JPH081156A - Ion exchange apparatus - Google Patents

Abstract

PURPOSE:To obtain pure water and ultrapure water with low TOC concentration by preventing surely the elution of TOC components from ion exchange resin. CONSTITUTION:An ion exchange apparatus is equipped with a heat exchanger 1 for cooling liquid to be treated and an ion exchange column 2 through which liquid cooled by the heat exchanger 1 passes. The elution of TOC components can be reduced by decreasing the temperature of raw water. The low temperature of raw water does not deteriorate the quality of treated water. Since water which was cooled by the heat exchanger is applied to the ion exchange column, the elution of the TOC components can surely be prevented to obtain highly purified water.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ion exchange device,
In particular, the present invention relates to an ion exchange device capable of preventing the elution of TOC components (total organic carbon components) from an ion exchange resin to obtain pure water or ultrapure water having a low TOC concentration.

[0002]

2. Description of the Related Art Pure water used for semiconductor manufacturing, power plants, pharmaceuticals, and foods is treated with industrial water, well water, river water, etc. by a pretreatment device such as a reverse osmosis membrane separation device, Water produced by partially removing salts and organic pollutants is used as raw water, which is then desalted by an ion exchange device.

Conventionally, raw water introduced into an ion exchange apparatus is not limited to such pure water production, but the temperature of the raw water is not particularly adjusted, and the raw water has an outside temperature or an outlet temperature of the pretreatment apparatus, that is, generally room temperature. The one (20 to 40 ° C.) is directly passed through.

By the way, in the ion exchange apparatus, the TOC component is eluted into the treated water from the ion exchange resin packed in the ion exchange tower during the passage treatment. That is, functional groups such as amine groups and sulfone groups that have been introduced into the ion-exchange resin are eluted in the treated water, or the bonds of the styrene resin and divinylbenzene, which are the base materials of the ion-exchange resin, are partially broken and the treated water is treated. Elutes into. These T
When the treated water in which the OC component is eluted is used as pure water for cleaning semiconductors, various troubles such as equipment troubles and product defects are caused.

Conventionally, T from such an ion exchange resin is used.
In order to prevent the elution of the OC component, the ion exchange resin is washed and treated after acid or alkali treatment before being packed in the ion exchange column. At the initial stage of the passage of the liquid, the TOC component is preliminarily eluted from the ion exchange resin by heating the raw water to pass the liquid. The effect is taken.

[0006] Attempts have also been made to develop an ion exchange resin in which the TOC component is less eluted.

[0007]

The conventional means for preventing the elution of the TOC component cannot sufficiently reduce the elution of the TOC component into the treated water. Therefore, the pure water used for semiconductor production, etc. As ultrapure water, treated water of sufficiently satisfactory quality cannot be obtained.

The present invention solves the above-mentioned conventional problems and surely prevents the TOC component from being eluted from the ion exchange resin,
It is an object of the present invention to provide an ion exchange device capable of obtaining pure water or ultrapure water having a low TOC concentration.

[0009]

The ion exchange apparatus of the present invention comprises a heat exchanger for cooling the liquid to be treated, and an ion exchange column through which the liquid to be treated cooled by the heat exchanger is passed. It is characterized by

[0010]

[Function] The water temperature of the raw water flowing into the ion exchange tower and the amount of TOC components eluted from the ion exchange resin into the treated water are in a proportional relationship as shown in FIG. 2, and the raw water temperature should be lowered. This makes it possible to reduce the amount of TOC component eluted.

On the other hand, the relationship between the water temperature of the raw water and the water quality (electrical conductivity) of the ion-exchange treated water is as shown in FIG. 2. Even if the water temperature of the raw water is lowered, the ion exchange capacity of the ion exchange resin is lowered. That is, there is almost no deterioration in the quality of the treated water obtained.

In the present invention, since the water cooled by the heat exchanger is passed through the ion exchange column, the low-temperature passage surely prevents the TOC component from being eluted from the ion exchange resin, thus providing high-purity pure water. Can be obtained.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The ion exchange apparatus of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a system diagram showing an embodiment of the ion exchange apparatus of the present invention.

The ion exchange apparatus shown in FIG.
Water having a water temperature of 20-40 ° C, such as water obtained by partially removing particle components, salts, and organic pollutant components from well water, river water, etc. with a pretreatment device (primary pure water device) such as a reverse osmosis membrane separation device Is used as raw water (liquid to be treated), and this raw water is supplied from the pipe 11 to the heat exchanger 1
Introduce to and cool. This cooling temperature is usually 1 to 5
It is preferably set to ° C.

The raw water cooled in the heat exchanger 1 is supplied to the pipe 12
It is introduced into the ion exchange tower 2 and subjected to ion exchange treatment. Upon this ion exchange, the water temperature of the raw water is low, so the elution of TOC components from the ion exchange resin is prevented,
High-quality ion-exchanged water having a low C concentration can be obtained. The ion-exchanged water (treated water) is introduced into the heat exchanger 3 through the pipe 13, returned to the same temperature as the raw water temperature, that is, about 20 to 40 ° C., and then fed to the next process through the pipe 14.

In this embodiment, as the heat exchangers 1 and 3, a heat pump system having a heat pump 4 is adopted, and the heat quantity obtained by the cooling heat exchanger 1 is used as the heating heat exchanger 3.
The energy cost is reduced by recovering the heat by using it as the energy for raising the temperature.

As this heat exchanger, other types such as a plate type and a tube type can be adopted. Also, there is no particular limitation on the model of the ion exchange tower, a mixed bed type,
Various types such as multi-tower type can be adopted.

INDUSTRIAL APPLICABILITY The ion exchange apparatus of the present invention is extremely useful as an ion exchange apparatus as a pure water production apparatus for semiconductor production, power plants, pharmaceuticals, foods, or as an ultrapure water production apparatus. By obtaining ultrapure water, it is possible to prevent product defects such as semiconductor cleaning and troubles such as contamination of harmful substances during food production.

The present invention will be described in more detail below with reference to specific examples and comparative examples.

Example 1 Using the ion exchange apparatus shown in FIG. 1, water temperature 25 ° C., TO
The raw water of C500 to 1500 ppb was treated.

The ion exchange tower 2 is a diamond ion PK.
228 and Diaion PA312 (both manufactured by Mitsubishi Kasei Co., Ltd.) are mixed bed type ion exchange towers, and the water temperature of raw water is cooled to 1 ° C. by a heat exchanger 1 and then passed through the ion exchange tower. The water temperature was returned to 25 ° C. by the heat exchanger 3.

The TOC concentration of the obtained treated water was as shown in Table 1.

Comparative Example 1 The procedure of Example 1 was repeated, except that the raw water was passed through the ion exchange column without cooling.

The TOC concentration of the obtained treated water was as shown in Table 1.

[0026]

[Table 1]

As is clear from Table 1, in Comparative Example 1 in which the raw water was passed through without being cooled, the TO
While C was 20 to 50 ppb, in Example 1 in which the raw water was cooled and passed, the TOC of the treated water was 10 ppb or less, and the TOC concentration was reduced to almost half or less.

[0028]

As described in detail above, according to the ion exchange apparatus of the present invention, the water cooled by the heat exchanger is passed through the ion exchange tower to ensure the elution of the TOC component from the ion exchange resin. Therefore, high-purity pure water having a low TOC component concentration can be obtained.

[Brief description of drawings]

FIG. 1 is a system diagram showing an embodiment of an ion exchange device of the present invention.

FIG. 2 is a graph showing the relationship between the water temperature of raw water flowing into an ion exchange tower and the amount of TOC components eluted from the ion exchange resin into the treated water.

FIG. 3 is a graph showing the relationship between the water temperature of raw water and the water quality (electrical conductivity) of ion-exchange treated water.

[Explanation of symbols]

 1,3 Heat exchanger 2 Ion exchange tower 4 Heat pump

Claims (1)

[Claims] 1. An ion exchange apparatus comprising a heat exchanger for cooling a liquid to be treated and an ion exchange column through which the liquid to be treated cooled by the heat exchanger is passed.