The foremost aeration industry experts agree that UFB generators provide the highest oxygen transfer efficiency of any aeration technology in the world. ClaasECO–Water, proudly hosts the largest variety of UFB equipment in the world, this backed up with services and support by professionals within the water and Agricultural sectors around the globe.
When a project requires an ultrafine bubble (UFB) generator two aspects are of importance to select the correct unit. One, the amount of water that needs to be treated. Two, the amount of gas that needs to be dissolved in the liquid and the concentration of bubbles required in the water. ClaasEco offers the wides range of UFB generators and related equipment in the word, this also backed up by professional installation and year on year operation support in the field. The most popular ones are, the eco-Bubble fine bubble generator, Nikuni KTM fine bubble generator, Acniti Turbiti high volume, enhanced DO ultra fine bubble generators, and the IDEC GaLF high concentration low water volume generators.
Besides having the best ultrafine bubble generators available, ClaasEco also offers a line of equipment that complement the UFB technology, to ultimately provide the client with the best sustainable solution addressing his/her needs. ClaasEco, after completing the needed “Value Engineering” will determine project specific UFB solutions to meet the clients requirements and quality standards.
Fine Bubbles are an innovative technology that’s invented in Japan. Japan took the initiative and approached ISO and setup the ISO Technical Committee 281 for fine bubbles standardization. ISO is the legal association based in Switzerland Geneva. The members of ISO are the “National Standards Bodies of 164 countries in the world on a national level these organizations organize standardization.
The first meeting of ISO fine bubbles was held in Kyoto in December 2013, where it was agreed that, compared with general bubbles, there was a wish to define fine bubbles as the ones whose diameter is 100-micron meters or less, and ultrafine bubbles as the ones whose diameter is 1 micron meter or less. This was the first step to have the common international concept of fine bubbles. The reason for setting the diameter as one of the parameters of fine bubbles is that fine or ultrafine bubbles are different in characteristics from the general larger bubbles.
Great things then happened when the world agreed. ISO published ISO20480-1 and 2 named “Fine bubble technology – General principles for usage and measurement-Part1:Terminology and Part2:Categorization of attributes of fine bubbles”. Keeping in mind that the goal of international standardization is to ease the exchange of goods and services by eliminating technical barriers. Chaos and confusion will exist with the use of Ultra Fine Bubble Technology without international standards.
ISO confirmed, “Applications of fine bubble technologies can be found in cleaning, environmental improvement, the food and drink sector, aeration systems, medicine, water and waste water treatment, as well as agriculture and aquaculture. Developing appropriate terminology for such diverse technologies is therefore critical to business trade or product acceptance by consumers.”
The distinguishing properties of ultrafine bubbles are:
- Fine bubbles can be present in both liquids and solids.
- Fine bubbles can contain air or another gas. O2, O3, CO2, also stay in the water and therefor remain effective.
- The bubble can be held in place by surface tension or be surrounded with a coating, e.g. a lipid.
- Fine bubbles generated for various applications can vary in size, gas content or bubble coating.
- The generation techniques used are also different.
- Very small, hence, not visible to the human eye or with a standard microscope.Pictured right, the image represents the size and visibility of nano bubbles illuminated by a green laser using a macro lens and long camera exposure on a black back ground. The micro bubble shows you the size and density difference.
Why are Micro Bubbles and Ultrafine (nano) Bubbles So Amazing?
Well, before jumping to the theory, we can achieve this with Micro Bubble and Ultrafine Bubble Technology, providing other amazing environmentally friendly sustainable solutions.
Small Bubble Size
- Ultrafine bubbles(UFB) are the smallest bubble size known to mankind, up to 10 000 times smaller than a human hair, or about the size of a virus.
- Large interfacial area – At this scale, far more ultrafine bubbles can fit in the same volume of water compared to other bubbles.
- They have several unique characteristics directly related to their miniature size that includes neutral buoyancy, a strong electric charge, and a high transfer efficiency.
- Larger bubbles do not possess these characteristics, making them less beneficial in a number of applications when compared to ultra fine bubbles.
- Bioactivity application field – 10-40 µm (micrometre) size bubbles
- Fluid physics application field – 100 µm (micrometre) size bubbles and less.
Slow rising velocity – Neutral buoyancy
The rising velocity of an Micro Bubbles (MB) depends on the physical properties of liquids. Stokes equation tells us for example that a 10 µm MB rise only 20 cm in one hour. Knowing that microbubbles are tiny bubbles with diameter of less than 100 µm, and that the bubbles decrease in size and eventually disappear underwater because of the rapid dissolution of the interior gas, they lack enough buoyancy to reach the surface and instead follow Brownian motion . ISO published results after stopping to monitor the presence of UFB in a water body, that after 3 months, it was still present in the water body.
The net effect is that UFB will remain suspended in water for months until they dissolve, traveling randomly throughout the body of water and efficiently aerating the entire water column. Subsequently, dissolved oxygen (DO) measured at the deepest parts of a water body will match the DO recorded near the surface. This unique behaviour enables MB and UFB to provide a homogenous distribution of oxygen throughout an entire body of water.
Exponentially Larger Interfacial Surface Area
Interfacial area of bubbles divided by volume A/V is obtained by the Equation A/V=6/d. With decreasing bubble diameter d, A/V increases and contributes to gas dissolution fraction.
Essentially this means that the smaller the bubble, the greater the surface area of the bubble exposed to the carrier liquid and a much greater gas transfer ability, when combined with the high internal gas pressure and lack of buoyancy, micro and ultrafine bubbles are an amazingly efficient aeration mechanism.
Large gas dissolution – Massive Gas Transfer Efficiency
Mass transfer rate from gas to liquid, or dissolving rate is measured in Mole Per Second (mol/s). Micro bubbles(MB) and Ultrafine bubbles (UFB) unique properties ensure a massive increase in the gas dissolution. When the mass transfer rate of the 1 mm bubble during 1 mm rise is considered as 1, mass transfer rates of 10 µm and 100 nm bubbles become 108 and 1018, respectively, due to the decrease in rising velocity.
The larger surface area allows for increased mass transfer, ensuring virtually any gas is effectively delivered to water. The unique bubble act like gas batteries in solution, as the liquids dissolved gas is consumed, micro and ultrafine bubble release the gas contained within into the surrounding liquid to replace the consumed dissolved gas and keep the solution in equilibrium according to Henry’s Law.
As oxygen is consumed from the water by biology, chemistry, or off-gassing, the MB and UFB rapidly diffuse more oxygen into the water, maintaining elevated dissolved oxygen levels until the UFB are depleted. This additional gas reserve, estimated up to 20% over the saturation point, enables industries to utilize gases more cost effectively than ever before.
MB and UFB high gas dissolution rate, at +90%, decreases the staggering energy demand to aerate water in waste water treatment facilities, as well as other agriculture, aquaculture, commercial and many other applications that requiring aeration or good supply of oxygen to saturate the water body.
Microbubble and ultrafine bubble longevity and large interfacial surface area are proven to be the most efficient aeration technique now available in the world.
If you are not using MB and UFB technology for aeration in your process, then you may be paying up to 90% more for your energy bill than needed.
With ever rising energy costs, ClaasEco Microbubble and Ultrafine bubble technology will allow plant operators to drastically decrease their energy costs, thus have additional money available to spend on much needed technology upgrades around the world.