While Berg was able to start with a standard product, specific modifications were necessary to suit the juice products to be processed at Sepallo Foods. For example, because the juice product would be in direct contact with the icemaker, daily cleaning and sanitation were paramount concerns. The machine would require daily flushing of the distribution lines and contact surfaces with high-pressure washers and sanitizing agents.
concern was the ability of the juice to flow through the distribution lines and
coat the freezing surfaces (evaporators) with the juice to produce frozen
fragments of “juice ice,” which would be mobilized easily at a later time for
further processing. A third concern was whether the icemaker could freeze a
product with such a high level of solids, and to what extent the icemaker could
maintain a consistent concentration of juice, both throughout the frozen nugget
and from batch to batch.
Berg had not previously frozen a
product with so much particulate matter using its shell icemaker machine, so
the company asked Sepallo to deliver a usable sample of the product to run
through a conventional unit. From those tests, Berg would be able to determine
what modifications would be required in the final solution.
pure water freezes first in the ice-making process, Berg was concerned that the
juice solids would wash off the tubes to concentrate in the recirculation tank
(as occurs when ice cubes are formed). The company also was concerned that the
juice product would not freeze well to the tube surface and would result in producing
juice slush rather than a hard frozen juice nugget. To address the preliminary
concerns about the juice product, only a few modifications were required to
prepare the conventional icemaker for the test. One involved opening the
distribution nozzles to allow the solids to pass through and coat the tubes
evenly with juice. The other was to ensure that there was ample refrigeration
capacity. The presence of an abundance of solids in the juice would mean that
the freeze point of the juice liquid would be lower than pure water. Berg
needed to ensure that the tube surface would get cold enough so that the liquid
and solids would freeze as one homogeneous product on the evaporator tubes,
leaving little opportunity for the solids to wash off.
some minor adjustments with the process timing controls, Berg was able to
accomplish the desired results. The concentration of juice solids remained
practically the same as the liquid juice supplied to the ice machine.
Additionally, the juice was hard frozen into manageable nuggets that were
Process Considerations for the Modified Icemaker
January 7, 2008