Flotation Tank with Direct Gas Injection for Water Cleaning
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Solution Overview
Problem
Current water cleaning methods, particularly Dissolved Air Flotation (DAF), face challenges such as high energy consumption and inability to effectively treat turbid or extremely muddy water, with membrane fouling issues in reverse osmosis desalination processes.
Innovation Solution
An apparatus combining flotation and membrane filtration in a single tank, where gas is injected directly into the contact zone without a liquid carrier, and a ceramic filtration unit is arranged offset from the gassing unit, allowing for improved water cleaning with reduced energy demand and minimal waste water production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If Dissolved Air Flotation (DAF) method is used for water precleaning, then organic substances and suspended matter can be separated, but energy consumption increases
Solution Approach 1:
The flotation tank is divided into distinct functional zones: a contact zone for gas-liquid interaction and bubble formation, and a separation zone for particle-bubble agglomerate separation. This spatial segmentation allows optimized local conditions in each zone, improving separation efficiency while reducing overall energy requirements compared to conventional DAF systems.
Solution Approach 2:
Gas bubbles act as an intermediary medium that facilitates the separation of hydrophobic particles from water. The bubbles attach to particles in the contact zone and transport them to the surface, enabling efficient separation without requiring high energy input for mechanical agitation or compression as in traditional DAF methods.
2Reliability
If conventional flotation methods are used, then organic substances can be removed, but turbid and extremely muddy water cannot be effectively treated
Solution Approach 1:
The apparatus is designed to handle multiple types of water contaminants and water quality conditions through a unified flotation mechanism. The contact zone generates bubbles that can attach to various particle types including organic substances, inorganic suspended matter, and turbid particles, making the system universally applicable to different water types without requiring fundamental design changes.
Solution Approach 2:
The contact zone is specifically designed to create optimal local conditions for bubble-particle interaction, with gas injection occurring in this dedicated region. This localized quality enhancement ensures effective treatment regardless of the overall water turbidity level, allowing the system to adapt to different water types while maintaining consistent performance.
3Reliability
If reverse osmosis is used for seawater desalination, then clean drinking water is obtained, but membrane fouling occurs due to retained substances
Solution Approach 1:
The flotation apparatus performs preliminary treatment of seawater by removing suspended matter, organic substances, and other contaminants before the water enters the reverse osmosis system. This pre-cleaning action prevents these substances from reaching and fouling the RO membrane, extending membrane life and maintaining consistent water quality without compromising the desalination efficiency.
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 combination enhances water cleaning efficiency, reduces energy consumption, and minimizes fouling, achieving better cleaning results with lower costs and environmental impact.
Implementation Method 1
Flotation is a gravity separation method for separating solid-liquid or liquid-liquid systems. In the process, gas bubbles are generated, for example from air, and introduced into the liquid phase, wherein hydrophobic particles present in the liquid phase, such as organic substances, attach to these likewise hydrophobic bubbles and due to the increased buoyancy caused by the gas bubbles rise to the surface.
Implementation Method 2
hydrophobic particles present in the liquid phase, such as organic substances, attach to these likewise hydrophobic bubbles and due to the increased buoyancy caused by the gas bubbles rise to the surface
Implementation Method 3
The reverse osmosis is a physical method for concentrating substances dissolved in liquids, in which the natural process of osmosis is reversed with pressure. On one side of a semipermeable membrane, a pressure greater than the natural osmotic pressure is generated.
Implementation Method 4
the first reverse osmosis plants for seawater desalination were established in the 1970ies, whose operation energetically is much more favorable as compared to a purely thermal water treatment
Implementation Method 5
a gas present in a liquid at elevated pressure in dissolved form is introduced into the liquid to be cleaned. Due to the pressure drop in the liquid to be cleaned, the gas escapes in the form of tiny bubbles, which have a diameter in the micrometer range.
Data Source
AI summary
The present invention relates an apparatus for cleaning water, in particular precleaning seawater, including at least one tank for receiving water containing at least one flocculating agent for separating organic and possibly biological constituents contained in the water. The at least one tank includes at least one contact zone K for contacting the water containing the flocculating agent with at least one gas, in particular air, and at least one separation zone S for separating the flocculated organic constituents buoyed up by the gas. At least one gassing unit is arranged in the at least one contact zone K and at least one filtration unit is arranged in the at least one separation zone S. The at least one gas is injected via the at least one gassing unit without using a liquid carrier.