GB991125A - Means for maintaining a controlled atmosphere within a space having an open side - Google Patents

Abstract

991,125. Refrigerators; air curtains. CHICAGO STOCK YARD TURBO REFRIGERATING CO. Jan. 30, 1962 [Feb. 27, 1961], No. 3503/62. Headings F4H and F4V. A nozzle assembly for maintaining air curtains of different characteristics across the open side of an otherwise enclosed space, comprises side by side nozzles each extending across one edge of the open side and each being subdivided, by a honeycomb section or by unequally spaced vanes extending continuously across the nozzle, into separate passages which align the air streams passing through them to form air curtains of substantially laminar flow. As shown, Figs. 1 and 2, two nozzles with their respective supply ducts 16, 18 are separated by a common wall 20 and have across their exits a series of parallel slats 12 spaced closer together at the outer sides of the nozzles. The lengths of the resulting passages 14 should be at least ¢ inch, and preferably 2 inches, and the vanes should give a total blockage of less than 25%, and preferably less than 10% of the gross nozzle area. Honeycomb may replace the vanes 12. The flow velocity and duct size should be such as to provide laminar flow. Fig. 3 shows nozzles in which a honeycomb section 53 is preceded by a section in which the flow in each nozzle is divided by thin walls 46, 48 offset from the nozzle centre into a main inner portion and a small outer portion, the latter including additional vanes or honeycombs 50. In Fig. 4, slat or honeycomb assemblies 64, 66 deflect the air streams through a right angle and form nozzle exits. The leading edges of the vanes lie along a curved line so arranged that less air is received by the outer sections of the nozzles than by the inner sections. In a refrigerated display cabinet, Fig. 6, air drawn through an evaporator 107 by a fan 108 passes through the passage 114 behind the storage compartment 105 and leaves the nozzle end of passage 116 to form a refrigerated inner air curtain 128 passing upward across the open front of the cabinet to enter a passage 118 behind a lip 130, and pass back to the evaporator. Ambient air is drawn through louvres 123 by a fan 122 and leaves the nozzle end of a passage 119 to form a guard curtain outside the refrigerated air curtain. The air of the guard curtain returns to atmosphere. U.S.A. Specification 2,862,369 is referred to.