Air pipe connecting device of preheater for cement production

Abstract

The utility model relates to the technical field of air pipe connecting devices, and discloses a preheater air pipe connecting device for cement production, which comprises a first high-temperature-resistant alloy steel flange plate, a connecting sealing mechanism is arranged outside the first high-temperature-resistant alloy steel flange plate, and a metal corrugated pipe expansion joint is arranged on the right side of the first high-temperature-resistant alloy steel flange plate. A second high-temperature-resistant alloy steel flange plate is arranged on the right side of the metal corrugated pipe expansion joint. According to the preheater air pipe connecting device for cement production, through the sealing layer arranged in the inner-layer lining, by means of the high-temperature-resistant property of the expanded graphite composite strip, sealing of the flange connecting position can be achieved under matched installation of the first fixing lantern ring, the second fixing lantern ring and the inner-layer lining, meanwhile, when the expanded graphite composite strip is replaced, the sealing effect is good, and the sealing effect is good. And the flange does not need to be disassembled, replacement can be carried out only by disassembling the bolt and disassembling the first fixing lantern ring and the second fixing lantern ring, and the convenience of installing and replacing the sealing element is improved.

Description

Technical Field

[0001] This utility model relates to the technical field of duct connection devices, specifically a duct connection device for a preheater used in cement production. Background Technology

[0002] The preheater in cement production is the core equipment of the suspension preheater system. It is mainly used to preheat and partially decompose the raw materials using high-temperature exhaust gas from the kiln tail before they enter the rotary kiln for calcination, thereby significantly improving thermal efficiency and reducing energy consumption. In the preheater system of cement production, the air duct (also known as the gas pipeline or connecting pipeline) is the core component connecting each stage of the cyclone separator. It undertakes the key functions of high-temperature gas and raw material flow, heat exchange, gas-solid mixing, and chemical reaction. During the connection and installation of the air duct, a connecting device is required to ensure a stable connection and reliable sealing between each stage of the cyclone separator and the air duct.

[0003] In existing technologies, flange connections and expansion joints are typically used when connecting and installing preheater ducts. High-temperature alloy steel flanges are bolted together, and a fire-resistant gasket is sandwiched between the two flanges to secure the duct to the preheater interface and ensure airtightness. The metal bellows expansion joint inside the two flanges in the connection device compensates for axial, lateral, or angular displacement of the pipeline caused by temperature changes. However, in actual use, the fire-resistant gasket becomes brittle at high temperatures and is prone to cracking after repeated thermal expansion and contraction, requiring frequent replacement. Replacing the fire-resistant gasket requires disassembling the flanges on both sides, making the replacement process inconvenient. Therefore, an improved preheater duct connection device for cement production is needed to solve the above problems. Utility Model Content

[0004] The purpose of this utility model is to provide a preheater duct connection device for cement production, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a preheater duct connection device for cement production, comprising a high-temperature alloy steel flange one, a connecting sealing mechanism provided on the outside of the high-temperature alloy steel flange one, a metal bellows expansion joint provided on the right side of the high-temperature alloy steel flange one, and a high-temperature alloy steel flange two provided on the right side of the metal bellows expansion joint.

[0006] Preferably, the connecting sealing mechanism includes a first fixing collar, which is disposed outside the first high-temperature alloy steel flange. A second fixing collar is disposed at the bottom of the first fixing collar. Both the first and second fixing collars are provided with an inner bushing. A sealing layer is disposed inside the inner bushing. Bolts are disposed inside the first and second fixing collars. Nuts are installed on the external threads of the bolts. Ordinary washers and wedge washers are disposed on the external surfaces of the bolts.

[0007] Preferably, the first and second fixing collars have holes inside, and the bolt is slidably installed inside the holes inside the first and second fixing collars.

[0008] Preferably, four ordinary washers are provided, and the four ordinary washers are located on the side close to the first fixing collar and the second fixing collar.

[0009] Preferably, the first and second fixing collars are made of Hastelloy C-276 and have a thickness of 8mm.

[0010] Preferably, the inner bushing is made of ceramic fiber and has a thickness of 3mm.

[0011] Preferably, the sealing layer is made of expanded graphite composite strip with a cross section of 10mm×6mm, containing a boron nitride coating with a thickness of 0.1mm.

[0012] Compared with the prior art, this utility model provides a preheater duct connection device for cement production, which has the following advantages:

[0013] This preheater duct connection device for cement production, through its connection and sealing mechanism, utilizes the high-temperature resistance of the expanded graphite composite strip within the inner bushing to achieve a seal at the flange connection. This is achieved through the cooperation of the fixing rings (first and second) and the inner bushing. Furthermore, when replacing the expanded graphite composite strip, there is no need to disassemble the flange; simply remove the bolts and the fixing rings (first and second) for replacement. The inclusion of both standard and wedge-shaped washers increases the tightening force of the bolts and nuts, preventing loosening or detachment and improving the ease of installing and replacing the seals. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the appearance and structure of this utility model;

[0016] Figure 2 This is a schematic diagram of the left-side appearance structure of this utility model;

[0017] Figure 3 This is a schematic diagram of the external structure of the connecting sealing mechanism of this utility model;

[0018] Figure 4 This is a cross-sectional schematic diagram of the inner bushing and its connection structure of this utility model.

[0019] In the diagram: 1. High-temperature alloy steel flange one; 2. Connecting sealing mechanism; 21. Fixing collar one; 22. Fixing collar two; 23. Inner bushing; 24. Sealing layer; 25. Bolt; 26. Nut; 27. Ordinary washer; 28. Wedge washer; 3. Metal bellows expansion joint; 4. High-temperature alloy steel flange two. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0021] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0022] Example:

[0023] Please see Figure 1-4 This utility model provides a technical solution: a preheater duct connection device for cement production, including a high-temperature alloy steel flange 1, a connecting sealing mechanism 2 is provided on the outside of the high-temperature alloy steel flange 1, a metal bellows expansion joint 3 is provided on the right side of the high-temperature alloy steel flange 1, and a high-temperature alloy steel flange 2 4 is provided on the right side of the metal bellows expansion joint 3.

[0024] Furthermore, the connecting sealing mechanism 2 includes a first fixing collar 21, which is located outside the high-temperature alloy steel flange 1. A second fixing collar 22 is located at the bottom of the first fixing collar 21. Both the first fixing collar 21 and the second fixing collar 22 have inner bushings 23 inside, and a sealing layer 24 is located inside the inner bushings 23. Bolts 25 are located inside the first fixing collar 21 and the second fixing collar 22. Nuts 26 are installed on the external threads of the bolts 25. Ordinary washers 27 and wedge washers 28 are installed on the external threads of the bolts 25. Through the connecting sealing mechanism 2, the connection gap between the high-temperature alloy steel flange 1 and the high-temperature alloy steel flange 2 can be sealed while the first fixing collar 21 and the second fixing collar 22 can be quickly disassembled to replace the sealing layer 24, avoiding the cumbersome disassembly of the entire flange.

[0025] Furthermore, the first fixing collar 21 and the second fixing collar 22 have holes inside, and the bolt 25 is slidably installed inside the holes in the first fixing collar 21 and the second fixing collar 22. Through the holes in the first fixing collar 21 and the second fixing collar 22, the bolt 25 can pass through, and then the ordinary washer 27 and the wedge washer 28 are used to lock the first fixing collar 21 and the second fixing collar 22.

[0026] Furthermore, four ordinary washers 27 are provided, and the four ordinary washers 27 are located on the side close to the first fixing ring 21 and the second fixing ring 22. The evenly distributed ordinary washers 27 can make the inner side of the wedge-shaped washer 28 contact the washer, thereby increasing the installation friction and preventing the bolt 25 from loosening and falling off due to micro-vibration.

[0027] Furthermore, the first retaining collar 21 and the second retaining collar 22 are made of Hastelloy C-276 with a thickness of 8mm. The retaining collar 21 and the second retaining collar 22 made of Hastelloy C-276 are combined with the ceramic fiber inner bushing 23 to withstand high temperatures and extend service life.

[0028] Furthermore, the inner bushing 23 is made of ceramic fiber and has a thickness of 3mm. The inner bushing 23, which is set inside the fixing ring 1 21 and the fixing ring 22, further enhances the heat resistance.

[0029] Furthermore, the sealing layer 24 is made of expanded graphite composite strip with a cross section of 10mm×6mm, containing a boron nitride coating with a thickness of 0.1mm. The sealing layer 24 can remain stable at high temperatures, avoiding the embrittlement and leakage problems of traditional refractory gaskets.

[0030] In actual operation, when this device is used, firstly, the fixing collar 1 21 and fixing collar 22 are clamped onto the outside of the high-temperature alloy steel flange 1 or the metal bellows expansion joint 3 after the flange is connected. Then, the fixing collar 1 21 and fixing collar 22 are pressed down to make the sealing layer 24 of the expanded graphite composite strip block the gap after the flange is connected. Then, the bolt 25 is passed through the fixing collar 1 21 and fixing collar 22, and the bolt 25 is tightened by the nut 26, ordinary washer 27 and wedge washer 28. The sealing of the flange connection is completed. When the sealing layer 24 is replaced, the fixing collar 1 21 and fixing collar 22 can be removed by simply removing the bolt 25 to replace the sealing layer 24.

[0031] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

Claims

1. A preheater duct connection device for cement production comprising a high temperature resistant alloy steel flange plate (1), characterized in that: The high-temperature alloy steel flange one (1) is provided with a connecting sealing mechanism (2) on the outside, and a metal bellows expansion joint (3) is provided on the right side of the high-temperature alloy steel flange one (1), and a high-temperature alloy steel flange two (4) is provided on the right side of the metal bellows expansion joint (3).

2. A preheater duct connection device for cement production according to claim 1, characterized in that: The connecting sealing mechanism (2) includes a first fixing collar (21), which is located outside the high-temperature alloy steel flange (1). A second fixing collar (22) is located at the bottom of the first fixing collar (21). Both the first fixing collar (21) and the second fixing collar (22) are provided with an inner bushing (23). A sealing layer (24) is provided inside the inner bushing (23). Bolts (25) are provided inside the first fixing collar (21) and the second fixing collar (22). Nuts (26) are installed on the external threads of the bolts (25). Ordinary washers (27) and wedge washers (28) are provided on the outside of the bolts (25).

3. The preheater duct connection device for cement production according to claim 2, characterized in that: The first fixing collar (21) and the second fixing collar (22) have holes inside, and the bolt (25) is slidably installed inside the holes opened inside the first fixing collar (21) and the second fixing collar (22).

4. A preheater duct connection device for cement production according to claim 2, characterized in that: Four ordinary washers (27) are provided, and the four ordinary washers (27) are located on the side close to the first fixing collar (21) and the second fixing collar (22).

5. A preheater duct connection device for cement production according to claim 2, characterized in that: The first fixing collar (21) and the second fixing collar (22) are made of Hastelloy C-276 and have a thickness of 8mm.

6. A preheater duct connection device for cement production according to claim 2, characterized in that: The inner bushing (23) is made of ceramic fiber and has a thickness of 3 mm.

7. A preheater duct connection device for cement production according to claim 2, characterized in that: The sealing layer (24) is made of expanded graphite composite strip with a cross section of 10mm×6mm, containing a boron nitride coating with a thickness of 0.1mm.

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