GB943083A - Liquid freezing apparatus - Google Patents

Abstract

943,083. Refrigerating; ice making. A. J. ROSS. Oct. 23, 1962 [Dec. 6, 1961], No. 40117/62. Heading F4H. In apparatus for freezing liquids, in which the liquid to be frozen is supplied to one side of a tubular freezing wall forming part of an evaporator, at least two separate passages for refrigerant flow extend along the other side of the freezing wall, the refrigerant in one passage flowing along the freezing wall in the opposite direction to the refrigerant in the other passage to provide substantially uniform cooling of the freezing wall. As shown, Fig. 2, the evaporator 11 is mounted in a chamber C formed by a cylindrical housing 10, and is immersed in the liquid to be frozen. The evaporator comprises the freezing wall 28, and an inner shell 21 having a solid upper end 22 and a flanged base 43, the interior of the shell forming a refrigerant accumulator 41 which is closed at its lower end by a cup-shaped plug 23. The shell 21 is formed with grooves 31a, 31b, 31c, 31d, Fig. 3, on its outer surface, separated by ribs 32, to provide helical refrigerant passages inside the freezing wall 28. Liquid refrigerant from a compressor type refrigeration system, not shown, reaches the evaporator through capillary tubes 18a and 18b, some passing from tube 18a through an inlet 35 into passage 31a, from this passage into passage 31b at 37, and into the accumulator chamber 41 through an outlet 39, and the rest passing from the tube 18b through an inlet 36 into passage 31d, from this passage into passage 31c at 38, and into the accumulator chamber 41 through an outlet 40. Gaseous refrigerant returns to the refrigerant compressor through a tube 19. The shell 21 is made to be an interference fit in the freezing wall 28, to seal the refrigerant passages. Ice is removed from the freezing wall and forced through an outlet 51 by a helical spring type ice remover 12 rotated by a drive unit 13 acting through a connecting sleeve 62 to which the ice remover 12 is fixed by a pin 63. The output shaft 74 of the drive unit 13 is splined to the connecting sleeve, to allow the drive unit to be lifted clear of the housing 10. The supply of liquid to be frozen is controlled by a float valve, not shown, to maintain the liquid level adjacent to top of the evaporator. In another form of the evaporator, Fig. 6, the shell 21 is replaced by helically coiled tubes 131a, 131b, 131c, 131d, arranged to form a passage layout similar to that of Fig. 3, these tubes being maintained in thermal contact with the freezing wall 128 by a soft solder 150 which can be melted by immersing the evaporator in boiling water, so that the wall 128 may be replaced without breaking the refrigerant circuit.