Continuous separation system based on nitration reaction continuous separator

Abstract

The invention belongs to the field of special chemical equipment, and particularly relates to a continuous separation system based on a nitration reaction continuous separator. A material storage tank is communicated with a material inlet N1 of a nitration reaction continuous separator through a material pipeline, and a material conveying pump and a material meter L1 are sequentially arranged on the material pipeline; a nitric acid storage tank is communicated with a nitric acid inlet N2 of the nitration reaction continuous separator through a nitric acid pipeline, and a nitric acid delivery pump and a nitric acid meter L2 are sequentially arranged on the nitric acid pipeline; materials and nitric acid are pumped into a primary mixing cavity formed between the outer wall of the isolation barrel and the inner wall of the shell through a material pipeline and a nitric acid pipeline respectively, then are sucked into a dispersion cavity formed by a barrel cavity of the small rotary barrel through a material guide barrel, and then enter a separation cavity formed by an inner cavity of the rotary drum through a communicating hole in the bottom face of the rotary drum; a nitration product separated and clarified by the rotary drum is centrifugally thrown out from a discharge hole in the top of the rotary drum, and is discharged into a nitration product storage tank from a nitration product outlet N3 in the upper part of the shell. According to the application, the continuity, high efficiency and safety of nitration reaction are ensured, and the operation purposes of systematization, high efficiency, continuous closed operation and intrinsic safety can be achieved.

Description

Technical Field

[0001] The present application belongs to the field of chemical industry-specific equipment, and specifically relates to a continuous separation system based on a nitration reaction continuous separator. Background Art

[0002] Nitration is generally a process of introducing nitro groups into organic compound molecules. The reaction process is a highly exothermic reaction and is prone to runaway. Currently, the main nitration methods 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 way to prepare amino compounds, and then to prepare phenols, fluorides and other compounds; the synthesis of high-performance energetic materials in the defense industry is also inseparable from the nitration process. Nitration reactions have special properties such as large heat release, fast heat release rate, easy runaway, and nitration products are flammable and explosive, most of which are fire and explosion hazards.

[0003] Nitration is a heterogeneous process, which requires the nitration reactor to be equipped with a good and strong stirring device to make the acid phase and the organic phase fully contact, so it puts forward high requirements on the stirring effect; at the same time, the nitration process is flammable and explosive, which requires the equipment to have good intrinsic safety and high reliability. At present, the nitration reaction mainly adopts a kettle structure, such as an enamel kettle, a steel kettle, a cast iron kettle or a stainless steel kettle. At the same time, considering the intensity of the nitration reaction, a single small amount of material addition is often adopted, accompanied by intermittent operation and limited stirring, resulting in limited mixing intensity of the entire process, insufficient production capacity, low efficiency and high labor intensity. Later, the microchannel reaction method gradually emerged to achieve the purpose of nitration. To put it simply, it is to transform from the "single small amount addition" of the traditional kettle equipment to the "continuous small amount supply" after breaking the whole into parts, splitting the overall equipment into parts, and then relying on microchannel connection, relying on the flow limiting characteristics of the microchannel pipeline to ensure the small but continuous addition of materials. Obviously, although the above-mentioned microchannel method solves the problem of continuous reaction, the defect of insufficient production capacity caused by a small amount of addition is still unsolved, making it difficult to apply in engineering; in addition, the nitrification reaction is often accompanied by the generation of some impurities, and a large amount of impurities will gradually accumulate in the microchannel and cannot be removed, causing pipe blockage problems, which is another fundamental reason why the microchannel method is difficult to apply in engineering. For this reason, it is urgent to develop a new type of nitrification reaction system to ensure the normal nitrification reaction itself while ensuring the continuity, efficiency and safety of its work. Summary of the invention

[0004] The purpose of the present application is to overcome the deficiencies of the above-mentioned prior art and to provide a continuous separation system based on a continuous separator for nitrification reaction, which utilizes the centrifugal field of the continuous separator for nitrification reaction in combination with an isolated channel, and cooperates with various storage tanks and pipelines to ensure the continuity, efficiency and safety of the nitrification reaction, and can achieve the purpose of systematic, high-efficiency, continuous closed operation and intrinsically safe operation.

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

[0006] A continuous separation system based on a nitration reaction continuous separator, characterized in that: it comprises a nitration reaction continuous separator, a material storage tank is connected to a material inlet N1 of the nitration reaction continuous separator through a material pipeline, and a material delivery pump and a material meter L1 are arranged in sequence on the material pipeline; a nitric acid storage tank is connected to a nitric acid inlet N2 of the nitration reaction continuous separator through a nitric acid pipeline, and a nitric acid delivery pump and a nitric acid meter L2 are arranged in sequence on the nitric acid pipeline;

[0007] The nitration reaction continuous separator comprises a shell, a drum located in the shell, and an isolation cylinder located in the shell and arranged at the bottom of the drum, wherein the top opening of the isolation cylinder is higher than the material inlet N1 and the nitric acid inlet N2; a material guide cylinder is coaxially extended upward from the bottom opening of the isolation cylinder, a small rotating cylinder is coaxially extended downward from the bottom of the drum, the bottom opening of the small rotating cylinder is coaxially wrapped around the outer wall of the material guide cylinder and the two form a swivel fit, and at this time, the area between the inner wall of the isolation cylinder and the outer wall of the small rotating cylinder constitutes a reaction isolation zone;

[0008] The material and nitric acid are pumped into the primary mixing chamber formed between the outer wall of the isolation cylinder and the inner wall of the shell through the material pipeline and the nitric acid pipeline respectively to complete the primary nitration reaction, and then enter the material guide cylinder to complete the secondary nitration reaction, and then are sucked into the dispersion chamber formed by the small drum cavity to realize the tertiary nitration reaction, and then enter the separation chamber formed by the inner cavity of the drum through the connecting hole at the bottom of the drum. The nitration product after separation and clarification by the drum is centrifugally thrown out from the discharge port located at the top of the drum, and discharged from the nitration product outlet N3 located at the upper part of the shell to the nitration product storage tank, completing the reaction process.

[0009] Preferably, an overflow port N3 is also arranged on the outer wall of the shell, and the overflow port N3 is connected to the primary mixing chamber. The inlet height of the overflow port N3 is lower than the top tube mouth height of the isolation tube and higher than the heights of the material inlet N1 and the nitric acid inlet N2. The overflow port N3 is connected to the material storage tank via an overflow pipe.

[0010] Preferably, an emptying port N7 connected to the primary mixing chamber and having an inlet located at the lowest point of the primary mixing chamber is arranged at the bottom of the shell, and the emptying port N7 is connected to the material storage tank via an emptying pipe.

[0011] Preferably, the inner wall of the drum is provided with prismatic lifting paddles inclined in the same direction, and the inclination direction of the lifting paddles is opposite to the rotation direction of the drum, so as to gradually lift the mixed liquid in the drum to the discharge port at the top of the drum under the action of centrifugal force.

[0012] Preferably, an extension shaft is coaxially extended downward from the rotating drum, and a self-priming paddle is installed on the portion of the extension shaft extending into the barrel cavity of the material guide barrel, so that a suction chamber is formed in the space between the barrel cavity of the material guide barrel and the self-priming paddle.

[0013] Preferably, a dispersion plate is radially arranged on the inner wall of the small drum to drive the mixed material to reach the synchronous speed of the drum.

[0014] Preferably, the drum includes a pressure cover, a rotor body, a bottom cover and a small rotating cylinder in order from top to bottom in the vertical direction; the connecting hole is arranged through the bottom cover and is arranged close to the wall of the small rotating cylinder; a discharge port is coaxially arranged on the pressure cover, and the diameter of the discharge port is smaller than the cylinder diameter of the rotor body.

[0015] Preferably, an annular transition groove with an upward notch is coaxially arranged on the inner wall of the shell at the top of the drum, and a strap extending toward the outer groove wall is fixed on the upper surface of the pressure cover, the strap is strapped on the outer groove wall and can generate a rotational motion relative to the outer groove wall when the drum rotates; the nitration product after separation and clarification by the drum is thrown out through the discharge port of the drum, and then enters the annular transition groove for collection by the strap, and then is discharged from the nitration product outlet N4 connected to the groove cavity of the annular transition groove and opened on the outer wall of the shell.

[0016] Preferably, a connection hole is opened in the axial direction of the drum wall, and a plurality of connection holes arranged in sequence around the circumference of the drum are connected to each other by means of transition rings located at both end surfaces 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;

[0017] After the refrigerant enters one of the refrigerant pipes through the refrigerant inlet N5, it enters the transition ring through the inlet pipe extending radially from the end face of the drum, and after flowing through the refrigerant channel, it flows through the outlet pipe extending radially from the end face of the drum to another refrigerant pipe, and finally is discharged from the refrigerant outlet N6, completing the direct cooling cycle; at this time, the refrigerant channel, refrigerant pipe, inlet pipe and outlet pipe together constitute a direct cooling component;

[0018] The refrigerant inlet N5 and the refrigerant outlet N6 are respectively connected to the inlet and outlet of the refrigerant storage tank.

[0019] Preferably, a cooling jacket is provided at the shell, and a water-cooled wall is arranged at the inner wall of the shell, and the cooling jacket and the water-cooled wall together constitute an auxiliary cooling component; the input end and the output end of the auxiliary cooling component are the inlet and the outlet of the refrigerant storage tank respectively.

[0020] The beneficial effects of this application are:

[0021] 1) Through the above scheme, on the one hand, the present application aims at the intensity of the nitration reaction, so an isolation cylinder is specially added; when the drum rotates and disperses and stirs, the mixed liquid around the drum will produce a violent reaction. At this time, relying on the existence of the isolation cylinder, the uncontrollability of the reaction caused by the high-speed rotation of the drum can be avoided, so that the nitric acid and materials that have just entered can have a relatively stable transition period and initial mixing period before entering the violent reaction area; the present application can achieve the multi-stage step-by-step reaction and intrinsic safety purpose of the nitration reaction from the equipment operation mechanism by decomposing the nitration reaction stage. On the other hand, the present application uses the clarification and separation operation of the drum, so that the solid phase in the mixed liquid is left on the drum surface, and subsequent periodic cleaning is sufficient, without considering the blockage problem of the traditional solid phase to the flow channel. Finally, in conjunction with various storage tanks and pipelines, the continuous closed operation characteristics of the nitration reaction can be guaranteed, and the efficiency and safety of the process can be ensured, and finally the operation purpose of systematization, high efficiency, continuous closed operation and intrinsic safety can be achieved.

[0022] In other words, the present application reserves a space between the isolation tube and the drum to provide sufficient safety space for the violent reaction of the material, and utilizes the isolation tube to directly divide the liquid-free reaction isolation zone in the inner cavity of the shell to ensure the effective isolation effect between the separation chamber in the high-speed turbulent environment and the primary mixing chamber for the initial liquid inlet; at the same time, it also solves the solid phase collection and blockage problems that are inevitably encountered in conventional continuous nitration reactions; and in conjunction with external auxiliary pipelines, the purpose of engineering application is maximized.

[0023] 2) The setting of the overflow port is another highlight of this application; on the one hand, there is a gap between the isolation tube and the shell, and at the same time, there is a gap between the isolation tube and the drum. Therefore, it is possible that the material and nitric acid overflow along the gap between the isolation tube and the shell, and then pour into the reaction isolation zone of the isolation tube from the top of the isolation tube, which is obviously strictly prohibited. Therefore, by arranging the overflow port, this application can prevent the initial mixed liquid formed by the material and nitric acid from rising into the reaction isolation zone under unexpected conditions such as too much feed or violent reaction, thereby preventing safety hazards, and realizing the effective extraction of the high-level initial mixed liquid, thereby improving the inherent safety and working reliability of this application.

[0024] 3) When the drum rotates at high speed, the mixed liquid at the bottom can be gradually lifted to the top under the action of centrifugal force; and more preferably, the present application also arranges lifting paddles inclined in the same direction inside the drum to further enhance the lifting effect of the mixed liquid, thereby enhancing the displacement and throwing effect of the discharge port at the top of the clarified drum under the premise of high-speed centrifugation and liquid separation effect; more noteworthy is that the evenly distributed lifting paddles can also avoid the useless work caused by the material "shaking" in the drum and being out of sync, with significant results.

[0025] 4) The high-speed rotation of the drum and the small drum will also generate a certain suction force on the connecting hole and even the guide barrel, thereby achieving the effect of the liquid phase moving from bottom to top; preferably, the present application also extends a self-priming blade at the drum, so as to use the self-priming pump structure formed by the combination of the self-priming blade and the guide barrel to speed up the self-priming effect, ensuring that the primary mixed liquid in the primary mixing chamber can be quickly pumped into the small drum, and finally sucked 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 drum to ensure that the liquid phase entering the small drum can quickly complete the same speed rotation as the drum, thereby laying the foundation for subsequent separation work.

[0026] 5) As for the drum, it is composed of a gland, a rotor body, a bottom cover, a small drum and even a self-priming blade. It should be noted that the discharge port diameter is preferably smaller than the diameter of the rotor body; in this way, the discharge port forms a structure similar to an overflow weir, which is conducive to improving the clarification and separation effect of the mixed liquid in the drum. The separated and clarified nitration product enters the nitration product outlet N4 through the annular transition groove and is discharged, completing the entire linear process.

[0027] 6) As the third highlight of the present application, the present 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 in the drum that is reacting at a high speed, while the auxiliary cooling components ensure the overall cooling effect inside the shell. Through the regulation of the above cooling temperature, the process temperature requirements of the reaction can be easily achieved, thereby completing the cooling heat exchange of the intense heat release of the nitration reaction, and ultimately ensuring the stability, reliability and continuity of the process. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a working state diagram of the nitration reaction continuous separator of the present application;

[0029] Figure 2 for Figure 1 A local enlarged view of part I;

[0030] Figure 3 for Figure 1 A partial enlarged view of part II;

[0031] Figure 4 is a structural cross-sectional view of the shell;

[0032] Figure 5 It is a structural cross-sectional view of the drum;

[0033] Figure 6 for Figure 5 AA section view;

[0034] Figure 7 This is the piping installation diagram for this application.

[0035] The actual correspondence between the reference numbers and component names in this application is as follows:

[0036] a-primary mixing chamber; b-suction chamber; c-dispersion chamber; d-separation chamber; e-reaction isolation zone;

[0037] 10-shell; 11-annular transition groove; 12-cooling jacket; 13-water-cooled wall;

[0038] 20-drum; 20a-connecting hole; 20b-discharging port; 20c-lifting paddle; 20d-self-priming paddle; 21-small drum; 21a-dispersing plate; 22-pressing cover; 23-rotor body; 24-bottom cover; 25-lap board;

[0039] 30-isolating cylinder; 31-material guide cylinder;

[0040] 40-frame; 41-power motor; 42-connecting ribs;

[0041] 51-connecting hole; 52-transition ring; 53-first refrigerant pipe; 54-second refrigerant pipe; 55-rotating joint; 56-inlet pipe; 57-outlet pipe;

[0042] 60- material storage tank; 61- material delivery pump; 70- nitric acid storage tank; 71- nitric acid delivery pump; 80- nitration product storage tank; 90- refrigerant storage tank 80. DETAILED DESCRIPTION

[0043] For ease of understanding, here we combine Figure 1-7 The specific structure and working mode of this application are further described as follows:

[0044] In actual operation, this application is formed as follows Figure 6The system structure shown. In the entire nitration reaction continuous separation system, the material storage tank 60 is loaded with material, and the material state can be monitored by a liquid level sensor, etc. The material delivery pump 61 pumps the material out of the material storage tank 60, and the material enters from the material inlet N1 through the material flow meter L1 on the pipeline; the nitric acid storage tank 70 is loaded with a certain concentration of nitric acid, and the loading state can be monitored by a liquid level sensor, etc. The nitric acid delivery pump 71 pumps nitric acid out of the nitric acid storage tank 70, and the nitric acid enters from the nitric acid inlet N2 through the nitric acid flow meter L2 on the pipeline. The two meet in the primary mixing chamber a, and are initially mixed and mass transferred under the action of their respective feed pressures; then, under the pumping action of the self-priming blade 20d, the preliminary mixture undergoes secondary and tertiary nitration reactions in the suction chamber b and the dispersion chamber c, respectively, and generates heat, and then enters the separation chamber d through the connecting hole 20a, and is gradually separated and cooled. Under the action of the lifting paddle 20c, the material is lifted and flows from the bottom of the rotor body 23 to the upper part, completing cooling and clarification. Due to their high density, trace impurities are thrown toward the inner wall of the rotor body 23 under the action of centrifugal force and are manually cleaned at certain intervals. The cooled, separated and clarified nitration products are centrifugally thrown out from the discharge port 20b, enter the annular transition tank 11, and are discharged from the nitration product outlet N4, and enter the nitration product storage tank 80 or the subsequent nitration product process, thus completing a continuous production process. The overflow port N3 and the emptying port N7 are also connected to the inlet of the material storage tank 60; the discharge of the overflow port N3 and the emptying port N7 is originally a mixture, the amount is not large, and it is not a pollutant. After returning to the material storage tank 60, it will re-enter the nitration reaction continuous separator to continue the reaction. The refrigerant storage tank 90 is connected to the corresponding refrigerant components.

[0045] Accordingly, the above-mentioned nitration reaction continuous separator is mainly composed of a drum 20, a shell 10, a frame 40 and a transmission component, as shown in detail. Figure 1 The drum 20 and the housing 10 are coaxially arranged, and 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 the speed can be accurately adjusted through the electrical control system to meet the material working conditions.

[0046] like Figure 4 As shown, the shell 10 is the place where materials (organic phase), nitric acid, etc. enter the equipment and where the accumulated liquid is discharged after the mixed mass transfer reaction. 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; at the same time, there are several refrigerant ports for cooling the auxiliary cooling components. In addition, an emptying port N7 is arranged at the bottom of the shell 10, and the emptying port N7 is located at the lowest point of the shell 10 and is generally provided with a valve.

[0047] The cylinder of the shell 10 is welded by a straight section and a head section. The head is located at the bottom of the straight section. The upper part of the straight section is coaxially welded with a circular flange to form an inner cavity. The material inlet N1 and the nitric acid inlet N2 are arranged 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 cylinder and the drum 20 to leave enough space for the violent reaction of the material. In order to avoid the uncontrollability of the reaction due to the high-speed rotation of the drum 20, an isolation cylinder 30 is provided between the cylinder and the drum 20. The upper edge of the isolation cylinder 30, that is, the top cylinder mouth, is higher than the material inlet N1 and the nitric acid inlet N2, so as to effectively isolate the high-speed rotation of the drum 20 from the feed mixing, and ensure that the initial liquid entering the primary mixing chamber a will not directly participate in the high-speed stirring and violent reaction process of the separation chamber d at the drum 20. At the same time, in order to prevent the material liquid level from rising and entering the reaction isolation area between the drum 20 and the isolation cylinder 30 under unexpected conditions such as too much material feed or violent reaction, thereby creating safety hazards, such as Figure 1-2 and Figure 4 As shown, the present application is also provided with an overflow port N3 at the upper edge of the isolation cylinder 30 to effectively guide the high liquid level material. In this way, the outer surface of the isolation cylinder 30, the lower part of the straight section of the cylinder and the inner surface of the head are enclosed to form the primary mixing chamber a, where the material contacts with nitric acid and begins to undergo a primary nitration reaction. A guide cylinder 31 is provided at the center of the isolation cylinder 30, and the guide cylinder 31 cooperates with the self-priming blade 20d. A suitable gap is left between the inner diameter of the guide cylinder 31 and the outer diameter of the self-priming blade 20d. The pumping effect is achieved by combining the blade shape, position, angle, size and other technical parameters on the self-priming blade 20d, as well as the rotation speed, steering, etc. Under the pumping effect, the mixed material of the primary nitration reaction undergoes a secondary nitration reaction with a larger contact surface and a shorter contact time, and enters the dispersion chamber c formed by the small rotating cylinder 21 at the bottom of the drum 20 through the guide cylinder 31. Under high-speed rotation, the material undergoes a tertiary nitration reaction.

[0048] Through the above-mentioned material transfer, the nitration reaction is decomposed into three levels, which alleviates the violent reaction process, relieves heat release, material boiling, etc., and enhances safety.

[0049] like Figure 3-4As shown, a liquid accumulation cylinder is provided at the upper part of the shell 10, which is combined with the upper part of the straight section of the cylinder to form an annular transition groove 11. After the nitration product is centrifugally clarified by the drum 20, it is centrifugally thrown out from the discharge port 20b at the top of the drum 20, enters the annular transition groove 11 through the strap 25, and is discharged from the nitration product outlet N4. In order to discharge 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 full contact with the straight section and the head section of the cylinder, thereby increasing the heat exchange area to the greatest extent; further, if the cooling area needs to be increased, a single-layer or double-layer coil 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, and together constitute an auxiliary cooling component.

[0050] like Figure 5-6 As shown, the drum 20 is mainly composed of a gland 22, a rotor body 23, a bottom cover 24 and a small drum 21 coaxially. Connecting holes 51 are arranged axially on the wall of the rotor body 23, and the connecting holes 51 are evenly distributed in sequence around the circumference of the rotor body 23. Considering the connection relationship of the connecting holes 51, a waist-shaped upper connecting groove with a certain depth is provided on the upper part of each connecting hole 51, and a waist-shaped lower connecting groove with a certain depth is provided on the lower part. The transition ring 52 formed by the upper connecting groove and the lower connecting groove is directly connected to the two ends of the connecting hole 51 to form a refrigerant channel similar to a squirrel cage. The power shaft is coaxial with the drum 20, and is driven by the power motor 41, and is fixed to the drum 20 by the connecting ribs 42 to realize the power transmission process. The power shaft is provided with a hollow hole, which is the first refrigerant pipe 53, and is connected to the refrigerant outlet N6 of the rotary joint 55; a second refrigerant pipe 54 is concentrically provided inside the first refrigerant pipe 53, and the upper part of the second refrigerant pipe 54 is also concentrically connected to the rotary joint 55, and is 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 the refrigerant is input into the transition ring 52 through the inlet pipe 56; then, the refrigerant flows from the upper transition ring 52 to the connecting hole 51, thereby transporting the refrigerant to the circumferential surface of the rotor body 23, directly contacting the material, and fully taking away the reaction heat of the material in the drum 20. The refrigerant is finally collected at the lower transition ring 52, and then the refrigerant after heat exchange is transported 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.

[0051] like Figure 5As shown, the bottom end of the bottom cover 24 is concentrically provided with an extension shaft, which rotates synchronously with the drum 20. A certain number, angle and external size of self-priming blades 20d are provided at the appropriate position of the extension shaft, and the outer diameter of the self-priming blade 20d maintains a certain gap δ with the inner diameter of the guide barrel 31. Controlling the number, angle, shape, gap δ, rotation speed and other parameters of the self-priming blade 20d will produce different upward suction forces and suction volumes, forming a suction chamber b. The mixed material after the first three stages of nitration reaction is stirred and mixed through the suction chamber b under the action of the self-priming blade 20d, completing the final nitration reaction, and then enters the dispersion chamber c, and under the action of centrifugal force, is thrown at the wall of the small rotating drum 21 at high speed. A certain number of dispersion plates 21a are provided in the small rotating drum 21, which can quickly drive the mixed material to reach the synchronous speed of the drum 20. The bottom cover 24 is close to the inner diameter of the rotor body 23, and a series of connecting holes 20a are evenly distributed to achieve the connection between the separation chamber d and the dispersion chamber c. After the reaction is completed, the mixed material enters the separation chamber d through the connecting hole 20a. Under the action of the lifting paddle 20c, the mixed material 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 nitration product after separation and clarification is thrown out of the rotor body 23 from 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 tilted at a certain angle in the rotor body 23; the tilt angle of the lifting paddle 20c should generate a force to lift the mixed material upward under the action of rotation. The evenly distributed lifting paddles 20c can also quickly drive the mixed material to synchronize, avoiding the material "shaking" in the rotor body 23 and causing useless work without synchronization.

[0052] Correspondingly, the entry of the refrigerant 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 body 23 by the water-cooled wall 13; the above two types of cooling can be called auxiliary cooling. The third part of the refrigerant enters the series of connecting holes 51 set on the cylinder wall of the rotor body 23 from the refrigerant inlet N5. The refrigerant is directly arranged on the cylinder wall of the rotor body 23, and directly contacts and exchanges heat with the material inside the rotor body 23, which can be called direct cooling. According to the process requirements, the connecting holes 51 can be set in single or double rows, with various variations and a wide range of adaptability; this part of the refrigerant is discharged from the refrigerant outlet N6 after heat exchange. In this way, the cooling and heat exchange of the intense heat release of the nitration reaction is completed, which ensures the stability, reliability and continuity of the process. From the perspective of the equipment operation mechanism, by decomposing the nitration reaction stage and multiple cooling methods, the inherent safety of the nitration reaction is achieved. Through the regulation of the cooling temperature of these three parts, it is also easy to achieve the process temperature requirements of the reaction.

[0053] It is worth noting that the connection holes 51 of the present application are arranged axially along the drum 20, not only to simply achieve the 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 general flow channel, thereby affecting the heat dissipation effect; and the multiple connection holes arranged axially can effectively avoid the bubble phenomenon caused by radial centrifugal force, thereby improving the cooling effect.

[0054] Of course, for those skilled in the art, the present application is not limited to the details of the above exemplary embodiments, but also includes the same or similar methods that can be implemented in other specific forms without departing from the spirit or basic features of the present application. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present application is limited by the attached claims rather than the above description.

[0055] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

[0056] The technical parts not described in detail in this application are all well-known technologies.

Claims

1. A continuous separation system based on a nitration reaction continuous separator, characterized in that: The invention comprises a nitration reaction continuous separator, wherein a material storage tank (60) is connected to a material inlet N1 of the nitration reaction continuous separator through a material pipeline, and a material delivery pump (61) and a material meter L1 are arranged in sequence on the material pipeline; a nitric acid storage tank (70) is connected to a nitric acid inlet N2 of the nitration reaction continuous separator through a nitric acid pipeline, and a nitric acid delivery pump (71) and a nitric acid meter L2 are arranged in sequence on the nitric acid pipeline; The nitration reaction continuous separator comprises a shell (10), a rotary drum (20) located in the shell (10), and an isolation cylinder (30) located in the shell (10) and arranged at the bottom of the rotary drum (20), wherein the top opening of the isolation cylinder (30) is higher than the material inlet N1 and the nitric acid inlet N2; a material guide cylinder (31) is coaxially extended upward from the bottom opening of the isolation cylinder (30), a small rotary drum (21) is coaxially extended downward from the bottom of the rotary drum (20), the bottom opening of the small rotary drum (21) is coaxially wrapped around the outer wall of the material guide cylinder (31), and the two form a swivel fit, and at this time, the area between the inner wall of the isolation cylinder (30) and the outer wall of the small rotary drum (21) constitutes a reaction isolation zone (e); The material and nitric acid are respectively pumped into a primary mixing chamber (a) formed between the outer wall of the isolation cylinder (30) and the inner wall of the shell (10) through a material pipeline and a nitric acid pipeline to complete a primary nitration reaction, and then enter the material guide cylinder (31) to complete a secondary nitration reaction, and then are sucked into a dispersion chamber (c) formed by the cylinder cavity of the small rotating cylinder (21) to achieve a tertiary nitration reaction, and then enter a separation chamber (d) formed by the inner cavity of the rotating drum (20) through a connecting hole (20a) at the bottom surface of the rotating drum (20). The nitration product separated and clarified by the rotating drum (20) is centrifugally thrown out from a discharge port (20b) located at the top of the rotating drum (20), and is discharged from a nitration product outlet N3 located at the upper part of the shell (10) into a nitration product storage tank (80), completing the reaction process.

2. The continuous separation system based on the nitration reaction continuous separator according to claim 1, characterized in that: An overflow port N3 is also arranged on the outer wall of the shell (10), and 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 tube mouth height of the isolation tube (30) and higher than the heights of the material inlet N1 and the nitric acid inlet N2. The overflow port N3 is connected to the material storage tank (60) via an overflow pipe.

3. The continuous separation system based on the nitration reaction continuous separator according to claim 1, characterized in that: The bottom of the shell (10) is arranged with an emptying port N7 which is connected to the primary mixing chamber (a) and the inlet is located at the lowest point of the primary mixing chamber (a). The emptying port N7 is connected to the material storage tank (60) via an emptying pipe.

4. The continuous separation system based on the nitration reaction continuous separator according to any one of claims 1 to 3, characterized in that: The inner wall of the drum (20) is provided with prismatic lifting paddles (20c) inclined in the same direction, and the lifting paddles (20c) are inclined in the opposite direction to the rotation direction of the drum (20), so as to gradually lift the mixed liquid in the drum (20) to the discharge port (20b) at the top of the drum (20) under the action of centrifugal force.

5. The continuous separation system based on the nitration reaction continuous separator according to claim 4, characterized in that: An extension shaft coaxially extends downward from the rotating drum (20), and a self-priming blade (20d) is installed on the portion of the extension shaft extending into the barrel cavity of the material guide barrel (31), so that a suction chamber (b) is formed in the space between the barrel cavity of the material guide barrel (31) and the self-priming blade (20d).

6. The continuous separation system based on the nitration reaction continuous separator according to any one of claims 1 to 3, characterized in that: A dispersion plate (21a) is radially arranged on the inner wall of the small rotating drum (21) to drive the mixed material to reach a synchronous rotation speed of the rotating drum (20).

7. The continuous separation system based on the nitration reaction continuous separator according to any one of claims 1 to 3, characterized in that: The rotary drum (20) comprises, in order from top to bottom in the vertical direction, a pressure cover (22), a rotor body (23), a bottom cover (24) and a small rotary cylinder (21); a connecting hole (20a) is arranged through the bottom cover (24) and is arranged close to the wall of the small rotary cylinder (21); a discharge port (20b) is coaxially arranged through the pressure cover (22), and the diameter of the discharge port (20b) is smaller than the diameter of the rotor body (23).

8. The continuous separation system based on the nitration reaction continuous separator according to claim 7, characterized in that: An annular transition groove (11) with an upward notch is coaxially arranged on the inner wall of the shell (10) at the top of the drum (20); a strap (25) extending toward the outer groove wall is fixed on the upper surface of the pressure cover (22); the strap (25) is strapped on the outer groove wall and can generate a rotational movement relative to the outer groove wall when the drum (20) rotates; the nitration product separated and clarified by the drum (20) is thrown out through the discharge port (20b) of the drum (20), enters the annular transition groove (11) for collection by the strap (25), and is then discharged from the nitration product outlet N4 which is connected to the groove cavity of the annular transition groove (11) and is opened on the outer wall of the shell (10).

9. The continuous separation system based on the nitration reaction continuous separator according to any one of claims 1 to 3, characterized in that: A connecting hole (51) is provided in the axial direction of the drum (20) at the cylinder wall. A plurality of connecting holes (51) arranged in sequence around the circumference of the drum (20) are connected to each other by means of transition rings (52) located at both end surfaces 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 into the first refrigerant pipe (53). The two refrigerant pipes are respectively connected to the refrigerant inlet N5 and the refrigerant outlet N6 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 inlet pipe (56) extending radially from the end face of the drum (20), and after flowing through the refrigerant channel, it flows through the outlet pipe (57) extending radially from the end face of the drum (20) to another refrigerant pipe, and is finally discharged from the refrigerant outlet N6, completing the direct cooling cycle; at this time, the refrigerant channel, the refrigerant pipe, the inlet pipe (56) and the outlet pipe (57) together constitute a direct cooling component; The refrigerant inlet N5 and the refrigerant outlet N6 are respectively connected to the inlet and outlet of the refrigerant storage tank (90).

10. The continuous separation system based on the nitration reaction continuous separator according to claim 9, characterized in that: A cooling jacket (12) is provided at the shell (10), and a water-cooled wall (13) is arranged at the inner wall of the shell (10). The cooling jacket (12) and the water-cooled wall (13) together constitute an auxiliary cooling component; the input end and the output end of the auxiliary cooling component are respectively the inlet and the outlet of the refrigerant storage tank (90).

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