Horizontal-Flow Sand Filtration Basin with Aeration Backwash

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Solution Overview

Problem

Conventional sand filtration technologies have limited filtration areas, underutilize the sand layer, and mix sand grains with different degrees of soiling during the flushing process, leading to inefficient filtration and cleaning.

Innovation Solution

A horizontal flow sand filter basin with a water distribution device that allows raw water to enter the sand filter bed horizontally, increasing filtration area and utilizing the sand layer more effectively, and a backwash process using aeration to separate and clean sand grains by degree of soiling without mixing them.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If vertical flow filtration is used in conventional sand filter basins, then the filtration process is simple to operate, but the filtration area is limited by the horizontal cross-sectional area and the sand layer is not fully utilized

Engineering Contradiction:
Improvefiltration areaVSAvoidfiltration structure complexity
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The patent transforms the conventional vertical flow filtration into horizontal flow filtration by changing the water flow direction from vertical (top to bottom) to horizontal (parallel to the sand layer). This dimensional change allows the filtration area to extend across the entire horizontal cross-section of the sand layer, maximizing the utilization of filter sand and increasing overall filtration capacity without requiring additional vertical space.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The sand filter basin is divided into multiple independent filtration zones or modules, each with its own water distribution and collection systems. This segmentation allows water to flow horizontally through different sections of the sand layer, increasing the effective filtration area while maintaining manageable operational complexity through modular design.

Inventive Principle:
Principle #1Segmentation

2Productivity

If conventional backwash process is used, then the operation is simple, but all sand grains are mixed and cannot be classified and treated according to the degree of soiling

Engineering Contradiction:
Improvebackwash efficiencyVSAvoidbackwash process complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The backwash system is designed with multiple independent backwash inlets positioned at different locations and orientations within the sand layer. Each inlet targets specific zones where sand grains with different degrees of soiling are located, allowing localized and differentiated cleaning actions. This enables sand grains to be classified and treated according to their soiling程度, improving backwash efficiency without requiring complex centralized control systems.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The backwash process transitions from a single vertical upward flow to multi-directional horizontal and vertical flows. Water is introduced from multiple directions (side walls, bottom, and top) to create complex flow patterns that facilitate the separation and classification of sand grains by soiling degree, enabling more effective differential cleaning while maintaining operational simplicity.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Productivity

If horizontal flow filtration is implemented, then the sand layer is fully utilized and filtration area increases, but the water distribution and collection systems become more complex

Engineering Contradiction:
Improvefiltration efficiencyVSAvoidwater distribution device complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The water distribution device is designed to serve multiple functions: it distributes water horizontally for filtration, collects backwash water, and provides structural support for the sand layer. This multi-functionality reduces the need for separate dedicated components, thereby increasing filtration efficiency while controlling overall system complexity through functional integration.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The horizontal flow distribution system utilizes the natural pressure gradient and flow characteristics of the incoming water to automatically distribute flow across the sand layer without requiring complex active control mechanisms. The system self-regulates flow distribution based on pressure differences, reducing the complexity of water distribution devices while maintaining high filtration efficiency.

Inventive Principle:
Principle #25Self-service

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The horizontal flow sand filter basin enhances filtration efficiency, reduces clean water consumption, and prolongs the backwash cycle, achieving better water quality and energy savings by maximizing sand filtration area and separating soiled sand grains during the backwash process.

Implementation Method 1

the aeration assembly is composed of an aeration pipe and multiple aeration devices connected to the aeration pipe... compressed air is fed into the aeration pipe, and enters the sand filter bed from bottom to top in the form of bubbles through the aeration device

Methodology Applied
Scientific EffectAeration: Aeration

Implementation Method 2

The sand filter basin can intercept impurities in water having a particle size much smaller than a gap in the filter material mainly through contact flocculation

Methodology Applied
Scientific EffectContact flocculation: Flocculation

Implementation Method 3

The sand filter basin can intercept impurities in water having a particle size much smaller than a gap in the filter material mainly through contact flocculation, and also through sieve filtration and precipitation

Methodology Applied
Scientific EffectSieve filtration: Filter (physical)

Implementation Method 4

The sand filter basin can intercept impurities in water having a particle size much smaller than a gap in the filter material mainly through contact flocculation, and also through sieve filtration and precipitation

Methodology Applied
Scientific EffectPrecipitation: Precipitation

Data Source

PatentEP3552679B1Horizontal-flow sand filtration basin and water treatment process thereof
Publication Date: 2023.06.07 PASSAVANT - GEIGER
  • EP3552679B1 patent drawingFigure 1~2
  • EP3552679B1 patent drawingFigure 2-1~3
  • EP3552679B1 patent drawingFigure 4

AI summary

A horizontal-flow sand filtration pool and a water treatment process thereof. The horizontal-flow sand filtration pool comprises a pool body (1), a raw water inlet assembly, a sand filtration bed (4), a filtered water outlet assembly, an aeration assembly, and a back washing assembly; the raw water inlet assembly comprises a water inlet pipe (2) and a water distribution device (3) that supplies raw water to the sand filtration bed (4); the water inlet pipe (2) is connected with the water distribution device (3), the water distribution device (3) is provided in the sand filtration bed (4), and a plurality of water outlet channels are uniformly distributed on the vertical surface of the water distribution device; the filtered water outlet assembly comprises a water collector (5) and a water outlet pipe (7); one side, adjacent to the sand filtration bed (4), of the water collector (5) has a water inlet channel, and the water outlet pipe (7) is communicated with the water collector (5); the back washing assembly comprises a back washing pipe (8) and a drainage pipe (9), the back washing pipe (8) is connected with the water outlet pipe (7), and the drainage pipe (9) is connected with the water distribution device (3). The horizontal-flow sand filtration pool is large in filtration area, thoroughly washes sand grains, and is water-saving and energy-saving; moreover, the horizontal-flow sand filtration pool is extended to a large variety of applications, so that the horizontal-flow sand filtration pool not only can simply serve as a filtration device, but also can be an aerobic/anoxic biological filtration pool integrating biological contact oxidation and suspended matter filtration bed intercepting functions.