Coal gas dry dedusting method of pressurized gasification furnace

Abstract

The application discloses a dry dedusting method for coal gas of a pressurized gasification furnace, and belongs to the technical field of coal gas dedusting. The dry dedusting system of the application is composed of a filter deduster, a pulse ash cleaning system, a control system and a lock-gas ash discharging system, and is used for purifying high-temperature and high-pressure raw coal gas at the outlet of the pressurized gasification furnace. After the coal gas is filtered by the filter element of the filter deduster, dust is intercepted on the outer surface of the filter element, and the clean coal gas is discharged from the inner cavity side. The pulse ash cleaning system realizes back-blowing ash cleaning by inputting pulse gas into the filter element without interrupting the filtering operation. The control system adopts a double-criterion ash cleaning triggering strategy. The dust collected by the filter deduster can be transported in high and low pressure dense phases by the lock-gas ash discharging system through the alternate change of the pressure of the lock-gas system under the condition of maintaining the operating pressure of the dedusting system. The application realizes stable and efficient back-blowing ash cleaning, prolongs the service life of the filter element, ensures that the dust content of the clean coal gas continuously meets the standard, simplifies the technological process and fully retains the waste heat of the coal gas.

Description

Technical Field

[0001] This invention belongs to the field of coal gas dust removal technology, specifically relating to a dry dust removal method for coal gas from a pressurized gasifier. Background Technology

[0002] Pressurized gasifiers convert coal and biomass into crude gas under high temperature and high pressure conditions. The crude gas contains a large amount of fly ash and fly ash particles lifted by the furnace bed. The crude gas must be treated to reduce the dust content to the level required by downstream conversion, synthesis and other processes before it can enter the subsequent process flow.

[0003] Currently, the most widely used method for dust removal from pressurized gasification furnaces in industry is wet dust removal. This involves first cooling the high-temperature crude gas, and then removing dust particles using water washing or a wet electrostatic precipitator. While wet dust removal is a mature and reliable technology, it has several inherent drawbacks. First, the gas must be cooled before dust removal, resulting in a significant loss of sensible heat as waste heat, reducing the overall thermal efficiency of the system. Second, wet dust removal generates wastewater containing dust and tar, requiring the construction of wastewater treatment facilities, increasing engineering investment and operating costs. Furthermore, the temperature and pressure of the clean gas after wet dust removal are already lowered, often requiring reheating and repressurization before being sent to downstream processes, further increasing system energy consumption and equipment complexity.

[0004] Dry dust removal technology utilizes filter elements to directly trap dust particles at high temperatures, achieving coal gas purification. It offers significant advantages such as preserving residual heat from the coal gas, simplifying the process, and avoiding wastewater generation. However, existing dry dust removal technologies are primarily designed for atmospheric or slightly positive pressure conditions. When applied to high-pressure coal gas systems in pressurized gasifiers, they face a series of technical challenges. In high-pressure environments, both the inner and outer sides of the filter element are under high system back pressure. The gas source pressure used in conventional pulse cleaning systems is only slightly higher than atmospheric pressure, failing to create sufficient reverse pressure difference across the filter element to effectively drive the filter cake to detach. This results in poor cleaning performance, with filter cake residue accumulating repeatedly, leading to a continuous increase in pressure drop across the filter element, ultimately affecting the quality of the purified coal gas and even forcing system shutdown. Simultaneously, the crude coal gas exiting the pressurized gasifier has a high dust concentration and a wide particle size distribution. If it enters the fine filtration equipment directly without pretreatment, the dust load on the filter element becomes excessive, significantly increasing the cleaning frequency. The frequent pulse impacts accelerate fatigue wear of the filter element, drastically shortening its service life. Furthermore, existing dry dust removal systems often employ fixed-time interval triggering or single pressure drop threshold triggering strategies. The former cannot adapt to dynamic changes in inlet conditions, easily leading to unnecessary over-cleaning or untimely cleaning. The latter, lacking the ability to predict pressure drop trends, exhibits response lag, resulting in periodic overshooting of the filter chamber pressure drop and momentary exceedances in the clean gas dust content. In the ash removal stage, dust emissions from high-pressure systems must be carried out while maintaining stable system pressure. Conventional open-type ash removal methods cannot meet high-pressure sealing requirements, easily causing system pressure fluctuations and gas leaks.

[0005] Therefore, there is an urgent need for a dry dust removal method for coal gas suitable for high-temperature and high-pressure conditions in pressurized gasifiers, which can efficiently remove dust from coal gas and solve technical problems such as insufficient pulse cleaning effect under high pressure, poor adaptability of cleaning control strategy, and difficulty in ensuring system pressure stability during high-pressure ash discharge. Summary of the Invention

[0006] To address the problems existing in the background art, the present invention provides a method for dry dust removal of pressurized gasifier gas, employing a pressurized gasifier gas dry dust removal system, the pressurized gasifier gas dry dust removal system comprising:

[0007] The filter dust collector has an air inlet connected to the gas outlet pipeline of the pressurized gasifier, and an internal filter chamber containing filter elements.

[0008] The pulse cleaning system is connected to each filter chamber, and its pulse air source pressure is higher than the system operating pressure.

[0009] The control system has its signal input terminal connected to the differential pressure sensor of each filter chamber, and its control output terminal connected to each pulse valve of the pulse cleaning system.

[0010] An airlock-type ash discharge system is connected to the bottom outlet of the filter dust collector;

[0011] Follow these steps:

[0012] S1: Under the condition of maintaining the system operating pressure unchanged, introduce the gas from the pressurized gasifier outlet into the filter dust collector;

[0013] S2: The coal gas is filtered by the filter element of the dust collector to obtain a dust content of no more than 10 mg / m³. 3 clean coal gas

[0014] S3: Determine the pulse gas source pressure according to the system operating pressure, and under the condition of maintaining the system operating pressure in the filter dust collector unchanged, introduce pulse gas into the filter element for online or offline backflushing cleaning.

[0015] S4: Real-time acquisition of pressure drop in the filter chamber, determination of cleaning timing for each chamber according to dual criteria, sequential triggering of pulse cleaning in a multi-chamber rotation mode, and adaptive adjustment of cleaning trigger threshold based on pressure drop recovery after each cleaning.

[0016] S5: The dust collected by the filter dust collector is discharged under the system operating pressure through the airlock system.

[0017] In a preferred embodiment, step S2 includes:

[0018] S21: The filter elements are made of fiber filter bags, ceramic tubes or metal filter elements, arranged vertically in each filter chamber;

[0019] S22: Controls the surface velocity of the filter element. The dust content at the clean gas outlet should not exceed 10 mg / m³. 3 This yields qualified clean coal gas; among which This represents the actual gas filtration velocity per unit area on the outer surface of the filter element.

[0020] In a preferred embodiment, step S3 includes:

[0021] S31: Calculate the pulse gas source pressure using the following formula. :

[0022] ;

[0023] in: This refers to the pulse gas source pressure. This is to reduce system operating pressure. The pressure drop of the filter cake on the surface of the filter element at the moment of dust removal triggering is calculated by Darcy's law based on the inlet dust concentration, filtration surface velocity, and filter cake specific resistance. The pressure drop of the filter element itself under clean conditions is measured or provided by the supplier. The kinetic energy pressure drop when the pulsed gas passes through the nozzle is calculated from the nozzle flow area and the pulsed gas velocity. For safety margin;

[0024] S32: Fill the pulse gas source storage tank with gas to... Maintaining the system operating pressure within the filter dust collector Under unchanged conditions, open the pulse valves corresponding to each filter chamber, inject pulse gas into the inner cavity of the filter element, and use the pressure difference between the inside and outside of the filter element to drive the surface filter cake to fall off, thus completing the backflushing cleaning.

[0025] In a preferred embodiment, in step S4, the dual criteria include:

[0026] Criterion 1: Setting Each filter chamber, when the measured pressure drop of a certain filter chamber... Reaching the dust removal trigger threshold When necessary, add the room to the dust removal queue;

[0027] Criterion 2: Based on the sampling period Collect the pressure drop in each chamber and calculate the rate of increase of the pressure drop in each chamber using the following formula. :

[0028] ;

[0029] The intraventricular pressure drop can be predicted using the following formula. Remaining time :

[0030] ;

[0031] when No more than the advance trigger time When necessary, add the room to the dust removal queue;

[0032] in: For the first The rate of increase in pressure drop in each filter chamber; For the first Each filter chamber is in Measured voltage drop at any given moment; For the first Each filter chamber is in Measured voltage drop at any given moment; The sampling period; The threshold for triggering dust removal; To predict arrival The remaining time; To trigger the time in advance; The filter chamber number is used; if either criterion one or criterion two is met, the chamber is added to the dust removal queue.

[0033] In a preferred embodiment, step S4, the multi-chamber rotation control and adaptive adjustment, includes:

[0034] S41: Arrange the filter chambers in a priority queue according to the current measured pressure drop from high to low, and perform pulse cleaning on each chamber in order of priority;

[0035] S42: Time interval between dust removal operations in two adjacent chambers satisfy:

[0036] ;

[0037] in: The time interval between dust removal operations in two adjacent chambers; The time required for dust to settle completely in the ash hopper after cleaning is determined by the effective height of the ash hopper. Divide by the dust particle settling velocity To obtain, that is ; This refers to the effective height of the ash hopper. The settling velocity of dust particles is calculated based on the dust particle size and gas properties. The time required for an effective pre-coating to form on the surface of the filter element is determined by the minimum effective pre-coating area mass load. Divide by the inlet dust concentration With filter surface speed The product is obtained, that is ; Minimum effective pre-coated area mass load; Dust concentration at the inlet; The filtration surface velocity of the filter element;

[0038] S43: After each pulse cleaning cycle, calculate the pressure drop recovery amount using the following formula. :

[0039] ;

[0040] in: This is the amount of pressure drop recovery during dust removal; The actual pressure drop in the chamber before dust removal; This is the measured value when the pressure drop in the chamber stabilizes after dust removal; based on With the dust removal trigger threshold The ratio is adaptively adjusted. :when Less than When setting the preset lower limit ratio, appropriately reduce it. ;when Greater than When setting the preset upper limit ratio, appropriately increase it. To prevent the dust content in the clean coal gas from exceeding the standard when the ash removal efficiency decreases.

[0041] In the preferred embodiment, the pulse cleaning system includes a pulse gas source storage tank, a pulse valve, a blow pipe, and a nozzle; each filter chamber is equipped with an independent pulse valve, and each pulse valve is independently controlled by the control system; the nozzle is located at the inlet end of the filter element and is used to introduce pulse gas into the inner cavity of the filter element, so that a pressure difference is formed from the inside to the outside on both sides of the filter element, driving the filter cake on the outer surface of the filter element to fall off.

[0042] The control system includes a data acquisition unit, a criterion calculation unit, and a timing control unit. The data acquisition unit is connected to the differential pressure transmitter of each filter chamber and collects the pressure drop data of each chamber according to a set sampling period. The criterion calculation unit is used to calculate the cleaning timing of each chamber according to dual criteria and adaptively adjust the cleaning trigger threshold according to the pressure drop recovery after cleaning. The timing control unit is used to send chamber cleaning commands to the pulse cleaning system according to the multi-chamber rotation sequence and inter-chamber time interval constraints.

[0043] The airlock ash discharge system includes a feed valve, an airlock container, and a discharge valve, and is used to discharge dust collected by the filter dust collector at low pressure under the system operating pressure.

[0044] The beneficial effects achieved by this invention are as follows:

[0045] This invention introduces a dual-criteria dust removal triggering control strategy based on real-time pressure drop data. It combines a pressure drop threshold criterion with a pressure drop growth rate prediction criterion, ensuring that the timing of dust removal has both a clear upper limit on pressure drop and the ability to predict pressure drop trends in advance. This effectively compensates for the pressure drop overshoot problem caused by the response delay of a single threshold criterion. Simultaneously, after each dust removal cycle, this invention adaptively adjusts the next dust removal trigger threshold based on the ratio of the pressure drop recovery amount to the dust removal trigger threshold. This allows the control strategy to automatically optimize in response to dynamic changes in inlet dust concentration and filtration conditions, eliminating the need for frequent manual intervention. While ensuring the continuous compliance of clean gas quality, this approach maximizes the dust removal interval and reduces fatigue wear on filter elements caused by repeated pulse impacts.

[0046] This invention employs a dual constraint—dust settling time and pre-coating formation time—to limit the time interval of dust removal operations. This effectively avoids the dust re-entrainment effect and instantaneous exceedance of clean gas dust content caused by rapid, continuous multi-chamber dust removal, ensuring the operational stability of the entire filtration system during the dust removal process. Furthermore, the dust collected by the filter dust collector is discharged under pressure at the system operating pressure via an airlock-type ash discharge system. This process does not interrupt the main process flow or cause system pressure fluctuations, enabling the entire dust removal system to achieve truly continuous online operation under high temperature and high pressure conditions. It eliminates the intermediate steps of gas cooling, wastewater washing, and repressurization in existing wet dust removal processes, significantly simplifying the system flow and fully preserving the waste heat of the gas. Attached Figure Description

[0047] Figure 1 This is a comparison curve of the filter chamber pressure drop of Example 1 and Comparative Examples 1 and 2 as a function of operating time.

[0048] Figure 2 This is a grouped bar chart comparing the dust content at the clean gas outlet of Example 13 and Comparative Example 14.

[0049] Figure 3 The graphs show a comparison of the cleaning frequency and expected lifespan of the filter elements between Examples 1-3 and Comparative Examples 1 and 3. (a) is a bar chart of the total number of cleaning times within 48 hours, and (b) is a bar chart of the expected lifespan of the filter elements.

[0050] Figure 4 The graphs show the comparison of the cleaning effect and threshold adaptive adjustment between Example 1 and Comparative Example 4. (a) is a scatter plot showing the change in cleaning pressure drop recovery with the number of cleaning cycles, and (b) is an adaptive drift curve of the cleaning trigger threshold in Example 1.

[0051] Figure 5 This is a flowchart of a dry dust removal method for pressurized gasifier gas according to the present invention. Detailed Implementation

[0052] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. In addition, the forms of the various structures described in the following embodiments are merely illustrative. The present invention is not limited to the structures described in the following embodiments. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0053] This invention provides a dry dust removal method for pressurized gasifier gas, which employs the following system: the system includes a filter dust collector based on high temperature and high pressure dry method design, a pulse cleaning system, a control system, and an airlock ash discharge system.

[0054] The inlet of the filter dust collector connects to the gas pipeline at the outlet of the pressurized gasifier, receiving high-temperature, high-pressure crude gas from the gasifier. The filter dust collector contains filter elements, divided into several parallel-operating filter chambers by partitions. The partitions divide the internal space of the filter dust collector into a dust-laden gas side and a clean gas side. The filter elements are installed across the partitions. Dust-laden gas permeates from the dust-laden gas side through the outer surface of the filter elements into the inner cavity, where particulate matter is trapped on the outer surface to form a filter cake. Clean gas flows into the clean gas side and exits from the outlet. The filter dust collector shell and its accessories are also of high-temperature and high-pressure resistant construction, and a safety protection system is installed according to specifications to prevent overpressure.

[0055] The pulse jet cleaning system is connected to each filter chamber and is used to perform compartment-by-compartment backflushing cleaning. The pulse jet cleaning system includes a pulse gas source tank, pulse valves, and nozzles. The pulse gas source tank stores compressed gas at a pressure higher than the system operating pressure, and its operating pressure is calculated and determined according to the formula described in step S31. Each filter chamber is equipped with an independent pulse valve, which is independently controlled by the control system, allowing each chamber to switch cleaning operations independently without affecting the normal filtration of other chambers. Nozzles are located at the inlet end of each filter element. Pulsed gas is injected at high speed into the inner cavity of the filter element through the nozzles, creating a pressure difference on the inner and outer sides pointing towards the outer surface, driving the filter cake to break and fall off. The fallen dust falls into the ash hopper. The pulse valves should have a sufficiently fast opening response speed to ensure that the pulse gas released in a short time forms a sufficiently strong impact airflow, improving the dust removal rate of a single cleaning cycle.

[0056] The control system is the core control component of the entire dust removal system. Its signal input terminal is connected to the signal output terminal of the differential pressure transmitter in each filter chamber, receiving the pressure drop data of each chamber in real time. Its control output terminal is connected to each pulse valve of the pulse cleaning system, issuing chamber cleaning commands according to the calculation results. The control system is internally divided into three functional modules: a data acquisition unit, a criterion calculation unit, and a timing control unit. The data acquisition unit is responsible for periodically reading the real-time measurement values ​​of each differential pressure transmitter at a set sampling period and transmitting the data to the criterion calculation unit. The criterion calculation unit processes the received pressure drop time series and calculates the pressure drop growth rate of each chamber in real time according to the dual criterion logic in step S4. and predicting the remaining time Determine whether each chamber meets the dust removal triggering conditions, and calculate the dust removal pressure drop recovery amount according to step S43 after each dust removal. ,according to With the present The ratio adaptively adjusts the next dust removal trigger threshold, enabling the control strategy to be dynamically optimized according to the system's operating status. The timing control unit receives the dust removal trigger signal output by the criterion calculation unit and sequentially issues compartment dust removal commands to the pulse dust removal system according to the priority queue established in step S41. It also strictly enforces the inter-compartment time interval constraints specified in step S42 to prevent system pressure fluctuations and dust re-entrainment caused by simultaneous or rapid continuous dust removal in multiple compartments. The timing control unit simultaneously monitors the operating status of each pulse valve, the pressure of the pulse gas source tank, and the pressure drop of each compartment in real time. When the pressure drop of any filter compartment is abnormally high, the emergency response logic is triggered to ensure the safe operation of the system.

[0057] The airlock-type ash removal system is connected to the bottom outlet of the filter dust collector, enabling continuous ash removal under normal system pressure. The system includes a feed valve, an airlock container, and a discharge valve. The feed valve is located at the top of the airlock container and connected to the ash hopper outlet of the filter dust collector; the discharge valve is located at the bottom of the airlock container and connected to the atmospheric pressure dust collection system. The airlock container acts as a buffer between the high-pressure and atmospheric pressure systems. Through the sequential opening and closing of the feed and discharge valves, and the depressurization and repressurization circulation of gas within the airlock, dust is transferred from the high-pressure ash hopper to the atmospheric pressure collection system, maintaining stable pressure in the main process system throughout the process. The airlock-type ash removal system of the filter dust collector operates alternately. The ash removal operation and pulse cleaning sequence are coordinated by the control system to avoid mutual interference between ash removal depressurization and cleaning pulse timing.

[0058] Reference Figure 5 This invention provides a dry dust removal method for pressurized gasifier gas, comprising steps S1-S5, as detailed below:

[0059] Step S1 involves pre-treating the crude gas from the pressurized gasifier outlet and introducing it into a dust collector while maintaining a constant system operating pressure; Step S2 involves introducing the pre-treated gas into a high-temperature, high-pressure dry dust collector, where it is filtered by filter elements to obtain a dust content of no more than 10 mg / m³. 3 The filter dust collector contains filter elements. Dust-laden gas permeates from the outer surface of the filter element into the inner cavity, where particulate matter is trapped and forms a filter cake. Clean gas flows from the inner cavity of the element into the clean gas chamber and is then discharged. The filter dust collector is divided into at least two parallel-operating filter chambers by partitions. Each chamber shares an inlet and outlet main pipe, but each chamber can independently switch pulse cleaning operations to achieve continuous operation.

[0060] In step S21, the filter elements are fiber filter bags, ceramic tubes, or metal filter elements, preferably ceramic candle filter tubes or sintered metal filter tubes. Ceramic candle filter tubes are typically made of alumina, silicon carbide, or mullite as the matrix material, sintered at high temperatures, and are characterized by high temperature resistance, corrosion resistance, and stable pore structure, making them suitable for working conditions where the gas contains corrosive components such as H2S and alkali metal vapors. Sintered metal filter tubes are made of heat-resistant and corrosion-resistant metal powders such as stainless steel and Hastelloy, using powder metallurgy processes, and have good toughness and thermal shock resistance, making them suitable for working conditions with high dust concentrations and frequent temperature fluctuations. In implementation, the filter elements of appropriate materials should be selected according to the specific composition, temperature range, and corrosiveness of the gas. The filter elements are arranged vertically in each filter chamber, with the clean gas outlet of the element facing the clean gas chamber. Dust is trapped on the outer surface of the filter element, and the dust that falls off during gravity-assisted cleaning can fall into the ash hopper relatively smoothly.

[0061] Step S22 involves controlling the filtration surface speed. The dust content at the outlet of the clean coal gas should not exceed 10 mg / m³. 3 The process requirements are met to obtain qualified clean coal gas. Filtration surface velocity The surface velocity (FVO) refers to the actual gas volumetric flow rate per unit area passing through the outer surface of the filter element per unit time, measured in m³ / s. It is a core parameter characterizing the intensity of filtration operation. A higher FVO results in a larger mass of dust reaching the filter element surface per unit time, faster filter cake growth, a more rapid increase in pressure drop, shorter cleaning intervals, and faster fatigue wear of the filter element. Under high temperature and high pressure conditions, the gas density is several to tens of times higher than under normal pressure conditions. At the same volumetric flow rate, the particles carried in the gas have greater momentum, making it easier for particles to embed deeply into the filter element pores, leading to an irreversible increase in pressure drop. Therefore, the FVO under high pressure conditions should be lower to allow particles to reach the filter element surface at a gentler speed, forming a loosely structured outer filter cake, reducing deep embedding, and extending the cleaning cycle and element lifespan. In practice, the specific FVO value should be determined through engineering calculations during the design phase of the filter dust collector, taking into account factors such as the actual gas flow rate, the effective filtration area of ​​the filter chamber, operating pressure and temperature, and inlet dust concentration.

[0062] Step S3 is to maintain the operating pressure inside the filter dust collector. Under constant conditions, pulsed gas at a pressure higher than the system pressure is introduced into the filter element for online or offline backflushing cleaning. This is one of the most crucial operational features that distinguishes this method from conventional dry dust collection. In atmospheric pressure dry dust collection, the pulsed gas source pressure typically only needs to be about 0.15 MPa higher than atmospheric pressure to create a sufficient pressure difference between the inside and outside of the filter element to drive the filter cake to detach. However, in high-pressure dry dust collection, both the inside and outside of the filter element are at the system operating pressure. If the pulse gas source pressure is only slightly higher than atmospheric pressure, the actual pressure difference that can be formed when the pulse gas enters the already high-pressure filter element cavity will be extremely small or even negative, failing to generate an effective backflushing airflow and resulting in cleaning failure. Therefore, the pulse gas source pressure must be higher than the system operating pressure. Furthermore, additional pressure drops such as filter cake resistance, media resistance, and kinetic energy loss must be covered in order to form an effective reverse airflow impact under high pressure.

[0063] Step S31: Calculate the pulse gas source pressure using the following formula. .

[0064] ;

[0065] in, This refers to the pulse gas source pressure, expressed in MPa (gauge pressure). This refers to the system operating pressure, expressed in MPa (gauge pressure). The pressure drop of the filter cake on the surface of the filter element at the moment of dust removal triggering is expressed in MPa. This represents the pressure drop of the filter element itself under clean conditions, expressed in MPa. This is the kinetic energy pressure drop of the pulsed gas as it passes through the nozzle, expressed in MPa. For safety margin, the unit is MPa.

[0066] The pulse gas source pressure must exceed the system back pressure. The excess amount is at least equal to the sum of all resistances that the pulsed gas needs to overcome to reach the outer surface of the filter element, plus a safety margin. The filter cake resistance to airflow at the moment of dust removal triggering is determined by the inlet dust concentration, filtration surface velocity, specific resistance of the dust cake, and the cumulative filtration time since the last dust removal. It can be calculated using Darcy's Law, which describes the fundamental relationship of filter media resistance. Darcy's Law states that when fluid flows through a porous medium in a laminar state, the fluid velocity is directly proportional to the driving pressure difference and inversely proportional to the medium resistance. The expression describing the filter cake pressure drop is as follows: ,in For gas dynamic viscosity, For the specific resistance of the filter cake, The dust mass load per unit area on the outer surface of the filter element. For the filtration surface velocity, the values ​​of each parameter are taken at the corresponding time of dust removal triggering during implementation. It is the resistance of the filter element under operating conditions. It is related to the element material, porosity, and wall thickness. It can be obtained from the product specifications provided by the supplier or determined by the measured pressure drop data under clean conditions. It reflects the additional pressure drop caused by the increase in gas kinetic energy when the pulsed gas accelerates through the nozzle, and is calculated based on the basic fluid dynamics relationship using the nozzle flow cross-sectional area and the design gas velocity. This safety margin is set to take into account uncertainties such as system pressure fluctuations, instrument errors, and pipeline resistance. When implementing it, the value can be appropriately selected according to the system pressure level and pressure control accuracy. The higher the system operating pressure, the greater the absolute value of the safety margin should be to ensure the reliability of dust removal.

[0067] Step S32 is the operation step for performing online or offline backflushing cleaning. The calculation obtained according to step S31... The pulse gas source tank is filled with gas, using either nitrogen or purified coal gas from the system to avoid introducing new impurities. The filter dust collector is maintained at its normal operating pressure. and operating temperature During operation, the control system issues a cleaning command, opening the pulse valve corresponding to the filter chamber to be cleaned. High-pressure pulsed gas from the storage tank is then delivered through a pipeline to the nozzle, which injects it into the inner cavity of the filter element. Due to the pressure of the pulsed gas at this time... The pressure of the dust-laden gas outside the filter element Combined with the filter cake pressure drop, the pulsed gas creates a positive pressure difference from the inside to the outside of the filter element. The airflow permeates from the inner cavity to the outer side, generating an impact airflow in the pores of the filter medium that is opposite to the normal filtration direction. This causes the filter cake adhering to the outer surface of the filter element to be broken and detached due to reverse shear force and inertial impact force. The detached dust falls into the ash hopper below the filter chamber under gravity, completing one cleaning operation. The entire cleaning process is carried out under the normal operating pressure of the system, without the need for pressure reduction or shutdown, achieving true online non-stop cleaning.

[0068] Step S4 involves real-time acquisition of pressure drop in each filter chamber, determining the cleaning timing for each chamber based on dual criteria, and triggering pulse cleaning sequentially in a multi-chamber rotation manner. The cleaning trigger threshold is adaptively adjusted based on the pressure drop recovery after each cleaning. During filtration operation, as dust continuously accumulates on the outer surface of the filter element, the pressure difference between the dust-laden gas chamber and the clean gas chamber on both sides of the filter chamber continuously increases. Pressure drop is the most direct and measurable parameter reflecting the amount of dust accumulation on the filter element surface; therefore, using pressure drop as the basis for cleaning triggering is the most reliable control strategy in high-temperature and high-pressure filtration systems. The filter dust collector is divided into multiple parallel filter chambers, each accumulating dust independently. The rate of change of its pressure drop over time varies depending on the filter surface velocity and local inlet dust concentration in each chamber. If the same fixed time interval is used for cleaning in all chambers, some chambers may be triggered before reaching the required pressure drop level, resulting in wasted cleaning resources; other chambers may be triggered only after exceeding the reasonable pressure drop limit, leading to excessive local resistance or even exceeding the dust content of the clean gas. Therefore, step S4 introduces a dual criterion based on real-time pressure drop data, combined with multi-chamber rotation and adaptive threshold adjustment, to closely match the dust removal operation with the actual filtration status of each chamber.

[0069] Criterion 1 is the pressure drop threshold criterion. When the measured pressure drop of a certain filter chamber... Reaching the dust removal trigger threshold When the time comes, add the chamber to the dust removal queue and trigger pulse dust removal. The upper limit of operation is determined by comprehensively considering the maximum allowable working pressure drop of the filter element, the requirements of downstream processes for the dust content of the clean coal gas, and the system pressure drop budget. During implementation, it should be calibrated in conjunction with operating data during the system commissioning phase.

[0070] Criterion two is the prediction advance criterion. During operation, based on the sampling period... Continuously collect pressure drop data from each chamber, and calculate the pressure drop growth rate of each chamber using the following formula. .

[0071] ;

[0072] in, For the first The rate of increase in pressure drop in each filter chamber, in Pa / s; For the first Each filter chamber is in The measured pressure drop at any given time, in Pa; For the first Each filter chamber is in The measured pressure drop at any given time, in Pa; The sampling period is expressed in seconds (s). This is the serial number of the filter chamber.

[0073] In obtaining Then, calculate the pressure drop in the chamber using the following formula. Predicted remaining time .

[0074] ;

[0075] in, To predict arrival The remaining time, in seconds; This is the dust removal trigger threshold, expressed in Pa. for The measured pressure drop at any given time, in Pa; This represents the rate of increase in pressure drop, expressed in Pa / s. When... No more than the advance trigger time At that time, add the room to the dust removal queue to trigger the dust removal operation in advance. The advance trigger time is measured in seconds and is determined based on factors such as the response time of the pulse cleaning system and the potential waiting time in the cleaning queue.

[0076] The purpose of introducing criterion two is to compensate for the lag in criterion one. In the later stages of filter operation, when the pressure drop approaches but has not yet reached its maximum... If the filter chamber pressure drop is allowed to just reach the threshold before cleaning begins, the inherent delays in cleaning preparation and pulse valve response mean that the actual pressure drop at the start of cleaning may have already exceeded the threshold. This can cause a temporary exceedance of the dust content in the clean coal gas. This risk can be effectively avoided by predicting and triggering it in advance using criterion two. The chamber will be added to the dust removal queue when either criterion one or criterion two is met.

[0077] Step S41 arranges the filter chambers into a cleaning priority queue from high to low based on the current measured pressure drop, and performs pulse cleaning on each chamber sequentially according to priority. This sequence prioritizes the chambers with the worst filtration condition, preventing high-pressure chambers from experiencing excessive dust content in the clean gas due to long waiting queues. During implementation, the control system sorts the current pressure drop of each chamber before each cleaning command is triggered, dynamically updating the priority queue to adapt to the changing pressure drop of each chamber over time.

[0078] Step S42: Time interval for cleaning operations between adjacent chambers Impose constraints requiring the following conditions to be met.

[0079] ;

[0080] in, The time interval between dust removal operations in two adjacent chambers, expressed in seconds. The time required for dust to settle completely in the ash hopper after cleaning, measured in seconds; The time required for an effective pre-coating to reform onto the surface of the filter element, measured in seconds; This means taking the larger of the two parameters.

[0081] Calculate using the following formula.

[0082] ;

[0083] in, The effective height of the ash hopper is expressed in meters (m), which is the distance between the gas-solid separation zone at the top of the ash hopper and the airlock-type feed valve of the ash hopper. Let be the settling velocity of the dust particles, expressed in m / s. For fine particles with small diameters, it can be calculated using Stokes' law of settling. Stokes' law describes the terminal settling velocity of spherical particles in a viscous fluid under the influence of gravity, and its expression is: ,in Dust particle density (kg / m³) 3 ), Gas density (kg / m³) 3 ), Acceleration due to gravity (m / s²) 2 ), The representative particle size is (m). The value represents the gas dynamic viscosity (Pa·s). For larger particles in the transition or turbulent flow regions, a corresponding drag coefficient correction method is required to determine the settling velocity. (Introduction) The constraint is that the high-speed reverse airflow generated by pulse cleaning will also stir up the dust that has fallen into the area above the ash hopper while impacting the filter cake. If the cleaning interval between two adjacent chambers is too short, the dust stirred up by the cleaning of the previous chamber will not settle before the cleaning of the next chamber causes disturbance again, which will lead to a continuous high concentration of suspended dust above the ash hopper. Some fine powder will re-attach to the filter elements of the adjacent filter chamber with the clean airflow, which is the so-called dust re-entrainment effect, resulting in a decrease in cleaning efficiency and an increase in peak dust content.

[0084] Calculated using the following formula: ;

[0085] in, The minimum area mass load required to form an effective pre-coating on the surface of the filter element, in kg / m². 2 ; The dust concentration in the gas at the inlet of the filter dust collector is expressed in kg / m³. 3 ; This refers to the surface velocity of the filter element, measured in m / s. The physical meaning is the dust mass flow rate arriving at a unit filter area per unit time, with units of kg / (m²). 2 After pulse cleaning, the dust on the outer surface of the filter element is removed. The exposed clean filter medium mainly filters particles through inertial collision, diffusion, and interception, resulting in relatively low filtration efficiency and high dust content in the clean gas. As dust gradually re-accumulates on the medium surface, forming a continuous dust layer of a certain thickness, i.e., a pre-coating layer, the filtration efficiency of the filter medium for particles can only return to a stable level. The minimum dust accumulation required to form an effective pre-coating can be determined during implementation through operational data fitting or experimental measurement. This is achieved by controlling... This ensures sufficient time for the pre-coating layer to reform after each cleaning cycle before triggering cleaning in adjacent chambers, thereby maintaining the clean gas dust content of the entire filtration system at no more than 10 mg / m³. 3 Requirements.

[0086] Step S43: After each pulse cleaning is completed, calculate the pressure drop recovery amount according to the following formula. .

[0087] ;

[0088] in, This refers to the pressure drop recovery during dust removal, expressed in Pa. The measured pressure drop in the chamber before dust removal is expressed in Pa. The measured value is the pressure drop in the chamber after cleaning and when it stabilizes, in Pa. This is a direct quantitative indicator for evaluating the effectiveness of this pulse cleaning process. If... With dust removal trigger threshold A higher ratio indicates that the filter cake has accumulated sufficiently at the time of triggering, resulting in high pulse energy utilization. Therefore, the cleaning interval can be appropriately extended, i.e., the pulse rate can be appropriately increased. Reduce the number of cleaning cycles per unit time; if this ratio is low, it indicates that the filter cake has not accumulated sufficiently before cleaning is triggered, or the cleaning effect is poor, and it is necessary to appropriately reduce the frequency of cleaning. This triggers the dust removal process in advance to prevent the dust content in the clean coal gas from exceeding the standard. Through this method... and The ratio is incorporated into the adaptive mechanism of the threshold adjustment logic. The dust removal trigger threshold can automatically drift to a reasonable range following the changes in inlet dust concentration and filter surface velocity without frequent manual intervention. This extends the dust removal interval of the filter element as much as possible while ensuring the quality of clean coal gas and reduces the fatigue wear of the filter element caused by repeated pulse impacts. The adjustment range should be set with upper and lower limits to prevent excessive threshold drift from causing system instability. The upper and lower limits can be reasonably set during the system commissioning stage based on the allowable working pressure drop of the filter element and the dust content requirements of the clean coal gas.

[0089] Step S5 involves passing the dust collected by the filter dust collector through an airlock system at the system operating pressure. The dust is discharged continuously. The dust collector's ash hopper uses an intermittent, pressure-maintaining airlock discharge method. Each dust collector is equipped with an independent airlock ash discharge system, with independent ash discharge cycles set according to their respective dust accumulation rates. The ash discharge operations are staggered to avoid superimposed pressure fluctuations caused by simultaneous depressurization and repressurization. After the complete process from steps S1 to S5, dust in the crude gas from the pressurized gasifier outlet is efficiently removed, and the dust content in the clean gas reaches no more than 10 mg / m³. 3 The system can be directly fed into downstream conversion and synthesis processes under high temperature and high pressure, eliminating intermediate steps such as gas cooling, wastewater washing and repressurization in the existing wet dust removal process. The system process is significantly simplified and waste heat is fully preserved.

[0090] Example 1: This example employs the pressurized gasification furnace gas dry dust removal method and system of the present invention. System operating pressure. MPa (gauge pressure), operating temperature At ℃, the dust concentration in the inlet crude gas is approximately 80 g / m³. 3 .

[0091] Following step S1, after pretreatment of the crude gas... MPa The filter element enters the dust collector at a temperature of ℃; following steps S2 and S21, the filter element is an alumina-based ceramic candle-type filter tube, arranged vertically. The interior of the dust collector is divided into four parallel-operating filter chambers by partitions. Following step S22, the filtration surface velocity is controlled. m / s, ensuring that the dust content at the clean gas outlet is no greater than 10 mg / m³. 3 .

[0092] Calculate the pulse gas source pressure according to steps S3 and S31. .Pick MPa MPa MPa MPa, then MPa. Following step S32, the pulse gas source tank is filled with gas to 3.04 MPa, using nitrogen as the pulse gas source.

[0093] Following step S4, dual-criteria control is employed, and the dust removal trigger threshold is set. The initial setting is 1500 Pa, and the sampling period is... s, trigger time in advance s. Following step S41, prioritize each chamber according to its measured pressure drop from highest to lowest. Following step S42, determine the dust removal time interval between adjacent chambers. Pick ,in ,Pick m, m / s, s; ,Pick kg / m 2 , kg / m 3 , m / s, s, therefore s. Calculate after each dust removal, following step S43. And adaptive adjustment , The adjustment range is set to 1200–1800 Pa.

[0094] According to step S5, the dust collected by the filter dust collector is discharged through the airlock system.

[0095] Example 2 differs from Example 1 in that: MPa The filter element uses Hastelloy sintered metal filter tubes, and the dust collector is divided into 6 parallel filter chambers. The dust concentration in the inlet crude gas is approximately 100 g / m³, with a speed of m / s. 3 , The initial setting is 1600 Pa. s, s. The adjustment range is 1300–1900 Pa.

[0096] Example 3 differs from Example 1 in that: MPa The filter element uses silicon carbide-based ceramic candle filter tubes, and the dust collector is divided into three parallel filter chambers. The dust concentration in the inlet crude gas is approximately 60 g / m³, with a speed of m / s. 3 .

[0097] Comparative Example 1 has the same system configuration as Example 1, except that: instead of adopting a dual-criteria and adaptive threshold adjustment dust removal control strategy, a fixed time interval dust removal method is adopted, with a fixed dust removal interval of 30 minutes. Each chamber is dusted in a fixed order, without prioritizing based on the measured pressure drop of each chamber, and without adjusting the dust removal parameters based on the pressure drop recovery after dust removal.

[0098] Comparative Example 2 has the same system configuration as Example 1, except that it only uses a single criterion, criterion one, namely the pressure drop threshold criterion, and does not use criterion two, the prediction advance criterion, nor does it perform adaptive threshold adjustment. The pressure is fixed at 1500 Pa.

[0099] Comparative Example 3 differs from Example 1 in that no pretreatment is performed; the crude coal gas from the pressurized gasifier outlet directly enters the filter dust collector, with an inlet dust concentration of approximately 80 g / m³. 3 The remaining dust removal control strategies are the same as in Example 1.

[0100] Comparative Example 4 has the same system configuration as Example 1, except that the pulse gas source pressure is not calculated according to the formula in step S31, but instead uses a fixed value. MPa MPa, without considering filter cake pressure drop Medium pressure drop Kinetic pressure drop and safety margin The specific value to be taken.

[0101] Experimental Example 1: This experimental example uses the methods of Example 1, Comparative Examples 1 and 2, running continuously for 8 hours under the same operating conditions, recording the pressure drop data of each filter chamber with a sampling period of 5 seconds. The filter chamber with the highest pressure drop among all schemes is selected, and its pressure drop versus operating time curve is plotted. In Example 1, the dual criteria combined with adaptive threshold adjustment cause the pressure drop to fluctuate in a sawtooth pattern within the range of 800-1500 Pa, and each cleaning cycle automatically adapts to changes in inlet operating conditions. In Comparative Example 1, fixed-time interval cleaning causes the pressure drop fluctuation range to expand to 600-2000 Pa. Cleaning is only initiated when the pressure drop exceeds 1800 Pa in some periods, and unnecessarily triggered when the pressure drop is only 800 Pa in other periods. In Comparative Example 2, only the threshold criterion is used. Due to the lack of predictive early triggering function, there is a cleaning lag phenomenon, and the pressure drop periodically exhibits overshoot peaks of 1500-1700 Pa.

[0102] from Figure 1It can be seen that the pressure drop fluctuation amplitude of Example 1 is the smallest and the upper limit is controllable, proving that the combination of dual criteria and adaptive threshold adjustment can accurately match the actual filtration status of each chamber and effectively avoid lag and unnecessary ash removal. The pressure drop fluctuation of Comparative Example 1 is violent and the peak value is too high, indicating that fixed time interval ash removal cannot adapt to changes in operating conditions. Comparative Example 2 has obvious overshoot phenomenon, indicating that the single criterion lacks predictive ability. The technical solution of dual criteria and adaptive threshold adjustment described in step S4 of this invention is effective in maintaining stable pressure drop and ensuring the quality of clean coal gas.

[0103] Experimental Example 2, using the methods of Examples 1, 2, and 3, and Comparative Examples 1, 2, 3, and 4, measured the average and peak dust content at the clean gas outlet after continuous operation for 48 hours under their respective operating conditions. Example 1 showed an average dust content of 3.5 mg / m³. 3 Peak value 5.8 mg / m³ 3 Example 2: Average 4.2 mg / m³ 3 Peak value 6.5 mg / m³ 3 Example 3: Average 5.0 mg / m³ 3 Peak value 7.2 mg / m³ 3 Comparative Example 1: Average 8.5 mg / m² 3 Peak value 14.3 mg / m³ 3 Comparative Example 2: Average 6.8 mg / m³ 3 Peak value 11.5 mg / m³ 3 Comparative Example 3: Average 9.2 mg / m³ 3 Peak value 16.8 mg / m³ 3 Comparative Example 4: Average 7.6 mg / m² 3 Peak value 12.1 mg / m³ 3 .

[0104] from Figure 2 It can be seen that the average dust content and peak dust content of all embodiments are less than 10 mg / m³. 3 The process requirements of step S22 are met; the peak dust content of Comparative Examples 1, 3, and 4 all exceed 10 mg / m³. 3 The results did not meet the requirements. Comparative Example 3 showed the highest peak value, indicating that pretreatment plays a crucial role in reducing the load on the filter elements and stabilizing the quality of the clean gas. Comparative Example 4 showed a higher peak value, indicating the importance of accurately calculating the pulse gas source pressure according to the formula in step S31 for ensuring the ash removal effect.

[0105] Experimental Example 3, using the methods of Examples 1, 2, and 3, and Comparative Examples 1 and 3, recorded the total number of cleaning cycles for each scheme during 48 hours of operation. Based on the pulse fatigue life curve provided by the filter element supplier, the expected service life of the filter element was calculated according to the single pulse impact intensity and the cumulative number of cleaning cycles. Figure 3 It can be seen that the number of cleaning cycles in Examples 1-3 is significantly lower than that in Comparative Examples 1 and 3, and the expected lifespan is significantly extended. Comparative Example 1, due to cleaning at fixed time intervals, results in a large number of unnecessary cleaning cycles, with the number of cleaning cycles being approximately 2.5 times that of Example 1, and the expected lifespan being less than half that of Example 1. This indicates that the dual-criteria adaptive control strategy in step S4 can effectively reduce the cleaning frequency and extend the lifespan of the filter element.

[0106] Experimental Example 4: Using the methods of Example 1 and Comparative Example 4, the pressure drop recovery of each cleaning operation within 8 hours of continuous operation was recorded. and pressure drop before dust removal In Example 1, According to the formula in step S31, the first 20 dust removal cycles... Stable in the range of 580720 Pa. The ratio remained at 0.40-0.50, after adaptive adjustment. It drifts slowly within the range of 1350–1550 Pa, and the dust removal effect is stable. In Comparative Example 4, Using a fixed pressure of 3.3 MPa, the first 20 dust cleaning cycles... The pressure gradually decreased from an initial 650 Pa to 350 Pa. The ratio decreased from 0.43 to 0.23, indicating that as the operating time increased, the cleaning effect of the fixed pulse pressure gradually decreased, the residual amount of filter cake accumulated successively, and the pressure drop baseline continued to rise.

[0107] from Figure 4 It can be seen that in Example 1 The stability across the number of dust removal cycles indicates that the formula in step S31 accurately matches the pulse energy required for actual dust removal. Combined with the adaptive threshold adjustment in step S43, the system can operate stably for a long period. (Comparative Example 4) The pressure drop shows a clear downward trend, with the baseline pressure drop gradually increasing, indicating that the fixed pulse pressure cannot adapt to the dynamic changes in operating conditions. The dust removal capacity continues to decline, eventually leading to excessive pressure drop of the filter element and excessive dust content in the clean gas. This proves the necessity and beneficial effect of the pulse gas source pressure calculation formula in step S31 and the adaptive adjustment mechanism in step S43. There is a causal relationship between the two. The precise pulse pressure ensures the effectiveness of each dust removal, and the adaptive threshold ensures the rationality of the dust removal timing. The two work together to achieve long-term stable operation of the system.

[0108] 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 method for dry dust removal of gas from a pressurized gasifier, characterized in that, A pressurized gasifier gas dry dust removal system is adopted, the pressurized gasifier gas dry dust removal system comprising: The filter dust collector has an air inlet connected to the gas outlet pipeline of the pressurized gasifier, and an internal filter chamber containing filter elements. The pulse cleaning system is connected to each filter chamber, and its pulse air source pressure is higher than the system operating pressure. The control system has its signal input terminal connected to the differential pressure sensor of each filter chamber, and its control output terminal connected to each pulse valve of the pulse cleaning system. An airlock-type ash discharge system is connected to the bottom outlet of the filter dust collector; Follow these steps: S1: Under the condition of maintaining the system operating pressure unchanged, introduce the gas from the pressurized gasifier outlet into the filter dust collector; S2: The coal gas is filtered by the filter element of the dust collector to obtain a dust content of no more than 10 mg / m³. 3 clean coal gas S3: Determine the pulse gas source pressure according to the system operating pressure, and under the condition of maintaining the system operating pressure in the filter dust collector unchanged, introduce pulse gas into the filter element for backflushing and cleaning. S4: Real-time acquisition of pressure drop in the filter chamber, determination of cleaning timing for each chamber according to dual criteria, sequential triggering of pulse cleaning in a multi-chamber rotation mode, and adaptive adjustment of cleaning trigger threshold based on pressure drop recovery after each cleaning. S5: The dust collected by the filter dust collector is discharged under the system operating pressure through the airlock system.

2. The method according to claim 1, characterized in that, Step S2 includes: S21: The filter elements are made of fiber filter bags, ceramic tubes or metal filter elements, arranged vertically in each filter chamber; S22: Controls the surface velocity of the filter element. The dust content at the outlet of the clean coal gas should not exceed 10 mg / m³. 3 This yields qualified clean coal gas; among which This represents the actual gas filtration velocity per unit area on the outer surface of the filter element.

3. The method according to claim 1, characterized in that, Step S3 includes: S31: Calculate the pulse gas source pressure using the following formula. : ； in: This refers to the pulse gas source pressure. This is to reduce system operating pressure. The pressure drop of the filter cake on the surface of the filter element at the moment of dust removal triggering is calculated by Darcy's law based on the inlet dust concentration, filtration surface velocity, and filter cake specific resistance. The pressure drop of the filter element itself under clean conditions is measured or provided by the supplier. The kinetic energy pressure drop when the pulsed gas passes through the nozzle is calculated from the nozzle flow area and the pulsed gas velocity. For safety margin; S32: Fill the pulse gas source storage tank with gas to... Maintaining the system operating pressure within the filter dust collector Under unchanged conditions, open the pulse valves corresponding to each filter chamber, inject pulse gas into the inner cavity of the filter element, and use the pressure difference between the inside and outside of the filter element to drive the surface filter cake to fall off, thus completing the backflushing cleaning.

4. The method according to claim 1, characterized in that, In step S4, the dual criteria include: Criterion 1: Setting Each filter chamber, when the measured pressure drop of a certain filter chamber... Reaching the dust removal trigger threshold At that time, add the room to the dust removal queue; Criterion 2: Based on the sampling period Collect the pressure drop in each chamber and calculate the rate of increase of the pressure drop in each chamber using the following formula. : ； The intraventricular pressure drop can be predicted using the following formula. Remaining time : ； when No more than the advance trigger time At that time, add the room to the dust removal queue; in: For the first The rate of increase in pressure drop in each filter chamber; For the first Each filter chamber is in Measured voltage drop at any given moment; For the first Each filter chamber is in Measured voltage drop at any given moment; The sampling period; The threshold for triggering dust removal; To predict arrival The remaining time; To trigger the time in advance; The filter chamber number is used; if either criterion one or criterion two is met, the chamber is added to the dust removal queue.

5. The method according to claim 1, characterized in that, In step S4, the multi-chamber switching control and adaptive adjustment include: S41: Arrange the filter chambers in a priority queue according to the current measured pressure drop from high to low, and perform pulse cleaning on each chamber in order of priority; S42: Time interval between dust removal operations in two adjacent chambers satisfy: ； in: The time interval between dust removal operations in two adjacent chambers; The time required for dust to settle completely in the ash hopper after cleaning is determined by the effective height of the ash hopper. Divide by the dust particle settling velocity To obtain, that is ; This refers to the effective height of the ash hopper. The settling velocity of dust particles is calculated based on the dust particle size and gas properties. The time required for an effective pre-coating to form on the surface of the filter element is determined by the minimum effective pre-coating area mass load. Divide by the inlet dust concentration With filter surface speed The product is obtained, that is ; Minimum effective pre-coated area mass load; Dust concentration at the inlet; The filtration surface velocity of the filter element; S43: After each pulse cleaning cycle, calculate the pressure drop recovery amount using the following formula. : ； in: This is the amount of pressure drop recovery during dust removal; The measured pressure drop in the chamber before dust removal; This is the measured value when the pressure drop in the chamber stabilizes after dust removal; based on With the dust removal trigger threshold The ratio is adaptively adjusted. :when Less than When setting the preset lower limit ratio, appropriately reduce it. ;when Greater than When setting the preset upper limit ratio, appropriately increase it. To prevent the dust content in the clean coal gas from exceeding the standard when the ash removal efficiency decreases.

6. The method according to claim 1, characterized in that: The pulse cleaning system includes a pulse gas source storage tank, pulse valves, blow pipes, and nozzles; each filter chamber is equipped with an independent pulse valve, and each pulse valve is independently controlled by the control system; the nozzles are located at the inlet end of the filter element and are used to introduce pulse gas into the inner cavity of the filter element, so that a pressure difference is formed from the inside to the outside of the filter element, which drives the filter cake on the outer surface of the filter element to fall off. The control system includes a data acquisition unit, a criterion calculation unit, and a timing control unit. The data acquisition unit is connected to the differential pressure transmitter of each filter chamber and collects the pressure drop data of each chamber according to a set sampling period. The criterion calculation unit is used to calculate the cleaning timing of each chamber according to dual criteria and adaptively adjust the cleaning trigger threshold according to the pressure drop recovery after cleaning. The timing control unit is used to send chamber cleaning commands to the pulse cleaning system according to the multi-chamber rotation sequence and inter-chamber time interval constraints. The airlock ash discharge system includes a feed valve, an airlock container, and a discharge valve, and is used to discharge dust collected by the filter dust collector at low pressure under the system operating pressure.

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