Cutting abrasive feeder, demand type

Abstract

The invention is directed to an improved hopper for feeding abrasive material of very small grit size to a cutting head. The device comprises an open hopper vertically disposed with a transverse positioned pick-up tube located in the lower portion of the hopper. The pick-up tube has a tubular center with a necked down diameter intermediate of its's ends. An opening extends from the bottom of the tube into the tubular center at a location centered in the necked down portion thereof. One end of the tube is vented to atmosphere through an adjustable orifice and the other end is connected to a source of low pressure created within the mixing chamber of the nozzle body assembly by high pressure water passing across the open end of the tube. This effect causes abrasive grit to be drawn through the opening in the bottom of the tube out the low pressure end of the tube to the cutting head. The flow of abrasive is regulated by controlling inlet/outlet air stream mass air flow or in combination with varying abrasive inlet sizes. The device is a passive, demand system, eliminating the need for mechanically controlled abrasive flow.