Pyrolysis gas pre-dedusting system

Abstract

The present application relates to the technical field of dust removal, and particularly relates to a high-temperature pyrolysis gas pre-dust removal system. The high-temperature pyrolysis gas pre-dust removal system comprises a dust remover tank body, the dust remover tank body is provided with an air inlet, an air outlet and a dust outlet, and a filter screen assembly is arranged in the dust remover tank body, so that the pyrolysis gas entering from the air inlet is guided out from the air outlet after passing through the filter screen assembly; the filter screen assembly is provided with a rotary driving member, so that the pyrolysis gas is subjected to centrifugal force after being in contact with the filter screen assembly; and the filter screen assembly is a plurality of metal screen surfaces arranged at intervals. The present application removes dust from the pyrolysis gas through the filtering effect of the metal screen surfaces and the centrifugal effect generated by the rotation of the metal screen surfaces, improves the dust removal effect and dust removal precision, and can also cool the pyrolysis gas during the dust removal process, so that the pyrolysis gas can meet the temperature requirement of subsequent dust removal.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of dust removal, and particularly relates to a high-temperature pyrolysis gas pre-dust removal system. BACKGROUND

[0002] The pyrolysis technology is gradually applied to the comprehensive treatment of solid waste due to its high degree of resource utilization and less pollution. The technical characteristics of the pyrolysis process determine that the pyrolysis gas is rich in combustible gas, gaseous tar and dust. These dusts are easy to block the subsequent equipment. Based on the characteristics of the pyrolysis gas, the high-temperature dry dust removal is suitable for the dust removal technology, and the corrosion resistance and filtering accuracy of the equipment need to be ensured.

[0003] The cyclone dust collector is a widely used dust removal device in industry, especially in harsh environments such as high temperature, high pressure, high dust concentration and strong corrosion. The dust particles entrained in the pyrolysis gas are fine and have small density, and the centrifugal force generated when rotating in the cyclone separator is small. Therefore, only using the cyclone dust collector to treat the pyrolysis gas cannot meet the industrial requirements in terms of dust removal accuracy. The cyclone separator has poor removal effect on particles below 10 μm, so the cyclone dust collector can only be used as a pre-dust removal device, and other dust removal devices such as bag dust collector and electrostatic dust collector need to be configured subsequently. However, these dust removal devices are sensitive to temperature, and the dust removal temperature of the bag dust collector is not higher than 100℃, and the dust removal temperature of the electrostatic dust collector is not higher than 200℃. The temperature of the pyrolysis gas after the cyclone dust collector is generally 300℃, which cannot meet the requirements of the subsequent dust removal temperature. Zhang Yinglong and Liu Zhao disclosed the application of a new type of cyclone dust collector in a straw pyrolysis gasification device (No. 1 Heavy Technology, the fifth issue, 2021). A sleeve and a cooling circulation system are installed outside the cyclone dust collector to reduce the temperature of the high-temperature straw pyrolysis gas. Although the above device can achieve the temperature reduction requirement of the pyrolysis gas, the dust removal effect is not good based on the characteristics of the cyclone dust collector. SUMMARY

[0004] The present application aims at the deficiencies of the prior art, and provides a high-temperature pyrolysis gas pre-dust removal system with high dust removal efficiency.

[0005] In order to achieve the above-mentioned purpose, the technical scheme of the present application is as follows:

[0006] The high-temperature pyrolysis gas pre-dust removal system comprises a dust collector tank body, the dust collector tank body is provided with a gas inlet, a gas outlet and a dust outlet, and a filter screen assembly is arranged in the dust collector tank body, so that the pyrolysis gas entering from the gas inlet is guided out from the gas outlet after passing through the filter screen assembly; the filter screen assembly has a rotary driving member, so that the pyrolysis gas is subjected to centrifugal force after contacting the filter screen assembly; and the filter screen assembly comprises a plurality of metal screen surfaces arranged at intervals.

[0007] The application concept of the present application is to use a rotating metal screen to remove dust from a high-temperature pyrolyzer.

[0008] Firstly, the metal screen is resistant to high temperature, simple in structure and low in cost.

[0009] Secondly, the pyrolysis gas passes through the metal screens arranged in sequence, so that a large number of dust particles are filtered.

[0010] Thirdly, after the pyrolysis gas collides with the metal screen, it is also subjected to the action of centrifugal force, which causes part of the dust particles to hit the inner wall of the dust remover tank, so that part of the dust particles slide along the inner wall of the dust remover tank. Since the filter screen assembly is a plurality of metal screens arranged in sequence, the pyrolysis gas is continuously subjected to centrifugal force during its travel in the dust remover tank, so the centrifugal removal effect is more obvious. The metal screen can also achieve self-cleaning during rotation, reducing the probability of the metal screen being blocked.

[0011] Fourthly, the dust particles trapped between adjacent metal screens are limited, and are not concentrated in a single area of the dust remover tank, so as not to cause blockage and facilitate the discharge of dust particles from the dust outlet.

[0012] After the dust remover tank is combined in series, the subsequent bag-type dust collector can be replaced by limiting the mesh aperture of the metal screen.

[0013] As an improvement, the mesh aperture of the metal screen decreases in sequence from the gas inlet to the gas outlet, achieving staged dust removal of the pyrolysis gas, removing large dust particles first, and then removing small dust particles, thereby increasing the dust removal precision. Another effect of limiting the mesh aperture is that dust particles of the same particle size are trapped between adjacent metal screens. The closer to the gas outlet, the finer the dust particles, so that the same space can accommodate more dust particles, and the opening frequency of the dust outlet can be reduced.

[0014] As an improvement, the filter screen assembly is provided with a screen cleaning piece, the screen cleaning piece is fixedly connected with the dust remover tank, one screen cleaning piece is arranged between adjacent metal screens, the screen cleaning piece is in contact with the metal screen, and the screen cleaning piece swings within a certain range under the action of the pyrolysis gas flow. And the metal screen rotates continuously, so that the screen cleaning piece cleans the metal screen in all directions, reducing the blocking of the metal screen.

[0015] As an improvement, the screen cleaning piece is a strip-shaped metal rod.

[0016] As an improvement, the screen cleaning piece is a strip-shaped metal sheet.

[0017] As an improvement, a purging circuit is provided on the dust collector tank. The purging circuit is connected to an external cleaning medium to periodically clean the metal mesh surface. The cleaning medium can be an inert gas, such as nitrogen.

[0018] As an improvement, the rotary drive includes a drive shaft and a drive motor. The drive shaft has a cooling medium channel inside, and the cooling medium can be cooling water to cool the pyrolysis gas.

[0019] As an improvement, the dust collector tank is equipped with a dust collection bin, which is located below the dust outlet. The dust outlet is sealed by a dust outlet sealing plate, which can be moved back and forth by a tension cylinder as needed to open the dust outlet.

[0020] In summary, this invention removes dust from pyrolysis gas through the filtering effect of the metal mesh and the centrifugal force generated by the rotation of the metal mesh, thereby improving the dust removal effect and accuracy. Furthermore, the pyrolysis gas can be cooled during the dust removal process, ensuring that the pyrolysis gas meets the temperature requirements for subsequent dust removal. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the present invention;

[0022] Figure 2 for Figure 1 Enlarged view of section A in the middle;

[0023] Figure 3 for Figure 1 Enlarged view of section B;

[0024] Figure 4 This is a cross-sectional view of the present invention;

[0025] In the diagram: 10. Dust collector tank; 11. Air inlet; 12. Air outlet; 13. Dust outlet; 131. Dust outlet sealing plate; 132. Tensioning cylinder; 14. Sinking groove; 20. Filter screen assembly; 30. Rotary drive component; 31. Drive shaft; 32. Drive motor; 33. Cooling medium channel; 40. Screen cleaning component; 50. Blowing circuit; 60. Ash collection bin. Detailed Implementation

[0026] like Figure 1 As shown, the high-temperature pyrolysis gas pre-dust removal system of the present invention is mainly a dust collector tank 10. An air inlet 11 and an air outlet 12 are opened on the top of the dust collector tank 10. A blowing circuit 50 is set at the air outlet 12, and the blowing circuit 50 is connected to the external cleaning medium.

[0027] like Figure 1 , Figure 2As shown, the inside of the dust collector tank 10 is provided with a filter screen assembly 20, which is a plurality of spaced metal screen surfaces. The filter screen assembly 20 is connected with a rotary drive 30, which provides driving force for the rotation of the filter screen assembly 20. The rotary drive 30 includes a drive shaft 31 and a drive motor 32, and the inside of the drive shaft 31 is provided with a cooling medium passage 33.

[0028] As shown in Figure 1 , Figure 3 , a sunken groove 14 is formed in the lower part of the dust collector tank 10. The sunken groove 14 is provided with dust outlets 13, which are arranged between adjacent metal screen surfaces. The dust collector tank 10 is provided with a conical dust collecting bin 60, which is located below the dust outlets 13. The dust outlets 13 are sealed by dust outlet sealing plates 131, which can be moved back and forth by a stretching cylinder 132 to open the dust outlets 13 as needed.

[0029] As shown in Figure 1 , Figure 4 , the filter screen assembly 20 is provided with screen surface cleaning members 40, one end of which is fixedly connected with the dust collector tank 10, and the other end is a free end. Each adjacent metal screen surface is provided with a screen surface cleaning member 40, which is in contact with the metal screen surface. The screen surface cleaning member 40 is a strip-shaped metal rod or strip.

[0030] Working process: The pyrolysis gas enters the inside of the dust collector tank 10 from the gas inlet 11. The metal screen surface is driven to rotate by the rotary drive 30. On the one hand, the centrifugal force generated by the rotating metal screen surface removes dust, and on the other hand, the metal screen surface filters the dust. The pore size of the metal screen surface decreases from the gas inlet 11 to the gas outlet 12 direction, so that the pyrolysis gas is subjected to staged dust removal. In this process, the metal screen surface is self-cleaning by rotation, and the screen surface cleaning member 40 can also clean the metal screen surface in all directions, thereby reducing the situation that the metal screen surface is blocked. Cooling water is introduced into the cooling medium passage 33 of the drive shaft 31 to cool the pyrolysis gas.

[0031] Cleaning process of the metal screen surface: high-pressure nitrogen gas is introduced into the blowback circuit 50, and the rotary drive assembly 30 is started to rotate the metal screen surface, and the high-pressure nitrogen gas is used to backwash the metal screen surface. In this process, the gas outlet needs to be closed.

[0032] Application effect

[0033] The initial temperature of the pyrolysis gas is 450℃, the initial dust concentration is 31g / m 3 , and the flow rate is 1000 m 3 / h, and the flow rate was 14 m / s. The diameter of the dust collector tank 10 was 0.8 m, and the length was 1.5 m. The number of metal mesh surfaces was 9, the thickness of the metal mesh surface was 5 cm, the metal mesh surface was made of SUS310S (stainless steel, temperature-resistant alloy steel), and the size was φ800 mm. The mesh hole diameters of the metal mesh surfaces from the gas inlet to the gas outlet were 20 μm, 15 μm, 10 μm, 8 μm, 6 μm, 4 μm, 3 μm, 2 μm, and 1 μm in this order. The rotation speed of the metal mesh surface was 15 r / min. Cooling medium channels were filled with cooling water, and the initial temperature of the cooling water was 25°C. After the pyrolysis gas passed through the dust collector, the temperature of the pyrolysis gas was 320°C, and the dust concentration was 6 g / m 3 . The dust removal efficiency was 80%.

[0034] The same pyrolysis gas was treated using a conventional cyclone dust collector, and the parameters of the cyclone dust collector were as follows: the inlet form was tangential, the treatment capacity was 1000 m 3 / h, the cylinder diameter was φ0.51 m, the straight cylinder length was 0.362 m, and the conical cylinder length was 1.450 m. After the pyrolysis gas with the same initial conditions passed through the cyclone dust collector, the temperature of the pyrolysis gas was 380°C, and the dust concentration was 12 g / m 3 . The dust removal efficiency was 60%.

Claims

1. A method for pre-dusting high-temperature pyrolysis gas, which utilizes a pre-dusting system to replace a cyclone dust collector to implement pre-dusting of high-temperature pyrolysis gas, the pre-dusting system comprising a dust collector tank (10) provided with a gas inlet (11), a gas outlet (12), and a dust outlet (13), the dust collector tank (10) being provided with a filter screen assembly (20) having a rotary drive (30) comprising a drive shaft (31) and a drive motor (32), the drive shaft (31) being provided with a cooling medium channel (33) inside; the filter screen assembly (20) comprising a plurality of metal screen surfaces arranged at intervals; the filter screen assembly (20) being provided with screen surface cleaning members (40) fixedly connected to the dust collector tank (10), one screen surface cleaning member (40) being arranged between adjacent metal screen surfaces and in contact with the metal screen surfaces; the metal screen surfaces are centrifugally rotated, so that the high-temperature pyrolysis gas introduced from the gas inlet (11) is subjected to a centrifugal force when colliding with the metal screen surfaces, part of the dust particles are made to collide against the inner wall of the dust collector tank (10), and part of the dust particles slide along the inner wall of the dust collector tank (10) to fall out of the dust collector tank, the high-temperature pyrolysis gas is sequentially guided out of the dust collector tank through the filter screen assembly (20) and the gas outlet (12); the metal screen surfaces are self-cleaned in the process of centrifugal rotation and continuous friction with the screen surface cleaning members (40).

2. The method of pre-dusting a high temperature pyrolysis gas of claim 1, wherein: The mesh hole diameter of the metal screen surfaces decreases in sequence from the gas inlet (11) to the gas outlet (12).

3. The method of pre-dusting a high temperature pyrolysis gas of claim 1, wherein: The screen surface cleaning members (40) are strip-shaped metal rods.

4. The method of pre-dusting a high temperature pyrolysis gas of claim 1, wherein: The screen surface cleaning members (40) are strip-shaped metal sheets.

5. The method for pre-dusting a high temperature pyrolysis gas of claim 1, wherein: The dust collector tank (10) is provided with a blowback circuit (50) in communication with an external cleaning medium.

6. The method of pre-dusting a high temperature pyrolysis gas of claim 1, wherein: The dust collector tank (10) is provided with an ash collection bin (60) located below the dust outlet (13), the dust outlet (13) being sealed by a dust outlet sealing plate (131) which can be moved back and forth by a stretching cylinder (132) to open the dust outlet (13) as needed.

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