Cooling- lubricating fluids

Fuel passing through certain hot zones of an aircraft can attain high temperatures moreover it is used to cool lubricants, hydraulic fluids, or air conditioning. It is therefore necessary to control the thermal stability of jet fuels, more particularly during supersonic flight where friction heat increases temperatures in the fuel tanks. 

METALWORKING FLUID Eluid applied to a tool and workpiece to cool, lubricate, carry away particles of waste and provide corrosion protection. Generally comprising neat mineral oils, or water-based materials, or a mixture of the two. Eluids may also contain emulsifiers, stabilizers, biocides, corrosion inhibitors, fragrances and extreme pressure additives. 

Mechanics Detergents, degreasers (solvents), lubricants, petroleum products, battery acids, soldering fluxes, cooling system fluids (PEG), metal shavings... 

The chip formation in abrasive processes defines the local interaction between abrasive grains and workpiece material in combination with the surrounding fluid media (cooling lubricant or air). It can mainly be distinguished between brittle and ductile removal mechanisms. 

Improved nozzles and nozzle settings form the prerequisite for a reduction of the necessary cooling lubricant volume. A turbulence-free feed of the fluid must be guaranteed to achieve the required jet qualities. In addition to the design of the nozzle, the design of the feed lines from the pump to the nozzle also contributes to the jet quality. Tight radii or sharp edges should hereby be avoided. 

Most metal-cutting operations require the use of cutting fluids, and even those operations that can be performed dry can often be carried out more efficiently by the use of a cutting fluid. Cutting fluids are often referred to as metalworking fluids, but can also be known as lubrication fluids, cooling emulsions or oils, and drilling fluids. 

Cooling Fluids (cont) Frigilux Bo cooling lubricant 4 23 30 6 Conditionally stable 2.6 95 Tensile strength Trogamid T Huls America Specimen ... 

In some of the experiments, a lubrication system (Unist Standard Cool-Lubricator) was used to provide a continuous supply of lubricant onto the rake face. This supply, in the form of an air-mist, was controlled by an air metering screw. The cutting fluid, Cool-Lube 2210, was delivered to the tool rake face as a spray through a mix nozzle that was coupled to a co-axial air hose. Cool-Lube 2210 (Triglycerol Propylene glycol esters of C8 CIO acid) is a vegetable-based metal cutting lubricant. 

The contact seal can be used under 1,000 psig. It is more complex, but has the advantage of not leaking while shut down. The contact seal is used extensively in refrigeration service where the compressor is part of a closed loop, and the shutdown feature is desirable. As mentioned, the seals must have a source of cooling and buffer fluid. In many cases, this fluid is lubricating oil. If contamination is not a problem, a combined lube and seal system can be used. 

Metalworking fluids contain mineral oils (refer to p. 80) or synthetic lubricants they are used neat or in admixture with water. They may contain small amounts of biocides, stabilizers, emulsifiers, coiTosion inhibitors, fragrances and extreme pressure additives. The formulations render them suitable for application to metal being worked, generally from a recirculatory system, to provide lubrication, corrosion protection, swarf removal and cooling of the tool and machined surface. 

Fluid at approximately 60% of discharge pressure is circulated through the bearings and over the rotor tor cooling and lubrication and returns through the hollow shaft to suction pressure. 

Figure 52.12 Heat is generated both by deformation of workpiece material and by the friction of the chip across the tool tip. A cutting fluid acts as a lubricant to reduce frictional heat and simultaneously cools the whole cutting zone...

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