Method and apparatus for monitoring particle laden pneumatic abrasive flow in an abrasive fluid jet cutting system

Patent metadata

Field	Value
Publication number	US-9586306-B2
Application number	US-201213645933-A
Country	US
Kind code	B2
Filing date	Oct 5, 2012
Priority date	Aug 13, 2012
Publication date	Mar 7, 2017
Grant date	Mar 7, 2017

Abstract

An abrasive jet cutting system may include a differential pressure measurement apparatus configured to measure a differential pressure between points in an abrasive supply system. The differential pressure may be used to determine one or more conditions of the jet and the abrasive delivery. The measured differential pressure may be used in a feedback control system, feed forward control system, and/or an alarm or safety system.

First claim

What is claimed is:

1. A method for monitoring an abrasive fluid jet cutting system, comprising:
providing an abrasive to an abrasive fluid jet nozzle by entraining abrasive particles in air through an abrasive supply tube;
measuring a differential pressure between at least two points along the abrasive supply tube;
setting a standard differential pressure; and
transmitting a control signal in response to the differential pressure deviating from the set standard differential pressure by more than a specified absolute or relative amount.

2. The method for monitoring an abrasive fluid jet cutting system of claim 1 , wherein the at least two points include respective pressure measurement ports in one or more fittings disposed in the abrasive supply tube at a specified distance between each other.

3. The method for monitoring an abrasive fluid jet cutting system of claim 1 , wherein transmitting the control signal includes sending a signal or ceasing to send a signal.

4. The method for monitoring an abrasive fluid jet cutting system of claim 1 , further comprising:
determining a condition of the flow of the abrasive based at least in part on the measured differential pressure.

5. The method for monitoring an abrasive fluid jet cutting system of claim 1 , further comprising:
measuring an average pressure from at least one of the two points along the abrasive supply tube.

6. The method for monitoring an abrasive fluid jet cutting system of claim 1 , further comprising:
controlling operation of the abrasive fluid jet cutting system responsive to the measured differential pressure, wherein controlling operation of the abrasive fluid jet cutting system includes at least one of controlling a pump and/or controlling an abrasive supply system.

7. The method for monitoring an abrasive fluid jet cutting system of claim 1 , wherein the air and entrained abrasive particles flow between the at least two points through a gas flow channel having substantially no flow constriction.

8. The method for monitoring an abrasive fluid jet cutting system of claim 1 , wherein measuring a differential pressure between at least two points along the abrasive supply tube includes measuring a differential partial vacuum between the at least two points.

9. The method for monitoring an abrasive fluid jet cutting system of claim 1 , wherein the at least two points are at a fixed distance to one another along the abrasive supply tube and a fixed distance to a cutting head.

10. The method for monitoring an abrasive fluid jet cutting system of claim 1 , wherein the abrasive supply tube between the at least two points has substantially the same surface properties and diameter as other regions along the abrasive supply tube.

11. The method for monitoring an abrasive fluid jet cutting system of claim 1 , wherein the abrasive supply tube between the at least two points differs in at least one of material, shape, surface texture, or form compared to other regions along the abrasive supply tube.

12. The method for monitoring an abrasive fluid jet cutting system of claim 1 , wherein the two points along the abrasive supply tube are disposed in physically separate components of the abrasive supply tube.

13. The method for monitoring an abrasive fluid jet cutting system of claim 1 , wherein the two points along the abrasive supply tube are disposed in a single physical piece of the abrasive supply tube.

14. The method for monitoring an abrasive fluid jet cutting system of claim 1 , wherein measuring a differential pressure between at least two points along the abrasive supply tube further comprises:
measuring a plurality of differential pressures or partial vacuums between a plurality of pairs of points along the abrasive supply tube.

15. The method for monitoring an abrasive fluid jet cutting system of claim 1 , wherein measuring the differential pressure between at least two points along the abrasive supply tube includes receiving pressures from at least two pressure measurement ports formed in the abrasive supply tube at respective different distances between an abrasive entry point and the nozzle.

16. The method for monitoring an abrasive fluid jet cutting system of claim 1 , wherein the measured differential pressure is substantially attributable to pressure drop created by air flow between the measurement points and around entrained particles.

17. The method for monitoring an abrasive fluid jet cutting system of claim 1 , further comprising:
determining a condition of the flow of the abrasive based at least in part on the measured differential pressure; and/or
determining a flow rate of the abrasive based at least in part on the measured differential pressure; and/or
determining the condition of the jet by measuring the differential pressure without abrasive flow.

18. The method for monitoring an abrasive fluid jet cutting system of claim 1 , further comprising:
measuring an average pressure, absolute pressure, or gauge pressure from at least one of the two points along the abrasive supply tube.

19. The method for monitoring an abrasive fluid jet cutting system of claim 1 , further comprising:
controlling operation of the abrasive fluid jet cutting system responsive to the measured differential pressure.

20. The method for monitoring an abrasive fluid jet cutting system of claim 19 , wherein controlling operation of the abrasive fluid jet cutting system includes at least one of controlling a pump, controlling an abrasive supply system, controlling a nozzle actuator, controlling an alarm, and displaying or transmitting a notification.

21. The method for monitoring an abrasive fluid jet cutting system of claim 1 , wherein measuring a differential pressure between at least two points along the abrasive supply tube includes measuring a change of partial vacuum between two points in the abrasive supply tube.

22. The method for monitoring an abrasive fluid jet cutting system of claim 1 , wherein measuring the differential pressure includes performing the measurement with one differential pressure sensor.

23. The method for monitoring an abrasive fluid jet cutting system of claim 1 , wherein measuring the differential pressure includes performing the measurement with two sensors and determining the difference in pressure or partial vacuum between the two sensors.

24. A method for monitoring an abrasive fluid jet cutting system, comprising:
providing an abrasive to an abrasive fluid jet nozzle by entraining abrasive particles in air through an abrasive supply tube; and
measuring a differential pressure between at least two points along the abrasive supply tube;
collecting a temporal series of differential pressure measurements; and
driving a pressure differential fault determination algorithm according to at least some of the series of differential pressure measurements or at least one parameter corresponding to the at least partial series of differential pressure measurements.

25. The method for monitoring an abrasive fluid jet cutting system of claim 24 , further comprising:
controlling operation of the abrasive fluid jet cutting system responsive to the measured differential pressure, wherein controlling operation of the abrasive fluid jet cutting system includes at least one of controlling a pump and/or controlling an abrasive supply system.

26. The method for monitoring an abrasive fluid jet cutting system of claim 24 ,

Assignees

• Omax Corp

Inventors

• Zhang Shijin
• Veenhuizen Scott
• Henning Axel

Classifications

• G01F22/00

  Methods or apparatus for measuring volume of fluids or fluent solid material, not otherwise provided for · CPC title

• G01F1/74

  Devices for measuring flow of a fluid or flow of a fluent solid material in suspension in another fluid · CPC title

• B65G53/66

  Use of indicator or control devices, e.g. for controlling gas pressure, for controlling proportions of material and gas, for indicating or preventing jamming of material {(controlling the flow of coal firing systems C21B5/003)} · CPC title

• B24C7/0046 Primary

  the abrasive material being fed in a gaseous carrier · CPC title

• G01F1/34

  by measuring pressure or differential pressure · CPC title