Abrasive jet system
AssigneeFinepart Sweden AB
InventorDonald Miller
Life of this patent
Estimating the term…
Abstract
An abrasive jet system for producing an abrasive cutting jet is provided. The system includes a source of abrasive suspension connected via a conduit to a cutting head. A source of displacement fluid is provided to flush abrasive suspension in the conduit towards the source of abrasive suspension, when the pressure at the source of abrasive suspension is below the pressure at the source of displacement fluid and no water jet is present in the cutting head. Also provided is a method for suspending a settled or partly settled bed of abrasive.
Claims39
An abrasive jet system for producing an abrasive cutting jet, the abrasive jet system comprising
- a cutting head adapted to receive pressurised water to generate a high velocity waterjet,
- a source of abrasive suspension,
- a conduit for providing the source of abrasive suspension in fluid communication with the cutting head,
- an abrasive suspension on/off valve provided in said conduit and having an open state and a closed state,
- a source of displacement fluid in fluid communication with a portion of said conduit located between the cutting head and the abrasive suspension on/off valve, wherein the pressure at said source of abrasive suspension is controllable to be below the pressure at said source of displacement fluid,
- wherein when said abrasive suspension on/off valve is open and said high velocity waterjet is present in the cutting head, the abrasive suspension flows via said conduit into the cutting head and is entrained by the high velocity waterjet to produce an abrasive cutting jet, and
- wherein when the cutting head is void of high velocity waterjet and said pressure at the source of abrasive suspension is below the pressure at said source of displacement fluid, and said abrasive suspension on/off valve is opened, abrasive suspension present in the conduit is displaced towards said source of abrasive suspension.
A method of suspending a settled or partly settled bed of abrasive particles provided in a hopper of an abrasive jet system, comprising
- providing a layer of cover water above said bed,
- providing an agitator suitable for agitating said bed,
- setting a limit value for a torque on the agitator,
- positioning the agitator in the cover water,
- starting up the agitator when positioned in the cover water,
- measuring the torque on the agitator, and
- moving the agitator into said bed at such a rate that said limit value is not exceeded.
A method of suspending a settled or partly settled bed of abrasive particles provided in a hopper of an abrasive jet system, comprising
- providing a layer of cover water above said bed,
- mounting the hopper on a weight sensor for determining the amount of abrasive particles in said hopper,
- setting a limit value for load changes on the weight sensor,
- providing an agitator suitable for agitating said bed,
- positioning the agitator in the cover water,
- starting up the agitator when positioned in the cover water, and
- moving the agitator into said bed at such a rate that said limit value is not exceeded.
An abrasive jet system for producing an abrasive cutting jet, the abrasive jet system comprising
- a cutting head adapted to receive pressurised water to generate a high velocity waterjet,
- a hopper containing a bed of abrasive particles which, in operation of the abrasive jet system, is suspended, wherein said hopper includes cover water above the bed of abrasive particles,
- a conduit for providing abrasive suspension to the cutting head,
- a control system, and
- an agitator for agitating said bed of abrasive particles, the agitator being controlled by the control system, wherein the dimensions of said hopper is such that the agitated bed of abrasive particles are maintained with a depth of cover water above the bed such that the cover water surface is essentially quiescent,
- wherein said control system is programmed to start up the agitator when the agitator is positioned in the cover water, and to move the started agitator into the abrasive bed at such a rate that a predetermined torque on the agitator is not exceeded, or at such a rate that a predetermined load change on an optional weight sensor is not exceeded.
Dependencies are inferred from the claim text.