A drying device

Abstract

The present invention discloses a drying device, which relates to the technical field of wet coal slime drying. The drying device includes a material storage bin, a preheating mechanism, a drying mechanism and a waste heat recovery mechanism. The preheating mechanism includes a first heat exchange component and a first bin, the first bin is communicated with the material storage bin, and the first heat exchange component can heat the materials in the first bin; it includes a drying bin and a heating component, the drying bin is communicated with the first bin, and the heating component can heat the materials in the drying bin; it includes a ventilation duct and a second heat exchange component, the ventilation duct is communicated with the drying bin, the heat extraction end of the second heat exchange component extends into the ventilation duct, and the heat release end of the second heat exchange component is heat exchange-connected with the first heat exchange component. This drying device can recover the waste heat after drying coal slime and preheat the coal slime, saving energy.

Description

Technical Field

[0001] The present invention relates to the technical field of wet slime drying, and particularly to a drying device. Background Art

[0002] With the continuous improvement of the society's requirements for low-carbon economy and awareness of energy conservation and emission reduction, slime, as a by-product of coal mining and processing, is difficult to be industrially applied due to its high moisture content, high viscosity, low calorific value and other disadvantages. It has been used as heating for people in coal mines and surrounding areas and for a part of low-calorific value industrial combustion. Not only is the thermal energy utilization rate low, but it also causes serious environmental pollution. Therefore, it is necessary to process low-grade, poor direct combustion rate and severely environmentally polluting inferior slime into high-quality clean energy to improve resource utilization rate. The slime drying technology is to solve the problems of environmental pollution caused by the long-term storage of slime in coal preparation plants and the inability to dispose of the recovered slime, increase the economic and social benefits of the comprehensive utilization of coal products, realize clean production, and meet the needs of the sustainable development strategy of the coal industry.

[0003] Since the slime has a very high humidity and a very low temperature, directly drying the slime not only has low efficiency but also requires a large amount of thermal energy, greatly increasing the slime drying cost. After drying the slime, a large amount of hot gas is directly discharged into the air, and the temperature of the dried slime is relatively high, and it needs to be cooled before transportation, resulting in a large amount of heat waste.

[0004] In view of the above problems, it is necessary to develop a drying device to solve the problem that the waste heat after drying slime cannot be effectively recovered and utilized. Summary of the Invention

[0005] The purpose of the present invention is to provide a drying device that can recover the waste heat after drying slime and use it to preheat the slime, saving energy.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A drying device, comprising:

[0008] A material storage bin;

[0009] A preheating mechanism, including a first heat exchange component and a first bin, the first bin is communicated with the material storage bin, and the first heat exchange component can heat the material in the first bin;

[0010] A drying mechanism, including a drying chamber and a heating component, the drying chamber is communicated with the first bin, and the heating component can heat the material in the drying chamber;

[0011] The waste heat recovery mechanism includes a ventilation duct and a second heat exchange component. The ventilation duct is connected to the drying bin. The heat intake end of the second heat exchange component extends into the ventilation duct, and the heat release end of the second heat exchange component is heat exchange connected to the first heat exchange component.

[0012] Preferably, the second heat exchange component includes a first heat pipe and a heat pump mechanism. The heat intake end of the first heat pipe extends into the ventilation duct. The heat intake end of the heat pump mechanism is heat exchange connected to the heat release end of the first heat pipe, and the heat release end of the heat pump mechanism is heat exchange connected to the first heat exchange component.

[0013] Preferably, it further includes a cooling mechanism. The cooling mechanism includes a third heat exchange component and a second bin. The second bin is connected to the drying bin, and the third heat exchange component is heat exchange connected to the heat intake end of the heat pump mechanism.

[0014] Preferably, the heating component includes a second heat pipe and a heating box. The heating box is arranged outside the drying bin. The heat release end of the second heat pipe extends into the drying bin, and the heat intake end of the second heat pipe extends into the heating box.

[0015] Preferably, the heat release end of the second heat pipe is spiral, and the drying mechanism further includes a driving component for driving the second heat pipe to rotate.

[0016] Preferably, the outside of the first bin, the second bin and the drying bin is covered with a heat preservation outer wall.

[0017] Preferably, the waste heat recovery mechanism further includes a dust removal component, and the dust removal component is connected in series in the ventilation duct.

[0018] Preferably, the waste heat recovery mechanism further includes an induced draft fan. The induced draft fan is arranged between the dust removal component and the first heat pipe, and the induced draft fan can introduce the air flow in the drying bin into the ventilation duct.

[0019] Preferably, the preheating mechanism further includes a first transmission component. The opposite ends of the first bin are provided with a feed inlet and a discharge outlet. The feed inlet is connected to the storage bin, and the discharge outlet is connected to the drying bin. The first transmission component can convey the material from the feed inlet to the discharge outlet. The first heat exchange component is laid between the first transmission component and the first bin and extends from the feed inlet to the discharge outlet.

[0020] Preferably, the first transmission component includes a screw rod and a driving motor, and the screw rod is in transmission connection with the output shaft of the driving motor.

[0021] The beneficial effects of the present invention:

[0022] The present invention provides a drying device. In this device, after the drying mechanism heats and dries the slime therein, the hot air exchanges heat with the heat-taking end of the second heat exchange component in the ventilation duct of the waste heat recovery mechanism, and the heat is absorbed by the second heat exchange component and then discharged. After the heat-taking end of the second heat exchange component absorbs the heat, its heat-releasing end releases the heat to the first heat exchange component, and the first heat exchange component heats the slime entering the preheating mechanism from the storage bin in the preheating mechanism, realizing the utilization of the drying waste heat. At the same time, since the slime has been heated before entering the drying chamber, the heat required in the drying chamber is greatly reduced, saving energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic structural diagram of the drying device provided by the present invention;

[0024] Figure 2 is a schematic structural diagram of the heat pump mechanism provided by the present invention.

[0025] 1, storage bin; 2, preheating mechanism; 3, drying mechanism; 4, waste heat recovery mechanism; 5, cooling mechanism; 6, heat preservation outer wall;

[0026] 21, first heat exchange component; 22, first bin; 23, first transmission component; 31, drying chamber; 32, heating component; 33, driving component; 41, ventilation duct; 42, second heat exchange component; 43, bag filter; 44, induced draft fan; 51, third heat exchange component; 52, second bin; 53, second transmission component;

[0027] 321, second heat pipe; 322, heating box; 421, first heat pipe; 422, heat pump mechanism; 4221, evaporator; 4222, compressor; 4223, condenser; 4224, throttle valve. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are intended to explain the present invention and should not be construed as limiting the present invention.

[0029] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions.

[0030] Unless otherwise clearly specified and defined, the terms "installed", "connected", "connected to", "fixed" should be understood in a broad sense. For example, it can be a fixed connection or a detachable connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. It can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] Unless otherwise clearly specified and defined, the first feature being "above" or "below" the second feature may include the first feature and the second feature being in direct contact, or may include the first feature and the second feature not being in direct contact but being in contact through other features therebetween. Moreover, the first feature being "above", "over" and "on" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the first feature is at a higher horizontal level than the second feature. The first feature being "below", "under" and "beneath" the second feature includes the first feature being directly below and obliquely below the second feature, or merely indicating that the first feature is at a lower horizontal level than the second feature.

[0032] The technical solution of the present invention will be further described below with reference to the drawings and through specific embodiments.

[0033] In this embodiment, the material is taken as coal slime for illustration.

[0034] This embodiment provides a drying device. As Figure 1As shown in the figure, the drying device includes a material storage bin 1, a preheating mechanism 2, a drying mechanism 3, and a waste heat recovery mechanism 4. The preheating mechanism 2 includes a first heat exchange component 21 and a first bin 22. The first bin 22 is connected to the material storage bin 1, and the first heat exchange component 21 can heat the slime in the first bin 22. The drying mechanism 3 includes a drying bin 31 and a heating component 32. The drying bin 31 is connected to the first bin 22, and the heating component 32 can heat the slime in the drying bin 31. The waste heat recovery mechanism 4 includes a ventilation duct 41 and a second heat exchange component 42. The ventilation duct 41 is connected to the drying bin 31. The heat extraction end of the second heat exchange component 42 extends into the ventilation duct 41, and the heat release end of the second heat exchange component 42 is heat-exchange connected to the first heat exchange component 21.

[0035] The heating component 32 heats and dries the slime in the drying bin 31. During the drying process, the waste heat in the drying bin 31 is discharged through the air. After heat exchange with the heat extraction end of the second heat exchange component 42 in the ventilation duct 41, it is discharged from the drying device. The waste heat of the drying bin 31 is released to the first heat exchange component 21 through the heat release end of the second heat exchange component 42 to raise its temperature, and pre-heats the slime in the first bin 22, realizing the utilization of the drying waste heat.

[0036] Since the dried slime is still at a relatively high temperature, if it is placed arbitrarily and allowed to cool freely in the air to room temperature, a large amount of heat will be wasted.

[0037] In order to effectively utilize the heat of the dried slime, the drying device further includes a cooling mechanism 5. The cooling mechanism 5 includes a third heat exchange component 51 and a second bin 52. The second bin 52 is connected to the drying bin 31, and the third heat exchange component 51 is heat-exchange connected to the heat extraction end of the heat pump mechanism 422.

[0038] Wherein, both opposite ends of the first bin 22 are provided with a feed inlet and a discharge outlet, and the feed inlet and the discharge outlet are arranged in the horizontal direction of the first bin 22. The feed inlet is at the upper part of one end, and the discharge outlet is at the lower part of the other end.

[0039] The horizontally arranged discharge outlet and feed inlet can make the slime move horizontally in the first bin 22 and the drying bin 31, and its speed is controllable, which can ensure the full progress of heat exchange.

[0040] Similarly, both the drying bin 31 and the second bin 52 are provided with a feed inlet and a discharge outlet, and the arranged positions and reasons are the same as those of the first bin 22.

[0041] It can be understood that the feed inlet of the first bin 22 is connected to the material storage bin 1, the discharge outlet of the first bin 22 is connected to the feed inlet of the drying bin 31, and the discharge outlet of the drying bin 31 is connected to the feed inlet of the second bin 52, forming a complete path.

[0042] Preferably, the preheating mechanism 2 further includes a first transmission component 23. The first transmission component 23 can convey the slime from the feed inlet of the preheating mechanism 2 to the discharge outlet of the preheating mechanism 2. The first heat exchange component 21 is laid between the first transmission component 23 and the first bin 22 and extends from the feed inlet of the preheating mechanism 2 to the discharge outlet of the preheating mechanism 2.

[0043] The slime is conveyed from the feed inlet to the discharge outlet through the first transmission component 23. The degree of preheating of the slime can be controlled by controlling the transmission speed of the first transmission component 23. And the first heat exchange component 21 is laid between the first transmission component 23 and the first bin 22, which can make the slime be evenly preheated in the first bin 22.

[0044] Preferably, the first transmission component 23 includes a screw rod and a driving motor. The screw rod is in transmission connection with the output shaft of the driving motor.

[0045] The driving motor drives the screw rod to rotate, stirring and crushing the slime during the process of conveying the slime, which can make the preheating of the slime in the first bin 22 more sufficient, also reduce the crushing difficulty in the drying bin 31, and improve the drying efficiency.

[0046] It can be understood that the cooling mechanism 5 further includes a second transmission component 53, whose structure and function effect are the same as those of the first transmission component 23, and will not be elaborated here.

[0047] Furthermore, the second heat exchange component 42 includes a first heat pipe 421. The heat-taking end of the first heat pipe 421 extends into the ventilation duct 41, and the heat-releasing end of the first heat pipe 421 is in heat exchange connection with the first heat exchange component 21.

[0048] The heat pipe has an extremely fast heat conduction ability. The working medium inside it absorbs heat and vaporizes at the heat-taking end of the heat pipe and flows towards the heat-releasing end of the heat pipe, and liquefies and releases a large amount of heat at the heat-releasing end of the heat pipe. The first heat pipe 421 can greatly improve the recovery efficiency of waste heat.

[0049] In order to further improve the utilization of waste heat, the second heat exchange component 42 further includes a heat pump mechanism 422. There is a flowing circulating working medium in the heat pump mechanism 422. The heat-taking end of the heat pump mechanism 422 is in heat exchange connection with the heat-releasing end of the first heat pipe 421, and the heat-releasing end of the heat pump mechanism 422 is in heat exchange connection with the first heat exchange component 21.

[0050] The heat-releasing end of the first heat pipe 421 releases heat at the heat-taking end of the heat pump mechanism 422. The circulating working medium absorbs the heat and the temperature rises. After the heat pump mechanism 422 does work on it, the temperature further rises, and the heat is transferred to the first heat exchange component 21 through the heat-releasing end, so that the slime is heated to a higher temperature in the first bin 22, and the output heat of the heating box 322 is further reduced.

[0051] Preferably, the heating component 32 includes a second heat pipe 321 and a heating box 322. The heating box 322 is arranged outside the drying bin 31. The heat-releasing end of the second heat pipe 321 extends into the drying bin 31, and the heat-absorbing end of the second heat pipe 321 extends into the heating box 322.

[0052] The heating box 322 heats the second heat pipe 321 at its heat-absorbing end, so that the heat is transferred to the heat-releasing end of the second heat pipe 321 for release to heat and dry the slime. The heating box 322 can generate heat by combustion or by electricity. No matter which method is used, a large amount of energy is consumed when heating the slime in the drying bin 31. Since the slime has been heated to a certain temperature before entering the drying bin 31, the heat required by the heating component 32 when drying the slime in the drying bin 31 is reduced, which can greatly reduce the energy consumption.

[0053] Further, a flowing first heat exchange medium is arranged in the first heat exchange component 21. The first heat exchange medium flows through the heat-releasing end of the first heat pipe 421 and exchanges heat with the heat-releasing end of the first heat pipe 421. The first heat exchange medium can be selected as ethylene glycol solution, which has the advantages of low specific heat capacity and is relatively easy to be heated to a higher temperature, so that the temperature difference between the first heat exchange component 21 and the slime increases and the heat exchange is more sufficient. For cost consideration, water can also be selected as the first heat exchange medium.

[0054] Preferably, a flowing second heat exchange medium is arranged in the third heat exchange component 51. The third heat exchange component 51 is used to cool the high-temperature dried slime, and at the same time, the absorbed heat is transferred to the heat-absorbing end of the heat pump mechanism 422 through the second heat exchange medium to recycle the waste heat and further increase the heat absorbed by the heat-absorbing end of the heat pump mechanism 422. The second heat exchange medium can be selected as water or ethylene glycol solution, which is the same as the reason for the first heat exchange medium and will not be elaborated here.

[0055] Further, as Figure 2 shown, the heat pump mechanism 422 further includes an evaporator 4221, a compressor 4222, a condenser 4223 and a throttle valve 4224, which are connected in sequence to form a circulating heat exchange loop. The compressor 4222 is used to compress the circulating working medium in the circulating heat exchange loop. The evaporator 4221 is heat-exchange connected to the heat-releasing end of the first heat pipe 421 and the third heat exchange component 51. The condenser 4223 is heat-exchange connected to the first heat exchange component 21. The throttle valve 4224 is used to adjust the flow rate of the circulating working medium. The circulating working medium can flow in the circulating heat exchange loop and can exchange heat with the second heat-releasing end of the second heat pipe 321 and the second heat exchange component 42 in the evaporator 4221, and can exchange heat with the first heat exchange component 21 in the condenser 4223.

[0056] The circulating working fluid absorbs the heat from the heat release end of the first heat pipe 421 and the second heat exchange component 42 in the evaporator 4221 and evaporates. When flowing through the compressor 4222, it is compressed into a high-temperature gas and flows to the condenser 4223, and releases heat in the condenser 4223 to heat the first heat exchange medium. During this process, the high-temperature gas liquefies and cools down, releasing a large amount of heat to ensure the temperature rise of the first heat exchange medium. At the same time, the throttle valve 4224 can be adjusted as needed to control the flow rate of the circulating working fluid, so as to reasonably control the temperature of the first heat exchange component 21 and save energy.

[0057] Among them, the circulating working fluid can be ammonia or freon.

[0058] The circulating working fluid is a substance that can be liquefied at normal temperature or lower temperature. It increases the heat change in a small temperature range through reversible phase change, thereby increasing the heat exchange efficiency.

[0059] Preferably, the throttle valve 4224 can be a capillary tube.

[0060] The circulating working fluid condensed into a liquid state flows through the capillary tube. Since it enters from a large tube into a small tube, the flow rate is restricted. Therefore, the pressure of the circulating working fluid after coming out decreases, and the temperature continues to drop, which can not only control the flow rate but also further reduce the temperature of the circulating working fluid, improving its heat exchange efficiency in the evaporator 4221.

[0061] The slime formed in production is prone to form a paste or block due to accumulation. When the slime is dried in the drying bin 31, the internal moisture does not have time to evaporate, resulting in incomplete drying of the slime. Therefore, it is necessary to break up the slime during the drying process.

[0062] Preferably, the heat release end of the second heat pipe 321 is set in a spiral shape, and the drying mechanism 3 further includes a driving component 33 for driving the second heat pipe 321 to rotate.

[0063] The second heat pipe 321 rotates under the drive of the driving component 33. The slime entering the drying bin 31 is continuously stirred and broken by the spiral structure during the process of being heated and dried, ensuring that the slime is fully dried.

[0064] Among them, the driving component 33 includes a DC motor and a transmission. The transmission is connected to the output shaft of the DC motor and the second heat pipe 321. The rotation speed of the second heat pipe 321 can be controlled through the transmission, and thus the degree of slime crushing can be controlled.

[0065] Furthermore, the waste heat recovery mechanism 4 further includes a dust removal component, which is connected in series in the path of the ventilation duct 41.

[0066] The moisture in the slime evaporates in the drying bin 31, and the hot and humid air in the drying bin 31 is discharged after exchanging heat with the first heat pipe 421 through the ventilation duct 41. During the drying process, a large amount of fine dust enters the ventilation duct 41 along with the hot and humid air and adheres to the surface of the first heat pipe 421, seriously affecting the absorption of waste heat by the first heat pipe 421. At the same time, the dust is discharged into the air along with the hot and humid air, causing serious environmental pollution. Therefore, a dust removal component needs to be set on the path of the ventilation duct 41 to filter out the dust from the hot and humid air mixed with dust in the ventilation duct 41.

[0067] Exemplarily, the dust removal component can be a bag filter 43.

[0068] The bag filter 43 is an efficient dry dust collector. It is a dust removal device that uses a bag-type filter element made of fiber fabric to capture solid particles in the dust-containing gas. Its working principle is that dust particles are intercepted by colliding with the fibers due to inertial force when they bypass the filter cloth fibers, and it can effectively filter dust.

[0069] Preferably, the waste heat recovery mechanism 4 further includes an induced draft fan 44. The induced draft fan 44 is arranged between the dust removal component and the first heat pipe 421 and can introduce the air flow in the drying bin 31 into the ventilation duct 41.

[0070] The induced draft fan 44 can extract the hot and humid air in the drying bin 31, promote the flow of the hot and humid air, and improve the waste heat recovery efficiency.

[0071] In order to further improve the heat exchange efficiency, both the first heat exchange component 21 and the second heat exchange component 42 include multiple heat exchange tubes through which the first heat exchange medium and the second heat exchange medium flow and exchange heat with the slime.

[0072] Preferably, the first transmission component 23 includes a screw rod and a driving motor, and the screw rod is in transmission connection with the output shaft of the driving motor.

[0073] The driving motor drives the screw rod to rotate, stirring and crushing the slime during the process of transporting the slime, which can make the preheating of the slime in the first bin 22 more sufficient, reduce the crushing difficulty in the drying bin 31, and improve the drying efficiency.

[0074] It can be understood that the second transmission component 53 has the same structure as the first transmission component 23.

[0075] The dried slime enters the second bin 52. At this time, the temperature of the slime is relatively high. The screw rod in the second bin 52 can stir and crush the unbroken dried slime again during rotation, break the lumpy slime that is not completely dried, reach the dry state under the action of its own temperature, and at the same time, the further crushed slime exchanges heat with the second heat exchange component 42 more fully, which is beneficial to the recovery of waste heat.

[0076] Preferably, the outer parts of the first silo 22, the second silo 52 and the drying silo 31 are covered with a heat-insulating outer wall 6.

[0077] The heat-insulating outer wall 6 can prevent the waste heat from escaping into the air through the silo wall, ensuring that the waste heat is recycled to the maximum extent.

[0078] The above content is only a preferred embodiment of the present invention. For those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. The content of this specification should not be construed as a limitation to the present invention.

Claims

1. A drying device, characterized in that, Comprising: A material storage bin (1); A preheating mechanism (2), including a first heat exchange component (21) and a first bin (22), the first bin (22) communicating with the material storage bin (1), and the first heat exchange component (21) being capable of heating the material in the first bin (22); A drying mechanism (3), including a drying bin (31) and a heating component (32), the drying bin (31) communicating with the first bin (22), and the heating component (32) being capable of heating the material in the drying bin (31); A waste heat recovery mechanism (4), including a ventilation duct (41) and a second heat exchange component (42), the ventilation duct (41) communicating with the drying bin (31), the heat extraction end of the second heat exchange component (42) extending into the ventilation duct (41), and the heat release end of the second heat exchange component (42) being in heat exchange connection with the first heat exchange component (21); The second heat exchange component (42) includes a first heat pipe (421) and a heat pump mechanism (422), the heat extraction end of the first heat pipe (421) extending into the ventilation duct (41), the heat extraction end of the heat pump mechanism (422) being in heat exchange connection with the heat release end of the first heat pipe (421), and the heat release end of the heat pump mechanism (422) being in heat exchange connection with the first heat exchange component (21); A flowing first heat exchange medium is provided in the first heat exchange component (21), the first heat exchange medium flowing through the heat release end of the first heat pipe (421), and the first heat exchange medium being capable of performing heat exchange with the heat release end of the first heat pipe (421); It further includes a cooling mechanism (5), the cooling mechanism (5) including a third heat exchange component (51) and a second bin (52), the second bin (52) communicating with the drying bin (31), and the third heat exchange component (51) being in heat exchange connection with the heat extraction end of the heat pump mechanism (422); A flowing second heat exchange medium is provided in the third heat exchange component (51), and the second heat exchange medium is capable of absorbing heat and transferring it to the heat extraction end of the heat pump mechanism (422); During the drying process, the waste heat in the drying bin (31) is discharged through the air, and after performing heat exchange with the heat extraction end of the second heat exchange component (42) in the ventilation duct (41), it is discharged from the drying device; The feed inlet of the first bin (22) communicates with the material storage bin (1), the discharge outlet of the first bin (22) communicates with the feed inlet of the drying bin (31), and the discharge outlet of the drying bin (31) communicates with the feed inlet of the second bin (52); The heating component (32) includes a second heat pipe (321) and a heating box (322), the heating box (322) being arranged outside the drying bin (31), the heat release end of the second heat pipe (321) extending into the drying bin (31), and the heat extraction end of the second heat pipe (321) extending into the heating box (322).

2. The drying device according to claim 1, characterized in that, The heat release end of the second heat pipe (321) is spiral, and the drying mechanism (3) further includes a driving component (33) for driving the second heat pipe (321) to rotate.

3. The drying device according to claim 1, characterized in that, The outer sides of the first silo (22), the second silo (52) and the drying silo (31) are covered with a heat-insulating outer wall (6).

4. The drying device according to claim 1, characterized in that, The waste heat recovery mechanism (4) further includes a dust removal component, and the dust removal component is connected in series in the ventilation duct (41).

5. The drying device according to claim 4, characterized in that, The waste heat recovery mechanism (4) further includes an induced draft fan (44). The induced draft fan (44) is arranged between the dust removal component and the first heat pipe (421), and the induced draft fan (44) can introduce the air flow in the drying silo (31) into the ventilation duct (41).

6. The drying device according to claim 1, characterized in that, The preheating mechanism (2) further includes a first transmission component (23). Feeding ports and discharging ports are arranged at opposite ends of the first silo (22). The feeding port is communicated with the material storage silo (1), and the discharging port is communicated with the drying silo (31). The first transmission component (23) can convey the material from the feeding port to the discharging port. The first heat exchange component (21) is laid between the first transmission component (23) and the first silo (22), and extends from the feeding port to the discharging port.

7. The drying device according to claim 6, characterized in that, The first transmission component (23) includes a screw rod and a driving motor, and the screw rod is in transmission connection with the output shaft of the driving motor.

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