Abstract: An innovative method of prepping a surface entails entraining a coating particle into a fluid stream, directing the fluid stream containing the coating particle at the surface to be prepped to thereby prep the surface using the coating particle. The prepped surface can then be coated using the same or substantially similar coating particle. This method can be used with a continuous airjet, a forced pulsed airjet, a continuous waterjet or a forced pulsed waterjet as the carrier stream. This invention solves the problem of foreign blasting particles becoming embedded in the atomic matrix of the surface to be prepped, which can result in unpredictable behavior of the surface properties and even catastrophic failure.

Abstract: An ultrasonic waterjet apparatus has a mobile generator module and a high-pressure water hose for delivering high-pressure water from the mobile generator module to a hand-held gun with a trigger and an ultrasonic nozzle. An ultrasonic generator transmits high-frequency electrical pulses to a piezoelectric or magnetostrictive transducer which vibrates to modulate a high-pressure waterjet flowing through the nozzle. The waterjet exiting the ultrasonic nozzle is pulsed into mini slugs of water. The ultrasonic waterjet apparatus may be used to cut and de-burr materials, to clean and de-coat surfaces, and to break rocks. The ultrasonic waterjet apparatus performs these tasks with much greater efficiency than conventional continuous-flow waterjet systems because of the repetitive waterhammer effect. A nozzle with multiple exit orifices or a rotating nozzle may be provided in lieu of a nozzle with a single exit orifice to render cleaning and de-coating large surfaces more efficient.

Abstract: A reverse-flow nozzle generates a cavitating and/or pulsed jet of pressurized liquid. The nozzle includes a body having an inlet for receiving a stream of liquid and a main channel through the body extending from the inlet to an outlet. A flow-reversing channel in the nozzle diverts a portion of the liquid from the main channel to a point downstream of a mixing chamber. The channel returns the diverted liquid back into the mixing chamber as a reverse-flow jet relative to a main stream of liquid flowing toward the outlet. This reverse-flow jet interacts with the main stream to generate the cavitating jet that discharges from the outlet. By angling the reverse-flow jet relative to the main stream, a naturally pulsed jet may be generated.

Abstract: An ultrasonic waterjet apparatus has a mobile generator module and a high-pressure water hose for delivering high-pressure water from the mobile generator module to a hand-held gun with a trigger and an ultrasonic nozzle. An ultrasonic generator transmits high-frequency electrical pulses to a piezoelectric or magnetostrictive transducer which vibrates to modulate a high-pressure waterjet flowing through the nozzle. The waterjet exiting the ultrasonic nozzle is pulsed into mini slugs of water. The ultrasonic waterjet apparatus may be used to cut and de-burr materials, to clean and de-coat surfaces, and to break rocks. The ultrasonic waterjet apparatus performs these tasks with much greater efficiency than conventional continuous-flow waterjet systems because of the repetitive waterhammer effect. A nozzle with multiple exit orifices or a rotating nozzle may be provided in lieu of a nozzle with a single exit orifice to render cleaning and de-coating large surfaces more efficient.

Abstract: Prepping a surface entails entraining a coating particle into a fluid stream, directing the fluid stream containing the coating particle at the surface to be prepped to thereby prep the surface using the coating particle. The prepped surface can then be coated using the same or substantially similar coating particle. This technique can be used with a continuous airjet, a forced pulsed airjet, a continuous waterjet or a forced pulsed waterjet as the carrier stream. This invention solves the problem of foreign blasting particles becoming embedded in the atomic matrix of the surface to be prepped, which can result in unpredictable behaviour of the surface properties and even catastrophic failure.

Abstract: An innovative method of prepping a surface entails entraining a coating particle into a fluid stream, directing the fluid stream containing the coating particle at the surface to be prepped to thereby prep the surface using the coating particle. The prepped surface can then be coated using the same or substantially similar coating particle. This method can be used with a continuous airjet, a forced pulsed airjet, a continuous waterjet or a forced pulsed waterjet as the carrier stream. This invention solves the problem of foreign blasting particles becoming embedded in the atomic matrix of the surface to be prepped, which can result in unpredictable behaviour of the surface properties and even catastrophic failure.

Abstract: An ultrasonic waterjet apparatus (10) has a mobile generator module (20) and a high-pressure water hose (40) for delivering high-pressure water from the mobile generator module (20) to a hand-held gun (50) with a trigger and an ultrasonic nozzle (60). An ultrasonic generator in the mobile generator module (20) transmits high-frequency electrical pulses to a piezoelectric or magnetostrictive transducer (62) which vibrates to modulate a high-pressure waterjet flowing through the nozzle (60). The waterjet exiting the ultrasonic nozzle (60) is pulsed into mini slugs of water, each of which imparts a waterhammer pressure on a target surface. The ultrasonic waterjet apparatus (10) may be used to cut and de-burr materials, to clean and de-coat surfaces, and to break rocks.

Abstract: An ultrasonic waterjet apparatus (10) has a mobile generator module (20) and a high-pressure water hose (40) for delivering high-pressure water from the mobile generator module (20) to a hand-held gun (50) with a trigger and an ultrasonic nozzle (60). An ultrasonic generator in the mobile generator module (20) transmits high-frequency electrical pulses to a piezoelectric or magnetostrictive transducer (62) which vibrates to modulate a high-pressure waterjet flowing through the nozzle (60). The waterjet exiting the ultrasonic nozzle (60) is pulsed into mini slugs of water, each of which imparts a waterhammer pressure on a target surface. The ultrasonic waterjet apparatus (10) may be used to cut and de-burr materials, to clean and de-coat surfaces, and to break rocks.

Abstract: A method of prepping a surface using a high-frequency forced pulsed waterjet entails generating a high-frequency signal having a frequency f using a high-frequency signal generator, applying the high-frequency signal to a transducer having a microtip to cause the microtip of the transducer to vibrate to thereby generate a forced pulsed waterjet through an exit orifice of a nozzle having an exit orifice diameter d and a length L. The forced pulsed waterjet prepares the surface to within a predetermined range of surface roughness. The surface roughness is determined by selecting operating parameters comprising a standoff distance (SD), a traverse velocity VTR of the nozzle, a water pressure P, a water flow rate Q, a length-to-diameter (L/d) ratio, a microtip-to-orifice distance (a), the frequency f, and an amplitude A of the high-frequency signal.

Abstract: An ultrasonic waterjet apparatus (10) has a mobile generator module (20) and a high-pressure water hose (40) for delivering high-pressure water from the mobile generator module (20) to a hand-held gun (50) with a trigger and an ultrasonic nozzle (60). An ultrasonic generator in the mobile generator module (20) transmits high-frequency electrical pulses to a piezoelectric or magnetostrictive transducer (62) which vibrates to modulate a high-pressure waterjet flowing through the nozzle (60). The waterjet exiting the ultrasonic nozzle (60) is pulsed into mini slugs of water, each of which imparts a waterhammer pressure on a target surface. The ultrasonic waterjet apparatus (10) may be used to cut and de-burr materials, to clean and de-coat surfaces, and to break rocks.

Abstract: An ultrasonic waterjet apparatus (10) has a mobile generator module (20) and a high-pressure water hose (40) for delivering high-pressure water from the mobile generator module (20) to a hand-held gun (50) with a trigger and an ultrasonic nozzle (60). An ultrasonic generator in the mobile generator module (20) transmits high-frequency electrical pulses to a piezoelectric or magnetostrictive transducer (62) which vibrates to modulate a high-pressure waterjet flowing through the nozzle (60). The waterjet exiting the ultrasonic nozzle (60) is pulsed into mini slugs of water, each of which imparts a waterhammer pressure on a target surface. The ultrasonic waterjet apparatus (10) may be used to cut and de-burr materials, to clean and de-coat surfaces, and to break rocks. The ultrasonic waterjet apparatus (10) performs these tasks with much greater efficiency than conventional continuous-flow waterjet systems because of the repetitive waterhammer effect.

Abstract: There is described an improved ultrasonic nozzle including a nozzle body having a fluid flow channel formed axially therethrough with an inlet at an upstream end of the channel for receiving a pressurized fluid and an orifice at the downstream end of the body for discharging the pressurized fluid towards a surface to be eroded, a transformer axially aligned within the flow channel to form, in cooperation with the flow channel, an annulus between the two for the flow of the pressurized fluid, a vibrator for ultrasonically oscillating the transformer to pulse the pressurized fluid prior to its discharge through the orifice. The flow channel and transformer taper conformably axially inwardly in the direction of flow of the pressurized fluid at a uniform rate so that the transverse width of the annulus remains constant along the length of the transformer.