used in formulations where low foaming detergents are required. It can be used to formulate rinse aids, high pressure spray cleaners, metal lubricants, textile jet scours and other low foaming products. 

Cloud point of a lubricant to be applied by a capillary feed system or wicking arrangement imisl be low so that the oil How does not stop due to deposition of crystals of wax in the capillary or wick interstice. -. Cloud point is hcli)ful in identifying the temperatures at which wax separation may clog the filter screens in the fuel intake system of diesel engines. Oils of naphthenic type, which are almost wax-free, show o ry low cloud iKiinfs and this fact may l-rc useful in identifying the source of the oil. 

When the gap width between two particles becomes very small, numerical calculations involved in both the bispherical coordinate method and the boundary collocation technique are computationally intensive because the number of terms in the series required to be retained to achieve a desired accuracy increases tremendously. To solve this near-contact motion more effectively and accurately, Loewenberg and Davis [43] developed a lubrication solution for the electrophoretic motion of two spherical particles in near contact along their line of centers with the assumption of infinitely thin ion cloud. The axisymmetric motion of the two particles in near contact can be approximated as the pairwise motion of the spheres in point contact plus a deviation stemming from their relative motion caused by the contact force. The lubrication results agree very well with those obtained from the collocation method. It is shown that near contact electrophoretic interparticle... 

Finally, biolubricants based on canola biodiesel have the potential to substitute petroleum-based automotive lubricants thus they present low cloud and pour point properties, good friction and antiwear properties, low phase transition temperature, and low viscosity (Sharma et al., 2015). 

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