Experimental Research On Formation Mechanism Of Pulse Cleaning Of Bag Filter

The bag dust collector has been widely used as dust purification equipment beacause of the representative pulse jet cleaning mode.Domestic and foreign scholars has been studied extensively for the various phenomena during the pulse blowing.So far,about leading the cleaning effect of pulse spraying air sign index parameters and its formation mechanism is still not fully understood.The lack of mature design method to guide the design of cleaning system lead to poor operation status of dust collector.Using Darcy's law and the gas jet theory derived the relation between jet section kinetic energy and flow and the nozzle diameter,exit gas velocity(air pressure)and spray blowing distance;According to the bag shape and size and resistance properties of the dust layer,in order to achieve the maximum instantaneous static pressure of air flow,according to the gas flow rate and kinetic energy at the bag mouth must be consistent with the cleaning gas flow rate and pressure in bag,complete the theoretical system of the calculation method of the structure related to the system of pulse blowing grey and operation parameters.Preliminaryly simulate the typical conditions with numerical simulation method,the correction coefficient of the nozzle diameter was about 1.134 when the pressure of bag reached the cleaning intensity index.It provides a reference for verification and correction of the subsequent experimental model.Through the model experiment measure the cleaning pressure peak in the bag,without venturi tube,inside the bag the maximum peak pressure only 844Pa,far less bag installation of venturi tube reached the peak pressure of 1507Pa;the correction coefficient of the four conditions required was about 1.4 when the peak pressure in the bag is increased to the peak pressure that the conditions required with the method of correcting the nozzle diameter,verify the correctness of the model and the reliability of the numerical simulation;The correction coefficient of the experiment contrastly determined the single nozzle diameter correction?the single nozzle gas velocity correction and the nozzle diameter and nozzle gas velocity correction at the same time is 1.395,1.29,1.2 and 1.18 respectively,through calculating we know when singlely correcte the nozzle diameter the effect of the correction coefficient of gas power is relatively small,when the correction coefficient is small,the method of correcting nozzle diameter is relatively reasonable.Installing rectify diffusion sleeve with automatic lift ring plate on the bag,the pressure peak in the bag is about 1300 Pa when blowing with theoretical nozzle diameter,under the same conditions when using ordinary venturi tube,the pressure peak in the bag is about 1500 Pa;Determining the resistance to filtered airflow under different filter speeds,the drag coefficient of filter air when the automatic sliding on limiting ring plate on the rectifying diffusion casing in the uplink and downlink positioning ring is 108.28 Pa·min2·m-2 23.44 Pa·min2·m-2 respectively.The results show that the new type rectifier diffusion casing can ensure that the cleaning pressure in the bag and greatly reduce the filtration resistance.Combined with the results of numerical simulation and the results of experiment model,comprehensive validate the theoretical system of the mechanism of pulse blowing air cleaning function.It provides guidance for the design of the energy conservation?efficient dust cleaning system.The research results have scientific significance of expounding cleaning mechanism and practical value of solving the design method of cleaning system.