Distillation device and distillation method for production and collection of triisopropyl borate

Abstract

The invention relates to the technical field of distillation, in particular to a distillation device for production and collection of triisopropyl borate and a distillation method.The distillation device comprises a distillation device body, the distillation device body comprises a distillation retort, the distillation retort comprises a retort body and a cover body internally provided with a rotating core structure, and the rotating core structure is composed of a mixing component and a guiding component which are coaxially connected; the mixing part is of a hollow spiral structure, and the guiding part is of a solid spiral structure. Heat generated by the spiral heating pipe in the wall of the tank body and the annular heat-conducting oil disc at the bottom can be quickly conducted into materials in the distillation cavity through a through heat conduction channel in the hollow mixing screw piece, the drainage screw piece rotates to drive the heated gaseous materials to form a spiral ascending flow field, and the spiral ascending flow field is formed by combining an umbrella-shaped flow guide cover; steam can be directionally guided to a gas state conveying opening, and disordered diffusion and reverse mixing of the steam are reduced; in addition, the raw materials directly enter the gas-liquid balance area through the middle feeding port, and the back-mixing probability is further reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of distillation, in particular to a distillation device and a distillation method for producing and collecting triisopropyl borate. Background Art

[0002] Triisopropyl borate, as an important organoboron compound, is widely used in organic synthesis, catalyst preparation, electronic materials and other fields. Currently, the production of triisopropyl borate mostly adopts the esterification reaction of boric acid and isopropyl alcohol. After the reaction is completed, the product is separated and purified by distillation. Distillation is a key separation step, and its device performance directly affects product quality. During the distillation process, the vaporized triisopropyl borate vapor needs to be transported from the top of the distillation tank to the condenser for condensation and collection. However, due to the disordered gas flow in the tank, some of the vapor will diffuse in the opposite direction and mix with the unvaporized liquid phase material, which is called "backmixing". Backmixing not only prolongs the residence time of the vapor in the tank and increases the probability of hydrolysis due to contact with trace moisture, but also causes the vapors of different components to interfere with each other, reducing the separation efficiency and the purity of the distillate. In addition, the vaporized triisopropyl borate vapor has a disordered flow path during its rise in the tank, and the time it reaches the condenser is inconsistent. Due to the excessive residence time, some of the vapor undergoes hydrolysis or decomposition, affecting the product collection efficiency. Furthermore, the incompletely reacted boric acid in the reaction system and the boric acid generated by hydrolysis are both solids with low solubility, easily depositing at the bottom of the distillation tank. Accumulation of these deposits can affect the heat transfer efficiency at the bottom of the tank, leading to uneven local heating and, in turn, overheating and decomposition of the material. Furthermore, the deposits can flow with the material, clogging the bottom discharge port or connecting pipes, affecting production continuity and increasing equipment maintenance costs. In view of this, a distillation apparatus and a distillation method for producing and collecting triisopropyl borate are urgently needed to solve the above problems. Summary of the Invention

[0003] The present invention provides a distillation apparatus and method for the production and collection of triisopropyl borate. The apparatus utilizes a spiral heating tube and an annular heat-conducting oil pan for synergistic heating, the rotation of a mixing screw and a drainage screw, and the auxiliary flow guidance of an umbrella-shaped flow guide cover to achieve uniform temperature distribution in a distillation chamber, sufficient mixing of materials, and efficient and directional transport of gaseous substances. This achieves stable vaporization, effective separation, and high-purity collection of raw materials during the distillation of triisopropyl borate, thereby solving the problems raised in the above-mentioned background art, namely: The vaporized triisopropyl borate vapor is back-mixed due to disordered flow, and its rising path is chaotic and the time it reaches the condenser is inconsistent, which increases the probability of hydrolysis or decomposition. In addition, the incompletely reacted boric acid and the boric acid generated by hydrolysis are easily deposited at the bottom of the distillation tank, affecting the heat transfer efficiency at the bottom of the tank and causing overheating and decomposition of the material.

[0004] To achieve the above objectives, one of the objectives of the present invention is to provide a distillation apparatus for the production and collection of triisopropyl borate, comprising a distillation apparatus body, which includes a distillation tank, a top of which is provided with a plurality of gas delivery ports; A connecting pipe, one end of which is connected to the inside of the gas delivery port and the other end is connected to the condenser; A condenser receives gaseous substances delivered from the distillation tank through a connecting pipe; The distillation tank includes a tank body and a cover body with a rotating structure installed inside. A feeding port is opened in the middle of the tank body, and a heating structure is set inside the tank wall. The rotating structure consists of a coaxially connected mixing component and a guiding component. The mixing component is a hollow spiral structure with a continuous heat conduction channel formed inside. The outer wall dynamically fits with the bottom of the distillation tank. During rotation, the friction removes the sediment on the bottom of the tank and conducts the heat from the tank wall to the interior of the raw material through the hollow structure. The raw materials enter the distillation tank from the feeding port for distillation. After the temperature rises, the material to be collected rises in the gaseous state. The guiding component is a solid spiral structure, which drives the gaseous material to form a spiral upward flow field and guides it in a direction to the gas delivery port.

[0005] In the above technical solution, because the vaporized triisopropyl borate vapor is easy to remix during the distillation process, the flow path is disordered, resulting in different residence times and affecting the product purity and collection efficiency, and the boric acid generated by incomplete reaction and hydrolysis is easy to deposit and affect heat transfer and block pipelines, a rotating structure is set up, in which the mixing component is a hollow spiral structure, and the outer wall is dynamically fitted with the bottom of the distillation tank. When rotating, it can remove the sediment at the bottom of the tank and at the same time conduct the heat from the tank wall to the inside of the raw material, solving the deposition problem and helping to uniformly heat; the guiding component is a solid spiral structure, which can drive the gaseous material to form a spiral upward flow field and directionally guide it to the gaseous delivery port, reducing remixing and disordered flow paths.

[0006] On this basis, the mixing component includes a central shaft rotating inside the distillation chamber, the upper end of the central shaft passes through the cover body and is coaxially connected to the output shaft of the motor; The lower end of the central shaft is wrapped with a hollow mixing screw, connected to the central shaft by multiple connecting rods. In the mixing unit, a motor drives the central shaft, which in turn drives the mixing screw via the connecting rods. The hollow mixing screw conducts heat into the raw material, promoting uniform heating. Its rotation also scrapes away sediment from the bottom of the tank, preventing clogging, and stirs the material, enhancing mixing efficiency.

[0007] Furthermore, a drainage screw is fixedly mounted on the outer wall of the upper end of the central axis, and a guide cavity is formed between the drainage screw and the central axis.

[0008] Specifically: when the central shaft rotates, the drainage screw is driven to rotate synchronously. The guide cavity formed by the drainage screw and the central shaft can guide the gaseous material to form a spiral upward flow field, so that the gaseous material flows in a direction toward the gas conveying port, reducing disordered diffusion and back mixing, and improving the gaseous material conveying efficiency.

[0009] As a further improvement of the present technical solution, the helix angle of the drainage screw is 20°-35°; The top end of the drainage screw is located 10-30 cm below the gas delivery port.

[0010] A second object of the present invention is to provide a distillation method for the production and collection of triisopropyl borate, using the above-mentioned distillation apparatus for the production and collection of triisopropyl borate, comprising the following steps: S1, the esterification reaction product of boric acid and isopropyl alcohol enters the distillation chamber through the feeding port in the middle of the distillation tank, so that the raw materials directly enter the gas-liquid equilibrium zone; S2. Start the spiral heating tube inside the tank wall and the annular heat transfer oil pan at the bottom. The two work together to form a three-dimensional temperature field, so that the material is heated evenly. S3. The motor drives the central shaft to rotate, driving the hollow mixing screw at the lower end to rotate: the mixing screw transfers heat from the tank wall to the material inside through its hollow structure, enhancing heat exchange; the bottom of the mixing screw dynamically fits against the tank bottom to scrape off sediment; the local vortex generated by the rotation keeps the boric acid particles suspended; S4. When the gaseous triisopropyl borate rises, the solid drainage screw at the upper end of the central axis drives the gas to form a spiral upward flow field, which is directed to the gas delivery port; S5. The steam enters the condenser through the connecting pipe, condenses into liquid triisopropyl borate and is collected, and the unvaporized heavy components are discharged through the exhaust port.

[0011] Compared with existing technologies, this solution eliminates the need for multiple independent functional components within the distillation tank. Instead, the split spiral structure achieves synergistic effects in heat conduction, backmixing prevention, and sedimentation prevention. This effectively addresses issues such as uneven heat conduction, purity loss due to backmixing of gaseous materials, and solid precipitation affecting equipment operation during the distillation of triisopropyl borate, thereby improving distillation efficiency and the stability of long-term product collection. Specifically, the hollow mixing screw made of aluminum alloy has a heat conduction channel running through it, which can quickly transfer the heat generated by the spiral heating tube in the tank wall and the annular thermal oil pan at the bottom to the material in the distillation chamber. Combined with the three-dimensional temperature field design, the heat exchange efficiency is greatly improved. At the same time, the wear-resistant scraping layer at the bottom of the mixing screw dynamically fits the tank bottom, removing deposits through friction during rotation. At the same time, the local eddy currents generated by its rotation can suspend tiny boric acid particles, reducing the blockage of the discharge port by deposits, and ensuring a continuous and stable distillation process. In addition, the drainage screw rotates at a spiral angle of 20°-35°, driving the heated gaseous material to form a spiral upward flow field. Combined with the umbrella-shaped guide cover, it can directionally guide the steam to the gaseous conveying port, reducing disordered diffusion and reverse mixing of steam. In addition, the central feeding port allows the raw materials to directly enter the gas-liquid equilibrium zone, further reducing the probability of back mixing. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the installation structure of the heating structure of the present invention; Figure 3 Schematic diagram of the internal structure of the distillation chamber of the present invention; Figure 4 It is a schematic diagram of the rotating structure of the present invention; Figure 5 It is a schematic structural diagram of the mixing component of the present invention; Figure 6 This is a schematic diagram of the internal structure of the upper end of the distillation chamber of the present invention; Figure 7 This is a schematic diagram of the installation structure of the umbrella-shaped deflector cover of the present invention; Figure 8 It is a schematic cross-sectional view of the installation position of the umbrella-shaped deflector of the present invention; Figure 9 This is a flow chart of the distillation and collection of triisopropyl borate of the present invention.

[0013] The meaning of each number in the figure is: 1. Distillation apparatus body; 11. Distillation tank; 111. Tank body; 112. Cover; 113. Distillation chamber; 114. Gas delivery port; 12. Connecting pipe; 13. Condenser; 14. Feed port; 15. Discharge port; 2. Heating structure; 21. Heating inner cavity; 22. Spiral heating tube; 3. Rotating structure; 31. Mixing component; 32. Guide component; 311, central shaft; 312, mixing screw; 313, connecting rod; 314, scraping layer; 321. Drainage screw; 322. Guide cavity; 4. Umbrella-shaped fairing. DETAILED DESCRIPTION

[0014] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0015] Example 1: Please refer to Figure 1 、 Figure 2 、 Figure 3 and Figure 9 As shown, the present embodiment aims to provide a distillation apparatus for the production and collection of triisopropyl borate, comprising a distillation apparatus body 1, which includes a distillation tank 11, a plurality of gas delivery ports 114 are opened on the top of the distillation tank, a connecting pipe 12, one end of which is connected to the interior of the gas delivery port 114, and the other end is connected to a condenser 13; the condenser 13 receives the gaseous substance delivered by the distillation tank 11 through the connecting pipe 12; The distillation tank 11 includes a tank body 111 and a cover body 112 with a rotating core structure 3 installed inside. A feeding port 14 is opened in the middle of the tank body 111, and a heating structure 2 is set inside the tank wall of the tank body 111; The rotating structure 3 is composed of a mixing component 31 and a guide component 32 connected coaxially. The mixing component 31 is a hollow spiral structure with a through heat conduction channel formed inside. The outer wall of the mixing component 31 is dynamically fitted with the bottom of the distillation tank 11. During rotation, the friction removes the sediment on the bottom of the tank and conducts the heat from the tank wall to the interior of the raw material through the hollow structure. The raw materials enter the distillation tank 11 from the feeding port 14 for distillation. After the temperature rises, the material to be collected rises in a gaseous state. The guide component 32 is a solid spiral structure, which drives the gaseous material to form a spiral upward flow field and guides it in a direction to the gas delivery port 114.

[0016] Since triisopropyl borate has a high requirement for temperature uniformity during the distillation process, local overheating can easily lead to its decomposition, and a single heating method is difficult to achieve comprehensive heating in the distillation chamber 113, the heating structure 2 includes a heating cavity 21 opened inside the inner wall of the tank body 111, and a spiral heating tube 22 is installed in the heating cavity 21. The spiral heating tube 22 is powered by an external power supply to achieve heating; A distillation chamber 113 is formed inside the tank body 111. A discharge port 15 is provided at the middle end of the bottom of the inner cavity of the distillation chamber 113, and an annular heat transfer oil pan is provided inside the bottom of the inner cavity. The cooperation between the spiral heating tube 22 and the heat-conducting oil pan enables multi-directional distillation heating of the distillation chamber 113 .

[0017] Combine Figure 2As shown, the spiral heating tube 22 is installed in the heating cavity 21 on the inner wall of the tank body 111, and generates heat through an external power supply (not shown in the figure) to heat the side wall area of ​​the distillation chamber 113. The annular heat transfer oil plate (using existing technology, not shown in the figure) is arranged inside the bottom of the distillation chamber 113 to heat the bottom area of ​​the cavity. The two work together to form a heating range covering the side walls and the bottom. The combination of the spiral heating tube 22 and the annular heat transfer oil plate makes the temperature distribution of each area in the distillation chamber 113 uniform, without local overheating or heating blind spots, ensuring that triisopropyl borate is stably vaporized within the set temperature range, reducing decomposition or hydrolysis caused by temperature fluctuations, and at the same time providing continuous and balanced heat support for the distillation process to ensure stable vaporization efficiency.

[0018] The mixing component 31 includes a central shaft 311 that rotates inside the distillation chamber 113. The upper end of the central shaft 311 passes through the cover 112 and is coaxially connected to the output shaft of the motor. A mixing screw 312 is wound around the lower end surface of the central shaft 311 . The mixing screw 312 is a hollow structure and is connected to the central shaft 311 via a plurality of connecting rods 313 .

[0019] See Figure 3 Combined with Figure 4 As shown, the core component of the mixing component 31 is the central shaft 311. A fixing piece is provided at the upper end of the central shaft 311, which is not shown in the figure. The fixing piece cooperates with the corresponding position of the cover 112 to effectively limit the radial shaking of the central shaft 311 during the rotation process, thereby assisting the central shaft 311 to achieve stable rotation. The upper end of the central shaft 311 passes through the cover 112 and is coaxially connected to the output shaft of the motor to ensure that the driving force of the motor can be transmitted to the central shaft 311, thereby driving the central shaft 311 to rotate at a set speed inside the distillation chamber 113; A mixing screw 312 is wound around the lower end surface of the central shaft 311. The mixing screw 312 is designed with a hollow structure to form a channel inside thereof for transferring heat. Figure 5 The mixing screw 312 is connected to the central shaft 311 through a plurality of evenly distributed connecting rods 313. The connecting rods 313 can fix the mixing screw 312 and, at the same time, drive the mixing screw 312 to rotate synchronously when the central shaft 311 rotates. When the mixing screw 312 rotates with the central axis 311, the mixing screw 312 maintains dynamic fit with the bottom of the distillation chamber 113. During the rotation, the solid matter deposited on the bottom can be scraped off through friction with the bottom of the chamber, thereby preventing these sediments from accumulating and clogging the discharge port 15 opened at the middle end of the bottom of the distillation chamber 113. At the same time, when the mixing screw 312 rotates, a local vortex is generated in the distillation chamber 113, which can keep tiny solids such as boric acid particles in the material in a suspended state, preventing them from settling and forming precipitation, thereby achieving an anti-deposition effect.

[0020] like Figure 4 The specific structure of the guide component 32 shown is as follows: a drainage screw 321 is fixedly mounted on the outer wall of the upper end of the central axis 311 , and a guide cavity 322 is formed between the drainage screw 321 and the central axis 311 .

[0021] Specifically, the drainage screw 321 of the guide component 32 is fixedly mounted on the outer wall of the upper end of the central shaft 311, and a guide cavity 322 is formed between the drainage screw 321 and the central shaft 311. When the central shaft 311 rotates under the drive of the motor, the drainage screw 321 rotates synchronously therewith. Its spiral structure generates an axial component of force on the rising gaseous material according to the Archimedean screw principle, forcing the gas to enter the guide cavity 322 along a spiral trajectory. At the same time, according to the Bernoulli effect in fluid mechanics, the rotating spiral channel causes the gas to form a high-speed spiral flow field in the guide cavity 322. The pressure in the central area decreases, and the surrounding gas is continuously drawn in and accelerated to flow toward the gas delivery port 114, forming a directional flow trend. The gas path that might have diffused randomly is constrained to a spiral ascending path, shortening the flow distance. At the same time, the centrifugal force generated by the high-speed spiral flow field allows the gas and liquid materials to be separated more thoroughly, reducing the contact time between the gas phase and the liquid phase, effectively reducing the back-mixing phenomenon, and the presence of the guide cavity 322 increases the directionality of the gas flow, reduces the probability of the formation of vortices and turbulence, and further optimizes the gas delivery efficiency.

[0022] The helix angle of the drainage screw 321 is set at 20°-35°: Based on the flow characteristics of the gaseous material during the distillation of triisopropyl borate and the dynamic balance of the drainage screw 321, it is known that the drainage screw 321 needs to guide the gaseous material to form a spiral upward flow field, and its spiral rise angle is Directly affects the distribution of axial thrust and radial resistance, the kinematic viscosity of gaseous triisopropyl borate About 0.000018-0.000022m² / s, density About 1.2-1.5kg / m³; Its axial conveying efficiency for gaseous materials is expressed by the formula Calculate, where is the airflow force ( is the air flow velocity, is the drag coefficient, is the projected area of ​​the drainage screw 321), when =20°, the axial force can push the airflow to obtain an additional speed of 0.8-1.2m / s; =35°, the axial additional speed can reach 1.5-1.8m / s; Residence time of gaseous material in the spiral channel By formula calculate( is the spiral radius, is the number of spiral turns), when =20°, the spiral path length It is 1.5 times of the vertical height, the residence time is about 0.5-0.8 seconds, and the gas-liquid separation rate is over 95%; =35°, the path length is 1.2 times the vertical height, the residence time is about 0.4-0.6 seconds, and the gas-liquid separation rate remains above 92%; At the same time, the resistance torque generated by the rotation of the screw By formula Calculate, where , analog display When the angle increases from 20° to 35°, the resistance torque only increases by 10%-18%, corresponding to a motor power increase of <5%, which will not significantly increase energy consumption. Therefore, the helix angle range is determined to be 20°-35°.

[0023] Based on the flow characteristics and collection requirements of the gaseous material during the distillation of triisopropyl borate, the gaseous material guided by the drainage screw 321 is in a spiral upward state. The distance between its top and the gas delivery port 114 will directly affect the gas collection effect. The gaseous triisopropyl borate will diffuse to the surroundings at a certain rate during the upward process.

[0024] like Figure 6 As shown, when the top of the drainage screw 321 is located 10-30 cm below the gas delivery port 114, the spirally rising gaseous material diffuses within the effective capture area of ​​the gas delivery port 114 before reaching the delivery port. From the flow process point of view, the spiral flow field guided by the drainage screw 321 can maintain good directionality within this distance. The gas will not escape from the capture range of the delivery port due to excessive diffusion during the rising process, nor will the flow field be turbulent due to the distance being too close.

[0025] Specifically, if the spacing is less than 10 cm, the gaseous material reaches the delivery port before the spiral flow field is completely stable, and the high-speed airflow is likely to collide with the edge of the gas delivery port 114 to generate turbulence, and part of the gas will be turned back, reducing the collection efficiency; when the spacing is greater than 30 cm, the diffusion range of the gaseous material expands during the rising process, and the proportion of gas beyond the capture range of the gas delivery port 114 increases, and the gas stays in the distillation chamber 113 for a longer time, which is easy to hydrolyze due to environmental influences, and will also increase the flow resistance, affecting the overall collection effect.

[0026] Therefore, a spacing of 10-30 cm can not only ensure that the gaseous material efficiently enters the gas delivery port 114, but also reduce unnecessary losses and adverse effects.

[0027] As the mixing screw 312 rotates along with the central axis 311, its bottom end needs to dynamically fit with the bottom of the distillation chamber 113 to scrape off the sediment. Long-term friction will cause wear on the bottom end of the screw, affecting the scraping effect. In addition, solid particles with higher hardness (such as unreacted boric acid particles) may remain at the bottom of the distillation chamber 113, further aggravating the wear. Therefore, a scraping layer 314 with wear-resistant properties is laid on the bottom end of the mixing screw 312.

[0028] Combine Figure 5 As shown, the scraping layer 314 at the bottom end of the mixing screw 312 can reduce direct wear between the bottom end of the mixing screw 312 and the bottom of the distillation chamber 113, thereby extending the service life of the mixing screw 312 and maintaining the continuity of the distillation process. The scraping layer 314 can be made of silicon carbide.

[0029] See Figure 6 As shown, an umbrella-shaped flow guide cover 4 is fixedly connected to the inner wall of the upper end of the distillation chamber 113, and its surface is inclined at 45°-60°.

[0030] Combine Figure 7 and Figure 8 As shown, the umbrella-shaped flow guide hood 4 is located on the inner wall of the upper end of the distillation chamber 113, and is located in the area below the gas delivery port 114. During the distillation operation, the gas phase components generated by the mixing screw 312 stirring the material are guided upward by the drainage screw 321. Part of the gas will diffuse toward the inner wall of the upper end of the distillation chamber 113 due to the disturbance of the flow field, and a small amount of liquid droplets that are not fully vaporized may be entrained in the gas phase. In order to regularize the flow path of this part of the gas phase and separate the droplets, the umbrella-shaped flow guide hood 4 is fixed on the inner wall of the upper end of the distillation chamber 113 to intervene in the gas phase and the entrained objects. The inclined surface of the umbrella-shaped flow guide hood 4 can allow the gas phase diffused toward the inner wall of the upper end of the distillation chamber 113 to be re-guided back to the mainstream gas phase channel, reducing the loss of the gas phase caused by disordered diffusion; the droplets entrained in the gas phase will slide back into the distillation chamber 113 along the inclined cover surface under the action of gravity, reducing the droplets entering the gas delivery port 114, ensuring the purity of the gas phase entering subsequent condensation and other links, and maintaining the distillation separation effect.

[0031] From the analysis of the physical process of gas phase flow and droplet separation, let the tilt angle be , the droplet sliding speed on the mask surface Related to the gravity component along the cover surface ( , is the acceleration due to gravity). When =45°, the droplet sliding power and the resistance of the gas phase flowing through the mask surface reach a balance, the droplet can slide smoothly, and the gas phase can pass more smoothly; when =60°, the droplet sliding speed is increased, which can accelerate the droplet separation. At the same time, the flow field disturbance caused by the obstruction of the mask surface on the gas phase is still within an acceptable range.

[0032] like <45°, the droplets slide slowly, easily accumulate on the cover, and secondary vaporize and mix into the gas phase, affecting the purity; if >60°, the resistance of gas phase flowing through the mask surface increases, which will reduce the gas phase conveying efficiency and may also cause flow field turbulence.

[0033] It should be noted that the angles shown in the drawings are for illustration only.

[0034] The mixing screw 312 is made of aluminum alloy, and the drainage screw 321 is made of copper-graphite composite material. A thermal expansion compensation gap is provided between the mixing screw 312 and the drainage screw 321 .

[0035] The mixing screw 312 needs to take into account both lightweight structure and basic thermal conductivity to adapt to the temperature conduction requirements when materials are mixed. Aluminum alloy has low density and high thermal conductivity, which can quickly transfer heat during the mixing process while ensuring the strength of the mixing screw 312 itself, thereby reducing local overheating. The drainage screw 321 requires high thermal conductivity and self-lubricating properties. In the copper-graphite composite material, copper provides high thermal conductivity to accelerate the heat transfer of gaseous materials, and the self-lubricating property of graphite can reduce the friction loss between the screw and the gas phase and the cavity wall when the screw rotates. However, the thermal expansion coefficients of the two materials are significantly different. Temperature fluctuations during the distillation process will cause different degrees of thermal deformation of the two. If there is no buffer, it is easy to cause the screw to get stuck and the cavity wall to wear. Therefore, a thermal expansion compensation gap is set between the mixing screw 312 and the drainage screw 321. The gap can absorb the thermal deformation (through the thermal expansion formula Calculations show that, assuming a temperature difference of 100°C, the deformation of a 1m long aluminum alloy screw is approximately 2.3mm, and that of copper-graphite is approximately 1.8mm). This prevents the screws from squeezing and interfering with each other due to thermal stress, ensures their continuous and stable rotation, maintains the flow field order of material mixing and gaseous drainage, and ensures the liquid mixing efficiency and gaseous delivery purity during the distillation process.

[0036] Working principle: First, the raw materials enter the distillation chamber 113 of the distillation tank 11 from the feeding port 14 in the middle of the tank body 111. After the cover body 112 is closed, the heating structure 2 is started: the spiral heating tube 22 in the inner wall heating cavity 21 of the tank body 111 generates heat through an external power supply to heat the side wall area of ​​the distillation chamber 113. At the same time, the annular heat transfer oil disk inside the bottom of the distillation chamber 113 heats the bottom area of ​​the chamber. The two work together to achieve multi-directional heating, so that the temperature in the distillation chamber 113 is evenly distributed, providing heat support for the stable vaporization of triisopropyl borate; The motor drives the central axis 311 of the rotating structure 3 to rotate. A fixed member at the upper end of the central axis 311 assists in its stable rotation. The mixing screw 312 at the lower end rotates synchronously with the central axis 311 via a connecting rod 313. The mixing screw 312 is a hollow aluminum alloy structure. During rotation, its internal heat conduction channel transfers heat from the tank wall to the interior of the raw materials. Simultaneously, its bottom dynamically mates with the bottom of the distillation chamber 113, scraping away sediment from the bottom through friction to prevent clogging of the discharge port 15. Furthermore, the local vortex generated by the rotation keeps tiny particles suspended, preventing sedimentation. After the raw material is heated and vaporized, the gaseous triisopropyl borate moves upward. The guide screw 321 at the upper end of the central shaft 311 rotates synchronously with the central shaft 311. Its spiral angle guides the gaseous material along a spiral trajectory into the guide cavity 322, forming a high-speed spiral flow field, which is directed to the gas delivery port 114. An umbrella-shaped flow deflector on the inner wall of the upper end of distillation chamber 113 blocks gaseous material from diffusing toward the inner wall, causing it to flow back into the mainstream flow field. It also allows entrained liquid droplets to slide down the deflector surface back into distillation chamber 113, improving gaseous purity. Finally, the gaseous material enters connecting pipe 12 through gas delivery port 114 and is transported to condenser 13 for condensation and collection, completing the distillation process.

[0037] Example 2: This example, based on the content provided in Example 1, aims to provide a distillation method for the production and collection of triisopropyl borate, and the specific steps are as follows: Step 1: The esterification reaction product of boric acid and isopropyl alcohol enters the distillation chamber 113 through the feeding port 14 in the middle of the distillation tank 11, so that the raw materials directly enter the gas-liquid equilibrium zone; Step 2: Start the spiral heating tube 22 in the wall of the tank 111 and the annular heat transfer oil pan at the bottom, which work together to form a three-dimensional temperature field to heat the material evenly; Step 3: The motor drives the central shaft 311 to rotate, driving the hollow mixing screw 312 at the lower end to rotate: the mixing screw 312 transfers heat from the tank wall to the material inside through its hollow structure, enhancing heat exchange; the bottom of the mixing screw 312 dynamically fits against the tank bottom to scrape off sediment; the local eddy current generated by the rotation keeps the boric acid particles suspended; Step 4: As the gaseous triisopropyl borate rises, the solid guide screw 321 at the upper end of the central axis 311 drives the gas to form a spiral upward flow field, which is then directed to the gas delivery port 114; Step 5: The steam enters the condenser 13 through the connecting pipe 12 and is condensed into liquid triisopropyl borate and then collected. The unvaporized heavy components are discharged through the exhaust port 15.

[0038] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely preferred examples of the present invention and are not intended to limit the present invention. Various changes and improvements may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and improvements fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A distillation apparatus for producing and collecting triisopropyl borate, comprising a distillation apparatus body (1), which includes a distillation tank (11) with a plurality of gas delivery ports (114) opened on the top; A connecting pipe (12), one end of which is connected to the interior of the gas delivery port (114) and the other end of which is connected to the condenser (13); A condenser (13) receives the gaseous material delivered by the distillation tank (11) through a connecting pipe (12); The distillation tank (11) comprises a tank body (111) and a cover body (112) with a rotating structure (3) installed therein, and a feeding port (14) is provided in the middle of the tank body (111). The distillation tank (11) is characterized in that: A heating structure (2) is provided inside the tank wall of the tank body (111); The rotating structure (3) is composed of a mixing component (31) and a guide component (32) connected in a coaxial manner. The mixing component (31) is a hollow spiral structure, and a through heat conduction channel is formed inside the mixing component. The outer wall is dynamically fitted with the bottom of the distillation tank (11). During rotation, the sediment on the bottom of the tank is removed by friction, and the heat of the tank wall is conducted to the interior of the raw material through the hollow structure. The raw materials enter the distillation tank (11) from the feeding port (14) for distillation. After the temperature rises, the material to be collected rises in a gaseous state. The guide component (32) is a solid spiral structure, which drives the gaseous material to form a spiral upward flow field and guides it in a direction to the gas delivery port (114). The mixing component (31) includes a central shaft (311) that rotates inside the distillation chamber (113), and the upper end of the central shaft (311) passes through the cover (112) and is coaxially connected to the output shaft of the motor; A mixing screw (312) is wound around the lower end surface of the central shaft (311). The mixing screw (312) is a hollow structure and is connected to the central shaft (311) via a plurality of connecting rods (313). A drainage screw (321) is fixedly mounted on the outer wall of the upper end of the central axis (311), and a guide cavity (322) is formed between the drainage screw (321) and the central axis (311).

2. The distillation apparatus for producing and collecting triisopropyl borate according to claim 1, wherein: The heating structure (2) includes a heating cavity (21) opened inside the inner wall of the tank body (111), a spiral heating tube (22) is installed in the heating cavity (21), and the spiral heating tube (22) is heated by power supplied by an external power source; A distillation chamber (113) is formed inside the tank body (111), a discharge port (15) is provided at the middle end of the bottom of the inner chamber of the distillation chamber (113), and an annular heat transfer oil pan is provided inside the bottom of the inner chamber; The spiral heating tube (22) cooperates with the heat-conducting oil pan to achieve multi-directional distillation heating of the distillation chamber (113).

3. The distillation apparatus for producing and collecting triisopropyl borate according to claim 1, wherein: The helical angle of the drainage screw (321) is 20°-35°.

4. The distillation apparatus for producing and collecting triisopropyl borate according to claim 3, wherein: The top end of the drainage screw (321) is located 10-30 cm below the gas delivery port (114).

5. The distillation apparatus for producing and collecting triisopropyl borate according to claim 1, wherein: The bottom end of the mixing screw (312) is provided with a scraping layer (314) having wear-resistant properties.

6. The distillation apparatus for producing and collecting triisopropyl borate according to claim 2, wherein: An umbrella-shaped flow guide cover (4) is fixedly connected to the inner wall of the upper end of the distillation chamber (113), and its surface is inclined at 45°-60°.

7. The distillation apparatus for producing and collecting triisopropyl borate according to claim 1, wherein: The mixing screw (312) is made of aluminum alloy, the drainage screw (321) is made of copper-graphite composite material, and a thermal expansion compensation gap is provided between the mixing screw (312) and the drainage screw (321).

8. A distillation method for producing and collecting triisopropyl borate, characterized in that: The distillation apparatus for producing and collecting triisopropyl borate according to claim 2 comprises the following steps: The esterification reaction product of S1, boric acid and isopropyl alcohol enters the distillation chamber (113) through the feeding port (14) in the middle of the distillation tank (11), so that the raw materials directly enter the gas-liquid equilibrium zone; S2, starting the spiral heating tube (22) in the wall of the tank (111) and the annular heat-conducting oil pan at the bottom, the two cooperate to form a three-dimensional temperature field, so that the material is heated evenly; S3, the motor drives the central shaft (311) to rotate, driving the hollow mixing screw (312) at the lower end to rotate: the mixing screw (312) conducts heat from the tank wall to the interior of the material through the hollow structure, thereby enhancing heat exchange; the bottom of the mixing screw (312) dynamically fits with the bottom of the tank to scrape off sediment; the local vortex generated by the rotation keeps the boric acid particles suspended; S4, when the gaseous triisopropyl borate rises, the solid drainage screw (321) at the upper end of the central axis (311) drives the gas to form a spiral upward flow field, and guides the gas in a direction to the gas delivery port (114); S5. The steam enters the condenser (13) through the connecting pipe (12), is condensed into liquid triisopropyl borate and then collected, and the unvaporized heavy components are discharged through the discharge port (15).

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