Control method for ultrapure water producing apparatus
AssigneeKurita Water Industries Ltd.
InventorsYasuharu Minato, Teruhisa Katou, Kouya Abe
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Abstract
In a primary pure water device, an electric deionization device communicated with a water supply pump is provided with a DC power supply, and desalted water from the electric deionization device can be supplied to a sub-tank. The sub-tank is provided with a level switch. In addition, while a control valve and a flow meter are provided in a flow path for the desalted water from the electric deionization device, a control valve and a flow meter are also provided in a flow path for concentrated water from the electric deionization device. The measurement data of the level switch and the flow meters can be transmitted to a control device, which can control the water supply pump and the control valves.
Claims3
A control method for an ultrapure water producing apparatus, the ultrapure water producing apparatus comprising:
- a primary pure water system having a reverse osmosis membrane, an electric deionization device, and a water supply pump provided upstream the electric deionization device;
- a water storage tank arranged downstream the electric deionization device and provided with a water level measuring means;
- and
- a subsystem that further processes primary pure water produced by the primary pure water system, and
- the control method comprising
- controlling an amount of supplied water being supplied to the electric deionization device so as to keep a constant water level in the water storage tank measured by the water level measuring means,
- calculating a load of the supplied water based on the amount of the supplied water and a specific resistance of the supplied water, and
- setting an operating current value of the electric deionization device in accordance with the load of the supplied water and a flow rate of the primary pure water.
Dependencies are inferred from the claim text.