Shallow Lavatory Extraction Fan with Carbon Filter
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Solution Overview
Problem
Unpleasant odors in lavatory systems, particularly public urinals, are not effectively addressed by existing methods which rely on flushing, masking with strong smells, or ventilation, as these approaches do not directly remove odors from their source.
Innovation Solution
A centrifugal fan-based extraction system with a shallow housing and axial inlet, mounted perpendicular to the rear wall, directs odour-laden air tangentially for discharge through an absorbent filter unit containing a carbon filter, which absorbs and can be regenerated, and optionally includes a perfume source for scenting the discharged air.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If ventilation is used to remove odors from the lavatory room, then the concentration of odorous substances in the room air is reduced, but the energy consumption increases and the odor source is not directly addressed
Solution Approach 1:
The patent extracts odorous air directly from the odor source (urinal) using a localized extraction system with a fan and housing, rather than ventilating the entire room. This targeted extraction removes odors at their origin, reducing the energy required compared to whole-room ventilation while effectively lowering odor concentration.
2Object-affected harmful factors
If strong smells are used to mask odors, then the perceived unpleasantness is reduced, but the actual odor concentration remains high and may cause discomfort
Solution Approach 1:
The patent converts the harmful odor molecules into a beneficial state by absorbing them onto carbon filter material. The carbon filter captures odorous substances, transforming the harmful concentrated odor into an absorbed state on the filter media, thereby removing rather than masking the odor.
3Object-affected harmful factors
If water traps are used to prevent sewer gas infiltration, then sewer gas is blocked, but odors upstream of the trap accumulate and require frequent flushing
Solution Approach 1:
The patent applies preliminary action by extracting odorous air from upstream of the water trap before it can accumulate. The extraction system continuously removes odors at their source, preventing accumulation that would otherwise require periodic flushing to clear, thereby reducing maintenance time and frequency.
4Reliability
If a deep housing is used for the centrifugal fan, then the fan can be mounted with proper airflow characteristics, but the installation space requirement increases
Solution Approach 1:
The patent redirects the fan's tangential airflow outlet from a radial direction to an axial direction, utilizing the dimension along the fan axis rather than requiring deep radial space. This dimensional reorientation allows the shallow housing to achieve proper airflow characteristics while minimizing installation space requirements.
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
This solution effectively reduces odors at their source with minimal power consumption, avoiding the need for masking smells and preventing sewer gas reversal, while allowing for easy maintenance of filter cartridges.
Implementation Method 1
an absorbent filter unit comprising an absorbent mass for absorbing odour consisting of a carbon filter
Data Source
Figure 1
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AI summary
An extraction system suitable for removing unpleasant lavatory odour comprises a shallow housing (1) having front (3) and rear (4) walls and side walls (9) interconnecting the front and rear walls, the depth of the housing from the front (3) to the rear (4) wall being substantially less than all distances across the front and rear walls from one side to the other thereof. The housing (1) mounts a centrifugal fan (2) with its axis perpendicular to the rear wall. The fan has an axial air inlet (6) located in the front wall for receiving odour-laden air, and an air outlet from the fan generally tangential to the fan and coupled to discharge air to atmosphere from the extraction system via an absorbent filter unit (101, 102) located within the housing downstream of the fan, the absorbent filter unit comprising an absorbent carbon filter mass (106), removable from the absorbent filter unit for regeneration, and a perfume source (109) also located within the housing within an accessible chamber for removal and replacement when spent, whereby air discharged to atmosphere is both substantially free of the odour and scented.