Anti-scale treatment device for Bayer process high-temperature dissolved water cooling system

Abstract

The utility model discloses an anti-scale treatment device for a Bayer process high-temperature dissolved water cooling system, which comprises a dissolved water cooler recovery system, the water inlet end of the dissolved water cooler recovery system is connected to a pumping system of an evaporation sewage treatment station through a water supply pipe system, and the water outlet end of the dissolved water cooler recovery system is connected with heating equipment through a water return pipe. The steam inlet end is connected with the dead steam outlet end of the dilution tank, and an auxiliary pipe for adding a scale inhibitor is arranged on the water supply pipe system and / or the water return pipe. The device is simple in structure, low in cost and high in operation convenience, continuous and efficient operation of the whole production line can be guaranteed, and cleaning and maintenance cost and human input are saved; in addition, in the adding process of the scale inhibitor, the scaling severity of the inner wall of the water return pipe is monitored in real time, the flow speed of the scale inhibitor is adjusted, the good scale inhibition effect can be guaranteed, the adding amount of the scale inhibitor can be greatly reduced, the use cost is saved, and good economic practicability is achieved.

Description

Technical Field

[0001] The utility model relates to a scale prevention and treatment device for a high-temperature dissolution water cooling system of a Bayer process, belonging to the technical field of producing alumina by the Bayer process. Background Art

[0002] Industrial wastewater refers to wastewater and waste liquids generated during industrial production, which contain pollutants that are lost through the water. With the rapid development of industry, the types and quantities of wastewater have increased dramatically, and water pollution has become increasingly widespread and serious, posing a threat to human health and safety. The best way to treat wastewater is through recycling. In recent years, with increased efforts to protect the environment, many Bayer-process alumina producers have optimized their production processes, reusing wastewater generated during the Bayer process and achieving zero wastewater discharge.

[0003] Currently, the highly alkaline wastewater generated during the Bayer process, the highly concentrated desalinated wastewater from power plants, cooling water for some equipment, and domestic sewage from the entire plant are all treated in evaporative wastewater treatment plants. These are then pumped into the dissolution water cooler via evaporative reuse water pumps as the cooling water medium for the waste heat absorption of the dilution tank's exhaust steam. This water is commonly referred to as evaporative reuse water in production. Evaporative reuse water is characterized by high alkalinity, high hardness, and high turbidity, with a pH of 9-12, a total hardness of 80-100 mg / l, and a turbidity greater than 80 NTU. After forced convection heat exchange through the dissolution water cooler, the outlet water temperature can reach 90°C or above. Under high temperature conditions, this water rapidly scales in the outlet pipe, causing the outlet pipe diameter to gradually change, ultimately leading to poor water discharge from the dissolution water cooler and affecting the normal operating cycle of the dissolution unit. The typical operating cycle of a dissolution unit is about 40 days. Due to severe scaling in the outlet pipe of the dissolution water cooler, which can be as thick as 30mm, the dissolution water cooler is blocked, forcing the unit to be shut down for pipe cleaning. This shortens the dissolution unit's operating cycle. Frequent pipe cleaning is not only time-consuming and labor-intensive, but also affects production, increases production costs, and causes significant economic losses. Utility Model Content

[0004] In view of this, the purpose of the present invention is to provide a scale prevention and treatment device for a Bayer process high-temperature dissolution water cooling system, which can overcome the shortcomings of the existing technology.

[0005] The purpose of this utility model is achieved through the following technical solutions:

[0006] The utility model discloses an anti-scaling treatment device for a Bayer process high-temperature dissolution water cooling system, comprising a dissolution water cooler recovery system, wherein the water inlet end of the dissolution water cooler recovery system is connected to the pumping system of an evaporative sewage treatment station through a water supply pipe system, the water outlet end is connected to a heating device through a return pipe, and the steam inlet end is connected to the exhaust steam outlet end of a dilution tank, and an auxiliary pipe for adding a scale inhibitor is provided on the water supply pipe system and / or the return pipe.

[0007] Furthermore, a regulating valve is provided on the auxiliary pipe.

[0008] Furthermore, a regulating device for regulating the flow rate of the scale inhibitor is provided in the water supply pipe system and the return pipe.

[0009] Furthermore, the regulating device includes an inner tube arranged in the water supply pipe system and the return pipe and having several seepage holes. There is a gap between the inner tube and the water supply pipe system and the return pipe. Several flow-blocking protrusions are arranged in the gap, and the flow-blocking protrusions are arranged on the downstream side of the seepage holes.

[0010] Furthermore, the flow-blocking protrusion is a square or triangular flow-blocking block.

[0011] Furthermore, the inner tube and the flow-blocking protrusion are an integrated structure, or the flow-blocking protrusion is fixed to the outer circumferential surface of the inner tube by welding.

[0012] Furthermore, the flow-blocking protrusion is arranged at a certain angle relative to the outer circumferential surface of the inner tube.

[0013] Furthermore, the angle is 45-90 degrees.

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

[0015] The utility model has a simple structure and low cost. It sends the high-alkalinity and high-hardness wastewater from the evaporation sewage treatment station in the Bayer process production process into the dissolution water cooler through the water supply pipe system, and recovers the waste heat of the exhaust steam from the dissolution dilution tank. Due to the high water temperature at the outlet of the dissolution water cooler, which is generally 90°C or above, the outlet pipe of the dissolution water cooler is easily scaled, resulting in poor water discharge and affecting the operation cycle of the dissolution unit. In order to suppress the scaling rate of the outlet pipe of the dissolution water cooler, it sends the preheated wastewater from the Bayer process production process into the dissolution water cooler recovery system through the water supply pipe system for waste heat recovery. At the same time, according to the total water inlet of the dissolution water cooler recovery system, a scale inhibitor is quantitatively added to the water supply pipe system and / or the return pipe. This effectively solves the problems pointed out in the background technology that when the existing dissolution water cooler recovery system recovers wastewater, the heated return water will cause serious scaling of the return pipe, the pipe cleaning is time-consuming and labor-intensive, and affects the operation of the entire production line. The high ease of operation can ensure the continuous and efficient operation of the entire production line, saving cleaning and maintenance costs and manpower input; in addition, during the scale inhibitor addition process, the severity of scaling on the inner wall of the return pipe is monitored in real time, and the flow rate of the scale inhibitor is adjusted, which can not only ensure a good scale inhibition effect, but also greatly save the amount of scale inhibitor added, save the cost of use, and has good economic practicality.

[0016] Other advantages, objectives, and features of the present invention will be described in detail in the following description and, to some extent, will be apparent to those skilled in the art upon examination and study of the following or may be learned from practice of the present invention. The objectives and other advantages of the present invention may be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings, in which:

[0018] Figure 1 This is a block diagram of the structural principle of Example 1 of the present utility model;

[0019] Figure 2 This is a block diagram of the structural principle of Example 2 of the present utility model;

[0020] Figure 3 Schematic diagram of the structure of the regulating device 4 Figure 1 ;

[0021] Figure 4 Schematic diagram of the structure of the regulating device 4 Figure 2 .

[0022] In the figure, 1. water supply pipe system; 2. dissolution water cooler recovery system; 3. return pipe; 4. regulating device; 401. inner pipe 401; 402. seepage hole; 403. flow-blocking protrusion; 5. auxiliary pipe; 6. regulating valve. DETAILED DESCRIPTION

[0023] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the preferred embodiments are only for illustrating the present invention and are not intended to limit the scope of protection of the present invention.

[0024] like Figure 1-Figure 4 As shown, a scale prevention and treatment device for a Bayer process high-temperature dissolution water cooling system includes a dissolution water cooler recovery system 2, the water inlet end of the dissolution water cooler recovery system 2 is connected to the evaporative sewage treatment station pumping system through a water supply pipe system 1, the water outlet end is connected to the heating equipment through a return pipe 3, and the steam inlet end is connected to the exhaust steam outlet end of the dilution tank. An auxiliary pipe 5 for adding scale inhibitors is provided on the water supply pipe system 1 and / or the return pipe 3.

[0025] A regulating valve 6 is provided on the auxiliary pipe 5. The regulating valve 6 can be used to adjust the opening and closing of the auxiliary pipe 5 or the amount of scale inhibitor added.

[0026] A regulating device 4 for adjusting the flow rate of the scale inhibitor is provided within the water supply pipe system 1 and the return pipe 3. Specifically, the regulating device 4 includes an inner tube 401 disposed within the water supply pipe system 1 and the return pipe 3 and having a plurality of seepage holes 402. A gap is left between the inner tube 401 and the water supply pipe system 1 and the return pipe 3, and a plurality of flow-blocking protrusions 403 are arranged within the gap. The flow-blocking protrusions 403 are located downstream of the seepage holes.

[0027] The flow-blocking protrusion 403 can be a square or triangular block. Specifically, the inner tube 401 and the flow-blocking protrusion 403 are integrally formed, or the flow-blocking protrusion 403 is welded to the outer circumference of the inner tube 401. Furthermore, the flow-blocking protrusion 403 is positioned at an angle relative to the outer circumference of the inner tube 401. The angle can be 45-90 degrees. During the flow of the scale inhibitor, the flow rate of the scale inhibitor is regulated by the flow-blocking protrusion 403, which facilitates the slow flow of the scale inhibitor from the seepage holes 402 into the return pipe 3, thereby increasing the scale inhibitor's reaction time.

[0028] Working principle and process of the device:

[0029] The high-alkalinity and high-hardness wastewater from the evaporation sewage treatment station in the Bayer process production process is sent to the dissolution water cooler recovery system 2 through the water supply pipe system 1 for waste heat recovery. At the same time, according to the total water inlet volume of the dissolution water cooler recovery system 2, high-temperature scale inhibitors are quantitatively added to the water supply pipe system 1 and / or the return pipe 3 through the corresponding auxiliary pipe 5. During the addition process, the severity of scaling on the inner wall of the return pipe 3 is monitored in real time to adjust the flow rate of the scale inhibitor.

[0030] At 500-550m 3 / h of total water inflow, the concentration of scale inhibitor is 10-15ppm, and the effective dosage is 5-15kg / h.

[0031] The scale inhibitor is ZC-506C.

[0032] The specific method for adjusting the flow rate of the antiscalant is:

[0033] s1. Real-time online monitoring of the instantaneous flow rate of return water in the return pipe 3, calculation of the pipe cross-sectional area, and then judgment of the severity of scaling on the inner wall of the pipe;

[0034] s2. According to the severity of the scaling on the inner wall of the pipeline, adjust the flow rate of the scale inhibitor so that the flow rate of the scale inhibitor slows down as the scaling on the inner wall of the pipeline deepens, thereby increasing the reaction time of the scale inhibitor.

[0035] In step s1, the instantaneous flow rate of the return water in the return pipe 3 is monitored online in real time, and the cross-sectional area of ​​the pipe is calculated to determine the severity of the scaling on the inner wall of the pipe. The calculation formula is:

[0036] Pipe cross-sectional area = flow rate / flow velocity,

[0037] Where, the flow rate is the online monitoring value at the outlet of return pipe 3;

[0038] The flow rate is the average water inlet velocity at the inlet end of the dissolution water cooler recovery system 2.

[0039] In step s2, according to the severity of scaling on the inner wall of the pipeline, antiscalant is slowly added into the water supply pipe system 1 and / or the return pipe 3, and the antiscalant flow rate: wastewater flow rate = 1-1.5:2.

[0040] Specifically, according to the concentration and amount of scale inhibitor added, the scale inhibitor can be directly added slowly into the water supply pipe system 1, and the scale inhibitor will flow through the water supply pipe system 1, the dissolution water cooler, and the return pipe 3 in sequence along with the water flow, thereby achieving scale prevention for the entire system pipeline. Alternatively, the scale inhibitor can be slowly added into the water supply pipe system 1 and the return pipe 3 simultaneously. Since the water temperature in the return pipe 3 is relatively high and scale is more likely to form, the amount of scale inhibitor added into the water supply pipe system 1 and the return pipe 3 is adjusted separately to ensure that the amount of scale inhibitor added is reduced while improving the scale prevention effect. Alternatively, the scale inhibitor can be slowly added into the water supply pipe system 1 first, and the instantaneous flow rate of the return water in the return pipe 3 is monitored online in real time, the cross-sectional area of ​​the pipe is calculated, and then the severity of the scale formation on the inner wall of the pipe is judged. When the scale inhibitor added into the water supply pipe system 1 cannot meet the needs of the return pipe 3, the scale inhibitor is slowly added into the return pipe 3.

[0041] A regulating device 4 can be installed in the water supply pipe system 1 and the return pipe 3 to adjust the flow rate of the scale inhibitor. Specifically, an inner tube 401 with several seepage holes 402 is installed in the return pipe 3. A gap is left between the inner tube 401 and the water supply pipe system 1 and the return pipe 3. Several flow-blocking protrusions 403 are arranged in the gap. The flow-blocking protrusions 403 are located downstream of the seepage holes. Wastewater passes through the inner tube 401, while the scale inhibitor passes through the gap between the inner tube 401 and the return pipe 3. During the flow of the scale inhibitor, the flow rate of the scale inhibitor is regulated by the flow-blocking protrusions 403, so that the scale inhibitor flows slowly from the seepage holes 402 into the return pipe 3, increasing the scale inhibitor reaction time and improving the scale inhibition effect.

[0042] The flow-blocking protrusion 403 may be a square or triangular flow-blocking block.

[0043] The flow-blocking protrusion 403 can be fixedly attached to the outer circumference of the inner tube 401 and positioned at a predetermined angle relative to the outer circumference of the inner tube 401. The angle can be between 45 and 90 degrees. During the flow of the scale inhibitor, the flow-blocking protrusion 403 regulates the flow rate of the scale inhibitor and facilitates the slow flow of the scale inhibitor from the seepage holes 402 into the return pipe 3, thereby increasing the scale inhibitor's reaction time.

[0044] The flow rate of the scale inhibitor can be adjusted by changing the size of the seepage holes 402 , the number of the flow-blocking protrusions 403 , or the angle between the flow-blocking protrusions 403 and the outer circumferential surface of the inner tube 401 .

[0045] Example 1

[0046] Taking the evaporation return water treatment in the Bayer process of producing alumina as an example

[0047] 1. Use six groups of dissolution water cooler recovery system 2 to carry out evaporation return water treatment.

[0048] 2. The water cooler operates for 40 days.

[0049] 3. Antiscalant addition:

[0050] (3.1) When the six groups of dissolution water cooler recovery systems were not using scale inhibitors, the scale in their return pipes was very serious, with the scale thickness of the pipes being 25mm and 28mm respectively.

[0051] (3.2) Add antiscalant to the six groups of dissolution water cooler recovery systems as follows:

[0052] The average total water inflow of the first group of dissolution water cooler recovery system is 521.5m 3 / h, scale inhibitor is added from the water supply pipe system 1, the effective dosage concentration of scale inhibitor is 14.87ppm, the monthly scale inhibitor addition amount is about 12kg / h, and no regulating device is set in the water supply pipe system 1 and the return pipe 3;

[0053] The average total water inflow of the second group of dissolution water cooler recovery system is 521.5m 3 / h, scale inhibitor is added from the water supply pipe system 1, the effective dosage concentration of scale inhibitor is 14.87ppm, the monthly scale inhibitor addition amount is about 12kg / h, and no regulating device is set in the water supply pipe system 1 and the return pipe 3;

[0054] The average total water inflow of the third group of dissolution water cooler recovery system is 521.5m 3 / h, scale inhibitor is added synchronously from the water supply pipe system 1 and the return pipe 3. The effective dosage concentration of scale inhibitor is 14.87ppm. The monthly scale inhibitor addition amount is about 8kg / h. No regulating device is set in the water supply pipe system 1 and the return pipe 3.

[0055] The average total water inflow of the fourth group of dissolution water cooler recovery system is 521.5m 3 / h, scale inhibitor is added from the water supply pipe 1 and the return pipe 3. The effective dosage concentration of scale inhibitor is 14.87ppm. The dosage ratio of water supply pipe 1 and return pipe 3 is 1:1.5. The monthly scale inhibitor addition amount is about 8kg / h. No regulating device is installed in the water supply pipe 1 and return pipe 3.

[0056] The average total water inflow of the fifth group of dissolution water cooler recovery system is 521.5m 3 / h, scale inhibitor is added to the water supply pipe 1 and return pipe 3 in sequence. The effective dosage concentration of scale inhibitor is 14.87ppm. The dosage ratio of water supply pipe 1 and return pipe 3 is 1:1.5. The monthly scale inhibitor addition amount is about 6kg / h. No regulating device is installed in the water supply pipe 1 and return pipe 3.

[0057] The average total water inflow of the sixth group of dissolution water cooler recovery system is 521.5m 3 / h, scale inhibitors are added to the water supply pipe system 1 and the return pipe 3 in sequence. The effective dosage concentration of the scale inhibitor is 14.87ppm, and the dosage ratio of the water supply pipe system 1 and the return pipe 3 is 1:1.5. The monthly scale inhibitor addition amount is about 6kg / h, and no regulating device is installed in the water supply pipe system 1 and the return pipe 3.

[0058] 4. Conclusion

[0059] The thickness of the scar on the return pipe wall (the appropriate measurement position at the connection between the return pipe and the dissolution water cooler) is used as the calculation basis. The calculation formula is as follows:

[0060] Scale inhibition efficiency = (scar thickness before use - scar thickness after use) / scar thickness before use * 100%.

[0061] Table 1. Scale inhibition efficiency of return pipes in six groups of dissolution water cooler recovery systems

[0062]

[0063] As shown in Table 1, after adding the scale inhibitor to the evaporation return water, the scale buildup on the upper and lower pipes of the dissolution water cooler was significantly reduced. The scale inhibition efficiency of all six dissolution water coolers reached over 90%, demonstrating that adding the scale inhibitor can achieve a good scale inhibition effect. Furthermore, properly adjusting the scale inhibitor addition method can significantly improve the scale inhibition effect while reducing the amount of scale inhibitor added.

[0064] Example 2

[0065] Taking the evaporation return water treatment in the Bayer process of producing alumina as an example

[0066] 1. Use six groups of dissolution water cooler recovery system 2 to carry out evaporation return water treatment.

[0067] 2. The water cooler operates for 40 days.

[0068] 3. Antiscalant addition:

[0069] (3.1) When the six groups of dissolution water cooler recovery systems were not using scale inhibitors, the scale in their return pipes was very serious, with the scale thickness of the pipes being 22mm and 23mm respectively.

[0070] (3.2) Add antiscalant to the six groups of dissolution water cooler recovery systems as follows:

[0071] The average total water inflow of the first group of dissolution water cooler recovery system is 554.1m 3 / h, scale inhibitor is added from the water supply pipe system 1, the effective dosage concentration of scale inhibitor is 11.07ppm, the monthly scale inhibitor addition amount is about 5kg / h, and no regulating device is set in the water supply pipe system 1 and the return pipe 3;

[0072] The average total water inflow of the second group of dissolution water cooler recovery system is 554.1m 3 / h, scale inhibitor is added from the water supply pipe system 1, the effective dosage concentration of scale inhibitor is 11.07ppm, the monthly scale inhibitor addition amount is about 5kg / h, and no regulating device is set in the water supply pipe system 1 and the return pipe 3;

[0073] The average total water inflow of the third group of dissolution water cooler recovery system is 554.1m 3 / h, scale inhibitor is added synchronously from the water supply pipe system 1 and the return pipe 3. The effective dosage concentration of scale inhibitor is 11.07ppm. The monthly scale inhibitor addition amount is about 5kg / h. No regulating device is set in the water supply pipe system 1 and the return pipe 3.

[0074] The average total water inflow of the fourth group of dissolution water cooler recovery system is 554.1m 3 / h, scale inhibitor is added from the water supply pipe 1 and the return pipe 3. The effective dosage concentration of scale inhibitor is 11.07ppm. The dosage ratio of water supply pipe 1 and return pipe 3 is 1:1.7. The monthly scale inhibitor addition amount is about 5kg / h. No regulating device is installed in the water supply pipe 1 and return pipe 3.

[0075] The average total water inflow of the fifth group of dissolution water cooler recovery system is 554.1m 3 / h, scale inhibitor is added to the water supply pipe 1 and return pipe 3 in sequence. The effective dosage concentration of scale inhibitor is 11.07ppm, and the dosage ratio of water supply pipe 1 and return pipe 3 is 1:1.7. The monthly scale inhibitor addition amount is about 5kg / h, and no regulating device is installed in the water supply pipe 1 and return pipe 3;

[0076] The average total water inflow of the sixth group of dissolution water cooler recovery system is 554.1m 3 / h, scale inhibitors are added to the water supply pipe system 1 and the return pipe 3 in sequence. The effective dosage concentration of the scale inhibitor is 11.07ppm, and the dosage ratio of the water supply pipe system 1 and the return pipe 3 is 1:1.7. The monthly scale inhibitor addition amount is about 5kg / h, and no regulating device is installed in the water supply pipe system 1 and the return pipe 3.

[0077] 4. Conclusion

[0078] The thickness of the scar on the return pipe wall (the appropriate measurement position at the connection between the return pipe and the dissolution water cooler) is used as the calculation basis. The calculation formula is as follows:

[0079] Scale inhibition efficiency = (scar thickness before use - scar thickness after use) / scar thickness before use * 100%.

[0080] Table 2. Scale inhibition efficiency of return pipes in six groups of dissolution water cooler recovery systems

[0081]

[0082] As can be seen from Table 2, the scale inhibition effect is significantly worse when the scale inhibitor concentration is reduced from 15ppm to 11ppm. In order to achieve a better scale inhibition effect, it is not advisable to further reduce the scale inhibitor concentration. However, by properly adjusting the scale inhibitor addition method, the scale inhibition effect can be greatly improved.

[0083] Example 3

[0084] Taking the evaporation return water treatment in the Bayer process of producing alumina as an example

[0085] 1. Use six groups of dissolution water cooler recovery system 2 to carry out evaporation return water treatment.

[0086] 2. The water cooler operates for 40 days.

[0087] 3. Antiscalant addition:

[0088] (3.1) When the six groups of dissolution water cooler recovery systems were not using scale inhibitors, the scale in their return pipes was very serious, with the scale thickness of the pipes being 24mm and 23mm respectively.

[0089] (3.2) Add antiscalant to the six groups of dissolution water cooler recovery systems as follows:

[0090] The average total water inflow of the first group of dissolution water cooler recovery system is 554.1m 3 / h, scale inhibitor is added from the water supply pipe system 1, the effective dosage concentration of scale inhibitor is 11.07ppm, the monthly scale inhibitor addition amount is about 5kg / h, and no regulating device is set in the return pipe 3;

[0091] The average total water inflow of the second group of dissolution water cooler recovery system is 554.1m 3 / h, scale inhibitor is added from the water supply pipe system 1, the effective dosage concentration of scale inhibitor is 11.07ppm, the monthly scale inhibitor addition amount is about 5kg / h, and no regulating device is set in the return pipe 3;

[0092] The average total water inflow of the third group of dissolution water cooler recovery system is 554.1m 3 / h, scale inhibitor is added synchronously from the water supply pipe system 1 and the return pipe 3. The effective dosage concentration of the scale inhibitor is 11.07ppm. The monthly scale inhibitor addition amount is about 5kg / h, and no regulating device is set in the return pipe 3;

[0093] The average total water inflow of the fourth group of dissolution water cooler recovery system is 554.1m 3 / h, scale inhibitor is added from the water supply pipe 1 and the return pipe 3. The effective dosage concentration of scale inhibitor is 11.07ppm. The dosage ratio of water supply pipe 1 and return pipe 3 is 1:1.7. The monthly scale inhibitor addition amount is about 5kg / h, and no regulating device is set in the return pipe 3.

[0094] The average total water inflow of the fifth group of dissolution water cooler recovery system is 554.1m 3 / h, scale inhibitor is added to the water supply pipe 1 and the return pipe 3 in sequence. The effective dosage concentration of the scale inhibitor is 11.07ppm, and the dosage ratio of the water supply pipe 1 and the return pipe 3 is 1:1.7. The monthly scale inhibitor addition amount is about 5kg / h, and no regulating device is installed in the return pipe 3;

[0095] The average total water inflow of the sixth group of dissolution water cooler recovery system is 554.1m 3 / h, scale inhibitor is added to the water supply pipe system 1 and the return pipe 3 in sequence. The effective dosage concentration of the scale inhibitor is 11.07ppm, the dosage ratio of the water supply pipe system 1 and the return pipe 3 is 1:1.7, the monthly scale inhibitor addition amount is about 5kg / h, and no regulating device is set in the return pipe 3.

[0096] 4. Conclusion

[0097] The thickness of the scar on the return pipe wall (the appropriate measurement position at the connection between the return pipe and the dissolution water cooler) is used as the calculation basis. The calculation formula is as follows:

[0098] Scale inhibition efficiency = (scar thickness before use - scar thickness after use) / scar thickness before use * 100%.

[0099] Table 3. Scale inhibition efficiency of return pipes in six groups of dissolution water cooler recovery systems

[0100]

[0101] As can be seen from Table 3, although the scale inhibition effect is significantly poorer when the scale inhibitor concentration is reduced from 15ppm to 11ppm, by reasonably adjusting the addition method of the scale inhibitor and adding a regulating device to increase the scale inhibitor reaction time, the scale inhibitor usage can be saved while improving the scale inhibition effect.

[0102] The above description is only a preferred embodiment of the present invention and does not constitute any form of confidentiality restriction on the present invention. Any simple modification, equivalent change and modification of the above embodiment made based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A scale prevention and treatment device for a Bayer process high-temperature dissolution water cooling system, comprising a dissolution water cooler recovery system (2), wherein the water inlet of the dissolution water cooler recovery system (2) is connected to the evaporative wastewater treatment station pumping system through a water supply pipe system (1), the water outlet is connected to the heating equipment through a return pipe (3), and the steam inlet is connected to the exhaust steam outlet of the dilution tank, characterized in that: An auxiliary pipe (5) for adding a scale inhibitor is provided on the water supply pipe system (1) and / or the return pipe (3); a regulating device (4) for regulating the flow rate of the scale inhibitor is provided in the water supply pipe system (1) and the return pipe (3); the regulating device (4) comprises an inner pipe (401) provided in the water supply pipe system (1) and the return pipe (3) and having a plurality of seepage holes (402); a gap is left between the inner pipe (401) and the water supply pipe system (1) and the return pipe (3); a plurality of flow-blocking protrusions (403) are arranged in the gap, and the flow-blocking protrusions (403) are provided on the downstream side of the seepage holes.

2. The anti-scaling treatment device for the Bayer process high-temperature dissolution water cooling system according to claim 1, characterized in that: The auxiliary pipe (5) is provided with a regulating valve (6).

3. The anti-scaling treatment device for the Bayer process high-temperature dissolution water cooling system according to claim 1, characterized in that: The flow-blocking protrusion (403) is a square or triangular flow-blocking block.

4. The anti-scaling treatment device for the Bayer process high-temperature dissolution water cooling system according to claim 3, characterized in that: The inner tube (401) and the flow-blocking protrusion (403) are an integrated structure, or the flow-blocking protrusion (403) is fixedly connected to the outer circumferential surface of the inner tube (401) by welding.

5. The anti-scaling treatment device for the Bayer process high-temperature dissolution water cooling system according to claim 4, characterized in that: The flow-blocking protrusion (403) is arranged at a certain angle relative to the outer circumferential surface of the inner tube (401).

6. The anti-scaling treatment device for the Bayer process high-temperature dissolution water cooling system according to claim 5, characterized in that: The angle is 45-90 degrees.

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