Hot Air Mixing
In order to maintain a liquid state so that products can be filled, drained, packaged etc. some potential PULSAIR customers must keep the temperatures above ambient during mixing. For instance, products such as butter are feasibly removed from IBCs or totes only when they are in a liquid state.
PULSAIR has been asked if the mixer is capable of raising a liquids temperature if the compressed air, used for mixing, is first heated. PULSAIR has conducted preliminary testing to determine if there are any advantages to injecting hot air into a tank or IBC. So far these tests have proven that the air will not impart temperature into the product. In fact, after prolonged testing, a time frame that would not be considered feasible on the production floor, we melted the air hose with no noticeable increase in liquid temperature.
These results parallel our oxidation testing in lube oils, which proved that the PULSAIR would not impart enough air to discolor or oxidize the product. These findings all lead in the same direction, that PULSAIR, while a fantastic mass mover and mixer, is a poor conductor of whatever it is carrying, i.e. heat, vapor etc.
Exploring the possibilities of mixing with hot air led us to other areas where we are making some progress. This is the area concerning food. It is acceptable to inject air into food products, provided that the air is "food grade." Air quality can be assured by understanding what it is exposed to on its way to the vessel. In a PULSAIR 5-55 Drum-Stick or 10-55 Tote-Stick the air passes through the controller's injection valve. Injection valves are lubricated with hydrocarbon grease, so they are not sanitary. This is overcome by utilizing food grade grease and therefore food grade injection valves.
Other areas of concern are the filter and regulator. The regulator issue is addressed again by using a food grade grease. The filter issue is addressed by using a Balston dairy grade filter. Other filters available in the market place can be specified so long as they are of high purity and meet food standards.
We placed the filter between a 5-55 Drum-Stick probe and the controller, thereby filtering the air after it had left the controller, but before it entered the liquid. The probe is easy to clean, however the additional volume of the filter adversely effects the intensity of the pulse. We were still able to mix the drum with this modification, however the pulse was softened and did not have the same punch as an unmodified Drum-Stick. We exchanged the Drum-Stick controller with a Tote-Stick controller and significantly improved the performance. We can now supply filters that will provide food grade air for mixing.
We believe that these two new modifications will help accelerate the food industry's acceptance of the 5-55 and 10-55. Anyone with potential customers should make them aware of these new modifications.
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