A sodium hypochlorite production device

Abstract

The utility model discloses a sodium hypochlorite production device relates to chlor alkali equipment technical field, including sodium hypochlorite reactor and storage tank, sodium hypochlorite reactor inside is equipped with sealed chamber, is equipped with two layers of baffle in the sealed chamber, and the chamber is divided into liquid inlet section, cooling section, liquid outlet section, be equipped with liquid inlet pipe and air inlet pipe on the liquid inlet section lateral wall, be equipped with the air outlet pipe on the liquid outlet section lateral wall, and the liquid outlet section bottom is equipped with the liquid outlet pipe, the liquid outlet pipe is connected with the liquid inlet pipe of storage tank, corresponding through -hole is equipped on two layers of baffle, and cooling pipe passes through the through -hole and enters cooling section and liquid outlet section, still be equipped with the return tube on the liquid inlet section lateral wall, and the return tube is connected with the liquid outlet pipe of storage tank. The device has solved the cooling difficulty of liquid inlet section, and the problem that salt crystallization is easy to produce and blocks the cooling pipe, can make the production process continuously steady.

Description

Technical Field

[0001] This utility model relates to the field of chlor-alkali equipment technology, and in particular to a sodium hypochlorite production device. Background Technology

[0002] In chlor-alkali enterprises, sodium hypochlorite is mostly produced by absorbing chlorine gas with caustic soda. The chemical reaction equation for the production of sodium hypochlorite is as follows:

[0003] Cl₂ + 2NaOH = NaClO + NaCl + H₂O (exothermic)

[0004] Traditional sodium hypochlorite production equipment uses a falling film absorber, which includes an inlet section, a cooling section, and an outlet section. Caustic soda solution and chlorine gas are introduced into the inlet section of the falling film absorber. After mixing, a chemical reaction occurs, releasing a large amount of heat while producing sodium hypochlorite, causing the reaction solution temperature to rise rapidly. When the reaction solution temperature exceeds 60°C, side reactions will occur.

[0005] 3NaClO = NaClO3 + 2NaCl

[0006] To reduce the temperature of the reaction solution and prevent side reactions, a shell-and-tube heat exchanger is installed in the cooling section of the falling film absorber. The reaction solution flows downward from inside the tubes and exchanges heat with the upward-flowing cooling water outside the tubes, removing the heat of reaction and thus reducing the temperature of the reaction solution.

[0007] Although the temperature of the reaction liquid can be reduced by using a shell-and-tube heat exchanger to prevent side reactions, localized overheating can still cause side reactions in the inlet section of the falling film absorber. These side reactions produce large amounts of sodium chlorate and sodium chloride salt crystals, which adhere to the inlet of the shell and tube, causing blockages. Chlorine and alkali solutions remain inside the falling film absorber, leading to increased pressure in the chlorine system pipeline, affecting emergency response capabilities and posing safety hazards. Furthermore, this reduces production efficiency, and frequent equipment maintenance and cleaning increase production costs, affecting the stable supply of products. Summary of the Invention

[0008] The purpose of this invention is to provide a sodium hypochlorite production device that prevents crystallization and blockage.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] A sodium hypochlorite production apparatus includes a sodium hypochlorite reactor and a storage tank. The sodium hypochlorite reactor has a sealed chamber with horizontally arranged upper and lower partitions dividing it into an upper inlet section, a middle cooling section, and a lower outlet section. The inlet section has a first inlet pipe and a first air inlet pipe on its side wall, the outlet section has an air outlet pipe on its side wall, and a first outlet pipe at the bottom of the outlet section. The first outlet pipe is connected to the inlet pipe of the storage tank. The upper partition has evenly spaced first through holes, and the lower partition has corresponding second through holes. A cooling pipe passes through the first through holes into the cooling section and extends downward through the corresponding second through holes to communicate with the outlet section. The upper end of the cooling pipe extends above the upper partition. A return pipe is also provided on the side wall of the inlet section and is connected to the outlet pipe of the storage tank.

[0011] Preferably, a baffle plate is fixedly provided on the upper partition plate, the baffle plate and the upper partition plate form a reaction chamber, the cooling pipes are all arranged in the reaction chamber, and an opening is formed at the top of the reaction chamber; the height of the baffle plate is higher than the first liquid inlet pipe and the liquid return pipe, and lower than the first air inlet pipe, and the first air inlet pipe extends horizontally to the upper part of the reaction chamber.

[0012] Preferably, the top of the baffle plate has a serrated protrusion.

[0013] Preferably, the baffle plate has a liquid inlet hole near the bottom.

[0014] Preferably, the number of liquid inlet holes is 2 to 4, and each liquid inlet hole is evenly spaced along the circumference of the baffle plate.

[0015] Preferably, the inlet end of the first air intake pipe is a slope.

[0016] Preferably, the sodium hypochlorite production apparatus further includes a front reactor, the side wall of which is provided with a second liquid inlet pipe and a second gas inlet pipe, the second gas inlet pipe being connected to the gas outlet pipe of the sodium hypochlorite reactor, the top of which is provided with a vacuum pipe, and the bottom of which is provided with a second liquid outlet pipe.

[0017] This utility model discloses a sodium hypochlorite production apparatus. By installing a reflux pipe in the inlet section of the sodium hypochlorite reactor, the cooled reaction liquid is refluxed back to the inlet section. This not only dilutes the sodium hydroxide solution, reduces the intensity of the chemical reaction between sodium hydroxide and chlorine, and reduces heat release, but also absorbs some of the heat released by the reaction, thereby lowering the temperature of the entire reaction system in the inlet section, preventing side reactions, and thus avoiding the formation of sodium chlorate and sodium chloride crystals in the inlet section. By setting up a pre-reactor, the sodium hydroxide solution reacts with the chlorine tail gas in the pre-reactor before entering the sodium hypochlorite reactor, which can further reduce the concentration of sodium hydroxide solution, reduce the intensity of the chemical reaction between sodium hydroxide and chlorine, and reduce heat release. By installing a baffle plate in the inlet section of the sodium hypochlorite reactor, the contact area between the sodium hydroxide solution and chlorine is increased, effectively reducing reaction fluctuations caused by uneven distribution of alkali solution, and improving the stability and efficiency of the reaction. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the connection of the sodium hypochlorite production device of this utility model;

[0019] Figure 2 This is a perspective view of the sodium hypochlorite reactor of this utility model;

[0020] Figure 3 This is a cross-sectional view of the sodium hypochlorite reactor of this utility model;

[0021] Figure 4 This is a top view of the inlet section of the sodium hypochlorite reactor of this utility model;

[0022] Figure 5 This is a perspective view of the inlet section of the sodium hypochlorite reactor of this utility model; Detailed Implementation

[0023] To better understand the purpose, structure, and function of this utility model, the following description, in conjunction with the accompanying drawings, provides a more detailed account of a sodium hypochlorite production apparatus according to this utility model.

[0024] Reference Figures 1-5As shown, this utility model discloses a sodium hypochlorite production device, including a sodium hypochlorite reactor 1. The sodium hypochlorite reactor 1 is a hollow cylindrical structure. Inside the sodium hypochlorite reactor 1, there is a sealed chamber 2 for containing sodium hydroxide solution and chlorine gas to react chemically. The sealed chamber 2 is provided with an upper partition 3 and a lower partition 4, which are arranged vertically and horizontally, dividing the sealed chamber 2 into three parts from top to bottom: an upper liquid inlet section 5, a middle cooling section 6, and a lower liquid outlet section 7. The side wall of the liquid inlet section 5 is provided with a first liquid inlet pipe 8 and a first air inlet pipe 9. The side wall of the cooling section 6 is provided with a cooling medium inlet and a cooling medium outlet (not shown). The side wall of the liquid outlet section 7 is provided with an air outlet pipe 10, and the bottom of the liquid outlet section 7 is provided with a first liquid outlet pipe 11. The upper partition 3 is provided with first through holes 12 evenly spaced, and the lower partition 4 is provided with corresponding second through holes 11. 3. Cooling pipe 14 enters cooling section 6 through first through hole 12 and extends downward through corresponding second through hole 13 to enter liquid outlet section 7. Sodium hydroxide solution and chlorine gas enter liquid inlet section 5 of sealed chamber 2 through first liquid inlet pipe 8 and first gas inlet pipe 9 respectively. The solution reacts with chlorine gas and releases heat. When the liquid level in liquid inlet section 5 reaches the inlet height of cooling pipe 14, the reaction liquid overflows into cooling pipe 14 and flows downward along the inner wall of cooling pipe 14. A reaction liquid channel is formed inside cooling pipe 14, and the outer wall is in contact with the cooling medium. The heat in the reaction liquid is removed by the temperature difference between the cooling medium and the reaction liquid to reduce the temperature of the reaction liquid. The cooled reaction liquid enters liquid outlet section 7 through cooling section 6 and enters storage tank 24 through first liquid outlet pipe 11 at the bottom of liquid outlet section 7. Chlorine gas that has not participated in the reaction is discharged through gas outlet pipe 10.

[0025] A return pipe 15 is also provided on the side wall of the inlet section 5. Figure 3 The positions of the return pipe 15 and the first inlet pipe 8 on the side wall circumference do not represent their actual positions, but are used to illustrate the height relationship between the return pipe 15 and the baffle plate 16 described below. A portion of the cooled reaction liquid in the storage tank 24 returns to the inlet section 5 through the return pipe 15. By mixing the cooled reaction liquid into the inlet section 5, the concentration of sodium hydroxide solution can be reduced, the intensity of the chemical reaction between sodium hydroxide and chlorine can be reduced, and heat release can be reduced. Moreover, the low-temperature reaction liquid can also absorb some of the heat generated by the chemical reaction, thereby reducing the temperature of the entire reaction system, preventing side reactions, and thus preventing the formation of sodium chlorate and sodium chloride crystals.

[0026] The upper partition 3, the lower partition 4, and the cooling pipe 14 are all made of materials with good thermal conductivity, with titanium being the preferred material due to its low price, corrosion resistance, and excellent thermal conductivity.

[0027] In some embodiments of this utility model, a baffle plate 16 is fixedly provided on the upper partition plate 3. The baffle plate 16 is preferably annular and adapted to the shape of the sodium hypochlorite reactor 1. The annular baffle plate 16 and the upper partition plate 3 form a reaction chamber 17. Cooling pipes 14 are all arranged in the reaction chamber 17. An opening is formed at the top of the reaction chamber 17. The height of the baffle plate 16 is higher than the first liquid inlet pipe 8 and the liquid return pipe 15, and lower than the first air inlet pipe 9. The first air inlet pipe 9 extends horizontally to the upper part of the reaction chamber 17. During the process of sodium hydroxide solution entering the inlet section 5 through the first inlet pipe 8, due to the spraying state of the solution, some sodium hydroxide solution does not fall onto the upper baffle 3, but falls into the cooling pipe 14, resulting in a short contact time between the sodium hydroxide solution and chlorine gas and an incomplete reaction. By setting up the baffle plate 16, the spraying solution can be blocked to prevent it from falling into the cooling pipe 14. In addition, an annular liquid storage area is formed between the side wall of the inlet section 5 and the baffle plate 16. When the liquid storage height in the storage area exceeds the baffle plate 16, the sodium hydroxide solution in the storage area flows down along the inner wall of the baffle plate 16 into the reaction chamber 17. The sodium hydroxide solution forms a uniform liquid film on the inner wall of the baffle plate 16, thereby increasing the contact area between the solution and the chlorine gas in the reaction chamber 17, effectively reducing the reaction fluctuations caused by uneven distribution of alkali solution, and improving the stability and efficiency of the reaction.

[0028] The top of the baffle plate 16 has a serrated protrusion, which divides the sodium hydroxide solution into fine water streams during the overflow process, making the sodium hydroxide solution more evenly distributed as it flows down the inner wall of the baffle plate 16, and further increasing the liquid film area.

[0029] The baffle plate 16 has a liquid inlet hole 18 near the bottom. The number of liquid inlets 18 can be one or more, preferably two to four, and the liquid inlets 18 are evenly spaced along the circumference of the baffle plate 16. Since some of the chlorine gas entering the reaction chamber 17 is deposited on the upper partition plate 3, by providing the liquid inlet hole 18 near the bottom of the baffle plate 16, the sodium hydroxide solution first enters the reaction chamber 17 through the liquid inlet hole 18 at the bottom, and the excess solution overflows into the reaction chamber 17, thereby further increasing the contact time between the solution and the chlorine gas and improving the reaction efficiency. In addition, when the machine is shut down for maintenance, the alkaline solution in the storage area can be discharged through the liquid inlet hole 18 for maintenance purposes.

[0030] The inlet end of the first air inlet pipe 9 is a slope. Setting the inlet end of the first air inlet pipe 9 as a slope can increase the outlet cross-sectional area, making the chlorine gas spray area in the pipe wider, thereby making the chlorine gas distribution relatively uniform, which can improve the contact area and reaction efficiency between chlorine gas and alkaline solution.

[0031] In some embodiments of this utility model, the sodium hypochlorite production apparatus further includes a pre-reactor 19. The pre-reactor 19 has a second liquid inlet pipe 20 and a second gas inlet pipe 21 on its side wall, a vacuum pipe 22 at the top to create a slightly negative pressure state inside the pre-reactor 19, and a second liquid outlet pipe 23 at the bottom. The gas outlet pipe 10 of the sodium hypochlorite reactor 1 is connected to the second gas inlet pipe 21. The chlorine tail gas that has not participated in the reaction in the sodium hypochlorite reactor 1 enters the pre-reactor 19 through the second gas inlet pipe 21. Before entering the sodium hypochlorite reactor 1, the sodium hydroxide solution first enters the pre-reactor 19 to react with the chlorine tail gas, thereby reducing the concentration of the sodium hydroxide solution before entering the sodium hypochlorite reactor 1. This further reduces the intensity of the chemical reaction between sodium hydroxide and chlorine, reduces heat release, and prevents side reactions from occurring.

[0032] The working process of the sodium hypochlorite production device disclosed in this utility model is as follows: Sodium hydroxide solution first enters the pre-reactor 19 through the second inlet pipe 20 and reacts chemically with the chlorine tail gas entering the pre-reactor 19 through the second gas inlet pipe 21. After the reaction is completed, the sodium hydroxide solution enters the inlet section of the sodium hypochlorite reactor 1 through the first inlet pipe and reacts chemically with the chlorine gas from the first gas inlet pipe 9. The reaction liquid overflows into the cooling pipe 14. After cooling, the reaction liquid enters the outlet section 7 and then enters the storage tank 24 through the first outlet pipe 11. The unreacted chlorine tail gas is discharged through the gas outlet pipe 10 and then enters the pre-reactor 19. Part of the reaction liquid in the storage tank 24 is returned to the inlet section 5 of the sodium hypochlorite production device through the return pipe 15, and the remaining reaction liquid is sent to the subsequent process.

[0033] This utility model discloses a sodium hypochlorite production apparatus. By installing a reflux pipe 15 in the inlet section 5 of the sodium hypochlorite reactor 1, the cooled reaction liquid is refluxed back to the inlet section 5. This not only dilutes the sodium hydroxide solution, reduces the intensity of the chemical reaction between sodium hydroxide and chlorine, and reduces heat release, but also absorbs some of the heat released by the reaction, thereby lowering the temperature of the entire reaction system in the inlet section 5, preventing side reactions, and thus avoiding the formation of sodium chlorate and sodium chloride salt crystals in the inlet section 5. By setting up a pre-reactor 19, the sodium hydroxide solution reacts with the chlorine tail gas in the pre-reactor 19 before entering the sodium hypochlorite reactor 1, which can further reduce the concentration of sodium hydroxide solution, reduce the intensity of the chemical reaction between sodium hydroxide and chlorine, and reduce heat release. By installing a baffle plate 16 in the inlet section 5 of the sodium hypochlorite reactor 1, the contact area between the sodium hydroxide solution and chlorine is increased, effectively reducing reaction fluctuations caused by uneven distribution of alkali solution, and improving the stability and efficiency of the reaction.

[0034] In summary, the sodium hypochlorite production apparatus disclosed in this utility model solves the problems of difficult cooling of the inlet section 5 of the sodium hypochlorite reactor 1 and easy salt crystallization clogging the cooling pipe, enabling the production process to proceed continuously and stably, avoiding production interruptions caused by equipment failure, greatly improving production efficiency, reducing equipment maintenance and cleaning work, and lowering labor costs and equipment wear and tear costs.

[0035] It is understood that the present invention has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the invention. Furthermore, under the teachings of the present invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of the present invention.

Claims

1. A sodium hypochlorite production apparatus, characterized in that, The system includes a sodium hypochlorite reactor (1) and a storage tank (24). The sodium hypochlorite reactor (1) has a sealed chamber (2) inside. The sealed chamber (2) is provided with a horizontally arranged upper partition (3) and lower partition (4), which divide the sealed chamber (2) into an upper liquid inlet section (5), a middle cooling section (6), and a lower liquid outlet section (7). The liquid inlet section (5) has a first liquid inlet pipe (8) and a first air inlet pipe (9) on its side wall. The liquid outlet section (7) has an air outlet pipe (10) on its side wall. The liquid outlet section (7) has a first liquid outlet pipe (11) at its bottom. The first outlet pipe (11) is connected to the inlet pipe of the storage tank (24). The upper partition (3) is evenly spaced with first through holes (12), and the lower partition (4) is provided with corresponding second through holes (13). The cooling pipe (14) passes through the first through hole (12) into the cooling section (6) and extends downward through the corresponding second through hole (13) to communicate with the outlet section (7). The upper end of the cooling pipe (14) is higher than the upper partition (3). The side wall of the inlet section (5) is also provided with a return pipe (15), which is connected to the outlet pipe of the storage tank (24).

2. The sodium hypochlorite production apparatus according to claim 1, characterized in that, A baffle plate (16) is fixedly provided on the upper partition plate (3). The baffle plate (16) and the upper partition plate (3) form a reaction chamber (17). The cooling pipes (14) are all arranged in the reaction chamber (17). An opening is formed at the top of the reaction chamber (17). The height of the baffle plate (16) is higher than the first liquid inlet pipe (8) and the liquid return pipe (15) and lower than the first air inlet pipe (9). The first air inlet pipe (9) extends horizontally to the upper part of the reaction chamber (17).

3. The sodium hypochlorite production apparatus according to claim 2, characterized in that, The top of the baffle plate (16) has a serrated protrusion.

4. The sodium hypochlorite production apparatus according to claim 3, characterized in that, The baffle plate (16) has an inlet hole (18) near the bottom.

5. The sodium hypochlorite production apparatus according to claim 4, characterized in that, The number of liquid inlet holes (18) is 2 to 4, and each liquid inlet hole (18) is evenly spaced along the circumference of the baffle plate (16).

6. The sodium hypochlorite production apparatus according to claim 4, characterized in that, The inlet end of the first air intake pipe (9) is a slope.

7. The sodium hypochlorite production apparatus according to claim 1, characterized in that, The sodium hypochlorite production device also includes a front reactor (19), which has a second liquid inlet pipe (20) and a second air inlet pipe (21) on its side wall. The second air inlet pipe (21) is connected to the air outlet pipe (10) of the sodium hypochlorite reactor (1). The front reactor (19) has a vacuum pipe (22) at the top and a second liquid outlet pipe (23) at the bottom.

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