Jan Newsletter
VOLUME 27 NO. 1
While mixed vegetable lines and other frozen vegetable handling equipment have always been part of Gem Equipment’s product line, recently there has not been much activity with this segment. Part of this lack of activity is due to Gem’s concentration on other segments of the food processing industry and part is because capital investment by vegetable processors has not been very robust, where this company does business. A mixed vegetable line uses one station for each product being mixed. Each station consists of a tote dumper, a loose freeze breaker, and a volumetric feeder. The loose freeze breaker and volumetric feeder are each gravity fed from a 5 foot square hopper. In order to reduce damage to fragile products, the loose freeze breaker can move out of the product stream. A vibrating conveyor transfers product from the volumetric feeders to conveyors, which convey product to packaging lines. Normally, this vibrating conveyor has a section of screen to remove snow and fines from the product.
Even though controlling product mix by weight is an option, for most mixed vegetable operations, controlling the mix by volume is more than adequate. This is definitely the norm when all ingredients have a relatively similar value. When one or two ingredients have a much higher value than the rest, it may be worthwhile to take added steps to assure that each package contains the same percentage of the high value ingredient. A recent development in fillers offers a big improvement for mixes with one or two high value ingredients. Fillers are now available that can put an exact weight of a single ingredient into each package. This is an improvement on the fillers that select a few portions from several available to achieve a high degree of accuracy in the weight of product put into each package. An upgraded version of these fillers selects exact weights for each package from two streams of product. The ability to handle 2 streams of product makes it possible to compensate for an ingredient that has variations in particle sizes. When a small portion of meat is added to a mixed vegetable pack, getting the amount correct and consistent assumes greater importance. The customer who gets a short ration of meat is much more apt to complain than one who gets shorted a few peas. The filler that selects accurate weights from 2 streams of product also reduces the potential for problems caused by product stratifying during handling after mixing. Stratifying will result in a higher concentration of one ingredient in one section of the product pile, which can result in variations in the percentage of ingredients from package to package.
If you think personnel operating mixed vegetable lines have a problem maintaining accurate proportions in each package, consider the plight of personnel mixing and packaging breakfast cereal. Not only do cereal processors have to maintain the correct ratios of ingredients in each package, they also have to make sure the mix is consistent throughout the package. Cereal consumers do not like to have all the raisins in one end of the package. Several years ago, Gem Equipment manufactured a vegetable mixing system for a Project Manager, who was very proud of recruiting an engineer for the project who had spent most of his career in a cereal plant. The Project Manager noted that not only had his Project Engineer learned how keep uniform portions of ingredients in each package, he also knew how to make sure the mix was consistent throughout the package. Another interesting situation was encountered with this project. The Plant Manager wanted a system with the portions controlled by weight. After considerable discussion between the Project Manager and the Plant Manager, they decided to stick with volumetric control of the mix. After the system went to operation, it was reported that the Plant Manager was satisfied with the results achieved by volumetric feeders to determine the proportions in the final mix.