A large-scale maintenance-free corrugated panel evaporator

Abstract

The present invention discloses a large-scale maintenance-free corrugated panel evaporator, which comprises a heat exchange tube bundle. The heat exchange tube bundle includes a plurality of heat exchange plates arranged in parallel. Each heat exchange plate comprises two metal thin plates stacked together, and the two metal thin plates are laser welded into a corrugated heat transfer unit. A plurality of heat exchange plates are made into a corrugated panel shell-type heat exchange tube bundle. An inlet branch pipe and an outlet branch pipe are provided on each heat exchange plate, and the inlet branch pipe and the outlet branch pipe on each heat exchange plate are respectively connected to a steam inlet header pipe and a condensate outlet header pipe. At least one side of the heat exchange tube bundle is provided with an ultrasonic vibration rod, and the ultrasonic vibration rod passes through the shell of the evaporator and is connected to an ultrasonic transducer. On the basis of maintaining the original advantages of the corrugated panel heat exchanger, the present invention adopts a variety of on-line descaling technologies to ensure that the corrugated panel heat exchanger can achieve on-line continuous descaling and scale prevention regardless of the material with any viscosity or serious scaling, avoid the influence brought by scaling, and provide equipment technical support for zero discharge of wastewater.

Description

Technical Field

[0001] The present invention belongs to the field of heat exchange equipment manufacturing, and particularly relates to a large-scale maintenance-free corrugated plate evaporator. Background Art

[0002] The performance of a corrugated plate shell-and-tube heat exchanger lies between that of a plate heat exchanger and a shell-and-tube heat exchanger. It overcomes the defects of a plate heat exchanger and combines the advantages of both a plate heat exchanger and a shell-and-tube heat exchanger. The heat transfer coefficient of a corrugated plate shell-and-tube heat exchanger is much higher than that of a shell-and-tube heat exchanger and is second only to that of a plate heat exchanger. Generally, for steam-water heat exchange, the K value can reach 4000 - 6000 W / m2·°C, and for water-water heat exchange, the K value can reach 2000 - 3500 W / m2·°C.

[0003] A corrugated plate heat exchanger is a new type of wall heat exchanger with a simple structure, which is convenient for processing and mass production. A corrugated plate heat exchanger is a heat exchange equipment with characteristics such as high heat transfer coefficient, compact equipment, small volume, reliable sealing method, simple structure, convenient disassembly, corrosion resistance, and long service life. It combines the comprehensive advantages of a shell-and-tube heat exchanger and a plate heat exchanger, and is not restricted by size, shape, and material. It can be made into an efficient heat exchange equipment through any combination. Therefore, its application prospect is generally optimistic. Currently, in many fields, such as winemaking, pharmaceuticals, food processing, wastewater treatment, chemical black liquor treatment, and the nuclear industry, corrugated plate heat exchangers have been widely used.

[0004] Although the corrugated plate surface forms continuously changing zigzag channels inside and outside the plate, enhancing the turbulent effect of the fluid inside and outside the plate, strengthening the scouring effect of the fluid on the entire heat transfer wall surface, and making the heat transfer surface less prone to fouling compared with shell-and-tube heat exchangers. However, the fouling problem of the plate in the process of treating high-salt wastewater and chemical black liquor is still very serious, which not only wastes energy, but also affects product quality and reduces production, increases maintenance, wastes manpower and material resources. In this environment, the high-efficiency heat transfer advantage of the corrugated plate heat exchanger cannot be exerted, and it also increases the energy consumption of wastewater treatment and reduces the treatment capacity. Especially for the evaporation treatment of the mother liquor of high-salt wastewater, due to more serious fouling and adhesion problems, the evaporation systems currently in use in the market cannot work continuously, and due to the rapid fouling problem, the energy consumption is very high, seriously affecting the treatment of the last "one kilometer" of zero wastewater discharge. Therefore, in order to save treatment costs, some enterprises or cities that produce concentrated high-salt wastewater mostly use concentrated pools or drying ponds to store this concentrated liquid. The natural drying and air-drying treatment capacity cannot handle the increasing concentrated liquid, and in many places, the capacity of the concentrated pool has no place to store this high-salt concentrated liquid. The core method to solve this problem is first and foremost a core link, which is to separate the solid and liquid of the concentrated liquid, and then comprehensively utilize or harmlessly discharge it. The most mature method for solid-liquid separation of high-salt concentrated wastewater at home and abroad is heating evaporation. The basic principle of improving evaporation efficiency is to increase the temperature difference and pressure difference of the mass transfer interface. In current engineering practice, in order to avoid fouling of the heat transfer surface, the methods of low-temperature evaporation and increasing flow rate are mostly used, which limits the application of high-efficiency evaporation technology and increases the power consumption of the circulation pump at the same time. Summary of the Invention

[0005] The object of the present invention is to provide an evaporation system with a non-fouling heat exchanger as the core, which can automatically remove scale during the evaporation process, always maintain a good operating state at the beginning of operation, realize an efficient and continuous high-salt wastewater evaporation process, and solve the problem of fouling of the heat transfer surface, a large-scale maintenance-free corrugated plate evaporator.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A large-scale maintenance-free corrugated plate evaporator, comprising a heat exchange plate bundle, the heat exchange plate bundle includes a plurality of heat exchange plates arranged in parallel, each heat exchange plate is formed by laser welding two superimposed metal thin plates into a waveform heat transfer unit, and a plurality of heat exchange plates are made into a corrugated plate shell-type heat exchange plate bundle; an inlet and an outlet branch pipe are provided on each heat exchange plate, and the inlet and outlet branch pipes on each heat exchange plate are respectively connected to a steam inlet main pipe and a condensate outlet main pipe; at least one side of the heat exchange plate bundle is provided with an ultrasonic vibration rod, and the ultrasonic vibration rod passes through the shell of the evaporator and is connected to an ultrasonic transducer.

[0008] Preferably, the heat exchange plate is made of a thin metal plate. Spot welding is used on the plate surface of the heat exchange plate (1), and the periphery of the heat exchange plate is formed into a corrugated heat transfer unit with an internal flow channel through seam welding and bulging.

[0009] Preferably, the solder joints on the plate surface of the heat exchange plate are arranged in a diamond pattern. After the diamond pattern is formed, the heat exchange tube bundle is a continuous and crisscross multi-corrugated curved surface structure.

[0010] Preferably, ultrasonic vibration rods are respectively arranged on both sides of the heat exchange plate bundle, and the ultrasonic vibration rods are distributed on both sides of the heat exchange plate bundle in a left-right staggered manner.

[0011] Preferably, the periphery of the heat exchange plate bundle is sealed by two passes of roll welding, so that no gasket is required during the heat transfer process and leakage will not occur.

[0012] Preferably, a spacing is left between adjacent heat exchange plates.

[0013] Preferably, a scraper device is arranged between adjacent heat exchange plates among the plurality of heat exchange plates, and the scraper device is connected to a scraper driving mechanism.

[0014] Preferably, the scraper device includes a scraper support. The scraper support is vertically arranged between adjacent heat exchange plates. The scraper support is made of an elastic metal plate. A scraping blade is arranged on one side surface of the scraper support, and the scraping blade is perpendicular to the side surface of the scraper support; the scraper support is connected to a front beam transmission rod through a front beam, and the front beam transmission rod is connected to the scraper driving mechanism through a transmission interface.

[0015] Preferably, the scraper driving mechanism includes a power device and a straight shaft. The power device is drivingly connected to the straight shaft. A plurality of groups of crankshafts are arranged on the straight shaft. The crankshafts adopt an open U-shaped structure, and the opening directions of the plurality of groups of crankshafts on the straight shaft are distributed in a staggered manner up, down, left, and right; the opening of the crankshaft is connected to the transmission interface on the front beam transmission rod through a crankshaft connecting arm.

[0016] Preferably, a water spraying device is arranged on the scraper support, and water spraying descaling is realized through the water spraying device to enhance the descaling effect.

[0017] Compared with the prior art, the present invention has the following advantages:

[0018] 1. High heat transfer coefficient. After adopting the corrugated plate heat exchange element, the flow velocity magnitude and direction of the fluid change continuously during the flow process, intensifying the turbulent effect of the fluid. Since there is no baffle plate in the plate bundle, there is no flow dead angle or dead zone.

[0019] 2. The enhanced heat transfer effect is remarkable. The metal particles of the heat exchange plates always maintain high-speed elliptical motion during the heat transfer process, generating application forces in the vertical and horizontal directions on the materials being evaporated. This effectively destroys the thermal resistance and flow resistance of the material stagnant layer, thereby increasing the heat conduction heat transfer and convective heat transfer capabilities. Even when the heat exchange plates are in a clean state before fouling, their heat transfer effect is enhanced - enhanced heat transfer.

[0020] 3. The effect of preventing and removing inorganic salt scale is remarkable. During the evaporation process, supersaturated inorganic salt scale-forming substances in the material first form calcite scale on the heat exchange plates. During this process, due to the heat exchange plates always maintaining high-frequency fluctuations, the energy of peeling and shearing is always exerted on the scale. Larger scale particles are driven away by elastic waves and cannot contact the heat exchange wall surface. A large part of the scale particles that have just adhered to the heat exchange wall surface are also vertically peeled off. Even the scale adhering to the heat exchange surface is under the action of horizontal shear force, preventing this part of the scale from developing into calcite scale. Finally, the calcite scale is easily washed away under the action of peeling, shearing force, and flow force, thus keeping the heat exchange surface clean and maintaining the heat transfer effect.

[0021] 4. The effect of preventing and removing organic salt scale is remarkable. Organic salt scale has high viscosity, strong adhesion, but is relatively soft. Sometimes, relying on the ultrasonic fluctuations of the heat exchange surface with a thickness of only a few micrometers cannot completely prevent the adhesion of organic fouling. Scrapers are arranged between each heat exchange plate. Based on the ultrasonic fluctuations of the heat exchange plates, combined with the movement of the scrapers, the problem of the adhesion of organic fouling can be completely solved.

[0022] 5. The equipment is compact and small in size. Since the problem of fouling on the heat exchange surface is avoided, and at the same time, the heat transfer is enhanced. Coupled with the advantages of high heat transfer coefficient and high heat transfer efficiency of the corrugated plate heat exchanger, the area of the heat transfer elements required to achieve the same heat transfer amount will decrease.

[0023] 6. The ultrasonic equipment has stable performance and a long service life. The ultrasonic transducer is made of magnetostrictive material, has a very high Curie temperature and a wide frequency band, and can adapt to complex on-site environments and equipment.

[0024] 7. The scraper structure is simple, light in weight, and reliable in performance. For the first time, the scraper is manufactured by cutting and folding the edge of a metal plate. The scraper has large stretchability and can keep in contact with the uneven corrugated plate heat exchange surface. It has the characteristics of light weight, simple structure, long working safety life, and reliable performance, laying a technical foundation for the application of the scraper technology to large heat exchange plates.

[0025] 8. Facilitate the formation of liquid film and improve heat transfer efficiency. During the falling film evaporation process, when the liquid film has a uniform thickness and a fast flow rate, it is beneficial to improve the heat transfer efficiency. In the present invention, the scraper blades are arranged vertically and move horizontally. That is, whether the scraper is moving or stationary, the scraper blades will not have an adverse effect on the liquid film. In addition, since the corrugated panel has an uneven structure, it is basically impossible to form a liquid film with a uniform thickness. In the present invention, the vertical scraper blades move horizontally, which can scrape the non-uniform liquid film to be more uniform, thus facilitating the heat transfer effect.

[0026] 9. The scraper has the functions of thorough scale removal and self-cleaning. The scraper blades on both the left and right sides are always in contact with the corrugated panel with ultrasonic energy, so that the scraper blades, the scraper bracket and other connected devices also carry ultrasonic energy, preventing dirt from adhering to the scraper device, that is, having the self-cleaning function. In addition, since the heat exchange plate is always in a micron-level fluctuation state of more than 10,000 times per second, and the scraper blade is in contact with the heat exchange plate, from a microscopic perspective, it can be found that the scraper blade and the heat exchange plate also perform micron-level fluctuations of more than 10,000 times per second simultaneously. This kind of fluctuation has two functions. One is to effectively remove various dirt, and the other is to effectively reduce the frictional resistance between the tube sheet and the heat exchange plate, so that multiple scrapers can move flexibly among the heat exchange plates.

[0027] 10. The scraper device adopts a crankshaft drive mode, which can not only make multiple scraper devices move flexibly in a staggered manner, reducing the driving force, but also has only one drive shaft interface on large heat exchangers, with a simple structure, fewer fault points, and good aesthetics.

[0028] 11. Have the function of spraying water for scale removal. Since a scraper bracket 7.1 is arranged between each heat exchange plate, and a water spray pipe is installed on the scraper bracket 7.1, a water spraying device can be provided between the heat exchange plates. It has two functions. One is to use high-pressure water spraying for scale removal through logical control under evaporation conditions, and the other is to continuously heat the heat exchange plate under the condition of stopping evaporation, and then suddenly spray water on the heat exchange plate to produce a steam explosion effect, so that the dirt falls off quickly.

[0029] 12. No temperature difference stress. Since the inlet and outlet pipes on each heat exchange plate are connected to the inlet and outlet header pipes in a flexible connection manner, although the inlet and outlet header pipes are rigidly connected to the shell, there is no rigid connection between the shell and the tube bundle, so there is no temperature difference stress, and the corrugated panel shell type heat exchanger can be used for heat exchange of fluids with a large temperature difference.

[0030] 13. The evaporation process runs stably and requires no maintenance. In the present invention, a combined scale removal and anti-scaling method is set up, including the corrugated panel heat exchange method, ultrasonic scale removal device, tube sheet scale removal device, and water spraying scale removal device. At the same time, strict quality control is carried out on the processing process and material of the corrugated panel, ensuring the long-term stable and efficient operation of the equipment of the present invention during the actual evaporation process, and it is a high-pressure concentrated liquid evaporation device that requires no maintenance.

[0031] On the basis of maintaining the original advantages of the corrugated panel heat exchanger, this invention combines and applies a variety of on-line descaling technologies. No matter what kind of viscous or severely fouled materials are processed by the corrugated panel heat exchanger, on-line continuous descaling and scale prevention can be realized, thus avoiding the adverse effects brought by fouling, and the evaporation system always maintains a highly efficient and stable operation state, providing equipment technical support for zero liquid discharge of wastewater. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic structural diagram of a large-scale maintenance-free corrugated panel evaporator proposed by this invention;

[0033] Figure 2 It is a schematic structural diagram of a scraper device in a large-scale maintenance-free corrugated panel evaporator proposed by this invention;

[0034] Figure 3 It is a partial structural schematic diagram of Embodiment 1 in a large-scale maintenance-free corrugated panel evaporator proposed by this invention;

[0035] Figure 4 It is a partial structural schematic diagram of Embodiment 2 in a large-scale maintenance-free corrugated panel evaporator proposed by this invention;

[0036] Figure 5 It is a schematic structural diagram of a scraper drive mechanism in a large-scale maintenance-free corrugated panel evaporator proposed by this invention.

[0037] Reference numerals in the figures:

[0038] 1, heat exchange plate; 2, steam inlet header; 3, condensate outlet header; 4, ultrasonic vibration rod; 5, seal; 6, ultrasonic transducer; 7, scraper device; 7.1, scraper support; 7.2, scraper blade; 7.3, front support beam; 7.4, rear support beam; 7.5, front support beam transmission rod; 7.6, transmission interface; 7.7, front support beam; 8, scraper drive mechanism; 8.1, power device; 8.2, straight shaft; 8.3, fixed bracket; 8.4, crankshaft; 8.5, crankshaft connecting arm. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0039] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Embodiment

[0040] As Figures 1 to 3As shown in the figure, the present invention provides a large-scale maintenance-free corrugated panel evaporator, which includes a heat exchange plate bundle. The heat exchange plate bundle includes a plurality of heat exchange plates 1 arranged in parallel. Each heat exchange plate 1 is formed by laser welding two metal thin plates of the same material and equal thickness stacked together, and spot welding is performed on the plate surfaces of the two stacked metal thin plates. The solder joints on the plate surfaces are arranged in a diamond pattern. The surface shape after the diamond pattern formation is a continuous and criss-cross multi-wave curved surface. Then, the peripheries of the two stacked metal thin plates are seam welded and bulged to form a corrugated heat transfer unit with an internal flow channel. A plurality of groups of the heat exchange plates 1 after the above welding process are made into a corrugated panel shell-type heat exchange plate bundle, and a certain distance is left between each heat exchange plate 1. The size of this distance can be set after design calculation according to the fluid flow rate.

[0041] An inlet branch pipe and an outlet branch pipe are provided on each heat exchange plate 1. The inlet branch pipe and the outlet branch pipe on each heat exchange plate 1 are respectively connected to a steam inlet header 2 and a condensate outlet header 3 through hoses. Ultrasonic vibration rods 4 are provided on both sides of the heat exchange plate bundle. The ultrasonic vibration rods 4 are distributed on both sides of the heat exchange plate bundle in a staggered manner and are connected by welding. The ultrasonic vibration rods 4 pass through the evaporator shell and are sealed with the shell through a seal 5. The ultrasonic vibration rods 4 passing through the shell are connected to an ultrasonic transducer 6 outside the evaporator shell to achieve the purpose of sealed box vibration transmission. The ultrasonic transducer 6 can generate a frequency-modulated pulse signal under the drive of an ultrasonic controller to generate synchronous power ultrasonic energy. Through the ultrasonic vibration rods 4, this energy is transmitted to each heat exchange plate 1, causing the metal particles of the heat exchange plate 1 to perform high-frequency elliptical motion at the micron level, generating a vibration force in the direction perpendicular to the plate surface and a shear force in the horizontal direction of the plate surface on the liquid to be processed thereon. These two forces not only have good anti-scaling and descaling capabilities, but also have the functions of reducing the viscosity of the liquid and increasing the kinetic energy of liquid molecules, that is, having good functions of enhancing heat transfer and mass transfer.

[0042] Furthermore, the number of the ultrasonic vibration rods 4 provided can be determined according to the size of the heat exchange plates 1 and the severity of the expected fouling during operation.

[0043] Furthermore, two rows of seam welding are used to seal around each heat exchange plate 1, so that the hot fluid (or cold fluid) in the internal flow channel of the plate will not leak without a gasket during the flow and heat transfer process.

[0044] Furthermore, the material of the heat exchange plates 1 can be selected according to the corrosion degree of the waste liquid to be processed, and metal materials such as stainless steel or titanium can be used.

[0045] Since in many fields of high-salt wastewater evaporation with a large amount of organic matter, its viscosity is very high, and the power ultrasonic technology with fluctuations of only a few microns cannot quickly remove the dirt on the heat exchange plates 1, especially in places where there are many short fibers and organic matter.

[0046] Therefore, in this embodiment, a scraper device 7 is arranged between the heat exchange plates 1, and the scraper device 7 is arranged in the spacing between adjacent heat exchange plates 1.

[0047] The scraper device 7 includes a scraper support 7.1, a scraper blade 7.2, a front support beam 7.3, a rear support beam 7.4, a front support beam transmission rod 7.5, and a transmission interface 7.6.

[0048] The scraper support 7.1 is vertically installed in parallel in the spacing between adjacent heat exchange plates 1. The scraper support 7.1 is made of elastic metal plate. By means of laser cutting and other methods, three sides of the whole elastic metal plate are cut into a rectangle, and then the middle position of the cut part is folded in different directions along the thin plate to form the scraper blade 7.2, thus making the scraper plate.

[0049] Scraper plates are placed in several adjacent heat exchange plates 1, and the distance between the scraper plates is equal to the distance between adjacent heat exchange plates 1, so as to facilitate the movement of the scraper plates between the heat exchange plates 1.

[0050] Since the material to be evaporated in the evaporator flows freely downward by gravity, this saves the power consumption of the circulation pump. In order to ensure the uniform flow of the material thin layer on the heat exchange plate 1, the setting of the scraper blade 7.2 cannot block the flow of the material flow layer. Therefore, the length direction of the scraper blade 7.2 is set perpendicular to the direction of the scraper support 7.1, and the scraper blade 7.2 is a part cut from the scraper support 7.1 and has the characteristics of an elastic metal plate at the same time. The movement direction of the scraper support 7.1 is the horizontal direction (that is, the scraper support 7.1 is arranged in parallel between the adjacent heat exchange plate spacings and moves horizontally in this spacing).

[0051] One end of each scraper plate (i.e., the scraper support 7.1) is connected to the front support beam 7.3. The front support beams 7.3 connected by the scraper plates between several heat exchange plates 1 are arranged side by side at equal distances and connected to the front support beam transmission rod 7.5. A transmission interface 7.6 is arranged at the front end of the center of the front support beam transmission rod 7.5, and the transmission interface 7.6 is connected to the scraper driving mechanism 8. The operation of the scraper driving mechanism 8 drives the transmission interface 7.6, thus playing the role of power transmission and support.

[0052] Such as Figure 5As shown in the figure, the scraper drive mechanism 8 provided in the present invention is mainly a power transmission device with a crankshaft structure driven by a power device 8.1, which includes a straight shaft 8.2, a fixed bracket 8.3, a crankshaft 8.4, and a crankshaft connecting arm 8.5. The power device 8.1 is connected to the straight shaft 8.2. A plurality of groups of crankshafts 8.4 are provided on the straight shaft 8.2. The crankshafts 8.4 adopt an open U-shaped structure, and the opening directions of the plurality of groups of crankshafts 8.4 on the straight shaft 8.2 are distributed in a staggered manner up, down, left, and right. The opening of the crankshaft 8.4 is connected to a transmission interface 7.6 on the front support beam transmission rod 7.5 through a crankshaft connecting arm 8.5.

[0053] Further, at the other end of each scraper blade (i.e., the scraper bracket 7.1), a rear support beam 7.4 is provided. A support member is provided below the rear support beam 7.4 to support the scraper device 7 and enable it to slide horizontally in the spacing between adjacent heat exchange plates 1, so as to more stably achieve the descaling function.

[0054] Further, the number of the scraper devices 7 is determined according to the size and number of the heat exchange plates 1.

[0055] Further, a water spraying device is provided on the scraper bracket 7.1 to achieve water spraying descaling through the water spraying device and enhance the descaling effect.

[0056] Further, in order to increase the descaling effect, the elastic telescopic distance of the scraping blade 7.2 on the scraper bracket 7.1 is not less than 1 / 2 of the thickness of the corrugated heat exchange plate 1.

[0057] Further, in order to increase the stability of the scraper drive mechanism 8 during operation, a fixed bracket 8.3 is installed on the straight shaft 8.2. The straight shaft 8.2 can rotate freely on the fixed bracket 8.3, and a shaft sleeve is provided at the rotating part. The fixed bracket 8.3 is connected to the outer shell of the heat exchanger or the fixed bracket of the heat exchange plate bundle.

[0058] The working principle of descaling of the present invention is as follows:

[0059] When the scraper drive mechanism 8 rotates during operation, when viewed from the vertical direction, the crankshaft 8.4 makes a circular motion along the straight shaft 8.2 and drives the scraper device 7 to make a horizontal forward and backward motion through the crankshaft connecting arm 8.5, so as to form the function of automatically cleaning the dirt between the heat exchange plates 1 by the scraper device 7. Embodiment

[0060] When the number of the scraper devices 7 is large and heavy, in the second embodiment on the basis of the first embodiment, as Figure 4As shown in the figure, the front end of the center of the front support beam transmission rod 7.5 is set to the structure of the front support beam 7.7, and a support member is provided at the bottom of the front support beam 7.7 to support and power-transmit the scraper device 7 and enable horizontal sliding. Referring to the method of installing the scraper drive mechanism 8 in the above-mentioned Embodiment 1, one end of the crankshaft connecting arm 8.5 is connected to the crankshaft 8.4, and the other end is connected to the front support beam 7.7.

[0061] On the basis of maintaining the original advantages of the corrugated plate heat exchanger, the present invention combines and applies a variety of online scale removal technologies, so that the corrugated plate heat exchanger can achieve online continuous scale removal and anti-scaling regardless of the material with any viscosity or severe scaling, thereby avoiding the adverse effects brought by scaling, and the evaporation system always maintains a highly efficient and stable operation state, providing equipment technical support for zero liquid discharge of wastewater.

[0062] To sum up, the present invention has the following advantages:

[0063] 1. High heat transfer coefficient. After adopting the corrugated plate heat exchange element, the flow velocity and direction of the fluid change continuously during the flow process, intensifying the turbulent effect of the fluid. Since there is no baffle plate in the tube bundle, there is no flow dead angle or dead zone.

[0064] 2. Remarkable heat transfer enhancement effect. The metal particles of the heat exchange plate always maintain a high-speed elliptical motion during the heat exchange process, generating application forces in the vertical and horizontal directions on the materials in this evaporation, effectively destroying the thermal resistance and flow resistance of the material stagnant layer, thereby increasing the heat conduction heat transfer and convective heat transfer capabilities. Even when the heat exchange plate is in a clean state before scaling, its heat transfer effect is enhanced - enhanced heat transfer.

[0065] 3. Remarkable effect in preventing and removing inorganic salt scale. During the evaporation process, the supersaturated inorganic salt scaling substances in the material first form calcite scale on the heat exchange plate. During this process, due to the heat exchange plate always maintaining high-frequency fluctuations, the scale is always kept with peeling and shearing energy. Larger scale particles are driven away by elastic waves and cannot contact the heat exchange wall surface. A large part of the scale particles that have just adhered to the heat exchange wall surface are also vertically peeled off. Even the scale adhering to the heat exchange surface is under the action of horizontal shear force, preventing this part of the scale from developing into calcite scale. Finally, the calcite scale is easily washed away under the action of peeling, shearing force and flow force scouring, thus keeping the heat exchange surface clean and maintaining the heat transfer effect.

[0066] 4. Remarkable effect in preventing and removing organic salt scale. Organic salt scale has high viscosity, strong adhesion, but is relatively soft. Sometimes, relying on the ultrasonic fluctuations of the heat exchange surface of a few micrometers cannot completely prevent the adhesion of organic fouling. Scrapers are provided between each heat exchange plate. On the basis of the ultrasonic fluctuations of the heat exchange plate, combined with the movement of the scrapers, the adhesion problem of organic fouling can be completely eliminated.

[0067] 5. The equipment is compact and small in size. Since the problem of fouling on the heat transfer surface is avoided, and the heat transfer is strengthened at the same time, combined with the advantages of high heat transfer coefficient and high heat transfer efficiency of the corrugated plate heat exchanger, the area of the heat transfer element required to achieve the same heat transfer amount will decrease.

[0068] 6. The ultrasonic equipment has stable performance and a long service life. The ultrasonic transducer is made of magnetostrictive material, has a very high Curie temperature and a wide frequency band, and can adapt to complex on-site environments and equipment.

[0069] 7. The scraper has a simple structure, light weight and reliable performance. For the first time, the scraper is manufactured by cutting and folding the edge on a single metal plate. The scraping blade has large stretchability and can keep in contact with the uneven corrugated plate heat transfer surface. It has the characteristics of light weight, simple structure, long working safety life and reliable performance, laying a technical foundation for the application of the scraper technology to large heat exchanger plates.

[0070] 8. It is beneficial to the formation of the liquid film and improves the heat transfer efficiency. During the falling film evaporation process, when the liquid film has a uniform thickness and a fast flow rate, it is beneficial to improve the heat transfer efficiency. In the present invention, the scraping blade is arranged vertically and moves horizontally. That is, whether the scraper is moving or stationary, the scraping blade will not have an adverse effect on the liquid film. In addition, since the corrugated plate has an uneven structure and it is basically impossible to form a liquid film with a uniform thickness, in the present invention, the vertical scraping blade moves horizontally, which can scrape the liquid film with uneven thickness to be more uniform, thus being beneficial to the heat transfer effect.

[0071] 9. The scraper has the functions of thorough fouling removal and self-cleaning. The scraping blades on both the left and right sides are always in contact with the corrugated plate with ultrasonic energy, so that the scraping blade, the scraper support and other connected equipment also carry ultrasonic energy, making it impossible for dirt to adhere to the scraper device, that is, it has the self-cleaning function. In addition, since the heat exchanger plate is always in a micron-level fluctuation state of more than 10,000 times per second, and since the scraping blade is in contact with the heat exchanger plate, from a microscopic perspective, it can be found that the scraping blade and the heat exchanger plate also perform micron-level fluctuations of more than 10,000 times per second at the same time. This kind of fluctuation has two functions. One is that it can effectively remove various dirt, and the other is that it can effectively reduce the frictional resistance between the tube sheet and the heat exchanger plate, so that multiple scrapers can move flexibly among the heat exchanger plates.

[0072] 10. The scraper device adopts a crankshaft-driven method, which can not only make multiple scraper devices move flexibly in a staggered manner, reducing the driving force, but also has only one driving shaft interface on a large heat exchanger, with a simple structure, fewer failure points and good aesthetics.

[0073] 11. It has the function of removing scale by spraying water. Since the scraper brackets 7.1 are arranged between each heat exchange plate, and the water spray pipes are installed on the scraper brackets 7.1, water spraying devices can be provided between the heat exchange plates. It has two functions. One is to remove scale by high-pressure water spraying through logical control under evaporation conditions, and the other is to continuously heat the heat exchange plates under the condition of stopping evaporation, and then suddenly spray water on the heat exchange plates to produce a steam explosion effect, so that the dirt falls off quickly.

[0074] 12. There is no thermal stress. Since the inlet and outlet pipes on each heat exchange plate and the inlet and outlet header pipes adopt a flexible connection method, although the inlet and outlet header pipes are rigidly connected to the shell, there is no rigid connection between the shell and the tube bundle, so there is no thermal stress. The corrugated plate shell heat exchanger can be used for heat exchange of fluids with a large temperature difference.

[0075] 13. The evaporation process runs stably and requires no maintenance. In the present invention, a combined scale removal and anti-scaling method is set up, including the corrugated plate heat exchange method, ultrasonic scale removal device, tube sheet scale removal device, and water spraying scale removal device. At the same time, strict quality control is carried out on the processing process and material of the corrugated plate, ensuring that the equipment of the present invention operates stably, efficiently, and for a long time during the actual evaporation process, and it is a high-pressure concentrated liquid evaporation device that requires no maintenance.

[0076] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0077] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality" means two or more, unless otherwise specifically defined.

[0078] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. A large-scale maintenance-free corrugated panel evaporator, comprising a heat exchange tube bundle, the heat exchange tube bundle comprising a plurality of heat exchange plates (1) arranged in parallel, characterized in that, Each heat exchange plate (1) includes two metal thin plates stacked together and laser welded into a corrugated heat transfer unit. A number of heat exchange plates (1) are made into a corrugated plate shell heat exchanger bundle; an inlet branch pipe and an outlet branch pipe are provided on each heat exchange plate (1), and the inlet branch pipe and the outlet branch pipe on each heat exchange plate (1) are respectively connected to the steam inlet main pipe 2 and the condensate outlet main pipe 3; at least one side of the heat exchanger bundle is provided with an ultrasonic vibration rod (4), and the ultrasonic vibration rod (4) passes through the shell of the evaporator and is connected to an ultrasonic transducer (6). A gap is left between adjacent heat exchange plates (1). Scraper devices (7) are arranged between adjacent heat exchange plates (1) among the number of heat exchange plates (1), and the scraper devices (7) are connected to a scraper driving mechanism (8). The scraper device (7) includes a scraper support (7.1), the scraper support (7.1) is vertically arranged between adjacent heat exchange plates (1), a scraper blade (7.2) is provided on one side surface of the scraper support (7.1), and the scraper blade (7.2) is perpendicular to the side surface of the scraper support (7.1); the scraper support (7.1) is connected to a front beam transmission rod (7.5) through a front beam (7.3), and the front beam transmission rod (7.5) is connected to the scraper driving mechanism (8) through a transmission interface (7.6); the scraper support (7.1) is made of an elastic metal plate, and a rectangle is cut on the whole elastic metal plate by laser cutting on three sides, and then the middle position of the cut part is folded in different directions along the thin plate to form the scraper blade (7.2) to make a scraper plate. The scraper driving mechanism (8) includes a power device (8.1) and a straight shaft (8.2), the power device (8.1) is drivingly connected to the straight shaft (8.2), a number of groups of crankshafts (8.4) are provided on the straight shaft (8.2), the crankshafts (8.4) adopt an open U-shaped structure, and the opening directions of the number of groups of crankshafts (8.4) on the straight shaft (8.2) are distributed in a staggered manner up, down, left and right; the opening of the crankshaft (8.4) is connected to the transmission interface (7.6) on the front beam transmission rod (7.5) through a crankshaft connecting arm (8.5). A water spraying device is provided on the scraper support (7.1), and water spraying descaling is realized through the water spraying device to enhance the descaling effect.

2. The large-scale maintenance-free corrugated panel evaporator according to claim 1, wherein Spot welding is used for connection on the plate surface of the heat exchange plate (1), and the periphery of the heat exchange plate (1) is bulged after seam welding to form a corrugated heat transfer unit with an internal flow channel.

3. A large-scale maintenance-free corrugated panel evaporator according to claim 2, characterized in that, The solder joints on the plate surface of the heat exchange plate (1) are arranged in a diamond shape, and after the diamond shape is formed, the heat exchanger bundle is a continuous and crisscross multi-corrugated curved surface structure.

4. A large-scale maintenance-free corrugated panel evaporator according to claim 1, characterized in that, Ultrasonic vibration rods (4) are respectively provided on both sides of the heat exchanger bundle, and the ultrasonic vibration rods (4) are distributed on both sides of the heat exchanger bundle in a staggered left and right manner.

5. A large-scale maintenance-free corrugated panel evaporator according to claim 1, characterized in that, Two passes of roll welding are used for sealing around the heat exchanger bundle, so that no gasket is required during the heat transfer process and no leakage will occur.

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