Method and system for treating feedwater

Abstract

A system for treating feedwater includes a fluidized bed heat exchanger unit connected to receive feedwater and a flash concentrator column connected to receive feedwater discharged from the fluidized bed heat exchanger unit. A spray dryer is provided to receive a solids/liquid slurry discharged from the flash concentrator column. Feedwater can be treated by converting dissolved solids in the feedwater to suspended solids, vaporizing a portion of the feedwater to produce a solids/liquid slurry, and separating solids from the solids/liquid slurry.

1 . A system for treating feedwater comprising:
 a fluidized bed heat exchanger unit connected to receive feedwater;   a flash concentrator column connected to receive feedwater discharged from said fluidized bed heat exchanger unit; and   a spray dryer connected to receive a solids/liquid slurry discharged from said flash concentrator column.   
     
     
         2 . The system of  claim 1  further comprising means for pre-concentrating feedwater received by said fluidized bed heat exchanger unit. 
     
     
         3 . The system of  claim 1  wherein said means for pre-concentrating includes a membrane distillation system. 
     
     
         4 . The system of  claim 3  wherein said membrane distillation system includes a membrane unit having at least one hydrophobic membrane. 
     
     
         5 . The system of  claim 1  wherein said flash concentrator column includes;
 a first inlet for receiving feedwater; 
 a second inlet for receiving feedwater discharged from said fluidized bed heat exchanger unit; 
 a first outlet for discharging vapor; 
 a second outlet for discharging feedwater; and 
 a third outlet for discharging said solids/liquid slurry. 
 
     
     
         6 . The system of  claim 5  wherein said fluidized bed heat exchanger unit includes an inlet for receiving feedwater discharged from said second outlet of said flash concentrator column and an outlet for discharging heated feedwater. 
     
     
         7 . The system of  claim 5  wherein said second inlet is configured to promote a tangential entry of a two-phase mixture. 
     
     
         8 . The system of  claim 1  further comprising a flash device located between said outlet of said fluidized bed heat exchanger unit and said second inlet of said flash concentrator column. 
     
     
         9 . The system of  claim 1  wherein said spray dryer is a fluidized bed spray dryer. 
     
     
         10 . A system for treating feedwater comprising:
 means for converting dissolved solids in said feedwater to suspended solids;   means for vaporizing a portion of said feedwater to produce a solids/liquid slurry; and   means for separating solids from said solids/liquid slurry.   
     
     
         11 . The system of  claim 10  wherein said means for converting includes a fluidized bed heat exchanger unit having an inlet for receiving feedwater and an outlet for discharging heated feedwater. 
     
     
         12 . The system of  claim 11  wherein said means for vaporizing includes a flash concentrator column having an inlet for receiving heated feedwater from said fluidized bed heat exchanger unit, an outlet for discharging said solids/liquid slurry, and another outlet for discharging vapor. 
     
     
         13 . The system of  claim 12  further comprising a condenser for condensing vapor discharged from said flash concentrator column. 
     
     
         14 . The system of  claim 10  wherein said means for separating comprises:
 an evaporation chamber; 
 means for introducing a stream of hot air into said evaporation chamber; and 
 at least one atomizer disposed in said evaporation chamber and connected to receive said solids/liquid slurry, said at least one atomizer being positioned so as to disperse droplets of said solids/liquid slurry into said stream of hot air whereby liquid in said solids/liquid slurry evaporates and solids in said solids/liquid slurry precipitate. 
 
     
     
         15 . The system of  claim 14  further comprising a fluidized bed of solid particles disposed in a lower section of said evaporation chamber. 
     
     
         16 . The system of  claim 14  wherein said means for separating further comprises a cyclone separator connected to receive vapor discharged from said evaporation chamber. 
     
     
         17 . The system of  claim 10  further comprising means for concentrating said feedwater prior to converting dissolved solids in said feedwater to suspended solids. 
     
     
         18 . The system of  claim 17  wherein said means for concentrating includes a membrane distillation system. 
     
     
         19 . The system of  claim 17  wherein said membrane distillation system includes a membrane unit having at least one hydrophobic membrane.