A shell-and-tube mixer

Abstract

The present application belongs to the technical field of mixers, and particularly relates to a shell-and-tube mixer. The mixer comprises a left tube box, an intermediate body and a right tube box. The left tube box comprises a left conical head configured to be open at both ends and capable of introducing ethylene. The intermediate body is connected to the right side of the left tube box and comprises a shell configured to be open at both ends, a left tube plate and a right tube plate connected to the left and right ends of the shell respectively, a first through hole formed in the left tube plate, a second through hole and a third through hole formed in the right tube plate, a central tube connected and arranged between the first through hole and the second through hole, and an oxygen inlet formed in the shell. The right tube box is connected to the right side of the intermediate body and comprises a right conical head configured to be open at both ends. The present application can realize uniform mixing of ethylene and oxygen and improve the stability and safety of equipment production operation.

Description

Technical Field

[0001] This invention belongs to the field of mixer technology, and specifically relates to a shell-and-tube mixer. Background Technology

[0002] Ethylene oxide is a very important downstream chemical product of ethylene, with a wide range of applications. Currently, the commonly used ethylene oxide production technology synthesizes ethylene oxide through the reaction of ethylene with oxygen. Before the reaction, ethylene and oxygen must be mixed. However, ethylene is a flammable and explosive chemical substance with a wide explosive range, and the mixing with oxygen, in particular, requires extremely high precision in terms of mixing ratio and uniformity.

[0003] Mixers enable the mixing of different types of gases. Currently, the main industrial application is an ethylene-oxygen mixer developed by SD Corporation in the United States. Its main structural feature is the insertion of an oxygen dispersion pipe inside the ethylene pipe, with an opening facing the ethylene flow direction. Oxygen enters the ethylene pipe through this opening, forming a mixed flow. However, this type of mixer suffers from poor control over the mixing ratio and uneven mixing. Furthermore, the oxygen dispersion pipe is subjected to significant impact and is prone to breakage, thus posing certain limitations on achieving effective ethylene-oxygen mixing and ensuring safe and stable production. Summary of the Invention

[0004] In view of the shortcomings of existing mixers for mixing ethylene and oxygen, such as poor proportion control, uneven mixing, and easy breakage of oxygen dispersion tubes, the present invention provides a shell-and-tube mixer.

[0005] The shell-and-tube mixer includes: The left tube box includes a left conical end cap configured to be open at both ends and capable of introducing ethylene; An intermediate body, connected to the right side of the left tube box, includes a shell with openings at both ends and a left tube plate and a right tube plate respectively connected to the left and right ends of the shell. A first through hole is formed on the left tube plate, and a second and a third through hole are formed on the right tube plate. A central tube is connected between the first and second through holes. An oxygen inlet is formed on the shell. The right tube box is connected to the right side of the intermediate body, and the right tube box includes a right conical end cap configured to be open at both ends.

[0006] As an extension of the above technical solution, the present invention also provides the following embodiments: The radius and number of the first through hole are equal to the radius and number of the second through hole. The radii R of the first and second through holes, the number N of the first and second through holes, the radius r of the third through hole, and the number n of the third through hole satisfy N ≥ (4r) 2 / R2 )·n .

[0007] The opening position of the first through hole corresponds to the opening position of the second through hole.

[0008] The second through hole is evenly distributed on several circles with different radii on the right tube plate, and the third through hole is staggered with the second through hole on the right tube plate, and the third through hole is evenly distributed on several circles with different radii on the right tube plate.

[0009] The oxygen inlets are evenly distributed along the circumference of the housing.

[0010] The intermediate body includes an elbow configured to connect to the oxygen inlet, a straight pipe connected to the other end of the elbow, and a ring pipe configured to communicate with all the straight pipes, with an oxygen supply port provided on the ring pipe.

[0011] The left tube box includes a left pipe flange connected to the left end face of the left conical head and a left container flange connected to the right end face of the left conical head. The left container flange is configured to connect to the left tube sheet.

[0012] The right tube box includes a right pipe flange connected to the right end face of the right conical head and a right container flange connected to the left end face of the right conical head. The right container flange is configured to connect to the right tube sheet.

[0013] An vent is provided at the top of the housing, and a drain outlet is provided at the bottom of the housing.

[0014] A saddle is provided below the housing to support the housing.

[0015] The advantages of this invention compared to the prior art are: Ethylene enters the right tube box through the left tube box and the intermediate, where it mixes with oxygen that enters the right tube box through the intermediate. Thanks to the unique air intake method and the design of the intermediate, uniform mixing and good control of the ratio of ethylene and oxygen are achieved, which also improves the stability of the equipment and the safety of production. Attached Figure Description

[0016] Figure 1 This is a schematic front cross-sectional view of the shell-and-tube mixer according to the present invention; Figure 2 This is a schematic diagram of the left-side structure of the shell-and-tube mixer according to the present invention; Figure 3 This is a schematic diagram of the right tube sheet structure; Figure 4 This is a schematic diagram of the left tube sheet.

[0017] All the accompanying drawings in this invention are schematic diagrams for illustrating the structure and principle, and are not necessarily drawn according to actual dimensions and proportions.

[0018] The specific meanings of the various labels in the figure are as follows: 1. Left tube box; 11. Left conical head; 12. Left connecting flange; 13. Left container flange; 2. Intermediate body; 21. Shell; 22. Left tube sheet; 221. First through hole; 23. Right tube sheet; 231. Second through hole; 232. Third through hole; 24. Central tube; 25. Oxygen inlet; 26. Elbow; 27. Straight pipe; 28. Ring pipe; 281. Oxygen supply port; 29. ​​Vent port; 2a. Drain port; 2b. Saddle; 2b1. Static grounding mechanism; 3. Right tube box; 31. Right conical head; 32. Right connecting flange; 33. Right container flange; 100. Shell and tube mixer. Detailed Implementation

[0019] The embodiments of the present invention will now be described in more detail with reference to the accompanying drawings.

[0020] Figure 1 This is a schematic diagram of the structure of a shell-and-tube mixer 100 according to the present invention. As shown, the shell-and-tube mixer 100 includes a left tube box 1, an intermediate body 2, and a right tube box 3. The left tube box 1 includes a left conical end cap 11 with open ends, capable of introducing ethylene into the shell-and-tube mixer 100. The intermediate body 2 is connected to the right side of the left tube box 1 and includes a shell 21 with open ends and a left tube plate 22 and a right tube plate 23 respectively connected to the left and right ends of the shell 21. A plurality of first through holes 221 are provided on the left tube plate 22, and a plurality of second through holes 231 and a plurality of third through holes 232 are provided on the right tube plate 23. The first through holes 221 and the second through holes 231 have a one-to-one correspondence. A central tube 24 is connected between each set of first through holes 221 and second through holes 231, and an oxygen inlet 25 for introducing oxygen into the shell-and-tube mixer 100 is provided on the shell 21. The right tube box 3 is connected to the right side of the intermediate body 2, and includes a right conical head 31 with openings at both ends.

[0021] In actual operation, ethylene is introduced through the left conical head 11, and flows sequentially through the first through hole 221, the central tube 24, and the second through hole 231 into the right conical head 31 of the right tube box 3. At the same time, oxygen enters the shell 21 through the oxygen inlet 25 and flows into the right conical head 31 through the third through hole 232. As ethylene and oxygen continue to flow in, they are mixed in the right conical head 31 and then flow out of the right conical head 31 into the subsequent processes.

[0022] This design enables uniform mixing of ethylene and oxygen, and because the central tube 24 for delivering oxygen is fixed between the left tube sheet 22 and the right tube sheet 23, the risk of breakage is greatly reduced, improving the stability and safety of the shell-and-tube mixer 100.

[0023] In some embodiments of the present invention, the two ends of the central tube 24 are welded to the left tube plate 22 and the right tube plate 23 respectively to realize the connection of the first through hole 221 and the second through hole 231.

[0024] like Figure 1 , Figure 3 and Figure 4 In some embodiments of the present invention, the first through hole 221, the second through hole 231, and the third through hole 232 are all circular. The radius and number of the first through hole 221 are equal to the radius and number of the second through hole 231. The radius R of the first through hole 221, the radius R of the second through hole 231, the radius r of the third through hole 232, the number N of the first through hole 221, the number N of the second through hole 231, and the number n of the third through hole 232 satisfy the equation N ≥ (4r) / n. 2 / R 2 Since the first through-hole 221, the second through-hole 231, and the third through-hole 232 are all circular, it is easy to see from the formula for the area of ​​a circle that, through this design, the area of ​​the second through-hole 231 on the right tube plate 23 is greater than or equal to four times the area of ​​the third through-hole 232. This ensures that, under the same feed pressure and feed rate for ethylene and oxygen, the volume percentage of ethylene in the ethylene-oxygen mixture is not less than 80%. Since the upper limit of the explosion limit for ethylene in the ethylene-oxygen mixture is 78%, this design ensures that the volume percentage of ethylene is always above the upper limit of the explosion limit, thus structurally guaranteeing the safety of the shell-and-tube mixer 100 during mixing operations and significantly reducing the possibility of combustion and explosion inside the shell-and-tube mixer 100.

[0025] like Figure 1 , Figure 3 and Figure 4 As shown, in some embodiments of the present invention, the opening position of the first through hole 221 on the left tube plate 22 corresponds to the opening position of the second through hole 231 on the right tube plate 23. Since the central tube 24 is disposed between the first through hole 221 and the second through hole 231, this design allows the central tube 24 to remain horizontal, ensuring the smooth flow of ethylene.

[0026] Furthermore, such as Figure 1 , Figure 3 and Figure 4As shown, in some embodiments of the present invention, in order to improve the uniformity of ethylene mixing, the second through hole 231 is evenly distributed on several circumferences with different radii on the right tube plate 23, and the third through hole 232 is staggered with the second through hole 231 on the right tube plate 23, and the third through hole 232 is also evenly distributed on several circumferences with different radii on the right tube plate 23.

[0027] Furthermore, such as Figure 1 , Figure 3 and Figure 4 As shown, in some embodiments of the present invention, in order to improve the uniformity of ethylene mixing, the second through hole 231 is evenly distributed on several concentric circles with different radii on the right tube plate 23, and the third through hole 232 is staggered from the second through hole 231 on the right tube plate 23, and the third through hole 232 is also evenly distributed on several concentric circles with different radii on the right tube plate 23. like Figure 1 and Figure 2 As shown, in some embodiments of the present invention, in order to improve the uniformity of oxygen entering the housing 21, thereby improving the uniformity of ethylene and oxygen mixing, the oxygen inlet 25 is uniformly distributed along the circumference of the housing 21.

[0028] Preferably, the projections of all oxygen inlets 25 onto the axial direction of the housing 21 coincide.

[0029] like Figure 1 As shown, in some embodiments of the present invention, the intermediate body 2 includes an elbow 26 configured to connect to the oxygen inlet 25, a straight pipe 27 connected to the other end of the elbow 26, and an annular pipe 28 configured to communicate with all the straight pipes 27, and an oxygen supply port 281 is provided on the annular pipe 28. This design allows oxygen to enter the oxygen inlet 25 surrounding the housing 21 more synchronously, thereby further improving the uniformity of oxygen entry and the uniformity of the mixture of ethylene and oxygen.

[0030] Preferably, the oxygen supply port 281 is located on the ring pipe 28 between two adjacent straight pipes 27.

[0031] like Figure 1 As shown, in some embodiments of the present invention, the left pipe box 1 includes a left connecting flange 12 connected to the left end face of the left conical head 11 and a left container flange 13 connected to the right end face of the left conical head 11. The left container flange 13 is configured to connect to the left tube sheet 22 (in this embodiment, the left tube sheet 22 is configured to also serve as a flange that mates with the left container flange 13). Since the left tube sheet 22 is configured to connect to the shell 21, the left container flange 13 is also configured to be indirectly connected to the shell 21. The left connecting flange 12 is used to connect to the ethylene pipeline.

[0032] Preferably, the left container flange 13 is connected to the left tube sheet 22 by fasteners such as bolts, and a gasket is provided between the left container flange 13 and the left tube sheet 22 to ensure the sealing after connection.

[0033] like Figure 1 As shown, in some embodiments of the present invention, the right pipe box 3 includes a right connecting flange 32 connected to the right end face of the right conical head 31 and a right container flange 33 connected to the left end face of the right conical head 31. The right container flange 33 is also configured to connect to the right tube sheet 23 (in this embodiment, the right tube sheet 23 is configured to also function as a flange that connects with the right container flange 33). Since the right tube sheet 23 is configured to connect to the shell 21, the right container flange 33 is also configured to indirectly connect to the shell 21. The right connecting flange 32 is used to connect to the pipeline of subsequent processes.

[0034] Preferably, the right container flange 33 is connected to the right tube sheet 23 by bolts or other fasteners, and a gasket is provided between the right container flange 33 and the right tube sheet 23 to ensure the sealing after connection.

[0035] like Figure 1 As shown, in some embodiments of the present invention, a vent 29 for venting gas inside the housing 21 is connected to the upper part of the housing 21, and a drain port 2a for draining liquid inside the housing 21 is connected to the lower part of the housing 21. Both the vent 29 and the drain port 2a are equipped with flange covers so that the vent 29 and the drain port 2a can be closed when not venting or not draining.

[0036] like Figure 1 As shown, in some embodiments of the present invention, a saddle 2b for supporting the housing 21 is provided below the housing 21, and the number of saddles 2b is at least two, so as to achieve stable support for the housing 21.

[0037] Furthermore, in some embodiments of the present invention, an electrostatic grounding mechanism 2b1 is connected and provided on the saddle 2b.

[0038] In some embodiments of the present invention, in order to adapt to different installation environments, there are two saddles 2b, one of which is fixed and the other is sliding.

[0039] According to the shell-and-tube mixer 100 of the present invention, the design of the left tube box 1, the intermediate body 2 and the right tube box 3 achieves uniform mixing of ethylene and oxygen, improves the controllability of the mixed gas ratio, and also greatly reduces the probability of oxygen pipeline breakage, thereby improving the stability of the equipment and the safety of production.

[0040] In this invention, the specific meanings of terms such as "upper," "lower," "left," "right," "inner," "outer," "middle," and "side" when indicating location are as follows: Figure 1 The drawing state of the shell-and-tube mixer 100 is for reference.

[0041] In this invention, "connection" includes "direct connection" and "indirect connection".

[0042] Finally, it should be noted that although the present invention has been described in detail with reference to preferred embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the invention. In particular, as long as there is no structural conflict, the technical features mentioned in the various embodiments can be combined in any way. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A shell-and-tube mixer, comprising: The left tube box (1) includes a left conical head (11) configured to be open at both ends and capable of introducing ethylene. An intermediate body (2), connected to the right side of the left tube box (1), includes a shell (21) with openings at both ends and a left tube plate (22) and a right tube plate (23) respectively connected to the left and right ends of the shell (21). A first through hole (221) is provided on the left tube plate (22), and a second through hole (231) and a third through hole (232) are provided on the right tube plate (23). A central tube (24) is connected between the first through hole (221) and the second through hole (231). An oxygen inlet (25) is provided on the shell (21); and The right tube box (3) is connected to the right side of the intermediate body (2), and the right tube box (3) includes a right conical end cap (31) configured to be open at both ends.

2. The shell-and-tube mixer according to claim 1, characterized in that: The radius and the number of the first through holes (221) are equal to the radius and the number of the second through holes (231), and the radius R of the first through holes (221) and the second through holes (231), the number N of the first through holes (221) and the second through holes (231), the radius r of the third through holes (232), and the number n of the third through holes (232) satisfy N≥(4r 2 / R 2 )·n.

3. The shell-and-tube mixer according to claim 2, characterized in that: The opening position of the first through hole (221) corresponds to the opening position of the second through hole (231).

4. The shell-and-tube mixer according to claim 3, characterized in that: The second through hole (231) is evenly distributed on several circumferences with different radii on the right tube plate (23). The third through hole (232) is offset from the second through hole (231) on the right tube plate (23), and the third through hole (232) is evenly distributed on several circumferences with different radii on the right tube plate (23).

5. The shell-and-tube mixer according to claim 4, characterized in that: The oxygen inlet (25) is uniformly distributed along the circumference of the housing (21).

6. The shell-and-tube mixer according to claim 5, characterized in that: The intermediate body (2) includes a bend (26) configured to be connected to the oxygen inlet (25), a straight pipe (27) connected to the other end of the bend (26), and a ring pipe (28) configured to be connected to all the straight pipes (27), with an oxygen supply port (281) provided on the ring pipe (28).

7. The shell-and-tube mixer according to any one of claims 1 to 6, characterized in that: The left tube box (1) includes a left pipe flange (12) connected to the left end face of the left conical head (11) and a left container flange (13) connected to the right end face of the left conical head (11), the left container flange (13) being configured to connect to the left tube sheet (22).

8. The shell-and-tube mixer according to claim 7, characterized in that: The right tube box (3) includes a right pipe flange (32) connected to the right end face of the right conical head (31) and a right container flange (33) connected to the left end face of the right conical head (31), the right container flange (33) being configured to connect to the right tube sheet (23).

9. The shell-and-tube mixer according to claim 8, characterized in that: An vent (29) is provided above the housing (21), and a drain (2a) is provided below the housing (21).

10. The shell-and-tube mixer according to claim 9, characterized in that: A saddle (2b) for supporting the housing (21) is provided below the housing (21).

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