English
Español
简体中文
Nederlands
How to lower the costs of Anti-foam Agents in Potato Processing Facilities
As water flows through a food processing facility, air becomes increasingly entrained within its volume. Once air makes its way to the surface, foam begins to form and grow.
'How to lower Costs of Anti-foam Agent in potato processing facilities' is based on materials provided to PotatoPro by ChemFree Defoam LLC. The content of the original article has been edited for clarity and to fit the PotatoPro platform.
If emerging water strikes the surface of the water in the tank (left), more air becomes entrained, thus, more foam is generated.However, by immersing the end of the pipe so as to have the emerging water exit below the surface (right) the effect of an air/water interface is greatly minimized
However, by immersing the end of the pipe so as to have the emerging water exit below the surface (right) the effect of an air/water interface is greatly minimized, reducing, or eliminating, the creation of additional foam.
This improvement can be attained by simply adding an extension to an existing pipe immersing it deep enough so as not to create unacceptable surface turbulence.
Water Entering Tanks from Flumes
Constraining the flow
Ideally, it would be advantageous to convert water emerging from a flume (a “waterfall” condition) so as to confine it to a closed pipe and treat it as mentioned before.
However, this can be a difficult task, due, in part, to foaming consequences of making any transition to water flow.
Water flow transitions, e.g., directional changes, flow speed changes, increasing confinement, etc., often result in unwanted turbulence and more foam. Thus, careful design considerations need to be taken into account should such an approach be implemented.
Utilizing turbulent flow
Another approach to controlling foam produced from the impact of processing water from a flume into a tank is to take advantage of its turbulent flow upon entering the water.
Turbulence, while a source for entraining air and subsequently producing foam, can also be used to an advantage in controlling foam.
Typically, no foam is produced in the immediate vicinity where the processing water strikes the surface of the tank water. Instead the turbulent flow carries the entrained air down into the water volume where it subsequently rises and emerges at the surface as foam. The distance from the impact area where this foam emerges is dependent upon the speed and direction of the processing water as it strikes the surface.
Foam that makes its way into the impact area is either destroyed or is carried back into the tank water.
Ideally, obstructions should be removed. If that is not possible, a smooth streamlined diversion that allows the water to “slip” by the obstruction without adhering to it (shown above)
-
“Hard” obstructions
These refer to physical objects such as pipes, flume discontinuities, and surface irregularities. Once identified, the ideal solution is to simply remove these obstructions.
Knowing this is not always reasonable, the second approach to solve the problem is to introduce a smooth streamlined diversion that allows the water to “slip” by the obstruction without adhering to it as illustrated above.Example of a proper design for an open trench (gutter)
-
“Soft” obstructions
- Foam: One type of soft obstruction is foam itself. Foam deposits become “seeds” for foam growth. Foam that comes in contact will easily adhere to it, especially if that foam is stationary.
The solution is to prevent these “seeds” from forming…the means for which is the subject of this article. -
Water: A second soft obstruction is water. When flowing water meets water from another source turbulence ensues - add air and foam is created.
Depending upon the flow dynamics, the flow of either source can slow down which can also contribute to additional foam creation.
To minimize this obstruction, the same design criteria as illustrated for a closed pipe or an open trench are recommended. -
Debris: Another obstruction classified as “soft” is debris. Food processing debris often collects in flumes, especially in drains.
This problem is usually alleviated by increasing the speed of the water flowing in the drain. Where possible the pitch is increased.
Other means include the insertion of a high impact nozzle directing water (preferably re-cycled water) toward the debris in the direction of the water flow.
- Foam: One type of soft obstruction is foam itself. Foam deposits become “seeds” for foam growth. Foam that comes in contact will easily adhere to it, especially if that foam is stationary.
Drain Covers
Drain covers can help keep foam down. They can be used for localized foaming areas and to direct foam to other areas for subsequent treatment.
Several materials are available for this purpose including polyvinyl chloride, urethane, and silicone-based materials.
Anti-Foam Distribution System
It is common throughout the food processing industry to inject anti-foam chemicals into one location of a closed loop water transport system. This loop usually consists of several potential foaming areas, i.e., multiple tanks, flumes, wash tables, starch recovery areas, etc.
Quite often the amount of anti-foam injected into each loop is controlled at a central location where the anti-foam and pumps are located.
While such a distribution system seems to be operationally efficient, it overuses defoamers and therefore wastes money.
There are several reasons for this:
- First, the anti-foam needs for each area on the loop will vary, which necessarily means that chemicals are being wasted - enough for one area is overkill for other areas.
- Second, anti-foam is also wasted because the effectiveness of the chemicals diminishes as it moves away from the injection point.
This is due to the dilution of the anti-foam chemicals by the large volume of water in the loop, the adherence of the anti-foam chemicals to product within the loop, and the performance degradation of anti-foam over time.
“Put the medicine where the pain is.”
Conclusion
Making reasonable modifications of the physical plant of existing food processing facilities and/or by incorporating these modifications into the design for new facilities will significantly reduce the expenses associated with using anti-foam chemicals.
Moreover, by combining these modifications with the recently available non-chemical means for foam destruction, chemical costs will dwindle…possibly to zero.
Search