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风雨182(金币+50):真不错，挺好的太谢谢你啦 2010-03-08 22:17
SPL, sonic frequency, bed temperature, particle size and other factors on the effect of mass thermal properties in sound field fluidized bed , and heat transfer law between sound field high-temperature fluidized bed and immersed surfaces of different shapes, are studied by pressure probe method via fluidized medium, which average diameters are 1200μm, 398μm, 74μm with respect to glass beads, quartz sand and catalytic cracking particles.
The results showed that: introduction of the sound field can significantly improve the heat transfer characteristics of high-temperature fluidized bed; heat transfer coefficient correspondingly increases as sound pressure level, or bed temperature augments; the smaller the particle size, the greater the heat transfer coefficient; fixed temperature, sound pressure level and heat transfer coefficient swell as the frequency accretes in the initial step and then decrease correspondingly, which leads to a maximum heat transfer coefficient among optimal frequency range. heat transfer coefficient of immersed surface among three different kinds of shapes distributes as a parabola of radial shape. Temperature and shape of submerged surface have a significant effect on heat transfer coefficients. When surface temperature is 850 ℃, the heat transfer coefficient is about 1 times larger than that under 300 ℃; 表面温度为850℃时的传热系数系数约是表面温度为300℃时2倍heat transfer coefficient of spherical immersed surface increased about 25 ℅ when replacing cylindrical surface.
Fixed sound pressure level and sound frequency, bed temperature on the effect of gas-solid heat transfer coefficient in sound field high-temperature fluidized bed. heat transfer coefficient markedly increases with the particle bed temperature improved, Influence on heat transfer coefficient is obvious in small size of particles by bed temperature, while there is no remarkable change in that of large-size particles. |
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