A series-tube reactor with uniform flow in the jacket to prevent impurity deposition

Abstract

The present invention relates to the technical field of petrochemical equipment, and particularly relates to a series pipe reactor with uniform flow and impurity deposition prevention in a jacket, which comprises a plurality of straight sleeve pipes, bent sleeve pipes and jacket connecting pipes. Each straight sleeve pipe comprises an inner pipe and an outer pipe, and the inner pipe is arranged through the outer pipe to form an annular straight jacket flow channel; each bent sleeve pipe comprises an outer elbow and an inner elbow, and the outer elbow is sleeved outside the inner elbow to form an annular bent jacket flow channel; sealing plates are arranged at both ends of the sleeve flow channel; the straight jacket flow channel and the bent jacket flow channel are connected in series through the jacket connecting pipes to form a cooling flow channel for conveying a cooling medium; a flow equalizing ring is arranged near the sealing plate in the straight jacket flow channel and / or the bent jacket flow channel. The flow equalizing ring is provided with a plurality of water holes facing the sealing plate, and the flow equalizing ring is communicated with the jacket connecting pipe. The flow equalizing ring avoids the dead angles of slow flow or even static flow at the end of the jacket, and maintains the continuity of the jacket cooling function; the water holes on the flow equalizing ring guide the cooling water to enter or exit, maintains the uniformity of the reaction in the inner pipe, can carry away the impurities at the end of the jacket, and avoids the deposition and scaling of impurities.

Description

Technical Field

[0001] The present invention relates to the technical field of petrochemical equipment, and particularly relates to a series pipe reactor with uniform flow and impurity deposition prevention in a jacket. Background Art

[0002] Polypropylene and polyethylene are the varieties with the largest production and consumption in general synthetic resins. There are three production technologies for them, namely slurry polymerization, gas phase polymerization, and solution polymerization. The slurry method technology is the main method, which can be divided into two types according to the reactor form, namely the stirred tank type and the series pipe reactor.

[0003] The traditional series pipe reactor mainly consists of several straight sleeve pipes, jacket connecting pipes, elbows, installation supports, and connecting beams, etc., depending on the production capacity. Among them, every two straight pipe cylinders and two elbows form a cycle. Since heat is generated during the polymerization reaction, the reaction heat is taken away by the cooling water in the jacket. A corrugated expansion joint, an installation support, and a support beam seat are arranged on the outer pipe of the straight sleeve pipe. The elbows are connected to both ends of the inner pipe of the straight sleeve pipe through flanges to connect the straight sleeve pipes into a whole process. The jacket connecting pipes connect the jackets of the straight sleeve pipes into a whole process. The connecting beam is connected to the support beam seat through bolts to combine the straight sleeve pipes into a three-dimensional framework. The series pipe reactor is supported by multiple bases, that is, each straight sleeve pipe has its own installation support. Many factors such as the errors in the length, axial position, orientation, elevation, and spacing of the straight sleeve pipes, as well as the parallelism of the straight sleeve pipes, the perpendicularity of the flanges, and the manufacturing errors of the elbows, will simultaneously affect the installation and sealing performance of the series pipes. The installation of the series pipe reactor can be divided into two types: vertical and inclined vertical. The latter occupies a slightly larger area, and its overall structure is more stable than the former.

[0004] For example, as Figure 1As shown in the figure, a vertically installed tube-in-tube reactor mainly consists of six straight sleeves (R1, R2,......R6), five 180° large elbows (A1, A2, A3, and two bottom elbows), and one 90° elbow connected in sequence to form a circulating whole. Through five jacket connecting pipes connected to the outer tube at the elbows, it is located on a relatively high platform foundation. An axial flow pump is installed at the bottom elbow of the tube-in-tube. The reaction material enters the tube-in-tube reactor from the reaction material inlet 1A, is stirred and circulated in the tube under the drive of the axial flow pump, reacts under the action of the catalyst to form slurry polypropylene, and is discharged from the reaction material outlet 1B into the granulation system; the cooling medium enters from the cooling medium inlet of the jacket flow channel and flows out from the cooling medium outlet of the jacket flow channel. Six mounting supports are located at the lower parts of the straight sleeves R1, R2, R3, R4, R5, and R6. There are five jacket connecting pipes connecting the jackets to each other. The cooling water in the jacket takes away the heat released by the reaction in the inner tube through the partition wall to maintain the normal operation of the reaction process. In order to coordinate the difference in thermal expansion displacement caused by different temperatures between the inner tube and the outer tube, expansion joints are attached to the jacket; expansion joints, support beam seats, and supports are also attached to the jacket. Adjacent jackets are connected by section steels to form several space platforms.

[0005] Problems with the basic structure:

[0006] Each straight sleeve 01 includes an inner tube and an outer tube. The inner tube is inserted through the outer tube to form an annular straight jacket flow channel; each bent sleeve 02 includes an outer elbow and an inner elbow. The outer elbow is sleeved outside the inner elbow to form an annular bent jacket flow channel; the inner elbow and the inner tube are sequentially connected in series via their main flanges 04 to form a medium flow channel for transporting reaction materials and carrying out reactions; sealing plates are respectively provided at both ends of the straight jacket flow channel and the bent jacket flow channel to seal the two ends of the straight jacket flow channel and the two ends of the bent jacket flow channel; the straight jacket flow channel and the bent jacket flow channel are connected in series by jacket connecting pipes to form a cooling flow channel for transporting the cooling medium. Combined with Figure 2As shown in the figure, the inner pipe of the straight sleeve 01 is connected to the inner bent pipe in the bent sleeve 02 through the main flange 04. The jacket flow channels of the straight sleeve 01 and the bent sleeve 02 are connected through the U-shaped connecting pipe 03. Side flanges (including the straight pipe jacket connecting pipe flange 051 and the bent pipe jacket connecting pipe flange 052) are respectively arranged at both ends of the U-shaped connecting pipe 03. Both ends of the U-shaped connecting pipe are respectively connected to the outer pipe of the straight sleeve 01 and the outer elbow of the bent sleeve 02. The opening positions of the outer pipe and the outer elbow should avoid forming an obstacle to the connection of the main flange between the inner pipes in space (because the main flange needs to wrap the outer insulation layer, install and disassemble fasteners, and requires space for daily maintenance), and also need to be at a certain distance from the sealing plate and the jacket circumferential weld, so that the opening needs to be at a certain distance from the sealing plate. This will cause dead zones with slow or even static flow at the end of the jacket, affecting the continuity of the jacket cooling function, the non-uniformity of the circumferential flow pattern at the end of the jacket, and the uniformity of the inner pipe reaction. In this way, impurities are easily accumulated at the end of the jacket, and the impurities deposit to form scale.

[0007] In summary, in order to quickly adapt to the current market environment with a large demand for high-capacity and large-structure series pipe reactors in new construction and expansion of petrochemical industry, to meet the requirements of capacity increase, energy expansion, and upgrading of traditional series pipe reactors, as well as the demand for high-capacity with a polypropylene production capacity of over 500,000 tons per year, developing a new structure of high-capacity series pipe reactors has profound and significant industrial and economic significance. Summary of the Invention

[0008] Aiming at the above technical problems existing in the prior art, the present invention provides a series pipe reactor with uniform flow in the jacket to prevent impurity deposition.

[0009] To achieve the above object, the present invention provides the following technical solutions:

[0010] Provide a series pipe reactor with uniform flow in the jacket to prevent impurity deposition, including multiple straight sleeves, bent sleeves, and jacket connecting pipes. Each straight sleeve includes an inner pipe and an outer pipe, and the inner pipe passes through the outer pipe to form an annular straight jacket flow channel; each bent sleeve includes an outer elbow and an inner elbow, and the outer elbow sleeves the inner elbow to form an annular bent jacket flow channel; the inner elbows and the inner pipes are sequentially connected in series through their main flanges to form a medium flow channel for conveying reaction materials and reacting; sealing plates are respectively arranged at both ends of the straight jacket flow channel and the bent jacket flow channel to seal both ends of the straight jacket flow channel and both ends of the bent jacket flow channel; the straight jacket flow channel and the bent jacket flow channel are connected in series through the jacket connecting pipe to form a cooling flow channel for conveying cooling medium; the feature is that a uniform flow ring is arranged near the sealing plate in the straight jacket flow channel and / or the bent jacket flow channel, the uniform flow ring is provided with a plurality of water holes facing the sealing plate along the length direction, and the uniform flow ring is connected to the jacket connecting pipe.

[0011] As a further alternative, a diversion elbow is welded and fixed to the outer pipe and / or the outer elbow. One end of the diversion elbow extends to communicate with the uniform flow ring, and the other end of the diversion elbow extends to communicate with the jacket connecting pipe.

[0012] As a further alternative, a side flange is provided between the diversion elbow and the jacket connecting pipe to achieve mutual sealing connection.

[0013] As a further alternative, the jacket connecting pipe is an S-shaped spiral elastic structure, and both ends of the jacket connecting pipe communicate with the diversion elbows corresponding to the opposite sides of the outer pipe and the outer elbow via side flanges respectively.

[0014] As a further alternative, the main flange is arranged in the vertical direction, and the side flange is arranged in the horizontal or vertical direction.

[0015] As a further alternative, the arc surface of the uniform flow ring close to the sealing plate is densely provided with the water holes, and the plurality of water holes are uniformly distributed or non-uniformly distributed.

[0016] As a further alternative, along the water outlet direction, the inner diameter of the water hole gradually decreases.

[0017] As a further alternative, a liquid passing space is left on the circumferential side of the uniform flow ring.

[0018] As a further alternative, the radial cross-section of the uniform flow ring is circular, polygonal, water droplet-shaped or oval.

[0019] As a further alternative, the uniform flow ring is an equal-diameter ring pipe, or the pipe diameter of the uniform flow ring varies along the length direction.

[0020] As a further alternative, a drain hole is opened on the diversion elbow near the inner wall of the outer pipe, and / or a drain hole is opened at the bottom of the sealing plate, and a threaded plug is provided for the drain hole.

[0021] Advantages of the present invention:

[0022] For the series pipe reactor with uniform flow and impurity deposition prevention in the jacket of the present invention, since a uniform flow ring is provided near the sealing plate, on the one hand, the surface of the uniform flow ring has a guiding effect on the cooling water, so that the cooling water flowing linearly in the straight jacket flow channel and / or the bent jacket flow channel is redirected to generate a turbulent flow near the sealing plate, avoiding the dead angle of slow flow or even static flow at the end of the jacket and maintaining the continuity of the jacket cooling function; on the other hand, the water holes on the uniform flow ring facing the sealing plate guide the cooling water to enter or exit, avoiding the non-uniformity of the circumferential flow state at the end of the jacket and maintaining the uniformity of the inner pipe reaction; the water holes can wash away or suck away the impurities at the end of the jacket, avoiding the deposition and scaling of impurities. Description of the drawings

[0023] Figure 1 It is a schematic diagram of a series pipe reactor in the prior art (the jacket connecting pipe is not shown).

[0024] Figure 2 It is a schematic diagram of the connection of two straight sleeves and one bent sleeve in the prior art.

[0025] Figure 3 It is a simple schematic diagram of the cooperation of the straight sleeve, the bent sleeve and the jacket connecting pipe in the first embodiment.

[0026] Figure 4 It is a schematic diagram of the structure of the flow equalizing ring and the diversion elbow in the jacket in the embodiment.

[0027] Figure 5 In the embodiment Figure 4 It is a schematic diagram of adding drain holes and threaded plugs on the basis.

[0028] Reference numerals:

[0029] Straight sleeve 1, inner pipe 11, outer pipe 12, straight jacket flow channel 13;

[0030] Bent sleeve 2, outer elbow 21, inner elbow 22, bent jacket flow channel 23;

[0031] Jacket connecting pipe 3, main flange 4, side flange 5, sealing plate 6, flow equalizing ring 7, diversion elbow 8, drain hole 81, threaded plug 9. Detailed implementation manners

[0032] The present invention will be described in detail below in conjunction with specific embodiments and the accompanying drawings.

[0033] A string tube reactor with a flow equalizing and impurity deposition preventing structure in the jacket in this embodiment, as Figure 3 and Figure 4 1]]shown, includes a plurality of straight sleeves 1, bent sleeves 2 and jacket connecting pipes 3. Each straight sleeve 1 includes an inner pipe 11 and an outer pipe 12, and the inner pipe 11 passes through the outer pipe 12 to form an annular straight jacket flow channel 13; each bent sleeve 2 includes an outer elbow 21 and an inner elbow 22, and the outer elbow 21 is sleeved outside the inner elbow 22 to form an annular bent jacket flow channel 23; a medium flow channel for conveying reaction materials and carrying out reactions is formed by connecting the inner elbow 22 and the inner pipe 11 in series through their main flanges 4 in sequence; sealing plates 6 are respectively arranged at both ends of the straight jacket flow channel 13 and the bent jacket flow channel 23, so as to seal both ends of the straight jacket flow channel 13 and both ends of the bent jacket flow channel 23; the straight jacket flow channel 13 and the bent jacket flow channel 23 are connected in series through the jacket connecting pipe 3 to form a cooling flow channel for conveying a cooling medium; the above technical features are the same as the structure of the string tube reactor in the prior art, and the string tube reactor in this embodiment also has the basic structure of the reactor in the prior art. The main improvement is:

[0034] A flow equalizing ring 7 is provided near the sealing plate 6 in the straight jacket flow channel 13 and / or the bent jacket flow channel 23. The flow equalizing ring 7 is provided with a plurality of water holes facing the sealing plate 6 along the length direction, and the flow equalizing ring 7 is communicated with the jacket communicating pipe 3. Specifically, a diversion elbow 8 is fixedly welded through the side wall of the outer pipe 12 and / or the outer elbow 21 in a sealed manner. One end of the diversion elbow 8 extends to communicate with the flow equalizing ring 7, and the other end of the diversion elbow 8 extends to communicate with the jacket communicating pipe 3. That is, in the jacket provided with the flow equalizing ring 7, a corresponding diversion elbow 8 is provided to connect the jacket communicating pipe 3. A side flange 5 is provided between the diversion elbow 8 and the jacket communicating pipe 3 to achieve mutual sealing connection. The main flange 4 is arranged in the vertical direction, and the side flange 5 is arranged in the horizontal or vertical direction. Compared with the existing multi-direction same-side connection, it is improved to a two-way connection, the structure is simplified, which is convenient for design, manufacturing and assembly, avoids the interactive influence of the statically indeterminate structure stress, and improves the connection reliability of the main flange 4. Of course, the side flange 5 can also be arranged in the vertical direction, so that all flanges are arranged unidirectionally.

[0035] In this embodiment, the jacket communicating pipe 3 is an S-shaped spiral elastic structure, which is installed around half of the circumference outside the jacket and is convenient for maintenance and repair towards the inside of the reactor. This structure has a certain flexibility in both the vertical and horizontal directions of the reactor main body and will not impose additional loads on the adjacent main flange 4 during installation and operation; the flexibility is increased, especially the three-dimensional flexibility, which can better adapt to various potential deformations in the modal analysis. The two ends of the jacket communicating pipe 3 are distributed on the opposite sides, which improves the circumferential uniformity. The two ends of the jacket communicating pipe 3 are respectively communicated with the corresponding diversion elbows 8 on the opposite sides of the outer pipe 12 and the outer elbow 21 through the side flanges 5.

[0036] In practice, for the arrangement of the water holes, they can be densely arranged on the arc surface of the flow equalizing ring 7 close to the sealing plate 6. Actually, multiple water holes can be evenly distributed or unevenly distributed. For example, the pressure is high near the diversion elbow 8, and the corresponding water holes can be arranged sparser, while the water holes become denser towards the direction away from the diversion elbow 8.

[0037] In practice, along the water outlet direction, the inner diameter of the water hole can be gradually reduced, and the inner surface of the water hole is conical to achieve the spraying effect. It can be seen from the figure that a liquid passing space is left on the circumferential side of the flow equalizing ring 7 to allow the cooling water to pass through smoothly.

[0038] In practice, the radial cross-section of the flow equalizing ring 7 is circular, polygonal, water droplet-shaped or oval. The circular outer wall enables the cooling water to pass smoothly on its surface; polygons and ovals are convenient for opening water holes; the water droplet shape is convenient for guiding the pressurized outflow of the cooling water in the flow equalizing ring 7.

[0039] In practice, the flow equalizing ring 7 can be an equal-diameter ring pipe, or the inner diameter of the flow equalizing ring 7 changes along the length direction. For example, towards the direction away from the diversion elbow 8, the inner diameter of the flow equalizing ring 7 gradually decreases to ensure a certain water pressure in the ring.

[0040] In practice, as Figure 5 shown, to drain the liquid, a small drain hole 81 can be opened on the diversion elbow 8 near the inner wall of the jacket. When parking, the cooling water in the diversion elbow 8 can be drained. Alternatively, a drain hole close to the inner wall of the jacket can be provided on the annular sealing plate 6. The drain hole at this location is sealed with a threaded plug 9, and the corresponding jacket flow channel can be opened by operating the threaded plug with an external force to drain the cooling water therein. As for the assembly sequence of the uniform distribution structure: taking the straight sleeve as an example: the inner pipe and the outer pipe are first assembled; a section of the outer pipe protrudes outside the inner pipe. After the diversion elbow 8 with the flow equalizing ring 7 fixed is welded to the outer pipe, then the protruding small section of the outer pipe is sleeved into the inner pipe together, and conversely, a small section of the inner pipe protrudes; the third step is to weld the sealing plate to this protruding section of the inner pipe; finally, the outer pipe and the sealing plate are welded.

[0041] In the description of the present invention, unless otherwise clearly specified and defined, the terms "installation", "connection", "connection", and "fixation" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0042] The standard parts used in the present invention can all be purchased from the market, and the special-shaped parts can be customized according to the description in the specification and the drawings. The specific connection methods of each part all adopt conventional means such as bolts, rivets, and welding that are mature in the prior art. The machinery, parts, and equipment all adopt conventional models in the prior art, and the circuit connection adopts the conventional connection method in the prior art, which will not be elaborated here.

[0043] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A series-tube reactor with uniform flow and impurity deposition prevention in the jacket, comprising a plurality of straight sleeve tubes, bent sleeve tubes and jacket connecting tubes. Each straight sleeve tube includes an inner tube and an outer tube, and the inner tube is inserted through the outer tube to form an annular straight jacket flow channel. Each bent sleeve tube includes an outer elbow and an inner elbow, and the outer elbow is sleeved outside the inner elbow to form an annular bent jacket flow channel. The inner elbow and the inner tube are sequentially connected in series via their main flanges to form a medium flow channel for conveying reaction materials and carrying out reactions. Sealing plates are respectively provided at both ends of the straight jacket flow channel and the bent jacket flow channel to seal the two ports of the straight jacket flow channel and the two ports of the bent jacket flow channel. The straight jacket flow channel and the bent jacket flow channel are connected in series through the jacket connecting tubes to form a cooling flow channel for conveying cooling medium. The characteristics are as follows: A flow equalizing ring is provided near the sealing plate in the straight jacket flow channel and / or the bent jacket flow channel. The flow equalizing ring is provided with a plurality of water holes facing the sealing plate along the length direction, and the flow equalizing ring is communicated with the jacket connecting pipe.

2. The series tube reactor with uniform flow and impurity deposition prevention in the jacket according to claim 1, characterized in that: A diversion elbow is welded and fixed to the outer pipe and / or the outer elbow. One end of the diversion elbow extends to communicate with the flow equalizing ring, and the other end of the diversion elbow extends to communicate with the jacket connecting pipe.

3. The string tube reactor with uniform flow and impurity deposition prevention in the jacket according to claim 2, characterized in that: A side flange is provided between the diversion elbow and the jacket connecting pipe to achieve mutual sealing connection.

4. A tube-in-tube reactor with uniform flow and impurity deposition prevention in the jacket according to claim 3, characterized in that: The jacket connecting pipe is an S-shaped spiral elastic structure. The two ends of the jacket connecting pipe are respectively communicated with the diversion elbows corresponding to the opposite side parts of the outer pipe and the outer elbow through the side flanges.

5. The series tube reactor with uniform flow and impurity deposition prevention in the jacket according to claim 4, characterized in that: The main flange is arranged in the vertical direction, and the side flange is arranged in the horizontal or vertical direction.

6. The series tube reactor with uniform flow and impurity deposition prevention in the jacket according to claim 1, characterized in that: The arc surface of the flow equalizing ring close to the sealing plate is densely distributed with the water holes, and the plurality of water holes are evenly distributed or unevenly distributed.

7. A series tube reactor with uniform flow and impurity deposition prevention in a jacket according to claim 1, characterized in that: Along the water outlet direction, the inner diameter of the water hole gradually decreases.

8. A series tube reactor with uniform flow and impurity deposition prevention in the jacket according to claim 1, characterized in that: A liquid passing space is left on the circumferential side of the flow equalizing ring; or the flow equalizing ring is an equal-diameter ring pipe, or the pipe diameter of the flow equalizing ring changes along the length direction.

9. A series tube reactor with uniform flow and impurity deposition prevention in a jacket according to claim 1, characterized in that: The radial cross-section of the flow equalizing ring is circular, polygonal, water droplet-shaped or elliptical.

10. A series tube reactor with uniform flow and impurity deposition prevention in a jacket according to claim 1, characterized in that: A drain hole is opened on the diversion elbow near the inner wall of the outer pipe, and / or a drain hole is opened at the bottom of the sealing plate. The drain hole is provided with a threaded plug.

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