Process for the production of crystalline adduct of bisphenol A and phenol and apparatus therefor
First Claim
1. A crystallization device, comprising:
- a first crystallization tower for containing a slurry of crystals of an adduct of bisphenol A and phenol dispersed in phenol and having a recycling port, a discharge port and a feed port;
a feed conduit connected to said feed port of said first crystallization tower for feeding a liquid mixture of bisphenol A and phenol;
a second crystallization tower containing a slurry of crystals of an adduct of bisphenol A and phenol dispersed in phenol and having a recycling port, a discharge port and a feed port;
a first group of two or more coolers each having inlet and outlet ports;
a second group of two or more coolers each having inlet and outlet ports;
a common cooler having inlet and outlet ports;
feed conduit means extending between said discharge port of said first crystallization tower and the feed port of said second crystallization tower and having feed pump means for feeding a portion of the slurry in said first crystallization tower into said second crystallization tower through said feed conduit means;
first introduction conduit means extending between said discharge port of said first crystallization tower and the inlet port of each of said coolers of said first group;
first recycling conduit means extending between said recycling port of said first crystallization tower and the outlet port of each of said coolers of said first group;
second introduction conduit means extending between said discharge port of said second crystallization tower and the inlet port of each of said coolers of said second group;
second recycling conduit means extending between said recycling port of said second crystallization tower and the outlet port of each of said coolers of said second group;
a recovery conduit in communication with said discharge port of said second crystallization port for discharging part of the slurry from said second crystallization tower therethrough for recovery;
common introduction conduit means for communicating the inlet port of said common cooler with the discharge port of each of said first and second crystallization towers;
common recycling conduit means for communicating the outlet port of said common cooler with the recycling port of each of said first and second crystallization towers;
first pump means operable to continuously discharge part of the slurry from said first crystallization tower, to pass the discharged slurry through said first group of coolers and to return the discharged slurry after the passage of said coolers to said recycling port of said first crystallization tower;
second pump means operable to continuously discharge part of the slurry from said second crystallization tower, to pass the discharged slurry through said second group of coolers and to return the discharged slurry after the passage of said coolers to said recycling port of said second crystallization tower;
third pump means operable to continuously discharge part of the slurry from said first or second crystallization tower, to pass the discharged slurry through said common cooler and to return the discharged slurry after the passage of said common cooler to said recycling port of said first or second crystallization tower; and
controlling means to control the operations of said first, second and third pump means so that selected one of said common cooler and first and second groups of cooler is prevented from being fed with the discharged slurry,whereby the slurry within each of said first and second crystallization towers is cooled with the recycled slurry which has been passed through the said coolers to cause the crystals in each of said first and second crystallization towers to grow.
1 Assignment
0 Petitions
Accused Products
Abstract
High purity, crystalline adduct of bisphenol A and phenol is produced multi-stage crystallization of a phenolic slurry of bisphenol A with a crystal separation and washing step being interposed between each of the two stages. Each of the crystallization stage includes a series of crystallization towers operated at decreasing temperatures. The crystallization of the slurry is performed by continuously discharging a portion of the slurry from each of the crystallization towers, introducing the discharged slurry into one or more coolers and then recycling the cooled slurry to the tower. Another portion of the slurry in each crystallization slurry is continuously discharged, heated for dissolving fine crystals of the adduct and then recycled to the crystallization tower so that large crystals are grown in each of the crystallization steps. An apparatus having a plurality of coolers and suitable for effecting the above crystallization is also disclosed.
18 Citations
1 Claim
-
1. A crystallization device, comprising:
-
a first crystallization tower for containing a slurry of crystals of an adduct of bisphenol A and phenol dispersed in phenol and having a recycling port, a discharge port and a feed port; a feed conduit connected to said feed port of said first crystallization tower for feeding a liquid mixture of bisphenol A and phenol; a second crystallization tower containing a slurry of crystals of an adduct of bisphenol A and phenol dispersed in phenol and having a recycling port, a discharge port and a feed port; a first group of two or more coolers each having inlet and outlet ports; a second group of two or more coolers each having inlet and outlet ports; a common cooler having inlet and outlet ports; feed conduit means extending between said discharge port of said first crystallization tower and the feed port of said second crystallization tower and having feed pump means for feeding a portion of the slurry in said first crystallization tower into said second crystallization tower through said feed conduit means; first introduction conduit means extending between said discharge port of said first crystallization tower and the inlet port of each of said coolers of said first group; first recycling conduit means extending between said recycling port of said first crystallization tower and the outlet port of each of said coolers of said first group; second introduction conduit means extending between said discharge port of said second crystallization tower and the inlet port of each of said coolers of said second group; second recycling conduit means extending between said recycling port of said second crystallization tower and the outlet port of each of said coolers of said second group; a recovery conduit in communication with said discharge port of said second crystallization port for discharging part of the slurry from said second crystallization tower therethrough for recovery; common introduction conduit means for communicating the inlet port of said common cooler with the discharge port of each of said first and second crystallization towers; common recycling conduit means for communicating the outlet port of said common cooler with the recycling port of each of said first and second crystallization towers; first pump means operable to continuously discharge part of the slurry from said first crystallization tower, to pass the discharged slurry through said first group of coolers and to return the discharged slurry after the passage of said coolers to said recycling port of said first crystallization tower; second pump means operable to continuously discharge part of the slurry from said second crystallization tower, to pass the discharged slurry through said second group of coolers and to return the discharged slurry after the passage of said coolers to said recycling port of said second crystallization tower; third pump means operable to continuously discharge part of the slurry from said first or second crystallization tower, to pass the discharged slurry through said common cooler and to return the discharged slurry after the passage of said common cooler to said recycling port of said first or second crystallization tower; and controlling means to control the operations of said first, second and third pump means so that selected one of said common cooler and first and second groups of cooler is prevented from being fed with the discharged slurry, whereby the slurry within each of said first and second crystallization towers is cooled with the recycled slurry which has been passed through the said coolers to cause the crystals in each of said first and second crystallization towers to grow.
-
Specification