Showing papers by "Young I. Cho published in 2006"
TL;DR: In this paper, the authors investigated the efficacy of a physical water treatment (PWT) technology using catalytic materials to mitigate mineral fouling in a heat exchanger and found that PWT decreased the fouling resistances by 17% to 38% depending on the flow velocity.
46 citations
TL;DR: In this paper, the authors investigated the effect of physical water treatment (PWT) on fouling mitigation in a simulated cooling tower operating at high cycles of concentration, where hard water was produced by evaporating pure water in a circulating open cooling tower, where dissolved calcium carbonate ions became concentrated with time.
Abstract: The purpose of the present study is to investigate the effect of a physical water treatment (PWT) technology on fouling mitigation in a simulated cooling tower operating at high cycles of concentration. Hard water was produced by evaporating pure water in a circulating open cooling tower, where dissolved calcium carbonate ions became concentrated with time. Heat transfer tests were conducted in a rectangular channel by varying the cycle of concentration (COC) from 5 to 10, and fouling resistances were measured over 270 hrs for each case with and without the PWT treatment. Another test was conducted with no blowdown case with and without the PWT treatment. The fouling resistance at 5 cycles with the PWT treatment was about 70% less than that in the case without the PWT treatment at the end of 270-hr tests. Even at 10 cycles, the PWT treatment reduced the fouling resistance by 60% from the value for the no treatment case. Thus, one can conclude that the PWT technology can help circulating cooling-tower wate...
7 citations
3 citations
TL;DR: In this paper, the initial biofouling behavior of living microorganisms is investigated by measuring the mass of bacteria deposited on various metallic surfaces immersed in stationary distilled water, and three different bacteria were used: Pseudomonas fluorescens, Escherichia coli, and Klebsiella aerogenes, all of which commonly exist in industrial water systems.
1 citations
01 Nov 2006
TL;DR: In this paper, a high speed motion camera was used to measure the viscosity of both Newtonian and non-Newtonian fluids from the velocity-time data, and the experimental results were in good agreement with the results obtained from a rotating Brookfield viscometer.
Abstract: This study introduces a new approach to a falling ball viscometer by using a high speed motion camera to measure the viscosity of both Newtonian and non-Newtonian fluids from the velocity-time data. This method involves capturing continuous photographs of the entire falling motion of the ball as the ball accelerates from the rest to the terminal velocity state. Ball’s velocity was determined from the distance traversed by the ball by examining video tape frame by frame using the marked graduations on the surface of the falling ball cylinder. Each frame was pre-set at 0.01. Glycerin 74% was used for Newtonian solution, while aqueous solutions of Polyacrylamide and Carboxymethyl Cellulose were for non-Newtonian solutions. The experimental viscosity data were in good agreements with the results obtained from a rotating Brookfield viscometer.