Self-cleaning streaming current monitor

Abstract

A streaming current detector which utilizes the test flow stream to keep the electrodes of the detector probe washed and its dielectric surfaces from becoming fouled. The test stream first enters a housing surrounding the probe at a position proximate the inlet to a transverse passageway within the probe. Most of the flow moves directly through the probe along the transverse passageway, but a small portion of this flow is sucked into capillary-sized channels within the probe by the action of a piston during its upstroke and then expelled from them back into the transverse passageway during the downstroke. The flow leaving the transverse passage plummets downwardly where it joins a smaller fraction of the test stream that did not enter the transverse passageway and together they are discharged out the bottom of the housing. There are no low velocity or stagnate areas where solids can accumulate either in the housing surrounding the probe or within the probe itself. The flow velocity is kept high everywhere so that floc which does come in contact with the probe is constantly washed off from the flow stream. In this manner, the inlet to the probe, its through passageway and its capillary-sized channels as well as the housing surrounding the probe are kept free from contamination allowing both a continuous operation and a higher electrical output. The higher electrical output makes possible a signal with remote sensing capabilities. This design answers the long standing problem of keeping a streaming current detector clean during operation.