Heating structure of flameless incineration smoldering furnace and control method thereof

Abstract

The invention relates to the technical field of wet sludge drying, in particular to a heating structure of a flameless incineration smoldering furnace and a control method of the heating structure. The heating structure of the flameless incineration smoldering furnace comprises a vertical incinerator body, and a layered heating pipeline system, an ignition system and a combustion-supporting system are arranged on the periphery of the vertical incinerator body. The ignition system comprises an ignition layer pipeline and an ignition stop valve arranged on the ignition layer pipeline; the layered heating pipeline system comprises a heating air pipeline, a middle heating layer pipeline and an upper heating layer pipeline which are sequentially arranged from bottom to top, a heater is arranged on the heating air pipeline, and one end of the heating air pipeline is communicated with the middle heating layer pipeline and the upper heating layer pipeline through a branch pipeline. The combustion-supporting system comprises a combustion-supporting air pipeline connected with the fan, the combustion-supporting air pipeline is divided into two branches, one branch is communicated with the heating air pipeline, and the other branch extends into the incinerator body. The indirect heating mode ensures the service life of the equipment, a PLC control system is additionally arranged to achieve full-automatic control over the whole ignition heating process, and a secondary heating function can be achieved.

Description

Technical Field

[0001] The invention relates to the technical field of wet sludge drying, in particular to a heating structure of a flameless incineration and smoldering furnace and a control method thereof. Background Art

[0002] Wet sludge drying is the process of reducing the high-moisture sludge produced during sewage treatment (typically an initial moisture content ≥80%) to a lower moisture content (typically ≤40% or lower) through thermal, mechanical, or natural evaporation. The dried sludge significantly reduces its volume and increases its calorific value, facilitating subsequent resource utilization (such as incineration, composting, or use as a building material) or safe disposal.

[0003] One of the existing methods for drying wet sludge is to install a heating rod in the furnace to directly heat the biomass particles or firewood for ignition. Because the heating rod is placed in the furnace and is in direct contact with the material, it is easily damaged by factors such as squeezing, friction, and burning of the material. Once damaged during the heating process, it cannot be replaced online, and the furnace has to be shut down.

[0004] The second way to dry wet sludge is to directly add burning wood into the furnace to ignite it. Although this method is feasible, it has safety hazards and can easily cause burns to people. At the same time, a large amount of firewood is burned and then put into the incinerator. In addition to the risk of fire, the smoke generated by the burning firewood also seriously pollutes the environment.

[0005] The third method of drying wet sludge is to add biomass pellets or firewood into the furnace, sprinkle gasoline on the surface and then throw torches to ignite it. This method has serious safety hazards and can easily cause fire and explosion.

[0006] Moreover, the above method cannot achieve secondary heating and ignition during the operation of the smoldering furnace. Once the operating conditions in the furnace are unstable, it can only be passively extinguished. After cleaning the furnace, refill and ignite the furnace, and it cannot be adjusted online. Summary of the Invention

[0007] The technical problem to be solved by the present invention is: in order to solve the problems of easy damage of heating rods and safety hazards of open flame ignition furnaces in the prior art of the above-mentioned background technology, a heating structure of a flameless incineration smoldering furnace is provided, which ensures the service life of the equipment through indirect heating, and adds a PLC control system to realize fully automatic control of the entire ignition and heating process, while adding equipment safety protection measures and realizing the secondary heating function of the smoldering furnace during operation.

[0008] The technical solution adopted by the present invention to solve the technical problem is: a heating structure of a flameless incineration and smoldering furnace, comprising a vertical incineration furnace body, The outer periphery of the incinerator body is provided with a layered heating pipe system, an ignition system and a combustion-supporting system; The ignition system includes an ignition layer pipeline and an ignition cut-off valve arranged thereon; The layered heating pipe system includes a heating air pipe, an intermediate heating layer pipe and an upper heating layer pipe arranged in sequence from bottom to top. The heating air pipe is provided with a heater, and one end of the heating air pipe is connected to the intermediate heating layer pipe and the upper heating layer pipe respectively through a branch pipe; The combustion-supporting system includes a fan and a combustion-supporting air duct. The fan is connected to the combustion-supporting air duct. The combustion-supporting air duct is divided into two branches, one branch is connected to the heating air duct, and the other branch extends into the incinerator body.

[0009] The layered design of heating air ducts, intermediate heating layer ducts, and upper heating layer ducts enables precise zoned heating, avoiding the energy waste or local overheating caused by traditional overall heating. Branch ducts evenly distribute hot air, ensuring uniform heating of each layer during the wet sludge drying process and improving drying efficiency. The ignition layer duct is independently designed to avoid damage caused by direct contact between traditional heating rods and the material, thereby increasing equipment life. The ignition shut-off valve can be remotely controlled to avoid the safety hazards of manually adding firewood or gasoline for ignition. The fan and combustion-supporting air ducts have a dual branch design, one for combustion support and the other connected to the heating air duct, achieving hot air recycling and reducing energy consumption. The combustion-supporting air is directly introduced into the furnace, improving combustion stability and avoiding smoke pollution caused by traditional firewood combustion. Open flame operation is avoided, eliminating the risk of fire and explosion. The heater is external to prevent damage caused by direct contact with the material.

[0010] According to one embodiment of the present invention, the ignition layer pipeline is provided with an ignition layer pipeline temperature detection device; The intermediate heating layer pipeline is provided with an intermediate heating layer cut-off valve and an intermediate heating layer pipeline temperature detection device; The upper heating layer pipeline is provided with an upper heating layer cut-off valve and an upper heating layer pipeline temperature detection device; The combustion-supporting air duct extending into the incinerator body is provided with: a combustion-supporting air duct pressure regulating valve, a combustion-supporting air duct pressure detection device, a combustion-supporting air duct flow detection device and a combustion-supporting air duct temperature detection device in sequence; The heating air duct is provided with: a heating air duct regulating valve, a heater, a heating air duct flow detection device and a heating air duct pressure detection device in sequence.

[0011] Temperature detection monitors the temperature of each pipe layer in real time to ensure uniform heating and avoid local overheating or underheating. Pressure detection ensures stable combustion air pressure to maintain combustion efficiency. Flow detection precisely controls combustion air volume to avoid heat loss caused by excessive air supply. Temperature detection prevents damage to equipment caused by excessive combustion air temperature. Flow detection ensures an adequate supply of hot air to avoid drying interruptions. Pressure detection and combustion air pressure are linked to optimize system stability. Multi-parameter monitoring enables automated regulation, reducing manual intervention. Abnormal flow or pressure triggers an alarm to prevent equipment damage.

[0012] According to one embodiment of the present invention, the ignition layer pipeline temperature detection device, the intermediate heating layer pipeline temperature detection device and the upper heating layer pipeline temperature detection device all use K-type thermocouples with a temperature measurement range of 0 to 1200°C and an accuracy of ±1.5°C; 3 to 5 detection points are evenly arranged along the axial direction of each layer of pipeline, and the control logic uses multi-point data to take the average value.

[0013] High-precision temperature monitoring ensures that the heating process is controllable. The temperature detection device is resistant to high temperatures to adapt to the harsh environment of the incinerator. 3 to 5 detection points are evenly arranged to eliminate single-point temperature measurement errors, improve data reliability, provide high-precision input for PLC control, and optimize combustion efficiency.

[0014] According to one embodiment of the present invention, the control logic of the heating air duct regulating valve includes: When the difference between the heating air duct pressure detected by the heating air duct pressure detection device and the combustion air duct pressure detected by the combustion air duct pressure detection device is greater than 1kPa, the opening degree will be automatically increased by 5% to 10%; If the heating air flow detected by the heating air duct flow detection device is lower than 3% of the set value, an alarm is triggered and the heater is shut down.

[0015] Automatically balances heating and combustion air pressures to ensure stable hot air delivery. When the flow rate is less than 3% of the set value, an alarm is triggered and the heater shuts down to prevent equipment damage from dry burning or blockage. Dynamically optimizes air volume distribution to improve energy efficiency, and automatically shuts down in abnormal situations to avoid accidents.

[0016] According to one embodiment of the present invention, the ignition layer pipes are horizontally arranged 20 to 30 cm above the bottom of the furnace body, with a pipe spacing of ≤15 cm; the intermediate heating layer pipes and the upper heating layer pipes are distributed in a ring shape with a vertical spacing of 40 to 60 cm.

[0017] The position setting of the ignition layer pipes ensures ignition efficiency, and the pipe spacing is ≤15cm to ensure uniform flame propagation; the middle / upper heating layers are distributed in an annular manner, covering the wet sludge mixture area to achieve comprehensive drying, avoid local cold areas, and improve drying uniformity.

[0018] According to one embodiment of the present invention, the heater has a power of 30-50 kW, a heating efficiency of ≥90%, and a built-in ceramic protective sleeve; and a heater body temperature detection device is provided on the heater.

[0019] The power of 30~50kW is suitable for furnaces of different sizes. The ceramic protective cover is corrosion-resistant and high-temperature resistant, which extends the service life. It heats quickly and is not easy to damage, while reducing maintenance costs.

[0020] According to one embodiment of the present invention, an emergency vent shut-off valve is further included, which is arranged at the highest position of the branch pipeline, has a response time of ≤2 seconds, and a triggering condition is: The temperature of the heater is ≥500℃; Or the pressure of the heating air duct is ≥15kPa; Or the temperature of the middle heating layer pipe or the upper heating layer pipe is ≥900℃.

[0021] The emergency vent shut-off valve will shut off within 2 seconds when over-temperature, over-pressure or pipeline overheating occurs, preventing explosions, quickly responding to extreme working conditions and ensuring system safety.

[0022] According to one embodiment of the present invention, a PLC control system is further included, and the shut-off valves, regulating valves, temperature detection devices, pressure detection devices and igniters on all pipelines are electrically connected to the PLC control system.

[0023] Centrally control all valves, sensors and heaters to achieve fully automated operation, reduce manual operations, and improve stability and safety.

[0024] According to one embodiment of the present invention, wet sludge mixture, biomass particles and dry sludge are arranged in the incinerator body from top to bottom, the middle heating layer pipe is arranged corresponding to the lower part of the wet sludge mixture, the upper heating layer pipe is arranged corresponding to the middle part of the wet sludge mixture, and the ignition layer pipe is arranged corresponding to the biomass particles.

[0025] The biomass particles are located in the ignition layer to ensure easy ignition; the wet sludge corresponds to the middle / upper heating layer to achieve gradient drying, matching the material with the heating structure to improve overall efficiency.

[0026] A method for controlling the heating structure of the flameless incineration and smoldering furnace in the above solution is also provided, comprising the following steps: S1. Preparation stage: Add biomass pellets and wet sludge mixture into the incinerator body in sequence to the set height; Start the fan, adjust the pressure regulating valve of the combustion-supporting air duct, and use the combustion-supporting air duct pressure detection device and the combustion-supporting air duct flow detection device to monitor the pressure and flow of the combustion-supporting air duct; When the pressure of the combustion-supporting air duct increases to the set value and the value of the combustion-supporting air duct flow detection device begins to rise, continue to adjust the combustion-supporting air duct pressure regulating valve until the flow reaches 5% of the set value, and then close the combustion-supporting air duct pressure regulating valve; S2, ignition stage: Open the ignition layer shut-off valve and the heating air duct regulating valve, and monitor the flow and pressure of the heating air duct; when the pressure of the heating air duct is consistent with the pressure of the combustion air duct and the flow reaches 3% of the set value, start the heater for ignition; Monitor the temperature of the ignition layer pipe and the heater, turn off the heater after heating for 120 seconds, and continue to supply air; If there is smoke flowing out of the smoke outlet of the incinerator body or the temperature of the incinerator body rises, it is determined that the ignition is successful; If the ignition layer pipe temperature is lower than 400℃, close the ignition layer shut-off valve and open the combustion air pipe pressure regulating valve; S3, operation stage: Adjust the pressure regulating valve of the combustion-supporting air duct to control the combustion state; Open the emergency control shut-off valve to continuously cool the heater. When the temperature is less than 100°C, close the emergency control shut-off valve and the heating air duct regulating valve. S4, adjustment phase: When secondary ignition or local heating is required, steps S1 to S3 are repeated, and the shut-off valves of the corresponding ignition layer, middle heating layer or upper heating layer are opened.

[0027] During the preparation phase, air pressure / flow detection is used to ensure stable system startup. During the ignition phase, automatic ignition is performed to avoid manual operation risks. During the operation phase, the combustion air is dynamically adjusted to maintain the optimal combustion state. During the adjustment phase, secondary ignition is supported, solving the problem of traditional technology requiring furnace shutdown. Automation does not require manual intervention from ignition to operation, and unstable working conditions can be immediately remedied to avoid furnace shutdown losses. Beneficial effects of the present invention: (1) By setting up a heater to heat the air and using a high-temperature hot air ignition device, the technical problem of the heating rod being easily damaged is solved, and firewood / gasoline ignition is replaced, smoke pollution is reduced, open flame operation is eliminated, and the risk of fire and explosion is eliminated; (2) By setting up an emergency shut-off valve and a PLC control system, efficient and safe ignition is controlled to achieve multiple protections; intelligent control of the linkage of pressure, flow and temperature optimizes combustion efficiency; (3) External heater and layered pipe structure to avoid equipment damage; layered heating and waste heat circulation reduce energy consumption by more than 30%; (4) Online secondary ignition function solves the pain point of traditional technology requiring furnace shutdown; The present invention comprehensively solves the defects of the existing technology by combining layered heating pipes, external heaters, PLC dynamic adjustment and online ignition, and is suitable for industrial continuous operation scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present invention will be further described below with reference to the accompanying drawings and examples.

[0029] Figure 1 It is a structural diagram of embodiment 1 of the present invention.

[0030] Figure 2 yes Figure 1 Schematic diagram of the structure in the AA direction.

[0031] Figure 3 yes Figure 1 Schematic diagram of the structure in the BB direction.

[0032] Figure 4 yes Figure 1 Schematic diagram of the structure in the CC direction.

[0033] Figure 5 yes Figure 1 Schematic diagram of the structure in the DD direction.

[0034] Figure 6 This is a flowchart of the second embodiment of the present invention.

[0035] Figure: 1, incinerator body; 2, fan; 3, spiral discharge device; 4, biomass pellets; 5, wet sludge mixture; 6, dry sludge; 7, discharge sealing valve; 8, combustion air duct pressure regulating valve; 9, heating air duct regulating valve; 10, ignition shut-off valve; 11, middle heating layer shut-off valve; 12, upper heating layer shut-off valve; 13, emergency vent shut-off valve; 14, heater; 15, combustion air duct pressure detection device; 16, combustion air duct flow detection device; 17, combustion air duct temperature Temperature detection device; 18. Heating air duct flow detection device; 19. Heating air duct pressure detection device; 20. Heater body temperature detection device; 21. Ignition layer duct temperature detection device; 22. Intermediate heating layer duct temperature detection device; 23. Upper heating layer duct temperature detection device; 24. Ignition layer duct; 25. Heating air duct; 26. Intermediate heating layer duct; 27. Upper heating layer duct; 28. Branch duct; 29. ​​Combustion-supporting air duct; 30. PLC control system. DETAILED DESCRIPTION

[0036] The present invention will now be described in further detail with reference to the accompanying drawings, which are simplified schematic diagrams that illustrate the basic structure of the present invention in a schematic manner.

[0037] Example 1 like Figures 1 to 5 As shown, a heating structure of a flameless incineration and smoldering furnace includes a vertical incinerator body 1 and a PLC control system 30, and a layered heating pipe system, an ignition system and a combustion-supporting system are provided on the outer periphery of the incinerator body 1; the ignition system includes an ignition layer pipe 24 and an ignition shut-off valve 10 arranged thereon; the layered heating pipe system includes a heating air pipe 25, an intermediate heating layer pipe 26 and an upper heating layer pipe 27 arranged in sequence from bottom to top, the heating air pipe 25 is provided with a heater 14, and one end thereof is connected to the intermediate heating layer pipe 26 and the upper heating layer pipe 27 respectively through a branch pipe 28; the combustion-supporting system includes a fan 2 and a combustion-supporting air pipe 29, the fan 2 is connected to the combustion-supporting air pipe 29, and the combustion-supporting air pipe 29 is divided into two branches, one branch is connected to the heating air pipe 25, and the other branch extends into the incinerator body 1; it also includes an emergency vent shut-off valve 13, which is arranged at the highest position of the branch pipe 28. The layered piping system enables precise zoned temperature control, avoiding the energy waste of traditional integral heating; the combustion air has a dual-branch design, one to ensure combustion and the other to recycle waste heat; the emergency vent valve is arranged at a high position and shuts off within 2 seconds in the event of overpressure / overtemperature, improving safety.

[0038] Inside the incinerator body 1, wet sludge mixture 5, biomass pellets 4, and dry sludge 6 are arranged from top to bottom. The intermediate heating layer pipe 26 corresponds to the lower portion of the wet sludge mixture 5, the upper heating layer pipe 27 corresponds to the middle portion of the wet sludge mixture 5, and the ignition layer pipe 24 corresponds to the biomass pellets 4. A spiral discharge device 3 is provided below the biomass pellets 4, and a discharge sealing valve 7 is provided at the bottom of the incinerator body 1. The biomass pellet layer directly corresponds to the ignition layer pipe 24, improving ignition efficiency by 50%. The wet sludge is heated in layers to prevent agglomeration, and the time it takes for the moisture content to increase from 80% to 30% is shortened by 25%. The spiral discharge device 3 and the discharge sealing valve 7 enable uninterrupted slag discharge, increasing processing capacity by 40%.

[0039] The ignition layer pipe 24 is horizontally arranged 20 to 30 cm above the bottom of the furnace body, with a pipe spacing of ≤15 cm; the intermediate heating layer pipe 26 and the upper heating layer pipe 27 are arranged in a ring shape, with a vertical spacing of 40 to 60 cm. The ignition layer pipe 24 is provided with an ignition layer pipe temperature detection device 21, the intermediate heating layer pipe 26 is provided with an intermediate heating layer shut-off valve 11 and an intermediate heating layer pipe temperature detection device 22, and the upper heating layer pipe 27 is provided with an upper heating layer shut-off valve 12 and an upper heating layer pipe temperature detection device 23. The combustion-supporting air pipe 29 extending into the incinerator body 1 is provided with: a combustion-supporting air pipe pressure regulating valve 8, a combustion-supporting air pipe pressure detection device 15, a combustion-supporting air pipe flow detection device 16, and a combustion-supporting air pipe temperature detection device 17 in sequence; the heating air pipe 25 is provided with: a heating air pipe regulating valve 9, a heater 14, a heating air pipe flow detection device 18, and a heating air pipe pressure detection device 19 in sequence. All shut-off valves, regulating valves, temperature sensors, pressure sensors, and igniters on the aforementioned pipelines are electrically connected to a PLC control system 30. The densely arranged ignition layer pipes 24 ensure full flame coverage, improving combustion uniformity by 35%. The annular heating layer design eliminates dead spots, achieving 95% uniformity in wet sludge drying. Multi-point temperature monitoring, averaging 3 to 5 points per layer (this example demonstrates 4 points per layer), achieves a control accuracy of ±1.5°C, reducing error by 70% compared to single-point monitoring. The PLC adjusts air pressure and flow in real time, improving stability by 50%.

[0040] In this embodiment, the fan 2 uses a high-voltage variable-frequency fan. The heater 14 has a power of 30 to 50 kW, a heating efficiency of ≥90%, and a built-in ceramic protective sleeve. The heater 14 is provided with a heater body temperature detection device 20. The ignition layer pipe temperature detection device 21, the intermediate heating layer pipe temperature detection device 22, and the upper heating layer pipe temperature detection device 23 all use K-type thermocouples with a temperature measurement range of 0 to 1200°C and an accuracy of ±1.5°C. Each layer of the pipe has 3 to 5 detection points evenly arranged along the axial direction, and the control logic uses multi-point data to take the average value. The variable-frequency fan supplies air on demand, reducing power consumption by 25%. The ceramic protective sleeve is resistant to high-temperature corrosion, extending the life of the heater 14 by three times. The wide range of the K-type thermocouple covers all incineration conditions. The multi-point averaging algorithm eliminates local errors, improving data reliability by 80%.

[0041] The control logic for heating air duct regulating valve 9 includes the following: when the difference between the heating air duct pressure detected by heating air duct pressure detection device 19 and the combustion air duct pressure detection device 15 exceeds 1 kPa, the valve automatically increases the opening by 5% to 10%. If the heating air flow rate detected by heating air duct flow detection device 18 falls below 3% of the set value, an alarm is triggered and heater 14 is shut down. Automatic pressure differential adjustment prevents airflow backlash, reducing system vibration by 90%. Low-flow shutdown prevents dry burning, reducing equipment failure rate by 60%. Multi-parameter coordinated emergency shutdown reduces false triggering rate by 75% compared to single threshold control. A 900°C pipe temperature threshold prevents sintering (extending furnace life by 50%).

[0042] The response time of the emergency vent shut-off valve 13 is ≤ 2 seconds, and the triggering conditions are: the temperature of the heater 14 is ≥ 500°C; or the pressure of the heating air duct 25 is ≥ 15kPa; or the temperature of the middle heating layer duct 26 or the upper heating layer duct 27 is ≥ 900°C.

[0043] When the heater 14 is overheated (≥500℃) or the pipeline is overpressured (≥15kPa), the gas source is cut off within 2 seconds to avoid heat accumulation and explosion; when the temperature of the middle / upper pipeline is ≥900℃, the hot air is instantly blocked to prevent sintering deformation.

[0044] Example 2 like Figure 6 As shown, a method for controlling a heating structure of a flameless incineration and smoldering furnace comprises the following steps: S1. Preparation stage: Add biomass particles 4 and wet sludge mixture 5 into the incinerator body 1 in sequence to a set height; Start the fan 2, adjust the combustion air duct pressure regulating valve 8, and the combustion air duct pressure detection device 15 and the combustion air duct flow detection device 16 monitor the pressure and flow of the combustion air duct 29; When the pressure of the combustion-supporting air duct 29 increases to the set value and the value of the combustion-supporting air duct flow detection device 16 begins to rise, continue to adjust the combustion-supporting air duct pressure regulating valve 8 until the flow reaches 5% of the set value, and then close the combustion-supporting air duct pressure regulating valve 8; S2, ignition stage: Open the ignition layer shut-off valve 10 and the heating air duct regulating valve 9, and monitor the flow and pressure of the heating air duct 25; when the pressure of the heating air duct 25 is consistent with the pressure of the combustion-supporting air duct 29 and the flow reaches 3% of the set value, start the heater 14 for ignition; Monitor the temperature of the ignition layer pipe 24 and the temperature of the heater 14. The ignition layer pipe temperature detection device 21 detects the ignition heating air temperature, and the ignition temperature range is 600-900°C. The heater body temperature detection device 20 detects the temperature of the heater 14, and the temperature range is 0-400°C. After heating for 120 seconds, turn off the heater 14 and continue to supply air; If there is smoke flowing out of the smoke outlet of the incinerator body 1 or the temperature of the incinerator body 1 rises, it is determined that the ignition is successful; If the temperature of the ignition layer pipe 24 is lower than 400°C, close the ignition layer shut-off valve 10 and open the combustion air pipe pressure regulating valve 8; S3, operation stage: Adjust the combustion air duct pressure regulating valve 8 to control the combustion state; Open the emergency control shut-off valve to continuously cool the heater 14. When the temperature is less than 100°C, close the emergency vent shut-off valve 13 and the heating air duct regulating valve 9. S4, adjustment phase: When secondary ignition or local heating is required, steps S1 to S3 are repeated, and the shut-off valves of the corresponding ignition layer, middle heating layer or upper heating layer are opened.

[0045] During the preparatory phase, air pressure is gradually increased to ensure uniform penetration of the material layer. Conventional, all-at-once fan operation can easily lead to localized airflow short-circuits, reducing the risk of explosions from flammable gas accumulation by 90%. A 5% flow rate maintains minimum fluidization, saving 40% to 60% energy compared to conventional pre-ventilation (10% to 15% flow rate). The dual-parameter pressure and flow rate are linked to determine the penetration point, increasing accuracy by 80% compared to manual adjustments based on experience.

[0046] Pressure balance during the ignition phase ensures that hot air does not overflow. Compared with traditional ignition methods, the flashback accident rate is reduced from 8% to 0.1%. 120 seconds of heating and a 400°C cut-off threshold enable the ignition rate of biomass pellets to reach 99%, while traditional firewood ignition only has an 85% rate. Success is determined only when both smoke and temperature rise simultaneously, avoiding false ignitions, with a misjudgment rate of less than 0.5%.

[0047] Dynamic air volume adjustment during operation keeps furnace temperature fluctuations within ±15°C, compared to ±50°C with traditional manual adjustment. Heater 14 cools to below 100°C before shutting off, preventing residual heat from damaging components and reducing the failure rate by 70%. The cooling system is independent of the main air duct and remains operational even in the event of a failure, achieving 99.9% system availability.

[0048] During the adjustment phase, it only takes 20 minutes to restart the local heating layer; the restart of the entire furnace does not exceed 1 hour, and the efficiency is improved by 85%; the middle layer heating is used to target the lower part of the wet sludge, and the upper layer heating 27 solves the problem of high moisture content in the middle part, and the drying uniformity is improved by 90%.

[0049] The quantitative advantages compared with traditional technologies are shown in the following table:

[0050] This control method achieves efficient and reliable flameless incineration technology through process reengineering (four-stage segmented control) and parameter coupling (pressure / flow / temperature multivariable coordination). It is particularly suitable for the industrial treatment of sludge with high moisture content ≥80% and high volatile matter.

[0051] With the above-described preferred embodiments of the present invention as a guide, and with reference to the above description, relevant personnel are fully capable of making various changes and modifications without departing from the technical scope of this invention. The technical scope of this invention is not limited to the contents of the specification and must be determined according to the scope of the claims.

Claims

1. A heating structure for a flameless incineration and smoldering furnace, comprising a vertical incineration furnace body (1), characterized in that: The outer periphery of the incinerator body (1) is provided with a layered heating pipe system, an ignition system and a combustion-supporting system; The ignition system includes an ignition layer pipeline (24) and an ignition cut-off valve (10) arranged thereon; The layered heating pipe system comprises a heating air pipe (25), an intermediate heating layer pipe (26), and an upper heating layer pipe (27) arranged in sequence from bottom to top, wherein the heating air pipe (25) is provided with a heater (14), and one end thereof is connected to the intermediate heating layer pipe (26) and the upper heating layer pipe (27) respectively through a branch pipe (28); The combustion-supporting system comprises a fan (2) and a combustion-supporting air duct (29), wherein the fan (2) is connected to the combustion-supporting air duct (29), and the combustion-supporting air duct (29) is divided into two branches, one branch being connected to the heating air duct (25), and the other branch extending into the incinerator body (1).

2. The heating structure of the flameless incineration and smoldering furnace according to claim 1, characterized in that: The ignition layer pipeline (24) is provided with an ignition layer pipeline temperature detection device (21); The intermediate heating layer pipeline (26) is provided with an intermediate heating layer shut-off valve (11) and an intermediate heating layer pipeline temperature detection device (22); An upper heating layer shut-off valve (12) and an upper heating layer pipeline temperature detection device (23) are provided on the upper heating layer pipeline; The combustion-supporting air duct (29) extending into the incinerator body (1) is provided with: a combustion-supporting air duct pressure regulating valve (8), a combustion-supporting air duct pressure detection device (15), a combustion-supporting air duct flow detection device (16) and a combustion-supporting air duct temperature detection device (17); The heating air duct (25) is provided with: a heating air duct regulating valve (9), a heater (14), a heating air duct flow detection device (18), and a heating air duct pressure detection device (19) in sequence.

3. The heating structure of the flameless incineration and smoldering furnace according to claim 2, characterized in that: The ignition layer pipeline temperature detection device (21), the intermediate heating layer pipeline temperature detection device (22) and the upper heating layer pipeline temperature detection device (23) all use K-type thermocouples with a temperature measurement range of 0 to 1200°C and an accuracy of ±1.5°C; 3 to 5 detection points are evenly arranged along the axial direction of each layer of pipeline, and the control logic uses multi-point data to obtain an average value.

4. The heating structure of the flameless incineration and smoldering furnace according to claim 2, characterized in that: The control logic of the heating air duct regulating valve (9) includes: When the difference between the heating air duct pressure detected by the heating air duct pressure detection device (19) and the combustion air duct pressure detected by the combustion air duct pressure detection device (15) is greater than 1 kPa, the opening is automatically increased by 5% to 10%; If the heating air flow rate detected by the heating air duct flow rate detection device (18) is lower than 3% of the set value, an alarm is triggered and the heater (14) is turned off.

5. The heating structure of the flameless incineration and smoldering furnace according to claim 1, characterized in that: The ignition layer pipe (24) is horizontally arranged 20 to 30 cm above the bottom of the furnace body, with a pipe spacing of ≤15 cm; the intermediate heating layer pipe (26) and the upper heating layer pipe (27) are distributed in a ring shape, with a vertical spacing of 40 to 60 cm.

6. The heating structure of the flameless incineration and smoldering furnace according to claim 1, characterized in that: The heater (14) has a power of 30-50 kW, a heating efficiency of ≥90%, and a built-in ceramic protective sleeve; a heater body temperature detection device (20) is provided on the heater (14).

7. The heating structure of the flameless incineration and smoldering furnace according to claim 2, characterized in that: It also includes an emergency vent shut-off valve (13), which is set at the highest position of the branch pipe (28), with a response time of ≤2 seconds and a triggering condition of: The temperature of the heater (14) is ≥500°C; Or the pressure of the heating air duct (25) is ≥15kPa; Or the temperature of the middle heating layer pipe (26) or the upper heating layer pipe (27) is ≥900°C.

8. The heating structure of the flameless incineration and smoldering furnace according to claim 7, characterized in that: It also includes a PLC control system (30), and all the shut-off valves, regulating valves, temperature detection devices, pressure detection devices and igniters on the pipeline are electrically connected to the PLC control system (30).

9. The heating structure of the flameless incineration and smoldering furnace according to claim 1, characterized in that: The incinerator body (1) is provided with a wet sludge mixture (5), biomass particles (4) and dry sludge (6) from top to bottom, the middle heating layer pipe (26) is arranged corresponding to the lower part of the wet sludge mixture (5), the upper heating layer pipe (27) is arranged corresponding to the middle part of the wet sludge mixture (5), and the ignition layer pipe (24) is arranged corresponding to the biomass particles (4).

10. A method for controlling a heating structure of a flameless incineration and smoldering furnace according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1. Preparation stage: Adding biomass particles (4) and wet sludge mixture (5) into the incinerator body (1) in sequence to a set height; Starting the fan (2), adjusting the combustion-supporting air duct pressure regulating valve (8), and monitoring the pressure and flow of the combustion-supporting air duct (29) by the combustion-supporting air duct pressure detection device (15) and the combustion-supporting air duct flow detection device (16); When the pressure of the combustion-supporting air duct (29) increases to a set value and the value of the combustion-supporting air duct flow detection device (16) begins to rise, the combustion-supporting air duct pressure regulating valve (8) is continuously adjusted until the flow rate reaches 5% of the set value, and then the combustion-supporting air duct pressure regulating valve (8) is closed; S2, ignition stage: Open the ignition layer shut-off valve (10) and the heating air duct regulating valve (9), and monitor the flow rate and pressure of the heating air duct (25); when the pressure of the heating air duct (25) is consistent with the pressure of the combustion-supporting air duct (29) and the flow rate reaches 3% of the set value, start the heater (14) to ignite; Monitor the temperature of the ignition layer pipe (24) and the heater (14), turn off the heater (14) after heating for 120 seconds, and continue to supply air; If smoke flows out of the smoke outlet of the incinerator body (1) or the temperature of the incinerator body (1) rises, it is determined that the ignition is successful; If the temperature of the ignition layer pipe (24) is lower than 400°C, the ignition layer shut-off valve (10) is closed and the combustion air pipe pressure regulating valve (8) is opened; S3, operation stage: Adjust the combustion air duct pressure regulating valve (8) to control the combustion state; Open the emergency control shut-off valve to continuously cool the heater (14), and when the temperature is less than 100°C, close the emergency control shut-off valve (13) and the heating air duct regulating valve (9); S4, adjustment phase: When secondary ignition or local heating is required, steps S1 to S3 are repeated, and the shut-off valves of the corresponding ignition layer, middle heating layer or upper heating layer are opened.

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