Preliminary Design of a Prototype Particulate Stack Sampler.

摘要

A preliminary design of a prototype particulate stack sampler (PPSS) has been prepared,and development of several components is under way. The objective of this Environmental Protection Agency (EPA)-sponsored program is to develop and demonstrate a prototype sampler with capabilities similar to EPA Method 5apparatus but without some of the more troublesome aspects. Features of the new design include higher sampling flow;display (on demand) of all variables and periodic calculation of percent isokinetic,sample volume,and stack velocity;automatic control of probe and filter heaters;stainless steel surfaces in contact with the sample stream;single-point particle size separation in the probe nozzle;null-probe capability in the nozzle;and lower weight in the components of the sampling train. Design considerations will limit use of the PPSS to stack gas temperatures under approximately 300exp 0 C,which will exclude sampling some high-temperature stacks such as incinerators. Although need for filter weighing has not been eliminated in the new design,introduction of a variable-slit virtual impactor nozzle may eliminate the need for mass analysis of particles washed from the probe. Component development has shown some promise for continuous humidity measurement by an in-line wet-bulb,dry-bulb psychrometer. (ERA citation 03:054946)