Defoamers
FLOFOAM ™ series
Why is a defoamer necessary?
Defoamer is extremely useful, because although in most cases light foam does not cause any problems, however, heavy foam often leads to technological inconveniences. This problem extends from inaccurate reading of values from instrumentation, such as temperature, level and sensor values, to poor mixing of chemical reagents in the reaction vessel and retention of products in the foam. Finally, the presence of foaming can adversely affect the customer’s opinion about the process. The presence of foam in sewage can lead to conflicts with local residents and authorities, even if the foam is absolutely harmless to people and the environment.
How does silicone antifoam work?
Defoamer FLOFOAM™, consists of silicone oil and silicon dioxide. Defoamer silicone – this is the best solution to the problem of foaming, thanks to a very attractive price / quality ratio. Foam is a dispersion of gas in the liquid or solid phase. It is formed by surface-active substances (surfactants) having an affinity for both air and liquid. Thus, the resulting bubbles are stabilized by the surfactant.
The basic principles of the defoamer FLOFOAM ™ are:
Distributed in the foam active silicone ingredient replaces the surfactant molecules on the surface of the bubble. Due to this, the film becomes thinner, leading to destabilization and collapse (rupture of the vesicle). | ![]() |
Particles of silicon dioxide move to the surface of the foamed bubble film, further destabilizing the foam. | ![]() |
The foam bubble bursts, and the air enclosed in it comes out. | ![]() |
Silicone Defoamers
Today silicone defoamers remain the best solution due to a better price / quality ratio compared to organic defoamers. Products based on silicone, fully meet the three basic requirements of effective defoamers:
Silicone defoamer has other interesting properties:
Silicone oil, called polydimethylsiloxane, and silicon dioxide are the two main components of a silicone antifoam.
Polymethylsiloxane
Defoamer silicone can be a compound (100% active substance), emulsion (various% active substance) or powder.
Defoamer silicone can be a compound (100% active substance), emulsion (various% of active substance) or powder http://genericoitalia.it/.
Defoamers from SNF Floerger are supplied in the form of emulsions. FLOFOAMT products are of the oil-in-water type, and are thus convenient for simple dispersion into an aqueous medium. Due to their relatively low viscosity, they are easily pumped by pumps.
Impact on the environment
Silicone defoamer is essentially a mixture of polydimethylsiloxane (PDMS) and silicon dioxide. Silicon dioxide is a natural element, the main component of sand. PDMS is a very inert compound. Studies have shown that PDMS does not interact with any constituent of sewage. Due to its insolubility in water, PDMS has low COD and BOD values. He does not enter into any reaction during the processing. Very well adsorbed on the sediment, so the bulk of the introduced PDMS precipitates with sediment. The precipitate is then discharged to a landfill, where PDMS abiotically decomposes into carbon dioxide, water, and silicon dioxide. All the remaining amount of PDMS (at the limit of analytical determination) leads to the binding of suspended particles in the treated water. After settling of suspended particles, PDMS again undergoes abiotic decomposition, as in the previous case.
Dosage and dilution
For maximum efficiency, use SNF Floerger defoamers undiluted. Industrial tests are the best way to determine the optimal dosages of a defoamer, however, preliminary laboratory experiments often give similar results for different products. In general, the optimum dosage of the defoamer is within 10-1000 ppm, depending on the application and stability of the foam. FLOFOAMT products can be diluted to obtain a better dispersion in the foam, this impairs the effectiveness of the defoamer. We recommend not to exceed the dilution limit of 1:10. The diluted product can be used directly.
Shake resistance
The effectiveness of silicone suds suppressors is based on the particle size. Therefore, transverse forces and turbulence are of great importance for the effectiveness of silicone antifoams. This rule is partially applicable to products already in a dispersed form, such as emulsions. Particles will be broken by transverse forces and the effectiveness of the defoamer falls in comparison with the initial unshaken products.
Pumping
Silicone emulsions need to be carefully pumped. We recommend using slow gear pumps, since they are able to measure even small amounts very accurately. As noted earlier, turbulence can destroy a product. So the flow velocity should be relatively slow (<1 m/s).
Storage
The stability of the product decreases at high temperatures (above 30 ° C) and in frost, the temperature drops should be eliminated. After opening the container or drum with a defoamer, the lid should be tightly closed again to prevent contamination by microorganisms.