Development of equipment for the drying of pectin

Abstract

As we know, pectin is used in the production of confectionaries (marmalades, jams), fruit beverages, juices, dairy products, etc. Pectin possesses valuable biological properties, the most familiar of which is the action that renders lead and other toxic metals harmless when they enter organisms. The All-Union Design, Planning, and Scientific--Research Institute of Chemical Machinery has developed drying apparatus for pectin, the initial raw materials for which are apple residues, citrus rinds, sugar-beet presses, etc. In the process of preparing initial data and technical knowledge, we inspected the existing production, and accumulated information on apparatus tbr the drying of pectin and experiments on laboratory drying apparatus. Analysis of the data obtained indicated the following: the driers and apparatus currently in service in our country fail to satisfy requirements relative to power, safety engineering, ergonomics, and economics. The driers and apparatus utilized abroad cannot be adopted for equipping domestic plants, since there are differences in the properties of the product being dried, and it is impossible to produce positive results. It was established that use of a two-stage drying apparatus with a closed cycle for the heat-transfer medium is rational. The All-Union Design, Planning, and Scientific--Research Institute of Chemical Machinery has developed two apparatus intended for different production lines for the manufacture of pectin. This paper presents the resuIts of a study of the drying of pectin obtained from citrus residues in accordance with the technology developed by the Nektar Scientific--Production Union (Kishinev). These data were used to build driers required for the fitting out of the pectin-production line developed by the Ukrainian Scientific--Research Institute of Chemical Machinery. Pectin is a light-beige dry powder, which, when dried, can form fluffy lightweight agglomerates, ks basic characteristics are as follows: initial and final moisture contents of 70 and N 10%, respectively; wet and dry masses (with compaction) of 250-300 and 230-340 kg/m 3, respectively; pectin dust is explosive when the aerosol content in the air is 27-45 g/m3; the heat capacity of the dry product is 1.6 kJ/(kg.deg); and, the maxinmm allowable heating temperature is 60~