Method and apparatus for sorting a mixture of particles

Claim 2

In a method of sorting particles including subjecting the particles to at least an air wash, screening and magnetic separation producing thereby a mixture comprising plastic blasting particles of a substantially uniform size and density and particles of substantially the same size and of a different density than the plastic blasting particles, the improvement comprising the steps of: supplying the mixture to a reservoir; pressurizing the reservoir such that the particles of the mixture collect at different levels in the reservoir in accordance with their density; removing the plastic blasting particles from their level in the reservoir; and removing the other particles from their levels in the reservoir separately from the plastic blasting particles.

Claim 3

In the method as defined in claim 1, wherein the mixture is supplied to the reservoir by gravity.

Claim 4

In the method as defined in claim 1, wherein the plastic blasting particles are removed from the reservoir by gravity.

Claim 5

In the method as defined in claim 1, the improvement further comprising the step of: vibrating the mixture in the pressurized reservoir to avoid surging, channeling and the like of the mixture as the particles collect at their defined levels.

Claim 6

In the method as defined in claim 4, wherein the vibrations are applied to the mixture near the bottom of the reservoir.

Claim 7

In the method as defined in claim 1, wherein the mixture is fluidized by the application of positive air flow to the reservoir.

Claim 8

In the method as defined in claim 1, further comprising the step of: maintaining the reservoir level thereby insuring a uniform depth of fluidized material.

Claim 11

The apparatus as defined in claim 8, wherein said mounting means comprises.

Claim 14

The apparatus as defined in claim 10, wherein said mounting means comprises spring mounting means.

Claim 15

In an apparatus for dry stripping paint from a substrate including means for separating a mixture of particles by at least an air wash, screening and magnetic separation producing thereby a mixture containing a first group of particles of substantially uniform size and density and second group of particles of substantially the same size as the particles of said first group and of a different density than the particles of said first group, the improvement comprising: means defining a reservoir having a bottom wall, an inlet opening and an outlet opening; a diffusion membrane coextensive with the bottom wall and spaced therefrom defining a gas manifold with the bottom wall; mixture supply means for introducing the mixture through the inlet opening in said reservoir, said mixture defining in said reservoir a bed extending from the diffusion membrane toward the outlet opening of said reservoir; means supplying a positive gas flow into the manifold, said gas passing through the diffusion membrane and the mixture bed and exhausting through the outlet opening, said mixture being fluidized by said gas such that the groups of particles collect at different levels in said bed in accordance with their density; and means for removing the groups of particles from the reservoir separately.

Claim 16

In an apparatus for dry stripping paint from a substrate including means for separating a mixture of particles by at least an air wash, screening and magnetic separation producing thereby a mixture containing a first group of particles of substantially uniform size and density and second group of particles of substantially the same size as the particles of said first group and of a different density than the particles of said first group, the improvement comprising: means defining a reservoir having a bottom wall, an inlet opening and an outlet opening; a diffusion membrane coextensive with the bottom wall and spaced therefrom defining a gas manifold with the bottom wall; mixture supply means for introducing the mixture through the inlet opening in said reservoir, said mixture defining in said reservoir a bed extending from the diffusion membrane toward the outlet opening of said reservoir; means supplying a positive gas flow into the manifold, said gas passing through the diffusion membrane and the mixture bed and exhausting through the outlet opening, said mixture being fluidized by said gas such that the groups of particles collect at different levels in said bed in accordance with their density; and means for removing the groups of particles from the reservoir separately.

Claim 17

The improvement as defined in claim 12, further comprising: vibration means situated in the reservoir above the diffusion membrane for vibrating the mixture in the fluidized bed reservoir above the diffusion membrane to avoid surging, channeling and the like of the mixture as the particles collect at their different levels.

Claim 18

The improvement as defined in claim 12, further comprising: means for maintaining the reservoir level thereby insuring a uniform depth of fluidized mixture.

Claim 19

In an apparatus for dry stripping paint from a substrate utilizing plastic blasting particles including means for separating a mixture of particles by at least an air wash, screening and magnetic separation producing thereby a mixture containing plastic blasting particles of a substantially uniform size and density and particles of substantially the same size and of a different density than the plastic blasting particles, the improvement comprising: means defining a reservoir having a bottom wall and an opened top; a diffusion membrane coextensive with the bottom wall and spaced therefrom defining a gas manifold with the bottom wall; mixture supply means for introducing the mixture after it has been subjected to at least an air wash, screening and magnetic separation, through the opened top into the reservoir, said mixture defining in said reservoir a bed extending from the diffusion membrane toward the opened top of the reservoir; means supplying a positive gas flow into the gas manifold, said gas passing through the diffusion membrane and the mixture bed and exhausting through the opened end of the reservoir, said mixture bed being fluidized such that the particles of the mixture collect at different levels in the bed in accordance with their density; and mixture removal means for removing the particles of the mixture collected at the different levels in the bed from the reservoir separately.

Claim 20

In an apparatus for dry stripping paint from a substrate utilizing plastic blasting particles including means for separating a mixture of particles by at least an air wash, screening and magnetic separation producing thereby a mixture containing plastic blasting particles of a substantially uniform size and density and particles of substantially the same size and of a different density than the plastic blasting particles, the improvement comprising: means defining a reservoir having a bottom wall and an opened top; a diffusion membrane coextensive with the bottom wall and spaced therefrom defining a gas manifold with the bottom wall; mixture supply means for introducing the mixture after it has been subjected to at least an air wash, screening and magnetic separation, through the opened top into the reservoir, said mixture defining in said reservoir a bed extending from the diffusion membrane toward the opened top of the reservoir; means supplying a positive gas flow into the gas manifold, said gas passing through the diffusion membrane and the mixture bed and exhausting through the opened end of the reservoir, said mixture bed being fluidized such that the particles of the mixture collect at different levels in the bed in accordance with their density; and mixture removal means for removing the particles of the mixture collected at the different levels in the bed from the reservoir separately.

Claim 21

The improvement as defined in claim 15, further comprising: vibration means situated in the reservoir above the diffusion membrane for vibrating the mixture in the fluidized bed reservoir above the diffusion membrane to avoid surging, channeling and the like of the mixture as the particles collect at their different levels.

Claim 22

The improvement as defined in claim 15, further comprising: means for maintaining the reservoir level thereby insuring a uniform depth of fluidized mixture.

Claim 23

In an apparatus for dry stripping paint from a substrate including means for separating a mixture of particles by at least an air wash, screening and magnetic separation producing thereby a mixture containing a first group of particles of substantially uniform size and density and second group of particles of substantially the same size as the particles of said first group and of a different density than the particles of said first group, the improvement comprising: means defining a reservoir having a bottom wall, an inlet opening and an outlet opening; a diffusion membrane coextensive with the bottom wall and spaced therefrom defining a gas manifold with the bottom wall; mixture supply means for introducing the mixture through the inlet opening in said reservoir, said mixture defining in said reservoir a bed extending from the diffusion membrane toward the outlet opening of said reservoir; means supplying a positive gas flow into the manifold, said gas passing through the diffusion membrane and the mixture bed and exhausting through the outlet opening, said mixture being fluidized by said gas such that the groups of particles collect at different levels in said bed in accordance with their density; means for removing the groups of particles from the reservoir separately; spring mounted means on which said means defining the reservoir is mounted permitting vertical displacement of said means defining the reservoir; and level sensing means for sensing a given mixture contamination level as a result of displacement of said means defining the reservoir.

Claim 24

In an apparatus for dry stripping paint from a substrate including means for separating a mixture of particles by at least an air wash, screening and magnetic separation producing thereby a mixture containing a first group of particles of substantially uniform size and density and second group of particles of substantially the same size as the particles of said first group and of a different density than the particles of said first group, the improvement comprising: means defining a reservoir having a bottom wall, an inlet opening and an outlet opening; a diffusion membrane coextensive with the bottom wall and spaced therefrom defining a gas manifold with the bottom wall; mixture supply means for introducing the mixture through the inlet opening in said reservoir, said mixture defining in said reservoir a bed extending from the diffusion membrane toward the outlet opening of said reservoir; means supplying a positive gas flow into the manifold, said gas passing through the diffusion membrane and the mixture bed and exhausting through the outlet opening, said mixture being fluidized by said gas such that the groups of particles collect at different levels in said bed in accordance with their density; means for removing the groups of particles from the reservoir separately; spring mounted means on which said means defining the reservoir is mounted permitting vertical displacement of said means defining the reservoir; and level sensing means for sensing a given mixture contamination level as a result of displacement of said means defining the reservoir.

Claim 25

In an apparatus for dry stripping paint from a substrate utilizing plastic blasting particles including means for separating a mixture of particles by at least an air wash, screening and magnetic separation producing thereby a mixture containing plastic blasting particles of a substantially uniform size and density and particles of substantially the same size and of a different density than the plastic blasting particles, the improvement comprising: means defining a reservoir having a bottom wall and an opened top; a diffusion membrane coextensive with the bottom wall and spaced therefrom defining a gas manifold with the bottom wall; mixture supply means for introducing the mixture after it has been subjected to at least an air wash, screening and magnetic separation, through the opened top into the reservoir, said mixture defining in said reservoir a bed extending from the diffusion membrane toward the opened top of the reservoir; means supplying a positive gas flow into the gas manifold, said gas passing through the diffusion membrane and the mixture bed and exhausting through the opened end of the reservoir, said mixture bed being fluidized such that the particles of the mixture collect at different levels in the bed in accordance with their density; mixture removal means for removing the particles of the mixture collected at the different levels in the bed from the reservoir separately; mounting means on which said means defining the reservoir is mounted permitting vertical displacement of said means defining the reservoir; and level sensing means for sensing a given mixture contamination level as a result of displacement of said means defining the reservoir.

Claim 26

In an apparatus for dry stripping paint from a substrate utilizing plastic blasting particles including means for separating a mixture of particles by at least an air wash, screening and magnetic separation producing thereby a mixture containing plastic blasting particles of a substantially uniform size and density and particles of substantially the same size and of a different density than the plastic blasting particles, the improvement comprising: means defining a reservoir having a bottom wall and an opened top; a diffusion membrane coextensive with the bottom wall and spaced therefrom defining a gas manifold with the bottom wall; mixture supply means for introducing the mixture after it has been subjected to at least an air wash, screening and magnetic separation, through the opened top into the reservoir, said mixture defining in said reservoir a bed extending from the diffusion membrane toward the opened top of the reservoir; means supplying a positive gas flow into the gas manifold, said gas passing through the diffusion membrane and the mixture bed and exhausting through the opened end of the reservoir, said mixture bed being fluidized such that the particles of the mixture collect at different levels in the bed in accordance with their density; mixture removal means for removing the particles of the mixture collected at the different levels in the bed from the reservoir separately; mounting means on which said means defining the reservoir is mounted permitting vertical displacement of said means defining the reservoir; and level sensing means for sensing a given mixture contamination level as a result of displacement of said means defining the reservoir.