Method for locating the surface of a polymer particle bed
View Patent ↗A method for determining the level of a bed of polymer particles in a vessel comprising providing water wet polymer particles and employing a guided wave radar probe unit carrying a pair of radar active probes spaced from the guided wave radar probe unit by a radar inactive member, and positioning the radar inactive member so that polymer particles that are introduced into the vessel first encounter the radar inactive member.
1. A method for determining the upper surface level of a bed of polymer particles that are contained in a vessel, said vessel having an upper section into which incoming polymer particles are introduced, said method comprising introducing into said upper section water wet polymer particles, providing a guided wave radar probe unit comprising a combined radar pulse transmitter and reflected radar pulse receiver, said guided wave radar probe unit having fixed thereto a first end of an elongate rigid radar inactive member, said radar inactive member carrying at its distal end a pair of spaced apart rigid radar active probes, said radar active probes being spaced from said radar probe unit by said radar inactive member, immersing said radar active probes at least in part into said bed of polymer particles, positioning said radar inactive member so that said incoming polymer particles impact said radar inactive member and not said radar active probes, transmitting a first radar pulse from said guided wave radar probe unit initiating at the top of said probes and proceeding along said probes into said bed of polymer particles, receiving a reflected radar pulse generated by said first radar pulse when said first radar pulse contacts said upper surface of said bed of polymer particles, and recovering said reflected radar pulse at said guided wave radar probe unit.
2. The method of claim 1 wherein the time difference between the initiation of said first radar pulse and the return of said reflected radar pulse is converted to a distance from which said upper surface level of said bed of polymer particles is calculated.
3. The method of claim 1 wherein said polymer particles are composed at least in part of polyethylene.
4. The method of claim 1 wherein said polymer particles are composed at least in part of high density polyethylene.
5. The method of claim 1 wherein said elongate rigid radar inactive member is of a length sufficient to prevent lateral impacting of said radar active probes with said incoming polymer particles.