A metallurgical high-temperature solid waste residue waste heat recovery device facilitating waste replacement

Abstract

The application discloses a metallurgical high-temperature solid waste residue waste heat recovery device convenient for replacing waste, and relates to the technical field of metallurgical waste heat recovery.The device comprises a receiving groove for receiving high-temperature solid waste residue from a metallurgical kiln, a crushing assembly arranged below the receiving groove for crushing the high-temperature solid waste residue from the receiving groove, a liquid inlet pipe for supplying heat exchange liquid to the crushing assembly so that the crushing assembly absorbs the heat of the high-temperature solid waste residue and transfers the heat to the heat exchange liquid during the crushing process, an outlet pipe arranged on the crushing assembly and used for discharging the heat exchange liquid, a collecting pipe connected to the lower part of the crushing assembly and having a whole trumpet shape, and an outer pipe connected to the lower part of the collecting pipe and used for regularly discharging the high-temperature solid waste residue from the crushing assembly; the liquid inlet pipe penetrates into the outer pipe from the outside of the outer pipe and extends upwards through the collecting pipe to supply the heat exchange liquid to the crushing assembly, so that sufficient heat exchange is realized.

Description

Technical Field

[0001] This invention relates to the field of metallurgical waste heat recovery technology, specifically to a waste heat recovery device for high-temperature solid waste residue in metallurgy that facilitates the replacement of waste materials. Background Technology

[0002] The metallurgical industry is a crucial foundation of the national economy, generating substantial amounts of high-temperature solid waste during its production processes. Taking iron and steel metallurgy as an example, the discharge temperatures of high-temperature solid waste such as blast furnace slag and converter slag typically range from 800℃ to 1200℃, containing considerable thermal energy resources. Statistics show that the sensible heat carried by high-temperature solid waste in the metallurgical industry accounts for approximately 10% to 15% of the total energy consumption of steel enterprises. Therefore, efficiently recovering and utilizing this thermal energy is of significant practical importance for reducing enterprise energy consumption and achieving energy conservation and emission reduction goals.

[0003] Currently, waste heat recovery technologies for high-temperature solid waste slag in metallurgy mainly include air quenching, water quenching, granulation, and mechanical crushing heat exchange. Among them, mechanical crushing heat exchange, which involves crushing high-temperature waste slag for heat exchange, has advantages such as high heat exchange efficiency and easy subsequent utilization of the waste slag, and has been applied to some extent in the industry.

[0004] However, in existing technologies, the crushing device and the heat exchange device are usually designed as separate units. That is, the high-temperature waste residue is first crushed by the crushing device, and then the crushed waste residue is transported to a separate heat exchange device for heat exchange. This separate design results in significant heat loss during the transfer from the crushing area to the heat exchange area, reducing the overall heat exchange efficiency. Furthermore, because the heat exchange device cannot penetrate deep into the core area of ​​the crushing operation, the contact area and contact time between the heat exchange fluid and the high-temperature waste residue are limited, making it difficult to achieve immediate and efficient heat recovery.

[0005] Furthermore, existing waste heat recovery devices typically employ a single-stage heat exchange mode, where the heat exchange fluid directly enters the main heat exchange zone to exchange heat with the high-temperature waste residue, lacking preheating treatment of the heat exchange fluid. This design results in the heat exchange fluid being at a relatively low temperature upon entering the main heat exchange zone. While this is beneficial for improving the temperature difference heat transfer efficiency of the main heat exchange zone, it also means that the device as a whole fails to fully utilize the waste heat resources of the waste residue at each stage of its descent.

[0006] Therefore, it is necessary to provide a metallurgical high-temperature solid waste slag waste heat recovery device that is easy to replace waste materials in order to solve the above problems. Summary of the Invention

[0007] To address the above problems, the present invention provides the following technical solution: a metallurgical high-temperature solid waste slag waste heat recovery device that facilitates waste material replacement, comprising:

[0008] The receiving tank is used to receive high-temperature solid waste residue from the metallurgical kiln;

[0009] A crushing assembly, located below the receiving tank, is used to crush high-temperature solid waste residue from the receiving tank.

[0010] The inlet pipe is used to supply heat exchange fluid to the crushing assembly so that the crushing assembly can absorb heat from the high-temperature solid waste residue during the crushing process and transfer it to the heat exchange fluid. The crushing assembly is also provided with an outlet pipe for discharging the heat exchange fluid.

[0011] The collecting pipe, which is connected to the bottom of the crushing component, is generally funnel-shaped;

[0012] An outer pipe, which is connected to the lower part of the collecting pipe, is used to periodically discharge high-temperature solid waste residue from the crushing component;

[0013] The inlet pipe enters the outer pipe from the outside and extends upward through the collecting pipe to supply heat exchange fluid to the crushing component.

[0014] Furthermore, preferably, the crushing component includes:

[0015] Crushing chamber;

[0016] Two symmetrically arranged crushing rollers are rotatably mounted in the crushing chamber, and the interior of each crushing roller has a cavity.

[0017] Both ends of the crushing roller are connected to shaft tubes, one end of which is rotatably mounted in the transmission chamber, and the other end of which is rotatably mounted in the collection chamber. The bottom of the collection chamber is connected to the liquid inlet pipe.

[0018] The transmission chamber is equipped with a gear transmission assembly for synchronizing the rotation of the two crushing rollers. The gear transmission assembly is also driven by a motor.

[0019] The shaft tubes in the transmission chamber are all connected to the rotary joints, and both rotary joints are connected to the liquid outlet pipe.

[0020] Furthermore, as a preferred embodiment, the inner wall of the outer tube is provided with a plurality of guide components at intervals. The guide components include a first arc plate, an elastic arc plate, and a second arc plate connected in sequence. The first arc plate is fixed to the inner wall of the outer tube, the guide components are generally arc-shaped, and the second arc plate is lower than the first arc plate.

[0021] Furthermore, as a preferred embodiment, both sides of the first and second arc plates are provided with bosses.

[0022] Furthermore, preferably, a control component is provided at the bottom of the outer tube, the control component comprising:

[0023] A control tube, which is connected to the bottom of the outer tube;

[0024] A control valve, which is installed on the control pipe, is used to control whether high-temperature solid waste residue is discharged;

[0025] An intake pipe, which is connected to the control pipe and located above the control valve, is used to connect to a high-pressure intake pump;

[0026] The outer tube is also equipped with a suction component for suctioning gas from the intake pipe, thereby achieving gas heat exchange.

[0027] Furthermore, preferably, the suction assembly includes:

[0028] A suction ring is fitted around the outside of the outer tube and communicates with the outer tube through a radial tube;

[0029] The suction ring is also connected in series with a suction pipe, a suction pump, and an external connector, wherein the external connector is used to connect to an external gas recovery chamber.

[0030] Furthermore, as a preferred embodiment, a mesh is provided in the radial tube.

[0031] Furthermore, preferably, the suction ring is located at 1 / 2 to 3 / 4 of the height of the outer tube.

[0032] Compared with the prior art, the present invention provides a metallurgical high-temperature solid waste slag waste heat recovery device that facilitates waste material replacement, and has the following beneficial effects:

[0033] In this invention, the crushing roller can fully contact the waste residue during the crushing process, with a large heat exchange area and long contact time, which significantly improves the heat exchange efficiency. Secondly, the chamber design allows the heat exchange fluid to penetrate deep into the core area of ​​the crushing operation, realizing the immediate recovery of heat energy and effectively avoiding the loss of heat during the transfer process.

[0034] In this invention, the inlet pipe enters from the outside of the outer pipe and extends upward through the collecting pipe to supply heat exchange liquid to the crushing component, forming a bottom-up pipeline arrangement. This realizes the pre-recovery of heat energy, effectively prolongs the contact time between the waste residue and the inlet pipe, further improves the pre-heat exchange efficiency, and realizes the cascade utilization of energy.

[0035] In this invention, the guide assembly adopts a three-section structure design in which a first arc plate, an elastic arc plate, and a second arc plate are connected in sequence. The elastic arc plate is connected between the first arc plate and the second arc plate, playing a key role in adaptive adjustment and preventing accumulation, which significantly improves the reliability and stability of the device operation. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the overall structure of a metallurgical high-temperature solid waste slag waste heat recovery device that facilitates waste material replacement.

[0037] Figure 2 This is a cross-sectional view of the crushing assembly and the outer tube.

[0038] Figure 3 A schematic diagram of the planar structure of the guide component;

[0039] Figure 4 A schematic diagram of a three-dimensional structure of a waste heat recovery device for high-temperature solid waste in metallurgy that facilitates waste material replacement. Figure 1 ;

[0040] Figure 5 A schematic diagram of a three-dimensional structure of a waste heat recovery device for high-temperature solid waste in metallurgy that facilitates waste material replacement. Figure 2 ;

[0041] In the diagram: 1. Metallurgical kiln; 2. Receiving tank; 3. Crushing assembly; 4. Inlet pipe; 5. Outlet pipe; 6. Collecting pipe; 7. Outer pipe; 8. Suction assembly; 9. Control assembly; 31. Crushing roller; 32. Chamber; 33. Shaft tube; 34. Collecting bin; 35. Transmission bin; 71. Guide assembly; 711. First arc plate; 712. Elastic arc plate; 713. Second arc plate; 714. Boss; 81. Suction ring; 82. Suction pipe; 83. Suction pump; 84. External connector; 91. Control pipe; 92. Air inlet pipe; 93. Control valve. Detailed Implementation

[0042] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms are interchangeable where appropriate; this is merely a way of distinguishing objects with the same attributes in the embodiments of this application. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion, so that a process, method, system, product, or apparatus that comprises a series of elements is not necessarily limited to those elements, but may include other elements not explicitly listed or inherent to those processes, methods, products, or apparatuses.

[0043] Example: In this embodiment of the invention, please refer to... Figures 1-5 A waste heat recovery device for high-temperature solid waste slag in metallurgy, which facilitates waste material replacement, is provided, comprising:

[0044] Receiving tank 2 is used to receive high-temperature solid waste residue from metallurgical kiln 1;

[0045] The crushing component 3 is disposed below the receiving tank 2 and is used to crush the high-temperature solid waste residue from the receiving tank 2.

[0046] The inlet pipe 4 is used to supply heat exchange fluid to the crushing component 3 so that the crushing component 3 can absorb heat from the high-temperature solid waste residue during the crushing process and transfer it to the heat exchange fluid. The crushing component 3 is also provided with an outlet pipe 5 for discharging the heat exchange fluid.

[0047] The collecting pipe 6 is connected to the lower part of the crushing component 3 and is generally funnel-shaped;

[0048] The outer pipe 7 is connected to the lower part of the collecting pipe 6 and is used to periodically discharge high-temperature solid waste residue from the crushing component 3.

[0049] The inlet pipe 4 enters the outer pipe 7 from the outside and extends upward through the collecting pipe 6 to supply heat exchange fluid to the crushing component 3.

[0050] In the metallurgical industry, the high-temperature solid waste slag discharged from the metallurgical kiln 1 typically has a temperature of 800℃ to 1200℃. During implementation, the high-temperature solid waste slag first exits from the metallurgical kiln 1 and falls into the receiving tank 2. The receiving tank 2, serving as the feed end of the entire unit, is usually made of high-temperature resistant and wear-resistant alloy steel, such as high-chromium cast iron or wear-resistant steel. The cross-sectional shape of the receiving tank 2 can be designed as a funnel or cone shape according to the actual working conditions, so that the high-temperature solid waste slag can enter the crushing assembly 3 under gravity. When the crushing assembly 3 mechanically crushes the high-temperature solid waste slag, the specific surface area of ​​the high-temperature solid waste slag increases significantly. According to the basic principles of heat transfer, the convective heat transfer rate is directly proportional to the heat transfer area, i.e., Q = hAΔT, where Q is the heat transfer rate, h is the convective heat transfer coefficient, A is the heat transfer area, and ΔT is the temperature difference. By crushing large pieces of waste slag into small particles, the heat transfer area can be increased several times or even tens of times, thereby significantly improving the heat exchange efficiency.

[0051] In addition, the inlet pipe 4 enters from the outside of the outer pipe 7 and extends upward through the collecting pipe 6 to supply heat exchange fluid to the crushing component 3. During the process of passing through the outer pipe 7 and the collecting pipe 6, the inlet pipe 4 can pre-exchange heat with the high-temperature waste residue or hot air in the outer pipe 7, so that the heat exchange fluid has already obtained a certain temperature rise before entering the crushing component 3, thereby improving the overall heat exchange efficiency.

[0052] In this embodiment, the crushing component 3 includes:

[0053] Crushing chamber;

[0054] Two symmetrically arranged crushing rollers 31 are rotatably disposed in the crushing chamber, and the interior of the crushing rollers 31 has a cavity 32;

[0055] Both ends of the crushing roller 31 are connected to shaft tubes 33. One end of the shaft tube 33 is rotatably installed in the transmission chamber 35, and the other end of the shaft tube 33 is rotatably installed in the collection chamber 34. The bottom of the collection chamber 34 is connected to the liquid inlet pipe 4.

[0056] The transmission chamber 35 is equipped with a gear transmission assembly for making the two crushing rollers 31 rotate synchronously. The gear transmission assembly is also driven by the motor 10.

[0057] The shaft tubes 33 in the transmission chamber 35 are all connected to the rotary joints, and the two rotary joints are connected to the liquid outlet pipe 5.

[0058] The crushing chamber is typically made of high-temperature resistant and wear-resistant metal materials, such as high-manganese steel, alloy steel, or wear-resistant cast iron. The inner wall of the crushing chamber can be fitted with replaceable wear-resistant liners for easy replacement after prolonged use, extending the equipment's service life.

[0059] In addition, the crushing roller 31 has an internal chamber 32, which provides a flow channel for the heat exchange fluid, allowing the fluid to circulate inside the crushing roller 31 and directly exchange heat with the high-temperature solid waste. The heat is conducted through the roller wall to the heat exchange fluid in the chamber 32. Because the crushing roller 31 is in full contact with the high-temperature solid waste during the crushing process, with a large heat exchange area and long contact time, the heat exchange efficiency is high. Secondly, the design of the chamber 32 allows the heat exchange fluid to penetrate deep into the core area of ​​the crushing operation, realizing immediate heat recovery and avoiding heat loss during the transfer process.

[0060] It should also be explained that the rotary joint has a rotating component and a stationary component inside. The rotating component rotates synchronously with the shaft tube 33, and the stationary component is fixedly connected to the liquid outlet pipe 5. The two are dynamically sealed by a sealing element to ensure that the heat exchange fluid can still flow smoothly in the rotating state without leakage. The rotary joint can be a hydraulic rotary joint, a pneumatic rotary joint, or a special heat exchange medium rotary joint, etc.

[0061] In this embodiment, the inner wall of the outer tube 7 is provided with a plurality of guide components 71 at intervals. The guide component 71 includes a first arc plate 711, an elastic arc plate 712 and a second arc plate 713 connected in sequence. The first arc plate 711 is fixed to the inner wall of the outer tube 7. The guide component 71 is arc-shaped as a whole, and the second arc plate 713 is lower than the first arc plate 711.

[0062] In this embodiment, the inlet pipe 4 enters from the outside of the outer pipe 7 and extends upward through the collecting pipe 6 to supply heat exchange fluid to the crushing component 3. Therefore, when the inlet pipe 4 passes through the area of ​​the collecting pipe 6, its outer surface is in direct contact with the high-temperature solid waste falling inside the collecting pipe 6. The heat exchange fluid flows from bottom to top in the inlet pipe 4, and its temperature gradually increases, so that the heat exchange fluid has already obtained a certain temperature rise before entering the crushing component 3, realizing the pre-recovery of heat energy.

[0063] The guide assembly 71 adopts a three-section structure design, including a first arc plate 711, an elastic arc plate 712, and a second arc plate 713. The first arc plate 711 is fixed to the inner wall of the outer tube 7, serving as the fixed end of the guide assembly 71. The first arc plate 711 is typically made of high-temperature resistant and wear-resistant metal materials, such as stainless steel or wear-resistant steel, and is fixed to the inner wall of the outer tube 7 by welding or bolting. The elastic arc plate 712 can be made of elastic materials such as high-temperature resistant rubber, silicone, metal corrugated pipe, or spring steel sheet. The elastic arc plate 712 connects the first arc plate 711 and the second arc plate 713, playing a role in self-adjustment and preventing accumulation. When the waste residue falls normally, the elastic arc plate 712 maintains its normal shape, guiding the waste residue to slide towards the outer surface of the liquid inlet pipe 4. When the waste residue accumulates at the guide assembly 71, the elastic arc plate 712 undergoes elastic deformation under the weight of the waste residue, self-adjusting and changing the guiding angle, allowing the accumulated waste residue to slide smoothly and avoiding blockage.

[0064] Furthermore, both sides of the first arc plate 711 and the second arc plate 713 are provided with bosses 714. The bosses 714 can enhance the structural strength and rigidity of the arc plates.

[0065] In this embodiment, a control component 9 is provided at the bottom of the outer tube 7, and the control component 9 includes:

[0066] Control tube 91, which is connected to the bottom of the outer tube 7;

[0067] Control valve 93, which is installed on the control pipe 91, is used to control whether high-temperature solid waste residue is discharged;

[0068] The intake pipe 92 is connected to the control pipe 91 and is located above the control valve 93, for connection to the high-pressure intake pump;

[0069] The outer tube 7 is also equipped with a suction component 8, which is used to suction gas from the air inlet pipe 92, thereby realizing gas heat exchange.

[0070] The control valve 93 can be a gate valve, ball valve, butterfly valve, or slide gate valve. For high-temperature solid waste, high-temperature resistant gate valves or slide gate valves are preferred, as these valves have advantages such as large flow area, low resistance, and resistance to clogging. The control valve 93 can be operated manually or configured with an electric or pneumatic actuator for automatic control, which will not be elaborated further here.

[0071] In this embodiment, the intake pipe 92 is connected to the control pipe 91 and located above the control valve 93. The intake pipe 92 is used to connect to the high-pressure intake pump to inject high-pressure gas into the control pipe 91. The high-pressure intake pump can be an air compressor, a high-pressure blower, or a nitrogen booster pump, etc. The suction assembly 8 is installed on the outer pipe 7 and is used to suction the gas from the intake pipe 92. After the high-pressure gas enters the outer pipe 7 from the intake pipe 92, it exchanges heat with the high-temperature waste residue in the outer pipe 7 during its upward flow. After absorbing the heat from the waste residue, the temperature rises. The suction assembly 8 then extracts the heated gas from the outer pipe 7 and transports it to the subsequent heat energy utilization equipment, realizing the recovery of gas waste heat. This gas heat exchange method supplements and enhances the liquid heat exchange of the crushing assembly 3, further improving the overall waste heat recovery efficiency.

[0072] Specifically, the suction component 8 includes:

[0073] A suction ring 81 is sleeved on the outside of the outer tube 7 and communicates with the outer tube 7 through a radial tube;

[0074] The suction ring 81 is also connected in series with a suction pipe 82, a suction pump 83, and an external connector 84, wherein the external connector 84 is used to connect to an external gas recovery chamber.

[0075] Furthermore, a baffle is installed in the radial tube. When hot gas enters the suction ring 81 from the outer tube 7 through the radial tube, the gas may carry a certain amount of fine waste particles or dust. If these particles enter components such as the suction ring 81, suction pipe 82, and suction pump 83, they may cause wear, blockage, or damage to the equipment. The baffle effectively solves this problem. When the gas flows through the baffle, gas molecules can pass through the mesh smoothly, while particles larger than the mesh size are intercepted on the surface or inside the mesh. The intercepted particles gradually accumulate under the action of gravity. When they accumulate to a certain extent, the particles will fall off the surface of the baffle and fall back into the outer tube 7.

[0076] Furthermore, the suction ring 81 is located at 1 / 2 to 3 / 4 of the height of the outer tube 7.

[0077] After the high-pressure gas enters the bottom of the outer pipe 7 through the inlet pipe 92, it exchanges heat with the high-temperature solid waste residue as it flows upward. The gas gradually absorbs heat from the waste residue during its flow, causing its temperature to gradually rise. If the suction ring 81 is installed at the bottom or lower part of the outer pipe 7, the gas's residence time inside the outer pipe 7 is short, resulting in insufficient contact time with the waste residue, inadequate heat exchange, and low waste heat recovery efficiency. If the suction ring 81 is installed at the top or upper part of the outer pipe 7, although the gas's residence time inside the outer pipe 7 is longer and heat exchange is more thorough, the gas will affect the falling posture of the waste residue near the top of the outer pipe 7.

[0078] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A waste heat recovery device for high-temperature solid waste slag in metallurgy that facilitates waste material replacement, characterized in that, include: The receiving tank (2) is used to receive high-temperature solid waste residue from the metallurgical kiln (1); The crushing component (3) is disposed below the receiving tank (2) and is used to crush the high-temperature solid waste residue from the receiving tank (2); The inlet pipe (4) is used to supply heat exchange fluid to the crushing assembly (3) so that the crushing assembly (3) can absorb heat from high-temperature solid waste residue during the crushing process and transfer it to the heat exchange fluid. The crushing assembly (3) is also provided with an outlet pipe (5) for discharging the heat exchange fluid. The collecting pipe (6) is connected below the crushing component (3) and is generally funnel-shaped; The outer pipe (7) is connected below the collecting pipe (6) and is used to periodically discharge high-temperature solid waste residue from the crushing component (3); The inlet pipe (4) enters the outer pipe (7) from the outside of the outer pipe (7) and extends upward through the collecting pipe (6) to supply heat exchange fluid to the crushing component (3).

2. The metallurgical high-temperature solid waste slag waste heat recovery device according to claim 1, characterized in that, The crushing component (3) includes: Crushing chamber; Two symmetrically arranged crushing rollers (31) are rotatably disposed in the crushing chamber, and the interior of the crushing rollers (31) has a cavity (32). Both ends of the crushing roller (31) are connected to shaft tubes (33), one end of which is rotatably installed in the transmission chamber (35), and the other end of which is rotatably installed in the collection chamber (34). The bottom of the collection chamber (34) is connected to the liquid inlet pipe (4). The transmission chamber (35) is equipped with a gear transmission assembly for making the two crushing rollers (31) rotate synchronously. The gear transmission assembly is also driven by a motor (10). The shaft tubes (33) in the transmission chamber (35) are all connected to the rotary joints, and the two rotary joints are connected to the liquid outlet pipe (5).

3. The metallurgical high-temperature solid waste slag waste heat recovery device according to claim 2, characterized in that, The inner wall of the outer tube (7) is provided with a plurality of guide components (71) at intervals. The guide components (71) include a first arc plate (711), an elastic arc plate (712) and a second arc plate (713) connected in sequence. The first arc plate (711) is fixed to the inner wall of the outer tube (7). The guide components (71) are arc-shaped as a whole, and the second arc plate (713) is lower than the first arc plate (711).

4. The metallurgical high-temperature solid waste slag waste heat recovery device according to claim 3, characterized in that, Both sides of the first arc plate (711) and the second arc plate (713) are provided with bosses (714).

5. A metallurgical high-temperature solid waste slag waste heat recovery device for easy waste material replacement according to claim 1, characterized in that, A control component (9) is provided at the bottom of the outer tube (7), the control component (9) including: A control tube (91) is connected to the bottom of the outer tube (7); A control valve (93) is provided on the control pipe (91) for controlling whether high-temperature solid waste residue is discharged; An intake pipe (92), which is connected to the control pipe (91) and located above the control valve (93), is used to connect to a high-pressure intake pump; The outer tube (7) is also equipped with a suction assembly (8) for suctioning gas from the inlet pipe (92) to achieve gas heat exchange.

6. A metallurgical high-temperature solid waste slag waste heat recovery device for easy waste material replacement according to claim 5, characterized in that, The suction assembly (8) includes: A suction ring (81) is sleeved on the outside of the outer tube (7) and communicates with the outer tube (7) through a radial tube; The suction ring (81) is also connected in series with a suction pipe (82), a suction pump (83), and an external connector (84), wherein the external connector (84) is used to connect to an external gas recovery chamber.

7. A metallurgical high-temperature solid waste slag waste heat recovery device for easy waste material replacement according to claim 6, characterized in that, A barrier net is installed in the radial tube.

8. A metallurgical high-temperature solid waste slag waste heat recovery device for easy waste material replacement according to claim 6, characterized in that, The suction ring (81) is located at 1 / 2 to 3 / 4 of the height of the outer tube (7).

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