BACKGROUND Shadikhan, in U. S. patent No. 5,820, 748 (Oct. 13, 1998), discloses safe removal of gasses, water and solvents from used lubricating oils with vacuum apparatus under mild temperature conditions. In particular, a vacuum apparatus and mild temperatures are employed so as to remove gasses, water and solvents such as fuel from the used oil, which, preferably, had been first treated to remove solid particulate matter. With that invention, the art of oil decontamination was taken to an almost incredible level of perfection, with saving intact of most of the unspent sophisticated additive components in the base oil stock.

Nonetheless, in some cases, it would be desirable to build upon the same.

SUMMARY The present invention provides, in one aspect, a system apparatus for decontamination of used oil comprising a precipitation vessel; a vacuum apparatus for safe removal of gasses, water and solvents, in fluid communication with the precipitation vessel; and a holding and blending vessel, in fluid communication with the precipitation vessel.

Optionally, the system apparatus can further have a vacuum apparatus analogous or in addition to if not one and the same as the aforesaid vacuum apparatus for safe removal of gasses, water and solvents, which is in fluid communication with the holding and blending vessel.

In a related aspect, provided is a method of decontamination of used oil comprising the following steps: first, providing a sample of used oil, and subjecting it to vacuum under mild temperature conditions so that gasses, water and solvents are safely removed from the sample so as to provide an initially partially decontaminated oil sample ; second, adding coagulant to the sample coagulating and precipitating particulate matter from the initially partially decontaminated oil sample under generally mildly elevated temperature conditions so as to provide a wet, decontaminated oil sample; and third, again subjecting the wet, decontaminated oil sample to vacuum under mild temperature conditions so that gasses, water and solvents are safely removed therefrom to provide a decontaminated oil sample. Optionally, the decontaminated oil sample may be subject to final polishing and/or additive augmentation to Z-3/513 2 provide a cleaned oil conforming to appropriate specifications.

The invention finds utility in on-site oil reclamation.

Significantly, by the invention, an even more incredible level of perfection is provided in oil reclamation technology, while the environment is safely protected. In a particular consideration, the same is provided in notable part by subjecting the used oil first to vacuum under mild temperature conditions, and then coagulating and precipitating particulates such as micron and sub-micron sized particles. The invention is highly efficient in its practice.

Numerous further advantages attend the invention.

DRAWINGS The drawings form part of the specification hereof.

With respect to the drawings, which are not necessarily drawn to scale, the following is briefly noted: FIG. 1 is a general plan view of a system apparatus of the invention for decontamination of used oil.

FIG. 2 is a side plan view of a precipitation vessel forming part of the system apparatus for decontamination of used oil seen within FIG. 1.

FIG. 3 is a top plan view of an upper part of the precipitation vessel shown in FIG. 2.

FIG. 4 is a top plan view of a lower part of the Z-3/513 3 precipitation vessel shown in FIG. 2.

FIG. 5 is a side plan view of an holding/blending vessel forming part of the system apparatus for decontamination of used oil seen within FIG. 1.

FIG. 6 is a top plan view of the holding/blending vessel shown in FIG. 5.

ILLUSTRATIVE DETAIL The invention can be further understood by the present detail, which may be read in view of the drawings. Such is to be taken in an illustrative and not necessarily limiting sense.

With respect to the drawings, which may include those found in the mentioned from the Shadikhan'748 patent, the entire system of the present invention may be considered to be one unit. This is so especially in the sense that the separate devices can be interconnected and operated in conjunction with one another.

In the practice of the present invention, gasses, solvents and water are first removed as a preliminary treatment from a used, dirty oil sample by use of vacuum under mild temperature conditions according to the teachings of the patent to Shadikhan, prior to adding water-based coagulant to flocculate micron and sub-micron sized insoluble particles. See, the'748 patent. A suitable coagulant for that is an aqueous-based composition containing hydroxylic and single or complex oxygen functionality amino compounds such as the so-called British Rail coagulant mentioned in the'748 patent. The coagulant is added to the heated, used, dirty, preliminarily treated oil sample in the precipitation vessel at a mildly elevated <BR> <BR> temperature, i. e. , a temperature about from sixty degrees<BR> C. , to below the flash point of water, say, about<BR> ninety-eight degrees C. , which is preferably about from sixty-five to ninety-five degrees C. The heated mixture is then very slowly agitated over a suitable period such that the coagulant can react with flocculatable substances, and form a flocculate with the same, followed by precipitation.

The period of agitation can be, for instance, from about one hour to twenty-four hours, for example, at the preferred mildly elevated temperatures with an engine oil sample, about eight hours. This allows the precipitation required without harming or removing in substance additives present in the base oil stock. Preferably, the used oil sample being treated in the precipitation tank is kept at a constant temperature, for instance, by providing an insulating layer and/or such layer with an additional insulating layer around the precipitation vessel, for example, by way of surrounding the precipitation vessel or its oil contents with heated air circulation, with is again surrounded by an additional insulating layer, so that Z-3/513 5 potential heat loss is minimized if not effectively prevented. The situation in the used oil sample in the precipitation vessel thus is substantially if not essentially thermo-current free, and free of interfering gasses, solvents and excess water, which allows the sediments to most effectively precipitate and be drained out as sludge, say, about two percent by weight of the oil sample, depending on the dirt contents. These are largely oxidized particles of both micron and sub-micron size, and other impurities commonly found in used oils. By this practice, highly cleaned oil is thus provided. See, FIGS.

1-4, and FIGS. 1 and 2 of the Shadikhan'748 patent.

Further, the cleaned oil can be tested and be provided with a set of additives to bring its additive package back to original standards, or to any other suitable standard.

Accordingly, in the practice of the present invention, the cleaned oil is drawn off or, as it were, decanted, from the precipitation vessel in to a clean vessel, say, a designated blending/holding tank. From there remaining gasses, solvents and especially water, as the coagulant is water-based, are removed with vacuum under mild temperature conditions, again according to the teachings of the Shadikhan patent. The totally decontaminated, if not pristine, oil, is then blended with any depleted and/or further additives if so desired or required. See, FIGS. 1, 5 and 6, and FIGS. 1 and 2 of the Shadikhan'748 patent.

As the oil, virtually any oil may be reclaimed.

Accordingly, the oil sample can be an engine oil, gear oil, hydraulic fluid, transformer oil, and so forth and the like.

Engine lubricating oils are particularly well adapted for employment herein.

Thus, the system is most beneficial, efficient, and practical.

CONCLUSION The present invention is thus provided. Various features, parts, subcombinations and combinations of the invention can be practiced with or without reference to other features, parts, subcombinations or combinations, and numerous adaptations and modifications can be effected within its spirit, the literal claim scope of which is particularly pointed out as follows: