Backwashing method of filter device and filter material

Abstract

The invention provides a filter device capable of obtaining adequate backwashing effect with a little backwashing water, and provides a backwashing method employing the filter device. The filter device comprises a base end side porous plate (32) capable of being arranged near an opening portion (12) at a downstream side of a shell (1), a pillar (31) supported to the base end side porous plate, an upstream side porous plate (33) supported to the pillar in a flange shape and capable of moving freely along the axis direction of the pillar, and a downstream side porous plate (34) configured between the base end side porous plate and the upstream side porous plate, the axis is configured to be along the water-conveying direction in the shell, the downstream side porous plate is supported to the pillar in a flange shape and can move freely along the axis direction of the pillar, one ends of core wires of filter materials are connected with the upstream side porous plate, and the other ends of the core wires are connected with the downstream side porous plate.

Description

technical field [0001] The invention relates to a device for filtering raw water by catching suspended matter from other raw water such as water and waste water, and a method for backwashing the filter material used in the filtering device. Background technique [0002] As a filter device in which the filter material is arranged in the housing, there is a structure in which a filter material longer than the distance between the two porous plates is provided between the porous plate constituting the filter medium support bottom plate and the upper porous plate opposite to the porous plate. filter material (refer to Patent Document 1). In this filtering device, the above-mentioned filter material is composed of a core wire and a suspended substance capturing material protruding to the peripheral side of the core wire. One end of the core wire is fixed to the upper perforated plate, and the other end is fixed to the lower perforated plate. During operation (when raw water is p...

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Problems solved by technology

[0003] However, there is the following problem: in the above-mentioned filter device, the filter material is set to be able to extend along the longitudinal direction in the housing with a uniform inner diameter, so even during backwashing, the distance between adjacent filter materials does not change, and cannot Make a proper amount of backwash water pass through the middle of adjacent filter materials, and cannot obtain sufficient backwash effect

[0008] However, the backwashing of the filter material of the above-mentioned filter device is to reversely press the backwash water from the discharge port, and the captured suspended matter is removed from the filter material by the continuously flowing backwash water, but when using such a method In the case of backwashing, not only a large amount of backwashing water is required, but also the water used for backwashing contains suspended matter, so the water is not reused but treated as drainage

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