Methyl chloroacetate esterification reaction heat exchange device

Abstract

The invention discloses a methyl chloroacetate esterification reaction heat exchange device, and relates to the technical field of chemical equipment. Comprising a feeding device as well as a chloroacetic acid inlet pipe, a methanol inlet pipe and a concentrated sulfuric acid inlet pipe which are connected to the feeding device, and a reaction and heat exchange unit consisting of a top shell, a bottom shell and a reaction and heat exchange part is arranged at the bottom of the feeding device. The reaction and heat exchange units are arranged and are of a modular stacked structure, so that reaction materials at each position are tightly wrapped by adjacent heat exchange faces on the two sides, and instant, synchronous and uniform heat exchange of material reaction heat is achieved in cooperation with uniform flow distribution brought by countercurrent flow heat exchange and material uniformizing plates; the inherent temperature gradient and local hot spots of a traditional jacket or coil pipe type reactor are eliminated, the temperature fluctuation of the whole reaction area is accurately controlled within an extremely small range, and the uniform temperature field not only greatly reduces side reactions caused by overheating, but also improves the consistency and one-way yield of products.

Description

Technical Field

[0001] This invention relates to the field of chemical equipment technology, specifically to a heat exchange device for the esterification reaction of methyl chloroacetate. Background Technology

[0002] Methyl chloroacetate is an important organic synthesis intermediate and solvent, widely used in industries such as pesticides, pharmaceuticals, dyes and fragrances. Its industrial production mainly adopts the esterification reaction of chloroacetic acid and methanol under the catalysis of concentrated sulfuric acid, which is a typical exothermic reaction.

[0003] Chinese invention patent application CN118936155A discloses a heat exchange device for the production of o-chlorophenylglycine, relating to the field of chemical heat exchange equipment. The device includes a shell, heat exchange tubes, tube sheet, and end caps. It transforms the heat exchange tubes in a tubular heat exchanger from one set to two sets, essentially cutting the existing length of the heat exchange tubes into two sections. This design shortens the heat exchange tubes, thereby reducing the difficulty of cleaning them and mitigating vibration and wear without reducing heat exchange efficiency or increasing space requirements. Simultaneously, it avoids the need for expansion joints on the shell, preventing them from weakening the shell's pressure-bearing capacity.

[0004] However, for the esterification reaction of methyl chloroacetate, existing technologies and reactors on the market mostly rely on jacketed or internal coil heat exchange, which have small heat transfer areas and low heat transfer efficiency, resulting in obvious temperature gradients and local hot spots. This not only exacerbates side reactions and affects product quality consistency, but also poses a safety hazard of thermal runaway due to untimely heat removal. In addition, existing stirrers generally rely on mechanical stirring to achieve macroscopic mixing of chloroacetic acid, methanol, and concentrated sulfuric acid. The mixing intensity is limited and uneven. If concentrated sulfuric acid, as a catalyst, is not sufficiently dispersed, it is very easy to form high acid concentration areas in local areas, inducing side reactions such as dehydration, carbonization, and over-esterification of chloroacetic acid, leading to a decrease in the selectivity of the target product and an increase in the impurity content. Summary of the Invention

[0005] The purpose of this invention is to provide a heat exchange device for the esterification reaction of methyl chloroacetate, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a heat exchange device for the esterification reaction of methyl chloroacetate, comprising a feeding device and chloroacetic acid inlet pipe, methanol inlet pipe and concentrated sulfuric acid inlet pipe connected to the feeding device, wherein the bottom of the feeding device is provided with a reaction and heat exchange unit consisting of a top shell, a bottom shell and reaction and heat exchange components. A feed chamber and a discharge chamber are formed between the reaction and heat exchange components and the top shell, and between the reaction and heat exchange components and the bottom shell, respectively. A vent pipe connected to the feed chamber is fixed on the top of the top shell. The discharge port of the feeding device is connected to the feeding chamber; A uniform material plate is fixed on the inner wall of the feeding chamber. Several uniform material holes are opened on the plate body. The diameter of the uniform material holes gradually increases from the center to the edge, so that the mixture entering the feeding chamber from the feeding device is evenly distributed when passing through the uniform material plate, avoiding local accumulation of materials in the feeding chamber, and allowing the materials flowing down through the uniform material plate to fully contact the reaction and heat exchange components. A cooling unit is installed at the bottom of the feeding device to cool the products obtained from the reaction.

[0007] Furthermore, the feeding device includes a mixing component, a first static mixer, a connecting pipe, and a second static mixer connected in sequence. The chloroacetic acid inlet and methanol inlet are connected to the top of the mixing unit, and the concentrated sulfuric acid inlet is connected to the connecting pipe.

[0008] Furthermore, the mixing component includes a shell, an annular tube fixed to the top of the shell, a chloroacetic acid inlet pipe fixedly connected to the annular tube, and a plurality of injection pipes fixedly connected to the bottom of the annular tube. The injection nozzles of the injection pipes are inclined to the central axis of the shell to guide the falling material to form a spiral flow. Several liquid outlet holes are provided on the vertical pipe of the methanol inlet pipe that extends into the shell; The vertical tube of the methanol inlet pipe coincides with the central axis of the annular pipe, and the methanol sprayed from the outlet hole can form a convective vortex with the chloroacetic acid sprayed from the injection pipe inside the shell.

[0009] Furthermore, the reaction and heat exchange component includes a protective shell and a core fixed inside the protective shell.

[0010] Furthermore, the core is formed by horizontally stacking and fixing several sets of reaction and heat exchange plates; The reaction and heat exchange plate includes a reaction plate, with partitions fixed on both sides of the reaction plate, and a heat exchange plate fixed on the side of one of the partitions; The reaction plate has several equally spaced flow holes in the vertical direction, and the heat exchange plate has several equally spaced cooling holes in the vertical direction. Heat exchange plates extend from the top and bottom of the reaction plate. Cover plates are fixed to the top and bottom of the reaction plate. Top heat exchange medium channels and bottom heat exchange medium channels are formed between the top and bottom cover plates and the heat exchange plates, respectively. The cover plate has several through slots equal in number to the reaction plates, and the mixture flows into the flow holes of the reaction plates through the through slots. The protective shell has several bottom medium branch pipes that are equal in number to and connected to the bottom heat exchange medium channels, and several top medium branch pipes that are equal in number to and connected to the top heat exchange medium channels. The bottom medium branch pipes and the top medium branch pipes are respectively fixed with a first medium inlet pipe and a first medium outlet pipe. A refrigeration unit is connected between the first medium inlet pipe and the first medium outlet pipe.

[0011] Furthermore, the cover plate has several arc-shaped surfaces, with the through groove located at the bottom of the arc-shaped surfaces.

[0012] Furthermore, the two outermost heat exchange plates of the core are respectively attached to the inner wall of the protective shell, so that each reaction plate is located between two adjacent heat exchange plates.

[0013] Furthermore, several ultrasonic anti-scaling modules are fixed to the top of the side of the protective shell.

[0014] Furthermore, the cooling unit includes a cooling cylinder, with a top jacket and a bottom jacket respectively provided at the top and bottom of the cooling cylinder; The bottom and top of the top jacket are respectively fixedly connected to a second medium inlet pipe and a second medium outlet pipe, and the bottom and top of the bottom jacket are respectively fixedly connected to a cold water inlet pipe and a hot water outlet pipe. Spiral plates are fixed to the inner walls of both the top and bottom jackets.

[0015] Furthermore, a heat exchanger is connected to the body of the methanol inlet pipe, a first connecting pipe is connected between the liquid inlet of the heat exchanger and the second medium outlet pipe, and a second connecting pipe is connected between the liquid outlet of the heat exchanger and the second medium inlet pipe. A heater is connected to the body of the second connecting pipe.

[0016] Compared with the prior art, the beneficial effects of the present invention are: This methyl chloroacetate esterification reaction heat exchange device is equipped with reaction and heat exchange units in a modular, stacked structure. This ensures that each reactant is tightly enveloped by adjacent heat exchange surfaces on both sides. Combined with countercurrent heat exchange and uniform flow distribution provided by the uniform distribution plate, it achieves instantaneous, synchronous, and uniform heat exchange of the reaction heat. This eliminates the inherent temperature gradient and local hot spots of traditional jacketed or coil reactors, and precisely controls the temperature fluctuation of the entire reaction zone within a very small range. The uniform temperature field not only significantly reduces side reactions caused by overheating and improves product consistency and single-pass yield, but more importantly, it eliminates the risk of thermal runaway that may be caused by untimely heat removal, resulting in high inherent safety.

[0017] In addition, by using a forced convection shear mixer consisting of a jet pipe at a specific angle and a radial liquid outlet, combined with a two-stage static mixer, chloroacetic acid, methanol, and the catalyst concentrated sulfuric acid are rapidly, violently, and uniformly mixed at the molecular scale before entering the main reaction zone. This completely solves the problem of uneven catalyst dispersion and the formation of local high acid concentration areas in traditional mechanical stirring, effectively avoiding side reactions such as chloroacetic acid dehydration and carbonization caused by this, and significantly improving reaction selectivity and initial product purity.

[0018] Furthermore, the integrated design of the cooling unit and heat exchanger utilizes the waste heat from the high-temperature products to preheat the low-temperature methanol feedstock, achieving active recovery and cascade utilization of the reaction waste heat. This reduces system energy consumption while avoiding energy waste and environmental thermal pollution caused by the direct emission of high-temperature products. Attached Figure Description

[0019] Figure 1 This is a left front axis view of the present invention; Figure 2 This is a left rear axis view of the present invention; Figure 3 This is a half-sectional view of the hybrid component of the present invention; Figure 4 This is an axial view of the reaction and heat exchange unit of the present invention; Figure 5 This is a cross-sectional view of the reaction and heat exchange unit of the present invention; Figure 6 This is an exploded view of the heat exchanger of the present invention; Figure 7 This is an exploded view of the cover plate, heat exchange plate, and reaction plate of the present invention; Figure 8 This is a cross-sectional view of the cooling unit of the present invention.

[0020] In the diagram: 1. Feeding device; 2. Mixing component; 201. Shell; 202. Annular pipe; 203. Injection pipe; 3. First static mixer; 4. Connecting pipe; 5. Second static mixer; 6. Chloroacetic acid inlet pipe; 7. Methanol inlet pipe; 701. Liquid outlet; 8. Concentrated sulfuric acid inlet pipe; 9. Reaction and heat exchange unit; 901. Top shell; 902. Bottom shell; 903. Blending plate; 904. Reaction and heat exchange component; 9041. Protective shell; 9042. Reaction plate; 9043. Partition plate; 9044. 1. Heat exchange plate; 9045. Cover plate; 9046. Arc-shaped surface; 9047. Through groove; 9049. First medium inlet pipe; 9050. First medium outlet pipe; 905. Vent pipe; 10. Ultrasonic anti-scaling module; 11. Cooling unit; 111. Cooling cylinder; 112. Top jacket; 113. Second medium inlet pipe; 114. Second medium outlet pipe; 115. Bottom jacket; 116. Cold water inlet pipe; 117. Hot water outlet pipe; 118. Spiral plate; 12. Heat exchanger; 13. First connecting pipe. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] like Figures 1-8 As shown, the present invention provides a technical solution: a heat exchange device for the esterification reaction of methyl chloroacetate, comprising a feeding device 1, a reaction and heat exchange unit 9 and a cooling unit 11 connected in sequence. After the raw materials methyl chloroacetate, methanol and concentrated sulfuric acid catalyst are fully premixed and initially reacted by the feeding device 1, they continuously enter the reaction and heat exchange unit 9 to complete the main esterification reaction and exchange heat with the heat exchange medium. The final product enters the cooling unit 11 and is rapidly cooled to a safe temperature before being discharged.

[0023] Specifically, such as Figure 1 As shown, the feeding device 1 includes a mixing unit 2, a first static mixer 3, a connecting pipe 4, and a second static mixer 5 connected sequentially by flanges. Chloroacetic acid inlet pipe 6 and methanol inlet pipe 7 are connected to the top of the mixing unit 2, and concentrated sulfuric acid inlet pipe 8 is connected to the connecting pipe 4. Figure 3 As shown, the mixing unit 2 is responsible for the initial mixing of chloroacetic acid and methanol. Its structure includes a housing 201, with an annular pipe 202 fixed at the top. The chloroacetic acid inlet pipe 6 is fixedly connected to the annular pipe 202, allowing for uniform distribution of liquid chloroacetic acid. Several injection pipes 203 are uniformly fixedly connected to the bottom of the annular pipe 202 along its circumference. The nozzles of these injection pipes 203 are inclined at a specific angle to the central axis of the housing 201, thereby guiding the falling chloroacetic acid liquid flow within the housing 201. A strong spiral flow is formed inside the shell 201. At the same time, the methanol inlet pipe 7, which extends into the shell 201, has its vertical section located exactly on the central axis of the shell 201. Several liquid outlet holes 701 are opened on this section of the pipe. Methanol is sprayed radially outward through the liquid outlet holes 701. It forms three-dimensional convection and shearing with the chloroacetic acid liquid flow that is sprayed in obliquely from the periphery. This achieves rapid and intense mixing of materials at the molecular scale, creating optimal conditions for the initiation of the esterification reaction.

[0024] The material initially mixed then flows through the first static mixer 3 for further homogenization. It then merges with the catalyst introduced from the concentrated sulfuric acid inlet pipe 8 at the connecting pipe 4 and immediately enters the second static mixer 5 for final dispersion, thereby initiating a preliminary esterification reaction and forming a homogeneous semi-reactant material. Both the first static mixer 3 and the second static mixer 5 employ SK-type static mixing units. Their internally staggered left-handed and right-handed blades continuously divide, shift, and re-merge the fluid, ensuring that the concentrated sulfuric acid catalyst achieves micron-level dispersion in the mixing system. This effectively avoids catalyst agglomeration caused by insufficient local shear force in traditional mechanical stirring, significantly reducing the probability of side reactions. The first static mixer 3 and the second static mixer 5 are mature existing technologies, and their specific structures and working principles will not be elaborated upon in this scheme.

[0025] The principle behind the design of the first static mixer 3 and the second static mixer 5 is that if sulfuric acid is added too early (e.g., before the first stage), the highly corrosive sulfuric acid mixture will be in contact with the equipment for a long time during the entire preheating and first-stage mixing process. Furthermore, there may be areas with high acid concentrations due to incomplete mixing, which can easily lead to side reactions in the preheating stage, such as dehydration and oxidation of chloroacetic acid. The two-stage design delays the addition of sulfuric acid to the last moment (the second-stage inlet), allowing the reactants to be homogenized first, followed by the addition of the catalyst. After instantaneous mixing, the mixture immediately enters the reactor for reaction. This greatly reduces the time and space window for side reactions to occur. In this way, not only is the overall corrosion prevention cost and risk of the system reduced, but the synthesis selectivity and product purity of methyl chloroacetate are also significantly improved.

[0026] The reaction and heat exchange unit 9 is located at the bottom of the feeding device 1, such as... Figures 4-7 As shown, the unit consists of a top shell 901, a bottom shell 902, and a reaction and heat exchanger 904 placed between the two. A feed chamber is formed between the top shell 901 and the reaction and heat exchanger 904, and a discharge chamber is formed between the bottom shell 902 and the reaction and heat exchanger 904. The discharge port of the feed device 1 is connected to the feed chamber. A vent pipe 905 connected to the feed chamber is also fixed on the top of the top shell 901 to maintain pressure balance. The vent pipe 905 can be connected to an external purification device to prevent overflowing steam from polluting the environment.

[0027] To ensure that the mixture entering the feed chamber from the feeding device 1 is evenly distributed and to avoid dead zones or short circuits at the inlet section of the reaction and heat exchanger 904, a uniform distribution plate 903 is fixed on the inner wall of the feed chamber. The uniform distribution plate 903 has several uniform distribution holes (not shown in the figure) on its plate body, and the diameter of these uniform distribution holes gradually increases from the center of the plate to the edge. This unique design can automatically adjust the material flow rate through different areas, so that the high flow rate area in the center is subject to greater resistance while the low flow rate area at the edge is subject to less resistance. This achieves uniform distribution of the material when it passes through the uniform distribution plate 903, so that the subsequent downstream material can fully and evenly contact the entire working surface of the reaction and heat exchanger 904.

[0028] like Figure 5 , Figure 6 and Figure 7As shown, the reaction and heat exchange component 904 includes a protective shell 9041 and a core fixed therein. The core is formed by horizontally stacking and fastening several sets of reaction and heat exchange plates. Each set of reaction and heat exchange plates includes a vertical reaction plate 9042. A partition 9043 is vertically fixed to both sides of the reaction plate 9042. A heat exchange plate 9044 is fixed to the outer side of one of the partition plates 9043. When multiple sets of plates are stacked, by fitting the two outermost heat exchange plates 9044 of the core against the inner wall of the protective shell 9041, it is ensured that each reaction plate 9042 is sealed between two adjacent heat exchange plates 9044, forming a unique... In this design, a baffle 9043 connects to a heat exchange plate 9044 in the reaction channel. This is based on two considerations: First, it resolves the "material conflict." Specifically, because the flowing substances are high-temperature chloroacetic acid, concentrated sulfuric acid, and methanol, which are highly corrosive, the reaction plate 9042 must be made of an expensive special corrosion-resistant alloy. The flowing substances are ordinary cooling water or heat transfer oil, which are non-corrosive, so the heat exchange plate 9044 can be made of ordinary carbon steel or stainless steel, which is inexpensive. If the reaction plate 9042 and heat exchange plate 9044 were an integrated structure, the entire plate would have to be made of an expensive special alloy, leading to a significant increase in equipment cost. The introduction of the baffle 9043 decomposes the system into: the reaction plate 9042, made of a special corrosion-resistant material, is dedicated to the reaction; the baffle 9043, also made of a special corrosion-resistant material, acts as a safety barrier; due to its small thickness, it is inexpensive; and the heat exchange plate, made of ordinary metal, is dedicated to heat exchange. In this way, only the parts in contact with corrosive materials use high-cost materials, significantly reducing costs. Secondly, to resolve the "manufacturing versus safety" conflict, specifically, directly welding two different metals (such as Hastelloy and carbon steel) over a large area in a sealed manner is technically extremely difficult and prone to generating brittle phases at the joint, becoming a source of stress corrosion cracking and a serious leakage hazard. Because the partition plate 9043 and the reaction plate 9042 are made of the same corrosion-resistant material, they can be welded together with high quality and high reliability (like welding of the same metal), forming an absolutely sealed and corrosion-resistant "safety shell". This "safety shell" as a whole is then tightly bonded to the outer heat exchange plate 9044 for heat transfer through mechanical means (such as bolts and shell clamping). There is no need for sealing welding of dissimilar metals between the two; there is only heat transfer contact, eliminating the risk of leakage.

[0029] Several equally spaced flow holes are formed vertically in the reaction plate 9042 to allow the reactants to flow and react. Several equally spaced cooling holes are formed vertically in the heat exchange plate 9044 to allow the heat exchange medium to flow. Figure 6As shown, heat exchange plates 9044 extend from the top and bottom of the reaction plate 9042 on both sides, and a cover plate 9045 is fixed on the extension section. A top heat exchange medium channel is formed between the top cover plate 9045 and the upper heat exchange plate 9044, and a bottom heat exchange medium channel is formed between the bottom cover plate 9045 and the lower heat exchange plate 9044. A through groove 9047 is opened on the plate body of the cover plate 9045 corresponding to the position of each reaction plate 9042, which serves as the inlet for material to flow from the feed chamber into the flow hole of each reaction plate 9042. In particular, in order to optimize the smoothness of material flow, several arc-shaped surfaces 9046 are formed on the plate body of the cover plate 9045, and each through groove 9047 is located at the bottom of an arc-shaped surface 9046. This structure can effectively guide the material to flow smoothly and without dead angles into the reaction channel, avoid material stagnation on the top cover plate 9045, and thus prevent coking or side reactions caused by local overheating.

[0030] On the shell walls on both sides of the protective shell 9041, there are several bottom medium branch pipes that are connected to all bottom heat exchange medium channels, and several top medium branch pipes that are connected to all top heat exchange medium channels. The ends of these branch pipes are respectively connected to the first medium inlet pipe 9049 and the first medium outlet pipe 9050. A refrigerator is connected between the first medium inlet pipe 9049 and the first medium outlet pipe 9050, forming a closed forced circulation heat exchange system. The cold medium enters from the bottom, flows through all bottom and top heat exchange medium channels, and then flows out from the top, forming an efficient countercurrent heat exchange with the material flowing from top to bottom in the reaction plate 9042, thereby uniformly removing the heat of esterification reaction and strictly controlling the reaction temperature within the ideal range.

[0031] In this design, each reaction plate 9042 is located between two heat exchange plates 9044, allowing the heat released by the reactants in the flow holes to be transferred simultaneously, equidistantly, and without delay to both sides. This heat is then instantly removed by the counter-current cooling medium in the flow channels of the heat exchange plates 9044. This structure eliminates the large temperature gradient from the reaction center to the wall in traditional jacketed reactors and avoids localized overcooling or overheating caused by coil-type heat exchangers. For the esterification reaction of chloroacetic acid and methanol, maintaining a uniform and precise temperature (typically 70-85℃) is crucial. Uniform temperature effectively suppresses side reactions caused by localized overheating (such as the formation of dimethyl ether and chloroacetic acid bimolecular condensation). The reaction plate 9042 is equipped with multiple vertically distributed flow holes, which significantly improve the purity and single-pass yield of the main product methyl chloroacetate (through processes such as carbonization of materials). This results in a significantly larger heat transfer area (specific surface area) per unit volume compared to traditional stirred tank reactors. After the heat of reaction is generated, it can be carried away by the heat exchange medium through the wall of the reaction plate 9042. The heat transfer path is short and the thermal resistance is low, which allows the removal rate of the heat of reaction to completely match or even exceed its generation rate. This allows for higher reactant throughput and reaction intensity while achieving the same production capacity and temperature control requirements. Furthermore, the volume and floor space of this device are much smaller than those of traditional reactors, demonstrating a high degree of structural compactness.

[0032] In addition, to address the potential decrease in heat exchange efficiency due to material crystallization or polymerization within the flow holes during long-term operation, several ultrasonic anti-scaling modules 10 are fixed to the top of the side of the protective shell 9041, utilizing the cavitation and vibration effects of ultrasonic waves to prevent or remove scale buildup.

[0033] like Figure 1 and Figure 8As shown, the high-temperature methyl chloroacetate mixture after the reaction is completed flows out of the discharge chamber and enters the cooling unit 11 for final cooling. The cooling unit 11 includes a cooling cylinder 111, with a top jacket 112 and a bottom jacket 115 respectively. The bottom and top of the top jacket 112 are respectively fixedly connected to a second medium inlet pipe 113 and a second medium outlet pipe 114. The bottom and top of the bottom jacket 115 are respectively fixedly connected to a cold water inlet pipe 116 and a hot water outlet pipe 117. To enhance the cooling effect, spiral plates 118 are fixedly installed on the inner walls of both the top jacket 112 and the bottom jacket 115 to extend the flow path of the cooling medium and enhance turbulence. To improve the energy utilization efficiency of the entire system, the device also integrates a heat recovery system. Specifically, a heat exchanger 12 is connected to the body of the methanol inlet pipe 7. The liquid inlet of the heat exchanger 12 is connected through a first... The connecting pipe 13 is connected to the second medium outlet pipe 114 of the cooling unit 11, and its outlet is connected to the second medium inlet pipe 113 through the second connecting pipe. A heater is connected to the pipe body of the second connecting pipe. In this way, the cooling medium (such as water) flowing out from the top jacket 112 and which has been preheated by the high-temperature product is not directly discarded, but is introduced into the heat exchanger 12 to preheat the low-temperature methanol feedstock from the methanol inlet pipe 7. After the temperature of the cooling medium that has recovered heat decreases, it is returned to the second medium inlet pipe 113 for recycling. The heater only provides auxiliary heating when the system is started or when the heat is insufficient. The bottom jacket 115 is supplied with fresh cold water through the cold water inlet pipe 116 to perform final deep cooling of the product. The heated water is discharged into the factory water network through the hot water outlet pipe 117 for use. This design realizes the cascade utilization of the reaction waste heat and significantly reduces production energy consumption.

[0034] It is known that, in the reaction and heat exchange unit 9, to achieve dynamic and precise temperature control of the mixed heat medium after heat exchange, temperature sensors are installed on the sidewalls of the first medium inlet pipe 9049, the first medium outlet pipe 9050, and the flow holes of the reaction plate 9042. These sensors transmit real-time temperature signals to the central controller. The material temperature in the reaction plate 9042 is used as the main controlled variable, and the flow rate of the heat exchange medium entering the first medium inlet pipe 9049 (through a regulating valve) is used as the main adjustment method. When the sensor detects that the reaction temperature is higher than the set value (e.g., 80°C), the controller will proportionally open the regulating valve to increase the cooling medium flow rate, thereby instantly increasing the heat exchange rate and pulling the reaction temperature back to the set point. Conversely, the flow rate will be reduced. This feedback regulation can quickly respond to changes in feed rate, concentration, or ambient temperature. To mitigate the heat fluctuations caused by environmental changes and control reaction temperature fluctuations within ±2℃ or even less to meet the requirements of highly selective reactions, temperature sensors are installed in the cooling unit 11 at the product inlet, outlet, top jacket 112, bottom jacket 115, and methanol inlet pipe 7 heated by heat exchanger 12 in the cooling cylinder 111 to achieve dynamic and precise temperature control of the mixed heat medium after heat exchange. These sensors monitor product temperature changes in real time and transmit the signals to the central control system. The control system adjusts the regulating valves on the second medium inlet pipe 113, the cold water inlet pipe 116, and the power of the heating engine according to the preset temperature curve to form a coordinated control, ensuring that the final product outlet temperature remains stable at the set target value regardless of fluctuations in the front-end reaction conditions.

[0035] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended embodiments and their equivalents.

Claims

1. A heat exchange device for the esterification reaction of methyl chloroacetate, comprising a feeding device (1) and a chloroacetic acid inlet pipe (6), a methanol inlet pipe (7) and a concentrated sulfuric acid inlet pipe (8) connected to the feeding device (1), characterized in that: The bottom of the feeding device (1) is provided with a reaction and heat exchange unit (9) consisting of a top shell (901), a bottom shell (902) and a reaction and heat exchange component (904). A feed chamber and a discharge chamber are formed between the reaction and heat exchanger (904) and the top shell (901) and between the reaction and heat exchanger (904) and the bottom shell (902), respectively. A vent pipe (905) connected to the feed chamber is fixed on the top of the top shell (901). The discharge port of the feeding device (1) is connected to the feeding chamber; A uniform material plate (903) is fixed on the inner wall of the feeding chamber. Several uniform material holes are opened on the plate body of the uniform material plate (903). The diameter of the uniform material holes gradually increases from the center to the edge, so that the mixture entering the feeding chamber from the feeding device (1) is evenly distributed when passing through the uniform material plate (903), avoiding local accumulation of materials in the feeding chamber, and allowing the materials flowing down through the uniform material plate (903) to fully contact the reaction and heat exchange components (904). The bottom of the feeding device (1) is equipped with a cooling unit (11) to cool the product obtained from the reaction.

2. The heat exchange device for the esterification reaction of methyl chloroacetate according to claim 1, characterized in that: The feeding device (1) includes a mixing component (2), a first static mixer (3), a connecting pipe (4), and a second static mixer (5) connected in sequence. Chloroacetic acid inlet (6) and methanol inlet (7) are connected to the top of the mixing unit (2), and concentrated sulfuric acid inlet (8) is connected to the connecting pipe (4).

3. The heat exchange device for the esterification reaction of methyl chloroacetate according to claim 2, characterized in that: The mixing component (2) includes a shell (201), an annular tube (202) is fixed to the top of the shell (201), a chloroacetic acid inlet pipe (6) is fixedly connected to the annular tube (202), and a number of injection pipes (203) are fixedly connected to the bottom of the annular tube (202). The injection port of the injection pipe (203) is inclined to the direction of the central axis of the shell (201) to guide the falling material to form a spiral flow. Several liquid outlet holes (701) are provided on the vertical tube of the methanol inlet pipe (7) extending into the shell (201). The vertical tube of the methanol inlet pipe (7) coincides with the central axis of the annular pipe (202). The methanol sprayed from the outlet hole (701) can form a convective swirling mixture with the chloroacetic acid sprayed from the spray pipe (203) inside the shell (201).

4. The heat exchange device for the esterification reaction of methyl chloroacetate according to claim 1, characterized in that: The reaction and heat exchange component (904) includes a protective shell (9041) and a core fixed inside the protective shell (9041).

5. The heat exchange device for the esterification reaction of methyl chloroacetate according to claim 4, characterized in that: The core is formed by horizontally stacking and fixing several sets of reaction and heat exchange plates; The reaction and heat exchange plate includes a reaction plate (9042), and partitions (9043) are fixed on both sides of the reaction plate (9042). A heat exchange plate (9044) is fixed on the side of one of the partitions (9043). The reaction plate (9042) has several flow holes that are equidistantly distributed in the vertical direction, and the heat exchange plate (9044) has several cooling holes that are equidistantly distributed in the vertical direction. The reaction plate (9042) has heat exchange plates (9044) extending from both the top and bottom. The reaction plate (9042) has cover plates (9045) fixed at both the top and bottom. The top and bottom cover plates (9045) and the heat exchange plates (9044) respectively form a top heat exchange medium channel and a bottom heat exchange medium channel. The cover plate (9045) has a number of through slots (9047) equal to the number of reaction plates (9042) on its plate body. The mixture flows into the flow holes of the reaction plates (9042) through the through slots (9047); The protective shell (9041) has several bottom medium branch pipes that are equal in number to and connected to the bottom heat exchange medium channels and several top medium branch pipes that are equal in number to and connected to the top heat exchange medium channels. The bottom medium branch pipes and the top medium branch pipes are respectively fixedly connected to the first medium inlet pipe (9049) and the first medium outlet pipe (9050). A refrigeration unit is connected between the first medium inlet pipe (9049) and the first medium outlet pipe (9050).

6. The heat exchange device for the esterification reaction of methyl chloroacetate according to claim 5, characterized in that: The cover plate (9045) has several arc-shaped surfaces (9046) formed on its body, and the through groove (9047) is located at the bottom of the arc-shaped surfaces (9046).

7. The heat exchange device for the esterification reaction of methyl chloroacetate according to claim 6, characterized in that: The two outermost heat exchange plates (9044) of the core are respectively attached to the inner wall of the protective shell (9041), so that each reaction plate (9042) is located between two adjacent heat exchange plates (9044).

8. The heat exchanger for the esterification reaction of methyl chloroacetate according to claim 6, characterized in that: Several ultrasonic anti-scaling modules (10) are fixed to the top of the side of the protective shell (9041).

9. The heat exchange device for the esterification reaction of methyl chloroacetate according to claim 1, characterized in that: The cooling unit (11) includes a cooling cylinder (111), and a top jacket (112) and a bottom jacket (115) are respectively provided at the top and bottom of the cooling cylinder (111). The bottom and top of the top jacket (112) are respectively fixedly connected to the second medium inlet pipe (113) and the second medium outlet pipe (114), and the bottom and top of the bottom jacket (115) are respectively fixedly connected to the cold water inlet pipe (116) and the hot water outlet pipe (117). The inner walls of the top jacket (112) and the bottom jacket (115) are both fixed with spiral plates (118).

10. The heat exchange apparatus for the esterification reaction of methyl chloroacetate according to claim 1, characterized in that: A heat exchanger (12) is connected to the body of the methanol inlet pipe (7). A first connecting pipe (13) is connected between the liquid inlet of the heat exchanger (12) and the second medium outlet pipe (114). A second connecting pipe is connected between the liquid outlet of the heat exchanger (12) and the second medium inlet pipe (113). A heater is connected to the body of the second connecting pipe.

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