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Fouling
About the author
Michael Radicone is president and chief science officer of I2 Air Fluid Innovation and Specialty Product Lead for HTRI . At I2 Air Fluid Innovation , he has developed and patented technologies that address heat exchange fouling , toxic mercury presence in fluids , flue gas scrubber enhancement , medical and dental waterline microbial fouling and aortic catheter disinfection . As specialty Product Lead for HTRI , he oversees development and integration of the Vapor Nano Bubble Infusion technology . He can be reached by email at mike . radicone @ htri . net
The results ( Table 1 ) indicate that infusing for three minutes , using simple diffuser and vapor infusion treatments created a significantly high density of relatively small ( under 200 nm ) bubbles . Of significance was the persistence of bubbles 48 hours post-infusion , indicating the neutral buoyancy of the nanobubbles .
Micro diffuser |
Persistence |
192 hours |
Density |
3.77 ( 10 7 ) |
Size |
53 – 62 nm |
Table 2 . NanoSight results using micro diffuser .
A snapshot of the nanobubble analysis seen in Figure 5 as provided by the NanoSight device clearly indicates bubble size and concentration . The analysis was conducted by Marco Ugalde-Valdés from Instituto Politécnico Nacional , Mexico City while visiting the Earthman Labs at UC Irvine . It is postulated that the vapor infusion treatment chemicals and shearing techniques facilitate the creation of microbubbles which shrink in size to nanobubbles . Vapor infusion currently uses elemental iodine , ammonium benzoate , and other vaporous chemicals , based on foulant type , system materials , and regulatory requirements .
Commercial application Vapor infusion using chemical vapors in a manner as described in this article allows for the formation of bubble emulsions including nanobubbles of a desired volume and size for use in industrial settings . The vapor infusion system utilizes a chemical treatment in an easily replaceable cartridge . As oil-free air of a necessary flow rate and pressure is directed through the cartridge , the chemical vapor treatment moves with the airflow to the heat exchanger injection site . The chemical vapor flow is sheared by the infusion quill into the cooling water pipe before it enters the heat exchanger . The creation of smaller microbubbles due to shearing hastens the creation of nanobubbles for internal and downstream presentation . The bubble emulsion , including nanobubbles , moves through the heat exchanger . The nanobubbles move in a non-coalescing , Brownian motion driven cloud , contacting surfaces within the heat exchanger . As the nanobubble cloud makes contact , the bubbles interact with fouling agents on heat transfer surfaces while imparting the chemical treatment . Vapor infusion occurs for a designed duration and frequency and does not require constant vapor presentation . The bubble emulsion then moves through the system for discharge . The results of several commercial applications bear out the efficacy of this protocol . In one such application , a Norwegian Cruise Line ship , was experiencing fouling within their engine coolers when infusion devices were installed . After installation the aft engine cooler plates were opened for inspection onboard ( Figure 6 ) and clearly showed a lack of fouling after three years of infusion without any other antifouling treatment . During this time , the electro chlorination system was turned off . This system is in use on other ships for engine and flue gas scrubber applications with comparable success .
Conclusion Nanobubbles can be produced by different methods , including vapor infusion , and have been shown to
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