# US 2016/0257576 A1 · Water treatment system and method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2016/0257576 A1 - Document ID: US20160257576A1 - Status: Published application - Kind: A1 - Application number: 14/638,550 - Filed: 2015-03-04 - Published: 2016-09-08 - Earliest claimed: 2015-03-04 - Assignees: Israel Aerospace Industries Ltd. - Applicants: Israel Aerospace Industries Ltd. - Inventors: Benaya HOZ - Web page: https://patentgrep.com/patent/US20160257576A1 ## CPC - C02F 1/008: {Control or steering systems not provided for elsewhere in subclass C02F} - B01D 61/025: {Reverse osmosis; Hyperfiltration} - B01D 61/027: {Nanofiltration} - B01D 61/12: Controlling or regulating - C02F 1/441: {by reverse osmosis} - C02F 1/442: {by nanofiltration} - B01D 2311/14: Pressure control - C02F 2103/08: Seawater, e.g. for desalination - C02F 2209/03: Pressure - C02F 2209/40: Liquid flow rate - Y02A 20/131: Reverse-osmosis - C02F: TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE (separation in general B01D; special arrangements on waterborne vessels of installations for treating water, waste water or sewage, e.g. for producing fresh water, B63J; adding materials to water to prevent corrosion C23F; treating radioactively-contaminated liquids G21F9/04; regeneration of reactants for recirculation into processes, see the relevant places for the processes) - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) - Y02A: TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE ## Abstract A method of treatment of liquid including supplying liquid to be treated to at least one liquid treatment module having a liquid inlet, a permeate outlet and a brine outlet, monitoring liquid pressure within the at least one liquid treatment module and upon exceedance of a liquid pressure threshold in the at least one liquid treatment module, reducing the liquid pressure in the at least one liquid treatment module by performing at least one of the following functions: opening a liquid pressure reducing valve at the brine outlet, increasing a liquid volume output of a circulation pump which removes brine from the at least one liquid treatment module, equilibrating liquid pressures between a liquid pressure inside the at least one liquid treatment module and inside a liquid feed tank and opening a liquid pressure reducing valve at the liquid inlet. ## Claims ### Claim 1 A method of treatment of liquid comprising: supplying liquid to be treated to at least one liquid treatment module employing at least one of reverse osmosis and nanofiltration membranes, said at least one module having a liquid inlet, a permeate outlet and a brine outlet; monitoring liquid pressure within said at least one liquid treatment module; and upon exceedance of a liquid pressure threshold in said at least one liquid treatment module, representing exceedence of a salinity threshold in the liquid therein, reducing said liquid pressure in said at least one liquid treatment module by performing at least one of the following functions: opening a liquid pressure reducing valve at said brine outlet, thereby reducing said liquid pressure at said brine outlet to a level above atmospheric pressure which exceeds osmotic pressure of said liquid in said at least one liquid treatment module; increasing a liquid volume output of a circulation pump which removes brine from said at least one liquid treatment module and supplies liquid to said water inlet from a liquid volume output at times other than upon and immediately following said exceedance; equilibrating liquid pressures between a liquid pressure inside said at least one liquid treatment module and inside a liquid feed tank; and opening a liquid pressure reducing valve at said liquid inlet, thereby providing a pressure reducing backflow liquid path from said liquid inlet of said at least one liquid treatment module which bypasses a liquid pressure increasing pump upstream of said liquid inlet. ### Claim 2 (depends on 1) A method of treatment of liquid according to claim 1 and wherein upon exceedance of a liquid pressure threshold in said at least one liquid treatment module, representing exceedence of a salinity threshold in the liquid therein, said liquid pressure in said at least one liquid treatment module is reduced by performing at least two of the following functions: opening a liquid pressure reducing valve at said brine outlet, thereby reducing said liquid pressure at said brine outlet to a level above atmospheric pressure which exceeds osmotic pressure of said liquid in said at least one liquid treatment module; increasing a liquid volume output of a circulation pump which removes brine from said at least one liquid treatment module and supplies liquid to said water inlet from a liquid volume output at times other than upon and immediately following said exceedance; equilibrating liquid pressures between a liquid pressure inside said at least one liquid treatment module and inside a liquid feed tank; and opening a liquid pressure reducing valve at said liquid inlet, thereby providing a pressure reducing backflow liquid path from said liquid inlet of said at least one liquid treatment module which bypasses a liquid pressure increasing pump upstream of said liquid inlet. ### Claim 3 (depends on 1) A method of treatment of liquid according to claim 1 and wherein upon exceedance of a liquid pressure threshold in said at least one liquid treatment module, representing exceedence of a salinity threshold in the liquid therein, said liquid pressure in said at least one liquid treatment module is reduced by performing at least three of the following functions: opening a liquid pressure reducing valve at said brine outlet, thereby reducing said liquid pressure at said brine outlet to a level above atmospheric pressure which exceeds osmotic pressure of said liquid in said at least one liquid treatment module; increasing a liquid volume output of a circulation pump which removes brine from said at least one liquid treatment module and supplies liquid to said water inlet from a liquid volume output at times other than upon and immediately following said exceedance; equilibrating liquid pressures between a liquid pressure inside said at least one liquid treatment module and inside a liquid feed tank; and opening a liquid pressure reducing valve at said liquid inlet, thereby providing a pressure reducing backflow liquid path from said liquid inlet of said at least one liquid treatment module which bypasses a liquid pressure increasing pump upstream of said liquid inlet. ### Claim 4 (depends on 1) A method of treatment of liquid according to claim 1 and wherein upon exceedance of a liquid pressure threshold in said at least one liquid treatment module, representing exceedence of a salinity threshold in the liquid therein, said liquid pressure in said at least one liquid treatment module is reduced by performing all of the following functions: opening a liquid pressure reducing valve at said brine outlet, thereby reducing said liquid pressure at said brine outlet to a level above atmospheric pressure which exceeds osmotic pressure of said liquid in said at least one liquid treatment module; increasing a liquid volume output of a circulation pump which removes brine from said at least one liquid treatment module and supplies liquid to said water inlet from a liquid volume output at times other than upon and immediately following said exceedance; equilibrating liquid pressures between a liquid pressure inside said at least one liquid treatment module and inside a liquid feed tank; and opening a liquid pressure reducing valve at said liquid inlet, thereby providing a pressure reducing backflow liquid path from said liquid inlet of said at least one liquid treatment module which bypasses a liquid pressure increasing pump upstream of said liquid inlet. ### Claim 5 A method of treatment of liquid comprising: supplying at least one water treatment module including at least one membrane and having a feed water inlet at a feed side of said at least one membrane, a permeate outlet at a permeate side of said at least one membrane and a brine outlet at a brine side of at least one membrane; pressurizing feed water supplied to said feed water inlet by employing a pump which normally maintains a fixed output feed water volume notwithstanding variations in water pressure at an outlet thereof, the energy consumption of said pump being a function of the variations in water pressure at said outlet; monitoring the water pressure at said outlet of said pump; and when a predetermined high pressure threshold is reached at said outlet of said pump, immediately making changes in the water supply to said module, thereby to cause immediate lowering of the water pressure at said outlet of said pump, to a pressure below the osmotic pressure at the feed side of part but not all of said module, thereby immediately reducing the energy consumption of said pump, thereby providing an overall energy cost savings per unit of water treated. ### Claim 6 A method for treatment of liquid in at least one liquid treatment module including at least a high pressure pump and a circulation pump, the method comprising: upon occurrence of an operational threshold representing exceedence of a salinity threshold in said at least one liquid treatment module, effecting the following: removing brine from the at least one liquid treatment module; and reducing, at an enhanced speed, pressure of said liquid in said at least one liquid treatment module by at least one of the following: opening a pressure reducing valve downstream of said high pressure pump; increasing the volume output of said circulation pump from its volume output when functioning as a concentrate circulation pump to a higher volume output when functioning as a feed water pump; and passing liquid from downstream of said high pressure feed pump to upstream of said high pressure feed pump. ### Claim 7 (depends on 6) A method for treatment of liquid according to claim 6 and wherein said passing liquid from downstream of said high pressure feed pump to upstream of said high pressure feed pump comprises passing said liquid via a flow restrictor arranged in parallel to said high pressure feed pump. ### Claim 8 (depends on 6) A method for treatment of liquid according to claim 6 and wherein said pressure of said liquid in said at least one liquid treatment module is reduced at an enhanced speed by at least two of the following: opening a pressure reducing valve downstream of said high pressure pump; increasing the volume output of said circulation pump from its volume output when functioning as a concentrate circulation pump to a higher volume output when functioning as a feed water pump; and passing liquid from downstream of said high pressure feed pump to upstream of said high pressure feed pump. ### Claim 9 (depends on 6) A method for treatment of liquid according to claim 6 and wherein said pressure of said liquid in said at least one liquid treatment module is reduced at an enhanced speed by all of the following: opening a pressure reducing valve downstream of said high pressure pump; increasing the volume output of said circulation pump from its volume output when functioning as a concentrate circulation pump to a higher volume output when functioning as a feed water pump; and passing liquid from downstream of said high pressure feed pump to upstream of said high pressure feed pump. ### Claim 10 (depends on 6) A method of treatment of liquid according to claim 6 and wherein said liquid treatment module is a water treatment module including at least one of at least one reverse osmosis membrane and at least one nanofiltration membrane and is operative for treatment of at least one of sea water, brackish water and waste water. ### Claim 11 A water treatment system comprising: at least one liquid treatment module operative to receive feed water at a water inlet thereof and to separate said feed water into permeate and concentrate, said permeate constituting treated water, said at least one liquid treatment module having a brine outlet for release of concentrate whose salinity is such that an operational threshold of said system is exceeded; a liquid pressure reducing valve at said brine outlet; a high pressure pump, operative to pressurize liquid to be treated received at a liquid feed inlet and to provide a pressurized feed water output to said at least one liquid treatment module; a feed water flow rate sensor located upstream of said high pressure pump and providing a feed water flow rate output; a pump controller receiving said feed water flow rate output and controlling the operation of said high pressure pump; a liquid pressure sensor for providing an output indication of liquid pressure at at least one of an inlet to said at least one liquid treatment module, an outlet from said at least one liquid treatment module and within said at least one liquid treatment module; a circulation pump which removes brine from said at least one liquid treatment module and supplies liquid to said water inlet; a liquid feed tank; a system controller receiving at least said output indication of liquid pressure within said at least one liquid treatment module, said system controller being operative, upon exceedance of a liquid pressure threshold in said at least one liquid treatment module, representing exceedence of a salinity threshold in the liquid therein, to reduce said liquid pressure in said at least one liquid treatment module by performing at least one of the following functions: opening said liquid pressure reducing valve at said brine outlet, thereby reducing said liquid pressure at said brine outlet to a level above atmospheric pressure which exceeds osmotic pressure of said liquid in said at least one liquid treatment module; increasing a liquid volume output of said circulation pump, which removes brine from said at least one liquid treatment module and supplies liquid to said water inlet from a liquid volume output at times other than upon and immediately following said exceedance; equilibrating liquid pressures between a liquid pressure inside said at least one liquid treatment module and inside said liquid feed tank; and opening a liquid pressure reducing valve at said liquid inlet, thereby providing a pressure reducing backflow liquid path from said liquid inlet of said at least one liquid treatment module which bypasses said high pressure pump upstream of said liquid inlet. ### Claim 12 (depends on 11) A water treatment system according to claim 11 and wherein said system controller is operative, upon exceedance of a liquid pressure threshold in said at least one liquid treatment module, representing exceedence of a salinity threshold in the liquid therein, to reduce said liquid pressure in said at least one liquid treatment module by performing at least two of the following functions: opening said liquid pressure reducing valve at said brine outlet, thereby reducing said liquid pressure at said brine outlet to a level above atmospheric pressure which exceeds osmotic pressure of said liquid in said at least one liquid treatment module; increasing a liquid volume output of said circulation pump, which removes brine from said at least one liquid treatment module and supplies liquid to said water inlet from a liquid volume output at times other than upon and immediately following said exceedance; equilibrating liquid pressures between a liquid pressure inside said at least one liquid treatment module and inside said liquid feed tank; and opening a liquid pressure reducing valve at said liquid inlet, thereby providing a pressure reducing backflow liquid path from said liquid inlet of said at least one liquid treatment module which bypasses said high pressure pump upstream of said liquid inlet. ### Claim 13 (depends on 11) A water treatment system according to claim 11 and wherein said system controller is operative, upon exceedance of a liquid pressure threshold in said at least one liquid treatment module, representing exceedence of a salinity threshold in the liquid therein, to reduce said liquid pressure in said at least one liquid treatment module by performing at least three of the following functions: opening said liquid pressure reducing valve at said brine outlet, thereby reducing said liquid pressure at said brine outlet to a level above atmospheric pressure which exceeds osmotic pressure of said liquid in said at least one liquid treatment module; increasing a liquid volume output of said circulation pump, which removes brine from said at least one liquid treatment module and supplies liquid to said water inlet from a liquid volume output at times other than upon and immediately following said exceedance; equilibrating liquid pressures between a liquid pressure inside said at least one liquid treatment module and inside said liquid feed tank; and opening a liquid pressure reducing valve at said liquid inlet, thereby providing a pressure reducing backflow liquid path from said liquid inlet of said at least one liquid treatment module which bypasses said high pressure pump upstream of said liquid inlet. ### Claim 14 (depends on 11) A water treatment system according to claim 11 and wherein said system controller is operative, upon exceedance of a liquid pressure threshold in said at least one liquid treatment module, representing exceedence of a salinity threshold in the liquid therein, to reduce said liquid pressure in said at least one liquid treatment module by performing all of the following functions: opening said liquid pressure reducing valve at said brine outlet, thereby reducing said liquid pressure at said brine outlet to a level above atmospheric pressure which exceeds osmotic pressure of said liquid in said at least one liquid treatment module; increasing a liquid volume output of said circulation pump, which removes brine from said at least one liquid treatment module and supplies liquid to said water inlet from a liquid volume output at times other than upon and immediately following said exceedance; equilibrating liquid pressures between a liquid pressure inside said at least one liquid treatment module and inside said liquid feed tank; and opening a liquid pressure reducing valve at said liquid inlet, thereby providing a pressure reducing backflow liquid path from said liquid inlet of said at least one liquid treatment module which bypasses said high pressure pump upstream of said liquid inlet. ### Claim 15 A water treatment system comprising: at least one water treatment module including at least one membrane and having a feed water inlet at a feed side of said at least one membrane, a permeate outlet at a permeate side of said at least one membrane and a brine outlet at a brine side of at least one membrane; a high pressure pump, which normally maintains a fixed output feed water volume notwithstanding variations in water pressure at an outlet thereof; a system controller receiving at least said output indication of liquid pressure within said at least one liquid treatment module, said system controller being operative, upon exceedance of a liquid pressure threshold in said at least one liquid treatment module, representing exceedence of a salinity threshold in the liquid therein, to reduce said liquid pressure in said at least one liquid treatment module by performing at least one of the following functions: pressurizing feed water supplied to said feed water inlet by employing said high pressure pump, the energy consumption of said high pressure pump being a function of the variations in water pressure at said outlet; monitoring the water pressure at said outlet of said high pressure pump; and when a predetermined high pressure threshold is reached at said outlet of said high pressure pump, immediately making changes in the water supply to said at least one liquid treatment module, thereby to cause immediate lowering of the water pressure at said outlet of said high pressure pump, to a pressure below the osmotic pressure at the feed side of part but not all of said at least one liquid treatment module, thereby immediately reducing the energy consumption of said high pressure pump, thereby provide an overall energy cost savings per unit of water treated. ### Claim 16 A water treatment system comprising: at least one water treatment module including at least one membrane and having a feed water inlet at a feed side of said at least one membrane, a permeate outlet at a permeate side of said at least one membrane and a brine outlet at a brine side of at least one membrane; a high pressure pump, which normally maintains a fixed output feed water volume notwithstanding variations in water pressure at an outlet thereof; a pressure reducing valve downstream of said high pressure feed pump; a circulation pump; a system controller receiving at least said output indication of liquid pressure within said at least one liquid treatment module, said system controller being operative, upon exceedance of a liquid pressure threshold in said at least one liquid treatment module, representing exceedence of a salinity threshold in the liquid therein, to reduce said liquid pressure in said at least one liquid treatment module by performing at least one of the following functions: upon occurrence of an operational threshold representing exceedence of a salinity threshold in said at least one liquid treatment module, effecting the following: removing brine from the at least one liquid treatment module; and reducing, at an enhanced speed, pressure of said liquid in said at least one liquid treatment module by at least one of the following: opening said pressure reducing valve downstream of said high pressure feed pump; increasing the volume output of said circulation pump from its volume output when functioning as a concentrate circulation pump to a higher volume output when functioning as a feed water pump; and passing liquid from downstream of said high pressure feed pump to upstream of said high pressure feed pump. ### Claim 17 (depends on 16) A water treatment system according to claim 16 and also comprising a flow restrictor arranged in parallel to said high pressure feed pump and wherein said passing liquid from downstream of said high pressure feed pump to upstream of said high pressure feed pump comprises passing said liquid via said flow restrictor. ### Claim 18 (depends on 16) A water treatment system according to claim 16 and wherein said pressure of said liquid in said at least one liquid treatment module is reduced at an enhanced speed by at least two of the following: opening said pressure reducing valve downstream of said high pressure feed pump; increasing the volume output of said circulation pump from its volume output when functioning as a concentrate circulation pump to a higher volume output when functioning as a feed water pump; and passing liquid from downstream of said high pressure feed pump to upstream of said high pressure feed pump. ### Claim 19 (depends on 16) A water treatment system according to claim 16 and wherein said pressure of said liquid in said at least one liquid treatment module is reduced at an enhanced speed by at least three of the following: opening said pressure reducing valve downstream of said high pressure feed pump; increasing the volume output of said circulation pump from its volume output when functioning as a concentrate circulation pump to a higher volume output when functioning as a feed water pump; and passing liquid from downstream of said high pressure feed pump to upstream of said high pressure feed pump.