Effect Of Water Flow Rate Research Articles

ラミナフロー冷却による高温鋼板の冷却能に及ぼす水量効果

ラミナフロー冷却による高温鋼板の冷却能に及ぼす水量効果

Radial liquid distribution in cocurrent two‐phase downflow in packed beds

AbstractRadial liquid distribution was measured experimentally for cocurrent, two‐phase downflow in packed beds. The effects of bed length, water and air flow rates, and type of packing were determined. The experimental data were obtained in the gas‐continuous, transition and pulsing trickling‐flow regimes. For all finite air rates, the liquid velocity profiles were approximately flat with the maximum average velocity occurring at the center of the packed column. Increasing the air rate increased the center liquid velocity. The gas rate effect was more pronounced in shorter beds. At higher gas rates the liquid rate had less effect on the radial liquid distribution than at lower gas rates. Operation at higher liquid rates resulted in a flatter radial liquid veilocity profile. It was observed that the bed of pellets operated at high liquid rate and low gas rate was unstable. Increasing the bed height increased the stability of the system and a better liquid distribution was obtained. The effects of water flow rate, bed length, and packing type on the shape of the liquid velocity profiles were minor.

The influence of sulfhydryl compounds on diuresis and renal and cardiac circulatory changes caused by mersalyl: Farah, A., and Maresh, G. J. Pharmacol. & Exper. Therap. 92:73 (Jan.), 1948

The most important factor affecting plant growth is solar radiation. One primary source of loss of solar radiation transmission of greenhouses is accumulation of dust and dirt on the exterior surface of cladding materials. In order to clean greenhouse film roofs, a fly-over disc brush cleaning device which mainly consists of driving mechanism, cambered support mechanism and cleaning mechanism is designed in this paper, and the structure parameters of the cleaning device were optimized. In order to explore the optimum working parameter, the effects of water flow rate, device cleaning speed and disc brush rotation speed were tested and analyzed by orthogonal test and variance analysis. The results show all the 3 aforementioned factors have particularly significant impacts on cleaning effectiveness (CE), and the interaction term of device cleaning speed and disc brush rotation speed are significant. With 360 mL/s water flow rate, cleaning speed of 35 mm/s and disc brush rotation speed of 100 r/min, the value of light transmittance of testing greenhouse films increases from 45% to 84.37%. The results prove that the cleaning device, which has the advantages of good CE, high efficiency, prominent water-saving, high safety and light in weight, is practicable to clean greenhouse film roofs. This research can provide reference for the design and development of cleaning device for greenhouse soft roofs.