Recirculation of wet abrasive material in abrasive waterjet systems and related technology

Patent metadata

Field	Value
Publication number	US-2023143795-A1
Application number	US-202318153961-A
Country	US
Kind code	A1
Filing date	Jan 12, 2023
Priority date	Dec 12, 2016
Publication date	May 11, 2023
Grant date	—

Abstract

An abrasive waterjet system in accordance with an embodiment of the present technology includes a cutting head, a catcher downstream from the cutting head, and a conveyance configured to carry slurry including abrasive material and liquid collected from the catcher toward the cutting head. The cutting head includes a jet-forming orifice and a mixing chamber downstream from the jet-forming orifice. The cutting head also includes a slurry inlet through which the mixing chamber receives slurry including abrasive material and liquid collected from the catcher. The abrasive waterjet system can be configured for substantially closed-loop recycling of wet abrasive material. This can be useful, for example, to increase abrasive material utilization efficiency and to decrease abrasive material disposal costs. These and/or other benefits may be realized both in the context of low pressure abrasive waterjet systems and in the context of high pressure abrasive waterjet systems.

First claim

I/We claim:

1 . A method for operating an abrasive waterjet system, the method comprising:
supplying pressurized liquid to a jet-forming orifice of a cutting head of the abrasive waterjet system; forming a jet from pressurized liquid at the jet-forming orifice; passing the jet through a mixing chamber of the cutting head while the mixing chamber contains slurry including abrasive material and liquid, wherein passing the jet through the mixing chamber causes abrasive material to become entrained in the jet; impacting the jet against a workpiece to alter the workpiece; diffusing the jet in a catcher of the abrasive waterjet system; collecting slurry including abrasive material and liquid from the catcher; and flowing slurry including abrasive material and liquid collected from the catcher into the mixing chamber.

2 . The method of claim 1 wherein flowing slurry including abrasive material and liquid collected from the catcher into the mixing chamber includes drawing slurry into the mixing chamber at least partially by the Venturi effect.

3 . The method of claim 1 wherein supplying pressurized liquid to the jet-forming orifice includes supplying all or most of a total supply of pressurized liquid to the jet-forming orifice at a pressure of at most 15,000 psi.

4 . The method of claim 1 , further comprising screening large particles of kerf material from abrasive material within the catcher.

5 . The method of claim 1 , further comprising screening large particles of kerf material from abrasive material collected from the catcher.

6 . The method of claim 1 , further comprising automatically decreasing a rate of movement of the cutting head at least partially in response to an increased fraction of spent abrasive material in slurry including abrasive material and liquid collected from the catcher.

7 . The method of claim 1 , further comprising, at a fines separator of the abrasive waterjet system, removing fines from slurry including abrasive material and liquid collected from the catcher, wherein flowing slurry including abrasive material and liquid collected from the catcher into the mixing chamber includes flowing slurry into the mixing chamber via the fines separator.

8 . The method of claim 1 wherein removing fines from slurry including abrasive material and liquid collected from the catcher includes removing fines at least partially by operation of a hydrocyclone.

9 . The method of claim 1 , further comprising storing abrasive collected from the catcher in a holding tank of the waterjet system.

10 . The method of claim 9 , further comprising agitating stored abrasive material in the holding tank.

11 . The method of claim 1 , further comprising automatically decreasing a rate of movement of the cutting head to at least partially compensate for an increased fraction of spent abrasive material in slurry including abrasive material and liquid flowing into the mixing chamber.

12 . The method of claim 1 , further comprising:
detecting a concentration of abrasive material in slurry including abrasive material and liquid collected from the catcher; and automatically adjusting a rate of movement of the cutting head at least partially in response the detected concentration.

13 . The method of claim 1 , further comprising:
detecting a concentration of abrasive material in slurry including abrasive material and liquid collected from the catcher; and automatically adjusting a flowrate of slurry including abrasive material and liquid flowing into the mixing chamber at least partially in response the detected concentration.

14 . The method of claim 1 , further comprising fluidizing abrasive material within the catcher, wherein collecting slurry includes collecting slurry including fluidized abrasive material from the catcher.

15 . The method of claim 14 wherein:
flowing slurry including abrasive material and liquid collected from the catcher into the mixing chamber includes flowing slurry via a conveyance of the abrasive waterjet system;
fluidizing abrasive material includes flowing fluidizing liquid toward abrasive material at a fluidizer of the abrasive waterjet system; and
the method further comprises—
increasing a flowrate of fluidizing liquid flowing toward abrasive material at the fluidizer to flush the conveyance with fluidizing liquid, and
ceasing forming the jet after increasing the flowrate of fluidizing liquid.

16 . The method of claim 15 , further comprising:
recharging the conveyance with slurry including fluidized abrasive material from the catcher after ceasing forming the jet; and resuming impacting the jet against the workpiece after recharging the conveyance with slurry.

17 . The method of claim 14 , further comprising settling abrasive material within a lower portion of the catcher by gravity, wherein a transverse cross-sectional area of the lower portion of the catcher decreases at successively lower elevations, and wherein fluidizing abrasive material includes fluidizing settled abrasive material within the catcher.

18 . The method of claim 14 wherein:
fluidizing abrasive material includes fluidizing abrasive material at a fluidizer of the abrasive waterjet system; and
collecting slurry includes collecting slurry via a slurry port of the fluidizer, wherein the fluidizer includes a manifold extending at least partially around a perimeter of the slurry port.

19 . The method of claim 18 wherein the slurry port is at a lower portion of the catcher, and wherein the method further comprises flowing liquid from an upper portion of the catcher to the lower portion of the catcher via the manifold.

20 . The method of claim 1 , further comprising:
ceasing forming the jet; removing spent abrasive material from the catcher while the jet is ceased; adding fresh abrasive material to the catcher while the jet is ceased; and resuming forming the jet after adding fresh abrasive material to the catcher.

21 . The method of claim 20 , further comprising automatically detecting a decreased cutting power of the jet, wherein ceasing forming the jet includes ceasing forming the jet at least partially in response to detecting the decreased cutting power.

22 . A method for operating an abrasive waterjet system, the method comprising:
supplying pressurized liquid to a jet-forming orifice of a cutting head of the abrasive waterjet system; forming a jet from pressurized liquid at the jet-forming orifice; passing the jet through a mixing chamber of the cutting head while the mixing chamber contains slurry including abrasive material and liquid, wherein passing the jet through the mixing chamber causes abrasive material to become entrained in the jet; and recycling the entrained abrasive material through a substantially closed-loop circuit including the mixing chamber, a catcher of the abrasive waterjet system, and a conveyance of the abrasive waterjet system, wherein the conveyance is configured to carry slurry including abrasive material and liquid collected from the catcher toward the cutting head.

23 . The method of claim 22 , further comprising:
adding fresh abrasive material to the catcher; and passing at least 90% by weight of the added fresh abrasive material through the circuit at least twice.

24 . The method of claim 23 wherein adding fresh abrasive material to the catcher includes adding fresh abrasive material to the catcher batchwise.

Assignees

• Omax Corp

Inventors

• Schubert Ernst H
• Henning Axel H

Classifications

• B24C9/006

  Treatment of used abrasive material · CPC title

• B24C7/003

  with means for preventing clogging of the equipment · CPC title

• B24C7/00

  Equipment for feeding abrasive material; Controlling the flowability, constitution, or other physical characteristics of abrasive blasts · CPC title

• B24C1/045

  for cutting (energy dissipating devices therefor B26F3/008) · CPC title

• B24C7/0023 Primary

  of feed pressure · CPC title