Study On The Drying Process And Equipment For Organic Fertilizer Pellets

The organic fertilizers are widely used in the most agricultural production areas,which are effective solutions to the land hardening,degradation and fertility decline in the country currently.In spite of,expert skills,inappropriate technology,high demand of energy,low production of the drying process,all these associated to the restriction of commercialized organic fertilizer development industry.To optimize the production process and innovate in production equipments,this study was conducted to investigate the physical and thermal characteristics of organic fertilizer particle basing on the combination of experimental study and simulation analysis.A triple-pass rotary drum drying technology was presented and a combined flight had been designed to make the organic fertility particle flowing in a backward gravity direction in the drum.The prototypes,which is applying this process had been designed and made,performance parameters of the prototype was determined by means of experiment.The experiment has selected the organic fertilizer particle which is made in Wofeng Agricultural Technology Limited Company.It indicates the relationship between the moisture content and the coefficient of rolling friction.The coefficient of elastic restitution and maximum static friction in different has been determined.The experiment has explores the laws for the moisture of organic fertilizer particle in the thin layer drying process with different temperature and thickness.The drying model has been made based on laws and it turns out the activation energy of drying process.The whole dehydration process of organic fertilizer has been reflected intuitively,based on the result of the internal moisture changes in drying process by COSMSOL.A combined flight which was installed along the tube inner surface has been designed according to the technical requirements for triple-pass rotary drum tilted and the movement's laws of particle in drum.The combined flights make particles have a certain kinetic energy when the particle left each flight,the particle would climbing in a backward gravity direction in the drum through a series of flights making the flow condition of particles between three layer drum.The rectangular lifting flight which is the inner flight could ensure the homogeneous degree of the particle scattering,increase the contact area between the particle and heat medium,ensures rapid water loss of particles in inner drum.According to the analysis result of the combined flight structure on the influence of particle residence time within the drum by EDEM,the relationship which among the drum rotating speed,drum Angle,Angle and residence time of the combined flight has been determined.The significance factors on the residence time which were the drum Angle and plane slide Angle were studied.By comparing the test result,it would turn out the mathematical relationship between the factors and the residence time.The three layers drum size has been designed according to the initial calculating results.The inner tube diameter is 0.70m and the length is 5.5m.The middle tube diameter is 1.10m and the length is 6m.The outside tube diameter is 1.6m and the length is 6.6m.Moisture evaporation is 642.86 kg/h.Import wet material quality is 3642.85 kg.Over drying fertilizer quality is 2550 kg/h.The total quantity of heat required 2605977.04 kJ.The air flow required 11443.3 1m3/h.According to the arrangement of drum and the characteristics of the operation,integration support system has been designed which including high strength gear wheel,roller and outside dish chain drive system.The research paper set up the equipment test program according to the corresponding national standard.The falling water rate is 12.906%on stable operation state.The drying rate is 0.414t/h.The unit moisture evaporation is 460kg/h.The unit heat consumption is 5033kJ/kg.The productivity is 2155kg/h.