某采石工序局部通风除尘系统设计

A design for local ventilation dust removal of a quarry screener sequence

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 local ventilation dust removal system of a certain quarry screener sequence and reached the requirement of national occupational exposure limits of the dust in the air of workplace. Methods According to a certain quarry screening post process characteristics and the basic properties,external exhaust hood,ventilation pipe,fan selection and selection of filter as the key point,local ventilation dust removal system were designed by ventilation designers,the dust control effect were determinated after installation. Results External exhaust hood with cover mouth size were 1. 6m × 1. 6 m on the flanged edges of suction exhaust hood,control the distance was 1. 1 m. The total row（ send） air volume for the dust removal system was 148 072 m3/ h. Fan air volume and air pressure was respectively 171 023 m3/ h and1 255. 5 Pa; the model for 4- 79 ordinary medium pressure fan and handling volume of 186 000 m3/ h WDJ47- 3 /1 type WDJ type horizontal electrostatic precipitator equipment were selected as the local ventilation dust removal system. After the introduction of local ventilation dust removal system installation,screening positions and dust in the air time weighted average concentration was 6. 2 mg / m3,below the national occupational exposure limit of 8. 0 mg/m3. Conclusion The design of local ventilation dust removal system meet the design requirements.