Apparatus and method for improving density uniformity of a fluidized bed medium, and/or for improved material fluidized bed sorting

An apparatus for providing a fluidized bed to effect a separation of a mixture of articles having at least a first density and a second density that is greater than the first density into separate groups, the apparatus comprising:

• an inclined channelization means having input and output ends and otherwise enclosed along the length of the sides and bottom thereof so as to form a continuous channel for containing a fluidized bed flowing under the influence of gravity from said input end to said output end;
• medium feed means for supplying to said input end of said channelization means said mixture of articles from which to create the fluidized bed in said channelization means:
• pneumatic means for forcing gas upwardly through said mixture of articles in said channelization means to create from said mixture of articles a fluidized bed;
• and
• vertical oscillation means for uniformly imparting to said entire inclined channelization means essentially only a vertical oscillatory movement of selected frequency and amplitude so that there is no significant horizontal movement imparted to said fluidized bed, said vertical oscillation means comprising eccentrically weighted rotation means for producing a periodic vertical force by rotating two eccentric weights at the same speed but in opposite direction and 180.degree. out of phase with each other.

An apparatus for providing a fluidized bed to effect a separation of a mixture of articles having at least a first density and a second density that is greater than the first density into separate groups, the apparatus comprising:

• a plurality of inclined channelization means each having input and output ends and otherwise enclosed along the length of the sides and bottom thereof so as to form a continuous channel for containing a fluidized bed flowing under the influence of gravity from said input end to said output end;
• medium feed means for supplying to the input end of at least one said channelization means said mixture of articles from which to create the fluidized bed in said channelization means;
• pneumatic means for forcing gas upwardly through said mixture of articles in said channelization means to create from said mixture of articles a fluidized bed;
• vertical oscillation means for uniformly imparting to each entire said inclined channelization means essentially only a vertical oscillatory movement of selected frequency and amplitude with no significant horizontal movement so as to create within said fluidized bed a plurality of separate layers each containing articles of different density, said vertical oscillation means comprising first adjustable means for selecting the amplitude of vertical oscillation and second adjustable means for selecting the frequency of the vertical oscillation, said first and second means being independently adjustable relative to one another;
• means for returning at least one said layer of said mixture exiting from an output end of at least one said channelization means to the input end of another of said channelization means;
• and
• means for off-loading different layers of said mixture which are vertically separated at the output end of each channelization means.

A method of providing a fluidized bed to effect a separation of articles having at least a first density and a second density that is greater than the first density into separate groups, comprising the steps of:

• supplying to an inclined trough having inlet and outlet ends a fluidization medium from which to produce a fluidized bed flowing uninterrupted under the influence of gravity through the length of said trough;
• forcing air upwardly through said fluidization medium in said trough to produce therefrom the fluidized bed;
• uniformally imparting to said entire trough essentially only a vertical oscillatory movement of selected frequency and amplitude with no significant horizontal movement imparted to the fluidized bed;
• and
• adjusting at least one of the frequency and amplitude of the vertical oscillatory movement.

A method of providing a fluidized bed to effect a separation of a mixture of articles having at least a first density and a second density that is greater than the first density into separate groups, comprising the steps of:

• supplying to an inclined trough having inlet and outlet ends a fluidization medium from which to produce a fluidized bed flowing uninterrupted under the influence of gravity through the length of said trough;
• forcing air upwardly through said fluidization medium in said trough to produce therefrom the fluidized bed;
• and
• uniformly imparting to said entire trough essentially only a vertical oscillatory movement of selected frequency and amplitude with no significant horizontal movement imparted to the fluidized bed by producing a periodic vertical force by rotating two weights at the same speed but in opposite direction and 180.degree. out of phase with each other.

A method of providing a fluidized bed to effect a separation of a mixture of articles having at least a first size and a second size, and having a first density and a second density that is greater than the first density into separate groups, comprising the steps of:

• supplying to a first inclined trough having inlet and outlet ends said mixture of articles from which to produce a fluidized bed flowing uninterrupted under the influence of gravity through the length of said first trough;
• forcing air upwardly through said mixture of articles in said first trough to produce therefrom the fluidized bed;
• uniformly imparting to said entire first trough essentially only a vertical oscillatory movement of selected frequency and amplitude with no significant horizontal movement imparted to the fluidized bed so that said mixture is separated into at least two groups of differing sizes;
• returning one of said groups to a second inclined trough having inlet and outlet ends;
• forcing air upwardly through said second trough to produce from said returned group a fluidized bed flowing uninterrupted under the influence of gravity through said second trough;
• and
• uniformly imparting to said entire second trough essentially only a vertical oscillatory movement of selected frequency and amplitude with no significant horizontal movement imparted to the fluidized bed, so that said returned group of articles is separated into further groups each having a different density but an essentially uniform size in each further group.