Research On Municipal Food Waste Solid-liquid Separation And Facility Development

Municipal food waste is the food remnants after daily diet,the emissions are huge.It can be characterized by high organic matter content,easy to corrupt and pathogen breeding.The comprehensive disposal of food waste can achieve resource regeneration and reduce environmental pollution.In order to improve the reduction rate and resource utilization efficiency of food waste,solid-liquid separation pretreatment is very necessary.The screw extruder is applied to study the efficient separation technology of food waste,the main research results are as follows:1.Based on the material properties of urban food waste,the mechanism of solid-liquid separation of two-phase materials was studied.The discrete calculation model of the micro-element segment considering the change of the physical property and the flow rate is constructed,the dehydration mechanism is analyzed.It is found that the structure parameters of screw and the initial material property are the main factors affecting the solid-liquid separation2.The effects of screw structure,rotational speed and outlet section on solid-liquid separation were studied by experimental and theoretical analysis.Increasing the cone angle and reducing the outlet cross section can increase the flow field pressure and reduce the moisture content.Improving the screw speed can't increase the pressure and reduces the water content.3.The prototype is designed by the combination of variable diameter screw,frequency control and outlet adjustment.In order to improve the efficiency of disposal and reduce the loss of organic matter,the combination of gravity dewatering and extruded dewatering can be promoted by the experiment.The experimental results show that the screw speed and the initial moisture content are important factors affecting the separation.4.The processing equipment with crusher,wedge filter and pressure regulating device is designed to solve the problem of filter plugging,bulk organic matter suppression separation and reduction of organic matter loss.The establishment of normal extrusion,intermittent rubbing and reverse extrusion of the working mode to improve the adaptability for the differences of food waste.