Abrasive Jet Nozzle Relieved Sidewall for Fine Kerf Cutting
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Solution Overview
Problem
Conventional abrasive waterjet (AWJ) and abrasive slurry jet (ASJ) systems face limitations in achieving fine kerf sizes due to energy losses and rapid wear, making it difficult to create kerfs less than 0.45 mm and resulting in inconsistent cutting and short nozzle service life.
Innovation Solution
A novel cutting head and nozzle design with a mixing stage and focusing stage, featuring a relieved sidewall and slurry port configuration that allows for the controlled entrainment of very fine abrasive particles, reducing energy loss and wear by minimizing particle impingement and promoting efficient particle acceleration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional AWJ systems use coarse abrasive particles (0.075-0.350 mm) with gravity feed, then kerf size can be achieved in the range of 0.45-2.5 mm, but the minimum kerf size is limited to above 0.45 mm and energy losses are high due to frictional losses in the mixing chamber and focusing tube
Solution Approach 1:
The patent changes the particle size parameter to very fine abrasive particles (5-225 microns) and modifies the transport method from gravity feed to pressurized slurry injection. This parameter change enables kerf sizes below 0.45 mm while reducing energy losses through more efficient particle acceleration in the mixed flow region.
Solution Approach 2:
The patent performs preliminary mixing of abrasive particles with water to create a slurry before injection into the jet stream. This preliminary action ensures uniform particle distribution and reduces frictional losses during acceleration, enabling finer kerf control with lower energy loss.
2Manufacturing precision
If ASJ systems use fine abrasive particles (0.008-0.080 mm) in pre-mixed slurry, then kerf size of 0.01-0.2 mm can be achieved, but rapid wear occurs making the system commercially unfeasible
Solution Approach 1:
The patent optimizes the particle size parameter to a specific range (5-225 microns) that balances cutting precision with nozzle durability. This parameter optimization achieves fine kerf sizes while reducing excessive wear compared to conventional ASJ systems using 0.008-0.080 mm particles.
Solution Approach 2:
The patent introduces a dynamic mixed flow region where abrasive particles are gradually accelerated along with the water jet rather than being forced through a long focusing tube. This dynamic approach reduces particle-wall impingement and extends nozzle service life while maintaining fine kerf capability.
3Manufacturing precision
If nozzle length is reduced to enable fine kerf cutting, then cutting precision improves, but particle acceleration distance is reduced potentially affecting cutting performance
Solution Approach 1:
The patent uses hydraulic principles to create a mixed flow region where water and abrasive particles accelerate together through co-flow. This hydraulic coupling enables efficient particle acceleration over a short distance, achieving fine kerf sizes without compromising cutting performance.
Solution Approach 2:
The patent merges the water jet and abrasive particle flow into a single mixed flow stream. This combination allows both the liquid and particles to accelerate simultaneously over a short distance, maintaining high cutting speed while achieving fine kerf dimensions.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables fine kerf cutting (0.050 to 0.45 mm) with extended nozzle service life, reducing energy losses and improving cutting consistency by using very fine abrasive particles (15-225 microns) and a shorter nozzle length, allowing for more efficient and precise cutting.
Implementation Method 1
high-pressure jets of abrasive-carrying liquid to cut a work-piece
Implementation Method 2
which often serves to accelerate the jet and entrained particles in the direction of liquid flow
Implementation Method 3
The focused water jet then exits through an outlet 24 of the focusing tube 20. The jet, including the entrained abrasive particles, can then be used to cut a work-piece 5 of metal or other material
Implementation Method 4
abrasive jet cutting systems that use high-pressure jets of abrasive-carrying liquid to cut a work-piece
Data Source
AI summary
The present invention provides a nozzle for high-pressure abrasive jet cutting systems that is particularly well-suited for fine-kerf cutting (e.g., 0.050 to 0.45 mm) using very fine abrasive particles (e.g., average particle size less than about 250 microns). The nozzle has a nozzle body defining an elongated channel extending along an axis. The elongated channel has a mixing stage and a focusing stage. The focusing stage has a focusing portion terminating in an outlet orifice for producing a high-pressure jet. The mixing stage has a sidewall defining a port in fluid communication with the elongated channel for admitting a low-pressure flow of a slurry comprising abrasive particles suspended in a fluid. The sidewall of the mixing stage is configured to have a relieved portion extending radially inwardly from the port toward the focusing stage. In certain embodiments, the taper is continuous from the port to the focusing stage.