Intermittent thermal desorption furnace structure facilitating gas-solid separation

Abstract

The present application belongs to the technical field of gas-solid separation, and in particular to a batch thermal desorption furnace structure facilitating gas-solid separation. In view of the problem that the traditional continuous thermal desorption furnace can cause gas leakage, the following scheme is proposed, which comprises a main support frame, the top end of the main support frame is provided with an extension cantilever frame extending obliquely to the upper right, the end of the extension cantilever frame is fixed with a motor frame, the top end of the main support frame is fixed with a feeding mechanism, the feeding mechanism comprises a feeding cylinder in the form of a cylindrical barrel structure, a discharge pipe extending vertically downward is inserted into the circumferential outer wall of the discharge end of the feeding cylinder, an S-shaped reaction box is communicated below the discharge pipe, and a microwave heating box is arranged on the outside of the S-shaped reaction box. The present application can not only accelerate the rapid and uniform preheating of the internal soil during the thermal desorption stage, cooperate with the temporarily formed closed reaction chamber, and improve the collection efficiency of the gas, but also can reverse the rotation of the stirring screw during discharging to accelerate the discharging and prevent the discharging from being blocked.

Description

Technical Field

[0001] This invention relates to the field of gas-solid separation technology, and in particular to an intermittent thermal desorption furnace structure that facilitates gas-solid separation. Background Technology

[0002] A thermal desorption furnace is a device used for environmental remediation and waste treatment. It is mainly used to remove volatile organic compounds, heavy metals, and other harmful substances from contaminated soil, sludge, or other solid materials. During operation, the thermal desorption furnace raises the furnace temperature to the set desorption temperature through internal heating elements (such as electric heaters or combustion systems). When the solid material (such as contaminated soil, sludge, etc.) is heated, the pollutants in the solid (such as volatile organic compounds, heavy metals, etc.) begin to evaporate. The high temperature causes the pollutants to be released from the solid matrix into the gas phase. The released gas is guided to a gas collection device through a special pipeline system.

[0003] According to our research, existing thermal desorption furnace systems typically operate continuously during gas-solid separation. While this method increases speed, it also causes gas to overflow before and after the separation section. Since the extraction mechanism cannot reach these areas, gas leakage becomes quite severe. To address this issue of severe gas leakage caused by continuous thermal desorption, we propose a novel intermittent thermal desorption furnace structure that improves gas collection efficiency. Summary of the Invention

[0004] To overcome the above-mentioned shortcomings in the prior art, the present invention provides an intermittent thermal desorption furnace structure that can improve gas collection efficiency:

[0005] This invention provides an intermittent thermal desorption furnace structure for easy gas-solid separation, including a main support frame. An extended cantilever frame extending obliquely upwards and to the right is provided at the top of the main support frame, and a motor frame is fixed to the end of the extended cantilever frame. A feeding mechanism is fixed at the top of the main support frame, and the feeding mechanism includes a conveying cylinder with an overall cylindrical structure. A vertically downward-extending discharge pipe is inserted into the outer circumference of the discharge end of the conveying cylinder. An S-shaped reaction box is connected below the discharge pipe, and a microwave heating box is provided on the outside of the S-shaped reaction box. An upper cover structure and a discharge baffle are respectively provided near the upper and lower ends of the S-shaped reaction box. An air extractor is fixed near the top of the upper surface of the microwave heating box, and an air extraction pipe is inserted into the air extraction end of the air extractor. An air extraction hole with a diameter matching the air extraction pipe is opened on the outer wall of the S-shaped reaction box between the microwave heating box and the upper cover structure. A stirring screw is provided inside the middle inclined section of the S-shaped reaction box, and a synchronous discharge mechanism is provided below the motor frame.

[0006] A further feature of the present invention is that a connecting plate is fixed on the side of the main support frame near the bottom end for connecting the microwave heating box and the main support frame.

[0007] A further feature of this invention is that a grooved support plate is fixed to the top of the main support frame, and the end of the conveying cylinder near the motor frame is higher than the feeding end. A spiral guide plate is provided inside the conveying cylinder, and a funnel-shaped material collection frame is reserved on the outer circumference of the end of the conveying cylinder away from the discharge pipe near the top. By setting the conveying cylinder with an inclined structure, the dense soil remaining inside the conveying cylinder can, to a certain extent, prevent the harmful gases generated from escaping from the material collection frame during gas-solid separation, thereby improving the safety performance of the device.

[0008] A further feature of this invention is that a soil-crushing mechanism is provided in the middle of the feeding pipe, and the soil-crushing mechanism includes a hollow disc that is sleeved through the middle of the feeding pipe. The hollow disc has a flat, disc-shaped structure, and the axis of the hollow disc is perpendicular to the axis of the conveying cylinder. A vertical hole matching the inner diameter of the feeding pipe is opened near the lower end of the upper surface of the hollow disc. An anti-slip bearing is embedded in the middle of the upper surface of the hollow disc, and a crushing motor is fixed above the top of the conveying cylinder near the anti-slip bearing. A transmission rod that passes through the anti-slip bearing and extends into the hollow disc is fixed at the top of the output shaft of the crushing motor, and a cutter head is fixed at the bottom end of the transmission rod. By providing a soil-crushing mechanism that can tilt and cut the falling soil through the middle of the feeding pipe, the soil to be heated can be crushed, which is beneficial for the soil surface to be fully heated and for the rapid dissipation of gas, and also avoids the accumulation of a small amount of soil in the hollow disc.

[0009] A further feature of the present invention is that the outer circumference of the cutter head is provided with a plurality of blades that are centrally symmetrically distributed, and the length of the blades covers the entire vertical hole, so that they can act on the soil falling in all areas.

[0010] A further feature of this invention is that the microwave heating box has an observation window on the front, and a receiving device is provided below the S-shaped reaction box. In this embodiment, a conveyor belt is provided below to transport the reacted soil away in a timely manner.

[0011] A further feature of this invention is that the upper cover structure is located inside the straight pipe section at the top of the S-shaped reaction chamber, and a guide ring is fixed to the inner circumference of the straight pipe section. The lower surface of the guide ring has a beveled surface. A clamping cover is rotatably connected to the inner circumference of the straight pipe section below the beveled surface. A rotating shaft is fixed to the top of the clamping cover near the beveled surface, and a rotating shaft hole adapted to the rotating shaft is opened on the straight pipe section. A permanent magnet is fixed to the lower surface of the clamping cover, and an electromagnet adapted to the permanent magnet is embedded between the two rotating shaft holes in the straight pipe section. When the electromagnet is energized, it can generate a repulsive force on the permanent magnet, so as to firmly press the clamping cover against the lower surface of the beveled surface, thereby forming a reaction chamber with the upper surface of the discharge baffle below.

[0012] A further feature of the present invention is that coaxial bearing holes are respectively opened on the upper and lower sides of the S-shaped reaction box near the two ends of the stirring screw, and a sealed bearing adapted to the diameter of the stirring screw is embedded in each of the two bearing holes. A worm gear coaxial with the stirring screw is also fixed at the top end of the stirring screw, and a servo motor is fixed at the top end of the worm gear. The servo motor is fixed at the top end of the motor frame.

[0013] A further feature of this invention is that the synchronous discharge mechanism includes an arc-shaped hinge frame fixed below the motor frame. The arc-shaped hinge frame is an overall groove-shaped structure with its opening facing away from the worm gear. A hinge hole is reserved in the middle of the groove bottom of the arc-shaped hinge frame. A vertical fan-shaped worm gear swing rod is rotatably connected in the hinge hole. The fan-shaped worm gear swing rod includes an arc-shaped tooth segment and a swing rod segment that mesh with the worm gear. A telescopic rod is hinged to the swing rod segment. A rectangular rotating hole is opened at the bottom end of the S-shaped reaction box near the rotating shaft of the discharge baffle. A rib plate is reserved in the middle of the lower surface of the discharge baffle. The bottom end of the rib plate is hinged to the bottom end of the telescopic rod.

[0014] A further feature of the present invention is that a retaining spring is fixed at the bottom of the grooves at both the upper and lower ends of the arc-shaped hinge frame to ensure that the worm gear completes normal switching at the critical point and can smoothly mesh with the arc-shaped tooth segment.

[0015] The beneficial effects of this invention are as follows:

[0016] 1. By using a stirring screw installed in the inclined section in the middle of the S-shaped reaction chamber, and a discharge baffle that changes its opening and closing state according to its rotation direction, it is possible not only to accelerate the rapid and uniform preheating of the soil inside during the thermal desorption stage, but also to improve the gas collection efficiency by temporarily forming a closed reaction chamber. Furthermore, the stirring screw can be rotated in the opposite direction during discharge to accelerate the discharge and prevent discharge blockage.

[0017] 2. By setting an inclined conveying cylinder, the dense soil remaining inside the conveying cylinder can, to a certain extent, prevent harmful gases generated during gas-solid separation from overflowing from the material collection frame, thereby improving the safety performance of the device.

[0018] 3. By setting up a soil-crushing mechanism that runs through the middle of the feed pipe and can tilt to cut the falling soil, the soil to be heated can be crushed, which is conducive to the full heating of the soil surface and the rapid dissipation of gas, and also avoids a small amount of soil accumulating in the hollow disc.

[0019] 4. With this setup, when the stirring screw rotates clockwise for stirring, it will drive the fan-shaped worm gear swing arm to rotate until its swing arm section reaches the lowest position. At this time, under the action of the telescopic rod, the discharge baffle will be tightly closed. Conversely, it will open the discharge baffle when rotating clockwise. In this way, it can be synchronized with the stirring screw to reduce energy consumption. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0021] Figure 2 This is a side view of the present invention;

[0022] Figure 3 For the present invention Figure 2 Schematic diagram of the cross-sectional structure along line AA;

[0023] Figure 4 This is an exploded view of the soil-breaking mechanism in this invention;

[0024] Figure 5 This is a schematic diagram of the half-section three-dimensional structure of the S-shaped reaction box in this invention;

[0025] Figure 6 This is a schematic diagram of the main support frame in this invention;

[0026] Figure 7 This is a schematic diagram of the structure during thermal desorption in this invention;

[0027] Figure 8 This is a three-dimensional structural diagram of the discharge baffle in this invention.

[0028] In the diagram: 1. Main support frame; 101. Connecting tray; 2. Microwave heating box; 3. S-shaped reaction box; 301. Bearing hole; 302. Air extraction hole; 303. Rotary shaft hole; 304. Rectangular rotating hole; 4. Telescopic rod; 5. Arc-shaped hinge frame; 6. Fan-shaped worm gear swing arm; 7. Motor frame; 8. Servo motor; 9. Soil crushing mechanism; 901. Crushing motor; 902. Hollow disc; 903. Vertical hole; 904. Transmission rod; 905. Cutter disc; 906. Anti-slip bearing; 10. Feeding pipe; 11. Feeding mechanism; 12. Air extraction fan; 13. Stirring screw rod; 14. Clamping spring; 15. Electromagnet; 16. Clamping cover; 17. Guide ring; 18. Discharge baffle; 181. Rib plate. Detailed Implementation

[0029] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0030] In this embodiment, refer to Figures 1-8 An intermittent thermal desorption furnace structure for easy gas-solid separation includes a main support frame 1. An extended cantilever frame extending obliquely upwards and to the right is provided at the top of the main support frame 1, and a motor frame 7 is fixed to the end of the extended cantilever frame. A feeding mechanism 11 is fixed at the top of the main support frame 1, and the feeding mechanism 11 includes a conveying cylinder with an overall cylindrical structure. A vertically downward extending discharge pipe 10 is inserted into the outer circumference of the discharge end of the conveying cylinder. An S-shaped reaction box 3 is connected below the discharge pipe 10, and a microwave heating box 2 is provided on the outside of the S-shaped reaction box 3. An upper cover structure and a discharge baffle 18 are respectively provided near the upper and lower ends of the S-shaped reaction box 3. A vacuum pump 12 is fixed near the top of the upper surface of the microwave heating box 2. An exhaust pipe is inserted into the exhaust end of the S-shaped reaction box 3, and an exhaust hole 302 with a diameter matching the exhaust pipe is opened on the outer wall between the microwave heating box 2 and the upper cover structure. A stirring screw 13 is installed inside the middle inclined section of the S-shaped reaction box 3, and a synchronous discharge mechanism is installed below the motor frame 7. By using the stirring screw 13 installed in the middle inclined section of the S-shaped reaction box 3, and the discharge baffle 18 which changes its switching state according to its rotation direction, it can not only accelerate the rapid and uniform preheating of the soil inside during the thermal desorption stage, but also improve the gas collection efficiency by temporarily forming a closed reaction chamber. Moreover, the stirring screw 13 can be rotated in the opposite direction during discharge to accelerate the discharge and prevent discharge blockage.

[0031] Reference Figure 6 A connecting plate 101 is fixed on the side of the main support frame 1 near the bottom, which is used to connect the microwave heating box 2 and the main support frame 1.

[0032] Reference Figure 3The top of the main support frame 1 is fixed with a trough-shaped support plate, and the end of the conveying cylinder near the motor frame 7 is higher than the feeding end. The inside of the conveying cylinder is equipped with a spiral guide plate, and the outer circumference of the end of the conveying cylinder away from the discharge pipe 10 is reserved with a funnel-shaped material collection frame near the top. By setting the inclined structure of the conveying cylinder, the dense soil remaining inside the conveying cylinder can, to a certain extent, prevent the harmful gases generated from overflowing from the material collection frame during gas-solid separation, thereby improving the safety performance of the device.

[0033] Reference Figure 3 and Figure 4 A soil-crushing mechanism 9 is provided in the middle of the feed pipe 10, and the soil-crushing mechanism 9 includes a hollow disc 902 that is sleeved through the middle of the feed pipe 10. The hollow disc 902 has a flat disc-shaped structure. The axis of the hollow disc 902 is perpendicular to the axis of the conveying cylinder. A vertical hole 903 that matches the inner diameter of the feed pipe 10 is opened near the lower end of the upper surface of the hollow disc 902. An anti-slip bearing 906 is embedded in the middle of the upper surface of the hollow disc 902, and the top of the conveying cylinder is close to the anti-slip bearing 906. A crushing motor 901 is fixed above the core. A transmission rod 904 is fixed at the top of the output shaft of the crushing motor 901, which passes through the anti-slip bearing 906 and extends into the hollow disc 902. A cutter disc 905 is fixed at the bottom of the transmission rod 904. By setting a soil crushing mechanism 9 that can tilt and cut the falling soil through the middle of the feed pipe 10, the soil to be heated can be crushed, which is conducive to the full heating of the soil surface and the rapid dissipation of gas, and also avoids a small amount of soil accumulating in the hollow disc 902.

[0034] Reference Figure 4 The outer circumference of the cutter head 905 is provided with multiple blades that are centrally symmetrically distributed. The length of the blades covers the entire vertical hole 903, so that they can act on the soil falling in all areas.

[0035] Reference Figure 1 and Figure 2 The microwave heating box 2 has an observation window on the front, and the S-shaped reaction box 3 has a receiving device at the bottom. In this embodiment, a conveyor belt is installed at the bottom to transport the reacted soil away in a timely manner.

[0036] Reference Figure 3 , Figure 5 and Figure 7The upper cover structure is located inside the straight pipe section at the top of the S-shaped reaction box 3, and a guide ring 17 is fixed on the inner circumference of the straight pipe section. The lower surface of the guide ring 17 is reserved with a beveled surface. The inner circumference of the straight pipe section is rotatably connected to the clamping cover 16 below the beveled surface. A rotating shaft is fixed at the top of the clamping cover 16 near the beveled surface, and a rotating shaft hole 303 adapted to the shaft is opened on the straight pipe section. A permanent magnet is fixed on the lower surface of the clamping cover 16, and an electromagnet 15 adapted to the permanent magnet is embedded between the two rotating shaft holes 303 on the straight pipe section. When the electromagnet 15 is energized, it can generate a repulsive force on the permanent magnet to press the clamping cover 16 tightly against the lower surface of the beveled surface, thereby forming a reaction chamber with the upper surface of the discharge baffle 18 below.

[0037] Reference Figure 5 , Figure 7 and Figure 8 The S-shaped reaction box 3 has coaxial bearing holes 301 on both the upper and lower sides near the two ends of the stirring screw 13. Each bearing hole 301 is fitted with a sealed bearing that matches the diameter of the stirring screw 13. The top of the stirring screw 13 is also fixed with a worm gear that is coaxial with it. The top of the worm gear is fixed with a servo motor 8, which is fixed to the top of the motor frame 7.

[0038] Reference Figure 5 , Figure 7 and Figure 8 The synchronous discharge mechanism includes an arc-shaped hinge frame 5 fixed below the motor frame 7. The arc-shaped hinge frame 5 has an overall slotted structure with its opening facing away from the worm gear. A hinge hole is reserved in the middle of the slot bottom of the arc-shaped hinge frame 5. A vertical fan-shaped worm gear swing rod 6 is rotatably connected to the hinge hole. The fan-shaped worm gear swing rod 6 includes an arc-shaped tooth section that meshes with the worm gear and a swing rod section. The swing rod section is hinged to a telescopic rod 4. A rectangular rotating hole 304 is opened at the bottom end of the S-shaped reaction box 3 near the rotating shaft of the discharge baffle 18. Furthermore, a rib plate 181 is pre-reserved in the middle of the lower surface of the discharge baffle 18, and the bottom end of the rib plate 181 is hinged to the bottom end of the telescopic rod 4. With this setting, when the stirring screw 13 rotates clockwise to stir, it will drive the fan-shaped worm gear swing rod 6 to rotate until its swing rod section reaches the lowest position. At this time, under the action of the telescopic rod 4, the discharge baffle 18 will be tightly closed, and vice versa, the discharge baffle 18 will be opened. In this way, it can be synchronized with the stirring screw 13 to reduce energy consumption.

[0039] Reference Figure 3 Both ends of the arc-shaped hinge frame 5 are fixed with a retaining spring 14 to ensure that the worm gear can complete normal switching at the critical point and maintain smooth meshing with the arc-shaped tooth segment.

[0040] Working principle: Before use, the stirring screw 13 is controlled to rotate clockwise, which in turn drives the fan-shaped worm gear swing arm 6 to rotate until its swing arm section reaches the lowest position. At this time, under the action of the telescopic rod 4, the discharge baffle 18 will be tightly closed. Then, the electromagnet 15 is de-energized, and then the material can be fed. The soil to be heated will slowly enter the discharge pipe 10 through the conveying cylinder. At the same time, the soil crushing mechanism 9 is activated to crush the soil to be heated, which is conducive to the full heating of the soil surface and the rapid dissipation of gas. Then, the soil is concentrated in the reaction chamber. After it is full, the sealing cover 16 is closed and the heater behind the microwave heating box 2 is turned on. Then, the vacuum pump 12 is turned on to simultaneously extract gas to the gas treatment system. After heating is completed, the stirring screw 13 is reversed. At this time, under the action of the telescopic rod 4, the discharge baffle 18 is also opened to discharge the material.

[0041] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A structure for an intermittent thermal desorption furnace that facilitates gas-solid separation, comprising a main support frame (1), wherein the top of the main support frame (1) is provided with an extended cantilever frame that extends obliquely to the upper right, and a motor frame (7) is fixed to the end of the extended cantilever frame; a feeding mechanism (11) is fixed to the top of the main support frame (1), and the feeding mechanism (11) includes a conveying cylinder with an overall cylindrical barrel structure, wherein a vertically downward extending discharge pipe (10) is inserted into the outer circumference of the discharge end of the conveying cylinder; characterized in that, The feed pipe (10) is connected to an S-shaped reaction box (3) below, and a microwave heating box (2) is provided on the outside of the S-shaped reaction box (3). The S-shaped reaction box (3) is provided with a top cover structure and a discharge baffle (18) near the top and bottom ends respectively. A vacuum pump (12) is fixed on the upper surface of the microwave heating box (2) near the top. A vacuum pipe is inserted into the vacuum end of the vacuum pump (12). The outer wall of the S-shaped reaction box (3) is provided with a vacuum hole (302) that matches the diameter of the vacuum pipe between the microwave heating box (2) and the top cover structure. A stirring screw (13) is provided inside the middle inclined section of the S-shaped reaction box (3), and a synchronous discharge mechanism is provided below the motor frame (7). The upper cover structure is located inside the straight pipe section at the top of the S-shaped reaction box (3), and a guide ring (17) is fixed on the inner circumference of the straight pipe section. The lower surface of the guide ring (17) is reserved with a beveled surface. The inner circumference of the straight pipe section is rotatably connected to a clamping cover (16) below the beveled surface. A rotating shaft is fixed at the top of the clamping cover (16) near the beveled surface. A rotating shaft hole (303) adapted to the shaft is opened on the straight pipe section. A permanent magnet is fixed on the lower surface of the clamping cover (16). An electromagnet (15) adapted to the permanent magnet is embedded between the two rotating shaft holes (303) of the straight pipe section. The S-shaped reaction box (3) has coaxial bearing holes (301) on both sides near the two ends of the stirring screw (13), and sealed bearings that match the diameter of the stirring screw (13) are installed in both bearing holes (301). The top end of the stirring screw (13) is also fixed with a worm gear that is coaxial with it. The top end of the worm gear is fixed with a servo motor (8), and the servo motor (8) is fixed to the top end of the motor frame (7). The synchronous discharge mechanism includes an arc-shaped hinge frame (5) fixed below the motor frame (7). The arc-shaped hinge frame (5) is an open groove structure facing away from the worm gear. A hinge hole is reserved in the middle of the groove bottom of the arc-shaped hinge frame (5). A vertical fan-shaped worm wheel swing rod (6) is rotatably connected in the hinge hole. The fan-shaped worm wheel swing rod (6) includes an arc-shaped tooth section and a swing rod section that mesh with the worm gear. The swing rod section is hinged to a telescopic rod (4). A rectangular rotating hole (304) is opened at the bottom end of the S-shaped reaction box (3) near the rotating shaft of the discharge baffle (18). A rib plate (181) is reserved in the middle of the lower surface of the discharge baffle (18). The bottom end of the rib plate (181) is hinged to the bottom end of the telescopic rod (4). The upper and lower ends of the arc-shaped hinge frame (5) are both fixed with a retaining spring (14).

2. The intermittent thermal desorption furnace structure for easy gas-solid separation according to claim 1, characterized in that, The main support frame (1) has a connecting plate (101) fixed on its side near the bottom.

3. The intermittent thermal desorption furnace structure for easy gas-solid separation according to claim 1, characterized in that, The top of the main support frame (1) is fixed with a grooved support plate, and the end of the conveying cylinder near the motor frame (7) is higher than the feeding end. The inside of the conveying cylinder is provided with a spiral guide plate, and the outer circumference of the end of the conveying cylinder away from the feeding pipe (10) is reserved with a funnel-shaped material gathering frame near the top.

4. The intermittent thermal desorption furnace structure for easy gas-solid separation according to claim 3, characterized in that, A soil-crushing mechanism (9) is provided in the middle of the feed pipe (10), and the soil-crushing mechanism (9) includes a hollow disc (902) that is sleeved through the middle of the feed pipe (10). The hollow disc (902) has a flat disc-shaped structure. The axis of the hollow disc (902) is perpendicular to the axis of the feed cylinder. A vertical hole (903) that matches the inner diameter of the feed pipe (10) is opened on the upper surface of the hollow disc (902) near the lower end. An anti-slip bearing (906) is embedded in the middle of the upper surface of the hollow disc (902). A crushing motor (901) is fixed above the top of the feed cylinder near the anti-slip bearing (906). A transmission rod (904) that passes through the anti-slip bearing (906) and extends into the hollow disc (902) is fixed at the top of the output shaft of the crushing motor (901). A cutter disc (905) is fixed at the bottom of the transmission rod (904).

5. The intermittent thermal desorption furnace structure for easy gas-solid separation according to claim 4, characterized in that, The outer circumferential wall of the cutter head (905) is provided with a plurality of blades that are centrally symmetrically distributed, and the length of the blades covers the entire vertical hole (903).

6. The intermittent thermal desorption furnace structure for easy gas-solid separation according to claim 1, characterized in that, The microwave heating box (2) has an observation window on the front, and the S-shaped reaction box (3) has a receiving device at the bottom.

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