Rotary furnace with in-furnace tube dynamic seal

Abstract

The utility model provides a kind of rotary furnace with inner furnace tube dynamic sealing, including furnace body, rotatable outer furnace tube is arranged in furnace body, inner furnace tube is arranged in outer furnace tube, and it is used for exhaust synchronous rotation, and the end of inner furnace tube protrudes the end surface of outer furnace tube, forms exposed extension section, and the feeding end and the discharging end of outer furnace tube are provided with feeding mechanism and discharging mechanism respectively, and the two ends of outer furnace tube are provided with hydrogen inlet, and hydrogen outlet is also provided in feeding end, hydrogen outlet is connected with exposed extension section of inner furnace tube, and the inner furnace tube dynamic sealing structure of synchronous rotation is arranged between hydrogen outlet and exposed extension section, to ensure that hydrogen does not leak.The rotary furnace provided by the utility model can realize simultaneous production of forward hydrogen reduction and reverse hydrogen reduction, and then through the cooperation of hydrogen outlet and inner furnace tube, the used hydrogen in rotary furnace is discharged through inner furnace tube, to avoid gas staying in furnace cavity to affect reduction efficiency and product quality.

Description

Technical Field

[0001] This utility model belongs to the technical field of rotary furnace equipment in powder metallurgy technology, specifically relating to an atmosphere-protected rotary furnace with coaxial inner furnace tubes and multiple independent rotating sealing structures. Background Technology

[0002] Existing industrial rotary kiln equipment typically has a front-end rotary sealing structure at the front feed position and a rear-end rotary sealing structure at the rear discharge position. This structure can only achieve sealing protection at the openings at both ends of the kiln body, and is used to maintain a positive or negative pressure process atmosphere inside the kiln, prevent gas leakage inside the kiln and external gas from entering the kiln, and ensure the system reaction effect.

[0003] However, in a double-cavity rotary kiln structure with inner and outer furnace tubes, the inner furnace tube rotates synchronously with the outer furnace tube, creating a continuous rotational fit gap between the inner furnace tube wall and the outer furnace tube connection point. Existing rotary kiln equipment does not have an independent, dedicated sealing structure for this rotational gap, causing the furnace atmosphere to easily leak outward along the gap between the inner furnace tube and the furnace exterior. Exhaust gas from external pipelines can also easily enter the furnace body in reverse along this gap, resulting in technical defects such as unstable furnace atmosphere, high gas loss, poor process consistency, and poor sealing effect, which cannot meet the requirements of high-precision atmosphere protection and reduction production.

[0004] To address the common technical problems in the industry mentioned above, this utility model solves the problems of gas leakage and cross-contamination in the rotating part of the inner furnace tube by adding a rotating sealing structure that connects the independent inner furnace tube to the external furnace system. Utility Model Content

[0005] To achieve the above objectives, this utility model proposes a rotary kiln with a dynamic seal for an inner furnace tube, comprising a furnace body, a rotatable outer furnace tube disposed within the furnace body, and a synchronously rotatable inner furnace tube disposed within the outer furnace tube for exhausting gas. One end of the inner furnace tube extends beyond the end face of the outer furnace tube, forming an exposed extension section. The length of the inner furnace tube is shorter than the length of the outer furnace tube. The inlet and outlet ends of the outer furnace tube are respectively provided with a feeding mechanism and a discharging mechanism. Both ends of the outer furnace tube are provided with hydrogen inlets, enabling simultaneous forward and reverse hydrogen reduction production. A hydrogen outlet is also provided at the inlet end, and the hydrogen outlet is connected to the exposed extension section of the inner furnace tube. A synchronously rotatable dynamic seal structure for the inner furnace tube is provided between the hydrogen outlet and the exposed extension section to ensure no hydrogen leakage.

[0006] Furthermore, one end of the inner furnace tube is fixedly connected to the outer furnace tube, and the other end is supported by a movable bracket structure. The movable bracket structure is fixedly connected to the outer furnace tube. The movable bracket structure can ensure that the inner furnace tube is supported and will not fall off, and can also achieve radial free thermal expansion and contraction.

[0007] Furthermore, both the feed end and the discharge end are equipped with a synchronously rotating sealing structure to further prevent hydrogen leakage.

[0008] Furthermore, the feed end is provided with a gas delivery pipe, the exposed extension section passes through the gas delivery pipe, the gas delivery pipe is connected to a heat exchanger, the heat exchanger includes a heat exchange barrel, the heat exchange barrel is provided with a gas inlet pipe, one end of the gas inlet pipe is opened as a hydrogen inlet, the other end is connected to the gas delivery pipe, and the heat exchange barrel is provided with a hydrogen outlet.

[0009] Furthermore, a dust collection bag is provided at the bottom of the heat exchange tank, and the dust collection bag is connected to a dust discharge port.

[0010] Furthermore, the dynamic sealing structure of the inner furnace tube includes a sealing cap installed on the gas supply pipe port and the heat exchanger. A sealing ring is provided between the inner furnace tube and the gas supply pipe to block the bidirectional flow of hydrogen in the furnace and the outside air, thereby achieving zero-leakage sealing of the rotating part of the inner furnace tube and maintaining a stable process atmosphere in the furnace.

[0011] Furthermore, the inner furnace tube is made of high-temperature resistant metal or ceramic material.

[0012] Furthermore, a rotating support structure is provided on the outer furnace tube.

[0013] This utility model has the following beneficial effects: 1. Based on the independent seals at both ends of the outer furnace tube, this utility model adds a dynamic sealing structure between the exposed extension section of the inner furnace tube and the hydrogen outlet. This specifically solves the problem of gas leakage caused by the lack of a seal in the rotation gap of the double-layer rotary furnace. It achieves three independent seals at both ends of the furnace body and the exposed extension section of the inner furnace tube, which comprehensively blocks the bidirectional flow between the furnace atmosphere and the outside air. This reduces the interference of waste gas overflow and air intrusion on the process, ensures the consistency of the material heat treatment process, and meets the needs of high-precision atmosphere-protected reduction production.

[0014] 2. The inner furnace tube of this utility model adopts a structure with one end fixed and the other end supported by a movable bracket structure. This not only ensures that the inner furnace tube is stably supported and will not fall off, but also reserves space for radial thermal expansion and contraction of the inner furnace tube, making it suitable for long-term continuous high-temperature rotation production conditions and extending the service life of the equipment. 3. The rotary kiln provided by this utility model is equipped with a heat exchanger and an inner furnace tube for exhaust. The inner furnace tube exhausts the hydrogen in the rotary kiln into the heat exchanger. The heat exchanger then uses the heat from the returned hydrogen in the heat exchange tank to preheat the cold hydrogen in the inlet pipe, which greatly reduces the power consumption of the equipment. Furthermore, the dust collection bag and dust discharge port can filter and collect the powder entrained in the hydrogen, preventing the powder from being discharged with the hydrogen and affecting the production environment.

[0015] 4. This utility model can simultaneously produce hydrogen reduction by simultaneously introducing hydrogen gas into both ends of the external furnace tube, thereby enhancing the destructive effect on material agglomerates and promoting the loosening of dense agglomerates. Attached Figure Description

[0016] Figure 1 This is a cross-sectional view of the overall structure of the rotary kiln of this utility model; Figure 2 This utility model Figure 1 Enlarged view of the structure at point A; Figure 3 This is a schematic diagram of the structure of the heat exchanger of this utility model; Figure 4 This is a schematic diagram of the movable structure of the bracket of this utility model.

[0017] In the diagram: 1. Furnace body; 2. Outer furnace tube; 3. Inner furnace tube; 4. Feeding mechanism; 5. Discharging mechanism; 6. Heat exchanger; 7. Gas transmission pipe; 8. Heat exchange tank; 9. Gas inlet pipe; 10. Hydrogen inlet; 11. Hydrogen outlet; 12. Dust collection bag; 13. Dust discharge port; 14. Sealing structure; 15. Dynamic sealing structure of inner furnace tube; 16. Sealing gland; 17. Sealing ring; 18. Movable bracket structure; 19. Rotating support structure. Detailed Implementation

[0018] To make the technical problems, technical solutions and advantages of this utility model clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0019] like Figures 1-4 As shown in the figure, the arrows indicate the direction of hydrogen flow, and the black particles represent the material. This utility model proposes a rotary kiln with a dynamic seal for the inner furnace tube, comprising a furnace body 1, a rotatable outer furnace tube 2 inside the furnace body 1, a rotating support structure 19 on the outer furnace tube 2, and a synchronously rotating inner furnace tube 3 inside the outer furnace tube 2 for exhaust. The inner furnace tube 3 is made of high-temperature resistant metal or ceramic material, and one end of the inner furnace tube 3 extends beyond the end face of the outer furnace tube 2, forming an exposed extension section. The length of the inner furnace tube 3 is less than the length of the outer furnace tube 2. The feed end and discharge end of the outer furnace tube 2 are respectively provided with a feed mechanism 4 and a discharge mechanism 5, and both ends of the outer furnace tube 2 are provided with hydrogen inlets 10, which can realize simultaneous forward and reverse hydrogen reduction production. A hydrogen outlet 11 is also provided at the feed end, and the hydrogen outlet 11 is connected to the exposed extension section of the inner furnace tube 3. A synchronously rotating dynamic seal structure 15 is provided between the hydrogen outlet 11 and the exposed extension section to ensure that hydrogen does not leak.

[0020] One end of the inner furnace tube 3 is fixedly connected to the outer furnace tube 2, and the other end is supported by a bracket movable structure 18. The bracket movable structure 18 is fixedly connected to the outer furnace tube 2. The bracket movable structure 18 can ensure that the inner furnace tube 3 is supported and will not fall off, and can also realize radial free thermal expansion and contraction.

[0021] Both the feed end and the discharge end are equipped with a synchronously rotating sealing structure 14 to further prevent hydrogen leakage.

[0022] A gas supply pipe 7 is provided at the feed end, and an exposed extension section runs through the gas supply pipe 7. The gas supply pipe 7 is connected to a heat exchanger 6. The heat exchanger 6 includes a heat exchange tank 8. An air inlet pipe 9 is provided inside the heat exchange tank 8. One end of the air inlet pipe 9 is opened as a hydrogen inlet 10, and the other end is connected to the gas supply pipe 7. A hydrogen outlet 11 is provided on the heat exchange tank 8. A dust collection bag 12 is provided at the bottom inside the heat exchange tank 8. The dust collection bag 12 is connected to a dust discharge port 13.

[0023] The inner furnace tube dynamic sealing structure 15 includes a sealing gland 16 installed at the port of the gas supply pipe 7 and the heat exchanger 6. A sealing ring 17 is provided between the inner furnace tube 3 and the gas supply pipe 7 to block the bidirectional flow of hydrogen in the furnace and the outside air, so as to achieve zero leakage sealing of the rotating part of the inner furnace tube 3 and maintain a stable process atmosphere in the furnace.

[0024] The working process of this utility model is as follows: Figure 1 As shown, the outer furnace tube 2 is started to rotate, which drives the inner furnace tube 3 to rotate. Then, hydrogen is simultaneously introduced into the two hydrogen inlets 10, namely forward hydrogen flow and reverse hydrogen flow, respectively. The material in the rotary kiln achieves simultaneous forward and reverse hydrogen reduction production. Since the inner furnace tube 3 is connected to the hydrogen outlet 11, a pressure difference is formed in the rotary kiln, which causes the used hydrogen in the rotary kiln to be discharged from the inner furnace tube 3. The hydrogen flow path is shown by the arrow in the figure. At the same time, the cold hydrogen in the inlet pipe 9 is preheated in the heat exchanger 6 through the heat return heat in the heat exchange tank 8.

Claims

1. A rotary kiln with an internal furnace tube dynamic seal, characterized in that: The furnace includes a furnace body (1), a rotatable outer furnace tube (2) is provided inside the furnace body (1), an inner furnace tube (3) that can be rotated synchronously for exhaust is provided inside the outer furnace tube (2), and one end of the inner furnace tube (3) extends out of the end face of the outer furnace tube (2) to form an exposed extension section. The length of the inner furnace tube (3) is less than the length of the outer furnace tube (2). The feed end and discharge end of the outer furnace tube (2) are respectively provided with a feed mechanism (4) and a discharge mechanism (5). Both ends of the outer furnace tube (2) are provided with hydrogen inlets (10), and a hydrogen outlet (11) is also provided at the feed end. The hydrogen outlet (11) is connected to the exposed extension section of the inner furnace tube (3). A synchronously rotatable inner furnace tube dynamic sealing structure (15) is provided between the hydrogen outlet (11) and the exposed extension section.

2. A rotary kiln with an internal furnace tube dynamic seal as described in claim 1, characterized in that: One end of the inner furnace tube (3) is fixedly connected to the outer furnace tube (2), and the other end is supported by a bracket movable structure (18), which is fixedly connected to the outer furnace tube (2).

3. A rotary kiln with an internal furnace tube dynamic seal as described in claim 1, characterized in that: Both the feed end and the discharge end are equipped with a synchronously rotating sealing structure (14).

4. A rotary kiln with an internal furnace tube dynamic seal as described in claim 1, characterized in that: The feed end is provided with a gas delivery pipe (7), the exposed extension section passes through the gas delivery pipe (7), the gas delivery pipe (7) is connected to a heat exchanger (6), the heat exchanger (6) includes a heat exchange barrel (8), the heat exchange barrel (8) is provided with an inlet pipe (9), one end of the inlet pipe (9) is opened as a hydrogen inlet (10), and the other end is connected to the gas delivery pipe (7), and the heat exchange barrel (8) is provided with a hydrogen outlet (11).

5. A rotary kiln with an internal furnace tube dynamic seal as described in claim 4, characterized in that: The bottom of the heat exchange tank (8) is provided with a dust collection bag (12), and the dust collection bag (12) is connected to a dust discharge port (13).

6. A rotary kiln with an internal furnace tube dynamic seal as described in claim 4, characterized in that: The inner furnace tube dynamic sealing structure (15) includes a sealing cap (16) installed on the port of the gas pipeline (7) and the heat exchanger (6), and a sealing ring (17) is provided between the inner furnace tube (3) and the gas pipeline (7).

7. A rotary kiln with an internal furnace tube dynamic seal as described in claim 1, characterized in that: The inner furnace tube (3) is made of high-temperature resistant metal or ceramic material.

8. A rotary kiln with an internal furnace tube dynamic seal as described in claim 1, characterized in that: The outer furnace tube (2) is provided with a rotating support structure (19).

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