Refrigerated point-of-use holding cabinet

• US 8,667,807 B2
• Filed: 08/06/2012
• Issued: 03/11/2014
• Est. Priority Date: 05/19/2010
• Status: Active Grant

• Current Assignee: Marmon Foodservice Technologies Incorporated (Berkshire Hathaway Incorporated)
• Original Assignee: Prince Castle LLC (Berkshire Hathaway Incorporated)
• Inventors: Veltrop, Loren
• Primary Examiner(s): ROHRHOFF, DANIEL J
• Application Number:
  US13/567,821
• Publication Number:
  US 20120297795A1
• Time in Patent Office: 582 Days
• Field of Search: 622/52, 622/53, 623/82, 624/31, 624/41, 622/08, 622/13, 622/10
• US Class Current: 62/252
• CPC Class Codes: A47F 3/06 with movable or removable shelves or receptacles A47F3/0486 takes precedence; display racks with movable parts A47F5/0081
• CPC Class Codes: F25B 21/02 using Peltier effect; using Nernst-Ettinghausen effect
• CPC Class Codes: F25D 19/006 Thermal coupling structure or interface
• CPC Class Codes: F25D 23/003 for cooling refrigerating machinery
• CPC Class Codes: F25D 25/028 Cooled supporting means
• CPC Class Codes: F25D 2700/16 Sensors measuring the temperature of products

Abstract

A refrigerated point-of-use food holding cabinet keeps food products cold in compartments having cross sections that are substantially U-shaped. Food products are kept refrigerated using heat-absorbing, heat-exchangers thermally coupled to the U-shaped compartment. Refrigeration is provided by either a conventional reversed-Brayton cycle, one or more Peltier devices or a chilled, re-circulating liquid that does not change phase as it circulates but which is chilled by another refrigeration system, such as a conventional refrigeration system. An optional cover helps prevent food flavor transfers between compartments. Semiconductor temperature sensors and a computer effectuate temperature control.

Claims

1. A method of refrigerating food in a food holding cabinet comprised of a plurality of tray-receiving members, the method comprising the steps of:

configuring a tray-receiving member to have a substantially horizontal bottom with upper and lower surfaces, the bottom being able to support a food holding tray;

configuring the tray-receiving member to have first and second substantially vertical and opposing side walls extending upwardly from the bottom; and

,

configuring the tray-receiving member to have first and second opposing open ends through which a food holding tray can pass and be placed onto the top surface of the bottom the tray-receiving member, the substantially horizontal bottom being able to make thermal contact with a food holding tray placed on the top surface of the bottom of the tray-receiving member;

attaching a liquid phase/vapor phase heat-absorbing refrigeration coil to the lower surface of the horizontal bottom of the tray-receiving member;

providing a pressurized gaseous refrigerated working fluid to the refrigeration coil;

sensing the temperature of the tray-receiving member using a semiconductor temperature sensor mechanically and thermally coupled to the tray-receiving member and which outputs an electrical signal, corresponding to the tray-receiving member temperature; and

in response to the electrical signal performing at least one of;

actuating a refrigeration system; and

de-actuating the refrigeration system.

2. The method of claim 1 wherein the step of sensing the temperature is comprised of sensing the temperature using a transistor, which is mechanically and thermally coupled to tray-receiving member.

3. A method of refrigerating food in a food holding cabinet comprised of a tray-receiving member having a generally horizontal bottom, first and second opposing open ends and side walls extending generally vertically from the horizontal bottom to provide a generally U-shaped cross section to the tray-receiving member, the bottom of the tray-receiving member having a top side between the side walls and having an opposite bottom side, the method comprising the steps of:

placing a food holding tray having a substantially planar bottom, into the tray-receiving member through at least one of the first and second opposing open ends, so that that the top side of the bottom of the tray-receiving member is in thermal communication with the bottom of the food holding tray;

conducting heat energy from the tray-receiving member and from the food holding tray, into a pressurized gaseous working fluid flowing through a refrigeration coil attached to the bottom side of the tray-receiving member, the pressurized gaseous working fluid being from a liquid phase/vapor phase refrigeration system;

sensing the temperature of the tray-receiving member using a semiconductor temperature sensor mechanically and thermally coupled to the bottom side of the tray-receiving member, the semiconductor temperature sensor outputting an electrical signal, corresponding to the tray-receiving member bottom side temperature; and

operating a compressor for a liquid phase/vapor phase refrigeration system responsive to the electrical signal output from the semiconductor temperature sensor.

4. The method of claim 3, wherein the step of sensing the temperature of the tray-receiving member using a semiconductor temperatures sensor comprises the steps of:

measuring a voltage across a transistor; and

outputting an electrical signal corresponding to the voltage measured across the transistor.

5. The method of claim 4, wherein the step of measuring a voltage across a transistor comprises measuring a base-emitter voltage.