A heavy metal contaminated soil thermal treatment remediation device

Abstract

The application relates to a heavy metal contaminated soil heat treatment remediation device, belonging to the technical field of soil remediation, which comprises a bin body, a feeding mechanism, a conveying mechanism and a heating mechanism, the feeding mechanism is used for inputting soil into the bin body, the conveying mechanism is used for moving the soil in the bin body, and the heating mechanism is used for heating the soil; the conveying mechanism comprises a material distribution assembly, the material distribution assembly is used for directionally arranging the soil in a particle size from small to large, the heating mechanism comprises a plurality of sequentially arranged heating parts, the arrangement direction is along the trend of the particle size of the soil from small to large, the heating parts generate heat radiation, and the power of the plurality of sequentially arranged heating parts gradually increases. The application first distinguishes the soil quality according to the particle size, and then applies different powers to different parts of the soil according to the particle size for heat treatment, so that the heat treatment effect on large-particle soil is improved, and the content of particulate matters in flue gas after treatment is reduced.

Description

Technical Field

[0001] This application relates to the field of soil remediation technology, and in particular to a thermal treatment remediation device for heavy metal contaminated soil. Background Technology

[0002] Soil, as a source and sink of environmental pollutants, is characterized by a wide range of pollutant sources, diverse types, coexistence of new and old pollutants, and the combined presence of inorganic and organic pollutants. Among them, inorganic pollutants are mainly heavy metals such as cadmium, mercury, copper, lead, chromium, zinc, and nickel.

[0003] Existing technologies include various soil remediation methods, such as thermodynamic remediation, which utilizes heat conduction (e.g., thermal blankets, thermal wells, or thermal walls) or thermal radiation and radio wave heating to remediate contaminated soil. Thermal treatment processes use physical methods to desorb mercury from the soil. This involves heating the soil to vaporize the mercury, which is then condensed into liquid mercury and collected by an exhaust gas treatment system. Soil thermal desorption equipment is required for soil thermal treatment.

[0004] In related technologies, soil thermal desorption equipment includes a silo, a feeding device, a conveying device, a heating device, and an exhaust system. The feeding device sends soil raw materials into the silo, the conveying device is used to transport the soil to the heating device for heat treatment, and the exhaust system is used to discharge mercury-containing vapor from the silo.

[0005] Soil particle size is one of the important factors affecting heat treatment efficiency. Under the condition that the heating power of the heating device is certain, if the soil particles are too large, the heat conduction efficiency will be low or the treatment effect will be poor; if the particles are too small, the particulate matter content in the flue gas will increase. Summary of the Invention

[0006] To address the aforementioned issues, this application provides a thermal treatment remediation device for heavy metal contaminated soil.

[0007] The thermal treatment remediation device for heavy metal contaminated soil provided in this application adopts the following technical solution:

[0008] A thermal treatment remediation device for heavy metal contaminated soil includes a silo, a feeding mechanism, a conveying mechanism, and a heating mechanism. The feeding mechanism is used to input soil into the silo, the conveying mechanism is used to move the soil within the silo, and the heating mechanism is used to heat the soil. The conveying mechanism includes a distributing component for directionally distributing the soil in ascending order of particle size. The heating mechanism includes several heating elements arranged sequentially, with the arrangement direction following the trend of increasing soil particle size. The heating elements generate thermal radiation, and the power of the sequentially arranged heating elements gradually increases.

[0009] By adopting the above technical solution, the soil distribution component arranges the soil particles according to their size. Soil particles of different sizes will then enter different heating sections for heat treatment. For large-particle soil, a higher heating power is used, which takes into account both the energy efficiency and the treatment effect of soil particles of different sizes.

[0010] Preferably, the material distribution assembly includes a bulldozer and a screen plate. The screen plate is fixedly connected to the silo body. A feed inlet is provided above the silo body and is located above the screen plate. The bulldozer slides relative to the screen plate in the same direction as the arrangement of the heating element. The screen plate has several soil distribution holes. The diameter of the soil distribution holes gradually increases along the direction of movement of the bulldozer. The heating element is located below the screen plate.

[0011] By adopting the above technical solution, based on the filtration principle, soil separation holes of different sizes allow soil particles of different sizes to pass through accordingly. In other words, the arrangement rules of the soil separation holes can realize the distribution control of soil particles.

[0012] Preferably, the bulldozing component is a conveyor belt, and the conveying mechanism further includes a drive source for directional movement of the conveyor belt. The upper surface of the screen plate is in contact with the conveyor belt, and the conveyor belt has soil seepage holes formed thereon. The diameter of the soil seepage holes is greater than or equal to the diameter of the largest soil separating hole.

[0013] By adopting the above technical solution, the conveyor belt continuously transports soil raw materials in a belt drive manner, and the soil infiltration holes on it also provide conditions for the soil to pass smoothly through the conveyor belt.

[0014] Preferably, the conveyor belt includes reinforcing ropes and a mesh screen. Two reinforcing ropes are provided and fixedly connected to opposite sides of the mesh screen. A guide groove is provided on the screen plate, and the reinforcing ropes are embedded in the guide groove and slide along it.

[0015] By adopting the above technical solution, the reinforcing rope serves as the skeleton of the conveyor belt, ensuring the morphological stability and structural strength of the conveyor belt. The guide groove guides the reinforcing rope, improving the stability of the conveyor belt during its movement.

[0016] Preferably, side guardrails are fixedly connected to both sides of the screen plate and the opposite sides of the conveyor belt, and a height limiting baffle is fixedly connected to the end of the screen plate near the feed inlet inside the bin. The height of the gap formed between the height limiting baffle and the screen plate is less than or equal to the height of the side guardrails.

[0017] By adopting the above technical solution, the height-limiting baffle is used to scrape and limit the height of the soil on the conveyor belt, reduce the height of the soil on the conveyor belt, and reduce the difficulty of soil seepage into the material distribution component.

[0018] Preferably, a soil-cutting roller is rotatably connected to one side edge of the height-limiting baffle near the screen plate. The axis of the soil-cutting roller is perpendicular to the moving direction of the conveyor belt and parallel to the surface of the screen plate. Several cutting rods are fixedly connected to the circumference of the soil-cutting roller. The soil-cutting roller is in contact with the reinforcing rope and there is static friction between them.

[0019] By adopting the above technical solution, during the movement of the conveyor belt, the reinforcing rope causes the cutting roller to rotate through static friction, and each cutting rod takes turns tamping the soil, making the soil distribution loose as it passes through the height limit baffle.

[0020] Preferably, in the projection perpendicular to the surface of the sieve plate, the trajectory of the guide groove along the moving direction of the conveyor belt is wavy.

[0021] By adopting the above technical solution, the guide groove can make the conveyor belt oscillate periodically from side to side during the movement of the conveyor belt, thereby increasing the probability that soil particles of various sizes can successfully pass through the infiltration holes and corresponding soil separation holes.

[0022] Preferably, the drive source includes a drive motor and several conveyor rollers. The conveyor rollers are rotatably connected to the silo body. The conveyor belt passes around each conveyor roller in sequence. The drive motor is fixedly connected to the silo body. The output shaft of the drive motor is coaxially fixedly connected to one of the conveyor rollers. A positioning ring groove is formed on the circumferential surface of the conveyor roller for the insertion of reinforcing ropes.

[0023] Preferably, the conveying mechanism further includes a heated conveyor belt located below the screen plate and moving within the bin, with the moving direction perpendicular to the moving direction of the conveyor belt; the heating mechanism includes several branched partitions fixedly connected to the bin, the length direction of the branched partitions being consistent with the moving direction of the heated conveyor belt, the branched partitions being oriented along the moving direction of the conveyor belt, a single heating element being located between two adjacent branched partitions, and a magnetron being provided within the branched partition.

[0024] By adopting the above technical solution, the space formed between two adjacent bifurcated partition walls allows soil to pass through. The magnetron emits microwaves into this space to heat the soil. Since each space is relatively independent, the heating power inside can be controlled separately.

[0025] Preferably, the feeding mechanism includes an air shut-off fan, which is fixedly installed on the silo body and located at the feeding inlet.

[0026] In summary, this application includes at least one of the following beneficial technical effects:

[0027] 1. By setting up a material distribution component and several heating units, the material distribution component oriented the soil particles according to their particle size. Soil particles of different particle sizes will enter different heating units for heat treatment. For large particles, higher heating power is used, which takes into account both the energy utilization efficiency and the treatment effect of soil particles of different particle sizes.

[0028] 2. With the wavy side guardrails and the back suction trough, the conveyor belt will periodically sway left and right when it runs above the screen plate. The soil accumulated on it will be repeatedly shaken by the conveyor belt and the side guardrails, which will increase the probability of soil particles of various sizes successfully passing through the infiltration holes and the corresponding soil separation holes. Attached Figure Description

[0029] Figure 1 This is a schematic diagram illustrating the structure of the thermal treatment and remediation device for heavy metal contaminated soil in the embodiments of this application.

[0030] Figure 2 This is a schematic diagram illustrating the structure of the conveying mechanism in the embodiments of this application.

[0031] Figure 3 This is a structural schematic diagram illustrating the sieve plate and side guardrail in the embodiments of this application.

[0032] Figure 4 This is a schematic diagram illustrating the operating principle of the cutting roller in the embodiments of this application.

[0033] Explanation of reference numerals in the attached drawings: 1. Bin body; 11. First soil outlet; 12. Second soil outlet; 13. Feed inlet; 2. Feeding mechanism; 21. Hopper; 22. Airlock; 3. Conveying mechanism; 31. Height limit baffle; 32. Soil cutting roller; 321. Cutting rod; 33. Side guardrail; 34. Guide groove; 4. Material distribution assembly; 41. Screen plate; 411. Soil distribution hole; 42. Conveyor belt; 421. Reinforcing rope; 422. Surface mesh; 423. Soil seepage hole; 43. Drive source; 431. Drive motor; 432. Conveyor roller; 433. Positioning ring groove; 5. Heating mechanism; 51. Heated conveyor belt; 52. Forked partition wall. Detailed Implementation

[0034] The following is in conjunction with the appendix Figure 1-4 This application will be described in further detail.

[0035] This application discloses a thermal treatment remediation device for heavy metal contaminated soil, such as... Figure 1As shown, it includes a silo body 1, on which a feeding mechanism 2, a conveying mechanism 3 and a heating mechanism 5 are provided; the feeding mechanism 2 is used to feed the soil raw material to be processed into the silo body 1, the conveying mechanism 3 is responsible for the directional transport of the soil entering the silo body 1, and the heating mechanism 5 is used to generate heat to heat treat the soil.

[0036] like Figure 1 As shown, the top of the silo 1 has a feed inlet 13, which opens vertically. The feeding mechanism 2 includes a hopper 21 and a fan 22. The fan 22 is fixedly installed outside the silo 1 at the feed inlet 13, and the hopper 21 is fixedly installed above the fan 22. The hopper 21, the fan 22, and the silo 1 are connected sequentially from top to bottom. A large amount of soil material is poured into the hopper 21, and the fan 22 is activated, causing the soil material in the hopper 21 to fall into the silo 1 in an orderly batch.

[0037] like Figure 1 , 2 As shown in Figure 3, the conveying mechanism 3 includes a material distribution component 4, which is used to distribute the soil in an oriented manner from small to large particle size. The material distribution component 4 includes a bulldozer, a screen plate 41, and a drive source 43. The screen plate 41 is placed horizontally and has a rectangular surface. The screen plate 41 is fixedly connected inside the silo 1 and located directly below the feed inlet 13. The soil entering the silo 1 will fall onto the screen plate 41. The bulldozer is used to push the soil on the screen plate 41 along the length direction of the screen plate 41. The screen plate 41 has a number of soil distribution holes 411. The screen plate 41 is divided into four stages along its own length direction. The diameter of the soil distribution holes 411 in a single stage is the same, while the diameter of the soil distribution holes 411 in each stage along the bulldozer's bulldozer direction increases sequentially. That is, different stages can allow soil of different particle sizes to pass through and continue to fall. The bulldozing component is a conveyor belt 42. The drive source 43 includes a drive motor 431 and several conveyor rollers 432. Each conveyor roller 432 is rotatably connected to the bin body 1. The drive motor 431 is fixedly installed on the bin body 1 and its output shaft is coaxially fixedly connected to one of the conveyor rollers 432. The conveyor belt 42 passes around each conveyor roller 432 in sequence. That is, the drive source 43 controls the conveyor belt 42 to move cyclically in the form of belt drive.

[0038] like Figure 1 , 2As shown in Figure 3, the portion of the conveyor belt 42 above the screen plate 41 contacts and rubs against the upper surface of the screen plate 41. The conveyor belt 42 includes reinforcing ropes 421 and a mesh surface 422. Two reinforcing ropes 421 are provided and fixedly connected to opposite sides of the mesh surface 422. In this embodiment, the reinforcing ropes 421 are strip-shaped polyurethane, and the mesh surface 422 is woven fabric. Each conveying roller 432 has two positioning ring grooves 433. A single positioning ring groove 433 allows one reinforcing rope 421 to be embedded for positioning. The cooperation between the two can improve the stability of the conveyor belt 42 during the conveying process. The mesh surface 422 has a number of densely distributed soil seepage holes 423, and the diameter of the soil seepage holes 423 is equal to the diameter of the largest soil separating hole 411. A side guardrail 33 is formed between the edge of the screen plate 41 and the inner wall of the silo 1. The side guardrail 33 serves as a side barrier for the movement of soil on the screen plate 41. A height limiting baffle 31 is fixedly connected inside the silo 1 at the end of the screen plate 41 near the feed inlet 13. The lower edge of the height limiting baffle 31 contacts the upper edge of the side guardrail 33. The gap formed between the lower edge of the height limiting baffle 31 and the screen plate 41 and the side guardrail 33 allows soil to pass through. That is, the height of the soil on the screen plate 41 is not higher than the height between the side guardrails 33.

[0039] like Figure 2 , 3 As shown in Figure 4, a soil cutting roller 32 is rotatably connected to one edge of the height limiting baffle 31 near the screen plate 41. The axis of the soil cutting roller 32 is set horizontally and perpendicular to the direction of soil movement. Several cutting rods 321 are fixedly connected to the circumference of the soil cutting roller 32, and the length direction of each cutting rod 321 is radial to the soil cutting roller 32. The surface of the soil cutting roller 32 is sanded. The roller surface of the soil cutting roller 32 is in contact with the reinforcing rope 421. During the movement of the conveyor belt 42, the reinforcing rope 421 causes the soil cutting roller 32 to rotate through static friction. Each cutting rod 321 takes turns tamping the soil, making the soil distribution of the soil passing through the height limiting baffle 31 loose.

[0040] like Figure 2 , 3As shown in Figure 4, guide grooves 34 are provided on both the sieve plate 41 and the side guardrail 33. The guide grooves 34 allow the reinforcing rope 421 to enter and cooperate with it. The cross-section of the guide groove 34 formed between the sieve plate 41 and the side guardrail 33 is C-shaped. The guide groove 34 guides the reinforcing rope 421, thereby improving the relative positional stability between the conveyor belt 42 and the sieve plate 41 and the shape stability of the mesh 422 when the conveyor belt 42 moves. In the projection perpendicular to the surface of the sieve plate 41, the trajectory of the guide groove 34 along the moving direction of the conveyor belt 42 is wavy. That is, as the conveyor belt 42 moves forward, the guide groove 34 can make the conveyor belt 42 produce a periodic left and right swing motion, thereby increasing the probability that soil of various particle sizes can successfully pass through the infiltration holes 423 and the corresponding soil separation holes 411. A first soil outlet 11 is provided on the bin body 1 and directly below the end of the screen plate 41 away from the feed inlet 13. If the soil on the conveyor belt 42 fails to fall through the soil separation hole 411 during the process of passing through the screen plate 41, it will continue to be carried by the conveyor belt 42. After the conveyor belt 42 leaves the screen plate 41, it goes around a conveyor roller 432 and then moves downward. The soil remaining on it will fall out of the bin body 1 from the first soil outlet 11. The operator can recycle, crush and refill the bin body 1 with this part of the soil.

[0041] like Figure 1 As shown in Figure 2, the conveying mechanism 3 also includes a heated conveyor belt 51 and several branched partitions 52. The heated conveyor belt 51 is located below the screen plate 41 and moves within the silo 1. The direction of movement is horizontal and perpendicular to the direction of movement of the conveyor belt 42. The branched partitions 52 are fixedly connected to the inner wall of the silo 1. The length direction of the branched partitions 52 is consistent with the direction of movement of the conveyor belt 42. Each branched partition 52 is arranged in this manner according to the direction of movement of the conveyor belt 42 on the screen plate 41. In this embodiment, there are five branched partitions 52, and four spaces are formed between the five branched partitions 52. Each space corresponds to one stage of the screen plate 41. That is, the channel between each two adjacent branched partitions 52 allows soil falling from the soil distribution hole 411 of the same stage of the screen plate 41 to pass through. Each adjacent branching partition 52 of the chain forms a heating section. A magnetron (not shown in the figure) is installed within each branching partition 52. The magnetron emits microwaves into the space between adjacent branching partitions 52 to heat the soil. The operating power of each magnetron needs to be set so that the heating power of each heating section is different. For soil with smaller particle size (i.e., soil particles falling relatively close to the feed inlet 13), the heating power is lower, while for soil with larger particle size, the heating power is higher. A second soil outlet 12 is provided on the bin 1 below the rear end of the heated conveyor belt 51. After the heated soil is conveyed by the heated conveyor belt 51, it falls out of the bin 1 through the second soil outlet 12. The operator collects this portion of soil for subsequent processing.

[0042] The implementation principle of the thermal treatment remediation device for heavy metal contaminated soil in this application embodiment is as follows:

[0043] During the process of the conveyor belt 42 carrying soil, the sieve plate 41 with soil separation holes 411 of different sizes can be used to make soil particles of different sizes fall at different positions, thereby changing the spatial distribution of the soil. Then, different heating power is selected according to the specific situation of soil particle size, taking into account the energy efficiency and the treatment effect of soil of different particle sizes, and reducing the negative impact of each link in the heating process.

[0044] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A thermal treatment remediation device for heavy metal contaminated soil, comprising a silo (1), a feeding mechanism (2), a conveying mechanism (3), and a heating mechanism (5), wherein the feeding mechanism (2) is used to input soil into the silo (1), the conveying mechanism (3) is used to move the soil within the silo (1), and the heating mechanism (5) is used to heat the soil, characterized in that: The conveying mechanism (3) includes a material distribution component (4), which is used to arrange the soil in a direction from small to large particle size. The heating mechanism (5) includes a number of heating parts arranged in sequence, with the arrangement direction following the trend of soil particle size from small to large. The heating parts generate heat radiation, and the power of the number of heating parts arranged in sequence gradually increases. The material distribution assembly (4) includes a bulldozer and a screen plate (41). The screen plate (41) is fixedly connected to the silo body (1). The silo body (1) has a feed inlet (13) above it. The feed inlet (13) is located above the screen plate (41). The bulldozer slides relative to the screen plate (41). The sliding direction is consistent with the arrangement direction of the heating part. The screen plate (41) has several soil distribution holes (411). Along the direction of movement of the bulldozer, the diameter of the soil distribution holes (411) gradually increases. The heating part is located below the screen plate (41). The bulldozing component is a conveyor belt (42); The sieve plate (41) is provided with a guide groove (34): In the projection perpendicular to the surface of the sieve plate (41), the trajectory of the guide groove (34) along the moving direction of the conveyor belt (42) is wavy.

2. The thermal treatment and remediation device for heavy metal contaminated soil according to claim 1, characterized in that: The conveying mechanism (3) further includes a drive source (43) for directional movement of the conveyor belt (42), the upper surface of the screen plate (41) is in contact with the conveyor belt (42), and the conveyor belt (42) has soil seepage holes (423) formed on it, the diameter of the soil seepage holes (423) being greater than or equal to the diameter of the largest soil dividing hole (411).

3. The thermal treatment and remediation device for heavy metal contaminated soil according to claim 2, characterized in that: The conveyor belt (42) includes reinforcing ropes (421) and a mesh (422). There are two reinforcing ropes (421) and they are fixedly connected to the opposite sides of the mesh (422). The reinforcing ropes (421) are embedded in the guide groove (34) and slide along it.

4. The thermal treatment and remediation device for heavy metal contaminated soil according to claim 3, characterized in that: Side guardrails (33) are fixedly connected to both sides of the screen plate (41) and the conveyor belt (42). A height limiting baffle (31) is fixedly connected to one end of the silo (1) near the feed inlet (13). The height of the gap formed between the height limiting baffle (31) and the screen plate (41) is less than or equal to the height of the side guardrails (33).

5. The thermal treatment and remediation device for heavy metal contaminated soil according to claim 4, characterized in that: The height limiting baffle (31) is rotatably connected to a soil cutting roller (32) near the edge of the screen plate (41). The axis of the soil cutting roller (32) is perpendicular to the moving direction of the conveyor belt (42) and parallel to the surface of the screen plate (41). Several cutting rods (321) are fixedly connected to the circumference of the soil cutting roller (32). The soil cutting roller (32) is in contact with the reinforcing rope (421) and there is static friction between them.

6. The thermal treatment and remediation device for heavy metal contaminated soil according to claim 3, characterized in that: The drive source (43) includes a drive motor (431) and several conveyor rollers (432). The conveyor rollers (432) are rotatably connected to the silo body (1). The conveyor belt (42) passes around each conveyor roller (432) in sequence. The drive motor (431) is fixedly connected to the silo body (1). The output shaft of the drive motor (431) is coaxially fixedly connected to one of the conveyor rollers (432). A positioning ring groove (433) is provided on the circumferential surface of the conveyor roller (432). The positioning ring groove (433) is used for the insertion of the reinforcing rope (421).

7. The thermal treatment and remediation device for heavy metal contaminated soil according to claim 2, characterized in that: The conveying mechanism (3) also includes a heated conveyor belt (51), which is located below the screen plate (41) and moves within the bin (1), with the moving direction perpendicular to the moving direction of the conveyor belt (42). The heating mechanism (5) includes several bifurcated partitions (52), which are fixedly connected to the hopper (1). The length direction of the bifurcated partitions (52) is consistent with the moving direction of the heating conveyor belt (51). The bifurcated partitions (52) are oriented along the moving direction of the conveyor belt (42). A single heating part is located between two adjacent bifurcated partitions (52). A magnetron is provided inside the bifurcated partition (52).

8. A thermal treatment and remediation device for heavy metal contaminated soil according to any one of claims 1-5, characterized in that: The feeding mechanism (2) includes a shut-off fan (22), which is fixedly installed on the silo body (1) and located at the feed inlet (13).

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