移動式顆粒床過濾器濾餅流場與過濾性能之研究

李宗霖(Tsung-lin Li)

指導教授 ： 蕭述三

國立中央大學/工學院/機械工程研究所碩士在職專班/碩士(2012年)

摘要

近年來歐美日大力發展廢棄物氣化發電系統與先進燃煤發電系統，這些系統均會產生高溫高壓之氣體，在進入氣渦輪機前必須有效除塵，方能使系統有效運作。以顆粒床過濾器淨化高溫氣體一直存在著濾材靜止區形成，而造成系統堵塞之問題。過去幾年研究，我們已成功發展顆粒床內置入流動校正單元設計，並可有效解決此靜止區問題。
　　因此，在本論文中將針對顆粒床中濾餅過濾行為進行深入探討，瞭解濾餅過濾行為與顆粒床過濾性能的影響。首先將進行顆粒床濾餅流場行為探討，在不同進口風速條件下對於濾餅流場行為的影響，並藉由濾餅殘留面積百分比分析，瞭解進口風速與濾餅流場間的關係。此外在顆粒床過濾性能的研究中，針對不同進口風速與濾材質量流率進行過濾性能實驗，由實驗結果可知當進口風速與濾材質量流率搭配呈現比例關係時，也就是進口風速與質流率應呈現正比關係，可得到較佳之過濾效率。
　　最後依據實驗結果可知，由濾餅行為來尋出最佳過濾效率外，再配合不同進口風速與濾材質量流率達到穩定壓降變化結果，將可提供設計實際雛形之依據，以期能實際與產業界結合。

關鍵字

濾餅厚度 ； 壓降 ； 過濾效率 ； 流動式顆粒床 ； 濾餅

並列摘要

The biomass gasification system for power generation and the advanced coal-fired power plants have been developed in United States, Europe and Japan in recent years. High temperature syngas is generated during the gasification of the biomass or the coal. The high temperature gas contains many dust particulates and fly ashes that should be filtrated before entering gas turbine. The moving granular bed used for filtration of the hot gas is one important apparatus under development. When the filter granules move downwards through the vertical channel, they may stop between two louvers and form a stagnation zone. The dust particulates are attached to the filter granules when the hot gas enters the filter. Therefore, the hot gas entrance may be plugged eventually and the filter efficiency would decrease remarkably. Putting a series of flow corrective elements has been proven to be a good solution to removing the stagnant zones and has been patented by our research group. However there still remain some systematic problems.
　　In this thesis, the influence of the cake filtration behavior on the granular bed filtration performance will be investigated. First, flow field behavior of the granular bed filter cake will be discussed at different inlet gas speed conditions. The relationship between the inlet gas speed and the filter cake flow, and the residue area percentage are analyzed. In addition, the experiments of the granular bed filter performance of different inlet gas speed and filter mass flow rate are performed and investigated.
　　Finally, the best filter efficiency could be achieved by setting the corresponding with inlet gas speed and mass flow rate of filter granules. The result will provide the basis for designing the prototype in industrial applications.

並列關鍵字

collection efficiency ； pressure drop ； cake thickness ； moving granular bed filter ； dust cake

參考文獻

28.蔡信安，2006，「流動式顆粒床過濾器之雙葉片型流動校正單元設計與冷性能過濾機制研究」，國立中央大學機械工程研究所。

2.Smith, D. H., Powell, V., Ahmadi, G., Ibrahim, E., 1997, “Analysis of operational filtration data Part I. Ideal candle filter behavior,” Powder Technol., No. 94, pp. 15-21.

3.Ahmadi, G., Smith, D. H., 1998, “Particle Transport and Deposition in a Hot-Gas Cleanup Pilot Plant,” Aerosol Science and Technology, No.29, pp. 183-205.

4.Ahmadi, G., Smith, D. H., 2002, “Gas flow and particle deposition in the hot-gas filter vessel of the Pinon Pine project,” Powder Technol., No. 128, pp. 1-10.

7.Ishikawa, K, Kawamata N. and Kamei K., 1993, “Development of a Simultaneous Sulfur and Dust Removel Process for IGCC Power Generation System,” in Gas Cleaning at High Temperatures, edited by R. Clift and J.P.K. Seville, Blackie Academic & Professional, pp. 419-435.