The present invention relates generally to a refrigerated cold box and more particularly to a method increasing the efficiency of the cold box.
Refrigerated cold box containers are well known in the art. However, when used in situations where they are remotely powered, they often too inefficient such that power is wasted to maintain freezing temperatures. Energy generated by the sun or stored in batteries needs to be used very efficiently in view of the high duty cycle of the cold box. Hence, the cold box must be as thermally efficient as possible.
The accompanying figures, where like reference numerals refer to identical or functionally similar elements throughout the separate views and which together with the detailed description below are incorporated in and form part of the specification, serve to further illustrate various embodiments and to explain various principles and advantages all in accordance with the present invention.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
Before describing in detail embodiments that are in accordance with the present invention, it should be observed that the embodiments reside primarily in combinations of method steps and apparatus components related to a method for increasing the efficiency of a refrigerated cold box. Accordingly, the apparatus components and method steps have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.
In this document, relational terms such as first and second, top and bottom, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms “comprises,” “comprising,” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by “comprises . . . a” does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.
Once the c-channel is installed, foam is then sprayed to all interior surfaces until a desired thickness and R value is achieved 121. A c-channel is then added to the doors and filled with foam insulation 123. A door seal gasket is added to the c-channel 125. Strip curtains are then added 127 and the interior bottom of the container is insulated 129. The exterior of the box can then be painted with ceramic paint 131 or the like and this process is repeated with the next container as necessary 133.
Generally, the amount of insulation needed in the cold box is determined by the temperature of refrigeration required. Other important factors include the airflow which must flow around the refrigerated contents within the box. To achieve airflow, air chutes is generally recommended, especially in longer trailers or in circumstances where constant temperature is desired throughout the cold box. When repurposing the cold box for use in solar powered application, those skilled in the art will recognize that insulation must be adequate on each of the walls, ceiling, floors and doors. The heat transport constant, referred to as “Ua value”, is a measure of the trailer's thermal efficiency where the higher the Ua number, the more refrigeration will be required.
Over time, insulation will degrade, crumble and absorb moisture, etc. This allows heat and cold will move more easily from outside and inside the trailer. Hence, when repurposing a cold box, it is wise to specify some additional reserve capacity allowing for this degradation. Moreover, the outer body color of the cold box can affect internal temperature such that the darker cold box surface, the more of the sun's heat will be absorbed and the more cooling capacity will be required to maintain temperature in warmer climates. Swing doors generally seal more completely than roll-up doors. Side doors can add delivery convenience, but introduce more openings through which cooled air will be lost. The cold box flooring typically will include channels that promote airflow underneath the cargo, as opposed to a flat or “diamond plate” type floor. Finally, a corrugated metal skin can be placed on the outside surface of the box.
In the foregoing specification, specific embodiments of the present invention have been described. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the present invention as set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of present invention. The benefits, advantages, solutions to problems, and any element(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential features or elements of any or all the claims. The invention is defined solely by the appended claims including any amendments made during the pendency of this application and all equivalents of those claims as issued.
Number | Date | Country | |
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20190030661 A1 | Jan 2019 | US |
Number | Date | Country | |
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62317176 | Apr 2016 | US |
Number | Date | Country | |
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Parent | PCT/US2017/025716 | Apr 2017 | US |
Child | 16148729 | US |