In China, although the application of drying equipment has a history of several decades, the development of drying technology on a large scale has been a thing of the past two decades. In these 20 years, after the efforts of the vast number of engineering and technical personnel, the development or imitation of a batch of drying equipment, most of the industrial models can be processed in China, basically reversed the situation of imports of drying equipment. Numerous drying technicians have been trained and a large number of drying equipment manufacturers have also emerged. It is estimated that there are about 400 drying equipment manufacturers in China. In terms of the number of manufacturers, it must be the world's largest country. However, in many drying equipment manufacturers, whether it is the drying technology or equipment manufacturing level has not yet appeared in the world have a certain influence, in the dry field of the manufacturers have a place, this can not but let us ponder. The vast majority of home-made drying equipment is supplied to the domestic market and is rarely exported to foreign countries, even if the price of the occasional export is not impressive. If things go on like this, it will be very unfavorable for the development of drying technology in our country and this situation should be changed as soon as possible. The main reasons for this situation are the following:
1 Basic research gap
Although drying technology has been developed for many years, it has indeed made great progress in theory. However, these theories still have some difficulties in practical application, and there are many imperfect contents. Therefore, there is still a lot of work to be done in theoretical research. In China, since the first National Drying Technology Exchange Conference was held in Nanjing in 1975, it has been held eight times. From the second session of the second session, each edition was edited and published. Each session had dozens of articles of various kinds to participate in exchanges. In recent years, although some colleges and universities or scientific research units are doing this work, the input of human and material resources is far from enough. The number and quality of papers published in various publications in recent years can reflect the reality of drying theory research in China. Level. In terms of theoretical research, there is still a big gap compared with Denmark, Canada, Japan and other countries. China's drying technology wants a new leap forward, and it is very important to strengthen the study of basic theories. It should arouse people's attention.
The physical properties and standards of dried medicines vary widely, and only a few drying equipments can not meet the production needs. Theoretical research is the basis for the development of new dryers. With the development of drying technology in China, it is necessary to cultivate a group of theoretical research and drying technology development workers to improve the technical content of drying equipment in China. After continuous efforts, the drying technology in the pharmaceutical industry in China can be brought close to or reach the advanced level in foreign countries.
2 insufficient experimental conditions
So far, neither the drying plant nor the theoretical research unit has a perfect experimental base. Drying is a very experimental technique. No matter if it is theoretical research or drying equipment manufacturing, experimental methods are indispensable. Through experiments, the drying temperature, drying time, product particle size, and hygiene index of various injections and granules were determined. Theoretical workers can summarize many rules in the drying process. The equipment manufacturer determines various process parameters through experiments. However, many units just ignore the importance of experimentation. Some equipment factories do not even have a set of experimental devices, so that there is a great deal of blindness in the design of equipment. Many theories summarize the general laws of drying technology, but when it comes to specific drugs, the nature of each drug's reaction in the drying process and the requirements for the product have their own particularities. Therefore, according to the general theory of treatment is not necessarily very appropriate, for specific drugs should also be subject to experimental results, so the experimental device must not be less. At present, the experimental means are weak mainly in these aspects. On the one hand, the equipment manufacturer does not have enough knowledge of the experimental process and considers it dispensable. On the other hand, there are many types of experimental devices, and the investment is huge. The non-general enterprises can afford it. The establishment of a sound experimental base is a top priority for China's drying technology research.
Drying is a profession in itself, but it is a device for handling drugs in other industries. Therefore, the drying equipment is different from other equipment, and the physical properties and requirements of the processing chemicals are very complicated. Drying is an industry that requires a comprehensive technology. Before the design, it is required to conduct an experimental analysis on the drug in order to carry out targeted design. The experimental means is one of the key conditions for the successful design of drying equipment.
3 processing technology gap
Drying equipment involves various processes such as drug delivery, heat transfer, and fluid mobility. The equipment or machinery processing and manufacturing requirements are higher. Over the years, China's drying equipment processing methods, processing equipment also take a more traditional hand-made, whether it is the use of equipment functions, appearance are greatly affected. Not only that, the manual single-piece manufacturing can not guarantee the good interchangeability of the parts' dimensions, and brings inconvenience to the maintenance of drying equipment and the exchange of wearing parts. Most foreign drying equipment adopts automatic welding technology, weld polishing, and the equipment surface is also polished or passivated. One of the signs of measuring the level of processing of equipment is the molding rate of the equipment during processing. The so-called mold pressure rate is the proportion of equipment used to suppress the mold. We have seen that the components of many foreign equipments are moulded and moulded, and manufacturing is very standard. China's current low mold-forming rate is mainly due to the small production capacity of equipment and the high cost of mold-opening, which cannot reach a certain scale of production. However, as a result, the quality of China's drying equipment will not have a qualitative leap, and a large number of drying equipment will go abroad and it will be difficult to achieve the occupation of the international market.
During the use of the dryer, the limitations of the processing quality often fail to meet the design requirements. For example, sticking and cleaning of medicines, sealing of various kinds of openings, and operation and inspection of equipment are all limited by the structure and quality. There is also a gap between the machining precision and processing quality of mechanical parts. For example, centrifugal atomizers, high-pressure pumps, and flash dryers have a certain gap between their drive components and similar foreign products. If China wants to become a world leader in the manufacture of dry equipment, it will not be able to solve the problems of processing methods and processing quality.
4 control level gap
The so-called drying process control is to adjust the key parameters affecting the drying process so that the dried medicine can reach a stable and uniform drying purpose. And under certain constraints, the objective function is optimized. The objective function should be designed with the target of minimum unit energy consumption. Obviously, drying control plays an important role in ensuring product quality and improving drying efficiency.
If the drying equipment is compared to a person, the control system is equivalent to human nerves, and the level of control determines the reaction speed of the drying equipment. Many dried medicines become products, that is, drying is often the last process of production (except for metering and packaging), and the stability of the drying process controls the quality of the product to some extent. Drying operations generally have two production methods. One is continuous production, and the other is batch production. No matter which production method, the control method plays an important role in stabilizing product quality. For the continuous production process, the correlation factors of various operating parameters, such as the heat, air volume, feed volume, equipment operating parameters, and the interlocking relationship between on-line measuring instruments should all be implemented with appropriate control measures. For the batch production process, the control of the drying end should also be controlled by the control device. Compared with foreign equipment, China's production of drying equipment mainly manual or semi-automatic control means, the parameters can not be related to each other, the operation of many human factors, and objectively affect the product quality.
Because the control level of the drying device is generally not high and there is no suitable and effective control method, the drying equipment often has the following conditions. When the drug is in the decelerating drying stage, the drying process needs more time than heat, but due to the control means, the drying process is still heated, which means that the drying process is not properly controlled. Finally, the product is overheated or the moisture is too low, causing unnecessary waste. Another situation is the lack of control measures for the drying process, often resulting in unstable or unqualified product quality. It is particularly important for the treatment of flammable, explosive, and organic solvent-based drug control systems. At this time, the control means is the key to the design decisions. At present, it has entered the era of intelligence, and various control instruments and meters can fully meet the needs of equipment. With the continuous development of control theory and control technology, the automation level of drying equipment in China should be improved as soon as possible. There are many computer control and fuzzy logic control systems. Successful examples. It is possible to increase the overall technical content of the device so that it can play its due role and increase the use value of drying equipment.
1 Basic research gap
Although drying technology has been developed for many years, it has indeed made great progress in theory. However, these theories still have some difficulties in practical application, and there are many imperfect contents. Therefore, there is still a lot of work to be done in theoretical research. In China, since the first National Drying Technology Exchange Conference was held in Nanjing in 1975, it has been held eight times. From the second session of the second session, each edition was edited and published. Each session had dozens of articles of various kinds to participate in exchanges. In recent years, although some colleges and universities or scientific research units are doing this work, the input of human and material resources is far from enough. The number and quality of papers published in various publications in recent years can reflect the reality of drying theory research in China. Level. In terms of theoretical research, there is still a big gap compared with Denmark, Canada, Japan and other countries. China's drying technology wants a new leap forward, and it is very important to strengthen the study of basic theories. It should arouse people's attention.
The physical properties and standards of dried medicines vary widely, and only a few drying equipments can not meet the production needs. Theoretical research is the basis for the development of new dryers. With the development of drying technology in China, it is necessary to cultivate a group of theoretical research and drying technology development workers to improve the technical content of drying equipment in China. After continuous efforts, the drying technology in the pharmaceutical industry in China can be brought close to or reach the advanced level in foreign countries.
2 insufficient experimental conditions
So far, neither the drying plant nor the theoretical research unit has a perfect experimental base. Drying is a very experimental technique. No matter if it is theoretical research or drying equipment manufacturing, experimental methods are indispensable. Through experiments, the drying temperature, drying time, product particle size, and hygiene index of various injections and granules were determined. Theoretical workers can summarize many rules in the drying process. The equipment manufacturer determines various process parameters through experiments. However, many units just ignore the importance of experimentation. Some equipment factories do not even have a set of experimental devices, so that there is a great deal of blindness in the design of equipment. Many theories summarize the general laws of drying technology, but when it comes to specific drugs, the nature of each drug's reaction in the drying process and the requirements for the product have their own particularities. Therefore, according to the general theory of treatment is not necessarily very appropriate, for specific drugs should also be subject to experimental results, so the experimental device must not be less. At present, the experimental means are weak mainly in these aspects. On the one hand, the equipment manufacturer does not have enough knowledge of the experimental process and considers it dispensable. On the other hand, there are many types of experimental devices, and the investment is huge. The non-general enterprises can afford it. The establishment of a sound experimental base is a top priority for China's drying technology research.
Drying is a profession in itself, but it is a device for handling drugs in other industries. Therefore, the drying equipment is different from other equipment, and the physical properties and requirements of the processing chemicals are very complicated. Drying is an industry that requires a comprehensive technology. Before the design, it is required to conduct an experimental analysis on the drug in order to carry out targeted design. The experimental means is one of the key conditions for the successful design of drying equipment.
3 processing technology gap
Drying equipment involves various processes such as drug delivery, heat transfer, and fluid mobility. The equipment or machinery processing and manufacturing requirements are higher. Over the years, China's drying equipment processing methods, processing equipment also take a more traditional hand-made, whether it is the use of equipment functions, appearance are greatly affected. Not only that, the manual single-piece manufacturing can not guarantee the good interchangeability of the parts' dimensions, and brings inconvenience to the maintenance of drying equipment and the exchange of wearing parts. Most foreign drying equipment adopts automatic welding technology, weld polishing, and the equipment surface is also polished or passivated. One of the signs of measuring the level of processing of equipment is the molding rate of the equipment during processing. The so-called mold pressure rate is the proportion of equipment used to suppress the mold. We have seen that the components of many foreign equipments are moulded and moulded, and manufacturing is very standard. China's current low mold-forming rate is mainly due to the small production capacity of equipment and the high cost of mold-opening, which cannot reach a certain scale of production. However, as a result, the quality of China's drying equipment will not have a qualitative leap, and a large number of drying equipment will go abroad and it will be difficult to achieve the occupation of the international market.
During the use of the dryer, the limitations of the processing quality often fail to meet the design requirements. For example, sticking and cleaning of medicines, sealing of various kinds of openings, and operation and inspection of equipment are all limited by the structure and quality. There is also a gap between the machining precision and processing quality of mechanical parts. For example, centrifugal atomizers, high-pressure pumps, and flash dryers have a certain gap between their drive components and similar foreign products. If China wants to become a world leader in the manufacture of dry equipment, it will not be able to solve the problems of processing methods and processing quality.
4 control level gap
The so-called drying process control is to adjust the key parameters affecting the drying process so that the dried medicine can reach a stable and uniform drying purpose. And under certain constraints, the objective function is optimized. The objective function should be designed with the target of minimum unit energy consumption. Obviously, drying control plays an important role in ensuring product quality and improving drying efficiency.
If the drying equipment is compared to a person, the control system is equivalent to human nerves, and the level of control determines the reaction speed of the drying equipment. Many dried medicines become products, that is, drying is often the last process of production (except for metering and packaging), and the stability of the drying process controls the quality of the product to some extent. Drying operations generally have two production methods. One is continuous production, and the other is batch production. No matter which production method, the control method plays an important role in stabilizing product quality. For the continuous production process, the correlation factors of various operating parameters, such as the heat, air volume, feed volume, equipment operating parameters, and the interlocking relationship between on-line measuring instruments should all be implemented with appropriate control measures. For the batch production process, the control of the drying end should also be controlled by the control device. Compared with foreign equipment, China's production of drying equipment mainly manual or semi-automatic control means, the parameters can not be related to each other, the operation of many human factors, and objectively affect the product quality.
Because the control level of the drying device is generally not high and there is no suitable and effective control method, the drying equipment often has the following conditions. When the drug is in the decelerating drying stage, the drying process needs more time than heat, but due to the control means, the drying process is still heated, which means that the drying process is not properly controlled. Finally, the product is overheated or the moisture is too low, causing unnecessary waste. Another situation is the lack of control measures for the drying process, often resulting in unstable or unqualified product quality. It is particularly important for the treatment of flammable, explosive, and organic solvent-based drug control systems. At this time, the control means is the key to the design decisions. At present, it has entered the era of intelligence, and various control instruments and meters can fully meet the needs of equipment. With the continuous development of control theory and control technology, the automation level of drying equipment in China should be improved as soon as possible. There are many computer control and fuzzy logic control systems. Successful examples. It is possible to increase the overall technical content of the device so that it can play its due role and increase the use value of drying equipment.