Method for deeply dechlorinating circulating water through electrolytic adsorption

Abstract

The invention discloses a circulating water electrolysis adsorption deep dechlorination method, which is characterized in that air aeration is added on an anode plate, air microbubbles and chlorine gas bubbles generated by an anode are combined to form new bubbles, and the new bubbles contain air and chlorine gas, so that on one hand, the retention time of the chlorine gas generated by the anode plate in water is shortened; on the other hand, newly generated bubbles contain air and chlorine, the contact probability of water and chlorine is reduced, and the purpose of reducing the proportion of chlorine dissolved in water is achieved. The invention aims to provide a circulating water electrolysis adsorption deep dechlorination method, and solves the problem that chlorine in circulating water is dissolved in water in the process of removing chloride ions by adopting an electrolysis adsorption technology.

Description

Technical Field

[0001] The invention relates to the technical field of circulating water electrolysis adsorption, and in particular to a circulating water electrolysis adsorption deep dechlorination method. Background Art

[0002] The circulating water saving technology is now gradually adopting the electrolytic adsorption technology. The key link of the technology is to use the electrolysis principle to remove the calcium and magnesium ions in the circulating water by generating calcium carbonate (scale), magnesium carbonate (scale), calcium hydroxide (scale), and magnesium hydroxide (scale) at the cathode, and to remove the chloride ions in the circulating water by generating chlorine gas at the anode. It is used to reduce the content of calcium, magnesium and chloride ions in the circulating water. The precipitated solid phase calcium and magnesium compounds can remove part of the suspended matter at the same time by the co-precipitation effect, improve the water quality, and make the water quality reach a certain equilibrium state under the condition of high concentration ratio (no external discharge).

[0003] When the Yellow River water (high in chloride ions) is used as circulating water, a large amount of chlorine is generated during the actual operation of the electrolytic adsorption technology. The electrolyzed chlorine dissolves in the water and reacts with water to form hydrochloric acid and hypochlorous acid, which will cause serious corrosion to water pumps, pipes and heat exchange equipment. Summary of the invention

[0004] The purpose of the present invention is to provide a circulating water electrolytic adsorption deep dechlorination method to solve the problem of chlorine dissolving in the circulating water during the process of removing chloride ions using electrolytic adsorption technology.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] The invention discloses a circulating water electrolytic adsorption deep dechlorination method, which increases air aeration on the anode plate, combines air microbubbles with chlorine bubbles generated by the anode to form new bubbles, wherein the new bubbles contain air and chlorine. On the one hand, the residence time of the chlorine generated by the anode plate in the water is shortened, and on the other hand, the newly generated bubbles contain air and chlorine, which reduces the contact probability between water and chlorine, thereby achieving the purpose of reducing the proportion of chlorine dissolved in water.

[0007] Furthermore, the degassing tube of the electrolytic tank is lowered from the top of the degassing chamber to near the liquid surface of the electrolytic tank so as to preferentially extract the precipitated chlorine. At the same time, as the upper gas flows toward the degassing tube close to the water surface, the contact area between the chlorine and the water surface will be reduced, thereby reducing the amount of chlorine dissolved in water.

[0008] Furthermore, the degassing fan capacity is increased, the negative pressure in the degassing chamber is increased, the fan flow rate is increased, and the probability of chlorine dissolving in water is reduced.

[0009] Furthermore, an axial flow fan is added above the dynamic membrane pool to make the gas on the membrane pool water surface flow in an orderly manner, and the chlorine precipitated above the membrane pool is taken away by the airflow, thereby reducing the residence time of chlorine on the membrane pool water surface and reducing the amount of chlorine accumulated above the membrane pool water surface and then dissolved in water.

[0010] Furthermore, a degassing tower process is added behind the dynamic membrane pool to completely remove the chlorine dissolved in the water.

[0011] Furthermore, after the water is filtered through the dynamic membrane pool, a water pump is used to pump the chlorine-containing water after electrolysis into a degassing tower. In the degassing tower, the circulating water dissolved with chlorine is evenly sprayed on the degassing tower filler through the degassing tower nozzle. The water dissolved with chlorine forms a water film on the filler and flows from top to bottom. The degassing tower draws air from the bottom of the degassing tower through the fan, and the air flows from bottom to top. The air and the water film on the filler are in close contact, thereby achieving the degassing purpose of taking away the chlorine on the water film with air.

[0012] The present invention also provides the application of the circulating water electrolysis adsorption deep dechlorination method to Baosteel's replenishment water system with high chloride ion content.

[0013] The present invention also provides the application of the circulating water electrolytic adsorption deep dechlorination method to all open circulating water systems.

[0014] Compared with the prior art, the beneficial technical effects of the present invention are:

[0015] The method of the invention solves the problem of "activated" chlorine gas being dissolved in water again during electrolytic adsorption, and improves the electrolytic adsorption process.

[0016] The method of the present invention completely solves the problem that chlorine is easily soluble in water in the electrolytic adsorption technology, chlorine returns to the circulating water system, forms hydrochloric acid and hypochlorous acid in the water, and causes serious corrosion to the equipment. It solves the difficult problem of the comprehensive treatment project of the No. 1 gas turbine circulating water of Baosteel Group, and achieves zero discharge of the No. 1 gas turbine circulating water. It has paved a new way for Baosteel to promote the use of electrolytic adsorption technology and made outstanding contributions to Baosteel's water conservation work.

[0017] The method of the present invention makes it possible to fully promote and apply the electrolytic adsorption technology. The electrolytic adsorption technology can be used in the water system with high chloride ion content in Baotou Steel, and can also be widely used in all open circulating water systems to achieve zero discharge of circulating water, thus contributing to the efficient utilization of my country's water resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention will be further described below in conjunction with the accompanying drawings.

[0019] Figure 1 The figure is a flow chart of the electrolytic adsorption process of the present invention. DETAILED DESCRIPTION

[0020] A method for deep dechlorination of circulating water using electrolytic adsorption technology, specifically comprising:

[0021] 1) Increase air aeration on the anode plate, combine air microbubbles with chlorine bubbles generated by the anode to form new bubbles, which contain air and chlorine: on the one hand, it can shorten the residence time of chlorine generated by the anode plate (from microbubbles to bubbles that are large enough to automatically float to the surface of the water), and at the same time, the newly generated bubbles contain air and chlorine, which can reduce the contact probability between water and chlorine, thereby achieving the purpose of reducing the proportion of chlorine dissolved in water.

[0022] 2) Lower the degassing tube of the electrolytic tank from the top of the degassing chamber to near the water surface of the electrolytic tank. The gas in the degassing chamber is composed of oxygen, nitrogen, chlorine, hydrogen and other gases. Chlorine has the largest specific gravity among these gases. If the degassing tube is at the top of the degassing chamber, it is easy for chlorine to be deposited on the water surface, and part of the precipitated chlorine will dissolve in the water again. Lowering the degassing tube from the top of the degassing chamber to near the liquid surface can preferentially extract the precipitated chlorine. At the same time, as the upper gas (oxygen, nitrogen, hydrogen, etc.) flows toward the degassing tube close to the water surface, the contact area between chlorine and the water surface will be reduced, which can reduce the amount of chlorine dissolved in water.

[0023] 3) Increase the degassing fan capacity, increase the negative pressure in the degassing chamber, increase the fan flow rate, and reduce the chance of chlorine dissolving in water.

[0024] 4) Adding an axial flow fan above the dynamic membrane pool makes the gas on the water surface of the membrane pool flow in an orderly manner, and the chlorine precipitated above the membrane pool is taken away by the airflow, thereby reducing the residence time of chlorine on the water surface of the membrane pool and reducing the amount of chlorine accumulated above the water surface of the membrane pool and then dissolved in water.

[0025] 5) Add a degassing tower process behind the dynamic membrane pool to completely remove the chlorine dissolved in the water. After the water is filtered through the dynamic membrane pool, a water pump is used to pump the electrolyzed chlorine-containing water into the degassing tower. In the degassing tower, the circulating water dissolved with chlorine is evenly sprayed on the degassing tower filler through the degassing tower nozzle. The water dissolved with chlorine forms a water film on the filler and flows from top to bottom. The degassing tower uses a fan to inhale air from the bottom of the degassing tower. The air flows from bottom to top, and the air and the water film on the filler are in close contact, achieving the purpose of degassing by taking away the chlorine on the water film.

[0026] Benefit Description:

[0027] The circulating water electrolysis adsorption deep dechlorination technology can achieve zero discharge of external drainage from Baosteel's No. 1 gas turbine circulating water system, saving 60m3 of water. 3 / h, annual (gas turbine runs about 335 days a year) water saving: 482400m 3 / h

[0028] Expected benefit = water saving × unit price of filtered water = 482400 × 2.097652 = 1011907 yuan.

[0029] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A circulating water electrolysis adsorption deep dechlorination method, characterized in that: Air aeration is added to the anode plate, and air microbubbles are combined with chlorine bubbles produced by the anode to form new bubbles. The new bubbles contain air and chlorine. On the one hand, the residence time of chlorine produced by the anode plate in the water is shortened, and on the other hand, the newly generated bubbles contain air and chlorine, which reduces the contact probability between water and chlorine, thereby achieving the purpose of reducing the proportion of chlorine dissolved in water.

2. The method for deep dechlorination of circulating water by electrolytic adsorption according to claim 1, characterized in that: The degassing tube of the electrolytic tank is lowered from the top of the degassing chamber to near the liquid surface of the electrolytic tank so as to preferentially extract the precipitated chlorine. At the same time, as the upper gas flows toward the degassing tube close to the water surface, the contact area between the chlorine and the water surface will be reduced, thereby reducing the amount of chlorine dissolved in water.

3. The method for deep dechlorination of circulating water by electrolytic adsorption according to claim 1, characterized in that: Increase the degassing fan capacity, increase the negative pressure in the degassing chamber, increase the fan flow rate, and reduce the chance of chlorine dissolving in water.

4. The method for deep dechlorination of circulating water by electrolysis adsorption according to claim 1, characterized in that: An axial flow fan is added above the dynamic membrane pool to make the gas on the membrane pool water surface flow in an orderly manner, and the chlorine precipitated above the membrane pool is taken away by the airflow, thereby reducing the residence time of chlorine on the membrane pool water surface and reducing the amount of chlorine accumulated above the membrane pool water surface and then dissolved in water.

5. The method for deep dechlorination of circulating water by electrolytic adsorption according to claim 1, characterized in that: A degassing tower process is added behind the dynamic membrane pool to completely remove the chlorine dissolved in the water.

6. The method for deep dechlorination of circulating water by electrolytic adsorption according to claim 5, characterized in that: After the water is filtered through the dynamic membrane pool, a water pump is used to pump the electrolyzed chlorine-containing water into the degassing tower. In the degassing tower, the circulating water dissolved with chlorine is evenly sprayed on the degassing tower filler through the degassing tower nozzle. The water dissolved with chlorine forms a water film on the filler and flows from top to bottom. The degassing tower draws air from the bottom of the degassing tower through the fan, and the air flows from bottom to top. The air and the water film on the filler are in close contact, achieving the degassing purpose of taking away the chlorine on the water film with air.

7. Application of the circulating water electrolysis adsorption deep dechlorination method according to any one of claims 1 to 6 in Baotou Steel's replenishment water system with high chloride ion content.

8. Application of the circulating water electrolysis adsorption deep dechlorination method according to any one of claims 1 to 6 to all open circulating water systems.

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