| 摘要 |
PROBLEM TO BE SOLVED: To provide an ultrapure water production method and apparatus wherein the temperature of primary pure water supplied to a secondary pure water production apparatus is prevented from becoming unnecessarily high, and wherein the heating cost of a heat exchanger of a primary pure water production apparatus is reduced.SOLUTION: In this ultrapure water production method and apparatus, the primary pure water is produced by passing raw water through the primary pure water production apparatus 10 including the heat exchanger 15 and a reverse osmotic membrane separation device 12, and ultrapure is produced by passing the primary pure water through the secondary pure water production apparatus 20. The temperature of the primary pure water supplied to the secondary pure water production apparatus 20 is detected by a temperature sensor 21a, a detection value of the temperature sensor 21a is input to a controller 60, a target temperature of outflow water of the heat exchanger 15 is set based on the detection temperature, and a valve 15b is controlled to make the target temperature to control a steam supply amount to the heat exchanger. |
