JPH0687985B2 - Ultrasonic cleaning regeneration method of ion-exchange resin contaminated with organic substances - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an ultrasonic cleaning and regenerating method of an ion exchange resin contaminated with an organic matter, and is widely used in a condensate desalination device of a thermal power plant or the like. The present invention relates to a method for ultrasonically regenerating an ion-exchange resin containing organic substances, which can efficiently and regenerate the ion-exchange resin at low cost.

[Conventional technology]

Since the once-through boiler of a thermal power plant requires extremely high-purity water supply to prevent corrosion, a condensate demineralizer using ion-exchange resin was installed to generate pollutants and corrosion due to seawater leakage. Impurities such as things are removed.

The ion exchange resin of the condensate demineralizer is so-called anion resin organic matter contamination when the anion resin is contaminated by a small amount of organic matter contained in the system water during operation of the power generation plant.

In order to remove the organic substances of these pollutants, there are examples of washing with hot saline solution or caustic soda water, but since they have the property that they are very difficult to remove, none of them have a washing effect. Has not established effective cleaning technology.

Further, Japanese Patent Publication Nos. Sho 57-136949, Sho 60-177300, and Examined Japanese Patent Publication No. 1-107850 disclose devices for cleaning and removing iron oxide adhering to the surface of an ion-exchange resin resin with an ultrasonic cleaner. Although disclosed, none of them have attempted to wash and remove the ion exchange resin contaminated with organic substances. Now, in the field of industrial cleaning using ultrasonic waves, mainly mechanical parts, electronic parts and glasses are used.

Therefore, under the present circumstances, the ion exchange resin, which has become unusable due to contamination by organic substances and the like, is discarded and replaced or replaced with a new resin to maintain its performance.

Next, the contamination mechanism of the contaminated ion exchange resin in the present situation and specific measures will be described.

The system water of a thermal power plant contains minute amounts of minute organic substances and pollutants such as iron.

The organic substances that are pollutants are adsorbed on the anion resin and coat the pores of the resin. As a result, the ion exchange performance that the ion exchange resin originally possesses is significantly reduced. A phenomenon occurs in which normal water quality cannot be obtained because it cannot be exchanged with acid ions.

The frequency of anion resin organic matter contamination cannot be unequivocally determined depending on the water quality of the system water, but after exchanging with a new resin, the ion exchange performance disappears in 3 to 4 months at the earliest and 9 to 10 months at the later. There is also.

Due to the above reasons, the total amount of ion-exchange resin that has been contaminated by operating the condensate desalination device of a thermal power plant is half an year to one year in the case of anion resin or is replenished (30 to 50%)
However, it is the current situation although it is trying to maintain the performance.

[Problems to be Solved by the Invention]

Anion exchange resins that have been contaminated by organic substances contained in system water have not been developed as effective cleaning techniques as described above, so they are discarded and replaced with new resins.

For this reason, the contaminated resin must be treated as industrial waste, and economical loss such as the purchase of expensive new resin is significantly increasing.

The present invention solves the above conventional problems, without using chemicals such as caustic soda water and saline, and safe, and
It is an object of the present invention to provide an ultrasonic cleaning regenerative method for an organic pollutant ion exchange resin which is low in cost and high in processing efficiency.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, the ultrasonic cleaning regenerative method of the organic matter-contaminated ion exchange resin of the present invention circulates the organic matter-contaminated ion exchange resin together with demineralized water through a circulation pipe consisting of a corrosion-resistant pipe installed in a water tank. Then, the ion-exchange resin is irradiated with ultrasonic waves to remove organic contaminants from the ion-exchange resin for cleaning. It is preferable to use warm water as the water in the aquarium.

〔Example〕

 Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a configuration diagram of an ultrasonic cleaning device for carrying out an ultrasonic cleaning regeneration method of an organic-contaminated ion exchange resin of the present invention.

In this ultrasonic cleaning device, first, the ultrasonic oscillator 1 used for cleaning the organic-ion-contaminated ion exchange resin is placed in the water tank 2, and the granular ion-exchange resin contaminated with organic substances is placed in the water above the ultrasonic oscillator 1. The stainless steel pipe 3 for circulating is installed.

Since the ultrasonic effect is higher when the thickness of the stainless steel pipe is thinner, it is preferably 1 mm or less.

In addition to the stainless steel tube 3, a rectangular stainless box may be used as the circulation device. The thickness of the contaminated ion-exchange resin that circulates in each circulation device is about 20.
mm. The reason for this is that if the thickness of the ion-exchange resin to be circulated is 20 mm or more, the circulation becomes insufficient and the intensity of ultrasonic waves is weakened, and the cleaning effect is reduced.

The stainless steel pipe 3 is installed below the surface of the water, and the water level at this time is about 200 mm from the surface of the isothermal wave oscillator, but it is preferable to adjust the position so that the power of the ultrasonic wave is maximized.

The water temperature is maintained at about 50 ° C in order to enhance the cleaning effect, but it should be 60 ° C or less in consideration of the life of the ultrasonic oscillator.

When circulating with a circulation pump prior to washing, in order to reduce pressure loss as much as possible, the amount of contaminated ion exchange resin to be washed is stored in a resin storage tank 4 that contains 2-3 times the amount of demineralized water. Put in.

The ion exchange resin contained in the resin storage tank 4 is fed into the stainless steel pipe via the inlet pipe 6 by the circulation pump 5,
It is circulated while returning from the outlet pipe 7 to the resin storage tank 4, and ultrasonic waves are generated at the maximum output of the ultrasonic oscillator 1 to wash the ion exchange resin contaminated with organic substances.

Since the cleaning time varies depending on the contamination status of the ion exchange resin, it is preferable to determine it by conducting a test in advance.

Further, the demineralized water is put into the resin storage tank 4 from the pipe 8 and discharged from the pipe 9 so that the pollutant removed by the ultrasonic cleaning does not adhere to the ion-exchange resin being washed again.

On the other hand, regarding the relationship between the frequency of ultrasonic waves and the cleaning effect, it is generally said that the lower the frequency is, the higher the cavitation strength for desorbing the adsorbate is. Most of the ultrasonic oscillators currently on the market have three frequencies of 24KHz, 28KHz and 48KHz.
We examined under two conditions of 8KHz, but the cleaning effect is similar in both cases.

The installation position of the ultrasonic oscillator is generally upward irradiation as described above, but the cleaning effect is the same for other downward irradiation and side irradiation.

In addition, as a matter of course, the larger the ultrasonic power, the higher the cleaning effect. Generally, the power of ultrasonic waves is expressed by the power density (W / cm ² ) obtained by dividing the output of ultrasonic waves by the surface area of the oscillator, but the ultrasonic oscillators currently on the market are 0.5 W / cm ²
And 1.0 W / cm ² are the most common, but 1.0 W / cm ² having a high power density is preferable for cleaning.

The main application of the present invention is to wash the ion exchange resin used in the condensate desalination device of a thermal power plant, but the ion exchange used in the desalination device of industrial water and other plants. Application to resin is also possible.

Next, an example of carrying out an ultrasonic cleaning and regeneration method of an organic exchanged ion exchange resin according to the present invention using the ultrasonic cleaning apparatus will be described. The present invention will be described in more detail with reference to examples below.
The present invention is not limited.

Ultrasonic oscillator 1 used for washing the ion exchange resin of the organic matter contamination, throw surface area 600 cm ² expression (power density: 1.0
W / cm ² , frequency: 28KHz, output 1,200W)
It was put in a water tank 2, and a stainless steel pipe 3 (outer diameter 10 mm, thickness 1 mm, length 7.9 m, inner surface area 2,000 cm ² ) for circulating the resin was installed above it.

Ion exchange resin 6 and demineralized water contaminated with organic substances used for cleaning
18 was put in the resin storage tank 4 and circulated in the stainless steel pipe 3 by the circulation pump 5.

Circulation was performed at 600 ml / min, ultrasonic power was raised to the rated value, and ultrasonic cleaning was performed under the conditions of a water bath temperature of 50 ° C. and a cleaning time of 60 minutes.

At this time, the water level from the surface of the throw-in type ultrasonic oscillator to the upper end of the stainless steel pipe in the water tank was about 160 mm. The ultrasonic conditions and cleaning conditions described above are summarized in Table 1.

When ultrasonic cleaning is carried out under the above cleaning conditions, the anion resin contaminated with organic substances can regenerate its performance to a reusable range and obtain high-purity water quality.

The method of evaluating whether or not the performance of the organic pollutant ion-exchange resin has been regenerated to a reusable range is shown below.

As described above, the organic matter contamination of the anion resin is a phenomenon in which anion leaks and normal water quality cannot be obtained because the ion exchange rate is remarkably reduced, and it is judged by a load test with a sodium sulfate solution.

FIG. 2 shows the results of a load test of an organic resin-contaminated anion resin with a sodium sulfate solution before and after ultrasonic cleaning. The test method is to put an ion exchange resin (anion resin: 100 ml, cation resin: 200 ml) into an ion exchange column (25φ × 800 mm), regenerate with sulfuric acid and caustic soda, and wash thoroughly. Next, demineralized water with an electrical conductivity of 0.5 μS / cm, then a sodium sulfate solution with an electrical conductivity of 5 μS / cm, and finally a sodium sulfate solution with an electrical conductivity of 20 μS / cm are passed through the water to apply a load, The ion exchange performance is measured by measuring the electric conductivity at the outlet of the ion exchange column.

The conditions of regeneration and water flow in this test method are simulated actual operating conditions of a condensate desalination device.

From the load test results of Fig. 2, before ultrasonic cleaning of organic pollutant ion exchange resin, when 5 μS / cm and 20 μS / cm sodium sulfate solutions were passed through, the electrical conductivity at the ion exchange column outlet was 0.17 μS. / cm, rose to 0.87μS / cm, and 0.15μ, which is the water quality standard value at the condensate demineralizer outlet of a thermal power plant.
Since it exceeds S / cm, it interferes with the operation of the power plant.
However, after the ultrasonic cleaning, contaminants such as organic substances and fine iron that had adhered to the contaminated ion exchange resin were cleaned and removed, so even if 5 μS / cm and 20 μS / cm sodium sulfate solutions were passed through the The electric conductivity at the outlet of the exchange column did not increase to 0.07 μS / cm and 0.11 μS / cm, and the sulfate ion, which is an anion in the sodium sulfate solution, can be quickly exchanged with hydrogen ion.

Therefore, the water quality standard value at the outlet of the condensate demineralizer is 0.15.
It clears that μS / cm or less is sufficiently cleared, and the organic matter-contaminated anion exchange resin can be regenerated to the operable range.

〔The invention's effect〕

According to the present invention, the ultrasonic cleaning and regeneration method of the organic-contaminated ion-exchange resin of the present invention is performed by circulating the organic-contaminated ion-exchange resin together with demineralized water through a circulation arrangement installed in a water tank, and irradiating ultrasonic waves. To remove organic contaminants,
Since the cleaning is performed, it is possible to safely regenerate the organic-ion-contaminated ion exchange resin, which has been conventionally unusable, without using chemicals, and it is possible to obtain high-purity water quality by the regenerated ion exchange resin.

[Brief description of drawings]

FIG. 1 is an ultrasonic cleaning apparatus for carrying out an ultrasonic cleaning regeneration method of an organic-contaminated ion-exchange resin of the present invention, and FIG. 2 compares load test results of the ion-exchange resin before and after ultrasonic cleaning of the present invention. FIG. 1 ... Ultrasonic oscillator, 2 ... Water tank, 3 ... Stainless steel piping, 4 ... Resin water tank, 5 ... Circulation pump.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Minoru Horikawa 1-1-1, Higashi Port, Seigo-cho, Kitakanbara-gun, Niigata Prefecture 155 Tohoku Electric Power Co., Inc. Higashi-Niigata Thermal Power Station (72) Inventor Takeshi Sugimoto Higashiko-cho, Kitakanbara-gun, Niigata Prefecture 1-chome 155 Tohoku Electric Power Co., Inc. Higashi Niigata Thermal Power Plant (72) Inventor Toichi Soma 1-chome, East Port 1-chome 155 Higashi Niigata Thermal Power Station, Niigata Prefecture Kitakanbara District

Claims (2)

[Claims] 1. When cleaning and regenerating an ion-exchange resin of an organic contaminant contaminated by the adsorption of an organic contaminant contained in system water, the organic contaminants are circulated through a circulation pipe made of a corrosion resistant pipe installed in a water tank. Ultrasonic waves of ion-exchange resin for organic contamination, characterized in that the ion-exchange resin is circulated together with demineralized water, and the ion-exchange resin is irradiated with ultrasonic waves to remove organic contaminants from the ion-exchange resin and washed. Wash regeneration method. 2. The method of ultrasonic cleaning and regeneration of an organic exchanged ion-exchange resin according to claim 1, wherein hot water is used as the water in the water tank.