An electrically heated stainless steel ferrule seal

Abstract

The utility model belongs to industrial furnace equipment technical field discloses an electric heating stainless steel sleeve sealing device, including with the outer stainless steel pipe of furnace shell fixed connection and the stainless steel sleeve of coaxial sleeve in the outer stainless steel pipe, the annular cavity is formed between the outer stainless steel pipe and stainless steel sleeve, just the inside of annular cavity is filled with sealed refractory, just the outer wall of furnace shell is welded with the outer stainless steel pipe, the port of outer stainless steel pipe outer end part is equipped with the material stopping part for stopping the sealed refractory, the outer wall of furnace shell is welded with the flange disc of outer stainless steel pipe outside, just the full welding connection of flange disc and furnace shell, the mounting hole diameter on furnace shell is slightly greater than the outer diameter of outer stainless steel pipe, forms 1-5mm's gap, the outer end of outer stainless steel pipe is provided with the pressure tight dress for the pressure tight of sealed refractory, the utility model has solved the problem that pure rigid refractory is easy to crack, also has solved the problem that pure soft material is not resistant to high temperature.

Description

Technical Field

[0001] This utility model relates to the field of industrial furnace and kiln equipment technology, and in particular to an electric heating stainless steel sleeve sealing device. Background Technology

[0002] In industrial furnaces and kilns in metallurgy, chemical industry, and other fields, it is often necessary to insert components such as electrodes and thermocouples from outside the furnace shell into the high-temperature furnace chamber. To ensure the furnace chamber's airtightness and prevent air from entering or the furnace medium from leaking out, sealing devices need to be installed at the penetration points. Existing sealing structures suffer from problems such as easy loosening of refractory materials, deterioration of sealing performance due to thermal expansion and contraction, and inability to compensate for wear online. Utility Model Content

[0003] To overcome the technical defects of the existing technology, this utility model provides an electrically heated stainless steel sleeve sealing device, which solves the problem of easy cracking of pure rigid refractory materials and the problem of pure soft materials not being resistant to high temperatures.

[0004] The technical solution adopted by this utility model is: an electric heating stainless steel sleeve sealing device, including an outer stainless steel tube fixedly connected to the furnace shell, and a stainless steel sleeve coaxially sleeved inside the outer stainless steel tube. An annular cavity is formed between the outer stainless steel tube and the stainless steel sleeve, and the interior of the annular cavity is filled with sealing refractory material. The outer stainless steel tube is welded to the outer wall of the furnace shell. The port at the inner end of the outer stainless steel tube is provided with a baffle for blocking the sealing refractory material. A flange is provided on the outside of the outer stainless steel tube and welded to the outer wall of the furnace shell. The flange is fully welded to the furnace shell. The mounting hole diameter on the furnace shell is slightly larger than the outer diameter of the outer stainless steel tube, forming a gap of 1-5mm. A clamping device for pressing the sealing refractory material is provided at the outer end of the outer stainless steel tube.

[0005] Preferably, the sealing material consists of a high-temperature resistant layer and an elastic sealing layer, wherein the high-temperature resistant layer is located near the high-temperature side and is a ceramic fiber module, and the elastic sealing layer is a high-purity graphite packing.

[0006] Preferably, the clamping device includes a pressure ring and a positioning ring block. The positioning ring block is installed at the outer end of the outer stainless steel tube, and the positioning ring block is provided with a plurality of adjusting bolts. The pressure ring is connected to the end of the sealing material through the adjusting bolts. Rotating the adjusting bolts can drive the pressure ring to move axially to clamp or loosen the sealing material.

[0007] Preferably, an inert gas interface is machined on the upper side wall of the outer stainless steel tube.

[0008] Preferably, an elastic compensation element is installed between the pressure ring and the sealing refractory material.

[0009] Preferably, the positioning ring block is threadedly connected to the outer end of the outer stainless steel tube.

[0010] The beneficial effects of this utility model are as follows: 1. The outer stainless steel tube of this utility model is provided with a flange welded to the outer wall of the furnace shell, and the flange is fully welded to the furnace shell, providing the strongest connection with the furnace shell, ensuring the overall stability and sealing of the device, and preventing overall loosening due to vibration or stress. A 1-5mm gap is left in the mounting holes: this is a very crucial and ingenious design. It allows the outer stainless steel tube to have a certain radial expansion space when heated, avoiding direct transmission of thermal stress to the furnace shell, and preventing furnace shell deformation or weld cracking. A baffle is provided at the inner end of the outer stainless steel tube for positioning the sealing refractory material, integrating the complex sealing refractory material into an independent stainless steel sleeve device, making it a standard module. Replacement or maintenance can be performed entirely or partially without large-area repair of the furnace shell body, greatly simplifying the maintenance process and shortening downtime.

[0011] In this invention, the high-temperature resistant layer, located near the high-temperature side, primarily serves to insulate against extreme temperatures, protecting the rear elastic sealing layer and metal structure from burn-out. The ceramic fiber module itself also possesses a certain degree of elastic recovery. The elastic sealing layer (high-purity graphite packing) mainly provides a continuous and flexible seal. Graphite packing exhibits excellent self-lubricating properties, high-temperature resistance, and chemical stability. Especially under the action of a clamping device, it can conform well to the stainless steel sleeve, compensating for its unevenness or slight oscillations, achieving a dynamic seal. This combination solves both the problem of cracking easily in purely rigid refractory materials and the problem of high-temperature resistance in purely soft materials.

[0012] This invention utilizes a specific clamping device, allowing for easy adjustment of the clamping force on the sealing material via rotating the adjusting bolt. It compensates for wear: when the sealing material wears or compacts after prolonged use, reducing the sealing force, tightening the bolt restores the clamping force and extends the seal's lifespan. It adapts to different operating conditions: the sealing pressure can be adjusted to the optimal level based on positive or negative pressure within the furnace. It facilitates installation and pre-tightening: when installing new sealing material, it can be easily clamped to the desired position. Attached Figure Description

[0013] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0014] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a schematic diagram of the outer stainless steel tube of this utility model; Figure 3 This is a schematic diagram of the pressing device of this utility model.

[0015] Explanation of reference numerals in the attached drawings: 1. Furnace shell; 2. Outer stainless steel pipe; 3. Stainless steel sleeve; 4. Sealing refractory material; 401. High-temperature resistant layer; 402. Elastic sealing layer; 5. Material retainer; 6. Flange; 7. Clamping device; 701. Pressure ring; 702. Positioning ring block; 703. Adjusting bolt; 8. Inert gas interface; 9. Elastic compensation component. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of this utility model clearer, the various embodiments of this utility model will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the various embodiments of this utility model to facilitate a better understanding of this application. However, the technical solutions claimed in the claims of this application can be implemented even without these technical details and with various variations and modifications based on the following embodiments.

[0017] like Figure 1-3 As shown, this embodiment provides an electrically heated stainless steel sleeve sealing device, including an outer stainless steel tube 2 fixedly connected to a furnace shell 1, and a stainless steel sleeve 3 coaxially sleeved inside the outer stainless steel tube. An annular cavity is formed between the outer stainless steel tube 2 and the stainless steel sleeve 3, and the interior of the annular cavity is filled with sealing refractory material 4. The outer stainless steel tube 2 is welded to the outer wall of the furnace shell 1. The port of the inner end of the outer stainless steel tube 2 is provided with a baffle part 5 for blocking the sealing refractory material 4. The outer stainless steel tube 2 is provided with a flange 6 welded to the outer wall of the furnace shell 1, and the flange 6 is fully welded to the furnace shell 1. The mounting hole diameter on the furnace shell 1 is slightly larger than the outer diameter of the outer stainless steel tube 2, forming a gap of 1-5 mm. The outer end of the outer stainless steel tube is provided with a clamping device 7 for pressing the sealing refractory material 4. The outer stainless steel tube 2 is equipped with a flange 6 welded to the outer wall of the furnace shell 1. The flange 6 is fully welded to the furnace shell 1, providing the strongest connection and ensuring the overall stability and sealing of the device, preventing loosening due to vibration or stress. A 1-5mm gap is left in the mounting holes: this is a crucial and ingenious design. It allows the outer stainless steel tube 2 some radial expansion space when heated, avoiding direct transfer of thermal stress to the furnace shell 1 and preventing deformation or weld cracking. A baffle 5 is provided at the inner end of the outer stainless steel tube 2 for positioning the sealing refractory material 4, integrating the complex sealing refractory material 4 into a single, independent stainless steel sleeve 3 device, making it a standard module. Replacement or maintenance can be performed entirely or partially without extensive repair of the furnace shell 1, greatly simplifying the maintenance process and shortening downtime.

[0018] The sealing refractory material 4 consists of a high-temperature resistant layer 401 and an elastic sealing layer 402. The high-temperature resistant layer 401, located near the high-temperature side, is a ceramic fiber module, while the elastic sealing layer 402 is high-purity graphite packing. The high-temperature resistant layer 401, located near the high-temperature side, primarily serves to insulate against extreme temperatures, protecting the subsequent elastic sealing layer 402 and the metal structure from burn-out. The ceramic fiber module itself also possesses a certain degree of elastic recovery. The elastic sealing layer 402 (high-purity graphite packing) primarily provides a continuous and flexible seal. Graphite packing exhibits excellent self-lubricating properties, high-temperature resistance, and chemical stability. Especially under the action of the clamping device 7, it can effectively conform to the stainless steel sleeve 3, compensating for unevenness or slight oscillations, thus achieving a dynamic seal. This combination solves both the problem of cracking in purely rigid refractory materials and the problem of high-temperature resistance in purely soft materials.

[0019] The clamping device 7 includes a clamping ring 701 and a positioning ring block 702. The positioning ring block 702 is installed at the outer end of the outer stainless steel tube 2, and multiple adjusting bolts 703 are provided on the positioning ring block 702. The clamping ring 701 is connected to the end of the sealing refractory material 4 through the adjusting bolts 703. Rotating the adjusting bolts 703 can drive the clamping ring 701 to move axially to clamp or loosen the sealing refractory material 4. By setting a specific clamping device 7, the clamping force on the sealing refractory material 4 can be adjusted at any time by rotating the adjusting bolts 703. Wear compensation: When the sealing material wears or compacts after long-term use, and the sealing force decreases, the clamping force can be restored by tightening the bolts, thus extending the sealing life. Adaptability to different working conditions: The sealing pressure can be adjusted to the optimal level according to the positive or negative pressure in the furnace. Easy installation and pre-tightening: When installing new sealing material, it can be easily clamped to the ideal state.

[0020] An inert gas inlet 8 is machined on the upper side wall of the outer stainless steel tube 2. When an inert gas (such as nitrogen) is introduced, a slight positive pressure is created within the annular cavity, effectively preventing harmful gases (such as CO and SO2) or air from permeating outwards, thus achieving an air curtain seal, which greatly enhances the mechanical seal. Oxidation prevention: The inert gas protects the stainless steel sleeve and outer steel tube, especially their high-temperature components, preventing oxidation at high temperatures and extending the service life of the metal parts.

[0021] An elastic compensation element 9, a disc spring, is installed between the pressure ring 701 and the sealing material 4, increasing the automatic compensation capability. When the sealing material is further compressed due to thermal vibration or wear, the disc spring can automatically release its elastic force, continuously pressing the sealing material and maintaining a constant sealing force, thus achieving "passive" continuous maintenance. Buffering and shock absorption: It can absorb minor vibrations generated during equipment operation, preventing bolt loosening and sealing material fatigue.

[0022] The positioning ring block 702 is threaded to the outer end of the outer stainless steel tube 2. When it is necessary to replace the sealing material or inspect the interior, the positioning ring block can be unscrewed, making maintenance extremely convenient.

[0023] Furthermore, any content not described in detail in this specification is existing technology known to those skilled in the art.

[0024] Working process: Before or after the device is installed on the furnace shell 1, ceramic fiber modules (high-temperature resistant layer 401) and high-purity graphite packing (elastic sealing layer 402) are filled into the annular cavity between the outer stainless steel tube 2 and the stainless steel sleeve 3. Pre-tightening device 7: By rotating the adjusting bolt 703 on the tightening device 7, the pressure ring 701 is driven to move forward, applying an initial pre-tightening force to the internal sealing refractory 4. This pre-tightening force causes the graphite packing to deform radially, tightly fitting against the outer wall of the stainless steel sleeve 3 and the inner wall of the outer sleeve, forming the initial, basic mechanical seal; When the furnace is started to heat up and the internal process reactions are underway, the unit faces challenges such as high temperature, thermal expansion, and pressure fluctuations inside the furnace.

[0025] To cope with thermal expansion: Both the stainless steel sleeve 3 and the outer stainless steel tube 2 will expand axially and radially after being heated. Since there is a gap of 1-5mm between the mounting hole of the furnace shell 1 and the outer stainless steel tube 2, space is provided for the radial expansion of the outer stainless steel tube 2, avoiding structural jamming or excessive thermal stress.

[0026] The sealing refractory material 4, especially the ceramic fiber module, will shrink to some extent at high temperatures. At this time, the clamping device 7 and any elastic compensation components 9 (such as disc springs) play a crucial role. The spring force of the disc spring will be released, pushing the pressure ring 701 to continue to press the sealing refractory material 4, automatically compensating for the gap caused by the shrinkage of the refractory material and maintaining the contact pressure of the sealing surface.

[0027] When the furnace is under positive pressure: the high temperature inside the furnace, and potentially corrosive gases (such as CO and SO2), will attempt to leak out through any gaps. These are first blocked and insulated by the high-temperature resistant layer 401. Subsequently, pressure acts on the elastic sealing layer 402, attempting to push it outwards. At this point, the sealing device resists in two ways: Mechanical seal force: The pressure provided by the pre-tightened clamping device 7 and the elastic compensation component 9 ensures that the graphite packing remains tightly pressed against the sleeve, blocking the gas passage. Gas curtain sealing (key step): Inert gases such as nitrogen are introduced through the inert gas interface 8. The inert gas forms a slightly positive pressure zone within the annular cavity, slightly higher than the furnace pressure. This pressure actively "pushes back" any furnace gas attempting to leak out, greatly enhancing the sealing effect and protecting the sealing refractory material 4 and metal components from the chemical corrosion of the furnace gas.

[0028] When the furnace is under negative pressure, external air will attempt to be drawn into it. At this time, the slightly positive pressure of the introduced inert gas also acts as a barrier, "blocking" the air that is trying to be drawn in, preventing air from entering the furnace and affecting the process (such as causing product oxidation), and also preventing external cold air from lowering the temperature of the sealing parts and causing condensation and other problems.

[0029] Those skilled in the art will understand that the above embodiments are specific examples of implementing the present invention, and in practical applications, various changes can be made to them in form and detail without departing from the spirit and scope of the present invention.

Claims

1. An electrically heated stainless steel sleeve sealing device, characterized in that: The system includes an outer stainless steel tube (2) fixedly connected to the furnace shell (1) and a stainless steel sleeve (3) coaxially sleeved inside the outer stainless steel tube (2). An annular cavity is formed between the outer stainless steel tube (2) and the stainless steel sleeve (3), and the interior of the annular cavity is filled with sealing refractory material (4). The outer stainless steel tube (2) is welded to the outer wall of the furnace shell (1). The port of the inner end of the outer stainless steel tube (2) is provided with a baffle part (5) for blocking the sealing refractory material (4). The outer stainless steel tube (2) is provided with a flange (6) welded to the outer wall of the furnace shell (1), and the flange (6) is fully welded to the furnace shell (1). The mounting hole diameter on the furnace shell (1) is slightly larger than the outer diameter of the outer stainless steel tube (2), forming a gap of 1-5 mm. The outer end of the outer stainless steel tube (2) is provided with a clamping device (7) for pressing the sealing refractory material (4).

2. The electrically heated stainless steel sleeve sealing device according to claim 1, characterized in that: The sealing refractory material (4) is composed of a high-temperature resistant layer (401) (such as a ceramic fiber module) and an elastic sealing layer (402). The high-temperature resistant layer (401) is close to the high-temperature side. The high-temperature resistant layer (401) is a ceramic fiber module, and the elastic sealing layer (402) is a high-purity graphite packing.

3. The electrically heated stainless steel sleeve sealing device according to claim 1, characterized in that: The clamping device (7) includes a clamping ring (701) and a positioning ring block (702). The positioning ring block (702) is installed on the outer end of the outer stainless steel tube (2), and the positioning ring block (702) is provided with a plurality of adjusting bolts (703). The clamping ring (701) is connected to the end of the sealing refractory material (4) through the adjusting bolts (703). Rotating the adjusting bolts (703) can drive the clamping ring (701) to move axially to clamp or loosen the sealing refractory material (4).

4. The electrically heated stainless steel sleeve sealing device according to claim 1, characterized in that: An inert gas interface (8) is machined on the upper side wall of the outer stainless steel tube (2).

5. The electrically heated stainless steel sleeve sealing device according to claim 3, characterized in that: An elastic compensation element (9) is installed between the pressure ring (701) and the sealing refractory (4).

6. The electrically heated stainless steel sleeve sealing device according to claim 3, characterized in that: The positioning ring block (702) is threaded to the outer end of the outer stainless steel tube (2).

Images