Microwave catalytic pyrolysis soil remediation equipment

Abstract

The utility model provides microwave catalytic pyrolysis soil remediation equipment. A stirring assembly is arranged in a stock bin and used for stirring materials, a microwave assembly is installed on the stock bin and used for emitting microwave radiation into the stock bin, and a heat storage assembly wraps the stock bin and is used for heat preservation in the stock bin. Microwave radiation is conducted on the interior of the stock bin through the microwave assembly, soil in the stock bin is radiated by microwaves to generate heat, meanwhile, heat is transmitted to the heat storage assembly, heat loss in the stock bin can be reduced, the temperature of the soil is increased rapidly through the combined action of the microwave assembly and the heat storage assembly, physical ex-situ remediation is conducted, and the volatilization speed of harmful substances is increased; the use cost and the time cost are reduced; by adopting the equipment disclosed by the utility model, the polluted soil can be subjected to pyrolysis remediation treatment at the temperature below 200 DEG C under the low-pressure condition, and the problems that the adaptability to a specific site needs to be considered, the remediation process consumes too long time, the equipment cannot be quickly opened and closed, the investment is higher and the like in the traditional physical remediation technology are solved.

Description

Technical Field

[0001] The utility model relates to the field of soil restoration, in particular to microwave soil restoration equipment. Background Art

[0002] After years of experience in soil remediation, three types of technical systems have gradually been formed: bioremediation, chemical remediation and physical remediation. Bioremediation is low-cost, safe and has no secondary pollution, but it is time-consuming and has harsh conditions, and is not suitable for the treatment of heavy metal pollution; chemical remediation has the advantages of good effect and easy operation, but it is expensive, has a narrow scope of use, and may be contaminated by oxidants; physical remediation mainly involves thermal desorption of soil, which has the advantages of no added chemicals and no secondary pollution to the environment, no complex processes, good effects and high efficiency. The disadvantages are that the remediation of specific sites needs to consider applicability and cost, high energy consumption, and the high abrasiveness of the feed needs to be considered. In addition, due to the high temperature of the pyrolysis furnace, it cannot be started and shut down quickly. Summary of the invention

[0003] Purpose of the invention: The purpose of the utility model is to address the deficiencies of the prior art and provide a microwave catalytic pyrolysis soil remediation equipment that uses microwave catalytic oxidation technology, has lower energy consumption and higher stability.

[0004] Technical solution: The present invention provides a microwave catalytic pyrolysis soil remediation device, comprising:

[0005] Silo;

[0006] A stirring component, which is arranged in the silo and is used to stir the material;

[0007] A microwave assembly, which is mounted on the silo and is used to emit microwave radiation into the silo;

[0008] The heat storage component covers the silo and is used for heat preservation inside the silo.

[0009] Further, the silo is constructed as a resonant cavity.

[0010] Furthermore, the stirring assembly includes a spiral stirring device arranged in the silo.

[0011] Furthermore, the stirring assembly is arranged along the length direction of the silo.

[0012] Furthermore, the spiral stirring devices are provided with at least two devices rotating in opposite directions.

[0013] Furthermore, the cross-section of the silo is W-shaped, and the bottom of the silo is provided with a supporting component with a herringbone cross-section.

[0014] Furthermore, it also includes a waste gas treatment component arranged in the silo, and the waste gas treatment component includes a microwave electrodeless lamp.

[0015] Furthermore, the heat storage component includes a graphite plate heat storage body coated on the outer wall of the silo.

[0016] Furthermore, the silo is provided with a feed port, a discharge port and a waste heat recovery port.

[0017] Furthermore, the microwave assembly includes magnetrons distributed on the upper side of the silo.

[0018] Beneficial effects: The utility model uses a microwave component to radiate microwaves in the silo, and the soil in the silo is heated by the microwave radiation. At the same time, the heat is transferred to the heat storage component to reduce the heat loss in the silo. The microwave component and the heat storage component work together to accelerate the temperature of the soil for physical ex situ repair, which speeds up the volatilization of harmful substances and reduces the use cost and time cost.

[0019] The utility model equipment can realize pyrolysis remediation treatment of contaminated soil under low pressure conditions below 200°C, which solves the problems of traditional physical remediation technology that needs to consider adaptability to specific sites, the remediation process is too time-consuming, cannot be quickly switched on and off, and has high investment. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is the front view of the device of the utility model;

[0021] Figure 2 It is a top view of the device of the utility model;

[0022] Figure 3 This is a top view of the stirring assembly inside the silo of the utility model;

[0023] Figure 4 This is a top view of the layout of the exhaust gas treatment components of the utility model;

[0024] Figure 5 It is a cross-sectional view of the device of the utility model. DETAILED DESCRIPTION

[0025] The technical solution of the utility model is described in detail below, but the protection scope of the utility model is not limited to the embodiments.

[0026] A microwave catalytic pyrolysis soil remediation device, such as Figure 1-5As shown, it includes a silo 1, a stirring component 2, a microwave component 3 and a heat storage component 4. The stirring component 2 is arranged in the silo 1, and is used to stir the material. The material involved in this scheme is mainly the soil to be repaired. The microwave component 3 is installed on the silo 1, and emits microwave radiation into the silo 1. While stirring, the material is subjected to microwave radiation for pyrolysis, so that the VOCs dissolved in the soil are volatilized, and various parasites and bacteria in the soil are killed. The heat storage component 4 covers the silo 1, keeps the material in the silo 1 warm, and maintains the temperature required for soil remediation.

[0027] In some embodiments, the silo 1 is constructed as a resonant cavity 104, which is a metal cavity used to allow the high-frequency electromagnetic field generated by microwaves to continuously oscillate therein while preventing microwave leakage. Since the electromagnetic field is completely concentrated in the cavity, there is no radiation loss, so it has a higher quality factor. The resonant cavity 104 can be set to a cubic or cylindrical shape. In the resonant cavity 104, the electromagnetic field can oscillate at a series of frequencies, and the frequency size is related to the shape, geometric dimensions and resonant wave mode of the resonant cavity 104.

[0028] In some embodiments, Figure 1-3 As shown, the silo 1 includes a feed port 101, a discharge port 102 and a waste heat recovery port 103. Figure 2 As shown, the diameter of the silo 1 in this embodiment is 900 mm, and the feed port 101 is arranged on the top surface of the silo 1, and the diameter of the feed port 101 is 500 mm. The discharge port 102 is arranged on the side of the silo 1 and is located on the other side of the feed port 101, and the diameter of the discharge port 102 is 200 mm. A stop valve with a handle can be arranged on the discharge port 102 to control the discharge. The waste heat recovery port 103 is opened on the wall of the silo 1 and can be constructed as a stainless steel pipe with a diameter of 100 mm.

[0029] In some embodiments, the stirring assembly 2 includes a spiral stirring device disposed in the silo 1 .

[0030] In some embodiments, the spiral stirring device is provided with at least two spiral stirring devices rotating in opposite directions.

[0031] In some embodiments, the stirring assembly 2 is disposed along the length direction of the silo 1 .

[0032] Specifically, Figure 3As shown, two groups of stirring components 2 are arranged side by side inside the silo 1, and each group of stirring components 2 includes a rotating shaft 201 and an auger 202 fixed on the rotating shaft 201 in a spiral shape. Among them, the rotating shaft 201 is arranged along the length direction of the silo 1, and the length is 10.5m. One end of the rotating shaft 201 is connected to the output shaft of the motor 203, so the rotating shaft 201 is driven to rotate by the motor 203. In this embodiment, the motor 203 is arranged outside the silo 1, and the output shaft of the motor 203 extends into the silo 1. The auger 202 fixed on the rotating shaft 201 has a diameter of 800mm and a spacing of 430mm. Therefore, the motor 203 provides power to the auger 202 through the rotating shaft 201, and the rotation direction of the auger 202 can be controlled by the forward and reverse rotation of the motor 203. The rotation of the auger 202 on the two groups of stirring components 2 can stir the material, so that the material is heated evenly and the material can be circulated and moved inside the silo 1.

[0033] In some embodiments, Figure 5 As shown, the cross-section of the silo 1 is W-shaped, so that two side-by-side resonant cavities 104 are formed, and a set of stirring components 2 is placed in each resonant cavity 104. The silo 1 can be installed on the frame 6, and a support component 5 with a herringbone cross-section is provided on the bottom center axis of the silo 1, and the bottom of the silo 1 can be fixed on the frame 6 through the support component 5. Exemplarily, the support component 5 can be formed by two stainless steel plates with a width of 380 mm and welded at 90 degrees.

[0034] In some embodiments, Figure 4-5 As shown, it also includes an exhaust gas treatment component arranged in the silo 1, and the exhaust gas treatment component includes a microwave electrodeless lamp 7. The microwave electrodeless lamp 7 is excited by the microwave component 3 to generate ultraviolet light, and the ultraviolet light converts oxygen in the air into ozone. Through the synergistic effect of microwaves, ultraviolet light and ozone, the exhaust gas generated by thermal desorption of the soil is treated. Further, the microwave electrodeless lamp 7 can be suspended in the silo 1 and evenly arranged at a certain distance along the length direction of the silo 1.

[0035] In some embodiments, Figure 5 As shown, the heat storage component 4 includes a graphite plate heat storage body coated on the outer wall of the silo 1. After the microwave component 3 emits microwaves, the graphite plate heat storage body is heated, and the heat storage body is attached to the stirring bin to make the material reach the temperature required for carbonization. Exemplarily, the heat storage body is tightly attached to the front and rear sides of the silo 1.

[0036] In some embodiments, each group of microwave components 3 includes a magnetron distributed on the upper side of the silo 1. Under the control of mutually perpendicular constant magnetic fields and constant electric fields, the electrons in the magnetron interact with the high-frequency electromagnetic field, converting the energy obtained from the constant electric field into microwave energy, thereby achieving the purpose of generating microwave energy.

[0037] Furthermore, the magnetron can be controlled by PLC, so that a stable and continuous electromagnetic wave field is generated inside the silo 1, which has the characteristics of high automation and precise control. In addition, a heat dissipation system and a safety control system can be set up. The heat dissipation system realizes heat exchange between the inside of the electrical cavity and the outside world through the action of the heat dissipation fan, thereby reducing the temperature inside the equipment. The safety control system includes a pressure sensor, a temperature probe and a pressure relief valve. When the equipment is powered on and the temperature of the internal material rises, the internal temperature of the equipment is observed through the temperature probe. When the temperature rises abnormally, the microwave generation module is promptly closed through PLC control; the pressure relief valve is a safety protection element. When the pressure sensor detects that the internal pressure is too high, the internal and external pressures are balanced through the pressure relief valve; the pressure sensor, temperature probe and pressure relief valve are all set on the leftmost side of the top of the equipment.

[0038] The microwave catalytic oxidation soil remediation equipment of this embodiment utilizes the combined action of microwaves and graphite plate heat storage bodies to thermally desorb the soil, and treats the exhaust gas through the synergistic action of microwaves, ultraviolet rays, and ozone.

[0039] 1. Microwave is a high-frequency electromagnetic wave. The frequency used for microwave heating is usually in the 915-2450MHz band. Water and organic matter are good microwave absorbers. Microwave's super strong electromagnetic radiation and penetrating power, as well as microwave catalytic combustion function, radiate and destroy organic matter, completely breaking the molecular chains of all organic matter, cracking and changing the material structure. Under the action of microwaves, water and organic matter produce electromagnetic resonance effect, and the internal molecules of water and organic matter intensify the movement to produce friction and heating effect, so that water and organic matter are rapidly heated.

[0040] Microwave, as the main energy source of soil remediation equipment, has the following characteristics:

[0041] (1) High heating efficiency:

[0042] Compared with traditional heating, microwave heating has a faster heating efficiency because it directly acts on the molecules or ions of the material, causing the vibration of the molecules or ions to generate heat, rather than transferring heat through traditional methods (heat conduction, heat convection, heat radiation). The heat and mass transfer mechanisms of microwave heating and conventional heating are different. Conventional heating heats the material from the outside to the inside through the principles of heat conduction, convection and radiation. There is inevitably a temperature gradient in the material (the surface temperature of the material is higher than the center temperature). Microwave heating generates heat through the friction inside the molecules caused by the interaction between the electromagnetic field and the molecules of the material. The inside and outside of the material are heated at the same time. Due to the heat dissipation of the surface, the heat continues to accumulate inside the material and transfer outward, causing the center temperature of the object to be higher than the surface temperature.

[0043] (2) Energy saving:

[0044] Compared with conventional electric heating methods, it can generally save 30% to 50% of electricity. In the process of microwave heating, the mechanism of microwave energy conversion into heat energy is mainly the dipole rotation mechanism. The dipole rotation mechanism is that the molecules inside the object cause the microwave radiation to cause mutual friction and generate heat energy. Since microwave heating is the result of direct interaction between electromagnetic waves and material molecules, the loss of microwaves when propagating in the air is very small, and the energy loss is mainly concentrated in the volume of the material. In addition, the microwave power conversion efficiency is high, so it can save electricity consumption and improve economic benefits.

[0045] (3) Crack macromolecules to accelerate the reaction rate:

[0046] The heating efficiency generated by the rotation of the dipole depends on the relaxation time, temperature and viscosity of the medium. The magnetron of the microwave generator receives power from the power supply to generate microwaves, which are transmitted to the microwave heater through the waveguide. The material to be heated is heated under the action of the microwave field. Theoretical analysis shows that the existence of the microwave field can not only increase the probability of molecular collision and increase the collision energy of molecules, but also change the type of molecular energy and the orientation of molecular collision. In the process of small-scale experiments, it was found that microwaves can not only accelerate the rate of chemical reactions, but also change the pathway of chemical reactions.

[0047] 2. In addition, this embodiment uses graphite plate as the heat storage material, which has the following functions: high-frequency electromagnetic waves are generated through the microwave module, and the electromagnetic waves are uniformly radiated to the heat storage body, causing the temperature of the heat storage body to rise. The hot heat storage body is used to heat the cold material, and the heat storage body releases the stored heat to heat the material to the required temperature. The heat storage body has the following properties:

[0048] The heat storage body has a strong ability to absorb microwaves. The heat storage body absorbs microwaves to increase its own temperature.

[0049] The heat storage body has a high heat capacity and heat storage capacity, which can provide heat for a long time and maintain the soil restoration temperature;

[0050] The heat storage body has good heat transfer performance and excellent thermal conductivity and thermal radiation performance, that is, it can quickly transfer heat to the colder soil during the soil remediation process, and can quickly cool down after the remediation is completed.

[0051] 3. Utilize the high-efficiency sterilization ability of high-energy UV light beam with a wavelength of 254nm to crack the molecular bonds of bacteria in the soil, destroy the nucleic acid (DNA) of bacteria, and crack toxic and harmful substances such as ammonia, trimethylamine, hydrogen sulfide, methyl sulfide, methyl mercaptan, methyl sulfide, dimethyl disulfide, carbon disulfide and styrene, sulfide H2S, VOC, benzene, toluene, and the molecular chain structure of xylene, so that the molecular chains of organic or inorganic high molecular compounds are rapidly degraded and transformed into low molecular compounds, such as CO2, H2O, etc., to completely achieve the purpose of deodorization and killing bacteria.

[0052] 4. Microwave catalytic oxidation waste gas treatment equipment uses high-energy UV ultraviolet light beams with a specific wavelength of 185nm to quickly decompose oxygen molecules in the air to produce free oxygen, that is, active oxygen. Because the positive and negative electrons carried by free oxygen are unbalanced, it needs to combine with oxygen molecules to produce sufficient ozone. Use high-energy C-wave ultraviolet light beams and ozone to carry out synergistic decomposition and oxidation reactions on toxic and harmful gases, so that toxic and harmful gas substances are degraded and converted into low molecular compounds, water and carbon dioxide.

[0053] The microwave catalytic pyrolysis soil remediation equipment of this embodiment is economical, applicable, portable, stable and safe:

[0054] 1. Economical

[0055] Solve the problem of large investment and high cost of traditional physical soil remediation technology;

[0056] Solve the problems of high energy consumption, high operating costs and poor economy of traditional physical soil remediation technology.

[0057] 2. Applicability

[0058] The composition of contaminated soil is complex, and traditional high-temperature pyrolysis furnaces need to consider their adaptability to specific sites. However, this equipment can process most contaminated soils, greatly enhancing its adaptability and reducing the difficulty of the entire remediation process.

[0059] 3. Portability

[0060] The equipment can be customized in different sizes according to the scale of the contaminated soil. At the same time, it has a modular design, which makes it easy to disassemble and assemble, transport and use in flexible locations.

[0061] 4. Stability

[0062] Microwave heating is uniform. No matter what the shape of each part of the object is, microwave heating can make the electromagnetic waves penetrate evenly inside and outside the object to generate heat energy. Therefore, the heating is uniform and stable, and there will be no external burning and internal burning phenomenon.

[0063] 5. Security

[0064] The entire equipment is controlled by high-precision automated instruments, which can accurately control the repair process and allow the soil to be quickly repaired at a constant temperature. No manual on-site operation is required throughout the process, thus avoiding a series of human operational errors.

[0065] Microwave heating is uniform. No matter what the shape of each part of the object is, microwave heating can make the electromagnetic waves penetrate evenly inside and outside the object to generate heat energy. Therefore, the heating is uniform and stable, and there will be no external burning and internal burning phenomenon.

[0066] As above, although the utility model has been shown and described with reference to a specific preferred embodiment, it should not be interpreted as limiting the utility model itself. Various changes can be made to it in form and detail without departing from the spirit and scope of the utility model defined in the attached claims.

Claims

1. A microwave catalytic pyrolysis soil remediation equipment, characterized in that: include: Silo; A stirring component, which is arranged in the silo and is used to stir the material; A microwave assembly, which is mounted on the silo and is used to emit microwave radiation into the silo; the microwave assembly includes a magnetron distributed on the upper side of the silo; A heat storage component covers a silo and is used for heat preservation inside the silo; the heat storage component includes a graphite plate heat storage body covered on the outer wall of the silo, and the silo is provided with a feed port, a discharge port and a waste heat recovery port.

2. The microwave catalytic pyrolysis soil remediation equipment according to claim 1 is characterized in that: The silo is configured as a resonant cavity.

3. The microwave catalytic pyrolysis soil remediation equipment according to claim 1 is characterized in that: The stirring assembly comprises a spiral stirring device arranged in the silo.

4. The microwave catalytic pyrolysis soil remediation equipment according to claim 1 or 3, characterized in that: The stirring assembly is arranged along the length direction of the silo.

5. The microwave catalytic pyrolysis soil remediation equipment according to claim 3 is characterized in that: The spiral stirring devices are provided with at least two spiral stirring devices with opposite rotation directions.

6. The microwave catalytic pyrolysis soil remediation equipment according to claim 5 is characterized in that: The cross-section of the silo is W-shaped, and a support component with a herringbone cross-section is provided at the bottom of the silo.

7. The microwave catalytic pyrolysis soil remediation equipment according to claim 1 is characterized in that: It also includes a waste gas treatment component arranged in the silo, and the waste gas treatment component includes a microwave electrodeless lamp.

Images