Segmented Vacuum Tank Structure for Low-Water Vacuum Toilets
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Solution Overview
Problem
Existing vacuum toilets face limitations in reducing flushing water requirements, especially when used as composting toilets, due to the need for a certain volume to generate sufficient suction, leading to clogging and cross-contamination of wastewater streams.
Innovation Solution
A vacuum tank design with a separating element forming a helically shaped channel and a funnel-shaped opening, dividing the tank into upper and lower volumes, and a three-way valve to separate wastewater streams based on type, combined with a macerator pump for homogenization and recirculation if necessary.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If the vacuum tank volume is reduced to save flushing water, then water consumption decreases, but the suction capability deteriorates and the tank becomes clogged more easily
Solution Approach 1:
The vacuum tank is divided into two separate chambers: a first chamber that receives the wastewater stream and a second chamber that generates vacuum. This segmentation allows each chamber to be optimized independently - the first chamber can be small and easy to clean, while the second chamber maintains sufficient volume for reliable vacuum generation without being exposed to wastewater
Solution Approach 2:
A valve mechanism acts as an intermediary between the two chambers, controlling the timing of vacuum application and wastewater discharge. The valve opens to allow vacuum generation, then closes to isolate the chambers during the flush, preventing wastewater contact with the vacuum chamber while maintaining system functionality
2Loss of substance
If the vacuum tank volume is reduced, then flushing water requirement decreases, but cross-contamination between successive wastewater streams increases
Solution Approach 1:
By separating the vacuum generation function from the wastewater reception function into different chambers, the system eliminates cross-contamination risks while maintaining low water consumption. The first chamber handles wastewater with minimal water volume, while the second chamber remains isolated and dedicated to vacuum generation
Solution Approach 2:
The valve mechanism serves as an intermediary that prevents direct contact between wastewater and the vacuum chamber, eliminating cross-contamination pathways while allowing the system to operate with reduced flushing water
3Reliability
If a larger vacuum tank is used to provide sufficient suction, then suction capability improves, but the device complexity and manufacturing cost increase
Solution Approach 1:
The tank is segmented into two functional chambers with distinct roles. The first chamber is optimized for receiving wastewater streams, while the second chamber is optimized for vacuum generation. This segmentation allows each chamber to be simpler in design for its specific function, reducing overall manufacturing complexity
Solution Approach 2:
The separated chamber design allows the vacuum generation chamber to serve dual purposes: generating vacuum for the flush operation and potentially serving as a holding chamber or treatment chamber for different types of wastewater streams, increasing system versatility
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
Reduces flushing water to 300 ml per cycle while ensuring complete tank cleaning and effective separation of wastewater streams, achieving low water consumption and energy-efficient treatment.
Implementation Method 1
the air in the tank can be vacuumed to a pressure below atmospheric pressure via the outlet opening or via further openings in the vacuum tank
Data Source
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AI summary
The invention relates to a vacuum tank (1) for a vacuum toilet, which tank comprises an inlet opening (2) which is located in a side wall of the tank and can be connected to the main drain (4) of a bowl (5) via a valve (3), and comprises an outlet opening (6) located at the deepest point for conveying the wastewater flow. The air in the tank can be vacuumed to a pressure below the atmospheric pressure via the outlet opening (6) or via additional openings in the vacuum tank (1). The vacuum tank (1) is subdivided into an upper volume (8) and a lower volume (9) by a separating element (7), the separating element (7) being arranged approximately at the height of the inlet opening (2) in the tank and forming a preferably helical, downwardly open groove (10) which extends across the periphery of the tank and, starting from the inlet opening (2), extends at least once around the horizontal periphery towards the lower volume (9). A through-opening (11) is located in the middle of the separating element (7) between the upper volume (8) and the lower volume (9). The invention also relates to a vacuum toilet having a vacuum tank (1) as described above.