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GEL WETTING METHOD Disclosure Number: IPCOM000033281D
Publication Date: 2004-Dec-03

Publishing Venue

The Prior Art Database


Dry gelatin is produced in the form of hollow noodles, which tend to float when added to a kettle in the traditional method of filling the kettle with water then dumping the dry gel on top of the water. When large quantities of dry gel are added in this traditional way, the gelatin will form a floating mound of gel that remains dry. The bottom of this floating gel mound is wet and swollen with water, and forms a sticky, tough layer or skin that prohibits further water penetration into the gel mound. If left undisturbed, this gel mound may continue to have dry portions within it for an indefinite period of time. If a mixer induces sufficient flow, this floating gel mound may be pulled beneath the surface of the liquid. However, the sticky layer of swollen gel on the bottom of the mound may hold intact the submerged gel and thus prevent dispersal and dissolution of all of the gel. The action of the mixer may pull an excessive quantity of air into the liquid, in addition to the gel mound. The end result is unacceptably high levels of entrained air and possibly some remaining pockets of dry gel encased in a tough skin of swollen gel (aka. "gel balls"). The root cause of these problems is insufficient wetting of the dry gel. A method of pre-wetting the gel with water has proven to be successful in avoiding these problems. This method involves adding the gelatin and water simultaneously rather than water followed by gelatin. The primary objective is to wet all of the gelatin as it is added to the kettle. Preferrably, the gel wetting is done immediately before the gelatin enters the kettle and in a continuous manner with steady feed rates of dry gel and water. A key to avoiding high levels of entrained air is to avoid mechanical shearing of the mixed stream while this stream contains a large volume of incorporated air. The air must be allowed to escape before the mixture is subjected to high shear. Otherwise the shearing action will emulsify the air into tiny bubbles that rise very slowly, making natural deaeration time consuming. There are many commercially available systems for wetting and dispersing dry materials, like dry gelatin, into liquid streams. A washdown style feed hopper (similar to those sold by Elmridge Jet Apparatus) is a conical funnel with a series of nozzles near the top that produce a flowing water film on the inside surface of the hopper. The dry gel is delivered at a steady rate directly onto this water film. The gelatin is continuously wetted and carried away by the flowing water. The wet gelatin flows out through the bottom of the hopper and falls into a kettle below. The majority of the air flowing with the gel and water through the hopper escapes naturally as the wet gel collects in the bottom of the kettle. This method has been used to successfully wet and completely dissolve dry gelatin with water at mixture ratios up to 50% gelatin by weight. This method can be used to aid in dispersal of any dry bulk material (powder, granular, etc.) into any liquid, but it is particularly beneficial when a dry bulk material requires excessive agitation to be sufficiently dispersed in a liquid using the traditional dumping method described above.