A gas regulation device and control method for a bag filter dust collector

Abstract

This invention relates to the field of lignite drying technology and proposes a gas control device and method for a bag filter dust collector. The device's induced draft fan outlet is connected to a phase change mixing chamber via a gas inlet pipe. The phase change mixing chamber outlet is connected to a compensation main pipe via a transition pipe. The compensation main pipe is connected to each filter chamber via multiple compensation branch pipes equipped with regulating valves. A return pipe with a valve is provided between the transition pipe and the induced draft fan inlet. In the temperature warning stage, the method switches valves to allow the gas to undergo closed-loop pre-cooling between the phase change mixing chamber and the return pipe. A dynamic calculation formula based on wind speed coupling is introduced, and after comprehensively determining whether the cold source meets the standard by combining wind speed fluctuation rate and temperature change slope, the qualified cold gas is directionally injected into the corresponding chamber during the over-temperature stage. This invention can intervene in local high temperatures through compensation pipelines without cutting off the main flue or performing a complete shutdown, helping to maintain the continuous operation of the downstream main process system and reducing capacity losses caused by unplanned shutdowns.

Description

Technical Field

[0001] This invention relates to the field of lignite drying equipment technology, and in particular to a gas regulation device and control method for a bag filter dust collector. Background Technology

[0002] In the drying and upgrading process of lignite (such as high-moisture lignite), drying processes such as cyclone depolymerization are often used. During the operation of this process, a large amount of high-temperature, high-humidity dust-laden flue gas is generated. This flue gas must be filtered by a bag filter and then sent to a desulfurization tower for treatment to meet emission standards before being discharged.

[0003] In the actual operation of the drying system, due to fluctuations in the operating conditions of the hot air furnace, abnormal increases in flue gas temperature often occur. To prevent the high-temperature flue gas from burning the filter bags inside the bag filter, the existing conventional safety protection strategy is to have the control system automatically open the bypass pipeline to directly exhaust the high-temperature hot flue gas generated by the hot air furnace.

[0004] The following problems exist: When high-temperature flue gas is bypassed, the inlet airflow and temperature inside the bag filter drop drastically. Because the flue gas from drying lignite itself has a very high moisture content, once the local temperature inside the dust collector rapidly drops below the dew point, water vapor will condense extensively on the surface of the filter bags, leading to severe condensation and bag clogging. This will cause a sharp increase in filter bag resistance and filtration failure.

[0005] Therefore, there is an urgent need for a gas regulation device for bag filters to solve the problems mentioned in the background art. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a gas regulation device for a bag filter dust collector to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A gas control device for a bag filter dust collector includes a bag filter dust collector with multiple independent filter chambers inside. The duct is connected to the air outlet of the bag filter. An exhaust fan is installed on the air duct; The gas inlet pipe is connected to the outlet of the induced draft fan; The compensation main pipe has its inlet end connected to the outlet end of the gas inlet pipe; Multiple compensation branch pipes, wherein the main compensation pipe is connected to each of the filter chambers through the multiple compensation branch pipes respectively; Regulating valves are respectively installed on each of the aforementioned compensating branch pipes; A flow guiding structure is provided at one end of each of the compensation branch pipes that extends into the filter chamber.

[0008] Preferably, the filter bag of the bag filter is provided with a plurality of first thermocouples.

[0009] Preferably, the plurality of independent filter chambers are connected in parallel.

[0010] Preferably, it further includes a phase change mixing cavity; The phase change mixing chamber is located on the gas inlet pipe, and the gas inlet pipe is connected to the compensation main pipe through the phase change mixing chamber. The compensation main pipe is connected to the outlet of the phase change mixing chamber via a transition pipe, and a first shut-off valve is provided on the transition pipe; The transition pipe is connected to the first shut-off valve and the compensation main pipe by a return pipe. The outlet end of the return pipe is connected to the air duct. A second shut-off valve is provided on the return pipe. The phase change mixing chamber is a vertically arranged closed structure with a guide plate inside; The phase change mixing chamber is equipped with an atomizing spray device.

[0011] Preferably, a second thermocouple is provided inside the compensation main pipe; a wind speed sensor is provided at the outlet of the induced draft fan; It also includes a controller, the input of which is electrically connected to a first thermocouple, a second thermocouple, and a wind speed sensor, respectively, and the output of which is electrically connected to a regulating valve on each compensation branch pipe. The controller is used to control the opening degree of the regulating valve based on the detection data of the first thermocouple, the second thermocouple, and the wind speed sensor.

[0012] Another object of the present invention is to provide a gas regulation method for a bag filter dust collector, applied to the aforementioned gas regulation device for a bag filter dust collector, comprising the following steps: S1: The gas from the outlet of the bag filter is led out through the gas inlet pipe; S2: The extracted gas is delivered to each filter chamber through the main compensation pipe and multiple compensation branch pipes; S3: The gas flow rate of each filter chamber is distributed by adjusting the opening of the regulating valve on each compensation branch pipe.

[0013] Preferably, step S1 further includes a phase change treatment step: Gas is introduced into the phase change mixing chamber, and the atomizing injection device is turned on to spray atomized liquid into the phase change mixing chamber; The gas and atomized liquid come into full contact and evaporate under the action of the guide plate; then it is delivered to the compensation main pipe.

[0014] Preferably, the phase change processing steps are divided into a debugging stage and a working stage; During the commissioning process, when the temperature detected by the first thermocouple exceeds the first preset temperature value, the regulating valve and the first shut-off valve are closed, the second shut-off valve is opened, the gas is introduced into the phase change mixing chamber, and the atomizing spray device is turned on to spray atomized liquid into the phase change mixing chamber. The commissioning process ends when the temperature of the circulating gas in the phase change mixing chamber meets the preset requirements. In the aforementioned working process, when the temperature detected by the first thermocouple exceeds the second preset temperature value, the regulating valve and the first shut-off valve are opened, the second shut-off valve is closed, and the gas is delivered to the compensation main pipe.

[0015] Preferably, the second preset temperature value is 5-8°C lower than the upper limit of the temperature bearing capacity of the cloth bag, and the first preset temperature value is 5-8°C lower than the second preset temperature value.

[0016] Preferably, the specific method for determining whether the circulating gas temperature in the phase change mixing chamber meets the preset requirements is as follows: Real-time acquisition of the detection temperature of the first thermocouple The detection temperature of the second thermocouple And the wind speed detected by the wind speed sensor ; According to the formula ; Calculate the target compensation temperature under the current state. ;in The preset temperature-wind speed coupling coefficient; When the detection temperature of the second thermocouple Less than or equal to the target compensation temperature When the fluctuation rate of the wind speed V detected by the wind speed sensor is less than the preset fluctuation threshold and continues for a second preset time, it is determined that the temperature of the circulating gas in the phase change mixing chamber meets the preset requirements, and the debugging process ends.

[0017] The present invention discloses a gas regulation device for a bag filter dust collector, which has the following beneficial effects.

[0018] This invention compensates for the coordination between the main pipe and multiple independent branch pipes, and adjusts the branch pipe valves individually based on temperature feedback from each chamber. This changes the previous method of only coarsely adjusting the main pipe, enabling directional airflow compensation for specific chambers at risk of localized temperature rise. This helps balance the temperature difference between filter chambers and alleviates the premature aging of filter bags due to uneven heating over a long period.

[0019] This invention transfers the vaporization and endothermic process of the atomized liquid to an externally located phase change mixing chamber, after which the cooled gas is introduced into the dust collector. This approach achieves a reduction in gas temperature by slightly increasing the moisture content inside the dust collector, structurally reducing the probability of filter bag clogging under high humidity conditions, while also preventing the filter bags from being directly burned through by sparks.

[0020] This invention allows for pre-cooling of gas by switching valves before the temperature reaches the warning value but before exceeding the limit. This creates a closed-loop circulation between the phase change mixing chamber and the induced draft fan inlet. During this pre-cooling stage, the cooled gas is isolated in the circulation pipeline and does not enter the bag filter area, reducing the direct impact of temperature fluctuations on the internal filtration conditions of the dust collector.

[0021] This invention introduces a calculation formula incorporating wind speed variables when determining whether the compensation gas meets the injection conditions, linking the target compensation temperature to the current air volume load. By combining a comprehensive assessment of wind speed fluctuation rate and temperature change slope, the cold source preparation standard can be dynamically adjusted to follow the actual exhaust load of the system, improving the stability of the temperature control strategy under variable load conditions. When facing overheating trends caused by fluctuations in the upstream heat source, there is no need to shut down the main flue or perform a complete shutdown; intervention can be made through the compensation pipeline to address localized high temperatures, helping to maintain the continuous operation of the downstream main process system and reducing capacity losses caused by unplanned shutdowns. Attached Figure Description

[0022] Figure 1 This is a schematic diagram showing the connection between the gas control device for the bag filter and its upstream and downstream devices as proposed in Embodiment 1 of this application.

[0023] Figure 2 This is a schematic diagram of the gas regulation device for a bag filter proposed in Embodiment 1 of this application.

[0024] Figure 3 This is a schematic diagram of the dust filtration of the gas control device for a bag filter proposed in Embodiment 1 of this application.

[0025] Figure 4 This is a schematic diagram of the gas regulation device for a bag filter proposed in Embodiment 2 of this application.

[0026] Figure 5 This is a cross-sectional schematic diagram of the phase change mixing cavity structure in Embodiment 2 of this application.

[0027] Figure 6 This is a schematic diagram of a gas control method for a bag filter proposed in Embodiment 3 of this application.

[0028] In the attached diagram: 1-bag filter; 2-gas inlet pipe; 3-compensation main pipe; 4-compensation branch pipe; 5-regulating valve; 6-air duct; 7-induced draft fan; 8-desulfurization tower; 9-flow guiding structure; 10-first thermocouple; 11-phase change mixing chamber; 111-flow guide plate; 112-atomizing spray device; 12-transition pipe; 13-return pipe; 14-second thermocouple; 15-wind speed sensor; 16-first shut-off valve; 17-second shut-off valve. Detailed Implementation

[0029] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0030] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Example 1

[0031] Reference Figures 1-3 As shown, a gas control device for a bag filter 1 includes a bag filter 1, which has multiple independent filter chambers inside. Duct 6 is connected to the air outlet of bag filter 1; The exhaust fan 7 is installed on the air duct 6; Gas inlet pipe 2, the inlet end of which is connected to the outlet of induced draft fan 7; The compensation main pipe 3 has its inlet end connected to the outlet end of the gas inlet pipe 2; Multiple compensation branch pipes 4, and the main compensation pipe 3 are connected to each filter chamber through multiple compensation branch pipes 4 respectively; Regulating valves 5 are respectively installed on each compensating branch pipe 4; The flow guiding structure 9 is located at one end of each compensation branch pipe 4 that extends into the filter chamber.

[0032] In this embodiment, the air inlet of the bag filter 1 is connected to the upstream turbulent temperature control pipe, and the air outlet of the induced draft fan 7 is connected to the downstream desulfurization tower 8. The bag filter 1 has a large steel structure shell, which is divided into 4 independent filter chambers by partitions. The air duct 6 is connected to the main air outlet pipe of the bag filter 1 through a flange. The induced draft fan 7 is connected to the air duct 6. The air inlet end of the gas inlet pipe 2 is welded to the top of the air duct 6 about 1 meter after the outlet of the induced draft fan 7. The negative pressure is stable at this point, which facilitates air intake. The air inlet end of the compensation main pipe 3 is connected to the air outlet end of the gas inlet pipe 2 through a flange. The compensation main pipe 3 is connected to 8 compensation branch pipes 4 through a tee joint. The 8 compensation branch pipes 4 pass through the shell of the bag filter 1 and extend into the corresponding filter chamber. Two compensation branch pipes 4 are set for each filter chamber. The regulating valve 5 is installed on the pipe section of each compensation branch pipe 4 located outside the dust collector through a flange. The flow guiding structure 9 is welded to the end of each compensation branch pipe 4 that extends into the filter chamber. In this embodiment, the end of the flow guiding structure 9 is closed, and the flow guiding structure 9 has 8 flow guiding holes with a diameter of Φ15mm evenly opened on the circumferential wall facing the bag, which are used to convert the concentrated jet into a uniform surface airflow.

[0033] Preferably, in this embodiment, a first thermocouple 10 (a K-type armored thermocouple with a range of 0-200℃) is fixed to the upper part of each filter chamber (near the top of the filter bag frame) by a thermocouple mounting base to monitor the local real temperature of the windward side of the filter bag.

[0034] Preferably, in this embodiment, multiple independent filter chambers are connected in parallel.

[0035] This invention utilizes the coordination of the main compensation pipe 3 and multiple independent branch pipes, combined with temperature feedback from each chamber, to individually adjust the valves of the branch pipes. This changes the previous method of simply adjusting the main pipe; it enables directional airflow compensation for specific chambers at risk of localized temperature rise, which helps balance the temperature difference between the filter chambers and alleviates the premature aging of localized filter bags due to uneven heating over a long period.

[0036] The device in this embodiment is particularly suitable for dust removal systems of flue gas with high moisture content, such as those used for lignite drying. Under such operating conditions, the flue gas has a high moisture content, and the temperature control window inside the bag filter 1 is extremely narrow (usually controlled within the range of 70°C to 105°C): temperatures below 70°C can easily lead to condensation and bag clogging, while temperatures above 105°C pose a risk of burning the filter bags.

[0037] When the temperature in one or more filter chambers exceeds the critical point of 105°C due to fluctuations in the front-end heat source (i.e., the data collected by the first thermocouple 10 of the corresponding chamber exceeds 105°C), the regulating valve 5 on the compensation branch pipe 4 of the corresponding chamber is opened, and the relatively low-temperature clean air from the outlet side of the induced draft fan 7 is introduced through the gas introduction pipe 2 and directed into the overheated chamber through the compensation main pipe 3 and the compensation branch pipe 4. Because the supplementary gas is at a lower temperature, it mixes with the original high-temperature and high-humidity flue gas after entering the chamber, which can quickly lower the local temperature of the chamber, bringing it back to the safe range of 70℃~105℃. At the same time, since the flue gas to be treated itself contains a certain amount of water vapor, the water vapor content will not decrease significantly after the flue gas passes through the bag filter 1. The clean gas return through the gas inlet pipe 2 can increase the water vapor content in the bag filter 1 to a certain extent, which can prevent sparks from directly igniting the filter bags. It should be noted that although the water vapor content in the bag filter 1 is high, the risk of condensation and bag clogging is higher. However, condensation and bag clogging can be avoided by controlling the internal temperature of the bag filter 1, thereby protecting the filter bags of the bag filter 1 and avoiding production interruption caused by overall shutdown. Example 2

[0038] Based on Example 1, referring to Figure 4-5 This embodiment adds a phase change cooling and closed-loop circulation system to cope with sudden high-temperature conditions in the lignite drying system. Specifically, the gas control device of the bag filter 1 also includes a phase change mixing chamber 11; The phase change mixing chamber 11 is located on the gas inlet pipe 2, and the gas inlet pipe 2 is connected to the compensation main pipe 3 through the phase change mixing chamber 11. The outlet of the compensation main pipe 3 and the phase change mixing chamber 11 are connected by a transition pipe 12, and a first shut-off valve 16 is provided on the transition pipe 12. Specifically, in this embodiment, the phase change mixing chamber 11 is a vertical cylindrical stainless steel pressure vessel. The phase change mixing chamber 11 is located on the gas inlet pipe 2. In this embodiment, the gas inlet pipe 2 is disconnected, and its outlet end is connected to the inlet flange at the bottom of the phase change mixing chamber 11. The top outlet flange of the phase change mixing chamber 11 is connected to the compensation main pipe 3 through the transition pipe 12. The first shut-off valve 16 installed on the transition pipe 12 is a pneumatic normally closed butterfly valve, which automatically closes when the gas source is lost. A return pipe 13 is connected between the first shut-off valve 16 and the compensation main pipe 3 in the transition pipe 12. The air outlet of the return pipe 13 is connected to the air duct 6. A second shut-off valve 17 is provided on the return pipe 13. In this embodiment, a return pipe 13 is led out from the pipe section between the first shut-off valve 16 and the compensation main pipe 3 in the transition pipe 12. The air outlet of the return pipe 13 is connected to the air pipe 6 in front of the inlet of the induced draft fan 7 through a tee. A second shut-off valve 17 is provided on the return pipe 13. The second shut-off valve 17 is a pneumatic normally closed butterfly valve. Therefore, when the first shut-off valve 16 is closed and the second shut-off valve 17 is open, the airflow path is: outlet side of induced draft fan 7 (positive pressure) → gas inlet pipe 2 → phase change mixing chamber 11 (cooling and humidification) → transition pipe 12 → return pipe 13 → inlet side of induced draft fan 7 (negative pressure), forming a closed loop that is completely isolated from the bag filter 1.

[0039] The phase change mixing chamber 11 is a vertically arranged closed structure, and a guide plate 111 is provided inside it; The phase change mixing chamber 11 is equipped with an atomizing spray device 112.

[0040] In this embodiment, six layers of staggered baffles 111 are horizontally welded in the upper middle part of the phase change mixing chamber 11 (forcing the airflow to rise in an "S" shape); an atomizing spray device 112 (specifically a dual-fluid pneumatic atomizing nozzle, connected to 0.4MPa compressed air and 0.2MPa process water to generate water mist with a particle size of 10-50μm) is inserted downward in the lower middle part of the phase change mixing chamber 11.

[0041] Preferably, in this embodiment, the compensation main pipe 3 is equipped with a second thermocouple 14 for monitoring the final temperature of the compensation gas that is about to be injected into the filter bag; the outlet of the induced draft fan 7 is equipped with a wind speed sensor 15 for collecting the flow rate of the main flue gas before entering the denitrification tower, and a Pitot tube wind speed transmitter is used. It also includes a controller, whose input terminal is electrically connected to the first thermocouple 10, the second thermocouple 14 and the wind speed sensor 15 respectively, and whose output terminal is electrically connected to the regulating valve 5 on each compensation branch pipe 4. The controller is used to control the opening degree of the regulating valve 5 according to the detection data of the first thermocouple 10, the second thermocouple 14 and the wind speed sensor 15.

[0042] The controller is a Siemens S7-1200 PLC. The analog input module of the controller is electrically connected to the first thermocouple 10, the second thermocouple 14, and the wind speed sensor 15. The digital output module of the PLC is connected to the solenoid pilot valves of the first shut-off valve 16 and the second shut-off valve 17 through an intermediate relay. The analog output module of the PLC is electrically connected to each regulating valve 5. By controlling the gain and loss of power of the solenoid valves, the air path direction of the pneumatic actuator is changed, thereby realizing the opening and closing action of the two shut-off valves. Example 3

[0043] Based on Example 2, such as Figure 6 As shown, in this embodiment, a gas regulation method for a bag filter 1 is provided, applied to the gas regulation device of the bag filter 1, including the following steps: S1: The gas from the outlet of the bag filter 1 is led out through the gas inlet pipe 2; S2: The extracted gas is delivered to each filter chamber through the compensation main pipe 3 and multiple compensation branch pipes 4; S3: The gas flow rate of each filter chamber is distributed by adjusting the opening of the regulating valve 5 on each compensation branch pipe 4.

[0044] Preferably, in this embodiment, S1 further includes a phase transition treatment step: Gas is introduced into the phase change mixing chamber 11, and the atomizing injection device 112 is turned on to spray atomized liquid into the phase change mixing chamber 11; Under the action of the guide plate 111, the gas and the atomized liquid are fully contacted and evaporated, and then transported to the compensation main pipe 3.

[0045] Preferably, in this embodiment, the phase change processing steps are divided into a debugging stage and a working stage; During the commissioning phase, if the temperature detected by any of the first thermocouples 10 exceeds the preset first temperature value, the system is deemed to have an over-temperature risk and immediately enters the commissioning phase. All regulating valves 5 and the first shut-off valve 16 are closed, while the second shut-off valve 17 is opened. At this time, the gas passage is cut off, and the gas forms a closed internal circulation between the phase change mixing chamber 11, the return pipe 13, and the inlet of the induced draft fan 7. Simultaneously, the atomizing injection device 112 is activated to spray atomized liquid into the phase change mixing chamber 11. The water mist fully contacts the circulating gas between the six baffles and evaporates, absorbing heat. The temperature of the circulating gas begins to decrease. The commissioning phase ends when the temperature of the circulating gas in the phase change mixing chamber 11 meets the preset requirements.

[0046] In the debugging phase, as a preferred embodiment, the specific method for determining whether the circulating gas temperature in the phase change mixing chamber 1111 meets the preset requirements is: real-time acquisition of the detection temperature of the first thermocouple 10. The detection temperature of the second thermocouple 14 And the wind speed detected by wind speed sensor 15 ; It should be noted that if the wind speed V is very high, it means that the main flue gas flow rate is large. At this time, the proportion of compensating cold air injected into the filter bag is small. Therefore, the temperature of the compensating gas must be lowered even further (i.e., (By reducing the size), the temperature of the fabric bag can be effectively lowered after actual mixing.

[0047] Based on this logic, according to the formula ; Calculate the target compensation temperature under the current state. ;in The preset temperature-wind speed coupling coefficient; In this embodiment, the k value is not a general constant, but a calibration parameter related to the pipeline structure and bag filter heat capacity of the lignite drying system. The specific method for confirming the k value in this embodiment is as follows: Based on the principles of fluid mechanics and thermodynamics, the compensating cooling gas mixes with the main flue gas in the filter chamber. Since the flow rate of the main flue gas is directly proportional to the wind speed V at the outlet of the induced draft fan, the required temperature drop of the compensating cooling gas must be proportional to the flow rate of the main flue gas to keep the mixed temperature within a safe range. By combining and simplifying the cross-sectional area constant, the compensating gas proportion constant, and the specific heat capacity of the flue gas in the above mixing model, the basic framework of the preliminary formula can be derived: .

[0048] Under the steady-state operating conditions of the bag filter 1, at least three different stable wind speed states are artificially created by adjusting the frequency of the front-end induced draft fan 7. Under each of these wind speed states, the water spray volume of the phase change mixing chamber 11 is manually fine-tuned, and the feedback value of the first thermocouple 10 is observed. When the local temperature of the filter bag detected by the first thermocouple 10 is just stably controlled within the critical safety value, the outlet temperature of the phase change mixing chamber 11 detected by the second thermocouple 14 at this time is recorded. This temperature is the actual critical target temperature required at that wind speed.

[0049] Substitute the multiple sets of data obtained from the above experiments into the formula model, and perform univariate linear regression fitting using the least squares method to obtain the slope.

[0050] In the lignite drying system of this embodiment, the initial slope calculated by fitting on-site measured data is 1.18 ℃ s / m. Considering the non-ideal factors in the industrial environment, such as heat loss from the pipeline insulation layer and ash accumulation on the filter bag surface leading to a decrease in heat transfer efficiency, a certain safety margin needs to be added to the initial slope. In this embodiment, the initial slope is rounded up by 6.7%, and the final temperature-wind speed coupling coefficient k of the system is determined to be 1.2 ℃ s / m.

[0051] When the following three conditions are met simultaneously and continue for a second preset time (set to 30 seconds in this embodiment to exclude transient interference from the sensor), it is determined that a qualified cold source has been "prepared" in the phase change mixing chamber 11, and the debugging process ends: ① The detection temperature of the second thermocouple 14 Less than or equal to the target compensation temperature (Possesses sufficient cooling potential); ② The fluctuation rate of the wind speed V detected by the wind speed sensor 15 is less than the preset fluctuation threshold (set to 5% in this embodiment, proving that the main system has not experienced abnormal operating conditions such as surge). ③ The detection temperature of the second thermocouple 14 The downward slope of the phase change cavity tends to be gentle (proving that the heat exchange in the phase change cavity has reached dynamic equilibrium).

[0052] During operation, if the temperature detected by the first thermocouple 1010 continues to rise and exceeds the second preset temperature value, the operation is immediately triggered, opening the regulating valve 5 and the first shut-off valve 16, closing the second shut-off valve 17, and delivering the gas to the compensation main pipe 3.

[0053] In this embodiment, after cold air is injected into the working process, the PLC continuously monitors for 5-10 minutes. If the temperature drop rate of a certain chamber is found to be too fast (e.g., exceeding 3℃ / min), in order to prevent the local temperature drop from exceeding 70℃ and causing condensation, the opening of the regulating valve 5 of that branch pipe is actively reduced to achieve balanced control of "cooling without condensation".

[0054] Preferably, in this embodiment, the second temperature preset value is 5-8°C lower than the upper limit of the temperature bearing capacity of the cloth bag, and the first temperature preset value is 5-8°C lower than the second temperature preset value.

[0055] This invention transfers the vaporization and endothermic process of the atomized liquid to an externally located phase change mixing chamber 11, after which the cooled gas is introduced into the dust collector. This approach reduces the gas temperature without directly increasing the moisture content inside the dust collector, and structurally reduces the probability of filter bag clogging under high humidity conditions.

[0056] This invention allows for pre-cooling of gas by switching valve states before the temperature reaches the warning value but before exceeding the limit. This creates a closed loop between the phase change mixing chamber 11 and the inlet of the induced draft fan 7. During this pre-cooling stage, the cooled gas is isolated in the circulation pipeline and does not enter the bag filter area, reducing the direct impact of temperature fluctuations on the internal filtration conditions of the dust collector.

[0057] This invention introduces a calculation formula incorporating wind speed variables when determining whether the compensation gas meets the injection conditions, linking the target compensation temperature to the current air volume load. By combining a comprehensive assessment of wind speed fluctuation rate and temperature change slope, the cold source preparation standard can be dynamically adjusted to follow the actual exhaust load of the system, improving the stability of the temperature control strategy under variable load conditions. When facing overheating trends caused by fluctuations in the upstream heat source, there is no need to shut down the main flue or perform a complete shutdown; intervention can be made through the compensation pipeline to address localized high temperatures, helping to maintain the continuous operation of the downstream main process system and reducing capacity losses caused by unplanned shutdowns.

[0058] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Substitutions may include replacements for some structures, devices, or method steps, or may be complete technical solutions. Equivalent substitutions or modifications made to the technical solutions and inventive concepts of the present invention should all be covered within the scope of protection of the present invention.

Claims

1. A gas regulation device for a bag filter dust collector, characterized in that, include: Baghouse dust collectors have multiple independent filtration chambers inside. The duct is connected to the air outlet of the bag filter. An exhaust fan is installed on the air duct; The gas inlet pipe is connected to the outlet of the induced draft fan; The compensation main pipe has its inlet end connected to the outlet end of the gas inlet pipe; Multiple compensation branch pipes, wherein the main compensation pipe is connected to each of the filter chambers through the multiple compensation branch pipes respectively; Regulating valves are respectively installed on each of the aforementioned compensating branch pipes; A flow guiding structure is provided at one end of each of the compensation branch pipes that extends into the filter chamber.

2. The gas regulation device for a bag filter dust collector according to claim 1, characterized in that, The filter bag of the bag filter is equipped with several first thermocouples.

3. The gas regulation device for a bag filter dust collector according to claim 1, characterized in that, The multiple independent filter chambers are connected in parallel.

4. The gas regulation device for a bag filter dust collector according to claim 2, characterized in that, It also includes a phase change mixing cavity; The phase change mixing chamber is located on the gas inlet pipe, and the gas inlet pipe is connected to the compensation main pipe through the phase change mixing chamber. The compensation main pipe is connected to the outlet of the phase change mixing chamber via a transition pipe, and a first shut-off valve is provided on the transition pipe; The transition pipe is connected to the first shut-off valve and the compensation main pipe by a return pipe. The outlet end of the return pipe is connected to the air duct. A second shut-off valve is provided on the return pipe. The phase change mixing chamber is a vertically arranged closed structure with a guide plate inside; The phase change mixing chamber is equipped with an atomizing spray device.

5. A gas regulation device for a bag filter dust collector according to claim 4, characterized in that, The compensation main pipe is equipped with a second thermocouple; the outlet of the induced draft fan is equipped with a wind speed sensor; It also includes a controller, the input of which is electrically connected to a first thermocouple, a second thermocouple, and a wind speed sensor, respectively, and the output of which is electrically connected to a regulating valve on each compensation branch pipe. The controller is used to control the opening degree of the regulating valve based on the detection data of the first thermocouple, the second thermocouple, and the wind speed sensor.

6. A gas regulation method for a bag filter dust collector, characterized in that, The gas control device for a bag filter as described in any one of claims 1 to 5 comprises the following steps: S1: The gas from the outlet of the bag filter is led out through the gas inlet pipe; S2: The extracted gas is delivered to each filter chamber through the main compensation pipe and multiple compensation branch pipes; S3: The gas flow rate of each filter chamber is distributed by adjusting the opening of the regulating valve on each compensation branch pipe.

7. A gas regulation method for a bag filter according to claim 6, characterized in that, S1 also includes a phase transition process: Gas is introduced into the phase change mixing chamber, and the atomizing injection device is turned on to spray atomized liquid into the phase change mixing chamber; The gas and atomized liquid come into full contact and evaporate under the action of the guide plate; then it is delivered to the compensation main pipe.

8. The gas regulation method for a bag filter according to claim 7, characterized in that, The phase change processing steps are divided into a debugging phase and a working phase. During the commissioning process, when the temperature detected by the first thermocouple exceeds the first preset temperature value, the regulating valve and the first shut-off valve are closed, the second shut-off valve is opened, the gas is introduced into the phase change mixing chamber, and the atomizing spray device is turned on to spray atomized liquid into the phase change mixing chamber. The commissioning process ends when the temperature of the circulating gas in the phase change mixing chamber meets the preset requirements. In the aforementioned working process, when the temperature detected by the first thermocouple exceeds the second preset temperature value, the regulating valve and the first shut-off valve are opened, the second shut-off valve is closed, and the gas is delivered to the compensation main pipe.

9. A gas regulation method for a bag filter according to claim 8, characterized in that, The second preset temperature value is 5-8°C lower than the upper limit of the temperature bearing capacity of the cloth bag, and the first preset temperature value is 5-8°C lower than the second preset temperature value.

10. A gas regulation method for a bag filter according to claim 8, characterized in that, The specific method for determining whether the temperature of the circulating gas in the phase change mixing chamber meets the preset requirements is as follows: Real-time acquisition of the detection temperature of the first thermocouple The detection temperature of the second thermocouple And the wind speed detected by the wind speed sensor ; According to the formula ; Calculate the target compensation temperature under the current state. ;in The preset temperature-wind speed coupling coefficient; When the detection temperature of the second thermocouple Less than or equal to the target compensation temperature When the fluctuation rate of the wind speed V detected by the wind speed sensor is less than the preset fluctuation threshold and continues for a second preset time, it is determined that the temperature of the circulating gas in the phase change mixing chamber meets the preset requirements, and the debugging process ends.

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