JPH0147225B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a determination method for determining whether or not a regeneration function is sufficient in a raw water treatment device that softens or purifies water used in a boiler. It is.

[Conventional technology]

Generally, tap water, well water, etc. are used as water for boilers, but in order to prevent scale adhesion, water is softened using a raw water treatment device equipped with a water softener, and the resulting soft water is supplied.

A water softener using ion exchange resin is usually used to soften the water, but once a certain amount of water is processed, it becomes saturated and the water softening function decreases. Regenerate and reactivate. As a method of regeneration, it is conventionally known to carry out a regeneration step in which saline is passed through a saturated ion exchange resin layer for a certain period of time, and then perform backwashing with raw water.

[Problem that the invention seeks to solve]

However, in this conventional method, there is no management of the regeneration start time, no management of the regeneration chemical solution, and no management of the operation of control equipment, so it is necessary to regenerate and impart a water softening function to the raw water treatment equipment. It is unclear whether the regeneration means has a sufficient regeneration function to meet the requirements, and the regeneration process is performed periodically while the regeneration function is insufficient.
As a result, there was a risk of hardness leakage.

The present invention eliminates the drawbacks of conventional methods and effectively manages the regeneration process by comparing the pattern of temporal changes in conductivity in the treatment process and backwashing process with a predetermined reference pattern to determine the regeneration function. It is an object of the present invention to provide a method for determining the regeneration function of a raw water treatment device, which maintains the treatment function and makes it possible to realize highly reliable raw water treatment.

[Means for solving problems]

In the present invention, when determining the regeneration function of a raw water treatment device that softens or purifies raw water using an ion exchange resin, the conductivity of the discharged liquid is determined in the regeneration process of the ion exchange resin and the subsequent backwashing process. This is a method for determining the regeneration function of a raw water treatment device, in which the regeneration function is determined by measuring temporal changes and comparing the pattern of the temporal changes with a predetermined reference pattern.

〔Example〕

The present invention will be explained by way of examples with reference to the drawings.

In FIG. 1, a resin tank 1 houses an ion exchange resin 2 therein and is combined with a saline tank 3 as a regenerating chemical tank.
It may be provided separately. There is a perforated plate 4 near the bottom of the saline tank 3, on which salt 5 is piled up as a regenerating agent, and below it, saline 6 is stored as a regenerating chemical solution, and the water surface is covered with the perforated plate. 4 and is always in contact with the salt 5, so that the salt solution 6 is always kept in a saturated state.

A switching valve 7 is provided at the top of the resin tank 1 to switch the flow paths of raw water and saline water. 8 is a raw water inflow pipe, 9 is a soft water discharge pipe, 10 is a soft water tank, 11 is a regeneration liquid pipe, 12 is a discharge liquid pipe, and 13 is a conductivity meter for detecting the electrical conductivity of the discharge liquid.
14 is a conduit provided in the center of the resin tank 1;
5 is a filter, and 16 is a free board.

In the softening process, the switching valve 7 connects the raw water inflow pipe 8 and the freeboard 16 and the conduit 14 and the soft water discharge pipe 9, as shown in FIG. In the process, as shown in FIG. 2, the regeneration liquid pipe 11 and the conduit 14,
The freeboard 16 and the drain pipe 12 are connected to each other.

[Effect]

To determine the regeneration function of this raw water treatment equipment, in the normal softening process, the switching valve 7 is placed in the position shown in Figure 1, and the raw water flowing in from the raw water inlet pipe 8 enters the free board 16 and the ion exchange resin 2. The water is softened through the filter 15 and the conduit 14.
The water enters the soft water tank 10 from the soft water discharge pipe 9 through
It is sent to the next process (such as a boiler).

As the softening process progresses, the ion exchange resin 2 becomes saturated and loses its softening ability. When a command to start regeneration is received by hardness detection or by determining the water flow amount based on the hardness of the raw water and the amount of treated water, the switching valve 7 is first switched to the position shown in FIG. 2. Next, the saline solution 6 is added to the regeneration liquid pipe 1.
1. It is introduced into the conduit 14 via the switching valve 7 and a regeneration process is performed. In this case, the saline solution 6 may be diluted by being sucked into the flow of raw water using an ejector and sent into the regeneration liquid pipe 11. The introduced saline solution passes through the filter 15 and between the ion exchange resins 2 and is regenerated, and the drained liquid overflows from the freeboard 16 and is discharged through the drained liquid pipe 12.

Next, only the raw water is introduced into the conduit 14, and the raw water is passed between the ion exchange resins 2, and the salt water as a regeneration liquid is discharged from the layer of the ion exchange resin 2 and replaced with the raw water to perform backwashing. In this backwashing process,
When the conductivity meter 13 detects the temporal change in the conductivity of the drained liquid passing through the drained liquid pipe 12, the concentration of the drained liquid gradually decreases as time passes.
The conductivity gradually decreases.

The absence of salt in the effluent can be confirmed by the fact that the conductivity has become equal to that of the raw water.

After a suitable period of time has elapsed, the backwashing process is completed and the switching valve 7 is switched to start the softening process again.

FIG. 3 shows examples of temporal changes in the electrical conductivity of the regenerated waste liquid during the softening, regeneration, and backwashing steps. A is a softening process (water passage process), B is a regeneration process, and C is a backwashing process.

The relationship between the type of each change pattern and the phenomenon estimated by this pattern is as follows.

(i) →→2A→→… pattern When a sufficient amount of saline solution (amount of Na ⁺ ) is supplied to regenerate the ion exchange resin. This curve is determined in advance through experiments and the like, and is used as a reference pattern.

It is compared with this reference pattern, and if it deviates from this, it is determined to be abnormal. For example, an abnormal pattern is (ii) →→2A′→→→ pattern. This rapid decrease in conductivity indicates that the amount of saline (Na ⁺ amount) is insufficient.

In other words, pattern (iii) →′→→→ pattern when the conductivity of wastewater does not increase.The reason why the conductivity is the same as that of raw water from the beginning is that the regeneration chemical solution, which was intended to be saline water, , indicating that it was just raw water. Possible causes of this include forgetting to supply the salt, formation of brine bridges on the surface of the saline that prevented the salt from falling, and failure to suction the saline due to blockage of the ejector. In other words, pattern (iv) → pattern when the electrical conductivity of the waste water does not maintain a predetermined value or higher for a certain period of time.If the electrical conductivity is zero from the beginning, it means that there is no liquid in the drain pipe 12, and the switching valve 7 Possible causes include blockage, blockage of the filter 15, etc.
In other words, the occurrence of trouble can be detected using patterns such as a pattern when the conductivity of the wastewater is 0, or a case when the conductivity of the wastewater increases and does not decrease, for example, when the conductivity sensor becomes short-circuited. .

Conventional methods could not detect the above-mentioned problems.

The electrical conductivity values of the reference pattern example in the state (i) are shown below.

Raw water (13℃) 150μS/cm Soft water (15℃) 160 〃 Effluent After 2 minutes (16℃) 10000 〃 5〃 (〃 ) 10000 〃 15〃 (15℃) 2600 〃 25〃 (〃 ) 1500 〃 90〃 (14℃) 150 〃 After the start of the regeneration process, at regular intervals (for example, 5
Measure the electrical conductivity (every minute), find its temporal change, and compare it with the reference pattern in (i) to estimate whether sufficient amount has been supplied for the regeneration of the saline (Na ⁺ ). From this, it is determined whether the regeneration ability is sufficient. In other words, when compared with the reference pattern in (i), if a pattern matching or close to this is shown, the supplied saline solution (Na ⁺ ) is sufficient and the regeneration process is carried out with sufficient regeneration ability. Therefore, it is presumed that the ion exchange resin 2 has recovered sufficient processing ability. If the conductivity of the wastewater does not meet the standard pattern, that is, if the conductivity of the wastewater does not rise, does not maintain above the specified value, or deviates from the standard pattern, such as 0 or rises but does not fall, the above It can be seen that various quantities are insufficient, and the cause can be estimated, making it easy to take countermeasures.

Although the above is an explanation regarding a hard water softening device, similar effects can be obtained in a pure water treatment device as well.

〔Effect of the invention〕

The present invention measures the temporal change in the conductivity of the discharged liquid during the regeneration process of the ion exchange resin and the subsequent backwashing process, and compares the pattern of the temporal change with a predetermined reference pattern. It is possible to easily and reliably detect whether or not the regeneration in the process has sufficient regeneration function, making it possible to prevent troubles such as hardness leakage due to misidentification of the regeneration function, and improving the regeneration process of raw water treatment equipment. can be managed and maintained stably, and has an extremely large practical effect.

[Brief explanation of drawings]

The drawings relate to embodiments of the present invention; FIGS. 1 and 2 are flow diagrams showing softening and regeneration, respectively, and FIG. 3 shows temporal changes in conductivity during softening, regeneration, and backwashing steps. FIG. 1...Resin tank, 2...Ion exchange resin, 3
... Salt water tank, 4 ... Perforated plate, 5 ... Salt,
6... Salt water, 7... Switching valve, 8... Raw water inflow pipe, 9... Soft water discharge pipe, 10... Soft water tank, 1
1... Regeneration liquid pipe, 12... Drainage liquid pipe, 13...
Conductivity meter, 14... Conduit, 15... Filter, 1
6...Free board.

Claims (1)

[Claims] 1. When determining the regeneration function of a raw water treatment device that softens or purifies raw water using an ion exchange resin, temporal changes in the electrical conductivity of the discharged liquid during the ion exchange resin regeneration process and the subsequent backwashing process. A method for determining the regeneration function of a raw water treatment device, which determines the regeneration function by measuring the temporal change pattern and a predetermined reference pattern.