Patent ID: 11926536
Assignee: NOMURA MICRO SCIENCE CO., LTD.
Field: Environmental technology (Chemistry)
Classification: CPC C  F | IPC C  F

Claim 7:
8. A hot ultrapure water production system, comprising:
an ultrapure water production device configured to produce ultrapure water;
a water temperature regulator configured to regulate a temperature of the ultrapure water produced by the ultrapure water production device and increase the temperature of the ultrapure water to a supply water temperature for supply to a point of use, to obtain hot ultrapure water;
a hot ultrapure water pipe made of a polyvinylidene fluoride (PVDF), through which ultrapure water pipe the hot ultrapure water flows, the hot ultrapure water pipe being disposed inside the water temperature regulator and between the water temperature regulator and the point of use; and
a controller configured to control the water temperature regulator so as to alternately prepare heated water obtained by increasing the temperature of the ultrapure water to higher than room temperature and cooled water obtained by decreasing the temperature of the ultrapure water to lower than the temperature of the heated water in a range of from room temperature to the supply water temperature for supply to the point of use, the heated water passing through the ultrapure water pipe for from 3 to 24 consecutive hours per water passing and the cooled water passing through the ultrapure water pipe for from 3 to 24 consecutive hours or less per water passing, thereby to leach fluorine contained in the hot ultrapure water pipe, as a part of a starting up of the ultrapure water production system.