An optical method of measuring particle mass flow rates

Particle flow instrumentation

“…Measurements of capacitance noise [3,4] were carried out at much higher densities of flow while the optical [2] measurements made at lower-density flow rates compare with that discussed in this paper and therefore it was not possible to make a direct comparison of the measurements. Currently there is no commercial instrument for this type of powder flow work.…”

“…The powder density is related to the ratio of injected charge to conveyed charge, and the velocity is obtained by 'time of flight' measurements between two sensors. This technique has the advantage of injecting a measurable quantity of charge into the flow and then comparing this with the downstream sensors while other techniques such as optical [2], capacitance [3,4] and microwave are dependent on the transmission of a signal through the walls of a pipe. This transmission can therefore be affected by deposition of powder on the walls of the sensor.…”