MEASUREMENT AND CONTROL IN HYDRAULIC TRANSPORT SYSTEMS USING CROSSCORRELATION MEASUREMENT SYSTEMS AND FLUIDIC DIVERTERS
Consideration is given of possible replacements for conventional flow measuring devices and control valves in hydraulic transport service, when operation is with other than clean fluids. As the fluids can contain suspensions of solids, which are abrasive or erosive, elements that can withstand conditions are required. For measurement purposes, application of methods using noise signals are described. These are of two types. Crosscorrelation flowmeters for determining total volume flow of slurries, and turbulence intensity flowmeters which measure the concentration of the solid component in a slurry. The former finds the transit time between two points of some definable characteristic or property of the flow. In this case the property is the natural turbulence of the flow, which can be detected at two points of known separation, by conductivity or ultrasonic transducers. Many laboratory and industrial trials have shown a reproducibility of results of 2% over a wide range of slurry composition and concentrations. The concentration of the solids component in a slurry can be measured with a turbulence intensity flowmeter. A system in which the magnitude of the turbulently induced conductivity fluctuations are used to measure concentrations is described. Instruments of this type are inexpensive as simple electrodes and straightforward electronic elements are employed. The conventional control valve is subject to blockage when operating with coarse slurries. The bistable fluidic diverter is a full bore device and is consequently much less susceptible to blockage by suspended solids. A further advantage of the diverter is the absence of close tolerance moving parts which can be affected by abrasive slurries. Control can be instituted by switching flow between the two outputs legs, with the demanded flow through the active side, and the remainder returned to the feed vessel. This operation can be controlled by a variable mark-space ratio pulse waveform from a computer or a separate controller. Operation can be open or close loop and, in the latter case, standard design methods are suitable for setting up the controller performance.
- Presented at HYDROTRANSPORT 3--Third International Conference on the Hydraulic Transport of Solids in Pipes, Colorado School of Mines, Golden, Colo., May 15-17, 1974. Sponsored by BHRA Fluid Engineering. Complete set of Conference papers available for $45.00.
Colorado School of Mines1500 Illinois Street
Golden, CO United States 80401
- Beck, M S
- Mendies, P J
- Walecki, T
- Gatland, H B
- Publication Date: 1974-5
- Pagination: 11 p.
- TRT Terms: Control systems; Flowmeters; Measuring instruments; Pipelines; Slurry; Solids
- Old TRIS Terms: Pipeline control systems; Pipeline metering; Solids concentration (Slurries)
- Subject Areas: Design; Marine Transportation; Pipelines; Terminals and Facilities;
- Accession Number: 00056472
- Record Type: Publication
- Source Agency: British Hydrodynamics Research Association
- Report/Paper Numbers: Paper F5
- Files: TRIS
- Created Date: Jul 15 1974 12:00AM