Distillation device for preparing glutaraldehyde by pyrane method

Abstract

The present invention relates to the field of glutaraldehyde production, and discloses a distillation apparatus for preparing glutaraldehyde by a pyrane method, the distillation apparatus comprises a kettle body, a separation plate arranged in the middle of the kettle body and a plurality of gas guide holes formed in the middle of the separation plate, and the bottom of the kettle body is provided with a liquid inlet pipe and a first liquid discharge pipe in a communicating manner; a second liquid discharge pipe is arranged in the middle of the kettle body in a communicating manner, the horizontal plane of the bottom of the second liquid discharge pipe is higher than that of the bottom of the partition plate, an exhaust pipe is arranged at the top of the kettle body, and a heating jacket is arranged at the bottom of the kettle body. A stirring mechanism is arranged in the middle of the kettle body; the method has the effect of simplifying the glutaraldehyde purification process.

Description

Technical Field

[0001] The invention relates to the technical field of glutaraldehyde production, in particular to a distillation device for preparing glutaraldehyde by a pyran process. Background Art

[0002] Glutaraldehyde solution is a very important fine chemical product, and its application is very extensive. The synthetic method of glutaraldehyde includes oxidation method, pyridine method, pyran method, etc. The oxidation method uses cyclopentene as raw material and hydrolyzes and opens the ring to prepare glutaraldehyde after low-temperature ozone oxidation or H2O2 oxidation; the pyridine method uses pyridine as raw material and is reduced by metallic sodium, and hydrochloric acid hydroxylamine is opened and then decomposed to prepare glutaraldehyde; the pyran method uses pyrans to hydrolyze under certain conditions to prepare glutaraldehyde. Because the pyran method is relatively simple in process, easy to operate, and has high yield, it is the most important method for industrial production of glutaraldehyde so far.

[0003] During the hydrolysis of pyran to produce glutaraldehyde, methanol is produced. Therefore, the hydrolyzed material is usually directly distilled to separate methanol, thereby obtaining a glutaraldehyde product with higher purity. However, the glutaraldehyde product prepared in this way still contains some by-products, which need to be further separated, resulting in a more complicated process. Summary of the invention

[0004] The invention aims to provide a distillation device for preparing glutaraldehyde by pyran process, which has the effect of simplifying the glutaraldehyde purification process.

[0005] The above technical objectives of the present invention are achieved through the following technical solutions: comprising a kettle, a partition disposed in the middle of the kettle, and a plurality of air guide holes opened in the middle of the partition, the bottom of the kettle is connected with a liquid inlet pipe and a first liquid discharge pipe, the middle of the kettle is connected with a second liquid discharge pipe, the bottom of the second liquid discharge pipe is located at a higher level than the bottom of the partition, the top of the kettle is provided with an exhaust pipe, the bottom of the kettle is provided with a heating jacket, and a stirring mechanism is provided in the middle of the kettle.

[0006] By adopting the above technical scheme, when glutaraldehyde needs to be purified, the glutaraldehyde reaction liquid (hereinafter referred to as the reaction liquid) is introduced into the kettle body from the liquid inlet pipe, and the heating jacket and the stirring mechanism are turned on at the same time. The reaction liquid at the bottom of the kettle body is heated by the heating jacket, and the reaction liquid is stirred by the stirring mechanism, so that the reaction liquid can be heated evenly, so that the temperature of the reaction liquid reaches a temperature higher than the boiling point of glutaraldehyde, and glutaraldehyde and methanol are evaporated from the reaction liquid, and then enter the top of the partition through the air guide hole. Since the space above the partition can only exchange heat from the bottom of the kettle body through the partition, the temperature of the space above the partition is lower than the boiling point of glutaraldehyde, but the temperature above the partition is controlled to be higher than the boiling point of methanol by controlling the heating temperature of the heating jacket (the boiling point of glutaraldehyde is 101°C, and the boiling point of methanol is 101°C). The boiling point of alcohol is 64.7°C), so after the vapors of glutaraldehyde and methanol enter the upper part of the partition, the glutaraldehyde is liquefied into liquid, the methanol is still in gaseous state and is discharged from the exhaust pipe, and the glutaraldehyde is subsequently discharged from the second liquid discharge pipe; therefore, by arranging the partition, the air guide hole and the stirring mechanism, the kettle body is divided into two upper and lower parts, the temperature of the bottom of the kettle body is made higher than the boiling point of glutaraldehyde by the heating jacket, and then the temperature above the partition is made between the boiling point of glutaraldehyde and the boiling point of methanol by the heat conduction of the partition and the heat absorption during the evaporation of glutaraldehyde and methanol, so that the glutaraldehyde can be liquefied and separated from the methanol after the vapors of glutaraldehyde and methanol enter the upper part of the partition, so that the purification of glutaraldehyde is achieved through one kettle body, and glutaraldehyde is separated from methanol and reaction by-products, thereby simplifying the purification process of glutaraldehyde and improving production efficiency.

[0007] The present invention is further configured as follows: the stirring mechanism comprises a stirring shaft rotatably arranged on the kettle body and a plurality of first stirring blades arranged at the bottom of the stirring shaft, and a reduction motor for driving the stirring shaft is arranged at the top of the kettle body.

[0008] By adopting the above technical solution, the reduction motor is turned on during distillation to drive the stirring shaft and the first stirring blade to rotate, stir the reaction liquid at the bottom of the kettle body, and increase the heating rate of the reaction liquid.

[0009] The present invention is further configured as follows: a heating oil pipe connected to the heating jacket is provided in the middle rotation of the kettle body, the stirring shaft sleeve is provided on the outside of the heating oil pipe, a first heating branch pipe connected to the heating oil pipe is provided inside the first stirring blade, a suction pump connected to the heating oil pipe is provided on the top of the kettle body, a reflux pipe connected to the heating jacket is provided on the suction pump, and the reflux pipe is located on the outside of the kettle body.

[0010] By adopting the above technical solution, when distillation is carried out, the reduction motor and the suction pump are turned on, and the suction pump sucks the hot oil in the heating jacket through the heating oil pipe, the first heating branch pipe and the reflux pipe in sequence. At the same time, the rotating shaft drives the heating oil pipe and the first heating branch pipe to rotate synchronously through the first stirring blade. During the rotation, the first heating branch pipe heats the reaction liquid through the first stirring blade, thereby further improving the heating efficiency of the reaction liquid. At the same time, the reaction liquid in the middle of the kettle body can be fully heated, so that glutaraldehyde and methanol in the reaction liquid can be fully distilled out, thereby improving the efficiency of distillation.

[0011] The present invention is further configured as follows: a first gear is disposed on the top of the stirring shaft, and a second gear meshing with the first gear is disposed at the output end of the reduction motor.

[0012] By adopting the above technical solution, a first gear and a second gear are provided, and the reduction motor drives the rotating shaft to rotate through the second gear and the first gear.

[0013] The present invention is further configured as follows: a plurality of second stirring blades are arranged on the stirring shaft, a set distance is provided between the bottom end of the second stirring blade and the top end of the partition, and a second heating branch pipe connected to the heating oil pipe is arranged inside the second stirring blade.

[0014] By adopting the above technical solution, a second stirring blade and a second heating branch pipe are provided, so that the hot oil passes through the second heating branch pipe after passing through the first heating branch pipe to heat the space above the partition. Since the hot oil exchanges heat with the reaction liquid during the process of passing through the first heating branch pipe, there is heat loss. While the second heating branch pipe and the second stirring blade are used to heat the space above the partition, the temperature above the partition is controlled within a suitable range. In addition, the rotating second stirring blade can contact the glutaraldehyde and methanol vapors coming out of the air guide holes from all directions, so that the glutaraldehyde vapor is cooled and liquefied after contacting the second stirring blade, thereby promoting the separation of glutaraldehyde and methanol and improving the efficiency of glutaraldehyde purification.

[0015] The present invention is further configured as follows: the partition includes a first annular sub-plate and a second truncated cone-shaped sub-plate, and the air guide hole is located at the top of the second sub-plate.

[0016] The present invention is further configured as follows: a cover plate is horizontally arranged at the top end of the second sub-plate, the cover plate can be movably fitted to the air guide hole, and the rotating shaft movably passes through the cover plate and the second sub-plate.

[0017] By adopting the above technical solution, the partition is set to two parts, namely the first partition plate and the second partition plate, so that the evaporated glutaraldehyde and methanol vapor are concentrated below the second partition plate, and then the cover plate is pushed up to allow the vapor to enter the top of the second partition plate through the air guide hole. Thereafter, the vapor entering the top of the second partition plate contacts the rotating second stirring blade, and the glutaraldehyde flows from the second partition plate to the first partition plate after cooling, and then flows out from the second drain pipe; therefore, the partition is set to have a second partition plate and a first partition plate with a certain height difference, and a cover plate is provided, so that the liquefied glutaraldehyde can flow from the cover plate and the second partition plate to the first partition plate, thereby preventing the liquefied glutaraldehyde from entering the bottom of the partition through the air guide hole and affecting the purification efficiency of the glutaraldehyde.

[0018] A further configuration of the present invention is that the partition is made of a thermal insulation material.

[0019] By adopting the above technical solution, the partition is made of a thermal insulation material to prevent the evaporated glutaraldehyde and methanol vapor from exchanging heat between the partition and the bottom of the partition, which may cause the partition temperature to be too high and cause the liquefied glutaraldehyde to evaporate again. Therefore, the partition is made of a thermal insulation material so that the top of the partition is heated by hot oil passing through the second heating branch pipe, so that the temperature above the partition can be accurately controlled.

[0020] The present invention is further configured as follows: a first temperature sensor and a second temperature sensor are provided in the kettle body, the first temperature sensor is located below the partition, and the second temperature sensor is located above the partition.

[0021] By adopting the above technical solution, a first temperature sensor and a second temperature sensor are set to perform real-time detection of the temperature above and below the partition. When the temperature above the partition is too low, the suction of the suction pump can be increased, thereby increasing the flow rate and rate of the hot oil passing through the second heating branch pipe to increase the temperature above the partition. When the temperature below the partition is too low, the temperature of the heating jacket can be increased while increasing the suction of the suction pump to increase the temperature below the partition. Therefore, by observing the temperature above and below the partition, it is convenient to timely regulate the temperature above and below the partition to ensure the purification efficiency of glutaraldehyde.

[0022] The present invention is further configured as follows: the second stirring blade can be movably fitted to the inner wall of the kettle body.

[0023] By adopting the above technical solution, the contact area between the second stirring blade and the glutaraldehyde and methanol vapor is increased, thereby ensuring that the glutaraldehyde vapor is completely liquefied after being cooled.

[0024] The beneficial effects of the present invention are:

[0025] 1. The kettle body is divided into an upper and lower part by arranging a partition, an air guide hole and a stirring mechanism, etc. The temperature of the bottom of the kettle body is made higher than the boiling point of glutaraldehyde by a heating jacket, and the temperature above the partition is made between the boiling point of glutaraldehyde and the boiling point of methanol by heat conduction of the partition and heat absorption during evaporation of glutaraldehyde and methanol, so that after the glutaraldehyde and methanol vapors enter the upper part of the partition, the glutaraldehyde can be liquefied and separated from the methanol, thereby achieving purification of glutaraldehyde through one kettle body, separating glutaraldehyde from methanol and reaction by-products, simplifying the purification process of glutaraldehyde and improving production efficiency.

[0026] 2. By setting a second stirring blade and a second heating branch pipe, the hot oil passes through the second heating branch pipe after passing through the first heating branch pipe to heat the space above the partition. Since the hot oil exchanges heat with the reaction liquid during the process of passing through the first heating branch pipe, there is heat loss. While the second heating branch pipe and the second stirring blade are used to heat the space above the partition, the temperature above the partition is controlled within a suitable range. In addition, the rotating second stirring blade can contact the glutaraldehyde and methanol vapors coming out of the air guide holes from all directions, so that the glutaraldehyde vapor is cooled and liquefied after contacting the second stirring blade, thereby promoting the separation of glutaraldehyde and methanol and improving the efficiency of glutaraldehyde purification.

[0027] 3. By setting the partition as a second sub-plate and a first sub-plate with a certain height difference and setting a cover plate, the liquefied glutaraldehyde can flow from the cover plate and the second sub-plate to the first sub-plate, thereby preventing the liquefied glutaraldehyde from entering the bottom of the partition through the air guide hole and affecting the purification efficiency of glutaraldehyde. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0029] Figure 1 It is a structural schematic diagram of an embodiment of a distillation device for preparing glutaraldehyde by a pyran process of the present invention;

[0030] Figure 2 It is a partial cross-sectional structural schematic diagram of an embodiment of a distillation device for preparing glutaraldehyde by a pyran process of the present invention;

[0031] Figure 3 yes Figure 2 A is an enlarged schematic diagram;

[0032] Figure 4 yes Figure 2 A magnified schematic diagram of B;

[0033] Figure 5 yes Figure 2 A magnified schematic diagram of C in the middle.

[0034] In the figure, 1, kettle body; 2, partition; 2a, first partition plate; 2b, second partition plate; 3, air guide hole; 4, liquid inlet pipe; 5, first liquid discharge pipe; 6, second liquid discharge pipe; 7, exhaust pipe; 8, heating jacket; 9, stirring mechanism; 9a, stirring shaft; 9b, first stirring blade; 10, reduction motor; 11, heating oil pipe; 12, first heating branch pipe; 13, suction pump; 14, reflux pipe; 15, first gear; 16, second gear; 17, second stirring blade; 18, second heating branch pipe; 19, cover plate; 20, first temperature sensor; 21, second temperature sensor. DETAILED DESCRIPTION

[0035] The technical solution of the present invention will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] The present invention provides a distillation device for preparing glutaraldehyde by pyran method, such as Figures 1 to 5 As shown, it comprises a kettle body 1, a partition 2 arranged in the middle of the kettle body 1, and a plurality of air guide holes 3 opened in the middle of the partition 2. The bottom of the kettle body 1 is connected with a liquid inlet pipe 4 and a first liquid discharge pipe 5. The middle of the kettle body 1 is connected with a second liquid discharge pipe 6. The horizontal plane of the bottom of the second liquid discharge pipe 6 is higher than the horizontal plane of the bottom of the partition 2. The top of the kettle body 1 is provided with an exhaust pipe 7. The bottom of the kettle body 1 is provided with a heating jacket 8. A stirring mechanism 9 is provided in the middle of the kettle body 1.

[0037] Furthermore, the stirring mechanism 9 includes a stirring shaft 9a rotatably arranged on the kettle body 1 and a plurality of first stirring blades 9b arranged at the bottom of the stirring shaft 9a. A reduction motor 10 for driving the stirring shaft 9a is arranged at the top of the kettle body 1.

[0038] Furthermore, a heating oil pipe 11 connected to the heating jacket 8 is provided in the middle of the kettle body 1, the stirring shaft 9a is sleeved on the outside of the heating oil pipe 11, and a first heating branch pipe 12 connected to the heating oil pipe 11 is provided inside the first stirring blade 9b. A suction pump 13 connected to the heating oil pipe 11 is provided on the top of the kettle body 1, and a reflux pipe 14 connected to the heating jacket 8 is provided on the suction pump 13, and the reflux pipe 14 is located on the outside of the kettle body 1.

[0039] Furthermore, a first gear 15 is disposed on the top of the stirring shaft 9 a , and a second gear 16 meshing with the first gear 15 is disposed on the output end of the reduction motor 10 .

[0040] Furthermore, a plurality of second stirring blades 17 are provided on the stirring shaft 9 a , a set distance is provided between the bottom end of the second stirring blade 17 and the top end of the partition 2 , and a second heating branch pipe 18 connected to the heating oil pipe 11 is provided inside the second stirring blade 17 .

[0041] Furthermore, the partition plate 2 includes a first annular sub-plate 2a and a truncated cone-shaped second sub-plate 2b, and the air guide hole 3 is located at the top of the second sub-plate 2b.

[0042] Furthermore, a cover plate 19 is horizontally disposed at the top of the second sub-plate 2b, and the cover plate 19 can be movably fitted to the air guide hole 3, and the rotation axis movably passes through the cover plate 19 and the second sub-plate 2b.

[0043] Furthermore, the partition 2 is made of thermal insulation material.

[0044] Furthermore, a first temperature sensor 20 and a second temperature sensor 21 are disposed in the kettle body 1 . The first temperature sensor 20 is located below the partition 2 , and the second temperature sensor 21 is located above the partition 2 .

[0045] Furthermore, the second stirring blade 17 can be movably fitted to the inner wall of the kettle body 1 .

[0046] When glutaraldehyde needs to be purified, the reaction liquid is introduced into the kettle body 1 from the liquid inlet pipe 4, and the heating jacket 8, the reduction motor 10 and the suction pump 13 are turned on at the same time. The reaction liquid at the bottom of the kettle body 1 is heated by the heating jacket 8, and the suction pump 13 sucks the hot oil so that the hot oil passes through the first heating branch pipe 12 and the second heating branch pipe 18 in sequence, and heats the upper and lower parts of the partition 2 respectively, so that the temperature below the partition 2 is higher than the boiling point of glutaraldehyde, and the temperature above the partition 2 is between the boiling point of glutaraldehyde and the boiling point of methanol. The boiling point can be adjusted by changing the heating temperature of the heating jacket 8 and adjusting the suction force of the suction pump 13. At the same time, the reduction motor 10 drives the stirring shaft 9a and the first stirring blade 9b to stir the reaction liquid, so that the reaction liquid can be heated evenly, so that the temperature of the reaction liquid can quickly reach a temperature higher than the boiling point of glutaraldehyde. Glutaraldehyde and methanol will evaporate from the reaction liquid, and then the cover plate 19 will be pushed to enter the upper part of the partition 2 through the air guide hole 3. After the steam of glutaraldehyde and methanol enters the upper part of the partition 2, the steam and the rotating The second stirring blade 17 contacts the glutaraldehyde to liquefy it into liquid, and the methanol is still in gaseous state and is discharged from the exhaust pipe 7. The glutaraldehyde flows from the second partition plate 2b to the first partition plate 2a and is discharged from the second liquid discharge pipe 6 (it should be noted that the liquid inlet pipe 4, the first liquid discharge pipe 5, the second liquid discharge pipe 6 and the exhaust pipe 7 are all provided with control valves, which are prior art, so a detailed description thereof will not affect the understanding of the technical scope actually protected by this scheme by those skilled in the art); therefore, by providing the partition plate 2, the air guide hole 3 and the stirring mechanism 9, etc., the kettle is The kettle body 1 is divided into two parts, the upper and lower parts. The temperature at the bottom of the kettle body 1 is made higher than the boiling point of glutaraldehyde by the heating jacket 8. Then, the temperature above the partition 2 is made between the boiling point of glutaraldehyde and the boiling point of methanol by the heat exchange of the second heating branch pipe 18 inside the second stirring blade 17. After the glutaraldehyde and methanol vapor enter the upper part of the partition 2, the glutaraldehyde can be liquefied and separated from the methanol. Thus, the purification of glutaraldehyde is achieved through the kettle body 1, and glutaraldehyde is separated from methanol and reaction by-products, thereby simplifying the purification process of glutaraldehyde and improving production efficiency.

[0047] When distillation is being carried out, the reduction motor 10 and the suction pump 13 are turned on, and the suction pump 13 sucks the hot oil in the heating jacket 8 through the heating oil pipe 11, the first heating branch pipe 12 and the reflux pipe 14 in sequence. At the same time, the rotating shaft drives the heating oil pipe 11 and the first heating branch pipe 12 to rotate synchronously through the first stirring blade 9b. During the rotation, the first heating branch pipe 12 heats the reaction liquid through the first stirring blade 9b, thereby further improving the heating efficiency of the reaction liquid. At the same time, the reaction liquid in the middle of the kettle body 1 can be fully heated, so that glutaraldehyde and methanol in the reaction liquid can be fully distilled out, thereby improving the efficiency of distillation.

[0048] By providing the first gear 15 and the second gear 16 , the reduction motor 10 drives the rotating shaft to rotate through the second gear 16 and the first gear 15 .

[0049] By arranging the second stirring blade 17 and the second heating branch pipe 18, the hot oil passes through the second heating branch pipe 18 after passing through the first heating branch pipe 12, and heats the space above the partition 2. Since the hot oil exchanges heat with the reaction liquid during passing through the first heating branch pipe 12, there is heat loss. While the second heating branch pipe 18 and the second stirring blade 17 are used to heat the space above the partition 2, the temperature above the partition 2 is controlled within a suitable range. In addition, the rotating second stirring blade 17 can contact the glutaraldehyde and methanol vapors coming out of the air guide hole 3 from all directions, so that the glutaraldehyde vapor is cooled and liquefied after contacting the second stirring blade 17, thereby promoting the separation of glutaraldehyde and methanol and improving the efficiency of glutaraldehyde purification.

[0050] By setting the partition 2 as two parts, namely, the first partition plate 2a and the second partition plate 2b, the evaporated glutaraldehyde and methanol vapor are concentrated to the bottom of the second partition plate 2b, and then the cover plate 19 is pushed up to allow the vapor to enter the top of the second partition plate 2b through the air guide hole 3. Thereafter, the vapor entering the top of the second partition plate 2b contacts the rotating second stirring blade 17, and the glutaraldehyde flows from the second partition plate 2b to the first partition plate 2a after cooling, and then flows out from the second drain pipe 6; therefore, the partition 2 is set as the second partition plate 2b and the first partition plate 2a with a certain height difference, and the cover plate 19 is set, so that the liquefied glutaraldehyde can flow from the cover plate 19 and the second partition plate 2b to the first partition plate 2a, thereby preventing the liquefied glutaraldehyde from entering the bottom of the partition 2 from the air guide hole 3, affecting the purification efficiency of the glutaraldehyde.

[0051] By setting the partition 2 to be made of thermal insulation material, it is prevented that the evaporated glutaraldehyde and methanol vapor perform heat exchange between the partition 2 and the bottom of the partition 2, resulting in the partition 2 temperature being too high, causing the liquefied glutaraldehyde to evaporate again. Therefore, the partition 2 is set to be made of thermal insulation material, so that the upper part of the partition 2 is heated by hot oil through the second heating branch pipe 18, so that the temperature above the partition 2 can be accurately controlled.

[0052] By setting the first temperature sensor 20 and the second temperature sensor 21, the temperature above and below the partition 2 is detected in real time. When the temperature above the partition 2 is too low, the suction of the suction pump 13 can be increased, thereby increasing the flow rate and rate of the hot oil passing through the second heating branch pipe 18 to increase the temperature above the partition 2. When the temperature below the partition 2 is too low, the temperature of the heating jacket 8 can be increased while increasing the suction of the suction pump 13 to increase the temperature below the partition 2. Therefore, by observing the temperature above and below the partition 2, it is convenient to timely regulate the temperature above and below the partition 2 to ensure the purification efficiency of glutaraldehyde.

[0053] By arranging the second stirring blade 17 to be movably attached to the inner wall of the kettle body 1 , the contact area between the second stirring blade 17 and the glutaraldehyde and methanol vapor is increased, thereby ensuring that the glutaraldehyde vapor is completely liquefied after being cooled.

[0054] It should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0055] The above description is only a description of the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention. Any changes or modifications made by a person skilled in the art in the field of the present invention based on the above disclosure shall fall within the scope of protection of the claims.

Claims

1. A distillation apparatus for preparing glutaraldehyde by a pyran process, characterized in that: The invention comprises a kettle body (1), a partition (2) arranged in the middle of the kettle body (1), and a plurality of air guide holes (3) opened in the middle of the partition (2); a liquid inlet pipe (4) and a first liquid discharge pipe (5) are arranged in communication at the bottom of the kettle body (1); a second liquid discharge pipe (6) is arranged in communication at the middle of the kettle body (1); the bottom of the second liquid discharge pipe (6) is located at a level higher than the bottom of the partition (2); an exhaust pipe (7) is arranged at the top of the kettle body (1); a heating jacket (8) is arranged at the bottom of the kettle body (1); and a stirring mechanism (9) is arranged in the middle of the kettle body (1).

2. A distillation apparatus for preparing glutaraldehyde by a pyran process according to claim 1, characterized in that: The stirring mechanism (9) comprises a stirring shaft (9a) rotatably arranged on the kettle body (1) and a plurality of first stirring blades (9b) arranged at the bottom of the stirring shaft (9a); a reduction motor (10) for driving the stirring shaft (9a) is arranged at the top of the kettle body (1).

3. A distillation apparatus for preparing glutaraldehyde by pyranization according to claim 2, characterized in that: A heating oil pipe (11) connected to the heating jacket (8) is provided in the middle of the kettle body (1); the stirring shaft (9a) is sleeved on the outside of the heating oil pipe (11); a first heating branch pipe (12) connected to the heating oil pipe (11) is provided inside the first stirring blade (9b); a suction pump (13) connected to the heating oil pipe (11) is provided on the top of the kettle body (1); a reflux pipe (14) connected to the heating jacket (8) is provided on the suction pump (13); and the reflux pipe (14) is located on the outside of the kettle body (1).

4. A distillation apparatus for preparing glutaraldehyde by pyran process according to claim 3, characterized in that: A first gear (15) is arranged at the top of the stirring shaft (9a), and a second gear (16) meshing with the first gear (15) is arranged at the output end of the reduction motor (10).

5. A distillation apparatus for preparing glutaraldehyde by a pyran process according to claim 3, characterized in that: A plurality of second stirring blades (17) are arranged on the stirring shaft (9a), a set distance is provided between the bottom end of the second stirring blade (17) and the top end of the partition (2), and a second heating branch pipe (18) connected to the heating oil pipe (11) is arranged inside the second stirring blade (17).

6. A distillation apparatus for preparing glutaraldehyde by a pyran process according to claim 2, characterized in that: The partition plate (2) comprises a first annular sub-plate (2a) and a truncated cone-shaped second sub-plate (2b), and the air guide hole (3) is located at the top end of the second sub-plate (2b).

7. A distillation apparatus for preparing glutaraldehyde by a pyran process according to claim 6, characterized in that: A cover plate (19) is horizontally arranged at the top end of the second split plate (2b); the cover plate (19) can be movably fitted to the air guide hole (3); and the rotation axis movably passes through the cover plate (19) and the second split plate (2b).

8. A distillation apparatus for preparing glutaraldehyde by a pyran process according to claim 5, characterized in that: The partition (2) is made of thermal insulation material.

9. A distillation apparatus for preparing glutaraldehyde by a pyran process according to claim 8, characterized in that: A first temperature sensor (20) and a second temperature sensor (21) are arranged in the kettle body (1); the first temperature sensor (20) is located below the partition (2), and the second temperature sensor (21) is located above the partition (2).

10. A distillation apparatus for preparing glutaraldehyde by pyran process according to claim 5, characterized in that: The second stirring blade (17) can be movably fitted to the inner wall of the kettle body (1).

Images