| 摘要 |
A method and apparatus for use in producing sugars from starch-bearing grains are disclosed which yield cooked, gelatinized products capable of short-time enzymatic conversion to sugars, particularly sugars subject to fermentation to alcohol. The method and apparatus involves the through-soaking of the starch-bearing material with water, and the cooking and gelatinization of the water-soaked material in its passage through the barrel of an extrusion cooker. The structure of the cooker is such that in the barrel water separates from the material being worked, the separated cooked, gelatinized starch material being extruded from the barrel through an extrusion die and the separated water being discharged through an additional outlet conduit in the barrel. The high production rates afforded through use of this extrusion equipment with high-moisture grains, and the short conversion time of the resultant products, is particularly advantageous for economical alcohol manufacture, both for alcoholic beverages and for use as fuel. Preferably, whole or cracked starch-bearing grain is presoaked in an excess of water to a substantial moisture level, and the resultant slurry is fed to the specialised extruder. In the extruder the water is at least partially separated and carried from the process, and the grain is highly cooked and gelatinized for subsequent conversion. The overall apparatus preferably includes presoak tanks for the grain, a grain-conveying feeder, an extrusion cooker, and enzyme conversion tanks; the apparatus is advantageously sized for batch-continuous operations to produce a continuous flow of sugars. Coversion times for the gelatinized starches are low, less than about 45 minutes, and moisture and extrusion conditions can be altered to further lower sugar conversion time. |
