Continuous drying of granular polyethylene terephthalate

Claim 1

A METHOD OF CONTINUOUSLY DRYING WATER-CONTAINING GRANULES OF AMORPHOUS POLYETHYLENE TEREPHTHALATE COMPRISING: (A) FORMING A LAYER OF POLYETHYLENE TEREPHTHALATE GRANULES CONSISTING OF FROM 5/ PERCENT TO 100 PERCENT BY WEIGHT OF AT LEAST PARTIALLY CRYSTALLIZED POLYETHYLENE TEREPHTHALATE GRANULES AND FROM 50 PERCENT TO 0 PERCENT BY WEIGHT AMORPHOUS POLYETHYLENE TEREPHTHALATE GRANULES, THE HEIGHT OF SAID LAYER BEING LESS THAN SUCH HEIGHT WHEREAT FLUIDIZATION AND MIXING OF THE GRANULES IS ADVERSELY AFFECTED TO THE EXTENT THAT STICKING TOGETHER AND CONGLOMERATION THEREOF OCCUR DURING STEP (B); (B) FLUIDIZING SAID LAYER OF POLYETHYLENE TEREPHTHALATE GRANULES BY MEANS OF A CONTINUOUS STREAM OF AN INERT GAS HAVING A TEMPERATURE OF AT LEAST 110*C. BUT LESS THAN 200*C., SO THAT THE RATIO OF THE HEIGHT OF THE LAYER OF THE THUS FLUIDIZED GRANULES TO THE HEIGHT OF THE LAYER OF THE NON-FLUIDIZED GRANULES OF STEP (A) IS AT LEAST TWO; (C) CONTINUOUSLY INTRODUCING INTO AND MIXING WITH THE SAID FLUIDIZED GRANULES THE WATER-CONTAINING AMORPHOUS POLYETHYLENE TEREPHTHALATE GRANULES TO BE DRIED, WHEREBY SAID WATER CONTAINING AMORPHOUS POLYETHYLENE TEREPHTHALATE GRANULES ARE AT LEAST PARTIALLY CRYSTALLIZED; (D) CONTINUOUSLY WITHDRAWING FROM THE RESULTING MIXTURE AT LEAST PARTIALLY CRYSTALLIZED POLYETHYLENE TETEPHTHALATE GRANULES; AND (E) THENCE AT ELEVATED TEMPERATURES CONTINUOUSLY DRYING SAID AT LEAST PARTIALLY CRYSTALLIZED GRANULES WHICH ARE IN AT MOST SLOW MOTION RELATIVE TO EACH OTHER; (F) THE RATIO OF THE HEIGHT OF THE LAYER OF SAID FLUIDIZED GRANULES TO THE HEIGHT OF THE LAYER OF SAID NONFLUIDIZED GRANULES CONTINUOUSLY IS AT LEAST TWO AND THE COMPOSITION OF SAID FLUIDIZED GRANULES CONTINUOUSLY CONSISTS OF FROM 50 PERCENT TO 100 PERCENT BY WEIGHT OF AT LEAST PARTIALLY CRYSTALLIZED POLYETHYLENE TEREPHTHALATE GRANULES AND FROM 50 PERCENT TO 0 PERCENT BY WEIGHT AMORPHOUS POLYETHYLENE TEREPHTHALATE GRANULES TO PREVENT STICKING TOGETHER OF THE AT LEAST PARTIALLY CRYSTALLIZED GRANULES DURING STEP (E).

Claim 2

A METHOD OF CONTINUOUSLY DRYING WATER-CONTAINING GRANULES OF AMORPHOUS POLYETHYLENE TEREPHTHALATE COMPRISING: (A) FORMING A LAYER OF POLYETHYLENE TEREPHTHALATE GRANULES CONSISTING OF FROM 5/ PERCENT TO 100 PERCENT BY WEIGHT OF AT LEAST PARTIALLY CRYSTALLIZED POLYETHYLENE TEREPHTHALATE GRANULES AND FROM 50 PERCENT TO 0 PERCENT BY WEIGHT AMORPHOUS POLYETHYLENE TEREPHTHALATE GRANULES, THE HEIGHT OF SAID LAYER BEING LESS THAN SUCH HEIGHT WHEREAT FLUIDIZATION AND MIXING OF THE GRANULES IS ADVERSELY AFFECTED TO THE EXTENT THAT STICKING TOGETHER AND CONGLOMERATION THEREOF OCCUR DURING STEP (B); (B) FLUIDIZING SAID LAYER OF POLYETHYLENE TEREPHTHALATE GRANULES BY MEANS OF A CONTINUOUS STREAM OF AN INERT GAS HAVING A TEMPERATURE OF AT LEAST 110*C. BUT LESS THAN 200*C., SO THAT THE RATIO OF THE HEIGHT OF THE LAYER OF THE THUS FLUIDIZED GRANULES TO THE HEIGHT OF THE LAYER OF THE NON-FLUIDIZED GRANULES OF STEP (A) IS AT LEAST TWO; (C) CONTINUOUSLY INTRODUCING INTO AND MIXING WITH THE SAID FLUIDIZED GRANULES THE WATER-CONTAINING AMORPHOUS POLYETHYLENE TEREPHTHALATE GRANULES TO BE DRIED, WHEREBY SAID WATER CONTAINING AMORPHOUS POLYETHYLENE TEREPHTHALATE GRANULES ARE AT LEAST PARTIALLY CRYSTALLIZED; (D) CONTINUOUSLY WITHDRAWING FROM THE RESULTING MIXTURE AT LEAST PARTIALLY CRYSTALLIZED POLYETHYLENE TETEPHTHALATE GRANULES; AND (E) THENCE AT ELEVATED TEMPERATURES CONTINUOUSLY DRYING SAID AT LEAST PARTIALLY CRYSTALLIZED GRANULES WHICH ARE IN AT MOST SLOW MOTION RELATIVE TO EACH OTHER; (F) THE RATIO OF THE HEIGHT OF THE LAYER OF SAID FLUIDIZED GRANULES TO THE HEIGHT OF THE LAYER OF SAID NONFLUIDIZED GRANULES CONTINUOUSLY IS AT LEAST TWO AND THE COMPOSITION OF SAID FLUIDIZED GRANULES CONTINUOUSLY CONSISTS OF FROM 50 PERCENT TO 100 PERCENT BY WEIGHT OF AT LEAST PARTIALLY CRYSTALLIZED POLYETHYLENE TEREPHTHALATE GRANULES AND FROM 50 PERCENT TO 0 PERCENT BY WEIGHT AMORPHOUS POLYETHYLENE TEREPHTHALATE GRANULES TO PREVENT STICKING TOGETHER OF THE AT LEAST PARTIALLY CRYSTALLIZED GRANULES DURING STEP (E).