JPH0422877Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to an ion exchange water treatment device for supplying water from which hardness and dissolved oxygen have been removed, and which is suitable for boiler water supply.

[Conventional technology]

As is well known, when supplying water to a boiler, soft water from which hardness components such as calcium ions and magnesium ions, which cause scale, are removed is used. is prevented. Devices for removing hardness generally include ion exchange type water softeners using Na ⁺ type cation exchange resins.

On the other hand, in order to use raw water as feed water for boilers, it is necessary to remove dissolved oxygen in raw water, which causes corrosion, as well as hardness. There are two main ways to remove it: One is to chemically treat the water by injecting chemicals such as oxygen scavengers, and the other is to preheat the feed water with steam using a deaerator.
It is a physical method to expel dissolved oxygen.

[The problem that the idea attempts to solve]

The above-described dissolved oxygen removal method has the following problems. First, the chemical method described above has a problem in that a reaction product caused by the oxygen scavenger increases the electrical conductivity of boiler can water, making carryover more likely to occur. Next, the latter physical method has the problem that it cannot be used when starting a boiler when sufficient steam is not generated. At startup, the inside of the can is most susceptible to corrosion, so not being able to use the boiler at startup is a very big problem.

[Means for solving the problem] In view of the above-mentioned problems, this invention provides a water treatment device that can simultaneously remove both hardness and dissolved oxygen in raw water. consists of a resin cylinder filled with strongly acidic cation exchange resin and strongly basic anion exchange resin with different specific gravities, a control valve attached to this resin cylinder, a raw water line connected to this control valve, a treated water line, and a recycled water line. A regenerant supply line, a drainage line, and a regenerant tank containing an appropriate regenerant and connected to the regenerant supply line are provided, and a regenerant tank is provided in the resin cylinder from the inner pipe and the outer pipe. A water collecting pipe consisting of the above is installed in a state connected to the control valve, the tip opening of the inner tube is connected to the bottom of the resin cylinder, and the tip opening of the outer tube is connected to the strongly acidic cation exchange resin layer. It is characterized in that the control valve 2 is provided with a switching means which is arranged near the boundary with the anion exchange resin layer and defines the state of communication between each line and the inner pipe 8a and the outer pipe 8b.

[Effect]

According to the ion exchange type water treatment device configured as described above, when water flowing into the resin cylinder from the raw water line passes through the resin layer, the hardness is replaced by the strongly acidic cation exchange resin, and the dissolved oxygen is replaced by the strongly basic anion exchange resin. Removed by ion exchange resin. Therefore, hardness and dissolved oxygen can be removed at the same time, and the water from which both have been removed is supplied to external equipment using the treated water through the treated water line. In addition, when the ion exchange resin becomes saturated and its ion exchange capacity decreases, a regenerating agent performs a regeneration operation, and the flow path is appropriately switched between the strongly acidic cation exchange resin and the strongly basic anion exchange resin. and can be played separately.

〔Example〕

Hereinafter, preferred embodiments of this invention will be described based on the drawings.

In the figure, 1 is a resin cylinder, and the inside thereof is filled with a strongly acidic cation exchange resin A and a strongly basic anion exchange resin B having different specific gravities. As the strongly acidic cation exchange resin, Na ⁺ , K ⁺ , NH ₄ ⁺ type, etc. are used, and as the strong basic anion exchange resin, SO ₃ ^2
- , NO ₂ ^- type, etc. are used.

2 is a control valve, which is attached to the top of the resin cylinder. This control valve switches the flow of water in the resin cylinder under timer control to perform an ion exchange resin regeneration operation. A water collection pipe 8 extends from the lower end of the control valve 2 toward the bottom of the resin cylinder 1, and during the water flow cycle, water that has passed through the ion exchange resin layer passes through this water collection pipe to the treated water line 4. It's flowing.

In addition to the treated water line, the control valve 2 is connected to a raw water line 3, a regenerant supply line 5, and a drainage line 6. The other end of the regenerant supply line 5 is connected to a regenerant tank 7. are connected. This regenerating agent tank stores an appropriate powdered or liquid regenerating agent, for example,
In the case of a combination of a Na ⁺ type cation exchange resin and a SO ₃ ^2- type anion exchange resin, Na ₂ SO ₃ is used as a regenerant.

The water collection pipe 8 has a double pipe structure consisting of an inner pipe 8a and an outer pipe 8b. One end of the water collection pipe 8 is connected to the control valve 2, and the other end is opened into the resin cylinder 1. There is. The tip opening of the inner tube 8a is placed at the bottom of the resin cylinder 1, and the tip opening of the outer tube 8b is placed approximately at the center of the resin cylinder 1. The tip opening position of the outer tube 8b is located between the strongly acidic cation exchange resin A layer and the strongly basic anion exchange resin B layer.
This corresponds to the position near the boundary with the layer. Further, the control valve 2 is provided with a switching means that defines the communication state between each of the lines and the inner pipe 8a and the outer pipe 8b.

In the ion exchange water treatment device configured as above, during the water flow cycle, water flowing from the raw water line 3 through the control valve 2 into the resin cylinder 1 passes through the ion exchange resin layer from above to below. At this time, the hardness is removed by the strongly acidic cation exchange resin A, and the dissolved oxygen is removed by the strongly basic anion exchange resin B. As a result, water from which both hardness and dissolved oxygen have been removed is transported to the water collection pipe 8.
That is, the water passes through the inner pipe 8a (the flow path between the inner pipe 8a and the outer pipe 8b is in a closed state), flows to the treated water line 4, and heads to the equipment (boiler) that uses the treated water. If the water treatment device is used continuously, the ion exchange resin will become saturated and the ion exchange capacity will decrease, so find an appropriate time to perform a regeneration operation.

During this regeneration cycle, the control valve 2 is switched to regenerate the cation exchange resin and the anion exchange resin separately.

The specific gravity of the ion exchange resin that is normally used is lighter than that of the cation exchange resin, and inside the resin cylinder 1, the upper half is the anion exchange resin B layer and the lower half is the cation exchange resin A layer. Become. For example, when using a Na ⁺ type strong acid cation exchange resin and an SO ₃ ^2- type strong basic anion exchange resin, SO ₃ ^2- combines with oxygen and becomes SO ₄ ^2- . SO 4 2- is adsorbed on the anion exchange resin as a form, and during regeneration, SO ₄ ^2- is precipitated on the anion exchange resin. On the other hand, with cation exchange resins, during regeneration, previously adsorbed Ca ²⁺ precipitates, and Ca ²⁺ and SO ₄ ^2- react.
CaSO ₄ is formed, which precipitates and blocks the ion exchange resin layer. As a countermeasure in this case, EDTA
There is also a method of blending dissolved components such as in the regenerating agent to prevent the formation of precipitates, but this is not desirable as it increases running costs. According to this invention, since the cation exchange resin and the anion exchange resin are regenerated separately, the above-mentioned problems can be solved.

The specific operations during the regeneration cycle are as follows. First, the control valve 2 is switched to perform backwashing, regeneration, and water washing of only the anion exchange resin layer. The channel of the inner tube 8a is closed, the channel of the outer tube 8b is opened, raw water is allowed to flow from the outer tube 8b, and the anion exchange resin layer is flowed from the bottom to the top to perform backwashing. The wastewater at this time is discharged to the outside through the drainage line 6. Next, moving on to actual regeneration, the control valve is switched, and the regenerant in the regenerant tank 7 is guided into the resin cylinder 1 through the regenerant supply line 5, and the regenerant is loosened by backwashing. The ion exchange resin layer is flowed from top to bottom. The ability of the ion exchange resin is restored by the regenerating agent, and the regenerated waste water is discharged to the outside from the drain line 6 through the outer pipe 8b. Then, the control valve is further switched to allow raw water to flow into the resin cylinder 1, thereby washing away the regenerating agent and recycled waste water that remained in the resin cylinder during the regeneration. The drainage water at this time is also discharged to the outside from the drainage line 6 through the outer pipe 8b.

After this water washing is completed, the cation exchange resin is subsequently regenerated. At this time, contrary to the above case, the regeneration operation is performed by opening the flow path of the inner tube 8a and closing the flow path of the outer tube 8b. The outline of the playback operation is as follows.
This is almost the same as the case described above, and the recycled waste water is discharged from the bottom of the resin cylinder through the channel of the inner tube 8a. In this way, the recycled waste water of the anion exchange resin will not infiltrate the cation exchange resin layer, and no precipitates will be formed. When the regeneration of the cation exchange resin is completed, the control valve is switched to the water flow cycle state.

[Effect of idea]

Since this invention has the above-described configuration, it is possible to simultaneously remove hardness and dissolved oxygen in raw water using an ion exchange method. Therefore, there is no carry-over caused by the inflow of reaction products into the boiler can, which was the case with conventional chemical injection, and complete cleaning can be achieved immediately from the start of operation of the equipment using treated water. Since treated water can be supplied, corrosion inside the boiler can be reliably prevented when the boiler is started.

In addition, the cation exchange resin and anion exchange resin are regenerated separately, and the recycled waste water from the anion exchange resin is prevented from penetrating into the cation exchange resin layer, so that the cation exchange resin and the anion exchange resin are regenerated separately, so that the recycled waste water from the anion exchange resin does not infiltrate the cation exchange resin layer. Clogging of the ion exchange resin layer is eliminated, and solubilizing agents such as EDTA are no longer required.

As described above, according to this invention, it is possible to provide a compact and low-cost water treatment device that has two functions, a water softening function and a deoxidizing function.

[Brief explanation of drawings]

FIG. 1 is a schematic vertical sectional view showing an embodiment of this invention. 1...Resin tube, 2...Control valve, 3
... Raw water line, 4 ... Treated water line, 5 ... Regenerant supply line, 6 ... Drainage line, 7 ... Regenerant tank, 8 ... Water collection pipe, 8a ... Inner pipe, 8b ...
...outer tube, A...strongly acidic cation exchange resin, B...
Strongly basic anion exchange resin.

Claims (1)

[Scope of utility model registration request] Resin cylinder 1 filled with strongly acidic cation exchange resin A and strongly basic anion exchange resin B having different specific gravities
And control valve 2 attached to this resin cylinder
The raw water line 3, treated water line 4, regenerant supply line 5, and drainage line 6 connected to this control valve housed an appropriate regenerant and were connected to the regenerant supply line. A water collection pipe 8 consisting of an inner pipe 8a and an outer pipe 8b is installed in the resin cylinder 1 in a state connected to the control valve 2, and the opening at the tip of the inner pipe 8a is installed. At the bottom of the resin cylinder 1, the tip openings of the outer tubes 8b are arranged near the boundary between the strongly acidic cation exchange resin A layer and the strongly basic anion exchange resin B layer, and the control valve 2, each line, inner pipe 8a and outer pipe 8b
An ion exchange water treatment device characterized by being provided with a switching means for regulating a state of communication with the ion exchange water treatment device.