Treatment method and special equipment for cracking and carbonizing domestic sludge by using ultra-high-temperature particles

Abstract

The invention relates to a treatment method and special equipment for cracking and carbonizing domestic sludge by using ultra-high-temperature particles, and belongs to the technical field of sludge treatment.The special equipment comprises a feeding system, an oxygen-free environment generating system, an ultra-high-temperature particle cracking reaction recycling system, a discharging and product collecting system and a central control system; ultrahigh-temperature particles (such as plasma heating particles) are used as heat carriers, so that instantaneous and bulk-phase heating of the sludge is realized, the temperature gradient problem of traditional external heating is avoided, and the heat efficiency is extremely high; high-temperature particles are recycled in the system, and only a small amount of loss caused by heat loss and entrainment needs to be supplemented; the generated synthesis gas can be recycled for energy supply, so that the external energy consumption is greatly reduced; the instant high-temperature cracking is beneficial to formation of biochar with a developed pore structure, the fixed carbon content is high, the adsorption performance is good, and the additional value is high. And meanwhile, generation of harmful substances such as dioxin can be effectively inhibited through rapid heating.

Description

Technical Field

[0001] This invention relates to the field of sludge treatment technology, and to a treatment method and special equipment for treating domestic sewage sludge by ultra-high temperature particle pyrolysis and carbonization. Background Technology

[0002] 1. Current Status and Problems of Domestic Sewage Sludge Treatment: With the acceleration of urbanization, the large amount of domestic sewage sludge generated by wastewater treatment plants has become a serious environmental problem. Traditional treatment methods such as landfill (occupying land and posing pollution risks), composting (long treatment cycle and odor), and incineration (producing toxic gases such as dioxins and high energy consumption) all have drawbacks to varying degrees. Therefore, it is urgent to find a treatment technology that achieves "volume reduction, stabilization, harmlessness, and resource recovery."

[0003] 2. Existing pyrolysis / carbonization technologies and their limitations: Sludge pyrolysis carbonization technology involves heating sludge in an anaerobic or low-oxygen environment to decompose organic matter, producing biochar, syngas, and pyrolysis oil. This is a promising resource recovery technology. However, existing technologies mostly employ external heating (such as rotary kilns and muffle furnaces) or internal heating (such as heat transfer fluids). Uneven heating: Traditional heating methods conduct heat from the outside to the inside, creating a temperature gradient that leads to overburning on the outside of the sludge block and incomplete pyrolysis inside.

[0004] High energy consumption: The entire reaction chamber needs to be continuously heated, resulting in low thermal efficiency.

[0005] Poor product quality: Due to the slow heating rate, it is not conducive to the rapid precipitation of volatiles, which easily leads to secondary reactions and affects the pore structure and fixed carbon content of biochar.

[0006] Equipment prone to coking: Under traditional heating methods, the tar produced by pyrolysis is prone to condense on the inner wall of the equipment, causing blockage and corrosion.

[0007] Therefore, there is an urgent need in this field for a new type of sludge carbonization equipment that can heat rapidly and uniformly, consume little energy, and produce high-quality products. To address the aforementioned issues, this application proposes a treatment method and specialized equipment for treating municipal sewage sludge using ultra-high temperature particle pyrolysis and carbonization. Summary of the Invention

[0008] This invention addresses the technical problems existing in the prior art by providing a method and dedicated equipment for treating domestic sewage sludge using ultra-high temperature particle pyrolysis and carbonization.

[0009] The technical solution of this invention to solve the above-mentioned technical problems is as follows: A special equipment for carbonizing domestic sewage sludge using ultra-high temperature particle pyrolysis includes a feeding system, an anaerobic environment generation system, an ultra-high temperature particle pyrolysis reaction recovery system, a discharge and product collection system, and a central control system. The feeding system is used to stably transport sludge to the pyrolysis reaction system and ensure an anaerobic environment inside. The anaerobic environment generation system is used to transport inert gas to the pyrolysis reaction system to ensure that the oxygen concentration inside is less than 1%. The ultra-high temperature particle pyrolysis reaction recovery system is used to heat the particles to ultra-high temperature, and after the particles are separated by the discharge and product collection system, the particles are recovered into the pyrolysis reaction system through the recovery system for reheating and reuse, and the sludge and particles inside are fully mixed to achieve rapid reaction. The discharge and product collection system is used to process the products after the reaction, separating the solid phase and the gas phase and utilizing them. The central control system is used to monitor and control various parameters.

[0010] Preferably, the ultra-high temperature particle pyrolysis reaction recovery system includes a pyrolysis reactor. Multiple rotating stirring blades are distributed inside the pyrolysis reactor, each driven by an independent motor. A particle generator is located at one end of the pyrolysis reactor, with its opening communicating with the interior of the reactor. A particle feed inlet is fixedly located at the upper end of the particle generator. Particles fed into the particle feed inlet are heated by the particle generator before entering the pyrolysis reactor. The particle generator is mounted on a lower mounting bracket, which is equipped with control equipment and a power supply box. The particle feed inlet also cooperates with an existing sealed lifting device. A discharge section is located at the other end of the pyrolysis reactor.

[0011] Preferably, the feeding system, the anaerobic environment generation system, and the discharge and product collection system use existing equipment, such as the discharge system including a sludge bin for storing sludge, and existing equipment such as a screw feeder and an airlock device, wherein the airlock device is a star-shaped discharge valve.

[0012] Preferably, the particle generator uses a plasma torch or a high-temperature electric arc device, which can instantly heat a specific carrier (such as inert quartz sand, ceramic microspheres or metal particles) to an ultra-high temperature state.

[0013] This application provides a method for treating municipal sewage sludge using ultra-high temperature particle pyrolysis carbonization, comprising the following steps: Sludge pretreatment (S1): The sludge is dried and dewatered to reduce its moisture content, and then placed in the feeding system; Anaerobic environment construction (S2): Inert gas is introduced into the closed system to reduce the oxygen content inside the equipment and create an anaerobic environment. Ultra-high temperature particle preparation (S3): Inert particles are heated to an ultra-high temperature state using an ultra-high temperature particle generator; Mixing and pyrolysis (S4): The pretreated sludge and ultra-high temperature particles are fed into the pyrolysis reactor at a certain mass ratio. Inside the reactor, they are fully mixed by a guide plate or a stirring device, so that the sludge is heated rapidly in a short time and pyrolyzed in an anaerobic environment; 8-12:1 is fed into the pyrolysis reactor and fully mixed under the action of a guide plate or a stirring device for rapid reaction. Product separation and recovery (S5): Gas-solid separation (S51): Separating the gas and solid mixture, wherein the solid enters the cyclone separator and the gas enters the condenser; Solid phase separation and utilization (S52): Solid phase substances are separated by a separation device, and the separated substances are collected and utilized; the cyclone separator will separate ultra-high temperature particles; Pyrolysis gas treatment (S53): The pyrolysis gas is processed and utilized; Process control (S6): The feed rate, inert gas flow rate, particle heating power, reaction temperature and system pressure are monitored and adjusted by the PLC or DCS control system.

[0014] Preferably, the domestic sludge in the sludge pretreatment (S1) is dried to a moisture content of ≤30% and fed through a screw feeder and a star-shaped discharge valve.

[0015] Preferably, the inert gas introduced in the oxygen-free environment construction (S2) is nitrogen, which reduces the oxygen concentration in the system to below 1%.

[0016] Preferably, in the ultra-high temperature particle preparation (S3), the carrier particles are heated to 1500°C by a particle generator. The carrier particles are quartz sand, ceramic microspheres or metal particles with a particle size of 0.5-1 mm.

[0017] Preferably, in the mixing and pyrolysis (S4), the sludge and ultra-high temperature particles are mixed at a mass ratio of 10:1. After being mixed by a stirring device, the sludge can be heated to 500-800°C within 2-5 seconds and pyrolyzed in an anaerobic environment to generate biochar and pyrolysis gas.

[0018] Preferably, in product separation and recovery (S5), the gas and solid mixture is separated by gas extraction; the solid mixture is separated by a cyclone separator or vibrating screen, wherein the recovery rate of ultra-high temperature particles is ≥99%, and the ultra-high temperature particles are returned to the pyrolysis reactor by an elevator; the remaining biochar is cooled to below 50°C by a water-cooled jacket discharge machine before being discharged; during the pyrolysis gas treatment, the pyrolysis gas is introduced into a condenser, and after condensation, liquid products and non-condensable gases are formed. The liquid products are separated by an oil-water separator and collected, and the non-condensable gases are burned by a burner to provide energy for the plasma torch or equipment.

[0019] The beneficial effects of this invention are: 1. Ultra-fast and efficient heating: Utilizing ultra-high temperature particles (such as plasma-heated particles) as a heat carrier, instantaneous, bulk heating of sludge is achieved, avoiding the temperature gradient problem of traditional external heating, resulting in extremely high thermal efficiency; 2. Significantly reduced energy consumption: High-temperature particles are circulated within the system, requiring only minor replenishment due to heat loss and entrainment; the generated syngas can be reused for energy supply, significantly reducing external energy consumption; 3. High product quality: Instantaneous high-temperature pyrolysis facilitates the formation of biochar with a well-developed porous structure, high fixed carbon content, good adsorption performance, and high added value. Simultaneously, rapid heating effectively inhibits the formation of harmful substances such as dioxins; 4. Thorough treatment and no secondary pollution: Ultra-high temperature can thoroughly kill pathogens and degrade organic pollutants, achieving harmless sludge treatment. The entire system is closed and oxygen-free, with no waste gas leakage, making it environmentally friendly; 5. Stable system operation: Direct heat exchange between particles and sludge results in high heat transfer efficiency, avoiding the operational instability problems caused by coking and scaling in traditional equipment. Attached Figure Description

[0020] Figure 1 This is a flowchart illustrating the overall process of this invention. Figure 2 This is a three-dimensional structural diagram of the "Ultra-high Temperature Particle Pyrolysis Reaction Recovery System" of the present invention; Figure 3 for Figure 2 The main view; Figure 4 for Figure 3 The structural diagram at "AA".

[0021] The attached diagram lists the components represented by each number as follows: 10 pyrolysis reactor, 11 particle generator, 12 particle feed inlet, 13 power supply box, 14 control equipment, 15 discharge section, and 16 stirring blades. Detailed Implementation

[0022] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0023] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0024] In the description of this application, the term "for example" is used to mean "used as an example, illustration, or description." Any embodiment described as "for example" in this application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to make and use the invention. Details are set forth in the following description for purposes of explanation. It should be understood that those skilled in the art will recognize that the invention can be made without using these specific details. In other instances, well-known structures and processes will not be described in detail to avoid obscuring the description of the invention with unnecessary detail. Therefore, the invention is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed in this application.

[0025] Reference Figure 1 - Figure 4 A method and specialized equipment for treating municipal sludge by ultra-high temperature particle pyrolysis carbonization includes a feeding system, an anaerobic environment generation system, an ultra-high temperature particle pyrolysis reaction and recovery system, a discharge and product collection system, and a central control system. The feed inlet of the feeding system is located on the pyrolysis reactor 10. The anaerobic environment generation system is introduced into the pyrolysis reactor 10 through a gas channel. The discharge and product collection system is located at the discharge section 15 at the tail of the pyrolysis reactor 10. The internal configuration of each system is existing technology and will not be described in detail.

[0026] The ultra-high temperature particle pyrolysis reaction and recovery system includes a pyrolysis reactor 10. The inner wall of the pyrolysis reactor 10 is lined with high-temperature resistant insulation material to ensure the normal operation of the reaction. Multiple rotating stirring blades 16 are distributed inside the pyrolysis reactor 10 and are rotatably connected to it. Each stirring blade 16 is driven by an independent motor, and the rotation of the stirring blades 16 by the motor helps to quickly mix the sludge and particles inside, accelerating the reaction. A particle generator 11 is installed at one end of the pyrolysis reactor 10, and the opening of the particle generator 11 is connected to the pyrolysis reactor 10. The internal structure of the pyrolysis reactor 10 is interconnected. A particle feed inlet 12 is fixedly provided at the upper end of the particle generator 11. The particles fed into the particle feed inlet 12 can be heated by the particle generator 11 and then enter the pyrolysis reactor 10. The particle generator is a plasma torch or a high-temperature electric arc device that can heat the particles to 1500°C. The particle generator 11 is mounted on the mounting component below. The mounting component is respectively provided with a control device 14 and a power supply box 13. The particle feed inlet 12 is also in cooperation with an existing closed lifting device. A discharge section 15 is provided on the other end face of the pyrolysis reactor 10. When a pyrolysis reaction is required, the oxygen content inside the pyrolysis reactor 10 is reduced to below 1% by the anaerobic environment generation system. Then, the particles fed in through the particle inlet 12 are heated to ultra-high temperature by the particle generator 11. The pretreated sludge is then fed into the pyrolysis reactor 10 by the feeding system. The stirring blades 16 are driven by a motor to work, which fully mixes the sludge and particles inside. Pyrolysis is carried out in an anaerobic environment. After being discharged through the discharge section 15, the reacted materials are separated and utilized by the discharge and product collection system.

[0027] The sludge treatment process described in this embodiment is as follows: Sludge pretreatment (S1): Dry the domestic sludge to a moisture content of 25% and connect it to the feeding system, which includes a sludge bin, a screw feeder and a rotary valve. Anaerobic environment construction (S2): Start the nitrogen storage device (inert gas source) and charge the system with nitrogen through the electromagnetic flow control valve to reduce the oxygen concentration in the pyrolysis reactor to 0.8%; Ultra-high temperature particle preparation (S3): Start the plasma torch (particle generator) to heat the quartz sand particles with a particle size of 0.5-1.0 mm to 1500°C at the discharge section to form an ultra-high temperature particle stream; Mixing and pyrolysis (S4): The feed rate of the screw feeder is set to 500 kg / h. The sludge enters the pyrolysis reactor (with an inner wall lined with alumina insulation material and 16 stirring blades inside) through the star-shaped discharge valve (airlock device). It is mixed with ultra-high temperature quartz sand particles at a mass ratio of 10:1 in the pyrolysis reactor. The temperature rises to 600℃ within 2-3 seconds, and the pyrolysis reaction occurs. Product separation and recovery (S5): S51 Gas-Solid Separation: The pyrolysis gas is extracted to the condenser, and the solid mixture is sent to the cyclone separator.

[0028] S52 Solid-phase separation and utilization: After separation by a cyclone separator, the separation efficiency of quartz sand particles is ≥99%. The separated quartz sand particles are returned to the plasma torch for recycling and heating via a bucket elevator. The remaining biochar enters a water-cooled jacketed spiral cooler, is cooled to 45°C, and is discharged through a discharge valve. The relevant parameters are tested and meet expectations. S53 pyrolysis gas treatment: The pyrolysis gas is condensed into a liquid mixture by a shell-and-tube condenser, and the liquid mixture is then sent to an oil-water separator for separation and collection; the non-condensable gases are purified by an activated carbon adsorption purifier (gas purification device), and the calorific value reaches 15 MJ / m³ at the discharge section. 3 The plasma torch is powered by a burner (heating device); Process control (S6): The plasma power of 200kW, reaction temperature of 600℃, and feed rate of 500kg / h are monitored and controlled in real time by the PLC control system to ensure the continuous and stable operation of the system.

[0029] Working principle: This application achieves efficient sludge treatment through a synergistic mechanism of "ultra-high temperature particle instantaneous heat transfer + anaerobic pyrolysis + resource recycling". Figure 1 The workflow logic is clearly demonstrated: First, an anaerobic environment generation system creates an anaerobic atmosphere to avoid the generation of harmful substances during the pyrolysis process; then, an ultra-high temperature particle stream is prepared by a particle generator and transported to the pre-treated sludge through a feeding system, allowing the sludge and particles to directly contact and mix in the pyrolysis reactor. Utilizing the high specific heat capacity and instantaneous heat transfer characteristics of the particles, the temperature gradient problem of traditional heating is solved, achieving rapid sludge pyrolysis; after gas-solid separation, the reaction products are circulated in a closed loop to reduce energy consumption, and biochar and pyrolysis gas are collected and treated through dedicated paths to achieve resource recovery; the entire process is controlled by a central control system to ensure parameter matching at each node and stable operation.

[0030] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0031] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for treating municipal sewage sludge using ultra-high temperature particle pyrolysis and carbonization, characterized in that, Includes the following steps: Sludge pretreatment (S1): The sludge is dried and dewatered to reduce its moisture content, and then placed in the feeding system; Anaerobic environment construction (S2): Inert gas is introduced into the closed system to reduce the oxygen content inside the equipment and create an anaerobic environment. Ultra-high temperature particle preparation (S3): Inert particles are heated to an ultra-high temperature state using an ultra-high temperature particle generator; Mixing and pyrolysis (S4): The pretreated sludge and ultra-high temperature particles are fed into the pyrolysis reactor at a certain mass ratio. Inside the reactor, they are fully mixed by a guide plate or a stirring device, so that the sludge is heated rapidly in a short time and pyrolyzed in an anaerobic environment; 8-12:1 is fed into the pyrolysis reactor and fully mixed under the action of a guide plate or a stirring device for rapid reaction. Product separation and recovery (S5): ① Gas-solid separation (S51): Separating the gas and solid mixture, wherein the solid enters the cyclone separator and the gas enters the condenser; ② Solid phase separation and utilization (S52): Solid phase substances are separated by a separation device, and the separated substances are collected and utilized; the cyclone separator will separate ultra-high temperature particles; ③ Pyrolysis gas treatment (S53): The pyrolysis gas is processed and utilized; Process control (S6): The feed rate, inert gas flow rate, particle heating power, reaction temperature and system pressure are monitored and adjusted by the PLC or DCS control system.

2. The method for treating municipal sewage sludge using ultra-high temperature particle pyrolysis carbonization according to claim 1, characterized in that, In the sludge pretreatment (S1), the domestic sludge is dried to a moisture content of ≤30% and fed through a screw feeder and a star-shaped discharge valve.

3. The method for treating municipal sewage sludge using ultra-high temperature particle pyrolysis carbonization according to claim 1, characterized in that, The inert gas introduced into the oxygen-free environment construction (S2) is nitrogen, which reduces the oxygen concentration in the system to below 1%.

4. The method for treating municipal sewage sludge using ultra-high temperature particle pyrolysis carbonization according to claim 1, characterized in that, In the preparation of ultra-high temperature particles (S3), the carrier particles are heated to 1500℃ by a particle generator. The carrier particles are quartz sand, ceramic microspheres or metal particles with a particle size of 0.5-1mm.

5. The method for treating municipal sewage sludge using ultra-high temperature particle pyrolysis carbonization according to claim 1, characterized in that, In the mixing and pyrolysis (S4) process, the sludge and ultra-high temperature particles are mixed at a mass ratio of 10:

1. After being mixed by a stirring device, the sludge can be heated to 500-800℃ within 2-5 seconds and pyrolyzed in an anaerobic environment to produce biochar and pyrolysis gas.

6. The method for treating municipal sewage sludge using ultra-high temperature particle pyrolysis carbonization according to claim 1, characterized in that, In the product separation and recovery (S5), the gas and solid mixture is separated by gas extraction; the solid mixture is separated by a cyclone separator or vibrating screen, wherein the recovery rate of ultra-high temperature particles is ≥99%, and the ultra-high temperature particles are returned to the pyrolysis reactor by an elevator. The remaining biochar is cooled to below 50°C by a water-cooled jacket discharge machine before being discharged; during the pyrolysis gas treatment, the pyrolysis gas is passed into a condenser, and after condensation, liquid products and non-condensable gases are formed. The liquid products are separated by an oil-water separator and collected, and the non-condensable gases are burned by a burner to provide energy for the plasma torch or equipment.

7. A dedicated device for treating municipal sewage sludge using ultra-high temperature particle pyrolysis carbonization according to any one of claims 1-6, characterized in that, The system includes a feeding system, an anaerobic environment generation system, an ultra-high temperature particle pyrolysis reaction and recovery system, a discharge and product collection system, and a central control system. The feeding system stably supplies sludge to the pyrolysis reaction system and ensures an anaerobic environment. The anaerobic environment generation system supplies inert gas to the pyrolysis reaction system to ensure that the oxygen concentration inside is below 1%. The ultra-high temperature particle pyrolysis reaction and recovery system heats the particles to ultra-high temperatures, and after the particles are separated by the discharge and product collection system, they are recovered into the pyrolysis reaction system for reheating and reuse. The system also thoroughly mixes the sludge and particles inside the system to achieve rapid reaction. The discharge and product collection system processes the reaction products, separating the solid phase and the gaseous phase for utilization. The central control system monitors and controls various parameters.

8. The specialized equipment for the treatment method of municipal sewage sludge using ultra-high temperature particle pyrolysis carbonization according to claim 7, characterized in that, The ultra-high temperature particle pyrolysis reaction recovery system includes a pyrolysis reactor 10. Multiple rotating stirring blades 16 are distributed inside the pyrolysis reactor 10, each driven by an independent motor. A particle generator 11 is located at one end of the pyrolysis reactor 10, with its opening communicating with the interior of the pyrolysis reactor 10. A particle feed inlet 12 is fixedly located at the upper end of the particle generator 11. Particles fed into the particle feed inlet 12 are heated by the particle generator 11 and then enter the pyrolysis reactor 10. The particle generator 11 is mounted on a mounting bracket below, which is equipped with a control device 14 and a power supply box 13. The particle feed inlet 12 also cooperates with an existing sealed lifting device. A discharge section 15 is located at the other end of the pyrolysis reactor 10.

9. A method for treating municipal sewage sludge using ultra-high temperature particle pyrolysis carbonization according to claim 7, characterized in that, The feeding system, the anaerobic environment generation system, and the discharge and product collection system use existing equipment and technology. For example, the discharge system includes a sludge bin for storing sludge, and existing equipment such as a screw feeder and an airlock device, with the airlock device being a star-shaped discharge valve.

10. A method for treating municipal sewage sludge using ultra-high temperature particle pyrolysis carbonization according to claim 4, characterized in that, The particle generator uses a plasma torch or high-temperature electric arc device to heat a specific carrier (such as inert quartz sand, ceramic microspheres or metal particles) to an ultra-high temperature state in an instant.

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