吸尘罩的优选及其在玉石雕刻防尘中的应用

目的对适用吸尘罩进行优选,并在实际通风除尘系统中应用。方法用示踪气体法对吸尘罩进行优选,比较不同吸尘罩捕集效率和风量的关系;对吸尘罩前风速分布进行测定,得出罩前风速分布模型。并对吸尘罩进行空气动力性能分析,测定雕刻排气中粉尘的粒径分级组成和除尘器的粉尘粒径分级除尘效率,评估除尘器的总除尘效率。结果优选出的雕刻吸尘罩,置于切割轮正前方0.11 m处,其控制风速为0.5 m/s,能有效地控制雕刻切割轮的粉尘不向周围扩散,工作地点空气粉尘浓度由无罩时的30-297 mg/m3降低至1.1-1.7 mg/m3,吸尘罩风量为255 m3/h,为其他类型吸尘罩的50%-77%。优选出的冲击水浴除尘器,其除尘效率为97%-98%,阻力为1.5 kPa;滤袋除尘器的效率为98%-99%,阻力为2.5 kPa;除尘后尾气的粉尘浓度为20-30 mg/m3。结论提出了优选吸尘罩的设计方法及实用的除尘器,可供实际应用。

Selection of Dust Exhaust Hood and Its Application to Dust Prevention of Jade Carving Workplace

Objective To select the dust exhaust hood and apply it to dust control system.Methods Tracer gas method was used to select the appropriate dust Exhaust hood.The capture efficiencies for hoods at different air flow rates were compared and the air velocities before the hoods were measured to obtain the velocity pattern.The hood aerodynamic character was analysed.The particle size distributions of dust of jade carving and the particle size fractional collecting efficiencies of dust collectors were measured.On this basis,the total dust collecting efficiencies of the dust collectors were evaluated.Results An optimized rectangular hood was installed 0.11 m in front of the cutting wheel.A control velocity of 0.5 m/s at dust source could effectively control the dust from carving,so the dust concentrations of workplace were lowered from 30~297 mg/m3(without hood)to 1.1~1.7 mg/m3.The air flow rate of the hood was 255 m3/h,being only 50%~77% of other hoods.The optimized impinging scrubber had a total dust collecting efficiency of 97%~98% with pressure drop of 1.5 kPa.The bag filter had a collecting efficiency of 98%~99% with pressure drop of 2.5 kPa.The dust concentrations in effluent air were 20~30 mg/m3.Conclusions The design of optimized dust exhaust hood and the dust collector feasible for practical use are provided.