Reaction device for producing propylene diamine

Abstract

The utility model discloses a reaction unit is used in production of propylenediamine, including reation kettle, the bottom of reation kettle is installed with transmission motor, and the inside connection of transmission motor's output has transmission shaft, and the top one side of reation kettle is installed with feed pipe, and the one side of feed pipe is installed with pressure gauge, and the lateral surface of reation kettle is connected with inlet pipe, and the surface of inlet pipe is installed with inlet valve, and the inside one side of reation kettle is installed with sealing plate, and the one side of sealing plate is equipped with transmission stirring mechanism, and the both sides of transmission stirring mechanism are equipped with transmission contact mechanism. The utility model has the following effect: through transmission stirring mechanism, can drive 3 - hydroxy propionitrile solution in reation kettle constantly upside -down tumble, make it and inside hydrogen gas contact fully, and in the stirring of while, through transmission contact mechanism, can drive catalyst in reation kettle moves up and down, make it and the solution of each place in reation kettle contact constantly, effectively promote overall reaction rate and conversion rate.

Description

Technical Field

[0001] This utility model relates to the field of chemical technology, and more specifically, to a reaction apparatus for the production of propylenediamine. Background Technology

[0002] 1,3-Propanediamine, commonly known simply as propylenediamine, is an important organic chemical intermediate. Due to the presence of two primary amino groups (–NH2) in its molecule, it exhibits high reactivity and has wide applications in the fine chemical industry. Propanediamine is mainly used in the synthesis of high-performance nylons (such as nylon 1010 and nylon 610), as a chelating agent (such as EDTA derivatives), as a water treatment agent, and as a highly efficient curing agent for epoxy resins. Market demand continues to grow.

[0003] Currently, the industrial preparation of propylenediamine mainly employs the catalytic hydrogenation method using 3-hydroxypropionitrile. This involves introducing a 3-hydroxypropionitrile solution and hydrogen gas into a reaction vessel, where a reduction reaction occurs under the action of a catalyst to produce propylenediamine. To improve reaction efficiency, existing technologies typically incorporate a stirring device within the reaction vessel to promote the dissolution and mass transfer of hydrogen in the liquid phase, while simultaneously ensuring sufficient contact between the reactants and the catalyst, thereby accelerating the reaction rate.

[0004] However, in actual production, the form in which the catalyst is used has a significant impact on the reaction effect and subsequent processing. If a powdered catalyst is used, although its large specific surface area and numerous active sites can effectively improve catalytic efficiency, the catalyst particles are small after the reaction, making it difficult to completely separate from the reaction liquid. This not only increases post-processing costs but may also affect product purity. If a large-volume block catalyst is used, although it is easy to separate, it is prone to depositing at the bottom of the reactor under gravity. Even with a stirring mechanism, it is difficult to ensure uniform contact between the catalyst and the reaction liquid in all areas of the reactor. In particular, mass transfer dead zones are prone to form in the lower part of the reactor, leading to incomplete local reactions, limiting the overall reaction rate, and affecting production efficiency and product yield. Utility Model Content

[0005] In view of the problems in the related technologies, this utility model proposes a reaction device for the production of propylenediamine to overcome the above-mentioned technical problems existing in the existing related technologies.

[0006] Therefore, the specific technical solution adopted by this utility model is as follows:

[0007] A reaction apparatus for producing propylenediamine includes a reaction vessel. A drive motor is installed at the bottom of the reaction vessel, and a drive shaft is connected to the output end of the drive motor inside the reaction vessel. A feed pipe is installed on one side of the top of the reaction vessel, and a pressure gauge is installed on one side of the feed pipe. An air inlet pipe is connected to the side surface of the reaction vessel, and an air inlet valve is installed on the surface of the air inlet pipe. A sealing plate is installed on one side of the inside of the reaction vessel, and a drive stirring mechanism is provided on one side of the sealing plate. Drive contact mechanisms are provided on both sides of the drive stirring mechanism.

[0008] Furthermore, in order to achieve sufficient contact between the solution and hydrogen in the reactor, the transmission stirring mechanism includes a drive gear mounted on the surface of the drive shaft, driven shafts rotatably connected to both sides inside the reactor, driven gears connected to the surface of the driven shafts, driven gears meshing with the drive gears, and a spiral stirring blade connected to one end of the drive shaft.

[0009] Furthermore, in order to enable the catalyst to contact the 3-hydroxypropionitrile solution and hydrogen at various points in the reactor, the transmission contact mechanism includes a lifting screw connected to the end of the driven shaft, a lifting cylinder threaded onto the surface of the lifting screw, a support frame connected to one side of the lifting cylinder, and a catalyst cage connected to the end of the support frame.

[0010] Furthermore, in order to limit the rotation of the lifting cylinder, lifting grooves are opened on both sides of the inner wall of the reactor, and a limit rod is connected to one side of the lifting cylinder, with one end of the limit rod slidably installed in the lifting groove.

[0011] Furthermore, in order to break up the hydrogen foam generated inside the reactor, a stirring paddle is installed on top of the spiral stirring blades.

[0012] Furthermore, in order to provide stable support for the reactor, a support rod is connected to the bottom of the reactor, and a PLC controller is installed on one side of the reactor surface.

[0013] Furthermore, to prevent the lifting cylinder from falling off the top of the lifting screw, a limit plate is connected to the top of the lifting screw.

[0014] The beneficial effects of this invention are as follows: the continuous rotation of the spiral stirring blades in the transmission stirring mechanism drives the 3-hydroxypropionitrile solution in the reactor to continuously tumble up and down, allowing it to fully contact and mix with the injected hydrogen. At the same time, the transmission contact mechanism enables the lifting cylinder to move the catalyst in the catalyst cage up and down, allowing it to continuously contact the solution in various parts of the reactor. This significantly enhances the contact area and contact efficiency between the catalyst and the 3-hydroxypropionitrile solution and hydrogen. The catalyst remains in a dynamic suspension state in the reaction solution, preventing it from settling to the bottom and facilitating its recovery, regeneration, or replacement. This effectively improves the overall reaction rate and conversion rate. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the surface structure of a reaction apparatus for producing propylenediamine according to an embodiment of the present invention;

[0017] Figure 2 This is a rear view of a reaction apparatus for producing propylenediamine according to an embodiment of the present invention;

[0018] Figure 3 This is an internal cross-sectional view of the reactor in a reaction apparatus for producing propylenediamine according to an embodiment of the present invention;

[0019] Figure 4 This is an internal cross-sectional side view of the reactor in a reaction apparatus for producing propylenediamine according to an embodiment of the present invention;

[0020] Figure 5 This is a detailed view of the surface structure of the lifting cylinder in a reaction apparatus for producing propylenediamine according to an embodiment of the present invention.

[0021] In the picture:

[0022] 1. Reactor; 2. Drive motor; 3. Drive shaft; 4. Feed pipe; 5. Pressure gauge; 6. Air inlet pipe; 7. Air inlet valve; 8. Sealing plate; 9. Driven stirring mechanism; 901. Driven gear; 902. Driven shaft; 903. Driven gear; 904. Spiral stirring blades; 10. Driven contact mechanism; 1001. Lifting screw; 1002. Lifting cylinder; 1003. Support frame; 1004. Catalytic cage; 1005. Lifting trough; 1006. Limiting rod; 11. Stirring paddle; 12. Support rod; 13. PLC controller; 14. Limiting plate. Detailed Implementation

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0024] According to an embodiment of the present invention, a reaction apparatus for the production of propylenediamine is provided.

[0025] like Figures 1-5 As shown, a reaction apparatus for producing propylenediamine according to an embodiment of this utility model includes a stainless steel reaction vessel 1. The reaction vessel 1 has an integrated heating resistor to achieve a heating effect during the reaction, and the top of the reaction vessel 1 is detachable. A drive motor 2 is installed at the bottom of the reaction vessel 1, and the output end of the drive motor 2 is connected to a drive shaft 3 inside the reaction vessel 1. A feed pipe 4 is installed on one side of the top of the reaction vessel 1 for injecting a 3-hydroxypropionitrile solution into the reaction vessel 1. A pressure gauge 5 is installed on one side of the feed pipe 4 to display the internal pressure of the reaction vessel 1. An air inlet pipe 6 is connected to the side surface of the reaction vessel 1, and an air inlet valve 7 is installed on the surface of the air inlet pipe 6 for injecting hydrogen into the reaction vessel 1. A sealing plate 8 is installed on one side of the inside of the reaction vessel 1, and a drive stirring mechanism 9 is provided on one side of the sealing plate 8 for stirring the 3-hydroxypropionitrile solution to ensure sufficient contact with hydrogen. Drive contact mechanisms 10 are provided on both sides of the drive stirring mechanism 9 to move the catalyst up and down while stirring the solution and gas, ensuring contact with the solution throughout the reaction vessel 1 and reducing dead zones in the reaction.

[0026] like Figures 1-5As shown, the transmission stirring mechanism 9 includes a drive shaft 3 with a drive gear 901 mounted on its surface. Driven shafts 902 are rotatably connected to both sides of the interior of the reactor 1. Driven gears 903 are connected to the surface of the driven shafts 902 and mesh with the drive gear 901. A spiral stirring blade 904 is connected to one end of the drive shaft 3. After the drive motor 2 drives the drive shaft 3 to rotate, the spiral stirring blade 904 can continuously rotate inside the reactor 1, causing the solution inside the reactor 1 to tumble up and down, ensuring continuous and sufficient contact with hydrogen gas. While shaft 3 rotates, the driving gear 901 can drive the two driven gears 903 and driven shaft 902 on both sides to rotate; the transmission contact mechanism 10 includes a lifting screw 1001 connected to the end of the driven shaft 902, a lifting cylinder 1002 threadedly connected to the surface of the lifting screw 1001, a support frame 1003 connected to one side of the lifting cylinder 1002, and a catalyst cage 1004 connected to the end of the support frame 1003. The top of the catalyst cage 1004 can be opened and closed for placing catalyst particles inside; the inner walls of the reactor 1 are on both sides A lifting groove 1005 is provided, and a limiting rod 1006 is connected to one side of the lifting cylinder 1002. One end of the limiting rod 1006 is slidably installed in the lifting groove 1005. When the driven shaft 902 rotates, the lifting cylinder 1002 is limited by the rotation of the limiting rod 1006, so that the lifting screw 1001 can drive the lifting cylinder 1002 to move up and down. This causes the catalyst cage 1004 to continuously move the catalyst inside the reactor 1, so that it can contact and react with the 3-hydroxypropionitrile solution and hydrogen. A stirring paddle is installed on the top of the spiral stirring blade 904. 11, used to break the bubbles generated by injecting hydrogen after rotation, so as to facilitate contact between hydrogen and solution; a support rod 12 is connected to the bottom of the reactor 1 for stable support of the reactor 1; a PLC controller 13 is installed on one side of the surface of the reactor 1 for controlling the switching of electrical components in the device and the forward and reverse rotation of the drive motor 2; a limit plate 14 is connected to the top of the lifting screw 1001 for limiting the upward movement of the lifting cylinder 1002 and preventing the lifting cylinder 1002 from falling off the top of the lifting screw 1001.

[0027] In practical use, firstly, the top of reactor 1 is disassembled, the top cover of catalyst cage 1004 is opened, granular catalyst is loaded into catalyst cage 1004 and closed, then the top of reactor 1 is reset and sealed. A suitable amount of 3-hydroxypropionitrile solution is injected into reactor 1 through feed pipe 4, and feed pipe 4 is closed. Then, hydrogen gas is introduced into reactor 1 through gas inlet pipe 6 and gas inlet valve 7, while pressure gauge 5 monitors the internal pressure of reactor 1 in real time to ensure the reaction proceeds safely under the set high-pressure conditions. According to the reaction requirements, the heating resistor is activated by PLC controller 13 to heat the material in reactor 1 to reach the appropriate reaction temperature. Once the reaction conditions are established, the PLC controller 13 starts the drive motor 2, which drives the drive shaft 3 to rotate periodically in both directions. The drive shaft 3 drives the spiral stirring blades 904 and the stirring paddle 11 at its end to rotate at high speed, causing the 3-hydroxypropionitrile solution to form a strong up-and-down circulating flow within the reactor 1, achieving thorough mixing of the liquid phase. Simultaneously, the stirring paddle 11 effectively breaks up bubbles formed after hydrogen enters the solution, increasing the gas-liquid contact area, promoting the dissolution and mass transfer of hydrogen in the liquid phase, and improving the efficiency of the hydrogenation reaction. On the other hand, the drive gear 901 on the drive shaft 3 rotates accordingly, driving the driven gears 903 and driven shaft 902 meshing with it on both sides to rotate synchronously. During rotation, the lifting cylinder 1002, connected to the end of the driven shaft 902, is restricted from rotation by the lifting groove 1005 embedded in the inner wall of the reactor 1 by the limiting rod 1006. Therefore, under the action of the threaded drive, the lifting cylinder 1002 makes a reciprocating linear motion along the lifting screw 1001. The lifting motion is transmitted to the catalyst cage 1004 via the support frame 1003, causing the catalyst inside to move up and down periodically in the vertical direction within the reactor 1. During this process, the catalyst continuously traverses different areas of the reaction liquid, effectively avoiding dead zones formed by its settling at the bottom due to gravity. This significantly enhances the dynamic contact frequency and range between the catalyst, the reaction liquid, and dissolved hydrogen, achieving highly uniform mixing of the gas-liquid-solid three phases, thereby greatly improving the catalytic reaction rate and conversion rate.

[0028] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A reaction apparatus for producing propylenediamine, characterized in that, The reactor includes a reactor (1), a drive motor (2) is installed at the bottom of the reactor (1), the output end of the drive motor (2) is connected to a drive shaft (3) inside the reactor (1), a feed pipe (4) is installed on one side of the top of the reactor (1), a pressure gauge (5) is installed on one side of the feed pipe (4), an air inlet pipe (6) is connected to the side surface of the reactor (1), an air inlet valve (7) is installed on the surface of the air inlet pipe (6), a sealing plate (8) is installed on one side of the inside of the reactor (1), a drive stirring mechanism (9) is provided on one side of the sealing plate (8), and a drive contact mechanism (10) is provided on both sides of the drive stirring mechanism (9).

2. The reaction apparatus for producing propylenediamine according to claim 1, characterized in that, The transmission stirring mechanism (9) includes a drive shaft (3) with a drive gear (901) mounted on its surface, a driven shaft (902) rotatably connected to both sides inside the reactor (1), a driven gear (903) connected to the surface of the driven shaft (902), the driven gear (903) meshing with the drive gear (901), and a spiral stirring blade (904) connected to one end of the transmission shaft (3).

3. The reaction apparatus for producing propylenediamine according to claim 2, characterized in that, The transmission contact mechanism (10) includes a lifting screw (1001) connected to the end of the driven shaft (902), a lifting cylinder (1002) threadedly connected to the surface of the lifting screw (1001), a support frame (1003) connected to one side of the lifting cylinder (1002), and a catalyst cage (1004) connected to the end of the support frame (1003).

4. The reaction apparatus for producing propylenediamine according to claim 3, characterized in that, The inner wall of the reactor (1) has lifting grooves (1005) on both sides. One side of the lifting cylinder (1002) is connected to a limit rod (1006), and one end of the limit rod (1006) is slidably installed in the lifting groove (1005).

5. A reaction apparatus for producing propylenediamine according to claim 2, characterized in that, A stirring paddle (11) is mounted on the top of the spiral stirring blade (904).

6. The reaction apparatus for producing propylenediamine according to claim 1, characterized in that, A support rod (12) is connected to the bottom of the reactor (1), and a PLC controller (13) is installed on one side of the surface of the reactor (1).

7. A reaction apparatus for producing propylenediamine according to claim 3, characterized in that, A limit plate (14) is connected to the top of the lifting screw (1001).

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