US 4,303,412 AGranted

Method and apparatus for compressively separating waste material

OwnerEugene M. A. Baikoffinventor

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Abstract

An apparatus for processing waste material comprises a piston arrangement acting upon a mass of refuse in a receptacle formed by a cylindrical wall and a counter-piston constituting the bottom. The counter-piston can rise in such a way as to block sludge outlets in the cylindrical wall during the initial phase of compression of the waste by the piston arrangement. Thereafter, the counter-piston descends so as to free the sludge outlets when a certain pressure is attained. The compression-piston arrangement comprises two coaxial pistons designed to ensure constant, substantially uniform pressure in the mass of waste. Thus, virtually all liquid, semisolid, or viscous materials can be extracted from the waste to obtain sludge useful in agriculture. Also obtained are virtually dry and non-brittle blocks of refuse which has not been crushed but subjected to internal shearing and contraction, thus yielding a good agglomerate. These blocks may be used as fuel briquettes.

Claims14

Dependent claims

In a method of compressively separating waste material, particularly waste composed at least partially of organic matter, in order to extract liquid or semisolid sludge containing water with organic matter and/or biologically useful materials, on the one hand, and solid blocks of compressed waste which are cohesive enough to be stored and handled in use, particularly as fuel briquettes, comprising the steps of

placing in an open-ended receptacle a quantity of waste material to be treated, said receptacle having sludge extraction apertures,
plugging the open end of the filled receptacle by means of a piston arrangement,
closing the said sludge extraction apertures,
thereafter causing a first compression of the waste material in the receptacle by means of a displacement of the piston arrangement to reduce the closed volume of the receptacle without allowing any material to escape therefrom,
thereafter opening the sludge-extraction apertures, the cross-section of said apertures having a predetermined size so as to prevent the escape therethrough of non-flowable particles larger than said predetermined size, and
then causing a further compression of the waste material in the receptacle by further displacement of the piston arrangement until virtually all of the liquid, semisolid, or viscous material has escaped through said apertures,
said first and further compression steps being effected by providing the said receptacle and said piston arrangement with such a structural conformation that the entire mass of waste material compressed in the receptacle is subjected to substantially uniform pressure, the internal contractions and shearings within the mass of waste material being effected without crushing and by a succession
of gradual elementary advances of the piston arrangement free of retractions and re-advances,
and subsequently removing the compressed mass of waste material from the receptacle in the form of a homogeneous, dry, and solid compressed block structure.

6 more elements

In an apparatus for compressively separating waste material, of the type comprising at least one cylindrical receptacle adapted to be filled with a quantity of waste material to be treated, a piston arrangement adapted to enter said receptacle to effect the compression of said waste material, said piston arrangement comprising an assembly of two coaxial pistons, an inner one and an outer one, the inside diameter of said receptacle corresponding to the outside diameter of the outer piston of the piston arrangement, and a counter-piston adapted to form the bottom of the receptacle and adapted to be advanced into said receptacle to block sludge-extraction apertures situated in the portion of the sidewall of the receptacle adjacent the bottom thereof in order to ensure pre-compression without any escape of the mass of waste material, said counter-piston thereafter being retracted to open said apertures while the piston arrangement continues its compression action thereby to cause the explusion through said apertures of all the liquid, semisolid, or viscous material from the mass of waste material, the improvement comprising:

a conformation of said inner piston of said piston arrangement including at least one piston having a pressure head of a shape exhibiting a frustoconical surface the generating line of which has a predetermined angle to the axis of the piston and, at the end of this frustconical surface, a conical surface, the generating line of which has a larger angle to the axis of the piston than said predetermined angle, the dimensions and the angles of said conical and frustoconical surfaces being so determined with respect to the dimensions of said cylindrical receptacle as to maintain, by virtue of the laws of soil mechanics, applied in the case of a volume of limited creep, a substantially uniform pressure throughout the mass of waste material in the receptacle.

Dependencies are inferred from the claim text.