Inlet connecting piece without forked cone and quenching heat exchanger with inlet connecting piece

Abstract

The utility model relates to the technical field of petrochemical equipment, in particular to an inlet connecting piece without a forked cone and a quenching heat exchanger with the same, the inlet connecting piece comprises a cooling medium connecting piece and a cracking furnace connecting pipe, the cooling medium connecting piece comprises an outer connecting pipe and an inner connecting pipe which are concentrically arranged, and an annular channel is formed between the outer connecting pipe and the inner connecting pipe. And the external pipe is provided with a cooling medium input pipe communicated with the annular channel. The cracking furnace connecting pipe is of a single-layer pipe structure, is welded and fixed to the bottom of the cooling medium connecting piece and is communicated with the inner connecting pipe, an anti-overheating structure is arranged at the connecting position of the cracking furnace connecting pipe and the cooling medium connecting piece, and the anti-overheating structure is one or a combination of more than two of a heat insulation structure, an attaching heat conduction structure and a water-cooling heat conduction structure. Compared with the prior art, the manufacturing and production of the single-layer pipe are relatively time-saving and labor-saving, and the manufacturing and maintenance cost is reduced. And the anti-overheating structure can prevent heat at the connection part of the cracking furnace connecting pipe and the cooling medium connecting piece from being excessively concentrated, so that safe and smooth use of equipment is guaranteed.

Description

Technical Field

[0001] This utility model relates to the field of petrochemical equipment technology, specifically to an inlet connector that eliminates the forked cone and a quench heat exchanger incorporating it. Background Technology

[0002] The cracking furnace is a key unit in an ethylene plant. After being cracked at high temperatures in the furnace tubes, the feedstock enters a quench heat exchanger for rapid cooling to prevent secondary reactions, reduce olefin loss, and recover heat energy to generate steam. With the development of quench technology in ethylene cracking furnaces, linear quench heat exchangers are now widely used in newly built and renovated cracking furnaces to further shorten the residence time in the adiabatic section of the quench heat exchanger and avoid uneven distribution of cracked gas.

[0003] As is well known, a linear quench heat exchanger consists of an inlet connector, double-tube heat exchange elements, a cooling medium connector, an outlet connector, a water-steam header, a high-temperature medium header, and a hydraulic descaling port. Based on this, the structural form of the linear quench heat exchanger is as follows: Each double-tube heat exchange element consists of two concentric tubes. The inner tube carries the high-temperature medium—cracking gas at approximately 800°C—while the annular gap between the outer and inner tubes carries the cooling medium—a water-steam mixture at approximately 350°C. Each double-tube heat exchange element is connected to a cracking furnace outlet tube via an inlet connector. The double-tube heat exchange elements are arranged in parallel in a single or double row and connected together via the water-steam header and the high-temperature medium header to form a linear quench heat exchanger.

[0004] For example, Chinese patent document CN101975527B discloses an inlet connector and a linear quench heat exchanger using the inlet connector. The inlet connector consists of an inlet cone, a heat insulation component, a sealing component, a protective sleeve, and a cooling medium connector. The cooling medium connector is a rotating body with an outwardly convex curved cross-section, which can effectively absorb the thermal expansion difference stress between the inner and outer tubes of the double-tube heat exchange element. The protective sleeve provides excellent thermal protection for the deep-hole weld joint and the inlet portion of the cooling medium connector.

[0005] For example, Chinese patent document CN203908384U discloses an inlet connector for a linear quench heat exchanger. One end of the inlet connector is connected to the outlet furnace tube of a pyrolysis furnace, and the other end is connected to a double-tube heat exchange element. The inlet connector mainly consists of an inlet cone, a heat insulation component, and a cooling medium connector. The cooling medium connector is a double-walled tube sheet connector structure. After butt welding with the double-tube heat exchange element, the lower gap of the cavity is larger than the upper gap, which can effectively reduce the thermal intensity of the inlet connector and the double-tube heat exchange element.

[0006] Existing technology connects two sleeves through an inlet "forked cone". The forked cone has an inner and outer double-layer structure. This complex double-layer structure is difficult to manufacture and process, and has high manufacturing and maintenance costs. Summary of the Invention

[0007] In view of the above-mentioned technical problems, the present invention provides an inlet connector with a forked cone and a quench heat exchanger with the forked cone.

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] A novel inlet connector with a forked cone shape is provided, comprising a cooling medium connector and a pyrolysis furnace inlet pipe. The cooling medium connector includes an outer inlet pipe and an inner inlet pipe arranged concentrically, forming an annular channel between the outer and inner inlet pipes. The outer inlet pipe is provided with a cooling medium inlet pipe communicating with the annular channel. Its distinguishing feature is:

[0010] The pyrolysis furnace connecting pipe is a single-layer pipe structure, which is welded and fixed to the bottom of the cooling medium connector and connected to the inner connecting pipe. The connection between the pyrolysis furnace connecting pipe and the cooling medium connector is equipped with an overheat protection structure, which is one or a combination of two or more of the following: heat insulation structure, heat-conducting structure, and water-cooled heat-conducting structure.

[0011] The heat insulation structure is a heat-insulating part installed on the inside of the connection between the inner pipe and the pyrolysis furnace pipe.

[0012] The heat-conducting structure includes a heat-conducting flange located at the end of the pyrolysis furnace nozzle. The heat-conducting flange is attached to the end face of the cooling medium connector, and the outer diameter of the heat-conducting flange is equal to or greater than the maximum outer diameter of the cooling medium connector.

[0013] The water-cooled heat conduction structure is an auxiliary water-cooling channel that allows cooling medium to flow near the connection between the inner pipe and the pyrolysis furnace pipe.

[0014] As a further alternative, the heat-insulating part is located on the inner wall of the inner pipe, and / or on the inner wall of the pyrolysis furnace pipe.

[0015] As a further alternative, the inner wall of the internal connecting pipe is flush with the inner wall of the cracking furnace connecting pipe.

[0016] As a further alternative, the inner wall of the inner pipe and / or the inner wall of the pyrolysis furnace pipe is provided with a receiving groove, and the heat-insulating part is disposed in the receiving groove, so that the surface of the heat-insulating part is flush with the inner wall surface.

[0017] As a further alternative, the auxiliary water cooling channel is connected to the cooling medium input pipe via a bypass pipe.

[0018] As a further alternative, the auxiliary water cooling channel is an annular hole near the inner wall of the inner pipe.

[0019] As a further optional solution, a thermally conductive filler layer is provided between the contact surfaces of the thermally conductive flange and the cooling medium connector.

[0020] As a further alternative, a niobium-molybdenum alloy pad or a nickel-platinum alloy pad can be used for the heat insulation section.

[0021] As a further optional feature, the cooling medium connector is also equipped with a normally closed drain pipe that connects to the annular channel.

[0022] As a further alternative, the cooling medium inlet pipe and the drain pipe are connected tangentially in a ring-shaped channel.

[0023] A quench heat exchanger includes an inner sleeve, an outer sleeve, an outlet connector, and an inlet connector. The inner sleeve is concentrically inserted into the outer sleeve, and an annular jacketed channel is formed between the outer wall of the inner sleeve and the inner wall of the outer sleeve. The inlet connector is a type of inlet connector without a forked cone as described above. The lower end of the inner sleeve is welded and fixed by the inner pipe, and the lower end of the outer sleeve is welded and fixed by the outer pipe.

[0024] The beneficial effects of this utility model are:

[0025] This utility model discloses an inlet connector with an eliminated forked cone and a quench heat exchanger incorporating it. Compared with existing technologies, the pipe connecting to the external pyrolysis furnace is replaced with a single-layer pipe, eliminating the forked cone. This reduces manufacturing time and labor costs, as well as manufacturing and maintenance costs. Furthermore, an overheat protection structure is designed to prevent excessive heat concentration at the connection between the pyrolysis furnace pipe and the cooling medium connector, ensuring safe and smooth operation of the equipment. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of an embodiment of the present invention, which eliminates the forked cone inlet connector and a quench heat exchanger with the forked cone.

[0027] Figure 2 This is a schematic diagram of Embodiment 2 of the present invention, which eliminates the forked cone inlet connector and includes a quench heat exchanger.

[0028] Figure 3 This is a schematic diagram of Embodiment 3 of the present invention, which describes an inlet connector without a forked cone and a quench heat exchanger with the forked cone.

[0029] Figure 4 This is a schematic diagram of Embodiment 4 of the present invention, which describes an inlet connector without a forked cone and a quench heat exchanger with the forked cone.

[0030] Figure 5 This is a schematic diagram of Embodiment 5 of the present invention, which eliminates the forked cone inlet connector and includes a quench heat exchanger.

[0031] Figure label:

[0032] Cooling medium connector 1, outer pipe 11, inner pipe 12, annular channel 13;

[0033] 2. Pyrolysis furnace nozzle; 21. Thermally conductive flange;

[0034] Cooling medium inlet pipe 3; heat insulation part 4;

[0035] 5. Auxiliary water cooling channel; 6. Bypass pipe; 7. Sewage pipe. Detailed Implementation

[0036] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0037] This embodiment provides an inlet connector without a forked cone and a quench heat exchanger incorporating it, such as... Figures 1 to 5 As shown, it includes a cooling medium connector 1 and a pyrolysis furnace connecting pipe 2. The cooling medium connector 1 includes an outer connecting pipe 11 and an inner connecting pipe 12 arranged concentrically, forming an annular channel 13 between the outer connecting pipe 11 and the inner connecting pipe 12. The outer connecting pipe 11 is provided with a cooling medium inlet pipe 3 communicating with the annular channel 13. The main improvement is:

[0038] The pyrolysis furnace connecting pipe 2 is a single-layer pipe structure, which is welded and fixed to the bottom of the cooling medium connector 1 and connected to the inner connecting pipe 12. The inner wall of the inner connecting pipe 12 is flush with the inner wall of the pyrolysis furnace connecting pipe 2. The pipe connected to the external pyrolysis furnace is changed to a single-layer pipe, which saves time and effort in manufacturing and reduces manufacturing and maintenance costs.

[0039] To prevent excessive heat concentration at the connection between the pyrolysis furnace pipe 2 and the cooling medium connector 1, an overheat protection structure is installed at this connection. There are three types of overheat protection structures:

[0040] The first type of overheat protection structure is as follows: Figure 1 The heat insulation structure shown is a heat-insulating part 4 located inside the connection between the inner pipe 12 and the pyrolysis furnace pipe 2. Preferably, the heat-insulating part 4 is a niobium-molybdenum alloy pad or a nickel-platinum alloy pad. Figure 1 The intermediate heat-resistant section 4 is located on the inner wall of the inner pipe 12, but it can actually be installed on the inner wall of the cracking furnace pipe 2, or as follows: Figure 2 The heat-insulating part 4 is simultaneously provided on the inner wall of the inner tube 12 and the inner wall of the pyrolysis furnace tube 2. The inner walls of both the inner tube 12 and the pyrolysis furnace tube 2 have receiving grooves, and the heat-insulating part 4 is disposed in the receiving grooves, thereby making the surface of the heat-insulating part 4 flush with the inner wall surface. The heat-insulating part 4 is connected by metallurgical atomic connections (such as 3D printing, cladding welding, etc.).

[0041] The second type of overheat protection structure is as follows: Figure 3 The heat-conducting structure shown includes a heat-conducting flange 21 located at the end of the pyrolysis furnace nozzle 2. The heat-conducting flange 21 is attached to the end face of the cooling medium connector 1. The outer diameter of the heat-conducting flange 21 is equal to or greater than the maximum outer diameter of the cooling medium connector 1, increasing the heat transfer area and thus preventing excessive heat concentration. In practice, a heat-conducting filler layer or a heat-conducting coating can be provided between the contact surfaces of the heat-conducting flange 21 and the cooling medium connector 1 to improve heat transfer efficiency.

[0042] The third type of overheat protection structure is as follows: Figure 4 The water-cooled heat conduction structure shown is an auxiliary water-cooling channel 5 near the connection between the inner pipe 12 and the cracking furnace pipe 2, through which the cooling medium can flow. Heat is carried away by the cooling water flowing alongside, preventing heat concentration. The auxiliary water-cooling channel 5 is connected to the cooling medium input pipe 3 and the annular channel 13 via a bypass pipe 6. The auxiliary water-cooling channel 5 is an annular hole near the inner wall of the inner pipe 12.

[0043] The above three overheat protection structures can be used individually or in combination of two or more, such as... Figure 5 The diagram shows the simultaneous use of the three methods.

[0044] In this embodiment, the cooling medium connector 1 is also provided with a normally closed drain pipe 7 that connects to the annular channel 13. The cooling medium inlet pipe 3 and the drain pipe 7 are tangentially connected to the annular channel 13.

[0045] When the inlet connector of this embodiment is applied to a linear quench heat exchanger, it can be used in accordance with conventional methods. Specifically, refer to the structure disclosed in Chinese Patent Document CN222165786U, which includes an inner sleeve, an outer sleeve, an outlet connector, and an inlet connector. The inner sleeve is concentrically inserted into the outer sleeve, and an annular jacketed channel is formed between the outer wall of the inner sleeve and the inner wall of the outer sleeve. The inlet connector is a type of inlet connector without the forked cone described above. The inner pipe is welded to and fixed to the lower end of the inner sleeve, and the outer pipe is welded to and fixed to the lower end of the outer sleeve. The outlet connector includes an upper central pipe and an outer outlet pipe. The upper central pipe connects to the upper end of the inner sleeve and is inserted into the outer outlet pipe. An upper annular channel with a sealed top is formed between the upper central pipe and the outer outlet pipe. The outer outlet pipe connects to the upper end of the outer sleeve and is connected to a laterally arranged cooling medium outlet pipe. The relative connections of these parts are all prior art.

[0046] In the description of this utility model, it is obvious that the described embodiments are only a part of the embodiments of this utility model, and not all of them. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0047] Therefore, the above detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0048] In the description of this utility model, it should be noted that the terms "middle," "upper," "lower," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use. They are used only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0049] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "set," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection. They can refer to a mechanical connection or an electrical connection. They can refer to a direct connection or an indirect connection through an intermediate medium, or a connection within two components. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

Claims

1. An inlet connector without a forked cone, comprising a cooling medium connector (1) and a pyrolysis furnace pipe (2), wherein the cooling medium connector (1) comprises an outer pipe (11) and an inner pipe (12) arranged concentrically, an annular channel (13) is formed between the outer pipe (11) and the inner pipe (12), and the outer pipe (11) is provided with a cooling medium inlet pipe (3) communicating with the annular channel (13), characterized in that: The pyrolysis furnace connecting pipe (2) is a single-layer pipe structure. It is welded and fixed to the bottom of the cooling medium connector (1) and connected to the inner connecting pipe (12). The connection between the pyrolysis furnace connecting pipe (2) and the cooling medium connector (1) is provided with an overheat protection structure. The overheat protection structure is one or a combination of two or more of the following: heat insulation structure, heat-conducting structure, and water-cooled heat-conducting structure. The heat insulation structure is a heat-insulating part (4) located on the inside of the connection between the inner pipe (12) and the pyrolysis furnace pipe (2); The heat-conducting structure includes a heat-conducting flange (21) located at the end of the pyrolysis furnace nozzle (2), the heat-conducting flange (21) is attached to the end face of the cooling medium connector (1), and the outer diameter of the heat-conducting flange (21) is equal to or greater than the maximum outer diameter of the cooling medium connector (1). The water-cooled heat conduction structure is an auxiliary water-cooling channel (5) that allows cooling medium to flow near the connection between the inner pipe (12) and the pyrolysis furnace pipe (2).

2. The inlet connector with a forked cone shape as described in claim 1, characterized in that: The heat-insulating part (4) is located on the inner wall of the inner pipe (12) and / or on the inner wall of the pyrolysis furnace pipe (2).

3. The inlet connector with a forked cone shape as described in claim 2, characterized in that: The inner wall of the inner pipe (12) is flush with the inner wall of the cracking furnace pipe (2).

4. An inlet connector with a forked cone shape as described in claim 3, characterized in that: The inner wall of the inner pipe (12) and / or the inner wall of the pyrolysis furnace pipe (2) has a receiving groove, and the heat-insulating part (4) is disposed in the receiving groove, so that the surface of the heat-insulating part (4) is flush with the inner wall surface.

5. An inlet connector with a forked cone shape as described in claim 1, characterized in that: The auxiliary water cooling channel (5) is connected to the cooling medium input pipe (3) via the bypass pipe (6).

6. An inlet connector with a forked cone shape as described in claim 1, characterized in that: The auxiliary water cooling channel (5) is an annular hole near the inner wall of the inner pipe (12).

7. An inlet connector with a forked cone shape as described in claim 1, characterized in that: A thermally conductive filler layer is provided between the mating surfaces of the thermally conductive flange (21) and the cooling medium connector (1).

8. An inlet connector with a forked cone shape as described in claim 1, characterized in that: Heat-insulating part (4) Niobium-molybdenum alloy pad or nickel-platinum alloy pad.

9. An inlet connector with a forked cone shape as described in claim 1, characterized in that: The cooling medium connector (1) is also provided with a normally closed drain pipe (7) that connects to the annular channel (13); the cooling medium input pipe (3) is tangentially connected to the annular channel (13) with the drain pipe (7).

10. A quench heat exchanger, comprising an inner sleeve, an outer sleeve, an outlet connector, and an inlet connector, wherein the inner sleeve is concentrically inserted within the outer sleeve, and an annular jacketed channel is formed between the outer wall of the inner sleeve and the inner wall of the outer sleeve; characterized in that: The inlet connector is an inlet connector without a fork cone as described in any one of claims 1 to 9, wherein the inner pipe (12) is welded to fix the lower end of the inner sleeve, and the outer pipe (11) is welded to fix the lower end of the outer sleeve.

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