Cleaning machines, enclosed

Vacuum-to-vacuum enclosed cleaning machines are covered in Chapter 2.1. 

Enclosed cleaning machines are the "next new thing," but they have been that for at least a generation. 

Recently, enclosed vacuum cleaning machines have been constructed in which narrow tubes up to 85 feet in length have been cleaned with these two solvents (Box ). 

Note that these distinaions are not mutually exclusive. Both airtight and airless enclosed cleaning machines are sealed vessels. They differ in how they are used. 

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. 

It is important to note the requirements for the vacuum pumps used in enclosed vacuum cleaning machines. They do not have to ... 

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. 

Required investment (pump normally supplied with enclosed cleaning machine) 4000 to 8000 1500 - 4000 to 8000 - 4000 to 8,000... 

The dimensions (diameter, or straight sides) of a cylindrical vessel to be used as the working chamber of an enclosed cleaning machine will be a compromise. Vessel volume is increased by the need to (1) connect all process flow inputs and outputs to the vessel and make them capable of performing their functions, (2) provide adequate volume in which to immerse the parts in liquid solvent or vapor spray and disperse both over all of their... 

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. 

An enclosed vacuum vapor degreaser was conceived, designed, and constructed for just this situation. But it wasn t until the latter part of the last decade that such machines became commonly available. Their existence would appear to contradict the NESHAP (Chapter 1.24) finding in 2007 that tube cleaning machines should be exempt from its requirements (Ref. 2, Chapter 4.15). 

All (certainly those shown in the above images) enclosed cleaning machines are custom-made for specific applications, and... 

A major European firm reports that they sell a half a dozen highly automated enclosed cleaning vapor degreasers and other enclosed cleaning machines within the US in a year. Total revenue from these sales is a few million dollars US. 

An enclosed cleaning machine is not simply a sealed container. The container exists only to allow or enable... 

In the remainder of this chapter, five examples will be related of how airless and airtight enclosed cleaning machines may be used to implement various cleaning processes with various part stiuctures. 

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. 

Vessels for vacuum service are normally preferred to be fabricated by seamless wall construction to avoid a possible incidence of crevices where particles, soiled solvent, and rinse fluid can be trapped Yet as noted above, seamless pipe and tubing are not available to fabricate vessels in sizes desired for enclosed cleaning machines Consequently, these vessels, such as those shown in Figures 2 19 through 2 26, are fabricated not from pipe or tubing but from stainless steel plate which is rolled to shape, seam welded to size, and then precision ground to achieve a desired internal surface finish. 

It s that simple. The cleaning machine could be a vacuum enclosed machine or an open tank without a cover. If the process uses more than one solvent, it s a cosolvent process. 

The off-gas produced when an enclosed cleaning machine (Table 2.1) is purged with air (or inert gas) to relieve pressure, and... 

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