Abstract:
An active temperature controlled modular shipping container may be in the active mode during flight. The container is also desirable for use in overland shipping operations as it provides accurate temperature control superior to known systems during transportation. The container can maintain a fixed temperature within 2° C. in ambient temperatures ranging from −20° C. to 49° C., using an integrated forced-air convection system for heating and cooling the cargo space of the container. The preferred embodiment of the container operates on rechargeable batteries and can maintain the selected temperature for at least 72 hours without recharging.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    Field of the Invention 
         [0002]    The subject invention is generally related to refrigerated/heated climate control shipping containers and is specifically directed to self-contained modular refrigerated/heated shipping containers capable of maintaining closely controlled temperatures for extended periods of time. 
         [0003]    Discussion of the Prior Art 
         [0004]    There is a compelling public interest in transportation of biomedical materials and other temperature sensitive materials both overland and by air. Typically, one of the drawbacks to these types of shipments is the inability to assure proper climate control during an extended period of time during transit and warehousing. A system having the ability to control the climate, particularly temperature, is essential in order to assure proper maintenance and viability of the materials. 
         [0005]    Temperature controlled shipping containers are part of a comprehensive cold chain which controls and documents the temperature of a product through its entire distribution cycle. When selecting a temperature controlled shipping container for a specific cargo, several factors need to be considered: the sensitivity of the product to temperatures (high and low) and to time at temperature, the specific distribution system being used, the expected (and worst case) time and temperatures, regulatory requirements, and the specific combination of packaging components and materials being used. 
         [0006]    Typically, a temperature controlled shipping container is an intermodal container used in freight transport for the transportation of temperature sensitive cargo. It is distinguishable from a refrigerated trailer (reefer) in that the container is self-contained with the cooling source carried in the container, whereas the reefer has an integral refrigeration unit for cooling all contents of the trailer and is typically powered by the diesel generator (or similar power supply) carried by the truck. 
         [0007]    Historically, temperature controlled containers fall into two categories, passive and active. An example of a passive container is the cryogenic cooling system, often referred to as total loss refrigeration, in which a source of cold air is provided by an element such as, by way of example, frozen carbon dioxide or liquid nitrogen. The cryogenically frozen gas slowly evaporates, and thus cools the container and is vented from it. The container is cooled for as long as there is frozen gas available in the system. The temperature is regulated by a thermostatically controlled electric fan. 
         [0008]    Active refrigerated containers utilize powered cooling systems. The level of reliability for valuable, temperature-sensitive, or hazardous cargo typically can only be achieved using containers with active cooling systems. There are numerous commercially available battery-powered systems in use today. However, in most cases the systems do not have the capability of assuring temperature control over an extended period, typically up to 72 hours, which is required to permit long distance shipping, particularly by air transit. This is particularly true for systems used in air transit. 
         [0009]    To date there are not any active systems meeting FAA approval unless the power system is shut down during flight. Specifically, prior art active systems must operate in a passive mode during flight. 
       SUMMARY OF THE INVENTION 
       [0010]    The subject invention is directed to an active temperature controlled modular shipping container that meets FAA standards and may be in the active mode during flight. The system has a self-contained power supply which does not interfere with FAA communication regulations. The container is also desirable for use in overland shipping operations as it provides accurate temperature control superior to known systems during transportation, and can be shipped in a non-temperature controlled cargo space. 
         [0011]    The self-powered, palletized shipping container of the preferred embodiment utilizes a high-efficiency compression cooling system when the ambient temperature is warmer than the desired temperature for the payload and an electric heating element to maintain temperature when the ambient temperature is below the desired temperature of the payload. High performance insulation in the sidewall panels, door and ceiling are of a thin wall construction, maximizing the cargo space inside the container. 
         [0012]    The container heating and cooling system operates autonomously on rechargeable batteries which are rechargeable at a standard 115/230 VAC outlet or a 24 VDC supply. 
         [0013]    The container may include as an option GPS and GSM global tracking. The temperature history of the container is collected, monitored and logged, with reporting function. The data may be downloaded on a standard flash drive, or directly to an off board computer system. Where desired, internet communication gateways are provided, permitting wireless communication with the container for both programming and monitoring the climate control. Smart phones and tablets and similar PDA&#39;s are also supported. 
         [0014]    When connected directly to an external power supply, the container will run indefinitely, without requiring recharging. In the event of power loss, the internal, rechargeable system will be automatically activated. 
         [0015]    The containers are stackable, and are palletized. 
         [0016]    In the preferred embodiment of the invention the container can maintain a fixed temperature within 2° C. in ambient temperatures ranging from −20° C. to 49° C., using an integrated forced-air convection system for heating and cooling the cargo space of the container. The preferred embodiment of the container operates on rechargeable batteries and can maintain the selected temperature for up to 72 hours without recharging. 
         [0017]    The container is defined by a rectangular box having a door at one end and the cooling system mounted in the opposite end and accessible from outside the cargo chamber. The cooling system is a condenser controlled evaporator system powered by rechargeable batteries. In the preferred embodiment the battery power supply comprises a number of 12 volt deep-cycle lead-acid batteries connected to provide 24 volt operating power of not less than 250 ampere-hours total capacity. The temperature sensors are calibrated to 0.1° C. Heaters consist of waterproof resistance heaters mounted under the evaporator coil. In the preferred embodiment the heaters have a total capacity of 150 watts at 24.1 volts and do not draw more than 8 amps peak current under full battery charge conditions. Internal fans are provided to assure air circulation in the cargo chamber. 
         [0018]    The cargo chamber is constructed to minimize heat flux between the interior of the chamber and the environment. This is achieved by utilizing a sandwich type, layered side-wall and roof construction comprising a multi-layer insulation system with minimum flow paths for transfer. A mechanical tie-through is achieved without introducing significant heat loss. Vacuum insulation panels compensate for limited wall thickness and are stacked or in multiple layers to provide redundancy and minimize thermal consequences from failure of any single panel. 
         [0019]    The floor, door and back wall insulation structures of the cargo chamber utilize dedicated heat or cooling paths for creating mechanical ties between the inner and outer structure without introducing significant heat loss. They are positioned to surround the cargo with airflow, assuring that the entire cargo area is of a common temperature. 
         [0020]    The container floor structure is adapted for permitting use of a forklift to load and unload cargo directly from the floor of the container, with the structure forming an integral component of the external air flow system. This permits stacking of the containers on all sides without restricting condenser air flow. 
         [0021]    The general air flow design of the cargo chamber incorporates fan control and thermostat control. Air flow is primarily distributed from the chamber ceiling and slots provided in the side walls and door. Return air flow is through the floor. The back wall of the cargo chamber forms the return air plenum. The evaporator coil can direct excess condensate to an integral drain or to an evaporating wick when it is essential to maintain humidity. 
         [0022]    Precision temperature control is provided by microprocessor controlled gates and valves. Integral data logging is also provided. The logging data may be accessed via wireless connectivity to cell phone, interne and satellite communication. 
         [0023]    A sealed sump is provided to permit condensation to be collected during transit and discharged at the destination. 
         [0024]    The temperature control system includes a monitor which can be read on-sight, or remotely via the Internet. The temperature can be programmed and adjusted while in transit by using the remote communications link. Continuous monitoring and logging of the climate data inside the box, including both temperature and humidity, is provided and may be downloaded either on-sight or remotely. 
         [0025]    The box may be reinforced for additional strength where desired. 
         [0026]    Typically, the box is designed to receive a cargo box which can slide into and out of the box and is of sufficient dimensions to sit tightly in the box without additional securing components. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0027]      FIG. 1  is a perspective view of the preferred embodiment of the container of the subject invention looking from the door end toward the back. 
           [0028]      FIGS. 2 a , 2 b  and 2 c    illustrate various stacking and loading configurations of the container of  FIG. 1 . 
           [0029]      FIG. 3  is a cutaway perspective view of the container of  FIG. 1 , showing the back chamber with the power supply, condenser cooling system, heating coils, and moisture collection sump. 
           [0030]      FIG. 4  is a cutaway perspective view showing the structural features of the inner and outer box of the container. 
           [0031]      FIG. 5  is a side view, with outer skin removed, showing the structure of the inner and outer box of the container. 
           [0032]      FIG. 6  is a rear view of the container, with the door removed, showing the heating/cooling/sump and power supply chamber. 
           [0033]      FIG. 7  is an enlarged fragmentary view showing the sandwiched insulation configuration. 
           [0034]      FIG. 8  is an illustration of the home screen of the control panel. 
           [0035]      FIG. 9  is an illustration of the log-in screen. 
           [0036]      FIG. 10  is an illustration of the home/default screen as it appears after log-in by an authorized user or administrator. 
           [0037]      FIG. 11  is an illustration of the alert and alarm screen. 
           [0038]      FIG. 12  is an illustration of an example of the informational screens available. 
       
    
    
     DETAILED DESCRIPTION 
       [0039]    As shown in  FIG. 1 , the container  10  of the subject invention is a box having sidewalls  11  (and an opposite wall  26 , see  FIG. 3 ) a top  12  and a bottom structure  13 . The front end  14  includes and access door  16  mounted on hinges  17  and including a locking and latching system  18 . As will be further described herein the back end  19  of the box includes an accessible chamber housing the on-board power supply, heating and cooling system and sealed sump. As shown in  FIGS. 1 and 3 , the bottom structure  13  includes a raised floor, mounted on or near the top of the bottom rails  21 ,  22 ,  23  and  24 . This permits a forklift or similar machine to lift and move the box by inserting the forks into the rail slots  25  provided in the rails  21 - 24 . Where desired, reinforcing bands  26  may be mounted on the outer structure for increasing the strength and rigidity of the box. 
         [0040]      FIGS. 2 a , 2 b  and 2 c    are illustrations of exemplary, but not exhaustive, configurations for stacking, loading and preparing the container  10 . As shown in  FIG. 2 a   , the containers are stackable, and may be positioned using a forklift (not shown) and engaging the loading slots  25  in the bottom rails.  21 - 24 . As shown in  FIG. 2 b   , the container may be loaded in a typical trailer by using a forklift (not shown) and engaging the loading slots. Other loading arrangements may be used as well, such as the end-to-end configuration of  FIG. 2 c    since the loading slots  25  are on all sides and ends of the container. 
         [0041]    The basic container structure is illustrated in  FIGS. 3-6 .  FIG. 3  shows the container  10  is perspective, looking from back to front, with the outer walls removed and exposing the operating chamber  30 . Integral racks are provided by mounting rails  32  on the outer skeleton of the container  10 . A cooling condenser  32 , and electric heating coils  34  are mounted on the lowest rack, as well as compressor  35 . A sealed sump system  37  is also located on the lowest rack. The upper two sets of racks provide support for the rechargeable battery array comprising batteries  36   a - n . A number of batteries have been removed for clarity. In the preferred embodiment the battery power supply comprises a number of 12 volt deep-cycle lead-acid batteries connected to provide 24 volt operating power of not less than 250 ampere-hours total capacity. The temperature sensors are calibrated to 0.1° C. Heaters shall consist of waterproof resistance heaters mounted under the evaporator coil. In the preferred embodiment the heaters have a total capacity of 150 watts at 24.1 volts and do not draw more than 8 amps peak current under full battery charge conditions. 
         [0042]    In the preferred embodiment of the invention, the container can maintain a fixed temperature within 2° C. in ambient temperatures ranging from −20° C. to 49° C., using an integrated forced-air convection system for heating and cooling the cargo space of the container. The preferred embodiment of the container operates on rechargeable batteries and can maintain the selected temperature for up to 72 hours without recharging. 
         [0043]    As best seen in  FIGS. 5 and 6 , the container comprises and inner box forming the cargo chamber  50  an outer box  52  spaced apart from the inner box. This provides a gap  54  between the inner box and the outer box, providing for the sandwiched insulation system between the inner and outer boxes. Air is drawn from the cargo compartment  50  of the container into the operating chamber  30  using the floor slats to provide additional air passageway, and into the condenser/heater plenum  38 , The treated air then flows back into the cargo chamber  50  under pressure via one or more fan blowers  49  (see  FIGS. 5-6 ) which distributes the air around the sidewalls and ceiling structure of the container. An isolation wall  60  separates the operating chamber  30  from the boxes  50  and  52 . An access door (not shown) is provided in the back wall  19  of the container to close the operating chamber  30  and to provide access to the chamber  30  for maintenance. 
         [0044]    The battery power supply may be connected to external power via a typical charger system  40  mounted in a sidewall of the box. In the preferred embodiment the rechargeable battery array may be charged using any external 115/130 VAC or 24 VDC source. 
         [0045]    The sump  37  collects condensate and retains it in a closed system, to be drained once the container reaches the destination where it is to be unloaded from the transport. 
         [0046]    A control panel  40  is located in a sidewall of the container and is connected to a typical electrical/electronic control module  42  for managing and controlling the system to maintain temperature inside the container at desired ranges. 
         [0047]    A skeletal frame  66  forms the outer box  52 . Inwardly of the frame  66  is a second skeletal frame  68  for forming the inner box, or cargo chamber  50 . The frames are typically constructed of rigid struts and beams, such as, by way of example, aluminum. The specific configuration and material is a matter of choice. However, in the preferred embodiment weight is taken into consideration, particularly when the containers are to be used for air transit. 
         [0048]    An enlarged, fragmentary cross-section of the insulation system in the gap between the inner box  50  and the outer box  52  is shown in  FIG. 7 . This is taken at an upper corner at the junction of top  12  and side wall. Starting at the outside and working in, a side or edge brace  70  of the sidewall  27  is secured to a top brace to a bracket  74 . In the preferred embodiment the skin  76 , such as a thin walled dibond, is secured to the braces in standard manner and comprises an outer wall for the container. A VIP (vacuum) panel  78  is mounted in contact with the skin. A first layer of rigid insulation  80  is then mounted in contact with the VIP panel  78 . Multiple layers of rigid insulation  80  may be employed, as indicated at  82 . An inner skin  84  (usually of the same material as the outer skin  76 ) is then mounted against the final layer of rigid insulation. The skeletal supports  86  for the inner box are then mounted against the inner skin  84  and the cargo chamber walls are then formed with a final skin layer  88 , also typically of the same material as the other skin layers. This sandwiched insulation system provides a high degree of insulation, typically in excess of R______, in a minimum of space. 
         [0049]      FIGS. 8-12  are examples of the information and control screens for the control module  40 . In the preferred embodiment the control panel is a touch screen. However, this should be considered as only an example. For example, a keypad input device could be used, as well as a remote input device. In additions, the system is may be controlled by any input device such as a PDA, tablet, smart phone, remote computer or similar device wirelessly via the internet. Further, as previously mentioned, GPS and GSM global positioning is available so the location of the container may be readily determined. 
         [0050]    The screen of  FIG. 8  is the home screen and is visible and access upon powering up of the system. The control module is for use at two levels of access. The first level can be accessed by any user, without password security. This will permit any user to determine the current conditions of the container, specifically temperature and or humidity, and battery life, for example. The unsecure user may also review alarms and will have access to the signal status. 
         [0051]    The second level of access is for an authorized operator with password access. This person will log in by pressing the log-in block on the screen of  FIG. 8  and progress to the log-in screen shown in  FIG. 9 . The authorized operator can then read the history, set or reset temperature parameters, turn the system on or off, as well as specific components and functions such as cooling, defrosting, and heating. 
         [0052]    As shown in  FIG. 10 , the authorized operator will be able to set temperature parameters, monitor the current cargo chamber temperature, stat and stop the system, turn on and off specific components and determine the status of the battery power system, among other functions. 
         [0053]    As shown in  FIG. 11 , when the alarm summary of the home screen of  FIG. 8  is depressed, the alarm summary screen appears, giving both access to current alarm status, and history of alarms, where desired. In the embodiment shown, to levels of alarms are incorporated in the system. On the right are alarms that will shut down the system and, therefore, place the cargo in jeopardy. On the left are operational alarms that indicate system issues which must be dealt with in order to keep the system running properly. Where desired the operational alarms may be made available to personnel not having password clearance. That is, they can determine the alarm condition, but then may have to contact authorized personnel to correct. 
         [0054]    The screen of  FIG. 12  is an informational screen showing current status. A log is also maintained of the system from power up to final power down, showing the temperature log for the entire operation, as well as other important data, including battery level, location of the container, time stamps and other desired information. This is essential when handling cargo that is temperature sensitive throughout its life. 
         [0055]    The data log may be read on screen, down loaded on a flash drive or the like, or downloaded via a plug-in hardwire connection to a laptop, PDA or the like. It may also be transmitted via the Internet to a remote location, both while in transit and when docked. 
         [0056]    While certain features and embodiments have been described in detail herein, it should be understood that the invention encompasses all modifications and enhancements within the scope and spirit of the following claims.