Acoustic instrumentation.

Abstract

This paper presents some of the work on acoustic instrumentation at ANL. It includes a basic description of the general acoustic system, some laboratory experiments, and operating and experimental information from experiments on prototype instruments installed in pilot plants. The findings of some initial theoretical feasibility studies were based on limited theoretical and experimental work found in the literature. These studies also indicated that acoustic/ultrasonic flowmeters were feasible for instrument operating frequencies below 500 kHz, and the frequency selected should be dependent on the size of the pipe. Laboratory and pilot plant experiments were performed to supplement and verify the initial theoretical findings. These measurements also indicated that transducer availability was important consideration, not only from the standpoint of high temperature serviceability, but also with regard to sensitivity of signal level transmission and reception. Based on the theoretical studies and experimental results, a high temperature acoustic Doppler flowmeter was developed. Reviewed are the results of testing of this Doppler flowmeter in the SRC-1 SRC-11, and H-Coal pilot plants. Other acoustic techniques and instruments including the active acoustic cross correlation flowmeter developed during the HYGAS experiments and refined with tests in the laboratory. The acoustic flow/no/flow monitor developed for the char return line of the BI-GAS pilot plant. This instrument was needed because char flow to the gasifier is essential for safe operation of the pilot plant. The findings of feasibility studies for temperature and level measurements using acoustic/ultrasonic techniques. (A)