Multi-stage formaldehyde recovery urea-formaldehyde resin production reactor

Abstract

The invention relates to the technical field of urea-formaldehyde resin production, in particular to a multistage formaldehyde recovery urea-formaldehyde resin production reactor, which comprises a reaction kettle main body used for a condensation polymerization reaction of urea and formaldehyde; and the multi-stage recovery mechanism comprises a first-stage tubular condenser and a second-stage absorption sprayer. Through a multi-stage recovery mechanism, formaldehyde generated in the reaction process is effectively recovered, waste of raw materials is reduced, the resource utilization rate is increased, harmful formaldehyde gas discharged into the atmosphere is reduced, pollution to the environment is reduced, a urea solution absorbs heat to provide a cold source for the condenser, meanwhile, redundant heat is absorbed in the process, and the energy consumption is reduced. The raw material temperature of the urea solution is increased, a large amount of energy does not need to be additionally consumed to heat the urea solution before the subsequent production reaction is carried out, the heating energy consumption during the subsequent production reaction by using the raw material is conveniently reduced, and the synergistic interaction of formaldehyde recovery and energy consumption reduction is realized through material and energy dual cycle optimization.

Description

Technical Field

[0001] The invention relates to the technical field of urea-formaldehyde resin production, in particular to a multi-stage formaldehyde recovery urea-formaldehyde resin production reactor. Background Art

[0002] Urea-formaldehyde resin, as a widely used thermosetting polymer, plays an important role in many fields such as wood processing, molding materials, and coatings due to its excellent performance and low cost. In the existing urea-formaldehyde resin production process, urea-formaldehyde resin is generally produced by a condensation reaction between urea and formaldehyde. However, in the actual production process, formaldehyde, as one of the key raw materials, is often unable to be completely converted into the target product during the reaction process, resulting in some formaldehyde escaping into the exhaust gas flow in the form of vapor. If these exhaust gases containing formaldehyde are directly discharged into the atmosphere without effective treatment, it will not only cause a waste of precious chemical raw material formaldehyde, but also pose a serious threat to the environment. Formaldehyde is a known carcinogen. Its release into the air will have an adverse effect on human health and may cause air pollution problems.

[0003] At present, in order to reduce the formaldehyde content in exhaust gas, condensation equipment is usually used to recover the formaldehyde in it. However, this method is usually inefficient and can only recover part of the formaldehyde. The remaining formaldehyde will still be discharged with the exhaust gas, which fails to fundamentally solve the problem of formaldehyde waste and pollution. In addition, the traditional process lacks effective means to optimize heat utilization, resulting in increased energy consumption, further aggravating production costs and environmental burdens. Summary of the invention

[0004] In view of this, the purpose of the present invention is to provide a multi-stage formaldehyde recovery urea-formaldehyde resin production reactor to solve the problems of low formaldehyde recovery efficiency and high energy consumption in the urea-formaldehyde resin production process.

[0005] Based on the above purpose, the present invention provides a multi-stage formaldehyde recovery urea-formaldehyde resin production reactor, comprising: a reactor body, used for the polycondensation reaction of urea and formaldehyde; The multi-stage recovery mechanism includes a first-stage tube condenser and a second-stage absorption sprayer, wherein: The primary tube condenser comprises a cylindrical shell, condensing tubes and a cooling medium cavity, wherein the cooling medium cavity is arranged inside the cylindrical shell, and the condensing tubes are arranged inside the cooling medium cavity; The secondary absorption sprayer comprises an absorption tower body and an atomizing nozzle, wherein the atomizing nozzle is arranged inside the absorption tower body and is interconnected with the urea dissolving tank; The urea dissolving mechanism comprises a urea dissolving tank, wherein the urea dissolving tank is connected with two ends of the cooling medium cavity through a circulation conveying pipe, and a solution circulation pump is arranged on the circulation conveying pipe; The top of the reactor body is connected to the primary tube condenser and the secondary absorption sprayer in sequence; The urea solution is transported to the cooling medium cavity through the circulation transport pipe, and is used to condense the formaldehyde vapor transported from the reactor body to the condensation tube array. The urea solution flows back to the urea dissolution tank after absorbing the heat of the formaldehyde vapor. The condensed formaldehyde solution flows back to the reactor body, and the incompletely condensed formaldehyde vapor enters the secondary absorption sprayer, and contacts and reacts with the urea solution transported from the urea dissolution tank to the atomizing nozzle.

[0006] Furthermore, the urea dissolution tank also includes: A granule feeding port is provided at the top of the urea dissolving tank and is used for feeding urea granules; A water inlet, disposed at the top of the urea dissolution tank, for injecting water to prepare a urea solution; A stirring mechanism is arranged in the middle of the urea dissolving tank, and the stirring mechanism comprises: A driving motor is arranged on the top of the urea dissolution tank and is used to provide power; A stirring shaft, one end of which is connected to the output shaft of the driving motor, and the other end of which extends to the bottom of the urea dissolution tank; The stirring blades are evenly fixed on the stirring shaft and include spiral blades and turbine blades to enhance the mixing effect.

[0007] Furthermore, the first-stage tube condenser also includes a closed tube sheet, which is arranged at the top and bottom of the first-stage tube condenser, and the two ends of the condensing tubes are respectively fixed on the closed tube sheets at the top and bottom of the cylindrical shell, and the cooling medium cavity is arranged between the closed tube sheets to accommodate the urea solution for circulating transportation. The cooling medium cavity is provided with a baffle to guide and extend the flow path of the urea solution in the cooling medium cavity.

[0008] Furthermore, the annular liquid collecting tank is arranged at the bottom of the condensation array tubes, and is used to collect the liquid formed by condensation. The liquid collecting delivery pipe is connected to the middle of the annular liquid collecting tank, and the outer end of the liquid collecting delivery pipe is connected to a first recovery tank. The first recovery tank is connected to the annular liquid collecting tank through the liquid collecting delivery pipe, and is used to store the formaldehyde solution recovered by condensation. A first metering pump is also arranged between the first recovery tank and the reactor body, and the first metering pump is used to quantitatively transport the formaldehyde solution stored in the first recovery tank to the inside of the reactor body for reaction production.

[0009] Furthermore, lateral air inlets are evenly arranged around the bottom of the side of the absorption tower body, an annular air inlet pipe is arranged on the outside of the lateral air inlet, the annular air inlet pipe is interconnected with the bottom end of the first-level tube-in-tube condenser, the central air outlet pipe is arranged at the center position of the top of the absorption tower body, and an exhaust fan is installed in the middle of the central air outlet pipe to promote the circulation and discharge of gas. The residual formaldehyde vapor output from the bottom end of the first-level tube-in-tube condenser enters the lateral air inlet through the annular air inlet pipe, and is transported to the inside of the absorption tower body to flow upward, and is finally discharged through the central air outlet pipe. A plurality of atomizing nozzles are also arranged inside the absorption tower body, and the urea solution is sprayed through the atomizing nozzle, contacts and reacts with the formaldehyde vapor, and further recovers the formaldehyde.

[0010] Furthermore, an annular delivery pipe is arranged around the inside of the absorption tower body, a boost delivery pump is connected to the outer end of the annular delivery pipe, the boost delivery pump is connected to the urea dissolution tank, a plurality of vertical delivery pipes are evenly connected around the middle of the annular delivery pipe, the vertical delivery pipes are arranged parallel to the absorption tower body, a plurality of atomizing nozzles are evenly arranged and connected along the vertical delivery pipes, the urea solution is evenly delivered to each vertical delivery pipe through the annular delivery pipe, and is sprayed out through the atomizing nozzle to fully contact and react with the formaldehyde vapor inside the absorption tower body.

[0011] Furthermore, a bottom liquid storage tank is provided at the bottom of the absorption tower body for collecting the liquid after the absorption reaction. The bottom liquid storage tank is interconnected with the second recovery tank through a pipeline, and the second recovery tank is interconnected with the reactor body through the second metering pump, so as to quantitatively transport the recovered formaldehyde solution to the interior of the reactor body for reaction production.

[0012] Furthermore, the reactor body comprises: A reactor container, used to contain urea solution and formaldehyde solution for polycondensation reaction; A heating jacket is arranged outside the reactor container to provide heat required for the reaction; A feeding mechanism, the feeding mechanism comprising: A urea solution feeding pipe is used to add a raw material urea solution. A metering delivery pump is connected to the outer end of the urea solution feeding pipe. The urea solution feeding pipe is connected to the urea dissolving tank through the metering delivery pump. The urea solution in the urea dissolving tank is delivered to the reactor container through the urea solution feeding pipe and the metering delivery pump. A formaldehyde solution feed pipe, used for adding raw formaldehyde solution, and the formaldehyde solution feed pipe is connected to the first metering pump and the second metering pump to transport the recovered formaldehyde solution to the reactor container; A discharging mechanism, the discharging mechanism comprising: A product discharge pipe, disposed at the bottom of the reactor container, for discharging the generated urea-formaldehyde resin product; The residual gas discharge pipe is arranged at the top of the reactor container and is used to discharge the gas that does not participate in the reaction. At the same time, the residual gas discharge pipe is interconnected with the first-stage tube condenser.

[0013] Furthermore, it also includes: The temperature monitoring module includes temperature sensors distributed in the reactor body, the primary tube condenser, the secondary absorption sprayer and the urea dissolving tank, and is used to monitor the temperature data of each part in real time; The flow control module comprises a flow meter and a regulating valve arranged on the connecting pipeline between the urea dissolving tank, the primary tube condenser and the secondary absorption sprayer, and is used for accurately controlling the fluid flow of each part.

[0014] Furthermore, it also includes: The central control unit is used to receive and process the signals from various sensors and adjust the operating parameters of each component according to preset programs or manual instructions; The central control unit is connected to each module via wired communication and adjusts the operating parameters of each component according to real-time data.

[0015] Beneficial effects of the present invention: As can be seen from the above, a multi-stage formaldehyde recovery urea-formaldehyde resin production reactor provided by the present invention can effectively recover the formaldehyde generated in the reaction process through a multi-stage recovery mechanism, reduce the waste of raw materials, improve resource utilization, reduce the emission of harmful formaldehyde gas into the atmosphere, and reduce pollution to the environment. The device provides a cold source for the condenser through heat absorption by the urea solution, and absorbs excess heat in the process to increase the temperature of the urea solution raw materials. Before the subsequent production reaction, there is no need to consume a large amount of additional energy to heat the urea solution, which is convenient for reducing the heating energy consumption when the raw materials are used for subsequent production reactions. Through the dual circulation optimization of materials and energy, the synergistic effect of formaldehyde recovery and energy consumption reduction is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the present invention or 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 in the following description are only for the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 It is a structural schematic diagram of a multi-stage recovery mechanism according to an embodiment of the present invention; Figure 2 It is a front structural schematic diagram of an embodiment of the present invention; Figure 3 Schematic diagram of the structure of the urea dissolving mechanism according to an embodiment of the present invention; Figure 4 A schematic diagram of a rear side connection structure of an embodiment of the present invention; Figure 5 This is a schematic structural diagram of a reactor body according to an embodiment of the present invention; Figure 6 Schematic diagram of the external structure of a urea dissolution tank according to an embodiment of the present invention; Figure 7 This is a schematic diagram of the internal structure of a urea dissolution tank according to an embodiment of the present invention; Figure 8 It is a structural schematic diagram of a primary tube condenser according to an embodiment of the present invention; Fig. 9 A schematic diagram of the internal structure of a cylindrical housing according to an embodiment of the present invention; Fig.10 A schematic diagram of the external structure of an absorption tower body according to an embodiment of the present invention; Fig.11 A schematic diagram of the internal structure of an absorption tower body according to an embodiment of the present invention; Fig.12 Schematic diagram of the control connection principle between the central control unit and various components of an embodiment of the present invention.

[0018] The markings in the figure are: 1. Reactor body; 101. Reactor container; 102. Heating jacket; 103. Feed mechanism; 104. Urea solution feed pipe; 105. Formaldehyde solution feed pipe; 106. Discharge mechanism; 107. Product discharge pipe; 108. Gas discharge pipe; 2. Urea dissolution mechanism; 201. Urea dissolution tank; 202. Particle feeding port; 203. Water inlet; 204. Circulation conveying pipe; 205. Solution circulation pump; 206. Measuring conveying pump; 3. Stirring mechanism; 301. Driving motor; 302. Stirring shaft; 303. Stirring blade; 304. Spiral blade; 305. Turbine blade; 4. Multi-stage recovery mechanism; 5. Primary tube condenser; 501. Columnar shell; 502. Condensation tube; 503, closed tube sheet; 504, cooling medium cavity; 505, baffle; 506, annular liquid collecting tank; 507, liquid collecting delivery pipe; 508, first recovery tank; 509, first metering pump; 6, secondary absorption sprayer; 601, absorption tower body; 602, lateral air inlet; 603, annular air inlet pipe; 604, central air outlet pipe; 605, exhaust fan; 7, annular delivery pipe; 701, vertical delivery pipe; 702, atomizing nozzle; 703, bottom liquid trough; 704, booster delivery pump; 705, second recovery tank; 706, second metering pump; 8, temperature monitoring module; 801, temperature sensor; 802, flow control module; 803, flow meter; 804, regulating valve; 9, central control unit. DETAILED DESCRIPTION

[0019] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments.

[0020] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0021] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5, Figure 6 , Figure 7 , Figure 8 , Fig. 9 , Fig.10 and Fig.11 As shown, a multi-stage formaldehyde recovery urea-formaldehyde resin production reactor comprises: The reactor body 1 is used for the polycondensation reaction of urea and formaldehyde; The multi-stage recovery mechanism 4 includes a first-stage tube condenser 5 and a second-stage absorption sprayer 6, wherein: The first-stage tube condenser 5 includes a cylindrical shell 501, condensing tubes 502 and a cooling medium cavity 504. The cooling medium cavity 504 is arranged inside the cylindrical shell 501, and the condensing tubes 502 are arranged inside the cooling medium cavity 504. The secondary absorption sprayer 6 includes an absorption tower body 601 and an atomizing nozzle, wherein the atomizing nozzle is arranged inside the absorption tower body 601 and is interconnected with the urea dissolving tank 201; The urea dissolving mechanism 2 includes a urea dissolving tank 201, which is connected to both ends of the cooling medium cavity 504 through a circulation conveying pipe 204, and a solution circulation pump 205 is provided on the circulation conveying pipe 204; The top of the reactor body 1 is connected to the primary tube condenser 5 and the secondary absorption sprayer 6 in sequence; The urea solution is transported to the cooling medium chamber 504 through the circulation transport pipe 204, and is used to condense the formaldehyde vapor transported from the reactor body 1 to the condensation tube array 502. The urea solution flows back to the urea dissolving tank 201 after absorbing the heat of the formaldehyde vapor. The condensed formaldehyde solution flows back to the reactor body 1 , and the incompletely condensed formaldehyde vapor enters the secondary absorption sprayer 6 , and contacts and reacts with the urea solution delivered to the atomizing nozzle by the urea dissolving tank 201 .

[0022] In this embodiment, the device performs a polycondensation reaction of urea and formaldehyde in the reactor body 1 to generate urea-formaldehyde resin. This process generates waste gas containing formaldehyde vapor. The waste gas containing formaldehyde vapor discharged from the reactor body 1 enters the primary tube condenser 5. In this condenser, the waste gas passes through a series of condensation tubes 502, and these tubes are surrounded by a cooling medium cavity 504. The circulating urea solution serves as a cooling medium and flows through the circulation conveying pipe 204 at both ends of the cooling medium cavity 504 to absorb the heat released by the formaldehyde vapor. At this time, the formaldehyde vapor generally exists in a mixed state with water vapor, and the overall condensation temperature is roughly the same as that of water, resulting in partial condensation of the formaldehyde vapor into a liquid formaldehyde solution. The condensed formaldehyde solution flows back to the reactor body 1, and the formaldehyde vapor that is not completely condensed continues to enter the secondary absorption sprayer 6. In the secondary absorption sprayer 6, the urea solution from the urea dissolution tank 201 forms fine droplets through an atomizing nozzle, which fully contacts with the formaldehyde vapor and undergoes a chemical reaction. The formaldehyde content in the exhaust gas can be further reduced. The urea solution used in the whole process is prepared by the urea dissolving tank 201 and is continuously recycled by the solution circulating pump 205 and the circulating conveying pipe 204. After passing through the first-stage tube condenser 5, the urea solution with increased temperature will flow back to the urea dissolving tank 201 so as to participate in the cooling process again. Through the multi-stage recovery mechanism, the formaldehyde generated in the reaction process can be effectively recovered, the waste of raw materials can be reduced, the resource utilization rate can be improved, the emission of harmful formaldehyde gas into the atmosphere can be reduced, and the pollution to the environment can be reduced. In addition, the device provides a cold source for the condenser through the heat absorption of the urea solution, and absorbs excess heat in the process to increase the temperature of the urea solution raw material. Before the subsequent production reaction, there is no need to consume a large amount of energy to heat the urea solution, which is convenient for reducing the heating energy consumption when the raw materials are used for the subsequent production reaction. Through the dual circulation optimization of materials and energy, the synergistic effect of formaldehyde recovery and energy consumption reduction can be achieved.

[0023] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7As shown, preferably, a particle feeding port 202 is provided on the top of the urea dissolution tank 201 of the device for feeding urea particles, and a water inlet 203 is also provided on the top of the urea dissolution tank 201 for injecting water to prepare a urea solution, and a stirring mechanism 3 is also provided inside the urea dissolution tank 201. The driving motor 301 installed on the top of the urea dissolution tank 201 drives all stirring blades 303 to rotate synchronously through the stirring shaft 302 to stir the internal solution, and the stirring blades 303 include spiral blades 304 and turbine blades 305, which are evenly fixed on the stirring shaft 302. The spiral blades 304 help to push the material from the bottom to the top, and the turbine blades 305 can enhance the shear force and turbulence of the liquid. The combination of the two can significantly improve the mixing effect, not only improve the up and down circulation speed of the material, but also enhance the turbulence inside the liquid, greatly accelerate the dissolution rate of the urea particles, and shorten the dissolution time.

[0024] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 and Fig. 9 As shown, preferably, the device is provided with closed tube sheets 503 at the top and bottom of the first-level tube condenser 5, and the closed tube sheets 503 provide fixing points for the condensing tubes 502, thereby ensuring the sealing of the entire condenser system. The two ends of the condensing tubes 502 are respectively fixed on the closed tube sheets 503 at the top and bottom of the cylindrical shell 501, forming a solid overall structure. The space between the closed tube sheets 503 is defined as a cooling medium cavity 504, which is used to accommodate the circulating urea solution to ensure that the urea solution can effectively contact the condensing tubes 502, thereby maximizing the heat exchange efficiency. In order to further optimize the heat exchange effect, a baffle 505 is provided inside the cooling medium cavity 504 to guide and extend the flow path of the urea solution in the cooling medium cavity 504, increase the contact time and area between the urea solution and the condensing tubes 502, thereby improving the heat exchange efficiency, so as to more effectively utilize the heat released by the urea solution absorbing formaldehyde vapor, and achieve a more efficient condensation process.

[0025] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 and Fig. 9As shown, preferably, an annular liquid collecting tank 506 is provided at the bottom of the condensation array tubes 502 of the device to ensure that all condensed liquids can be effectively collected, and a liquid collecting conveying pipe 507 is provided in the middle of the annular liquid collecting tank 506, which connects the annular liquid collecting tank 506 with the first recovery tank 508. The first recovery tank 508 is connected to the annular liquid collecting tank 506 through the liquid collecting conveying pipe 507, and is specially used for storing the formaldehyde solution recovered by condensation. A first metering pump 509 is provided between the first recovery tank 508 and the reactor body 1, and the first metering pump 509 can be used to quantitatively convey the formaldehyde solution stored in the first recovery tank 508 to the inside of the reactor body 1 according to the requirements of the production process, thereby ensuring the accuracy and stability of the reaction conditions, being able to effectively recover the formaldehyde generated during the reaction process, reducing the waste of raw materials, and improving resource utilization.

[0026] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 , Fig. 9 , Fig.10 and Fig.11 As shown, preferably, the device is evenly arranged with multiple lateral air inlets 602 on the side and bottom of the absorption tower body 601, and an annular air inlet pipe 603 is connected to the outside of these air inlets. The annular air inlet pipe 603 is interconnected with the bottom end of the first-stage tube-in-tube condenser 5, so that the remaining formaldehyde vapor output from the bottom end of the first-stage tube-in-tube condenser 5 can smoothly enter the lateral air inlet 602 through the annular air inlet pipe 603 and be transported to the inside of the absorption tower body 601. A central air outlet pipe 604 is arranged at the center position of the top of the absorption tower body 601, and an exhaust fan 605 is installed in the middle of the air outlet pipe. The main function of the exhaust fan 605 is to promote the circulation of gas in the absorption tower, ensure that the formaldehyde vapor that is not completely condensed can effectively flow upward and be discharged through the central air outlet pipe 604, and also help to maintain the negative pressure state in the absorption tower, thereby improving the exhaust gas treatment efficiency. A plurality of atomizing nozzles are also arranged inside the absorption tower body 601, and these nozzles are connected to the urea dissolution tank 201. Urea solution is sprayed out through these atomizing nozzles to form fine droplets, which fully contact and react chemically with the upward flowing formaldehyde vapor to further recover the formaldehyde. This not only improves the recovery rate of formaldehyde, but also effectively reduces the formaldehyde content in the exhaust gas and reduces the impact on the environment.

[0027] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 , Fig. 9 , Fig.10 and Fig.11 As shown, preferably, an annular delivery pipe 7 is arranged around the inside of the absorption tower body 601 of the device, and the annular delivery pipe 7 is interconnected with the urea dissolution tank 201 through a boost delivery pump 704. A plurality of vertical delivery pipes 701 are evenly connected around the middle of the annular delivery pipe 7, and a plurality of atomizing nozzles 702 are evenly arranged and connected along the vertical delivery pipes 701. The boost delivery pump 704 boosts and delivers the urea solution in the urea dissolution tank 201 to the annular delivery pipe 7, and further evenly delivers it to all the vertical delivery pipes 701, and then evenly sprays it out through the atomizing nozzle 702, so that the urea solution can be evenly distributed along the height direction of the absorption tower body 601, thereby increasing the chance of contact with formaldehyde vapor. The urea solution is evenly delivered to each vertical delivery pipe 701 through the annular delivery pipe 7, and sprayed out through the atomizing nozzle 702, and fully contacts and chemically reacts with the formaldehyde vapor flowing upward in the absorption tower body 601, thereby effectively improving the recovery efficiency of formaldehyde.

[0028] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 , Fig. 9 , Fig.10 and Fig.11 As shown, preferably, the device is provided with a bottom liquid storage tank 703 at the bottom of the absorption tower body 601, which is used to collect the liquid after the absorption reaction. The bottom liquid storage tank 703 is interconnected with the second recovery tank 705 through a pipeline, and the second recovery tank 705 is interconnected with the reactor body 1 through a second metering pump 706, which is used to quantitatively transport the recovered formaldehyde solution to the inside of the reactor body 1 for reaction production, which can effectively recover the formaldehyde generated in the reaction process, reduce the waste of raw materials, and improve resource utilization.

[0029] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 , Fig. 9 , Fig.10 , Fig.11 and Fig.12As shown, preferably, the device contains urea solution and formaldehyde solution by a reactor container 101 for polycondensation reaction, and a heating jacket 102 is arranged on the outside of the reactor container 101 to provide heat required for the reaction. The feeding mechanism 103 of the device mainly includes a urea solution feeding pipe 104 for adding a raw material urea solution and a formaldehyde solution feeding pipe 105 for adding a raw material formaldehyde solution, and the urea solution in the urea dissolving tank 201 can be quantitatively transported to the reactor container 101 through the urea solution feeding pipe 104 and the metering delivery pump 206. At the same time, the formaldehyde solution feed pipe 105 is interconnected with the first metering pump 509 and the second metering pump 706, so that the recovered formaldehyde solution can be transported to the reactor container 101. The product discharge pipe 107 of the discharge mechanism 106 is arranged at the bottom of the reactor container 101, and is used to discharge the generated urea-formaldehyde resin product. The residual gas discharge pipe 108 of the discharge mechanism 106 is arranged at the top of the reactor container 101, and is used to discharge the gas that does not participate in the reaction. At the same time, the residual gas discharge pipe 108 is interconnected with the first-stage tube condenser 5 to facilitate the recovery and treatment of the gas.

[0030] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 , Fig. 9 and Fig.10As shown, preferably, the temperature monitoring module 8 provided in the device includes temperature sensors 801 distributed in the reactor body 1, the first-level tube condenser 5, the second-level absorption sprayer 6 and the urea dissolution tank 201, which are used to monitor the temperature data of each part in real time and transmit the information to the central control unit 9, which helps to ensure that each link operates under the optimal temperature conditions, thereby improving the overall efficiency and product quality, and the flow control module 802 includes a flow meter 803 and a regulating valve 804 provided on the urea dissolution tank 201, the first-level tube condenser 5, the second-level absorption sprayer 6 and the circulation conveying pipe 204, which are used to accurately control the fluid flow of each part to ensure that the material supply at each stage is accurate. The flow meter 803 is responsible for measuring the fluid flow, and the regulating valve 804 adjusts the opening according to the need to control the flow size. At the same time, the device is also provided with a heat recovery optimization module, which is controlled by the central control The control unit 9 is interconnected with the temperature monitoring module 8 and the flow control module 802. By analyzing the data from the temperature sensor 801 and the flow meter 803, the circulation speed and condensation temperature of the urea solution can be dynamically adjusted by the central control unit 9. Based on the data analysis results, the system can automatically adjust the operating parameters to maximize the heat recovery efficiency. For example, when it is found that the heat loss in a certain area is large, the system can increase the circulation speed of the cooling medium or adjust the condensation temperature to achieve more efficient energy utilization. The central control unit 9 is used to receive and process signals from various sensors, and adjust the operating parameters of various components according to preset programs or manual instructions. The central control unit 9 is connected to various modules and components through wired communication, and adjusts the operating parameters of various components according to real-time data, thereby realizing real-time monitoring and precise regulation of key parameters in the production process, and improving product quality and consistency.

[0031] Those skilled in the art should understand that the discussion of any of the above embodiments is only exemplary and is not intended to imply that the scope of the present invention is limited to these examples; under the concept of the present invention, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other changes in different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity. Any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A multi-stage formaldehyde recovery urea-formaldehyde resin production reactor, characterized in that: include: The reactor body (1) is used for the polycondensation reaction of urea and formaldehyde; The multi-stage recovery mechanism (4) includes a first-stage tube condenser (5) and a second-stage absorption sprayer (6), wherein: The primary tube condenser (5) comprises a cylindrical shell (501), condensing tubes (502) and a cooling medium cavity (504), wherein the cooling medium cavity (504) is arranged inside the cylindrical shell (501), and the condensing tubes (502) are arranged on the inner side of the cooling medium cavity (504); The secondary absorption sprayer (6) comprises an absorption tower body (601) and an atomizing nozzle, wherein the atomizing nozzle is arranged inside the absorption tower body (601) and is interconnected with the urea dissolving tank (201); The urea dissolving mechanism (2) comprises a urea dissolving tank (201), wherein the urea dissolving tank (201) is connected to both ends of the cooling medium cavity (504) via a circulation conveying pipe (204), and a solution circulation pump (205) is provided on the circulation conveying pipe (204); The top of the reactor body (1) is connected to a primary tube condenser (5) and a secondary absorption sprayer (6) in sequence; The urea solution is transported to the cooling medium chamber (504) through the circulation transport pipe (204) to condense the formaldehyde vapor transported from the reactor body (1) to the condensation tube array (502), and the urea solution flows back to the urea dissolution tank (201) after absorbing the heat of the formaldehyde vapor; The condensed formaldehyde solution flows back to the reactor body (1), and the incompletely condensed formaldehyde vapor enters the secondary absorption sprayer (6) and contacts and reacts with the urea solution delivered to the atomizing nozzle from the urea dissolving tank (201).

2. The multi-stage formaldehyde recovery urea-formaldehyde resin production reactor according to claim 1, characterized in that: The urea dissolving tank (201) further comprises: A particle feeding port (202) is provided at the top of the urea dissolving tank (201) and is used for feeding urea particles; A water inlet (203) is provided at the top of the urea dissolution tank (201) and is used for injecting water to prepare a urea solution; The stirring mechanism (3) is arranged at a middle position inside the urea dissolving tank (201), and the stirring mechanism (3) comprises: A driving motor (301) is arranged on the top of the urea dissolving tank (201) and is used to provide power; a stirring shaft (302), one end of the stirring shaft (302) being connected to the output shaft of the driving motor (301), and the other end of the stirring shaft (302) extending to the bottom of the urea dissolution tank (201); The stirring blades (303) are evenly fixed on the stirring shaft (302), and include spiral blades (304) and turbine blades (305) to enhance the mixing effect.

3. The multi-stage formaldehyde recovery urea-formaldehyde resin production reactor according to claim 2, characterized in that: The first-stage tube condenser (5) further comprises a closed tube sheet (503), wherein the closed tube sheet (503) is arranged at the top and the bottom of the first-stage tube condenser (5), and the two ends of the condensing tubes (502) are respectively fixed on the closed tube sheets (503) at the top and the bottom of the cylindrical shell (501), and the cooling medium cavity (504) is arranged between the closed tube sheets (503) for accommodating the urea solution for circulating transportation, and a baffle (505) is arranged inside the cooling medium cavity (504) for guiding and extending the flow path of the urea solution in the cooling medium cavity (504).

4. The multi-stage formaldehyde recovery urea-formaldehyde resin production reactor according to claim 3, characterized in that: The annular liquid collecting tank (506) is arranged at the bottom of the condensation array tube (502) and is used to collect the liquid formed by condensation. The liquid collecting conveying pipe (507) is connected to the middle of the annular liquid collecting tank (506). The outer end of the liquid collecting conveying pipe (507) is connected to a first recovery tank (508). The first recovery tank (508) is connected to the annular liquid collecting tank (506) through the liquid collecting conveying pipe (507) and is used to store the formaldehyde solution recovered by condensation. A first metering pump (509) is also arranged between the first recovery tank (508) and the reactor body (1). The first metering pump (509) is used to quantitatively convey the formaldehyde solution stored in the first recovery tank (508) to the inside of the reactor body (1) for reaction production.

5. The multi-stage formaldehyde recovery urea-formaldehyde resin production reactor according to claim 4, characterized in that: The bottom of the side of the absorption tower body (601) is evenly surrounded by lateral air inlets (602), and an annular air inlet pipe (603) is arranged outside the lateral air inlet (602). The annular air inlet pipe (603) is interconnected with the bottom end of the primary tube-in-tube condenser (5). The central air outlet pipe (604) is arranged at the center of the top of the absorption tower body (601), and an exhaust fan (605) is installed in the middle of the central air outlet pipe (604) to promote the circulation and discharge of gas. The remaining formaldehyde vapor output from the bottom end of the primary tube-in-tube condenser (5) enters the lateral air inlet (602) through the annular air inlet pipe (603), and is transported to the inside of the absorption tower body (601) to flow upward, and finally discharged through the central air outlet pipe (604). A plurality of atomizing nozzles are also arranged inside the absorption tower body (601), and the urea solution is sprayed through the atomizing nozzles to contact and react with the formaldehyde vapor to further recover the formaldehyde.

6. The multi-stage formaldehyde recovery urea-formaldehyde resin production reactor according to claim 5, characterized in that: An annular delivery pipe (7) is arranged around the inside of the absorption tower body (601), and a booster delivery pump (704) is connected to the outer end of the annular delivery pipe (7), and the booster delivery pump (704) is connected to the urea dissolving tank (201). A plurality of vertical delivery pipes (701) are evenly connected around the middle of the annular delivery pipe (7), and the vertical delivery pipes (701) are arranged in parallel with the absorption tower body (601). A plurality of atomizing nozzles (702) are evenly arranged and connected along the vertical delivery pipes (701). The urea solution is evenly delivered to each vertical delivery pipe (701) through the annular delivery pipe (7), and is sprayed out through the atomizing nozzles (702) to fully contact and react with the formaldehyde vapor inside the absorption tower body (601).

7. The multi-stage formaldehyde recovery urea-formaldehyde resin production reactor according to claim 6, characterized in that: A bottom liquid storage tank (703) is provided at the bottom of the absorption tower body (601) for collecting liquid after the absorption reaction. The bottom liquid storage tank (703) is interconnected with the second recovery tank (705) through a pipeline. The second recovery tank (705) is interconnected with the reactor body (1) through the second metering pump (706) for quantitatively transporting the recovered formaldehyde solution to the inside of the reactor body (1) for reaction production.

8. The multi-stage formaldehyde recovery urea-formaldehyde resin production reactor according to claim 7, characterized in that: The reactor body (1) comprises: A reaction kettle container (101) is used to contain a urea solution and a formaldehyde solution for polycondensation reaction; A heating jacket (102) is disposed outside the reactor container (101) and is used to provide heat required for the reaction; A feeding mechanism (103), wherein the feeding mechanism (103) comprises: A urea solution feeding pipe (104) is used to add a raw material urea solution. Meanwhile, a metering delivery pump (206) is connected to the outer end of the urea solution feeding pipe (104). The urea solution feeding pipe (104) is connected to the urea dissolving tank (201) via the metering delivery pump (206). The urea solution in the urea dissolving tank (201) is delivered to the reactor container (101) via the urea solution feeding pipe (104) and the metering delivery pump (206); A formaldehyde solution feed pipe (105) is used to add raw formaldehyde solution. The formaldehyde solution feed pipe (105) is connected to the first metering pump (509) and the second metering pump (706) to transport the recovered formaldehyde solution to the reactor container (101); A discharging mechanism (106), wherein the discharging mechanism (106) comprises: A product discharge pipe (107), disposed at the bottom of the reactor container (101), for discharging the generated urea-formaldehyde resin product; The residual gas discharge pipe (108) is arranged at the top of the reactor container (101) and is used to discharge the gas that does not participate in the reaction. At the same time, the residual gas discharge pipe (108) is connected to the first-stage tube condenser (5).

9. The multi-stage formaldehyde recovery urea-formaldehyde resin production reactor according to claim 8, characterized in that: Also includes: The temperature monitoring module (8) comprises temperature sensors (801) distributed in the reactor body (1), the primary tube condenser (5), the secondary absorption sprayer (6) and the urea dissolving tank (201), and is used to monitor the temperature data of each part in real time; The flow control module (802) comprises a flow meter (803) and a regulating valve (804) arranged on the connecting pipeline between the urea dissolving tank (201), the primary tube condenser (5), and the secondary absorption sprayer (6), and is used to accurately control the fluid flow of each part.

10. The multi-stage formaldehyde recovery urea-formaldehyde resin production reactor according to claim 9, characterized in that: Also includes: A central control unit (9) is used to receive and process signals from various sensors and adjust the operating parameters of various components according to a preset program or manual instructions; The central control unit (9) is connected to each module via wired communication and adjusts the operating parameters of each component according to real-time data.

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