Abstract: A refrigerated display case having an ambient air automatic defrost system and a method of operating such a case. The display case has an access opening in one wall for enabling products within the display section to be removed. The access opening can be either in the top of front wall of the display case. At least one air conduit extends in an approximately C-shaped formation around the display case. The air conduit has openings at both ends, with such openings being located on opposite sides of the access opening. Arranged within the air conduit is at least one reversible fan and a set of refrigeration coils. During a refrigeration cycle the fan circulates air through the air conduit in a first direction towards the refrigeration coils. When frost buildup within the display case has reached a certain level, the system is switched to a defrost cycle. During the defrost cycle, the fan circulates in the opposite direction through the air conduit and draws in ambient air from outside of the display case.

Abstract: A refrigerated display case having a defrost means which combines the supply of hot refrigerant gas to the refrigeration coils with the supply of ambient air in order to provide defrost action during a defrost cycle. The ambient air band is taken into and propelled out of the air conduit in a manner to prevent ambient air from being forced into the product display space in order to avoid thawing of the stored refrigerated products. The defrost air is ejected away from the access opening in order to allow a cold air layer to remain on top of stored products in an open top case. In front cases, a defrost air band is established across the access opening to form a protective air curtain in order to exclude the contacting of the stored products with high temperature and moist ambient air. The ambient air band is unidirectional during the entire defrost cycle.

Abstract: A well type open top refrigerated display case has a primary air conduit extending around the cabinet and main fans for circulating air through the primary conduit and across the open top of the cabinet in the form of an air curtain. Defrost fans are mounted in the case to draw ambient air from above the refrigerated display case into an upper portion of the primary conduit at a higher pressure than the air pressure in the region of the open top. Defrost control means are provided for energizing the defrost fans at the start of a defrost cycle to propel a portion of the higher pressure ambient air out of the primary conduit through an air opening to collide with an air curtain flowing across the open top, the flow of the air curtain being thereby reversed and caused to flow over the top of and outside the display case. A further portion of ambient air is drawn downwardly by the main fans to flow through the primary conduit and assist in defrosting the coils.

Abstract: A closed circuit refrigeration system includes a compressor, a remote condenser connected to the output of the compressor, and one or more evaporators coupled within the system. A hot gas defrost system is included to rapidly obtain a high operating defrost gas pressure upon the initiation of a defrost cycle and to thereafter maintain an adequate pressure for hot gas defrosting of the evaporators. The hot gas defrost system includes a differential pressure regulated valve which closes the compressor discharge line to shunt the hot gas discharge directly into a hot gas defrost manifold. The differential valve is controlled by a defrost control means. The refrigeration system can also include a receiver tank and a by-pass conduit for shunting refrigerant liquid through the by-pass conduit rather than through the receiver tank depending upon operating conditions. A method of operating a closed circuit refrigeration system with the above features is set forth.

Abstract: An automatically operated flexible barrier cover for the access openings of refrigerated display cabinets. The barrier cover limits the contact between the refrigerated air within the cabinet and the ambient air. The barrier cover can be moved over the access opening during non-customer use time periods when the retail food outlet is closed. The barrier cover can be arranged as a unitary assembly which can be manufactured and sold separately from the display cabinet as a retrofit device to effect energy savings.The flexible barrier cover can be stored in a reeled-up position or can be arranged as a folded flexible barrier which can be fanned out across the access opening. Various traction means are provided for moving the flexible barrier across the access opening.

Abstract: A refrigerated display case having a display space and an access opening, reversible fans for circulating air through an inner air conduit and across the access opening between a first outlet and a first inlet in a refrigeration mode to establish a primary air band; a second set of fans for circulating air through a second air conduit and across the access opening adjacent to and outwardly of the inner primary air band between a second outlet and second inlet to establish a secondary air band; and defrost cycle control means for reversing the air flow direction of the primary air band during a defrost cycle while maintaining the air flow direction of the second air band continuously in the same direction during both refrigeration and defrost cycles.

Abstract: An open top refrigerated display case having mechanisms for establishing an inner refrigerated air band encircling the display portion of the case and an outer air band also encircling the display portion and being positioned outside of the inner air band. An inner air conduit passes around the side and bottom walls of the cabinet of the display case and has an outlet opening at one end of the opening in the top of the cabinet and an inlet opening at the other end of the top opening in the cabinet. A fan circulates air through this inner air conduit with the air leaving the outlet opening and being directed toward and received by the inlet opening of the conduit, thereby establishing an inner air band along with an inner air curtain across the opening in the top of the cabinet. An evaporator coil arranged within the inner air conduit serves to refrigerate the air passing along the inner air band during a refrigeration cycle of operation.

Abstract: An improvement in refrigeration assemblies for use in conjunction with cooler structures in which food products are preserved in which an assembly of unitary, modular construction is utilized to selectively provide the refrigeration of the air mass. The assembly can be air defrosted by arranging for the flow through of ambient air to defrost the evaporator coils. At the same time, the flow of ambient air can be blocked against entry into the refrigerated air mass by the use of movable baffles. Cover gates are arranged on the assembly to permit the through flow of ambient air during the defrost cycle of operation.The refrigeration assemblies can be employed for retrofitting and on an interchangeable basis for structures to be refrigerated.

Abstract: An island refrigerated display case can be constructed so as to in effect constitute to back-to-back display cases that can be arranged as a separate aisle within a supermarket. Such an island refrigerated display case has two interior display spaces separated by a partition wall with each display space having its own access opening so as to enable refrigerated products to be removed from that portion of the case. Encircling each of the interior display spaces is an associated refrigeration air conduit. Each of the refrigeration air conduits has an inlet and outlet opening positioned so as to direct air across the corresponding access opening for the interior display space. Thus during the refrigeration cycle of operation, a refrigerated air curtain is formed between the corresponding outer wall and the center partition wall so as to extend across the associated access opening. The portions of the refrigeration air conduits that extend through the partition wall can be joined so as to form a single chamber.

Abstract: A refrigerated display case for displaying refrigerated products. The display case is formed in a cabinet that has an interior area for holding the refrigerated products. The cabinet has an access opening for enabling access to the refrigerated products. A first air conduit extends around the cabinet and has inlet and outlet air openings for directing air across the access opening in the cabinet. During a refrigeration cycle of operation, the air traveling through the first air conduit is refrigerated by a set of evaporator coils. A second air conduit extends partially around the cabinet along a path lying outwardly of the first air conduit. The second air conduit has an outlet opening positioned adjacent to the outlet opening of the first air conduit. During the refrigeration cycle, partially cooled air is emitted from the outlet opening of the second air conduit along a path across the access opening of the cabinet but lying outwardly of the air emitted from the outlet opening of the first air conduit.

Abstract: A low temperature refrigerant gas heater system for warming structural parts of refrigerated display cabinets sufficiently to prevent the formation of moisture condensate. A desuperheating means is provided for an auxiliary gas flow line taken off from a primary refrigeration circuit in order to lower the temperature of a portion of the refrigerant gas flow to within the range of about 80.degree. F. to 130.degree. F. for this purpose. The auxiliary gas have pressure-temperature-enthalpy conditions located in the superheated region or the saturation envelope area of a pressure-enthalpy diagram within these temperature limits. The use of low temperature refrigerant gas in the auxiliary flow line avoids heater line warping and buckling and customer inconvenience and discomfort problems which are incurred by use of high temperature compressor refrigerant gas.

Abstract: A refrigeration system having an increasing efficiency of operation and reduction in power consumption. Low head pressure and subcooling the liquid refrigerant emitted from the remote condenser, the efficiency of operation of the compressor of the refrigeration system can be substantially increased. The particular type of refrigeration system of concern generally includes a compressor for compressing a gaseous refrigerant, a condenser for condensing the gaseous refrigerant and subcooling the liquid refrigerant, a receiver for receiving the liquid and a plurality of display cases having evaporators for evaporating the liquid refrigerant. The gaseous refrigerant passing through the condenser is first condensed into a liquid at a condensing temperature of approximately 10.degree. to 25.degree. F. above a preselected cooling temperature. The condensed liquid is then subcooled to the preselected cooling temperature which should be preferably either approximately 50.degree. F.

Abstract: A multiband refrigerated display case having: an outer cabinet, an inner cabinet having an open product display space therein, and a divider between the inner and outer cabinets for dividing the space between the cabinets into adjacent first and second conduits. The divider comprises a first relatively fixed bottom panel member and a second removable panel member. The first bottom panel member has a U-shaped region for loosely receiving one end portion of the second panel member. Support legs are located on the underside of the second panel member for supporting the second panel member on the bottom portion of the outer cabinet in spaced relation thereto. Inlet grill means are loosely supported on the second panel in a position to cover the first and second conduit inlets; and a removable bottom shelf defining the bottom of the inner cabinet and display space is loosely supported on the removable second panel.

Abstract: An open top refrigerated display case having an ambient air defrost system and a method of operating such display case, at least one air conduit extends in a U-shaped formation along opposing side walls and a bottom wall of the refrigerated display case. Each of the air conduits has an opening at both ends with such openings being located at upper portions of the side walls and in alignment so as to direct air across the access opening for recirculation through the air conduit during a refrigeration cycle of operation. Arranged within the primary air conduit is a set of refrigeration coils and at least one reversible fan for circulating air through such air conduit. During a refrigeration cycle of operation, the fan circulates air through the air conduit in a first direction through the refrigeration coils. During a defrost cycle of operation, the fan circulates air through the air conduit in the opposite direction and draws in ambient air from outside of the display case.

Abstract: An improved refrigerated merchandiser cabinet for food products storage and displaying which is equipped with both transparent barrier doors and an air defrost system to improve the energy efficiency. The barrier doors are openable for product entry and customer usage as well as by an air defrost system which creates a gap between the barrier door and the covered access opening to permit flow-through of ambient air for use during the defrost cycle. Operation of the refrigerated cabinet with either a single or multiple air bands during a refrigeration cycle is provided for. During the defrost cycle a number of ambient air flow pattern can be employed, including the use of an auxiliary air fan. Reversal of the air band flow pattern during a defrost cycle is provided for. The method of operating the improved refrigeration display cabinet is also included.

Abstract: An improvement in open front refrigerated cabinets for food product storage and displaying in which transparent barrier doors and an air defrost system are provided for improving the energy efficiency. Barrier doors and an air defrost system can be retrofitted onto an open front refrigerated display case in order to permit operation of the cabinet with lower energy consumption. The air defrost system selectively creates a gap between the barrier doors and the associated access opening in order to provide for through-flow of ambient air during a defrost cycle. Open front cabinets having either single or multiple circulated air bands can be improved with this invention. The method of retrofitting such cabinets and the method of operations thereof is also included.

Abstract: A door operating mechanism for use with refrigerated display cases in which provision is made for one or more circulated air bands and an air defrost means. The door operating mechanism functions to selectively create a gap between the barrier door and the associated access opening of the case to carry out defrosting and to also permit the gap to be closed by the application of outside force. A motion take-up means is provided within the door operating mechanism to permit closing of a door through the operation of a flexing means which is preferably a compression spring. Temporary closing of the door gap by customers and employees is operatively provided for by the door operating mechanism.

Abstract: A refrigeration system having an increased efficiency of operation and reduction in power consumption. Low head pressure and subcooling the liquid refrigerant emitted from the remote condenser, the efficiency of operation of the compressor of the refrigeration system can be substantially increased. The particular type of refrigeration system of concern generally includes a compressor for compressing a gaseous refrigerant, a condenser for condensing the gaseous refrigerant and subcooling the liquid refrigerant, a receiver for receiving the liquid and a plurality of display cases having evaporators for evaporating the liquid refrigerant. The gaseous refrigerant passing through the condenser is first condensed into a liquid at a condensing temperature of approximately 10.degree. to 25.degree. F. above a preselected cooling temperature. The condensed liquid is then subcooled to the preselected cooling temperature which should be preferably either approximately 50.degree. F.

Abstract: An energy efficient refrigerated display cabinet having glass barrier doors and one or more guard air bands to protect the primary refrigerated air band. A single guard air band is circulated about the primary refrigerated air band in order to protect the same from contact with the inner walls of the cabinet or the ambient air upon opening of the barrier doors. The cabinet can be provided with an air defrost system in which ambient air is taken in through ports in the cabinet which are selectively closed by gates or through a gap between the barrier doors and the associated access opening. An ambient air band can also be provided for circulation across the outer surface of the barrier doors in order to slightly raise the heat transfer into the glass panes in order to aid reduction of moisture condensate formation on the glass panes.

Abstract: A refrigerated display case comprising an outer cabinet having a bottom portion which slopes downwardly to form a drain region for collecting fluid material by gravity flow and a product display space within and spaced from the outer cabinet; one or more circulation conduits having an outlet opening and inlet opening on opposite sides of the cabinet access opening are defined between the outer cabinet and the walls of the display space. The conduits are further defined by a first relatively fixed bottom panel member and a second removable panel member. One end of the second panel member is loosely supported on the first bottom panel member. Support means are provided for loosely supporting the second panel member on the bottom portion of the cabinet in spaced relation thereto. A removable bottom shelf defines the bottom of the display space and is loosely supported above and in spaced relation to the second panel member.