A high-efficiency vacuum mother liquor drying system

Abstract

This invention discloses a high-efficiency vacuum mother liquor drying system, belonging to the field of mother liquor drying technology. It includes a low-temperature dryer with a steam inlet, a mother liquor inlet, a gas outlet, a liquid outlet, and a solid outlet; a gas-liquid separator, with the gas outlet of the low-temperature dryer connected to the gas-liquid separator; a secondary steam cooler, with the gas outlet of the gas-liquid separator connected to the secondary steam cooler; and a condensate tank, with the liquid outlets of the low-temperature dryer, the gas-liquid separator, and the secondary steam cooler all connected to the condensate tank. This invention provides a high-efficiency vacuum mother liquor drying system that, through the low-temperature dryer, gas-liquid separator, and secondary steam cooler, effectively solves the problem of equipment scaling and reduces secondary exhaust gas pollution during mother liquor drying.

Description

Technical Field

[0001] This invention belongs to the field of mother liquor drying technology, specifically relating to a high-efficiency vacuum mother liquor drying system. Background Technology

[0002] In the context of today's rapid industrial development, the treatment of high-concentration saline wastewater has become a key challenge in the environmental protection field. This type of wastewater widely originates from numerous industries such as chemical, pharmaceutical, and electroplating, and its salt content often exceeds 5%, while also carrying a large amount of complex components such as organic matter and heavy metals.

[0003] Traditional treatment methods, such as multi-effect evaporation and mechanical vapor recompression (MVR) evaporation, can achieve the goal of wastewater desalination. However, they generate high-concentration mother liquor during the operation process, and the subsequent treatment of this mother liquor has become a new and thorny problem.

[0004] Traditional vacuum mother liquor drying systems exhibit numerous drawbacks when dealing with high-salt, high-COD mother liquors. Firstly, scaling and wall adhesion easily occur inside the equipment. These deposits obstruct heat transfer on the equipment's surfaces, reducing heat transfer efficiency, leading to higher energy consumption and longer processing times, significantly impacting overall efficiency. Secondly, secondary exhaust gases may be generated during the vacuum mother liquor drying process. If these exhaust gases are not properly treated and are directly emitted, they will pollute the surrounding environment and put pressure on the ecological environment.

[0005] Therefore, it is urgent to develop a high-efficiency vacuum mother liquor drying system that can effectively solve the problem of equipment scaling and wall adhesion and reduce the environmental impact of secondary exhaust gas. This is of great significance for promoting environmental protection and achieving sustainable industrial development. Summary of the Invention

[0006] The purpose of this invention is to provide a high-efficiency vacuum mother liquor drying system, so as to effectively solve the problem of scaling and wall adhesion on equipment and reduce secondary exhaust gas pollution during mother liquor drying.

[0007] To achieve the above objectives, embodiments of the present invention provide a high-efficiency vacuum mother liquor drying system, comprising: A low-temperature drying machine, wherein the low-temperature drying machine has a steam inlet, a mother liquor inlet, a gas outlet, a liquid outlet, and a solid outlet; A gas-liquid separator, wherein the gas outlet of the low-temperature dryer is connected to the gas-liquid separator; A secondary steam cooler, wherein the gas outlet of the gas-liquid separator is connected to the secondary steam cooler; The liquid outlets of the low-temperature dryer, the gas-liquid separator, and the secondary steam cooler are all connected to the condensate tank.

[0008] For example, at least one embodiment of this disclosure provides a high-efficiency vacuum mother liquor drying system, which further includes: A condensate pump, connected to the condensate tank, is used to drain condensate. A vacuum pump is connected to the gas outlet of the secondary steam cooler for recovering steam; A water supply tank, which is connected to the vacuum pump, is used to supply water to the vacuum pump; A cooler is connected to the water supply tank for cooling the water supply tank.

[0009] For example, at least one embodiment of this disclosure provides a high-efficiency vacuum mother liquor drying system, wherein the low-temperature dryer includes: A cylindrical body, wherein the liquid outlet is located at the bottom and the gas outlet is located at the top; An evaporating drum is rotatably disposed inside the cylinder body, and an annular space is formed between the evaporating drum and the cylinder body. The interior of the evaporating drum is connected to the steam inlet. A spray plate is disposed within the annular space and faces the outer wall of the evaporation cylinder. The mother liquor inlet is connected to the spray plate and is used to spray mother liquor onto the outer wall of the evaporation cylinder, thereby causing the mother liquor to evaporate and crystallize into a solid on the outer wall of the evaporation cylinder. A scraper is disposed on the inner wall of the cylinder and its end slides against the outer wall of the evaporation cylinder to scrape off the solid material on the outer wall of the evaporation cylinder. A receiving cone is disposed below the scraper and has a solid material outlet at its lower end, extending through the cylinder body to the outside of the cylinder body.

[0010] For example, at least one embodiment of this disclosure provides a high-efficiency vacuum mother liquor drying system, wherein the evaporation drum is conical and the scraper is inclined, the bottom of the evaporation drum has a water outlet, and the water outlet leads to the liquid outlet.

[0011] For example, at least one embodiment of this disclosure provides a high-efficiency vacuum mother liquor drying system, wherein the scraper is slidably arranged and further includes a first elastic member, one end of which abuts against the scraper and the other end of which abuts against the cylinder, providing a force for the scraper to approach and abut against the outer wall of the evaporation cylinder.

[0012] For example, at least one embodiment of this disclosure provides a high-efficiency vacuum mother liquor drying system, wherein the low-temperature dryer further includes: A sliding evaporator plate is horizontally slidably disposed on the evaporation drum and rotates with the evaporation drum. There are several sliding evaporator plates arranged in multiple circles. The sliding evaporator plate has an extended state for receiving mother liquor and a retracted state for discharging material. When it is in the extended state for receiving mother liquor, the sliding evaporator plate extends into the annular space to receive the mother liquor sprayed from the spray plate. When the sliding evaporator plate rotates to the top of the receiving cone, the sliding evaporator plate changes to the retracted state for discharging material, and the solid material on the sliding evaporator plate is scraped into the receiving cone. The second elastic element has one end acting on the sliding evaporation plate and the other end acting on the evaporation drum, providing a force for the sliding evaporation plate to retract into the unloading state.

[0013] For example, at least one embodiment of this disclosure provides a high-efficiency vacuum mother liquor drying system, wherein the low-temperature dryer further includes: An installation shaft is disposed within the cylinder, and the evaporating drum is rotatably mounted on the installation shaft. The installation shaft has a shaft cavity, which has a steam inlet and a steam communication port, and the steam communication port communicates with the inside of the evaporating drum.

[0014] For example, at least one embodiment of this disclosure provides a high-efficiency vacuum mother liquor drying system, wherein the low-temperature dryer further includes: The guide is mounted on the mounting shaft and has several cam grooves. The sliding evaporator plate has a sliding part that is slidably disposed in the cam groove. The cam groove has a recessed part. When the sliding part rotates and slides to the recessed part, the sliding evaporator plate changes from an extended state to a retracted state to a discharging state.

[0015] For example, at least one embodiment of this disclosure provides a high-efficiency vacuum mother liquor drying system, wherein the sliding evaporation plate has a heat conduction cavity that is connected to the inside of the evaporation drum, thereby allowing steam to enter.

[0016] For example, at least one embodiment of this disclosure provides a high-efficiency vacuum mother liquor drying system, wherein the upper surface of the sliding evaporator plate is zigzag-shaped.

[0017] The significant technical effects of the embodiments of the present invention are as follows: The low-temperature dryer ensures uniform heating of the mother liquor during evaporation, preventing scaling and wall adhesion caused by localized overheating, further enhancing the drying effect and ensuring efficient drying. The multiple gas-liquid separation structures within the gas-liquid separator effectively separate droplets from the secondary steam, reducing the amount of droplets entering the secondary steam cooler, improving steam cooling efficiency, and thus reducing droplets entrained in uncooled non-condensable gases, lowering the pollution level of secondary exhaust gases. The secondary steam cooler cools and transforms most of the water vapor into liquid for recovery; only a small amount of non-condensable gas is extracted by a vacuum pump, significantly reducing the emission of secondary exhaust gases, lowering pollution to the surrounding environment, and meeting environmental protection requirements. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art 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.

[0019] Figure 1 This is a schematic diagram of the structure of a high-efficiency vacuum mother liquor drying system in one embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of a low-temperature drying machine in another embodiment of the present invention; Figure 3 for Figure 2 A top view of the low-temperature dryer in the embodiment; Figure 4 for Figure 3 Schematic diagram of the sectional structure of the middle AA section; Figure 5 for Figure 3 Schematic diagram of the cross-sectional structure of the middle BB; Figure 6 for Figure 2 A side view of the low-temperature dryer in the embodiment; Figure 7 for Figure 6 Schematic diagram of the cross-sectional structure of the middle CC section; In the diagram: Low-temperature dryer 100, steam inlet 110, mother liquor inlet 120, gas outlet 130, liquid outlet 140, solid outlet 150, cylinder 160, evaporation drum 170, annular space 171, water outlet 172, spray plate 180, scraper 190, receiving cone 191, first elastic element 192, sliding evaporation plate 193, sliding part 1931, second elastic element 194, mounting shaft 195, shaft cavity 1951, steam connection port 1952, guide element 196, cam groove 1961, recess 1962, gas-liquid separator 200, secondary steam cooler 300, condensate tank 400, condensate pump 500, vacuum pump 600, makeup water tank 700, cooler 800. Detailed Implementation The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0021] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0022] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0023] In the description of the embodiments of this application, the term "and / or" is merely a description of the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship. In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple groups" refers to two or more groups (including two groups), and "multiple pieces" refers to two or more pieces (including two pieces).

[0024] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0025] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation", "connection", "linking", and "fixing" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components.

[0026] Please see Figure 1 This illustration shows a high-efficiency vacuum mother liquor drying system according to an embodiment of the present invention, including a low-temperature dryer 100, a gas-liquid separator 200, a secondary steam cooler 300, and a condensate tank 400. The low-temperature dryer 100 has a steam inlet 110, a mother liquor inlet 120, a gas outlet 130, a liquid outlet 140, and a solid outlet 150. The gas outlet 130 of the low-temperature dryer 100 leads to the gas-liquid separator 200, and the gas outlet of the gas-liquid separator 200 leads to the secondary steam cooler 300. The liquid outlet 140 of the low-temperature dryer 100, the liquid outlet of the gas-liquid separator 200, and the liquid outlet of the secondary steam cooler 300 all lead to the condensate tank 400.

[0027] It also includes a condensate pump 500, a vacuum pump 600, a water supply tank 700, and a cooler 800. The condensate pump 500 is connected to the condensate tank 400 for draining condensate. The gas outlet of the secondary steam cooler 300 is connected to the vacuum pump 600 for recovering steam. The water supply tank 700 is connected to the vacuum pump 600 for supplying water to the vacuum pump 600. The water supply tank 700 is connected to the cooler 800 for cooling the water supply tank 700.

[0028] For example, the low-temperature dryer 100 is equipped with a steam inlet 110, a mother liquor inlet 120, a gas outlet 130, a liquid outlet 140, and a solid outlet 150. Steam enters the low-temperature dryer 100 through the steam inlet 110, providing heat for the evaporation of the mother liquor. The mother liquor enters the dryer through the mother liquor inlet 120 and evaporates at a low temperature of 40-45℃. During the evaporation process, water vaporizes into secondary steam and is discharged from the gas outlet 130, the incompletely evaporated liquid flows out from the liquid outlet 140, and the solid material formed after drying is discharged from the solid outlet 150.

[0029] The gas-liquid separator 200 is a tank with a certain volume, internally equipped with various gas-liquid separation structures, such as baffles, cyclone separators, or wire mesh demisters. Baffles change the direction of gas flow, causing liquid droplets in the gas to collide with and separate due to inertia; cyclone separators utilize centrifugal force to separate gas and liquid; and wire mesh demisters capture tiny liquid droplets in the gas through the interception effect of the wire mesh. The tank is equipped with an inlet connected to the gas outlet 130 of the low-temperature dryer 100, as well as a gas outlet and a liquid outlet.

[0030] Secondary steam from the low-temperature dryer 100 enters the gas-liquid separator 200, where its internal gas-liquid separation structure separates the liquid droplets. The separated liquid flows from the liquid outlet to the condensate tank 400, while the gas exits from the gas outlet and enters the secondary steam cooler 300, achieving effective gas-liquid separation and improving the efficiency of subsequent steam cooling and recovery.

[0031] Secondary steam coolers (type 300) typically employ shell-and-tube or plate-type structures. Taking the shell-and-tube type as an example, the shell side is used for secondary steam introduction, while the tube side carries the cooling medium, such as cooling water or chilled brine. The heat exchange tubes of the cooler utilize high-efficiency heat transfer materials, such as copper or stainless steel tubes, to improve heat exchange efficiency. Simultaneously, the cooler is equipped with temperature sensors and flow control valves, which can adjust the flow rate of the cooling medium according to the steam temperature and flow rate to ensure sufficient cooling of the steam.

[0032] The gas discharged from the gas-liquid separator 200 enters the secondary steam cooler 300. Under the action of the cooling medium, the water vapor in the gas is cooled and changes phase into liquid, flowing from the liquid outlet into the condensate tank 400. The uncooled non-condensable gas is extracted by the vacuum pump 600 connected to the gas outlet of the secondary steam cooler 300, realizing the cooling of secondary steam and the recovery of condensate, reducing the environmental impact of exhaust gas emissions.

[0033] The condensate tank 400 is a storage tank with multiple inlets connected to the liquid outlet 140 of the cryogenic dryer 100, the liquid outlet of the gas-liquid separator 200, and the liquid outlet of the secondary steam cooler 300, as well as an outlet connected to the condensate pump 500. The tank is typically equipped with a level sensor to monitor the condensate level in real time. The condensate tank 400 collects condensate from the cryogenic dryer 100, the gas-liquid separator 200, and the secondary steam cooler 300. By monitoring the liquid level with the level sensor, the condensate pump 500 starts when the level reaches a certain height, discharging the condensate and ensuring normal circulation and treatment of the condensate within the system.

[0034] The condensate pump 500 is driven by a motor to rotate an impeller, generating centrifugal force to draw condensate from the condensate tank 400 and discharge it. The condensate pump 500 is responsible for drawing condensate from the condensate tank 400 and transporting it to a designated location for treatment or discharge, ensuring that condensate does not accumulate in the system and maintaining the normal operation of the system.

[0035] The inlet of the vacuum pump 600 is connected to the gas outlet of the secondary steam cooler 300. It is used to extract the non-condensable gas that has not been cooled in the secondary steam cooler 300, create a vacuum environment in the system, ensure that the mother liquor in the low temperature dryer 100 can be smoothly evaporated at low temperature, and at the same time recover steam to improve energy utilization.

[0036] The water replenishment tank 700 is a water storage container with an outlet connected to the vacuum pump 600 and an inlet / outlet connected to the cooler 800. A level gauge is typically installed on the tank to monitor the water level. The water replenishment tank 700 provides water to the vacuum pump 600, maintaining its stable operation. When the working fluid in the vacuum pump 600 becomes insufficient due to water evaporation or consumption during operation, the water in the water replenishment tank 700 will replenish the vacuum pump 600, ensuring its stable performance and thus guaranteeing normal evaporation of the entire system.

[0037] Cooler 800 is connected to water tank 700 and has a similar structure to secondary steam cooler 300, which can be either shell-and-tube or plate type. It cools the water in water tank 700 by introducing a cooling medium, such as cooling water or cold air. Cooler 800 lowers the temperature of the water in water tank 700, maintaining it within a suitable operating range for vacuum pump 600. A suitable water temperature helps improve the efficiency and stability of vacuum pump 600, thereby ensuring the normal operation of the entire vacuum mother liquor drying system.

[0038] During operation, high-salt, high-COD mother liquor enters the low-temperature dryer 100 through mother liquor inlet 120. Simultaneously, steam enters the low-temperature dryer 100 through steam inlet 110, transferring heat to the mother liquor via a heat exchanger. The mother liquor is uniformly heated at a low temperature of 40-45℃ and begins to evaporate. The secondary steam generated by evaporation is discharged from gas outlet 130, while the incompletely evaporated liquid flows out from liquid outlet 140, and the dried solid material is discharged from solid outlet 150. This low-temperature evaporation process effectively reduces scaling and wall adhesion inside the equipment, improving drying efficiency.

[0039] Secondary steam discharged from the low-temperature dryer 100 enters the gas-liquid separator 200. Inside the gas-liquid separator 200, liquid droplets in the secondary steam are separated using gas-liquid separation structures such as baffles, cyclone separators, or wire mesh demisters. The separated liquid flows from the liquid outlet to the condensate tank 400, while the gas exits from the gas outlet and enters the secondary steam cooler 300. In the secondary steam cooler 300, a cooling medium is introduced to cool the gas, causing water vapor to condense into liquid, which flows from the liquid outlet into the condensate tank 400. Uncooled non-condensable gases are extracted by the vacuum pump 600, reducing secondary exhaust gas emissions and mitigating environmental impact.

[0040] The condensate discharged from the liquid outlet 140 of the low-temperature dryer 100, the liquid outlet of the gas-liquid separator 200, and the liquid outlet of the secondary steam cooler 300 all flow into the condensate tank 400. The condensate tank 400 monitors the liquid level via a level sensor. When the liquid level reaches a certain height, the condensate pump 500 starts, discharging the condensate. Simultaneously, the water in the makeup water tank 700 is kept at a suitable temperature by the cooling effect of the cooler 800. When the working fluid of the vacuum pump 600 is insufficient, the makeup water tank 700 replenishes it, maintaining the stable operation of the vacuum pump 600 and ensuring that the entire system can continuously and stably perform vacuum mother liquor drying treatment.

[0041] The low-temperature evaporation process of 40-45℃ is adopted. Compared with the traditional high-temperature evaporation, it reduces the possibility of salt and organic matter in the mother liquor crystallizing and adhering on the equipment surface, effectively reducing the occurrence of scaling and wall adhesion, extending the service life of the equipment, and improving the operational stability and processing efficiency of the equipment.

[0042] The low-temperature dryer 100 ensures that the mother liquor is heated evenly during the evaporation process, avoiding scaling and wall adhesion caused by local overheating, further improving the drying effect and ensuring the efficient operation of the drying process.

[0043] The multiple gas-liquid separation structures inside the gas-liquid separator 200 can effectively separate liquid droplets from the secondary steam, reducing the amount of liquid droplets entering the secondary steam cooler 300, improving steam cooling efficiency, thereby reducing the liquid droplets entrained in the uncooled non-condensable gas and reducing the pollution level of the secondary exhaust gas.

[0044] The secondary steam cooler 300 cools and transforms most of the water vapor into liquid for recovery, with only a small amount of non-condensable gas being extracted by the vacuum pump 600. This greatly reduces the amount of secondary exhaust gas emitted, lowers the pollution to the surrounding environment, and meets environmental protection requirements.

[0045] The combination of condensate tank 400 and condensate pump 500 ensures timely collection and discharge of condensate within the system, preventing condensate accumulation from affecting equipment operation and guaranteeing the normal operation of the system.

[0046] The water supply tank 700 and the cooler 800 provide a stable supply of water to the vacuum pump 600 and ensure that the water supply temperature is suitable, thus maintaining the stable operation of the vacuum pump 600 and ensuring the stable evaporation process of the entire vacuum mother liquor drying system.

[0047] Please see Figures 2-7 In some examples, the low-temperature dryer 100 includes a cylinder 160, an evaporating drum 170, a spray plate 180, a scraper 190, and a receiving cone 191. The cylinder 160 has a liquid outlet 140 at the bottom and a gas outlet 130 at the top. The evaporating drum 170 is rotatably disposed within the cylinder 160, and an annular space 171 is formed between the evaporating drum 170 and the cylinder 160. The evaporating drum 170 is connected to a steam inlet 110. The spray plate 180 is disposed within the annular space 171 and faces the evaporating drum. The outer wall of the cylinder 170 has a mother liquor inlet 120 connected to a spray plate 180 for spraying mother liquor onto the outer wall of the evaporation cylinder 170, thereby causing the mother liquor to evaporate and crystallize into a solid on the outer wall of the evaporation cylinder 170. A scraper 190 is disposed on the inner wall of the cylinder 160, and its end slides against the outer wall of the evaporation cylinder 170 for scraping off the solid material on the outer wall of the evaporation cylinder 170. A receiving cone 191 is disposed below the scraper 190, and its lower end has a solid material outlet 150, which extends through the cylinder 160 to the outside of the cylinder 160.

[0048] The cylinder 160 is the main outer shell of the low-temperature dryer 100, and is cylindrical in shape. A liquid outlet 140 is located at the bottom to discharge incompletely evaporated liquid; a gas outlet 130 is located at the top to discharge secondary steam. The cylinder 160 is typically made of corrosion-resistant stainless steel to withstand the corrosive environment of high-salt, high-COD mother liquor. Its internal space accommodates components such as the evaporation drum 170 and scraper 190, providing a space for the drying of the mother liquor.

[0049] The cylinder 160 not only provides physical support for the internal components but also acts as a seal, ensuring that the drying process takes place in a relatively closed environment and maintaining the vacuum level within the system, which is beneficial for the evaporation of the mother liquor at low temperatures. Simultaneously, it performs preliminary separation and guidance of the gas, liquid, and solid phases generated during the drying process, allowing secondary steam to exit from the top, unevaporated liquid to flow out from the bottom, and the dried solid material to be discharged from the solid material outlet 150 through the scraper 190 and the receiving cone 191.

[0050] The evaporating drum 170 is rotatably mounted inside the cylinder 160 and arranged coaxially with the cylinder 160. An annular space 171 is formed between the evaporating drum 170 and the cylinder 160. The evaporating drum 170 is made of a metal with good thermal conductivity and corrosion resistance to ensure efficient heat transfer and resist corrosion from the mother liquor. Its interior is connected to the steam inlet 110, allowing steam to enter the interior of the evaporating drum 170.

[0051] The rotating evaporator 170 is the main component for mother liquor evaporation. After steam enters its interior, it transfers heat to the mother liquor within the annular space 171 through the cylinder wall. The mother liquor evaporates on the outer wall of the rotating evaporator 170. Due to the rotation of the cylinder, a uniform liquid film forms on its outer wall, increasing the evaporation area and improving evaporation efficiency. Simultaneously, the rotating evaporator 170 ensures continuous renewal of the mother liquor's contact with the heated wall surface during evaporation, further preventing scaling and wall adhesion.

[0052] The spray plate 180 is installed inside the annular space 171 and faces the outer wall of the evaporation drum 170. It is connected to the mother liquor inlet 120 through a pipe, and its structural design enables the mother liquor to be sprayed evenly on the outer wall of the evaporation drum 170.

[0053] The spray plate 180 sprays the mother liquor in a mist onto the outer wall of the evaporation drum 170, causing the mother liquor to quickly form a uniform liquid film on the outer wall of the drum. This greatly increases the contact area between the mother liquor and the hot wall surface, accelerating the evaporation process. This spraying method helps the mother liquor to evaporate and crystallize into a solid at a lower temperature, improving drying efficiency, while reducing the possibility of scale and wall adhesion caused by local accumulation of mother liquor.

[0054] A scraper 190 is disposed on the inner wall of the cylinder 160, and its end slides against the outer wall of the evaporation drum 170. The scraper 190 can effectively scrape off solid material adhering to the outer wall of the evaporation drum 170 without damaging it. The shape and size of the scraper 190 are designed according to the diameter of the evaporation drum 170 and the internal structure of the cylinder 160 to ensure complete coverage of the outer wall of the evaporation drum 170.

[0055] As the evaporation drum 170 rotates, the scraper 190 scrapes off the solid material formed by evaporation and crystallization on the outer wall of the drum, preventing excessive accumulation of solid material on the outer wall of the drum, which would affect evaporation efficiency and equipment operation. The scraped-off solid material falls into the receiving cone 191 below and is discharged through the solid material outlet 150, realizing timely collection and discharge of dried solid material and ensuring the continuity of the drying process.

[0056] The receiving cone 191 is located below the scraper 190 and has a tapered structure that is wider at the top and narrower at the bottom. Its upper opening is relatively large, allowing it to fully receive the solid material scraped off by the scraper 190. The lower end has a solid material outlet 150 that extends through the cylinder body 160 and outwards. The receiving cone 191 is made of the same corrosion-resistant stainless steel as the cylinder body 160 to ensure durability during the receiving and discharging of solid materials.

[0057] The receiving cone 191 is responsible for collecting the solid material scraped off by the scraper 190 and guiding it out of the cylinder 160 through the solid material outlet 150. The conical structure facilitates the natural sliding of the solid material, prevents blockage during collection, and ensures that the dried solid material can be smoothly discharged from the low-temperature dryer 100, providing convenience for subsequent processing.

[0058] During operation, the mother liquor enters the pipe connected to the spray plate 180 through the mother liquor inlet 120. The spray plate 180 evenly sprays the mother liquor onto the outer wall of the rotating evaporator cylinder 170. Simultaneously, steam enters the interior of the evaporator cylinder 170 through the steam inlet 110, transferring heat to the mother liquor on the outer wall through the cylinder wall. At a low temperature of 40-45℃, the mother liquor rapidly evaporates on the outer wall of the evaporator cylinder 170. The water vaporizes into secondary steam and exits from the gas outlet 130 at the top of the cylinder 160, while the salts and organic matter in the mother liquor gradually crystallize and adhere to the outer wall of the evaporator cylinder 170.

[0059] As the evaporation drum 170 continues to rotate, solid material adhering to its outer wall accumulates. The end of the scraper 190 slides against the outer wall of the evaporation drum 170, scraping off the solid material. The scraped-off solid material falls into the receiving cone 191 and is discharged from the low-temperature dryer 100 through the solid material outlet 150 at the lower end of the receiving cone 191, completing the collection of dried solid material.

[0060] During the evaporation of the mother liquor, the unevaporated liquid will flow downwards along the outer wall of the evaporation drum 170 and the inner wall of the drum 160, and finally be discharged from the liquid outlet 140 at the bottom of the drum 160 and enter the condensate tank 400 for further processing.

[0061] The spray plate 180 sprays the mother liquor onto the outer wall of the evaporation drum 170 to form a uniform liquid film. The rotation of the evaporation drum 170 also causes the mother liquor to continuously renew its contact with the hot wall surface, which greatly increases the evaporation area of ​​the mother liquor, accelerates the evaporation process, and improves the drying efficiency. Compared with traditional evaporation methods, it can process more mother liquor in a shorter time.

[0062] The evaporation drum 170 is made of a material with good thermal conductivity, and steam flows inside it. It efficiently transfers heat to the mother liquor through the drum wall, which improves the heat transfer efficiency and further promotes the evaporation of the mother liquor, achieving rapid drying under low temperature conditions.

[0063] The mother liquor is sprayed in a mist onto the outer wall of the rotating evaporator drum 170, ensuring uniform heating and preventing scaling and wall adhesion caused by localized overheating. Simultaneously, the rotating drum keeps the mother liquor flowing, reducing the possibility of it lingering in one area for an extended period and crystallizing.

[0064] The scraper 190 promptly scrapes off the solid material from the outer wall of the evaporation drum 170, preventing the solid material from accumulating on the outer wall of the drum. This further reduces the frequency of scaling and wall adhesion, and extends the continuous operating time and service life of the equipment.

[0065] The elastic and wear-resistant design of the scraper 190 ensures that it can effectively scrape off the solid material on the outer wall of the evaporation drum 170, improving the scraping efficiency of solid material and reducing the amount of solid material remaining on the outer wall of the drum.

[0066] The conical structure of the receiving cone 191 facilitates the natural sliding and collection of solid materials, prevents material blockage, and ensures that the dried solid materials can be smoothly discharged from the low-temperature dryer 100, thereby improving the operational stability and processing capacity of the entire drying system.

[0067] In some examples, the evaporation drum 170 is conical, and the scraper 190 is inclined. The bottom of the evaporation drum 170 has a water outlet 172 that leads to the liquid outlet 140. The scraper 190 is slidably disposed and also includes a first elastic member 192. One end of the first elastic member 192 abuts against the scraper 190, and the other end abuts against the drum body 160, providing a force for the scraper 190 to approach and abut against the outer wall of the evaporation drum 170.

[0068] For example, the evaporation drum 170 is designed as a cone shape, narrower at the top and wider at the bottom. This shape helps the mother liquor stay on the outer wall of the evaporation drum 170 for a longer period of time. A water outlet 172 is provided at the bottom of the drum, which is connected to the liquid outlet 140 at the bottom of the drum body 160. The interior of the evaporation drum 170 remains connected to the steam inlet 110 to ensure heat transfer.

[0069] The conical evaporation drum 170 allows the mother liquor to remain on the outer wall of the evaporation drum 170 for a longer period of time. At the same time, as the mother liquor flows downward, the inclined structure of the drum can more effectively increase the contact with the hot wall surface. The water outlet 172 is responsible for guiding the liquid that is not completely evaporated during the evaporation process and the condensate that may be generated to the liquid outlet 140, so as to achieve effective discharge of the liquid.

[0070] The scraper 190 is inclinedly disposed on the inner wall of the cylinder 160 and slides against the outer wall of the conical evaporator 170. The inclination angle of the scraper 190 is designed according to the taper of the evaporator 170 to ensure that the scraper can thoroughly and effectively scrape off the solid material on the outer wall of the evaporator 170. The scraper 190 is made of a wear-resistant and somewhat elastic material, such as polyurethane rubber, to adapt to long-term sliding contact with the outer wall of the evaporator 170.

[0071] The inclined scraper 190 works better with the conical evaporation drum 170. As the drum rotates, the scraper can smoothly scrape off the solid material formed during the crystallization process as it flows from top to bottom. The inclined scraper allows the solid material to slide more smoothly along the inclined direction of the scraper into the receiving cone 191 after being scraped off, avoiding the accumulation of solid material on the scraper and improving the collection efficiency of solid material.

[0072] The scraper 190 is slidably disposed on the inner wall of the cylinder 160. One end of the first elastic element 192 abuts against the scraper 190, and the other end is fixed to the inner wall of the cylinder 160. The first elastic element 192 is usually a spring, and its elastic coefficient is selected according to actual needs to provide appropriate elastic force.

[0073] The first elastic element 192 provides a continuous force for the scraper 190 to approach and abut against the outer wall of the evaporation drum 170. As the evaporation drum 170 wears down during long-term operation and undergoes minor deformations under different operating conditions, the slidingly mounted scraper 190, under the action of the first elastic element 192, maintains good contact with the outer wall of the evaporation drum 170, ensuring that the scraper can effectively remove solid materials. Even when the equipment operating parameters change, it can maintain a stable scraping effect, ensuring the continuity and stability of the drying process.

[0074] The conical evaporation drum 170 causes the mother liquor to form a thinner and more uniform liquid film under the action of gravity, increasing the evaporation area and allowing the mother liquor to come into more full contact with the hot wall surface, thereby accelerating the evaporation rate and improving the drying efficiency. Compared with ordinary cylindrical drums, it can evaporate more mother liquor in the same amount of time.

[0075] The inclined scraper 190, in conjunction with the conical evaporation drum 170, can more effectively scrape off solid materials and allow the scraped solid materials to slide smoothly down the inclined direction of the scraper into the receiving cone 191, reducing the residue and accumulation of solid materials on the scraper, improving the collection efficiency of solid materials, and ensuring the timely discharge of solid materials during the drying process.

[0076] The sliding scraper 190, under the action of the first elastic element 192, can adapt to the wear of the evaporation drum 170 and the slight deformation of the equipment, and always maintain good contact with the outer wall of the drum, ensuring the stability of the scraping effect. Even after long-term operation, it can maintain the efficient solid material scraping ability and extend the stable operation cycle of the equipment.

[0077] The water outlet 172 at the bottom of the evaporation drum 170 effectively guides the incompletely evaporated liquid and condensate to the liquid outlet 140, preventing the liquid from accumulating inside the evaporation drum 170, ensuring smooth liquid discharge, helping to maintain the normal operation of the drying process, and preventing the evaporation efficiency and equipment performance from being affected by the accumulation of liquid.

[0078] In some examples, the low-temperature dryer 100 also includes a sliding evaporator plate 193 and a second elastic element 194. The sliding evaporator plate 193 is horizontally slidably disposed on the evaporation drum 170 and rotates with the evaporation drum 170. There are several of them, arranged in multiple circles. The sliding evaporator plate 193 has an extended state for receiving mother liquor and a retracted state for discharging material. When it is in the extended state for receiving mother liquor, the sliding evaporator plate 193 extends to the annular space 171 to receive the mother liquor sprayed from the spray plate 180. When the sliding evaporator plate 193 rotates to the top of the receiving cone 191, the sliding evaporator plate 193 changes to the retracted state for discharging material, and the solid material on the sliding evaporator plate 193 is scraped into the receiving cone 191. One end of the second elastic element 194 acts on the sliding evaporator plate 193 and the other end acts on the evaporation drum 170, providing the force for the sliding evaporator plate 193 to change to the retracted state for discharging material.

[0079] The low-temperature dryer 100 also includes a mounting shaft 195 and a guide member 196. The mounting shaft 195 is disposed inside the cylinder 160, and the evaporation drum 170 is rotatably mounted on the mounting shaft 195. The mounting shaft 195 has a shaft cavity 1951, which has a steam inlet 110 and a steam connection port 1952. The steam connection port 1952 communicates with the inside of the evaporation drum 170. The guide member 196 is disposed on the mounting shaft 195 and has several cam grooves 1961. The sliding evaporation plate 193 has a sliding part 1931, which is slidably disposed in the cam grooves 1961. The cam grooves 1961 have recesses 1962. When the sliding part 1931 rotates and slides to the recesses 1962, the sliding evaporation plate 193 changes from an extended state to a retracted state to a discharging state.

[0080] For example, several sliding evaporation plates 193 are horizontally slidably mounted on the evaporation drum 170, arranged in multiple circular rings. Each sliding evaporation plate 193 has a sliding structure, allowing it to extend and retract on the evaporation drum 170. The sliding evaporation plates 193 are made of materials with good thermal conductivity and corrosion resistance to ensure efficient heat transfer and corrosion resistance during the receiving and evaporation of mother liquor. It has a sliding part 1931 for engaging with the cam groove 1961 of the guide member 196 to achieve precise state switching.

[0081] When the sliding evaporator plate 193 is in the extended receiving state, it extends into the annular space 171 to receive the mother liquor sprayed from the spray plate 180. Due to its excellent thermal conductivity, the mother liquor can be rapidly heated and evaporated on the sliding evaporator plate 193, further increasing the evaporation area and improving evaporation efficiency. When the sliding evaporator plate 193 rotates with the evaporation drum 170 to above the receiving cone 191, it retracts to the discharging state, scraping the solid material on it into the receiving cone 191, achieving efficient collection of dried solid material. This design makes the evaporation of mother liquor and the collection of solid material more orderly and efficient.

[0082] The second elastic element 194 acts on the sliding evaporator plate 193 at one end and on the evaporator drum 170 at the other end. A spring is usually selected as the second elastic element 194, and its elastic coefficient is selected according to actual needs to provide appropriate elastic force to ensure that the sliding evaporator plate 193 can reliably change from the extended state to the retracted state to the discharging state.

[0083] When the sliding evaporator plate 193 rotates to the top of the receiving cone 191, the sliding evaporator plate 193 rotates to the sliding part 1931 and slides to the recessed part 1962. Under the elastic force of the second elastic element 194, the sliding evaporator plate 193 becomes a retracted unloading state, scraping off the solid material and ensuring the timeliness and reliability of solid material collection.

[0084] The mounting shaft 195 is disposed within the cylinder 160, and the evaporating drum 170 is rotatably mounted on the mounting shaft 195. The mounting shaft 195 has a shaft cavity 1951, which is provided with a steam inlet 110 and a steam connection port 1952. The shaft cavity 1951 provides a passage for steam, allowing steam to enter from the steam inlet 110 and enter the evaporating drum 170 through the steam connection port 1952. The mounting shaft 195 is typically made of a high-strength, corrosion-resistant metal material to ensure that it can withstand the pressure of steam and the corrosion of the mother liquor while supporting the rotation of the evaporating drum 170.

[0085] The mounting shaft 195 not only provides rotational support for the evaporation drum 170, ensuring its stable rotation, but also facilitates steam transport through the shaft cavity 1951, providing a channel for steam to enter the interior of the evaporation drum 170 and ensuring the heat supply required for mother liquor evaporation. It is an important component of the entire heat transfer system of the low-temperature dryer 100.

[0086] The guide member 196 is mounted on the mounting shaft 195 and has several cam grooves 1961. The shape and layout of the cam grooves 1961 are designed according to the movement trajectory and state switching requirements of the sliding evaporator plate 193. The cam groove 1961 has a recess 1962. When the sliding part 1931 of the sliding evaporator plate 193 slides to the recess 1962, the sliding evaporator plate 193 changes from an extended state to a retracted state for discharging mother liquor under the action of the second elastic member 194. The guide member 196 is usually made of wear-resistant metal material to ensure the shape and accuracy of the cam grooves 1961 during long-term use, ensuring accurate guidance of the sliding evaporator plate 193.

[0087] In order to avoid the scraper 190 from contacting the sliding evaporator 193, the recess 1962 should be designed to be located on one side of the scraper 190. This way, when the sliding evaporator 193 is close to the scraper 190, under the action of the second elastic member 194, the sliding part 1931 of the sliding evaporator 193 can slide to the recess 1962, so as to change from the extended state to the retracted state to the discharging state, and make way to avoid the sliding evaporator 193 from colliding with the scraper 190.

[0088] The guide member 196 engages with the sliding part 1931 of the sliding evaporator plate 193 via the cam groove 1961, controlling the movement state of the sliding evaporator plate 193. During the rotation of the evaporator drum 170, the sliding part 1931 slides within the cam groove 1961. When the sliding part 1931 reaches the recess 1962, the sliding evaporator plate 193 changes its state under the action of the second elastic member 194, realizing the control of mother liquor reception and solid material discharge, thus improving the automation and stability of the drying process.

[0089] During operation, the mother liquor is sprayed out through the spray plate 180. At this time, the sliding evaporator plate 193 is extended to receive the mother liquor, reaching into the annular space 171. Steam enters from the steam inlet 110 of the shaft cavity 1951 of the mounting shaft 195 and enters the evaporation drum 170 through the steam communication port 1952. Heat is transferred to the mother liquor on the sliding evaporator plate 193 through the wall of the evaporation drum 170. At a low temperature of 40-45℃, the mother liquor evaporates on the sliding evaporator plate 193, and the water turns into secondary steam and is discharged from the gas outlet 130 at the top of the cylinder 160. The salt and organic matter in the mother liquor gradually crystallize to form solids that adhere to the sliding evaporator plate 193.

[0090] As the evaporation drum 170 rotates, the sliding evaporation plate 193 rotates accordingly. When the sliding part 1931 of the sliding evaporation plate 193 slides along the cam groove 1961 of the guide member 196 to the recess 1962, under the action of the second elastic member 194, the sliding evaporation plate 193 changes from an extended state to a retracted state to a material discharge state, scraping the solid material on it into the receiving cone 191. The receiving cone 191 guides the solid material to the solid material outlet 150 and discharges it from the low-temperature dryer 100.

[0091] During the evaporation of the mother liquor, the unevaporated liquid and any condensate that may be generated flow through the water outlet 172 at the bottom of the evaporation drum 170 to the liquid outlet 140 at the bottom of the drum body 160, and then enter the condensate tank 400 for further processing.

[0092] Multiple sliding evaporation plates are arranged in multiple rings around the 193 circumference, which greatly increases the evaporation area of ​​the mother liquor, allowing more mother liquor to be heated and evaporated at the same time. Compared with the previous structure, the evaporation efficiency is further improved, and more mother liquor can be processed in a shorter time.

[0093] The sliding evaporation plate 193 is made of a material with good thermal conductivity and is in direct contact with the evaporation drum 170, which can quickly transfer heat, allowing the mother liquor to evaporate rapidly at low temperature, thus optimizing the heat transfer process and improving energy utilization efficiency.

[0094] The cooperation between the guide member 196 and the sliding evaporator 193 enables the sliding evaporator 193 to precisely switch between the extended state for receiving mother liquor and the retracted state for discharging material. When the sliding evaporator 193 rotates above the receiving cone 191, it accurately scrapes off the solid material, avoiding spillage and residue, and improving the accuracy and efficiency of solid material collection.

[0095] The second elastic element 194 provides a reliable retraction and material removal force for the sliding evaporator plate 193, ensuring that the sliding evaporator plate 193 can move quickly to scrape off the solid material when material removal is required, thus ensuring the timeliness and stability of solid material collection during the drying process.

[0096] The mounting shaft 195 provides stable rotational support for the evaporator drum 170, ensuring its smooth operation during high-speed rotation, reducing vibration and wear, and extending its service life. Simultaneously, the mounting shaft 195's role in steam transport ensures the stable operation of the heat transfer system.

[0097] The guide component 196 guides the sliding evaporator plate 193, enabling the movement state of the sliding evaporator plate 193 to be accurately switched according to design requirements, thereby improving the automation and stability of the drying process and reducing the probability of failure caused by human factors or component movement deviations.

[0098] In some examples, the sliding evaporator 193 has a heat conduction cavity that communicates with the inside of the evaporation drum 170, thereby allowing steam to enter, and the upper surface of the sliding evaporator 193 is zigzag-shaped.

[0099] For example, the sliding evaporator plate 193 has a heat conduction cavity inside, which communicates with the interior of the rotating evaporator cylinder 170, allowing steam to enter the heat conduction cavity from the rotating evaporator cylinder 170. The shape and layout of the heat conduction cavity are designed according to the external shape of the sliding evaporator plate 193, and typically consist of multiple interconnected channels evenly distributed inside the sliding evaporator plate 193 to ensure that the steam can uniformly provide heat to the sliding evaporator plate 193. The inner wall of the heat conduction cavity is made of a high thermal conductivity material, such as an alloy of copper or silver, to improve heat transfer efficiency.

[0100] The heat transfer chamber further enhances the heat transfer capability of the sliding evaporator 193. After steam enters the heat transfer chamber, it directly transfers heat to the sliding evaporator 193 through the chamber wall, allowing the mother liquor to be heated and evaporated more quickly and evenly on the sliding evaporator 193. This direct steam heating method, compared to relying solely on heat transfer through the walls of the evaporator drum 170, significantly improves heat utilization and reduces heat loss during the transfer process, contributing to more efficient mother liquor drying under low-temperature conditions.

[0101] The upper surface of the sliding evaporator 193 is designed as a polygonal shape, consisting of multiple inclined planes. The angles and lengths of these inclined planes are optimized according to the flow characteristics of the mother liquor and the evaporation requirements. The polygonal upper surface increases the surface area of ​​the sliding evaporator 193, while changing the flow path of the mother liquor on the sliding evaporator 193.

[0102] The zigzag-shaped upper surface significantly increases the contact area between the mother liquor and the sliding evaporator plate 193, allowing the mother liquor to be more widely distributed on the plate, increasing the evaporation area and accelerating the evaporation rate. Furthermore, the different flow velocities and patterns of the mother liquor flowing on the zigzag-shaped surface facilitate mixing and uniform heat transfer, further preventing localized overheating and scaling. During solid material discharge, the special structure of the zigzag-shaped upper surface promotes the sliding of solid materials, improving discharge efficiency.

[0103] The heat conduction chamber allows steam to directly provide heat to the sliding evaporator plate 193, reducing heat transfer steps and improving heat transfer efficiency. The mother liquor can absorb heat more quickly, accelerating the evaporation process and allowing more mother liquor to evaporate in the same amount of time, thus improving overall drying efficiency.

[0104] The zigzag-shaped upper surface increases the contact area between the mother liquor and the sliding evaporation plate 193, creating more favorable conditions for mother liquor evaporation. More mother liquor can participate in evaporation simultaneously, further improving evaporation efficiency and facilitating efficient mother liquor drying at low temperatures.

[0105] The unique structure of the zigzag-shaped upper surface makes it easier for solid materials to slide off when the sliding evaporator 193 retracts, improving the discharge efficiency and reducing the residue of solid materials on the sliding evaporator 193. This helps keep the sliding evaporator 193 clean, ensuring its continuous and efficient reception and evaporation of mother liquor.

[0106] By combining the guide component 196 and the second elastic component 194, the precise state switching of the sliding evaporation plate 193 and the material removal advantage of the zigzag upper surface work together to further improve the stability and reliability of solid material collection and ensure the continuity of the drying process.

[0107] The design of the heat conduction cavity optimizes the heat transfer path, making the temperature distribution of the sliding evaporator plate 193 more uniform, reducing the risk of equipment damage caused by local overheating or overcooling, and enhancing the stability of system operation.

[0108] The zigzag-shaped upper surface can adapt to mother liquors with different viscosities and flow rates. By changing the flow state of the mother liquor, it ensures that the mother liquor is uniformly heated and evaporated on the sliding evaporation plate 193, thereby improving the system's adaptability to different mother liquor characteristics.

[0109] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of protection of the claims of the present invention.

Claims

1. A high-efficiency vacuum mother liquor drying system, characterized in that, include: A low-temperature dryer (100) has a steam inlet (110), a mother liquor inlet (120), a gas outlet (130), a liquid outlet (140), and a solid outlet (150). Gas-liquid separator (200), the gas outlet (130) of the low-temperature dryer (100) leads to the gas-liquid separator (200); A secondary steam cooler (300) is provided, wherein the gas outlet of the gas-liquid separator (200) is connected to the secondary steam cooler (300). The condensate tank (400), the liquid outlet (140) of the low-temperature dryer (100), the liquid outlet of the gas-liquid separator (200) and the liquid outlet of the secondary steam cooler (300) are all connected to the condensate tank (400).

2. The high-efficiency vacuum mother liquor drying system according to claim 1, characterized in that, Also includes: A condensate pump (500) is connected to the condensate tank (400) for draining condensate. A vacuum pump (600) is connected to the gas outlet of the secondary steam cooler (300) for recovering steam; A water supply tank (700) is connected to the vacuum pump (600) and is used to supply water to the vacuum pump (600); Cooler (800), the water tank (700) is connected to the cooler (800) for cooling the water tank (700).

3. The high-efficiency vacuum mother liquor drying system according to claim 1, characterized in that, The low-temperature drying machine (100) includes: The cylinder (160) has the liquid outlet (140) at the bottom and the gas outlet (130) at the top. An evaporating drum (170) is rotatably disposed inside the cylinder body (160), and an annular space (171) is formed between the evaporating drum (170) and the cylinder body (160). The evaporating drum (170) is connected to the steam inlet (110). A spray plate (180) is disposed in the annular space (171) and faces the outer wall of the evaporation cylinder (170). The mother liquor inlet (120) is connected to the spray plate (180) and is used to spray mother liquor onto the outer wall of the evaporation cylinder (170), so that the mother liquor evaporates and crystallizes into a solid on the outer wall of the evaporation cylinder (170). Scraper (190), the scraper (190) is disposed on the inner wall of the cylinder (160) and its end slides against the outer wall of the evaporation drum (170) for scraping off the solid material on the outer wall of the evaporation drum (170); A receiving cone (191) is disposed below the scraper (190) and has the solid material outlet (150) at its lower end, extending through the cylinder (160) to the outside of the cylinder (160).

4. The high-efficiency vacuum mother liquor drying system according to claim 3, characterized in that, The evaporation drum (170) is conical, and the scraper (190) is inclined. The bottom of the evaporation drum (170) has a water outlet (172), which leads to the liquid outlet (140).

5. The high-efficiency vacuum mother liquor drying system according to claim 4, characterized in that, The scraper (190) is slidably disposed and further includes a first elastic element (192), one end of the first elastic element (192) abutting against the scraper (190) and the other end abutting against the cylinder (160), providing a force for the scraper (190) to approach and abut against the outer wall of the evaporation cylinder (170).

6. The high-efficiency vacuum mother liquor drying system according to claim 4, characterized in that, The low-temperature dryer (100) also includes: A sliding evaporator plate (193) is horizontally slidably disposed on the evaporation drum (170) and rotates with the evaporation drum (170). There are several sliding evaporator plates arranged in multiple circles. The sliding evaporator plate (193) has an extended state for receiving mother liquor and a retracted state for discharging material. When it is in the extended state for receiving mother liquor, the sliding evaporator plate (193) extends to the annular space (171) to receive the mother liquor sprayed from the spray plate (180). When the sliding evaporator plate (193) rotates to the top of the receiving cone (191), the sliding evaporator plate (193) changes to the retracted state for discharging material, and the solid material on the sliding evaporator plate (193) is scraped into the receiving cone (191). The second elastic element (194) acts on the sliding evaporator plate (193) at one end and on the evaporator drum (170) at the other end, providing a force for the sliding evaporator plate (193) to retract into the unloading state.

7. The high-efficiency vacuum mother liquor drying system according to claim 6, characterized in that, The low-temperature dryer (100) also includes: The mounting shaft (195) is disposed inside the cylinder (160), and the evaporation drum (170) is rotatably disposed on the mounting shaft (195). The mounting shaft (195) has a shaft cavity (1951), the shaft cavity (1951) has the steam inlet (110) and the steam communication port (1952), and the steam communication port (1952) is connected to the inside of the evaporation drum (170).

8. The high-efficiency vacuum mother liquor drying system according to claim 7, characterized in that, The low-temperature dryer (100) also includes: The guide (196) is disposed on the mounting shaft (195) and has a plurality of cam grooves (1961). The sliding evaporator plate (193) has a sliding part (1931) which is slidably disposed in the cam groove (1961). The cam groove (1961) has a recess (1962). When the sliding part (1931) rotates and slides to the recess (1962), the sliding evaporator plate (193) changes from an extended state to a retracted state to a discharging state.

9. A high-efficiency vacuum mother liquor drying system according to claim 6, characterized in that, The sliding evaporation plate (193) has a heat conduction cavity that is connected to the inside of the evaporation drum (170), thereby allowing steam to enter.

10. A high-efficiency vacuum mother liquor drying system according to claim 6, characterized in that, The upper surface of the sliding evaporator plate (193) is zigzag-shaped.

Images