Study On Parameter Optimization Of Air Jet Mill AFG100

With the development of modern powder technology,modern high-tech industries such as pharmaceutical industry have put forward higher requirements for equipment,preparation efficiency,particle size and preparation cost of powder materials.Ultrafine powders can be used to improve powder processing and increase bioavailability of active pharmaceutical ingredients(API)to facilitate absorption by the body.According to research,an important equipment for preparing ultrafine powder of medicinal materials is jet mill.The determination of certain process parameters and structural parameters of the equipment depends on a large number of experiments and experience,which is costly for precious Chinese medicinal materials.In this paper,the Chinese herbal medicine Panax notoginseng ultrafine powder is used as the powder discharge object,this paper studies the methods to improve the discharge rate of Panax notoginseng,the process parameters of the pulverization process were optimized by the fluidized bed air jet mill AFG100 and the parameter closed-loop control method based on industrial grade single-chip microcomputer was proposed:(1)The position distribution of AFG100 nozzle was analyzed and modeled,and particle backflow affecting the discharge rate was found.On this basis,the position distribution of AFG100 nozzle was changed,due to the wide position of the bottom of the cavity and the accumulation of material,the bottom nozzle is added,which effectively reduces the backflow formed around the nozzle.Based on the gully flow theory,the backflow formed around the nozzle can cause the material to circulate in the crushing zone,unable to be crushed or to be separated from the crushing zone and settle to the bottom of the AFG100 cavity,material accumulation in the crushing area or at the bottom of the cavity may result in excessive material holding in the cavity,thus reducing the efficiency of product delivery,After the bottom nozzle is added,the material settled at the bottom of the cavity is blown up,so that the particles are concentrated in the crushing zone,and the product discharge rate is improved.(2)The orthogonal test was designed for four parameters: nozzle angle,grading speed,feed speed and back pressure.The simulation results were analyzed by visual analysis and variance analysis.The conclusions of parameter optimization were obtained: the influence of nozzle angle and grading speed on the discharge rate was significant.(3)Based on the above process parameters,the influence on the discharge rate is significant.A closed-loop control system based on industrial grade STC single-chip microcomputer and Beijing Kunlun open state MCGS touch screen is designed for AFG100,which realizes automatic feedback adjustment control of feed rate.To make the influence of the parameters more controllable,the discharge rate of the fluidized bed air jet mill is further improved.