The Fluidization Backwash Method of Filter Beds by Air-water Bubbly Flow
A novel fluidization backwash method by the air-water bubbly flow with air bubbles of various sizes has been proposed for rapid filters. The backwash efficiency is closely related to the bubble wake motion. Bubble coalescence, bed contraction and jet generation caused by t...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Japan Society on Water Environment
2020-01-01
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| Series: | Journal of Water and Environment Technology |
| Subjects: | |
| Online Access: |
https://www.jstage.jst.go.jp/article/jwet/18/6/18_20-014/_pdf
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| _version_ | 1818338985115648000 |
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| author | Masao Kuroda Anri Yoshida Emi Obuchi Hironoshin Kawabata Tadao Arai |
| author_facet | Masao Kuroda Anri Yoshida Emi Obuchi Hironoshin Kawabata Tadao Arai |
| author_sort | Masao Kuroda |
| collection | DOAJ |
| description | A novel fluidization backwash method by the air-water bubbly flow with air bubbles of various sizes has been proposed for rapid filters. The backwash efficiency is closely related to the bubble wake motion. Bubble coalescence, bed contraction and jet generation caused by the motion of air bubble wakes strikingly enhance the discharge of retained sludge. The effect of the bubble wakes on the backwash efficiency is ensured by controlling the fluidizing condition which is easily identified visually. The size of air bubbles should be controlled properly, and the air bubble size at the dense bed surface must be within several centimeters to prevent the loss of filter media particles from filter beds. The backwash efficiency of the filter bed achieved 94% in average by optimizing the air bubble size in the air-water bubbly flow. The air-water bubbly flow backwash method was also applied to a self-backwash filter where the backwash flow rate depends on an elevated water tank, and the backwash efficiency was as high as that for the constant flow rate backwash method. |
| first_indexed | 2024-12-13T15:19:48Z |
| format | Article |
| id | doaj.art-fa6644a7644f4d8bae0aa0f7f126aa42 |
| institution | Directory Open Access Journal |
| issn | 1348-2165 1348-2165 |
| language | English |
| last_indexed | 2024-12-13T15:19:48Z |
| publishDate | 2020-01-01 |
| publisher | Japan Society on Water Environment |
| record_format | Article |
| series | Journal of Water and Environment Technology |
| spelling | doaj.art-fa6644a7644f4d8bae0aa0f7f126aa422022-12-21T23:40:36ZengJapan Society on Water EnvironmentJournal of Water and Environment Technology1348-21651348-21652020-01-0118634935810.2965/jwet.20-01410.2965/jwet.20-014The Fluidization Backwash Method of Filter Beds by Air-water Bubbly FlowMasao Kuroda0Anri Yoshida1Emi Obuchi2Hironoshin Kawabata3Tadao Arai4 Yamato Corporation Environmental Technology Research Center, Maebashi, Japan Yamato Corporation Environmental Technology Research Center, Maebashi, Japan Yamato Corporation Environmental Technology Research Center, Maebashi, Japan Yamato Corporation Environmental Technology Research Center, Maebashi, Japan Yamato Corporation Environmental Technology Research Center, Maebashi, Japan A novel fluidization backwash method by the air-water bubbly flow with air bubbles of various sizes has been proposed for rapid filters. The backwash efficiency is closely related to the bubble wake motion. Bubble coalescence, bed contraction and jet generation caused by the motion of air bubble wakes strikingly enhance the discharge of retained sludge. The effect of the bubble wakes on the backwash efficiency is ensured by controlling the fluidizing condition which is easily identified visually. The size of air bubbles should be controlled properly, and the air bubble size at the dense bed surface must be within several centimeters to prevent the loss of filter media particles from filter beds. The backwash efficiency of the filter bed achieved 94% in average by optimizing the air bubble size in the air-water bubbly flow. The air-water bubbly flow backwash method was also applied to a self-backwash filter where the backwash flow rate depends on an elevated water tank, and the backwash efficiency was as high as that for the constant flow rate backwash method. https://www.jstage.jst.go.jp/article/jwet/18/6/18_20-014/_pdf backwashingair-water washingself-backwashingbubbly flowgranular filtration |
| spellingShingle | Masao Kuroda Anri Yoshida Emi Obuchi Hironoshin Kawabata Tadao Arai The Fluidization Backwash Method of Filter Beds by Air-water Bubbly Flow Journal of Water and Environment Technology backwashing air-water washing self-backwashing bubbly flow granular filtration |
| title | The Fluidization Backwash Method of Filter Beds by Air-water Bubbly Flow |
| title_full | The Fluidization Backwash Method of Filter Beds by Air-water Bubbly Flow |
| title_fullStr | The Fluidization Backwash Method of Filter Beds by Air-water Bubbly Flow |
| title_full_unstemmed | The Fluidization Backwash Method of Filter Beds by Air-water Bubbly Flow |
| title_short | The Fluidization Backwash Method of Filter Beds by Air-water Bubbly Flow |
| title_sort | fluidization backwash method of filter beds by air water bubbly flow |
| topic | backwashing air-water washing self-backwashing bubbly flow granular filtration |
| url |
https://www.jstage.jst.go.jp/article/jwet/18/6/18_20-014/_pdf
|
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