Title:
FINE SAND-USED SLOW FILTRATION APPARATUS AND OPERATING METHOD THEREFOR
Document Type and Number:
Japanese Patent JP3698678
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide a sand filter for obtaining safe and purified water without using a chemical, whose maintenance is made easier as compared with a standard slow filtration method and in which the raw water which is not so much turbid but contains minute leaf mold or becomes turbid after heavy rain can also be purified, and to provide a method for operating the sand filter.
SOLUTION: The fine sand-used slow filtration apparatus 1 is constituted by arranging a water collecting/separating part 2 in the lowermost part of the apparatus 1, forming a cobble stone layer 3 and a gravel layer 4 or a perforated plate on the part 2 and forming a fine sand layer 5 packed with the fine sand having 0.05-0.2 mm particle size on the layer 4 or the perforated plate. Raw water is made to flow in the apparatus 1 at 2-100 m/day filtration velocity. When the apparatus 1 is clogged, the apparatus 1 is regenerated by backward washing the fine sand portion. The timing for backward washing is determined by using a timer or by the filtering pressure loss.
Inventors:
Kosuke Takahashi
Murakami
Murakami
Application Number:
JP2002085195A
Publication Date:
September 21, 2005
Filing Date:
March 26, 2002
Export Citation:
Assignee:
Development Kogyo Co., Ltd.
Murakami
Murakami
International Classes:
C02F3/06; B01D24/02; B01D24/46; B01D24/48; B01D29/60; C02F1/00; C02F3/10; (IPC1-7): C02F3/06; B01D24/02; B01D24/46; B01D24/48; B01D29/60; C02F1/00; C02F3/10
Domestic Patent References:
| JP2003024717A |
Attorney, Agent or Firm:
Takao Itagaki
Yoshihiro Morimoto
Yoshihiro Morimoto