烧结厂转运点高浓度粉尘的吸尘罩捕收规律

Collecting Rules of High Concentration Dust in Sintering Transfer Station by Exhaust Hood

通过对烧结厂皮带机转运点扬尘理化特性、吸尘罩内粉尘流、抽风参数与所捕收粉尘粒度与质量变化规律等的研究，探讨了吸尘罩对高浓度粉尘的捕收规律．结果表明，该处扬尘浓度大于3000mg／m^3，真密度为4．040g／cm^3，球形度为0．51-0．93，TFe和CaO的总含量高达62％-64％（Cω）．随抽气速度增大，吸尘罩内粉尘浓度逐渐升高，抽吸气流的捕尘作用逐渐取代诱导气流的扬尘作用，当抽气量增加到一定值后，抽吸气流开始激发附着在料床上静止的粉尘．随抽气速度增大，吸尘罩所捕收粉尘的总质量和最大粒度不断增大，呼吸性粉尘量大幅降低．为避免大量激发料床上静止的粉尘，吸尘罩的经济抽风速度应不高于9．20m／s，捕收的粉尘颗粒小于112．62μm的占97％．

Dust emission in sintering ore transfer station of belt conveyor is chosen to determine its physical and chemistry property, observe the dust flow in exhaust hood, and study the relation between the granularity or total quantity of collected dust and the suction parameters for obtaining the collecting rules of high concentration dust with exhaust hood. The result indicates that the concentration of emission dust is more than 3 000 mg/m3, its true density 4.040 g/cm3, and particle sphericity 0.51-0.93, and the content of total-iron （TFe） and calcium oxide （CaO） reaches 62%-64%. With increasing of suction velocity, the dust concentration in exhaust hood rises gradually, and the dust emission processing aroused by induced air is replaced by collecting processing of suction flow. When the suction airflow increases to a certain value, it has an effect on raising motionless dust attached on materials bed. With rising of suction velocity, the total quantity and maximum granularity of collected dust increase. But, the ratio of respirable dust is obviously reduced. In order to avoid a large amount of dust being blown away from material bed, the energy-saving suction velocity should not exceed 9.20 m/s. And the sizes of 97% particles in all collected dust should be less than 112.62 μm.