Heat exchange device for a dryer and drying system

Abstract

This invention discloses a heat exchange device and drying system for a dryer, comprising: a main shaft and a drive mechanism; multiple blade mechanisms are circumferentially connected to the main shaft, and the blade mechanisms are used to contact and exchange heat with the material and tumble the material under power drive; the main shaft has an oil inlet channel and an oil return channel, and the blade mechanisms have heat medium flow channels, which are connected between the oil inlet channel and the oil return channel, for the passage of heat transfer medium to facilitate contact and heat exchange between the blade mechanisms and the material. The dryer also includes a cylinder and one or more drying chambers arranged along the direction of gravity inside the cylinder, with the main shaft located at the axis of the cylinder; a main oil inlet and a main oil outlet are provided on the outer wall of the cylinder for the entry and exit of the heat transfer medium, respectively; and a discharge port is also provided on the bottom wall of the cylinder. This invention effectively solves the problems of low thermal efficiency and serious heat loss from exhaust gas in traditional hot air drying, as well as the inability to recover waste heat and large heat loss in conventional contact drying, significantly improving the overall thermal efficiency of the system and significantly reducing the comprehensive operating energy consumption.

Description

Technical Field

[0001] This invention relates to the field of industrial drying equipment and energy-saving technology, specifically to a heat exchange device and drying system for a dryer. Background Technology

[0002] In industries such as environmental protection, chemicals, pharmaceuticals, and agricultural processing, large quantities of highly viscous materials, including pastes and filter cakes, with a moisture content of 60%–85%, are continuously generated. If these high-moisture, high-viscosity materials are directly landfilled or disposed of arbitrarily without effective drying and volume reduction treatment, it not only results in a serious waste of usable resources but also easily leads to a series of ecological and environmental problems such as leachate pollution, odor diffusion, and large land occupation. Meanwhile, industrial drying is a high-energy-consuming unit operation, with energy consumption in the drying process accounting for 10%–20% of total industrial energy consumption. Traditional drying methods generally suffer from low thermal energy utilization, high operating energy consumption, and serious waste of waste heat. Therefore, developing a targeted, stable, and highly efficient energy-saving drying technology specifically for high-viscosity materials has significant engineering application value and industrialization promotion significance.

[0003] Among existing technologies, the most widely used drying technologies are hot air drying and contact drying. Hot air drying uses high-temperature hot air as the drying medium, achieving convective heat transfer through direct gas-solid contact, which promotes the rapid evaporation and removal of internal moisture from the material. Typical equipment includes rotary drum dryers, belt dryers, fluidized bed dryers, and airflow dryers. This type of equipment has a simple structure, high single-unit processing capacity, and mature technology, and is widely applicable to continuous drying operations of granular and powdery loose materials. However, the overall thermal efficiency of this process is relatively low, generally only maintained at 30% to 50%. During the drying process, a large amount of heat is directly discharged into the air with the wet exhaust gas, resulting in serious energy loss; the emission of dusty wet exhaust gas is large, requiring additional dust removal, deodorization, and other exhaust gas treatment facilities, increasing operation and maintenance costs. Meanwhile, the technology has limited adaptability. For high-moisture and high-viscosity paste-like materials such as sludge, drug residue, and filter cake, it is very easy to cause problems such as wall adhesion and clumping, material caking, and dead bed accumulation, resulting in poor drying uniformity. Moreover, the exhaust temperature generally reaches 70-100℃, and the waste heat resources are not effectively recovered, resulting in significant overall energy consumption and environmental pressure.

[0004] Contact drying technology relies on the direct contact between a heated wall surface and the material, transferring heat through heat conduction to evaporate the moisture inside the material. Mainstream representative equipment includes hollow paddle dryers, disc dryers, thin-film evaporators, and drum dryers. This type of drying method boasts high heat transfer efficiency, with an overall thermal efficiency of 70%–85%. It generates minimal waste gas and dust, resulting in lower exhaust gas treatment pressure and superior overall environmental performance. It is well-suited for drying highly viscous materials such as pastes and filter cakes. However, the generated hot and humid waste gas is directly emitted, and the latent heat of vaporization in the waste gas is not recovered, leading to a heat loss of approximately 20%–30%. Single-stage equipment is difficult to use for drying high-moisture materials in a single step, and large-scale manufacturing of horizontal structures is challenging.

[0005] For example, Chinese utility model patent CN 203964624 U discloses a dryer capable of breaking up dried materials. The dryer includes a main body with a breaking structure for separating the dried materials. This breaking structure includes a motor, a rotating shaft, and at least three pairs of blades. The two ends of the rotating shaft are connected to the blades and the motor, respectively. Each pair of blades is located on both sides of the rotating shaft, symmetrically distributed around the axis of rotation. The motor is located on one side of the dryer. Each pair of blades is distributed sequentially from top to bottom along the rotating shaft, with the stirring diameter of each pair increasing sequentially from top to bottom. However, this dryer only uses mechanical breaking up and does not address efficiency improvement, waste gas treatment, or resource recovery, making it unsuitable for direct application in industrial drying.

[0006] Therefore, developing an energy-saving drying device that adapts to the rheological properties of high-viscosity materials such as pastes and filter cakes, and achieving low energy consumption, high drying efficiency, and continuous and stable operation, can not only significantly reduce the operating costs of the drying process for enterprises, but also provide core equipment support for industrial solid waste reduction, resource recycling, and carbon emission reduction. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of the prior art, effectively solve the problems of low thermal efficiency, high energy consumption and poor adaptability to high-viscosity materials in traditional hot air drying, achieve high-performance drying of paste-like and filter cake-like high-viscosity materials, and realize low energy consumption, high drying efficiency and continuous and stable operation of the device; and provide a heat exchange device and drying system for a dryer.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A heat exchange device for a dryer includes a main shaft and a drive mechanism. The main shaft is connected to the output shaft of the drive mechanism. A plurality of blade mechanisms are circumferentially connected to the main shaft. The blade mechanisms are used to contact and exchange heat with the material and flip the material under power drive.

[0010] The main shaft is provided with an oil inlet channel and an oil return channel. The blade mechanism is provided with a heat transfer medium channel, which is connected between the oil inlet channel and the oil return channel, for the passage of heat transfer medium to allow the blade mechanism to contact the material for heat exchange.

[0011] Preferably, the spindle is hollow inside and has a concentric inner tube inserted through it. The inner tube is hollow inside and serves as an oil return channel. The outer wall of the inner tube and the inner wall of the spindle form an annular sandwich layer, which serves as an oil inlet channel.

[0012] The blade mechanism includes blades and an oil inlet branch pipe and an oil return branch pipe located at the root of the blades. The heat medium flow channel is located inside the blades. The inlet of the heat medium flow channel is connected to the annular interlayer inside the main shaft via the oil inlet branch pipe, and the outlet of the heat medium flow channel is connected to the inner pipe via the oil return branch pipe.

[0013] Preferably, the blade head is provided with a scraper, which is connected to the blade head by a spring plate, and the scraper is used to scrape off materials in motion.

[0014] A drying system includes a dryer, the dryer employing the aforementioned device, the dryer further including a cylinder and one or more drying chambers arranged along the direction of gravity within the cylinder, the top of the cylinder being provided with a material inlet and an exhaust gas outlet; the main shaft is located at the axis of the cylinder, and in each drying chamber, the main shaft is circumferentially connected with multiple blade mechanisms.

[0015] The outer wall of the cylinder is provided with a main oil inlet and a main oil outlet, which are used for the heat transfer medium to enter and flow out, respectively. The main oil inlet is connected to the oil inlet channel, and the main oil outlet is connected to the oil return channel.

[0016] The bottom wall of the cylinder is also provided with a discharge port for discharging the dried material.

[0017] The vertical multi-stage drying chamber allows materials to fall in stages for gradient dehydration, overcoming the shortcomings of insufficient dehydration capacity in single-stage contact drying. This significantly improves the drying uniformity and processing efficiency of high-moisture materials. A drive mechanism rotates the main shaft and the blade mechanism connected to it, fully tumbling the material. Oil inlet and return channels within the main shaft, forming a loop with the heat transfer medium channel inside the blade mechanism, allow the heat transfer medium to flow within the heat transfer medium channel, thereby exchanging heat with the material and improving drying efficiency. Heat is extracted from the exhaust gas stage by staged heat pump modules before being discharged, avoiding heat waste.

[0018] Preferably, the device further includes a waste heat recovery device, which includes at least a first heat pump module. The first heat pump module is used to recover the heat in the waste gas discharged through the exhaust gas outlet of the dryer and heat the heat transfer medium for use by the dryer.

[0019] Preferably, a heat-conducting jacket is provided on the side wall of the cylinder at a position corresponding to each drying chamber;

[0020] The first heat pump module includes a first evaporator, a first compressor, and a first heat exchanger.

[0021] The first evaporator includes a first air inlet, a first air outlet, a first refrigerant outlet, and a first refrigerant return port. The first air inlet is connected to the exhaust gas outlet. The first evaporator is used to absorb heat from the exhaust gas through liquid refrigerant and output gaseous refrigerant through the first refrigerant outlet, and to discharge exhaust gas through the first air outlet.

[0022] The inlet of the first compressor is connected to the outlet of the first refrigerant, and the outlet of the first compressor is connected to the inlet of the first heat exchanger. The first compressor is used to compress the gaseous refrigerant and output the compressed refrigerant to the first heat exchanger.

[0023] The first heat exchanger includes a first inlet, a first outlet, a heat transfer oil inlet, and a heat transfer oil outlet. The first outlet is connected to the first refrigerant return port of the first evaporator. The heat transfer oil outlet is used to communicate with the main oil inlet and one or more heat transfer jacket inlets, respectively. The heat transfer oil inlet is used to communicate with the main oil outlet and one or more heat transfer jacket outlets, respectively. The first heat exchanger is used to convert the compressed refrigerant into a liquid state and return it to the first evaporator, and to heat the heat transfer medium for use by the dryer.

[0024] Preferably, the drying chamber is provided with at least three stages, and the corresponding heat-conducting jackets are a primary heat-conducting jacket, a secondary heat-conducting jacket, and a tertiary heat-conducting jacket. The heat-conducting oil outlet is connected to the inlet of the primary heat-conducting jacket and the inlet of the secondary heat-conducting jacket through an oil supply pipeline. The outlet of the primary heat-conducting jacket and the outlet of the secondary heat-conducting jacket are both connected to the inlet of the tertiary heat-conducting jacket through an oil supply pipeline. The outlet of the tertiary heat-conducting jacket is connected to the heat-conducting oil inlet through an oil supply pipeline.

[0025] Preferably, the waste heat recovery device further includes a second heat pump module, which is cascaded with the first heat pump module. The waste gas discharged from the waste gas outlet flows through the first heat pump module and the second heat pump module in sequence, and the heat is recovered step by step.

[0026] The second heat pump module is used to heat the compressed air using the recovered heat and then supply it to the dryer.

[0027] Preferably, a hot air inlet is provided on the side wall of the cylinder at a position corresponding to each stage of the drying chamber;

[0028] The second heat pump module includes a second evaporator, a second compressor, and a second heat exchanger.

[0029] The second evaporator includes a second air inlet, a second air outlet, a second refrigerant outlet, and a second refrigerant return port. The second air inlet is connected to the first air outlet of the first evaporator. The second evaporator is used to absorb heat from the exhaust gas through liquid refrigerant and output gaseous refrigerant through the second refrigerant outlet, and to discharge exhaust gas through the second air outlet.

[0030] The inlet of the second compressor is connected to the outlet of the second refrigerant, and the outlet of the second compressor is connected to the second inlet of the second heat exchanger. The second compressor is used to compress the gaseous refrigerant and output the compressed refrigerant to the second heat exchanger.

[0031] The second heat exchanger includes a second inlet, a second outlet, a compressed air inlet, and a hot air outlet. The second outlet is connected to the second refrigerant return port of the second evaporator. The compressed air inlet is used to introduce external compressed air, and the hot air outlet is used to communicate with one or more hot air inlets. The second heat exchanger is used to convert the compressed refrigerant into a liquid state and return it to the second evaporator, and to heat the compressed air for use by the dryer.

[0032] Preferably, it further includes:

[0033] An anti-sticking and dispersing component is used for material entry and for dispersing and deagglomerating the material;

[0034] The first variable frequency screw feeding mechanism is used to quantitatively feed the dispersed material;

[0035] A preheater is used to preheat the dispersed material;

[0036] The second variable frequency screw feeding mechanism is used to quantitatively feed the preheated material and transport the material to the dryer;

[0037] The waste heat recovery device also includes a third heat pump module, which is cascaded with the second heat pump module. The waste gas discharged from the exhaust outlet flows sequentially through the first heat pump module, the second heat pump module and the third heat pump module, and the heat is recovered step by step.

[0038] The third heat pump module is used to heat water using the recovered heat and then supply it to the preheater.

[0039] Preferably, the third heat pump module includes a third evaporator, a third compressor, and a third heat exchanger.

[0040] The third evaporator includes a third air inlet, a third air outlet, a third refrigerant outlet, and a third refrigerant return port. The third air inlet is connected to the second air outlet of the second evaporator, and the third air outlet is connected to a fan. The third evaporator is used to absorb heat from the waste gas through liquid refrigerant and output gaseous refrigerant through the third refrigerant outlet, and to discharge waste gas through the third air outlet.

[0041] The inlet of the third compressor is connected to the outlet of the third refrigerant, and the outlet of the third compressor is connected to the third inlet of the third heat exchanger. The third compressor is used to compress the gaseous refrigerant and output the compressed refrigerant to the third heat exchanger.

[0042] The third heat exchanger includes a third inlet, a third outlet, a hot water outlet, and a hot water inlet. The third outlet is connected to the third refrigerant return port of the third evaporator. The hot water inlet is used to connect to the water outlet on the preheater, and the hot water outlet is used to connect to the water inlet on the preheater. The third heat exchanger is used to convert the compressed refrigerant into a liquid state and return it to the third evaporator, as well as to heat the water for use by the preheater.

[0043] Preferably, the dryer further includes a moisture content detection mechanism, a spiral mechanism, and an intelligent control module. The moisture content detection mechanism is located inside the cylinder and is used to detect the moisture content of the material and output a moisture content signal. The spiral mechanism is located on the discharge port side at the bottom of the cylinder and is used to push the dried material out of the discharge port through rotating spiral blades. The intelligent control module is electrically connected to the moisture content detection mechanism and the spiral mechanism respectively, and is used to process the moisture content signal output by the moisture content detection mechanism to obtain moisture content data, compare the moisture content data with the target value, and control the spiral mechanism to open or close according to the comparison result.

[0044] This invention's dryer employs contact drying and utilizes an auxiliary heat pump module to introduce hot air, achieving composite drying. A heat-conducting jacket is installed on the dryer wall to heat the surface, and internal blades with heat transfer channels directly contact and turn the material. This prevents paste-like materials from sticking to the walls, clumping, or becoming stuck in the bed, ensuring stable drying of highly viscous materials. Simultaneously, a tiered heat pump module recovers heat energy from the humid waste gas generated during drying, utilizing low-grade heat from the exhaust gas to reduce energy consumption, avoiding direct emission of waste gas, and recovering latent heat of vaporization to reduce heat loss. A vertical, multi-stage drying chamber stacked structure allows materials to fall and dry step-by-step, achieving deep dehydration of high-moisture materials and bringing them to standard in one step. The vertical, multi-layered structure and modular, layered manufacturing, separate transportation, and on-site assembly effectively solve the processing, transportation, and thermal deformation problems caused by the excessively long main shaft of horizontal contact dryers, avoiding the need for large-scale equipment.

[0045] This invention employs three cascaded heat pump modules connected in series to achieve tiered waste heat recovery. The high-temperature and high-humidity exhaust gas discharged from the dryer flows sequentially through the evaporators of each heat pump module. The front-end heat pump prioritizes capturing the high-temperature, high-latent-heat high-quality exhaust gas waste heat to prepare a high-temperature heat transfer medium (heat transfer oil) to supply the blades as the main drying heat source. After the exhaust gas is cooled down step by step, the rear-end heat pump sequentially recovers medium-temperature and low-temperature residual heat, producing medium-temperature hot air for auxiliary convection dehydration in the drying chamber and low-temperature heat energy for preheating the material feed. This effectively realizes the high-value utilization of high-grade heat and the low-value reuse of low-grade heat, fully recovering the sensible heat and latent heat of vaporization in the exhaust gas, and eliminating the heat waste caused by the direct discharge of humid and hot exhaust gas. Attached Figure Description

[0046] The present invention will now be described in further detail with reference to the accompanying drawings:

[0047] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present invention;

[0048] Figure 2 This is a schematic diagram of the dryer of the present invention;

[0049] Figure 3 This is an enlarged schematic diagram of the structure at the bottom of the dryer of the present invention;

[0050] Figure 4 This is a process flow diagram of the present invention.

[0051] Figure label:

[0052] 1-Dryer; 101-Cylinder; 102-First-stage drying chamber; 103-Second-stage drying chamber; 104-Third-stage drying chamber; 105-Fourth-stage drying chamber; 106-Material inlet; 107-Exhaust gas outlet; 108-Discharge outlet; 109-Flange; 110-Heat-conducting jacket; 111-Main oil inlet; 112-Main oil outlet; 113-Main shaft; 114-Inner tube; 115-Rotary joint; 116-Oil outlet pipe; 117-Oil inlet pipe; 118-Blade 119-Oil inlet branch pipe; 120-Oil return branch pipe; 121-Scraper; 122-Screw mechanism; 123-Conical distribution plate; 124-Shaft seal; 201-First heat pump module; 202-Second heat pump module; 203-Third heat pump module; 3-Anti-sticking and dispersing component; 4-First variable frequency screw feeding mechanism; 5-Preheater; 6-Second variable frequency screw feeding mechanism; 7-Discharge pipe; 701-Main material outlet; 702-Discharge valve; 8-Drive mechanism; 9-Fan.

[0053] First evaporator 1C, first compressor 1D, first heat exchanger 1E; first throttle valve 1F; second evaporator 2C; second compressor 2D; second heat exchanger 2E; second throttle valve 2F; third evaporator 3C; third compressor 3D; third heat exchanger 3E; third throttle valve 3F;

[0054] First air inlet 1C1; First air outlet 1C2; First refrigerant outlet 1C3; First refrigerant return port 1C4;

[0055] Second air inlet 2C1; Second air outlet 2C2; Second refrigerant outlet 2C3; Second refrigerant return port 2C4;

[0056] Third air inlet 3C1; Third air outlet 3C2; Third refrigerant outlet 3C3; Third refrigerant return port 3C4;

[0057] First compressor inlet 1D1; First compressor outlet 1D2; Second compressor inlet 2D1, Second compressor outlet 2D2; Third compressor inlet 3D1, Third compressor outlet 3D2; First inlet 1E1, First outlet 1E2; Heat transfer oil inlet 1E3 and heat transfer oil outlet 1E4; Second inlet 2E1, Second outlet 2E2; Compressed air inlet 2E3 and hot air outlet 2E4; Third inlet 3E1, Third outlet 3E2, Hot water inlet 3E3; Hot water outlet 3E4; Oil supply interface G1, Oil outlet interface G2; First-stage heat transfer jacket inlet B1, First-stage heat transfer jacket outlet B2, Second-stage heat transfer jacket inlet B3, Second-stage heat transfer jacket outlet B4, Third-stage heat transfer jacket inlet B5, Third-stage heat transfer jacket outlet B6, Fourth-stage heat transfer jacket inlet B7, Fourth-stage heat transfer jacket outlet B8; H1 - Water inlet; H2 - Water outlet; Main material inlet I1; Exhaust gas outlet I2. Detailed Implementation

[0058] Example 1

[0059] like Figure 1 As shown, the present invention provides a heat exchange device for a dryer, including a main shaft 113 and a drive mechanism 8. The main shaft 113 is connected to the output shaft of the drive mechanism 8. A plurality of blade mechanisms are circumferentially connected to the main shaft 113. The blade mechanisms are used to contact and exchange heat with the material and flip the material under power drive.

[0060] The main shaft 113 has an oil inlet channel and an oil return channel inside, and a heat transfer medium channel is provided inside the blade mechanism for the circulation of heat transfer oil. The heat transfer medium channel connects the oil inlet channel and the oil return channel, allowing the heat transfer medium to pass through so that the blade mechanism can contact the material for heat exchange. In this embodiment, heat transfer oil is used as the heat transfer medium.

[0061] The main shaft 113 is hollow inside and is fixedly fitted with a concentric inner tube 114, which is also hollow inside. The inner tube 114 serves as a return oil channel, and its outer wall and the inner wall of the main shaft 113 form an annular sandwich layer, which serves as an oil inlet channel.

[0062] The blade mechanism includes a blade 118 and an oil inlet branch pipe 119 and an oil return branch pipe 120 located at the root of the blade 118. The heat medium flow channel is located inside the blade 118. The inlet of the heat medium flow channel is connected to the annular jacket inside the main shaft 113 via the oil inlet branch pipe 119, and the outlet of the heat medium flow channel is connected to the inner pipe 114 via the oil return branch pipe 120. The blade 118 has a jacketed structure.

[0063] Specifically, the inlet of the heat transfer medium channel is connected to the annular jacket inside the main shaft 113 via the oil inlet branch pipe 119, and the outlet of the heat transfer medium channel is connected to the inner tube 114 via the oil return branch pipe 120. The heat transfer oil first enters the annular jacket (oil inlet channel) inside the main shaft 113, and flows from the annular jacket (oil inlet channel) inside the main shaft 113 into the heat transfer medium channel inside the blade 118 via the oil inlet branch pipe 119 at the root of the blade 118. The heat transfer oil circulates inside the blade 118 and exchanges heat with the material through contact with the surface of the blade 118. After that, it flows into the inner tube 114 (oil return channel) via the oil return branch pipe 120 at the root of the blade 118. The heat transfer oil returns from top to bottom inside the inner tube 114 and then flows out from the bottom of the inner tube 114.

[0064] A scraper 121 is provided at the head of the blade 118. The scraper 121 is connected to the head of the blade 118 via a spring plate. The scraper 121 is used to scrape off materials during operation. Both the blade 118 and the scraper 121 have an anti-stick coating to further reduce material adhesion. In application, the blade mechanism can be placed inside the dryer, so that the scraper 121 is in contact with the cylinder wall under spring force, with a gap of no more than 1 mm. This allows it to scrape off materials adhering to the inner wall of the cylinder during operation. The scraper 121 remains in close contact with the cylinder wall under spring force. When the main shaft 113 rotates, the scraper 121 continuously scrapes off the material adhering to the cylinder wall, preventing dead bed formation and scaling.

[0065] The working process of this invention is as follows:

[0066] The main shaft 113 and the blade mechanism are installed inside the dryer 1, and the annular jacket is connected to the external oil supply source, and the inner tube 114 is connected to the external heat transfer oil recovery mechanism. When the dryer 1 starts to run, the drive mechanism 8 is turned on to drive the main shaft 113 to rotate. At the same time, the blades 118 rotate around the main shaft 113 to tumble the material. Meanwhile, the external oil supply source supplies oil to the inside of the annular jacket, and the heat transfer oil flows from the annular jacket to the heat medium flow channel inside the blades 118. The heat transfer oil circulates inside the blades 118 and exchanges heat with the material through the contact surface of the blades 118 before flowing into the inner tube 114. From the inner tube 114, it flows into the external heat transfer oil recovery mechanism, realizing heat transfer oil circulation heat exchange drying, improving drying thermal efficiency, reducing equipment energy consumption, and achieving continuous and stable operation.

[0067] Example 2

[0068] The difference from Embodiment 1 above is that the present invention also provides a drying system, including a dryer 1 and a waste heat recovery device.

[0069] like Figure 2 and Figure 3 As shown, the dryer 1 employs the aforementioned heat exchange device for dryers. The dryer 1 also includes a cylinder 101 and one or more drying chambers arranged along the direction of gravity within the cylinder 101. To improve drying efficiency, in this embodiment, the drying chambers are multi-stage. The top of the cylinder 101 is provided with a material inlet 106 and a waste gas outlet 107. The bottom wall of the cylinder 101 is also provided with a discharge outlet 108 for discharging the dried material. Figure 4 As shown, the discharge port 108 is connected to the feeding pipe 7, and the end of the feeding pipe 7 is the main material outlet 701. A feeding valve 702 is installed on the feeding pipe 7. The material conveyed by the second variable frequency screw feeding mechanism 6 enters the cylinder 101 through the material inlet 106, and then undergoes stage-by-stage drying in multiple drying chambers from top to bottom; the dried material exits from the discharge port 108 to the main material outlet 701. The waste gas generated during drying is discharged through the waste gas outlet 107 and then discharged after heat recovery by a waste heat recovery device.

[0070] The cylinder 101 is composed of multiple shells, each forming a primary drying chamber. Flanges 109 are installed at the joints between shells of adjacent drying chambers. By adopting a modular, layered design for each drying chamber, manufacturing, separate transportation, and on-site stacking assembly are facilitated, solving the problem of large-scale production. The vertical multi-stage drying chambers allow materials to fall step by step and undergo gradient dehydration, overcoming the shortcomings of insufficient dehydration capacity in single-stage contact drying, and significantly improving the drying uniformity and processing efficiency of high-moisture materials.

[0071] The main shaft 113 is located at the axis of the cylinder 101. In each drying chamber, multiple blade mechanisms are connected circumferentially to the main shaft 113. In this embodiment, in each drying chamber, 6 blades 118 (the included angle between adjacent blades is 60°) are evenly installed along the circumference of the main shaft 113.

[0072] The outer wall of the cylinder 101 is provided with a main oil inlet 111 and a main oil outlet 112, which are used for the entry and exit of the heat transfer medium, respectively. The main oil inlet 111 is connected to the oil inlet channel, and the main oil outlet 112 is connected to the oil return channel. The main shaft 113 and the inner tube 114 form a sleeve. The bottom end of the sleeve is connected to a rotary joint 115. The bottom end of the inner tube 114 is connected to the first interface of the rotary joint 115. The first interface of the rotary joint 115 is also connected to the main oil outlet 112 through an oil outlet pipe 116. The oil inlet channel (annular jacket) is connected to the second interface of the rotary joint 115. The second interface of the rotary joint 115 is connected to the main oil inlet 111 through an oil inlet pipe 117. The rotary joint 115 ensures that the oil inlet pipe 117 and the oil outlet pipe 116 at the bottom of the dryer 1 are fixed and do not move when the main shaft 113 and the inner tube 114 rotate, and are sealed and leak-proof.

[0073] Specifically, the inlet of the heat transfer medium channel is connected to the annular jacket inside the main shaft 113 via the oil inlet branch pipe 119, and the outlet of the heat transfer medium channel is connected to the inner tube 114 via the return oil branch pipe 120. The heat transfer oil flows from the main oil inlet 111 through the oil inlet pipe 117 to the second interface of the rotary joint 115, then enters the annular jacket (oil inlet channel) inside the main shaft 113, and flows from the annular jacket (oil inlet channel) inside the main shaft 113 into the heat transfer medium channel inside the blade 118 via the oil inlet branch pipe 119 at the root of the blade 118. The heat transfer oil circulates within the blade 118, exchanging heat with the material through contact with the surface of the blade 118, and then flows into the inner tube 114 (oil return channel) via the return oil branch pipe 120 at the root of the blade 118. Inside the inner tube 114, the heat transfer oil returns from top to bottom to the first interface of the rotary joint 115, and then flows out from the main oil outlet 112 via the oil outlet pipe 116.

[0074] A heat-conducting jacket 110 is provided on the side wall of the cylinder 101 at a position corresponding to each stage of the drying chamber; the heat-conducting jacket 110 is used for heat exchange with the outer wall of the cylinder 101 after being filled with heat-conducting oil. In another embodiment, the heat-conducting jacket 110 may also be filled with hot water.

[0075] In this embodiment, the drying chamber is provided with four stages, which are, from top to bottom, the first stage drying chamber 102, the second stage drying chamber 103, the third stage drying chamber 104 and the fourth stage drying chamber 105.

[0076] The first-stage drying chamber 102 has a primary heat-conducting jacket on the side wall of the cylinder 101; the second-stage drying chamber 103 has a secondary heat-conducting jacket on the side wall of the cylinder 101; the third-stage drying chamber 104 has a tertiary heat-conducting jacket on the side wall of the cylinder 101; and the fourth-stage drying chamber 105 has a quaternary heat-conducting jacket on the side wall of the cylinder 101. Each heat-conducting jacket 110 has an inlet and an outlet, namely: primary heat-conducting jacket inlet B1, primary heat-conducting jacket outlet B2, secondary heat-conducting jacket inlet B3, secondary heat-conducting jacket outlet B4, tertiary heat-conducting jacket inlet B5, tertiary heat-conducting jacket outlet B6, quaternary heat-conducting jacket inlet B7, and quaternary heat-conducting jacket outlet B8.

[0077] The waste heat recovery device includes a first heat pump module 201, which is used to recover the heat in the waste gas discharged through the exhaust gas outlet 107 of the dryer 1 and heat the heat transfer medium for use by the dryer 1.

[0078] The first heat pump module 201 includes a first evaporator 1C, a first compressor 1D, a first heat exchanger 1E, and a first throttling valve 1F. The first evaporator 1C includes a first inlet 1C1, a first outlet 1C2, a first refrigerant outlet 1C3, and a first refrigerant return port 1C4. The first inlet 1C1 is connected to the exhaust outlet 107. The exhaust gas after heat recovery is discharged through the first outlet 1C2. The first refrigerant outlet 1C3 is connected to the inlet 1D1 of the first compressor 1D. The outlet 1D2 of the first compressor 1D is connected to the first inlet 1E1 of the first heat exchanger 1E. The first heat exchanger 1E includes a first inlet 1E1, a first outlet 1E2, a heat transfer oil inlet 1E3, and a heat transfer oil outlet 1E4. The first outlet 1E2 of the first heat exchanger 1E is connected to the first refrigerant return port 1C4 of the first evaporator 1C. The heat transfer oil outlet 1E4 is used to communicate with the main oil inlet 111 and one or more heat transfer jacket inlets, respectively. The heat transfer oil inlet 1E3 is used to communicate with the main oil outlet 112 and one or more heat transfer jacket outlets, respectively. The first throttle valve 1F is connected in the pipeline between the first outlet 1E2 and the first refrigerant return port 1C4, and is used to regulate the flow rate.

[0079] In the refrigerant circulation path of the first heat pump module 201, the liquid refrigerant in the first evaporator 1C absorbs heat from the exhaust gas and is converted into a gaseous state. The gaseous refrigerant is then output to the first compressor 1D. The first compressor 1D compresses the gaseous refrigerant and outputs the compressed refrigerant to the first heat exchanger 1E. The first heat exchanger 1E is used to convert the compressed refrigerant into a liquid state and return it to the first evaporator 1C. This enables the refrigerant to circulate between the first evaporator 1C, the first compressor 1D, and the first heat exchanger 1E. By consuming a small amount of electrical energy, heat is "pumped" from a low-temperature environment to a high-temperature environment, thereby efficiently transferring heat.

[0080] In this embodiment, in order to improve circulation efficiency, the heat transfer oil outlet 1E4 of the first heat exchanger 1E is connected to the main oil inlet 111, the first-stage heat transfer jacket inlet B1, and the second-stage heat transfer jacket inlet B3 through the first oil supply pipeline. The first-stage heat transfer jacket outlet B2 and the second-stage heat transfer jacket outlet B4 are both connected to the third-stage heat transfer jacket inlet B5 through the second oil supply pipeline. The main oil outlet 112 and the third-stage heat transfer jacket outlet B6 are connected to the heat transfer oil inlet 1E3 through the third oil supply pipeline.

[0081] Furthermore, the first oil supply pipeline is equipped with an oil supply interface G1, which is connected to the main oil inlet 111 and is used to connect to an external oil supply source. The third oil supply pipeline is equipped with an oil outlet interface G2, which is connected to the main oil outlet 112 and is used to connect to an external heat transfer oil recovery mechanism. When the system starts running, heat transfer oil is supplied to the system from the external oil supply source. Once the heat transfer oil circulation within the system stabilizes, the oil supply interface G1 is shut off to stop the external oil supply. When the system finishes running, the oil outlet interface G2 is opened to recover the oil in the oil circuit to the external heat transfer oil recovery mechanism.

[0082] The bottom of the cylinder 101 is provided with a conical distribution plate 123 for circumferentially collecting dried materials; the main shaft 113 passes through the conical distribution plate 123, and a shaft seal 124 is provided at the connection between the two to improve the sealing performance.

[0083] To monitor the drying status of the material inside the dryer 1 and discharge it in a timely manner, the dryer 1 also includes a moisture content detection mechanism, a spiral mechanism 122, and an intelligent control module. The moisture content detection mechanism is located inside the cylinder 101, for example, on the conical distribution plate 123, and is used to detect the moisture content of the material and output a moisture content signal. The spiral mechanism 122 is located on one side of the discharge port 108 at the bottom of the cylinder 101 and is used to push the dried material out of the discharge port 108 through the rotating spiral blades. The intelligent control module is electrically connected to the moisture content detection mechanism and the spiral mechanism 122 respectively. It is used to process the moisture content signal output by the moisture content detection mechanism to obtain moisture content data, compare the moisture content data with the target value, and control the spiral mechanism 122 to open or close based on the comparison result.

[0084] The working process of this invention is as follows:

[0085] The system operation is divided into a material line and an energy line. On the material line, high-viscosity materials (such as those with a moisture content of 60%~85%) are fed into dryer 1. The materials pass through four drying chambers in sequence by gravity. In each drying chamber, the rotating blades 118 turn and renew the surface, while the materials exchange heat with the heat transfer oil flowing inside the blades 118 through contact with the surface of the blades 118. Finally, after the moisture content of the materials is reduced to the target value, they are collected circumferentially along the conical distribution plate 123 at the bottom of the cylinder 101. The materials are then continuously output to the discharge port 108 by the spiral mechanism 122 placed on the side wall of the cylinder 101. After being discharged from the discharge port 108, the dry materials reach the main material outlet 701 through the discharge pipe 7.

[0086] On the energy line, the hot and humid exhaust gas (approximately 100~120℃) discharged from the dryer flows out from the exhaust gas outlet 107 and into the first evaporator 1C, where heat is extracted. The first heat exchanger 1E produces high-temperature heat transfer oil at 140~160℃, which is supplied to the blades 118 and the heat transfer jacket 110. When the system starts running, the external heat transfer oil enters the heat transfer jackets 110 at each stage to heat the wall of the dryer 1. After stabilization, a circulation is formed in the oil circuit. In a stable state, the high-temperature heat transfer oil flows out from the first heat exchanger 1E and enters the main shaft 113 and inner tube 114 from the bottom of the dryer 1 through the rotary joint 115 installed at the bottom of the main shaft 113 and inner tube 114. It is then transported upward along the annular jacket of the main shaft 113 and sequentially supplied to the blades 118 corresponding to the four-stage drying chamber. High-temperature heat transfer oil flows from the annular jacket of the main shaft 113 into the blades 118 via the inlet branch pipe 119. After circulating and releasing heat inside the blades 118, it flows back into the inner pipe 114 via the return branch pipe 120 and returns to the first heat exchanger 1E for reheating, forming a closed loop. Simultaneously, the high-temperature heat transfer oil flowing out of the first heat exchanger 1E enters the inlet B1 of the first-stage heat transfer jacket and the inlet B3 of the second-stage heat transfer jacket. After circulating inside the first-stage and second-stage heat transfer jackets, the high-temperature heat transfer oil flows from the outlet B2 of the first-stage heat transfer jacket and the outlet B4 of the second-stage heat transfer jacket to the inlet B5 of the third-stage heat transfer jacket. After circulating inside the third-stage heat transfer jacket, the high-temperature heat transfer oil returns to the first heat exchanger 1E from the outlet B6 of the third-stage heat transfer jacket for reheating, forming a closed loop.

[0087] This invention utilizes a first heat pump module 201 to recover waste heat. The high-temperature, high-humidity exhaust gas discharged from the dryer 1 is captured by the first heat pump module 201, which extracts the high-temperature, high-latent-heat waste gas to prepare a high-temperature heat transfer medium (heat transfer oil) to supply the blades 118 as the primary drying heat source. This effectively achieves high-value utilization of high-grade heat, recovering the sensible heat and latent heat of vaporization in the exhaust gas and eliminating heat waste caused by direct discharge of humid and hot exhaust gas. Simultaneously, this invention effectively solves the problems of low thermal efficiency and severe heat loss in traditional hot air drying, as well as the inability to recover waste heat and significant heat loss in conventional contact drying. The overall thermal efficiency of the system is significantly improved, and the comprehensive operating energy consumption is significantly reduced.

[0088] Example 3

[0089] The difference from Embodiment 1 above is that, in this embodiment, as... Figure 4 As shown, the waste heat recovery device also includes a second heat pump module 202, which is cascaded with the first heat pump module 201. The waste gas discharged from the waste gas outlet 107 flows through the first heat pump module 201 and the second heat pump module 202 in sequence, and the heat is recovered step by step.

[0090] The second heat pump module 202 is used to heat compressed air using the recovered heat and then supply it to the dryer 1.

[0091] Hot air inlets are provided on the side wall of the cylinder 101 at positions corresponding to each drying chamber; the hot air inlets are used to supply dry air to the dryer 1 for convective composite drying.

[0092] In this embodiment, each drying chamber has two hot air inlets on the side wall of the cylinder 101: two hot air inlets (A1 and A2) on the side wall of the cylinder 101 corresponding to the first drying chamber 102; two hot air inlets (A3 and A4) on the side wall of the cylinder 101 corresponding to the second drying chamber 103; two hot air inlets (A5 and A6) on the side wall of the cylinder 101 corresponding to the third drying chamber 104; and two hot air inlets (A7 and A8) on the side wall of the cylinder 101 corresponding to the fourth drying chamber 105.

[0093] The second heat pump module 202 includes a second evaporator 2C, a second compressor 2D, a second heat exchanger 2E, and a second throttle valve 2F.

[0094] The second evaporator 2C includes a second inlet 2C1, a second outlet 2C2, a second refrigerant outlet 2C3, and a second refrigerant return port 2C4. The second inlet 2C1 is connected to the first outlet 1C2 of the first evaporator 1C. The second evaporator 2C is used to absorb heat from the exhaust gas through liquid refrigerant and output gaseous refrigerant through the second refrigerant outlet 2C3, and to discharge exhaust gas through the second outlet 2C2.

[0095] The second refrigerant outlet 2C3 is connected to the inlet 2D1 of the second compressor 2D, and the outlet 2D2 of the second compressor 2D is connected to the second inlet 2E1 of the second heat exchanger 2E. The second compressor 2D is used to compress the gaseous refrigerant and output the compressed refrigerant to the second heat exchanger 2E.

[0096] The second heat exchanger 2E includes a second inlet 2E1, a second outlet 2E2, a compressed air inlet 2E3, and a hot air outlet 2E4. The second outlet 2E2 is connected to the second refrigerant return port 2C4 of the second evaporator 2C. The compressed air inlet 2E3 is used to introduce external compressed air, and the hot air outlet 2E4 is used to communicate with one or more hot air inlets. The second heat exchanger 2E is used to convert the compressed refrigerant into a liquid state and return it to the second evaporator 2C, and to heat the compressed air for use by the dryer 1. The second throttle valve 2F is connected in the pipeline between the second outlet 2E2 and the second refrigerant return port 2C4.

[0097] In this embodiment, the hot air outlet 2E4 is connected to the two hot air inlets (A3 and A4) corresponding to the second-stage drying chamber 103, the two hot air inlets (A5 and A6) corresponding to the third-stage drying chamber 104, and the two hot air inlets (A7 and A8) corresponding to the fourth-stage drying chamber 105.

[0098] Specifically, in the refrigerant circulation path of the second heat pump module 202, the liquid refrigerant in the second evaporator 2C absorbs heat from the exhaust gas and is converted into a gaseous state. The gaseous refrigerant is then output to the second compressor 2D. The second compressor 2D compresses the gaseous refrigerant and outputs the compressed refrigerant to the second heat exchanger 2E. The second heat exchanger 2E is used to convert the compressed refrigerant into a liquid state and return it to the second evaporator 2C, thereby realizing the circulation of refrigerant between the second evaporator 2C, the second compressor 2D, and the second heat exchanger 2E. By consuming a small amount of electrical energy, heat is "pumped" from a low-temperature environment to a high-temperature environment to efficiently transfer heat.

[0099] The working process of this invention is as follows:

[0100] The system operation is divided into a material line and an energy line. On the material line, high-viscosity materials (such as those with a moisture content of 60%~85%) enter the anti-sticking and dispersing component 3 from the main material inlet I1. After being dispersed and deagglomerated, they are quantitatively fed into the preheater 5 by the first variable frequency screw feeding mechanism 4 for preheating, and then fed into the dryer 1 by the second variable frequency screw feeding mechanism 6. The material passes through four drying chambers sequentially by gravity. In each drying chamber, the rotating blades 118 agitate and renew the surface, while the material exchanges heat with the heat transfer oil flowing inside the blades 118 through contact with the surface of the blades 118. The second heat exchanger 2E produces medium-temperature hot air at 75~90℃, which is introduced into the second, third, and fourth drying chambers to form convection within the chambers and assist in heat and mass transfer. Finally, after the moisture content of the material is reduced to the target value, it is collected circumferentially along the conical distribution plate 123 at the bottom of the cylinder 101. The material is continuously output to the discharge port 108 by the spiral mechanism 122 placed on the side wall of the cylinder 101. After the dry material is output from the discharge port 108, it reaches the main material outlet 701 through the feeding pipe 7.

[0101] On the energy line, the hot and humid exhaust gas (approximately 100-120°C) discharged from the dryer flows out from the exhaust gas outlet 107 and sequentially passes through the first evaporator 1C and the second evaporator 2C, where heat is extracted stage by stage. The first heat exchanger 1E produces high-temperature heat transfer oil at 140-160°C, which is supplied to the blades 118. The second heat exchanger 2E produces hot air at 75-90°C, which is sent into the drying chamber. The hot and humid exhaust gas is discharged after completing two stages of evaporation.

[0102] Example 4

[0103] The difference from Embodiment 3 above is that, in this embodiment, as... Figure 4 As shown, the system of the present invention also includes an anti-sticking and dispersing component 3, a first variable frequency screw feeding mechanism 4, a preheater 5, and a second variable frequency screw feeding mechanism 6. The material first enters the anti-sticking and dispersing component 3 from the main material inlet I1, and then sequentially enters the first variable frequency screw feeding mechanism 4, the preheater 5, and the second variable frequency screw feeding mechanism 6, and finally enters the dryer 1.

[0104] An anti-sticking and dispersing component 3 is located on the feed side, used for material entry, and for dispersing and deagglomerating the material (highly viscous material) to obtain broken and deagglomerated blocky material. A first variable frequency screw feeder 4 is used for quantitative feeding of the dispersed material. The first variable frequency screw feeder 4 uses a variable frequency motor as its power source, and a frequency converter changes the power frequency to adjust the motor speed, driving the feeding screw blades to push the material, thus achieving quantitative feeding. The first variable frequency screw feeder 4 also integrates an arch breaker, using variable frequency speed control to break up arches during conveying, preventing material from arching, blocking, or clumping, ensuring that the material can continuously and evenly fall into the next mechanism. An anti-sticking coating is also provided inside the first variable frequency screw feeder 4 at the material contact points to prevent material from sticking to the wall. A preheater 5 is used to preheat the dispersed material. A second variable frequency screw feeder 6 is used for quantitative feeding of the preheated material and conveying the material to the dryer 1. The structure of the second variable frequency screw feeder 6 is the same as that of the first variable frequency screw feeder 4. The anti-sticking and dispersing component 3, the first variable frequency screw feeding mechanism 4, and the second variable frequency screw feeding mechanism 6 are all mature existing technologies, and will not be described in detail here.

[0105] The waste heat recovery device also includes a third heat pump module 203, which is cascaded with the second heat pump module 202. The waste gas discharged from the waste gas outlet 107 flows through the first heat pump module 201, the second heat pump module 202 and the third heat pump module 203 in sequence, and the heat is recovered step by step.

[0106] The third heat pump module 203 is used to heat water using the recovered heat and then supply it to the preheater 5.

[0107] The third heat pump module 203 includes a third evaporator 3C, a third compressor 3D, a third heat exchanger 3E, and a third throttle valve 3F.

[0108] The third evaporator 3C includes a third inlet 3C1, a third outlet 3C2, a third refrigerant outlet 3C3, and a third refrigerant return port 3C4. The third inlet 3C1 is connected to the second outlet 2C2 of the second evaporator 2C, and the third outlet 3C2 is connected to the fan 9. The third evaporator 3C is used to absorb heat from the exhaust gas through liquid refrigerant and output gaseous refrigerant through the third refrigerant outlet 3C3, and to discharge exhaust gas through the third outlet 3C2.

[0109] The third refrigerant outlet 3C3 is connected to the inlet 3D1 of the third compressor 3D, and the outlet 3D2 of the third compressor 3D is connected to the third inlet 3E1 of the third heat exchanger 3E. The third compressor 3D is used to compress the gaseous refrigerant and output the compressed refrigerant to the third heat exchanger 3E.

[0110] The third heat exchanger 3E includes a third inlet 3E1, a third outlet 3E2, a hot water outlet 3E4, and a hot water inlet 3E3. The third outlet 3E2 is connected to the third refrigerant return port 3C4 of the third evaporator 3C. The hot water inlet 3E3 is used to connect to the water outlet H2 on the preheater 5, and the hot water outlet 3E4 is used to connect to the water inlet H1 on the preheater 5. The third heat exchanger 3E is used to convert the compressed refrigerant into a liquid state and return it to the third evaporator 3C, as well as to heat the water for use by the preheater 5. The third throttle valve 3F is connected in the pipeline between the third outlet 3E2 and the third refrigerant return port 3C4.

[0111] Specifically, in the refrigerant circulation path of the third heat pump module 203, the liquid refrigerant in the third evaporator 3C absorbs heat from the exhaust gas and is converted into a gaseous state. The gaseous refrigerant is then output to the third compressor 3D. The third compressor 3D compresses the gaseous refrigerant and outputs the compressed refrigerant to the third heat exchanger 3E. The third heat exchanger 3E is used to convert the compressed refrigerant into a liquid state and return it to the third evaporator 3C. This allows the refrigerant to circulate between the third evaporator 3C, the third compressor 3D, and the third heat exchanger 3E. By consuming a small amount of electrical energy, heat is "pumped" from a low-temperature environment to a high-temperature environment, thus efficiently transferring heat.

[0112] In this embodiment, the heat pump module has three stages: a first heat pump module 201, a second heat pump module 202, and a third heat pump module 203, corresponding to high-temperature heating heat pump, medium-temperature supplementary heating heat pump, and low-temperature recovery heat pump, respectively. Using the hot, humid waste gas discharged from dryer 1 as the heat source, the waste gas flows sequentially through the evaporators of the high-temperature heating heat pump, the medium-temperature supplementary heating heat pump, and the low-temperature recovery heat pump, extracting waste heat step by step according to the waste gas temperature from high to low. The waste gas first undergoes upgrading by the high-temperature heating heat pump, generating a high-temperature heat transfer medium (heat transfer oil) to provide heat for the blades 118. The waste gas output from the first evaporator 1C enters the medium-temperature supplementary heating heat pump for upgrading, generating medium-temperature hot air, which is sent into the drying chamber to assist in convection dehydration. The output waste gas then enters the low-temperature recovery heat pump for upgrading, generating a low-temperature heat transfer medium for preheating the material feed. This strictly follows the principle of heat energy cascade matching, achieving graded recovery and on-demand reuse of waste heat.

[0113] Specifically, in the exhaust gas treatment path, the first air inlet 1C1 on the first evaporator 1C is connected to the exhaust gas outlet 107, the first air outlet 1C2 on the first evaporator 1C is connected to the second air inlet 2C1 on the second evaporator 2C, the second air outlet 2C2 on the second evaporator 2C is connected to the third air inlet 3C1 on the third evaporator 3C, and the third air outlet 3C2 of the third evaporator 3C is connected to the fan 9, and the exhaust gas is discharged from the exhaust gas outlet I2 by the fan 9.

[0114] The working process of this invention is as follows:

[0115] The system operation is divided into a material line and an energy line. On the material line, high-viscosity materials (such as those with a moisture content of 60%~85%) enter the anti-sticking and dispersing component 3 from the main material inlet I1. After being dispersed and deagglomerated, they are quantitatively fed into the preheater 5 by the first variable frequency screw feeding mechanism 4 for preheating, and then fed into the dryer 1 by the second variable frequency screw feeding mechanism 6. The material passes through four drying chambers sequentially by gravity. In each drying chamber, the rotating blades 118 agitate and renew the surface, while the material exchanges heat with the heat transfer oil flowing inside the blades 118 through contact with the surface of the blades 118. The second heat exchanger 2E produces medium-temperature hot air at 75~90℃, which is introduced into the second, third, and fourth drying chambers to form convection within the chambers and assist in heat and mass transfer. Finally, after the moisture content of the material is reduced to the target value, it is collected circumferentially along the conical distribution plate 123 at the bottom of the cylinder 101. The material is continuously output to the discharge port 108 by the spiral mechanism 122 placed on the side wall of the cylinder 101. After the dry material is output from the discharge port 108, it reaches the main material outlet 701 through the feeding pipe 7.

[0116] On the energy line, the hot and humid exhaust gas (approximately 100-120°C) discharged from the dryer flows out from the exhaust gas outlet 107 and sequentially passes through the first evaporator 1C, the second evaporator 2C, and the third evaporator 3C, where heat is extracted stage by stage. The first heat exchanger 1E produces high-temperature heat transfer oil at 140-160°C, which is supplied to the blades 118. The second heat exchanger 2E produces hot air at 75-90°C, which is sent into the drying chamber. The third heat exchanger 3E produces hot water at 45-55°C, which is supplied to the preheater 5 for preheating the feed. After completing the three-stage evaporation, the hot and humid exhaust gas cools to approximately 40°C and is discharged from the exhaust gas outlet I2 by the fan 9. External heat transfer oil enters the heat transfer jackets 110 of each stage to heat the cylinder wall of dryer 1, and forms a circulation in the oil circuit after stabilization. In a stable state, high-temperature heat transfer oil flows out from the first heat exchanger 1E, enters the main shaft 113 and inner tube 114 from the bottom of dryer 1 through the rotary joint 115 installed at the bottom of the main shaft 113 and inner tube 114, and is transported upward along the annular jacket of the main shaft 113, sequentially supplying oil to the blades 118 corresponding to the four-stage drying chamber. The high-temperature heat transfer oil flows from the annular jacket of the main shaft 113 into the blades 118 through the oil inlet branch pipe 119, circulates and releases heat inside the blades 118, and then flows back into the inner tube 114 through the oil return branch pipe 120, returning to the first heat exchanger 1E for reheating, forming a closed loop. Meanwhile, the high-temperature heat transfer oil flowing out from the first heat exchanger 1E enters the inlet B1 of the first-stage heat transfer jacket and the inlet B3 of the second-stage heat transfer jacket. After circulating inside the first-stage and second-stage heat transfer jackets, the high-temperature heat transfer oil flows from the outlet B2 of the first-stage heat transfer jacket and the outlet B4 of the second-stage heat transfer jacket to the inlet B5 of the third-stage heat transfer jacket. After circulating inside the third-stage heat transfer jacket, the high-temperature heat transfer oil flows back to the first heat exchanger 1E from the outlet B6 of the third-stage heat transfer jacket for reheating, forming a closed loop.

[0117] This invention employs three cascaded heat pump modules connected in series to achieve tiered waste heat recovery. The high-temperature and high-humidity exhaust gas discharged from dryer 1 flows sequentially through the evaporators of each heat pump module. The front-end heat pump prioritizes capturing the high-temperature, high-latent-heat high-quality exhaust gas waste heat to prepare a high-temperature heat transfer medium (heat transfer oil) to supply blades 118 as the main drying heat source. After the exhaust gas is cooled down step by step, the rear-end heat pump sequentially recovers medium-temperature and low-temperature residual heat, producing medium-temperature hot air for auxiliary convection dehydration in the drying chamber and low-temperature heat energy for preheating the material feed. This effectively realizes the high-value utilization of high-grade heat and the low-value reuse of low-grade heat, fully recovering the sensible heat and latent heat of vaporization in the exhaust gas, and eliminating the heat waste caused by the direct discharge of humid and hot exhaust gas.

[0118] This invention effectively solves the problems of low thermal efficiency and severe heat loss from exhaust gas in traditional hot air drying, as well as the inability to recover waste heat and significant heat loss in conventional contact drying. The overall thermal efficiency of the system is greatly improved, and the comprehensive energy consumption is significantly reduced. The equipment operates in a completely closed system; exhaust gas is cooled and dehumidified by a multi-stage heat pump before being discharged in compliance with standards. Condensed wastewater can be recycled, and there is no dust or odor leakage, making it highly environmentally friendly. Simultaneously, the system can automatically control the closed loop, reducing manual operation and lowering equipment maintenance costs. The modular vertical structure also facilitates large-scale manufacturing and on-site assembly, making it more suitable for industrial-scale applications.

[0119] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A heat exchange device for a dryer, characterized in that, It includes a main shaft and a drive mechanism. The main shaft is connected to the output shaft of the drive mechanism. Multiple blade mechanisms are circumferentially connected to the main shaft. The blade mechanisms are used to contact and exchange heat with the material and flip the material under power drive. The main shaft is provided with an oil inlet channel and an oil return channel. The blade mechanism is provided with a heat transfer medium channel, which is connected between the oil inlet channel and the oil return channel, for the passage of heat transfer medium to allow the blade mechanism to contact the material for heat exchange.

2. The apparatus according to claim 1, characterized in that, The spindle is hollow inside and has a concentric inner tube inserted through it. The inner tube is hollow inside and serves as an oil return channel. The outer wall of the inner tube and the inner wall of the spindle form an annular sandwich layer, which serves as an oil inlet channel. The blade mechanism includes blades and an oil inlet branch pipe and an oil return branch pipe located at the root of the blades. The heat medium flow channel is located inside the blades. The inlet of the heat medium flow channel is connected to the annular interlayer inside the main shaft via the oil inlet branch pipe, and the outlet of the heat medium flow channel is connected to the inner pipe via the oil return branch pipe.

3. The apparatus according to claim 2, characterized in that, The blade head is equipped with a scraper, which is connected to the blade head via a spring plate. The scraper is used to scrape off materials during movement.

4. A drying system, characterized in that, The device includes a dryer, wherein the dryer employs the apparatus described in any one of claims 1-3, and the dryer further includes a cylinder and one or more drying chambers arranged along the direction of gravity within the cylinder. The top of the cylinder is provided with a material inlet and a waste gas outlet. The main shaft is located at the axis of the cylinder, and in each drying chamber, the main shaft is circumferentially connected with multiple blade mechanisms. The outer wall of the cylinder is provided with a main oil inlet and a main oil outlet, which are used for the heat transfer medium to enter and flow out, respectively. The main oil inlet is connected to the oil inlet channel, and the main oil outlet is connected to the oil return channel. The bottom wall of the cylinder is also provided with a discharge port for discharging the dried material.

5. The system according to claim 4, characterized in that, It also includes a waste heat recovery device, which includes at least a first heat pump module. The first heat pump module is used to recover the heat in the waste gas discharged through the exhaust gas outlet of the dryer and heat the heat transfer medium for use by the dryer.

6. The system according to claim 5, characterized in that, A heat-conducting jacket is provided on the side wall of the cylinder at a position corresponding to each stage of the drying chamber; The first heat pump module includes a first evaporator, a first compressor, and a first heat exchanger. The first evaporator includes a first air inlet, a first air outlet, a first refrigerant outlet, and a first refrigerant return port. The first air inlet is connected to the exhaust gas outlet. The first evaporator is used to absorb heat from the exhaust gas through liquid refrigerant and output gaseous refrigerant through the first refrigerant outlet, and to discharge exhaust gas through the first air outlet. The inlet of the first compressor is connected to the outlet of the first refrigerant, and the outlet of the first compressor is connected to the inlet of the first heat exchanger. The first compressor is used to compress the gaseous refrigerant and output the compressed refrigerant to the first heat exchanger. The first heat exchanger includes a first inlet, a first outlet, a heat transfer oil inlet, and a heat transfer oil outlet. The first outlet is connected to the first refrigerant return port of the first evaporator. The heat transfer oil outlet is used to communicate with the main oil inlet and one or more heat transfer jacket inlets, respectively. The heat transfer oil inlet is used to communicate with the main oil outlet and one or more heat transfer jacket outlets, respectively. The first heat exchanger is used to convert the compressed refrigerant into a liquid state and return it to the first evaporator, and to heat the heat transfer medium for use by the dryer.

7. The system according to claim 6, characterized in that, The drying chamber is provided with at least three stages, with corresponding heat-conducting jackets being a primary heat-conducting jacket, a secondary heat-conducting jacket, and a tertiary heat-conducting jacket. The heat-conducting oil outlet is connected to the inlet of the primary heat-conducting jacket and the inlet of the secondary heat-conducting jacket via oil supply pipelines. The outlets of the primary and secondary heat-conducting jackets are both connected to the inlet of the tertiary heat-conducting jacket via oil supply pipelines. The outlet of the tertiary heat-conducting jacket is connected to the heat-conducting oil inlet via an oil supply pipeline.

8. The system according to claim 6, characterized in that, The waste heat recovery device also includes a second heat pump module, which is cascaded with the first heat pump module. The waste gas discharged from the exhaust outlet flows through the first heat pump module and the second heat pump module in sequence, and the heat is recovered step by step. The second heat pump module is used to heat the compressed air using the recovered heat and then supply it to the dryer.

9. The system according to claim 8, characterized in that, Each stage of the drying chamber is provided with a hot air inlet on the side wall of the cylinder. The second heat pump module includes a second evaporator, a second compressor, and a second heat exchanger. The second evaporator includes a second air inlet, a second air outlet, a second refrigerant outlet, and a second refrigerant return port. The second air inlet is connected to the first air outlet of the first evaporator. The second evaporator is used to absorb heat from the exhaust gas through liquid refrigerant and output gaseous refrigerant through the second refrigerant outlet, and to discharge exhaust gas through the second air outlet. The inlet of the second compressor is connected to the outlet of the second refrigerant, and the outlet of the second compressor is connected to the second inlet of the second heat exchanger. The second compressor is used to compress the gaseous refrigerant and output the compressed refrigerant to the second heat exchanger. The second heat exchanger includes a second inlet, a second outlet, a compressed air inlet, and a hot air outlet. The second outlet is connected to the second refrigerant return port of the second evaporator. The compressed air inlet is used to introduce external compressed air, and the hot air outlet is used to communicate with one or more hot air inlets. The second heat exchanger is used to convert the compressed refrigerant into a liquid state and return it to the second evaporator, and to heat the compressed air for use by the dryer.

10. The system according to claim 9, characterized in that, Also includes: An anti-sticking and dispersing component is used for material entry and for dispersing and deagglomerating the material; The first variable frequency screw feeding mechanism is used to quantitatively feed the dispersed material; A preheater is used to preheat the dispersed material; The second variable frequency screw feeding mechanism is used to quantitatively feed the preheated material and transport the material to the dryer; The waste heat recovery device also includes a third heat pump module, which is cascaded with the second heat pump module. The waste gas discharged from the exhaust outlet flows sequentially through the first heat pump module, the second heat pump module and the third heat pump module, and the heat is recovered step by step. The third heat pump module is used to heat water using the recovered heat and then supply it to the preheater.

11. The system according to claim 10, characterized in that, The third heat pump module includes a third evaporator, a third compressor, and a third heat exchanger. The third evaporator includes a third air inlet, a third air outlet, a third refrigerant outlet, and a third refrigerant return port. The third air inlet is connected to the second air outlet of the second evaporator, and the third air outlet is connected to a fan. The third evaporator is used to absorb heat from the waste gas through liquid refrigerant and output gaseous refrigerant through the third refrigerant outlet, and to discharge waste gas through the third air outlet. The inlet of the third compressor is connected to the outlet of the third refrigerant, and the outlet of the third compressor is connected to the third inlet of the third heat exchanger. The third compressor is used to compress the gaseous refrigerant and output the compressed refrigerant to the third heat exchanger. The third heat exchanger includes a third inlet, a third outlet, a hot water outlet, and a hot water inlet. The third outlet is connected to the third refrigerant return port of the third evaporator. The hot water inlet is used to connect to the water outlet on the preheater, and the hot water outlet is used to connect to the water inlet on the preheater. The third heat exchanger is used to convert the compressed refrigerant into a liquid state and return it to the third evaporator, as well as to heat the water for use by the preheater.

12. The system according to claim 4, characterized in that, The dryer also includes a moisture content detection mechanism, a spiral mechanism, and an intelligent control module. The moisture content detection mechanism is located inside the cylinder and is used to detect the moisture content of the material and output a moisture content signal. The spiral mechanism is located on the discharge port side at the bottom of the cylinder and is used to push the dried material out of the discharge port through rotating spiral blades. The intelligent control module is electrically connected to the moisture content detection mechanism and the spiral mechanism respectively, and is used to process the moisture content signal output by the moisture content detection mechanism to obtain moisture content data, compare the moisture content data with the target value, and control the spiral mechanism to open or close based on the comparison result.

Images