Numerical Simulation Of Key Equipment In Dust Removal System Of Granulator

In the domestic and foreign granulator equipment,the two-stage filter dust removal system of bag dust collector and filter cylinder dust collector in series is generally adopted,and the primary dust removal is the bag dust collector located on the top of the granulator.As the mainstream dust removal method of pelletizing equipment at present,this kind of bag dust remover has disadvantages such as large pressure loss,high cost of operation and maintenance,insufficient filtration area,etc.At present,the dust removal system of pharmaceutical granulation equipment is mostly improved,but only limited to the use of rigid filter material such as sintered mesh filter bag instead of the original cloth bag.relevant pelletizing enterprises in the industry have only limited attempts to replace the filter dust removal of cloth bags.After analyzing the working conditions and particle characteristics of all kinds of dust remover in the pelletizing process,a research and development scheme of "bag-to-rotation" was proposed,that is,a kind of efficient axial flow cyclone separator was developed to replace the original bag type dust remover,and the structure improvement and technical innovation of dust removal equipment in the actual pelletizer were achieved.Focusing on the key equipment and technology involved in the dust removal system,the following work is done:Firstly,the k-ε turbulence model was used to model and numerically simulate the internal flow field of the axial flow cyclone separator and the filter cartridge dust collector,and the movement characteristics and main characteristics of the internal flow field were studied,and the key parameters of the dust flow velocity,pressure and the movement state of dust particles were obtained.Secondly,in view of the low separation efficiency of the axial flow cyclone separator for fine particles and the unclear relationship between the structure parameters,it was determined that the inlet wind speed,blade exit angle and exhaust pipe diameter are the key parameters that affect the separation efficiency after study.Then,the relationship between the above and the working performance of the separator is investigated,and the structure of the separator is optimized.The results show that when the flow rate is 20 m/s,the separation efficiency of 4 μm particles can reach92.3%,and the separation efficiency of 10 μm and above particles can reach 100%;and the calculation model of separation efficiency is given by weighting method under the condition of particle size d≥4 μm and inlet wind speed of 4～20 m/s.Finally,through the numerical simulation and analysis of the original dust removal system and the improved dust removal system,the feasibility and applicability of the "bag-to-rotation" scheme is clarified.After improvement,the airflow handling capacity is increased by 195% under the same working condition.The pressure loss and dust removal efficiency are not different from the original system,but the pressure drop is adjustable and the elasticity is increased,and the applicability is stronger.The energy consumption of the developed axial cyclone separator is obviously better than that of the original bag filter.