Patents by Inventor Prakash Narayan Govindan

Prakash Narayan Govindan has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 10301198
    Abstract: Disclosed herein are systems and methods in which multivalent ions are selectively retained in an aqueous stream. According to certain embodiments, multiple separations may be used to process an aqueous feed stream containing solubilized monovalent ions and solubilized multivalent ions to produce a stream enriched in the solubilized multivalent ions. The separations may be arranged, according to certain embodiments, to enhance the overall separation process such that the product stream contains—relative to the initial aqueous feed stream—a high amount of solubilized multivalent ions, a high amount of water from the aqueous feed stream, and/or a high ratio of solubilized multivalent ions to solubilized monovalent ions.
    Type: Grant
    Filed: August 12, 2016
    Date of Patent: May 28, 2019
    Assignee: Gradiant Corporation
    Inventors: Maximus G. St. John, Looh Tchuin Choong, Prakash Narayan Govindan
  • Patent number: 10294123
    Abstract: Embodiments described generally relate to systems comprising a humidifier (e.g., a bubble column humidifier) and a heating device (e.g. a heat exchanger), and associated methods. In certain embodiments, the heating device heats a first liquid stream comprising a condensable fluid in liquid phase (e.g., water) and a dissolved salt (e.g., NaCl) to a relatively low temperature (e.g., about 90° C. or less) prior to the first liquid stream entering the humidifier through a main humidifier liquid inlet. In some cases, the system comprising the humidifier and the heating device requires only low-grade heat to operate, which may be advantageous due to the low cost and high availability of such heat.
    Type: Grant
    Filed: May 20, 2016
    Date of Patent: May 21, 2019
    Assignee: Gradiant Corporation
    Inventors: Steven Lam, Conor Thomas Wilson, Maximus G. St. John, Prakash Narayan Govindan
  • Patent number: 10286335
    Abstract: Condensing apparatuses and their use in various heat and mass exchange systems are generally described. The condensing apparatuses, such as bubble column condensers, may employ a heat exchanger positioned external to the condensing vessel to remove heat from a bubble column condenser outlet stream to produce a heat exchanger outlet stream. In certain cases, the condensing apparatus may also include a cooling device positioned external to the vessel configured and positioned to remove heat from the heat exchanger outlet stream to produce a cooling device outlet stream. The condensing apparatus may be configured to include various internal features, such as a vapor distribution region and/or a plurality of liquid flow control weirs and/or chambers within the apparatus having an aspect ratio of at least 1.5. A condensing apparatus may be coupled with a humidifier to form part of a desalination system, in certain cases.
    Type: Grant
    Filed: September 12, 2014
    Date of Patent: May 14, 2019
    Assignee: Gradiant Corporation
    Inventors: Prakash Narayan Govindan, Steven Lam, Maximus G. St. John
  • Publication number: 20190106334
    Abstract: Selective scaling in water treatment systems in which desalination is performed is generally described. According to certain embodiments, the location of the formation of solid scale within a water treatment system is controlled by adjusting one or more system parameters, such as the temperature and/or flow velocity of a saline stream within the water treatment system.
    Type: Application
    Filed: August 20, 2018
    Publication date: April 11, 2019
    Applicant: Gradiant Corporation
    Inventors: Prakash Narayan Govindan, Steven Lam, Maximus G. St. John, Jonn-Ross Andrews
  • Patent number: 10245555
    Abstract: Disclosed herein are systems and methods in which ion-selective separation and multi-stage osmotic separation is used to produce multivalent-ion-rich process streams. According to certain embodiments, multiple separations may be used to process an aqueous feed stream containing solubilized monovalent ions and solubilized multivalent ions to produce a stream enriched in the multivalent ions. The separations may be arranged, according to certain embodiments, to enhance the overall separation process such that the product stream contains—relative to the initial aqueous feed stream—a high amount of multivalent ions, a high amount of water from the aqueous feed stream, and/or a high ratio of multivalent ions to monovalent ions.
    Type: Grant
    Filed: August 12, 2016
    Date of Patent: April 2, 2019
    Assignee: Gradiant Corporation
    Inventors: Maximus G. St. John, Looh Tchuin Choong, Prakash Narayan Govindan
  • Patent number: 10239765
    Abstract: A counter-flow simultaneous heat and mass exchange device is operated by directing flows of two fluids into a heat and mass exchange device at initial mass flow rates where ideal changes in total enthalpy rates of the two fluids are unequal. At least one of the following state variables in the fluids is measured: temperature, pressure and concentration, which together define the thermodynamic state of the two fluid streams at the points of entry to and exit from the device. The flow rates of the fluids at the points of entry and/or exit to/from the device are measured; and the mass flow rate of at least one of the two fluids is changed such that the ideal change in total enthalpy rates of the two fluids through the device are brought closer to being equal.
    Type: Grant
    Filed: January 9, 2017
    Date of Patent: March 26, 2019
    Assignee: Gradiant Corporation
    Inventors: Prakash Narayan Govindan, Maximus G. St. John, Karim M. Chehayeb, Steven Lam
  • Publication number: 20190084842
    Abstract: Systems and methods related to desalination systems are described herein. According to some embodiments, the desalination systems are hybrid systems comprising one or more first desalination units and one or more second desalination units. In some embodiments, the one or more second desalination units, which may form a fluidic circuit that is located downstream from the one or more first desalination units, may be configured to desalinate higher salinity liquid streams than the one or more first desalination units. In certain embodiments, the one or more first desalination units are operated under steady-state conditions and/or configured to operate under steady-state conditions. In certain embodiments, the one or more second desalination units are transiently operated and/or configured to facilitate transient operation.
    Type: Application
    Filed: February 22, 2017
    Publication date: March 21, 2019
    Applicant: Gradiant Corporation
    Inventors: Maximus G. St. John, Steven Lam, Prakash Narayan Govindan
  • Publication number: 20190031531
    Abstract: Temperature-matching of an injected influent stream with a location along a humidifier feed stream flow path is generally described. According to embodiments, an influent stream can be injected into and combined with a feed stream of a humidifier at a location on the humidifier feed stream flow path at which the temperature of the feed stream most closely matches the temperature of hot influent stream.
    Type: Application
    Filed: July 31, 2017
    Publication date: January 31, 2019
    Applicant: Gradiant Corporation
    Inventors: Steven Lam, Prakash Narayan Govindan
  • Publication number: 20190022550
    Abstract: The present disclosure is related to systems and methods for the formation of solid salts using a humidifier. According to certain embodiments, the flow velocity of a gas in the humidifier can be relatively high during the formation of the solid salt. In some embodiments, the humidifier comprises a multi-stage bubble column humidifier.
    Type: Application
    Filed: January 20, 2017
    Publication date: January 24, 2019
    Applicant: Gradiant Corporation
    Inventors: Steven Lam, Maximus G. St. John, Prakash Narayan Govindan, Conor Thomas Wilson
  • Patent number: 10179296
    Abstract: Systems and methods related to desalination systems are described herein. According to some embodiments, the desalination systems are transiently operated and/or configured to facilitate transient operation. In some embodiments, a liquid stream comprising water and at least one dissolved salt is circulated through a fluidic circuit comprising a desalination system. In some embodiments, a portion of the desalination system (e.g., a humidifier) is configured to remove at least a portion of the water from the liquid stream to produce a concentrated brine stream enriched in the dissolved salt. In certain cases, the concentrated brine stream is recirculated through the fluidic circuit until the concentrated brine stream reaches a relatively high density (e.g., at least about 10 pounds per gallon) and/or a relatively high salinity (e.g., a total dissolved salt concentration of at least about 25 wt %).
    Type: Grant
    Filed: May 21, 2015
    Date of Patent: January 15, 2019
    Assignee: Gradiant Corporation
    Inventors: Prakash Narayan Govindan, Maximus G. St. John, Steven Lam, Mark Zaloudek, Karim M. Chehayeb, Samar Shah
  • Publication number: 20190009218
    Abstract: Provided herein are osmotic desalination methods and associated systems. According to certain embodiments, multiple osmotic membranes may be used to perform a series of osmosis steps, such that an output stream having a relatively high water purity—compared to a water purity of an aqueous feed stream—is produced. In some embodiments, multiple draw streams can be NI used to produce aqueous product streams having sequentially higher purities of water. Certain embodiments are related to osmotic desalination systems and methods in which forward osmosis is used to produce a first product stream having a relatively high water purity relative to an aqueous feed stream, and reverse osmosis is used to perform a second step (and/or additional steps) on the first product stream. In some embodiments, multiple reverse osmosis steps can be used in series to perform a net desalination process.
    Type: Application
    Filed: July 29, 2016
    Publication date: January 10, 2019
    Applicant: Gradiant Corporation
    Inventors: Looh Tchuin Choong, Prakash Narayan Govindan, Maximus G. St. John, Steven Lam, Jonn-Ross Andrews, Karim M. Chehayeb
  • Publication number: 20190002306
    Abstract: Systems and methods related to desalination systems are described herein. According to some embodiments, the desalination systems are transiently operated and/or configured to facilitate transient operation. In some embodiments, a liquid stream comprising water and at least one dissolved salt is circulated through a fluidic circuit comprising a desalination system. In some embodiments, a portion of the desalination system (e.g., a humidifier) is configured to remove at least a portion of the water from the liquid stream to produce a concentrated brine stream enriched in the dissolved salt. In certain cases, the concentrated brine stream is recirculated through the fluidic circuit until the concentrated brine stream reaches a relatively high density (e.g., at least about 10 pounds per gallon) and/or a relatively high salinity (e.g., a total dissolved salt concentration of at least about 25 wt %).
    Type: Application
    Filed: April 30, 2018
    Publication date: January 3, 2019
    Applicant: Gradiant Corporation
    Inventors: Prakash Narayan Govindan, Maximus G. St. John, Steven Lam, Mark Zaloudek, Karim M. Chehayeb, Samar Shah
  • Patent number: 10167218
    Abstract: Water treatment systems and associated methods are generally described. Certain embodiments of the water treatment systems and methods described herein may be used to treat water comprising one or more contaminants (e.g., oil, grease, suspended solids, scale-forming ions, volatile organic material) to remove at least a portion of the one or more contaminants. In some embodiments, at least a portion of the treated water may be used directly in certain applications (e.g., oil and/or gas extraction processes). In some embodiments, at least a portion of the treated water may undergo desalination to produce substantially pure water and/or concentrated brine.
    Type: Grant
    Filed: February 11, 2016
    Date of Patent: January 1, 2019
    Assignee: Gradiant Corporation
    Inventors: Maximus G. St. John, Steven Lam, Prakash Narayan Govindan
  • Patent number: 10143935
    Abstract: Embodiments described herein generally relate to apparatuses that include a vessel comprising a humidification region (e.g., a bubble column humidification region) and a dehumidification region (e.g., a bubble column dehumidification region), and associated systems and methods. In certain embodiments, the apparatuses are configured to include various internal features, such as vapor distribution regions and/or liquid flow control weirs and/or baffles. In some cases, the apparatuses are used in water purification systems, such as desalination systems. The water purification systems may comprise additional devices external to the apparatuses, such as one or more heat exchangers, one or more heating devices, and/or one or more cooling devices.
    Type: Grant
    Filed: May 21, 2015
    Date of Patent: December 4, 2018
    Assignee: Gradiant Corporation
    Inventors: Prakash Narayan Govindan, Steven Lam, Maximus G. St. John
  • Patent number: 10143936
    Abstract: Embodiments described herein generally relate to apparatuses that include a vessel comprising a humidification region (e.g., a bubble column humidification region) and a dehumidification region (e.g., a bubble column dehumidification region), and associated systems and methods. In certain embodiments, the apparatuses are configured to include various internal features, such as vapor distribution regions and/or liquid flow control weirs and/or baffles. In some cases, the apparatuses are used in water purification systems, such as desalination systems. The water purification systems may comprise additional devices external to the apparatuses, such as one or more heat exchangers, one or more heating devices, and/or one or more cooling devices.
    Type: Grant
    Filed: May 21, 2015
    Date of Patent: December 4, 2018
    Assignee: Gradiant Corporation
    Inventors: Prakash Narayan Govindan, Steven Lam, Maximus G. St. John
  • Patent number: 10144654
    Abstract: Selective scaling in water treatment systems in which desalination is performed is generally described. According to certain embodiments, the location of the formation of solid scale within a water treatment system is controlled by adjusting one or more system parameters, such as the temperature and/or flow velocity of a saline stream within the water treatment system.
    Type: Grant
    Filed: November 17, 2015
    Date of Patent: December 4, 2018
    Assignee: Gradiant Corporation
    Inventors: Prakash Narayan Govindan, Steven Lam, Maximus G. St. John, Jonn-Ross Andrews
  • Publication number: 20180327278
    Abstract: A feed liquid flows into a second-stage humidifier chamber to form a second-stage humidifier bath. A first remnant of the feed liquid from the second-stage humidifier chamber then flows into a first-stage humidifier chamber to form a first-stage humidifier bath having a temperature lower than that of the second-stage bath. A second remnant of the feed liquid is then removed from the first-stage humidifier. Meanwhile, a carrier gas is injected into and bubbled through the first-stage humidifier bath, collecting a vaporizable component in vapor form from the first remnant of the feed liquid to partially humidify the carrier gas. The partially humidified carrier gas is then bubbled through the second-stage humidifier bath, where the carrier gas collects more of the vaporizable component in vapor form from the feed liquid to further humidify the carrier gas before the humidified carrier gas is removed from the second-stage humidifier chamber.
    Type: Application
    Filed: July 23, 2018
    Publication date: November 15, 2018
    Applicant: Massachusetts Institute of Technology
    Inventors: Prakash Narayan Govindan, Mostafa H. Elsharqawy, Steven Lam, Maximus G. St. John, John H. Lienhard
  • Publication number: 20180244545
    Abstract: Disclosed herein are systems and methods in which multivalent ions are selectively retained in an aqueous stream. According to certain embodiments, multiple separations may be used to process an aqueous feed stream containing solubilized monovalent ions and solubilized multivalent ions to produce a stream enriched in the solubilized multivalent ions. The separations may be arranged, according to certain embodiments, to enhance the overall separation process such that the product stream contains—relative to the initial aqueous feed stream—a high amount of solubilized multivalent ions, a high amount of water from the aqueous feed stream, and/or a high ratio of solubilized multivalent ions to solubilized monovalent ions.
    Type: Application
    Filed: August 12, 2016
    Publication date: August 30, 2018
    Applicant: Gradiant Corporation
    Inventors: Maximus G. St. John, Looh Tchuin Choong, Prakash Narayan Govindan
  • Publication number: 20180236406
    Abstract: Disclosed herein are systems and methods in which ion-selective separation and multi-stage osmotic separation is used to produce multivalent-ion-rich process streams. According to certain embodiments, multiple separations may be used to process an aqueous feed stream containing solubilized monovalent ions and solubilized multivalent ions to produce a stream enriched in the multivalent ions. The separations may be arranged, according to certain embodiments, to enhance the overall separation process such that the product stream contains—relative to the initial aqueous feed stream—a high amount of multivalent ions, a high amount of water from the aqueous feed stream, and/or a high ratio of multivalent ions to monovalent ions.
    Type: Application
    Filed: August 12, 2016
    Publication date: August 23, 2018
    Applicant: Gradiant Corporation
    Inventors: Maximus G. St. John, Looh Tchuin Choong, Prakash Narayan Govindan
  • Publication number: 20180236372
    Abstract: Disclosed herein are systems and methods in which an aqueous stream comprising solubilized monovalent ions and solubilized multivalent ions is processed such that multivalent ions are selectively retained and monovalent ions are selectively removed. According to certain embodiments, an aqueous feed stream is transported through an ion-selective separator to produce a multivalent-ion-enriched stream and a monovalent-ion-enriched stream. The monovalent-ion-enriched stream may be transported through a desalination apparatus to produce a substantially pure water stream and a concentrated aqueous stream.
    Type: Application
    Filed: August 12, 2016
    Publication date: August 23, 2018
    Applicant: Gradiant Corporation
    Inventors: Prakash Narayan Govindan, Maximus G. St. John