Cooling and fire extinguishing system for feeding and conveying equipment of rotary kiln

Abstract

The utility model relates to a cooling and fire extinguishing system of rotary kiln feeding and conveying equipment, the rotary kiln feeding and conveying equipment is used for conveying materials to a rotary kiln, the cooling and fire extinguishing system of the rotary kiln feeding and conveying equipment comprises a shell, the shell comprises a feeding port and a discharging port, and the discharging port extends to a high-temperature section of the rotary kiln; the rotary conveying mechanism is arranged in the shell, and the rotary conveying mechanism is configured to convey materials from the feeding port to the discharging port; and the steam cooling mechanism is arranged at the discharging opening and is configured to spray cooling steam to the materials and the end, located at the high-temperature section of the rotary kiln, of the rotary conveying mechanism. According to the cooling and fire extinguishing system of the rotary kiln feeding and conveying equipment, the tool bit end of the rotary conveying mechanism located at the discharging port is cooled under the action of cooling steam, the tool bit end is prevented from being twisted and deformed when working at the high temperature of 850-1100 DEG C for a long time, the shutdown overhaul time and the overhaul cost are reduced, and the operation cycle of the equipment is prolonged.

Description

Technical Field

[0001] This disclosure relates to the field of rotary kiln technology, and in particular to a cooling and fire extinguishing system for a rotary kiln feeding and conveying equipment. Background Technology

[0002] Currently, rotary kilns are a highly efficient method for treating hazardous waste. Hazardous waste is crushed and then transported to the rotary kiln for high-temperature incineration. The conveying mechanism typically uses a screw conveyor, suitable for conveying granular or powdery materials. During the high-temperature incineration process, the cutter head of the conveyor needs to penetrate deep into the high-temperature incineration zone inside the kiln. Operating continuously in a temperature range of 850-1100℃, the cutter head can become twisted and deformed, leading to malfunctions in material transport and unplanned shutdowns. Generally, the conveyor's screw blades need to be replaced approximately every three months, reducing the equipment's operating cycle and increasing maintenance and equipment procurement costs.

[0003] Moreover, flames frequently appear at the tip of the conveyor, causing the tip to burn out and even posing a risk of backfire. Utility Model Content

[0004] The purpose of this disclosure is to overcome the shortcomings of the prior art and provide a cooling and fire extinguishing system for a rotary kiln feeding and conveying equipment.

[0005] According to a first aspect of this disclosure, a rotary kiln feed conveyor is used to convey materials to a rotary kiln, and the cooling and fire extinguishing system of the rotary kiln feed conveyor includes:

[0006] The housing includes a feed inlet and a discharge outlet, the discharge outlet extending to the high-temperature section of the rotary kiln;

[0007] A rotary conveyor mechanism is disposed within the housing and configured to convey material from the inlet to the outlet;

[0008] A steam cooling mechanism is provided at the discharge port and configured to spray cooling steam onto the material and the end of the rotary conveyor located in the high-temperature section of the rotary kiln.

[0009] In one embodiment of this disclosure, the steam cooling mechanism includes a steam pipe having a first fitting fixed to the housing and a second fitting bent from one port of the first fitting toward the discharge port, the second fitting having a plurality of steam injection ports toward the cutter end of the rotary conveying mechanism.

[0010] In one embodiment of this disclosure, the first pipe fitting includes a horizontal section disposed along the material conveying direction and a vertical section at one end of the vertical horizontal section;

[0011] The second pipe fitting is connected to the port of the vertical section.

[0012] In one embodiment of this disclosure, a plurality of the steam injection ports are arranged in a rectangular array.

[0013] In one embodiment of this disclosure, the first pipe fitting and the second pipe fitting are integrally formed.

[0014] In one embodiment of this disclosure, the cooling and fire extinguishing system of the rotary kiln feeding conveyor further includes a guide plate, which is inclined downward at a preset angle and configured to guide the output direction of the material.

[0015] In one embodiment of this disclosure, the tilt angle of the guide plate is 50-60°.

[0016] In one embodiment of this disclosure, the second pipe fitting includes a curved section and a straight section. One end of the curved section is connected to a port of the first pipe fitting, and the other end of the curved section extends downward to form a straight section, which is disposed opposite to the guide plate.

[0017] In one embodiment of this disclosure, the housing includes a first housing and a second housing that are fixedly arranged sequentially along the material conveying direction. Only the second housing is provided with a circulating water cooling chamber and an inlet and an outlet communicating with the circulating water cooling chamber, and is configured to cool the rotary conveying mechanism and the material.

[0018] In one embodiment of this disclosure, the length ratio of the first housing to the second housing along the material conveying direction is 1.6:1.

[0019] One beneficial effect of the cooling and fire extinguishing system for the rotary kiln feeding conveyor disclosed herein is that the rotary conveying mechanism is housed within the casing, transporting material from the feed inlet to the discharge outlet. A steam cooling mechanism is located at the discharge outlet and injects cooling steam into it. The cutter head of the rotary conveying mechanism at the discharge outlet cools down under the action of the cooling steam, preventing the cutter head from twisting and deforming due to prolonged operation at 850-1100℃. This reduces downtime and maintenance costs, and improves the equipment's operating cycle. Furthermore, when material comes into contact with high-temperature flue gas at the cutter head of the rotary conveying mechanism, the cooling steam lowers both the temperature and oxygen concentration, thus extinguishing the fire and preventing the cutter head from burning out or even experiencing a backfire risk. Attached Figure Description

[0020] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments of the present disclosure and, together with their description, serve to explain the principles of the present disclosure.

[0021] Figure 1 This is a schematic diagram of the cooling and fire extinguishing system of the rotary kiln feeding conveyor provided in one embodiment of the present disclosure;

[0022] Figure 2 This is a schematic diagram of the structural principle of the cooling and fire extinguishing system of the rotary kiln feeding and conveying equipment provided in one embodiment of the present disclosure;

[0023] Figure 3 yes Figure 1 A schematic cross-sectional view of the connection between the first and second shells;

[0024] Figure 4 This is a schematic diagram of the steam cooling mechanism provided in one embodiment of the present disclosure.

[0025] Figures 1-4 The one-to-one correspondence between the component names and the reference numerals in the figures is as follows:

[0026] Shell: 11-First shell; 111-Inlet; 12-Second shell; 121-Outlet; 122-Circulating water cooling chamber; 123-Water inlet; 124-Water outlet;

[0027] 2- Rotary conveyor mechanism;

[0028] Steam cooling mechanism: 31-First fitting; 311-Horizontal section; 312-Vertical section; 32-Second fitting; 321-Bent section; 322-Straight section; 323-Steam nozzle;

[0029] 4-Guide plate. Detailed Implementation

[0030] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present disclosure.

[0031] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this disclosure or its application or use.

[0032] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0033] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0034] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0035] In this article, terms such as "up," "down," "front," "back," "left," and "right" are used only to indicate the relative positional relationship between related parts, rather than to define the absolute position of these related parts.

[0036] In this article, "first," "second," etc., are used only to distinguish one another, and not to indicate degree of importance, order, or prerequisite for each other.

[0037] In this document, terms such as “equal” and “same” are not strict mathematical and / or geometric limitations, but also include errors that are understandable to those skilled in the art and permissible in manufacturing or use.

[0038] Existing rotary kiln feeding conveyor equipment suffers from damage due to the conveying mechanism's end being constantly exposed to the high-temperature zone of the rotary kiln, requiring frequent shutdowns for maintenance, and even posing a risk of backfire at the conveying mechanism's end. Therefore, this disclosure provides a cooling and fire suppression system for rotary kiln feeding conveyor equipment. For ease of understanding, the following refers to... Figures 1-4 The specific structure and working principle of this disclosure will be described in detail with reference to the embodiments.

[0039] The rotary kiln feeding conveyor is used to convey materials into the rotary kiln. The cooling and fire extinguishing system of the rotary kiln feeding conveyor includes a shell, a rotary conveying mechanism 2, and a steam cooling mechanism. The shell includes a feed inlet 111 and a discharge outlet 121, with the discharge outlet 121 extending to the high-temperature section of the rotary kiln. The rotary conveying mechanism 2 is located inside the shell and is configured to convey materials from the feed inlet 111 to the discharge outlet 121. The steam cooling mechanism is located at the discharge outlet 121 and is configured to spray cooling steam onto the materials and the end of the rotary conveying mechanism 2 located in the high-temperature section of the rotary kiln.

[0040] Specifically, refer to Figure 2 , Figure 3 The incinerator consists of a rotary kiln, a second combustion chamber, and a fuel gas burner. The rotary kiln, the material incineration equipment, is divided into several parts, including the kiln head, the main body, and the kiln tail. Material is fed into the rotary kiln body via a conveying mechanism for high-temperature combustion, where it is completely burned into high-temperature flue gas and ash. The material is specifically hazardous waste, and the high-temperature section of the rotary kiln is the main body of the kiln.

[0041] The shell has a U-shaped cross-section and houses a rotary conveying mechanism 2. The rotary conveying mechanism 2 includes two parallel spiral rods rotating in opposite directions. A drive motor is fixedly mounted inside the shell. A meshing drive gear and driven gear are rotatably mounted within the shell. The drive shaft of the drive motor is fixedly connected to the drive gear, which is also fixedly connected to one of the spiral rods. The driven gear is fixedly connected to the other spiral rod. The two spiral rods rotate through the meshing of a pair of gears at the extension of the drive motor shaft. Spiral blades are fixedly mounted on the spiral rods, and the spiral blades of the two spiral rods are closely spaced, forming a material conveying channel between them. A sealing cover is provided at the U-shaped opening of the shell to prevent leakage or the entry of external substances during material conveying. A feed inlet 111 is located at one end of the shell, facing upwards and situated outside the rotary kiln. A discharge outlet 121 is located at the other end of the shell, facing the material conveying direction and situated in the high-temperature section of the rotary kiln. Granular or powdery materials are fed into the housing through inlet 111. A drive motor drives two screws to rotate in opposite directions. The helical blades on the screws propel the material from inlet 111 to outlet 121, where it enters the high-temperature section of the rotary kiln. The material continuously tumbles and mixes during transport, improving its flowability and uniformity. For viscous materials, the relative motion of the double screws can also break up clumps, preventing agglomeration during transport.

[0042] A steam cooling mechanism is installed at the discharge port 121, and cooling steam is injected into the discharge port 121. The cooling steam is specifically low-pressure steam with a pressure of 0.5 MPa and a temperature of 230°C. The cutter head of the rotary conveyor mechanism 2 located at the discharge port 121 is cooled down by the cooling steam, preventing the cutter head from twisting and deforming due to long-term operation at a high temperature of 850-1100°C. This reduces downtime and maintenance time and costs, and improves the equipment's operating cycle. In addition, when the material comes into contact with high-temperature flue gas at the cutter head of the rotary conveyor mechanism 2, the cooling steam lowers both the temperature and the oxygen concentration, thus extinguishing the fire and preventing the cutter head of the rotary conveyor mechanism 2 from burning out or even experiencing a backfire risk.

[0043] In one embodiment, the steam cooling mechanism includes a steam pipe having a first fitting 31 fixed to the housing and a second fitting 32 bent from one port of the first fitting 31 toward the discharge port 121, the second fitting 32 having a plurality of steam nozzles 323 toward the cutter end of the rotary conveying mechanism 2.

[0044] Specifically, the steam pipe includes a first fitting 31 and a second fitting 32. The first fitting 31 is fixedly connected to the sealing cover plate on the upper surface of the shell, and the steam pipe can be fixed directly by welding. The first fitting 31 extends from the inlet of the rotary kiln to the outlet 121 along the material conveying direction. A steam channel is also provided on the outside of the rotary kiln, which is connected to the port of the first fitting 31 at the rotary kiln inlet, allowing cooling steam to be introduced into the first fitting 31. The cooling steam can be generated by a steam generator or can be directly used from the self-generated steam in other processes of the incineration system. The second fitting 32 is connected to the port of the first fitting 31 facing the outlet 121. The second fitting 32 bends towards the outlet 121, and several steam injection ports 323 are provided on the curved surface. The steam injection ports 323 are all directed towards the cutter head of the rotary conveying mechanism 2 located at the outlet 121. The second fitting 32 receives the cooling steam introduced by the first fitting 31 and sprays the cooling steam into the cutter head of the rotary conveying mechanism 2 and the material through the steam injection ports 323. The cooling steam itself is not flammable. When released into the discharge port 121, it rapidly diffuses and occupies space, diluting the oxygen in the air to a level insufficient to sustain a flame. Typically, most substances cease to burn when the oxygen concentration drops below approximately 16%. The cooling steam absorbs a significant amount of heat during its transition from liquid to gas, which helps to rapidly cool the cutter head of the rotary conveyor 2 and its surrounding environment, significantly reducing the temperature and making it difficult for the cutter head to reach its ignition point. This achieves the cooling and extinguishing of the cutter head and the material within the rotary conveyor 2.

[0045] In one embodiment, the first pipe fitting 31 includes a horizontal section 311 arranged along the material conveying direction and a vertical section 312 at one end of the horizontal section 311; the second pipe fitting 32 is connected to the port of the vertical section 312.

[0046] Specifically, refer to Figure 2 The first pipe fitting 31 is divided into two sections. One section is a horizontal section 311 arranged along the material conveying direction, which extends to the top of the discharge port 121 of the shell. The other section is a vertical section 312 arranged perpendicularly to the end of the horizontal section 311 above the discharge port 121.

[0047] It should be noted that, since the rotary kiln needs to be tilted so that the material is conveyed from the kiln head to the kiln tail, the horizontal section 311 and the vertical section 312 are not in an absolutely horizontal and vertical position, but rather the horizontal section 311 is set parallel to the shell along the material conveying direction; similarly, the vertical section 312 is set perpendicular to the shell along the material conveying direction.

[0048] The first pipe 31 introduces cooling steam into the rotary kiln through the horizontal section 311. At the position above the discharge port 121, the cooling steam enters the vertical section 312. The cooling steam changes from being along the material conveying direction to being perpendicular to the material conveying direction and downward. The second pipe 32 is connected to the port of the vertical section 312. The cooling steam is directly sprayed through the second pipe 32 onto the discharge port 121 located below the steam cooling mechanism. By changing the direction of the cooling steam in advance, the pressure is maintained when the cooling steam is sprayed out.

[0049] In one embodiment, a plurality of steam nozzles 323 are arranged in a rectangular array.

[0050] Specifically, the material inlet of the shell and the conveying mechanism into the rotary kiln is rectangular, so the shape of the outlet 121 of the shell is correspondingly set to be rectangular. The second pipe 32 is a rectangular shape that bends toward the outlet 121. The steam nozzle 323 is directly opposite the outlet 121 and is arranged in a rectangular array, with seven rows arranged horizontally and five columns arranged vertically, so that the cooling sprayed from the steam nozzle 323 neatly and completely covers the outlet 121, thereby achieving cooling of the material and the cutter head of the rotary conveying mechanism 2.

[0051] In one embodiment, the first pipe fitting 31 and the second pipe fitting 32 are integrally formed.

[0052] Specifically, the first pipe fitting 31 and the second pipe fitting 32 are integrally formed. Because there are no seams or connection points, the steam cooling mechanism has higher overall structural integrity. When the steam cooling mechanism is welded to the shell, it performs well under pressure and stress. Furthermore, since the steam cooling mechanism is used to introduce fluids such as cooling steam, the integral forming reduces the risk of leakage due to poor connections.

[0053] In one embodiment, the cooling and fire extinguishing system of the rotary kiln feed conveyor further includes a guide plate 4, which is tilted downward at a preset angle and configured to guide the output direction of the material.

[0054] Specifically, refer to Figure 2 The guide plate 4 is set to extend downward from the shell located at the discharge port 121, which can guide the material to be output to a deeper position in the high temperature section of the rotary kiln, effectively reducing the amount of material returned to the rotary kiln, reducing the time of shutdown for material return, and improving the equipment operation cycle.

[0055] In one embodiment, the tilt angle of the guide plate 4 is 50-60°.

[0056] Specifically, the guide plate 4 is tilted downward at an angle of 50-60° relative to the material conveying direction. The larger the tilt angle, the smoother the material is output under its own gravity. The smaller the tilt angle, the deeper the material is conveyed. Within the 50-60° angle range, it can ensure that the material is conveyed deep into the high-temperature section of the rotary kiln and that the material is conveyed smoothly without accumulating on the guide plate 4.

[0057] In one embodiment, the second pipe 32 includes a curved section 321 and a straight section 322. One end of the curved section 321 is connected to one port of the first pipe 31, and the other end of the curved section 321 extends downward to form the straight section 322, which is disposed opposite to the guide plate 4.

[0058] Specifically, refer to Figure 2 , Figure 4 The second pipe fitting 32 is divided into two sections. One end is a curved section 321 that bends toward the outlet 121. The upper end of the curved section 321 is connected to the port of the vertical section 312 of the first pipe fitting 31. The lower end of the curved section 321 extends downward to form a straight section 322, which is positioned opposite to the guide plate 4. That is, the steam nozzles 323 on the straight section 322 are all facing the guide plate 4, so that the cooling steam cools the material output along the guide plate 4 and prevents the material from contacting the high-temperature flue gas and pre-combusting.

[0059] In one embodiment, the housing includes a first housing 11 and a second housing 12 that are fixedly arranged in sequence along the material conveying direction. Only the second housing 12 is provided with a circulating water cooling chamber 122 and an inlet 123 and an outlet 124 that communicate with the circulating water cooling chamber 122, and is configured to cool the rotary conveying mechanism 2 and the material.

[0060] Specifically, refer to Figure 1 , Figure 3 The kiln shell adopts a segmented design. The first shell 11 is located outside the rotary kiln and serves only as a wear-resistant shell. Part of the second shell 12 is located outside the rotary kiln, and another part extends into the high-temperature section of the kiln. The second shell 12 is equipped with a circulating water cooling chamber 122. The portion of the second shell 12 outside the rotary kiln also has an inlet 123 and an outlet 124 communicating with the circulating water cooling chamber 122. The inlet 123 and outlet 124 are connected to a water tank located outside the rotary kiln via pipelines. The water tank is equipped with a water pump to pump circulating cooling water through the inlet 123 into the circulating water cooling chamber 122. The feed inlet 111 is located on the first shell 11, and the discharge outlet 121 is located on the second shell 12. The first shell 11 and the second shell 12 are connected by flanges adapted to their cross-sectional shapes. Fireproof rock wool is also installed inside the rotary kiln.

[0061] Since only the shell entering the rotary kiln requires cooling, any leak in the shell necessitates stopping the circulating water for repairs, increasing downtime and maintenance. Furthermore, installing circulating cooling chambers in areas where cooling is unnecessary would waste circulating cooling water. Therefore, the shell is designed in sections, with circulating cooling chambers only located in the section entering the rotary kiln. This reduces the risk of leaks in the shell and minimizes the waste of circulating cooling water.

[0062] In one embodiment, the length ratio of the first housing 11 to the second housing 12 along the material conveying direction is 1.6:1.

[0063] Specifically, the length of the first shell 11 is 3200mm and the length of the second shell 12 is 2000mm. The lengths of the first shell 11 and the second shell 12 can be appropriately increased or decreased according to actual needs. However, the length ratio of the first shell 11 to the second shell 12 along the material conveying direction is 1.6:1, so that the conveying mechanism and the material are sufficiently cooled before entering the high-temperature section of the rotary kiln to prevent combustion.

[0064] Furthermore, to facilitate better understanding, the following section will describe in detail the usage process of the cooling and fire extinguishing system for the rotary kiln feeding conveyor, using the actual application scenario of the system.

[0065] 1. Start the cooling and fire extinguishing system of the rotary kiln feeding conveyor, turn on the water pump, and introduce circulating cooling water into the circulating water cooling chamber 122. Turn on the drive motor and the rotating conveyor 2 will start working.

[0066] 2. The material enters the shell through the feed inlet 111. Under the action of the rotary conveyor 2, the material is pushed to the discharge outlet 121. During this process, the material is cooled by the circulating cooling water of the second shell 12.

[0067] 3. Cooling steam is introduced into the steam cooling mechanism, and the cooling steam is sprayed through the steam nozzle 323 to the cutter head end of the rotary conveying mechanism 2;

[0068] 4. The material is cooled by cooling steam as it passes through guide plate 4;

[0069] 5. The material is conveyed to the high-temperature section of the rotary kiln for combustion.

[0070] The various embodiments of this disclosure have been described above. These descriptions are exemplary and not exhaustive, and are not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein. The scope of this disclosure is defined by the appended claims.

Claims

1. A cooling and fire extinguishing system for a rotary kiln feeding conveyor, the rotary kiln feeding conveyor being used to convey materials to a rotary kiln, characterized in that, The cooling and fire extinguishing system of the rotary kiln feeding conveyor includes: The housing includes a feed inlet (111) and a discharge outlet (121), the discharge outlet (121) extending to the high-temperature section of the rotary kiln; A rotary conveyor (2) is disposed within the housing and configured to convey material from the feed inlet (111) to the discharge outlet (121). A steam cooling mechanism is provided at the discharge port (121) and configured to spray cooling steam onto the material and the end of the rotary conveyor (2) located in the high-temperature section of the rotary kiln.

2. The cooling and fire extinguishing system for the rotary kiln feeding conveyor according to claim 1, characterized in that, The steam cooling mechanism includes a steam pipe having a first fitting (31) fixed to the housing and a second fitting (32) bent from one port of the first fitting (31) toward the discharge port (121), the second fitting (32) having a plurality of steam nozzles (323) toward the cutter end of the rotary conveying mechanism (2).

3. The cooling and fire extinguishing system for the rotary kiln feeding conveyor according to claim 2, characterized in that, The first pipe fitting (31) includes a horizontal section (311) arranged along the material conveying direction and a vertical section (312) at one end of the vertical horizontal section (311). The second pipe fitting (32) is connected to the port of the vertical section (312).

4. The cooling and fire extinguishing system for the rotary kiln feeding conveyor according to claim 2, characterized in that, Several of the steam injection ports (323) are arranged in a rectangular array.

5. The cooling and fire extinguishing system for the rotary kiln feeding conveyor according to claim 2, characterized in that, The first pipe fitting (31) and the second pipe fitting (32) are integrally formed.

6. The cooling and fire extinguishing system for the rotary kiln feeding conveyor according to any one of claims 2-5, characterized in that, The cooling and fire extinguishing system of the rotary kiln feeding conveyor also includes a guide plate (4), which is tilted downward at a preset angle and configured to guide the output direction of the material.

7. The cooling and fire extinguishing system for the rotary kiln feeding conveyor according to claim 6, characterized in that, The tilt angle of the guide plate (4) is 50-60°.

8. The cooling and fire extinguishing system for the rotary kiln feeding conveyor according to claim 6, characterized in that, The second pipe fitting (32) includes a curved section (321) and a straight section (322). One end of the curved section (321) is connected to one port of the first pipe fitting (31), and the other end of the curved section (321) extends downward to form a straight section (322). The straight section (322) is arranged opposite to the guide plate (4).

9. The cooling and fire extinguishing system for the rotary kiln feeding conveyor according to claim 1, characterized in that, The housing includes a first housing (11) and a second housing (12) fixedly arranged in sequence along the material conveying direction. Only the second housing (12) is provided with a circulating water cooling chamber (122) and an inlet (123) and an outlet (124) communicating with the circulating water cooling chamber (122), and is configured to cool the rotary conveying mechanism (2) and the material.

10. The cooling and fire extinguishing system for the rotary kiln feeding conveyor according to claim 9, characterized in that, The length ratio of the first housing (11) to the second housing (12) along the material conveying direction is 1.6:1.

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