Reaction kettle flow control device for methyl isocyanate production

Abstract

The invention discloses a reaction kettle flow control device for methyl isocyanate production, and relates to the field of reaction containers, the reaction kettle flow control device comprises a reaction kettle, a stirrer, a guide cylinder, an atomizer and a flow control disc are arranged in the reaction kettle, the flow control disc is arranged above the guide cylinder, and the flow control disc can move in the axial direction of the reaction kettle to get close to or away from the guide cylinder; a plurality of conical holes with large upper parts and small lower parts are formed in the flow control disc in a penetrating manner, when liquid in the reaction kettle circularly flows, the liquid in the guide cylinder flows upwards and rushes out from the conical holes of the flow control disc, and the rushed liquid is in contact and mixed with atomized liquid drops sprayed by the atomizer; by arranging the flow control disc and the conical holes formed in the flow control disc, liquid in the flow guide cylinder flows upwards and rushes out of the conical holes of the flow control disc, so that the liquid level is reconstructed into a thick umbrella-shaped liquid film which is uniformly distributed on the premise of not influencing the stirring effect, the liquid level is effectively expanded, and the stirring effect is improved. The adding speed and the stirring speed of the atomizer are adjusted in real time according to the mixing process, and the absorption efficiency is improved.

Description

Technical Field

[0001] The invention relates to reaction container technology, in particular to a reaction kettle flow control device for producing methyl isocyanate. Background Art

[0002] The production process of methyl isocyanate is usually carried out in a closed reactor. The main raw materials are sodium cyanate, o-dichlorobenzene and dimethyl sulfate. As the core equipment, the reactor needs to have efficient mixing and mass transfer capabilities. The reaction is a fast and highly exothermic process, and the reaction rate needs to be strictly controlled to avoid the formation of by-products. This places high demands on the mass transfer efficiency and temperature homogenization capability of the reactor. In the prior art, in order to improve the reaction efficiency, most processes adopt methods such as optimizing the stirring paddle structure and improving the dispersion of atomized droplets. However, under the constraint of a fixed reactor diameter, the contact area between the atomized droplets and the reaction liquid is limited to the physical size range of the liquid surface. Although traditional mechanical stirring can accelerate the liquid surface renewal rate, it cannot break through the inherent limitations of the liquid surface area. The effective contact interface between the gas and liquid phases is difficult to further expand. In large-scale production, relying solely on stirring may also cause local overheating or excessive shearing, affecting the yield of the product. Summary of the invention

[0003] The object of the present invention is to provide a flow control device for a reactor in the production of methyl isocyanate to solve the above-mentioned deficiencies in the prior art.

[0004] In order to achieve the above-mentioned purpose, the present invention provides the following technical scheme: a flow control device for a reactor for producing methyl isocyanate, comprising a reactor, wherein an agitator and a guide tube are arranged in the reactor, wherein an atomizer and a flow control disk are also arranged in the reactor, wherein the flow control disk is arranged above the guide tube, and wherein the diameter of the flow control disk is smaller than the inner diameter of the reactor, wherein the flow control disk can move along the axial direction of the reactor to approach or move away from the guide tube, wherein a plurality of conical holes which are larger at the top and smaller at the bottom are penetrated through the flow control disk, and when the liquid in the reactor circulates, the liquid in the guide tube flows upward and gushes out from the conical holes of the flow control disk, and the gushered liquid contacts and mixes with the atomized droplets sprayed by the atomizer.

[0005] Furthermore, there are a plurality of atomizers which are distributed in a ring shape along the inner wall of the reactor, and the nozzles of the atomizers are tilted downward with an inclination angle of 15°-30°.

[0006] Furthermore, the flow control disc is in the shape of a cone that bulges upward.

[0007] Furthermore, an elastic member is disposed on the top of the flow control disc, and the elastic force of the elastic member acts on the flow control disc to make it tend to approach the guide tube.

[0008] Furthermore, the elastic member includes a fixed seat and a first sleeve, the surface of the first sleeve is slidably connected to the inner wall of the fixed seat, the bottom of the first sleeve is connected to the flow control disk, and the surface of the first sleeve located between the flow control disk and the fixed seat is sleeved with a first spring.

[0009] Furthermore, a plurality of guide plates distributed in a circular array are arranged near the peripheral side of the bottom of the flow control disc, and the guide plates are inclined from the inner side to the outer side of the flow control disc.

[0010] Furthermore, the diameter of the tapered hole on the flow control disk gradually increases from the outside to the inside.

[0011] Furthermore, the elastic member further includes a limiting assembly, and the limiting assembly is used to limit the flow control disc from rotating relative to the fixing seat.

[0012] Furthermore, the limiting assembly includes at least one limiting groove opened on the inner wall of the fixed seat, the end of the first sleeve is connected to at least one limiting rod along its radial sliding, and a second spring is arranged on one side of the limiting rod, and the elastic force of the second spring acts on the limiting rod to make it have a tendency to move away from the axial direction.

[0013] Furthermore, the guide tube is in a cone shape that is small at the top and large at the bottom.

[0014] Compared with the prior art, the reactor flow control device for producing methyl isocyanate provided by the present invention has the following beneficial effects: The reactor flow control device for producing methyl isocyanate is provided with a flow control disk and a conical hole opened thereon, so that the liquid in the guide tube flows upward and flows out from the conical hole of the flow control disk, thereby reconstructing the liquid surface into a thicker umbrella-shaped liquid film with more uniform distribution without affecting the stirring effect, effectively expanding the liquid surface, adjusting the atomizer addition speed and the stirring speed in real time according to the mixing process, and improving the absorption efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0016] Figure 1 A cross-sectional view of the overall structure of a reactor provided in an embodiment of the present invention; Figure 2 A schematic diagram of the liquid flow direction (the direction indicated by the dotted arrow) in a reactor provided by an embodiment of the present invention; Figure 3 A schematic diagram of a structure in which an elastic member is arranged on a flow control disc provided in an embodiment of the present invention; Figure 4 A schematic diagram of the structure of an elastic member and a limiting assembly provided in an embodiment of the present invention; Figure 5 A schematic diagram of the structure of one of the limiter components provided in an embodiment of the present invention; Figure 6 The embodiment of the present invention provides Figure 5 The enlarged view of point A in the middle; Figure 7 A schematic structural diagram of another limiting assembly provided in an embodiment of the present invention; Figure 8 A schematic diagram of the structure of a flow control disc provided in an embodiment of the present invention in a cone shape protruding upward; Fig. 9 A schematic diagram of a structure in which the diameter of a tapered hole provided by an embodiment of the present invention gradually increases from the outside to the inside; Fig.10 A schematic diagram of the structure in which a guide plate is arranged at the bottom of a flow control disk provided in an embodiment of the present invention.

[0017] Description of reference numerals: 1. Reactor; 11. Feed port; 12. Observation port; 13. Jacket; 14. Liquid inlet pipe; 15. Liquid outlet pipe; 16. Discharge port; 2. Agitator; 21. Agitator rod; 3. Guide tube; 4. Atomizer; 41. Sprinkler; 42. Liquid supply assembly; 5. Flow control disc; 51. Conical hole; 52. Guide plate; 6. First drive member; 61. Electric telescopic rod; 62. Connecting rod; 63. Extension support Frame; 7, elastic member; 71, fixed seat; 72, first sleeve; 73, first spring; 8, limit assembly; 801, limit groove; 802, limit rod; 803, second spring; 804, limit seat; 805, first disc; 806, second disc; 807, third spring; 808, second sleeve; 809, sphere; 810, spherical groove; 811, support; 812, guide rod. DETAILED DESCRIPTION

[0018] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0019] For examples, see Figure 1 - Fig.10 A flow control device for a reactor 1 for producing methyl isocyanate, comprising a reactor 1, wherein the reactor 1 is provided with a feed port 11, a discharge port 16, an observation port 12 and a jacket 13, wherein the jacket 13 is provided with a liquid inlet pipe 14 and a liquid outlet pipe 15, and wherein the reactor 1 is provided with an agitator 2 and a guide tube 3. Figure 1As shown, the guide tube 3 is arranged around the blades on the stirring rod 21 in the stirrer 2, and the guide tube 3 is at a certain distance from the bottom of the reactor 1. Its diameter is smaller than the inner diameter of the reactor 1 and is spaced apart from the inner wall of the reactor 1. The blades of the stirrer 2 are radial flow type inclined blade turbine impellers or axial flow impellers, etc., which are used to form a low pressure area in the guide tube 3. When the blades rotate, the fluid is pushed to move upward along the axial direction of the guide tube 3, and then flows back downward along the outer ring of the guide tube 3. The fluid re-enters the guide tube 3 from the bottom of the guide tube 3 to form a closed cycle, as shown in FIG. Figure 2 As shown; The reactor 1 is also provided with an atomizer 4 and a flow control disc 5. The atomizer 4 supplies liquid through a liquid supply assembly 42 arranged outside the reactor 1. The flow control disc 5 is arranged above the flow guide tube 3, and its diameter is smaller than the inner diameter of the reactor 1. The flow control disc 5 can move along the axial direction of the reactor 1 to approach or move away from the flow guide tube 3. A plurality of tapered holes 51 with a larger top and a smaller bottom are formed through the flow control disc 5. When the liquid in the reactor 1 circulates, the liquid in the flow guide tube 3 flows upward and gushes out from the tapered holes 51 of the flow control disc 5, and the gushered liquid contacts and mixes with the atomized droplets sprayed by the atomizer 4. When the liquid in the reactor 1 forms the above-mentioned closed circulation flow state, when the flow control disc 5 moves downward and approaches the guide tube 3, the flowing fluid is blocked by the flow control disc 5 and flows out from the tapered hole 51. When flowing out, the fluid decelerates when passing through the expanded outlet, and the kinetic energy is converted into static pressure energy, forming a thicker umbrella-shaped liquid film with uniform distribution.

[0020] In the synthesis process of methyl isocyanate, the specific implementation scenario is: Preprocessing stage: After cleaning the inner wall of the reactor 1 (using steam jet to clean the inner wall of the reactor 1 and nitrogen purging to the moisture content), nitrogen is introduced to replace the air in the reactor 1 (inert gas protection); Mixing stage: Add o-dichlorobenzene solvent into the reactor 1, start the stirrer 2 for stirring, then slowly add sodium cyanate, stir for a certain time to make the sodium cyanate dispersed completely, add dimethyl sulfate through the atomizer 4 provided in the reactor 1, and the speed of atomization and dripping is adjusted by real-time feedback through the mass flow meter. During the process of adding dimethyl sulfate, cold water is passed into the jacket 13 of the reactor 1 to control the temperature in the reactor to avoid local overheating and causing violent heat release; Reaction phase: After the addition of dimethyl sulfate is completed, the jacket 13 switches to heat the heat transfer oil for heating. After the temperature reaches the required temperature, the reaction is carried out. Stirring is continued during the reaction. The flow control disk 5 is moved to a position away from the liquid surface. After the reaction is completed, subsequent treatment is performed to collect the product. The post-treatment process is not described in detail here.

[0021] In the mixing stage of the above-mentioned embodiment, although the addition of raw materials through the atomizer 4 in the prior art has practical applications, during atomization and spraying, only the liquid flowing to the liquid surface position can contact the atomized droplets. Although the liquid on the liquid surface is constantly refreshed under the stirring of the stirring device, the area of ​​the liquid surface is limited by the diameter of the cylinder of the reactor 1, and the rate of absorption of droplets per unit time is limited. Even if factors such as the liquid flow rate and the atomization amount are increased, it is difficult to increase the upper limit. In other words, when the diameter of the reactor 1 is constant, the contact between the atomized droplets and the reaction liquid is limited by the liquid surface area. Traditional stirring only increases the liquid surface renewal rate, but cannot break through this limitation, resulting in limited absorption efficiency. By providing the flow control disk 5 and the tapered hole 51 opened thereon, the liquid in the guide tube 3 flows upward and gushes out from the tapered hole 51 of the flow control disk 5, thereby reconstructing the liquid surface into a thicker umbrella-shaped liquid film with a more uniform distribution without affecting the stirring effect, effectively expanding the liquid surface, and adjusting the addition speed and stirring speed of the atomizer 4 in real time according to the mixing process to improve the absorption efficiency; Specifically, after the sodium cyanate is completely dispersed, the flow control disk 5 is driven to move downward. When its bottom contacts the circulating liquid surface, the flowing liquid is blocked by the flow control disk 5 and gushes out from the conical hole 51. The gushing state can be adjusted by the degree to which the flow control disk 5 is close to the guide tube 3 and the stirring speed. The atomizer 4 sprays the atomized droplets onto the surface of the gushing liquid and is absorbed. Then the liquid flows toward the inner wall of the reactor 1 and joins the original circulating liquid for further mixing, thereby shortening the time required for the process of adding dimethyl sulfate.

[0022] In one embodiment of the present invention, the flow control disc 5 is connected to a first driving member 6 for driving the flow control disc 5 to move along the axial direction of the reactor 1; In one embodiment of the present invention, a plurality of atomizers 4 are provided and distributed in a ring along the inner wall of the reactor 1. The nozzle 41 of the atomizer 4 is tilted downward, and the tilt angle is 15°-30° to ensure that the atomized droplets can better cover the space inside the reactor 1, thereby improving the contact efficiency and reaction uniformity between the atomized droplets and the liquid gushing out of the conical hole 51. At the same time, the energy loss of the droplets with a parabolic trajectory when penetrating the gas-liquid interface is smaller, thereby effectively improving the probability of collision absorption.

[0023] In one embodiment of the present invention, the flow control disc 5 is in an upwardly convex conical shape, such as Figure 7As shown, during the addition of dimethyl sulfate, the flow control disc 5 is arranged in a conical shape, and the liquid gushes out along the inclined surface of the flow control disc 5. Even if the liquid surface expands less when the liquid gushes out, it is larger than the liquid surface area of ​​only circulating flow, and the inclined surface also helps the liquid absorbing the atomized droplets to flow downward quickly and be added to the circulating liquid for further mixing. In addition, it also forms a corresponding receiving angle with the inclined nozzle 41 of the atomizer 4, and the gushing liquid can further uniformly contact with the droplets sprayed by the atomizer 4 per unit time; It should be understood that the tapered angle of the flow control disc 5 should not be too large, and the angle between its waistline and the plane where the bottom is located is 0°-20°, which is specifically set according to the setting height of the guide tube 3 and the liquid level during use.

[0024] In one embodiment of the present invention, the diameter of the tapered hole 51 on the flow control disk 5 gradually increases from the outside to the inside (e.g. Fig. 9 As shown in the figure, the conical hole 51 at the position that initially contacts the circulating liquid can have a larger outflow rate. The edge position has a smaller aperture because of the reduced flow rate, which is conducive to forming the required liquid film. In addition, since the size of the droplets sprayed by the atomizer 4 will also vary, it is easy for relatively more droplets to move to the central area farther away from it. The increase in the flow rate of the conical hole 51 at the corresponding position is conducive to coping with this situation and avoiding excessive concentration in local areas.

[0025] In one embodiment of the present invention, an elastic member 7 is disposed on the top of the flow control disc 5, and the elastic force of the elastic member 7 acts on the flow control disc 5 to make it tend to approach the guide tube 3; In one embodiment of the present invention, the elastic member 7 includes a fixed seat 71 and a first sleeve 72. The surface of the first sleeve 72 is slidably connected to the inner wall of the fixed seat 71. The bottom of the first sleeve 72 is connected to the flow control disc 5. The surface of the first sleeve 72 located between the flow control disc 5 and the fixed seat 71 is sleeved with a first spring 73. Figure 5 or Figure 7As shown, the first driving member 6 is connected to the fixed seat 71, and the flow control disc 5 is driven to move by driving the fixed seat 71 to move. After the flow control disc 5 enters the working position, the flow control disc 5 is in a lower initial position under the action of its own weight. When the circulating liquid flows through the flow control disc 5, even if the conical hole 51 can be used for the flow of liquid, the flow control disc 5 will still hinder the circulation of the liquid. Although it is in the mixing stage at this time and will not have a significant impact on the subsequent reaction, it will still affect the stability of the conical hole 51 when the liquid flows out and the mixing efficiency. From another perspective, the amount of liquid that can flow out of the conical hole 51 per unit time is not only limited by its own size but also directly related to the speed of the liquid circulation. After the elastic member 7 is set, when the flow rate of the circulating liquid increases, the force of the liquid on the flow control disc 5 will cause the flow control disc 5 to compress the first spring 73 and move upward. On the one hand, it prevents the liquid from flowing out of the conical hole 51 from being too fast, affecting the shape of the formed liquid film. On the other hand, the spacing between the flow control disc 5 and the guide tube 3 increases, and the smoothness of the liquid circulation increases.

[0026] In one embodiment of the present invention, the first driving member 6 includes an electric telescopic rod 61, which is fixedly mounted on the top of the reactor 1. The output shaft of the electric telescopic rod 61 extends into the reactor 1 and is fixed to an extension bracket 63 through a connecting rod 62. The extension bracket 63 is fixedly connected to a fixing seat 71. In one embodiment of the present invention, a plurality of guide plates 52 distributed in an annular array are arranged near the circumference of the bottom of the flow control disc 5. The guide plates 52 are inclined from the inner side of the flow control disc 5 to the outer side. Fig.10 As shown, the rotating flowing liquid will drive the flow control disk 5 to rotate under the setting of the guide plate 52, causing it to rotate, further accelerating the flow of the liquid after absorbing the atomized droplets, so that it can be more fully mixed with the circulating liquid, thereby improving the overall mixing efficiency.

[0027] After the elastic member 7 and the guide plate 52 are provided, when the flow control disc 5 moves downward to the working position and contacts the circulating liquid, the flow control disc 5 will directly rotate, which is not conducive to judging whether the flow control disc 5 has moved to a suitable position (the form of the liquid gushing out of the conical hole 51). In one embodiment of the present invention, a method for solving the above problem is provided. Specifically, the elastic member 7 further includes a limit assembly 8, which is used to limit the flow control disc 5 from rotating relative to the fixing seat 71. In one embodiment of the present invention, a specific example of a limiting assembly 8 is provided, which includes at least one limiting groove 801 opened on the inner wall of the fixing seat 71, and at least one limiting rod 802 is slidably connected to the end of the first sleeve 72 along its radial direction. A second spring 803 is provided on one side of the limiting rod 802, and the elastic force of the second spring 803 acts on the limiting rod 802 to make it have a tendency to move away from the axial direction, such as Figure 5 and Figure 6 As shown, a support 811 is fixedly installed on the top of the first sleeve 72, and a guide rod 812 is fixedly connected to one side of the support 811. The guide rod 812 is slidably connected to the inner wall of the limit rod 802, and the end of the limit rod 802 is triangular or arc-shaped. Figure 6 Taking a triangular shape as an example, the corresponding limiting groove 801 is also a conical groove adapted to its end, and the flow control disc 5 is limited by the limiting rod 802 and the limiting groove 801. When the first sleeve 72 is close to rotating, the force acting on the limiting rod 802 is not enough to compress the second spring 803 to make it disengage from the limiting groove 801, and the flow control disc 5 will not be able to rotate, so that it remains stable under the action of the limiting assembly 8; In one embodiment of the present invention, another specific example of a limiting assembly 8 is provided, which includes a limiting seat 804 fixedly connected to the bottom of the first sleeve 72, a first disc 805 and a second disc 806 are arranged in the inner cavity of the annular limiting seat 804, a third spring 807 is arranged between the first disc 805 and the inner wall of the annular limiting seat 804, the second disc 806 is located below the first disc 805, a second sleeve 808 is fixedly connected to the bottom of the second disc 806, the bottom of the second sleeve 808 is fixedly connected to the top of the flow control disc 5, the annular limiting seat 804 is rotatably connected to the surface of the second sleeve 808, a circular array of spheres 809 are installed on the top of the second disc 806, the center of the sphere 809 is located below the plane where the top of the second disc 806 is located, and a spherical groove 810 adapted to each sphere 809 is opened at the bottom of the first disc 805; like Figure 7 As shown, the difference between this method and the previous method is that the previous method directly limits the position in the radial direction, while this method forms an axial limit through the contact between the ball 809 and the bottom of the first disc 805. When the flow control disc 5 tends to rotate, the second disc 806 will drive the ball 809 to produce a displacement trend relative to the spherical groove 810 of the first disc 805. Since the center of the ball 809 is located below the top plane of the second disc 806, when the flow control disc 5 is subjected to an external torsional force, an inclined contact surface will be generated between the ball 809 and the spherical groove 810, so that the first disc 805 is subjected to an upward axial component of force. At this time, the third spring 807 is compressed. If the external torque is not sufficient to overcome the combined force of the elastic force of the third spring 807 and the friction force of the contact surface, the ball 809 will be restricted in the spherical groove 810 and cannot slip out, thereby realizing self-locking axial limit. When the external torque exceeds the critical value, the ball 809 will slide out of the current position along the slope of the spherical groove 810, and embed into the adjacent spherical grooves 810 in sequence during the continuous rotation of the flow control disc 5, forming a ratchet-type stepped positioning. Compared with the radial limit method, this design is more suitable for axial load conditions, and the stress dispersion of spherical contact significantly improves the wear resistance. At the same time, the synchronous meshing structure of multiple balls 809 enhances the limit stability.

[0028] In one embodiment of the present invention, the guide tube 3 is in a tapered shape that is small at the top and large at the bottom, so that the flow rate of the liquid flowing upward from the guide tube 3 gradually increases. Under some conditions of low stirring speed, sufficient driving force is provided for the flow control disk 5, so that the flow control disk 5 can be used normally. In addition, it is also applicable to some reactors 1 with lower heights.

[0029] The above only describes some exemplary embodiments of the present invention by way of illustration. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the present invention.

Claims

1. A reactor flow control device for producing methyl isocyanate, comprising a reactor (1), wherein an agitator (2) and a draft tube (3) are arranged in the reactor (1), characterized in that: The reactor (1) is further provided with an atomizer (4) and a flow control disc (5). The flow control disc (5) is arranged above the flow guide tube (3) and has a diameter smaller than the inner diameter of the reactor (1). The flow control disc (5) can move along the axial direction of the reactor (1) to approach or move away from the flow guide tube (3). The flow control disc (5) is provided with a plurality of tapered holes (51) which are larger at the top and smaller at the bottom. When the liquid in the reactor (1) circulates, the liquid in the flow guide tube (3) flows upward and gushes out from the tapered holes (51) of the flow control disc (5), and the gushered liquid contacts and mixes with the atomized droplets sprayed by the atomizer (4).

2. The reactor flow control device for producing methyl isocyanate according to claim 1, characterized in that: The atomizers (4) are provided in a plurality and are distributed in a ring shape along the inner wall of the reaction kettle (1); the nozzles (41) of the atomizers (4) are tilted downwards, and the tilt angle is 15°-30°.

3. The reactor flow control device for producing methyl isocyanate according to claim 1, characterized in that: The flow control disc (5) is in the shape of a cone that bulges upward.

4. The reactor flow control device for producing methyl isocyanate according to claim 1, characterized in that: An elastic member (7) is provided on the top of the flow control disc (5), and the elastic force of the elastic member (7) acts on the flow control disc (5) so that it has a tendency to approach the flow guide cylinder (3).

5. The reactor flow control device for producing methyl isocyanate according to claim 4, characterized in that: The elastic member (7) comprises a fixed seat (71) and a first sleeve (72); the surface of the first sleeve (72) is slidably connected to the inner wall of the fixed seat (71); the bottom of the first sleeve (72) is connected to the flow control disc (5); and a first spring (73) is sleeved on the surface of the first sleeve (72) located between the flow control disc (5) and the fixed seat (71).

6. The reactor flow control device for producing methyl isocyanate according to claim 5, characterized in that: A plurality of guide plates (52) distributed in a circular array are arranged near the circumference of the bottom of the flow control disc (5), and the guide plates (52) are inclined from the inside to the outside of the flow control disc (5).

7. A reactor flow control device for producing methyl isocyanate according to claim 1 or 3, characterized in that: The diameter of the tapered hole (51) on the flow control disc (5) gradually increases from the outside to the inside.

8. The reactor flow control device for producing methyl isocyanate according to claim 5, characterized in that: The elastic member (7) further comprises a limiting assembly (8), wherein the limiting assembly (8) is used to limit the flow control disc (5) from rotating relative to the fixing seat (71).

9. The reactor flow control device for producing methyl isocyanate according to claim 8, characterized in that: The limiting assembly (8) comprises at least one limiting groove (801) formed on the inner wall of the fixing seat (71); the end of the first sleeve (72) is connected to at least one limiting rod (802) in a radially sliding manner; a second spring (803) is provided on one side of the limiting rod (802); the elastic force of the second spring (803) acts on the limiting rod (802) to cause it to have a tendency to move away from the axial direction.

10. The reactor flow control device for producing methyl isocyanate according to claim 1, characterized in that: The guide tube (3) is in a cone shape that is smaller at the top and larger at the bottom.

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