Cement raw meal mill pulse bag type superfine dust filtering device

Abstract

The application discloses a cement raw material mill pulse bag type superfine dust filtering device, and particularly relates to the technical field of dust filtering, which comprises a shell, a horizontal baffle plate arranged in the shell for partition, a plurality of filter bag chambers arranged at the bottom of the horizontal baffle plate, and filter bags arranged in each filter bag chamber respectively, the middle part of the filter bag is provided with an inner cylinder, the middle part of the inner cylinder is provided with a flow guide cylinder, and a treatment cavity is formed between the inner cylinder and the flow guide cylinder. The application forms a three-stage filtering structure through the filter membrane of the inner wall of the flow guide cylinder, the inner cylinder and the filter bag. Dust-containing air flow is first subjected to primary filtering by the filter membrane to intercept superfine particles, then subjected to secondary filtering by the inner cylinder, and finally subjected to three-stage fine filtering by the filter bag. The application realizes the step-by-step interception of superfine dust from the structure, solves the problem that the existing single-layer filter bag is difficult to efficiently capture micron-level superfine dust, and provides a structural basis for improving filtering efficiency and reducing emission concentration.

Description

Technical Field

[0001] This invention relates to the field of dust filtration technology, and more specifically, to a pulse bag ultrafine dust filtration device for cement raw material mills. Background Technology

[0002] The cement raw meal mill is a core grinding equipment in the cement production process, grinding raw materials such as limestone, clay, and iron powder into qualified raw meal powder. During operation, the flue gas discharged from the raw meal mill contains a large amount of raw meal dust. This dust has extremely fine particle size (a large number of micron-sized ultrafine particles), high concentration, and a certain degree of alkalinity. Direct emission would cause serious air pollution and resource waste. Therefore, the raw meal mill system must be equipped with a dust filtration device to both recover the raw meal powder for return to the production process and meet environmental protection ultra-low emission requirements.

[0003] Pulse jet baghouse dust collectors are commonly used dry, high-efficiency dust collection devices in raw material grinding systems. Their basic working principle is as follows: After the dust-laden airflow enters the dust collector shell, large dust particles settle into the ash hopper due to inertia; the dust-laden airflow passes through the filter bags, and ultrafine dust is trapped on the outer surface of the filter bags, while clean gas passes through the filter bags into the diversion chamber and is discharged by the induced draft fan; when the dust accumulation on the surface of the filter bags reaches a certain thickness, the pulse jet system instantly sprays high-pressure gas into the filter bags, shaking the dust on the surface of the filter bags into the ash hopper, thus completing the dust removal.

[0004] Existing pulse jet baghouse dust collectors have several areas for improvement when handling ultrafine dust from cement raw material mills: First, the raw material dust particles are extremely fine, with a large number of particles below the micrometer level. Relying solely on the surface filtration of the filter bags is insufficient for efficient collection. Ultrafine particles easily penetrate the filter bags or agglomerate within the pores, leading to a rapid increase in filtration resistance and fluctuations in emission concentration. Second, the dust-laden airflow is unevenly distributed after entering the filter bag chamber. Some filter bags are overloaded and clogged prematurely, while others are underloaded, affecting overall filtration efficiency and filter bag lifespan. Third, during pulse jet cleaning, the airflow instantaneously impacts the filter bags, causing dust to primarily fall from the outer surface. However, fine dust deposited inside the filter bags and on the supporting structure is difficult to remove completely, resulting in a gradual decrease in cleaning efficiency after long-term operation. Furthermore, the dust-laden airflow moves in a unidirectional direction within the filter bag chamber, causing dust to accumulate in localized areas and affecting the uniform distribution of the airflow. Summary of the Invention

[0005] In order to overcome the above-mentioned defects of the prior art, the present invention provides a pulse bag ultrafine dust filtration device for cement raw material mill, which aims to solve the problems of low ultrafine dust collection efficiency, uneven airflow distribution and poor dust removal effect mentioned in the background art.

[0006] The present invention provides the following technical solution: a pulse bag ultrafine dust filtration device for cement raw material mill, comprising a shell, a horizontal baffle disposed within the shell for separation, a plurality of filter bag chambers disposed at the bottom of the horizontal baffle, and filter bags disposed in each of the filter bag chambers respectively; The filter bag has an inner cylinder in the middle, and a flow guide cylinder is provided in the middle of the inner cylinder. A processing cavity is formed between the inner cylinder and the flow guide cylinder. A filter membrane is provided on the inner wall of the flow guide cylinder. Several flow diversion holes are respectively opened on the inner cylinder and the flow guide cylinder. The middle part of the guide tube is rotatably connected to a rotating shaft, and the top of the rotating shaft is provided with several guide plates, which are stacked and combined to form a frustum shape. The top of the filter bag is fixedly provided with several support rings. Each support ring is located between two adjacent guide plates and is rotatably connected to the guide plates. The inner wall of the support ring and the outer side of the guide plate are respectively provided with guide vanes. When the shaft rotates, the dust-laden airflow is drawn through the guide vanes on the outer side of the guide plate, and the guide vanes on the inner wall of the support ring block the transported airflow.

[0007] Furthermore, a conical top cover is provided at the top of the rotating shaft, and a diversion chamber is provided at the top of the horizontal baffle. The diversion chamber is provided with several partitions located on one side of the top of the corresponding filter bag chamber, for the dust-laden airflow to enter the diversion chamber and be diverted and transported to each of the filter bag chambers by the partitions.

[0008] Furthermore, the top of the housing is provided with an air inlet for air intake, and the bottom end of the air inlet extends into the distribution chamber and communicates with the distribution chamber, so that the dust-laden airflow enters the distribution chamber through the air inlet.

[0009] Furthermore, a blowpipe is provided on the top side of the housing, and a plurality of pulse valves are provided on the blowpipe. One end of each pulse valve extends to the top of the inner cavity of the corresponding filter bag chamber, for delivering clean airflow into the filter bag chamber for cleaning.

[0010] Furthermore, a connecting cover is provided at the top of the inner cavity of the filter bag chamber, and the connecting cover abuts against the top of the support ring to provide positioning and constraint for the support ring and the guide plate.

[0011] Furthermore, a drive module for driving the shaft to rotate is provided at the bottom of the rotating shaft, and a dust hopper is provided at the bottom of the filter bag for discharging dust.

[0012] Furthermore, a support base is provided at the bottom of the ash hopper to support the drive module and the filter bag in the filter bag chamber.

[0013] Furthermore, a normally closed bypass valve is provided on the outside of the filter bag, and a dispersion plate is provided on the top of the filter bag to disperse the dust-laden airflow entering the inner cylinder and the guide cylinder.

[0014] The technical effects and advantages of this invention are as follows: This invention forms a three-stage filtration structure through the filter membrane, inner cylinder, and filter bag on the inner wall of the guide tube. The dust-laden airflow first undergoes primary filtration through the filter membrane to intercept ultrafine particles, then undergoes secondary filtration through the inner cylinder, and finally undergoes tertiary fine filtration through the filter bag. Structurally, this invention achieves step-by-step interception of ultrafine dust, solving the problem that existing single-layer filter bags are unable to efficiently capture micron-level ultrafine dust, and providing a structural basis for improving filtration efficiency and reducing emission concentration. Based on the above-mentioned three-stage filtration, this invention drives the rotation of multiple frustum-shaped guide plates through a rotating shaft. The guide vanes on the outer side of the guide plates generate a swirling extraction effect on the dust-laden airflow, causing the dust-laden airflow to form a spiral downward flow state between the guide plates. In conjunction with the above-mentioned three-stage filtration function, the ultrafine dust is guided to the inner wall of the guide tube by centrifugal force during the swirling process and is intercepted by the filter membrane, which improves the collection efficiency of ultrafine dust. At the same time, the swirling flow makes the dust-laden airflow more evenly distributed in the filter bag chamber. Because the inner wall of the support ring is provided with guide vanes, when the guide plate rotates to extract airflow, the guide vanes on the inner wall of the support ring block the clean airflow that has been delivered to the processing chamber, preventing the clean airflow from flowing back. In conjunction with the above-mentioned swirling extraction function, it ensures that the airflow passes through each filter layer in one direction, avoids airflow short-circuiting and falling back, and improves the stability and efficiency of filtration. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in this disclosure, the accompanying drawings used in some embodiments will be briefly described below. Obviously, the drawings described below are only drawings of some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings. In addition, the drawings described below can be regarded as schematic diagrams and are not intended to limit the actual size of the product, the actual flow of the method, the actual timing of the signals, etc. involved in the embodiments of this disclosure.

[0016] Figure 1 This is a front view of the overall structure of the pulse bag ultrafine dust filter device for cement raw material mill of the present invention; Figure 2 This is a schematic diagram of the structure of the housing, horizontal baffle, air inlet, pulse valve, and filter bag chamber of the present invention. Figure 3 This is a cross-sectional view of the connecting cover, filter bag, inner cylinder, normally closed bypass valve, drive module, rotating shaft, ash hopper, guide plate, support ring and guide vane of the present invention. Figure 4 This is a schematic diagram of the structure of the filter bag and dispersion plate of the present invention; Figure 5 This is a schematic diagram of the structure of the conical top cover, connecting cover, support ring, guide vane and inner cylinder of the present invention; Figure 6 This is a schematic diagram of the structure of the guide tube, rotating shaft, support ring, conical top cover and connecting cover of the present invention; Figure 7 This is a schematic diagram of the structure of the inner cylinder and drive module of the present invention.

[0017] Figure 8 This is an exploded structural diagram of the support ring, conical top cover, guide plate, guide vane, filter membrane, guide cylinder, diversion hole and rotating shaft of the present invention.

[0018] Explanation of reference numerals in the attached drawings: 1. Shell; 2. Horizontal baffle; 3. Filter bag chamber; 4. Filter bag; 5. Inner cylinder; 6. Guide cylinder; 7. Filter membrane; 8. Diverter hole; 9. Rotating shaft; 10. Guide plate; 11. Support ring; 12. Guide vane; 13. Conical top cover; 14. Drive module; 15. Connecting cover; 16. Ash hopper; 17. Diverter chamber; 18. Air inlet; 19. Pulse pipe; 20. Pulse valve; 21. Support base; 22. Normally closed bypass valve; 23. Dispersion plate. Detailed Implementation

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0020] Example 1:

[0021] Please see Figure 1 and Figure 2 This embodiment provides a pulse bag ultrafine dust filtration device for a cement raw meal mill, including a housing 1 and a flow-guiding dust removal and filtration assembly disposed within the housing 1. This device is used in conjunction with a cement raw meal mill system to filter and purify dust-laden flue gas discharged from the raw meal mill, recover raw meal powder, and meet environmental emission requirements.

[0022] The housing 1 is a rectangular box structure made of welded steel plates. The inner and outer surfaces of housing 1 are treated with anti-corrosion measures to withstand the corrosive effects of alkaline components in the dust-laden flue gas. Support legs are provided at the bottom of housing 1 to support the entire device on the ground or a steel structure platform. An inspection door is located on the front of housing 1 for easy access to and replacement of the internal filter bags and filter components. A clean air outlet is located on the side of housing 1, through which the filtered clean gas is discharged by the induced draft fan.

[0023] Please see Figure 1 and Figure 2The flow-guiding dust removal filter assembly includes a horizontal baffle 2 located inside the housing 1. The horizontal baffle 2 is a welded steel plate structure that divides the interior of the housing 1 into two chambers: the upper chamber is a flow-diverting chamber 17, and the lower chamber is a filter bag chamber 3. Several mounting holes are provided on the horizontal baffle 2, and a filter bag chamber 3 is provided at each mounting hole.

[0024] The diversion chamber 17 is located above the horizontal baffle 2. Several partitions are installed inside the diversion chamber 17, which divide the diversion chamber 17 into several air inlet channels. Each air inlet channel is located on one side of the top of the corresponding filter bag chamber 3. After the dust-laden airflow enters the diversion chamber 17 through the air inlet 18, it is diverted by the partitions and transported to each filter bag chamber 3.

[0025] An air inlet 18 is provided on the top of the housing 1. The air inlet 18 is a circular tubular interface, and its bottom end extends into and connects with the distribution chamber 17. The dust-laden flue gas discharged from the raw material mill enters the distribution chamber 17 through the air inlet 18 via a pipeline. The diameter of the air inlet 18 is designed according to the processing air volume.

[0026] A blowpipe 19, a circular steel pipe, is installed on one side of the top of the housing 1 and is horizontally mounted on the top of the housing 1. Several pulse valves 20, which are electromagnetic pulse valves, are installed on the blowpipe 19. The nozzle of each pulse valve 20 extends to the top of the corresponding filter bag chamber 3, aligned with the center of the filter bag 4. The air inlet of the pulse valve 20 is connected to the blowpipe 19, which is connected to a high-pressure air reservoir containing compressed air. When the pulse valve 20 is opened, compressed air is instantaneously injected into the filter bag 4 from the nozzle, performing pulse-jet cleaning of the filter bag 4 and the filter membrane 7.

[0027] Please see Figure 1 and Figure 3 The filter bag chambers 3 are several independent chambers located below the horizontal baffle 2, and each filter bag chamber 3 contains a filter bag 4. The filter bag 4 is a cylindrical long bag made of sewn filter media. The filter media is a membrane-coated needle-punched felt, with a polytetrafluoroethylene microporous membrane covering the surface of the needle-punched felt, providing good air permeability and filtration accuracy. The top of the filter bag 4 is fixed to the mounting hole in the horizontal baffle 2, and the bottom opening of the filter bag 4 is connected to the ash hopper 16. The outer diameter of the filter bag 4 is designed according to the inner diameter of the filter bag chamber 3, with an appropriate gap between them.

[0028] Please see Figure 3 , Figure 6 , Figure 7 and Figure 8 The filter bag 4 has an inner cylinder 5 in the middle. The inner cylinder 5 is a cylindrical porous cylinder with several diversion holes 8 on its wall. The top of the inner cylinder 5 is fixed to the top of the inner cavity of the filter bag chamber 3 by a connecting cover 15, and the bottom of the inner cylinder 5 is fixed to the bottom of the ash hopper 16 by a support seat 21.

[0029] A guide tube 6 is located in the middle of the inner cylinder 5. The guide tube 6 is a cylindrical porous tube, coaxially arranged with the inner cylinder 5. Several diversion holes 8 are also formed on the wall of the guide tube 6, and a filter membrane 7 is installed on the inner wall of the guide tube 6. An annular processing cavity is formed between the inner cylinder 5 and the guide tube 6. The filter membrane 7 is a microporous filtration membrane, capable of efficiently capturing micron-sized ultrafine dust.

[0030] After the dust-laden airflow enters from the top of the filter bag chamber 3, it first enters the interior of the guide tube 6 through the diversion effect of the guide plate 10. The dust-laden airflow is filtered by the filter membrane 7 on the inner wall of the guide tube 6. The ultrafine dust is intercepted by the filter membrane 7, and the clean gas passes through the filter membrane 7 and the diversion hole 8 on the wall of the guide tube 6 and enters the treatment chamber between the inner tube 5 and the guide tube 6. Then, the gas in the treatment chamber passes through the diversion hole 8 on the wall of the inner tube 5 and enters the interior of the inner tube 5, where it undergoes secondary filtration. Finally, the gas enters the interior of the filter bag 4 from the bottom of the inner tube 5, undergoes tertiary filtration by the filter bag 4, and is then discharged.

[0031] Please see Figure 3 , Figure 5 , Figure 6 and Figure 7 A rotating shaft 9 is rotatably connected to the middle of the guide tube 6. The rotating shaft 9 is a vertically arranged cylindrical shaft that is rotatably mounted at the center of the inner tube 5 via bearings. The top of the rotating shaft 9 extends to the upper part of the filter bag chamber 3, and the bottom of the rotating shaft 9 extends to the bottom of the ash hopper 16.

[0032] Several guide plates 10 are arranged on the top of the rotating shaft 9. The guide plates 10 are stacked along the axial direction of the rotating shaft 9, and their diameter gradually decreases from bottom to top, forming a frustum-shaped structure. The guide plate 10 is a disc-shaped or annular plate with a frustum-shaped inclined surface on its outer edge. The dust-laden airflow is diverted by the frustum-shaped inclined surface of the guide plate 10, so that the airflow is evenly diffused in all directions.

[0033] A conical top cover 13 is provided at the top of the rotating shaft 9. The conical top cover 13 is a conical component and is fixed at the top of the rotating shaft 9. The tip of the conical top cover 13 faces upward and is used to divert the dust-laden airflow entering from above to the surrounding areas to prevent the airflow from directly impacting the center of the guide plate 10.

[0034] The top of the filter bag 4 is provided with several support rings 11. The support rings 11 are annular components and are fixed to the upper part of the inner cavity of the filter bag chamber 3. Each support ring 11 is located between two adjacent guide plates 10. A bearing or sliding fit surface is provided between the support ring 11 and the guide plate 10, so that the guide plate 10 can rotate relative to the support ring 11. Guide vanes 12 are respectively provided on the inner wall of the support ring 11 and the outer side of the guide plate 10. The guide vanes 12 are blade-shaped components and are evenly arranged in the circumferential direction. When the guide vanes 12 on the support ring 11 and the guide plate 10 are staggered, the conveyed airflow is blocked.

[0035] When the rotating shaft 9 drives the guide plate 10 to rotate, the guide vanes 12 on the outer side of the guide plate 10 rotate synchronously with the guide plate 10. When the guide vanes 12 rotate, they generate an extraction and swirling effect on the surrounding dust-laden airflow, causing the dust-laden airflow to form a spiral flow state along the frustum-shaped inclined surface of the guide plate 10. The guide vanes 12 on the inner wall of the support ring 11 are fixed and do not rotate. Their blade direction is opposite to that of the guide vanes 12 on the outer side of the guide plate 10, which has a blocking effect on the clean airflow that has been delivered into the processing chamber, preventing the clean airflow from flowing back and ensuring unidirectional airflow.

[0036] Please see Figure 3 and Figure 8 A drive module 14, which is a geared motor, is installed at the bottom of the rotating shaft 9 and is vertically mounted at the bottom of the ash hopper 16. The output shaft of the drive module 14 is connected to the bottom end of the rotating shaft 9. The drive module 14 drives the rotating shaft 9 to rotate around its own axis, which can be adjusted according to the processing air volume and dust concentration.

[0037] The dust hopper 16 has a conical structure and is connected to the bottom of the filter bag 4. The large end of the dust hopper 16 is connected to the bottom of the filter bag 4, and the small end faces downward. The dust hopper 16 is used to collect the dust that falls off the filter bag 4 and the filter membrane 7. The collected dust is discharged through the unloading device at the bottom of the dust hopper 16, such as a star-shaped unloading valve, and returned to the production process.

[0038] A support base 21 is provided at the bottom of the ash hopper 16. The support base 21 is a frame-type or plate-type structure and is fixed to the bottom plate of the ash hopper 16. The support base 21 simultaneously supports and fixes the bottom ends of the drive module 14 and the inner cylinder 5, ensuring the coaxiality and stability of the rotating shaft 9 and the inner cylinder 5.

[0039] Please see Figure 3 and Figure 4 A normally closed bypass valve 22 is provided on the outside of the filter bag 4. The normally closed bypass valve 22 is a tubular interface that extends horizontally from the side wall of the filter bag 4 and passes through the wall of the housing 1. The normally closed bypass valve 22 is used to introduce bypass airflow under special operating conditions or as an observation port during maintenance.

[0040] A dispersion plate 23 is provided on the top of the filter bag 4. The dispersion plate 23 is a disc-shaped plate and is fixed at the top opening of the filter bag 4. The dispersion plate 23 is provided with radially arranged diversion blades. The dust-laden airflow entering the filter bag chamber 3 from the diversion chamber 17 is further dispersed and evenly distributed by the diversion blades of the dispersion plate 23, so as to avoid the airflow concentrating and impacting the local area of ​​the guide plate 10.

[0041] A connecting cover 15 is provided at the top of the inner cavity of the filter bag chamber 3. The connecting cover 15 is a disc-shaped cover plate, which is fixed to the top opening of the filter bag chamber 3 by bolts. The bottom surface of the connecting cover 15 abuts against the top of the support ring 11, positioning and constraining the support ring 11 and the guide plate 10 to prevent the guide plate 10 from axially moving during rotation. The central hole of the connecting cover 15 allows the conical top cover 13 and the rotating shaft 9 to pass through.

[0042] In this embodiment, all major structural components, including the shell 1, horizontal baffle 2, filter bag chamber 3, inner cylinder 5, guide tube 6, support ring 11, conical top cover 13, and ash hopper 16, are made of high-quality carbon structural steel or stainless steel. The filter membrane 7 is made of polytetrafluoroethylene microporous membrane, the filter bag 4 is made of membrane-coated needle-punched felt filter media, the guide plate 10 and guide vanes 12 are made of steel plate stamping or casting followed by surface hardening treatment, the drive module 14 is a vertical geared motor with a reduction gearbox, and the pulse valve 20 is a right-angle electromagnetic pulse valve. All rotating mating surfaces, such as the shaft 9 and bearings, and the guide plate 10 and support ring 11, should maintain precise fit and be lubricated with high-temperature resistant grease.

[0043] The above is a structural description of this embodiment. The specific working principle of this embodiment will be described in detail below.

[0044] I. Working principle of dust-laden airflow entry and uniform distribution: Dust-laden flue gas discharged from the raw material mill enters the distribution chamber 17 at the top of the casing 1 through the inlet 18 via a duct. Within the distribution chamber 17, the dust-laden airflow is divided by baffles and evenly distributed to the top inlets of each filter bag chamber 3. Each filter bag chamber 3 has a dispersion plate 23 at its inlet. As the dust-laden airflow passes through the radially distributed blades of the dispersion plate 23, it is further dispersed into a uniform airflow, preventing concentrated airflow from impacting the central area of ​​the guide plate 10.

[0045] The dispersed dust-laden airflow flows downward from the top of the filter bag chamber 3, first passing through the uppermost conical top cover 13. The conical top cover 13 divides the airflow in all directions, allowing the airflow to be evenly diffused along the frustum-shaped inclined surface of the guide plate 10 to the entire cross-section of the filter bag chamber 3. Then the airflow enters the gap between two adjacent guide plates 10, forming a swirling flow under the action of the guide vanes 12.

[0046] During the airflow entry process, the drive module 14 drives the rotating shaft 9 to rotate continuously, and the rotating shaft 9 drives the guide plates 10 of each layer to rotate synchronously. The guide vanes 12 on the outer side of the guide plate 10 rotate with the guide plate 10, generating an extraction and pushing effect on the surrounding dust-laden airflow, causing the dust-laden airflow to form a spiral downward swirling flow between the guide plates 10 of each layer. The swirling motion causes the dust particles in the airflow to be subjected to centrifugal force, moving towards the outer wall of the guide tube 6 and the filter bag 4, which is beneficial for the dust to be intercepted by the filter material.

[0047] II. Working principle of multi-stage filtration: Dust-laden airflow enters the guide tube 6 in a swirling state for filtration: the dust-laden airflow passes through the filter membrane 7 and the microporous membrane on the inner wall of the guide tube 6, where micron-sized ultrafine dust particles are intercepted by the filter membrane 7 on the inner wall surface of the guide tube 6. Clean gas passes through the filter membrane 7 and the diversion holes 8 on the wall of the guide tube 6, and enters the annular processing chamber between the inner cylinder 5 and the guide tube 6.

[0048] The airflow undergoes a second stage of filtration within the processing chamber: the gas in the processing chamber passes through the diversion holes 8 on the inner cylinder 5 wall and enters the central channel inside the inner cylinder 5.

[0049] After flowing out from the bottom of the inner cylinder 5, the airflow enters the interior of the filter bag 4. The gas passes through the filter material of the filter bag 4 from the inside to the outside, and the dust particles remaining in the gas are trapped on the inner surface of the filter bag 4. After passing through the filter bag 4, the clean gas enters the annular space between the filter bag 4 and the inner wall of the filter bag chamber 3, and is discharged through the channel on the horizontal baffle 2, and finally discharged from the clean gas outlet on the shell 1.

[0050] The multi-stage filtration design ensures that dust particles of different sizes are intercepted at different filtration levels: coarser particles are thrown towards filter bag 4 by centrifugal force during the swirling process and are intercepted by filter bag 4; medium-sized particles are intercepted by inner cylinder 5; and ultrafine particles are intercepted by filter membrane 7. This graded filtration method improves the overall filtration efficiency, reduces the filtration load of a single filter media, and helps extend the service life of filter bag 4.

[0051] III. Working principle of vortex extraction and anti-fallback: During the filtration process, the guide plate 10 rotates continuously, and the guide vanes 12 on the outer side of the guide plate 10 rotate with the guide plate 10, thereby drawing in the dust-laden airflow inside the guide cylinder 6. This drawing in produces the following effects: First, it accelerates the speed at which the dust-laden airflow passes through the filter membrane 7, promoting the airflow and uniform surface renewal, thereby improving the filtration efficiency of the filter membrane 7. Second, the swirling motion causes the dust particles to move against the inner wall of the guide tube 6 under the action of centrifugal force, which is conducive to the uniform deposition of dust on the surface of the filter membrane 7 and avoids local dust accumulation. Third, the axial airflow generated by the swirling motion pushes the airflow out from the lower part of the guide tube 6, and completes the subsequent filtration through the inner tube 5 and the filter bag 4.

[0052] Meanwhile, the guide vanes 12 fixed to the inner wall of the support ring 11 block the airflow within the treatment chamber. The direction of the guide vanes 12 on the inner wall of the support ring 11 is opposite to that of the guide vanes 12 on the outer side of the guide plate 10. When the airflow attempts to flow back from the treatment chamber to the gap in the guide plate 10, the fixed guide vanes 12 create resistance to the airflow, preventing backflow. This design ensures that the airflow can only flow along a unidirectional path: inside the guide cylinder 6 → treatment chamber → inside the inner cylinder 5 → filter bag 4, avoiding airflow short-circuiting and backflow, and improving the stability of filtration.

[0053] As the filtration process continues, more and more dust accumulates on the surfaces of the filter membrane 7 and filter bag 4, and the filtration resistance gradually increases. When the filtration resistance reaches the set value, the control system initiates the pulse jet cleaning program.

[0054] During pulse jet cleaning, the pulse valve 20 on the jet pipe 19 opens instantaneously, and the compressed air in the air storage tank is ejected at high speed from the nozzle of the pulse valve 20, inducing the surrounding clean air to enter the filter bag 4. The high-speed airflow creates an instantaneous positive pressure inside the filter bag 4, causing the filter bag 4 to expand and deform instantly, shaking the dust on the filter bag 4 into the ash hopper 16.

[0055] Simultaneously, a high-speed jet of air enters the guide tube 6, blowing away the dust on the surface of the filter membrane 7. During the blowing process, the guide plate 10 continues to rotate, and the guide vanes 12 disturb and guide the jet of air, ensuring that the jet of air is evenly distributed to all parts of the filter membrane 7, avoiding excessive or insufficient local blowing intensity. The rotating guide vanes 12 also generate a vibration effect, assisting in the removal of dust from the surface of the filter membrane 7.

[0056] During dust removal, the drive module 14 can appropriately increase the rotation speed of the guide plate 10 to enhance the swirling turbulence effect, allowing the dust on the filter membrane 7 and filter bag 4 to be removed more thoroughly. The removed dust falls into the ash hopper 16 under the action of gravity and swirling airflow, and is discharged through the unloading device at the bottom of the ash hopper 16.

[0057] Dust particles detaching from the filter membrane 7, inner cylinder 5, and filter bag 4 settle downwards under gravity and fall into the dust hopper 16. At the same time, the swirling airflow generated by the rotation of the guide plate 10 also propels the dust particles toward the dust hopper 16, accelerating the settling and collection of the dust.

[0058] The ash hopper 16 has a conical structure, and dust gradually accumulates inside. When the dust level in the ash hopper 16 reaches a set height, the star-shaped discharge valve at the bottom of the ash hopper 16 automatically opens to discharge the dust. The discharged raw material dust is then sent back to the raw material grinding system for re-grinding via a conveying device, achieving resource recycling.

[0059] A level gauge, such as a capacitive level gauge or a weighted level gauge, can be installed on the ash hopper 16 to monitor the dust level in real time. When the level is too high, the control system will issue an alarm and open the discharge valve; when the level is too low, the discharge valve will be closed to prevent external air from leaking in.

[0060] The device in this embodiment also includes an electrical control system for automating the entire process of filtration, dust removal, and dust discharge. The electrical control system includes a controller, a frequency converter, solenoid valves, pressure sensors, temperature sensors, level gauges, and a human-machine interface.

[0061] The controller, a programmable logic controller or industrial control computer, is installed in an electrical control cabinet. It features digital input / output interfaces, analog input / output interfaces, and a communication interface. The controller stores control programs and operating parameters, including filter resistance setpoints, spray intervals, spray pulse widths, and guide vane rotation speed setpoints.

[0062] The frequency converter is electrically connected to the drive module 14, and the control terminal of the frequency converter is connected to the analog output interface of the controller. The controller outputs a frequency command to the frequency converter according to the preset rotation speed setting of the guide vane. The frequency converter outputs AC power of the corresponding frequency according to the frequency command, driving the module 14 to rotate at the set speed. The controller can automatically adjust the rotation speed of the guide vane 10 according to changes in the processed air volume, dust concentration, and filtration resistance to achieve optimal filtration. When the filtration resistance increases, the rotation speed is appropriately increased to enhance the cyclone extraction effect; when the filtration resistance is low, the rotation speed is decreased to save energy.

[0063] The solenoid valves are electrically connected to each pulse valve 20, and the control terminals of the solenoid valves are connected to the digital output interface of the controller. The controller sequentially controls the on / off state of each solenoid valve according to a preset blowing sequence, thereby controlling the opening and closing of each pulse valve 20. The blowing sequence can be set to timed blowing, blowing at fixed time intervals, or constant resistance blowing, blowing when the filtration resistance reaches a set value. The two modes can be switched according to actual operating conditions.

[0064] A pressure sensor is installed between the filter bag chamber 3 and the diversion chamber 17, or at the air inlet 18 and the clean air outlet, to detect the pressure difference before and after filtration in real time, i.e., the filtration resistance. The output of the pressure sensor is connected to the analog input interface of the controller. The controller determines whether the filtration resistance meets the pulse jetting conditions based on the feedback signal from the pressure sensor. When the filtration resistance reaches the set value, the pulse jetting program is automatically started.

[0065] A temperature sensor is installed at the air inlet 18 to monitor the temperature of the dust-laden flue gas in real time. The temperature of the flue gas discharged from the raw material mill is typically between 80 and 120°C. If the temperature is too high, it may damage the filter bag 4 and the filter membrane 7; if the temperature is too low, condensation may occur, leading to dust adhesion. The controller monitors whether the flue gas temperature is within the safe range based on the feedback signal from the temperature sensor, and issues an alarm signal when the temperature is abnormal.

[0066] A level gauge is installed on the ash hopper 16 to monitor the dust level within the hopper in real time. The output of the level gauge is connected to the digital or analog input interface of the controller. The controller controls the opening and closing of the star-shaped discharge valve based on the feedback signal from the level gauge, thereby achieving automatic ash discharge from the ash hopper 16.

[0067] The human-machine interface is a touch screen, located on the control panel of the device. Operators can use the human-machine interface to set parameters such as filtration resistance, spray interval, spray width, and rotation speed, view the current operating status such as differential pressure, temperature, and material level, manually start or stop each piece of equipment, and view fault alarm information.

[0068] The electrical control system can also be connected to the central control system of cement production via a communication interface to achieve coordinated control between the filtration device and the raw meal mill system. For example, when the raw meal mill starts, the filtration device starts automatically; when the raw meal mill stops, the filtration device continues to run for a period of time to remove the dust-laden flue gas from the pipeline before stopping.

[0069] Example 2:

[0070] This embodiment has a structure that is basically the same as that of Embodiment 1, except that in this embodiment, the filter membrane 7 uses a nanofiber filter membrane instead of a polytetrafluoroethylene microporous membrane. The nanofiber filter membrane is made by electrospinning, and the fiber diameter is between 100 and 500 nanometers, which has extremely high filtration accuracy and low filtration resistance. The nanofiber filter membrane is bonded or hot-pressed to the inner wall of the guide tube 6, which has a higher collection efficiency for micron-sized ultrafine dust discharged from the cement raw material mill, meeting the strict ultra-low emission requirements.

[0071] Furthermore, in this embodiment, the surfaces of the guide vane 10 and the guide blade 12 are coated with a wear-resistant coating, such as a tungsten carbide coating or a ceramic coating, to resist the abrasion of hard particles in the dust-laden airflow and extend the service life of the guide vane and the guide blade. After applying the wear-resistant coating, the service life of the guide vane and the guide blade can be increased by 2 to 3 times.

[0072] Example 3:

[0073] This embodiment is basically the same in structure as Embodiment 1, except that the guide vanes 12 on the inner wall of the support ring 11 adopt an adjustable angle structure. Each support ring 11 is equipped with an adjustment mechanism, which includes an adjusting screw and a locking nut. The guide vanes 12 are mounted on the support ring 11 via a hinge shaft, and one end of the adjusting screw is connected to the guide vanes 12. By rotating the adjusting screw, the installation angle of the guide vanes 12 can be adjusted, thereby changing the direction and resistance of the blocking airflow. This adjustable angle design allows the device to adapt to dust of different properties and different processing air volumes. When handling ultrafine dust or high air volume conditions, the guide vanes 12 are adjusted to a larger angle to enhance the blocking effect; when handling coarser dust or low air volume conditions, the guide vanes 12 are adjusted to a smaller angle to reduce airflow resistance.

[0074] In addition, in this embodiment, the inner wall of the ash hopper 16 is provided with an aeration plate, which is connected to a compressed air pipeline. During ash discharge, a small amount of compressed air is introduced into the aeration plate to fluidize the dust in the ash hopper 16, preventing dust from bridging or caking in the ash hopper and ensuring smooth ash discharge. The air source for the aeration plate is supplied separately by a small air compressor, and the air volume is adjusted according to the volume of the ash hopper.

[0075] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A pulse bag ultrafine dust filtration device for cement raw material mill, comprising a housing (1), a transverse baffle (2) disposed within the housing (1) for separation, a plurality of filter bag chambers (3) disposed at the bottom of the transverse baffle (2), and filter bags (4) disposed in each of the filter bag chambers (3), characterized in that: The filter bag (4) has an inner cylinder (5) in the middle, and a guide cylinder (6) is provided in the middle of the inner cylinder (5). A processing cavity is formed between the inner cylinder (5) and the guide cylinder (6). A filter membrane (7) is provided on the inner wall of the guide cylinder (6). Several diversion holes (8) are respectively opened on the inner cylinder (5) and the guide cylinder (6). The middle part of the guide tube (6) is rotatably connected to a rotating shaft (9), and the top of the rotating shaft (9) is provided with several guide plates (10), and each guide plate (10) is stacked and combined into a frustum shape. The top of the filter bag (4) is fixedly provided with several support rings (11). Each support ring (11) is located between two adjacent guide plates (10) and is rotatably connected to the guide plate (10). The inner wall of the support ring (11) and the outer side of the guide plate (10) are respectively provided with guide vanes (12). When the rotating shaft (9) rotates, the dust-laden airflow is extracted through the guide vanes (12) on the outer side of the guide plate (10). The guide vanes (12) on the inner wall of the support ring (11) block the transported airflow.

2. The pulse bag ultrafine dust filter for cement raw meal mills according to claim 1, characterized in that: The top of the rotating shaft (9) is provided with a conical top cover (13), and the top of the horizontal baffle (2) is provided with a diversion chamber (17). The diversion chamber (17) is provided with a number of partitions located on one side of the top of the corresponding filter bag chamber (3), which are used to divert the dust-laden airflow into the diversion chamber (17) and then to each filter bag chamber (3) through the partitions.

3. The pulse bag ultrafine dust filter for cement raw meal mills according to claim 2, characterized in that: The top of the housing (1) is provided with an air inlet (18) for air intake. The bottom end of the air inlet (18) extends into the diversion chamber (17) and is connected to the diversion chamber (17) for dust-laden airflow to enter the diversion chamber (17) through the air inlet (18).

4. The pulse bag ultrafine dust filter for cement raw meal mill according to claim 2, characterized in that: A blowpipe (19) is provided on one side of the top of the housing (1). Several pulse valves (20) are provided on the blowpipe (19). One end of each pulse valve (20) extends to the top of the inner cavity of the corresponding filter bag chamber (3) for delivering clean airflow into the filter bag chamber (3) for cleaning.

5. The pulse bag ultrafine dust filter for cement raw meal mill according to claim 1, characterized in that: A connecting cover (15) is provided at the top of the inner cavity of the filter bag chamber (3). The connecting cover (15) abuts against the top of the support ring (11) and is used to position and constrain the support ring (11) and the guide plate (10).

6. The pulse bag ultrafine dust filter for cement raw meal mills according to claim 1, characterized in that: The bottom of the rotating shaft (9) is provided with a drive module (14) for driving the rotating shaft (9) to rotate, and the bottom of the filter bag (4) is provided with a dust hopper (16) for discharging dust.

7. The pulse bag ultrafine dust filter for cement raw meal mills according to claim 6, characterized in that: The bottom of the ash hopper (16) is provided with a support base (21) for supporting the drive module (14) and the filter bag (4) in the filter bag chamber (3).

8. The pulse bag ultrafine dust filter for cement raw meal mill according to claim 1, characterized in that: A normally closed bypass valve (22) is provided on the outside of the filter bag (4), and a dispersion plate (23) is provided on the top of the filter bag (4) to disperse the dust-laden airflow entering the inner cylinder (5) and the guide cylinder (6).

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