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目的对某采石场筛分工序的局部通风除尘系统进行设计,使工作场所空气中粉尘水平达到国家职业接触限值的要求。方法根据某采石场筛分岗位工艺特点及粉尘性质等基础资料,由工程通风设计人员以外部排风罩、通风管、风机选型和除尘器的选择为重点,设计局部通风除尘系统,安装后测定其粉尘控制效果。结果外部排风罩采用罩口尺寸为1.6 m×1.6 m的带法兰边框的上吸式排风罩,控制距离为1.1 m。除尘系统的总排(送)风量为148 072 m~3/h;风机的风量和风压分别为171 023 m~3/h和1 255.5 Pa;据此选择型号为4-79的普通中压风机和处理风量为186 000 m~3/h的WDJ47-3/1型WDJ型卧式电除尘器设备作为局部通风除尘系统。局部通风除尘系统安装实施后,筛分岗位空气中粉尘时间加权平均浓度为6.2 mg/m~3,低于国家职业接触限值8.0 mg/m~3。结论所设计的局部通风除尘系统达到设计要求。
Objective To design a local ventilation and dust removal system for a screening process in a quarry to make the level of dust in the air of the workplace meet the requirements of the national occupational exposure limit. Methods Based on the basic information of the craft characteristics and the nature of the dust of a quarry, the design of the local ventilation and dust removal system was designed by the engineering ventilation designers with the selection of external exhaust hoods, ventilation ducts, fan selection and dust remover After measuring the dust control effect. As a result, the external exhaust hood has a flanged, frame-mounted, suction hood with a hood opening of 1.6 m × 1.6 m with a controlled distance of 1.1 m. The total discharge volume of the dust removal system is 148 072 m 3 / h; the air volume and air pressure of the fan are respectively 171 023 m 3 / h and 1 255.5 Pa; accordingly, an ordinary medium pressure blower of type 4-79 is selected And WDJ47-3 / 1 type WDJ horizontal electrostatic precipitator equipment with a capacity of 186 000 m 3 / h as a local ventilation and dust removal system. After the implementation of the local ventilation and dust removal system, the time-weighted average concentration of dust in the air of screening posts is 6.2 mg / m 3, which is lower than the national occupational exposure limit of 8.0 mg / m 3. Conclusion The design of local ventilation and dust removal system meets the design requirements.