A flue gas treatment system for in-situ pyrolysis of degraded soil and its use method

Abstract

The invention discloses a flue gas treatment system for in-situ pyrolysis of degraded soil, comprising a reaction chamber, a spray tower, a water reservoir and a control platform, characterized in that: the upper end of the reaction chamber is connected to an exhaust pipe, the other end of the exhaust pipe is connected to the spray tower, a plurality of groups of atomizing nozzles are in the spray tower, the upper end of the spray tower is connected to an exhaust pipe and an exhaust fan, and the lower end of the spray tower is connected to a water reservoir; a sewage filter is installed in the water reservoir, and the clean water tank is connected to the atomizing nozzle through a water pump. The invention uses an exhaust fan to allow air to pass through the exhaust pipe and the spray tower from the air inlet pipe and then be discharged from the air outlet pipe, and the flowing air brings the smoke overflowing the reaction chamber into the spray tower for air washing, and is discharged into the environment after removing particulate matter, thereby avoiding environmental pollution; the atomizing nozzle is used to atomize water to increase the contact area between water and air; the water mist and smoke are convective to further enhance the smoke removal effect; the sewage is filtered and reused to save water resources; it is easy to disassemble and transport, and is convenient to use in harsh and complex terrains.

Description

Technical Field

[0001] The present invention belongs to the technical field of mine soil remediation, and in particular relates to a flue gas treatment system for in-situ pyrolysis of degraded soil and a use method thereof. Background Art

[0002] With the rapid economic development and further advancement of urbanization, increasing irrational human activities have led to the deterioration of soil properties, the decline or even complete loss of soil comprehensive productivity or sustainable development capacity of soil quality, which has had a great impact on soil productivity and stability. In recent decades, global problems such as soil acidification, soil desertification, soil salinization and fertility decline have become increasingly serious. The total area of ​​soil degradation in my country has reached more than 4.6 million hectares, accounting for about 48% of the total land area. Soil degradation may cause ecological and secondary environmental problems such as food security and climate change.

[0003] Tailings are byproducts of mineral processing and are usually stored in tailings ponds without being treated. They are a mixture of sand, fine solid matter, water and a large amount of heavy metals. At present, with the development of my country's mining industry, tailings emissions have also increased. The cumulative tailings emissions in my country have exceeded 10 billion tons, and there are more than 12,000 existing tailings ponds. Tailings ponds where tailings are piled up occupy a large area of ​​land, including farmland and forest land. On the one hand, tailings accumulation destroys land resources; on the other hand, firstly, the tailings contain a large amount of metal sulfides, which undergo acidification and oxidation under the action of air and water to form acidic mine wastewater, bringing serious disasters to the environment; secondly, the tailings contain a large amount of toxic and harmful heavy metals. Under the action of rainwater, the heavy metals will flow into water bodies and soil with the water flow, causing serious harm to river water bodies and soil plants; at the same time, the fine particles in the tailings are brought into the air, causing air pollution. The physical and chemical properties of tailings degradation make tailings an unusable land resource. Tailings have low pH, high salt content, low water retention capacity, high concentration of heavy metals, low fertility and lack of nutrients, making them soil incapable of plant growth.

[0004] A Chinese patent (CN202110750678.1) proposes a method for in-situ pyrolysis of copper tailings using biomass: using a multi-layer covering and burning method of natural biomass and tailings, and mixing the burned biochar with the tailings. This method can fully utilize agricultural and forestry waste and tailings by-products while achieving soil matrix improvement.

[0005] However, this method does not treat the flue gas generated during the pyrolysis of biomass, and the particulate matter in the flue gas will affect the local air quality. Since the in-situ pyrolysis tailings of biomass is a technology that has only been proposed in recent years, there is currently no feasible method for treating the flue gas generated during the actual application of this technology, especially in remote mountainous areas. If the traditional flue gas treatment system is applied to this technology, there will be problems such as difficult transportation, inconvenient loading and unloading, high transportation costs, large water consumption and high treatment costs. Therefore, it is urgent to find a method to effectively treat the flue gas generated during the in-situ pyrolysis tailings of biomass.

[0006] Therefore, in order to solve the above problems, this paper proposes a flue gas treatment system for in-situ pyrolysis of degraded soil and a method of using the same. Summary of the invention

[0007] In order to solve the above technical problems, the present invention designs a flue gas treatment system for in-situ pyrolysis of degraded soil and a method of using the same, which solves the problem of purifying particulate matter in flue gas when degraded soil and biomass are pyrolyzed in situ in remote areas; the detachable flue gas treatment system is light in weight, small in size, and easy to assemble and disassemble, which solves the problem of inconvenient transportation and difficulty in transporting equipment in remote areas; the detachable flue gas treatment system is provided with a water collection tank, and the water in the tank can be used for greening on site after the flue gas is purified by a circulating pump for a period of time, thereby making full use of water resources under water-scarce conditions.

[0008] In order to achieve the above technical effects, the present invention is implemented through the following technical solutions: a flue gas treatment system for in-situ pyrolysis of degraded soil, comprising a reaction chamber, a spray tower, a water reservoir and a control platform, characterized in that: the reaction chamber is a cover with an opening at the lower end, the upper end of the reaction chamber is connected to the exhaust pipe, the other end of the exhaust pipe is connected to the side wall of the lower section of the spray tower, there are several groups of atomizing nozzles in the spray tower, the upper end of the spray tower is connected to the air outlet pipe, an exhaust fan is fixedly installed at the end of the air outlet pipe, and the lower end of the spray tower is connected to the water reservoir; the water reservoir comprises a sewage tank and a clean water tank, a sewage filter is installed between the sewage tank and the clean water tank, a water pump is installed in the clean water tank, and the water outlet of the water pump is connected to the atomizing nozzle.

[0009] Furthermore, the upper section of the reaction chamber is a cone that gradually decreases from bottom to top, and a plurality of ignition ports are arranged on the side wall of the lower section of the reaction chamber, and a sealing cover is arranged on the ignition ports.

[0010] Furthermore, the side wall of the exhaust pipe is fixedly connected to the intake pipe near the reaction chamber; the intake pipe is connected to the exhaust pipe, and the direction of the intake pipe is inclined downward; a valve for adjusting the size of the intake pipe opening is installed at the intake pipe.

[0011] Furthermore, a plurality of groups of atomizing nozzles are installed at equal intervals inside the spray tower and at the upper section where the spray tower is connected to the exhaust pipe, and the number of nozzles in each group of atomizing nozzles is not less than 5.

[0012] Furthermore, the air outlet pipe includes a vertical section and a horizontal section that are integrally connected, and a smoke sensor is installed in the air outlet pipe.

[0013] Furthermore, the inner bottom surface of the spray tower is an inclined surface, and the lowest point of the bottom surface of the spray tower is connected to the sewage pool through a pipeline.

[0014] Furthermore, a one-way valve is installed at the sewage filter.

[0015] Furthermore, a control unit is provided in the control platform, and the power supply, speaker, control panel, exhaust fan, smoke sensor, and water pump are all electrically connected to the control unit; the power supply and speaker are installed in the control platform, and the control panel is installed on the outer wall of the control platform; the control panel includes a screen and buttons.

[0016] Another object of the present invention is to provide a method for using a flue gas treatment system for in-situ pyrolysis of degraded soil, characterized in that:

[0017] (1) Start the exhaust fan, water pump and smoke sensor through the control platform;

[0018] (2) Covering the completed in-situ pyrolysis material with a reaction chamber, igniting it from the ignition port and closing the cover;

[0019] (3) Adjust the opening size of the air inlet pipe;

[0020] (4) Regulate the speed of the exhaust fan and water pump through the control platform;

[0021] (5) If the smoke sensor detects no smoke, it means that the smoke has been processed; if the smoke sensor detects a smoke signal, the speaker will immediately alarm.

[0022] The beneficial effects of the present invention are:

[0023] The present invention is based on an in-situ pyrolysis soil remediation method. The air is discharged from the air outlet pipe through the exhaust pipe and the spray tower through an exhaust fan. The flowing air brings the smoke overflowing the reaction chamber into the spray tower for air washing, and is discharged into the environment after removing particulate matter to avoid polluting the environment. The water is atomized by an atomizing nozzle to increase the contact area between water and air. The water mist and smoke are convected to further enhance the smoke removal effect. The sewage is filtered and reused to save water resources. It is easy to disassemble and transport and is convenient to use in harsh and complex terrains. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0025] Figure 1 It is a schematic diagram of the main components of the present invention;

[0026] Figure 2 It is a schematic diagram of the overall structure of the present invention;

[0027] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0028] 1. Reaction chamber; 2. Spray tower; 3. Water reservoir; 4. Control platform; 5. Ignition port; 6. Side wall of reaction chamber; 7. Cone; 8. Inlet pipe; 9. Exhaust pipe; 10. Atomizing nozzle; 11. Sewage tank; 12. Sewage filter; 13. Clean water tank; 14. Water pump; 15. Exhaust pipe; 16. Smoke sensor; 17. Exhaust fan. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] Example 1

[0031] See also Figure 1 to Figure 2 As shown, a flue gas treatment system for in-situ pyrolysis of degraded soil comprises a reaction chamber 1, a spray tower 2, a water reservoir 3 and a control platform 4, characterized in that: the reaction chamber 1 is a cover with an opening at the lower end, which covers the reactor, isolates oxygen, and is conducive to the carbonization of reactants; the upper end of the reaction chamber 1 is connected to an exhaust pipe 9, the other end of the exhaust pipe 9 is connected to the side wall of the lower section of the spray tower 2, and there are several groups of atomizing nozzles 10 in the spray tower 2; the upper end of the spray tower 2 is connected to an air outlet pipe 15, and an exhaust fan 17 is fixedly installed at the end of the air outlet pipe 15, and the exhaust fan 17 draws air, and the outside air enters from the air inlet, passes through the exhaust pipe 9 and the spray tower 2, and is discharged from the air outlet pipe 15; the lower end of the spray tower 2 is connected to the water reservoir 3; the water reservoir 3 comprises a sewage pool 11 and a clean water pool 13, a sewage filter 12 is installed between the sewage pool 11 and the clean water pool 13, a water pump 14 is installed in the clean water pool 13, and the water outlet of the water pump 14 is connected to the atomizing nozzle 10.

[0032] The upper section of the reaction chamber 1 is a cone 7 that gradually decreases from bottom to top, which is conducive to the discharge of smoke. The side wall of the lower section of the reaction chamber 1 is provided with a plurality of ignition ports 5, and ignition is ignited from the ignition ports 5. The ignition ports 5 are provided with covers to prevent outside air from entering.

[0033] The side wall of the exhaust pipe 9 is fixedly connected to the intake pipe 8 near the reaction chamber 1; the intake pipe 8 is connected to the exhaust pipe 9, and the intake pipe 8 is tilted downward to prevent outside air from entering the reaction chamber 1 to provide oxygen for combustion, which is not conducive to the carbonization of the reactants; the intake pipe 8 is installed with a valve for adjusting the opening size of the intake pipe 8, which is adjusted according to the amount of smoke.

[0034] Several groups of atomizing nozzles 10 are installed at equal intervals inside the spray tower 2 and at the upper part of the connection between the spray tower 2 and the exhaust pipe 9. The number of nozzles in each group of atomizing nozzles 10 is not less than 5, which atomize the flowing water and convect with the smoke to absorb the particulate matter in the smoke; multi-layer dense coverage ensures the adsorption efficiency.

[0035] The air outlet pipe 15 includes a vertical section and a horizontal section that are integrally connected. A smoke sensor 16 is installed in the air outlet pipe 15 to detect the smoke removal efficiency.

[0036] The inner bottom surface of the spray tower 2 is an inclined surface, and the lowest point of the bottom surface of the spray tower 2 is connected to the sewage pool 11 through a pipe. The water mist adsorbed with particulate matter gathers into a water flow, which converges at the bottom of the spray tower 2 and flows into the sewage pool 11 through a pipe.

[0037] A one-way valve is installed at the sewage filter 12 to prevent clean water from diffusing into the sewage pool 11 .

[0038] A control unit is provided in the control platform 4, and the power supply, speaker, control panel, exhaust fan 17, smoke sensor 16, and water pump 14 are all electrically connected to the control unit; the power supply and speaker are installed in the control platform 4, and the control panel is installed on the outer wall of the control platform 4, which is used to control the working speed of the exhaust fan 17 and the water pump 14; the control panel includes a screen and buttons.

[0039] Example 2

[0040] A flue gas treatment system for in-situ pyrolysis of degraded soil, wherein a reaction chamber 1 comprises a front side plate, a rear side plate, a left side plate, a right side plate, and a cover top, wherein the front side plate, the rear side plate, the left side plate, and the right side plate are all 200 cm long and 150 cm wide, and the height of the conical cover top is 70 cm; the diameter of the circular hole on the cover top is 20 cm, and the material is 310S stainless steel plate with a thickness of 0.4 mm; a section of circular threaded pipe is arranged on the cover top, with a length of 10 cm and a diameter of 12 cm, and the outer diameter of the threaded pipe is 9.729 mm, the inner diameter is 8.567 mm, the pitch is 0.907 mm, and the tooth height is 0.581 mm;

[0041] The assembled gas collection hood is set above the pile-type biomass pyrolysis weathering, which can effectively collect 95-99% of the flue gas generated during pyrolysis. The assembled exhaust pipe 9 is made of aluminum foil, each section is 3m long and 12cm in diameter, with a 10cm long threaded pipe at each end, and the specifications are compatible with the circular threaded pipe on the top of the reaction chamber 1, which is used to connect the reaction chamber 1 and the simple spray tower 2; the simple spray tower 2 is a PP spray tower 2, with a diameter of 80cm and a height of 200cm; the exhaust fan 17 uses HZ-100, with a power of 40W, and is equipped with a 100-120mm smoke pipe reducer, which is used to transport the flue gas collected by the assembled gas collection hood through the assembled exhaust pipe 9 Sent to the simple spray tower 2; there are 15 atomizing nozzles 10 in total, divided into three layers, five in each layer, one at the center of the cross section of the spray tower 2, and the other four are equidistantly distributed around it, covering the entire cross section of the spray tower 2, all of which are made of ABS and are set in the simple spray tower 2; the sewage pool 11 and the clean water pool 13 are PP water tanks, 180cm long, 80cm wide, and 150cm high; the water pump 14 model is MP-20R, with a power of 15W, set in the clean water tank, connected to the atomizing nozzle 10 through a pipeline, and provides the required water source. The power supply adopts a diesel generator model JZ4900, single-phase 220V, which is connected to the induced draft fan and circulating pump through the line.

[0042] The exhaust pipe 9 connects the reaction chamber 1 and the simple spray tower 2, and cooperates with the exhaust fan 17 to transport the flue gas overflowing from the upper end of the reaction chamber 1 to the simple spray tower 2. The atomizing nozzle 10 is arranged inside the simple spray tower 2, and is connected to the water pump 14 through a pipeline, and is used to spray water mist to settle particulate matter in the flue gas. The treated flue gas is discharged from the outlet pipe 15 at the top.

[0043] The diesel generator is the main power supply device, which is arranged beside the simple spray tower 2 and connected to the induced draft fan and the circulating pump through lines to provide the electric energy required for the above equipment to work.

[0044] The present invention solves the problem of purifying particulate matter in flue gas when degraded soil and biomass are pyrolyzed in situ in remote areas; the detachable flue gas treatment system is light in weight, small in size, and easy to assemble and disassemble, thus solving the problem of inconvenient transportation and difficult transportation of equipment in remote areas; the detachable flue gas treatment system is provided with a sewage pool 11, and the water in the sewage pool 11 can be circulated and sprayed after passing through a sewage filter 12. Since the main components of the particulate matter are unburned bark, pine branches, straw, miscanthus, etc., and there are no harmful substances, the sewage can be used on-site for irrigation and greening, making full use of water resources under water-scarce conditions.

[0045] Example 3

[0046] Directions:

[0047] Start the exhaust fan 17, water pump 14 and smoke sensor 16 through the control platform 4; use the reaction chamber 1 to cover the placed in-situ pyrolysis material, ignite it from the ignition port 5 and close the cover; adjust the opening size of the air inlet pipe; control the speed of the exhaust fan 17 and water pump 14 through the control platform 4; if the smoke sensor 16 does not detect smoke, it means that the smoke has been processed cleanly; if the smoke sensor 16 detects a smoke signal, the speaker will immediately alarm.

[0048] The present invention is based on an in-situ pyrolysis soil remediation method. The air is discharged from the air inlet pipe 8 through the exhaust pipe 9 and the spray tower 2 through the exhaust fan 17. The flowing air brings the smoke overflowing the reaction chamber 1 into the spray tower 2 for air washing, and is discharged into the environment after removing particulate matter to avoid polluting the environment; the water is atomized by the atomizing nozzle 10 to increase the contact area between water and air; the water mist and the smoke are convected to further enhance the smoke removal effect; the sewage is filtered and reused to save water resources; it is easy to disassemble and transport, and is convenient to use in harsh and complex terrains.

[0049] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0050] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A flue gas treatment system for in-situ pyrolysis of degraded soil, comprising a reaction chamber, a spray tower, a water reservoir and a control platform. Features: The reaction chamber is a cover with an opening at the lower end, the upper end of the reaction chamber is connected to an exhaust pipe, the other end of the exhaust pipe is connected to the side wall of the lower section of the spray tower, there are several groups of atomizing nozzles in the spray tower, the upper end of the spray tower is connected to an air outlet pipe, an exhaust fan is fixedly installed at the end of the air outlet pipe, and the lower end of the spray tower is connected to a water reservoir; the water reservoir includes a sewage pool and a clean water pool, a sewage filter is installed between the sewage pool and the clean water pool, a water pump is installed in the clean water pool, and the water outlet of the water pump is connected to the atomizing nozzle; The side wall of the exhaust pipe is fixedly connected to the intake pipe near the reaction chamber; the intake pipe is connected to the exhaust pipe, and the direction of the intake pipe is inclined downward; a valve for adjusting the size of the intake pipe opening is installed at the intake pipe.

2. A flue gas treatment system for in-situ pyrolysis of degraded soil according to claim 1, Features: The upper section of the reaction chamber is a cone that gradually decreases from bottom to top, and the side wall of the lower section of the reaction chamber is provided with a plurality of ignition ports, and the ignition ports are provided with sealing covers.

3. A flue gas treatment system for in-situ pyrolysis of degraded soil according to claim 1, Features: Several groups of atomizing nozzles are installed at equal intervals inside the spray tower and at the upper section where the spray tower is connected to the exhaust pipe, and the number of nozzles in each group of atomizing nozzles is not less than 5.

4. A flue gas treatment system for in-situ pyrolysis of degraded soil according to claim 1, Features: The air outlet pipe comprises a vertical section and a horizontal section which are integrally connected, and a smoke sensor is installed in the air outlet pipe.

5. A flue gas treatment system for in-situ pyrolysis of degraded soil according to claim 1, Features: The inner bottom surface of the spray tower is an inclined surface, and the lowest point of the bottom surface of the spray tower is connected to the sewage pool through a pipeline.

6. A flue gas treatment system for in-situ pyrolysis of degraded soil according to claim 1, Features: A one-way valve is installed at the sewage filter.

7. The flue gas treatment system for in-situ pyrolysis of degraded soil according to claim 1, Features: A control unit is provided in the control platform, and a power supply, a speaker, a control panel, an exhaust fan, a smoke sensor, and a water pump are all electrically connected to the control unit; the power supply and the speaker are installed in the control platform, and the control panel is installed on the outer wall of the control platform; the control panel includes a screen and buttons.

8. A method for using a flue gas treatment system for in-situ pyrolysis of degraded soil according to claim 7, Features: (1) Start the exhaust fan, water pump and smoke sensor through the control platform; (2) Covering the completed in-situ pyrolysis material with a reaction chamber, igniting it from the ignition port and closing the cover; (3) Adjust the opening size of the air inlet pipe; (4) Regulate the speed of the exhaust fan and water pump through the control platform; (5) If the smoke sensor detects no smoke, it means that the smoke has been processed; if the smoke sensor detects a smoke signal, the speaker will immediately alarm.

9. Application of a flue gas treatment system for in-situ pyrolysis of degraded soil according to any one of claims 1 to 7 in the field of mine soil remediation technology.

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