Structural Design And Analysis Of Fermenter And Agitator

With the promulgation of the “Water Ten” and the new environmental protection law,the water quality exceeding the standard “Peace by Day” and “Pawning and Responsibility” are the most stringent in history,and the implementation of “African Hog” and new landmarks for aquaculture wastewater can be described as Adding to the snow.The pig farm sewage has a typical "three high" characteristics,CODCr up to 3000 ~ 12000 mg / L,ammonia nitrogen up to 800 ~ 2200 mg / L,SS exceeds the number of dozens of times,and generally contain inhibition of biological bacteria and difficult to degrade activity Ingredients,therefore,these wastewaters are discharged through anaerobic-aerobic-deep treatment.Among them,anaerobic fermentation is an indispensable part of the most important,but suffering from pig farming is a low-profit industry.Building a fermenter that is cheap,durable and effective is a much-needed product for many pig farmers.At present,higher concentration(5-30%)anaerobic fermentation tanks and agitators use structural formulas for structural design,poor applicability,short life,poor durability,poor mixing effect,dead angles,easy acidification of materials,bacterial necrosis,etc..In this paper,based on theoretical analysis,numerical calculation and field test,the structure design of fermenter and agit ator is combined with hydrodynamic analysis and field test to optimize the installation position and inclination of the agitator.And the results are as follows:(1)According to the design conditions,the structural mechanics analysis of the fermenter and the opening reinforcement,the agitator,the heat exchange coil,etc.,completed the structural design of the fermenter as a whole and the agitator;(2)Using the computational fluid dynamics analysis software,the fluid-solid coupling model is established,and the different concentration flow fields under the influence of the installation position,inclination angle and rotation speed of the agitator are analyzed,and the maximum influence of the rotational speed on the flow field is obtained.Secondly,the placement position and installation angle have an influence on each other,and the optimal placement position and inclination angle of the agitator are obtained;(3)According to the characteristics of large fertility tank with high aspect ratio,wind load and easy to overturn under seismic load,the dynamic finite element model of fermenter was established,and the modal and seismic response analysis was carried out,and the corresponding stiffness and strength design was obtained.Limit value;for the agitator process,the blade deformation and bending are easy to occur,resulting in unsatisfactory agitation.The finite element model of the agitator is established,and the unidirectional fluid-solid coupling analysis is carried out to obtain the strength of the agitator under different parameters stiffness limit.(4)In view of the rugged roads,narrow roads and difficult access of the pigs,the tanks and tank tops were lightly designed to obtain better structural forms and parameters.At the same time,combined with field tests for fermentation under stirring.The uniformity of the flow field in the tank was tested and analyzed to meet the established design requirements.