A polymerization reactor for uniform temperature control

Abstract

The present invention discloses a polymerization reactor for uniform temperature control, comprising a shell, a manifold channel and a plurality of parallel circulating coil groups; the manifold channel is arranged on the shell, a manifold inlet pipe is connected to the manifold channel on one side, and a manifold outlet pipe is connected to the manifold channel on the opposite side; the inlet and outlet of the circulating coil group are respectively connected to the manifold channels on both sides; a group of coils comprises an inlet bottom winding pipe, a circulating coil group and an outlet bottom winding pipe, one end of the circulating coil group is connected to the inlet bottom winding pipe, and the other end of the circulating coil group is connected to the outlet bottom winding pipe. The present invention has a simple structure, is not limited by the diameter of the reactor, has strong adaptability, and has a relatively uniform hot oil flow in the parallel heat exchange coils; the heat exchange coils cover the entire area inside the device, and there is no area without heat exchange pipes, so the temperature at various places inside the device is more uniformly controlled.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical engineering devices, and particularly relates to a polymerization reactor for uniform temperature control. Background Art

[0002] The polymerization reactor is a key device in the continuous polymerization process and is a plug flow reactor. The reaction temperature is controlled by removing heat through an internally installed hot oil heat exchange coil, so as to ensure precise process control and produce uniform high-quality polymer products. In a general polymerization reactor, the hot oil heat exchange coil is wound into a sheet shape, and multiple groups of coils are then connected in parallel and stacked together to form a coil assembly. With the expansion of the device scale, the diameter of the polymerization reactor is also increasing. There are differences in the total length of each sheet-shaped coil, and there is unevenness in the flow rate of the hot oil in the parallel-connected coils. At the same time, in the bow-shaped area near the wall of the cylindrical reactor, no heat exchange coil can be arranged due to space limitations, resulting in no heat exchange coil in this area. The above defects will cause uneven temperature control in the reactor and affect the quality of the product.

[0003] Such as Figure 1 In [reference], the conventional hot oil circulation coil assembly mainly consists of a shell 2, a knot-type coil 3, and a collecting ring pipe 7. The polymer solution of the reaction system flows in from the equipment polymer solution inlet 6 and flows out from the equipment polymer solution outlet 1. There is a circulating heat transfer medium inside the equipment, which enters from the collecting pipe inlet 8, passes through the collecting ring pipe 7, circulates in each group of knot-type coils 3, and then flows out from the collecting pipe outlet 5. By adopting this hot oil circulation method, precise control of the polymerization reaction temperature can be adjusted to achieve different conversion rates, and thus different grades of polymer products can be obtained.

[0004] The disadvantages of the existing structure are as follows: Each group of knot-type coils is welded to the collecting ring pipe 7 in a parallel manner. The total lengths of the knot-type coil groups near the center of the equipment and the knot-type coil groups at the edge of the equipment are different, and the two groups of coils form different resistance differences, resulting in uneven flow rates of the medium in the coils and inaccurate temperature control. The larger the diameter of the equipment, if this coil arrangement method is still adopted, the difference in the total length of each sheet-shaped coil will be greater, the flow rate unevenness will be greater, the temperature control effect will become worse, the reaction conversion rate will decrease, and the area without heat exchange coils in the bow-shaped area near the wall of the cylindrical reactor will be larger, the temperature control effect will become worse, which will affect the product quality. Summary of the Invention

[0005] To achieve the above object, the present invention provides a polymerization reactor for uniform temperature control, comprising a shell, a header pipe channel, and multiple groups of coiled pipes connected in series and parallel; the header pipe channel is arranged on the shell, a header pipe inlet nozzle is communicated with the header pipe channel on one side, and a header pipe outlet nozzle is communicated with the header pipe channel on the opposite side; the inlets and outlets of the coiled pipes are respectively communicated with the header pipe channels on both sides; one group of the coiled pipes includes an inlet bottom winding pipe, a circulating coiled pipe group, and an outlet bottom winding pipe, one end of the circulating coiled pipe group is communicated with the inlet bottom winding pipe, and the other end of the circulating coiled pipe group is communicated with the outlet bottom winding pipe.

[0006] In another preferred embodiment, the circulating coiled pipe group includes multiple groups of circulating coiled pipes connected in series and is communicated through a top winding pipe.

[0007] In another preferred embodiment, the whole circulating coiled pipe is sheet-shaped, and both sides of the long side are away from the shell.

[0008] In another preferred embodiment, the shell is a tubular structure, and two plate structures are respectively fixed on the inner side wall of the shell, and the header pipe channel is enclosed on the opposite side of the inner wall of the shell.

[0009] In another preferred embodiment, the circulating coiled pipe is parallel to the plate structure.

[0010] In another preferred embodiment, the internal space of the shell between the two plate structures is equally divided by the circulating coiled pipe group.

[0011] In another preferred embodiment, the internal space of the shell between the two plate structures is divided into a first region and a second region by the plane of the central axis of the shell, the first region is close to the header pipe inlet nozzle, and the second region is close to the header pipe outlet nozzle; the first circulating coiled pipe far from the header pipe inlet nozzle in the first region is communicated with the first circulating coiled pipe close to the header pipe outlet nozzle in the second region through a top winding pipe, and the second circulating coiled pipe far from the header pipe inlet nozzle in the first region is communicated with the second circulating coiled pipe close to the header pipe outlet nozzle in the second region through a top winding pipe, and so on.

[0012] In another preferred embodiment, the inlet bottom winding pipes are in different horizontal planes in batches.

[0013] In another preferred embodiment, the outlet bottom winding pipes are in different horizontal planes in batches.

[0014] In another preferred embodiment, the top winding pipes are in different horizontal planes in batches.

[0015] Adopting the above technical solutions, compared with the prior art, the present invention has the following technical effects:

[0016] In the direction parallel to the circulation coil, an arcuate hot oil collecting pipe channel is provided. The circulating hot oil enters through the collecting pipe inlet connecting pipe, flows through the arcuate collecting channel, and then into the circulation coil group, which can timely remove the reaction heat and is beneficial to temperature control.

[0017] By combining the long and short circulation coils, that is, the coils with a longer total length and the coils with a shorter total length are connected in series, the length difference between each coil group in the original scheme is reduced, thereby reducing the resistance difference of the hot oil medium, making the hot oil distribution uniform, avoiding the influence on the temperature difference control of the equipment caused by the uneven distribution of the hot oil in the coil pipe, and ensuring the product quality.

[0018] At the same time, arranging the collecting pipe channel in the arcuate area close to the wall of the cylindrical reactor can eliminate the defect of no heat exchange pipes in the arcuate area.

[0019] The structure of the present invention is simple, not limited by the diameter of the reactor at the same time, has strong adaptability, and the hot oil flow in the parallel heat exchange coils is relatively uniform; the heat exchange coils cover the entire inner area of the reactor, there is no area without heat exchange pipes, and the temperature everywhere in the reactor is more evenly controlled. It is modularly assembled, easy to install, and can be popularized to other similar polymerization reactors. Description of the Drawings

[0020] Figure 1 It is a schematic structural diagram of a conventional hot oil circulation coil assembly;

[0021] Figure 2 In Figure 1 It is a schematic cross-sectional structure diagram of A-A in

[0022] Figure 3 It is a schematic structural diagram of a polymerization reactor for uniform temperature control in the present invention;

[0023] Figure 4 In Figure 3 It is a schematic B-direction structure diagram of the circulation coil group in

[0024] Figure 5 In Figure 3 It is a schematic cross-sectional structure diagram of C-C in

[0025] Figure 6 In Figure 3 It is a schematic cross-sectional structure diagram of D-D in

[0026] Figure 7 In Figure 3 It is a schematic cross-sectional structure diagram of E-E in

[0027] Figure 8 In Figure 3 It is a schematic cross-sectional structure diagram of F-F in

[0028] Figure 9 Middle view Figure 3 Schematic diagram of the cross-sectional structure of G-G in the middle

[0029] Figure 10 Middle view Figure 3 Schematic diagram of the cross-sectional structure of H-H in the middle

[0030] Figure 11 Middle view is a schematic diagram of a structure of a circulating coil group

[0031] The markings in the figure indicate the following explanations

[0032] 1 - Outlet of equipment polymer solution, 2 - Shell, 3 - Structured coil, 4 - Equipment flange, 5 - Outlet of header, 6 - Inlet of equipment polymer solution, 7 - Collector loop pipe, 8 - Inlet of header, 9 - Outlet connection pipe of header, 10 - Flow direction of circulating hot oil, 11 - Header channel, 12 - Coil, 13 - Shell, 14 - Inlet connection pipe of header, 15 - First coil, 16 - Second coil, 17 - Bottom winding pipe at the inlet of the first coil group, 18 - Bottom winding pipe at the outlet of the first coil group, 19 - Top winding pipe Detailed implementation manners

[0033] The present invention will be described in detail and specifically through specific embodiments to better understand the present invention. However, the following embodiments do not limit the scope of the present invention

[0034] The present invention provides a polymerization reactor for uniform temperature control, such as Figure 3 in the middle, including a shell 13, a header channel 11, and multiple groups of parallel coils 12

[0035] Specifically, the header channel 11 is disposed inside the shell 13. In a specific implementation manner, two plate structures and the arcuate region of the inner side wall of the shell enclose two header channels 11, and the two header channels 11 are symmetrically arranged on the inner side wall of the shell. An inlet connection pipe 14 of the header is communicated with one side of the header channel 11, and an outlet connection pipe 9 of the header is communicated with the header channel 11 on the opposite side

[0036] In the direction parallel to the circulating coils, an arcuate hot oil header channel is provided. The circulating hot oil enters through the inlet connection pipe of the header, flows through the arcuate collection channel, and flows into the circulating coil group, which can timely remove the reaction heat and is beneficial to temperature control. At the same time, arranging the header channel in the arcuate region close to the wall of the cylindrical reactor can eliminate the defect of no heat exchange tubes in the arcuate region

[0037] Specifically, the inlets and outlets of each group of coil pipes 12 are respectively communicated with the header channels on both sides. In a specific embodiment, a group of coil pipes 12 includes an inlet bottom winding pipe, a circulating coil pipe group, and an outlet bottom winding pipe. One end of the circulating coil pipe group is communicated with the inlet bottom winding pipe, and the other end of the circulating coil pipe group is communicated with the outlet bottom winding pipe.

[0038] The structure of the present invention is simple, and it is not limited by the diameter of the reactor, with strong adaptability. The hot oil flow in the parallel heat exchange coil pipes is relatively uniform; the heat exchange coil pipes cover the entire inner area of the reactor, there is no area without heat exchange pipes, and the temperature everywhere in the reactor is more uniformly controlled. It is modularly assembled and easy to install, and can be extended to other similar polymerization reactors.

[0039] In another preferred embodiment, the inlet bottom winding pipe and the outlet bottom winding pipe are perpendicular to the sheet-shaped circulating coil pipe group, and the inlet bottom winding pipe and the outlet bottom winding pipe are transitioned to the circulating coil pipe group through smooth right-angle elbows.

[0040] In another specific embodiment, the inlet bottom winding pipes are in different horizontal planes in batches. Preferably, as Figures 5 - 6 shown, adjacent inlet bottom winding pipes are not in the same horizontal plane.

[0041] In another preferred embodiment, the outlet bottom winding pipes are in different horizontal planes in batches. Preferably, as Figures 5 - 6 shown, adjacent outlet bottom winding pipes are not in the same horizontal plane.

[0042] In another preferred embodiment, the circulating coil pipe group includes multiple groups of circulating coil pipes connected in series and communicated through a top winding pipe 19.

[0043] Figures 9 - 10 , which shows the plate-shaped structure enclosing the header channel 11. The plate-shaped structure is provided with holes respectively communicated with the inlet bottom winding pipe and the outlet bottom winding pipe.

[0044] Figure 4 Eight groups of circulating coil pipe groups are provided in Figures 4 - 8 shown. Taking the first coil pipe group as an example, the specific circulation route of the circulating hot oil is as follows: as shown, the circulating hot oil enters the header channel 11 on one side through the header inlet connecting pipe 14, is distributed by the header channel 11 to the inlet bottom winding pipe 17 of the first coil pipe group, enters the first coil pipe group (including the first coil pipe 15 and the second coil pipe 16), starts to wind around on the first coil pipe 15 (on 1), reaches the top of the first coil pipe group 15, enters the second coil pipe 16 (under 8) through the top winding pipe 19, starts to wind around on the second coil pipe 16, reaches the bottom of the first coil pipe group, is communicated with the outlet bottom winding pipe 18 of the first coil pipe group, flows out to the header channel 11 on the other side, and flows out through the header outlet connecting pipe 9.

[0045] By means of combining long and short circulating coils, that is, the coils with a longer total length (the coils on the upper part of 1, close to the central axis) and the coils with a shorter total length (the coils on the lower part of 8, far from the central axis) are connected in series, reducing the length difference between each coil group in the original solution, thereby reducing the resistance difference of the hot oil medium, making the hot oil distribution uniform, avoiding the influence on the temperature difference control of the equipment caused by the uneven distribution of the hot oil in the coil pipes, and ensuring the product quality.

[0046] In another preferred embodiment, the whole circulating coil is sheet-shaped, and both sides of the long side are far from the shell.

[0047] In another preferred embodiment, the circulating coil is parallel to the plate structure.

[0048] In another preferred embodiment, the internal space of the shell between the two plate structures is equally divided by the circulating coil group.

[0049] In another preferred embodiment, the internal space of the shell between the two plate structures is divided into a first region and a second region by a plane passing through the central axis of the shell. The first region is close to the inlet nozzle of the header, and the second region is close to the outlet nozzle of the header; the circulating coil in the first region that is the first to be far from the inlet nozzle of the header is connected to the circulating coil in the second region that is the first to be close to the outlet nozzle of the header through a top bypass pipe, and the circulating coil in the first region that is the second to be far from the inlet nozzle of the header is connected to the circulating coil in the second region that is the second to be close to the outlet nozzle of the header through a top bypass pipe, and so on.

[0050] In another preferred embodiment, as Figures 7 - 8 described in, the top bypass pipes are batchwise at different horizontal planes.

[0051] The specific embodiments of the present invention have been described in detail above, but they are only examples, and the present invention is not limited to the specific embodiments described above. For those skilled in the art, any equivalent modifications and substitutions to the present invention are also within the scope of the present invention. Therefore, equivalent transformations and modifications made without departing from the spirit and scope of the present invention should be covered within the scope of the present invention.

Claims

1. A polymerization reactor for uniform temperature control, characterized in that, It includes a housing, a header duct passage, and multiple groups of parallel circulating coil groups; the header duct passage is arranged on the housing, a header inlet connection pipe is communicated with the header duct passage on one side, and a header outlet connection pipe is communicated with the header duct passage on the opposite side; the inlets and outlets of the circulating coil groups are respectively communicated with the header duct passages on both sides; one group of the coils includes an inlet bottom winding pipe, a circulating coil group, and an outlet bottom winding pipe, one end of the circulating coil group is communicated with the inlet bottom winding pipe, and the other end of the circulating coil group is communicated with the outlet bottom winding pipe; The housing is a tubular structure, two plate structures are respectively fixed on the inner side wall of the housing, and the header duct passage is enclosed on the opposite sides of the inner wall of the housing; The circulating coils are parallel to the plate structures; The internal space of the housing between the two plate structures is equally divided by the circulating coil groups; The internal space of the housing between the two plate structures is divided into a first region and a second region by a plane of the central axis of the housing. The first region is close to the header inlet connection pipe, and the second region is close to the header outlet connection pipe; the circulating coil in the first region that is the first to be far from the header inlet connection pipe is communicated with the circulating coil in the second region that is the first to be close to the header outlet connection pipe through a top winding pipe, and the circulating coil in the first region that is the second to be far from the header inlet connection pipe is communicated with the circulating coil in the second region that is the second to be close to the header outlet connection pipe through a top winding pipe, and so on.

2. The polymerization reactor for uniform temperature control according to claim 1, characterized in that, The circulating coil group includes multiple groups of circulating coils connected in series and is communicated through top winding pipes.

3. The polymerization reactor for uniform temperature control according to claim 2, wherein The whole circulating coil is sheet-shaped, and both sides of the long side are close to the housing.

4. The polymerization reactor for uniform temperature control according to claim 1, wherein The inlet bottom winding pipes are in different horizontal planes in batches.

5. The polymerization reactor for uniform temperature control according to claim 1, wherein The outlet bottom winding pipes are in different horizontal planes in batches.

6. The polymerization reactor for uniform temperature control according to claim 2, characterized in that, The top winding pipes are in different horizontal planes in batches.

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