Reverse osmosis system with control based on flow rates in the permeate and brine streams
A reverse osmosis system includes a membrane chamber having a feed line. The chamber generates a permeate stream and a brine stream from the feed line. A feed pump pressurizes the feed line. A first flow meter generates a first flow signal corresponding to a flow of fluid in the permeate stream. A booster device has a turbine in fluid communication with the brine stream and a pump in fluid communication with the feed line. A motor is coupled to the turbine device and a variable frequency drive is attached to the turbine device operating in response to the first flow signal. A second flow meter generates a second flow signal corresponding to a flow of fluid in the brine stream and a variable size nozzle operates an opening in response to the second flow meter.
1. A multi-stage reverse osmosis system having a feed manifold coupled to a plurality of reverse osmosis stages, each stage comprising a reverse osmosis membrane within a membrane chamber that generates a permeate stream and a brine stream, and each stage having a booster device with a turbine portion comprising:
each stage comprising:
a first flow meter generating a first flow signal corresponding to a first flow of fluid in the permeate stream of a respective stage;
a second flow meter generating a second flow signal corresponding to a second flow of fluid in the brine stream of the respective stage;
a controller coupled to the first flow meter and the second flow meter;
a motor coupled to the turbine portion,
a variable frequency drive attached to and operating the motor in response to the first flow signal in the permeate stream of the respective stage; and
a variable size nozzle fluidically coupled to the turbine portion, said controller operating the variable size nozzle to the turbine portion in response to the second flow signal.
2. A multi-stage reverse osmosis system as recited in claim 1 wherein each of the stages is controlled independently.
3. A multi-stage reverse osmosis system as recited in claim 2 further comprising a feed pump; and
wherein each stage further comprising a first isolation valve disposed between the feed pump and each booster device.
4. A multi-stage reverse osmosis system as recited in claim 2 further comprising a brine manifold; and
wherein each stage further comprising a second isolation valve disposed between each booster device and the brine manifold.
5. A multi-stage reverse osmosis system as recited in claim 2 wherein each stage further comprising a third isolation valve in fluid communication with the permeate stream.
6. A multi-stage reverse osmosis system as recited in claim 2 wherein each motor comprises an induction motor.
7. A multi-stage reverse osmosis system as recited in claim 2 wherein each variable frequency drive comprises a regenerative variable frequency drive.
8. A multi-stage reverse osmosis system as recited in claim 2
wherein each motor acts as a generator to generate electrical power in response to the second flow signal.