Low-backmixing dimethyl ketene dimerization continuous reactor

Abstract

The utility model relates to the technical field of chemical synthesis, and discloses a low-backmixing dimethyl ketene dimerization continuous reactor, which comprises a reaction kettle and a plurality of baffle plates arranged in the reaction kettle, the baffle plates divide the reaction kettle into a plurality of reaction chambers, stirring devices are arranged in the reaction chambers, each stirring device comprises a rotating shaft and a stirring paddle arranged on the rotating shaft, and the stirring paddles are arranged on the rotating shaft. The stirring paddle comprises a rotating disc and a plurality of stirring pieces arranged on the bottom surface of the rotating disc, windows and gaps are formed in the baffle plates, and the windows and the gaps of the adjacent baffle plates are arranged in a staggered manner; according to the reactor, the back-mixing effect of reaction liquid is remarkably reduced by arranging the baffle plates, the reaction conversion rate is remarkably improved, in addition, the problem of dead zones caused by arrangement of the baffle plates is reduced by arranging the stirring paddles, arranging the windows and the gaps on the baffle plates and arranging the windows and the gaps on the adjacent baffle plates in a staggered manner, and the reaction efficiency is improved. The reactor is a single reaction kettle, the occupied area is extremely small, and the equipment cost is low.

Description

Technical Field

[0001] The utility model relates to the technical field of chemical synthesis, in particular to a low-backmixing dimethylketene dimer continuous reactor. Background Art

[0002] 2,2,4,4-Tetramethyl-1,3-cyclobutanedione is an important chemical raw material for the copolyester monomer 2,2,4,4-tetramethyl-1,3-cyclobutanediol. In the method for preparing 2,2,4,4-tetramethyl-1,3-cyclobutanedione and its application disclosed in the prior art CN117342937A, it is pointed out that the production route of 2,2,4,4-tetramethyl-1,3-cyclobutanedione is based on isobutyric anhydride as the raw material, which generates dimethylketene through pyrolysis and then obtains the product through rapid cooling and dimerization reaction. Therefore, to improve the conversion rate of the reactants, the process of the above dimerization reaction needs to be optimized.

[0003] Currently, the optimization process for the above dimerization reaction is mainly carried out through chemical absorbents. In addition, through further research and analysis, it is found that the reason for the low conversion rate of the reactants in the above dimerization reaction is still that there is a serious backmixing effect when the above secondary reaction is carried out in a single stirred tank. The backmixing effect leads to a decrease in the raw material concentration and a decrease in the conversion rate of the product. Therefore, in order to solve the problem of large backmixing in the single reaction kettle, a tubular reactor is usually used in the prior art. However, the tubular reactor is long and occupies a large area. Therefore, a dimethylketene dimer continuous reactor with a small floor area and a low backmixing effect needs to be provided. Summary of the Utility Model

[0004] In order to overcome the problem of low reaction conversion rate caused by large backmixing in the dimethylketene dimer continuous reactor in the prior art, the utility model provides a low-backmixing dimethylketene dimer continuous reactor. The reactor significantly reduces the backmixing effect of the reaction liquid by setting baffle plates, significantly improves the reaction conversion rate. In addition, the reactor reduces the dead zone problem caused by setting baffle plates by setting stirring paddles, setting windows and gaps on the baffle plates, and staggering the windows and gaps on adjacent baffle plates, ensuring the efficient conversion of the reaction. The reactor has a very small floor area for a single reaction kettle and low equipment cost.

[0005] The specific technical solution of the utility model is as follows:

[0006] A low-backmixing dimethylketene dimer continuous reactor, comprising a reaction kettle and a plurality of baffle plates arranged in the reaction kettle. The baffle plates divide the reaction kettle into a plurality of reaction chambers. A stirring device is arranged in the reaction chamber. The stirring device includes a rotating shaft and stirring paddles arranged on the rotating shaft. The stirring paddle includes a rotating disc and a plurality of blades arranged on the bottom surface of the rotating disc. Windows and gaps are arranged on the baffle plates, and the windows and gaps on adjacent baffle plates are staggered.

[0007] The utility model provides a low backmixing dimethylketene dimer continuous reactor, which is a single reaction kettle with a small floor area and low equipment cost. There are several baffle plates in the reactor. The baffle plates divide the reaction kettle into several reaction chambers. Through the baffle plates, the backmixing effect of the reaction liquid in each reaction chamber can be significantly reduced, and the raw materials in the front reaction chamber and the products in the end reaction chamber will not contact each other in the reaction chambers between the front and the end, thus significantly improving the conversion rate of the reaction products.

[0008] In addition, the utility model finds that if one end of the baffle is directly closed after the baffle is set, dead zones will appear in the reaction chamber, that is, areas where the flow rate is slow and close to zero will appear. The appearance of these areas will lead to a decrease in the local concentration update rate and also lead to a decrease in the reaction rate. Therefore, in order to avoid the above dead zones, the utility model sets windows and gaps on the baffle plates to accelerate the liquid flow rate in the dead zones through the windows and gaps. The utility model also optimizes the stirring paddle, and sets paddles on the disc of the stirring paddle to increase the horizontal liquid flow exchange in the reaction chamber, improve the liquid update rate in the whole liquid reaction area, and increase the conversion rate of the reaction products.

[0009] Preferably, the number of the reaction chambers is preferably 5.

[0010] Preferably, the volume of the reaction chamber is 1.4 - 4.3m 3 .

[0011] The optimal number of reaction chambers of the utility model is 5. Compared with 4 and 6 reaction chambers, the conversion rate of the reactants in 5 reaction chambers is the highest and the equipment utilization rate is the highest. The conversion rate of the reactants in 4 reaction chambers is relatively low, while the conversion rate of the reactants in 6 reaction chambers is not much different from that in 5 reaction chambers, but the equipment cost is high and the equipment utilization rate is low.

[0012] Preferably, a heat exchange coil is also arranged in the reaction chamber, and the rapid heating and rapid cooling of the dimerization reaction are realized by arranging the heat exchange coil.

[0013] Preferably, a number of circulation holes are also arranged on the turntable, and the liquid above and below the turntable circulates through the arrangement of the circulation holes, increasing the longitudinal liquid update exchange in the reaction chamber.

[0014] Preferably, the aperture of the circulation hole is 1 - 10mm.

[0015] Preferably, a liquid inlet, a gas inlet, a liquid outlet and a bottom valve are arranged on the reaction kettle.

[0016] Preferably, the reaction kettle is a horizontal reaction kettle.

[0017] Preferably, the distance between the upper edge and the lower edge of the window is 10 - 500 mm.

[0018] Preferably, the distance between the upper edge and the lower edge of the gap is 1 - 10 mm.

[0019] Compared with the prior art, the present application has the following technical effects:

[0020] A low backmixing dimethylketene dimer continuous reactor is provided. By arranging baffle plates, the backmixing effect of the reaction liquid is significantly reduced, and the reaction conversion rate is significantly improved. In addition, by arranging stirring paddles, setting windows and gaps on the baffle plates, and staggering the windows and gaps on adjacent baffle plates, the dead zone problem caused by the arrangement of baffle plates is reduced, ensuring the efficient conversion of the reaction. The reactor has a very small floor area for a single reaction kettle and low equipment costs. Description of the Drawings

[0021] Figure 1 It is a sectional view of the present utility model.

[0022] Figure 2 It is a top view of the stirring paddle of the present utility model.

[0023] Figure 3 It is a bottom view of the stirring paddle of the present utility model.

[0024] In the figure, there are reaction kettle 1, liquid inlet 101, gas inlet 102, liquid outlet 103, bottom valve 104, baffle plate 2, window 201, gap 202, reaction chamber 3, first reaction chamber 301, second reaction chamber 302, third reaction chamber 303, fourth reaction chamber 304, fifth reaction chamber 305, stirring device 4, stirring paddle 401, turntable 411, paddle 412, circulation hole 413 and heat exchange coil 5. Detailed Embodiments

[0025] The present utility model will be further described below in conjunction with embodiments.

[0026] Embodiment 1:

[0027] As Figure 1As shown in the figure, a low backmixing dimethylketene dimer continuous reactor includes a horizontal reaction kettle 1. The surface of the reaction kettle is provided with a liquid inlet 101, a gas inlet 102, a liquid outlet 103 and two bottom valves 104. The liquid inlet is located on the side of the front end of the reaction kettle, the gas inlet is located on the top surface of the horizontal reaction kettle, the liquid outlet hole is located at the end of the reaction kettle, and the two bottom valves are located on the bottom surface of the reaction kettle. Four baffle plates 2 are arranged inside. The baffle plates are fixedly connected to the inner wall of the horizontal reaction kettle. The baffle plates are provided with windows 201 and gaps 202. The distance between the upper edge and the lower edge of the window is 200 mm, and the distance between the upper edge and the lower edge of the gap is 6 mm. The baffle plates divide the reaction kettle into five reaction chambers 3. The volumes of the first reaction chamber 301, the second reaction chamber 302, the third reaction chamber 303, the fourth reaction chamber 304 and the fifth reaction chamber 305 are all 2.0 m 3 , and a stirring device 4 and a heat exchange coil 5 are arranged in each reaction chamber. The stirring device includes a rotating shaft and two parallel stirring paddles 401 sleeved on the rotating shaft;

[0028] As Figure 2 and Figure 3 shown, the stirring paddle includes a turntable 411 and six blades 412 arranged along the outer circumference of the bottom surface of the turntable. A number of circulation holes are also arranged on the turntable, and the aperture of the circulation holes is 4 mm.

[0029] Example 2:

[0030] As Figure 1 shown, a low backmixing dimethylketene dimer continuous reactor includes a horizontal reaction kettle 1. The surface of the reaction kettle is provided with a liquid inlet 101, a gas inlet 102, a liquid outlet 103 and two bottom valves 104. The liquid inlet is located on the side of the front end of the reaction kettle, the gas inlet is located on the top surface of the horizontal reaction kettle, the liquid outlet hole is located at the end of the reaction kettle, and the two bottom valves are located on the bottom surface of the reaction kettle. Four baffle plates 2 are arranged inside. The baffle plates are fixedly connected to the inner wall of the horizontal reaction kettle. The baffle plates are provided with windows 201 and gaps 202. The distance between the upper edge and the lower edge of the window is 200 mm, and the distance between the upper edge and the lower edge of the gap is 6 mm. The baffle plates divide the reaction kettle into five reaction chambers 3. The volume of the first reaction chamber 301 is 4.3 m 3 , and the volumes of the second reaction chamber 302, the third reaction chamber 303, the fourth reaction chamber 304 and the fifth reaction chamber 305 are all 1.4 m 3 , and a stirring device 4 and a heat exchange coil 5 are arranged in each reaction chamber. The stirring device includes a rotating shaft and two parallel stirring paddles 401 sleeved on the rotating shaft;

[0031] As Figure 2 and Figure 3 shown, the stirring paddle includes a turntable 411 and six blades 412 arranged along the outer circumference of the bottom surface of the turntable. A number of circulation holes are also arranged on the turntable, and the aperture of the circulation holes is 4 mm.

[0032] Example 3:

[0033] As Figure 1 shown, a low-backmixing dimethylketene dimer continuous reactor includes a horizontal reaction kettle 1. The surface of the reaction kettle is provided with a liquid inlet 101, a gas inlet 102, a liquid outlet 103 and two bottom valves 104. The liquid inlet is located on the side of the front end of the reaction kettle, the gas inlet is located on the top surface of the horizontal reaction kettle, the liquid outlet hole is located at the end of the reaction kettle, and the two bottom valves are located on the bottom surface of the reaction kettle. There are four baffle plates 2 inside, and the baffle plates are fixedly connected to the inner wall of the horizontal reaction kettle. The baffle plates are provided with windows 201 and gaps 202. The distance between the upper edge and the lower edge of the window is 200 mm, and the distance between the upper edge and the lower edge of the gap is 6 mm. The baffle plates divide the reaction kettle into five reaction chambers 3. The volumes of the first reaction chamber 301, the second reaction chamber 302, the third reaction chamber 303, and the fourth reaction chamber 304 are all 1.4 m 3 , and the volume of the fifth reaction chamber 305 is 4.3 m 3 . A stirring device 4 and a heat exchange coil 5 are provided in each reaction chamber. The stirring device includes a rotating shaft and two parallel stirring paddles 401 sleeved on the rotating shaft;

[0034] As Figure 2 and Figure 3 shown, the stirring paddle includes a turntable 411 and six blades 412 located on the bottom surface of the turntable and arranged circumferentially along the outer edge of the bottom surface of the turntable. A number of circulation holes are also provided on the turntable, and the aperture of the circulation holes is 4 mm.

[0035] Comparative Example 1:

[0036] Compared with Example 1, in Comparative Example 1, the reaction kettle is divided into four reaction chambers by baffle plates, and the other conditions are the same as those in Example 1. A low-backmixing dimethylketene dimer continuous reactor includes a horizontal reaction kettle 1. The surface of the reaction kettle is provided with a liquid inlet 101, a gas inlet 102, a liquid outlet 103 and two bottom valves 104. The liquid inlet is located on the side of the front end of the reaction kettle, the gas inlet is located on the top surface of the horizontal reaction kettle, the liquid outlet hole is located at the end of the reaction kettle, and the two bottom valves are located on the bottom surface of the reaction kettle. There are three baffle plates 2 inside, and the baffle plates are fixedly connected to the inner wall of the horizontal reaction kettle. The baffle plates are provided with windows 201 and gaps 202. The distance between the upper edge and the lower edge of the window is 200 mm, and the distance between the upper edge and the lower edge of the gap is 6 mm. The baffle plates divide the reaction kettle into five reaction chambers 3. The volumes of the first reaction chamber 301, the second reaction chamber 302, the third reaction chamber 303, and the fourth reaction chamber 304 are all 2.5 m 3, a stirring device 4 and a heat exchange coil 5 are provided in each reaction chamber. The stirring device includes a rotating shaft and two parallel stirring paddles 401 sleeved on the rotating shaft; the stirring paddle includes a turntable 411 and six paddles 412 located on the bottom surface of the turntable and arranged circumferentially along the outer edge of the bottom surface of the turntable. A number of circulation holes are provided on the turntable, and the aperture of the circulation holes is 4 mm.

[0037] Comparative Example 2:

[0038] Compared with Example 1, in Comparative Example 2, the reaction kettle is divided into six reaction chambers by baffle plates, and the other conditions are the same as those in Example 1; A low-backmixing dimethylketene dimer continuous reactor includes a horizontal reaction kettle 1. The surface of the reaction kettle is provided with a liquid inlet 101, a gas inlet 102, a liquid outlet 103 and two bottom valves 104. The liquid inlet is located on the side of the front end of the reaction kettle, the gas inlet is located on the top surface of the horizontal reaction kettle, the liquid outlet hole is located at the end of the reaction kettle, and the two bottom valves are located on the bottom surface of the reaction kettle. Five baffle plates 2 are provided inside. The baffle plates are fixedly connected to the inner wall of the horizontal reaction kettle. The baffle plates are provided with windows 201 and gaps 202. The distance between the upper edge and the lower edge of the window is 200 mm, and the distance between the upper edge and the lower edge of the gap is 6 mm. The baffle plates divide the reaction kettle into five reaction chambers 3. The volumes of the first reaction chamber 301, the second reaction chamber 302, the third reaction chamber 303, the fourth reaction chamber 304, the fifth reaction chamber 305 and the sixth reaction chamber are all 1.7 m 3 , a stirring device 4 and a heat exchange coil 5 are provided in each reaction chamber. The stirring device includes a rotating shaft and two parallel stirring paddles 401 sleeved on the rotating shaft; the stirring paddle includes a turntable 411 and six paddles 412 located on the bottom surface of the turntable and arranged circumferentially along the outer edge of the bottom surface of the turntable. A number of circulation holes are provided on the turntable, and the aperture of the circulation holes is 4 mm.

[0039] Comparative Example 3:

[0040] Compared with Example 1, in Comparative Example 3, no stirring paddle is provided in the reaction kettle, and the other conditions are the same as those in Example 1;

[0041] A low-backmixing dimethylketene dimer continuous reactor includes a horizontal reaction kettle 1. The surface of the reaction kettle is provided with a liquid inlet 101, a gas inlet 102, a liquid outlet 103 and two bottom valves 104. The liquid inlet is located on the side of the front end of the reaction kettle, the gas inlet is located on the top surface of the horizontal reaction kettle, the liquid outlet hole is located at the end of the reaction kettle, and the two bottom valves are located on the bottom surface of the reaction kettle. Four baffle plates 2 are provided inside. The baffle plates are fixedly connected to the inner wall of the horizontal reaction kettle. The baffle plates are provided with windows 201 and gaps 202. The distance between the upper edge and the lower edge of the window is 200 mm, and the distance between the upper edge and the lower edge of the gap is 6 mm. The baffle plates divide the reaction kettle into five reaction chambers 3. The volumes of the first reaction chamber 301, the second reaction chamber 302, the third reaction chamber 303, the fourth reaction chamber 304 and the fifth reaction chamber 305 are all 2.0 m3 , a stirring device 4 and a heat exchange coil 5 are provided in each reaction chamber.

[0042] Comparative Example 4:

[0043] Compared with Example 1, in Comparative Example 4, no paddles are provided on the turntable, and the other conditions are the same as those in Example 1;

[0044] A low backmixing dimethylketene dimer continuous reactor comprises a horizontal reaction kettle 1. The surface of the reaction kettle is provided with a liquid inlet 101, a gas inlet 102, a liquid outlet 103 and two bottom valves 104. The liquid inlet is located on the side surface at the front end of the reaction kettle, the gas inlet is located on the top surface of the horizontal reaction kettle, the liquid outlet hole is located at the end of the reaction kettle, and the two bottom valves are located on the bottom surface of the reaction kettle. Four baffle plates 2 are arranged inside. The baffle plates are fixedly connected with the inner wall of the horizontal reaction kettle. Windows 201 and gaps 202 are provided on the baffle plates. The distance between the upper edge and the lower edge of the window is 200 mm, and the distance between the upper edge and the lower edge of the gap is 6 mm. The baffle plates divide the reaction kettle into five reaction chambers 3. The volumes of the first reaction chamber 301, the second reaction chamber 302, the third reaction chamber 303, the fourth reaction chamber 304 and the fifth reaction chamber 305 are all 2.0 m 3 , a stirring device 4 and a heat exchange coil 5 are provided in each reaction chamber. The stirring device comprises a rotating shaft and two parallel stirring paddles 401 sleeved on the rotating shaft; The stirring paddle comprises a turntable 411, and a plurality of circulation holes are further provided on the turntable. The aperture of the circulation holes is 4 mm.

[0045] Comparative Example 5:

[0046] Compared with Example 1, in Comparative Example 4, no circulation holes are provided on the turntable, and the other conditions are the same as those in Example 1;

[0047] A low backmixing dimethylketene dimer continuous reactor comprises a horizontal reaction kettle 1. The surface of the reaction kettle is provided with a liquid inlet 101, a gas inlet 102, a liquid outlet 103 and two bottom valves 104. The liquid inlet is located on the side surface at the front end of the reaction kettle, the gas inlet is located on the top surface of the horizontal reaction kettle, the liquid outlet hole is located at the end of the reaction kettle, and the two bottom valves are located on the bottom surface of the reaction kettle. Four baffle plates 2 are arranged inside. The baffle plates are fixedly connected with the inner wall of the horizontal reaction kettle. Windows 201 and gaps 202 are provided on the baffle plates. The distance between the upper edge and the lower edge of the window is 200 mm, and the distance between the upper edge and the lower edge of the gap is 6 mm. The baffle plates divide the reaction kettle into five reaction chambers 3. The volumes of the first reaction chamber 301, the second reaction chamber 302, the third reaction chamber 303, the fourth reaction chamber 304 and the fifth reaction chamber 305 are all 2.0 m 3, a stirring device 4 and a heat exchange coil 5 are provided in each reaction chamber. The stirring device includes a rotating shaft and two parallel stirring paddles 401 sleeved on the rotating shaft; the stirring paddle includes a turntable 411 and six blades 412 arranged circumferentially along the outer edge of the bottom surface of the turntable.

[0048] Comparative Example 6:

[0049] Compared with Example 1, no heat exchange coil is provided on the turntable in Comparative Example 4, and the other conditions are the same as those in Example 1;

[0050] A low-backmixing dimethylketene dimer continuous reactor includes a horizontal reaction kettle 1. The surface of the reaction kettle is provided with a liquid inlet 101, a gas inlet 102, a liquid outlet 103 and two bottom valves 104. The liquid inlet is located on the side of the front end of the reaction kettle, the gas inlet is located on the top surface of the horizontal reaction kettle, the liquid outlet hole is located at the end of the reaction kettle, and the two bottom valves are located on the bottom surface of the reaction kettle. Four baffle plates 2 are provided inside. The baffle plates are fixedly connected to the inner wall of the horizontal reaction kettle. The baffle plates are provided with windows 201 and gaps 202. The distance between the upper edge and the lower edge of the window is 200 mm, and the distance between the upper edge and the lower edge of the gap is 6 mm. The baffle plates divide the reaction kettle into five reaction chambers 3. The volumes of the first reaction chamber 30¹, the second reaction chamber 30², the third reaction chamber 30³, the fourth reaction chamber 30⁴ and the fifth reaction chamber 30⁵ are all 2.0 m 3 , a stirring device 4 is provided in each reaction chamber. The stirring device includes a rotating shaft and two parallel stirring paddles 401 sleeved on the rotating shaft; the stirring paddle includes a turntable 411 and six blades 412 arranged circumferentially along the outer edge of the bottom surface of the turntable.

[0051] Comparative Example 7:

[0052] Compared with Example 1, no baffle plate is provided in the reaction kettle in Comparative Example 7, and the other conditions are the same as those in Example 1.

[0053] Detection Example:

[0054] Apply the above Examples 1 to 3 and Comparative Examples 1 to 7 to the dimethylketene dimerization reaction, and calculate the final reactant conversion rate. The calculation results are shown in Table 1

[0055] Table 1 Reactant Conversion Rate

[0056] Reactant conversion rate (%) Example 1 99.0 Example 2 98.8 Example 3 98.7 Comparative Example 1 98.6 Comparative Example 2 99.2 Comparative Example 3 51.2 Comparative Example 4 55.6 Comparative Example 5 95.6 Comparative Example 6 99.9 Comparative Example 7 88.9

[0057] As shown in Table 1, the reactant conversion rates of Examples 1 to 3 are 98.7 to 99.0%. Among them, the reaction conversion rate of Example 1 with equal reaction chamber volumes can reach 99.0%, which is the highest reactant conversion rate. In Comparative Example 1, four reaction chambers are used. Compared with Example 1, the reactant conversion rate decreases. In Comparative Example 2, six reaction chambers are used. Compared with Example 1, the difference in reactant conversion rate is small. In Comparative Example 3, no stirring paddle is provided. Compared with Example 1, the reactant conversion rate decreases significantly. In Comparative Example 4, no paddle is provided on the turntable. Compared with Example 1, the reactant conversion rate decreases. In Comparative Example 5, no circulation holes are provided on the turntable. Compared with Example 1, the reactant conversion rate decreases.

[0058] In Comparative Example 6, no heat exchange coil is provided. Compared with Example 1, the reactant conversion rate increases, but the rapid increase in temperature will cause a large amount of DMK to vaporize, and there is a safety risk in the reaction kettle. In Comparative Example 7, no baffle is provided, and a traditional single reaction kettle is used. Compared with Example 1, the reactant conversion rate decreases significantly.

[0059] The above are only the preferred embodiments of the present invention, and do not limit the present invention in any way. Any simple modifications, changes, and equivalent transformations made to the above embodiments according to the technical essence of the present invention still belong to the protection scope of the technical solution of the present invention.

Claims

1. A low back-mixing dimethyl ketene dimerization continuous reactor, characterized in that: The invention comprises a reactor (1) and a plurality of baffles (2) arranged in the reactor, wherein the baffles divide the reactor into a plurality of reaction chambers (3), wherein a stirring device (4) is arranged in the reaction chamber, wherein the stirring device comprises a rotating shaft and a stirring paddle (401) arranged on the rotating shaft, wherein the stirring paddle comprises a rotating disk (411) and a plurality of paddles (412) arranged on the bottom surface of the rotating disk, wherein windows (201) and gaps (202) are provided on the baffles, and the windows and gaps of adjacent baffles are arranged in a staggered manner.

2. The low back-mixing dimethyl ketene dimerization continuous reactor according to claim 1, characterized in that: The number of the reaction chambers is 5.

3. The low back-mixing dimethyl ketene dimerization continuous reactor according to claim 1 or 2, characterized in that: The volume of the reaction chamber is 1.4~4.3 m 3 .

4. The low back-mixing dimethyl ketene dimerization continuous reactor according to claim 1 or 2, characterized in that: A heat exchange coil (5) is also provided in the reaction chamber.

5. The low back-mixing dimethyl ketene dimerization continuous reactor according to claim 1, characterized in that: The turntable is also provided with a plurality of circulation holes (413).

6. The low back-mixing dimethyl ketene dimerization continuous reactor according to claim 5, characterized in that: The diameter of the circulation hole is 1-10 mm.

7. The low back-mixing dimethyl ketene dimerization continuous reactor according to claim 1, characterized in that: The reactor is provided with a liquid inlet (101), an air inlet (102), a liquid outlet (103) and a bottom valve (104).

8. The low back-mixing dimethyl ketene dimerization continuous reactor according to claim 1, characterized in that: The reactor is a horizontal reactor.

9. The low back-mixing dimethyl ketene dimerization continuous reactor according to claim 1, characterized in that: The distance between the upper edge and the lower edge of the window is 10~500 mm.

10. The low back-mixing dimethyl ketene dimerization continuous reactor according to claim 1, characterized in that: The distance between the upper edge and the lower edge of the gap is 1-10 mm.

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