Material conveying apparatus with shut down valves

Abstract

Disclosed is a system and method for conveying particulate material. A plurality of injector arrangements are arranged along the conveying pipeline, for injecting a continuous flow of conveying gas into the pipeline. Each injector arrangement is operable to increase the flow rate at which conveying gas is injected into the pipeline on of pressure conditions in the conveying pipeline indicative of locally decreased material permeability. Each injector arrangement comprises a piloted shut-off valve positioned between the flow rate adjustment arrangement and the conveying pipeline and operable to close in response to a received pilot signal indicative of a pressure condition in the conveying pipeline below a lower threshold pressure condition. The continuous flow of conveying gas injected by each of the injector arrangements prevents particulate material from entering any part of the injector arrangements, thereby reducing the risk of blockage of nozzles, injection pathway selection valves and the like. The continuous injection of conveying gas along the pipeline also maintains a degree of permeability particulate material in the pipeline and promotes stable conveying. The piloted shut-off valve of each injector arrangement is operable to independently detect a large pressure drop in the pipeline, and to close in order to store pressurised conveying gas in the injector arrangement and supply thereto.