# US 11,992,810 B2 · Method of detecting defects in separation membrane element and apparatus for detecting defects in separation membrane element > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,992,810 B2 - Document ID: US11992810B2 - Status: Granted - Kind: B2 - Application number: 17/270,109 - Filed: 2019-10-18 - Published: 2021-06-17 - Granted: 2024-05-28 - Earliest claimed: 2018-10-18 - Assignees: LG Chem, Ltd. - Applicants: LG Chem, Ltd. - Inventors: Ja Min Hong; Hyungjoon Jeon; Chong Kyu Shin; Byoungsoo Lee - Web page: https://patentgrep.com/patent/US11992810B2 ## CPC - B01D 65/102: {Detection of leaks in membranes} - B01D 63/10: Spiral-wound membrane modules - B01D 65/10: Testing of membranes or membrane apparatus; Detecting or repairing leaks - B01D 71/56: Polyamides, e.g. polyester-amides - G01N 13/04: Investigating osmotic effects - G01N 15/0806: {Details, e.g. sample holders, mounting samples for testing} - B01D 2311/2661: Addition of gas - B01D 2325/20: Specific permeability or cut-off range - G01N 2015/084: {Testing filters} - 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) - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) ## Abstract Provided is a method for detecting defects of a separation membrane element, and an apparatus for detecting defects of a separation membrane element. ## Claims ### Claim 1 A method for detecting defects of a separation membrane element, the method comprising: positioning the separation membrane element in a case inside a pressure vessel, the pressure vessel comprising a gas supply unit at one end of the pressure vessel and a gas discharge unit at the other end of the pressure vessel, wherein the separation membrane element comprises a center tube, one or more separation membranes wound around the center tube, and the case contains the one or more separation membranes wound around the center tube inside the case, and the pressure vessel is configured to accommodate the separation membrane element in the case, and the gas supply unit is provided so as to supply the gas between the center tube and the case, and the center tube is connected to the gas discharge unit; and supplying a gas comprising nitrogen, oxygen, and carbon dioxide to the gas supply unit of the pressure vessel at a pressure of 0.25 MPa to 0.45 MPa; discharging gas passing through the separation membrane element and collected in the center tube to the gas discharge unit; and detecting defects in the separation membrane element by measuring a permeability of the separation membrane element using a flow meter attached to the gas discharge unit to measure an amount of the gas passing through the separation membrane element to the gas discharge unit, wherein a measurement of the amount of the gas passing through the separation membrane element to the gas discharge unit of 0.095 L/min (95 ccm) or greater indicates defects of the separation membrane element, wherein the one or more separation membranes comprise a porous layer and an active layer provided on the porous layer, and the active layer is a polyamide active layer formed by interfacial polymerization of an amine compound-comprising aqueous solution and an organic solution comprising an acyl halide compound; and the separation membrane element is a spiral wound module. ### Claim 2 (depends on 1) The method of claim 1, further comprising evaluating salt rejection of the separation membrane element under a condition of sodium chloride (NaCl) 250 g/L, 0.41 MPa, 25° C. and 15% recovery, wherein a salt rejection of the separation membrane element of 97% or less indicates defects of the separation membrane element. ### Claim 3 (depends on 1) The method of claim 1, further comprising evaluating flux of the separation membrane element under a condition of sodium chloride (NaCl) 250 g/L, 0.41 MPa, 25° C. and 15% recovery, wherein a flux of the separation membrane element of 340 L/day (90 GPD) or greater indicates defects of the separation membrane element. ### Claim 4 An apparatus for detecting defects of a separation membrane element, the apparatus comprising: a pressure vessel comprising a gas supply unit at one end of the pressure vessel and a gas discharge unit at the other end of the pressure vessel, wherein the separation membrane element comprises a center tube, one or more separation membranes wound around the center tube and a case containing the one or more separation membranes wound around the center tube inside the case, and the pressure vessel is configured to accommodate the separation membrane element in the case, and the gas supply unit is provided so as to supply the gas between the center tube and the case; a sealing unit within the pressure vessel configured to receive an end of the center tube and connected to the gas discharge unit; and a measurement unit comprising a flow meter attached to the gas discharge unit by a discharge line, the measurement unit measuring permeability of the separation membrane element using a flow of gas passing through the separation membrane element and discharged to the gas discharge unit, wherein the one or more separation membranes comprise a porous layer and an active layer provided on the porous layer, and the active layer is a polyamide active layer formed by interfacial polymerization of an amine compound-comprising aqueous solution and an organic solution comprising an acyl halide compound; and the separation membrane element is a spiral wound module. ### Claim 5 (depends on 4) The apparatus of claim 4, wherein the gas discharge unit is provided to discharge the gas out of the pressure vessel when the gas passing through the separation membrane element is discharged from one end of the separation membrane element.