INSTRUMENT FOR MEASURING CONCENTRATION OF PARTICULATE MATTER IN PIPING

摘要

PURPOSE:To make prompt measurement by providing >=1 pairs of ultrasonic oscillators and receivers to the circumference of a piping, measuring the attenuation quantity of the ultrasonic waves in the ultrasonic propagation routes formed therebetween and detecting the concn. of particulate matter in accordance with the attenuation quantity. CONSTITUTION:Three pairs of the oscillators 3 and receivers 4 are mounted to the outer side of a circular piping 1 in which pulverized coal and the air for transporting this coal flow in the form of solid-gas two-phase flow 2. The instrument is constituted in such a manner and the signal from a computer 7 is amplified by an amplifier 6 to drive the transmitters 3. The ultrasonic waves received by the receivers 4 are converted to electric signals by the receivers. The electric signals are amplified by an amplifier 6A and are returned to the computer 7. The attenuation quantity of the respective propagation lines connecting the oscillators 2 and the receivers 4 from the reception level is determined at this time and the concn. of the powder is detected from the calibration chart of the previously measured ultrasonic transmittance and the concn. of the pulverized coal. The detected concns. are respectively displayed on a distribution display device 8 and an average value display device 9. The pressure drop in the piping is eliminated in this way and the errors by the moisture in the fluid are eliminated as well.