Multistage heat exchange equipment for producing phosphorus trichloride

Abstract

The present application relates to the technical field of phosphorus trichloride production, and particularly relates to a multistage heat exchange equipment for phosphorus trichloride production, which comprises a shell, a chute, a liquid inlet and a liquid outlet, the chute is horizontally arranged on the outer wall of the shell, the liquid inlet and the liquid outlet are both arranged on the outer wall of the shell and are located at opposite angles of the shell, the outer wall of the shell is provided with an adjusting mechanism, the adjusting mechanism covers the outside of the chute, and the bottom end of the outer wall of the shell is horizontally provided with a pressure relief mechanism. The present application can scrape off the sundries attached to the surface of the heat transfer pipe, effectively maintain the heat exchange capacity of the heat transfer pipe, avoid the interruption of the production process, ensure the continuity of heat exchange, provide a basic guarantee for the temperature adjustment of the phosphorus trichloride raw material, and ensure that the phosphorus trichloride raw material can be accurately adjusted to the expected temperature of the process; the temperature of the phosphorus trichloride raw material can be accurately adjusted to the expected value according to the requirements of different process stages of the phosphorus trichloride production.

Description

Technical Field

[0001] This invention relates to the field of phosphorus trichloride production technology, and in particular to a multi-stage heat exchange device for phosphorus trichloride production. Background Technology

[0002] Phosphorus trichloride is an important basic chemical raw material in the phosphorus chemical industry, widely used in organic synthesis, pesticide production, pharmaceutical intermediate preparation, and dye manufacturing. Its industrial production typically involves a direct chlorination reaction between yellow phosphorus and chlorine. Precise temperature control is crucial for ensuring stable reaction rates, product purity, and production safety throughout the entire process of phosphorus trichloride synthesis, refining, and transportation. Therefore, heat exchange equipment is a key component of the phosphorus trichloride production line. Currently, fixed baffle plate shell-and-tube heat exchangers are commonly used in phosphorus trichloride production to heat or cool the material. These devices use fixed baffle plates in the shell side to force the material to flow along a tortuous path, extending its residence time and increasing the contact area with the heat transfer tubes, thus achieving heat exchange. They are characterized by large processing capacity and simple structure.

[0003] However, in practical production applications, the temperature control range of existing shell-and-tube heat exchangers is very limited and cannot adapt to the needs of multi-condition production. Because the baffles are fixed, the number of material deflections, flow path length, and heat exchange contact area are all fixed values, which can only correspond to a single heat exchange intensity. This makes it difficult to match the differentiated temperature requirements of different process stages in phosphorus trichloride production, such as reaction preheating, distillation condensation, and finished product cooling. Temperature control flexibility is poor, and it is impossible to accurately control the material temperature to the expected process value, easily leading to fluctuations in product purity and high production energy consumption. At the same time, trace amounts of unreacted yellow phosphorus, byproducts, and mechanical impurities contained in phosphorus trichloride easily deposit and adhere to the outer wall of the heat transfer tubes, forming a scale layer that significantly reduces the heat transfer coefficient, resulting in a continuous decline in heat exchange efficiency. Due to the limitations of the fixed baffle structure, existing equipment cannot achieve online descaling; it must be shut down periodically for manual cleaning, which not only directly interrupts the production process and reduces continuous production efficiency but also increases maintenance costs and the safety risks of personnel coming into contact with corrosive materials.

[0004] In addition, existing heat exchangers have significant shortcomings in safety protection and liquid accumulation handling capabilities. Phosphorus trichloride is highly corrosive and reactive. If impurities are mixed into the material during production, abnormal side reactions occur, or temperature runaway expansion occurs, the shell-side pressure will rise sharply. Existing heat exchangers mostly use electrically controlled pressure relief devices, which are easily affected by power outages, line faults, and other factors, and may fail, posing safety hazards such as equipment explosion and material leakage. At the same time, when the equipment is shut down for maintenance, it is difficult to completely drain the residual phosphorus trichloride material in the shell side. Long-term liquid accumulation will aggravate the corrosion and aging of the shell, heat transfer tubes, and baffles, significantly shortening the overall service life of the equipment. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, such as small temperature range, difficulty in adjusting raw materials to the expected temperature, and inability to perform emergency pressure relief, the present invention provides a multi-stage heat exchange device for phosphorus trichloride production.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a multi-stage heat exchange device for phosphorus trichloride production, comprising a shell, a chute, an inlet, and an outlet. The chute is horizontally formed on the outer wall of the shell. The inlet and outlet are both installed on the outer wall of the shell, and are located diagonally opposite each other, allowing phosphorus trichloride raw material to enter from the right side of the shell and exit from the leftmost side. An adjustment mechanism is installed on the outer wall of the shell, covering the outside of the chute. A pressure relief mechanism is horizontally installed at the bottom of the outer wall of the shell to relieve pressure on the phosphorus trichloride raw material. Tube sheets are installed at both ends of the inner cavity of the shell. Heat transfer tubes are evenly installed on the outer wall of the tube sheets. Several baffles are sleeved on the outer wall of the heat transfer tubes from left to right, and the baffle located at the center is fixed to the inner wall of the shell. The baffles change the flow direction of phosphorus trichloride raw material and expand the contact area with the heat transfer tubes. Insert rods are installed on the outer wall of the baffles. The position of the baffles is adjusted by adjusting the mechanism in cooperation with the insert rods. Tube boxes are installed at both ends of the shell. The above components constitute a heat exchange system to adjust the phosphorus trichloride raw material to a predetermined temperature to assist in the production of phosphorus trichloride.

[0007] Preferably, the adjustment mechanism includes a base mounted on the outer wall of the housing, a rotating component mounted inside the base via a bearing, a transmission box mounted on the right side wall of the base, and a drive component mounted on the lower surface of the transmission box, which drives the rotating component to rotate.

[0008] Preferably, the rotating assembly includes a first rotating shaft mounted on the right side wall of the base via a bearing. A roller located in the inner cavity of the base is mounted on the left end of the first rotating shaft. The roller is hollow to reduce its weight. The outer wall of the roller has several guide grooves symmetrically arranged from the center to the outside. The insertion rod is inserted into the inner cavity of the guide groove. Two bevel gears opposite to each other are mounted on the outer wall of the first rotating shaft. Two bevel gears work in conjunction with the drive assembly to make the drum rotate clockwise and counterclockwise alternately, allowing the baffle to slide back and forth on the heat transfer tube. This not only removes impurities from the heat transfer tube but also adjusts the number of baffles for the phosphorus trichloride feedstock.

[0009] Preferably, several guide grooves are inclinedly distributed on the outer wall of the drum, and the inclination of the guide grooves on the same side is different, with the end of the outermost guide groove being parallel to the circumference of the drum.

[0010] Preferably, the drive assembly includes a motor mounted on the lower surface of the transmission box, a turntable mounted on the output end of the motor, and a plurality of teeth that mesh with bevel gears are mounted circumferentially along the outer edge of the upper surface of the turntable.

[0011] Preferably, the range of the arrangement of several teeth is one-half of the circumference of the turntable.

[0012] Preferably, the pressure relief mechanism includes a plurality of valve bodies equidistantly installed on the lower surface of the housing from left to right. The top of each valve body is fitted with a connector that communicates with the inner cavity of the housing. A pressure relief pipe is installed on the lower surface of the valve body, through which the valve body is drained. A switch assembly is installed on the outer wall of the valve body via a bearing.

[0013] Preferably, the switch assembly includes a second rotating shaft mounted on the outer wall of the valve body via a bearing. Several baffles are mounted on the outer wall of the second rotating shaft from left to right. The baffles are located in the inner cavity of the valve body. A counterweight is mounted on the right end of the second rotating shaft. Under the action of the counterweight, the second rotating shaft is driven to rotate, causing the baffles to rotate upward and close the bottom of the connector. The counterweight provides torque to the second rotating shaft, which has an explosion-proof function and can also drain residual phosphorus trichloride raw material in the housing.

[0014] Preferably, the second rotating shaft is eccentrically mounted on the valve body.

[0015] Preferably, the outer wall of the counterweight has screw holes.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention uses a motor to drive a turntable to rotate, causing the teeth on the turntable to alternately mesh with two bevel gears on the first rotating shaft. This, in turn, drives the drum to rotate alternately clockwise and counterclockwise. The inclined guide grooves on the outer wall of the drum press the insert rod, enabling the baffles to move on the heat transfer tube and flexibly adjust their spacing. As the baffles slide back and forth along the heat transfer tube, they can directly scrape off the debris attached to the surface of the heat transfer tube, effectively maintaining the heat exchange capacity of the heat transfer tube. This eliminates the need for frequent shutdowns to clean the heat transfer tube, avoiding production interruptions and ensuring the continuity of heat exchange. At the same time, it provides a basic guarantee for the temperature regulation of phosphorus trichloride raw material, ensuring that the phosphorus trichloride raw material can be accurately regulated to the expected process temperature.

[0017] 2. This invention relies on the special structural design of the guide groove on the outer wall of the drum. When the insertion rod slides into the circumferential end of the outermost guide groove, the outermost baffle plate can contact the end of the shell, thereby reducing the amount of baffle plate used and the number of raw material deflections. When the baffle plate moves inward, the amount of baffle plate used increases accordingly, and the number of raw material deflections increases simultaneously. This enables controllable adjustment of the number of phosphorus trichloride raw material deflections, significantly expanding the temperature range of phosphorus trichloride raw material. It can accurately adjust the temperature of phosphorus trichloride raw material to the expected value according to the needs of different process stages in phosphorus trichloride production, effectively improving the production quality and product purity uniformity of phosphorus trichloride.

[0018] 3. This invention provides torque to the second rotating shaft through a counterweight, achieving a normal seal between the baffle and the valve body joint. During heat exchange, if the pressure inside the shell surges due to raw material expansion, impurities clogging, or other reasons, when the pressure exceeds the torque of the counterweight on the baffle, the baffle automatically swings downward. Furthermore, the driving direction of the counterweight on the baffle changes after rotating beyond the centerline, allowing phosphorus trichloride to be quickly discharged through the pressure relief pipe. This achieves automatic emergency pressure relief of the shell, fundamentally eliminating the safety hazard of shell rupture and improving the safety of equipment operation. Simultaneously, the counterweight can be manually rotated to open the baffle, completely discharging any residual phosphorus trichloride trapped inside the shell. This effectively prevents waste of phosphorus trichloride, reduces production costs, and avoids corrosion of the shell, heat transfer tubes, baffles, and other equipment components caused by accumulated liquid, significantly extending the overall service life of the equipment. Attached Figure Description

[0019] Figure 1 This is a perspective view of the present invention; Figure 2 For the present invention Figure 1 Enlarged view of point A in the middle; Figure 3 This is a perspective view of the adjustment mechanism of the present invention; Figure 4 This is a perspective view of the rotating component of the present invention; Figure 5 For the present invention Figure 4 Enlarged view at point B in the middle; Figure 6 This is a perspective view of the driving component of the present invention; Figure 7 This is a perspective view of the pressure relief mechanism of the present invention; Figure 8 This is a perspective view of the switch assembly of the present invention.

[0020] In the diagram: 1. Shell; 2. Slide groove; 3. Liquid inlet; 4. Liquid outlet; 5. Adjustment mechanism; 6. Pressure relief mechanism; 7. Tube sheet; 8. Heat transfer tube; 9. Baffle plate; 10. Insert rod; 11. Tube box; 51. Base; 52. Rotating assembly; 53. Transmission box; 54. Drive assembly; 521. First rotating shaft; 522. Roller; 523. Guide groove; 524. Bevel gear; 541. Motor; 542. Turntable; 543. Gear; 61. Valve body; 62. Connector; 63. Pressure relief pipe; 64. Switch assembly; 641. Second rotating shaft; 642. Baffle; 643. Counterweight. 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] This invention provides a technical solution: a multi-stage heat exchange device for phosphorus trichloride production, such as... Figures 1-8 As shown, the device includes a shell 1, a chute 2, an inlet 3, and an outlet 4. The chute 2 is horizontally opened on the outer wall of the shell 1. The inlet 3 and outlet 4 are both installed on the outer wall of the shell 1, and they are located diagonally opposite each other, allowing phosphorus trichloride to enter from the right side of the shell 1 and exit from the leftmost side. An adjustment mechanism 5 is installed on the outer wall of the shell 1, covering the outside of the chute 2. A pressure relief mechanism 6 is horizontally installed at the bottom of the outer wall of the shell 1 to relieve pressure on the phosphorus trichloride. Tube sheets 7 are installed at both ends of the inner cavity of the shell 1, and heat transfer tubes are evenly installed on the outer wall of the tube sheets 7. 8. The tube sheet 7 divides the fluid, allowing it to flow evenly through the heat transfer tube 8, enabling the heat transfer tube 8 to exchange heat with the phosphorus trichloride feedstock. Several baffles 9 are fitted onto the outer wall of the heat transfer tube 8 from left to right, with the baffle 9 located in the center fixed to the inner wall of the shell 1. The baffles 9 change the flow direction of the phosphorus trichloride feedstock, increasing the contact area with the heat transfer tube 8. Insert rods 10 are installed on the outer wall of the baffles 9, and the position of the baffles 9 is adjusted by the adjustment mechanism 5 in cooperation with the insert rods 10. Tube boxes 11 are installed at both ends of the shell 1, with one tube box 11 responsible for diverting the flow and the other tube box 11 responsible for converging the flow.

[0023] As a preferred embodiment, the adjustment mechanism 5 further includes a base 51 mounted on the outer wall of the housing 1, a rotating component 52 mounted inside the base 51 via a bearing, a transmission box 53 mounted on the right side wall of the base 51, and a drive component 54 mounted on the lower surface of the transmission box 53, which drives the rotating component 52 to rotate.

[0024] As a preferred embodiment, the rotating assembly 52 further includes a first rotating shaft 521 mounted on the right side wall of the base 51 via bearings. A roller 522 located inside the cavity of the base 51 is mounted on the left end of the first rotating shaft 521. The roller 522 is hollow to reduce its weight and the rotational load on the first rotating shaft 521. The outer wall of the roller 522 has several symmetrical guide grooves 523 extending from the center outwards. The insert rod 10 is inserted into the cavity of the guide groove 523. The guide grooves 523 are inclinedly distributed on the outer wall of the roller 522, and the inclination of the guide grooves 523 on the same side is different. When the roller 522 rotates clockwise or counterclockwise, the guide grooves 523 are inclined... The surface can press the insert rod 10 outward or inward, making the distance between the baffles 9 increase or decrease equidistantly. The end of the outermost guide groove 523 is parallel to the circumference of the roller 522. Once the insert rod 10 enters the end of the outermost guide groove 523, as the roller 522 rotates, the insert rod 10 is fixed laterally, allowing the outermost baffle 9 to move to the edge of the housing 1 and remain stationary, thereby reducing the amount of baffle 9 used. Two bevel gears 524 are installed on the outer wall of the first rotating shaft 521. When the driving direction remains unchanged, the two bevel gears 524 rotate in opposite directions, allowing the first rotating shaft 521 to drive the roller 522 to rotate clockwise and counterclockwise alternately.

[0025] In this embodiment, the roller 522 with multiple guide grooves 523 forms a cylindrical camshaft transmission structure. The inclination of the guide groove 523 corresponds to the guide groove lift angle in the cam transmission. When the roller 522 rotates around its own axis, the inner sidewall of the guide groove 523 serves as the working surface of the cam profile, applying an axial component force to the insertion rod 10 and pushing the insertion rod 10 to move linearly along the housing 1. Under a unit rotation angle of the roller 522, the axial displacement of the insertion rod 10 is positively correlated with the size of the lift angle of the corresponding guide groove 523.

[0026] Since the baffle 9 at the center is fixed to the inner wall of the shell 1, it serves as the axial displacement reference for all baffles 9. The remaining baffles 9 are symmetrically distributed along the heat transfer tube 8 with the central baffle as the axis of symmetry. To ensure that the spacing between adjacent baffles 9 remains equal during the spacing adjustment process, the baffles 9 farther from the central reference require a larger total axial displacement. The rise angle of each guide groove 523 arranged from the center to the outside on the corresponding roller 522 increases sequentially, and the size of the rise angle of the guide groove is linearly matched with the distance from the corresponding baffle 9 to the central reference.

[0027] When the drum 522 rotates through any angle, the axial displacement of each insert rod 10 driven by the corresponding baffle 9 is proportional to the distance from the baffle 9 to the center reference. Thus, the change in the spacing between adjacent baffles 9 remains consistent, achieving equidistant increases or decreases in the spacing between the baffles 9.

[0028] The guide channels 523 are arranged symmetrically from left to right and inclined from the center to the outside. The inclination of the guide channels 523 on the same side is different. The end of the outermost guide channel 523 is set as a circumferential parallel structure, which takes into account the dual functions of adjusting the spacing and controlling the number of baffles 9. This allows for flexible adjustment of the number of baffles for phosphorus trichloride raw materials, greatly expands the temperature range of phosphorus trichloride raw materials, and adapts to the temperature requirements of different process stages in the production of phosphorus trichloride.

[0029] Two opposing bevel gears 524 work in conjunction with a single drive source to achieve alternating clockwise and counterclockwise rotation of the shaft while maintaining the same drive direction. This eliminates the need for an additional reversing mechanism, simplifies the transmission structure, reduces potential failure points, and improves the overall operational reliability and service life of the component.

[0030] By sliding the insertion rod 10 into the guide groove 523, the rotational motion of the drum 522 is precisely converted into the linear motion of the baffle plate 9. The transmission is stable and the adjustment is highly accurate. The equidistant movement of the baffle plate 9 ensures the uniformity of the flow path of phosphorus trichloride raw material in the shell, avoids uneven heat exchange caused by local flow field turbulence, ensures the accuracy of phosphorus trichloride raw material temperature control, and improves the production quality of phosphorus trichloride.

[0031] The automated adjustment and online self-cleaning functions enable continuous operation of the heat exchange equipment, avoiding production interruptions caused by downtime for adjustment or cleaning, and improving the continuity and efficiency of phosphorus trichloride production.

[0032] As a preferred embodiment, the drive assembly 54 further includes a motor 541 mounted on the lower surface of the transmission housing 53. A turntable 542 is mounted on the output end of the motor 541. A plurality of teeth 543 that mesh with bevel gears 524 are mounted circumferentially along the outer edge of the upper surface of the turntable 542. The arrangement range of the plurality of teeth 543 is half the circumference of the turntable 542, so that the length of the teeth 543 is just enough to alternately mesh with the two bevel gears 524, avoiding simultaneous meshing and transmission intermittent.

[0033] As a preferred embodiment, the pressure relief mechanism 6 further includes a plurality of valve bodies 61 equidistantly mounted on the lower surface of the housing 1 from left to right. A connector 62 communicating with the inner cavity of the housing 1 is mounted on the top of the valve body 61. A pressure relief pipe 63 is mounted on the lower surface of the valve body 61, through which the valve body 61 is connected. A switch assembly 64 is mounted on the outer wall of the valve body 61 via a bearing.

[0034] As a preferred embodiment, the switch assembly 64 further includes a second rotating shaft 641 mounted on the outer wall of the valve body 61 via a bearing. The second rotating shaft 641 is eccentrically mounted on the valve body 61. A baffle 642 uses the second rotating shaft 641 as a fulcrum, allowing the pressure of the phosphorus trichloride raw material inside the housing 1 to apply pressure to the baffle 642. Several baffles 642 are installed from left to right on the outer wall of the second rotating shaft 641. A rubber gasket is adhered to the upper surface of the baffle 642 to improve the sealing performance between the baffle 642 and the connector 62. The baffle 642 is located in the inner cavity of the valve body 61. A counterweight 643 is installed at the right end of the second rotating shaft 641. Under the action of the gravity of the counterweight 643, the second rotating shaft 641 is driven to rotate, causing the baffle 642 to rotate upward. The baffle 642 closes the bottom of the connector 62. A screw hole is provided on the outer wall of the counterweight 643, which can add or remove weights. By changing the torque of the counterweight 643, the pressure relief pressure of the baffle 642 can be changed.

[0035] When there is no abnormal pressure, the gravity torque of the counterweight 643 drives the second rotating shaft 641 to rotate, causing the baffle 642 to move upward and tightly fit against the bottom of the joint 62, achieving a seal through the rubber gasket and ensuring normal heat exchange of the shell 1. When the pressure inside the shell 1 surges and exceeds the torque threshold of the counterweight 643, the downward pressure of the raw material on the baffle 642 is greater than the counterweight torque, pushing the baffle 642 to swing downward, causing the second rotating shaft 641 to rotate, opening the joint 62, and the phosphorus trichloride raw material flows through the valve body 61 into the pressure relief pipe 63 for discharge, realizing emergency pressure relief of the shell 1. After the heat exchange is completed, the counterweight 643 is manually rotated to drive the second rotating shaft 641 to rotate and cause the baffle 642 to open downward, allowing the residual phosphorus trichloride raw material in the shell 1 to be discharged through the joint 62, valve body 61, and pressure relief pipe 63, completing the drainage of the accumulated liquid.

[0036] Based on the raw material pressure characteristics at different stages of phosphorus trichloride production, weights are screwed onto or removed from the screw holes of counterweight 643 to increase or decrease the counterweight torque, thereby adjusting the pressure relief threshold of baffle 642 to meet the safety requirements of different heat exchange conditions.

[0037] Without electrical control components, it is unaffected by power outages, line faults, or other factors. When the pressure on shell 1 exceeds the limit, it can respond and open immediately, eliminating the safety hazard of shell 1 exploding, and is suitable for the safety requirements of industrial production.

[0038] The baffle can be manually opened to empty the residual raw material inside the shell 1, which not only avoids the waste of phosphorus trichloride raw material and reduces production costs, but also prevents the residual raw material from corroding the shell, heat transfer tube and other components, significantly extending the overall service life of the equipment.

[0039] Working principle: Step 1: The two tube boxes 11 are responsible for water inlet and outlet respectively. After the flow is split by the tube sheet 7, the temperature-controlled fluid flows through the heat transfer tube 8. The phosphorus trichloride raw material enters the shell 1 from the liquid inlet 3. The baffle plate 9 restricts the flow direction of the phosphorus trichloride raw material, allowing the phosphorus trichloride raw material to pass through the heat transfer tube 8 during the flow process. The heat transfer tube 8 exchanges heat with the phosphorus trichloride raw material and finally discharges from the liquid outlet 4, realizing the preheating of the phosphorus trichloride raw material. Step 2: When the motor 541 drives the turntable 542 to rotate, the teeth 543 follow the turntable 542 to rotate. The teeth 543 alternately mesh with the two bevel gears 524, causing the first rotating shaft 521 to drive the roller 522 to rotate alternately clockwise and counterclockwise. The guide groove 523 presses the insert rod 10 outward or inward. Due to the different inclinations of the guide groove 523, the distance between the baffles 9 increases or decreases at equal intervals. When the baffles 9 move back and forth along the heat transfer tube 8, they can scrape off the substances attached to the surface of the heat transfer tube 8, ensuring the heat conduction performance of the heat transfer tube 8. Step 3: When the baffle 9 moves inward, the distance between the baffles 9 decreases, the amount of baffle 9 used increases, the number of baffles in the phosphorus trichloride feedstock is increased, and the heat exchange efficiency is improved. If the baffle 9 moves outward, the distance between the baffles 9 increases, and after the insertion rod 10 enters the end of the outermost guide groove 523, the outermost baffle 9 is close to the shell 1, the amount of baffle 9 used decreases, the number of baffles in the phosphorus trichloride feedstock is reduced, the heat exchange efficiency is reduced, and the temperature regulation range of the phosphorus trichloride feedstock is expanded. Step 4: If other substances are mixed into the phosphorus trichloride raw material in the shell 1 or if it expands rapidly due to temperature changes, the pressure generated will be greater than the torque of the counterweight 643 on the baffle 642. The baffle 642 will rotate downward until the counterweight 643 rotates beyond the center line. The weight of the counterweight 643 and the pressure of the phosphorus trichloride raw material will both drive the baffle 642 to swing downward. The connector 62 will open stably, allowing the phosphorus trichloride raw material to enter the pressure relief pipe 63 along the valve body 61 to achieve pressure relief of the shell 1 and prevent the shell 1 from exploding. Step 5: If the counterweight 643 is turned manually, the baffle 642 can still be opened by swinging downwards. This is used to discharge the residual liquid in the shell 1, which not only avoids waste of raw materials, but also prevents the shell 1, heat transfer tube 8, etc. from being corroded over a long period of time. Step six: Installing or removing weights on the screw holes of counterweight 643 can increase or decrease the torque on baffle 642, and adjust the pressure relief pressure according to the heat exchange pressure of phosphorus trichloride raw material.

[0040] 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 claims and their equivalents.

Claims

1. A multi-stage heat exchange device for phosphorus trichloride production, comprising a shell (1), a chute (2), an inlet (3), and an outlet (4), wherein the chute (2) is horizontally opened on the outer wall of the shell (1), and the inlet (3) and outlet (4) are both installed on the outer wall of the shell (1) and are located diagonally opposite each other on the shell (1), allowing phosphorus trichloride raw material to enter from the right side of the shell (1) and then exit from the leftmost side of the shell (1), characterized in that, An adjustment mechanism (5) is installed on the outer wall of the shell (1). The adjustment mechanism (5) covers the outside of the slide groove (2). A pressure relief mechanism (6) is installed horizontally at the bottom of the outer wall of the shell (1). The pressure relief mechanism (6) is used to relieve the pressure of phosphorus trichloride raw material. Tube sheets (7) are installed on both the left and right ends of the inner cavity of the shell (1). Heat transfer tubes (8) are evenly installed on the outer wall of the tube sheet (7). Several baffles (9) are sleeved on the outer wall of the heat transfer tubes (8) from left to right. The baffle (9) located in the center is fixed to the inner wall of the shell (1). The baffle (9) changes the flow direction of phosphorus trichloride raw material and expands the contact area with the heat transfer tubes (8). A rod (10) is installed on the outer wall of the baffle (9). The position of the baffle (9) is adjusted by the adjustment mechanism (5) and the rod (10). Tube boxes (11) are installed on both the left and right ends of the shell (1). The adjustment mechanism (5) includes a base (51) installed on the outer wall of the housing (1), a rotating component (52) is installed inside the base (51) via a bearing, a transmission box (53) is installed on the right side wall of the base (51), and a drive component (54) is installed on the lower surface of the transmission box (53), which drives the rotating component (52) to rotate. The rotating assembly (52) includes a first rotating shaft (521) mounted on the right side wall of the base (51) via a bearing. A roller (522) located in the inner cavity of the base (51) is mounted on the left end of the first rotating shaft (521). The roller (522) is hollow to reduce the weight of the roller (522). A number of guide grooves (523) symmetrically arranged from the center to the outside are provided on the outer wall of the roller (522). The insert rod (10) is inserted into the inner cavity of the guide groove (523). Two bevel gears (524) opposite to each other are installed on the outer wall of the first rotating shaft (521). The pressure relief mechanism (6) includes a plurality of valve bodies (61) equidistantly installed on the lower surface of the housing (1) from left to right. The top of the valve body (61) is equipped with a connector (62) communicating with the inner cavity of the housing (1). The lower surface of the valve body (61) is equipped with a pressure relief pipe (63) to collect the flow of the valve body (61). The outer wall of the valve body (61) is equipped with a switch assembly (64) through a bearing. The switch assembly (64) includes a second rotating shaft (641) mounted on the outer wall of the valve body (61) via a bearing. Several baffles (642) are mounted on the outer wall of the second rotating shaft (641) from left to right. The baffles (642) are located in the inner cavity of the valve body (61). A counterweight (643) is mounted on the right end of the second rotating shaft (641). Under the gravity of the counterweight (643), the second rotating shaft (641) is driven to rotate, causing the baffles (642) to rotate upward and close the bottom of the connector (62).

2. The multi-stage heat exchange equipment for phosphorus trichloride production according to claim 1, characterized in that, Several guide grooves (523) are inclinedly distributed on the outer wall of the roller (522), and the inclination of the guide grooves (523) on the same side is different. The end of the outermost guide groove (523) is parallel to the circumference of the roller (522).

3. The multi-stage heat exchange equipment for phosphorus trichloride production according to claim 2, characterized in that, The drive assembly (54) includes a motor (541) mounted on the lower surface of the transmission box (53). A turntable (542) is mounted on the output end of the motor (541). A plurality of teeth (543) that mesh with a bevel gear (524) are mounted circumferentially on the outer edge of the upper surface of the turntable (542).

4. A multi-stage heat exchange device for phosphorus trichloride production according to claim 3, characterized in that, The range of the arrangement of several teeth (543) is half the circumference of the turntable (542).

5. A multi-stage heat exchange device for phosphorus trichloride production according to claim 4, characterized in that, The second rotating shaft (641) is eccentrically mounted on the valve body (61).

6. A multi-stage heat exchange device for phosphorus trichloride production according to claim 5, characterized in that, The outer wall of the counterweight (643) is provided with screw holes.

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