A circulating water treatment combined device and process for realizing water conservation and emission reduction in the whole plant

Abstract

The present invention relates to a combined device and process for circulating water treatment to achieve water conservation and emission reduction in the whole plant. The device includes: an open cooling circulating water treatment unit, which includes a first cooling tower, a circulating water treatment tank with an electrochemical device, a first unit to be cooled, etc.; a closed crystallization unit, which includes a second cooling tower (closed cooling tower), an ECH microcrystal unit, and a second unit to be cooled (service object). The ECH microcrystal unit is arranged at the bottom of the second cooling tower, and the cooling water flowing down from the upper part of the second cooling tower and treated with ECH microcrystal reagent by the ECH microcrystal unit also returns to the upper part of the second cooling tower through a first branch. A second branch is led out from the lower part of the second cooling tower and connected to the second unit to be cooled, and then returns to the top of the second cooling tower. Compared with the prior art, the present invention can achieve the target requirements of water conservation and emission reduction at the source in the circulating cooling water system, and has relatively prominent advantages compared with the traditional circulating cooling water treatment.

Description

Technical Field

[0001] The present invention belongs to the technical field of water saving and emission reduction, and relates to a circulating water treatment combined device and process for realizing the water saving and emission reduction of the whole plant. Background Art

[0002] Coal chemical enterprises generally have the environmental protection requirement of "zero" discharge of wastewater. Enterprises often invest a large amount of money in building equipment such as wastewater hardening pretreatment, membrane concentration, and evaporation crystallization. The sewage discharged from the circulating water system, as one of the main incoming waters of the sewage treatment unit, together with other wastewater, enters the double-membrane system after pretreatment. The produced water is reused as reclaimed water and reused as the makeup water of the circulating water again. The RO concentrate is further treated by the membrane concentration unit, and the produced water is reused in the circulating water system, while the concentrate enters the crystallization evaporation unit. During production operation, the double-membrane treatment unit, the membrane concentration unit, and the evaporation crystallization unit all require a large amount of manpower and material resources to maintain the normal operation of the sewage treatment facilities; the excessive sewage treatment volume and the long sewage treatment process make the subsequent treatment units have a large production load. Especially when the water quality of the circulating water system is abnormal and the sewage discharge and replacement volume are increased, the production pressure of the sewage treatment system is further increased, resulting in increased equipment loss and maintenance costs, and ultimately causing the sewage treatment cost to remain high, increasing the operating burden of the enterprise.

[0003] According to the requirements of water use in the process and "zero" discharge of wastewater reuse in coal chemical enterprises, it is generally divided into industrial water treatment systems, demineralized water treatment systems, circulating cooling water treatment systems, wastewater treatment systems, reclaimed water treatment systems, and "zero" discharge treatment systems, etc. The whole-plant water use structure is shown in Figure 1 . From Figure 1 It can be seen that in order to achieve "zero" discharge of the whole-plant wastewater, the industrial water treatment system, the industrial wastewater treatment system, the reclaimed water treatment system, etc. are closely related. For example, if the discharge volume of the circulating cooling water system is large, the treatment pressure of the reclaimed water treatment system and the "zero" discharge system will be large; and for the circulating cooling water system that consumes the reclaimed water volume, if the discharge volume is large, the makeup water volume will be large. Summary of the Invention

[0004] The purpose of the present invention is to provide a circulating water treatment combined device and process for realizing the water saving and emission reduction of the whole plant, so as to achieve the target requirement of water saving and emission reduction from the source of the circulating cooling water system, and to help achieve the requirement of approximate "zero" discharge of the whole-plant wastewater.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] One of the technical solutions of the present invention provides a circulating water treatment combined device for realizing the water saving and emission reduction of the whole plant, including:

[0007] Open cooling water treatment unit: It includes a first cooling tower, a circulating water treatment tank with electrochemical equipment, and a first unit to be cooled, which are connected in sequence to form a cycle. The circulating water treatment tank is also connected with an external circulating water make-up pipeline;

[0008] Closed crystallization unit: It includes a second cooling tower, an ECH microcrystal unit that can provide ECH microcrystal agents, and a second unit to be cooled. The ECH microcrystal unit is arranged at the bottom of the second cooling tower. The cooling water that flows down from the upper part of the second cooling tower and is treated with ECH microcrystal agents by adding ECH microcrystal agents through the ECH microcrystal unit also returns to the upper part of the second cooling tower through a first branch. The lower part of the second cooling tower also leads out a second branch to connect to the second unit to be cooled and then returns to the top of the second cooling tower;

[0009] The circulating water treatment tank also leads out a drainage branch to connect to the second cooling tower.

[0010] Further, the electrochemical equipment is placed in the circulating water treatment tank or on a bypass connecting the circulating water treatment tank. When the electrochemical equipment is placed in the circulating water treatment tank, the circulating water treatment tank includes a treatment tank body with an open top. The electrochemical equipment includes one or several open electrolytic cells installed in the treatment tank body and communicating with the water body in the treatment tank body.

[0011] Furthermore, a descaling tank connecting the bottom of the open electrolytic cell is also provided at the bottom of the treatment tank body. More preferably, an electromagnetic valve is also provided at the bottom outlet of the descaling tank.

[0012] Further, a first circulation pump is also provided between the circulating water treatment tank and the first unit to be cooled.

[0013] Further, the ECH microcrystal unit includes an ECH microcrystal tank and an ECH dosing tank connected to the ECH microcrystal tank and internally provided with microcrystal purification materials.

[0014] Further, a second circulation pump is also provided on the first branch.

[0015] Further, a third circulation pump is also provided on the first branch.

[0016] The second technical solution of the present invention provides a circulating water treatment combined process for realizing the water saving and emission reduction of the whole plant, including the following steps:

[0017] (1) In the open cooling water treatment unit, the circulating water is cooled and cooled down by the first cooling tower and then sent into the circulating water treatment tank for electrochemical scale inhibition treatment. A part of the treated circulating water returns to the top of the first cooling tower after passing through the first unit to be cooled, and the other part is used as the make-up water for the closed crystallization unit. At the same time, the whole unit also replenishes the circulating water through the external circulating water make-up pipeline;

[0018] (2) In the closed crystallization unit, after the circulating water is cooled by the second cooling tower, a part of it is discharged from the side and sent to the second unit to be cooled for heat exchange, and then returns to the top of the second cooling tower. Another part is discharged into the ECH microcrystal unit, and after purification treatment, it returns to the second cooling tower again.

[0019] Compared with the prior art, the present invention has the following advantages:

[0020] (1) It can operate safely and stably under high concentration multiple conditions, greatly reducing the makeup water volume of the circulating water and the dosage of chemicals.

[0021] (2) It can achieve zero discharge of sewage, reducing the wastewater treatment and construction costs.

[0022] (3) Compared with the traditional evaporation crystallization technology, the operation of the new technology can reduce and control the salt in the water system from the source. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic flow diagram of the circulating water treatment combined device of the present invention;

[0024] Figure 2 It is a schematic structural diagram of the circulating water treatment tank;

[0025] Description of the marks in the figure:

[0026] 1 - Open cooling circulating water treatment unit, 11 - First cooling tower, 12 - Circulating water treatment tank, 121 - Treatment tank body, 122 - Open electrolytic cell, 123 - Scale removal tank, 124 - Electromagnetic valve, 13 - First unit to be cooled, 14 - First circulation pump;

[0027] 2 - Closed crystallization unit, 21 - Second cooling tower, 22 - ECH microcrystal unit, 23 - Second unit to be cooled, 24 - Second circulation pump, 25 - Third circulation pump. DETAILED DESCRIPTION OF THE INVENTION

[0028] The present invention will be described in detail below with reference to the drawings and specific embodiments. This embodiment is implemented on the premise of the technical solution of the present invention, and the detailed implementation manners and specific operation processes are given, but the protection scope of the present invention is not limited to the following embodiments.

[0029] In the following embodiments or examples, the microcrystalline purification material is a microcrystalline purifying agent or a microcrystalline adsorbent. For the rest of the raw materials or treatment technologies without special instructions, it means that they are all conventional commercially available raw materials or conventional treatment technologies in the art.

[0030] To meet the target requirements of water conservation and emission reduction at the source in the circulating cooling water system, etc., the present invention provides a combined device for circulating water treatment to achieve water conservation and emission reduction in the whole plant. Please refer to Figure 1 as shown, including:

[0031] Open cooling circulating water treatment unit 1: It includes a first cooling tower 11, a circulating water treatment tank 12, and a first unit to be cooled 13 that are connected in sequence to form a cycle. The circulating water treatment tank 12 is also connected to an external circulating water make-up pipeline;

[0032] Closed crystallization unit 2: It includes a second cooling tower 21, an ECH microcrystal unit 22, and a second unit to be cooled 23. A first branch is led out from the bottom outlet of the second cooling tower 21 and connected to the ECH microcrystal unit 22, and then returns to be connected to the upper part of the second cooling tower 21. A second branch is led out from the lower part of the second cooling tower 21 and connected to the second unit to be cooled 23, and then returns to the top of the second cooling tower 21;

[0033] A drainage branch is also led out from the circulating water treatment tank 12 and connected to the ECH microcrystal unit 22.

[0034] In some specific embodiments, please refer to Figure 2 as shown. The circulating water treatment tank 12 includes a treatment tank body 121 with an opening at the top, and one or several open electrolytic cells 122 installed in the treatment tank body 121 and communicating with the water body in the treatment tank body 121. Further, a scale removal tank 123 connecting to the bottom of the open electrolytic cell 122 is provided at the bottom of the treatment tank body 121. More preferably, an electromagnetic valve 124 is provided at the bottom outlet of the scale removal tank 123. By using the open electrolytic cell 122, the hydrogen and chlorine generated by electrolysis will not be sealed in the tank body, thus avoiding system corrosion caused by the inability to discharge chlorine and hydrogen. At the same time, both the cathode and anode in the electrolytic cell can be made of titanium and coated with a noble metal coating to improve their service life. In addition, through pole inversion and frequency oscillation, the water scale automatically falls off to the scale removal tank 123 at the bottom of the open electrolytic cell 122 and is discharged through the scale removal tank 123, thereby effectively reducing the scaling ions such as calcium and magnesium in the circulating water and crystallizing out the salt substances in the circulating water, which can improve the concentration multiple of the open circulating cooling water system.

[0035] In some specific embodiments, please refer to Figure 1 as shown. A first circulation pump 14 is also provided between the circulating water treatment tank 12 and the first unit to be cooled 13.

[0036] In some specific embodiments, the ECH microcrystal unit 22 includes an ECH microcrystal tank and an ECH dosing tank connected to the ECH microcrystal tank and containing microcrystal purification materials.

[0037] In some specific embodiments, please refer to again Figure 1 As shown, a second circulation pump 24 is further provided on the first branch.

[0038] In some specific embodiments, please refer to again Figure 1 As shown, a third circulation pump 25 is further provided on the first branch.

[0039] In addition, on the basis of the above combined device, the present invention also provides a combined process for circulating water treatment for realizing the water conservation and emission reduction of the whole plant. Similarly, refer to Figure 1 As shown, it includes the following steps:

[0040] (1) In the open cooling circulating water treatment unit 1, the circulating water is cooled by the first cooling tower 11 and then sent into the circulating water treatment pool 12 for electrochemical scale inhibition treatment. A part of the discharged sewage effluent returns to the top of the first cooling tower 11 after passing through the first cooled unit 13, and the other part serves as the makeup water for the closed crystallization unit 2. At the same time, the circulating water in the circulating water treatment pool 12 is supplemented through an external circulating water makeup pipeline;

[0041] (2) In the closed crystallization unit 2, the circulating water is cooled by the second cooling tower 21. A part of it is discharged from the side and sent to the second cooled unit 23 for heat exchange, and then returns to the top of the second cooling tower 21. The other part is discharged into the ECH microcrystal unit 22, and after purification treatment, it returns to the second cooling tower 21.

[0042] In the above embodiments, any one of them can be implemented alone, or any two or more combinations can be implemented.

[0043] The above embodiments will be described in more detail below with specific examples.

[0044] Example 1:

[0045] To meet the target requirements of water conservation and emission reduction from the source in the circulating cooling water system, etc., this example provides a combined device for circulating water treatment for realizing the water conservation and emission reduction of the whole plant. Please refer to Figure 1 As shown, it includes:

[0046] Open cooling circulating water treatment unit 1: It includes a first cooling tower 11, a circulating water treatment pool 12 with electrochemical equipment, and a first cooled unit 13 that are connected in sequence to form a cycle. The circulating water treatment pool 12 is also connected with an external circulating water makeup pipeline;

[0047] Closed crystallization unit 2: It includes a second cooling tower 21, an ECH microcrystal unit 22 that can provide ECH microcrystal agents, and a second cooled unit 23. The ECH microcrystal unit 22 is arranged at the bottom of the second cooling tower 21. The cooling water that flows down from the upper part of the second cooling tower 21 and is treated with ECH microcrystal agents added by the ECH microcrystal unit 22 also returns to the upper part of the second cooling tower 21 through the first branch. The lower part of the second cooling tower 21 also leads out a second branch to connect the second cooled unit 23, and then returns to the top of the second cooling tower 21;

[0048] The circulating water treatment tank 12 also leads out a drainage branch to connect to the second cooling tower 21.

[0049] Please refer to again Figure 2 As shown, the circulating water treatment tank 12 includes a treatment tank body 121 with an open top. Its electrochemistry equipment includes one or several open electrolytic cells 122 installed in the treatment tank body 121 and communicating with the water body in the treatment tank body 121. A scale removal tank 123 connecting to the bottom of the open electrolytic cell 122 is also provided at the bottom of the treatment tank body 121. More preferably, an electromagnetic valve 124 is also provided at the bottom outlet of the scale removal tank 123.

[0050] Please refer to again Figure 1 As shown, a first circulation pump 14 is also provided between the circulating water treatment tank 12 and the first cooled unit 13.

[0051] The ECH microcrystal unit 22 includes an ECH microcrystal tank and an ECH dosing tank connected to the ECH microcrystal tank and internally provided with microcrystal purification materials.

[0052] Please refer to again Figure 1 As shown, a second circulation pump 24 is also provided on the first branch.

[0053] Please refer to again Figure 1 As shown, a third circulation pump 25 is also provided on the first branch.

[0054] In addition, on the basis of the above combined device, the present invention also provides a circulating water treatment combined process for realizing the water saving and emission reduction of the whole plant. Also refer to Figure 1 As shown, it includes the following steps:

[0055] (1) In the open cooling circulating water treatment unit 1, the circulating water is cooled and temperature-reduced by the first cooling tower 11 and then sent into the circulating water treatment tank 12 for electrochemical scale inhibition treatment. A part of the obtained sewage effluent returns to the top of the first cooling tower 11 after passing through the first cooled unit 13, and another part is used as the makeup water for the closed crystallization unit 2. At the same time, the circulating water in the circulating water treatment tank 12 is also supplemented through the external circulating water makeup pipeline;

[0056] (2) In the closed crystallization unit 2, after the circulating water is cooled by the second cooling tower 21, a part of it is discharged from the side and sent to the second unit to be cooled 23 for heat exchange, and then returns to the top of the second cooling tower 21. Another part is discharged into the ECH microcrystal unit 22, and after purification treatment, it returns to the second cooling tower 21 again.

[0057] The electrochemical processor uses a safety voltage below 36V and can automatically match the current and voltage at a certain power according to the water quality in the circulating water tank.

[0058] After the mixing frequency sweep processing, it specifically plays the following roles: 1) Dispersing water molecular clusters, fully dissolving and surrounding calcium and carbonate ions to achieve an effective scale inhibition effect; 2) The rapid frequency conversion can extend the passivation period of the electrochemical anode, thereby increasing the service life of the anode; 3) Interfering with the crystallization and scaling of calcium and carbonate through shock waves (generated by current frequency conversion); 4) The high-frequency shock wave will destroy the metabolic functions of bacteria and microorganisms, thereby achieving a more effective sterilization function.

[0059] After applying the combined process of this embodiment, compared with the conventional chemical reagent method, it has the following comparative advantages, as shown in Table 1 and Table 2 below.

[0060] Table 1

[0061]

[0062]

[0063] Table 2 (taking 10000m 3 / h of net circulating water as an example)

[0064]

[0065] Generally speaking, the present invention introduces the electrochemical scale inhibition water treatment technology into the conventional open-circuit circulating cooling water system, quickly adsorbs and captures scaling ions such as calcium and magnesium onto the scale collector, and crystallizes and precipitates the salt substances in the circulating water. In this way, the concentration ratio of the open-circuit circulating cooling water system can be increased, and the sewage discharged from the open system can be used as the makeup water for the secondary spray water in the closed system. At the same time, a closed crystallization system is introduced to make full use of the heat source in the circulating water, give play to the characteristics of the ECH microcrystal purification technology in dealing with high concentration ratios, make the secondary spray circulating water reach the limit concentration, crystallize and precipitate the salt substances in the water, and achieve water saving and emission reduction of the circulating cooling water. By combining the two water treatment technologies of electrochemical scale inhibition and ECH microcrystal purification in the combined process, the goal requirements of water saving and emission reduction from the source of the circulating cooling water system are achieved.

[0066] The above description of the embodiments is provided to enable those of ordinary skill in the art to understand and use the invention. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative efforts. Therefore, the present invention is not limited to the above embodiments, and all improvements and modifications made by those skilled in the art without departing from the scope of the present invention according to the disclosure of the present invention should be within the protection scope of the present invention.

Claims

1. A combined circulating water treatment device for realizing water saving and emission reduction in the whole plant, characterized in that Comprising: Open cooling water treatment unit: It includes a first cooling tower, a circulating water treatment tank with electrochemical equipment, and a first unit to be cooled, which are connected in sequence to form a cycle. The circulating water treatment tank is also connected with an external circulating water make-up pipeline; Closed crystallization unit: It includes a second cooling tower, an ECH microcrystal unit that can provide ECH microcrystal agent, and a second unit to be cooled. The ECH microcrystal unit is arranged at the bottom of the second cooling tower, and the cooling water flowing down from the upper part of the second cooling tower and treated with ECH microcrystal agent by adding the ECH microcrystal agent in the ECH microcrystal unit also returns to the upper part of the second cooling tower through a first branch. A second branch is led out from the lower part of the second cooling tower and connected to the second unit to be cooled, and then returns to the top of the second cooling tower; A drainage branch is also led out from the circulating water treatment tank and connected to the bottom of the second cooling tower; The ECH microcrystal unit includes an ECH microcrystal tank and an ECH dosing tank connected to the ECH microcrystal tank and internally provided with microcrystal purification materials; A first circulation pump is also provided between the circulating water treatment tank and the first unit to be cooled; A second circulation pump is also provided on the first branch; A third circulation pump is also provided on the first branch.

2. The circulating water treatment combined device for realizing the whole-plant water saving and emission reduction according to claim 1, wherein, The electrochemical equipment is placed in the circulating water treatment tank or on a bypass connecting the circulating water treatment tank. When the electrochemical equipment is placed in the circulating water treatment tank, the circulating water treatment tank includes a treatment tank body with an open top, and the electrochemical equipment includes one or several open electrolytic cells installed in the treatment tank body and communicating with the water body in the treatment tank body.

3. The circulating water treatment combined device for realizing the whole-plant water saving and emission reduction according to claim 2, wherein A scale removal tank connected to the bottom of the open electrolytic cell is also provided at the bottom of the treatment tank body.

4. The combined circulating water treatment device for realizing the water saving and emission reduction of the whole plant according to claim 3, wherein, An electromagnetic valve is also provided at the bottom outlet of the scale removal tank.

5. A combined process for circulating water treatment for realizing water conservation and emission reduction in the whole plant, which is implemented based on the combined device for circulating water treatment as described in claim 1, and is characterized in that, Including the following steps: (1) In the open cooling water treatment unit, the circulating water is cooled by the first cooling tower and then sent into the circulating water treatment tank for electrochemical scale inhibition treatment. The treated circulating water returns to the top of the first cooling tower after passing through the first unit to be cooled, and another part is used as the make-up water for the closed crystallization unit. At the same time, the entire open cooling water treatment unit also replenishes the circulating water through the external circulating water make-up pipeline; (2) In the closed crystallization unit, the circulating water is cooled by the second cooling tower. One part is discharged from the side and sent to the second unit to be cooled for heat exchange, and then returns to the top of the second cooling tower. Another part is discharged into the ECH microcrystal unit, and after purification treatment, it returns to the second cooling tower.

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