Improvements in or relating to the measurement of the flow of particulate material

Author:  Beck, Maurice Sidney
Source:  UK Patent 1,270,112
Doc ID:  1972016
Year of Publication:  1972
Abstract:  
The invention relates to the measurement of the flow of particlulate materials conveyed hydrodynamically by means of a flowing fluid and more particularly, but not exclusively, to the measurement of the flow of powdered materials. When powdered solids are transported by means of pneumatic conveyors the air to solids reatio is usually high, for example it may be about 500:1, and , therefore, the particles of the powder are free to move independantly of one another. This results in a random perturbation due to turbulence naturally occuring in the conveying air being superimposed upon the general motion of the particles along the conveyor. This random perturbation of the gereral motion of the particles is know as flow noise. It has been proposed to measure the rates of flow of powdered solids in pneumatic conveyors by measuring the passage of flow noise disturbances between two positions in the conveyor that are separated by a known distance. However, as the flow noise is continually changeing it is necessary to use sophisticated mathematical techniquees to enable a disturbance arriveing at the second position to be recognized as a disturbance which has passed the first position some time previously. These techniques require the use of an on-line computer, which may not be readily available.