玉石雕刻作业粉尘控制的适宜技术

目的 提供玉石雕刻行业适宜的防尘技术措施。方法 车间粉尘浓度的测定按照GB／T5748－85、通风除尘系统的测定按照GB／T16157－1996的规定进行，使用WY－1型7级冲击式尘粉分级仪测定排气中粉尘的粒径分级组成和除尘器的粒径分级除尘效率。结果 采用了湿式作业，设置了适用的局部通风除尘系统：设计了专门的条缝型吸尘罩，其侧上吸罩罩口风速为2.5m/s、风量为600m^3/h；根据吸尘罩的数量及各风管的风量选定各支、干风管及总风管的直径；选择了冲击式水浴除尘器或滤袋除尘器，对玉石雕刻通风系统排出的含尘空气进行了除尘净化，除尘器的总除尘效率，前者可达97.0%，后者可达98.0%；根据通风除尘系统所需的风量、克服该系统最大阻力管线所需全压及除尘器的阻力确定了风机的机型和参数。结论 实践结果表明，所提供的玉石雕刻作业粉尘控制的适宜技术，可使作业地点粉尘浓度降低到国家卫生标准或接近卫生标准的要求；通风除尘系统排出的含尘空气可以满足排放标准的要求。

Appropriate dust control measures for jade carving operations

Objective To provide the appropriate dust control measures for jade carving operations. Methods Dust concentrations in the workplace were measured according to GB/T 5748 85.Ventilation system of dust control were measured according to GB/T 16157 1996.Dust particle size distributions for different sources and particle size fraction collecting efficiencies of the dust collectors were measured with WY 1 in stack 7 stage cascade impactors. Results On the basis of adopting wet process in the carving operations,local exhaust ventilation system for dust control was installed,which included:the special designed slot exhaust hoods with hood face velocity of 2.5 m/s and exhaust volume of 600 m 3/h.The pipe sizes were determined according to the air volume passing through the pipe and the reasonable air velocities.Impinging scrubber or bag filter dust collector were selected to treat the dust laden air from the local exhaust ventilation system,which gave a total collecting efficiency of 97% for impinging scrubber and 98% for bag filter;The type of fan and its size were selected according to the total air volume of the ventilation system and maximum total pressure needed for the longest pipe line plus the pressure drop of the dust collector. Conclusions Practical application showed that,after installation and use of the appropriate dust control measures,the dust concentrations in the workplaces could meet or nearly meet the national hygienic standard and the dust laden air at the local exhaust ventilation system could meet the national emission standard.