Plug Flow of Bulk Solids Using Gas Pressure Control

Abstract

This paper considers interstitial fluid pressure as an additional characteristic effecting bulk solids flowability. It describes a method for improving flow control of cement, powdered coal, sand, etc. through a converging hopper by applying particle stress-ratio control. In some applications, flowability of bulk solids can be modified rather than make costly modifications to the hopper. The patented method combines a baffle, a slot opening and gas pressure control modifying flowability in a converging channel. Plug-flow, a preferred type of mass flow, has been achieved flowing cement through hoppers open to the atmosphere as well as through enclosed, pressurized hoppers.