Research > Abrasive (Slurry) water jet cutting >
Prevention of nozzle wear in Abrasive Water Suspension Jets using Porous Lubricated Nozzles
Post Doctoral Fellow      Umang Anand
Project supervisors      Prof. Joseph Katz

Outline           Facility           Publications

Outline


Abrasive Water suspension jets, namely water jets containing abrasive particles, have a considerable niche in the material processing industry. Like laser cutting instruments they are accurate, easily managed and cause very little loss of material. However, abrasive jet cutting does not involve high temperatures, which is characteristic to laser cutting, and as a result they are suitable for practically any material. Furthermore, the instrumentation required for high-speed jets is simpler and much cheaper. Consequently, jet cutting can be implemented in a broad range of industries, ranging from small machine shops and quarries, to large sheet metal, composites or ceramic processing in the car and aircraft industries.

The most troublesome difficulty associated with high speed slurry jets, which presently limits their usefulness, is wear of the nozzle walls. Since the jet speed ranges between 100-500 m/sec, and the particle size can be as high as 40% of the nozzle diameter, it does not take long to destroy a nozzle. Consequently, in current systems nozzles must be replaced frequently, sometimes every 10-20 minutes requiring constant maintenance, inspection, loss of accuracy and machine down time.

This project introduces a novel method for preventing nozzle wear in high-speed slurry jets. The method consists of using a nozzle with porous walls and lubricating the internal walls of the nozzle with oil forced under pressure through the porous walls. The resulting oil film protects the walls from impact and shear caused by the abrasive particles.

We have constructed two facilities:

  • Two-dimensional nozzle facility - to visualize the flow and optimize the parameters
  • Axisymmetric nozzle facility - to test the extent of nozzle wear

Several techniques have been used during the experiments:

Facility


Principles of the method for preventing nozzle wear
Schematic of the setup supplying slurry particles and lubricant
Two dimensional nozzle facility
Setup for data acquisition
Axisymmetric facility

Publications


Anand, U., Katz, J., 2003, "Prevention of nozzle wear in Abrasive Water Suspension Jets (AWSJ) using porous lubricated nozzles," ASME Journal of Tribology, Vol. 125 (1), pp. 168-180.

Anand, U., Katz, J., 2001, "Using Porous Lubricated Nozzles to prevent Nozzle Wear in Abrasive Water Suspension Jets (AWSJ)", Proceedings of the American Water Jet Conference, Minneapolis, Minnesota, USA, August 18-21.

Anand, U., Katz, J., 2001, "Improving the Life Span of Nozzles in Abrasive Water Suspension Jets using Porous Lubricated Nozzles", Proceedings of the ASME Fluids Engineering Division Summer Meeting, New Orleans, USA, May 27 - June 1.

Anand, U., Katz, J., 2000, "Prevention of nozzle wear in high-speed slurry jets using porous lubricated nozzles", Proceedings of the 6th Pacific Rim International Conference on Water Jetting technology, Sydney, Australia, October 8-11.

Anand, U., Katz, J., 2000, "Lubricated nozzles for high-speed slurry jets", Proceedings of the ASME Fluids Engineering Division Summer Meeting, Boston, June 11-15.

Department of Mechanical Engineering, The Johns Hopkins University
200 Latrobe Hall, 3400 N. Charles Street, Baltimore, MD 21218
Tel: (410) 516 5427; Fax: (410) 516 4316
lefd@titan.me.jhu.edu