US12569813USUSPTO Grant XML

Method and program for determining cleaning trouble in fresh water generator

The present invention provides a fresh water generator operating method and a determination program that are employed in a method for cleaning a separation membrane module following membrane filtration, and that, while various cleaning steps such as reverse pressure cleaning, air cleaning, chemical solution cleaning are taking place after completion of the membrane filtration, determines cleaning troubles by calculating a temporal change in resistance increase rate on the basis of an increase in membrane differential pressure.

Patent

Brief

Patent brief

Problem

How can microplastics and similar contaminants be removed from wastewater?

Novelty

Membrane filtration is reinforced by front-page matches on membrane filtration.

Uses

Wastewater treatment, Industrial effluent, Water cleanup

Assignee

Toray Industries, Inc.

Published

Mar 10, 2026

Inventors

Kazuki Hagawa, Kazunori Tomioka, Hiroshi Hamada

Domain

Environmental systems

Plain-English summary

Problem

How can microplastics and similar contaminants be removed from wastewater?

Solution

provides a fresh water generator operating method and a determination program that are employed in a method for cleaning a separation membrane module following membrane filtration, and that, while various cleaning steps such as reverse pressure cleaning, air cleaning, chemical solution cleaning are taking place after completion of the membrane filtration, determines cleaning troubles by calculating a temporal change in resistance increase rate on the basis of an increase in membrane differential pressure.

Key novelty

Membrane filtration is reinforced by front-page matches on membrane filtration.

Applications

Wastewater treatmentIndustrial effluentWater cleanup

Relevant search intents

membrane filtration

Claims preview

1 . A method for determining cleaning trouble in a fresh water generator, the method comprising: a filtration step of filtering water to be treated by a separation membrane to obtain treated water; a first cleaning step of cleaning the separation membrane at the end of the filtration step; and a second cleaning step of chemically cleaning the separation membrane with a chemical solution having a concentration of 50 mg/L to 10,000 mg/L performed following performance of the filtration step and/or the first cleaning step a plurality of times, wherein when a temporal change A in a resistance increase rate between performance of the first cleaning step a plurality of times which is calculated based on a resistance increase rate during performance of the filtration step a plurality of times is larger than a reference value, insufficiency or trouble in the first cleaning step is determined, and when a temporal change B in a resistance increase rate between performance of the second cleaning step a plurality of times is larger than a reference value, insufficiency or trouble in the second cleaning step is determined, wherein the temporal change A in the resistance increase rate is calculated by a slope of a regression line obtained by a least square method or by the following Equation (1) and the temporal change B in the resistance increase rate is calculated by a slope of a regression line obtained by a least square method or by the following Equation (2): [ Equation 1 ] ( R filt_cycle t filt_cycle ) t filt_ 1 st = temporal change A in resistance increase rate ( 1 ) R filt_cycle : resistance increase during filtration step t filt_cycle : time of filtration step t filt_1st : total filtration time between first cleaning steps [ Equation 2 ] ( R after 2 nd_filt _cycle t filt_cycle ) t filt_ 2 nd = temporal change B in resistance increase rate ( 2 ) R after2nd_filt_cycle : resistance increase during filtration step immediately after second cleaning step t filt_2nd : total filtration time between second cleaning steps. 2 . The method for determining cleaning trouble in a fresh water generator according to claim 1 , wherein change amounts or change rates of the temporal change A in the resistance increase rate and the temporal change B in the resistance increase rate from a reference value are compared, insufficiency or a trouble in the first cleaning step is determined when an increase of the temporal change A in the resistance increase rate is larger, and insufficiency or a trouble in the second cleaning step is determined when an increase of the temporal change B in the resistance increase rate is larger. 3 . The method for determining cleaning trouble in a fresh water generator according to claim 1 , wherein in determination of the cleaning trouble in the second cleaning step, the cleaning trouble in the second cleaning step is determined by combining at least one selected from a pH, an oxidation-reduction potential (ORP), a residual chlorine concentration, and a chemical solution storage tank liquid level of the chemical solution as an index.

Linked approaches

Membrane filtration

Fine filtration methods for capturing microplastics and fine contaminants.

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