The effect of filtration velocity on the filtration efficiency of a dual-layer granular bed 400°C was studied. The results showed that the bed filtration efficiency decreased from 99.87% to 99.85% as the average filtration velocity increased from 0.20 to 0.35 m/s. The effects of the filtration velocity on the efficiency of the upper and lower filtration layers were different. For the upper filtering layer, a higher filtration velocity resulted in decreased filtration efficiency, whereas the grade filtration efficiency increased with an increase in the particle size at the beginning of the test. However, toward the end of the test, it first decreased and then increased, with the critical point appearing at 0.23 μm. For the lower filtering layer, increasing the filtration velocity resulted in higher filtration efficiency. The grade filtration efficiency curve was V-shaped, with the critical points moving from 1.52, 1.45, and 1.32 μm at the beginning of the test to 1.63, 1.54, and 1.37 μm at the end of the test, respectively. In addition, the dust concentration at the outlet was maintained below 18 mg/m³. The dual-layer granular beds maintained efficient and reliable performance at high temperatures.

中文翻译：

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过滤速度对双层粒床高温过滤效率的影响

研究了过滤速度对 400°C 双层颗粒床过滤效率的影响。结果表明，随着平均过滤速度从0.20增加到0.35 m/s，床过滤效率从99.87%下降到99.85%。过滤速度对上下过滤层效率的影响不同。对于上层过滤层，较高的过滤速度导致过滤效率降低，而分级过滤效率随着测试开始时粒径的增加而增加。然而，在测试结束时，它先下降后上升，临界点出现在 0.23 μm。对于较低的过滤层，增加过滤速度导致更高的过滤效率。分级过滤效率曲线呈V形，临界点从试验开始时的1.52、1.45和1.32μm分别移动到试验结束时的1.63、1.54和1.37μm。此外，出口粉尘浓度保持在18mg/m以下³ . 双层颗粒床在高温下保持高效可靠的性能。