JP2518541B2 - Ion-exchange resin regeneration method for water softening equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for regenerating an ion exchange resin in a water softening device.

[0002]

2. Description of the Related Art Tap water and well water used for boiler water, food industry water, etc. are clean and transparent in appearance,
Among them, various impurities (hardness components such as calcium and magnesium) are included. If this tap water or well water is used as it is, it may cause scale adhesion or corrosion. Therefore, a water softening device is used to remove hardness of these impurities. In this water softening device, generally, a Na-type strongly acidic cation exchange resin is used to remove impurities (such as Ca ²⁺ and Mg ²⁺ ) in the raw water from N.
It is designed to be replaced with a ⁺ .

By the way, when the water softening device is used for a long time, the ion exchange resin is sequentially converted from Na type to Ca type, and finally all the ion exchange resins are converted to Ca type. If this happens, the hardness component in the raw water cannot be completely removed, so it is necessary to appropriately regenerate the ion exchange resin by the control device of the water softening device. In the water softening device, the softening of the hard water and the regeneration of the ion-exchange resin are alternately performed to surely soften the hard water.

Salt water is generally used to regenerate the ion exchange resin. Conventionally, salt water has been produced by a salt water apparatus as shown in FIG. 1 using powdery normal salt sold by a monopoly company. Referring to FIG. 1, reference numeral 1 in the figure is a salt water tank, which is provided with a net 2 for horizontally partitioning the inside of the salt water tank, and a powdery normal salt 3 is put on the net. Water is supplied to the upper line of the moisturizing section 5 on the net through the salt water valve 4 provided at the lower portion of the salt water tank. The salt in the wet portion is dissolved in water to obtain a salt water having a predetermined concentration, and the salt in the upper portion falls by its own volume by the dissolved volume to the wet portion to replenish the salt.

The salt water of this salt water device is sucked from the salt water valve 4 and used for regeneration of the ion exchange resin by the function of a control device (not shown) of the water softening device.
When the regeneration operation is completed, water is replenished into the salt water tank through the salt water valve.

[0006]

In the above operation, the normal salt often solidifies to form a salt bridge in the upper part of the wet part, and the salt does not drop into the wet part and is not supplied, so that a predetermined salt water concentration cannot be obtained. There was a problem. Further, the powdery normal salt had poor water permeability, and the contact between water and the salt was insufficient, and it took a long time to reach the saturated solubility. Further, iron and manganese adhering to the surface of the ion exchange resin during softening of hard water cannot be sufficiently removed during regeneration with only salt water, which is a cause of early deterioration of the ion exchange resin. The present invention solves these problems and makes it possible to easily adjust the concentration of the chelating agent in the salt water to a predetermined value without increasing the size and cost of the apparatus, and to efficiently remove iron and manganese. The purpose is to

[0007]

The present invention has been made in order to achieve the above-mentioned object, and a solid salt is dissolved in water in a salt water tank to produce salt water, and this salt water is used. In a method of regenerating an ion exchange resin in a water softening device for regenerating an ion exchange resin, a chelating agent is added to a powdery salt as the solid salt, and the chelate agent is molded into pellets. Is.

[0008]

According to the above means, since the voids between the solid salts are very large and the contact area between the solid salts is small, the formation of salt bridges can be reliably prevented and the water permeability can be improved. Good and easy to dissolve the salt, and the salt water has a predetermined saturated solubility (concentration) in a short time. At the same time, the chelating agent contained in the solid salt also dissolves as the salt dissolves, and when the salt water becomes saturated in solubility, the concentration of the chelating agent is also maintained at a predetermined value.
Further, since the chelating agent is contained in the salt water, the iron and manganese adhering to the ion exchange resin are masked by the chelating agent during the regeneration, and easily dissolved and removed.

[0009]

EXAMPLE A solid salt used in the regenerating method of the present invention is prepared by adding a chelating agent acting as an activator to a powdery salt and mixing it.
This is molded into a pellet shape such as a spherical shape (a), a cylindrical shape (b), an elliptical shape (c) or a polygonal columnar shape (d) by a press or the like, for example.

When the solid salt of the present invention is used in a salt water apparatus to regenerate the ion-exchange resin, the voids between the solid salts are very large and the contact area between the solid salts is small. It is possible to reliably prevent the generation of the salt water, the water permeability is good, the salt is easily dissolved, and the salt water having a predetermined saturated solubility (concentration) can be obtained in a short time. Further, according to the present invention, since the chelating agent will be contained in the salt water, at the time of regeneration, iron and manganese attached to the ion exchange resin are masked by the chelating agent,
Easily dissolved and removed. Therefore, the regeneration of the ion exchange resin becomes reliable.

[0011]

Since the present invention is constructed as described above, it has the following effects. The generation of salt bridges can be reliably prevented, the water permeability is good, salt dissolution is easy, and salt water with a predetermined saturation solubility (concentration) can be obtained in a short time. The performance can be improved. By the action of the chelating agent contained in salt water, it masks iron and manganese attached to the ion exchange resin,
It can be easily dissolved and removed, premature deterioration of the ion exchange resin can be prevented (the ion exchange capacity of the ion exchange resin can always be maintained at a high value), and the life of the ion exchange resin can be extended. be able to. Since the solid salt contains the salt and the chelating agent in a solid state in a fixed ratio, the chelating agent can be dissolved in water as much as the salt is dissolved, and the concentration of the chelating agent can be adjusted to a certain level. The concentration can be easily adjusted and iron and manganese can be removed efficiently. In the water softener, there is no need for an automatic feeding mechanism of the chelating agent or an automatic concentration adjusting mechanism for adjusting the concentration of the chelating agent to a predetermined value, without increasing the size and cost of the water softening device. Dosing and concentration adjustment can be performed.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a conventional salt water device.

FIG. 2 is a perspective view showing an example of a solid salt pellet shape in the present invention.

[Explanation of symbols]

 1 ... salt water tank 2 ... net 3 ... salt 4 ... salt water valve 5 ... wetting part 6 ... salt bridge

Claims (1)

(57) [Claims] 1. A solid salt is dissolved in water in a salt water tank,
In an ion exchange resin regeneration method of a water softening device that produces salt water and regenerates an ion exchange resin using this salt water,
A method for regenerating an ion-exchange resin in a water softening device, characterized in that a chelating agent is added to a powdery salt as the solid salt, and the chelating agent is molded into pellets.