9 research outputs found
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Research and development of improved cavitating jets for deep-hole drilling
Improved cavitating nozzles have been developed as part of an on-going program to increase the rate of penetration of deep-hole drill bits. Based on the four criteria of: incipient cavitation number, amplitude of pressure fluctuation (and hence enhanced structuring of the jet flow), rock cutting, and cleaning chips from the hole bottom - these new, STRATOJET (STRuctured Acoustically Tuned Oscillating JET) cavitating nozzle systems have out-performed both conventional drill bit nozzles and the basic CAVIJET cavitating jets. Although nozzle designs which provide large amplitude pressure modulations are now available for the operation in water, additional research is needed to optimize self-resonating jets for use: (a) in mud, (b) in specific drill bit designs, and (c) at higher system pressures than now currently used for deep-hole drilling
Método para determinação de distribuição de tamanho de microbolhas (DTMB) em sistemas flotação (FAD) para tratamento de águas utilizando a análise de imagem digital Method for measuring bubbles sizes distribution (BSD) in drinking water treatment flotation (DAF) systems by using digital image analysis
O artigo apresenta um método proposto para determinação de tamanho de microbolhas de ar (DTMB) em sistemas de tratamento de água por flotação por ar dissolvido (FAD), utilizando a análise de imagem digital. Adicionalmente, é apresentado um estudo de caso com emprego de unidade em escala piloto. A aquisição das imagens foi realizada com uma câmera digital de 5.1MPixel, acoplada a conjunto de lentes. As imagens de microbolhas foram adquiridas em sistema com escoamento contínuo para eliminar as interferências causadas pela captura de amostras. O tratamento e obtenção das feições foram realizadas com o programa (freeware) "ImageTool". Os resultados apresentaram coerência com os valores reportados na literatura utilizando métodos tradicionais. O sistema mostrou-se eficaz e o método desenvolvido pode constituir ferramenta útil para estudos em outras subáreas de conhecimento.<br>An image analysis method proposed for assessing bubble size distribution applied to dissolved air flotation (DAF) systems for drinking water treatment is presented. Further, a pilot plant investigation is presented. A digital camera together with a group of lens was used. In order to eliminate samples interferences the images were captured in a continuous flow system working in steady state. The freeware ImageTool was applied for treating and obtaining size distribution. Results were presented in good relationship with traditional methods. The role image system showed to be efficient for image capturing and the proposed method may be an useful tool to other researches areas