| Budget Amount *help |
¥13,100,000 (Direct Cost: ¥13,100,000)
Fiscal Year 1997: ¥4,700,000 (Direct Cost: ¥4,700,000)
Fiscal Year 1996: ¥8,400,000 (Direct Cost: ¥8,400,000)
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| Research Abstract |
As filtration goes on, dusts are collected on a ceramic filter element and form a dust cake layr on it. The filtration conditions and particle properties affect the accumulated amount and its shape on the element. Once dust cake is formed, the appearance of the filter changes and thus the flow around it also changes. This means that both flow field and the shape of dust layr interact with each other and they change with time, i.e., filtration performance changes with time. To elucidate the change in the flow around the filter element and accumulation process with time, a new analysis method has been proposed. Its capability has been demonstrated by solving them at filtration velocity of 5 Ncm/s varying gas temperature from 293 to 1123 K,pressure from 1 to 10 atmosphere and packing from 0.03 and 0.12.
As a result, it is found that dust cake forms a non-uniform layr on the element at any filtration condition, i.e., the maximum deposition appears at the front of the element and the minimum is observed around 120-150 degree from the front. It shifts forward as temperature rises but backward as pressure rises. With the increasing pressure, temperature and packing density, the uniformity of the dust layr increases. Suction velocity to the element, i.e., filtration velocity, decreases with time because of the increase in the resistance due to the accumulated dust. This also results in the suppression of accumulation rate of dust on the element with time. This effect is significant at high pressure and high temperature. Furthermore, pressure drop across the element increases non-linearly with time and it shows higher drops when temperature and pressure are high.
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