Steel sleeve steel straight pipe section for pneumatic conveying of high-temperature materials

Abstract

The utility model belongs to the field of material conveying, and relates to a steel sleeve steel straight pipe section for pneumatic conveying of high-temperature materials. The straight pipe section is composed of an outer pipe, an inner pipe, a sealing filler base, a sealing filler gland, a gland bolt, a small-head sealing filler, an inner and outer pipe connecting plate, an inner and outer pipe connecting bolt, an inner and outer pipe connecting pad, a large-head sealing filler, a sealing filler pre-tightening spring, a heat insulation layer and a flange sealing assembly. The inner pipe is a reducer pipe, an inlet large end is in bolted connection with the outer pipe, and an outlet small end can be inserted into a connected pipe section large end. And a heat insulation layer is filled between the inner and outer pipes to reduce heat loss. Double sealing of the sealing filler is achieved through the pre-tightening spring and the gland bolt, and gas is prevented from entering. The design effectively solves the problems of thermal expansion and sealing of the pipeline in pneumatic conveying of high-temperature materials, and the conveying efficiency and safety are improved.

Description

Technical Field

[0001] This utility model belongs to the field of material conveying and relates to a steel-jacketed straight pipe section for pneumatic conveying of high-temperature materials. Background Technology

[0002] In industrial production, pneumatic conveying of high-temperature materials is a crucial process widely used in metallurgy, chemical engineering, building materials, and other fields. This conveying process requires pipeline systems to operate stably under harsh environments of high temperature and high pressure, while also withstanding the erosion and wear of materials to ensure conveying efficiency and product quality. However, traditional single-layer high-temperature material conveying pipelines often have many shortcomings in meeting these challenges.

[0003] First, high-temperature materials transfer heat to the pipeline during transport, causing the pipeline temperature to rise. Ordinary carbon steel pipelines operating at temperatures above 425℃ for extended periods are at risk of creep, which affects their strength. Therefore, if single-layer pipelines are used to transport high-temperature and high-pressure materials, alloy materials with better wear resistance and temperature resistance must be selected, thus increasing costs.

[0004] Secondly, single-layer pipelines operate directly at high temperatures, resulting in significant expansion. The piping system requires compensators with substantial compensation capacity, or multiple compensators, to prevent bending deformation, leading to difficulties in selection and increased maintenance costs.

[0005] To address the aforementioned issues, steel-jacketed steel pipeline structures are increasingly being applied to the pneumatic conveying of high-temperature materials. A steel-jacketed steel pipeline consists of an inner and an outer pipe. The inner pipe withstands the high-temperature environment and the erosion and abrasion of the material, while the outer pipe withstands the pressure of the conveyed gas. Insulation material is filled between the inner and outer pipes to isolate the outer pipe from the high-temperature environment and reduce its operating temperature. However, existing steel-jacketed steel pipeline structures still have some shortcomings in coping with the challenges of high temperature, high pressure, and material erosion and abrasion.

[0006] On the one hand, the difference in operating temperature between the inner and outer pipes leads to a difference in thermal expansion. If the piping system is not designed properly, this can cause bending and deformation of the pipeline system. This deformation not only affects the stability and safety of the pipeline system, but also increases the risk of leakage at pipe connections.

[0007] On the other hand, during pneumatic conveying, pressure fluctuations may occur within the pipeline, causing the conveyed gas to leak between the inner and outer pipes. This not only causes erosion and wear on the insulation material but also increases the operating temperature of the outer pipe, further exacerbating the risk of deformation and leakage in the pipeline system.

[0008] Therefore, designing a steel-jacketed steel pipeline structure for pneumatic conveying of high-temperature materials that can effectively control thermal expansion and prevent air leakage between the inner and outer pipes has become an urgent problem to be solved. Utility Model Content

[0009] In view of this, the purpose of this utility model is to provide a steel-jacketed straight pipe section for pneumatic conveying of high-temperature materials, so as to solve the above problems.

[0010] To achieve the above objectives, this utility model provides the following technical solution: a steel-jacketed straight pipe section for pneumatic conveying of high-temperature materials, characterized in that it includes an outer pipe, an inner pipe, a sealing packing base, a sealing packing gland, gland bolts, a small-end sealing packing, an inner and outer pipe connecting plate, an inner and outer pipe connecting bolts, an inner and outer pipe connecting gasket, a large-end sealing packing, a sealing packing pre-tightening spring, a heat insulation layer, and a flange sealing assembly.

[0011] The inner tube is a reducing pipe, with the inlet side being the larger end and the outlet side being the smaller end; the outer tube and the inner tube are connected by an inner and outer tube connecting plate, an inner and outer tube connecting bolt, and an inner and outer tube connecting gasket, and the outer tube is welded to the inner and outer tube connecting plate.

[0012] Optionally, the large end of the inner tube is provided with a large end sealing packing and a sealing packing pre-tightening spring, and the outer side of the small end is provided with a sealing packing base, a small end sealing packing and a sealing packing gland in sequence. The sealing packing base is welded to the outer tube, and the gland bolts connect the sealing packing base and the sealing packing gland.

[0013] Optionally, the small-head sealing packing is placed between the sealing packing base and the sealing packing gland, and radial sealing is achieved by the axial preload applied by the gland bolts;

[0014] The sealing packing pre-tightening spring acts on the large-end sealing packing. The sealing packing pre-tightening spring and the large-end sealing packing are placed in the cavity between the connecting plate, the inner tube and the sealing packing gland. The large-end sealing packing achieves radial sealing through the elastic deformation force of the pre-tightening spring.

[0015] Optionally, multiple steel-cased straight pipe sections are connected along the medium flow direction via flange sealing assemblies, with the small end of the front inner pipe inserted into the large end of the rear inner pipe.

[0016] Optionally, both the sealing packing base and the inner and outer tube connecting plate are provided with vent holes.

[0017] Optionally, the heat insulation layer is filled between the outer tube and the inner tube and is made of aluminum silicate.

[0018] Optionally, the inner tube is a bimetallic tube.

[0019] Optionally, the small-head sealing packing and the large-head sealing packing are high-temperature resistant graphite packing.

[0020] Optionally, the sealing packing preload spring is made of a high-temperature nickel-based alloy.

[0021] Optionally, the inner and outer tube connecting pad is placed between the inner and outer tube connecting plate and the inner tube.

[0022] The beneficial effects of this utility model are as follows:

[0023] Controllable expansion prevents pipe system bending and deformation: In this steel-jacketed straight pipe section design, the inner pipe expands independently in segments, avoiding pipe system bending and deformation caused by mutual compression of the inner pipes. This feature ensures the stability and safety of the pipeline system in high-temperature environments and reduces the risk of leakage caused by pipe deformation.

[0024] Highly efficient sealing to prevent gas ingress: Pre-tightening force is applied to the sealing packing on both the inlet and outlet sides of this straight pipe section to ensure a tight seal. This design effectively prevents gas from entering between the inner and outer pipes due to pressure fluctuations or differences in inner pipe deformation, thus avoiding the problems of insulation material erosion and wear, and excessively high operating temperature of the outer pipe.

[0025] Excellent high temperature resistance: The inner tube is made of bimetallic material, with the outer side being 15CrMo and the inner side being ZG45NI35CR26. Both of these materials have good high temperature resistance and can withstand the high temperature environment during the transportation of high-temperature materials, thus extending the service life of the pipeline.

[0026] Excellent thermal insulation: A thermal insulation layer made of aluminum silicate is filled between the inner and outer pipes, which effectively reduces the operating temperature of the outer pipe, minimizes heat loss, and improves energy efficiency. At the same time, this also protects the outer pipe from high-temperature environments, enhancing the overall stability of the pipeline system.

[0027] Easy maintenance and replacement: When the inner pipe is severely worn and needs replacement, simply disassemble the flange sealing assemblies on both sides of the outer pipe inlet and outlet, as well as the farthest steel-cased steel pipe assembly, loosen the gland bolts and the connecting bolts between the inner and outer pipes, and the inner pipe can be removed and replaced. This design greatly simplifies the maintenance process and reduces maintenance costs.

[0028] Compact structure and easy installation: This steel-jacketed straight pipe section adopts a standardized design with tight connections between components, resulting in a compact structure. Furthermore, multiple straight pipe sections can be easily connected into the required length using flange sealing assemblies, meeting the conveying needs under various working conditions.

[0029] Improving production efficiency and product quality: Due to its excellent high-temperature resistance, high-pressure sealing performance, and erosion resistance, this steel-jacketed straight pipe section can operate stably in harsh environments with high temperature, high pressure, and material erosion. This helps improve production efficiency, reduce downtime caused by pipeline failures, and also helps maintain the stability and consistency of conveyed materials, thereby improving product quality.

[0030] Other advantages, objectives, and features of this invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination and study, or may be learned from practice of this invention. The objectives and other advantages of this invention can be realized and obtained through the following description. Attached Figure Description

[0031] To make the objectives, technical solutions, and advantages of this utility model clearer, the preferred embodiments of this utility model will be described in detail below with reference to the accompanying drawings, wherein:

[0032] Figure 1 This is a schematic diagram of the structure of this utility model patent;

[0033] Figure 2 This is a partial enlarged view of the present utility model patent.

[0034] Reference numerals: 1. Outer tube; 2. Inner tube; 3. Sealing packing base; 4. Sealing packing gland; 5. Gland bolt; 6. Small-head sealing packing; 7. Inner and outer tube connecting plate; 8. Inner and outer tube connecting bolt; 9. Inner and outer tube connecting gasket; 10. Large-head sealing packing; 11. Sealing packing preload spring; 12. Thermal insulation layer; 13. Flange sealing assembly. Detailed Implementation

[0035] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this utility model. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0036] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the present invention. To better illustrate the embodiments of the present invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0037] In the accompanying drawings of this utility model, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are 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, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this utility model. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0038] Please see Figure 1 and Figure 2 This is a steel-jacketed straight pipe section for pneumatic conveying of high-temperature materials. The steel-jacketed straight pipe section includes an outer pipe 1, an inner pipe 2, a sealing packing base 3, a sealing packing gland 4, a gland bolt 5, a small-end sealing packing 6, an inner and outer pipe connecting plate 7, an inner and outer pipe connecting bolt 8, an inner and outer pipe connecting gasket 9, a large-end sealing packing 10, a sealing packing pre-tightening spring 11, a heat insulation layer 12, and a flange sealing assembly 13.

[0039] Furthermore, the length of the steel-clad straight pipe section is 1000mm to 4000mm.

[0040] Furthermore, the outer tube 1 is a seamless carbon steel pipe with an outer diameter of 530mm to 720mm and a wall thickness of 10mm to 15mm.

[0041] Furthermore, inner pipe 2 is a reducing pipe, and when viewed in the direction of medium flow, the inlet side is the larger end and the outlet side is the smaller end.

[0042] Furthermore, the inner tube 2 is made of bimetallic tubing and produced using centrifugal casting technology, with a total thickness of 30mm; the outer side is made of 15CrMo material with a thickness of 15-20mm; the inner side is made of ZG45NI35CR26 material with a wall thickness of 10-15mm.

[0043] Furthermore, the inner tube 2 needs to have a blind hole with internal thread for connecting bolts 8 between the inner and outer tubes machined on its larger end side.

[0044] Furthermore, the inner tube 2 needs to have a groove machined on the larger end side to install the sealing packing preload spring 11.

[0045] Furthermore, the outer tube 1 and the inner tube 2 are connected by the inner and outer tube connecting plate 7, the inner and outer tube connecting bolt 8, and the inner and outer tube connecting gasket 9. The outer tube 1 and the inner and outer tube connecting plate 7 are connected by welding.

[0046] Furthermore, the sealing packing base 3 is fitted onto the outer side of the small end of the inner tube 2 and is connected to the outer tube 1 by welding.

[0047] Furthermore, the gland bolt 5 is used to apply a preload between the sealing packing base 3 and the sealing packing gland 4 to compress and deform the small-head sealing packing 6, thereby achieving a small-head outer seal.

[0048] Furthermore, several steel-cased straight pipe sections can be interconnected through flange sealing assembly 13 to form a steel-cased straight pipe of a certain length, and looking in the direction of medium flow, the small end of the inner pipe 2 of the first steel-cased straight pipe section can be inserted into the large end of the inner pipe 2 of the second steel-cased straight pipe section.

[0049] Furthermore, the sealing packing pre-tightening spring 11 provided at the large end of the inner tube 2 deforms during the tightening of the flange sealing assembly 13 and presses the large end sealing packing 10 onto the sealing packing gland 4, thereby achieving a large end side seal.

[0050] Furthermore, the sealing packing preload spring 11 is made of Inconel X-750 high-temperature nickel-based alloy.

[0051] Furthermore, the sealing packing base 3 and the inner and outer tube connecting plate 7 are provided with vent holes to reduce the fluctuation of the outer tube working pressure.

[0052] Furthermore, the thermal insulation layer 12 is made of aluminum silicate to reduce the fluctuation of the working pressure of the outer pipe.

[0053] Furthermore, both the small-head sealing packing 6 and the large-head sealing packing 10 are made of high-temperature resistant graphite packing.

[0054] Specific implementation steps:

[0055] S1, Assembly of the outer and inner tubes: Place the inner tube 2 inside the outer tube 1, and connect and fix the outer tube 1 and inner tube 2 using the inner and outer tube connecting plate 7, inner and outer tube connecting bolts 8, and inner and outer tube connecting gaskets 9. Ensure the connection is tight and without looseness.

[0056] S2, Installation of sealing packing:

[0057] S21, a sealing packing base 3 is fitted onto the outer side of the small end of the inner tube 2 and welded to the outer tube 1 for fixation.

[0058] S22, install the small-head sealing packing 6 between the sealing packing base 3 and the inner tube 2, and apply pre-tightening force using the sealing packing gland 4 and gland bolt 5 to compress and deform the small-head sealing packing 6, thereby achieving a small-head outer seal.

[0059] S23, install the large-end sealing packing 10 and the sealing packing pre-tightening spring 11 at the large end of the inner tube 2 to ensure that the large-end sealing packing 10 is compressed during the tightening of the flange sealing assembly 13, thereby achieving a large-end side seal.

[0060] S3, Insulation layer filling: Insulation layer 12 is filled between inner tube 2 and outer tube 1. It is made of aluminum silicate to reduce heat loss and protect outer tube 1 from high temperature.

[0061] S4, Installation of flange sealing assembly:

[0062] S41, Install the flange sealing assembly 13 on the inlet and outlet sides of the outer pipe 1 to ensure that the sealing surface is flat and free of scratches or impurities.

[0063] S42, use bolts to tighten the flange sealing assembly 13 to ensure a good seal.

[0064] S5, Connection of multiple straight pipe sections: As needed, multiple steel-clad steel straight pipe sections are connected into a straight pipe section of the required length via flange sealing assembly 13. Ensure a good seal at the connection point and no leakage.

[0065] Example 1:

[0066] Application scenario: Pneumatic conveying system for blast furnace gas in a steel plant

[0067] Implementation steps:

[0068] S1, a seamless steel pipe of 20# steel with an outer diameter of 630mm and a wall thickness of 10mm is selected as the outer pipe 1, with a length of 4000mm.

[0069] S2 uses bimetallic tubing as the inner tube 2, with a total thickness of 30mm. The outer side is made of 15CrMo material with a thickness of 20mm, while the inner side is made of ZG45NI35CR26 material with a wall thickness of 10mm. The inner tube 2 is 4000mm long, with a large end outer diameter of 430mm and a small end outer diameter of 360mm.

[0070] S3. Following the specific implementation steps, assemble the outer pipe 1 and the inner pipe 2 together, and install the sealing filler, the heat insulation layer 12 and the flange sealing assembly 13.

[0071] S4 connects multiple steel-clad straight pipe sections into a straight pipe section of the required length through flange sealing assembly 13, and installs it into the blast furnace gas pneumatic conveying system.

[0072] S5, conduct system debugging and operation testing to ensure stable operation of the pipeline system and no leakage.

[0073] Implementation Results: This steel-jacketed straight pipe section performed excellently in the blast furnace gas pneumatic conveying system, effectively withstanding the challenges of high temperature, high pressure, and material erosion. The pipeline system operated stably without leakage, improving production efficiency and product quality.

[0074] Example 2:

[0075] Application scenario: Pneumatic conveying system for clinker in a cement plant

[0076] Implementation steps:

[0077] S1, a seamless carbon steel pipe with an outer diameter of 530mm and a wall thickness of 12mm is selected as the outer pipe 1, with a length of 3000mm.

[0078] S2, the same bimetallic tube as in Example 1 is selected as the inner tube 2, but the length is adjusted to 3000mm to meet the system requirements.

[0079] S3. Following the specific implementation steps described above, assemble the outer pipe 1 and the inner pipe 2 together, and install the sealing filler, the heat insulation layer 12, and the flange sealing assembly 13.

[0080] S4 connects multiple steel-clad straight pipe sections into a straight pipe section of the required length through flange sealing assembly 13, and installs it into the cement plant clinker pneumatic conveying system.

[0081] S5, conduct system debugging and operation testing to ensure stable operation of the pipeline system and meet the requirements of clinker pneumatic conveying.

[0082] Implementation Results: This steel-jacketed straight pipe section also performed excellently in the cement plant's clinker pneumatic conveying system, effectively addressing the challenges of high temperature, high pressure, and material erosion. The pipeline system operated stably with high conveying efficiency, meeting the cement plant's production needs. Furthermore, the design of this straight pipe section facilitates maintenance and replacement, reducing maintenance costs.

[0083] In operation, this invention allows for independent expansion of the inner sleeves in segments, preventing problems such as pipe bending and deformation, and flange leakage caused by mutual compression of the inner sleeves. Simultaneously, pre-tightening force is applied to the sealing packing on both the inlet and outlet sides to ensure a tight seal and prevent gas from seeping between the inner and outer pipes due to pressure fluctuations or varying deformation of the inner sleeves, which could erode the insulation material or cause excessively high operating temperatures in the outer pipe.

[0084] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of this technical solution, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A steel-jacketed straight pipe section for pneumatic conveying of high-temperature materials, characterized in that: Includes outer tube, inner tube, sealing packing base, sealing packing gland, gland bolt, small-head sealing packing, inner and outer tube connecting plate, inner and outer tube connecting bolt, inner and outer tube connecting gasket, large-head sealing packing, sealing packing preload spring, thermal insulation layer and flange sealing assembly; The inner tube is a reducing pipe, with the inlet side being the larger end and the outlet side being the smaller end; the outer tube and the inner tube are connected by an inner and outer tube connecting plate, an inner and outer tube connecting bolt, and an inner and outer tube connecting gasket, and the outer tube is welded to the inner and outer tube connecting plate.

2. A steel-jacketed straight pipe section for pneumatic conveying of high-temperature materials according to claim 1, characterized in that: The large end of the inner tube is provided with a large end sealing packing and a sealing packing pre-tightening spring. The outer side of the small end is provided with a sealing packing base, a small end sealing packing and a sealing packing gland in sequence. The sealing packing base is welded to the outer tube, and the gland is bolted to connect the sealing packing base and the sealing packing gland.

3. A steel-jacketed straight pipe section for pneumatic conveying of high-temperature materials according to claim 2, characterized in that: The small-head sealing packing is placed between the sealing packing base and the sealing packing gland, and radial sealing is achieved by the axial preload applied by the gland bolts; The sealing packing pre-tightening spring acts on the large-end sealing packing. The sealing packing pre-tightening spring and the large-end sealing packing are placed in the cavity between the connecting plate, the inner tube and the sealing packing gland. The large-end sealing packing achieves radial sealing through the elastic deformation force of the pre-tightening spring.

4. A steel-jacketed straight pipe section for pneumatic conveying of high-temperature materials according to claim 1, characterized in that: Multiple steel-clad straight pipe sections are connected along the medium flow direction via flange sealing assemblies, with the small end of the front inner pipe inserted into the large end of the rear inner pipe.

5. A steel-jacketed straight pipe section for pneumatic conveying of high-temperature materials according to claim 1, characterized in that: Vent holes are provided on both the sealing packing base and the inner and outer tube connecting plate.

6. A steel-jacketed straight pipe section for pneumatic conveying of high-temperature materials according to claim 1, characterized in that: The heat insulation layer is filled between the outer tube and the inner tube and is made of aluminum silicate.

7. A steel-jacketed straight pipe section for pneumatic conveying of high-temperature materials according to claim 1, characterized in that: The inner tube is a bimetallic tube.

8. A steel-jacketed straight pipe section for pneumatic conveying of high-temperature materials according to claim 1, characterized in that: The small-head and large-head sealing packings are high-temperature resistant graphite packings.

9. A steel-jacketed straight pipe section for pneumatic conveying of high-temperature materials according to claim 1, characterized in that: The sealing packing preload spring is made of a high-temperature nickel-based alloy.

10. A steel-jacketed straight pipe section for pneumatic conveying of high-temperature materials according to claim 1, characterized in that: The inner and outer tube connecting pad is placed between the inner and outer tube connecting plate and the inner tube. The connecting bolt passes through the connecting plate and the connecting pad and is then fixedly connected to the inner tube. The inner and outer tube connecting pad is made of aluminum silicate.

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