A continuous separator for nitration reaction

Abstract

This application belongs to the field of chemical special equipment, specifically relating to a continuous separator for nitration reactions. The application includes an isolation cylinder, the top opening of which is higher than the material inlet N1 and the nitric acid inlet N2. A guide cylinder extends coaxially upward from the bottom opening of the isolation cylinder, and a small rotating cylinder extends coaxially downward from the bottom of the drum. The bottom opening of the small rotating cylinder is coaxially wrapped around the outer wall of the guide cylinder, forming a rotary fit between the two. The material and nitric acid enter the primary mixing chamber formed between the outer wall of the isolation cylinder and the inner wall of the shell through their respective inlets, and are then drawn into the dispersion chamber formed by the small rotating cylinder through the guide cylinder. Subsequently, they enter the separation chamber formed by the inner cavity of the drum through a connecting hole at the bottom of the drum. The nitration products, after separation and clarification in the drum, are centrifugally ejected from the outlet located at the top of the drum. At this point, the area between the inner wall of the isolation cylinder and the outer wall of the small rotating cylinder constitutes a reaction isolation zone. This application ensures the continuity, efficiency, and safety of the nitration reaction, achieving the operational objectives of large capacity, continuous closed operation, and intrinsic safety.

Description

Technical Field

[0001] This application belongs to the field of chemical special equipment, specifically relating to a continuous separator for nitration reaction. Background Technology

[0002] Nitration is generally the process of introducing a nitro group into an organic compound molecule. It is a strongly exothermic reaction, prone to runaway reactions. Current nitration methods mainly include: dilute nitric acid nitration, concentrated nitric acid nitration, nitric acid nitration in concentrated sulfuric acid, nitric acid nitration in organic solvents, and heterogeneous mixed acid nitration. For example, aromatic hydrocarbon nitration is an important route for preparing amino compounds, and subsequently phenols, fluorides, and other compounds. The synthesis of high-performance energetic materials in the defense industry also relies heavily on nitration reactions. Nitration reactions are characterized by high exothermic activity, rapid exothermic rates, a tendency to runaway reactions, and the presence of flammable and explosive nitration products, all of which pose fire and explosion hazards.

[0003] Nitrification is a heterogeneous process, requiring nitration reactors equipped with strong and efficient agitation to ensure sufficient contact between the acid and organic phases. This places high demands on agitation performance. Simultaneously, the flammable and explosive nature of nitration necessitates inherently safe and highly reliable equipment. Currently, nitration reactions primarily utilize batch reactors, such as enamel-lined, steel, cast iron, or stainless steel reactors. Considering the intensity of the nitration reaction, small, single-batch feeding is often employed, accompanied by intermittent operation and limited agitation. This results in limited mixing intensity, insufficient production capacity, low efficiency, and high labor intensity. Later, microchannel reactors emerged to achieve nitration. In simple terms, this involves shifting from the traditional batch reactor's "small, single-batch addition" to a "continuous, small-batch supply" by breaking down the entire reactor into smaller, interconnected components. The flow-limiting characteristics of the microchannels ensure a small but continuous supply of materials. Clearly, while the microchannel method described above solves the problem of continuous reaction, the drawback of insufficient production capacity due to small-scale addition remains, hindering its engineering application. Furthermore, nitration reactions are often accompanied by the generation of impurities, which gradually accumulate within the microchannels and cannot be removed, causing blockages. This is another fundamental reason why the microchannel method is difficult to implement in engineering. Therefore, there is an urgent need to develop a new type of nitration reaction equipment that ensures the normal operation of the nitration reaction while guaranteeing its continuity, efficiency, and safety. Summary of the Invention

[0004] The purpose of this application is to overcome the shortcomings of the prior art and provide a continuous separator for nitration reaction, which uses a centrifugal force field combined with an isolated channel to ensure the continuity, efficiency and safety of the nitration reaction, and achieves the operational goals of large capacity, continuous closed operation and intrinsic safety.

[0005] To achieve the above objectives, this application adopts the following technical solution:

[0006] A continuous separator for nitration reaction includes a shell and a rotating drum located inside the shell. The separator further includes an isolation cylinder located inside the shell and positioned below the rotating drum. The top opening of the isolation cylinder is higher than the material inlet N1 and the nitric acid inlet N2. A guide cylinder extends coaxially upward from the bottom opening of the isolation cylinder, and a small rotating drum extends coaxially downward from the bottom of the rotating drum. The bottom opening of the small rotating drum is coaxially wrapped around the outer wall of the guide cylinder, and the two form a rotary fit. After the material and nitric acid enter the primary mixing chamber formed between the outer wall of the isolation cylinder and the inner wall of the shell through their respective inlets, they are then drawn into the dispersion chamber formed by the small rotating drum through the guide cylinder. Subsequently, they enter the separation chamber formed by the inner cavity of the rotating drum through a connecting hole at the bottom of the rotating drum. The nitration product, after separation and clarification by the rotating drum, is centrifugally ejected from the outlet located at the top of the rotating drum. At this time, the area between the inner wall of the isolation cylinder and the outer wall of the small rotating drum constitutes a reaction isolation zone.

[0007] Preferably, the inner wall of the drum is provided with prismatic lifting paddles that are inclined in the same direction. The direction of inclination of the lifting paddles is opposite to the direction of rotation of the drum, so as to gradually lift the mixture in the drum to the discharge port at the top of the drum under the action of centrifugal force.

[0008] Preferably, the drum has an extension shaft extending downwards coaxially, and the portion of the extension shaft that extends into the guide cylinder cavity is equipped with a self-priming blade, so that a suction cavity is formed between the guide cylinder cavity and the self-priming blade.

[0009] Preferably, a dispersing plate is radially arranged on the inner wall of the small rotating drum to drive the mixture to reach the synchronous rotation speed of the drum.

[0010] Preferably, the drum comprises, from top to bottom, a pressure cap, a rotor body, a bottom cap, and a small rotating drum in a vertical direction; a connecting hole is arranged through the bottom cap and is located close to the wall of the small rotating drum; a discharge port is coaxially provided on the pressure cap and the diameter of the discharge port is smaller than the diameter of the rotor body.

[0011] Preferably, an annular transition groove with its opening facing upward is coaxially provided on the inner wall of the shell at the top of the drum. A plate extending towards the outer wall is fixed on the upper surface of the cover. The plate rests on the outer wall and can rotate relative to the outer wall when the drum rotates. After the nitration product separated and clarified by the drum is thrown out through the outlet of the drum, it enters the annular transition groove through the plate for collection, and is then discharged from the nitration product outlet N4, which is connected to the cavity of the annular transition groove and opened on the outer wall of the shell.

[0012] Preferably, the housing is mounted on the frame, and a power motor is arranged on the frame. The power shaft of the power motor extends vertically downward through the discharge port and into the rotor body of the drum. It is connected to the rotor body through radially extending connecting ribs, thereby realizing the purpose of power transmission from the power motor to the drum.

[0013] Preferably, an overflow port N3 is also arranged on the outer wall of the shell. The overflow port N3 is connected to the primary mixing chamber. The inlet height of the overflow port N3 is lower than the top opening height of the isolation cylinder and higher than the material inlet N1 and the nitric acid inlet N2.

[0014] Preferably, the drum wall has a connecting hole along the axial direction, and several connecting holes arranged in sequence around the drum are connected to each other by transition rings located at both ends of the drum, thereby forming a refrigerant channel. A first refrigerant pipe is coaxially arranged through the power shaft at the top of the drum, and a second refrigerant pipe is coaxially inserted in the first refrigerant pipe. The two refrigerant pipes are respectively connected to the refrigerant inlet N5 and the refrigerant outlet N6 through a rotary joint.

[0015] Preferably, after the refrigerant enters one of the refrigerant pipes through the refrigerant inlet N5, it enters the transition ring through the radially extending inlet pipe at the drum end face, and after flowing through the refrigerant channel, it flows through the radially extending outlet pipe at the drum end face to another refrigerant pipe, and finally exits through the refrigerant outlet N6, completing the direct cooling cycle; at this time, the refrigerant channel, refrigerant pipe, inlet pipe and outlet pipe together constitute the direct cooling component.

[0016] Preferably, a cooling jacket is provided at the shell, and a water-cooled wall is arranged on the inner wall of the shell. The cooling jacket and the water-cooled wall together constitute an auxiliary cooling component.

[0017] The beneficial effects of this application are as follows:

[0018] 1) Through the above scheme, on the one hand, this application specifically adds an isolation cylinder to address the intensity of the nitration reaction; when the drum rotates and disperses the mixture around the drum, a violent reaction will occur. At this time, the presence of the isolation cylinder can avoid the uncontrollability of the reaction caused by the high-speed rotation of the drum, allowing the newly introduced nitric acid and materials to have a relatively stable transition period and initial mixing period before entering the violent reaction zone; this application achieves the purpose of multi-stage gradual reaction and intrinsic safety of the nitration reaction from the perspective of equipment operation mechanism by decomposing the nitration reaction stage. On the other hand, this application utilizes the clarification and separation operation of the drum, which also allows the solid phase in the mixture to be left on the drum surface, which can be cleaned periodically afterward, without having to consider the clogging problem of traditional solid phase flow channels, etc.

[0019] In other words, this application provides sufficient safety space for the vigorous reaction of materials by leaving space between the isolation cylinder and the rotating drum. The isolation cylinder directly divides the inner cavity of the shell into a liquid-free reaction isolation zone, ensuring effective isolation between the high-speed turbulent separation chamber and the initial mixing chamber where liquid initially enters. Simultaneously, it solves the problems of solid phase collection and clogging that are unavoidable in conventional continuous nitration reactions. Thus, this application ultimately ensures both normal, efficient, and continuous operation, while maintaining the compactness and safety of the overall structure, achieving the goals of high capacity, continuous closed operation within the separator, and intrinsic safety.

[0020] 2) When the drum rotates at high speed, the mixture at the bottom can be gradually lifted to the top under the action of centrifugal force. More preferably, this application also arranges lifting paddles inclined in the same direction inside the drum to further enhance the lifting effect of the mixture. Thus, under the premise of high-speed centrifugation and liquid phase separation, the displacement and throwing effect of the clarified phase towards the top discharge port of the drum are improved. More importantly, the evenly distributed lifting paddles can also avoid the material from "shaking" asynchronously in the drum, resulting in wasted effort, with significant effect.

[0021] 3) The high-speed rotation of the drum and the small rotating cylinder also generates a certain suction force on the connecting hole and even the feed tube, thereby achieving the effect of the liquid phase moving from bottom to top. Preferably, this application also extends a self-priming blade at the drum, thereby utilizing the self-priming pump structure formed by the combination of the self-priming blade and the feed tube to accelerate the self-priming effect, ensuring that the initial mixed liquid in the primary mixing chamber can be quickly pumped into the small rotating cylinder, and finally drawn into the separation chamber where the drum is located through the connecting hole to complete the separation purpose. Of course, a dispersion plate is also arranged in the small rotating cylinder to ensure that the liquid phase entering the small rotating cylinder can quickly complete the rotation at the same speed as the drum, thereby laying the foundation for subsequent separation work.

[0022] 4) The rotary drum itself consists of a gland, rotor body, bottom cover, small rotating drum, and even self-priming blades. It is important to note that the discharge port diameter is preferably smaller than the rotor body's diameter; this creates a weir-like structure at the discharge port, which improves the clarification and separation of the mixture within the drum. The separated and clarified nitration products then enter the nitration product outlet (N4) via an annular transition tank, completing the entire linear process.

[0023] 5) The overflow port design is another highlight of this application. On the one hand, there are gaps between the isolation cylinder and the shell, and on the other hand, there are gaps between the isolation cylinder and the rotating drum. Therefore, it is possible for materials and nitric acid to overflow along the gaps between the isolation cylinder and the shell and enter the reaction isolation zone of the isolation cylinder from the top opening, which is obviously strictly prohibited. Therefore, by arranging an overflow port, this application can prevent the initial mixture formed by the materials and nitric acid from rising and entering the reaction isolation zone under unexpected situations such as excessive feed or violent reaction, thus avoiding safety hazards. It achieves effective removal of the high-level initial mixture, improving the inherent safety and operational reliability of this application.

[0024] 6) As the third highlight of this application, this application provides a series of cooling components, including direct cooling components and auxiliary cooling components. The direct cooling components are used to directly cool the liquid undergoing high-speed heating reaction inside the drum, while the auxiliary cooling components ensure the overall cooling effect inside the shell. By controlling the cooling temperature as described above, the process temperature requirements of the reaction can be easily achieved, thereby completing the cooling and heat exchange of the intensely exothermic nitration reaction, ultimately ensuring the stability, reliability, and continuity of the process. Attached Figure Description

[0025] Figure 1 This is a diagram showing the operating status of the continuous separator for the nitration reaction in this application;

[0026] Figure 2 for Figure 1 A magnified view of part I;

[0027] Figure 3 for Figure 1 Enlarged view of part II;

[0028] Figure 4 This is a structural sectional view of the shell;

[0029] Figure 5 This is a cross-sectional view of the drum structure;

[0030] Figure 6 Arrangement diagram for lifting propellers;

[0031] Figure 7 This is the piping installation diagram for this application.

[0032] The actual correspondence between the reference numerals and component names in this application is as follows:

[0033] a- Primary mixing chamber; b- Suction chamber; c- Dispersion chamber; d- Separation chamber; e- Reaction isolation zone;

[0034] 10-Shell; 11-Annular transition groove; 12-Cooling jacket; 13-Water-cooled wall;

[0035] 20-Drum; 20a-Connecting hole; 20b-Discharge port; 20c-Lifting paddle; 20d-Self-priming paddle; 21-Small drum; 21a-Dispersion plate; 22-Pressure cap; 23-Rotor body; 24-Bottom cover; 25-Panel;

[0036] 30 - Isolation cylinder; 31 - Feed guide cylinder;

[0037] 40 - Frame; 41 - Power motor; 42 - Connecting rib;

[0038] 51-Connecting hole; 52-Transition ring; 53-First refrigerant pipe; 54-Second refrigerant pipe; 55-Rotary joint; 56-Inlet pipe; 57-Outlet pipe;

[0039] 60 - Material storage tank; 61 - Material transfer pump; 70 - Nitric acid storage tank; 71 - Nitric acid transfer pump; 80 - Nitration product storage tank; 90 - Refrigerant storage tank. Detailed Implementation

[0040] For ease of understanding, this section combines... Figure 1-7 The specific structure and working method of this application are further described below:

[0041] This application mainly consists of a drum 20, a housing 10, a frame 40, and transmission components, as detailed below. Figure 1 The drum 20 and the housing 10 are arranged coaxially. The drum 20 is fixed to the large plate on the top of the frame 40 through a bearing seat. The motor of the transmission component drives the drum 20 to rotate at high speed through a pulley pair, and its speed can be precisely adjusted through the electrical control system to adapt to the material working conditions.

[0042] like Figure 4 As shown, the shell 10 is the place where materials (organic phase), nitric acid, etc. enter the equipment and where the liquid accumulated after the mixing and mass transfer reaction is discharged. It is equipped with a material inlet N1, a nitric acid inlet N2, an overflow port N3, a nitration product outlet N4, a refrigerant inlet N5, and a refrigerant outlet N6; it also has several refrigerant ports for cooling auxiliary cooling components. In addition, a vent N7 is arranged at the bottom of the shell 10, and the vent N7 is located at the lowest point of the shell 10 and is generally equipped with a valve.

[0043] The shell 10 is welded from a straight section and a head section. The head is located at the bottom of the straight section, and the upper part of the straight section is coaxially welded to a circular flange to form an inner cavity. The material inlet N1 and the nitric acid inlet N2 are located on the outer wall of the shell 10 near the bottom of the inner cavity. A suitable space is left between the inner diameter of the shell and the rotating drum 20 to allow sufficient room for vigorous material reactions. To avoid the uncontrollability of the reaction due to the high-speed rotation of the rotating drum 20, an isolation cylinder 30 is provided between the shell and the rotating drum 20. The upper edge of the isolation cylinder 30, i.e., the top opening, is higher than the material inlet N1 and the nitric acid inlet N2, so as to effectively isolate the high-speed rotation of the rotating drum 20 from the feeding mixture, ensuring that the initial liquid entering the primary mixing chamber a does not directly participate in the high-speed stirring and vigorous reaction process of the separation chamber d at the rotating drum 20. At the same time, to prevent the material level from rising and entering the reaction isolation zone between the rotating drum 20 and the isolation cylinder 30 in case of unexpected situations such as excessive material feeding or vigorous reaction, thus creating a safety hazard, such as… Figure 1-2 and Figure 4 As shown, this application also includes an overflow port N3 at the upper edge of the isolation cylinder 30 to effectively discharge materials with high liquid levels. Thus, the primary mixing chamber a is formed by the outer surface of the isolation cylinder 30, the lower part of the straight section of the cylinder body, and the inner surface of the end cap. The material comes into contact with nitric acid here and begins the primary nitration reaction. A guide cylinder 31 is located at the center of the isolation cylinder 30. The guide cylinder 31 cooperates with the self-priming blade 20d, with a suitable gap between the inner diameter of the guide cylinder 31 and the outer diameter of the self-priming blade 20d. The pumping action is achieved by considering the shape, position, angle, and size of the blades on the self-priming blade 20d, as well as factors such as rotation speed and direction. Under the pumping action, the mixture from the primary nitration reaction undergoes a secondary nitration reaction with a larger phase contact surface and a shorter contact time. It then enters the dispersion chamber c, composed of small rotating cylinders 21, at the bottom of the rotating drum 20 through the guide cylinder 31. Under high-speed rotation, the material undergoes a tertiary nitration reaction.

[0044] By transferring materials in the above manner, the nitration reaction is broken down into three stages, which alleviates the violent reaction process, reduces heat release and material boiling, and enhances safety.

[0045] like Figure 3-4As shown, the upper part of the shell 10 is provided with a liquid collection cylinder, which, together with the upper part of the straight section of the cylinder, forms an annular transition groove 11. After nitration, the nitration product is centrifuged and clarified by the drum 20, and then centrifugally ejected from the discharge port 20b at the top of the drum 20, enters the annular transition groove 11 via the ramp 25, and is discharged from the nitration product outlet N4. In order to dissipate the heat released during the nitration reaction as quickly as possible, a cooling jacket 12 is also provided on the outside of the shell 10. The jacket cavity of the cooling jacket 12 is in complete contact with the straight section and the end cap section of the cylinder, maximizing the heat exchange area. Furthermore, if it is necessary to increase the cooling area, a single or double layer of coils can be added inside the shell 10 to form a water-cooled wall 13. The cooling jacket 12 and the water-cooled wall 13 are both auxiliary cooling parts, which together form an auxiliary cooling assembly.

[0046] like Figure 5-6 As shown, the drum 20 is mainly composed of a pressure cap 22, a rotor body 23, a bottom cover 24, and a small rotating drum 21, all coaxially arranged. Connecting holes 51 are arranged axially on the wall of the rotor body 23, and these connecting holes 51 are evenly distributed around the circumference of the rotor body 23. Considering the connectivity of each connecting hole 51, each connecting hole 51 has an upper waist-shaped connecting groove of a certain depth at its upper part and a lower waist-shaped connecting groove of a certain depth at its lower part. The transition ring 52 formed by the upper and lower connecting grooves directly connects to both ends of the connecting hole 51, forming a refrigerant channel similar to a squirrel cage. The power shaft is coaxial with the drum 20 and is driven by a power motor 41, while also being fixed to the drum 20 by connecting ribs 42 to achieve the power transmission process. The drive shaft has a hollow hole serving as the first refrigerant pipe 53, which connects to the refrigerant outlet N6 of the rotary joint 55. A second refrigerant pipe 54 is concentrically located inside the first refrigerant pipe 53, its upper part also concentrically connected to the rotary joint 55 and connected to the refrigerant inlet N5 of the rotary joint 55. The lower part of the second refrigerant pipe 54 is sealed by a sealing ring, and refrigerant is introduced into the transition ring 52 through the inlet pipe 56. Subsequently, the refrigerant flows from the upper transition ring 52 to the connecting hole 51, thereby delivering the refrigerant to the circumferential surface of the rotor body 23, directly contacting the material and effectively removing the reaction heat of the material in the drum 20. The refrigerant finally collects in the lower transition ring 52 and then, after heat exchange, is delivered to the first refrigerant pipe 53 through the outlet pipe 57, and discharged from the refrigerant outlet N6, completing the direct cooling heat exchange process.

[0047] like Figure 5As shown, the bottom cover 24 has an extension shaft concentrically positioned at its bottom end, rotating synchronously with the drum 20. A certain number of self-priming blades 20d, with varying angles and dimensions, are positioned at appropriate locations on the extension shaft. The outer diameter of the self-priming blades 20d maintains a certain gap δ with the inner diameter of the guide cylinder 31. Controlling the number, angle, shape, gap δ, and rotational speed of the self-priming blades 20d generates different upward suction forces and suction volumes, forming the suction chamber b. After the first three stages of nitration, the mixture is stirred and mixed in the suction chamber b under the action of the self-priming blades 20d, completing the final nitration reaction. It then enters the dispersion chamber c and, under centrifugal force, is thrown at high speed towards the wall of the small rotating drum 21. The small rotating drum 21 contains a certain number of dispersion plates 21a, which can quickly drive the mixture to the synchronous rotational speed of the drum 20. A series of connecting holes 20a are evenly distributed near the inner diameter of the rotor body 23 on the bottom cover 24, enabling communication between the separation chamber d and the dispersion chamber c. After the reaction is complete, the mixture enters the separation chamber d through the connecting hole 20a. Under the action of the lifting paddle 20c, the mixture moves from the bottom to the top of the rotor body 23 and fully contacts the cooling area of ​​the aforementioned connecting hole 51, completing the direct cooling heat exchange process. Finally, the separated and clarified nitration product is thrown out of the rotor body 23 through the discharge port 20b at the top of the drum 20, falls into the annular transition groove 11, and is then discharged from the nitration product outlet N4. The lifting paddles 20c are evenly distributed and obliquely placed inside the rotor body 23 at a certain angle; the oblique angle of the lifting paddles 20c should generate an upward force to lift the mixture under the action of rotation. The evenly distributed lifting paddles 20c can also quickly drive the mixture synchronously, avoiding the material "shaking" and being out of sync inside the rotor body 23, resulting in wasted work.

[0048] In actual operation, the continuous nitration separator of this application also requires auxiliary material conditioning facilities to form, as shown in the following example. Figure 6The system structure is shown. In the entire nitration reaction continuous separation system, the material storage tank 60 contains material, and the material status can be monitored by liquid level sensors, etc. The material transfer pump 61 pumps the material out of the material storage tank 60, and the material enters through the material inlet N1 via the material flow meter L1 on the pipeline; the nitric acid storage tank 70 contains nitric acid of a certain concentration, and the loading status can be monitored by liquid level sensors, etc. The nitric acid transfer pump 71 pumps the nitric acid out of the nitric acid storage tank 70, and the nitric acid enters through the nitric acid inlet N2 via the nitric acid flow meter L2 on the pipeline. The two meet in the primary mixing chamber a, and under their respective feed pressures, they undergo preliminary mixing and mass transfer reactions; then, under the pumping action of the self-priming impeller 20d, the preliminary mixture undergoes secondary and tertiary nitration reactions in the suction chamber b and dispersion chamber c, respectively, generating heat, and then enters the separation chamber d through the connecting hole 20a, where it is gradually separated and cooled. Under the action of the lifting impeller 20c, the material is lifted and flows from the bottom of the rotor body 23 to the top, completing cooling and clarification. Trace impurities, due to their higher density, are thrown towards the inner wall of rotor 23 under centrifugal force and are manually cleaned periodically. The cooled and clarified nitration products are centrifuged out of outlet 20b, enter the annular transition tank 11, and are discharged from nitration product outlet N4, entering nitration product storage tank 80 or subsequent nitration product processes, thus completing a continuous production process. Overflow outlet N3 and vent outlet N7 are both connected to the inlet of material storage tank 60; the discharge from overflow outlet N3 and vent outlet N7 is a mixture, small in quantity, and not a contaminant, and after returning to material storage tank 60, it will re-enter the continuous nitration reaction separator to continue the reaction. The refrigerant storage tank 90 is connected to the corresponding refrigerant components.

[0049] Correspondingly, the refrigerant inlet is divided into three parts: the first part cools the entire exterior of the cylinder through the cooling jacket 12; the second part cools the space between the cylinder and the rotor 23 through the water-cooled wall 13; these two types of cooling can be referred to as auxiliary cooling. The third part of the refrigerant enters through the refrigerant inlet N5 into a series of connecting holes 51 set on the cylinder wall of the rotor 23. The refrigerant is directly distributed on the cylinder wall of the rotor 23, directly contacting and exchanging heat with the material inside the rotor 23, which can be referred to as direct cooling. Depending on the process requirements, the connecting holes 51 can be set in a single row or double row, with various variations and a wide range of applications; after heat exchange, this part of the refrigerant is discharged through the refrigerant outlet N6. This completes the cooling and heat exchange for the intensely exothermic nitration reaction, ensuring the stability, reliability, and continuity of the process. From the perspective of equipment operation mechanism, through the decomposition of the nitration reaction stage and multiple cooling methods, the inherent safety of the nitration reaction is achieved. By controlling the cooling temperature of these three parts, the process temperature requirements of the reaction can also be easily achieved.

[0050] It is worth noting that the connection holes 51 of this application are arranged along the axial direction of the drum 20. This is not only to achieve a simple cooling effect, but also to take into account that the centrifugal force generated by the high-speed rotation of the drum will cause bubbles to be generated in the flow channel, thereby affecting the heat dissipation effect. The multiple connection holes arranged along the axial direction can effectively avoid the bubble phenomenon caused by radial centrifugal force, so as to improve the cooling effect.

[0051] Of course, those skilled in the art will recognize that this application is not limited to the details of the exemplary embodiments described above, but also includes the same or similar methods that can be implemented in other specific forms without departing from the spirit or essential characteristics of this application. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of this application is defined by the appended claims rather than the foregoing description.

[0052] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0053] All technical parts not described in detail in this application are publicly known technologies.

Claims

1. A continuous separator for nitration reaction, comprising a shell (10) and a rotating drum (20) located within the shell (10), characterized in that: It also includes an isolation cylinder (30) located inside the shell (10) and nestled at the bottom of the drum (20). The top opening of the isolation cylinder (30) is higher than the material inlet N1 and the nitric acid inlet N2. A guide cylinder (31) extends coaxially upward from the bottom opening of the isolation cylinder (30), and a small rotating cylinder (21) extends coaxially downward from the bottom of the drum (20). The bottom opening of the small rotating cylinder (21) is coaxially wrapped around the outer wall of the guide cylinder (31), and the two form a rotary fit. The material and nitric acid enter the outer wall of the isolation cylinder (30) through the corresponding inlet and... After the primary mixing chamber (a) formed between the inner walls of the shell (10), the product is then drawn into the dispersion chamber (c) formed by the small rotating drum (21) through the feed guide (31). Subsequently, it enters the separation chamber (d) formed by the inner cavity of the rotating drum (20) through the connecting hole (20a) at the bottom of the rotating drum (20). The nitration product separated and clarified by the rotating drum (20) is centrifugally ejected from the discharge port (20b) located at the top of the rotating drum (20). At this time, the area between the inner wall of the isolation cylinder (30) and the outer wall of the small rotating drum (21) constitutes the reaction isolation zone (e). An overflow port N3 is also arranged on the outer wall of the shell (10). The overflow port N3 is connected to the primary mixing chamber (a). The inlet height of the overflow port N3 is lower than the top opening height of the isolation cylinder (30) and higher than the height of the material inlet N1 and the nitric acid inlet N2. A connecting hole (51) is provided along the axial direction on the cylinder wall of the drum (20). Several connecting holes (51) arranged in sequence around the circumference of the drum (20) are connected to each other by transition rings (52) located at both ends of the drum (20), thereby forming a refrigerant channel. A first refrigerant pipe (53) is coaxially arranged through the power shaft at the top of the drum (20). A second refrigerant pipe (54) is coaxially inserted in the first refrigerant pipe (53). The two refrigerant pipes are connected to the refrigerant inlet N5 and the refrigerant outlet N6 respectively through a rotary joint (55). After the refrigerant enters one of the refrigerant pipes through the refrigerant inlet N5, it enters the transition ring (52) through the radially extending inlet pipe (56) at the end face of the drum (20), and after flowing through the refrigerant channel, it flows through the radially extending outlet pipe (57) at the end face of the drum (20) to another refrigerant pipe, and finally exits through the refrigerant outlet N6, completing the direct cooling cycle; at this time, the refrigerant channel, refrigerant pipe, inlet pipe (56) and outlet pipe (57) together constitute the direct cooling component.

2. The nitration reaction continuous separator according to claim 1, characterized in that: The inner wall of the drum (20) is provided with prismatic lifting paddles (20c) that are inclined in the same direction. The lifting paddles (20c) are inclined in the opposite direction to the rotation direction of the drum (20) so as to gradually lift the mixture in the drum (20) to the discharge port (20b) at the top of the drum (20) under the action of centrifugal force.

3. A continuous separator for nitration reaction according to claim 1, characterized in that: An extension shaft extends coaxially downward from the drum (20), and a self-priming blade (20d) is installed on the part of the extension shaft that extends into the cavity of the guide cylinder (31) so that a suction cavity (b) is formed between the cavity of the guide cylinder (31) and the self-priming blade (20d).

4. A continuous separator for nitration reaction according to claim 1, characterized in that: The inner wall of the small rotating drum (21) is radially arranged with a dispersing plate (21a) for driving the mixture to reach the synchronous speed of the rotating drum (20).

5. A continuous separator for nitration reaction according to any one of claims 1-4, characterized in that: The drum (20) includes, from top to bottom, a pressure cap (22), a rotor body (23), a bottom cover (24), and a small rotating drum (21) in the vertical direction; a connecting hole (20a) is arranged through the bottom cover (24) and is located close to the wall of the small rotating drum (21); a discharge port (20b) is coaxially arranged on the pressure cap (22) and the diameter of the discharge port (20b) is smaller than the diameter of the rotor body (23).

6. A continuous separator for nitration reaction according to claim 5, characterized in that: An annular transition groove (11) with its opening facing upward is coaxially provided on the inner wall of the shell (10) at the top of the drum (20). A plate (25) extending outward to the outer wall is fixed on the upper surface of the cover (22). The plate (25) rests on the outer wall and can rotate relative to the outer wall when the drum (20) rotates. After the nitration product separated and clarified by the drum (20) is thrown out through the discharge port (20b) of the drum (20), it enters the annular transition groove (11) through the plate (25) for collection, and is then discharged through the nitration product outlet N4, which is connected to the cavity of the annular transition groove (11) and opened on the outer wall of the shell (10).

7. A continuous separator for nitration reaction according to claim 5, characterized in that: The housing (10) is mounted on the frame (40), and the power motor (41) is arranged at the frame (40). The power shaft of the power motor (41) passes vertically downward through the discharge port (20b) and extends into the rotor body (23) of the drum (20). The rotor body (23) is connected by a radially extending connecting rib (42), thereby realizing the purpose of power transmission from the power motor (41) to the drum (20).

8. A continuous separator for nitration reaction according to claim 1, characterized in that: A cooling jacket (12) is provided at the housing (10), and a water-cooled wall (13) is arranged on the inner wall of the housing (10). The cooling jacket (12) and the water-cooled wall (13) together constitute an auxiliary cooling assembly.

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