Jet reactor for HDI biuret production and application thereof

Abstract

The invention relates to a jet reactor for HDI biuret production and application thereof.The jet reactor for HDI biuret production comprises a reactor body and a feeding pipe, the reactor body is provided with an HDI feeding channel, a reaction chamber and a flash chamber which are sequentially communicated, the reaction chamber is provided with an expansion section, and the expansion section is arranged close to an outlet of the HDI feeding channel; at least part of the feeding pipe is arranged in the HDI feeding channel and extends towards an outlet of the HDI feeding channel, a rotating rod is arranged in the feeding pipe in a penetrating mode, one end of the rotating rod is in transmission connection with a driving mechanism, the driving mechanism drives the rotating rod to rotate, the other end of the rotating rod is provided with a rotating head with the outer surface in an expanded shape, and at least part of the rotating head extends out of an outlet of the feeding pipe. When the jet reactor is applied to the production of HDI biuret, the blockage of equipment or pipelines can be effectively avoided, the high-temperature decomposition reaction of HDI can be effectively avoided, and the safety risk is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of chemical industry, in particular to a jet reactor for producing HDI biuret and application thereof. Background Art

[0002] The HDI (hexamethylene diisocyanate) amine-based biuret production process mainly involves spraying liquid hexamethylene diamine into high-temperature HDI for reaction through a spray reactor, generating a high-flow rate of hexamethylene diamine liquid flow through a small-hole nozzle, strengthening the dispersibility of hexamethylene diamine in HDI, and reducing the generation of overpolymers, and then removing the HDI monomer from the obtained reaction liquid through an evaporator to obtain a biuret product. However, in the existing spray reactor, when spraying liquid hexamethylene diamine, hexamethylene diamine can only be sprayed into part of the high-temperature HDI through the spray hole, and hexamethylene diamine and high-temperature HDI react very quickly, resulting in hexamethylene diamine reacting with high-temperature HDI before it has time to diffuse in large quantities, making it impossible for hexamethylene diamine to be evenly dispersed in HDI, thereby affecting the yield. In addition, in the process, by-products such as polymer solids are formed, which can easily cause pipeline or equipment blockage and affect the stable operation of the reaction.

[0003] At the same time, in the process of producing HDI biuret, high-temperature HDI will decompose to produce carbonimide and carbon dioxide. The higher the temperature and the longer the residence time, the more carbon dioxide will be produced by the HDI decomposition reaction. Moreover, the synthesis of biuret by HDI and hexamethylenediamine is an exothermic reaction, which will further aggravate the overpressure risk of the device and thus pose a great safety hazard. Summary of the invention

[0004] Based on this, it is necessary to provide a jet reactor for HDI biuret production and its application in view of the above problems. The jet reactor can effectively avoid equipment or pipeline blockage and improve the yield in the production of HDI biuret, and can effectively avoid HDI high temperature decomposition reaction and reduce safety risks.

[0005] A jet reactor for HDI biuret production, comprising:

[0006] A reactor body, wherein the reactor body has an HDI feed channel, a reaction chamber, and a flash chamber that are sequentially connected, wherein the reaction chamber has an expansion section, and the expansion section is arranged near the outlet of the HDI feed channel;

[0007] A feed pipe, wherein the feed pipe is at least partially disposed in the HDI feed channel and extends toward the outlet of the HDI feed channel, a rotating rod is passed through the feed pipe, one end of the rotating rod is transmission-connected to a driving mechanism, the driving mechanism drives the rotating rod to rotate, and the other end of the rotating rod is provided with a rotating head with an expanded outer surface, and the rotating head at least partially extends out of the outlet of the feed pipe.

[0008] In one embodiment, the rotating head is conical, and the cone angle is 110°-150°;

[0009] And / or, the spin head at least partially extends into the reaction chamber.

[0010] In one of the embodiments, a plurality of guide structures are provided at intervals along the circumferential direction on the outer surface of the rotating head, and the guide structures extend from an end of the rotating head close to the rotating rod to an end away from the rotating rod.

[0011] In one embodiment, the angle between adjacent guide structures is 45°-120°;

[0012] And / or, the cross-sectional shape of the guide structure is any one of a triangle, a fan, and a trapezoid;

[0013] And / or, the guide structure extends to the rotating rod and is connected to the rotating rod.

[0014] In one embodiment, the length of the reaction chamber along the material flow direction is 300 mm-1000 mm;

[0015] And / or, the reaction chamber is trumpet-shaped.

[0016] In one embodiment, the reaction chamber further comprises a straight pipe section connected to the expansion section, and the length of the expansion section is 50 mm-200 mm.

[0017] In one embodiment, the outlet of the feed pipe is located at the outlet of the HDI feed channel;

[0018] And / or, the feed pipe includes a straight pipe section and a tapered section connected in sequence.

[0019] A production system of HDI biuret comprises a reactor and a distillation device which are connected in sequence, wherein the reactor is the jet reactor for producing HDI biuret as described above.

[0020] In one embodiment, the HDI biuret production system further includes a multi-stage coupled heat exchanger and a multi-stage heater, wherein the upper-stage coupled heat exchanger in the multi-stage coupled heat exchanger has an inlet for new raw material HDI, the upper-stage coupled heat exchanger is connected to the gas phase outlet of the reactor, the lower-stage coupled heat exchanger in the multi-stage coupled heat exchanger is connected to the liquid phase outlet of the reactor, the lower-stage coupled heat exchanger is connected to the distillation equipment, the inlet of the upper-stage heater in the multi-stage heater is connected to the lower-stage coupled heat exchanger, and the outlet of the lower-stage heater in the multi-stage heater is connected to the inlet of the HDI feed channel of the reactor.

[0021] A method for producing HDI biuret using the HDI biuret production system as described above comprises the following steps:

[0022] HDI is introduced into the reactor through the HDI feed channel, hexamethylenediamine is introduced into the feed pipe and dispersed in the reactor and reacts with HDI under the rotation of the rotating head of the rotating rod to obtain a reaction liquid, and then the reaction liquid is flash-evaporated to obtain a crude liquid;

[0023] The crude liquid is subjected to rectification and separation to obtain HDI biuret.

[0024] In one embodiment, the method for producing HDI biuret further satisfies at least one of the following conditions:

[0025] (1) before the HDI is introduced into the reactor through the HDI feed channel, the HDI is subjected to heating and pressurizing treatment, wherein the heating temperature is 160° C.-230° C., and the pressurizing pressure is 0.2 MPa-0.5 MPa;

[0026] (2) The flow rate of HDI into the reactor is 1300kg / h-3000kg / h, and the flow velocity is 10m / s-24m / s;

[0027] (3) before the hexamethylenediamine is dispersed in the reactor through the feed pipe under the rotation of the rotating head of the rotating rod, it also includes heating treatment and pressurizing treatment, the temperature of the heating treatment is 60° C.-120° C., and the pressure of the pressurizing treatment is 2 MPa-12 MPa;

[0028] (4) the flow rate of hexamethylenediamine into the reactor is 65kg / h-150kg / h, and the flow velocity is 60m / s-140m / s;

[0029] (5) The mass ratio of the HDI to the hexamethylenediamine is 15:1-30:1;

[0030] (6) The rotation speed of the rotating rod is 200 r / min-600 r / min;

[0031] (7) In the step of flash evaporating the reaction solution, a gas phase is also obtained, and the gas phase is mixed with new raw material HDI;

[0032] (8) The temperature of the crude liquid obtained after flash evaporation is 190° C.-210° C.;

[0033] (9) Before the crude liquid is subjected to distillation separation, the crude liquid is subjected to heat exchange treatment, and the temperature of the crude liquid after the heat exchange treatment is 160° C.-180° C.

[0034] In the jet reactor for HDI biuret production of the present invention, a rotating rod is arranged in a feed pipe, and the rotating rod drives a rotating head to rotate under the drive of a driving mechanism. Since the outer surface of the rotating head is in an expansion shape, the raw material (such as hexamethylenediamine) generates a certain radial flow velocity when it is ejected from the outlet of the feed pipe, thereby enhancing the dispersibility of the raw material (such as hexamethylenediamine) in HDI and reducing the content of the polymer in the reaction liquid, thereby avoiding equipment or pipeline blockage, ensuring the stable operation of the reactor, and improving the yield; at the same time, by arranging a flash chamber in the reactor, the formed reaction liquid can be directly subjected to flash cooling treatment, the temperature of the reaction liquid is timely reduced, and the high-temperature decomposition reaction of HDI is effectively avoided, thereby reducing the overpressure risk of the reactor and improving the safety of the reactor.

[0035] Therefore, when the jet reactor for HDI biuret production of the present invention is applied to the production of HDI biuret, it can effectively avoid equipment or pipeline blockage and improve the yield, and at the same time can effectively avoid the high-temperature decomposition reaction of HDI and reduce safety risks. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art 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 be obtained based on these drawings without paying creative work.

[0037] Figure 1 The cross-sectional schematic diagram of a jet reactor for HDI biuret production provided in one embodiment of the present invention, wherein in the figure, A represents HDI flash steam, and B represents crude product liquid;

[0038] Figure 2 It is a schematic diagram of the structure of a rotating rod in a jet reactor for HDI biuret production provided in one embodiment of the present invention, wherein, in the figure, θ represents the cone angle;

[0039] Figure 3 A schematic top view of a conical rotating head at the end of a rotating rod in a jet reactor for HDI biuret production provided in one embodiment of the present invention;

[0040] Figure 4 It is a schematic structural flow diagram of a HDI biuret production system provided in one embodiment of the present invention.

[0041] Description of the drawings: 1. Reactor body; 2. Feed pipe; 3. HDI feed channel; 4. Reaction chamber; 5. Flash chamber; 6. Rotating rod; 7. Driving mechanism; 8. Rotating head; 9. Guide structure; 10. Reactor; 11. First-stage coupled heat exchanger; 12. Second-stage coupled heat exchanger; 13. First-stage heater; 14. Second-stage heater; 15. Distillation equipment. DETAILED DESCRIPTION

[0042] For ease of understanding of the present invention, the present invention will be described in more detail below. However, it should be understood that the present invention can be implemented in many different forms and is not limited to the embodiments or examples described herein. On the contrary, the purpose of providing these embodiments or examples is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific implementation methods or embodiments, and are not intended to limit the present invention. The optional scope of the term "and / or" used herein includes any one of two or more related listed items, and also includes any and all combinations of related listed items, and the combinations include any two related listed items, any more related listed items, or all related listed items.

[0044] like Figure 1-3 As shown, the present invention provides a jet reactor for HDI biuret production, the jet reactor comprising: a reactor body 1 and a feed pipe 2, the reactor body 1 having an HDI feed channel 3, a reaction chamber 4 and a flash chamber 5 which are sequentially connected, wherein the reaction chamber 4 has an expansion section, and the expansion section is arranged near the outlet of the HDI feed channel 3; the feed pipe 2 is at least partially arranged in the HDI feed channel 3 and extends toward the outlet of the HDI feed channel 3, a rotating rod 6 is penetrated in the feed pipe 2, one end of the rotating rod 6 is transmission-connected with a driving mechanism 7, and the driving mechanism 7 drives the rotating rod 6 to rotate, and the other end of the rotating rod 6 is provided with a rotating head 8 with an expanded outer surface, and the rotating head 8 at least partially extends out of the outlet of the feed pipe 2.

[0045] Specifically, the jet reactor for HDI biuret production in the present invention is suitable for preparing HDI biuret by water method or preparing HDI biuret by amine method, preferably preparing HDI biuret by amine method. It can be understood that the feed pipe 2 in the present invention is used for feeding water or hexamethylenediamine, preferably hexamethylenediamine.

[0046] Taking the preparation of HDI biuret by the amine process as an example, that is, when hexamethylenediamine is introduced into the jet reactor through the feed pipe 2, compared with the conventional jet reactor used in the production of HDI biuret, in the jet reactor for the production of HDI biuret of the present invention, a rotating rod 6 is arranged in the feed pipe 2, and the rotating rod 6 drives the rotating head 8 to rotate under the drive of the driving mechanism 7. Since the outer surface of the rotating head 8 is in an expansion shape, the raw material (such as hexamethylenediamine) generates a certain radial flow velocity when it is ejected from the outlet of the feed pipe 2, and the raw material hexamethylenediamine is dispersed in a large angle shape, reducing the linear diffusion distance of hexamethylenediamine, thereby increasing the diffusion area, strengthening the dispersibility of hexamethylenediamine in HDI, and avoiding the reaction of hexamethylenediamine with HDI before it has time to disperse, thereby reducing the content of overpolymers in the reaction solution, avoiding blockage of equipment or pipelines, ensuring the stable operation of the reactor 10, and improving the yield; and it can also reduce the ratio of HDI to hexamethylenediamine to a certain extent, thereby reducing the subsequent distillation energy consumption.

[0047] At the same time, compared with the traditional HDI biuret production system, the jet reactor and the flash evaporation equipment are independently arranged. In the present invention, by arranging the flash evaporation chamber 5 in the jet reactor, the reaction liquid formed by the reaction in the reaction chamber 4 can be directly subjected to flash evaporation and cooling treatment, and the temperature of the reaction liquid can be reduced while removing the HD monomer, thereby avoiding the high-temperature decomposition reaction of HDI and the generation of CO2, reducing the overpressure risk of the reactor 10, reducing the safety risk, and thus improving the safety of the use of the reactor 10.

[0048] In addition, since the reaction of HDI and hexamethylenediamine in the present invention is a continuous reaction and the flash evaporation of the formed reaction solution is carried out in the jet reactor, the material inventory of the reaction system is small and the impact after the risk occurs is also small.

[0049] Therefore, the jet reactor for HDI biuret production of the present invention can effectively avoid equipment or pipeline blockage and improve the yield when applied to the production of HDI biuret, especially in the preparation of HDI biuret by the amine process, and can effectively avoid the high-temperature decomposition reaction of HDI and reduce safety risks.

[0050] It should be noted that the driving mechanism 7 may be a motor. Specifically, one end of the rotating rod 6 is drivingly connected to the output shaft of the motor.

[0051] like Figure 2-3 As shown, the rotating head 8 is conical, and the cone is selected from a cone or a pyramid, preferably a cone. Since the rotating head 8 is conical, when the hexamethylenediamine liquid flow is ejected through the feed pipe 2, it is dispersed with a hollow cone angle.

[0052] Furthermore, the cone angle θ is 110°-150°.

[0053] Optionally, the rotating head 8 at least partially extends into the reaction chamber 4, which is beneficial to improve the dispersion effect and enable the HDI and hexamethylenediamine to react fully.

[0054] Optionally, a plurality of guide structures 9 are provided on the outer surface of the rotating head 8 at intervals along the circumferential direction, and the guide structures 9 extend from an end of the rotating head 8 close to the rotating rod 6 to an end away from the rotating rod 6 .

[0055] Such an arrangement can better enhance the dispersion of the raw material (such as hexamethylenediamine) liquid flow in the radial direction, and further increase the dispersion effect of the raw material (such as hexamethylenediamine) in HDI.

[0056] Furthermore, the angle between adjacent guide structures 9 is 45°-120°, which helps to improve the dispersion effect.

[0057] Optionally, the cross-sectional shape of the guide structure 9 is any one of a triangle, a sector, and a trapezoid, preferably a triangle. Such a configuration is beneficial to increase the radial flow velocity of hexamethylenediamine, so that hexamethylenediamine is better dispersed in the HDI liquid flow in a short time.

[0058] Optionally, the guide structure 9 extends to the rotating rod 6 and is connected to the rotating rod 6. Such an arrangement facilitates equipment installation and guide structure maintenance and replacement.

[0059] Furthermore, the guide structure 9 is a baffle, and the number of the baffles is 3-8.

[0060] It should be noted that the guide structure 9 in the present invention may also be other structures as long as it can further increase the dispersion effect of the raw materials in the radial direction.

[0061] Optionally, the length of the reaction chamber 4 along the material flow direction is 300 mm-1000 mm. In this way, the high temperature duration of the reaction liquid can be shortened as much as possible while ensuring the rapid balance between the components in the reaction liquid (such as biuret, pentamer, heptamer, nonamer, undecamer, polymer and other components) so that the generated polymer can be quickly decomposed into oligomers.

[0062] Optionally, the reaction chamber 4 further comprises a straight pipe section connected to the expansion section, and the length of the expansion section is 50 mm to 200 mm. Such a configuration is conducive to faster and better dispersion of the raw material (such as hexamethylenediamine) in the HDI in the reaction chamber 4.

[0063] Optionally, the reaction chamber 4 is trumpet-shaped as a whole.

[0064] In one embodiment, the reaction chamber 4 is a reaction tube, and further, the reaction tube is a reaction throat.

[0065] In one embodiment, the flash chamber 5 is provided with a liquid phase outlet and a gas phase outlet.

[0066] In one embodiment, the inlet of the HDI feed channel 3 and the inlet of the feed pipe 2 are both configured as spray holes (not shown in the figure), and the raw materials are sprayed into the reactor 10 through the spray holes.

[0067] Optionally, the feed pipe 2 comprises a straight pipe section and a tapered section connected in sequence. This arrangement can further increase the injection speed of the raw material.

[0068] It should be noted that, in the present invention, there is a gap between the inner wall of the HDI feed channel 3 close to the reaction chamber 4 and the outer wall of the feed pipe 2 close to the reaction chamber 4 .

[0069] Optionally, the outlet of the feed pipe 2 is located at the outlet of the HDI feed channel 3 .

[0070] like Figure 4 As shown, the present invention further provides a production system of HDI biuret, comprising a reactor 10 and a distillation device 15 which are connected in sequence, wherein the reactor 10 is the jet reactor for HDI biuret production as described above.

[0071] Optionally, the HDI biuret production system further includes a multi-stage coupled heat exchanger and a multi-stage heater, wherein the upper-stage coupled heat exchanger in the multi-stage coupled heat exchanger has an inlet for new raw material HDI, the upper-stage coupled heat exchanger is connected to the gas phase outlet of the reactor 10, the lower-stage coupled heat exchanger in the multi-stage coupled heat exchanger is connected to the liquid phase outlet of the reactor 10, the lower-stage coupled heat exchanger is connected to the distillation equipment 15, the inlet of the upper-stage heater in the multi-stage heater is connected to the lower-stage coupled heat exchanger, and the outlet of the lower-stage heater in the multi-stage heater is connected to the inlet of the HDI feed channel 3 of the reactor 10.

[0072] Such an arrangement can realize the preheating of HDI while making full use of the heat in the gas phase (HDI flash steam) and the reaction liquid, thereby reducing energy consumption; at the same time, the purpose of HDI recycling is achieved.

[0073] It should be noted that, according to the requirements, the multi-stage coupled heat exchanger in the present invention can be a two-stage coupled heat exchanger, a three-stage coupled heat exchanger, or a four-stage coupled heat exchanger, etc. The present invention is preferably a two-stage coupled heat exchanger, such as Figure 4 As shown, it includes a first-stage coupling heat exchanger 11 and a second-stage coupling heat exchanger 12 that are connected to each other.

[0074] Similarly, the multi-stage heater can be a two-stage heater, or a three-stage heater, or a four-stage heater, etc. In the present invention, a two-stage heater is preferred, such as Figure 4 As shown, a first-stage heater 13 and a second-stage heater 14 are connected.

[0075] In one embodiment, the distillation equipment 15 includes a buffer kettle, a falling film evaporator and a wiped film evaporator which are connected in sequence, and the buffer kettle is used to receive the reaction liquid in the reactor 10 and continuously transport it to the falling film evaporator. In this way, the reaction liquid extracted from the reactor 10 is first refined by the falling film evaporator, and then refined by the wiped film evaporator for the second time to remove the remaining HDI, and HDI biuret is obtained from the discharge pipe of the wiped film evaporator.

[0076] In addition, the present invention also provides a method for producing HDI biuret using the HDI biuret production system as described above, the production method comprising the following steps, and the reaction mechanism is shown in the following reaction equations 1-3:

[0077] HDI is introduced into the reactor 10 through the HDI feed channel 3, hexamethylenediamine is introduced into the feed pipe 2 and dispersed in the reactor 10 and reacted with HDI under the rotation of the rotating head 8 of the rotating rod 6 to obtain a reaction liquid, and then the reaction liquid is flash-evaporated to obtain a crude liquid;

[0078] The crude liquid is subjected to rectification and separation to obtain HDI biuret.

[0079] The reaction mechanism of preparing HDI biuret by amine method in the present invention is as follows:

[0080] Reaction equation 1:

[0081]

[0082] Reaction equation 2:

[0083]

[0084] Reaction equation 3:

[0085]

[0086] Combining reaction equations 1-3, it can be seen that the reaction liquid formed by HDI and hexamethylenediamine in the reaction chamber 4 of the reactor 10 in the present invention has a reversible reaction between components such as biuret, pentamer, heptamer, nonamer, undecamer, and high polymer in the reaction liquid. If the above-mentioned high polymer cannot be quickly decomposed into oligomers, the amount of multipolymers (such as solid hyperpolymers) in the reaction liquid will increase, resulting in blockage of pipelines or equipment, affecting the stable operation of the reactor 10.

[0087] To this end, in the present invention, before the HDI is introduced into the reactor 10 through the HDI feed channel 3, the HDI is also subjected to heating and pressurizing treatment, the temperature of the heating treatment is 160° C.-230° C., and the pressure of the pressurizing treatment is 0.2 MPa-0.5 MPa.

[0088] Furthermore, the flow rate of HDI introduced into the reactor 10 is 1300kg / h-3000kg / h, and the flow velocity is 10m / s-24m / s.

[0089] Optionally, before the hexamethylenediamine is dispersed in the reactor 10 through the feed pipe 2 and under the rotation of the rotating head 8 of the rotating rod 6, heating treatment and pressurization treatment are also included, the temperature of the heating treatment is 60°C-120°C, and the pressure of the pressurization treatment is 2MPa-12MPa.

[0090] Furthermore, the flow rate of the hexamethylenediamine introduced into the reactor 10 is 60 m / s-140 m / s, preferably 80 m / s-140 m / s.

[0091] It can be understood that the temperature of HDI injected into the reactor 10 through the nozzle at the inlet of the HDI feed channel 3 is 160°C-230°C, the pressure is 0.2MPa-0.5MPa, the flow rate is 1400kg / h-3000kg / h, and the flow velocity is 10m / s-24m / s; the temperature of hexamethylenediamine injected into the reactor 10 through the nozzle at the inlet of the feed pipe 2 is 60°C-130°C, the pressure is 2MPa-12MPa, the flow rate is 65kg / h-150kg / h, and the flow velocity is 60-140m / s. By regulating the temperature, pressure, flow rate and flow rate of hexamethylenediamine and HDI, the reaction temperature in the reaction chamber 4 is regulated to be 230°C-300°C, so that the reversible reactions among the components such as biuret, pentamer, heptamer, nonamer, undecamer and polymer in the reaction liquid can be further balanced quickly, so that the generated polymer can be quickly decomposed into oligomers, further reducing the polymer content in the reaction liquid, avoiding clogging of equipment or pipelines during the transportation of the reaction liquid, and improving the HDI biuret yield.

[0092] Optionally, the rotation rate of the rotating rod 6 is 200 r / min-600 r / min, preferably 300 r / min-500 r / min. In this way, by adjusting the rotation rate of the rotating rod 6 and controlling the rotation rate of the conical rotating head 8, the radial flow rate of hexamethylenediamine can be better regulated, thereby improving the dispersion effect of hexamethylenediamine in HDI.

[0093] Optionally, the mass ratio of the HDI to the hexamethylenediamine is 15:1-30:1, preferably 18:1-25:1, which is beneficial to reduce the content of by-products (such as polymers) and increase the yield of HDI biuret.

[0094] Optionally, in the step of flash evaporating the reaction liquid, a gas phase is also obtained, and the gas phase is mixed with the new raw material HDI. This arrangement can further reduce the feed ratio of HDI / hexamethylenediamine and reduce the subsequent distillation energy consumption.

[0095] Optionally, the temperature of the crude liquid obtained after flash evaporation is 190°C-210°C.

[0096] Optionally, before the crude liquid is subjected to rectification and separation, the crude liquid is also subjected to heat exchange treatment, and the temperature of the crude liquid after the heat exchange treatment is 160° C.-180° C. Such an arrangement can fully utilize the heat and achieve energy-saving effect.

[0097] In one embodiment, the solid (such as polymer) content in the crude liquid obtained in the present invention is less than 0.5%, the NCO content in HDI biuret is 21.75%-22.10%, and the viscosity of HDI biuret is 8000mpa·s-13000mpa·s.

[0098] Hereinafter, the jet reactor for HDI biuret production and its application will be further described by the following specific examples. However, it will be understood by those skilled in the art that the following examples are only used to illustrate the present invention and should not be considered as limiting the scope of the present invention. If no specific conditions are specified in the examples, the conditions are carried out according to conventional conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be obtained commercially.

[0099] It should be noted that, in the present invention, the testing method for the solid (such as polymer) content of the crude liquid in Examples 1-15 and Comparative Example 1 and the reaction liquid in Comparative Example 2 is as follows: the crude liquid in Examples 1-15 and Comparative Example 1 and the reaction liquid in Comparative Example 2 are filtered to obtain the corresponding solids, and the obtained solids are weighed to obtain the corresponding solid masses, and then the solid content is calculated according to the formula: solid content = solid mass / ((hexamethylenediamine flow rate + HDI flow rate) × time). At the same time, the NCO content in the HDI biuret in Examples 1-15 and Comparative Example 1-2 is detected by an automatic potentiometric titrator, and the viscosity of the HDI biuret in Examples 1-15 and Comparative Example 1-2 is detected by a rheometer RSX.

[0100] Example 1

[0101] Hexamethylenediamine with a temperature of 100°C, a flow rate of 110kg / h, a flow velocity of 100m / s and a pressure of 4.1MPa is sprayed out through the nozzle of the feed pipe in the reactor, and the rotating rod is driven by a driving motor to rotate, and under the rotation of the rotating head of the rotating rod, a certain radial flow velocity is generated and dispersed into the reaction chamber, wherein the rotation rate of the rotating rod is 400r / min, the rotating head is conical, and the cone angle is 130°, and the outer surface of the rotating head is provided with 6 baffles with triangular cross-sections at intervals along the circumferential direction, and the angle between adjacent baffles is 60°, the reaction chamber is trumpet-shaped, and the length of the reaction chamber is 500mm. At the same time, HDI with a temperature of 200° C., a flow rate of 2200 kg / h, a flow rate of 17 m / s, and a pressure of 0.3 MPa enters the reaction chamber through the HDI feed channel in the reactor, and reacts rapidly with hexamethylenediamine in the reaction chamber to obtain a reaction liquid, wherein the mass ratio of HDI to hexamethylenediamine is 20:1, and the reaction temperature is 267° C. The reaction liquid enters the flash chamber for flash cooling treatment to obtain HDI flash steam and a crude liquid with a temperature of 200° C. The HDI flash steam is recycled after heat exchange with new raw material HDI through a first-stage coupling heat exchanger, and the crude liquid is heat exchanged and cooled to 160° C. through a second-stage coupling heat exchanger, and then enters a buffer kettle, a falling film evaporator, and a scraped film evaporator in sequence to obtain HDI biuret.

[0102] Example 2

[0103] Compared with Example 1, Example 2 differs only in that the flow rate of hexamethylenediamine is 88 kg / h, the flow rate is 80 m / s, the pressure is 2.7 MPa, the flow rate of HDI is 1760 kg / h, the flow rate is 14 m / s, and the other conditions are the same to obtain HDI biuret.

[0104] Example 3

[0105] The only difference between Example 3 and Example 1 is that the flow rate of hexamethylenediamine is 150 kg / h, the flow rate is 140 m / s, and the pressure is 12 MPa, and the flow rate of HDI is 3000 kg / h, the flow rate is 24 m / s, and the pressure is 0.5 MPa. The other conditions are the same, and HDI biuret is obtained.

[0106] Example 4

[0107] Compared with Example 1, Example 4 differs only in that the temperature of HDI is 160° C., the reaction temperature is 230° C., and the other conditions are the same to obtain HDI biuret.

[0108] Example 5

[0109] Compared with Example 1, Example 5 differs only in that the temperature of HDI is 230° C., the reaction temperature is 300° C., and the other conditions are the same to obtain HDI biuret.

[0110] Example 6

[0111] Compared with Example 1, Example 6 differs only in that the flow rate of HDI is 1980 kg / h, the flow velocity is 16 m / s, the mass ratio of HDI to hexamethylenediamine is 18:1, the reaction temperature is 288°C, and the other conditions are the same to obtain HDI biuret.

[0112] Example 7

[0113] Compared with Example 1, Example 7 differs only in that the flow rate of HDI is 2750 kg / h, the pressure is 0.4 MPa, the mass ratio of HDI to hexamethylenediamine is 25:1, the reaction temperature is 254° C., and the other conditions are the same to obtain HDI biuret.

[0114] Example 8

[0115] The only difference between Example 8 and Example 1 is that the reaction temperature is 265° C., the rotation rate of the rotating rod is 300 r / min, and the other conditions are the same to obtain HDI biuret.

[0116] Example 9

[0117] The only difference between Example 9 and Example 1 is that the reaction temperature is 265° C., the rotation rate of the rotating rod is 500 r / min, and the other conditions are the same to obtain HDI biuret.

[0118] Example 10

[0119] Compared with Example 1, Example 10 differs only in that the reaction temperature is 265° C. and the cone angle is 120°. The other conditions are the same, and HDI biuret is obtained.

[0120] Embodiment 11

[0121] Compared with Example 1, Example 11 differs only in that the reaction temperature is 265° C. and the cone angle is 140°. The other conditions are the same, and HDI biuret is obtained.

[0122] Example 12

[0123] Compared with Example 1, Example 12 differs only in that the length of the reaction chamber is 300 mm, and other conditions are the same to obtain HDI biuret.

[0124] Example 13

[0125] Compared with Example 1, Example 13 differs only in that the length of the reaction chamber is 700 mm, and other conditions are the same to obtain HDI biuret.

[0126] Embodiment 14

[0127] Compared with Example 1, Example 14 differs only in that the number of baffles is 4, the angle between adjacent baffles is 90°, and the other conditions are the same to obtain HDI biuret.

[0128] Embodiment 15

[0129] Compared with Example 1, Example 15 differs only in that the number of baffles is 8, the angle between adjacent baffles is 45°, and the other conditions are the same to obtain HDI biuret.

[0130] Comparative Example 1

[0131] The only difference between Comparative Example 1 and Example 1 is that no rotating rod is provided in the feed pipe, that is, a nozzle with a spray hole is provided near the inlet of the feed pipe, and the overall spray direction of the nozzle is conically distributed with a cone angle of 120°. The other conditions are the same, and HDI biuret is obtained.

[0132] Comparative Example 2

[0133] Comparative Example 2 is different from Example 1 only in that no flash chamber is provided in the reactor, the obtained reaction liquid is collected and then passed into a flash evaporation device for treatment, and the other conditions are the same to obtain HDI biuret.

[0134] The solid (such as polymer) content of the crude liquid in Examples 1-15 and Comparative Example 1 and the reaction liquid in Comparative Example 2 was tested, and the test results are shown in Table 1; at the same time, the NCO content in the HDI biuret and the viscosity of the HDI biuret in Examples 1-15 and Comparative Example 1-2 were tested, and the test results are shown in Table 1.

[0135] Table 1

[0136]

[0137] It should be noted that, in Comparative Document 2, since no flash chamber is provided in the reactor, the reaction liquid cannot be flash-evaporated and cooled in time, resulting in a high temperature of the extracted reaction liquid, causing thermal decomposition of HDI to produce carbonimide and carbon dioxide, aggravating the overpressure risk of the device and posing a great safety hazard.

[0138] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0139] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A jet reactor for HDI biuret production, characterized in that: include: A reactor body, wherein the reactor body has an HDI feed channel, a reaction chamber, and a flash chamber that are sequentially connected, wherein the reaction chamber has an expansion section, and the expansion section is arranged near the outlet of the HDI feed channel; A feed pipe, wherein the feed pipe is at least partially disposed in the HDI feed channel and extends toward the outlet of the HDI feed channel, a rotating rod is passed through the feed pipe, one end of the rotating rod is transmission-connected to a driving mechanism, the driving mechanism drives the rotating rod to rotate, and the other end of the rotating rod is provided with a rotating head with an expanded outer surface, and the rotating head at least partially extends out of the outlet of the feed pipe.

2. The jet reactor for HDI biuret production according to claim 1, characterized in that: The rotating head is conical, and the cone angle is 110°-150°; And / or, the spin head at least partially extends into the reaction chamber.

3. The jet reactor for HDI biuret production according to claim 1, characterized in that: A plurality of guide structures are arranged at intervals along the circumferential direction on the outer surface of the rotating head, and the guide structures extend from an end of the rotating head close to the rotating rod to an end away from the rotating rod.

4. The jet reactor for HDI biuret production according to claim 1, characterized in that: The angle between adjacent guide structures is 45°-120°; And / or, the cross-sectional shape of the guide structure is any one of a triangle, a fan, and a trapezoid; And / or, the guide structure extends to the rotating rod and is connected to the rotating rod.

5. The jet reactor for HDI biuret production according to claim 1, characterized in that: The length of the reaction chamber along the material flow direction is 300mm-1000mm; And / or, the reaction chamber is trumpet-shaped.

6. The jet reactor for HDI biuret production according to claim 1, characterized in that: The reaction chamber also has a straight pipe section connected to the expansion section, and the length of the expansion section is 50mm-200mm.

7. The jet reactor for HDI biuret production according to claim 1, characterized in that: The outlet of the feed pipe is located at the outlet of the HDI feed channel; And / or, the feed pipe includes a straight pipe section and a tapered section connected in sequence.

8. A production system for HDI biuret, characterized in that: It comprises a reactor and a distillation device which are connected in sequence, and the reactor is a jet reactor for producing HDI biuret as claimed in any one of claims 1 to 7.

9. The HDI biuret production system according to claim 8, characterized in that: The HDI biuret production system also includes a multi-stage coupled heat exchanger and a multi-stage heater, wherein the upper-stage coupled heat exchanger in the multi-stage coupled heat exchanger has an inlet for new raw material HDI, the upper-stage coupled heat exchanger is connected to the gas phase outlet of the reactor, the lower-stage coupled heat exchanger in the multi-stage coupled heat exchanger is connected to the liquid phase outlet of the reactor, the lower-stage coupled heat exchanger is connected to the distillation equipment, the inlet of the upper-stage heater in the multi-stage heater is connected to the lower-stage coupled heat exchanger, and the outlet of the lower-stage heater in the multi-stage heater is connected to the inlet of the HDI feed channel of the reactor.

10. A method for producing HDI biuret using the HDI biuret production system according to claim 8 or claim 9, characterized in that: The following steps are involved: HDI is introduced into the reactor through the HDI feed channel, hexamethylenediamine is introduced into the feed pipe and dispersed in the reactor and reacts with HDI under the rotation of the rotating head of the rotating rod to obtain a reaction liquid, and then the reaction liquid is flash-evaporated to obtain a crude liquid; The crude liquid is subjected to rectification and separation to obtain HDI biuret.

11. The method for producing HDI biuret according to claim 10, characterized in that: The HDI biuret production method also satisfies at least one of the following conditions: (1) before the HDI is introduced into the reactor through the HDI feed channel, the HDI is subjected to heating and pressurizing treatment, wherein the heating temperature is 160° C.-230° C., and the pressurizing pressure is 0.2 MPa-0.5 MPa; (2) The flow rate of HDI into the reactor is 1300kg / h-3000kg / h, and the flow velocity is 10m / s-24m / s; (3) before the hexamethylenediamine is dispersed in the reactor through the feed pipe under the rotation of the rotating head of the rotating rod, it also includes heating treatment and pressurizing treatment, the temperature of the heating treatment is 60° C.-120° C., and the pressure of the pressurizing treatment is 2 MPa-12 MPa; (4) the flow rate of hexamethylenediamine into the reactor is 65kg / h-150kg / h, and the flow velocity is 60m / s-140m / s; (5) The mass ratio of the HDI to the hexamethylenediamine is 15:1-30:1; (6) The rotation speed of the rotating rod is 200 r / min-600 r / min; (7) In the step of flash evaporating the reaction solution, a gas phase is also obtained, and the gas phase is mixed with new raw material HDI; (8) The temperature of the crude liquid obtained after flash evaporation is 190° C.-210° C.; (9) Before the crude liquid is subjected to distillation separation, the crude liquid is subjected to heat exchange treatment, and the temperature of the crude liquid after the heat exchange treatment is 160° C.-180° C.

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