Method of automatic debris separation
AssigneeWellman, Inc.
InventorsJames A. Lindsey, Daniel A. Allen, Jr., Jonathan W. Skelley
Life of this patent
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Abstract
The invention is an automatic debris separation process for effecting air separation of fragmented materials, such as size-reduced fiber feedstocks derived from textile wastes. The process uses high-velocity air within an elutriation assembly to efficiently remove ferrous and non-ferrous metal debris from recyclable polymer fibers. In particular, the process may employ automatic process control strategies to vary airflow within the elutriation assembly in process-controlled response to measured metal contamination, thereby ensuring that post-separation metal contamination is maintained at or below an upper contamination limit.
Claims38
A separation method employing a closed-loop automatic process control system, comprising:
- introducing a material, feedstock into a substantially vertical separation chamber having an upper light-fraction material outlet and a lower heavy-fraction material outlet, the material feedstock comprising a fragmented textile feedstock;
- directing an upward airflow within the separation chamber to separate the material feedstock into a light fraction and a heavy fraction such that the light fraction exits the separation chamber though the light-fraction material outlet and the heavy fraction exits the separation chamber though the heavy-fraction material outlet;
- continually assessing material contamination;
- and
- continually adjusting the airflow within the separation chamber in process-controlled response to the material contamination.
A process for removing metal contaminants from a fiber feedstock, comprising:
- providing a substantially vertical separation chamber having an upper light-fraction material outlet and a lower heavy-fraction material outlet;
- continually introducing a fiber feedstock into the separation chamber via an air stream that has an average velocity more than 500 feet per minute within the separation chamber;
- continually separating the fibers feedstock into (i) a light fraction that exits the separation chamber though the light-fraction material outlet and (ii) a heavy fraction that exits the separation chamber though the heavy-fraction material outlet;
- measuring metal contamination;
- and
- manipulating the air stream velocity within the separation chamber in response to the measured metal contamination.
A process-controlled process for removing metal contaminants from a polymer fiber feedstock, comprising:
- providing a substantially vertical separation chamber having an upper light-fraction material outlet and a lower heavy-fraction material outlet;
- continuously introducing a polymer fiber feedstock into the separation chamber via an air stream that has an average velocity more than 500 feet per minute within the separation chamber;
- continuously separating the polymer fiber feedstock into (i) a light fraction that exits the separation chamber though the light-fraction material outlet and (ii) a heavy fraction that exits the separation chamber though the heavy-fraction material outlet;
- continuously measuring metal contamination in the light fraction;
- transmitting, to a controller, measurement signals indicating the metal contamination in the light fraction;
- transmitting, from the controller, control signals to a control element that manipulates air velocity within the separation chamber;
- and
- continually manipulating the air stream velocity within the separation chamber in process-controlled response to the control signals.
Dependencies are inferred from the claim text.