Device for removing microparticles contained in water and ultrapure-water prouction and supply system

Patent metadata

Field	Value
Publication number	US-2018044205-A1
Application number	US-201615552434-A
Country	US
Kind code	A1
Filing date	Feb 22, 2016
Priority date	Feb 23, 2015
Publication date	Feb 15, 2018
Grant date	—

Abstract

In a subsystem or water-feed path located upsteam of a use point in an ultrapure water production/supply process, fine particles having a particle diameter of 50 nm or less, in particular 10 nm or less are highly removed. A device for removing fine particles in water has a membrane filtration device including a microfiltration membrane or an ultrafiltration membrane having a weak cationic functional group. The microfiltration membrane or the ultrafiltration membrane having a weak cationic functional group is preferred to have a polyketone film with the weak cationic functional group. Negatively-charged particles in water are adsorbed by the weak cationic functional group and can thus be removed.

First claim

1 . A device for removing microparticles contained in water in a process for producing ultrapure water, the device comprising a membrane filtration unit including a microfiltration or ultrafiltration membrane including a weakly cationic functional group.

2 . The device for removing microparticles contained in water according to claim 1 , wherein the microfiltration or ultrafiltration membrane including a weakly cationic functional group is prepared by introducing a weakly cationic functional group to a polyketone membrane.

3 . The device for removing microparticles contained in water according to claim 1 , wherein the weakly cationic functional group is a tertiary amino group.

4 . The device for removing microparticles contained in water according to claim 1 , the device further comprising another membrane filtration unit disposed upstream or downstream of the membrane filtration unit including the microfiltration or ultrafiltration membrane including a weakly cationic functional group, the other membrane filtration unit including a microfiltration or ultrafiltration membrane that does not include an ion-exchange group.

5 . The device for removing microparticles contained in water according to claim 1 , wherein the microparticles are nanoparticles having a size of 10 nm or less.

6 . The device for removing microparticles contained in water according to claim 1 , the device being disposed in a subsystem included in an ultrapure-water production apparatus, the subsystem producing ultrapure water from primary pure water; in a water-feed path through which the ultrapure water is fed from the subsystem to a point of use; or at the point of use.

7 . An ultrapure-water production and supply system comprising an ultrapure-water production apparatus including a subsystem that produces ultrapure water from primary pure water; a water-feed path through which the ultrapure water is fed from the subsystem to a point of use; and the device for removing microparticles contained in water according to claim 1 , the device being disposed in the subsystem or the water-feed path.

Assignees

• Kurita Water Ind Ltd
• Asahi Chemical Ind

Inventors

• Kawakatsu Takahiro
• Iino Hideaki
• Fukui Takeo
• Kaneda Masayuki
• Sato Daisuke

Classifications

• B01D61/18

  Apparatus therefor · CPC title

• B01J41/13

  obtained otherwise than by reactions only involving unsaturated carbon-to-carbon bonds · CPC title

• B01D69/02

  characterised by their properties · CPC title

• C02F2103/04

  for obtaining ultra-pure water · CPC title

• B01D61/145

  Ultrafiltration · CPC title