Optimized Design Of Ventilation And Mixing Device For Cartridge Type Aerobic Compost Reactor

Reactor composting has become an inevitable trend in the field of aerobic composting,replacing the traditional open composting method.This paper addresses the optimization of the dispersion performance of the ventilating and stirring structure,a key structure affecting aerobic compost reactors.In this paper,with the help of a compost reactor ventilating and stirring device with good dispersion performance,the main structural parameters of the ventilating and stirring device,such as the number of layers of stirring paddle blades,blade slope placement angle and blade stirring radius,are tested by CFD numerical simulation,and on this basis,orthogonal optimization is carried out to select a better combination of structural parameters.The main contents and conclusions of this paper are as follows:(1)The 3D model of aerobic compost reactor was established by using Solidworks software,in which the 3D model of the ventilation and mixing system was mainly constructed and meshed,and the flow field characteristics of the aerobic compost reactor were analyzed on the basis of numerical simulation.Studies have shown that the number of layers of mixing paddle blades,blade stirring diameter,blade bevel placement angle and other structural parameters can have a certain impact on the dispersion performance of the ventilation mixing system.(2)Single-factor analysis was performed on three structural parameters of the aerobic compost reactor ventilation and stirring device: number of stirring paddle blade layers,blade ramp placement angle,and blade stirring radius,and the flow field characteristics of each model group were observed and compared after numerical simulations:(a)The gas content in the reactor tends to increase with the number of layers when the selected number of intermediate blades of the stirring paddles is 5 to 7.(b)The gas content in the reactor tends to increase and then decrease with the angle of the stirrer blade inclination of 40°to 50°.(c)The peak occurs in the selected stirring paddle blade stirring radius range from1780 mm to 1960 mm,and the dispersion performance of the ventilated stirring structure of the compost reactor in this range shows a rising and then decreasing trend with increasing stirring paddle blade stirring radius.(3)The three levels with better effect were pre-selected among the parameters,followed by a three-factor,three-level orthogonal test for each parameter,and the test scheme was determined by the orthogonal test table,and CFD numerical simulation was performed to obtain the orthogonal optimized structural parameter combinations..And the two optimization results after orthogonal test optimization were compared,and the optimal parameter selection of the two models was reconfirmed by numerical simulation and cloud analysis.After a comprehensive analysis of the flow field velocity cloud diagram,flow field gas distribution cloud diagram and blade surface pressure distribution diagram,the number of blade layers n=6,blade bevel placement angle α=50°,blade stirring diameter l=1780mm,the average gas content rate reaches 8.368%,the gas unevenness index is only0.227,and the average pressure of the middle blade is 33131 pa,in the range of structural parameters in this paper,this The structure is optimal in dispersion performance.In this paper,the influence of different structural factors on the dispersion performance of the ventilating and stirring device of aerobic composting reactor is discussed through the analysis of the ventilating and stirring device,which provides theoretical basis and reference for the future development and optimization of the ventilating and stirring device as well as the development,improvement and operation of subsequent composting reactors.