High-efficiency disc-type evaporative drying device, evaporative drying system and drying method

Abstract

This invention discloses a high-efficiency disc-type evaporative drying device, evaporative drying system, and drying method. A drying cylinder is mounted on a frame, and a rotating shaft is positioned inside the drying cylinder. Disc-shaped heating plates are evenly distributed on the rotating shaft, and a scraper mechanism is installed between adjacent heating plates. A partition is installed within the cavity of the rotating shaft, dividing the cavity into a steam chamber and a drainage chamber. The heating plates are hollow and have internal partitions. A speed-regulating mechanism drives the rotating shaft to rotate. A material spraying mechanism feeds liquid material from a material tank onto the surface of the disc-shaped heating plates inside the drying cylinder. A secondary steam compression mechanism is connected to the steam outlet of the drying cylinder to compress the secondary steam and return it to the rotating shaft. A condensate heat recovery mechanism recovers heat from the condensate. This invention achieves highly efficient and energy-saving operation of the drying device. Through integrated disc layout, adaptive scraper contact, and heat recovery, it achieves compact equipment and minimized energy consumption.

Description

Technical Field

[0001] This invention relates to the field of drying equipment technology, specifically to a high-efficiency disc-type evaporative drying device, evaporative drying system, and drying method. Background Technology

[0002] A drum scraper dryer is a type of liquid drying equipment that uses internal heating and conductive continuous drying. The material to be dried adheres to the outer wall of the rotating drum by distributing the liquid below the surface of the lower material tank, forming a liquid film. A heat source is transported to the inner wall of the drum through pipes, transferring heat to the material. This causes the solvent portion of the material adhering to the outer wall of the drum to evaporate, while suspended solids and solidified solutes are scraped off the drum surface and fall onto a screw conveyor below, transporting them to a packaging machine.

[0003] However, rotary drum scraper dryers have a large footprint and low effective heat transfer area per unit, as only the outer ring of the drum is an effective heat transfer area; the equipment has thick drum walls and is heavy, requiring a heat source to heat the drum walls when starting up, which wastes a lot of preheating heat and takes a long preheating time, resulting in low energy utilization efficiency; when the amount of material to be evaporated is large, multiple machines need to be configured to process it simultaneously, which doubles the footprint.

[0004] In addition, existing drying equipment generally suffers from the following shortcomings: the layout of steam conveying channels and condensate discharge channels is not entirely reasonable, and condensate is prone to backflow during operation, affecting heat transfer efficiency; scrapers mostly adopt a fixed installation structure, and cannot be compensated for after long-term wear; coupled with the thermal expansion effect during equipment operation, the contact state between the scraper and the heating surface is difficult to maintain stably, affecting the scraping effect; the circumferential area of ​​the heating surface is often not fully utilized, limiting the expansion of the effective drying area; the secondary steam and condensate waste heat generated during the drying process are not fully recovered and utilized, resulting in high overall energy consumption; and the discharge of solid materials is mostly limited to the normal pressure environment, making it difficult to adapt to the continuous discharge requirements under negative pressure conditions.

[0005] In recent years, with increasingly stringent environmental policies, industries that generate high-salinity wastewater, such as coal chemical industry, are facing increasingly urgent pressure to achieve zero emissions. According to the relevant requirements of the Ministry of Ecology and Environment, the construction, renovation, and expansion of coal chemical projects are prohibited from setting up evaporation ponds, and existing evaporation ponds must be eliminated within a specified timeframe to achieve near-zero wastewater discharge. The locations of these projects generally lack external steam sources, and existing evaporation drying technologies mostly rely on external steam, resulting in high energy consumption and operating costs, making it difficult to meet the low-cost requirements of zero-emission treatment. Therefore, there is an urgent need for an evaporation drying technology solution that does not rely on external steam, has low energy consumption, and can achieve continuous and stable output. Summary of the Invention

[0006] The purpose of this invention is to provide a high-efficiency disc-type evaporation drying device, evaporation drying system and drying method to solve the above-mentioned problems existing in the prior art.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: This invention discloses a high-efficiency disc-type evaporation and drying device, comprising a frame, a drying cylinder, a rotating shaft, a drive speed regulation mechanism, a material spraying mechanism, a scraper mechanism, a secondary steam compression mechanism, a condensate heat recovery mechanism, and a solid negative pressure discharge mechanism. The drying cylinder is mounted on the frame, and the rotating shaft is disposed inside the drying cylinder. Disc-shaped heating plates are evenly distributed on the rotating shaft, and the scraper mechanism is disposed between two adjacent heating plates. The rotating shaft has a cavity, and a partition is disposed along the length of the cavity, dividing the cavity into a steam chamber and a drainage chamber. One end of the rotating shaft has an opening communicating with the steam chamber. The heating plate has a vent at one end and a drain outlet at the other end, which communicates with the drain cavity. The heating plate is hollow and has an internal partition plate. The rotating shaft has an air inlet and a drain outlet communicating with the inner cavity of the heating plate. The air inlet and the drain outlet are separated by the partition plate. The drain outlet has an extension tube that extends into the cavity of the rotating shaft. When the rotating shaft rotates and the drain outlet reaches the bottom, the extension tube prevents condensate from flowing back into the heating plate. To improve the scraping effect of the scraper, the scraper mechanism is a follow-up scraper mechanism, including a base, a blade holder, a blade, and a pressure... The device comprises a cover, a compression spring, a sliding rail, a circumferential scraper, and a circumferential auxiliary solid scraper. The sliding rail is parallel to the rotation axis and fixed to the frame. The base is mounted on the sliding rail and can slide freely along the rail. The blade holder is rotatably connected to the base via a hinge. The blade is fixed to the blade holder. A screw is fixed to the base. The compression spring is sleeved on the screw. The cover presses the blade tightly under the elastic force of the compression spring, so that the blade edge is in close contact with the side of the heating plate. The circumferential scraper and the circumferential auxiliary solid scraper are respectively fixed to the frame. The liquid plate is in close contact with the circumference of the heating plate in the liquid distribution area, and the circumferential auxiliary solid scraper is in close contact with the circumference of the heating plate in the drying area. The drive speed regulation mechanism is used to drive the rotating shaft to rotate. The material spraying mechanism is used to send the liquid material in the material tank into the drying cylinder and spray it onto the surface of the heating plate. The secondary steam compression mechanism is connected to the steam outlet of the drying cylinder and is used to compress the secondary steam and send it back to the rotating shaft. The condensate heat recovery mechanism is connected to the drain outlet of the rotating shaft and is used to recover the heat of the condensate. The solid negative pressure discharge mechanism is connected to the discharge port of the drying cylinder and is used to discharge solid material under negative pressure.

[0008] Furthermore, the secondary steam compression mechanism includes a screw compressor and a demister. The inlet of the demister is connected to the steam outlet of the drying cylinder via a pipe, and the outlet is connected to the inlet of the screw compressor. The outlet of the screw compressor delivers the compressed steam to the heating steam inlet pipe of the rotating shaft via a pipe. The condensate heat recovery mechanism includes a heat exchanger, a steam ejector, and a flash buffer tank. The condensate inlet of the flash buffer tank is located in the upper part of the cylinder and is a horizontal tangential inlet, connected to the drain outlet of the rotating shaft. The top of the flash buffer tank is provided with a steam flash exhaust port, which is connected to the intake port of the steam ejector via a pipe. The bottom of the flash buffer tank is connected to the heat exchanger via a valve. The heat exchanger is connected to the material tank located below the heating plate via a valve. The steam ejector is also connected to the screw compressor, and its output end is connected to the vent of the rotating shaft.

[0009] Furthermore, to facilitate uniform spraying of the liquid material and ensure sufficient contact between the liquid material and the disc-shaped heating plate to improve the drying effect, the material spraying mechanism includes a material tank, a spray pump, a slurry agitator, and a spray gun. The material tank is positioned below the heating plate, the slurry agitator is installed inside the material tank, and the spray gun is located in the lower middle part of both sides of the heating plate and is fixed to the frame by an adjustable bracket. One end of the spray pump is connected to the material tank, and the other end is connected to the spray gun through a delivery pipe and a hose.

[0010] Furthermore, the solid negative pressure discharge mechanism includes a bidirectional screw conveyor, a vacuum shut-off valve, and a negative pressure switching buffer tank. The bidirectional screw conveyor is connected to the discharge port at the bottom of the drying cylinder. The bidirectional screw conveyor has two discharge ports, which are respectively connected to the vacuum shut-off valve. The vacuum shut-off valve is connected to the negative pressure switching buffer tank, and the negative pressure switching buffer tank is equipped with a discharge valve.

[0011] Furthermore, the drive speed regulation mechanism includes a motor, a gear reducer, and a sprocket. The motor drives the rotating shaft to rotate through the gear reducer and the sprocket. An infrared online thermometer is installed on the inner wall of the drying cylinder. The infrared online thermometer is linked with the motor and the gear reducer. The infrared online thermometer measures the relationship between the surface temperature of the drying area on the heating plate and the moisture content of the dried solid. Combined with a set algorithm, the degree of dryness of the solid is determined, and the rotation speed is automatically adjusted.

[0012] Furthermore, in order to monitor the temperature inside the drying drum in real time, the degree of dryness of the solids is indirectly determined by comparing the relationship between this temperature and the moisture content of the dried solids, combined with the set algorithm. The rotation speed is automatically adjusted by the frequency converter, and the drying time is increased or shortened to adjust the degree of dryness of the discharged solids. Therefore, an infrared online thermometer is installed on the inner wall of the drying drum, which is linked with the motor and gear reducer through the frequency converter.

[0013] Furthermore, to facilitate cleaning inside the drying cylinder, an online cleaning mechanism is also included. The online cleaning mechanism includes multiple spray cleaning balls arranged between the heating plates, a cleaning pump connected to the spray cleaning balls, and a liquid receiving tank. The liquid receiving tank is detachably connected to the discharge port of the drying cylinder.

[0014] Furthermore, the heating plate is made of metal with hard chrome plating on the outside.

[0015] Furthermore, in order to improve the overall strength of the heating plate and enhance its turbulence effect, the inner cavity of the heating plate is uniformly provided with several tie rods distributed in a ring.

[0016] The present invention also provides an evaporation drying system, including the aforementioned high-efficiency disc-type evaporation drying device and a steam conveying device, a raw material conveying device, an exhaust device, and a condensate conveying device connected to the high-efficiency disc-type evaporation drying device.

[0017] The present invention also provides a drying method using the aforementioned evaporation drying system, comprising the following steps: S1. The liquid material is fed into the material tank of the high-efficiency disc evaporation dryer through the raw material conveying device; S2. Drive the rotating shaft to rotate through the speed regulation mechanism, and drive the disc-shaped heating plate to rotate at the same angular velocity; S3. Heating steam is introduced into the steam chamber inside the rotating shaft from the rotary joint at one end of the rotating shaft through the steam conveying device, and enters the cavity of the disc-shaped heating plate through the air inlet provided on the rotating shaft. S4. The liquid material in the material tank is sprayed onto the two sides of the disc-shaped heating plate through the conveying pipe and spray gun by the spray pump. The liquid adhering to the outside of the disc-shaped heating plate rotates with the disc-shaped heating plate and exchanges heat with the steam inside the disc-shaped heating plate. After the solvent vaporizes, it is discharged from the exhaust device at the top of the drying cylinder. S5. Heating steam transfers heat to the material on the outside through both sides of the disc-shaped heating plate and then condenses into water. The condensate is discharged into the drain chamber of the rotating shaft through the drain hole on the rotating shaft and discharged to the condensate conveying device from the rotary joint at the other end of the rotating shaft. S6. Solutes or suspended solids in the material adhere to the disc-shaped heating plate during rotation and are dried. The dried solids fall off the disc-shaped heating plate under the action of the blades of the follow-up scraper mechanism and fall into the bidirectional screw conveyor. S7. The dried solids are conveyed by a bidirectional screw conveyor and discharged from the drying cylinder under negative pressure through a vacuum shut-off valve and a negative pressure switching buffer tank. S8. The secondary steam discharged from the steam outlet of the drying cylinder is filtered by the dust collector and then enters the compressor for compression, heating and pressurization. The compressed steam is then sent back into the rotating shaft for recycling. S9. The high-temperature condensate discharged from the drain outlet of the rotating shaft enters the flash buffer tank for flash evaporation. The generated secondary steam is compressed by the steam ejector and sent into the rotating shaft. The condensate after flash evaporation exchanges heat with the material through the heat exchanger and is then discharged.

[0018] Compared with the prior art, the beneficial technical effects of the present invention are as follows: 1. This invention significantly improves the integration of heat exchange area by evenly distributing multiple disc-shaped heating plates on a rotating shaft, achieving lightweight and miniaturized drying equipment. It effectively shortens preheating time during startup, reducing waste of preheating heat source. Simultaneously, a partition within the rotating shaft divides the cavity into a steam chamber and a drain chamber. A partition inside the heating plates separates the air inlet and drain outlet, ensuring that heating steam and condensate flow separately. In particular, the drain outlet uses an elongated tube structure extending into the rotating shaft cavity. When the rotating shaft rotates and the drain outlet reaches the bottom, it effectively prevents condensate from flowing back into the heating plates. Combined with the annularly distributed reinforcing ribs within the heating plates enhancing steam turbulence and optimizing steam distribution between the main and auxiliary air inlets, the heat transfer efficiency on the heating side is significantly improved.

[0019] 2. The follow-up scraper mechanism of the present invention is equipped with a sliding track. When the device expands due to heat, the scraper can adjust and adapt accordingly. At the same time, the compression spring above the scraper holder maintains a suitable clamping force on the blade, keeping the tight contact force with the disc-shaped heating plate surface within a suitable range at all times. This ensures sufficient contact force so that the scraper can smoothly scrape off the dried solids on the plate surface, while preventing excessive contact force from wearing off the scraper and the plate surface. Meanwhile, the circumferential scraper plate fixed on the frame is in close contact with the circumference of the heating plate in the liquid distribution area, which can scrape off excess liquid and effectively control the liquid film thickness. The circumferential auxiliary solid scraper is in close contact with the circumference of the heating plate in the drying area, scraping off the dried solids. Through the synergistic effect of the scraper mechanism, the entire heat exchange surface of the two sides and the circumference of the disc-shaped heating plate is fully utilized, effectively increasing the drying area.

[0020] 3. This invention achieves tiered heat recovery and utilization during the drying process by setting up a secondary steam compression mechanism and a condensate heat recovery mechanism. The secondary steam compression mechanism purifies the secondary steam discharged from the drying cylinder through a dust collector and then compresses and heats it to reach the temperature and pressure required for heating the drying device before sending it back into the rotating shaft for recycling. At the same time, the high-temperature condensate discharged from the rotating shaft drain enters the flash buffer tank for flash evaporation. The generated secondary steam is drawn in by a steam ejector, compressed and heated, and returned to the heating pipe. The high-temperature condensate after flash evaporation exchanges heat with the low-temperature material through a heat exchanger, transferring heat to the material before being discharged from the system. The three-stage heat recovery system of secondary steam latent heat recovery, condensate flash steam recovery, and condensate sensible heat recovery works in synergy to significantly reduce or even replace the input of external live steam, resulting in significant energy savings.

[0021] 4. The solid negative pressure discharge mechanism of this invention continuously transports the dried solids to the negative pressure switching buffer tank via a bidirectional screw conveyor. Combined with the periodic switching of the vacuum shut-off valve and the discharge valve, it reliably achieves continuous solid discharge under negative pressure conditions, overcoming the shortcomings of atmospheric pressure discharge which is difficult to adapt to negative pressure conditions. The infrared online thermometer configured in the drive speed regulation mechanism can measure the surface temperature of the drying area on the heating plate in real time. By comparing the relationship between this temperature and the moisture content of the dried solids, and combining it with a set algorithm, the rotation speed is automatically adjusted to control the degree of drying of the discharged solids, adapting to the processing needs of different materials. The spray gun of the material spraying mechanism can be easily adjusted in terms of spray position and angle via a hose and adjustable bracket. The slurry agitator in the spray tank prevents solid particle deposition. The online cleaning mechanism enables convenient online cleaning. The auxiliary mechanisms work in coordination with the main body of the drying device, further improving the ease of operation, reliability, and applicability of the device. Based on the synergistic effect of the above-mentioned three-stage heat recovery system and negative pressure continuous discharge technology, the device of the present invention is particularly suitable for zero-discharge treatment scenarios of coal chemical wastewater in the absence of external steam sources, and can achieve low-cost drying treatment without the need for external steam input. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the overall structure of the high-efficiency disc-type evaporation and drying device according to Embodiment 1 of the present invention; Figure 2 This is a partial structural schematic diagram of the high-efficiency disc-type evaporation and drying device according to Embodiment 1 of the present invention; Figure 3 This is a schematic diagram of the online cleaning mechanism in the high-efficiency disc-type evaporation and drying device of Embodiment 1 of the present invention; Figure 4 This is a schematic diagram of the structure of the rotating shaft and the disc-shaped heating plate in the high-efficiency disc-type evaporation and drying device of Embodiment 1 of the present invention; Figure 5 This is a schematic diagram of the ventilation holes and drainage holes in the high-efficiency disc-type evaporation and drying device of Embodiment 1 of the present invention; Figure 6 This is a schematic diagram of the main structure of the scraper mechanism in the high-efficiency disc-type evaporation and drying device of Embodiment 1 of the present invention; Figure 7 This is a side view of the scraper mechanism in the high-efficiency disc-type evaporation and drying device of Embodiment 1 of the present invention. Figure 8 This is a schematic diagram of the structure of the circumferential scraper and the circumferential auxiliary solid scraper in the high-efficiency disc-type evaporation and drying device of Embodiment 1 of the present invention; Figure 9 This is a schematic diagram of the evaporation and drying system of Embodiment 2 of the present invention.

[0024] Explanation of reference numerals in the attached drawings: 1. Frame; 2. Drying cylinder; 3. Rotating shaft; 4. Bearing housing and bearing; 5. Motor; 6. Gear reducer; 7. Sprocket; 8. Disc-shaped heating plate; 9. Follow-up scraper mechanism; 10. Mechanical seal; 11. Spray pump; 12. Material tank; 13. Hose; 14. Spray gun; 15. Adjustable bracket; 16. Slurry agitator; 17. First valve; 18. Second valve; 19. Liquid receiving tank; 20. Cleaning pump; 21. Spray cleaning ball; 22. Steam outlet; 23. Dust collector; 24. Compressor; 25. Heat exchanger; 26. 27. Flash buffer tank; 28. Steam ejector; 29. ​​Vent; 30. Drain outlet; 31. Baffle plate; 32. Tie rod; 33. Drain hole; 34. Air inlet; 35. Divider plate; 36. Infrared online thermometer; 37. Bidirectional screw conveyor; 38. Vacuum shut-off valve; 39. Negative pressure switching buffer tank; 90. Discharge valve; 91. Base; 92. Knife holder; 93. Hinge; 94. Blade; 95. Pressure cap; 96. Compression spring; 97. Screw; 98. Locking nut; 99. Sliding rail; 910. Circumferential auxiliary solid scraper; 911. Circumferential scraper. Detailed Implementation

[0025] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying 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 with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0026] In the description of this invention, it should be understood that the terms "length," "width," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0027] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0028] The technical solutions provided by the various embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0029] Example 1 like Figures 1 to 8 As shown, the high-efficiency disc-type evaporation and drying device of this embodiment 1 includes a frame 1, a drying cylinder 2 set on the frame 1, a rotating shaft 3 set inside the drying cylinder 2, a drive speed regulating mechanism that can drive the rotating shaft 3 to rotate, a material spraying mechanism that can feed liquid materials into the drying cylinder 2, a solid negative pressure discharge mechanism that can discharge solid materials from the drying cylinder 2, an online cleaning mechanism that can clean the inside of the drying cylinder 2, and a secondary steam compression mechanism and a condensate heat recovery mechanism that can realize heat recovery. Among them, heating discs 8 are evenly distributed on the rotating shaft 3, and a scraper mechanism 9 is set between two adjacent heating discs 8. The two ends of the rotating shaft 3 are rotatably connected to the bearing seat and the bearing 4, respectively. A rotary joint is installed at each end of the rotating shaft 3. A mechanical seal 10 is set at the connection between the rotating shaft 3 and the drying cylinder 2.

[0030] Specifically, the drive speed regulation mechanism includes a motor 5, a gear reducer 6, and a sprocket 7. The motor 5 drives the rotating shaft 3 to rotate through the gear reducer 6 and the sprocket 7. The gear reducer 6 and the sprocket 7 can drive the rotating shaft 3 to rotate at a lower speed. At the same time, an infrared online thermometer 35 is installed on the inner wall of the drying cylinder 2. The infrared online thermometer 35 measures the relationship between the surface temperature of the drying area on the heating plate 8 and the moisture content of the dried solid. Combined with the set algorithm, the degree of dryness of the solid is determined, and the rotation speed is automatically adjusted. The drying time is increased or decreased to adjust the degree of dryness of the discharged solid.

[0031] Furthermore, the material spraying mechanism includes a material tank 12, a spray pump 11, a slurry agitator 16, a hose 13, an adjustable bracket 15, and spray guns 14. The material tank 12 is located directly below the heating plate 8. The material is connected to several spray guns 14 via the spray pump 11, a conveying pipe, and the hose 13. The spray guns 14 are distributed in the lower middle part of both sides of the heating plate 8. Under the action of gravity, a liquid film is formed on the heating plate 8, and excess material falls back into the material tank 12. The spray guns 14 are fixed to the frame 1 by the adjustable bracket 15, and their position and rotation angle can be adjusted back and forth to adjust the appropriate position of the material sprayed on the heating plate 8.

[0032] In this embodiment 1, the secondary steam compression mechanism consists of a screw compressor 24 and a demister 23. The inlet of the demister 23 is connected to the steam outlet 22 of the drying cylinder 2 via a pipe, and the outlet of the demister 23 is connected to the inlet of the screw compressor 24. The outlet of the screw compressor 24 delivers the compressed steam to the conveying pipe of the steam conveying device via a pipe.

[0033] The condensate heat recovery mechanism includes a heat exchanger 25, a steam ejector 27, and a flash buffer tank 26. The heat exchanger 25 is connected to the flash buffer tank 26, which is connected to the drain outlet of the rotating shaft 3. The steam ejector 27 is connected to both the screw compressor 24 and the flash buffer tank 26, and its output end is connected to the vent of the rotating shaft 3. The heat exchanger 25 is either a plate heat exchanger or a shell-and-tube heat exchanger. A level gauge is installed on the flash buffer tank 26. The condensate inlet of the flash buffer tank 26 is located in the upper part of the tank and is a horizontal tangential inlet. A steam flash exhaust port is located at the top and is connected to the intake port of the steam ejector 27 via a pipe. The bottom of the flash buffer tank 26 is connected to the heat exchanger 25 via a second valve 18, and the heat exchanger 25 is connected to the material tank 12 via a first valve 17.

[0034] Meanwhile, the solid negative pressure discharge mechanism consists of a bidirectional screw conveyor 36, two vacuum shut-off valves 37, two negative pressure switching buffer tanks 38, and two discharge valves 39. The inlet of the bidirectional screw conveyor 36 is connected to the outlet at the bottom of the drying cylinder 2, and it is equipped with two discharge ports, which are respectively connected to the two vacuum shut-off valves 37. A negative pressure switching pipe and a discharge valve 39 are installed after each vacuum shut-off valve 37.

[0035] like Figure 3 As shown, the online cleaning mechanism includes multiple spray cleaning balls 21 arranged between the heating plates 8 and above the material tank 12, as well as a cleaning pump 20 and a liquid receiving tank 19 connected to the spray cleaning balls 21. The liquid receiving tank 19 is a detachable structure and is connected to the discharge port of the drying cylinder 2 by a flange or threaded connection. When the material is a food material with high hygiene requirements, the online cleaning function can be realized by quickly installing and connecting the liquid receiving tank 19 and the cleaning pump 20 and the pipeline between them, saving a lot of manpower.

[0036] like Figure 4 , Figure 5 As shown, the rotating shaft 3 has a cavity, and a partition 30 is arranged along its length inside the cavity. The partition 30 divides the cavity into a steam chamber and a drain chamber. One end of the rotating shaft 3 has an air inlet 28 connected to the steam chamber, and the other end has a drain outlet 29 connected to the drain chamber. Steam inlet holes 33 of different sizes are opened on one side of the partition 30 at the position where it connects to the heating plate 8, including a main air inlet hole and an auxiliary air inlet hole. Multiple steam inlet holes optimize the distribution of heating steam and improve the discharge method of steam condensate, thereby improving the heat transfer efficiency on the heating side. They are connected to the inside of the heating plate 8 and are used to transport steam. This setting can improve the distribution efficiency of steam in the heating plate 8, so that the steam can be evenly distributed in the heating plate 8, eliminating heat exchange dead zones and improving heat transfer efficiency. A drain hole 32 is provided on the other side of the partition 30, communicating with the interior of the heating plate 8, for draining condensate. An extension tube of the drain hole 32 extends into the rotating shaft 3. When the rotating shaft 3 rotates, causing the drain hole 32 to reach the bottom, it prevents the condensate drained into the rotating shaft 3 from flowing back into the heating plate 8, thus increasing the drainage speed and improving heat transfer efficiency. The air inlet 33 and the drain hole 32 are separated by a partition plate 34.

[0037] Preferably, the heating plate 8 is a disc-shaped heating plate, which is also a hollow structure. It is fitted onto the outside of the hollow rotating shaft and fixed with bolts. One or more disc-shaped heating plates can be installed depending on the processing capacity. Because the disc-shaped heating plate is flat, the heat exchange area on both sides is large. A partition plate 34 is provided inside the disc-shaped heating plate to separate the heating steam and condensate. The plate is made of metal, and the outer side can be electroplated with hard chrome to enhance its hardness and corrosion resistance, thereby coping with harsh working conditions. Several tie rods 31 are evenly arranged in a ring inside the heating plate 8, which can enhance the turbulence of steam inside the heating plate 8 and improve heat transfer efficiency.

[0038] like Figures 6 to 8 As shown, the scraper mechanism is a follower scraper mechanism, including a base 91, a blade holder 92, a blade 94, a pressure cap 95, a compression spring 96, a sliding rail 99, a circumferential scraper 911, and a circumferential auxiliary solid scraper 910. The sliding rail 99 is parallel to the rotation axis 3 and fixed on the frame 1. The base 91 is mounted on the upper sliding rail 99 and can slide freely along the sliding rail 99. A hinge 93 is provided on the base 91, and the blade holder 92 can rotate around the hinge 93. The blade 94 is fixed on the blade holder 92. Two screws 97 are fixed in the middle of the base 91. The pressure cap 95 has two round holes facing the screws 97. The pressure cap 95 presses the blade 94 with the compression spring 96 and the locking nut 98, so that the blade edge of the blade 94 is pressed tightly against the side of the disc-shaped heating plate. The circumferential scraper 911 is fixed on the frame 1 and is in close contact with the circumference of the heating plate 8 near the liquid distribution area; the circumferential auxiliary solid scraper 910 is fixed on the frame 1 and is in close contact with the circumference of the heating plate 8 in the drying area.

[0039] Example 2 like Figure 9 As shown, the evaporation and drying system of this embodiment 2 includes the high-efficiency disc evaporation and drying device 100 and a steam conveying device 300, a raw material conveying device 200, an exhaust device 500 and a condensate conveying device 400 connected to the high-efficiency disc evaporation and drying device 100.

[0040] In the operation of the evaporation and drying system of this embodiment 2, the liquid material is first fed into the material tank of the high-efficiency disc-type evaporation and drying device 100 by the raw material conveying device 200. The speed regulating mechanism drives the hollow rotating shaft to rotate through the sprocket, which in turn drives the disc-shaped heating plates to rotate at the same angular velocity. Heating steam is fed in by the steam conveying device 300, which enters the steam chamber inside the rotating shaft through the rotary joint at one end of the rotating shaft, and enters the cavity of the disc-shaped heating plates through the air inlet provided on the rotating shaft. After the steam transfers heat to the material on the outside through both sides of the disc-shaped heating plates, it condenses into water and is discharged into the rotating shaft through the drain hole on the rotating shaft. It is then discharged to the condensate conveying device 400 through the rotary joint at the other end of the rotating shaft. After the material is conveyed to the material spraying mechanism, it is pressurized by the spray pump and lifted into the conveying pipe. The spray gun at the outlet of the conveying pipe is aimed at the lower middle part of both sides of the disc-shaped heating plates, adhering to the disc-shaped heating plates. The liquid on the outside of the hot plate rotates with the plate and exchanges heat with the steam inside the disc-shaped heating plate, rapidly heating up. The solvent vaporizes and is discharged from the exhaust device 500 at the top of the drying cylinder. Solutes or suspended solids in the material adhere to the hot disc-shaped heating plate during rotation and gradually dry. Finally, they are detached by the blades of the scraper mechanism tightly attached to the disc-shaped heating plate and fall into the liquid receiving tank before being sent to the packaging bag or packaging machine. The secondary steam compression mechanism compresses the steam discharged from the steam outlet, raises its temperature and pressure, and sends it back into the rotating shaft to improve the drying effect. The condensate heat recovery mechanism flashes the condensate for heat exchange, and the heat is also sent into the rotating shaft. The secondary steam compression mechanism can be turned off and the exhaust fan of the direct exhaust device can be used to transport the exhaust gas generated during drying. After removing the solid negative pressure discharge mechanism, the material is discharged at atmospheric pressure. The high-efficiency disc-type evaporation dryer can be adjusted to work under atmospheric pressure conditions.

[0041] Example 3 The drying method in this embodiment 3, using the aforementioned evaporation drying system, includes the following steps: S1. The liquid material is fed into the material tank 12 of the high-efficiency disc evaporation dryer 100 by the raw material conveying device 200. S2. Drive the rotating shaft 3 to rotate through the speed regulation mechanism, and drive the disc-shaped heating plate 8 to rotate at the same angular velocity. S3. Heating steam is introduced into the steam chamber inside the rotating shaft 3 from the rotary joint at one end of the rotating shaft 3 by the steam conveying device 300, and enters the cavity of the disc-shaped heating plate 8 through the air inlet 33 provided on the rotating shaft 3. S4. The liquid material in the material tank 12 is sprayed through the spray pump 11 to the two sides of the disc-shaped heating plate 8 via the conveying pipe and spray gun 14. The liquid adhering to the outside of the disc-shaped heating plate 8 rotates with the disc-shaped heating plate 8 and exchanges heat with the steam inside the disc-shaped heating plate 8. After the solvent vaporizes, it is discharged from the exhaust device 500 at the top of the drying cylinder 2. S5. The heating steam transfers heat to the material on the outside through both sides of the disc-shaped heating plate 8 and then condenses into water. The condensate is discharged into the drain chamber of the rotating shaft 3 through the drain hole 32 on the rotating shaft 3, and then discharged to the condensate conveying device 400 from the rotary joint at the other end of the rotating shaft 3. S6. The solute or suspended matter in the material adheres to the disc-shaped heating plate 8 during the rotation process and is dried. The dried solids fall off the disc-shaped heating plate 8 under the action of the blade of the follow-up scraper mechanism 9 and fall into the bidirectional screw conveyor 36. S7. The dried solids are conveyed by the bidirectional screw conveyor 36 and discharged from the drying cylinder 2 under negative pressure through the vacuum shut-off valve 37 and the negative pressure switching buffer tank 38. S8. The secondary steam discharged from the steam outlet of the drying cylinder 2 is filtered by the dust collector 23 and then enters the compressor 24 for compression, heating and pressurization. The compressed steam is then sent back into the rotating shaft 3 for recycling. S9. The high-temperature condensate discharged from the drain outlet of the rotating shaft 3 enters the flash buffer tank 26 for flash evaporation. The generated secondary steam is compressed by the steam ejector 27 and sent into the rotating shaft 3. The condensate after flash evaporation exchanges heat with the material through the heat exchanger 25 and is then discharged.

[0042] In summary, this invention, by arranging disc-shaped heating plates in a stacked manner on a rotating shaft, achieves both miniaturization and lightweight design of the equipment, while providing a structural foundation for efficient operation of subsequent stages. The partition plates within the rotating shaft and the heating plates separate the steam chamber and drainage chamber, allowing heating steam to be evenly distributed to each plate for heat exchange. The condensate formed after heat exchange is smoothly discharged through the extended pipe structure of the drainage hole, preventing backflow. This smooth steam-water circulation ensures continuous and stable heat exchange efficiency. This stable heat exchange efficiency ensures sufficient and controllable secondary steam and condensate waste heat generated during the drying process, creating favorable conditions for heat recovery. Combined with the secondary steam compression mechanism and the condensate heat recovery mechanism consisting of a flash buffer tank, steam ejector, and heat exchanger, the latent heat of the secondary steam and the sensible heat of the condensate, which would otherwise be directly discharged, can be recovered in stages and reused in the drying process, significantly reducing external energy input. On the material drying side, the follow-up scraper mechanism, through the coordination of sliding rails, hinged blade holders, and compression springs… Simultaneously, the device adaptively adjusts the bonding pressure when the equipment expands thermally and the blades wear. At the same time, the circumferential scraper and the circumferential auxiliary solid scraper scrape the liquid and material from the circumferential surfaces of the discs in the liquid distribution area and the drying area, respectively. The three work together to ensure that the dried solids on all heat exchange surfaces can be continuously and thoroughly removed. This maintains the cleanliness of the heat exchange surfaces to ensure the heat exchange efficiency of the aforementioned steam-water circulation, and avoids material accumulation and operational failures caused by incomplete scraping. On this basis, the solid negative pressure discharge mechanism realizes the continuous discharge of dried solids under negative pressure conditions. The infrared online thermometer and the drive speed regulation mechanism work together to realize the automatic control of the degree of drying of the discharged material. The adjustable spray mechanism and the online cleaning mechanism further improve the uniformity of material distribution and the convenience of equipment maintenance. This makes the various functional modules of the entire device form a synergistic effect in multiple dimensions such as structural improvement, heat recovery, scraping and discharge, and intelligent control, and together achieve the overall technical effect of equipment miniaturization, high heat exchange efficiency, minimum energy consumption, and stable operation.

[0043] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A high-efficiency disc-type evaporation and drying device, characterized in that, The utility model relates to a kind of drying machine, including rack (1), drying cylinder (2), rotating shaft (3), drive speed regulation mechanism, material spray mechanism, scraper mechanism, secondary steam compression mechanism, condensate heat recovery mechanism and solid negative pressure discharge mechanism, the drying cylinder (2) is set on the rack (1), the rotating shaft (3) is arranged in the drying cylinder (2), the rotating shaft (3) is evenly distributed with dish-shaped heating disc (8), adjacent two heating disc (8) are provided with scraper mechanism, the rotating shaft (3) has cavity, the cavity is provided with baffle (30) along length direction, the baffle (30) divides the cavity into steam cavity and drainage cavity, the rotating shaft (3) one end is provided with with the steam cavity intercommunication's air vent, the other end is provided with with the drainage cavity intercommunication's drainage port, the heating disc (8) is hollow structure and is provided with partition (34) inside, the rotating shaft is provided with with the heating disc inner cavity intercommunication's air inlet (33) and drainage hole (32), the air inlet (33) and the drainage hole (32) are separated by the partition (34), the drainage hole (32) has a section elongated tube, the elongated tube is inserted into the cavity of the rotating shaft (3), when the rotating shaft (3) rotates and makes the drainage hole (32) turn to bottom, the elongated tube is used to prevent condensate in the rotating shaft (3) from flowing back into the heating disc (8).The scraper mechanism is a follower scraper mechanism (9), including a base (91), a blade holder (92), a blade (94), a pressure cap (95), a compression spring (96), a sliding rail (99), a circumferential scraper plate (911), and a circumferential auxiliary solid scraper (910). The sliding rail (99) is parallel to the rotating shaft (3) and fixed on the frame (1). The base (91) is mounted on the sliding rail (99) and can slide freely along the rail. The blade holder (92) is rotatably connected to the base (91) through a hinge (93). The blade (94) is fixed on the blade holder (92). A screw (97) is fixed on the base (91). The compression spring (96) is sleeved on the screw (97). The pressure cap (95) presses the blade (94) tightly under the elastic force of the compression spring (96) so that the blade edge of the blade (94) is in contact with the heating plate (8). The circumferential scraper (911) and the circumferential auxiliary solid scraper (910) are respectively fixed on the frame (1). The circumferential scraper (911) is in close contact with the circumference of the heating plate (8) in the liquid distribution area, and the circumferential auxiliary solid scraper (910) is in close contact with the circumference of the heating plate (8) in the drying area. The drive speed adjustment mechanism is used to drive the rotating shaft (3) to rotate. The material spraying mechanism is used to send the liquid material in the material tank (12) into the drying cylinder (2) and spray it onto the surface of the heating plate (8). The secondary steam compression mechanism is connected to the steam outlet of the drying cylinder (2) and is used to compress the secondary steam and send it back to the rotating shaft (3). The condensate heat recovery mechanism is connected to the drain outlet of the rotating shaft (3) and is used to recover the heat of the condensate. The solid negative pressure discharge mechanism is connected to the discharge outlet of the drying cylinder (2) and is used to discharge solid material under negative pressure.

2. The high-efficiency disc-type evaporation and drying device according to claim 1, characterized in that, The secondary steam compression mechanism includes a screw compressor (24) and a demister (23). The inlet of the demister (23) is connected to the steam outlet (22) of the drying cylinder (2) via a pipe, and the outlet is connected to the inlet of the screw compressor (24). The outlet of the screw compressor (24) delivers the compressed steam to the heating steam inlet pipe of the rotating shaft (3) via a pipe. The condensate heat recovery mechanism includes a heat exchanger (25), a steam ejector (27), and a flash buffer tank (26). The condensate inlet of the flash buffer tank (26) is located in the upper part of the cylinder. The inlet is horizontal and tangential, and is connected to the drain outlet of the rotating shaft (3). The top of the flash buffer tank (26) is provided with a steam flash exhaust port, and is connected to the air intake of the steam ejector (27) through a pipe. The bottom end of the flash buffer tank (26) is connected to the heat exchanger (25) through the second valve (18). The heat exchanger (25) is connected to the material tank (12) located below the heating plate (8) through the first valve (17). The steam ejector (27) is also connected to the screw compressor (24), and its output end is connected to the air vent of the rotating shaft (3).

3. The high-efficiency disc-type evaporation and drying device according to claim 1, characterized in that, The material spraying mechanism includes a material tank (12), a spray pump (11), a slurry agitator (16), and a spray gun (14). The material tank (12) is located below the heating plate (8). The slurry agitator (16) is installed inside the material tank (12). The spray gun (14) is located in the lower middle part of the two sides of the heating plate (8) and is fixed on the frame (1) by an adjustable bracket (15). One end of the spray pump (11) is connected to the material tank (12), and the other end is connected to the spray gun (14) through a conveying pipe and a hose (13).

4. The high-efficiency disc-type evaporation and drying device according to claim 1, characterized in that, The solid negative pressure discharge mechanism includes a bidirectional screw conveyor (36), a vacuum shut-off valve (37), and a negative pressure switching buffer tank (38). The bidirectional screw conveyor (36) is connected to the discharge port at the bottom of the drying cylinder (2). The bidirectional screw conveyor (36) is provided with two discharge ports, which are respectively connected to the vacuum shut-off valve (37). The vacuum shut-off valve (37) is connected to the negative pressure switching buffer tank (38). The negative pressure switching buffer tank (38) is provided with a discharge valve (39).

5. The high-efficiency disc-type evaporation and drying device according to claim 1, characterized in that, The drive speed regulation mechanism includes a motor (5), a gear reducer (6), and a sprocket (7). The motor (5) drives the rotating shaft (3) to rotate through the gear reducer (6) and the sprocket (7). An infrared online thermometer (35) is installed on the inner wall of the drying cylinder (2). The infrared online thermometer (35) is linked with the motor (5) and the gear reducer (6). The infrared online thermometer (35) measures the relationship between the surface temperature of the drying area on the heating plate (8) and the moisture content of the dried solid. The degree of dryness of the solid is determined by the set algorithm, and the rotation speed is automatically adjusted.

6. The high-efficiency disc-type evaporation and drying device according to claim 1, characterized in that, It also includes an online cleaning mechanism, which includes multiple spray cleaning balls (21) arranged between the heating plates (8), a cleaning pump (20) connected to the spray cleaning balls (21), and a liquid receiving tank (19). The liquid receiving tank (19) is detachably connected to the discharge port of the drying cylinder (2).

7. The high-efficiency disc-type evaporation and drying device according to claim 1, characterized in that, The heating plate (8) is made of metal and has hard chrome plating on the outside.

8. The high-efficiency disc-type evaporation and drying apparatus according to any one of claims 1-7, characterized in that, The heating plate (8) has several tie rods (31) evenly arranged in a ring shape inside its cavity.

9. An evaporation drying system, characterized in that, It includes the high-efficiency disc evaporation dryer (100) as described in any one of claims 1-8, and a steam conveying device (300), a raw material conveying device (200), an exhaust device (500), and a condensate conveying device (400) connected to the high-efficiency disc evaporation dryer (100).

10. A drying method, characterized in that, The evaporation drying system as described in claim 9 includes the following steps: S1. The liquid material is fed into the material tank (12) of the high-efficiency disc evaporation dryer (100) by the raw material conveying device (200); S2. Drive the rotating shaft (3) to rotate through the speed regulation mechanism, and drive the disc-shaped heating plate (8) to rotate at the same angular velocity; S3. Heating steam is introduced into the steam chamber inside the rotating shaft (3) from the rotary joint at one end of the rotating shaft (3) by the steam conveying device (300), and enters the cavity of the disc-shaped heating plate (8) through the air inlet (33) provided on the rotating shaft (3); S4. The liquid material in the material tank (12) is sprayed through the conveying pipe and spray gun (14) to the two sides of the disc-shaped heating plate (8) by the spray pump (11). The liquid adhering to the outside of the disc-shaped heating plate (8) rotates with the disc-shaped heating plate (8) and exchanges heat with the steam inside the disc-shaped heating plate (8). After the solvent vaporizes, it is discharged from the exhaust device (500) at the top of the drying cylinder (2). S5. The heating steam transfers heat to the material on the outside through the disc-shaped heating plate (8) and then condenses into water. The condensate is discharged into the drain chamber of the rotating shaft (3) through the drain hole (32) on the rotating shaft (3) and discharged to the condensate conveying device (400) from the rotating joint at the other end of the rotating shaft (3). S6. The solute or suspended matter in the material adheres to the disc-shaped heating plate (8) during the rotation process and is dried. The dried solid falls off the disc-shaped heating plate (8) under the action of the blade of the follow-up scraper mechanism (9) and falls into the bidirectional screw conveyor (36). S7. The dried solids are conveyed by a bidirectional screw conveyor (36) and discharged from the drying cylinder (2) under negative pressure through a vacuum shut-off valve (37) and a negative pressure switching buffer tank (38). S8. The secondary steam discharged from the steam outlet of the drying cylinder (2) is dusted by the dust collector (23) and then enters the compressor (24) for compression, heating and pressurization. The compressed steam is then sent back into the rotating shaft (3) for recycling. S9. The high-temperature condensate discharged from the drain of the rotating shaft (3) enters the flash buffer tank (26) for flash evaporation. The generated secondary steam is compressed by the steam ejector (27) and sent into the rotating shaft (3). The condensate after flash evaporation is discharged after heat exchange with the material through the heat exchanger (25).

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