Acoustic Doppler flowmeter for dense slurry flow measurement. Part II. High temperature tests

It was clearly demonstrated that, without any gases in a liquid-solid slurry line, the high-temperature acoustic Doppler flowmeter measures the flow velocity of such media. This is a major accomplishment in the field of high-temperature solid-liquid flow measurement. The characteristics of its components are not suitable for lengthy operation in pilot plants. It will be essential to design and build a prototype in which pilot-plant conditions are the basis. That is, the transducers, as well as all connections and electronic components, should be protected. The range of operation of the high-temperature acoustic Doppler flowmeter should be examined by considering the effects of temperature, viscosity, concentration, particle size, and particle-size distribution. Sound-attenuation measurements should be made in highly viscous media found in coal-liquefaction plants. The sound-attenuation measurements are very important, because they could lead to a density measurement. This statement is based on the results of measurements at the HYGAS pilot plant in 1978. It was observed there that the sound attenuation is proportional to coal concentration in the line. If this is true, then the high-temperature acoustic Doppler flowmeter, which now measures flow velocity, can be upgraded to a mass flowmeter.