Performance Analysis And Structure Design Of Pulverized-coal Mixer Based On Energy Recovery

Pulverized-coal mixer is the important equipment of high-pressure pulverized coaltransportation, and it is the key equipment in the production of the blast furnace coal injectionand pulverized boiler process. The structural form of the pulverized-coal mixer maydetermine whether the pulverized-coal is mixed with the compressed air evenly, and thepulverized-coal concentration, the ability of transporting, the amount of pulverized-coal usedafter mixing. The existing pulverized-coal mixer are used to offset the pressure of thepulverized-coal with high pressure at first, and then mixed with high pressure air. This maynot only cause a serious pressure energy waste of the pulverized-coal, but also need externalenergy to assist offsetting pressure energy of the pulverized-coal, that causing dual energyconsumption. At the same time the pulverized-coal may be mixed unevenly.In connection with the problem of uneven mix and energy waste in high pressurepulverized-coal mixing, conducted a comprehensive analysis to the traditional coal mixerworks and fluid energy recycling technology currently, design a new pulverized coal mixerbased on energy recovery. In improving the mixing uniformity of pulverized-coal, thehigh-pressure pressure pulverized coal can be recovered. In this paper the main researchingcontent and innovative achievements are as follows:(1) Complete the design of a new coal mixer based on the principle of multi-leafdiversion channel, impeller mechanical energy conversion characteristics, and the law ofenergy conservation. Design a straight closed vane wheel in improving the mixing uniformityof pulverized-coal while reducing the coal ratio and saving coal consumption; design asymmetrical straight-through hollow shaft which the pressure of high pressure pulverized coalcan be converted into the wheel’s mechanical energy and by straight-through hollow shaftrotor driven the generator rotor to power, thus achieve high pressure energy recycling of thepulverized-coal.(2) Complete preliminary calculation for the new pulverized-coal mixer based on thefluid mechanical design methods. Establish its three-dimensional model in Solidworks, meshthe internal fluid in ANSA and establish mesh model of the internal fluid, and completenumerical simulation of the full three-dimensional field of internal pulverized-coal understeady turbulent flow in Fluent. (3) Complete preliminary calculation for the flow of liquid water and pulverized-coalrespectively, and analysis the similarities and differences flow conditions between liquid andpowder.(4)Use the method of digital iterative design process: the preliminary design-numericalsimulation-modified design, complete the internal flow simulation and contrast respectivelywith6blades and8blades when the8blades performed better. Then optimize the angle ofimport and export blade. According to the contrast of simulation results and completeperformance analysis. Finally, prove the feasibility and economy of the new pulverized-coalmixer.In this paper, According to the problem of pressure energy waste in industrialpulverized-coal, design a new kind of pulverized-coal mixer. On the basis of structure design,complete numerical simulation of the internal flow field, structural optimization, and itsperformance analysis. The results show that the pulverized-coal and air can be mixed evenlyin the new pulverized-coal so as to reduce the consumption of coal, in addition it can alsotranslate the high pressure energy of pulverized-coal into mechanical energy of the impeller,that realized the recycle of pressure energy.It played a significant role in promoting theindustrial production to an aspect of low-cost and high efficiency. Put forward a new pressureenergy recovery technology using powder pressure to generate electricity which has greatreference value for the development of powder mechanism in the future.