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FIELD EVALUATION OF AN AUTOISOKINETIC STACK PARTICULATE SAMPLING SYSTEM
Citation:
Smith, W. AND E. Stewart. FIELD EVALUATION OF AN AUTOISOKINETIC STACK PARTICULATE SAMPLING SYSTEM. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/2-77/035.
Description:
The performance of a prototype autoisokinetic stack particulate sampling system, designed to maintain automatically isokinetic sampling conditions, was evaluated in field tests at stationary sources. Tests were conducted to determine the operating limits and characteristics of the system. Preliminary tests demonstrated the necessity of making several modifications to the existing system to improve the level of performance for the field evaluation program. Improvements were made in the problem areas of the performance of the mass flowmeter, flow totalizer, and flow control valve systems and in the sampling nozzles. The autoisokinetic sampler was tested at four field installations selected to provide a wide range of sampling conditions. The results of the testing and analysis showed that the sampling system maintained acceptable isokinetic sampling rates of 100% + or - 10 at only one of four sources. An inverse relationship between the percent of isokinetic rate and the temperature of the gas stream being sampled was found. The evaluation revealed that the sampler will operate only in the narrow range of stack gas static pressures of + or - 3 inches water column. The physical hardware was found to be fragile and difficult to operate in the field. Overall, the autoisokinetic sampling system failed to meet the design goals.