Cleaning machines, enclosed types

There are many types of vacuum pumps, designed to produce various levels of vacuum for specific types of research, development, and production work, and for use in enclosed cleaning machines. The four t5rpes most commonly used with enclosed cleaning machines are desaibed below. 

This popular type of rotating impeller positive displacement vacuum pump is often used in vacuum enclosed cleaning machines. 

These are the fourth type of positive-displacement vacuum pumps used as the "engines" of enclosed vacuum cleaning machines. 

All fom of these types of pumps act to both extract vapor from a work chamber and then to increase its pressure — although there is usually little value of the latter outcome in an enclosed cleaning machine. 

End caps (heads) of pressure vessels have a variety of shapes which are chosen based on cost or availability for a given chamber diameter and working pressure. Factors affecting that choice are size of flat blank needed, ease and cost of fabrication, need for welded nozzles in the cap, retained fluid volume, etc. The choice of type of end cap should be left to the supplier of the enclosed cleaning machine as it has no bearing on cleaning operations. For completeness, various types of end caps are briefly described below. 

P. Systems that initially remove air with vacuum and later remove solvent with vacuum are referred to as vacuum-to-vacuum systems within the EPA NESH/ P literature. It is perfectly possible, and some firms have done or are doing so, to use more than one type of vacuum pump in an enclosed cleaning machine. For example, some firms use rotary piston pumps to remove air from the work chamber These pumps require oil changes and mist eliminators. But they don t contaminate the cleaning solvent with seal oil because solvent never contacts the pump. 

But stabilizers are not wanted in enclosed vapor degreasers because (1) it s difficult for them to leave as other than solid debris on supposedly clean parts, and (2) they have to be purchased and their use controlled. One doesn t want to discard a key value of enclosed airless or airtight machines of any type — that the solvent in them can... 

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