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US 3,981,739 AGranted
Continuous crystallization
AssigneeAmstar Corporation
InventorsMorris Dmitrovsky, Antoine H. Kokke
Life of this patent
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AssigneeAmstar Corporation
InventorsMorris Dmitrovsky, Antoine H. Kokke
Estimating the term…
A crystallizable solute is crystallized from a solution containing the same by introducing a solution of said solute into a first stage evaporative-crystallization zone together with seed solute crystals. Within the first stage evaporative-crystallization zone the solution is concentrated to yield a saturated first stage concentrate containing crystals of said solute. The crystals of said solute are substantially larger than said seed crystals and are suspended in a solution more concentrated with respect to said solute than the solution supplied to said first evaporative-crystallization zone. A stream of said first concentrate is removed from said first evaporative-crystallization zone and transferred to a second evaporative-crystallization zone for further concentration or crystallization of solute and for the production of solute crystals of increased size. There is continuously recovered from the second evaporative-crystallization zone a slurry having a total solute or solids content of about 86-94 percent by weight and containing the solute crystals of desired crystal size.
A method of continuously crystallizing sugar from a sugar-containing solution which comprises substantially continuously introducing a sugar syrup to a first stage vacuum evaporative-crystallization zone, substantially continuously introducing into said first stage vacuum evaporative-crystallization zone seed sugar crystals for contact with said sugar syrup therein, concentrating the sugar syrup thus-introduced into said first stage vacuum evaporative-crystallization zone to produce therein a saturated first stage syrup having a higher dissolved solids content with concomitant growth and production of sugar crystals in said first stage syrup, substantially continuously withdrawing a stream of first stage syrup from said first stage vacuum evaporative-crystallization zone and substantially continuously introducing the withdrawn first stage syrup into a second stage vacuum evaporative-crystallization zone for additional evaporative crystallization therein to produce a second stage slurry having a total solids content of about 86-94 percent by weight and containing sugar crystals having a crystal size larger than the sugar crystals contained in said withdrawn first stage syrup and substantially continuously withdrawing said second stage slurry from said second stage vacuum evaporative-crystallization zone.
A method of continuously crystallizing sugar from sugar-containing solution which comprises substantially continuously introducing a sugar syrup to a first stage evaporative-crystallization zone, substantially continuously introducing into said first stage evaporative-crystallization zone seed sugar crystals for contact with said sugar syrup therein, concentrating the sugar syrup thus-introduced into said first stage evaporative-crystallization zone to produce therein a saturated first stage syrup having a higher dissolved solids content with concomitant growth and production of sugar crystals in said first stage syrup, substantially continuously withdrawing said first stage syrup from said first stage evaporative-crystallization zone, treating said withdrawn first stage syrup, with or without an intervening treatment, by eventual introduction into a second stage evaporative-crystallization zone to produce therein a second stage slurry having a total solids content of about 86-94 percent by weight and containing sugar crystals having a crystal size larger than the sugar crystals content in said first stage syrup and substantially continuously withdrawing said second stage slurry from said second stage evaporative-crystallization zone.
A method of continuously crystallizing crystallizable solute from a solution containing said solute which comprises substantially continuously introducing said solution into a first stage evaporative-crystallization zone, substantially continuously introducing into said first stage evaporative-crystallization zone seed crystals of said solute, concentrating the solution thus-introduced into said first stage evaporative-crystallization zone to produce therein a first stage solution having said solute dissolved therein at a concentration greater than the concentration of said solute in said solution with concomitant growth and production of crystals of said solute in said first stage solution, said solute crystals in said first stage solution having an average crystal size substantially greater than the average crystal size of said solute seed crystals, substantially continuously withdrawing a stream of said first stage solution from said first stage evaporative-crystallization zone and substantially continuously introducing said first stage solution into a second stage evaporative-crystallization zone for evaporative crystallization therein to produce a second stage solution having a total solute content greater than that of said first stage solution and containing solute crystals having an average crystal size substantially greater than the average crystal size of the crystals of said solute in said first stage solution and substantially continuously withdrawing said second stage solution from said second stage evaporative-crystallization zone.
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