| Granulators in the pharmaceutical industry at home and abroad generally use bag filter-based dust removal systems to filter out industrial tail gas containing solid particles generated in production,meeting the requirements of the country and industry for environmental protection standards for corresponding industrial gas emissions.The bag filter has mature technology,high dust removal efficiency and a wide range of applications.However,as the primary dust removal equipment of the boiling granulator,there are large cleaning workloads,high operation and maintenance costs,large fluctuations in working conditions and difficult to control,and filter bags.The problems such as the serious shortage of the filtration area of the granulator have brought great trouble to the production of the enterprise,and seriously restricted the stability and improvement of the production efficiency of the granulator.Faced with this problem,the pharmaceutical industry has also made some attempts to improve technology,such as using metal sintered mesh to replace filter bags,etc.However,the principle of dust removal of the equipment has not changed.Compared with the original filter bag,the sintered mesh is not only expensive and heavy.,its inherent rigidity is also difficult to clean,and the microporous structure that mainly plays the role of mechanical filtration is complex and easy to cause permanent blockage,etc.There are many similar problems.These structural technical problems make the effect not ideal.Therefore,according to the actual working conditions of the granulator and the characteristics of dust particles,the existing dust removal methods are analyzed,and the solution of the "bag-rotation" dust removal system is proposed,that is,the axial flow cyclone dust removal technology is used to replace the original bag.Dust removal technology: In-depth research on the operation process of equipment including dust removal system,and research and development of high-efficiency axial-flow cyclone dust collector and supporting systems,in order to realize the replacement and innovation of dust removal technology of granulator.The main contents are as follows:(1)The effects of some important parameters,such as the inlet velocity,the diameter of the equipment barrel and the extraction rate of the dust settling area,on the movement characteristics and collection efficiency of the dust particles in the swirl separation area of the axial flow cyclone dust collector were analyzed by CFD-DEM coupling calculation method.After completing the corresponding multi-objective and multi-parameter collaborative optimization,the best parameter combination is obtained.The results show that with the increase of inlet velocity or the decrease of cylinder diameter in the cyclone separation zone,the separation efficiency of fine particles increases obviously.The overall dust removal efficiency of axial flow cyclone dust collector can be improved by using air extraction method.(2)A diversion and pressure regulating device is designed and researched.The main structure is two rotors with different blade shapes in the front and rear,which can be rotated and positioned relative to each other,so as to adapt to the change of the working pressure drop and the dust-laden airflow after the "bag re-rotation".Precise control over a wider range of operating parameters.The numerical simulation of the air pressure characteristics of the device was completed under the condition of velocity of 10～20m/s;when the air velocity in the main pipeline was 15m/s,the adjustable pressure range could reach 0～3733.5pa.(3)According to the "bag-to-rotation" scheme,the technical improvement design,numerical simulation and operation characteristic analysis of the boiling granulation system are carried out.First of all,it is determined that the pressure drop changes of the clean filter material and the dust-covered filter material of the original bag filter under different air intake speeds,the influence on the air extraction rate of the dust exhaust pipe of the axial cyclone dust collector is less than 3%,which can be ignored.Secondly,after comparing and analyzing the dust removal efficiency,energy loss,operation and maintenance costs,and granulation output of the dust removal system,the results show that after using the new dust removal system,its dust removal efficiency,operation and maintenance costs,and granulation output Compared with the original dust removal system,the improvement is obvious,and the energy loss is slightly increased compared with the original dust removal system. |
PDF Full Text Request