Dielectric sensor for detecting capsules moving through pipelines

Recent advancement in the technology of hydraulic capsule pipeline (HCP) for transporting freight in capsules has made it imperative to use a practical sensor to detect capsule movement in pipelines. The detection of capsules is especially needed in the pump bypass of HCPs for the control of valves that must be opened and closed periodically and frequently without touching and damaging the capsules. A new sensing technique is described for the detection of capsules and coal logs moving in pipelines. An equivalent electric circuit of the sensor is proposed and verified experimentally. Test data show the effectiveness and reliability of this sensor. This new sensor may also have application to detecting "pigs" used in ordinary liquid and gas pipelines, and detecting the interface of multiphase or multiproduct flow in pipelines.