Novel Ultrasonic Cleaning Equipment Using Waveguide Mode

Abstract

The clarity of the trace testifies to the accuracy and stability of the apparatus. A test was also carried out on a non-inductive circuit carrying alternating current. With a supply voltage of 250 V. r.m.s. it was found that current interception could be secured at a current peak up to 300 mA. There was no difficulty in maintaining a steady break at a zero of current up to a r.m.s. current of I A. A discussion upon contact material, suppression of the arc, etc. will be found in referenceb) in the bibliography. APPLICATIONSExamples have been given of the recording of rapid 50 cis transients by means of this apparatus. At the other end of the scale, the recording of current surges in incandescent lighting loads, when a considerable time must be allowed for the lamps to heat and cool, may also be carried out. The apparatus has also a possible application in the production of very low frequency square waves to a high degree of precision. As at present in use by the authors, it has a lower switching frequency of 40 timesimin. (which can readily be reduced by slight modification to the multivibrator circuit) and an upper switching frequency of 12.5 times/sec. The duration of the on or off condition may be reduced to 3% sec. independently of the switching frequency. There is no reason why currents alternating at frequencies greater than 50 cis should not be switched but, assuming constant relay errors, the accuracy will fall proportionately as the frequency is raised. CONCLUSIONThe authors believe that this apparatus will be a valuable tool for research into the transient effects occurring in non-linear networks. It can be shown that the effect of such transients in circuits containing current transformers is to reduce permanently the accuracy of the transformer until, by some means, the resulting polarization of the magnetic core has been removed. It is believed that this effect results in 'through fault instability' in protection systems for power networks employing current transformers, and it is the authors' immediate object to use the apparatus described here to record the results of such transients using small current transformers as models of those used in power engineering. REFERENCES ( I ) SKILLING, H. H. ABSTRACT.A simple electrical viscometer has been designed enabling instantaneous indications of viscosities of liquids at any point in an industrial plant. The transmitter unit consists of a twophase electric motor operated from single-phase mains and SO designed and constructed that large variations of current in one phase are produced by small changes in viscous drag on the rotating part. The indicator unit is essentially an ammeter in one of the motor phases and is directly calibrated in viscosity units. Models have been designed for operation within pipe lines and containers up to high pressures and high temperatures (about 250' C.) and for rapid testing of samples. INTRODUCTIONFor some years now there has been a demand for a viscometer to indicate directly and continuously, without the necessity of taking...

Application of Novel Ultrasonic Cleaning Equipment That Uses the Waveguide Mode for the Single-Wafer Cleaning Process

“…However, an increase in the standing wave component induced by reflected waves from the waveguide end was observed only around the waveguide end. 6) Therefore, if we adopt measures to absorb the reflected waves, bubble collapse in the meniscus of the cleaning solution would be suppressed.…”

“…We previously proposed waveguide-type ultrasonic cleaning equipment that uses a quartz glass tube as the ultrasonic irradiator. 4,5) We estimated the acoustic amplitude irradiated from the waveguide side to be over 100 kPa, and we showed that the vibration velocity distribution of the waveguide side had a traveling wave distribution. 6) In a traveling ultrasonic wave field, bubbles receive radiation force in the traveling direction, and this force is expected to prevent the collapse of bubbles trapped at pressure antinodes.…”

“…We previously measured the vibration distribution of the waveguide side using a laser Doppler velocimeter (LDV), and a standing wave ratio (SWR) of 2.2-3.1 was obtained. 6) The SWR is expressed as the ratio of the maximum and minimum amplitudes. SWR ¼ 1 indicates a perfect traveling wave distribution, whereas SWR ¼ 1 means a perfect standing wave distribution.…”

Application of Novel Ultrasonic Cleaning Equipment Using Waveguide mode for Post-Chemical-Mechanical-Planarization Cleaning

“…The sound source has the same configuration as the conventional Spot Shower. 10) In the Megatube, ultrasound supply point can be located anywhere within the cleaning equipment as the ultrasonic wave is directed through a thin quartz glass tube acting as a waveguide. Thus, it is possible to supply ultrasonic waves at a distance from the ultrasonic generator.…”

Effect of Ultrasonic Frequency on Enzymatic Hydrolysis of Cellulose

“…When ultrasound is irradiated onto liquid, physical and chemical effects occur due to vibration, cavitation, and streaming. These characteristics of ultrasound are applied to cleaning, [1][2][3] homogenization, atomization 4) and chemical reactions. 5,6) Recently, Li et al 7) have reported that the enzymatic hydrolysis of cellulose is enhanced by ultrasonic irradiation.…”