Hydrolyzer

an apparatus for conducting the hydrolysis reaction in starch. It may have intermittent or continuous action. The former type of hydrolyzer is divided in turn into apparatus operating at atmospheric pressure (cooking vats) and at increased pressure (convetors).

In a cooking vat, water and acid are brought to a vigorous boil, and starch milk is fed into the vat from a measuring tank. The hydrolysis (saccharification) of the starch occurs simultaneously with evaporation of the syrup. The cooking and saccharification lasts 4-4.5 hours. In convetors the hydrolysis is carried out at high pressures and temperatures and lasts only 18-20 minutes.

Continuous hydrolysis has a number of advantages: it is a continuous process that makes possible the regulation of saccharification and consequently the improvement of the syrup; there is more uniform use of steam; and fuel consumption is cut. All the processes proceed simultaneously over various parts of the starch milk, which passes continuously and successively from one zone to another. Such a hydrolyzer consists of saccharifiers and a tubular five-section heater. The starch is converted to paste in the heater, and the paste is heated to the saccharification temperature (about 145° C). The syrup then passes into two saccharifiers that are located in series, in which the saccharification is completed. The hydrolysis lasts 8-10 minutes.