Research On Negative Pressure Wetting Dustfall Device In Transfer Point Of Belt Conveyor

The coal is still one of the world’s most important basic energy now. Withthe rapid development of global economy, the demand for coal is growingrapidly, which results that the exploitation quantity of coal is growing. The dustis produced inevitably during the process of mining and transporting. The dustof high concentration can affect the health of workers’ seriously, and even causethe coal explosion and damage equipments. The transfer point of belt conveyoris one of the important dust sources in coal production and transportation. Atpresent, the dustfall method in transfer point of belt conveyor is the sprinklingwater dustfall by opening the water valve. This way need the person responsible,and the effect of dust reduction is not ideal. Therefore, the design and developon a kind of dustfall device in transfer point of belt conveyor is very necessary,which is great significance to effectively improve working conditions forworkers.The production and damage of coal dust was analyzed, the distributioncharacteristics, stress status and diffusion model of dust in transfer point werestudied. The geometry model of transfer point was established and meshed by GAMBIT, and simulated by FLUENT. The location range of the maximum dustconcentration in transfer point was obtained, which laid the foundation fordesigning negative pressure wetting dustfall device in transfer point of beltconveyor.The negative pressure wetting dustfall device was put forward byanalyzing the advantages and disadvantages of the existing dustfall technologyin transfer points and combined with the actual situation of transfer point. Thedust-laden air is sucked into the device for the negative pressure which is madeby high-speed rotating impellers, and the dust is removed in limited spacethrough the nozzle spray mist. The atomizing and catching dust process of thisdevice was analyzed from the aspect of theoretic; the water consumption of thedevice was calculated under certain stress conditions. Then the impeller, nozzle,electronic control parts were designed and analyzed. And the match parameterswere obtained. This device is simple to install and convenient operation, lowcost, which can effectively inhibit the proliferation of dust in transfer point.The single nozzle, spray air duct system and the whole device field weresimulated by using FLUENT software. Research showed that there wasrelatively smaller eddy current loss in streamlined nozzles than that of conenozzles, atomization effect of streamlined nozzles was well. The matchingparameters for limited space remove dust as follows: the wind speed in air ductshould be controlled at3~12m/s, nozzle pressure is controlled in the range of2~6MPa, the number of nozzle is3, and the rotation speed of the motor is 1450r/min. In this case, the mist field distribution is uniformity in air duct, fullof space, and the dustfall effect is best.The laboratory experiment of negative pressure wetting dustfall device wasmade. The negative effects and spray effects and device operating conditionswere actually tested. Results showed that, the overall operation condition of thedevice was well and all aspects of its performance can meet the designrequirements.