Wet material three-section drying system
Through the three-stage drying process and waste heat utilization, the problems of insufficient heat energy utilization and high exhaust gas purification cost in the prior art are solved, and efficient sand drying and low-cost production are achieved.
Patent Information
- Application Number
- CN202422071977.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-26
- Publication Date
- 2025-07-11
- Estimated Expiration
- 2034-08-26
AI Technical Summary
In the existing sand processing wet material drying system, the thermal energy utilization is insufficient, resulting in low drying efficiency and high exhaust gas purification cost, which increases processing cost.
The three-stage drying process is adopted, including a front-mounted auxiliary drying device, a dryer and a silo. The three-stage drying is used to use waste heat and the exhaust gas is purified through sand to reduce the dependence on high-cost air purification systems.
It improves the thermal energy utilization rate, reduces the cost of exhaust gas purification, significantly improves the drying efficiency and reduces production costs.
Smart Images
Figure CN223090997U_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of drying equipment, and specifically relates to a three-stage drying system for wet materials. Background Art
[0002] During the production process of sand, it is necessary to dry wet materials. The existing technology is to place the wet materials in a hopper, and the screw conveyor at the bottom of the hopper transports the wet materials to a drum dryer. One end of the drum of the dryer is connected to a hot blast stove, and the hot air from the hot blast stove directly enters the dryer to contact the rolling sand for drying. Then the dried sand is discharged from the discharge port of the dryer, while the hot air tail gas and moisture need to be treated through a complete set of air purification systems, including adsorption towers, desorption towers, atomizers, dust collectors, flocculation precipitation devices, etc. The dust collector generally uses a bag filter, and generally 300 - 500 are required for the whole system, costing at least 200,000 - 300,000 yuan. As a result, the processing cost of sand increases, and the existing wet material drying system for sand processing has insufficient utilization of the heat energy of the hot blast stove, reducing the sand drying efficiency. Summary of the Invention
[0003] In view of the above problems, the present invention provides a three-stage drying system for wet materials. This system performs three-stage drying on granular wet materials by making full use of waste heat, and at the same time can purify the tail gas of the hot blast stove. It can not only improve the heat energy utilization rate, but also greatly reduce the tail gas purification cost, and can achieve energy savings of more than 50%.
[0004] To achieve the above object, the technical solution adopted by the present invention is:
[0005] A three-stage drying system for wet materials, comprising a pre - auxiliary drying device, a screw conveyor, a dryer, and a silo, which are connected in sequence according to the material processing procedure;
[0006] The pre - auxiliary drying device includes a box body. Inside the box body, from top to bottom, there are: a screw circulation conveyor, a tail gas discharge pipe, a hot air pipe, a screen, and a screw conveyor; there are exhaust holes at the bottom of the tail gas discharge pipe; the bottom of the screw circulation conveyor is distributed with blanking cylinders inserted into the wet materials;
[0007] The dryer includes a rotatable outer cylinder, and an inner cylinder is arranged inside the outer cylinder. The input end of the inner cylinder is connected to a second hot blast stove; the inner wall of the outer cylinder is distributed with conveying blades; one end of the outer cylinder is connected to a feed port, and the other end is connected to a discharge port;
[0008] A baffle is arranged inside the silo, and an intake pipe for discharging waste heat tail gas is arranged below the baffle;
[0009] The input end of the hot air pipe is connected to the first hot blast stove, and the output end is connected to the outer cylinder through a pipeline; the output end of the outer cylinder is connected to the second dust collector through a pipeline, and the output end of the second dust collector is connected to the tail gas discharge pipe through a pipeline;
[0010] The outlet of the inner cylinder is connected to the first dust collector through a pipeline, and the output end of the first dust collector is respectively connected to the input end of the outer cylinder and the intake pipe through branch pipelines.
[0011] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0012] In the present invention, a three-stage drying process is adopted to dry the granular wet material. The first stage is a preposed auxiliary drying device, which performs auxiliary drying before the wet material enters the dryer, and can remove a part of the moisture in advance. The second stage is the dryer to remove most of the moisture, and the third stage is the storage bin to remove the final moisture. Not only the drying efficiency is high, but also the waste heat utilization efficiency of the hot blast stove is high. Moreover, there is no need to adopt a conventional set of high-cost air purification system to purify the tail gas. The tail gas can not only be purified by the wet material, but also plays a role in drying the wet material, greatly reducing the processing cost of the wet material.
[0013] As a further improvement of the above solution, the first hot air discharged from the first hot blast stove enters the hot air pipe, heats the hot air pipe, and then enters the outer cylinder through a pipeline to dry the sand in the outer cylinder, and uses the mixture of sand and tail gas to achieve primary purification; then the first hot air enters the second dust collector from the other end of the outer cylinder, and then returns to the tail gas discharge pipe through a pipeline, and is directly discharged into the wet sand material from the exhaust hole to complete absorption and purification;
[0014] The second hot air discharged from the second hot blast stove enters the inner cylinder of the dryer to heat the inner cylinder; then it enters the first dust collector through a pipeline, and then branches into two streams. One stream enters the storage bin through a pipeline to finally dry the sand in the storage bin, and mixes with the sand to achieve primary absorption and purification of the tail gas, and finally discharges from the top dust collector at the top of the storage bin; the other stream returns to the outer cylinder of the dryer through a pipeline, then mixes with the first hot air in the outer cylinder, heats the sand in the outer cylinder, and finally enters the tail gas discharge pipe together with the first hot air.
[0015] The technical effects of the above improvement are as follows: The hot air of the hot blast stove is fully utilized to dry the sand, improving the thermal energy utilization efficiency, and at the same time, the tail gas is purified by the sand, realizing mutual utilization, improving the sand drying efficiency and reducing the production cost.
[0016] As a further improvement of the above solution, the spiral circulating conveyor includes two conveying troughs arranged side by side, and a spiral conveyor shaft is arranged in the conveying trough; communication ports communicating with each other are provided at both ends of the two conveying troughs; the conveying directions of the two spiral conveyor shafts are different; a feed hopper is arranged above one of the conveying troughs.
[0017] The technical effect of the above improvement is that the spiral circulating conveyor can make the sand flow cyclically above the box body and automatically supplement it into the blanking cylinder at any time, ensuring that the sand in the box body can be dried more quickly and evenly, and ensuring the height stability of the sand surface, so that the tail gas purification effect remains stable.
[0018] As a further improvement of the above solution, the input end of the tail gas discharge pipe is branched and connected with a shunt pipe, and an adjustment valve is arranged on the shunt pipe; the blanking cylinders are communicated with each other through the shunt pipe.
[0019] The technical effect of the above improvement is that the waste heat tail gas can directly enter the blanking cylinder through the shunt pipe, and then rise into the spiral circulating conveyor to dry the sand flowing cyclically in the spiral circulating conveyor; the flow rate of the waste heat tail gas entering the shunt pipe can be adjusted through the adjustment valve.
[0020] As a further improvement of the above solution, blanking cylinders are distributed at the bottom of the conveying trough of the spiral circulating conveyor; the blanking cylinders include a first blanking cylinder and a second blanking cylinder; the length of the first blanking cylinder is greater than that of the second blanking cylinder; the first blanking cylinder is located between adjacent tail gas discharge pipes; the second blanking cylinder is located directly above the tail gas discharge pipe.
[0021] The technical effect of the above improvement is that the first blanking cylinder is inserted into the sand, located between adjacent tail gas discharge pipes. The sand directly above the tail gas discharge pipe descends slowly due to the blockage of the tail gas discharge pipe, while the sand between adjacent tail gas discharge pipes dries quickly, has a high downward flow frequency, and forms a high frequency of local cavities. Therefore, wet materials can quickly fall into the local cavities from the first blanking cylinder to fill them, thus making full use of the characteristics of high drying speed and high flow speed in this part to improve the drying efficiency of wet materials; the second blanking cylinder is located above the required lowest sand surface and directly above the tail gas discharge pipe. When the sand surface drops, the wet materials in the second blanking cylinder will fill this position, thus ensuring the overall height of the sand surface remains stable. Only when the sand surface height is stable can the stable efficiency of tail gas purification be achieved.
[0022] As a further improvement of the above solution, spiral blades are arranged inside the inner cylinder; heat dissipation fins are arranged on the outer wall of the inner cylinder along the axial direction.
[0023] The technical effects of the above improvements are as follows: The spiral blades can increase the residence time of the hot air in the inner cylinder. At the same time, the spiral blades can improve the absorption effect of heat energy and transfer it to the outer wall of the inner cylinder, thereby improving the heat utilization efficiency.
[0024] As a further improvement of the above solution, the output end of the screw conveyor is connected to the first elevator. A transition hopper is arranged at the output end of the first elevator. A conveyor belt is arranged below the transition hopper. The output end of the conveyor belt is connected to the feed inlet; the discharge port is connected to the second elevator, and the second elevator is connected to the feed port of the silo.
[0025] The technical effects of the above improvements are as follows: The use of elevators and conveyor belts can achieve stable transportation of sand in the whole system.
[0026] As a further improvement of the above solution, the baffle is an upwardly convex arc plate.
[0027] The technical effects of the above improvements are as follows: The use of an upwardly convex arc plate can block the outlet of the intake pipe, preventing the sand in the silo from entering the intake pipe. At the same time, the arc plate can promote the downward flow of the hot air discharged from the intake pipe, thereby improving the drying effect of the silo.
[0028] As a further improvement of the above solution, a dust collector is arranged at the upper end of the silo.
[0029] The technical effects of the above improvements are as follows: It is convenient for the hot air entering the silo through the intake pipe to be discharged, and the tail gas is purified once.
[0030] As a further improvement of the above solution, an annular heat dissipation plate is arranged on the hot air pipe.
[0031] The technical effects of the above improvements are as follows: Improve the heat energy utilization rate of the hot air pipe.
[0032] As a further improvement of the above solution, a vibrator is arranged on the side of the screen.
[0033] The technical effects of the above improvements are as follows: Controlling the vibration of the screen through the vibrator can promote the flow of sand and prevent the sand from blocking. Brief Description of the Drawings
[0034] Figure 1 It is a schematic diagram of the overall structure of this system.
[0035] Figure 2 It is a schematic diagram of a structure of the pre - auxiliary drying device.
[0036] Figure 3 It is a schematic diagram of a second structure of the pre - auxiliary drying device.
[0037] Figure 4This is the third structural schematic diagram of the front auxiliary drying device.
[0038] Figure 5 This is the bottom view of the tail gas discharge pipe.
[0039] Figure 6 This is the structural schematic diagram of the hot air pipe.
[0040] Figure 7 This is the position distribution relationship diagram of the tail gas discharge pipe and the hot air pipe.
[0041] Figure 8 This is the structural schematic diagram of the spiral circulation conveyor.
[0042] Figure 9 This is the structural schematic diagram of the dryer.
[0043] Figure 10 This is the end face sectional view structural schematic diagram of the dryer.
[0044] Figure 11 This is the structural schematic diagram of the silo.
[0045] In the figure: 1. First hot blast stove; 2. Screw conveyor; 3. Front auxiliary drying device; 4. First elevator; 5. Transition hopper; 7. Second hot blast stove; 8. Dryer; 9. First dust collector; 10. Second elevator; 11. Top-of-silo dust collector; 12. Silo; 13. Air lock; 14. Second dust collector; 15. Inlet pipe; 16. Baffle; 17. Feed port; 18. Discharge conveyor belt; 31. Spiral circulation conveyor; 32. Feed hopper; 33. Box body; 34. First blanking cylinder; 35. Second blanking cylinder; 36. Tail gas discharge pipe; 37. Hot air pipe; 38. Screen; 39. Vibrator; 40. Diverging pipe; 41. Control valve; 81. Outer cylinder; 82. Conveyor blade; 83. Heat sink; 84. Inner cylinder; 85. Spiral blade; 86. Discharge port; 87. Feed port; 88. Driving wheel; 89. Driving motor; 90. Support seat; 91. First fixed cylinder; 92. Second fixed cylinder; 93. Tail gas pipe; 311. Conveyor trough; 312. Spiral conveyor shaft; 313. Communication port; 314. Gear; 361. Exhaust hole; 371. Heat dissipation plate. Detailed implementation manners
[0046] In order to enable those skilled in the art to better understand the technical solution, the present invention will be described in detail below in conjunction with embodiments. The description of this part is only exemplary and explanatory, and should not have any restrictive effect on the protection scope of the present invention.
[0047] Embodiment 1:
[0048] As Figures 1-9As shown in the figure, the specific solution of this embodiment is as follows: A three-stage drying system for wet materials includes a pre-aid drying device 3, a screw conveyor 2, a dryer 8, and a silo 12 that are sequentially connected according to the material processing process;
[0049] Specifically, the bottom of the pre-aid drying device 3 is connected to the screw conveyor 2. The output end of the screw conveyor 2 is connected to the input end of the first elevator 4, and an air lock 13 is also provided at the input end of the first elevator 4; A transition hopper 5 is arranged below the output end of the first elevator 4 for collecting the sand output from the first elevator 4. The lower outlet of the transition hopper 5 is designed with a conveyor belt, and the sand is conveyed into the dryer 8 through the conveyor belt; After the sand is dried in the dryer 8, it is discharged from the discharge port 86 into the second elevator 10, and the second elevator 10 lifts the sand up and sends it into the silo 12; After the sand is collected and dried in the silo 12, it falls into the discharge conveyor belt 18 and is conveyed out; An air lock 13 is arranged above the discharge conveyor belt 18.
[0050] In the present invention, the pre-aid drying device has three structures:
[0051] Such as Figure 2 、 5 -8 shows the first structure of the pre-aid drying device, which includes a box body 33 for holding wet materials. Inside the box body 33, from top to bottom, there are: a spiral circulating conveyor 31, an exhaust gas discharge pipe 36, a hot air pipe 37, and a screen 38; The bottom outlet of the box body 33 is provided with a screw conveyor 2; An exhaust hole 361 is provided at the bottom of the exhaust gas discharge pipe 36; The bottom of the spiral circulating conveyor 31 is distributed with blanking cylinders inserted into the wet materials; One end of the hot air pipe 37 is connected to the first hot blast stove 1; The inlet of the exhaust gas discharge pipe 36 is connected to the pipeline of the hot air exhaust gas.
[0052] Specifically, the upper end of the box body 33 is open, the lower end is in the shape of a hopper, and the bottom outlet is designed with a screw conveyor 2; The box body 33 is used to hold wet sand materials; The wet materials first enter the spiral circulating conveyor 31 from the feed hopper 32, and the spiral circulating conveyor 31 evenly conveys the sand into the box body 33; A layer of hot air pipes 37 is distributed inside the box body 33. The hot air pipes 37 are formed by arranging multiple pipes side by side to form a frame structure. One end is connected to the first hot blast stove 1, and the other end extends out from the side wall of the box body 33; Heat dissipation plates 371 can be added to the hot air pipes 37 to improve the heat dissipation effect; A layer of exhaust gas discharge pipes 36 is distributed above the hot air pipes 37; The exhaust gas discharge pipes 36 are formed by arranging multiple pipes side by side to form a frame structure. One end extends out through the side wall of the box body 33; Exhaust holes 361 are evenly distributed at the bottom of the exhaust gas discharge pipes 36, which are used to discharge the high-temperature exhaust gas into the wet sand materials to dry the sand while purifying the exhaust gas; The exhaust gas discharge pipes 36 and the hot air pipes 37 are installed in a criss-cross manner.
[0053] Above the exhaust pipe 36 is the spiral circulation conveyor 31; the structure of the spiral circulation conveyor 31 is basically the same as that of the double spiral conveyor 2; the spiral circulation conveyor 31 includes two conveying troughs 311 arranged side by side, and a spiral conveyor shaft 312 is arranged in the conveying trough 311; communication ports 313 that communicate with each other are opened at both ends of the two conveying troughs 311; the conveying directions of the two spiral conveyor shafts 312 are different; a feed hopper 32 is arranged above one of the conveying troughs 311; one end of one spiral conveyor shaft 312 is connected to a motor, and the other end of the spiral conveyor shaft 312 is driven by a gear 314.
[0054] The wet material enters one of the conveying troughs 311 from the feed hopper 32, is conveyed to the end along with the spiral conveyor shaft 312 and then enters the other conveying trough 311 from the communication port 313 at this end. The spiral conveyor shaft 312 in this conveying trough 311 has the opposite conveying direction, conveys the wet material to the other end, then passes through the communication port 313 at this end and enters the previous conveying trough 311, so that the wet material circulates and flows in the spiral circulation conveyor 31. When the sand in one of the blanking cylinders at the bottom of the conveying trough 311 falls, the wet material in the spiral circulation conveyor 31 immediately fills into the blanking cylinder.
[0055] The number of spiral circulation conveyors 31 is determined according to the area size of the upper port of the box body 33. Generally, 2-3 are used to achieve the effect of evenly discharging the wet material; blanking cylinders are distributed at the bottom of the conveying trough 311 of the spiral circulation conveyor 31, and the blanking cylinders are inserted into the wet material.
[0056] In the present invention, the combination of the spiral circulation conveyor 31, the blanking cylinder, the exhaust pipe 36, and the hot air pipe 37 has the following technical effects:
[0057] The hot air pipe 37 directly introduces the hot air of the first hot blast stove 1 to dry the wet material in the box body 33; the hot air enters the dryer at the rear end of the hot air pipe 37 for secondary utilization; then it returns to the exhaust pipe 36 for tertiary utilization; at the same time, the exhaust pipe 36 can not only directly dry the sand by using the waste heat of the exhaust gas, but also absorb and purify the exhaust gas by using the wet sand material; the moisture in the sand has a good absorption effect on the particulate matter in the exhaust gas, and the gaps between the sands form a honeycomb structure to block and filter the exhaust gas; after the wet material absorbs enough particulate matter in the exhaust gas, it drops to the bottom of the box body 33 as the sand flows, and the new wet material falls down to absorb the exhaust gas newly, continuously, which has a good effect on the purification treatment of the exhaust gas.
[0058] The sand directly above the exhaust gas discharge pipe 36 descends slowly due to the obstruction of the exhaust gas discharge pipe 36, while the sand between adjacent exhaust gas discharge pipes 36 dries quickly, has a high downward flow frequency, and forms a high local cavity frequency. Therefore, the wet material can quickly fall from the first feeding cylinder 34 into the local cavity to fill it, thus making full use of the characteristics of high drying speed and high flow speed in this part to improve the drying efficiency of the wet material; at the same time, the flowing wet material is used to purify the exhaust gas.
[0059] While the exhaust gas enters the wet sand through the exhaust gas discharge pipe 36 and is absorbed and purified, the exhaust gas will rise and enter the spiral circulation conveyor 31 from the feeding cylinder to dry the sand circulating in the spiral circulation conveyor 31, improving the drying effect.
[0060] A layer of screen 38 is arranged below the hot air pipe 37, and a vibrator 39 can be installed on the screen 38; when the moisture in the wet material is reduced to a certain extent, the cohesion between the sands decreases, and they will fall into the spiral conveyor 2 from the screen 38; the vibrator 39 can further promote the falling speed of the sands and prevent the sands from clogging.
[0061] As Figure 3 shown, it is the second structure of the pre - auxiliary drying device 3. On the basis of the first structure, the input end of the exhaust gas discharge pipe 36 is branched and connected with a shunt pipe 40, and a regulating valve 41 is arranged on the shunt pipe 40; the feeding cylinders are interconnected through the shunt pipe 40.
[0062] The waste heat exhaust gas can directly enter the feeding cylinder through the shunt pipe 40, then rise and enter the spiral circulation conveyor 31 to dry the sand circulating in the spiral circulation conveyor 31; the flow rate of the waste heat exhaust gas entering the shunt pipe 40 can be adjusted through the regulating valve 41.
[0063] As Figure 4 shown, it is the third structure of the pre - auxiliary drying device 3. On the basis of the first structure, the feeding cylinder includes a first feeding cylinder 34 and a second feeding cylinder 35; the length of the first feeding cylinder 34 is greater than that of the second feeding cylinder 35; the first feeding cylinder 34 is located between adjacent exhaust gas discharge pipes 36; the second feeding cylinder 35 is located directly above the exhaust gas discharge pipe 36.
[0064] The first blanking cylinder 34 is inserted into the sand, located between adjacent tail gas discharge pipes 36. The sand directly above the tail gas discharge pipes 36 has a slow downward speed due to the obstruction of the tail gas discharge pipes 36. While the sand between adjacent tail gas discharge pipes 36 has a high drying speed, a high downward flow frequency, and a high frequency of forming local cavities. Therefore, the wet material can quickly fall from the first blanking cylinder 34 into the local cavities for filling, thus making full use of the characteristics of high drying speed and high flow speed in this part to improve the drying efficiency of the wet material. The second blanking cylinder 35 is located above the required lowest sand surface and directly above the tail gas discharge pipes 36. When the sand surface drops, the wet material in the second blanking cylinder 35 will fill this position, thereby ensuring the overall height of the sand surface remains stable. Only when the sand surface height is stable can the stable efficiency of tail gas purification be achieved.
[0065] Working principle of the pre - installed auxiliary drying device 3:
[0066] The wet sand material first enters the spiral circulation conveyor 31 from the feed hopper 32 and circulates in the spiral circulation conveyor 31. When the sand in one of the blanking cylinders drops, the wet material in the spiral circulation conveyor 31 will immediately fill into this blanking cylinder, ensuring that the sand can quickly fill each blanking cylinder. While achieving uniform distribution, it improves the drying efficiency of the sand.
[0067] The first blanking cylinder 34 is inserted into the sand, located between adjacent tail gas discharge pipes 36. The sand directly above the tail gas discharge pipes 36 has a slow downward speed due to the obstruction of the tail gas discharge pipes 36. While the sand between adjacent tail gas discharge pipes 36 has a high drying speed, a high downward flow frequency, and a high frequency of forming local cavities. Therefore, the wet material can quickly fall from the first blanking cylinder 34 into the local cavities for filling, thus making full use of the characteristics of high drying speed and high flow speed in this part to improve the drying efficiency of the wet material. The second blanking cylinder 35 is located above the required lowest sand surface and directly above the tail gas discharge pipes 36. When the sand surface drops, the wet material in the second blanking cylinder 35 will fill this position, thereby ensuring the overall height of the sand surface remains stable. Only when the sand surface height is stable can the stable efficiency of tail gas purification be achieved.
[0068] While the tail gas enters the wet sand material through the tail gas discharge pipes 36 and is absorbed and purified, the tail gas will rise and enter the spiral circulation conveyor 31 from the blanking cylinder, drying the sand circulating in the spiral circulation conveyor 31 to improve the drying effect.
[0069] The hot air pipe 37 dries the sand, and the tail gas discharge pipe 36 discharges into the wet material from the exhaust hole 361 at the bottom. While the wet material purifies the tail gas, the wet material absorbs the waste heat of the tail gas for drying; the purpose of the tail gas discharge pipe 36 being located above the hot air pipe 37 is to ensure that the tail gas can contact the wet material to improve the purification effect; as the moisture in the sand decreases, the fluidity of the sand increases, and finally it falls into the screw conveyor 2 from the screen 38;
[0070] This equipment is used for the pre-drying process in the sand wet material drying system. Through this equipment, about 65 - 75% of the moisture in the wet material can be removed.
[0071] As Figures 9-10 shown, it is the structure of the dryer. The dryer includes a support base 90, and a rotatable outer cylinder 81 is arranged on the support base 90; an inner cylinder 84 is coaxially arranged inside the outer cylinder 81, and the sandwich cavity between the outer cylinder 81 and the inner cylinder 84 is used for drying materials; the input end of the inner cylinder 84 is connected to the second hot blast stove 7, and the output end is connected to the tail gas pipeline 93 through a rotary joint; the tail gas pipeline 93 is directly or indirectly connected to the input end of the outer cylinder 81 through a pipeline; conveying blades 82 are distributed on the inner wall of the outer cylinder 81; heat dissipation fins 83 are arranged on the outer wall of the inner cylinder 84 along the axial direction; the input end of the outer cylinder 81 is connected to the feed inlet 87, and the output end is connected to the discharge outlet 86.
[0072] Specifically, the dryer 8 also includes a support base 90, a driving wheel 88 is arranged on the support base 90, and the driving wheel 88 is connected to the driving motor 89 through a chain or a belt; there are two groups of driving wheels 88, two in each group, and the two groups of driving wheels 88 respectively support both ends of the outer cylinder 81; an annular track or a toothed ring is arranged on the outer wall of the outer cylinder 81 to cooperate with the driving wheel 88; the outer cylinder 81 is driven to rotate by the driving wheel 88, and the inner cylinder 84 and the outer cylinder 81 can be fixedly connected to form synchronous rotation. At this time, the inner cylinder 84 and the outer cylinder 81 are connected to each other through internal connecting rods, and both ends of the inner cylinder 84 are connected to other pipelines through rotary joints; if the outer cylinder 81 and the inner cylinder 84 are not connected to each other, only the outer cylinder 81 rotates and the inner cylinder 84 does not rotate. At this time, a rotary joint is not required; one end of the inner cylinder 84 is connected to the second hot blast stove 7, and the other end is connected to a pipeline for discharging the tail gas;
[0073] The purpose of the inner cylinder 84 is to generate heat. Spiral blades 85 can be designed inside the inner cylinder 84 to improve the heat absorption effect of the inner cylinder 84 on the hot air; the pitch of the spiral blades 85 gradually increases from the input end to the output end of the inner cylinder 84 to improve the thermal energy utilization rate and the temperature uniformity of the inner cylinder.
[0074] The inner wall of the outer cylinder 81 is provided with a heat preservation coating, which can improve the heat preservation and heat insulation effect, and the heat preservation coating can adopt nano-ceramic particles.
[0075] The outer wall of the inner cylinder 84 is provided with heat dissipation fins 83 to improve the heat dissipation effect of the inner cylinder 84; the sandwich cavity between the outer cylinder 81 and the inner cylinder 84 is used for drying the wet sand material; the conveying blades 82 are evenly distributed on the inner wall of the outer cylinder 81.
[0076] As the outer cylinder 81 rotates, the sand flows in the outer cylinder 81 and is conveyed forward through the conveying blades 82; at the same time, the conveying blades 82 also drive the sand to move above the outer cylinder 81 with the rotation of the outer cylinder 81 and then fall onto the inner cylinder 84. The heat dissipation fins 83 on the outer wall of the inner cylinder 84 can block the sand, increase the residence time of the sand on the inner cylinder 84, and improve the drying effect of the sand.
[0077] The two ends of the outer cylinder 81 are respectively rotatably connected to a first fixed cylinder 91 and a second fixed cylinder 92; the fixed cylinders are installed on the support base 90 and do not rotate. There is a feed port 87 above the first fixed cylinder 91, and a discharge port 86 is arranged at the bottom or end of the second fixed cylinder 92; an air outlet is designed above the second fixed cylinder 92; an inclined plate can be designed in the first fixed cylinder 91 to guide the sand entering from the feed port 87 so that the sand falls into the outer cylinder 81.
[0078] As Figure 11 shown, it is the structure of the silo. A baffle 16 is arranged in the silo 12, and the outlet of the intake pipe 15 is arranged below the baffle 16;
[0079] Specifically, the silo 12 is of a cavity structure, used for storing sand and drying the sand finally; there are a feed port 17 and a dust collector 11 on the top of the silo 12; there is a discharge port at the bottom, and there is a discharge conveyor belt 18 below the discharge port; there is a baffle 16 in the middle of the silo 12 to prevent the sand from falling into the pipe orifice of the intake pipe 15; the outlet of the intake pipe 15 is located below the baffle 16 and is used for discharging the tail gas into the silo 12 for drying; the baffle 16 is preferably an arc plate, generally a hemispherical structure.
[0080] The output end of the outer cylinder 81 is connected to the second dust collector 14 through a pipeline, and the output end of the second dust collector 14 is connected to the tail gas discharge pipe 36 through a pipeline; generally, both the first dust collector 9 and the second dust collector 14 adopt bag dust collectors or cyclone dust collectors.
[0081] The outlet of the inner cylinder 84 is connected to the first dust collector 9 through a pipeline, and the output end of the first dust collector 9 is respectively connected to the input end of the outer cylinder 81 and the intake pipe 15 through branch pipelines.
[0082] The conveying process of the sand:
[0083] The wet sand first enters the spiral circulating conveyor 31 from the feed hopper 32 and circulates within the spiral circulating conveyor 31; when the sand in one of the blanking cylinders drops, the wet material in the spiral circulating conveyor 31 will immediately fill into this blanking cylinder, ensuring that the sand can fill each blanking cylinder as soon as possible. While achieving uniform distribution, the drying efficiency of the sand is improved;
[0084] The hot air pipe 37 dries the sand. The tail gas discharge pipe 36 discharges into the wet material from the exhaust hole 361 at the bottom. While the wet material purifies the tail gas, the wet material absorbs the waste heat of the tail gas for drying; the purpose of the tail gas discharge pipe 36 being located above the hot air pipe 37 is to ensure that the tail gas can contact the wet material to improve the purification effect; as the moisture in the sand decreases, the fluidity of the sand increases, and finally it falls from the screen 38 into the spiral conveyor 2; the pre - installed auxiliary drying device 3 can remove about 65 - 75% of the moisture in the wet material;
[0085] The spiral conveyor 2 conveys the sand to the first elevator 4, then it falls into the transition hopper 5, and then is conveyed to the dryer 8 through the conveyor belt; the sand enters the outer cylinder 81 of the dryer 8 and tumbles while moving forward, and the inner cylinder 84 emits heat to heat and dry the sand; the dryer 8 can remove the remaining about 24 - 33% of the moisture in the sand;
[0086] After the sand comes out of the dryer 8, it is conveyed to the silo 12 through the second elevator 10. The exhaust gas is discharged from the intake pipe 15 in the silo 12. The waste heat of the exhaust gas is used to conduct a final drying of the sand, and the exhaust gas can also be subjected to a certain absorption and purification treatment in the silo 12; the silo 12 can remove the remaining about 1 - 2% of the moisture in the sand; finally, it falls from the bottom of the silo 12 onto the discharge conveyor belt 18 and is conveyed out.
[0087] The conveying process of the hot air:
[0088] The first hot air discharged from the first hot blast stove 1 enters the hot air pipe 37 and heats the hot air pipe 37; then the hot air enters the outer cylinder 81 through the pipeline and directly contacts and heats and dries the sand in the outer cylinder 81; and the sand is used to absorb and treat the tail gas particulate matter; then the tail gas enters the second dust collector 14 from the other end of the outer cylinder 81 for the first time, and then returns to the tail gas discharge pipe 36 in the pre - installed auxiliary drying device 3 through the pipeline and is directly discharged into the wet sand material from the tail gas discharge pipe 36 to complete absorption and purification;
[0089] The hot air discharged from the second hot blast stove 7 enters the inner cylinder 84 of the dryer 8 to heat the inner cylinder 84; then it enters the first dust collector 9 through a pipeline for the first time, and then branches into two streams. One stream enters the silo 12 through a pipeline to finally dry the sand in the silo 12, and performs a certain absorption and purification treatment on the tail gas, and finally discharges from the dust collector 11 at the top of the silo 12; the other stream returns to the outer cylinder 81 of the dryer 8 through a pipeline, and then mixes with the first stream of hot air in the outer cylinder 81 to heat the sand in the outer cylinder 81, and finally enters the tail gas discharge pipe 36 together with the first stream of hot air to heat and dry the wet material and perform self-purification treatment.
[0090] During the transportation of hot air through the pipeline, a blower can be installed on the pipeline to promote the flow of hot air.
[0091] The target effect of the present invention: The drying production capacity can be increased by more than one time, the comprehensive drying cost can be reduced by more than 50%, and the emission reduction effect can reach more than 80%.
[0092] The analysis principle for achieving the effect is as follows:
[0093] 1. Principle of emission reduction:
[0094] The traditional dryer uses a low-pressure large blower, with an air volume of 10,000 - 50,000 cubic meters per hour. After adopting the present invention, only 10% of the original amount needs to be discharged, and a large amount of air returns to the front end of drying. Therefore, the emission reduction effect reaches more than 80%. The pressure of the bag dust removal equipment at the rear end is reduced by 90%, the cost of the dust removal equipment can also be greatly reduced, the service life is increased, and the purpose of emission reduction is achieved.
[0095] 2. Principle of production capacity improvement:
[0096] The inlet temperature at the front end of the traditional dryer is about 600 degrees Celsius, 300 degrees Celsius in the middle, and the tail gas exhaust takes away about 100 degrees Celsius of moisture. After adopting the present invention, the overall temperature inside the dryer can be maintained above 300 - 400 degrees Celsius, the drying effect is doubled, and the drying output can be easily increased by more than one time. Therefore, the production capacity can be increased by more than one time with the same original equipment.
[0097] 3. Principle of reducing the comprehensive drying cost by more than 50%:
[0098] The present invention uses the same calorific value and the same raw materials. By doubling the production capacity, the power consumption does not need to increase. Therefore, the comprehensive cost can be reduced by more than 50%.
[0099] 4. Principle of assisting in reducing raw material cost:
[0100] Traditional drying equipment uses biomass pellets, which cost about 1,000 yuan per ton at the factory. The present invention can be used to directly burn biomass, which costs 300-400 yuan per ton at the factory. The calorific value is equivalent to that of biomass pellets, and the price is more than half lower, so the cost of raw materials is greatly reduced.
[0101] The dust content of the dried product is also significantly reduced compared to traditional drying methods.
[0102] Due to the large return air volume, a cyclone dust collector is installed on the return duct, and the cyclone dust removal is performed multiple times, which is much better than the traditional one-time dust removal.
[0103] In summary, the energy-saving effect of the present invention is very significant, and the drying effect can be easily achieved, which can more than double the drying capacity. It can also greatly reduce emissions and reduce the overall cost by 50%. It achieves multiple goals at one stroke and is worthy of vigorous promotion.
[0104] It should be noted that, in this article, the terms include, contain or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. Specific examples are used in this article to illustrate the principle and implementation of the technical solution of the present invention. The above examples are only used to help understand the method of the present invention and its core idea. The above is only a preferred implementation of the present invention. It should be pointed out that due to the limitations of textual expression and the objective existence of infinite specific structures, for ordinary technicians in this technical field, without departing from the principle of the present invention, several improvements, modifications or changes can be made, and the above technical features can also be combined in an appropriate manner; these improvements, modifications, changes or combinations, or the direct application of the concept and technical solution of the invention to other occasions without improvement, should be regarded as the protection scope of the present invention.
Claims
1. A three-stage drying system for wet materials, characterized in that, It includes a pre - auxiliary drying device (3), a screw conveyor (2), a dryer (8), and a silo (12) that are connected in sequence according to the material processing process; The pre - auxiliary drying device (3) includes a box body (33). Inside the box body (33) from top to bottom are: a screw - type circulating conveyor (31), an exhaust gas discharge pipe (36), a hot air pipe (37), a screen (38), and a screw conveyor (2); an exhaust hole (361) is provided at the bottom of the exhaust gas discharge pipe (36); a first blanking cylinder (34) inserted into the wet material is distributed at the bottom of the screw - type circulating conveyor (31); The dryer (8) includes a rotatable outer cylinder (81). An inner cylinder (84) is arranged inside the outer cylinder (81). The input end of the inner cylinder (84) is connected to the second hot - air furnace (7); conveying blades (82) are distributed on the inner wall of the outer cylinder (81); one end of the outer cylinder (81) is connected to the feed port (87), and the other end is connected to the discharge port (86); A baffle (16) is arranged inside the silo (12), and an intake pipe (15) for discharging the waste heat exhaust gas is arranged below the baffle (16); The input end of the hot air pipe (37) is connected to the first hot - air furnace (1), and the output end is connected to the outer cylinder (81) through a pipeline; the output end of the outer cylinder (81) is connected to the second dust collector (14) through a pipeline, and the output end of the second dust collector (14) is connected to the exhaust gas discharge pipe (36) through a pipeline; The outlet of the inner cylinder (84) is connected to the first dust collector (9) through a pipeline, and the output end of the first dust collector (9) is respectively connected to the input end of the outer cylinder (81) and the intake pipe (15) through a branch pipeline.
2. The wet material three-stage drying system according to claim 1, wherein The first hot air discharged from the first hot - air furnace (1) enters the hot air pipe (37), heats the hot air pipe (37), and then enters the outer cylinder (81) through a pipeline to dry the sand inside the outer cylinder (81), and uses the mixture of sand and exhaust gas to achieve primary absorption and purification of exhaust gas particles; then the first hot air enters the second dust collector (14) from the other end of the outer cylinder (81), and then returns to the exhaust gas discharge pipe (36) through a pipeline, and is directly discharged into the wet sand through the exhaust hole (361) to complete absorption and purification; The second hot air discharged from the second hot - air furnace (7) enters the inner cylinder (84) of the dryer (8) to heat the inner cylinder (84); then it enters the first dust collector (9) through a pipeline, and then branches into two streams. One stream enters the silo (12) through a pipeline to finally dry the sand in the silo (12) and mix with the sand to achieve absorption and purification, and finally is discharged from the top - of - silo dust collector (11) at the top of the silo (12); the other stream returns to the outer cylinder (81) of the dryer (8) through a pipeline, then mixes with the first stream of hot air inside the outer cylinder (81), heats the sand inside the outer cylinder (81), and finally enters the exhaust gas discharge pipe (36) together with the first stream of hot air.
3. The wet material three-stage drying system according to claim 1, characterized in that The spiral circulating conveyor (31) includes two conveying troughs (311) arranged side by side, and a spiral conveying shaft (312) is arranged in the conveying trough (311); communication ports (313) that communicate with each other are formed at both ends of the two conveying troughs (311); the conveying directions of the two spiral conveying shafts (312) are different; a feed hopper (32) is arranged above one of the conveying troughs (311).
4. A wet material three-stage drying system according to claim 1, wherein, The input end of the tail gas discharge pipe (36) is branched and connected with a shunt pipe (40), and a regulating valve (41) is arranged on the shunt pipe (40); the blanking cylinders are communicated with each other through the shunt pipe (40).
5. A wet material three-stage drying system according to claim 1, characterized in that, Blanking cylinders are distributed at the bottom of the conveying trough (311) of the spiral circulating conveyor (31); the blanking cylinders include a first blanking cylinder (34) and a second blanking cylinder (35); the length of the first blanking cylinder (34) is greater than that of the second blanking cylinder (35); the first blanking cylinder (34) is located between adjacent tail gas discharge pipes (36); the second blanking cylinder (35) is located directly above the tail gas discharge pipe (36).
6. The wet material three-stage drying system according to claim 1, characterized in that, A spiral blade (85) is arranged in the inner cylinder (84); heat dissipation fins (83) are arranged on the outer wall of the inner cylinder (84) along the axial direction.
7. A wet material three-stage drying system according to claim 1, characterized in that The output end of the spiral conveyor (2) is connected to a first elevator (4), a transition hopper (5) is arranged at the output end of the first elevator (4), a conveyor belt is arranged below the transition hopper (5), and the output end of the conveyor belt is connected to the feed port (87); the discharge port (86) is connected to a second elevator (10), and the second elevator (10) is connected to the feed port (17) of the silo (12).
8. A wet material three-stage drying system according to claim 1, characterized in that, A dust collector (11) is arranged at the upper end of the silo (12).
9. The wet material three-stage drying system according to claim 1, characterized in that, An annular heat dissipation plate (371) is arranged on the hot air pipe (37).
10. A wet material three-stage drying system according to claim 1, characterized in that, A vibrator (39) is arranged on the side of the screen (38).