Auger type ice flaking machine with enhanced heat transfer capacity

Abstract

An auger type ice flaking machine has an evaporator section defined in part by a vertically oriented flaker barrel with closed upper and lower ends, and a knurled longitudinally intermediate exterior side surface positioned within an annular hollow jacket structure externally and coaxially mounted on the barrel and having an outlet opening positioned adjacent its upper end and communicating with the accumulator portion of an associated refrigeration circuit. Spirally wrapped tightly around the knurled surface is a coiled length of refrigerant tubing having an open lower end, and an upper end connected to the outlet of the expansion valve portion of the refrigeration circuit, adjacent coils of the tubing being longitudinally spaced apart. During operation of the machine, refrigerant is flowed downwardly through the tubing, into the jacket interior, and then upwardly through the jacket and outwardly through its outlet opening. This causes water flowed into the barrel to freeze in a thin ice layer on its interior side surface. A motor-driven auger positioned within the barrel continuously scrapes the ice layer and forces the resulting flake ice upwardly within the barrel and outwardly through a discharge opening communicating with an upper interior end portion thereof. The knurled barrel surface advantageously functions to significantly enhance the barrel-to-refrigerant heat transfer rate, thereby substantially increasing the freezing capacity of the evaporator section without the necessity of increasing its physical size.