Conveying Mechanical Analysis And Experiment Of Spiral Sand Conveyor

With the massive exploitation of oil,the oil reserves in our country are decreasing year by year,the difficulty in the exploitation of oil is increasing,the depth of the oil well is increasing.Fracturing is one of the effective measures to improve oil production and improve oil recovery.The quality of fracturing fluid and composition ratio of fracturing fluid directly determine the success or failure of the whole fracturing process.Fracturing sand is an important component of fracturing fluid and plays a supporting role in fracturing.Screw conveyer is an important component of a sand mixing vehicle,providing fracturing sand in the mixing process of fracturing fluid.During the design process,the conveying efficiency of the sand conveyor should be maximally increased based on ensuring the mixture ratio of the mixing liquid.Therefore,must analyze the various structural parameters on the influence of conveyer conveying efficiency,and can accurately calculate the mass flow rate of sand transport export.In this paper,the spiral sand conveyor is the object.The conveying mechanism are studied with the model theory of granular material,continual mechanics,particle swarm theory of slip conveyer theory.Transport process is simulated with discrete element.The model theory is validated with experiment.The theoretical calculation formula of the flow rate and power consumption of the outlet of the sand conveyer can provide a reference for the intelligent control of the later sand conveyer and the improvement of the high efficiency transportation.The main work and findings of the research are as follows:(1)Applying discrete mechanics,establishing the granular mechanics model,getting the helix angle of particles within various rotation speed,inclination angles,pitch diameter ratio.Applying continuum mechanics and particle swarm theory,research determines equation of free surface and distribution of stress.Establishing the theoretical calculation model of mass flow rate and power consumption within various rotation speed,inclination angles,pitch diameter ratio.Provides an effective theoretical support for the design of main parameters of conveyer.(2)The rolling friction coefficient of fractured sand is calibrated by using the particle accumulation angle test and the discrete element software EDEM fitting method.The particle motion path,particle size distribution and particle velocity distribution are studied when the conveyer conveying stability.Analyzing the mass flow rate and power consumption within various rotation speed,inclination angles,pitch diameter ratio.The collision of particles in transportation process is studied,and the energy spectrum of particle collision is obtained.(3)Establishing shrinkage model of spiral sand conveyor,developing.Applying shrinkage model,research mass flow rate within various otation speed,inclination angles,pitch diameter ratio.The experimental value of mass flow rate is compared with the theoretical value,which proves that the test can effectively verify the theory.The experiment shows that the inclination of the sand conveyer is 40°and50°,and the ratio of the pitch diameter is 6/8,the mass flow rate of the sand conveyer is the largest.the inclination of the sand conveyer is 45°and 55°and the diameter ratio of the pitch is 5/8,the mass flow rate of the sand conveyer is the greatest.