1. Field of the Invention
This invention provides a means for centrifugally separating residual oil or other liquid contamination from shredded or granulated containers used to package said oil or other liquid. In principle, the apparatus consists of a shredder or cutter assembly at the in-feed area which reduces the container to chips or shreds. The chips or shreds are then fed into a centrifugal device which separates the oil (or other liquid) from the container material. The separated liquid is subsequently drained through a series of filters into a holding tank, while the chipped or shredded container material is discharged into a holding vessel.
With an understanding of the present need to protect both our natural environment and to optimize the use of natural resources, the importance of this apparatus should be readily apparent. In a first case, a mechanical separation of the residual liquid (most notably, motor oil) from its chipped or shredded container assures less pollutants introduced into the waste stream from cleaning operations in the form of an emulsion of water, detergents, and the specific material in the container. In a second case, a mechanical separation assures a greater return of product into its highest value usage with the least energy expended; that is, motor oil may be recovered in the form of pure motor oil rather than as an emulsion which requires expensive reprocessing for commercial reuse.
2. Description of the Prior Art
The technology of centrifugally separating residual liquid which was packaged within a container from the material proper of said container subsequent to shredding or comminution of the container has not heretofore been addressed in any patent available at the time of this application. This is particularly true of plastic containers in the form of blow molded bottles which have contained motor oils or similar non-water soluble liquids.
A new body of technology is growing for the purpose of reclaiming such plastic and other container materials. In most cases, however, the technology has used mechanical agitation in conjunction with washing and soaking bathes to remove said contaminant from the chipped or shredded container.
Centrifugal separation of a residual liquid contaminant of a container, and the shredded material proper from said container, is a novel innovation as suggested in this invention.
However, note must be taken of an older technology which uses centrifugal mechanical separation of cutting fluids and oils from metal chips, borings, and the like as encountered in machine shop operations. In this regard, the patents of Dudley et al. (U.S. Pat. Nos. 4,137,176 and 4,253,960), Areaux et al. (U.S. Pat. No 4,186,096), Weininger et al. (U.S. Pat. No. 4,122,014), Steimel (U.S. Pat. No. 3,366,318), and Ziherl (U.S. Pat. No. 2,878,943) deserve attention. (Note that the two patents of Dudley and the patent of Areaux are refinements of the same practice.)
In reviewing the prior art, it is apparent that Dudley and Areaux (U.S. Pat. Nos. 4,137,176, 4,253,960, and 4,186,096) have devised a technology which is continuous. Furthermore, the above mentioned art loads the material at the bottom of the rotating sieve, and discharges it at the top. Whereas the present invention uses a batch process where the material is held within the rotating sieve throughout a single process run. The present invention further loads the material from the top of the rotating sieve and discharges it from the bottom with the aid of a dumping mechanism. Ziherl (U.S. Pat. No. 2,878,943) is similar to Dudley and Areaux in that his process is continuous and the liquid discharge is at the top. However, Ziherl discharges the solid material at the bottom. Nonetheless, as regards the present invention, the differences between Ziherl and Dudley and Areaux are inconsequential. Refer to the arguments above as to the differences between the present invention and Dudley and Areaux as being similar to the differences between the present invention and Ziherl.
Weininger et al. (U.S. Pat. No. 4,122,014) must be reviewed because of certain apparent similarities with the present invention. Weininger is both a batch process, and feeds the material into the top, and discharges from the bottom, of the rotating sieve. However, as can readily be seen, Weininger primarily teaches the use of a moving distributing plate which in no way anticipates the unique claims of this invention. Nor, does Weininger anticipate the bottom dumping mechanism as developed in this invention.