An alkali dissolving device

Abstract

This utility model relates to an alkali-dissolving device, including an alkali-dissolving tank with a jacket on its outer side. A steam delivery pipe and a condensate return pipe are located at the top of the tank. A U-shaped liquid seal pipe is installed on the condensate return pipe. A heat exchanger is installed on the U-shaped liquid seal pipe and the steam delivery pipe. The alkali-dissolving tank is equipped with a stirring device, a first temperature sensor, and a liquid level sensor. The stirring device includes a stirring shaft, stirring blades, and a stirring motor. A first circulating water delivery pipe is installed on the jacket, and a first regulating valve, a first liquid flow sensor, a second temperature sensor, and a first booster pump are installed on the first circulating water delivery pipe. This device can reduce the volume of anhydrous methanol that cannot participate in the reaction between anhydrous methanol and sodium hydroxide due to evaporation from the alkali-dissolving tank when heated. This utility model is easy to use and has broad market prospects.

Description

Technical Field

[0001] This utility model relates to the field of alkali dissolving equipment, specifically to an alkali dissolving device. Background Technology

[0002] Sodium methoxide is the most basic sodium alkoxide, also known as sodium methoxy. At room temperature and pressure, it is a white powder. Sodium methoxide solution is a colorless, viscous liquid with a boiling point above 450℃. It is soluble in methanol and ethanol, and readily soluble in water. It is particularly sensitive to air and water, readily decomposing in water to produce methanol and sodium hydroxide. It is insoluble in benzene, toluene, etc. Sodium methoxide in methanol is a colorless or slightly yellow viscous liquid. Currently, there are two main production methods: the metallic sodium method and the alkaline method. The metallic sodium method involves the direct reaction of solid or molten metallic sodium with lower alcohols to produce sodium methoxide and hydrogen. The advantages of this method are high purity of sodium methoxide, simple process, and low equipment cost. The disadvantages are the high price of raw material metallic sodium and high industrialization costs. The alkaline method involves the reaction of methanol and sodium hydroxide to produce sodium methoxide and water. The advantages of this method are cheap and readily available raw materials, lower cost, and safe operation. However, because it is a reversible reaction, it is prone to incomplete reaction, often resulting in free alkali in the product. Simultaneously, separation operations such as distillation are necessary to minimize impurities.

[0003] Currently, the mainstream production process involves using liquid sodium hydroxide instead of solid sodium hydroxide in a countercurrent distillation column with methanol. Replacing solid sodium hydroxide with liquid sodium hydroxide reduces both methanol vapor and solid sodium hydroxide consumption, thus lowering production costs. The liquid sodium hydroxide mentioned in this article refers to the crude sodium methoxide methanol solution produced by the reaction of solid sodium hydroxide and anhydrous methanol. Because the reaction between solid sodium hydroxide and anhydrous methanol is exothermic and water is generated during the reaction, the crude sodium methoxide methanol solution has a high water content. Therefore, as the liquid feedstock in the sodium methoxide synthesis column, the water is gradually removed during the distillation process to form a refined sodium methoxide methanol solution with a lower water content. Since the reaction between solid sodium hydroxide and anhydrous methanol is exothermic, without intervention, the heat generated during the reaction will cause methanol in the liquid phase to volatilize, leading to a reduction in the liquid phase and causing the volume of the produced sodium methoxide methanol solution to fall below the predetermined range. Furthermore, since water is produced as a product of the reaction between solid sodium hydroxide and anhydrous methanol, and the boiling point of anhydrous methanol is lower than that of water, the proportion of methanol in the vapor released by solid sodium hydroxide and anhydrous methanol due to heating is higher. The increased volatilization of anhydrous methanol will also lead to the moisture content of the crude sodium methoxide methanol solution exceeding the standard.

[0004] However, excessively low temperatures can also slow down the reaction. Therefore, in the reaction process of anhydrous methanol and sodium hydroxide, the reaction temperature needs to be controlled within a preset range to ensure that the reaction proceeds normally and that the volume of the crude sodium methoxide solution produced as an intermediate product is within the preset range, preventing excessive production of methanol vapor. Furthermore, the existing technology still has room for improvement, aiming to increase the utilization rate of the methanol solution, that is, to reduce the amount of methanol that cannot participate in the reaction process due to thermal volatilization during the reaction of anhydrous methanol and sodium hydroxide at a suitable reaction temperature. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a dissolving device that reduces the volume of anhydrous methanol that cannot participate in the reaction between anhydrous methanol and sodium hydroxide due to thermal volatilization and escape from the dissolving tank, thereby overcoming the deficiencies in existing technologies.

[0006] The technical solution adopted by this utility model is as follows: an alkali dissolving device, including an alkali dissolving tank, a jacket is provided on the outside of the alkali dissolving tank, the top of the alkali dissolving tank is provided with an inlet end of a steam conveying pipe and an outlet end of a condensate return pipe, the outlet end of the condensate return pipe is provided with an outlet end of a U-shaped liquid seal pipe, the inlet end of the U-shaped liquid seal pipe and the outlet end of the steam conveying pipe are provided with heat source channels of a heat exchanger, the alkali dissolving tank is provided with a stirring device, a first temperature sensor and a liquid level sensor, the stirring device includes a stirring shaft provided on the alkali dissolving tank, stirring blades provided on the stirring shaft inside the alkali dissolving tank and a stirring motor drivenly connected to the stirring shaft, a first circulating water conveying pipe is provided at the inlet end of the jacket, and a first regulating valve, a first liquid flow sensor, a second temperature sensor and a first booster pump are sequentially arranged along the direction from near the jacket to away from the jacket on the first circulating water conveying pipe.

[0007] Preferably, the top of the alkali dissolving tank is provided with the outlet end of the caustic soda flake conveying pipe, and the caustic soda flake conveying pipe is provided with a first feeder, a first butterfly valve, a weighing tank, a second feeder, and a second butterfly valve in sequence along the direction from near to far from the alkali dissolving tank. The first feeder and the second feeder are each provided with a feeding motor.

[0008] Preferably, the first circulating water delivery pipe between the first liquid flow sensor and the second temperature sensor is provided with the inlet end of the second circulating water delivery pipe, the outlet end of the second circulating water delivery pipe is connected to the inlet end of the heat exchanger cold source channel, the second circulating water delivery pipe is provided with the second regulating valve and the second liquid flow sensor, the outlet end of the heat exchanger cold source channel is provided with the inlet end of the third circulating water delivery pipe, and the third circulating water delivery pipe is provided with the third temperature sensor.

[0009] Preferably, the bottom of the alkali dissolving tank is provided with a first connecting pipe, the bottom of the first connecting pipe is provided with a first connecting flange, a filter pipe is provided inside the first connecting flange and the first connecting pipe, the filter pipe adopts a cylindrical structure with an open bottom made of microporous filter plate, a second connecting flange is provided on the filter pipe below the first connecting flange, a first sealing ring is provided between the first connecting flange and the second connecting flange, a first fastening bolt is provided on the second connecting flange and the first connecting flange, the inlet end of the filter pipe is provided with a connector, and the outlet end of the connector is provided with an intermediate product conveying pipe.

[0010] Preferably, the intermediate product conveying pipe is provided with a first pressure sensor, a third regulating valve and a second booster pump in sequence along the direction from near the connector to away from the connector, and the alkali dissolving tank is provided with a second pressure sensor.

[0011] Preferably, the bottom of the filter tube adopts a stepped structure including a large end and a small end. The structure at the top of the connector and the structure at the bottom of the filter tube are matched. The small end of the filter tube is fitted onto the top of the connector. A second sealing ring is provided between the small end of the filter tube and the connector. A connecting wing plate is provided on the outside of the connector. The number of connecting wing plates is several. The several connecting wing plates are evenly distributed in a star shape on the outside of the connector. The bottom of a second fastening bolt is hinged to each connecting wing plate. The top of the second fastening bolt is fitted onto the first connecting flange. Each of the several second fastening bolts above the first connecting flange is provided with a fastening nut.

[0012] The beneficial effects of this utility model are as follows: First, this utility model delivers the steam produced during the reaction of anhydrous methanol and sodium hydroxide in the alkali dissolving tank to the heat source channel of the heat exchanger and the second part of the circulating water continuously delivered to the cold source channel of the heat exchanger. After heat exchange and liquefaction, the liquefied water is sent back to the alkali dissolving tank to continue participating in the reaction of anhydrous methanol and sodium hydroxide. The liquefied steam sent back to the alkali dissolving tank after liquefaction serves as an auxiliary cooling source for the reaction of anhydrous methanol and sodium hydroxide in the alkali dissolving tank. The remaining heat is absorbed by the first part of the circulating water continuously delivered to the jacket, thereby ensuring that the parameters fed back by the first temperature sensor are always within the preset range, thus reducing the amount of steam produced during the reaction of anhydrous methanol and sodium hydroxide in the alkali dissolving tank.

[0013] Secondly, the first circulating water conveying pipe of this utility model is sequentially provided with a first regulating valve, a first liquid flow sensor, a second temperature sensor, and a first booster pump along the direction from near the jacket to far away from the jacket; the installation of the first liquid flow sensor facilitates the feedback of flow parameters, and the installation of the second temperature sensor facilitates the feedback of temperature parameters.

[0014] Furthermore, a third temperature sensor is installed on the third circulating water conveying pipe of this utility model. Installing the third temperature sensor facilitates the feedback of the temperature parameters of the medium delivered to the third circulating water conveying pipe through the outlet end of the heat exchanger cold source channel, thereby indirectly providing feedback on the temperature parameters of the medium discharged through the outlet end of the heat exchanger heat source channel.

[0015] This utility model has a simple structure, is easy to operate, and has a clever design, which greatly improves work efficiency and has good social and economic benefits. It is a product that is easy to promote and use. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of this utility model.

[0017] Figure 2 for Figure 1 A magnified view of detail A. Detailed Implementation

[0018] like Figure 1 and Figure 2 As shown, an alkali dissolving device includes an alkali dissolving tank 1. A jacket 2 is provided on the outside of the alkali dissolving tank 1. The top of the alkali dissolving tank 1 is provided with the inlet end of a steam conveying pipe 3 and the outlet end of a condensate return pipe 4. The outlet end of the condensate return pipe 4 is provided with the outlet end of a U-shaped liquid seal pipe 5. The inlet end of the U-shaped liquid seal pipe 5 and the outlet end of the steam conveying pipe 3 are provided with the heat source channel of a heat exchanger 6. The alkali dissolving tank 1 is provided with a stirring device, a first temperature sensor 7 and a liquid level sensor 46. The liquid level sensor 46 is installed to facilitate the feedback of the liquid level parameters of the alkali dissolving tank 1. The stirring device includes a stirring shaft 8 provided on the alkali dissolving tank 1, stirring blades 9 provided on the stirring shaft 8 inside the alkali dissolving tank 1 and a stirring motor 10 driven to the stirring shaft 8. A first circulating water conveying pipe 11 is provided on the inlet end of the jacket 2. A first regulating valve 12, a first liquid flow sensor 13, a second temperature sensor 14 and a first booster pump 15 are sequentially provided on the first circulating water conveying pipe 11 along the direction from near the jacket 2 to away from the jacket 2. The top of the alkali dissolving tank 1 is provided with the outlet end of the caustic soda flake conveying pipe 16. The caustic soda flake conveying pipe 16 is vertically installed on the alkali dissolving tank 1. Along the direction from near to far from the alkali dissolving tank 1, the caustic soda flake conveying pipe 16 is sequentially provided with a first feeder 17, a first butterfly valve 18, a weighing tank 19, a second feeder 20, and a second butterfly valve 21. Each of the first feeder 17 and the second feeder 20 is respectively provided with a feeding motor 22. A caustic soda flake storage tank 23 is provided at the inlet end of the caustic soda flake conveying pipe 16. The caustic soda flake storage tank 23 is located above the caustic soda flake conveying pipe 16. A level gauge 24 is provided inside the caustic soda flake storage tank 23. The level gauge 24 is installed in the lower middle part of the inner cavity of the caustic soda flake storage tank 23 to provide feedback on the lowest usable sodium hydroxide level stored in the level gauge 24.

[0019] The first circulating water delivery pipe 11 between the first liquid flow sensor 13 and the second temperature sensor 14 is provided with the inlet end of the second circulating water delivery pipe 25. The outlet end of the second circulating water delivery pipe 25 is connected to the inlet end of the cold source channel of the heat exchanger 6. The second circulating water delivery pipe 25 is provided with the second regulating valve 26 and the second liquid flow sensor 27. The outlet end of the cold source channel of the heat exchanger 6 is provided with the inlet end of the third circulating water delivery pipe 28. The third circulating water delivery pipe 28 is provided with the third temperature sensor 29. The installation of the first temperature sensor 7, the second temperature sensor 14 and the third temperature sensor 29 is for the purpose of facilitating the feedback of temperature parameters.

[0020] The bottom of the alkali dissolving tank 1 is provided with a first connecting pipe 30, and the bottom of the first connecting pipe 30 is provided with a first connecting flange 31. A filter pipe 32 is provided inside the first connecting flange 31 and the first connecting pipe 30. The filter pipe 32 adopts a cylindrical structure with an open bottom made of microporous filter plate. A second connecting flange 33 is provided on the filter pipe 32 below the first connecting flange 31. A first sealing ring 34 is provided between the first connecting flange 31 and the second connecting flange 33. The installation of the first sealing ring 34 helps to reduce the gap between the first connecting flange 31 and the second connecting flange 33. A first fastening bolt 35 is provided on the second connecting flange 33 and the first connecting flange 31. The inlet end of the connector 36 is provided on the open end of the filter pipe 32, and an intermediate product conveying pipe 37 is provided on the outlet end of the connector 36. The intermediate product conveying pipe 37 is provided with a first pressure sensor 38, a third regulating valve 39 and a second booster pump 40 in sequence along the direction from near the connector 36 to away from the connector 36, and a second pressure sensor 41 is provided in the alkali dissolving tank 1; the parameters fed back by the first pressure sensor 38 and the second pressure sensor 41 make it easy for the staff to judge the flow resistance provided by the filter pipe 32.

[0021] The bottom of the filter tube 32 adopts a stepped structure including a large end and a small end. The top part of the connector 36 and the bottom part of the filter tube 32 are fitted together. The small end of the filter tube 32 is fitted onto the top of the connector 36. A second sealing ring 42 is provided between the small end of the filter tube 32 and the connector 36. Several connecting wing plates 43 are provided on the outer side of the connector 36, evenly distributed in a star shape. The bottom of a second fastening bolt 44 is hinged to each connecting wing plate 43. The top of the second fastening bolt 44 is fitted onto the first connecting flange 31. Each of the several second fastening bolts 44 above the first connecting flange 31 is provided with a fastening nut 45. By providing several connecting wing plates 43, and using the second fastening bolts 44 installed on each connecting wing plate 43 to pass through the first connecting flange 31 and then installing the corresponding fastening nut 45, the connector 36 is easily fixed.

[0022] The usage instructions for this product are as follows: Figure 1 and Figure 2 As shown, it includes the following steps:

[0023] S1. First, add a preset amount of anhydrous methanol into the alkali dissolving tank 1; then, open the second butterfly valve 21 and the feeding motor 22 of the second feeder 20. At this time, the sodium hydroxide stored in the caustic soda storage tank 23 is gradually transported to the weighing tank 19 under the deceleration of the second feeder 20. When the parameters fed back by the weighing tank 19 reach the preset range, close the feeding motor 22 of the second feeder 20 and the second butterfly valve 21.

[0024] S2. Turn on the stirring device on the alkali dissolving tank 1, the feeding motor 22 of the first feeder 17, and the first butterfly valve 18. At this time, the sodium hydroxide temporarily stored in the weighing tank 19 is gradually transported to the anhydrous methanol in the alkali dissolving tank 1 under the deceleration of the second feeder 20. After the sodium hydroxide temporarily stored in the weighing tank 19 has been transported, turn off the feeding motor 22 of the first feeder 17 and the first butterfly valve 18.

[0025] During this period, the sodium hydroxide and anhydrous methanol react in the alkali-dissolving tank 1. Operators need to pay attention to the parameters fed back by the first temperature sensor 7, and simultaneously turn on the first booster pump 15 and adjust the opening of the first regulating valve 12 and the second regulating valve 26. At this time, the circulating water supplied by the upstream circulating water supply system enters the first circulating water delivery pipe 11 through the inlet end. After being pressurized by the first booster pump 15, it is divided into two parts: a first part of circulating water and a second part of circulating water. The first part of circulating water is delivered to the inner cavity of the jacket 2 for indirect heat exchange with the solution in the alkali-dissolving tank 1. Then, the first part of circulating water is discharged from the outlet end of the jacket 2 and returned to the downstream circulating water return system. The second part of circulating water is delivered to the cold source channel of the heat exchanger 6 for heat exchange with the medium continuously supplied to the heat source channel of the heat exchanger 6. Then, it is delivered to the third circulating water delivery pipe 28, where the temperature is fed back by the third temperature sensor 29, and discharged from the outlet end of the third circulating water delivery pipe 28 to the downstream circulating water return system.

[0026] The reaction of anhydrous methanol and sodium hydroxide in the alkali-dissolving tank 1 is continuously stirred by the stirring device in the alkali-dissolving tank 1. Part of the heat released by the reaction of the anhydrous methanol and sodium hydroxide in the alkali-dissolving tank 1 is continuously carried away by the first part of the circulating water in the jacket 2. The steam generated by the heated anhydrous methanol in the alkali-dissolving tank 1 is transported through the steam conveying pipe 3 to the heat source channel of the heat exchanger 6 and exchanged with the second part of the circulating water continuously supplied to the cold source channel of the heat exchanger 6. The steam is then liquefied and discharged from the outlet end of the heat source channel of the heat exchanger 6. The liquefied steam is then returned to the alkali-dissolving tank 1 through the U-shaped liquid seal pipe 5 as reflux liquid to help lower the temperature of the anhydrous methanol and sodium hydroxide reaction system in the alkali-dissolving tank 1.

[0027] S3. After the anhydrous methanol and sodium hydroxide in the alkali dissolving tank 1 have reacted for a preset time, the stirring device on the alkali dissolving tank 1 is turned off, and the second booster pump 40 is turned on. After the solution in the alkali dissolving tank 1 is filtered through the filter tube 32, the liquid phase is the crude solution of sodium methoxide methanol solution. The liquid phase passes through the inner cavity of the filter tube 32 and enters the intermediate product conveying pipe 37 through the connector 36. After being pressurized by the second booster pump 40, it is conveyed to the downstream process. The solid phase is temporarily stored in the alkali dissolving tank 1 to participate in the next alkali dissolving process.

[0028] In this embodiment, the steam produced during the reaction of anhydrous methanol and sodium hydroxide in the alkali dissolving tank 1 is transported to the heat source channel of the heat exchanger 6 and the second part of the circulating water continuously transported to the cold source channel of the heat exchanger 6 is liquefied and then sent back to the alkali dissolving tank 1 to continue participating in the reaction of anhydrous methanol and sodium hydroxide. The liquefied steam sent back to the alkali dissolving tank 1 after liquefaction serves as an auxiliary cooling source for the reaction of anhydrous methanol and sodium hydroxide in the alkali dissolving tank 1. The remaining heat is absorbed by the first part of the circulating water continuously transported to the jacket 2, thereby ensuring that the parameters fed back by the first temperature sensor 7 are always within the preset range, thereby reducing the amount of steam produced during the reaction of anhydrous methanol and sodium hydroxide in the alkali dissolving tank 1.

[0029] The embodiments described above are merely preferred embodiments of this utility model and are not intended to limit the scope of implementation of this utility model. Therefore, all equivalent changes or modifications made to the structure, features and principles described in the patent claims of this utility model should be included within the scope of the patent application of this utility model.

Claims

1. A device for dissolving alkali, characterized by: The system includes a alkali dissolving tank (1), which has a jacket (2) on its outer side. The top of the alkali dissolving tank (1) has an inlet end of a steam conveying pipe (3) and an outlet end of a condensate return pipe (4). The outlet end of the condensate return pipe (4) has an outlet end of a U-shaped liquid seal pipe (5). The inlet end of the U-shaped liquid seal pipe (5) and the outlet end of the steam conveying pipe (3) have heat source channels for a heat exchanger (6). The alkali dissolving tank (1) is equipped with a stirring device, a first temperature sensor (7), and a liquid level sensor (46). The stirring device includes a stirring shaft (8) on the alkali dissolving tank (1), stirring blades (9) on the stirring shaft (8) inside the alkali dissolving tank (1), and a stirring motor (10) connected to the stirring shaft (8). A first circulating water conveying pipe (11) is provided on the inlet end of the jacket (2). A first regulating valve (12), a first liquid flow sensor (13), a second temperature sensor (14), and a first booster pump (15) are sequentially provided on the first circulating water conveying pipe (11) along the direction from near the jacket (2) to away from the jacket (2).

2. The alkali dissolving device according to claim 1, characterized in that: The top of the alkali dissolving tank (1) is provided with the outlet end of the caustic soda flake conveying pipe (16). The caustic soda flake conveying pipe (16) is provided with a first feeder (17), a first butterfly valve (18), a weighing tank (19), a second feeder (20), and a second butterfly valve (21) in sequence along the direction from near the alkali dissolving tank (1) to away from the alkali dissolving tank (1). The first feeder (17) and the second feeder (20) are each provided with a feeding motor (22).

3. The alkali dissolving device according to claim 1, characterized in that: The first circulating water conveying pipe (11) between the first liquid flow sensor (13) and the second temperature sensor (14) is provided with the inlet end of the second circulating water conveying pipe (25). The outlet end of the second circulating water conveying pipe (25) is connected to the inlet end of the cold source channel of the heat exchanger (6). The second circulating water conveying pipe (25) is provided with the second regulating valve (26) and the second liquid flow sensor (27). The outlet end of the cold source channel of the heat exchanger (6) is provided with the inlet end of the third circulating water conveying pipe (28). The third circulating water conveying pipe (28) is provided with the third temperature sensor (29).

4. The alkali-dissolving device according to claim 1, characterized in that: The bottom of the alkali dissolving tank (1) is provided with a first connecting pipe (30), the bottom of the first connecting pipe (30) is provided with a first connecting flange (31), a filter pipe (32) is provided inside the first connecting flange (31) and the first connecting pipe (30), the filter pipe (32) adopts a cylindrical structure with an open bottom made of microporous filter plate, a second connecting flange (33) is provided on the filter pipe (32) below the first connecting flange (31), a first sealing ring (34) is provided between the first connecting flange (31) and the second connecting flange (33), a first fastening bolt (35) is provided on the second connecting flange (33) and the first connecting flange (31), the inlet end of the connector (36) is provided on the open end of the filter pipe (32), and an intermediate product conveying pipe (37) is provided on the outlet end of the connector (36).

5. The alkali-dissolving apparatus according to claim 4, characterized in that: The intermediate product conveying pipe (37) is provided with a first pressure sensor (38), a third regulating valve (39) and a second booster pump (40) in sequence along the direction from near the connector (36) to away from the connector (36), and a second pressure sensor (41) is provided in the alkali dissolving tank (1).

6. The alkali-dissolving apparatus according to claim 4, characterized in that: The bottom of the filter tube (32) adopts a stepped structure including a large end and a small end. The top part of the connector (36) and the bottom part of the filter tube (32) are matched. The small end of the filter tube (32) is fitted on the top of the connector (36). A second sealing ring (42) is provided between the small end of the filter tube (32) and the connector (36). A connecting wing plate (43) is provided on the outside of the connector (36). The number of connecting wing plates (43) is several. The several connecting wing plates (43) are evenly distributed in a star shape on the outside of the connector (36). The bottom of the second fastening bolt (44) is hinged on each connecting wing plate (43). The top of the second fastening bolt (44) is fitted on the first connecting flange (31). A fastening nut (45) is provided on each of the several second fastening bolts (44) above the first connecting flange (31).

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