Techniques for managing scale formation in reverse osmosis (RO) and nanofiltration (NF) systems and a hybrid filtration architecture implementing the same
AssigneeClean H2O Technologies, LLC
InventorStanton Russel Smith
Life of this patent
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Abstract
The present disclosure is directed to filtering technologies that combine elements of continuous and batch NF/RO based on the constraints of the end-user facility to achieve a target balance between, for instance, recovery and power consumption, and to reduce long term operating cost of a plant. A method for extending batch operation into a second induction period with antiscalant injection is also disclosed herein, with the second induction period allowing for yet higher water recovery.
Claims10
A method for operating a filtration system, the filtration system having an inlet fluidly coupled to at least one feed stream, at least one filter membrane fluidly coupled to the inlet to receive feed water from the at least one feed stream and at least one pump to generate a pressure to displace the feed water from the at least one feed stream into the at least one filter membrane and produce an output permeate stream, the method comprising:
- prior to adding an antiscalant to the at least one feed stream, causing a first driving signal to be provided to the at least one pump to cause the generated pressure to produce the output permeate stream at a recovery rate that is substantially equal to a first target recovery rate during a first period of time, the first target recovery rate being greater than a maximum non-scaling recovery rate for the at least one filter membrane and less than 100%, wherein the maximum non-scaling recovery rate is a water recovery at which scaling initiates or when super-saturation of a scaling compound of interest first occurs while maintaining the first target recovery rate, determining when a predetermined moment will occur, the predetermined moment associated with when a pre-antiscalant maximum non-scaling recovery state will be reached for the at least one filter membrane;
- and
- in response to determining when the predetermined moment will occur, causing one or a plurality of antiscalant doses to be provided to the at least one filter membrane prior to the pre-antiscalant maximum non-scaling recovery state being reached to increase an amount of time between when a post-antiscalant maximum non-scaling recovery state is reached and when subsequent scaling and/or fouling of the at least one filter membrane occurs;
- and
- causing a second driving signal to be provided to the at least one pump to cause the generated pressure to produce the output permeate stream at a recovery rate substantially equal to a second target recovery rate during a second period of time which exceeds the maximum non-scaling recovery rate for the at least one filter membrane and the first target recovery rate,
- wherein the at least one filter membrane is not flushed between the steps of causing the first driving signal and causing the second driving signal.
Dependencies are inferred from the claim text.