A rectification device for acetophenone

Abstract

This invention discloses a distillation apparatus for acetophenone, belonging to the field of chemical equipment. The apparatus includes a distillation tank with a feed pipe fixedly connected to it and a valve on the feed pipe. A base is fixedly connected to the bottom of the distillation tank. A heating mechanism for dynamically heating the solution inside the tank is fixedly connected to the tank. The heating mechanism includes a thermoelectric cooler and a sliding rheostat electrically connected in series with the cooler. This invention achieves this by reducing the resistance of the rheostat as the pressure inside the tank decreases, ensuring that the heat released from the thermoelectric cooler is within the required distillation temperature range for acetophenone. When the pressure inside the tank reaches approximately 2133 Pa, the spring is fully compressed, causing the baffle to press against the second pressure-sensitive switch. At this point, the pressure inside the tank and the heat released from the thermoelectric cooler meet the distillation conditions for acetophenone.

Description

Technical Field

[0001] This invention relates to the field of chemical equipment technology, specifically to a distillation apparatus for acetophenone. Background Technology

[0002] Acetophenone, also known as acetylbenzene, is an organic compound with the molecular formula C6H5COCH3. It can be used as an intermediate in the manufacture of pharmaceuticals, resins, flavorings, and tear gas, and can also be used to manufacture sleeping pills. Currently, acetophenone is mostly obtained as a byproduct of the oxidation of cumene to phenol and acetone. It can also be produced by acetylation of benzene with acetyl chloride.

[0003] Anhydrous benzene (excess) reacts with anhydrous aluminum trichloride. Once the generated hydrogen chloride gas stops escaping, the mixture is heated in a water bath for 30 minutes to ensure complete reaction. After slight cooling, the mixture is poured into a mixture of concentrated hydrochloric acid and crushed ice to completely dissolve the aluminum salt. Then, diethyl ether is added, and the mixture is allowed to stand for separation. The aqueous layer is extracted with diethyl ether, and the extract is combined with the organic layer. The extract is washed with 10% sodium hydroxide until the washings are alkaline, then washed with water. The mixture is allowed to stand for separation, and the organic layer is dried with anhydrous calcium chloride. Then, the mixture is distilled. First, benzene and diethyl ether are distilled off, and then the mixture is distilled under reduced pressure. The fraction at 88–89 °C is collected at around 2133 Pa, which is the final product.

[0004] Existing equipment requires manual adjustment of the temperature inside the distillation tank to reach the temperature range required for acetophenone distillation when distilling acetophenone, resulting in low automation and reduced production efficiency. Summary of the Invention

[0005] The purpose of this invention is to provide a distillation apparatus for acetophenone, which has the advantage of automatically adjusting the temperature required for distillation, thus solving the problem of low production efficiency.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a distillation apparatus for acetophenone, comprising a distillation tank, a feeding pipe fixedly connected to the distillation tank, a valve provided on the feeding pipe, a base fixedly connected to the bottom of the distillation tank, a motor fixedly connected to the base, a rotating shaft fixedly connected to the output end of the motor, a stirring rod fixedly connected to the rotating shaft, the stirring rod being rotatably connected inside the distillation tank, a pressure reducing mechanism for reducing pressure inside the distillation tank provided at the top of the distillation tank, and a heating mechanism for dynamically heating the solution inside the distillation tank fixedly connected to the distillation tank, the heating mechanism comprising a semiconductor refrigeration chip and a sliding rheostat electrically connected in series with the semiconductor refrigeration chip.

[0007] Preferably, the heating mechanism further includes a mounting bracket, which is fixedly connected to the outer wall of the distillation tank. A mounting rod is slidably connected to the mounting bracket. The distillation tank has a through hole that cooperates with the mounting rod. The slider of the sliding rheostat is fixedly connected to the mounting rod. The semiconductor cooling chip is fixedly connected to the distillation tank, and the heat-releasing end of the semiconductor cooling chip penetrates the tank wall of the distillation tank and extends into the interior of the distillation tank.

[0008] Preferably, the heating mechanism further includes a spring sleeved on the mounting rod, with a baffle fixedly connected to one end of the mounting rod away from the distillation tank, and the two ends of the spring fixedly connected to the mounting frame and the baffle, respectively.

[0009] Preferably, a first pipe is fixedly connected to the distillation tank, and a second pipe is fixedly connected inside the first pipe. Both the first pipe and the second pipe are connected to the distillation tank. A receiving box for receiving acetophenone is installed at the end of the second pipe away from the distillation tank. A receiving plate is fixedly connected to the upper part of the receiving box, and the opening at the end of the first pipe away from the distillation tank faces the receiving plate.

[0010] Preferably, a visual sensor for monitoring the amount of material discharged from the first pipeline is fixedly connected to the receiving box.

[0011] Preferably, the pressure reduction mechanism includes a negative pressure fan, a mounting platform is fixedly connected to the top of the distillation tank, an electric slide controlled by a vision sensor is slidably connected to the mounting platform, the negative pressure fan is fixedly connected to the electric slide, a first bevel gear is fixedly connected to the top of the rotating shaft, and a second bevel gear is fixedly connected to the drive shaft of the negative pressure fan, the second bevel gear and the first bevel gear meshing intermittently.

[0012] Preferably, the pressure reducing mechanism further includes an extraction pipe fixedly connected to the negative pressure fan, with one end of the extraction pipe away from the negative pressure fan connected to the distillation tank, and a one-way valve provided on the extraction pipe.

[0013] Preferably, the first pipe has a through hole adapted to the heat-absorbing end of the semiconductor refrigeration chip, and the second pipe is attached to the heat-absorbing end of the semiconductor refrigeration chip.

[0014] Preferably, a solenoid valve is provided on both the first and second pipes, an L-shaped frame is fixedly connected to the mounting platform, and a first pressure-sensitive switch for controlling the solenoid valve is fixedly connected to the L-shaped frame. The electric slide table intermittently abuts against the first pressure-sensitive switch.

[0015] Preferably, the mounting bracket is provided with a second pressure-sensitive switch for controlling the electric slide, the baffle intermittently abuts against the second pressure-sensitive switch, and the electric slide is controlled by the second pressure-sensitive switch with higher priority than the vision sensor.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0017] 1. This invention utilizes atmospheric pressure to overcome the spring force and slide the mounting rod into the distillation tank when the pressure inside the tank decreases. This causes the slider of the sliding rheostat, fixedly connected to the mounting rod, to slide on the rheostat's wire tie. The resistance of the rheostat decreases, leading to an increase in the current received by the thermoelectric cooler. Consequently, the heat absorbed or released by the heat-absorbing and heat-releasing ends of the thermoelectric cooler increases. The heat released by the heat-releasing end of the thermoelectric cooler ultimately reaches the distillation temperature range required for acetophenone. The pressure that the spring can withstand corresponds to the thrust exerted on the mounting rod by atmospheric pressure when the pressure inside the distillation tank is around 2133 Pa. Specifically, when the pressure inside the distillation tank reaches around 2133 Pa, the spring is fully compressed, causing the baffle to press against the second pressure-sensitive switch. At this point, the pressure inside the distillation tank and the heat released by the heat-releasing end of the thermoelectric cooler perfectly meet the distillation conditions for acetophenone.

[0018] 2. By discharging the distillation of acetophenone and the distillation of benzene and diethyl ether through the second pipe and the first pipe respectively, this invention ensures that acetophenone is not mixed with benzene and diethyl ether. At the same time, by setting the second pipe inside the first pipe and using a semiconductor cooling chip for cooling and condensation, the amount of condenser used can be reduced, thereby saving electricity. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the external structure of the present invention;

[0020] Figure 2 This is a schematic diagram of the internal structure of the present invention;

[0021] Figure 3 This is a schematic diagram of the pressure reduction mechanism of the present invention;

[0022] Figure 4 This is a schematic diagram of the structure at the second pipe of the present invention;

[0023] Figure 5 This is a schematic diagram of the structure of the sliding rheostat in this invention;

[0024] Figure 6 This is a schematic diagram of the structure of the receiving plate of the present invention.

[0025] In the diagram: 1. Distillation tank; 11. Feed pipe; 12. Valve; 13. Base; 2. Motor; 21. Shaft; 22. Stirring rod; 23. First bevel gear; 3. First pipe; 31. Second pipe; 32. Solenoid valve; 33. Receiving box; 34. Receiving plate; 35. Vision sensor; 4. Mounting platform; 41. Electric slide table; 42. Negative pressure fan; 43. Second bevel gear; 44. Suction pipe; 45. One-way valve; 46. L-shaped frame; 47. First pressure-sensitive switch; 5. Semiconductor cooling chip; 51. Sliding rheostat; 52. Mounting bracket; 53. Mounting rod; 54. Spring; 55. Baffle; 56. Second pressure-sensitive switch. Detailed Implementation

[0026] 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.

[0027] Example 1

[0028] Reference Figure 1 , Figure 2 , Figure 4 , Figure 5 and Figure 6 The present invention provides a technical solution: a distillation apparatus for acetophenone, comprising a distillation tank 1, a feeding pipe 11 fixedly connected to the distillation tank 1, a valve 12 provided on the feeding pipe 11, a base 13 fixedly connected to the bottom of the distillation tank 1, a motor 2 fixedly connected to the base 13, a rotating shaft 21 fixedly connected to the output end of the motor 2, a stirring rod 22 fixedly connected to the rotating shaft 21, the stirring rod 22 being rotatably connected inside the distillation tank 1, a pressure reducing mechanism for reducing pressure inside the distillation tank 1 provided at the top of the distillation tank 1, and a heating mechanism for dynamically heating the solution inside the distillation tank 1 fixedly connected to the distillation tank 1, the heating mechanism comprising a semiconductor refrigeration chip 5 and a sliding rheostat 51 electrically connected in series with the semiconductor refrigeration chip 5.

[0029] Open valve 12 and add the solution into distillation tank 1 through feed pipe 11 to a suitable amount. After the solution is added, close valve 12 and energize the semiconductor cooling chip 5. The heat-releasing end of the semiconductor cooling chip 5 is located inside distillation tank 1 and can heat the solution in distillation tank 1, causing the solution added into distillation tank 1 to evaporate. At the same time, start motor 2 to make the rotating shaft 21 fixedly connected to the output end of motor 2 rotate. Then, the stirring rod 22 fixedly connected to the rotating shaft 21 can stir the solution in distillation tank 1, making the solution in distillation tank 1 homogenized. At the same time, the stirring of the solution in distillation tank 1 by the stirring rod 22 also makes the solution in distillation tank 1 heat more evenly.

[0030] Furthermore, the heating mechanism also includes a mounting bracket 52, which is fixedly connected to the outer wall of the distillation tank 1. A mounting rod 53 is slidably connected to the mounting bracket 52. A through hole is provided on the distillation tank 1 to cooperate with the mounting rod 53. The slider of the sliding rheostat 51 is fixedly connected to the mounting rod 53. The semiconductor cooling chip 5 is fixedly connected to the distillation tank 1, and the heat-releasing end of the semiconductor cooling chip 5 penetrates the tank wall of the distillation tank 1 and extends into the interior of the distillation tank 1.

[0031] When the pressure inside the distillation tank 1 decreases, the mounting rod 53 slides into the interior of the distillation tank 1 against the elastic force of the spring 54 under atmospheric pressure. At this time, the slider of the sliding rheostat 51, which is fixedly connected to the mounting rod 53, can slide on the wire of the sliding rheostat 51. At this time, the resistance of the sliding rheostat 51 decreases, and the current received by the thermoelectric cooler 5 increases. As a result, the heat absorbed or released by the heat-absorbing end and the heat-releasing end of the thermoelectric cooler 5 increases. The heat released by the heat-releasing end of the thermoelectric cooler 5 can eventually be within the distillation temperature range required for acetophenone.

[0032] Furthermore, the heating mechanism also includes a spring 54 sleeved on the mounting rod 53. A baffle 55 is fixedly connected to one end of the mounting rod 53 away from the distillation tank 1. The two ends of the spring 54 are fixedly connected to the mounting frame 52 and the baffle 55, respectively.

[0033] The pressure that spring 54 can withstand is equivalent to the thrust generated by atmospheric pressure on mounting rod 53 when the pressure inside distillation tank 1 is around 2133 Pa. That is, when the pressure inside distillation tank 1 reaches around 2133 Pa, spring 54 is just fully compressed and the baffle 55 just squeezes the second pressure-sensitive switch 56. At this time, the pressure inside distillation tank 1 and the heat released by the heat-releasing end of semiconductor cooling chip 5 are exactly in line with the distillation conditions of acetophenone.

[0034] Furthermore, a first pipe 3 is fixedly connected to the distillation tank 1, and a second pipe 31 is fixedly connected inside the first pipe 3. Both the first pipe 3 and the second pipe 31 are connected to the distillation tank 1. A receiving box 33 for receiving acetophenone is installed at the end of the second pipe 31 away from the distillation tank 1. A receiving plate 34 is fixedly connected to the upper part of the receiving box 33. The opening at the end of the first pipe 3 away from the distillation tank 1 faces the receiving plate 34.

[0035] In the initial state, the solenoid valve 32 controls the second pipe 31 to be closed, that is, the second pipe 31 is not connected to the distillation tank 1, while the first pipe 3 is connected to the distillation tank 1. At this time, the resistance of the sliding rheostat 51 is relatively large, so the heat absorbed and dissipated by the heat-absorbing end and the heat-releasing end of the semiconductor refrigeration chip 5 is not high. That is, the heat generated by the heat-releasing end is within the range required for the distillation of benzene and diethyl ether. At this time, benzene and diethyl ether are first separated from the solution. The evaporated benzene and diethyl ether are discharged through the first pipe 3. The heat-absorbing end of the semiconductor refrigeration chip 5 is located at the first pipe 3. Then, the evaporated benzene and diethyl ether can be condensed when passing through the heat-absorbing end of the semiconductor refrigeration chip 5. The condensed benzene and diethyl ether and other impurities are discharged through the first pipe 3 to the receiving plate 34, and then flow out through the receiving plate 34. At this time, benzene and diethyl ether can be received at the receiving plate 34.

[0036] Furthermore, a visual sensor 35 for monitoring the amount of material discharged from the first pipe 3 is fixedly connected to the receiving box 33.

[0037] The vision sensor 35 monitors the benzene and ether droplets discharged from the first pipe 3. When the benzene and ether droplets are no longer discharged from the first pipe 3 for a period of time, it indicates that the benzene and ether contained in the solution in the distillation tank 1 have been completely separated. At this time, the vision sensor 35 will control the electric slide 41 to slide.

[0038] Example 2

[0039] Reference Figure 2 , Figure 3 , Figure 4 and Figure 6 Based on Embodiment 1, the pressure reduction mechanism further includes a negative pressure fan 42, a mounting platform 4 is fixedly connected to the top of the distillation tank 1, an electric slide 41 controlled by a vision sensor 35 is slidably connected to the mounting platform 4, the negative pressure fan 42 is fixedly connected to the electric slide 41, a first bevel gear 23 is fixedly connected to the top of the rotating shaft 21, a second bevel gear 43 is fixedly connected to the drive shaft of the negative pressure fan 42, and the second bevel gear 43 intermittently meshes with the first bevel gear 23.

[0040] The electric slide 41 slides towards the first bevel gear 23, and the negative pressure fan 42, which is fixedly connected to the electric slide 41, moves synchronously towards the first bevel gear 23 with the electric slide 41. This causes the second bevel gear 43 on the drive shaft of the negative pressure fan 42 to mesh with the first bevel gear 23. Since the motor 2 is in working condition at this time, and the first bevel gear 23 is fixedly connected to the rotating shaft 21 on the motor 2, the rotating first bevel gear 23 can drive the second bevel gear 43 to rotate, and the negative pressure fan 42 starts at this time.

[0041] Furthermore, the pressure reducing mechanism also includes an extraction pipe 44 fixedly connected to the negative pressure fan 42. One end of the extraction pipe 44 away from the negative pressure fan 42 is connected to the distillation tank 1, and a one-way valve 45 is provided on the extraction pipe 44.

[0042] When the first bevel gear 23 and the second bevel gear 43 mesh, the electric slide 41 simultaneously contacts the first pressure-sensitive switch 47 on the L-shaped frame 46 and squeezes the first pressure-sensitive switch 47. At this time, the solenoid valve 32 controlled by the first pressure-sensitive switch 47 operates and interrupts the connection between the first pipe 3 and the distillation tank 1. The second pipe 31 is in a connected state with the distillation tank 1, and the receiving box 33 installed on the second pipe 31 is also in a sealed state. Thus, when the negative pressure fan 42 is running, it can evacuate the distillation tank 1 through the suction pipe 44, thereby reducing the internal pressure of the distillation tank 1. When the baffle 55 squeezes the second pressure-sensitive switch 56, the electric slide 41 controlled by the second pressure-sensitive switch 56 will slide away from the first bevel gear 23. At this time, the second bevel gear 43 no longer meshes with the first bevel gear 23, and the negative pressure fan 42 stops working. Due to the setting of the one-way valve 45 on the suction pipe 44, the external air will not enter the distillation tank 1 through the suction pipe 44 under atmospheric pressure.

[0043] Furthermore, the first pipe 3 has a through hole adapted to the heat-absorbing end of the semiconductor refrigeration chip 5, and the second pipe 31 is attached to the heat-absorbing end of the semiconductor refrigeration chip 5.

[0044] The evaporated benzene and ether are discharged through the first pipe 3. The heat-absorbing end of the semiconductor refrigeration chip 5 is located at the first pipe 3, so the evaporated benzene and ether can condense when passing through the heat-absorbing end of the semiconductor refrigeration chip 5. The condensed benzene and ether and other impurities are discharged through the first pipe 3 to the receiving tray 34 and then flow out through the receiving tray 34. At this time, the benzene and ether can be collected at the receiving tray 34. After the acetophenone evaporates, it enters the second pipe 31. When the vapor of acetophenone passes through the heat-absorbing end of the semiconductor refrigeration chip 5, it will condense and drip into the receiving box 33 for collection.

[0045] Furthermore, a solenoid valve 32 is provided on both the first pipe 3 and the second pipe 31. An L-shaped frame 46 is fixedly connected to the mounting platform 4. A first pressure-sensitive switch 47 for controlling the solenoid valve 32 is fixedly connected to the L-shaped frame 46. The electric slide table 41 and the first pressure-sensitive switch 47 are intermittently abutted against each other.

[0046] When the first bevel gear 23 and the second bevel gear 43 mesh, the electric slide 41 simultaneously contacts the first pressure-sensitive switch 47 on the L-shaped frame 46 and squeezes the first pressure-sensitive switch 47. At this time, the solenoid valve 32 controlled by the first pressure-sensitive switch 47 runs and interrupts the connection between the first pipe 3 and the distillation tank 1. The second pipe 31 is connected to the distillation tank 1, and the receiving box 33 installed on the second pipe 31 is also in a sealed state. Thus, when the negative pressure fan 42 is running, it can evacuate the distillation tank 1 through the suction pipe 44, thereby reducing the internal pressure of the distillation tank 1.

[0047] Furthermore, the mounting bracket 52 is provided with a second pressure-sensitive switch 56 for controlling the electric slide 41. The baffle 55 intermittently abuts against the second pressure-sensitive switch 56, and the electric slide 41 is controlled by the second pressure-sensitive switch 56 with higher priority than the vision sensor 35.

[0048] When the pressure inside the distillation tank 1 decreases, under the action of atmospheric pressure, the mounting rod 53 overcomes the elastic force of the spring 54 and slides into the interior of the distillation tank 1. At this time, the slider of the sliding rheostat 51, which is fixedly connected to the mounting rod 53, can slide on the wire of the sliding rheostat 51. The resistance of the sliding rheostat 51 decreases, and the current received by the thermoelectric cooler 5 increases. Consequently, the heat absorbed or released by the heat-absorbing and heat-releasing ends of the thermoelectric cooler 5 increases. The heat released by the heat-releasing end of the thermoelectric cooler 5 ultimately reaches the distillation temperature range required for acetophenone. The spring 54's... The pressure it can withstand is equivalent to the thrust generated by atmospheric pressure on the mounting rod 53 when the pressure inside the distillation tank 1 is around 2133 Pa. That is, when the pressure inside the distillation tank 1 reaches around 2133 Pa, the spring 54 is just fully compressed, and the baffle 55 just squeezes the second pressure-sensitive switch 56. At this time, the pressure inside the distillation tank 1 and the heat released by the heat-releasing end of the semiconductor refrigeration chip 5 are exactly in line with the distillation conditions of acetophenone. After the acetophenone evaporates, it enters the second pipe 31. When the vapor of acetophenone passes through the heat-absorbing end of the semiconductor refrigeration chip 5, it will condense and drip into the receiving box 33 for collection.

[0049] Working principle: When using this acetophenone distillation device, valve 12 is opened and the solution is added to the distillation tank 1 through the feed pipe 11 to a suitable amount. After the solution is added, valve 12 is closed and the semiconductor cooling chip 5 is energized. The heat-releasing end of the semiconductor cooling chip 5 is located inside the distillation tank 1, which can heat the solution in the distillation tank 1, causing the solution added in the distillation tank 1 to evaporate. At the same time, the motor 2 is started, causing the rotating shaft 21 fixedly connected to the output end of the motor 2 to rotate. The stirring rod 22 fixedly connected to the rotating shaft 21 can stir the solution in the distillation tank 1, making the solution in the distillation tank 1 homogenized. At the same time, the stirring of the solution in the distillation tank 1 by the stirring rod 22 also makes the solution in the distillation tank 1 more evenly heated.

[0050] In the initial state, the solenoid valve 32 controls the second pipe 31 to be closed, that is, the second pipe 31 is not connected to the distillation tank 1, while the first pipe 3 is connected to the distillation tank 1. At this time, the resistance of the sliding rheostat 51 is relatively large, so the heat absorbed and dissipated by the heat-absorbing end and the heat-releasing end of the semiconductor cooling chip 5 is not high. That is, the heat generated by the heat-releasing end is within the range required for the distillation of benzene and diethyl ether. At this time, benzene and diethyl ether are first separated from the solution. The evaporated benzene and diethyl ether are discharged through the first pipe 3. The heat-absorbing end of the semiconductor cooling chip 5 is located at the first pipe 3. Then, the evaporated benzene and diethyl ether can be condensed when passing through the heat-absorbing end of the semiconductor cooling chip 5. The condensed benzene and diethyl ether and other impurities are discharged through the first pipe 3 to the receiving plate 34, and then flow out through the receiving plate 34. At this time, benzene and diethyl ether can be received at the receiving plate 34.

[0051] The vision sensor 35 monitors the benzene and ether droplets discharged from the first pipe 3. When the first pipe 3 stops discharging benzene and ether droplets for a period of time, it indicates that the benzene and ether in the solution in the distillation tank 1 have been completely separated. At this time, the vision sensor 35 controls the electric slide 41 to slide, causing the electric slide 41 to slide towards the first bevel gear 23. Then, the negative pressure fan 42, which is fixedly connected to the electric slide 41, can move synchronously with the electric slide 41 towards the first bevel gear 23, thereby causing the second bevel gear 43 on the drive shaft of the negative pressure fan 42 to mesh with the first bevel gear 23. Since the motor 2 is in working condition at this time, and the first bevel gear 23 is fixedly connected to the motor 2... On the rotating shaft 21, the first bevel gear 23, which is in a rotating state, can drive the second bevel gear 43 to rotate. At this time, the negative pressure fan 42 starts. When the first bevel gear 23 and the second bevel gear 43 mesh, the electric slide table 41 simultaneously contacts the first pressure-sensitive switch 47 on the L-shaped frame 46 and squeezes the first pressure-sensitive switch 47. At this time, the solenoid valve 32 controlled by the first pressure-sensitive switch 47 runs and interrupts the connection between the first pipe 3 and the distillation tank 1. The second pipe 31 is connected to the distillation tank 1, and the receiving box 33 installed on the second pipe 31 is also in a sealed state. Thus, when the negative pressure fan 42 runs, it can evacuate the distillation tank 1 through the suction pipe 44, thereby reducing the internal pressure of the distillation tank 1.

[0052] When the pressure inside the distillation tank 1 decreases, under the action of atmospheric pressure, the mounting rod 53 overcomes the elastic force of the spring 54 and slides into the interior of the distillation tank 1. At this time, the slider of the sliding rheostat 51, which is fixedly connected to the mounting rod 53, can slide on the wire of the sliding rheostat 51. The resistance of the sliding rheostat 51 decreases, and the current received by the thermoelectric cooler 5 increases. Consequently, the heat absorbed or released by the heat-absorbing and heat-releasing ends of the thermoelectric cooler 5 increases. The heat released by the heat-releasing end of the thermoelectric cooler 5 ultimately reaches the distillation temperature range required for acetophenone. The spring 54's... The pressure that can withstand is the thrust generated by atmospheric pressure on the mounting rod 53 when the pressure inside the distillation tank 1 is around 2133 Pa. That is, when the pressure inside the distillation tank 1 reaches around 2133 Pa, the spring 54 is just fully compressed and the baffle 55 just squeezes the second pressure-sensitive switch 56. At this time, the pressure inside the distillation tank 1 and the heat released by the heat-releasing end of the semiconductor refrigeration chip 5 are exactly in line with the distillation conditions of acetophenone. After the acetophenone evaporates, it enters the second pipe 31. When the vapor of acetophenone passes through the heat-absorbing end of the semiconductor refrigeration chip 5, it will condense and drip into the receiving box 33 for collection.

[0053] The distillation of acetophenone and the distillation of benzene and diethyl ether are discharged through the second pipe 31 and the first pipe 3 respectively, which can ensure that acetophenone is not mixed with benzene and diethyl ether. At the same time, the second pipe 31 is set in the first pipe 3 and a semiconductor cooling chip 5 is used for cooling and condensation, which can save the amount of condenser used and thus save electricity.

[0054] When the baffle 55 presses the second pressure-sensitive switch 56, the electric slide 41 controlled by the second pressure-sensitive switch 56 will slide away from the first bevel gear 23. At this time, the second bevel gear 43 will no longer mesh with the first bevel gear 23, and the negative pressure fan 42 will stop working. Due to the setting of the one-way valve 45 on the exhaust pipe 44, the outside air will not enter the distillation tank 1 through the exhaust pipe 44 under atmospheric pressure.

[0055] In actual use, a weight plate is placed at the bottom of the receiving box 33 to detect the weight of the receiving box 33. When the weight of the receiving box 33 no longer increases, it indicates that the distillation of acetophenone is complete. At this time, the operation of motor 2 can be stopped. The negative pressure in the distillation tank 1 can be released by opening valve 12 or by removing the receiving box 33 from the second pipe 31. After the negative pressure in the distillation tank 1 is released, the mounting rod 53 can return to its original position under the action of spring 54. When the next distillation is performed, the first pressure-sensitive switch 47 is pressed manually, so that the solenoid valve 32 controls the first pipe 3 to connect with the distillation tank 1 while the second pipe 31 is no longer connected to the distillation tank 1.

[0056] 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 distillation apparatus for acetophenone, comprising a distillation tank (1), characterized in that: A feeding pipe (11) is fixedly connected to the distillation tank (1), and a valve (12) is provided on the feeding pipe (11). A base (13) is fixedly connected to the bottom of the distillation tank (1), and a motor (2) is fixedly connected to the base (13). A rotating shaft (21) is fixedly connected to the output end of the motor (2), and a stirring rod (22) is fixedly connected to the rotating shaft (21). The stirring rod (22) is rotatably connected inside the distillation tank (1). A pressure reducing mechanism for reducing the pressure inside the distillation tank (1) is provided at the top of the distillation tank (1). A heating mechanism for dynamically heating the solution inside the distillation tank (1) is fixedly connected to the distillation tank (1). The heating mechanism includes a semiconductor cooling chip (5) and a sliding rheostat (51) electrically connected in series with the semiconductor cooling chip (5). The heating mechanism also includes a mounting bracket (52), which is fixedly connected to the outer wall of the distillation tank (1). A mounting rod (53) is slidably connected to the mounting bracket (52). A through hole that cooperates with the mounting rod (53) is opened on the distillation tank (1). The slider of the sliding rheostat (51) is fixedly connected to the mounting rod (53). The semiconductor cooling chip (5) is fixedly connected to the distillation tank (1), and the heat-releasing end of the semiconductor cooling chip (5) penetrates the tank wall of the distillation tank (1) and extends into the interior of the distillation tank (1). The heating mechanism also includes a spring (54) sleeved on the mounting rod (53). A baffle (55) is fixedly connected to one end of the mounting rod (53) away from the distillation tank (1). The two ends of the spring (54) are fixedly connected to the mounting frame (52) and the baffle (55) respectively.

2. The acetophenone distillation apparatus according to claim 1, characterized in that: A first pipe (3) is fixedly connected to the distillation tank (1), and a second pipe (31) is fixedly connected inside the first pipe (3). Both the first pipe (3) and the second pipe (31) are connected to the distillation tank (1). A receiving box (33) for receiving acetophenone is installed at the end of the second pipe (31) away from the distillation tank (1). A receiving plate (34) is fixedly connected to the upper part of the receiving box (33). The opening at the end of the first pipe (3) away from the distillation tank (1) faces the receiving plate (34). A solenoid valve (32) is provided on both the first pipe (3) and the second pipe (31).

3. The acetophenone distillation apparatus according to claim 2, characterized in that: A visual sensor (35) for monitoring the amount of material discharged from the first pipe (3) is fixedly connected to the receiving box (33).

4. The acetophenone distillation apparatus according to claim 1 or 3, characterized in that: The pressure reduction mechanism includes a negative pressure fan (42), a mounting platform (4) is fixedly connected to the top of the distillation tank (1), an electric slide (41) controlled by a vision sensor (35) is slidably connected to the mounting platform (4), the negative pressure fan (42) is fixedly connected to the electric slide (41), a first bevel gear (23) is fixedly connected to the top of the rotating shaft (21), a second bevel gear (43) is fixedly connected to the drive shaft of the negative pressure fan (42), and the second bevel gear (43) and the first bevel gear (23) mesh intermittently.

5. The acetophenone distillation apparatus according to claim 4, characterized in that: The pressure reducing mechanism also includes an extraction pipe (44) fixedly connected to the negative pressure fan (42). The end of the extraction pipe (44) away from the negative pressure fan (42) is connected to the distillation tank (1). A one-way valve (45) is provided on the extraction pipe (44).

6. The acetophenone distillation apparatus according to claim 2, characterized in that: The first pipe (3) has a through hole adapted to the heat-absorbing end of the semiconductor refrigeration chip (5), and the second pipe (31) is attached to the heat-absorbing end of the semiconductor refrigeration chip (5).

7. The acetophenone distillation apparatus according to claim 4, characterized in that: An L-shaped frame (46) is fixedly connected to the mounting platform (4), and a first pressure-sensitive switch (47) is fixedly connected to the L-shaped frame (46). The electric slide (41) and the first pressure-sensitive switch (47) are intermittently abutted against each other.

8. The acetophenone distillation apparatus according to claim 4, characterized in that: The mounting bracket (52) is provided with a second pressure-sensitive switch (56) for controlling the electric slide (41). The baffle (55) intermittently abuts against the second pressure-sensitive switch (56). The electric slide (41) is controlled by the second pressure-sensitive switch (56) with a higher priority than the vision sensor (35).

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