Marine plate heat exchanger

Abstract

The utility model provides a marine plate heat exchanger, including: a front fixed plate and a single heat exchange plate, the two sides and lower end of the front fixed plate are respectively fixedly connected with one end of a side rod and one end of a bottom rod, the other end of the side rod and the other end of the bottom rod are fixedly connected with a rear fixed plate, one end of the side rod close to the rear fixed plate is screwed with a fastening sleeve, and the fastening sleeve is screwed with the single heat exchange plate. The upper surface of the bottom rod is slidably connected with a single heat exchange plate and a double heat exchange plate, the extrusion plate is slidably connected with the side rod through a through hole, main transition pipes are fixedly connected into a hot fluid inlet and a hot fluid outlet formed in the single heat exchange plate, and auxiliary transition pipes are fixedly connected into a cold fluid inlet and a cold fluid outlet formed in the single heat exchange plate. And auxiliary transition pipes are fixedly connected into hot fluid inlets and hot fluid outlets formed in the double heat exchange plates. Through the cooperation of the sealing layer, the sealing strip, the main transition pipe and the auxiliary transition pipe, the sealing performance of the joint between the single heat exchange plate and the double heat exchange plates can be effectively enhanced, and the probability of fluid leakage is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of plate heat exchangers for ships, in particular to a plate heat exchanger for ships. Background Art

[0002] Plate heat exchanger is a new type of high-efficiency heat exchanger made of a series of metal sheets with a certain corrugated shape. Thin rectangular channels are formed between various plates, and heat is exchanged through the plates. Compared with conventional shell and tube heat exchangers, its heat transfer coefficient is much higher under the same flow resistance and pump power consumption. It has a tendency to replace shell and tube heat exchangers within the applicable scope. Plate heat exchanger is an ideal equipment for liquid-liquid and liquid-steam heat exchange. It has the characteristics of high heat exchange efficiency, small heat loss, compact and light structure, small footprint, easy installation and cleaning, wide application and long service life. Heat exchangers are widely used, but the available resources on board are limited, so marine plate heat exchangers are usually Seawater is used as a cooling medium. Due to the poor quality of seawater and the presence of a large number of algae in the seawater, the seawater must be filtered before entering the plate heat exchanger to avoid corrosion of the heat exchanger components and to prevent microorganisms from attaching to the heat exchanger channels, causing blockage of the heat exchanger and a decrease in heat exchange efficiency. However, the existing marine plate heat exchangers have a complex structure and are inconvenient to install and disassemble, which increases the difficulty of subsequent cleaning. If they are not cleaned for a long time, the heat exchange efficiency will be reduced. In addition, the ship will shake during operation, making the inside of the heat exchanger easy to loosen and the stability is relatively poor. In addition, some marine plate heat exchangers are prone to liquid leakage after loosening, which will corrode the heat exchanger and reduce the heat exchange efficiency. Utility Model Content

[0003] In order to overcome the defects of the prior art, a marine plate heat exchanger is provided to solve the problems raised in the above background technology.

[0004] In order to achieve the above-mentioned purpose, a marine plate heat exchanger is provided, comprising: a front fixing plate and a single heat exchange plate, wherein the upper and lower ends of one side of the front fixing plate are respectively provided with a hot fluid inlet and a hot fluid outlet, and the upper and lower ends of the other side of the front fixing plate are symmetrically provided with a cold fluid outlet and a cold fluid inlet, the two sides and the lower end of the front fixing plate are respectively fixedly connected to one end of the side rod and the bottom rod, the other ends of the side rod and the bottom rod are fixedly connected to the rear fixing plate, and the end of the side rod close to the rear fixing plate is screwed to the fastening sleeve, and the upper surface of the bottom rod is slidably connected to the single heat exchange plate and the double heat exchange plate, and the extrusion plate is slidably connected to the side rod through the through hole At the same time, a hot fluid inlet, a hot fluid outlet, a cold fluid inlet and a cold fluid outlet are provided on the surface of the single heat exchange plate and the double heat exchange plate. The hot fluid inlet and the hot fluid outlet provided by the single heat exchange plate are fixedly connected to the main transition pipe, and the cold fluid inlet and the cold fluid outlet provided by the single heat exchange plate are fixedly connected to the secondary transition pipe, and the hot fluid inlet and the hot fluid outlet provided by the double heat exchange plate are fixedly connected to the secondary transition pipe, and the cold fluid inlet and the cold fluid outlet provided by the double heat exchange plate are fixedly connected to the main transition pipe, and the outer sides of the single heat exchange plate and the double heat exchange plate are fixedly connected to the sealing layer.

[0005] Preferably, the front fixing plate and the rear fixing plate are both rectangular structures, and three sets of side rods are fixedly connected in parallel and equidistantly on both sides of the front fixing plate, while the side rods and the bottom rod are both cylindrical structures, and a threaded structure is provided at one end of the side rod close to the rear fixing plate.

[0006] Preferably, the sealing layer has a U-shaped structure, and an installation groove is provided on the inner side of the sealing layer, and the inner side of the sealing layer is fixedly connected to the single heat exchange plate and the double heat exchange plate through the installation groove, and three groups of sealing strips are fixedly connected at equal intervals on one side of the sealing layer surface close to the front fixed plate, and a sealing groove is provided on the other side of the sealing layer corresponding to the position of the sealing strip, and the single heat exchange plate and the double heat exchange plate are distributed alternately.

[0007] Preferably, the sealing strip is in a U-shaped structure, and the sizes of the three groups of sealing strips on the surface of the sealing layer gradually increase from the inside to the outside, and the cross-section of the sealing strip is in a semicircular structure, and the sizes of the sealing strip and the sealing groove are matched, and at the same time, a sealing groove is opened on the surface of the front fixed plate corresponding to the position of the sealing strip.

[0008] Preferably, the extrusion plate has a rectangular structure, through holes are provided on the surface of the extrusion plate corresponding to the positions of the side rods and the bottom rod, and the size of the extrusion plate is larger than that of a single heat exchange plate. At the same time, the sealing strip fixedly connected to the surface of the extrusion plate faces the sealing groove provided on the surface of the sealing layer.

[0009] Preferably, the surfaces of the single heat exchange plate and the double heat exchange plate are provided with a hot fluid inlet, a hot fluid outlet, a cold fluid inlet and a cold fluid outlet, and are fixedly connected to positioning rings, which are in a circular ring structure, and the side of the positioning ring close to the rear fixed plate is fixedly connected to a sealing sleeve, which is in a cylindrical structure.

[0010] Preferably, the main transition pipe and the auxiliary transition pipe are both cylindrical structures, and are fixedly connected to the side of the positioning ring close to the front fixed plate, and the side of the main transition pipe and the auxiliary transition pipe away from the positioning ring are in a truncated cone structure, and at the same time, the side of the auxiliary transition pipe is symmetrically opened with through openings, and the through openings are in an arc-shaped structure.

[0011] Compared with the prior art, the beneficial effects of the utility model are as follows: through the cooperation of the front fixing plate, the side rod, the bottom rod, the extrusion plate, the fastening sleeve and the rear fixing plate, the single heat exchange plate and the double heat exchange plate can be conveniently loaded and unloaded, thereby reducing the difficulty of subsequent cleaning, ensuring that the plate heat exchanger still has good heat exchange efficiency after long-term use on board, and at the same time, through the cooperation of the sealing layer, the sealing strip, the main transition pipe, the secondary transition pipe, the positioning ring and the sealing sleeve, the sealing and stability of the connection between the front fixing plate, the single heat exchange plate, the double heat exchange plate and the extrusion plate can be effectively enhanced, avoiding the problem of loosening of the connection between the single heat exchange plate and the double heat exchange plate due to the shaking of the ship during operation, thereby effectively enhancing the overall sealing effect of the plate heat exchanger, reducing the probability of liquid leakage, and ensuring the safety and heat exchange efficiency of the plate heat exchanger. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a front view schematic diagram of an embodiment of the utility model.

[0013] Figure 2 It is a front view disassembly schematic diagram of an embodiment of the utility model.

[0014] Figure 3 It is a front view schematic diagram of the double heat exchange plates and the rear fixing plate of an embodiment of the utility model.

[0015] Figure 4 For the utility model embodiment Figure 2 An enlarged schematic diagram of point A.

[0016] In the figure: 1. front fixing plate; 2. hot fluid inlet; 3. main transition pipe; 4. positioning ring; 5. auxiliary transition pipe; 6. single heat exchange plate; 7. double heat exchange plate; 8. hot fluid outlet; 9. sealing layer; 10. bottom rod; 11. rear fixing plate; 12. side rod; 13. extrusion plate; 14. fastening sleeve; 15. sealing strip; 16. cold fluid inlet; 17. cold fluid outlet. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0018] Reference Figures 1 to 4 As shown, the utility model provides a marine plate heat exchanger, comprising: a front fixing plate 1 and a single heat exchange plate 6, wherein the upper and lower ends of one side of the front fixing plate 1 are respectively provided with a hot fluid inlet 2 and a hot fluid outlet 8, and the upper and lower ends of the other side of the front fixing plate 1 are symmetrically provided with a cold fluid outlet 17 and a cold fluid inlet 16, the two sides and the lower end of the front fixing plate 1 are respectively fixedly connected to one end of a side rod 12 and a bottom rod 10, the other ends of the side rod 12 and the bottom rod 10 are fixedly connected to a rear fixing plate 11, and one end of the side rod 12 close to the rear fixing plate 11 is screwed to a fastening sleeve 14, and the upper surface of the bottom rod 10 is slidably connected to the single heat exchange plate 6 and the double heat exchange plate 7, and the extrusion plate 13 is slidably connected to the side rod 12 through a through hole. Rod 12, and at the same time, a hot fluid inlet 2, a hot fluid outlet 8, a cold fluid inlet 16 and a cold fluid outlet 17 are provided on the surface of the single heat exchange plate 6 and the double heat exchange plate 7, the hot fluid inlet 2 and the hot fluid outlet 8 provided by the single heat exchange plate 6 are fixedly connected to the main transition pipe 3, and the cold fluid inlet 16 and the cold fluid outlet 17 provided by the single heat exchange plate 6 are fixedly connected to the secondary transition pipe 5, and the hot fluid inlet 2 and the hot fluid outlet 8 provided by the double heat exchange plate 7 are fixedly connected to the secondary transition pipe 5, and the cold fluid inlet 16 and the cold fluid outlet 17 provided by the double heat exchange plate 7 are fixedly connected to the main transition pipe 3, and the outer sides of the single heat exchange plate 6 and the double heat exchange plate 7 are fixedly connected to the sealing layer 9.

[0019] In this embodiment, when the ship needs to install a plate heat exchanger, the extrusion plate 13 pushes the single heat exchange plate 6 to move, and the single heat exchange plate 6 pushes the double heat exchange plate 7 to move synchronously, and the front fixing plate 1 limits the moving positions of the single heat exchange plate 6 and the double heat exchange plate 7, so the front fixing plate 1 and the extrusion plate 13 cooperate to complete the fixed connection between the single heat exchange plate 6 and the double heat exchange plate 7, and rotate the fastening sleeve 14 so that the fastening sleeve 14 can abut against the extrusion plate 13, and connect the hot fluid injection pipe and the hot fluid discharge pipe to the hot fluid inlet of the front fixing plate 1 respectively. 2 and hot fluid outlet 8, the cold fluid injection pipe and the cold fluid discharge pipe are connected to the hot fluid inlet 2 and the hot fluid outlet 8 of the front fixed plate 1 respectively, and the assembly of the plate heat exchanger is completed. In the process of the single heat exchange plate 6 squeezing the double heat exchange plate 7, the main transition pipe 3 and the auxiliary transition pipe 5 on the surface of the single heat exchange plate 6 will abut the positioning ring 4 set in the double heat exchange plate 7, and the sealing strip 15 of the outer sealing layer 9 of the single heat exchange plate 6 will be correspondingly embedded in the sealing groove correspondingly opened on the outer sealing layer 9 of the double heat exchange plate 7, thereby completing the single heat exchange plate 6 and the double heat exchange plate 7. The sealing of the connection between them is improved, and the sealing layer 9 close to the front fixed plate 1 will be inserted into the sealing groove corresponding to the sealing strip 15, and the sealing strip 15 on the surface of the extrusion plate 13 will be embedded in the corresponding sealing groove, thereby completing the sealing and strengthening of the stability of the connection between the front fixed plate 1, the single heat exchange plate 6, the double heat exchange plate 7 and the extrusion plate 13. After that, the hot fluid will flow through the main transition pipe 3 of the single heat exchange plate 6 to the secondary transition pipe 5 of the double heat exchange plate 7, and then can flow in from the secondary transition pipe 5 at the upper end of the double heat exchange plate 7, and flow out from the secondary transition pipe 5 at the lower end of the double heat exchange plate 7. Out, that is, it flows in from the hot fluid inlet 2 and flows out from the hot fluid outlet 8, and the cold fluid will flow to the secondary transition pipe 5 of the single heat exchange plate 6 through the main transition pipe 3 of the double heat exchange plate 7, and then the cold fluid flows in from the secondary transition pipe 5 at the lower end of the single heat exchange plate 6 and flows out from the secondary transition pipe 5 at the upper end of the single heat exchange plate 6, that is, it flows in from the cold fluid inlet 16 and flows out from the cold fluid outlet 17, so that the single heat exchange plate 6 and the double heat exchange plate 7 are alternately distributed between the cold fluid and the hot fluid, so that the marine plate heat exchanger can smoothly perform the corresponding heat exchange processing on the ship.

[0020] As a preferred embodiment, the front fixing plate 1 and the rear fixing plate 11 are both rectangular structures, and three sets of side rods 12 are fixedly connected in parallel and equidistantly on both sides of the front fixing plate 1, while the side rods 12 and the bottom rod 10 are both cylindrical structures, and a threaded structure is provided at one end of the side rod 12 close to the rear fixing plate 11.

[0021] In this embodiment, if Figure 1 and Figure 2 The front fixing plate 1 and the rear fixing plate 11 are fixedly connected by the side rods 12 and the bottom rods 10, which can help enhance the stability of the plate heat exchanger when it is placed. At the same time, the position distribution of the side rods 12 and the bottom rods 10 can ensure the stable loading and unloading of the single heat exchange plate 6 and the double heat exchange plate 7, thereby reducing the difficulty of loading and unloading the plate heat exchanger.

[0022] As a preferred embodiment, the sealing layer 9 has a U-shaped structure, and an installation groove is provided on the inner side of the sealing layer 9, and the inner side of the sealing layer 9 is fixedly connected to the single heat exchange plate 6 and the double heat exchange plate 7 through the installation groove, and three groups of sealing strips 15 are fixedly connected at equal intervals on one side of the surface of the sealing layer 9 close to the front fixed plate 1, and a sealing groove is provided on the other side of the sealing layer 9 corresponding to the position of the sealing strip 15, and the single heat exchange plate 6 and the double heat exchange plate 7 are alternately distributed.

[0023] In this embodiment, if Figure 2 and Figure 3 The sealing layer 9 can be made of soft rubber material, which can help enhance the sealing of the connection between the single heat exchange plate 6 and the double heat exchange plate 7. Moreover, the single heat exchange plate 6 and the double heat exchange plate 7 are alternately distributed to facilitate the staggered flow of hot fluid and cold inflow, thereby ensuring the normal operation of the plate heat exchanger.

[0024] As a preferred embodiment, the sealing strip 15 is in a U-shaped structure, and the sizes of the three groups of sealing strips 15 on the surface of the sealing layer 9 gradually increase from the inside to the outside, and the cross-section of the sealing strip 15 is in a semicircular structure, and the sizes of the sealing strip 15 and the sealing groove are matched. At the same time, a sealing groove is opened on the surface of the front fixed plate 1 corresponding to the position of the sealing strip 15.

[0025] In this embodiment, if Figure 1 , Figure 2 and Figure 3 The provision of the sealing strip 15 and the sealing groove can help enhance the sealing of the connection between adjacent sealing layers 9, and can also help enhance the stability of the connection between the front fixing plate 1, the sealing layer 9 and the extrusion plate 13, thereby avoiding the problem of loosening of the single heat exchange plate 6 and the double heat exchange plate 7 due to the shaking of the ship during operation.

[0026] As a preferred embodiment, the extrusion plate 13 has a rectangular structure, and through holes are opened on the surface of the extrusion plate 13 corresponding to the positions of the side rods 12 and the bottom rod 10. The size of the extrusion plate 13 is larger than the size of the single heat exchange plate 6. At the same time, the sealing strip 15 fixedly connected to the surface of the extrusion plate 13 is opposite to the sealing groove opened on the surface of the sealing layer 9.

[0027] In this embodiment, if Figure 1 , Figure 2 and Figure 3 The size of the extrusion plate 13 is larger than that of the single heat exchange plate 6, which makes it easier for the extrusion plate 13 to fully extrude the corresponding single heat exchange plate 6, so that the single heat exchange plate 6 and the double heat exchange plate 7 can fit tightly together, and the fastening sleeve 14 screwed to the side rod 12 through the threaded structure can effectively enhance the fixing effect of the extrusion plate 13 on the single heat exchange plate 6 and the double heat exchange plate 7.

[0028] As a preferred embodiment, a hot fluid inlet 2, a hot fluid outlet 8, a cold fluid inlet 16 and a cold fluid outlet 17 are provided on the surface of the single heat exchange plate 6 and the double heat exchange plate 7, and are fixedly connected to a positioning ring 4, which has a circular ring structure, and a sealing sleeve is fixedly connected to the side of the positioning ring 4 close to the rear fixed plate 11, and the sealing sleeve has a cylindrical structure.

[0029] In this embodiment, if Figure 3 and Figure 4 The sealing sleeve can be made of soft rubber material, and the setting of the sealing sleeve enhances the sealing performance of the connection between the main transition pipe 3 and the auxiliary transition pipe 5 between the adjacent single heat exchange plates 6 and the double heat exchange plates 7 and the corresponding positioning ring 4, thereby reducing the probability of cold fluid and hot fluid mixing failure in the plate heat exchanger.

[0030] As a preferred embodiment, the main transition pipe 3 and the auxiliary transition pipe 5 are both cylindrical structures, and the main transition pipe 3 and the auxiliary transition pipe 5 are both fixedly connected to the side of the positioning ring 4 close to the front fixed plate 1, and the side of the main transition pipe 3 and the auxiliary transition pipe 5 away from the positioning ring 4 is a truncated cone structure, and at the same time, the side of the auxiliary transition pipe 5 is symmetrically opened with through openings, and the through openings are an arc-shaped structure.

[0031] In this embodiment, if Figure 1 and Figure 3 The structural arrangement of the main transition pipe 3 and the secondary transition pipe 5 can reduce the difficulty of embedding into the corresponding sealing sleeve, and can also assist in enhancing the structural strength of the connection between the adjacent single heat exchange plates 6 and the double heat exchange plates 7, thereby further reducing the probability of the internal structure of the plate heat exchanger loosening due to the shaking of the ship's operation, and through the cooperation of the main transition pipe 3 and the secondary transition pipe 5, the hot fluid and the cold fluid can flow in a staggered manner in the plate heat exchanger, thereby improving the heat exchange effect.

[0032] The marine plate heat exchanger of the utility model can effectively enhance the sealing of the connection between the single heat exchange plate 6 and the double heat exchange plate 7 through the cooperation of the sealing layer 9, the sealing strip 15, the main transition pipe 3 and the secondary transition pipe 5, and reduce the probability of fluid leakage. The sealing strip 15, the sealing groove, the main transition pipe 3 and the secondary transition pipe 5 can effectively enhance the stability of the connection between the internal components of the plate heat exchanger, thereby reducing the probability of loosening of the components and reducing the failure rate of fluid leakage.

[0033] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A marine plate heat exchanger, comprising: A front fixing plate (1) and a single heat exchange plate (6), wherein the upper and lower ends of one side of the front fixing plate (1) are respectively provided with a hot fluid inlet (2) and a hot fluid outlet (8), and the upper and lower ends of the other side of the front fixing plate (1) are symmetrically provided with a cold fluid outlet (17) and a cold fluid inlet (16), characterized in that: the two sides and the lower end of the front fixing plate (1) are respectively fixedly connected to one end of a side rod (12) and a bottom rod (10), the other ends of the side rod (12) and the bottom rod (10) are fixedly connected to a rear fixing plate (11), and one end of the side rod (12) close to the rear fixing plate (11) is screwed to a fastening sleeve (14), and the upper surface of the bottom rod (10) is slidably connected to the single heat exchange plate (6) and the double heat exchange plate (7), and the extrusion plate (13) is slidably connected to the side rod (12) through a through hole, and at the same time, the single heat exchange plate (6) The surfaces of the double heat exchange plates (7) are provided with a hot fluid inlet (2), a hot fluid outlet (8), a cold fluid inlet (16) and a cold fluid outlet (17); the hot fluid inlet (2) and the hot fluid outlet (8) provided on the single heat exchange plate (6) are fixedly connected to the main transition pipe (3); the cold fluid inlet (16) and the cold fluid outlet (17) provided on the single heat exchange plate (6) are fixedly connected to the secondary transition pipe (5); the hot fluid inlet (2) and the hot fluid outlet (8) provided on the double heat exchange plate (7) are fixedly connected to the secondary transition pipe (5); the cold fluid inlet (16) and the cold fluid outlet (17) provided on the double heat exchange plate (7) are fixedly connected to the main transition pipe (3); and the outer sides of the single heat exchange plate (6) and the double heat exchange plate (7) are fixedly connected to the sealing layer (9).

2. A marine plate heat exchanger according to claim 1, characterized in that: The front fixing plate (1) and the rear fixing plate (11) are both rectangular in structure, and three sets of side rods (12) are fixedly connected in parallel and at equal intervals on both sides of the front fixing plate (1), while the side rods (12) and the bottom rod (10) are both cylindrical in structure, and a threaded structure is provided at one end of the side rod (12) close to the rear fixing plate (11).

3. A marine plate heat exchanger according to claim 1, characterized in that: The sealing layer (9) is in a U-shaped structure, and a mounting groove is provided on the inner side of the sealing layer (9), and the inner side of the sealing layer (9) is respectively fixedly connected to the single heat exchange plate (6) and the double heat exchange plate (7) through the mounting groove, and three groups of sealing strips (15) are fixedly connected at equal intervals on one side of the surface of the sealing layer (9) close to the front fixed plate (1), and a sealing groove is provided on the other side of the sealing layer (9) corresponding to the position of the sealing strip (15), and the single heat exchange plate (6) and the double heat exchange plate (7) are alternately distributed.

4. A marine plate heat exchanger according to claim 3, characterized in that: The sealing strip (15) is in a U-shaped structure, and the size of the three groups of sealing strips (15) on the surface of the sealing layer (9) gradually increases from the inside to the outside, and the cross-section of the sealing strip (15) is in a semicircular structure. The size of the sealing strip (15) and the sealing groove are matched, and the sealing groove is provided on the surface of the front fixing plate (1) corresponding to the position of the sealing strip (15).

5. A marine plate heat exchanger according to claim 1, characterized in that: The extrusion plate (13) has a rectangular structure, and through holes are provided on the surface of the extrusion plate (13) at positions corresponding to the side rods (12) and the bottom rod (10). The size of the extrusion plate (13) is larger than the size of the single heat exchange plate (6), and the sealing strip (15) fixedly connected to the surface of the extrusion plate (13) faces the sealing groove provided on the surface of the sealing layer (9).

6. A marine plate heat exchanger according to claim 1, characterized in that: The surfaces of the single heat exchange plate (6) and the double heat exchange plate (7) are provided with a hot fluid inlet (2), a hot fluid outlet (8), a cold fluid inlet (16) and a cold fluid outlet (17), and are all fixedly connected to a positioning ring (4), the positioning ring (4) being in a circular ring structure, and a sealing sleeve being fixedly connected to a side of the positioning ring (4) close to the rear fixed plate (11), the sealing sleeve being in a cylindrical structure.

7. A marine plate heat exchanger according to claim 1, characterized in that: The main transition pipe (3) and the auxiliary transition pipe (5) are both cylindrical in structure, and are both fixedly connected to a side of the positioning ring (4) close to the front fixing plate (1), and the sides of the main transition pipe (3) and the auxiliary transition pipe (5) away from the positioning ring (4) are truncated cone-shaped in structure, and the side of the auxiliary transition pipe (5) is symmetrically provided with through openings, and the through openings are in an arc-shaped structure.

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