Double cone vacuum dryer needs upgrading

Changzhou fengneng drying is an enterprise with unique design and continuous innovation in drying industry in China! There are many domestic manufacturers of biconical rotary vacuum dryer, but the overall design and manufacturing level are relatively low There is no upgrading of this classic practical equipment (only a few domestic manufacturers have made upgrading efforts) The real reason is that they can not combine theory to study the performance and application of biconical rotary vacuum dryer, or do Upgrading Research and development Based on the theory of vacuum drying, this paper discusses the upgrading of double cone rotary vacuum dryer in China, and puts forward some suggestions for the reference of people with lofty ideals The purpose is to improve the manufacturing and application level of double cone rotary vacuum dryer in China 1 Why double cone rotary vacuum dryer as a classic equipment to discuss? The double cone rotary vacuum dryer is widely used in the production of API in the past few years This is because in the process of vacuum drying, the pressure in the cylinder is always lower than the atmospheric pressure, the number of gas molecules is small, the density is low, and the oxygen content is low, so it can dry the drug production which is easy to be oxidized and reduce the chance of material contamination In the process of vaporization, the temperature of water is directly proportional to the steam pressure, so the water in the material can vaporize at low temperature during vacuum drying to achieve low-temperature drying The double cone rotary vacuum dryer produced by Changzhou fengneng drying is especially suitable for the production of heat sensitive materials in drugs At the same time, vacuum drying can eliminate the phenomenon of surface hardening caused by atmospheric hot air drying This is because the pressure difference between the inner and the surface of vacuum drying materials is large Under the effect of pressure gradient, the water quickly moves to the surface without surface hardening In addition, the temperature gradient between the inside and outside of the material is small during the vacuum drying, and the reverse osmosis makes the solvent move and collect independently, which effectively overcomes the phenomenon of solvent loss caused by the hot air drying From the function point of view, Changzhou fengneng drying double cone rotary vacuum dryer is a drying equipment which integrates mixing and vacuum drying It is applied as a classical equipment with the characteristics of simplicity, convenience and double effect It has the practical and economic side, and is difficult to be replaced by other equipment But in recent years, it has been diluted by people The basic reason is the lack of research and structure improvement by manufacturers It is mainly reflected in the difficulty of CIP / SIP and optimization of drying performance in structure Therefore, it is necessary to think about its upgrading 2 The concept of vacuum drying speed In the process of vacuum drying, people always want to speed up the drying speed and shorten the drying time, but the factors that affect the drying speed are as follows: (1) the condition of the dried material (such as the shape, size and stacking method of the material), the moisture content, density, viscosity and other properties of the material itself Generally, the material particles are fine and uniform, stacked loosely, and the thickness is thin, so the internal moisture is easy to spread If the initial temperature of the material is increased, the material is pretreated by vacuum filtration, and the moisture content of the material is reduced, the speed of vacuum drying can be increased (2) The higher the vacuum degree is, the better the water vaporizes at a lower temperature However, the higher the vacuum degree is, the worse the heat conduction is, and the heating effect on the material will be affected In order to improve the drying speed of materials, the vacuum degree should be considered comprehensively according to the characteristics of materials Generally, the vacuum degree is not less than 1 × 104 PA 3 Discussion and suggestions on the factors affecting the vacuum drying speed of double cone rotary vacuum dryer (1) The drying process of the double cone rotary vacuum dryer is tested with vacuum degree, drying temperature, steam pressure and drying time as parameters respectively The curve of the test shows that the drying process of the double cone rotary vacuum dryer can be divided into five stages: temperature rise, * constant temperature, second temperature rise, second constant temperature and temperature drop Among them: * heating is the preheating stage for heating materials In this stage, the amount of water vaporization in the material is very small; * constant temperature is a constant speed drying stage, in this stage, the free water, surface water and capillary water of the material vaporize a lot Therefore, the temperature and vacuum are in a constant state, and the vacuum degree is approximately equal to the saturated steam pressure of the water at the temperature of the drying equipment; the second temperature rise is the process of heating the material to transfer the internal moisture to the surface of the material, because the vaporized moisture is very little, the temperature and the real degree of the material increase accordingly; The second constant temperature is the stage in which the vaporization is wrapped with water and part of the crystallized water Because the water mobility is determined by the vaporization rate, the temperature and vacuum are in a stable state At the beginning of the cooling stage, the heating steam is turned off, and the cooling water is sent to the jacket of the cylinder, which cools the cylinder to reduce the temperature of the internal materials, so as to unload the dried products Now, the average drying process parameters of a product are listed in Table 1 below Table 14 Expand the function of double cone rotary vacuum dryer to adapt to wider application: it can be seen from the table that the nature of different stages of drying process of Changzhou fengneng rotary vacuum dryer is also different, so different operation parameters should be set according to different stages, so that the function of the equipment can be used more effectively However, many operating parameters of the practical double cone rotary vacuum dryer are constant (such as rotation speed) or automatic control (such as working vacuum degree, drying temperature, etc.) The following discusses the influence of operating parameters of different drying stages on the vacuum drying speed, and puts forward suggestions for improvement In this regard, it is suggested to select temperature sensing elements so that the control of heat or cooling capacity in the jacket of double cone rotary vacuum dryer can be changed during operation, and there is a menu to set the selected temperature in different time periods, that is to say, there should be a time temperature relationship To increase the mixing and granulation function, a tube with a nozzle (which can spray adhesive) can be inserted into the vacuum tube of the double cone rotary vacuum dryer, and a fixed mixing blade can be added at the place where the vacuum tube enters the barrel When the cylinder is rotating, the stirring blade fixed on the vacuum tube forces the material to flow through its two sides, so that when the material slides along the cylinder wall, the radial movement is increased Therefore, it can effectively improve the effect of mixing and stirring materials, accelerate the wet partial vaporization, and improve the drying speed After that, at the end of the powder material process, the corresponding adhesive can be ejected from the pipe with a nozzle (which can spray the adhesive), and the powder like dry material can be made into a granular product 5 Develop CIP / SIP structure to adapt to aseptic production The CIP / SIP structure of double cone rotary vacuum dryer should be developed in a different way In addition to the ideas mentioned above, it can be connected to the cylinder through quick opening external spray cleaning device When it is shut down, it can be connected to the cylinder and form a cleaning loop system It can also be assumed that the barrel of the whole Changzhou fengneng drying double cone rotary vacuum dryer can be disassembled (such as the clamping type square cone mixer structure), so that the whole barrel can enter the cleaning station to complete cleaning and sterilization, of course, this assumption is too difficult This is also the basis for upgrading the double cone rotary vacuum dryer, so that it can adapt to the production of sterile level
This paper discusses the vacuum drying speed of double cone rotary vacuum dryer in theory, analyzes the imperfections of the structure of some domestic double cone rotary vacuum dryers, and puts forward to upgrade the research and development of the double cone rotary vacuum dryer based on the vacuum drying theory, so as to improve the research and development and Application level of Changzhou fengneng drying double cone rotary vacuum dryer in general Practical products radiate new vitality However, the Technology Department of Changzhou fengneng Co., Ltd only put forward some suggestions for its upgrading, in order to feed people with lofty ideals for reference, so that the manufacturing and application of double cone rotary vacuum dryer is becoming more and more beautiful.