A dust removal device and method for a thermal power plant ash silo

Abstract

The present application relates to the technical field of dust removal of thermal power plant, and discloses a dust removal device and method for ash silo of thermal power plant. The device comprises a negative pressure pump, a negative pressure tank, a scattered dust collection bin, a bag-type dust collector, a first air pressure balance valve, a second air pressure balance valve, an ash discharge valve and a control unit. The top of the negative pressure tank is provided with a dust filter, the air inlet of the negative pressure pump is connected with the dust filter, the negative pressure tank is connected with the scattered dust collection bin through the second air pressure balance valve, and the scattered dust collection bin is connected with the bag-type dust collector through the first air pressure balance valve. The control unit controls the switching of dust suction and ash discharge modes. The method comprises a dust suction stage and an ash discharge stage, and realizes the graded treatment of dust through three-stage separation. The pressure is balanced before ash discharge. The present application realizes the graded collection of dust, the automatic switching of dust suction and ash discharge, effectively solves the problem of scattered dust during ash discharge, and improves the dust removal efficiency.

Description

Technical Field

[0001] This invention relates to the field of dust removal equipment technology for thermal power plants, specifically to a dust removal device and method for ash silos in thermal power plants. Background Technology

[0002] Thermal power plants generate a large amount of fly ash during production. This fly ash is usually transported to ash silos for storage via pneumatic conveying systems. When it needs to be transported externally or utilized comprehensively, it must be unloaded from the ash discharge bins at the bottom of the ash silos.

[0003] Currently, during ash unloading at thermal power plant ash silos, a large amount of fine dust escapes from around the unloading port due to the gap between the unloading port and the tank opening of the transport vehicle, and the strong induced airflow generated by the falling ash during unloading. This escaped dust not only seriously pollutes the surrounding environment and affects the air quality of the plant area, but also poses a threat to the occupational health of on-site operators. Existing dust control measures are mostly simple spraying or localized dust collection hoods, but they have the following shortcomings: First, spraying has limited dust suppression effect and can cause secondary pollution from ash water; second, localized dust collection hoods cannot effectively cover the entire unloading area, making it difficult to completely collect the escaped dust; third, there is a lack of complete sets of dust collection equipment specifically designed for ash silo unloading conditions, and existing equipment generally suffers from low dust collection efficiency, easy clogging, and difficult maintenance. Therefore, there is an urgent need for an ash silo dust collection device that can effectively collect the dust escaped during ash unloading and prevent environmental pollution. Summary of the Invention

[0004] (a) Technical problems to be solved To address the shortcomings of existing technologies, this invention provides a dust removal device and method for ash silos in thermal power plants. It has the advantages of graded collection and treatment of scattered dust, automatic switching between dust collection and ash discharge, and effective prevention of secondary pollution. It solves the problems of serious dust dispersion, lack of effective dust removal equipment, low dust collection efficiency, easy clogging, and easy environmental pollution caused by existing technologies in thermal power plant ash silos.

[0005] (II) Technical Solution To achieve the above objectives, the present invention provides the following technical solution: This invention provides a dust removal device for ash silos in thermal power plants, comprising: A negative pressure pump; A negative pressure tank is connected to the air inlet of the negative pressure pump and is provided with a suction port for drawing in dust-laden gas; An escape dust collection chamber is connected to the outlet of the negative pressure pump; A bag filter is connected to the escaping dust collection chamber via a first pressure balancing valve; A second pressure balancing valve, the two ends of which are respectively connected to the negative pressure tank and the escaping dust collection chamber; An ash discharge valve is installed at the bottom discharge port of the negative pressure tank; A control unit is electrically connected to the negative pressure pump, the first air pressure balancing valve, the second air pressure balancing valve, and the ash discharge valve, respectively. The control unit is configured to selectively perform vacuuming and dust removal operations.

[0006] The negative pressure tank is equipped with a dust filter at the top, and the air inlet of the negative pressure pump is sealed to the air outlet of the dust filter; the negative pressure tank is connected to the escaping dust collection chamber through a pipeline, and the second air pressure balancing valve is installed on the pipeline; the bottom of the negative pressure tank is discharged through a ash discharge pipeline, and the ash discharge valve is located on the aforementioned ash discharge pipeline.

[0007] The second pressure balancing valve is a normally closed solenoid valve, with its first end connected to the top of the negative pressure tank and its second end connected to the top of the escaping dust collection chamber.

[0008] The first air pressure balancing valve is a normally open solenoid valve, whose inlet is connected to the outlet of the dust collection chamber and whose outlet is connected to the inlet of the bag filter.

[0009] The dust suction ports are multiple and are evenly arranged around the ash unloading hopper of the thermal power plant ash silo to form an enclosed dust suction structure; each dust suction port is equipped with an independent manual adjustment valve between itself and the negative pressure tank.

[0010] The negative pressure tank is also equipped with a level gauge, which is connected to the control unit and is used to send a signal to the control unit when the dust in the negative pressure tank reaches a preset level; the bottom of the escaping dust collection bin is equipped with a ash discharge port, which is used to discharge the dust that naturally settles in the escaping dust collection bin.

[0011] Another aspect of the present invention provides a dust removal method using the dust removal device for a thermal power plant ash silo as described above, comprising: Vacuuming stage: S1. Start the negative pressure pump through the control unit and close the second air pressure balance valve to create negative pressure in the negative pressure tank; S2. The dust-laden gas that escapes during ash removal is drawn into the negative pressure tank through the dust suction port; S3. The dust-laden gas slows down inside the negative pressure tank, and large dust particles naturally settle to the bottom of the negative pressure tank. S4. The airflow carrying the remaining dust passes through the dust filter in the negative pressure tank, where the dust is intercepted and the clean gas enters the negative pressure pump. S5. The negative pressure pump discharges the gas into the escaping dust collection chamber, where the residual trace dust in the gas further settles naturally. S6. The gas enters the bag filter for final filtration after passing through the first pressure balancing valve and is then discharged. Ash removal stage: T1. When ash discharge is required, the control unit shuts off the negative pressure pump; T2. The control unit opens the second air pressure balance valve to balance the pressure between the negative pressure tank and the dust collection chamber, eliminating the negative pressure state in the negative pressure tank. T3. The control unit opens the ash discharge valve at the bottom of the negative pressure tank, allowing the dust that has settled in the negative pressure tank to be discharged under the action of gravity. T4. After the ash discharge is completed, the control unit closes the ash discharge valve and the second air pressure balance valve.

[0012] In the ash removal stage T1, the conditions for triggering ash removal are: when the level gauge in the negative pressure tank detects that the dust has reached the preset level, it automatically sends a signal to the control unit, or it is manually triggered by the operator.

[0013] The dust collection stage S6 also includes adjusting the opening of the first air pressure balance valve to match the exhaust pressure of the negative pressure pump, so as to stabilize the airflow at the inlet of the bag filter.

[0014] (III) Beneficial Effects Compared with the prior art, the present invention provides a dust removal device and method for ash silos in thermal power plants, which has the following beneficial effects: 1. This invention achieves graded collection and treatment of dust by setting up a three-stage separation structure of negative pressure tank, fugitive dust collection chamber and bag filter: negative pressure tank is used to settle large dust particles, fugitive dust collection chamber is used to further settle residual dust, and bag filter is used for final fine filtration, which effectively reduces the processing load of each stage of equipment, improves the overall dust removal efficiency, and reduces the risk of clogging of bag filter.

[0015] 2. This invention connects the negative pressure tank and the dust collection chamber with a second air pressure balancing valve and configures a control unit to automatically switch between dust collection mode and dust discharge mode. During dust discharge, the second air pressure balancing valve balances the pressure between the negative pressure tank and the dust collection chamber, eliminating the negative pressure state in the negative pressure tank and allowing the dust in the negative pressure tank to be discharged smoothly under the action of gravity, thus solving the problem of poor dust discharge caused by negative pressure in existing equipment.

[0016] 3. This invention automatically detects the amount of dust in the negative pressure tank by setting a level gauge, which can realize automatic ash discharge control without frequent manual intervention, thus improving the automation level and operational reliability of the equipment. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the connection structure of the present invention.

[0018] In the diagram: 1. Negative pressure pump; 2. Negative pressure tank; 3. Dust suction port; 4. Escaped dust collection bin; 5. Bag filter; 6. First air pressure balancing valve; 7. Second air pressure balancing valve; 8. Ash discharge valve; 9. Control unit; 10. Dust filter; 11. Ash discharge pipe; 12. Level gauge; 13. Ash discharge port. Detailed Implementation

[0019] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0020] Example 1 Please see Figure 1 The first aspect of the present invention provides a dust removal device for an ash silo in a thermal power plant, comprising: One negative pressure pump 1; A negative pressure tank 2 is connected to the air inlet of the negative pressure pump 1 and is provided with a dust suction port 3 for sucking in dust-laden gas; An escape dust collection chamber 4 is connected to the outlet of the negative pressure pump 1; A bag filter 5 is connected to the escaping dust collection chamber 4 via a first air pressure balancing valve 6; A second pressure balancing valve 7 is connected at both ends to the negative pressure tank 2 and the escaping dust collection chamber 4, respectively. An ash discharge valve 8 is installed at the bottom discharge port of the negative pressure tank 2; A control unit 9 is electrically connected to the negative pressure pump 1, the first air pressure balance valve 6, the second air pressure balance valve 7 and the ash discharge valve 8 respectively; The control unit 9 is configured to selectively perform vacuuming and dust removal operations.

[0021] It should be noted that the control unit 9 can be a programmable logic controller (PLC) or a microcontroller, which has pre-set control programs for dust collection and ash removal modes. Through the unified scheduling of the control unit 9, the automatic switching between the two working modes of dust collection and ash removal is realized, avoiding possible errors in manual operation and improving the automation level and operational reliability of the system.

[0022] In this embodiment, a dust filter 10 is provided on the top of the negative pressure tank 2, and the air inlet of the negative pressure pump 1 is sealed to the air outlet of the dust filter 10; the negative pressure tank 2 is connected to the escaping dust collection chamber 4 through a pipeline, and the second air pressure balance valve 7 is provided on the pipeline; the bottom of the negative pressure tank 2 is discharged through the ash discharge pipeline 11, and the ash discharge valve 8 is located on the ash discharge pipeline 11.

[0023] It should be noted that the dust filter 10 is located on the top surface inside the negative pressure tank 2. Its function is to intercept residual dust floating in the air when the airflow enters the negative pressure pump 1, preventing dust from entering the interior of the negative pressure pump 1, thereby protecting the core components of the negative pressure pump 1 from dust wear and extending the service life of the equipment. At the same time, placing the dust filter 10 on the top surface inside the negative pressure tank 2 can make full use of the space in the negative pressure tank 2, making the overall structure more compact.

[0024] In this embodiment, the second air pressure balancing valve 7 is a normally closed solenoid valve, with its first end connected to the top of the negative pressure tank 2 and its second end connected to the top of the escaping dust collection chamber 4.

[0025] It should be noted that the second pressure balancing valve 7 remains closed during dust collection to ensure a stable negative pressure environment within the negative pressure tank 2. When dust removal is required, the control unit 9 first shuts off the negative pressure pump 1, then opens the second pressure balancing valve 7 to quickly balance the pressure between the negative pressure tank 2 and the escaping dust collection chamber 4, eliminating the negative pressure state within the negative pressure tank 2. At this point, the dust discharge valve 8 is opened, allowing the settled dust within the negative pressure tank 2 to be smoothly discharged under gravity. This pressure balancing mechanism effectively solves the technical problem of poor or even impossible dust removal caused by negative pressure within the tank in traditional negative pressure dust collection equipment.

[0026] In this embodiment, the first air pressure balance valve 6 is a normally open solenoid valve, whose air inlet is connected to the air outlet of the escaping dust collection chamber 4, and whose air outlet is connected to the air inlet of the bag filter 5.

[0027] It should be noted that the first air pressure balancing valve 6 is in the open state during dust collection operations, allowing the gas in the dust collection chamber 4 to smoothly enter the bag filter 5 for final purification. The opening degree of this valve can be adjusted in conjunction with the exhaust pressure of the negative pressure pump 1. When the exhaust pressure of the negative pressure pump 1 fluctuates, adjusting the opening degree of the first air pressure balancing valve 6 can stabilize the airflow at the inlet of the bag filter 5, ensuring the filtration effect and service life of the bag filter 5.

[0028] In this embodiment, there are multiple dust suction ports 3, which are evenly arranged around the ash unloading hopper of the thermal power plant ash silo to form an enclosed dust suction structure; each dust suction port 3 is provided with an independent manual adjustment valve (not shown in the figure) between it and the negative pressure tank 2.

[0029] It should be noted that by evenly arranging multiple suction ports 3 around the ash unloading hopper, a comprehensive dust collection coverage can be formed during the ash unloading process. No matter which direction the dust escapes from, it can be sucked up in time, effectively avoiding the dust dead zone problem of traditional single-point dust collection. Each suction port 3 is equipped with an independent manual adjustment valve. The operator can adjust the suction power of each suction port 3 according to the actual situation on site (such as wind direction, ash unloading speed, etc.), so that the dust collection effect is more balanced and efficient.

[0030] In this embodiment, a level gauge 12 is also provided in the negative pressure tank 2. The level gauge 12 is connected to the control unit 9 and is used to send a signal to the control unit 9 when the dust in the negative pressure tank 2 reaches a preset level. A dust discharge port 13 is provided at the bottom of the escaping dust collection chamber 4 to discharge the dust that naturally settles in the escaping dust collection chamber 4.

[0031] It should be noted that the level gauge 12 enables automated triggering of the ash discharge operation. When the dust in the negative pressure tank 2 accumulates to the preset level, the level gauge 12 automatically sends a signal to the control unit 9, which then automatically executes the ash discharge mode. This eliminates the need for frequent manual observation and intervention, significantly reducing the workload of operators. Simultaneously, the bottom of the escaping dust collection bin 4 is equipped with an ash discharge port 13, facilitating regular cleaning of naturally settled dust within the bin and ensuring the long-term stable operation of the system.

[0032] It should be further noted that the level gauge 12 should be lower than the bottom surface of the dust filter 10 to prevent the dust filter 10 from becoming clogged.

[0033] Example 2 A second aspect of the present invention provides a dust removal method for a thermal power plant ash silo using the dust removal device of the first aspect described above, comprising: Vacuuming stage: S1. Start the negative pressure pump 1 through the control unit 9 and close the second air pressure balance valve 7 to create negative pressure in the negative pressure tank 2; S2. The dust-laden gas that escapes during ash removal is drawn into the negative pressure tank 2 through the dust suction port 3; S3. The dust-laden gas slows down in the negative pressure tank 2, and the large dust particles naturally settle to the bottom of the negative pressure tank 2. S4. The airflow carrying the remaining dust passes through the dust filter 10 in the negative pressure tank 2, the dust is intercepted, and the clean gas enters the negative pressure pump 1. S5. Negative pressure pump 1 discharges gas into the escaping dust collection chamber 4, where residual trace dust in the gas further settles naturally. S6. The gas enters the bag filter 5 through the first pressure balancing valve 6 for final filtration before being discharged.

[0034] It should be noted that the dust collection stage employs a three-stage separation process: the first stage is gravity settling within the negative pressure tank 2, used to separate large dust particles; the second stage is filtration by the dust filter 10 at the top of the negative pressure tank 2, used to intercept medium-sized dust particles; and the third stage is natural settling within the fugitive dust collection chamber 4 and fine filtration by the bag filter 5, used to treat fine dust. This tiered treatment design ensures a reasonable distribution of the processing load at each stage, guaranteeing overall dust removal efficiency while reducing the risk of clogging in individual devices, thus improving system reliability and ease of maintenance.

[0035] Ash removal stage: T1. When ash discharge is required, control unit 9 shuts down negative pressure pump 1; T2, control unit 9 opens the second air pressure balance valve 7 to balance the pressure between negative pressure tank 2 and dust collection chamber 4, and eliminates the negative pressure state in negative pressure tank 2. T3, control unit 9 opens the ash discharge valve 8 at the bottom of negative pressure tank 2, so that the dust settled in negative pressure tank 2 is discharged under the action of gravity; T4. After the ash discharge is completed, the control unit 9 closes the ash discharge valve 8 and the second air pressure balance valve 7.

[0036] It should be noted that the core of the ash removal stage lies in the execution order of steps T2 and T3: the second pressure balancing valve 7 must be opened first to balance the pressure, and then the ash removal valve 8 must be opened. If the order is reversed, opening the ash removal valve 8 while the negative pressure tank 2 is still under negative pressure will not only prevent the dust from being discharged smoothly, but may also cause the dust to be re-entrained due to backflow of external air. The ash removal method of this invention strictly follows the order of "balancing the pressure first, then opening the ash removal valve," ensuring a smooth and environmentally friendly ash removal process.

[0037] In this embodiment, during the ash removal stage T1, the conditions for triggering ash removal are: when the level gauge 12 in the negative pressure tank 2 detects that the dust has reached the preset level, it automatically sends a signal to the control unit 9, or it is manually triggered by the operator.

[0038] It should be noted that this invention provides two ash discharge triggering methods: automatic triggering and manual triggering. The automatic triggering method is suitable for normal operating conditions; when dust accumulates in the negative pressure tank 2 to a set amount, ash discharge is automatically executed, achieving unmanned operation. The manual triggering method is suitable for special operating conditions, such as equipment maintenance, system debugging, or emergency handling; operators can manually start the ash discharge program at any time. The two methods complement each other, improving the system's adaptability and operational flexibility.

[0039] In this embodiment, the dust collection stage S6 also includes adjusting the opening of the first air pressure balance valve 6 to match the exhaust pressure of the negative pressure pump 1, so as to stabilize the airflow at the inlet of the bag filter 5.

[0040] It should be noted that the exhaust pressure of the negative pressure pump 1 may fluctuate due to changes in operating conditions during operation. Directly introducing these fluctuating airflows into the bag filter 5 would affect its filtration efficiency and could even cause mechanical damage to the filter bags. This invention addresses this by linking the opening of the first pressure balancing valve 6 with the exhaust pressure of the negative pressure pump 1. When the exhaust pressure increases, the valve opens wider; when the exhaust pressure decreases, the valve closes narrower, thus ensuring a relatively stable airflow pressure entering the bag filter 5 and effectively extending its service life.

[0041] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A dust removal device for an ash silo in a thermal power plant, characterized in that, include: A negative pressure pump; A negative pressure tank is connected to the air inlet of the negative pressure pump and is provided with a suction port for drawing in dust-laden gas; An escape dust collection chamber is connected to the outlet of the negative pressure pump; A bag filter is connected to the escaping dust collection chamber via a first pressure balancing valve; A second pressure balancing valve, the two ends of which are respectively connected to the negative pressure tank and the escaping dust collection chamber; An ash discharge valve is installed at the bottom discharge port of the negative pressure tank; A control unit is electrically connected to the negative pressure pump, the first air pressure balancing valve, the second air pressure balancing valve, and the ash discharge valve, respectively. The control unit is configured to selectively perform vacuuming and dust removal operations.

2. The dust removal device for ash silos in thermal power plants according to claim 1, characterized in that, A dust filter is installed on the top of the negative pressure tank, and the air inlet of the negative pressure pump is sealed to the air outlet of the dust filter; the negative pressure tank is connected to the escaping dust collection chamber through a pipeline, and the second air pressure balancing valve is installed on the pipeline; the bottom of the negative pressure tank is discharged through a ash discharge pipeline, and the ash discharge valve is located on the aforementioned ash discharge pipeline.

3. The dust removal device for ash silos in thermal power plants according to claim 1, characterized in that, The second pressure balancing valve is a normally closed solenoid valve, with its first end connected to the top of the negative pressure tank and its second end connected to the top of the escaping dust collection chamber.

4. The dust removal device for ash silos in thermal power plants according to claim 1, characterized in that, The first air pressure balancing valve is a normally open solenoid valve, whose air inlet is connected to the air outlet of the dust collection chamber and whose air outlet is connected to the air inlet of the bag filter.

5. The dust removal device for ash silos in thermal power plants according to claim 1, characterized in that, The dust suction ports are multiple and are evenly arranged around the ash unloading hopper of the thermal power plant ash silo to form an enclosed dust suction structure; each dust suction port is equipped with an independent manual adjustment valve between itself and the negative pressure tank.

6. The dust removal device for ash silos in thermal power plants according to claim 1, characterized in that, The negative pressure tank is also equipped with a level gauge, which is connected to the control unit and is used to send a signal to the control unit when the dust in the negative pressure tank reaches a preset level; the bottom of the escaping dust collection bin is equipped with a ash discharge port, which is used to discharge the dust that naturally settles in the escaping dust collection bin.

7. A dust removal method based on the dust removal device for a thermal power plant ash silo according to any one of claims 1-6, characterized in that, include: Vacuuming stage: S1. Start the negative pressure pump through the control unit and close the second air pressure balance valve to create negative pressure in the negative pressure tank; S2. The dust-laden gas that escapes during ash removal is drawn into the negative pressure tank through the dust suction port; S3. The dust-laden gas slows down inside the negative pressure tank, and large dust particles naturally settle to the bottom of the negative pressure tank. S4. The airflow carrying the remaining dust passes through the dust filter in the negative pressure tank, where the dust is intercepted and the clean gas enters the negative pressure pump. S5. The negative pressure pump discharges the gas into the escaping dust collection chamber, where the residual trace dust in the gas further settles naturally. S6. The gas enters the bag filter for final filtration after passing through the first pressure balancing valve and is then discharged. Ash removal stage: T1. When ash discharge is required, the control unit shuts off the negative pressure pump; T2. The control unit opens the second air pressure balance valve to balance the pressure between the negative pressure tank and the dust collection chamber, eliminating the negative pressure state in the negative pressure tank. T3. The control unit opens the ash discharge valve at the bottom of the negative pressure tank, allowing the dust that has settled in the negative pressure tank to be discharged under the action of gravity. T4. After the ash discharge is completed, the control unit closes the ash discharge valve and the second air pressure balance valve.

8. The dust removal method according to claim 7, characterized in that, In the ash removal stage T1, the conditions for triggering ash removal are: when the level gauge in the negative pressure tank detects that the dust has reached the preset level, it automatically sends a signal to the control unit, or it is manually triggered by the operator.

9. The dust removal method according to claim 7, characterized in that, The dust collection stage S6 also includes adjusting the opening of the first air pressure balance valve to match the exhaust pressure of the negative pressure pump, so as to stabilize the airflow at the inlet of the bag filter.

Images