Overheated oil

Place in the flask 2 g. of benzophenone, 15 ml. of isopropanol and 2 5 g. of aluminium isopropoxide. This mixture has now to be heated gently under reflux so that the temperature registered by the thermometer in the column does not exceed 80°, i.e., so that only acetone distils. For this purpose, the flask should preferably be heated in an oil-bath direct heating, even over an asbestos sheet, may cause local overheating and decomposition the use of a water-bath on the other hand may make the column undesirably damp. 

Boiler Deposits. Deposition is a principal problem in the operation of steam generating equipment. The accumulation of material on boiler surfaces can cause overheating and/or corrosion. Both of these conditions frequentiy result in unscheduled downtime. Common feed-water contaminants that can form boiler deposits include calcium, magnesium, iron, copper, aluminum, siUca, and (to a lesser extent) silt and oil. Most deposits can be classified as one of two types scale that crystallized directiy onto tube surfaces or sludge deposits that precipitated elsewhere and were transported to the metal surface by the flowing water. 

Sometimes the motor may appear to be running overheated. In faet it may not be so. The easiest way to measure the temperature at site is by a thermometer which can be eonveniently inserted into the hole of the lifting hook. In very small motors where a lifting hook may not have been provided, a small oil cavity can be drilled in between the top fins allowing the thermometer to be embedded there (Figure lO. lO). 

Defective pressure gauge. 10. Plugged oil sump strainer. 11. Defective oil relief valve. PACKING OVERHEATING 1. Lubrication failure. 2. Improper lube oil and/or insufficient lube rate. 3. Insufficient cooling. 

No appreciable decomposition of the ethoxalyl ester into ethyl methylmalonate takes place when the distillation is carried out at 10 mm. To prevent overheating, the use of an oil bath and a heated column is recommended. 

The pump feeding an oil stream to the tubes of a furnace failed. The operator closed the oil valve and intended to open a steam valve to purge the furnace tubes. He opened the wrong valve, there was no flow to the furnace, and the tubes were overheated and collapsed. 

Heat sources for distillation must be closely controlled to prevent overheating or too rapid distillation. The best heat sources are electrically heated liquid baths. Mineral oil or wax is a satisfactory medium for heat exchange up to about 240°. The medium may be... 

Extending the inteiwal between oil changes in automobiles and machinery is another way to conserve lubricants. Oil life is limited by depletion of oil additives, overheating, chemical contamination, and contamination of the oil by foreign particles. Using improved additives and filtering of particles, oil life can be considerably extended. 

In electrical equipment arcing or overheating causes fires, but continued combustion is usually due to insulation, oil or other combustible material associated with the installation. If the electrical apparatus remains alive, only... 

Probably the most important single property of hydraulic oil is its viscosity. The most suitable viscosity for a hydraulic system is determined by the needs of the pump and the circuit too low a viscosity induces back-leakage and lowers the pumping efficiency while too high a viscosity can cause overheating, pump starvation and possibly cavitation. 

In piston-type compressors, the oil serves three functions in addition to the main one of lubricating the bearings and cylinders. It helps to seal the fine clearances around piston rings, piston rods and valves, and thus minimizes blow-by of air (which reduces efficiency and can cause overheating). It contributes to cooling by dissipating heat to the walls of the crankcase and it prevents corrosion that would otherwise be caused by moisture condensing from the compressed air. 

Although the presence of oil in the boiler water, or water starvation may also cause overheating. 

At 220°C a water-paraffin mixture is distilled off in a circulating evaporator (8). The product mixture passes to a second circulating evaporator (9) where the paraffin is stripped at 270°C with overheated water vapor, and finally the paraffin content in the resulting alkanesulfonate melt is further reduced by vapor stripping in a packed column (10). A heat transfer oil dissipates excess heat. 

Shortly after interruption of vacuum distillation from an oil-bath at 115°C to change a thermometer, the ester exploded violently and this was attributed to overheating [1], A commercial sample of undetermined age exploded violently just after vacuum distillation had begun [2], In an examination of thermal explosion behaviour, the title compound was used as a model compound in autoclave... 

B. 2,4-Dinitrobenzenesulfenyl chloride. Dry 2,4-dinitrophenyl benzyl sulfide (232 g., 0.80 mole) and 400 ml. of dry ethylene chloride are placed in a 2-1., one-necked, round-bottomed flask equipped with a stirrer (Note 3). Sulfuryl chloride (119 g., 0.88 mole) (Note 4) is added to the resulting suspension at room temperature. A mildly exothermic reaction causes the solid to dissolve quickly, usually within 1 to 2 minutes, with a temperature rise of 10-15° (Note 5). The resulting clear yellow solution is concentrated to an oil by heating under aspirator vacuum on a steam bath (Note 6). Caution Do not heat with gas or electricity because the product, like many nitro compounds, can explode if overheated.) The residual oil is cooled to 50-60°, and 3-4 volumes of dry petroleum ether (b.p. 30-60°) are added with vigorous handswirling. The oil quickly crystallizes. The mixture is cooled to room temperature and filtered to separate 2,4-dinitrobenzene-sulfenyl chloride as a yellow crystalline solid. The sulfenyl chloride is washed well with dry petroleum ether and dried at 60-80° (Note 7) weight 150-170 g. (80-90%) m.p. 95-96° (Notes 8, 9). 

Such steam heating is even, and avoids the risk of overheating and decomposition that can occur in hot spots when external heating is used. The steam condenses back into water and the droplets coagulate to form liquid oil. Esters and essential oils do not mix with water, so phase separation occurs on cooling, and we see a layer of oil forming above a layer of condensed water. The oil is decanted or skimmed off the surface of the water, dried, and packaged. 

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