Multi-Layer FOG Filtration After Gravity Separation

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Solution Overview

Problem

Conventional FOG/water separators struggle to effectively remove emulsified and high-density FOG droplets from water due to their immiscibility and varying densities, leading to blockages and environmental pollution.

Innovation Solution

A multi-layered filter system comprising stainless steel casing, non-woven thermally bonded polyester, activated carbon, and granular activated carbon layers, combined with a separator to remove FOGs of varying densities and sizes, ensuring near-zero FOG concentration in discharged water.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional FOG/water separators are used to remove FOGs from water, then low-density FOGs can be separated by gravity, but emulsified and high-density FOG droplets cannot be effectively removed

Engineering Contradiction:
ImproveFOG removal effectivenessVSAvoidability to handle varying FOG densities and sizes
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The filter is divided into five distinct layers, each with specific pore sizes and materials designed to capture different sizes and densities of FOG droplets. The layers progress from larger pore sizes at the top to smaller pore sizes at the bottom, creating segmented zones that handle different types of contamination separately and systematically

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Each layer of the filter is given different local qualities - varying pore sizes, different materials (polyester, activated carbon, granular activated carbon), and specific thicknesses - to optimize performance for capturing specific types of FOG droplets. The top layers handle larger, lower-density droplets while bottom layers capture smaller, higher-density droplets

Inventive Principle:
Principle #3Local quality

2Reliability

If multi-layered filtration is implemented to capture all FOG droplets, then FOG removal efficiency increases, but device complexity increases

Engineering Contradiction:
ImproveFOG removal efficiencyVSAvoidfilter structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The filter utilizes five layers of porous materials with progressively smaller pore sizes, including polyester fabric and activated carbon layers. These porous materials naturally trap FOG droplets of different sizes as water passes through, providing high removal efficiency without requiring complex mechanical components or moving parts

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The filter combines multiple composite materials - non-woven thermally bonded polyester, activated carbon, and granular activated carbon - each selected for its specific adsorption and filtration properties. This composite structure achieves superior FOG removal across all droplet types while maintaining a relatively simple passive filter design

Inventive Principle:
Principle #40Composite materials

3Reliability

If FOG droplets are allowed to accumulate in sewerage systems, then gravity separation can occur, but blockages and fatbergs form causing environmental pollution

Engineering Contradiction:
Improvesewerage system functionalityVSAvoidblockages and environmental pollution
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The filter performs preliminary removal of FOG droplets from wastewater at the source (kitchen drainage) before the water enters the sewerage system. By capturing FOGs upstream, the system prevents their accumulation in sewers, eliminating the formation of blockages and fatbergs before they can cause harm to the sewerage infrastructure or environment

Inventive Principle:
Principle #10Preliminary action

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 system achieves near-zero FOG concentration by effectively capturing and adsorbing FOG droplets of all densities and sizes, preventing blockages and environmental pollution, suitable for commercial, industrial, and household kitchens.

Implementation Method 1

separating FOGs from water contaminated by FOGs, using the property that FOGs having a lower density than water ('low density FOGs') will naturally separate from the water and will float on top of the water

Methodology Applied
Scientific EffectGravity separation: Gravitation

Implementation Method 2

The third layer is impregnated with carbon which traps and removes smaller FOG molecules from the water

Methodology Applied
Scientific EffectAdsorption: Adsorption

Implementation Method 3

The fourth layer comprises granular activated carbon (GAC) pieces bonded together and wrapped in polyester... As water passes through the pores of the GAC in this fourth layer, a majority of the FOG droplets present in the water will be adsorbed and trapped by the granular activated carbon and removed from the water

Methodology Applied
Scientific EffectAbsorption: Absorption (physical)

Data Source

PatentEP3994100B1A device for removing fats, oils and/or grease (FOGS) from water
Publication Date: 2026.03.11 BUTTRESS GROUP LTD
  • EP3994100B1 patent drawingFigure 1
  • EP3994100B1 patent drawingFigure 2
  • EP3994100B1 patent drawingFigure 3

AI summary

The invention relates to a filter, a device and a method for removing fats, oils and/or grease ("FOGs") from water. The device comprises a separator for removing FOGs from water, wherein the separator removes the FOGs that separate from the water under gravity; and a filter wherein the filter removes the FOGs remaining in the water after the water has passed through the separator. The filter comprises several layers having different compositions suitable for removing FOGs from water, including a layer comprising granular activated carbon (GAC) bonded together and wrapped in polyester.