The Structural Parameter Optimization Research Of Three Sections Dense Medium Cyclone Used In Pressure-reseparation Of Middings

China is a big country for coal production,and it is also a big country for coal consumption.As the country's main energy source,coal plays an irreplaceable role and provides an inexhaustible motive force for the country's economic development.Although China's coal resources are abundant,coking coal resources are scarce and they need to be imported from abroad for a long time.The irrational use of resources in actual production and application has led to a large amount of wasted resources.In particular,coking coal in the coking coal preparation plant has been burned directly as steam coal due to a slightly higher ash content,resulting in great waste of resources.In recent years,with the continuing downturn in the coal industry,optimizing product mix,improving the quality of clean coal,and deepening the implementation of clean coal strategy have been called the urgent need for coal enterprise reforms to overcome difficulties.With the frequent occurrence of haze and weather,and the party's 18 th Congress pointed out the problems related to the environment,protecting the environment has become a top priority.The coal industry plays a very important role in protecting the environment.According to a rough calculation,approximately 80 million tons of scarce coking coal resources in China are burned directly each year,so coking coal has great value for development and utilization.Recovering clean coal from China Coal can not only improve the economic efficiency of enterprises,but also increase energy efficiency.The use of efficiency,but also has a profound significance for environmental protection.There are many researches on re-election of China Coal at home and abroad.Through analysis,we can see that China Coal can be divided into two major categories.The first method is to directly sort the coal after it is crushed.The broken coal and raw coal enter the sorting system together or add a set of medium coal sorting system.The second method is to recover the clean coal after fine grinding of the coal.After the fine coal grinding,the clean coal is recovered by flotation.The topic of this thesis is mainly to develop a new three-stage heavy-medium cyclone for the re-election of China Coal.This equipment is developed on the basis of traditional three-product cyclones.This new three-stage heavy-medium cyclone is mainly used to solve the problem of entrainment loss of medium coal in the actual production process at the site.The new three-stage heavy-medium cyclone for medium coal re-election is a series of suitable cyclones in series behind the traditional three-product heavy-medium cyclones.According to the development history of the cyclone and the design experience of the cyclone,a three-stage heavy medium cyclone model with pressure and re-election of medium coal was designed.This paper first explores the theoretical feasibility of the new three-stage heavy-medium cyclone.By analyzing the test data,it is concluded that the three-stage heavy-medium cyclone is feasible to recover the entrained clean coal from the medium coal,and also confirms that the third-stage coal re-selection cyclone and the inlet mirror should be filled with mirror symmetrical openings.Adding a proper amount of clear water reduces the sorting density of the medium-coal re-selection cyclone.The main part of this thesis is the optimization of structural parameters of three-stage heavy-medium cyclones.From the structural parameters affecting cyclone sorting,three more important parameters were selected,the diameter of the underflow port,the overflow pipe,and the insertion depth of the overflow pipe to optimize the structural parameters and find the optimal combination.On the basis of finding the optimal combination,the trial will explore the water supplement of the third-stage coal re-selection cyclone supplement pipe.Taking the raw coal of the Huaibei Coal Mining Group's Guobei Coal Preparation Plant as the test object,the screening of the raw coal was carried out first,and the optional curve was drawn to find out the theoretical separation density for the predetermined ash,which was used as a reference for the structure.The optimal combination of parameters and the optimal amount of water are verified.