As with other industrial technologies, drying technology has also made great strides in the application process. At present, there are more than 400 types of dryers, and about 200 dryers have been used in industrial production. Many new dryers have appeared, some of which have structural improvements to ordinary dryers. The reference draws on the advantages of other dryers, and some are completely new ideas.
Drying is a unit operation with considerable industrial energy consumption. According to the data, 14% of the industrial energy consumption in developed countries is used for drying. In some industries, the dry energy consumption accounts for 35% of the total energy consumption, and this figure Constantly increasing. At the same time, the use of fossil fuels as a heat source for drying operations produces a large amount of gas such as carbon dioxide. The exhaust of drying equipment (which contains some dust in the gas) has a negative impact on the atmospheric environment, which is a great challenge for the “environmental protection†that is increasingly attracting global attention.
Almost all industries are inseparable from drying operations. Although it is helpful to understand the working mechanism of drying and drying equipment to successfully complete the drying process, we still need to continuously invest human and material resources to further study the drying technology. Developed to enable efficient use of energy while reducing high-quality products, reducing environmental impacts, and making process operations and controls easier.
First, the characteristics of dry technology wood Dry technology has a wide range of applications, facing a wide range of industries, physical and chemical properties of different materials, product quality and other aspects of different requirements, drying technology is a cross-industry, interdisciplinary, A technique with experimental scientific properties. Generally, three aspects of knowledge and technology are required in the development and application of drying technology. * It is necessary to understand the physical and chemical properties of the materials being dried and the characteristics of the use of the products; the second is to be familiar with the principle of transfer engineering, namely the principle of energy transfer such as mass transfer, heat transfer, fluid mechanics and aerodynamics; The means of engineering design for drying processes, main equipment, and electrical instrument control. Obviously, these three aspects of knowledge and technology do not belong to a subject area. In practice, these three aspects of knowledge and technology are indispensable. So drying technology is a cross-industry, interdisciplinary technology.
Although modern drying technology has a history of more than one hundred years, it still belongs to the category of experimental science. Most drying technologies currently lack scientific theories and design methods that accurately guide practice. In practical applications, relying on empirical and small-scale experimental data to guide industrial design is still the main way, the reasons for this situation are as follows:
One of the reasons is that some basic disciplines relying on drying technology (mainly subject to the discipline of transfer engineering) have the characteristics of experimental science. For example, the development of aerodynamic research is driven by the “wind tunnel†experiment, which indicates that it has not left the scope of experimental science, and the development level of these basic disciplines directly affects and determines the development level of drying technology.
The second reason is that many drying processes are the process of multi-disciplinary technology convergence, involving a wide range of factors, many changing factors, and complex mechanisms. For example, in the field of spray drying technology, the trajectory of the atomized droplets in the drying tower is the key to engineering design. The trajectory of the droplet is related to its volume, mass, initial velocity and direction, and the flow and velocity of other droplets and hot air around it. However, due to the mass transfer and heat transfer processes, these parameters change all the time, and in the initial state, neither the size of the droplets nor the distribution of hot air can be uniform. Obviously, engineering design based on theoretical calculations for such complex and varied processes is not reliable.
The third reason is that the types of materials to be dried are various, and their physical and chemical properties are also different. The mass transfer and heat transfer rates of different materials may vary greatly even under the same drying conditions. If not treated differently, it may have unsatisfactory consequences. For example, the drying of some Chinese herbal medicines, although belonging to the same medicinal materials, only needs to change the drying conditions because of the difference in the origin or harvest period of the medicinal materials, otherwise the quality of the products will be affected.
The above three reasons determine that the development and application of drying technology should be based on experiments. However, these characteristics of dry search are often ignored by people intentionally or unintentionally. Manufacturers often avoid the drying experiments that should be done because of the lack of experimental devices or incomplete models (which is a common phenomenon in China), and users often give up the requirements of necessary experiments because they do not understand the characteristics of drying technology. The result is that the device is not working well and even causes the design failure. In China, such cases are not uncommon. There has been a set of lessons learned from the industrial drying unit worth 20 million yuan because it could not be used. Therefore, before constructing industrial drying equipment, especially larger ones, it is necessary to conduct sufficient and convincing experiments, and use the experimental results as the basis for industrial equipment design. This is a distinctive feature of drying technology applications.
In addition, a wide variety of drying equipment, each with its own use is also a feature of drying technology. Each technology has its own field of application. In engineering practice, the type of drying technology to be applied should be selected according to the specific situation. This will have a major impact on investment costs, operating costs, product quality, environmental requirements and other aspects. For example, in a certain enterprise, three types of box drying, spray drying and rapid drying of rotary air flow have been used in the drying of white carbon black filter cake. The final result of zui proves that these three technologies have their own strengths. The box-type drying production of white carbon black has good production efficiency and high labor intensity, but the product quality is good. The product produced after kneading with rubber has a high breaking strength value. Rotating airflow rapid drying equipment is compact, low investment, high production efficiency, but the strength index of the rubber products produced is the difference between the three. Spray drying produces white carbon black. The products are in the middle of the three indicators, but have good product fluidity and low dust pollution, which is very popular among users and operators. In the 1990s, the question of which drying method was more advanced in the production of white carbon black had caused controversy in the dry world of China. In fact, each of the three types of equipment has its own characteristics. Which type of machine is selected depends on the user's own conditions and product requirements. There is no conclusion that any technology is more advanced. There are many similar examples that show the wide variety of drying equipment and their own use. Therefore, in the application, it is necessary to carefully compare and carefully select the technical solution, and it is also an indispensable step to evaluate the technical solution through the drying experiment.
Second, the development status of industrial drying equipment Drying is a very important unit operation in many production, because drying is not only a simple solid-liquid separation process here, but more importantly, the production process is followed by a process, the quality of the product. The dosage form depends to a large extent on the combined application of drying technology and equipment. From an economic point of view, the dryer is expensive and the engineering investment is large. On the other hand, drying is a high-energy process, and the thermal efficiency fluctuates within a range of 15% to 80%. The operating cost of the equipment is closely related to the design of the dryer, so the decision makers of the enterprise This has always been more important. There are many varieties of materials to be dried, and their physical and chemical properties vary greatly. Even the different production processes of the same variety and the different product requirements of the same variety may lead to differences in drying conditions, thus determining the complexity of the drying process. It can be seen that the drying process is more technical than other unit operations.
China's drying equipment is basically blank before liberation. There are only drying rooms, ovens and drum dryers. The drying technology is backward and the production equipment is original. The vacuum squeezing dryer appeared in 1957, and the drying technology developed rapidly after 1964. Throughout the development history of China's drying technology and equipment, it has experienced a development stage from simple to complex, from low to high in decades. Now there are more than ten series of drying equipment commonly used in production, plus combined drying. There are about 50 kinds of equipments, plus special drying equipment is more difficult to count. It is not easy to select these drying equipment reasonably. The premise of selection is to understand the basic working principle, structural characteristics and applicable materials of these equipments. Scope, so avoid detours when selecting.
In recent years, due to the development of drying technology, more complicated factors have been brought to the screening equipment. Even the design, manufacture or user of drying equipment often fails to figure out how to choose the right equipment. Since the salesmen of drying equipment are only interested in the types of dryers they sell on the market, but not the other types, the users have to rely on the relevant modern drying technology reference materials to decide on the choice of equipment. . There is no doubt that users need the laboratory, experimental scope and technical and economic aspects provided by the promoters. Therefore, it is necessary to be familiar with most drying equipment to make it possible to select a reasonable equipment. It should be emphasized that in a particular production operation state, there are likely to be many more suitable dryers, but it must also be known that in a particular working state, there is no strict rule that specifies extremely accurate drying equipment. Each product has its own unique production method. There are many factors that influence the choice of drying equipment, such as intermittent drying or continuous drying, consumption of fossil fuels, electricity consumption, local environmental laws or noise pollution restrictions. Product yield is a major factor in the choice of dryer.
Third, the use of drying equipment Overview As mentioned earlier, drying equipment is widely used in many industrial production. Over the years, a variety of models have been used in industrial production, such as air dryers, fluidized bed dryers, spray dryers, drum dryers, drier dryers, freeze dryers, infrared drying and combined drying. There are dozens of them. Why are there many types of drying equipment? This is mainly due to the different types and properties of dry materials, and the materials to be processed have various specific requirements.
With the rapid development of production technology in various industries in China, domestic drying technology and equipment have also developed rapidly. In the drying of granular materials, fluidization technology has gained wider application and new development in recent years. Fluidized drying fully improves the gas-solid phase contact conditions (increased evaporation surface area), the vigorous agitation of the material, greatly reduces the film resistance, and creates extremely favorable conditions for the heat transfer medium. In addition to the rapid development of the use of earlier airflow drying in domestic drying technology, fluidized drying equipment has developed rapidly in recent years. It is mainly manifested in the use of fluidization technology combined with the characteristics and requirements of various materials to be dried to create a number of new and efficient fluidized dryers, as described below.
The straight pipe airflow dryer is an early fluidized drying equipment used in China. After several years of production practice, it is considered that the airflow drying is ideal for drying dry materials, especially heat sensitive materials. It is superior to oven drying in terms of production volume and floor space, so it is currently used more widely in the pharmaceutical, plastics, food, fertilizer and other industries. However, airflow drying also has the disadvantages of low heat utilization rate, high equipment, and low relative speed of gas-solid two phases. In recent years, new airflow devices such as pulsed airflow dryers, cyclone airflow dryers, and pulverized airflow dryers have been created to overcome the shortcomings of straight pipe airflow drying. In addition to reducing the height, the pulverizing airflow also expands the use range of the airflow dryer, so that the oxidizable material can use air as a drying medium, which not only reduces the drying power consumption, but also improves the output and quality of the product, and also adopts more The stage airflow drying process and the combined airflow drying process, in the application of the airflow dryer, many projects adopt a two-stage series method, which is more reasonable in the drying of some materials and also improves the thermal efficiency. Straight pipe air drying is very mature in production operations. Pulsed airflow and cyclone airflow drying have been industrialized for many years, and the operation has been relatively mature, but the theoretical design is still lacking. Further improvement is needed in the future development of practice.
Most of the heat sensitive and easily oxidizable materials are air dried. Generally, the material having an initial humidity of 10% to 25% can be dried to 1% to 0.05%, the particle size of the dried material is generally 60-100 mesh, and the yield is generally 100-200 kg/h. At present, it is widely used in the pharmaceutical, food, plastic and other industries. With the rapid development of China's production technology, airflow drying must be applied more widely in future industrial production.
Fluidized drying is another drying technique developed by Zui in recent years. It has been proved by production practice that it has many advantages and can realize large-scale production of small equipment. Because of the large heat capacity coefficient and the adjustable residence time, it is suitable for materials containing surface water and drying stage. It is especially suitable for dispersion. Drying of the granular material. Zui has been developed and industrialized in the following types: single-layer cylindrical, multi-layer round tube, vibrating fluidized bed, horizontal multi-chamber fluidized bed dryer, stirred fluidized bed, and built-in heat pipe flow. Chemical beds, etc., of which the latter develops more rapidly. It has been widely used in the pharmaceutical, fertilizer, food, plastics, petrochemical and other industries. After several years of practice, domestic fluidized drying has developed to a more mature stage in terms of operation and equipment structure. From the perspective of use, the horizontal multi-chamber fluidized dryer has the advantages of simple structure, convenient operation and stability, wide material adaptability, and can obtain a product with uniform water content and less power consumption. It is ideal for fluidized dry and granular materials. The equipment is worth promoting and developing in the future. The built-in heat pipe is a combination of convective heat transfer and conduction heat transfer in a fluidized bed. It has high thermal efficiency and good drying effect. It is a new type of machine that has been recommended in recent years.
Domestic conical fluidized bed is divided into three types according to operation: one is thick overflow and overflow material. In recent years, it is mostly used in fluidized granulation in China; the other is sprinkling bed drying, which is discharged from the top of the bed. The product is collected in a cyclone or intermittently operated at the bottom of the bed. The structure is simpler than the fluidized bed structure, the equipment is small, the output is large, the drying strength is high, the bed is isothermal, and local overheating does not occur. In the past, it has only been applied to large granular materials (polyvinyl chloride), which has been developed in recent years to be applied to the drying of fine-grained materials. Currently used in plastics, grains, pharmaceuticals and other departments. However, due to the large power consumption, the use is limited.
In the drying of solution or slurry materials, new developments have also been made. In addition to the new development of spray drying, in recent years, cone-shaped fluidized beds have been successfully used for spray granulation production. And has gradually developed and improved. The spray fluidized granulation dryer is first used in chemical fertilizers and has been used in medicine, food and other industries. Spray drying has been used in China for more than 20 years and is relatively mature in design and operation. In recent years, spray drying has made progress in the following areas:
(1) In addition to the large-scale development of the drying chamber, the relevant units of the nozzle atomizer performance have also done more experimental research work and achieved remarkable results;
(2) In addition to the heat-sensitive solution, spray drying is more widely used, and in recent years, the slurry has also been successfully spray-dried;
(3) Spray drying combined with other drying techniques to achieve the purpose of drying or drying granulation at the same time, which is also the embodiment of the further development of China's drying technology;
(4) At present, the experiment of low-temperature spray drying is carried out, which is to use air with extremely low moisture content and low temperature as a carrier, and the air is pre-dehydrated and dried, and the product temperature does not exceed 35'C during the drying process, so it is suitable for Drying of heat sensitive materials, such as medicine, food dehydration, etc.
Shangyu Xingxing Instrument Equipment Co., Ltd. is located in Daoxu Town, Shangyu District, Shaoxing City, Zhejiang Province. It is an enterprise integrating production, product research and development, processing and trade. The company's main products: drying box series, incubator series, laboratory muffle furnace series, distilled water series, as well as clean workbench, air shower, fume hood, biological safety cabinet and other complete purification equipment.
The company has a strong technical research and development team, a strong after-sales guarantee service system, is the linger of the Chinese laboratory complete sets of equipment manufacturers, welcome customers to buy.
Drying is a unit operation with considerable industrial energy consumption. According to the data, 14% of the industrial energy consumption in developed countries is used for drying. In some industries, the dry energy consumption accounts for 35% of the total energy consumption, and this figure Constantly increasing. At the same time, the use of fossil fuels as a heat source for drying operations produces a large amount of gas such as carbon dioxide. The exhaust of drying equipment (which contains some dust in the gas) has a negative impact on the atmospheric environment, which is a great challenge for the “environmental protection†that is increasingly attracting global attention.
Almost all industries are inseparable from drying operations. Although it is helpful to understand the working mechanism of drying and drying equipment to successfully complete the drying process, we still need to continuously invest human and material resources to further study the drying technology. Developed to enable efficient use of energy while reducing high-quality products, reducing environmental impacts, and making process operations and controls easier.
First, the characteristics of dry technology wood Dry technology has a wide range of applications, facing a wide range of industries, physical and chemical properties of different materials, product quality and other aspects of different requirements, drying technology is a cross-industry, interdisciplinary, A technique with experimental scientific properties. Generally, three aspects of knowledge and technology are required in the development and application of drying technology. * It is necessary to understand the physical and chemical properties of the materials being dried and the characteristics of the use of the products; the second is to be familiar with the principle of transfer engineering, namely the principle of energy transfer such as mass transfer, heat transfer, fluid mechanics and aerodynamics; The means of engineering design for drying processes, main equipment, and electrical instrument control. Obviously, these three aspects of knowledge and technology do not belong to a subject area. In practice, these three aspects of knowledge and technology are indispensable. So drying technology is a cross-industry, interdisciplinary technology.
Although modern drying technology has a history of more than one hundred years, it still belongs to the category of experimental science. Most drying technologies currently lack scientific theories and design methods that accurately guide practice. In practical applications, relying on empirical and small-scale experimental data to guide industrial design is still the main way, the reasons for this situation are as follows:
One of the reasons is that some basic disciplines relying on drying technology (mainly subject to the discipline of transfer engineering) have the characteristics of experimental science. For example, the development of aerodynamic research is driven by the “wind tunnel†experiment, which indicates that it has not left the scope of experimental science, and the development level of these basic disciplines directly affects and determines the development level of drying technology.
The second reason is that many drying processes are the process of multi-disciplinary technology convergence, involving a wide range of factors, many changing factors, and complex mechanisms. For example, in the field of spray drying technology, the trajectory of the atomized droplets in the drying tower is the key to engineering design. The trajectory of the droplet is related to its volume, mass, initial velocity and direction, and the flow and velocity of other droplets and hot air around it. However, due to the mass transfer and heat transfer processes, these parameters change all the time, and in the initial state, neither the size of the droplets nor the distribution of hot air can be uniform. Obviously, engineering design based on theoretical calculations for such complex and varied processes is not reliable.
The third reason is that the types of materials to be dried are various, and their physical and chemical properties are also different. The mass transfer and heat transfer rates of different materials may vary greatly even under the same drying conditions. If not treated differently, it may have unsatisfactory consequences. For example, the drying of some Chinese herbal medicines, although belonging to the same medicinal materials, only needs to change the drying conditions because of the difference in the origin or harvest period of the medicinal materials, otherwise the quality of the products will be affected.
The above three reasons determine that the development and application of drying technology should be based on experiments. However, these characteristics of dry search are often ignored by people intentionally or unintentionally. Manufacturers often avoid the drying experiments that should be done because of the lack of experimental devices or incomplete models (which is a common phenomenon in China), and users often give up the requirements of necessary experiments because they do not understand the characteristics of drying technology. The result is that the device is not working well and even causes the design failure. In China, such cases are not uncommon. There has been a set of lessons learned from the industrial drying unit worth 20 million yuan because it could not be used. Therefore, before constructing industrial drying equipment, especially larger ones, it is necessary to conduct sufficient and convincing experiments, and use the experimental results as the basis for industrial equipment design. This is a distinctive feature of drying technology applications.
In addition, a wide variety of drying equipment, each with its own use is also a feature of drying technology. Each technology has its own field of application. In engineering practice, the type of drying technology to be applied should be selected according to the specific situation. This will have a major impact on investment costs, operating costs, product quality, environmental requirements and other aspects. For example, in a certain enterprise, three types of box drying, spray drying and rapid drying of rotary air flow have been used in the drying of white carbon black filter cake. The final result of zui proves that these three technologies have their own strengths. The box-type drying production of white carbon black has good production efficiency and high labor intensity, but the product quality is good. The product produced after kneading with rubber has a high breaking strength value. Rotating airflow rapid drying equipment is compact, low investment, high production efficiency, but the strength index of the rubber products produced is the difference between the three. Spray drying produces white carbon black. The products are in the middle of the three indicators, but have good product fluidity and low dust pollution, which is very popular among users and operators. In the 1990s, the question of which drying method was more advanced in the production of white carbon black had caused controversy in the dry world of China. In fact, each of the three types of equipment has its own characteristics. Which type of machine is selected depends on the user's own conditions and product requirements. There is no conclusion that any technology is more advanced. There are many similar examples that show the wide variety of drying equipment and their own use. Therefore, in the application, it is necessary to carefully compare and carefully select the technical solution, and it is also an indispensable step to evaluate the technical solution through the drying experiment.
Second, the development status of industrial drying equipment Drying is a very important unit operation in many production, because drying is not only a simple solid-liquid separation process here, but more importantly, the production process is followed by a process, the quality of the product. The dosage form depends to a large extent on the combined application of drying technology and equipment. From an economic point of view, the dryer is expensive and the engineering investment is large. On the other hand, drying is a high-energy process, and the thermal efficiency fluctuates within a range of 15% to 80%. The operating cost of the equipment is closely related to the design of the dryer, so the decision makers of the enterprise This has always been more important. There are many varieties of materials to be dried, and their physical and chemical properties vary greatly. Even the different production processes of the same variety and the different product requirements of the same variety may lead to differences in drying conditions, thus determining the complexity of the drying process. It can be seen that the drying process is more technical than other unit operations.
China's drying equipment is basically blank before liberation. There are only drying rooms, ovens and drum dryers. The drying technology is backward and the production equipment is original. The vacuum squeezing dryer appeared in 1957, and the drying technology developed rapidly after 1964. Throughout the development history of China's drying technology and equipment, it has experienced a development stage from simple to complex, from low to high in decades. Now there are more than ten series of drying equipment commonly used in production, plus combined drying. There are about 50 kinds of equipments, plus special drying equipment is more difficult to count. It is not easy to select these drying equipment reasonably. The premise of selection is to understand the basic working principle, structural characteristics and applicable materials of these equipments. Scope, so avoid detours when selecting.
In recent years, due to the development of drying technology, more complicated factors have been brought to the screening equipment. Even the design, manufacture or user of drying equipment often fails to figure out how to choose the right equipment. Since the salesmen of drying equipment are only interested in the types of dryers they sell on the market, but not the other types, the users have to rely on the relevant modern drying technology reference materials to decide on the choice of equipment. . There is no doubt that users need the laboratory, experimental scope and technical and economic aspects provided by the promoters. Therefore, it is necessary to be familiar with most drying equipment to make it possible to select a reasonable equipment. It should be emphasized that in a particular production operation state, there are likely to be many more suitable dryers, but it must also be known that in a particular working state, there is no strict rule that specifies extremely accurate drying equipment. Each product has its own unique production method. There are many factors that influence the choice of drying equipment, such as intermittent drying or continuous drying, consumption of fossil fuels, electricity consumption, local environmental laws or noise pollution restrictions. Product yield is a major factor in the choice of dryer.
Third, the use of drying equipment Overview As mentioned earlier, drying equipment is widely used in many industrial production. Over the years, a variety of models have been used in industrial production, such as air dryers, fluidized bed dryers, spray dryers, drum dryers, drier dryers, freeze dryers, infrared drying and combined drying. There are dozens of them. Why are there many types of drying equipment? This is mainly due to the different types and properties of dry materials, and the materials to be processed have various specific requirements.
With the rapid development of production technology in various industries in China, domestic drying technology and equipment have also developed rapidly. In the drying of granular materials, fluidization technology has gained wider application and new development in recent years. Fluidized drying fully improves the gas-solid phase contact conditions (increased evaporation surface area), the vigorous agitation of the material, greatly reduces the film resistance, and creates extremely favorable conditions for the heat transfer medium. In addition to the rapid development of the use of earlier airflow drying in domestic drying technology, fluidized drying equipment has developed rapidly in recent years. It is mainly manifested in the use of fluidization technology combined with the characteristics and requirements of various materials to be dried to create a number of new and efficient fluidized dryers, as described below.
The straight pipe airflow dryer is an early fluidized drying equipment used in China. After several years of production practice, it is considered that the airflow drying is ideal for drying dry materials, especially heat sensitive materials. It is superior to oven drying in terms of production volume and floor space, so it is currently used more widely in the pharmaceutical, plastics, food, fertilizer and other industries. However, airflow drying also has the disadvantages of low heat utilization rate, high equipment, and low relative speed of gas-solid two phases. In recent years, new airflow devices such as pulsed airflow dryers, cyclone airflow dryers, and pulverized airflow dryers have been created to overcome the shortcomings of straight pipe airflow drying. In addition to reducing the height, the pulverizing airflow also expands the use range of the airflow dryer, so that the oxidizable material can use air as a drying medium, which not only reduces the drying power consumption, but also improves the output and quality of the product, and also adopts more The stage airflow drying process and the combined airflow drying process, in the application of the airflow dryer, many projects adopt a two-stage series method, which is more reasonable in the drying of some materials and also improves the thermal efficiency. Straight pipe air drying is very mature in production operations. Pulsed airflow and cyclone airflow drying have been industrialized for many years, and the operation has been relatively mature, but the theoretical design is still lacking. Further improvement is needed in the future development of practice.
Most of the heat sensitive and easily oxidizable materials are air dried. Generally, the material having an initial humidity of 10% to 25% can be dried to 1% to 0.05%, the particle size of the dried material is generally 60-100 mesh, and the yield is generally 100-200 kg/h. At present, it is widely used in the pharmaceutical, food, plastic and other industries. With the rapid development of China's production technology, airflow drying must be applied more widely in future industrial production.
Fluidized drying is another drying technique developed by Zui in recent years. It has been proved by production practice that it has many advantages and can realize large-scale production of small equipment. Because of the large heat capacity coefficient and the adjustable residence time, it is suitable for materials containing surface water and drying stage. It is especially suitable for dispersion. Drying of the granular material. Zui has been developed and industrialized in the following types: single-layer cylindrical, multi-layer round tube, vibrating fluidized bed, horizontal multi-chamber fluidized bed dryer, stirred fluidized bed, and built-in heat pipe flow. Chemical beds, etc., of which the latter develops more rapidly. It has been widely used in the pharmaceutical, fertilizer, food, plastics, petrochemical and other industries. After several years of practice, domestic fluidized drying has developed to a more mature stage in terms of operation and equipment structure. From the perspective of use, the horizontal multi-chamber fluidized dryer has the advantages of simple structure, convenient operation and stability, wide material adaptability, and can obtain a product with uniform water content and less power consumption. It is ideal for fluidized dry and granular materials. The equipment is worth promoting and developing in the future. The built-in heat pipe is a combination of convective heat transfer and conduction heat transfer in a fluidized bed. It has high thermal efficiency and good drying effect. It is a new type of machine that has been recommended in recent years.
Domestic conical fluidized bed is divided into three types according to operation: one is thick overflow and overflow material. In recent years, it is mostly used in fluidized granulation in China; the other is sprinkling bed drying, which is discharged from the top of the bed. The product is collected in a cyclone or intermittently operated at the bottom of the bed. The structure is simpler than the fluidized bed structure, the equipment is small, the output is large, the drying strength is high, the bed is isothermal, and local overheating does not occur. In the past, it has only been applied to large granular materials (polyvinyl chloride), which has been developed in recent years to be applied to the drying of fine-grained materials. Currently used in plastics, grains, pharmaceuticals and other departments. However, due to the large power consumption, the use is limited.
In the drying of solution or slurry materials, new developments have also been made. In addition to the new development of spray drying, in recent years, cone-shaped fluidized beds have been successfully used for spray granulation production. And has gradually developed and improved. The spray fluidized granulation dryer is first used in chemical fertilizers and has been used in medicine, food and other industries. Spray drying has been used in China for more than 20 years and is relatively mature in design and operation. In recent years, spray drying has made progress in the following areas:
(1) In addition to the large-scale development of the drying chamber, the relevant units of the nozzle atomizer performance have also done more experimental research work and achieved remarkable results;
(2) In addition to the heat-sensitive solution, spray drying is more widely used, and in recent years, the slurry has also been successfully spray-dried;
(3) Spray drying combined with other drying techniques to achieve the purpose of drying or drying granulation at the same time, which is also the embodiment of the further development of China's drying technology;
(4) At present, the experiment of low-temperature spray drying is carried out, which is to use air with extremely low moisture content and low temperature as a carrier, and the air is pre-dehydrated and dried, and the product temperature does not exceed 35'C during the drying process, so it is suitable for Drying of heat sensitive materials, such as medicine, food dehydration, etc.
Shangyu Xingxing Instrument Equipment Co., Ltd. is located in Daoxu Town, Shangyu District, Shaoxing City, Zhejiang Province. It is an enterprise integrating production, product research and development, processing and trade. The company's main products: drying box series, incubator series, laboratory muffle furnace series, distilled water series, as well as clean workbench, air shower, fume hood, biological safety cabinet and other complete purification equipment.
The company has a strong technical research and development team, a strong after-sales guarantee service system, is the linger of the Chinese laboratory complete sets of equipment manufacturers, welcome customers to buy.
NINJA KEY MILLING CUTTER SERIES
NINJA KEY MILLING CUTTER SERIES
Product features
1 Material: imported high hardness and high wear resistance carbide material, ultra-fine grain and good wear resistance
2 Manufacturing process: full-automatic grinding center with high gloss grinding, sharp and low noise, suitable to process key with high speed, speed rotate 12000RPM
3 Character : accurate size, high precision of cutting key; sharp edge, aimed at the high speed of the electronic key machine, we design back angle of easy chip removal, cut fast and light
4 Advantages: sharp, cut brass key and nickel silver copper key smooth without burrs;
Suit for machine: NINJA VORTEX, NINJA TOTAL, VERSA
Suit for processing keys: all internal milling slots and external milling slot keys, suitable for processing nickel silver copper keys, can efficiently process original high-hardness key blanks, such as Honda original keys, STRATTEC key blanks, etc.
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ZHANGJIAGANG KEYCUT CO.,LTD , https://www.keycutblade.com