Testing of air leaks in controlled atmosphere containers

Abstract

A controlled atmosphere container controller for a controlled atmosphere container is provided. The controlled atmosphere container includes a cargo space for storing cargo, and the controller is configured to perform a test on air leaks in the controlled atmosphere container. The testing includes the controlled atmosphere container controller: causing a first characteristic of an atmosphere in the cargo space to have a first value; stopping causing the first characteristic to have the first value; receiving, for a period of time after the stop, a signal from a sensor configured to sense a second characteristic of the atmosphere in the cargo space, the signal representing a value of the second characteristic of the atmosphere in the cargo space during the period of time; and performing an action based on the signal to allow determination of an air leak in the controlled atmosphere container.

Description

Technical Field

[0001] The present invention relates to a controlled atmosphere container controller configured to test air leaks in a controlled atmosphere container, a method and a kit of parts for performing the test, a controlled atmosphere container including the controlled atmosphere container controller, and a vessel including the controlled atmosphere container controller or the controlled atmosphere container. Background Art

[0002] Many types of goods can be stored in containers including atmosphere control systems for controlling the atmosphere in the container. Such containers may be referred to as controlled atmosphere containers. Such controlled atmosphere containers include transportable storage units or transport units for transporting goods on container ships. These can be used to facilitate the storage and transportation of perishable items (such as fruits, vegetables, or fresh or frozen meat or fish or other items, such as medicines) in transport units. Such transport units include refrigerated containers and / or may be refrigerated trucks or trailers, and refrigerated containers may be TEU or 2-TEU containers designed to be transported on container ships, road vehicles or railway trucks. Controlled atmosphere containers also include storage units for storing and / or ripening items in warehouses (such as ripening warehouses).

[0003] Although curtains may be installed on the doors of controlled atmosphere containers in an attempt to seal the container, most controlled atmosphere containers are not completely airtight. This means that, over time, the atmosphere surrounding the controlled atmosphere container may leak into the container, and / or the controlled atmosphere in the container may leak out of the container. It is desirable to limit the rate at which air can leak into the container. If the leakage rate is too high, it may be more difficult to control the atmosphere in the container. This may reduce the efficiency of the controlled atmosphere container, and / or cause the goods transported in the container to spoil. Summary of the invention

[0004] According to a first aspect of the present invention, a controlled atmosphere container controller for a controlled atmosphere container is provided, the controlled atmosphere container comprising a cargo space for storing cargo, the controlled atmosphere container controller being configured to perform an air leakage test on the controlled atmosphere container, the test comprising the controlled atmosphere container controller: causing a first characteristic of the atmosphere in the cargo space to have a first value; stopping causing the characteristic to have the first value; receiving a signal from a sensor within a certain time period after the stopping, the sensor being configured to sense a second characteristic of the atmosphere in the cargo space, the signal representing the value of the second characteristic of the atmosphere in the cargo space during the time period; and performing an action based on the signal to allow determination of air leakage in the controlled atmosphere container.

[0005] In this way, a controlled atmosphere container controller can perform an air leak test while the controlled atmosphere container is in use, such as when the controlled atmosphere container is in transit, such as on a container ship. Thus, the test can be performed while the controlled atmosphere container is used to transport items such as perishable products in a cargo hold. The test can also be performed automatically and / or remotely, such as without the need for maintenance personnel to be present and / or providing auxiliary equipment. In this way, the container may not need to be taken out of service while the test is performed. The test can also be performed more regularly, and / or in response to a suspected air leak in the controlled atmosphere container, such as in situations where the controlled atmosphere container is unable or difficult to maintain a desired controlled atmosphere in the cargo space.

[0006] By being able to perform air leak tests when needed by the controlled atmosphere container controller, potential air leaks can be identified more quickly, while reducing downtime during which the container is unavailable. Similarly, the cost of performing the tests can be reduced or eliminated. In addition, the controlled atmosphere containers can be tested more regularly, and / or multiple controlled atmosphere containers in a group can be tested simultaneously. This can improve the efficiency of the controlled atmosphere containers and / or groups, because air leaks can be more easily identified and corrected.

[0007] It should be understood that "air leakage" can include the external atmosphere outside the cargo space and / or the controlled atmosphere container (which can be the atmosphere surrounding the controlled atmosphere container) leaking into the cargo space, such as through a gap in the controlled atmosphere container. "Air leakage" can also include the atmosphere in the cargo space leaking outside the cargo space and / or the controlled atmosphere container through such a gap. A controlled atmosphere container may not be completely airtight. Therefore, in many examples, the determination of "air leakage" herein can refer to determining that the air leakage is above an allowable air leakage threshold.

[0008] A controlled atmosphere container controller may be referred to herein as a "controller."

[0009] Optionally, the first characteristic comprises a pressure of the atmosphere in the cargo space. Optionally, the first value is different from a value of a pressure of an external atmosphere outside the cargo space. In other words, causing the first characteristic to have the first value may comprise causing the atmosphere to have a pressure different from a pressure of the external atmosphere.

[0010] Optionally, causing the atmosphere in the cargo space to have a first value includes the controller changing (such as decreasing) the pressure of the atmosphere in the cargo space. Optionally, the first value is lower than the value of the pressure of the external atmosphere. Changing the pressure of the atmosphere in the cargo space may include decreasing the pressure of the atmosphere relative to the pressure of the external atmosphere. Alternatively, the first value may be higher than the value of the pressure of the external atmosphere. In some such cases, changing the pressure of the atmosphere in the cargo space may include increasing the pressure of the atmosphere relative to the pressure of the external atmosphere.

[0011] In some examples, the controller causing the pressure of the atmosphere in the cargo space to have the first value may be performed by the controller causing the temperature of the atmosphere to have a first temperature value. In other words, the temperature of the atmosphere in the cargo space may be caused to change to cause the pressure of the atmosphere in the cargo space to change. For example, the test may include the controller causing the temperature of the atmosphere in the cargo space to decrease, such as in a cooling mode of the atmosphere control system, so as to cause a corresponding decrease in the pressure of the atmosphere in the cargo space. Similarly, the test may include the controller causing the temperature of the atmosphere to increase, such as in a heating mode of the atmosphere control system, so as to cause a corresponding increase in the pressure of the atmosphere in the cargo space.

[0012] Optionally, the first characteristic comprises a temperature of the atmosphere in the cargo space. Optionally, the first characteristic comprises a composition of the atmosphere in the cargo space, such as a level of oxygen and / or carbon dioxide in the cargo space.

[0013] It should be understood that the controller causing the first characteristic to have the first value may include the controller causing the controlled atmosphere container and / or its atmosphere control system to operate in an operating mode such as a cooling mode or a heating mode and / or a mode of controlling the composition of the atmosphere in the cargo space. This may cause the pressure and / or temperature of the atmosphere in the space to have a first value (such as a change) during the operating mode. This in turn may result in a pressure and / or temperature difference between the atmosphere in the cargo space and the external atmosphere outside the cargo space during operation of the controlled atmosphere container in the operating mode. The controller ceasing to cause the first characteristic to have the first value may include the controller ceasing to operate the controlled atmosphere in the operating mode, such as by ceasing the controlled atmosphere container to cause cooling or heating of the atmosphere in the cargo space.

[0014] Optionally, the second characteristic includes the first characteristic. For example, both the first characteristic and the second characteristic may include the pressure of the atmosphere in the cargo space. In this way, the test may include the controller causing the pressure of the atmosphere in the cargo space to have the first value, which may be performed by causing a decrease and / or increase in the pressure and / or the temperature in the cargo space as described above. The test may then include the controller ceasing to cause the pressure to have the first value. The signal received by the controller during the time period after the ceasing may then represent the value of the pressure of the atmosphere in the cargo space during the time period after the ceasing. The test may include the controller monitoring the received signal, such as monitoring a change in pressure after the ceasing. Such a change in pressure may indicate an air leak in the controlled atmosphere container.

[0015] Alternatively, the second characteristic may not include the first characteristic, and / or may be different from the first characteristic. For example, one of the first characteristic and the second characteristic may be or may include the pressure of the atmosphere, and the other of the first characteristic and the second characteristic may be or may include the composition and / or temperature of the atmosphere. This may be particularly beneficial when the cargo contains ripenable agricultural products because the level of O2 in the atmosphere during the ripening process may be reduced. In this way, a potential air leak may be detected when an external atmosphere outside the cargo space (whose O2 content is higher than the atmosphere in the cargo space) leaks into the controlled atmosphere container, thereby increasing the level of O2 in the atmosphere in the cargo space after stopping. More generally, it should be understood that each of the first characteristic and the second characteristic may be or may include any suitable characteristic described herein, which may be the same characteristic or different characteristics.

[0016] Optionally, the controlled atmosphere container controller performs an action including the controlled atmosphere container controller comparing the value of the second characteristic during the time period to the first value. For example, the action may include determining the extent to which the value of the second characteristic deviates from the first value during the time period after the stopping. If an air leak occurs, the second characteristic may deviate from the first characteristic more quickly after the stopping.

[0017] Optionally, the action includes the controller comparing the value of the second characteristic to a threshold second characteristic and / or an equilibrium characteristic. The threshold second characteristic may include a value of pressure, temperature and / or composition that a controlled atmosphere container with an acceptable air leakage rate is expected to reach after a given period of time, as will be described in more detail below. Alternatively or additionally, the threshold second characteristic and / or the equilibrium characteristic may include a value of pressure, temperature and / or composition that the controlled atmosphere container is expected to reach when "at rest" (such as when it is not operating in the above-mentioned operating mode). The equilibrium characteristic may include a value of pressure, temperature and / or composition that the controlled atmosphere container is expected to reach when it is not sealed (such as if a door of the controlled atmosphere container is opened).

[0018] The equilibrium characteristic is reached when the pressure, temperature and / or composition of the atmosphere in the cargo space is equalized with the pressure, temperature and / or composition of the external atmosphere as described above. If an air leak occurs, the atmosphere in the cargo space may reach an equilibrium state faster than when the container is sealed. The threshold second characteristic may be a value between the first characteristic and the equilibrium characteristic. This may be an intermediate value between the first characteristic and the equilibrium characteristic. Alternatively, the threshold second characteristic is any other suitable value between the first characteristic and the equilibrium characteristic. For example, the threshold second characteristic may be away from the first characteristic or the equilibrium characteristic by an amount that is less than or greater than one-third of the difference between the first characteristic and the equilibrium characteristic, or less than or greater than one-quarter of the difference. In this way, a potential air leak in the controlled atmosphere container may be detected or determined when the value of the second characteristic during the time period after the stop exceeds the threshold second characteristic, decreases below the threshold second characteristic and / or is within a tolerance range of the threshold second characteristic.

[0019] Optionally, the testing comprises the controlled atmosphere container controller receiving, during the testing, a further signal from the sensor or a further sensor, the further signal representing a further value of the second characteristic during the testing. Optionally, performing the action comprises comparing the value of the second characteristic during the time period with the further value of the second characteristic during the testing.

[0020] Optionally, the further signal is received during the time period before, at and / or after the cessation of causing the characteristic to have the first value. Optionally, the further value is a further value during the time period before, at and / or after the cessation of causing the characteristic to have the first value.

[0021] Optionally, said performing said action comprises determining a change in said value of said second characteristic during said time period. This may for example be based on comparing said value of said second characteristic during said time period with said first value and / or said further value of said second characteristic. Optionally, said performing said action comprises comparing said change in said second characteristic with a threshold change in said second characteristic.

[0022] Optionally, said performing said action comprises determining a time taken for said second characteristic to reach, exceed or decrease below said threshold second characteristic described above after said stopping. Optionally, said performing said action comprises determining a time taken for said change in said value of said second characteristic during said time period after said stopping to reach or exceed a threshold change in said value of said second characteristic. Optionally, said performing said action comprises comparing said time taken with a threshold time, which may represent an acceptable amount of time for said second characteristic to reach said threshold second characteristic. When there is an unacceptable air leak, said second characteristic may tend toward said equilibrium threshold faster than when there is no air leak or when there is an acceptable air leak. Thus, if the time taken reaches or decreases below a threshold time, a potential air leak may be identified.

[0023] Optionally, the controller performing the action comprises the controller monitoring the value of the second characteristic during a time period after the stopping, such as intermittently and / or continuously. In other words, the controller may determine the value of the second characteristic a plurality of times after the stopping, such as based on the signal and / or the further signal. The controller may then compare the second characteristic at one or more of the plurality of times with the first value, the threshold second characteristic, the equilibrium characteristic and / or the one or more further values ​​of the second characteristic.

[0024] Optionally, the action includes determining that there is or may be an air leak in the controlled atmosphere container. For example, this can be determined by the controller: the value of the second characteristic has reached, exceeded, or dropped below a threshold second characteristic; the change in the second characteristic has reached, exceeded, or dropped below a threshold change in the second characteristic; the time taken for the second characteristic to reach, exceed, or drop below a threshold second characteristic, or the time taken for the change in the second characteristic to reach, exceed, or drop below a threshold change in the second characteristic has reached, or dropped below a threshold time.

[0025] Optionally, the action includes transmitting any of the values ​​or determined qualities described above. These values ​​or determined qualities include: the first value; the value of the second characteristic during the time period; the additional value of the second characteristic; the change in the second characteristic; the time taken for the second characteristic to reach, exceed, or fall below a threshold value of the second characteristic; the time taken for the change in the second characteristic to reach or exceed the threshold change in the second characteristic; and the result of determining that there is or may be a leak in the controlled atmosphere container. The transmission can be transmitted, for example, to a user device and / or another controller, such as another controller of the controlled atmosphere container, and / or a controller of a remote control system remote from the controlled atmosphere container. This can allow a user at a remote location to take remedial action in response to a potential air leak, such as marking the container for further inspection, and / or causing the controlled atmosphere container to operate in a different manner, such as adjusting the cooling level of the atmosphere in the cargo space.

[0026] Optionally, the action includes saving any of the above-mentioned values ​​or determined qualities to a memory. These values ​​or determined qualities include: the first value; the value of the second characteristic during the time period; the additional value of the second characteristic; the change in the second characteristic; the time taken for the second characteristic to reach, exceed or fall below the threshold of the second characteristic; the time taken for the change in the second characteristic to reach or exceed the threshold change of the second characteristic; and the result of determining that there is or may be a leak in the controlled atmosphere container. The memory can be, for example, a memory of the controlled atmosphere container controller, a memory of the controlled atmosphere container, a memory of a user device and / or a memory of a remote control system remote from the controlled atmosphere container. This can allow the development of an air leak in the controlled atmosphere container to be tracked over time (such as in subsequent tests). This can allow anticipated remedial measures to be taken, such as in the event that the incidence of such air leaks is observed to increase over a short period of time. This can allow the efficiency of the controlled atmosphere container to be maintained or improved.

[0027] Optionally, the action includes displaying the first value, the value of the second characteristic during the time period, and / or the additional value of the second characteristic. For example, the display may be performed on a display of the controlled atmosphere control system, on a display of a user device, and / or on a display of a remote control system remote from the controlled atmosphere container. This may allow a user to quickly identify if there is an air leak in the controlled atmosphere container and take appropriate remedial action.

[0028] Optionally, the action includes determining a rate at which the external atmosphere leaks into the cargo space and / or a rate at which the atmosphere in the cargo space leaks out of the cargo space. The leakage rate may be determined based on a rate of change of a second characteristic (such as pressure) in the cargo space and / or based on a free volume in the cargo space. The free volume in the cargo space may be the volume of the cargo space that accommodates the atmosphere in the cargo space. That is, the free volume may be the volume of the cargo space that is not occupied by cargo or other items. Optionally, the free volume is predetermined. Optionally, the free volume is defined when the cargo space is loaded with cargo (such as by a user). Optionally, the free volume is estimated, such as based on a typical free volume of the controlled atmosphere container when loaded with cargo in use.

[0029] Optionally, the controller is configured to, upon determining that there is an air leak in the container, such as in response to a leak rate exceeding a leak rate threshold, issue a signal indicating that there is an air leak in the container. Issuing a signal indicating an air leak may include triggering an alarm or alert to alert a user (such as maintenance personnel) that there is an air leak in the controlled atmosphere container. The alert may allow the user to take remedial action in response to the determined air leak, such as stopping use of the container, and / or controlling the atmosphere in the container to compensate for the air leak. This may also improve the quality of the goods stored in the controlled atmosphere container even if an air leak occurs.

[0030] Optionally, the controlled atmosphere container controller is configured to perform the test while the controlled atmosphere container is in use, such as when ripenable agricultural products are stored or ripened in the container, such as in a ripening warehouse or during transportation of the controlled atmosphere container.

[0031] Optionally, the controlled atmosphere container controller is configured to perform the test in response to the composition of the atmosphere satisfying one or more predetermined composition criteria. The one or more predetermined composition criteria may include the level of O2 and / or CO2 reaching a corresponding O2 and / or CO2 threshold, which may be a predetermined O2 and / or CO2 threshold. This may be particularly beneficial when the cargo in the cargo space is perishable agricultural products, particularly respiring agricultural products that mature over time (such as bananas). During the respiration process, the agricultural products may change the composition of the atmosphere in the cargo space, such as consuming O2 and emitting CO2. In this way, when the agricultural products begin to respire (such as during transportation) and / or the agricultural products have reached a predetermined maturity stage, the predetermined O2 and / or CO2 threshold may be reached. This may indicate that the controlled atmosphere container is sealed and / or is operating to control the atmosphere in the cargo space, because changes in the atmosphere composition may not occur. This may allow the test to be automatically performed during each use of the controlled atmosphere container (e.g., each time the composition reaches a predetermined composition threshold), such as without user intervention.

[0032] Optionally, the controlled atmosphere container controller is configured to perform the test in response to a start signal, such as a start signal received from another control system (such as a control system of the controlled atmosphere container or a control system remote from the controlled atmosphere container). Optionally, the start signal is received from a user (such as a maintenance person), such as via a user device or via a control interface of the controlled atmosphere container. In this way, the user can start the test, such as by sending a signal remotely, and / or by operating the control interface of the controlled atmosphere container. This allows the air leak test to be easily performed in response to a suspected air leak and / or during routine maintenance.

[0033] Optionally, the controlled atmosphere container comprises a valve, the valve being configurable to open access to the cargo space, such as to the atmosphere in the cargo space. Optionally, the controlled atmosphere container comprises a pump, the pump being arranged to fluidly couple the valve to an external atmosphere outside the cargo space. Optionally, the controlled atmosphere container controller is configured to cause the first characteristic to have the first value by causing the valve to open access to the cargo space and / or by causing the pump to operate, such as to fluidly couple the atmosphere in the cargo space to the external atmosphere. Optionally, the controlled atmosphere container controller is configured to cause the first characteristic to have the first value by causing the valve to close and / or by causing the pump to cease operating, such as to fluidly separate the atmosphere in the cargo space from the external atmosphere.

[0034] Optionally, the controlled atmosphere container includes a filter (such as a membrane) configured to allow a fluid to flow therethrough to adjust the composition of the atmosphere in the cargo space. Optionally, the pump is arranged to connect both the filter and the valve to the external atmosphere. That is, the pump is operable to pump the atmosphere from the cargo space to the external atmosphere via one or both of the valve and the filter. In other words, the valve and the filter are connected to the pump in a parallel fluid arrangement. In this way, the pump can generate a greater pressure difference between the atmosphere in the cargo space and the external atmosphere by extracting the atmosphere through the valve rather than just through the filter. This is because the flow rate through the filter may be limited when the atmosphere is filtered through the filter. It should be understood that the filter and the valve can be fluidly connected or connectable to the cargo space and / or the external atmosphere outside the cargo space in a fluid arrangement in parallel with each other without a pump. In addition, the valve can be fluidly connected or connectable between the cargo space and the external atmosphere in a fluid arrangement in parallel with both the filter and the pump. For example, the valve can be operated to connect the cargo space with the external atmosphere while bypassing the filter and the pump. In some such examples, the valve may be coupled to an additional pump operable to cause atmosphere in the cargo space to move through the valve to an external atmosphere outside the cargo space, or from the external atmosphere to the cargo space via the valve.

[0035] A second aspect of the present invention provides a controlled atmosphere container comprising the controlled atmosphere container controller of the first aspect and a cargo space for storing cargo.

[0036] Optionally, the controlled atmosphere container includes a valve, which can be configured to open the atmosphere in the space, such as the cargo space. Optionally, the controlled atmosphere container includes a pump, which is arranged to connect the valve to the external atmosphere around the controlled atmosphere container. Optionally, the controlled atmosphere container includes a filter (such as a membrane) configured to allow a fluid to flow therethrough to adjust the composition of the atmosphere in the cargo space. Optionally, the pump is arranged to connect both the filter and the valve to the external atmosphere. That is, the pump is operable to pump the atmosphere from the cargo space to the external atmosphere via one or both of the valve and the filter. It should be understood that the filter and the valve can be fluidly connected or connectable to the cargo space and / or the external atmosphere outside the cargo space in a fluid arrangement in parallel with each other without a pump. In addition, the valve can be fluidly connected or connectable between the cargo space and the external atmosphere in a fluid arrangement in parallel with both the filter and the pump. For example, the valve can be operated to connect the cargo space with the external atmosphere while bypassing the filter and the pump. In some such examples, the valve may be coupled to an additional pump operable to cause atmosphere in the cargo space to move through the valve to an external atmosphere outside the cargo space, or from the external atmosphere to the cargo space via the valve.

[0037] The controlled atmosphere container controller may be configured to cause the valve to open, and / or cause the pump to operate, to cause the first characteristic to have the first value. This may reduce the pressure of the atmosphere in the cargo space, such as relative to the pressure of the external atmosphere outside the cargo space. The controlled atmosphere container controller may be configured to stop causing the first characteristic to have the first value by causing the valve to close and / or by causing the pump to cease operation.

[0038] Optionally, the controlled atmosphere container comprises a sensor from which the signal and / or the further signal is received. Optionally, the controlled atmosphere container comprises the further sensor (if provided). Optionally, the sensor and / or the further sensor are located in the cargo space. Alternatively, the sensor and / or the further sensor may be located in any other suitable location.

[0039] Optionally, the controlled atmosphere container and / or its controller may be configured to issue the start signal received by the controlled atmosphere container controller. Specifically, the start signal may be issued when the efficiency and / or capacity of the controlled atmosphere container or its atmosphere control system is reduced to below a corresponding threshold capacity and / or threshold efficiency. The capacity may be the cooling and / or heating capacity of the controlled atmosphere container or the atmosphere control system. If an air leak occurs, the capacity may be reduced because, as described above, air leaking into and / or out of the cargo space tends to "equalize" the pressure, temperature and / or composition of the atmosphere in the cargo space. The efficiency of the controlled atmosphere container or atmosphere control system may similarly decrease with an increase in the energy required to maintain a controlled atmosphere in the cargo space, which may occur in the event of an air leak. In this way, in the event that the controlled atmosphere container and / or its atmosphere control system has difficulty maintaining a controlled atmosphere in the cargo space, a start signal may be issued to cause the controlled atmosphere container controller to perform a test. Optionally, the controlled atmosphere container controller itself is configured to determine the capacity and / or efficiency of the controlled atmosphere container and / or atmosphere control system and initiate testing in response to the capacity and / or efficiency falling below a corresponding threshold capacity and / or threshold efficiency.

[0040] The controlled atmosphere container may be a transport unit, such as a transport unit for transporting perishable and / or respirable items, such as fresh and / or frozen produce, in a cargo space. The controlled atmosphere container may be transported on a vehicle, such as a ship, a truck or a train. The controlled atmosphere container may be a refrigerated container, or a refrigerated truck or trailer. Optionally, the controlled atmosphere container is a ripening unit, such as for use in a ripening warehouse. Optionally, the controlled atmosphere container comprises a curtain for sealing or at least partially sealing a door into the controlled atmosphere container.

[0041] It will be appreciated that the controlled atmosphere container may benefit from any of the advantages and optional features attributed to the controlled atmosphere container controller of the first aspect.

[0042] A third aspect of the present invention provides a kit of parts for testing air leaks in a controlled atmosphere container, the kit of parts comprising: the controlled atmosphere container controller of the first aspect, wherein the controlled atmosphere container includes a cargo space for storing cargo; and a valve, the valve being configurable to selectively connect the cargo space with an external atmosphere fluid outside the cargo space.

[0043] Optionally, the kit is used to test the controlled atmosphere container of the second aspect for air leakage. Optionally, the controlled atmosphere container of the second aspect includes the kit. It should be understood that the kit can benefit from any optional features and advantages of the first aspect and / or the second aspect. In particular, the kit may include the above-mentioned pump, filter, sensor from which the signal and / or further signal is received, and / or further sensor.

[0044] The kit of parts can be advantageously retrofitted to an existing controlled atmosphere container, such as by installing any one or more of a controlled atmosphere container controller, valve, pump, filter, sensor, and / or additional sensor to the controlled atmosphere container. This is particularly advantageous where the controlled atmosphere container already includes a filter and pump, in which case the valve can be easily installed to a line connecting, for example, the filter and pump. This can allow the valve to open to increase the flow rate of the atmosphere out of the cargo space, which otherwise might be limited by the filter. This can enable a greater pressure differential to be achieved between the atmosphere and the external atmosphere, thereby improving the accuracy of air leak testing.

[0045] A fourth aspect is a method for testing for air leakage in a controlled atmosphere container, the controlled atmosphere container comprising a controller and a cargo space for storing cargo, the method comprising the controller: causing a first characteristic of the atmosphere in the cargo space to have a first value; stopping causing the characteristic to have the first value; receiving a signal from a sensor within a certain time period after the stopping, the sensor being configured to sense a second characteristic of the atmosphere in the cargo space, the signal representing the value of the second characteristic of the atmosphere in the cargo space during the time period; and performing an action based on the signal to allow determination of air leakage in the controlled atmosphere container.

[0046] Optionally, the controller is the controlled atmosphere container controller of the first aspect. Optionally, the controlled atmosphere container is the controlled atmosphere container of the second aspect.

[0047] The method may include any of the optional actions that the controlled atmosphere container controller of the first aspect is configured to perform. Therefore, it should be understood that the method may benefit from any optional features and advantages attributed to the controlled atmosphere container controller of the first aspect, the controlled atmosphere container of the second aspect, and / or the kit of parts of the third aspect.

[0048] A fifth aspect of the invention provides a non-transitory computer-readable storage medium storing instructions which, when executed by a processor of a controlled atmosphere container controller, cause the processor to perform a method according to the fourth aspect.

[0049] It should be understood that the non-transitory computer readable storage medium can benefit from the optional features and / or advantages of any one of the first to fourth aspects. Specifically, the processor can be a processor of the controlled atmosphere container controller of the first aspect. That is, the controlled atmosphere container controller of the first aspect can include a processor configured to execute instructions that cause the processor to perform the method of the fourth aspect.

[0050] A sixth aspect of the present invention provides a vessel comprising the controlled atmosphere container controller of the first aspect, the controlled atmosphere container of the second aspect, the kit of parts of the third aspect, or the non-transitory computer-readable storage medium of the fifth aspect.

[0051] It will be appreciated that the vessel may benefit from the optional features and / or advantages of any one of the first to fifth aspects.

[0052] A seventh aspect of the present invention provides a controlled atmosphere container comprising: a cargo space for storing cargo; a filter (such as a membrane) configured to allow fluid flow to adjust the composition of the atmosphere in the cargo space, the filter leading to the cargo space; a valve that opens to the cargo space; and a pump connected to the valve and the filter and operable to cause the atmosphere in the cargo space to move through the filter and / or the valve and into an external atmosphere outside the cargo space.

[0053] In other words, the valve and the filter are connected to the pump in a parallel fluid arrangement. In this way, the pump can create a greater pressure difference between the atmosphere in the cargo space and the outside atmosphere by drawing the atmosphere through the valve rather than just through the filter. This is because when the atmosphere is filtered through the filter, the flow rate through the filter may be restricted.

[0054] It should be understood that the filter and the valve can be fluidly connected or connectable to the cargo space and / or the external atmosphere outside the cargo space in a fluid arrangement in parallel with each other without the need for a pump. In addition, the valve can be fluidly connected or connectable between the cargo space and the external atmosphere in a fluid arrangement in parallel with both the filter and the pump. For example, the valve can be operated to connect the cargo space to the external atmosphere while bypassing the filter and the pump. In some such examples, the valve can be connected to an additional pump that is operable to cause the atmosphere in the cargo space to move through the valve to the external atmosphere outside the cargo space, or from the external atmosphere to the cargo space via the valve.

[0055] Optionally, the controlled atmosphere container includes the controller of the first aspect. It should be understood that the controlled atmosphere container of the seventh aspect may include any optional features of the controlled atmosphere container of the second aspect. Similarly, the controlled atmosphere container of the seventh aspect may benefit from any advantages attributed to the controlled atmosphere container of the second aspect.

[0056] An eighth aspect of the present invention provides a method of configuring a controlled atmosphere container to perform an air leak test, the controlled atmosphere container comprising: a cargo space for storing cargo; a filter (such as a membrane) configured to allow fluid flow to adjust the composition of the atmosphere in the cargo space, the filter opening to the cargo space; and a pump connected to the filter and operable to cause the atmosphere in the cargo space to move through the filter and into an external atmosphere outside the cargo space; wherein the method comprises connecting a valve to the pump in a fluid arrangement in parallel with the filter, wherein the valve is configurable to open to the space.

[0057] In this way, the valve may be opened to allow atmosphere to move from the cargo space to the outside atmosphere via the valve and pump. This may allow an increase in the flow rate of atmosphere from the cargo space to the outside atmosphere, which may otherwise be restricted by the filter. This may allow for a more accurate air leak test to be performed.

[0058] Optionally, the method of the eighth aspect includes connecting the valve and the pump to a controlled atmosphere container controller configured to perform an air leak test. Optionally, the method of the eighth aspect includes providing and / or installing a controlled atmosphere container controller in the controlled atmosphere container. Optionally, the method of the eighth aspect includes configuring an existing controller of the controlled atmosphere container to perform an air leak test. This may include configuring a processor of the existing controller to execute instructions that cause the processor to perform the method of the fourth aspect. Optionally, the method of the eighth aspect includes installing the non-transitory computer-readable storage medium of the fifth aspect in the controlled atmosphere container, such as by connecting a processor of the existing controller to the non-transitory computer-readable storage medium of the fifth aspect.

[0059] Optionally, the controlled atmosphere container controller is the controlled atmosphere container controller of the first aspect. Optionally, the controlled atmosphere container is the controlled atmosphere container of the second aspect. Optionally, the valve and the controlled atmosphere container controller are part of the kit of parts of the third aspect. Optionally, the method of the eighth aspect includes performing the method of the fourth aspect to perform an air leak test.

[0060] It will be appreciated that the method of the eighth aspect may benefit from any optional features and / or advantages of any of the first to sixth aspects.

[0061] More generally, it should be understood that features described in any of the above aspects may be combined with features of any other of the above aspects. Similarly, any of the optional features of one aspect may be combined with those optional features of another aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0063] Figure 1 is a schematic diagram of a controlled atmosphere container including a controlled atmosphere container controller according to an example;

[0064] Figure 2 According to the example shown Figure 1 A graph of the pressure change during the air leak test of a controlled atmosphere container;

[0065] Figure 3 According to the example, the Figure 1 controlled atmosphere containers;

[0066] Figure 4 According to the example, Figure 1 Method for performing air leak testing in a controlled atmosphere container;

[0067] Figure 5 According to an example, a method for Figure 1 A set of parts for performing air leakage tests in controlled atmosphere containers;

[0068] Figure 6 A non-transitory computer-readable storage medium according to an example is shown; and

[0069] Figure 7 A method of configuring a controlled atmosphere container to perform an air leak test according to an example is shown. DETAILED DESCRIPTION

[0070] Figure 1 An example of a controlled atmosphere container 10 is shown, which includes a controlled atmosphere container controller 20 (referred to herein as "controller 20"). The controlled atmosphere container 10 includes a cargo space 11 and a door 12 for accessing the cargo space. The cargo space is configured to store cargo 15 in use. In this example, the controlled atmosphere container 10 is used for, for example, Figure 3 The vessel 1 is shown as a transport unit transporting cargo 15. The vessel 1 is a container ship, but may be any other suitable vessel. Alternatively, the controlled atmosphere container 10 may be any other suitable container, such as a storage unit for storing cargo 15 in a warehouse.

[0071] The cargo 15 in this example includes agricultural products, and specifically ripenable agricultural products. Alternatively, the cargo 15 may include other fresh or frozen agricultural products, pharmaceuticals, or any other suitable cargo 15. The ripenable agricultural products are stored in pallet boxes 17, which are in communication with the atmosphere in the cargo space 11. In this way, the atmosphere can be controlled to control the ripening process of the cargo 15, as described in more detail below.

[0072] The controlled atmosphere container 10 includes a curtain 13 for sealing or substantially sealing the closed door 12. This can prevent or limit the atmosphere from leaking into and / or out of the cargo space 11 through the door 12 during use, such as through a gap in the closed door 12. The controlled atmosphere container 10 is otherwise sealed to isolate the external atmosphere outside the cargo space 11. However, the controlled atmosphere container 10 may not be completely airtight. That is, the atmosphere may still leak into and / or out of the cargo space, such as gaps in the container 10, such as gaps around valves, conduits, or other components of the wall of the container 10 that lead to the cargo space and / or pass through the enclosed cargo space.

[0073] The controlled atmosphere container 10 of the present example includes an atmosphere control system 16 for controlling the atmosphere in the cargo space 11. The atmosphere control system 16, or at least a portion thereof, may be operated by a controlled atmosphere container controller 20.

[0074] The atmosphere control system 16 is operable to control the composition of the atmosphere in the cargo space 11, such as the level of O2 and / or CO2 in the cargo space. Specifically, the atmosphere control system 16 includes a membrane 21 in the cargo space 11. The membrane 21 is fluidly connected or connectable to a pump 22, in this example specifically through a conduit 24. The pump may be configured to lead to an external atmosphere outside the cargo space 11 via a pump outlet 28. The pump 22 here is a vacuum pump, but in other examples it may be any other suitable pump. The pump 22 is operable to move the atmosphere from the cargo space 11 through the membrane 21 and the pump outlet 28 to the external atmosphere. The pump 22 may be a positive displacement pump, or any other suitable pump 22. The membrane 21 is configured to allow carbon dioxide (CO2) in the atmosphere to pass therethrough, but prevent or limit oxygen (O2) and / or nitrogen (N2) in the atmosphere from passing therethrough. In this way, the membrane 21 is configured to filter CO2 from the atmosphere. Then, the CO2 filtered using the membrane 21 is transmitted to the external atmosphere via the pump 22. Most or all of the O 2 and N 2 from the atmosphere that passes through the membrane 21 remains in the cargo space 11 .

[0075] The ripenable agricultural product 15 converts O2 in the atmosphere of the cargo space 11 into CO2 when ripening during the ripening process. Therefore, the level of CO2 in the cargo space 11, which is sealed or substantially sealed from the external atmosphere when in use, may increase over time. The increase in CO2 may subsequently increase the ripening rate of the ripenable agricultural product 15. Therefore, the atmosphere in the cargo space 11 may be caused to move through the membrane 21 to extract CO2 from the atmosphere in order to control (such as limit) the ripening rate. This may allow the ripenable agricultural product to be stored for a longer period of time, such as allowing the agricultural product to be transported a longer distance while arriving at its destination at a desired degree of maturity.

[0076] To monitor the levels of O2, CO2, and / or N2 in the cargo space 11, the atmosphere control system 16 includes a sensor system 26 for sensing one or more characteristics of the atmosphere in the cargo space 11. The sensor system 26 in this example includes an O2 sensor 26a and a CO2 sensor 26b for sensing the O2 level and CO2 level in the atmosphere in the cargo space 11, respectively. That is, the O2 sensor and the CO2 sensor are each configured to sense the composition of the atmosphere in the cargo space 11. The sensor system also includes a pressure sensor 26c for sensing the pressure of the atmosphere in the cargo space 11, and a temperature sensor 26d for sensing the temperature of the atmosphere in the cargo space 11. Each of the sensors 26a-26d in the sensor system 26 and / or the entire sensor system 26 are communicatively coupled to the controlled atmosphere container controller 20. In this manner, the sensors 26a-26d and / or the sensor system 26 are configured to send signals to the controller 20 indicating the characteristics of the atmosphere, such as the composition, pressure, and / or temperature of the atmosphere in the cargo space 11. The controller 20 is configured to receive signals from the sensors 26a-26d and / or the sensor system 26. As will be appreciated from the following disclosure, in various examples, any one or more of the sensors 26a-26d in the sensor system 26 may be omitted or may not be part of the sensor system 26. Here, the sensors 26a-26d are located in the cargo space 11. In other examples, one or more of the sensors 26a-26d are located elsewhere, such as outside the cargo space 11, while being in a suitable position to sense corresponding characteristics in the cargo space 11.

[0077] The atmosphere control system 16 also includes a conduit pressure sensor 23 configured to sense the pressure in a conduit 24 that fluidly connects the membrane 21 and the pump 22. The conduit pressure sensor 23 is communicatively coupled to the controller 20 and is configured to send a signal representing the pressure in the conduit 23 to the controller 20. That is, the conduit pressure sensor 23 is configured to sense the pressure difference generated by the pump 22 during pump operation. The conduit pressure sensor 23 may alternatively be part of the sensor system 26 and / or may be communicatively coupled to the sensor system 26.

[0078] The atmosphere control system 16 also includes a fresh air valve 29 that can be configured to fluidly couple the atmosphere in the cargo space 11 to an external atmosphere outside the cargo space 11. Specifically, in this example, the fresh air valve 29 can be opened and closed to selectively allow the external atmosphere to flow into the cargo space 11. This can allow the O2 and / or N2 levels in the atmosphere in the cargo space 11 to be controlled, such as during the ripening process of the ripenable agricultural product 15. Specifically, as described above, due to the respiration of the ripenable agricultural product 15 during the ripening process, the O2 level in the atmosphere in the cargo space 12 may decrease and, in particular, be converted into CO2. Therefore, while the membrane 21 is configured to remove CO2 from the atmosphere in the cargo space, the fresh air valve 29 is configured to allow the external atmosphere (which may include external air enriched with O2) to enter the cargo space 11 to increase the O2 level in the atmosphere in the cargo space 11. The external atmosphere can flow into the cargo space due to the presence of a vacuum in the cargo space 11, such as by extracting the atmosphere in the cargo space 11 through the membrane 21 with the aid of the vacuum pump 22, and / or by any other means described herein.

[0079] The fresh air valve 29 is communicatively coupled to the controller 20. The controller 20 is configured to cause the fresh air valve to open and close to control the level of O2 in the atmosphere in the cargo space 11. More generally, the controller 20 is configured to control the composition of the atmosphere in the cargo space. For example, the atmosphere in the cargo space 11 is caused to move out of the cargo space 11 by the controller, such as via the membrane 21, such as by causing the pump 22 to operate. This may also be caused, for example, by the controller to cause the outside atmosphere to move into the cargo space 11, such as by operating the fresh air valve 29.

[0080] In some examples, although not shown here, the atmosphere control system 16 is configured to operate in a cooling mode to reduce the temperature of the atmosphere in the cargo space 11, and / or in a heating mode to increase the temperature of the atmosphere in the cargo space 11. In other words, the atmosphere control system 16 can be configured to control the temperature of the cargo 15 in the cargo space 11. It should be understood that the atmosphere control system 16 can include any components suitable for cooling and / or heating the atmosphere of the cargo space, such as a heat exchanger optionally connected in a refrigeration cycle. The atmosphere control system 16 may also include a fluid moving device for moving the atmosphere in the cargo space 11, such as for moving the atmosphere through or through a heat exchanger. By operating in a cooling mode to cool the atmosphere in the cargo space 11, the atmosphere control system 16 can control the ripening process of the ripening agricultural product 15. Specifically, low temperatures may inhibit the ripening of the agricultural product 15, or reduce its ripening rate. In addition, during the ripening process, the agricultural product 15 releases heat, which can be extracted from the cargo space 11 by the atmosphere control system to control further ripening.

[0081] The controller 20 may be configured to cause the atmosphere control system 16 to operate in a cooling and / or heating mode. The temperature sensor 26c and / or any other suitable temperature sensor in the atmosphere control system 16 and / or the controlled atmosphere container 10 may be used to perform closed-loop control of the temperature of the atmosphere in the cargo space 11. Alternatively, the atmosphere control system 16 may include an additional controller (not shown) for causing the atmosphere control system 16 to operate in a cooling and / or heating mode. Alternatively, the atmosphere control system 16 may be caused to operate in this manner by a remote controller 30 remote from the controlled atmosphere container 10, as will be described in more detail below. The additional controller and / or remote controller 30 may be communicatively coupled to the controller 20 to allow information about the state of the atmosphere in the cargo space 11 and / or information about the integrity of the controlled atmosphere container 10 to be transmitted between different systems. In other examples, the atmosphere control system 16 is not configured to control the temperature in the cargo space 11. In some such examples, the controlled atmosphere container 10 includes an additional atmosphere control system for controlling the temperature in the cargo space 11.

[0082] Finally, in this example, the controlled atmosphere container 10, and in particular the atmosphere control system 16, includes a valve 25 that can be configured to open a passage into the cargo space 11. The valve 25 is fluidly connected or connectable to the pump 22 in parallel with the membrane 21. This is achieved by connecting the valve 25 to a conduit 24 that fluidly connects the membrane 21 to the pump 22. In other examples, the valve 25 can be connected at any other suitable location, such as at one end of the membrane 21. In any case, the valve 25 is operable so that the atmosphere in the cargo space 25 can be drawn from the cargo space 25 via the pump. The atmosphere can flow through the valve 25 at a higher flow rate than through the membrane 21, and the flow rate of the atmosphere flowing through the membrane is limited due to the filtering effect of the membrane 21. Therefore, the valve 25 can allow the vacuum pump 22 to create a greater pressure difference between the atmosphere in the cargo space 11 and the external atmosphere than using the membrane 21 alone. In other examples, the pump 22 is operable to vent outside air into the cargo space 11 via the valve 25 in order to increase the pressure in the cargo space 11 relative to the external atmosphere outside the cargo space 11 .

[0083] It should be understood that in other examples, any one or more of the components described above, such as valve 25, fresh air valve 29, sensor system 26, pump 22 and / or membrane 21, may not be part of the atmosphere control system 16, but may be included in another system connected to or as part of the controlled atmosphere container 10.

[0084] As described above, in some examples, the controlled atmosphere container 10 may not be completely airtight. Thus, when there is a pressure difference between the atmosphere in the cargo space 11 and the external atmosphere outside the cargo space, the external atmosphere may leak into the cargo space 11, or the atmosphere in the cargo space 11 may leak out of the cargo space 11. Some leakage is acceptable, but increased leakage may reduce the ability of the atmosphere control system 16 to control the atmosphere in the cargo space 11, which in turn may cause undesirable and / or premature ripening of the agricultural products.

[0085] Thus, the controlled atmosphere container controller 20 of the present example is configured to test the controlled atmosphere container 10 for air leaks (referred to herein as an "air leak test"). The air leak test will be described in more detail below, but generally includes the controller 20 causing a pressure differential between the atmosphere in the cargo space 11 and the external atmosphere outside the cargo space, such as by causing the pump 22 to operate and causing the valve 25 to open. Alternatively or additionally, the controller 20 may cause the pressure differential by causing the temperature of the atmosphere in the cargo space 11 to decrease, thereby causing a corresponding decrease in the pressure in the cargo space 11. The controller 20 then stops causing the pressure differential, such as by causing the pump 22 to stop operating, closing the valve 25, and / or stopping cooling the air in the cargo space 11. The controller 20 then monitors the pressure of the atmosphere in the cargo space 11 over time, and the pressure of the atmosphere increases as the external atmosphere leaks into the cargo space 15. The greater the leak, the faster the pressure increases.

[0086] Figure 2 The process is shown in more detail. Here, the pressure of the atmosphere in the cargo space 11 (shown on the y-axis) is reduced from an initial pressure P0 at the zeroth time T0 (time on the x-axis) to a reduced pressure P1 at the first time T1. P0 may correspond to the pressure in the cargo space when the door 12 is open, which may be the same as the ambient pressure of the external atmosphere. Alternatively, P0 may be the pressure in the container 10 when the container 10 is in use (such as when the atmosphere control system 16 is operated in a cooling mode). In the example shown, P1 is lower than P0, indicating a pressure reduction, such as caused by operating the vacuum pump 22 and optionally opening the valve 25, and / or reducing the temperature of the atmosphere in the cargo space 11 as described above. At time T1, the controller 20 stops causing the pressure in the cargo space 11 to decrease, and allows the pressure to "equalize". That is, the pressure is allowed to increase toward the "equilibrium" pressure. When the pressure is so equalized, the container 10 can be said to be in an equilibrium state. The equilibrium pressure may be the pressure P0. Alternatively, the equilibrium pressure may be another pressure, such as the pressure of the external atmosphere. This is particularly true if the operating mode of the atmosphere control system 16 changes after time T0 (such as before, at, or after time T1). In any case, as the external atmosphere leaks into the cargo space 11, the pressure changes toward this equilibrium pressure. The pressure may increase logarithmically, and therefore it may take a long time to reach the equilibrium pressure. Thus, the controller 20 in this example is configured to compare the pressure after the stop with the threshold pressure PT reached at a time TT after the stop. The controller 20 is also configured to determine that there is an air leak in the container 10. As discussed in more detail below, for example, an air leak can be identified when the time TT taken for the pressure to reach the threshold pressure is less than the threshold time. This indicates that external air is leaking into the container, causing the pressure to increase, and the rate of increase is faster than an acceptable rate.

[0087] In some examples, time T1 is up to 5 minutes, up to 10 minutes, up to 15 minutes, or more than 15 minutes from T0. In some examples, vacuum pump 22 can generate a pressure difference when extracting atmosphere through membrane 21 alone, such as a pressure difference sensed by conduit pressure sensor 23, which is up to 20 mbar, up to 40 mbar, up to 60 mbar, up to 80 mbar, or more than 80 mbar. In some examples, vacuum pump 22 can generate a pressure difference when operating alone through valve 25 or in combination with membrane 21 to extract atmosphere, such as a pressure difference sensed by conduit pressure sensor 23, which is greater than the pressure difference when vacuum pump 22 is operated alone through membrane 21 to extract atmosphere. For example, when operating the pump to extract atmosphere through valve 25, the pressure difference detected by the pressure sensor may be up to 200 mbar, up to 300 mbar, up to 400 mbar, up to 500 mbar, up to 600 mbar, or more than 600 mbar. In this way, the pressure difference between the atmosphere in the cargo space 11 and the outside atmosphere can be created more quickly and / or a greater pressure difference can be created by extracting the atmosphere through the valve 25. For example, the atmosphere control system 16 can be operated, such as by operating the pump 22 and opening the valve 25, to create a pressure difference between the atmosphere in the cargo space 11 and the outside atmosphere of up to 2 mbar, up to 4 mbar, up to 8 mbar, or more than 8 mbar. The time required to create such a pressure difference may be, for example, up to 5 minutes, up to 8 minutes, up to 10 minutes, up to 15 minutes, or more than 15 minutes.

[0088] Now go to Figure 4 , more generally describes a method 400 of performing an air leak test. The dashed boxes represent optional features of the method 400. The method 400 includes the controller 20 causing 410 a first characteristic of the atmosphere in the cargo space 11 to have a first value. In this case, the first characteristic is pressure, and is caused by the controller 20 to have a first value. Figure 2 410. In the example shown, this is achieved by the controller 20 causing 411 the valve 25 to open and / or causing 412 the pump to operate. It should be understood that the controller 20 in this example is also configured to cause the fresh air valve 29 to close and / or remain closed during the air leak test in an attempt to keep the container 10, and in particular the cargo space 11, in a sealed state. That is, the method 400 may include the controller 20 causing 413 the fresh air valve 29 to close and / or remain closed.

[0089] In other examples, causing 410 the first characteristic to have the first value includes the controller 20 causing 414 the atmosphere control system 16 to operate in the cooling mode or the heating mode. It should be appreciated that in other examples, the first characteristic may be any other suitable characteristic, such as the temperature and / or composition of the atmosphere in the cargo space 11. That is, the method 400 may include the controller 20 causing 410 the temperature of the atmosphere to have the first value, such as causing a corresponding decrease in the pressure in the cargo space 11.

[0090] Then, the method 400 includes the controller 20 stopping 420 causing the first characteristic to have the first value, such as in any of the ways described above. For example, the method 400 may include the controller 20 causing 421 the valve 25 to close and / or causing 422 the pump 22 to stop operating. Alternatively or additionally, the method 400 may include the controller 20 causing 423 the atmosphere control system 16 to stop operating in the cooling or heating mode.

[0091] The method 400 then includes the controller 20 receiving 430 a signal from one or more of the sensors 26a-26d in the sensor system 26 within a period of time after the stop 420. The signal represents a value of a second characteristic of the atmosphere in the cargo space 11 during the period of time. Figure 2 , in this example, the controller 20 receives a signal from the pressure sensor 26c, the signal being indicative of the pressure of the atmosphere in the cargo space 11. In other words, in this example, the second characteristic is the pressure. That is, the second characteristic contains the first characteristic, and the second characteristic is in fact the first characteristic. Alternatively, the second characteristic may be or may include any other suitable characteristic, such as the temperature and / or composition of the atmosphere in the cargo space 11. That is, the controller 20 may receive 430 a signal from one or more of: the temperature sensor 26d; the O2 sensor 26a; and / or the CO2 sensor 26b. For example, an increase in the level of O2 in the atmosphere may be due to leakage of the external atmosphere (which may be rich in oxygen) into the cargo space 11. Thus, the controller 20 may cause 410 the pressure of the atmosphere to decrease to a first value, and then receive and / or monitor a signal representing the level of O2 in the atmosphere after the stopping 420.

[0092] Finally, the method 400 includes the controller 20 performing 440 an action based on the received signal to allow for determination of an air leak in the controlled atmosphere container 10. As described above, in this example, the controller 20 performing 440 an action includes the controller 20 comparing 441 the value of the second characteristic (in this case, pressure) during the time period after the stop 420 with a threshold pressure PT. More generally, the method includes the controller 20 comparing 441 the value of the second characteristic with a threshold second characteristic. Thus, if the second characteristic is the temperature and / or composition of the atmosphere, the threshold second characteristic may be a threshold temperature and / or a threshold composition.

[0093] The threshold second characteristic comprises a value of the second characteristic that will be reached after a given time after the stopping for the container 10 to have acceptable air leakage. For example, if the pressure exceeds a threshold pressure PT at a time TT, the container may have unacceptable air leakage. The situation may be similar if the pressure reaches the threshold pressure PT at a time less than the threshold time as described above. Therefore, the performing 440 action may include determining 442 the time it takes for the second characteristic to reach, exceed, or drop below the threshold second characteristic after the stopping (such as when the pressure in the cargo space 11 is caused to increase 410 during the test). Then, the performing 440 action may include the controller 20 comparing 443 the time it takes to the threshold time.

[0094] The threshold second characteristic and / or threshold time may be predetermined and / or may be determined by the controller 20 prior to or during the test. For example, the controller 20 may be configured to determine the threshold second characteristic based on one or more of: the pressure difference between the atmosphere and the external atmosphere when the controller stops 420 causing the second characteristic to have the first value; the temperature of the atmosphere in the cargo space 11; the temperature of the external atmosphere outside the cargo space 11; the composition of the atmosphere in the cargo space 11; the operating mode of the atmosphere control system 16 during the test; and whether the operating mode of the atmosphere control system 16 changes during the test. For example, if the pressure difference at the stop 420 is relatively large, then it can be expected that the leakage of the external atmosphere into the cargo space 11 will also be correspondingly large. In this case, the threshold pressure (and / or threshold time) may be greater than when the pressure difference at the stop 420 is relatively low. Similarly, in some examples, the atmosphere control system 16 may be operated in a cooling mode at or before the stop 420, and may be caused to stop operating or operate in a heating mode during the time period after the stop 420. In such a case, the temperature and / or pressure in the atmosphere may increase more rapidly during the time period following the stopping than if the controlled atmosphere container continued to operate in a cooling mode during the test or than if the controlled atmosphere container was never operated during the test.

[0095] The determined and / or predetermined threshold second characteristic may be between the first value and the equilibrium characteristic. The equilibrium characteristic may be a value that the second characteristic may be expected to take when the container is in the above-mentioned equilibrium state. For example, the equilibrium characteristic may be the equilibrium pressure described above. In other examples, the equilibrium characteristic may be the value assumed by the first characteristic before or at the beginning of the air leak test. In some examples, the threshold second characteristic is separated from the first characteristic or the equilibrium characteristic by an amount that is less than or greater than one-third of the difference between the first characteristic and the equilibrium characteristic, or less than or greater than one-quarter of the difference. In this way, a potential air leak in the controlled atmosphere container may be detected or determined when the value of the second characteristic during the time period after the stop exceeds the threshold second characteristic, decreases below the threshold second characteristic, and / or is within the tolerance range of the threshold second characteristic.

[0096] In some examples, the performing 440 action includes the controller 20 comparing 444 the value of the second characteristic to the equilibrium characteristic. In some examples, the performing 440 action includes the controller comparing 445 the value of the second characteristic in the time period after the stopping 420 to the first value. That is, the action may include determining the extent to which the value of the second characteristic deviates from the first value in the time period after the stopping. If an air leak occurs, the second characteristic may deviate from the first characteristic more quickly after the stopping.

[0097] In some examples, the performing 440 action includes the controller 20 determining 446 that an air leak exists or may exist in the controlled atmosphere container 10. For example, the controller 20 determines that: the value of the second characteristic has reached, exceeded, or dropped below a threshold second characteristic; or the time taken for the second characteristic to reach, exceed, or drop below a threshold second characteristic has reached, or dropped below a threshold time. In some examples, the determining 446 that an air leak exists or may exist in the controlled atmosphere container 10 includes determining a rate at which the external atmosphere leaks into the cargo space 11, and / or determining a rate at which the atmosphere in the cargo space 11 leaks out of the cargo space 11. In some examples, determining 446 that an air leak exists or may exist in the controlled atmosphere container 10 includes determining whether the leak rate exceeds a leak rate threshold.

[0098] In some examples, the performing 440 action includes the controller 20 transmitting 447 any of the above values ​​or qualities of the determination, such as one or more of: the first value; the value of the second characteristic during the time period; the time it takes for the second characteristic to reach, exceed, or fall below a threshold second characteristic; and the determination that there is or may be a leak in the controlled atmosphere container 10. The transmission can be, for example, to a user device (not shown) and / or another controller, such as another controller of the atmosphere control system 16, another controller of the controlled atmosphere container 10, and / or the remote controller 30. In some examples, the transmission 447 includes issuing an alarm or alert, such as notifying a user that an air leak has been determined to have occurred.

[0099] In some examples, the performing 440 action includes saving 448 any of the values ​​or determined qualities to a memory, such as instead of transmitting the values, or before or after transmitting the values. The memory may be a memory of the controller 20, another memory of the controlled atmosphere container, and / or a remote memory, such as a memory of the remote controller 30. In some examples, the performing 440 action includes the controller 20 displaying 449 any of the values, such as on a display of the controlled atmosphere container 10, on a display of a user device (not shown), or on a display of a remote system, such as on a remote system including the remote controller 30.

[0100] It should be understood that the controller 20 is configured to perform the air leakage test when the door 12 is closed and the seal 13 is installed. More specifically, the controller 20 is configured to perform the air leakage test when the controlled atmosphere container 10 is operating to control the atmosphere in the cargo space (such as using the atmosphere control system 16). This may be when the controlled atmosphere container is in transit. In this way, the controller 20 can advantageously perform the air leakage test "on the fly" and may not require the controlled atmosphere container to be taken out of operation.

[0101] The controller 20 is configured to perform the test when the controller 20 receives a start signal. The start signal may be received from a control panel of the container 10, a remote system (such as the remote controller 30), and / or another system of the controlled atmosphere container 10. The start signal may be manually issued by a user, or automatically issued, such as in response to a condition of the atmosphere in the cargo space meeting one or more criteria. Alternatively, the controller 20 may be configured to monitor the condition of the atmosphere in the cargo space 11, and perform the test in response to the condition meeting one or more criteria (such as, without receiving a start signal).

[0102] One or more criteria may include a decrease in the level of O2 in the atmosphere, such as up to 1%, up to 2%, up to 5%, or more than 5%, compared to the initial level of O2 in the atmosphere, such as shortly before or after the door is closed. Alternatively or additionally, one or more criteria may include an increase in the level of CO2 in the atmosphere, such as up to 1%, up to 2%, up to 5%, or more than 5%, compared to the initial level of O2 in the atmosphere. This may indicate that the agricultural product 15 has begun to breathe. This may mean that the container 10 is closed and there is breathing cargo 15 inside, which may be a suitable time to perform the test. Alternatively or additionally, this may mean that the ripening process starts too early, indicating that there may be an air leak. In some examples, one or more criteria include an indication that the atmosphere control system 16 is operating in a cooling mode and / or a heating mode. In some examples, one or more criteria include changes in temperature and / or pressure in the cargo space. In other examples, one or more criteria include a decrease in the efficiency and / or cooling capacity of the atmosphere control system to below a corresponding efficiency and / or cooling capacity threshold, which may indicate the presence of a potential leak. It should be appreciated that the one or more criteria may include any other suitable criteria indicating, for example, that the door 12 is closed, the controlled atmosphere container 10 contains produce (such as a respiring produce) in the cargo space 11 , and / or that there is a suspected air leak.

[0103] In some examples, leaks may exist when the curtain 13 is not installed correctly, such as when there is a gap between the curtain and the wall and / or door of the container 10. In various examples, the controlled atmosphere container includes a drain (not shown), such as located in the cargo space 11, which can be opened when in use to allow liquid to drain from the container 10, such as water condensed in the cargo space 11. In some such examples, leaks may occur when the drain is not blocked after use. In other examples, the leak may exist due to defects in any other part of the container that separates the atmosphere in the cargo space 11 from the external atmosphere outside the cargo space 11.

[0104] Figure 5 A kit of parts 500 for performing a test for air leaks in a controlled atmosphere container 10 is shown. The kit of parts 500 includes a controlled atmosphere container controller 20 and a valve 25. The kit of parts 500 can be used, for example, to retrofit an existing controlled atmosphere container 10 to allow an air leak test to be performed. This can be used in situations where the container 10 does not include a valve 25 and / or controller 20 configured to perform an air leak test. In other examples, the kit of parts can include a non-transitory computer-readable storage medium storing instructions that, when executed by a processor, cause the processor to perform Figure 4In this way, the processor of the existing controller of the controlled atmosphere container 10 can be configured to execute instructions stored on a non-transitory computer-readable storage medium. The non-transitory computer-readable storage medium can be the following reference Figure 6 Non-transitory computer-readable storage medium 700 is described.

[0105] In some examples, such as Figure 5 As shown, the kit 500 may include Figure 1 Other components of the atmosphere control system 16 are shown, such as the membrane 21, the pump 22, the fresh air valve 29, the sensors 26a-26d and / or the sensor system 26. These components can be provided when an existing controlled atmosphere container 10 needs to be reconfigured for air leak testing and lacks these components. Alternatively, a kit of parts 500 can be provided to be installed in a new controlled atmosphere container 10 during the manufacture of the controlled atmosphere container 10.

[0106] Figure 6 A schematic diagram of a non-transitory computer-readable storage medium 600 according to an example is shown. The non-transitory computer-readable storage medium 600 stores instructions 630 that, when executed by a processor 620 of a controller 610, cause the processor 620 to perform a method according to the example. In some examples, the controller 610 is the controlled atmosphere container controller 20 described above or any variation thereof discussed herein. The instructions 630 include: causing 631 a first characteristic of the atmosphere in the cargo space 11 to have a first value; stopping 632 causing the first characteristic to have the first value; within a certain period of time after stopping, receiving 633 a signal from a sensor 26c, the sensor configured to sense a second characteristic of the atmosphere in the cargo space 11, the signal representing the second characteristic of the atmosphere in the cargo space 11 during the time period; and performing 634 an action based on the signal that allows determination of an air leak in the controlled atmosphere container. In other examples, the instructions 630 include instructions for performing any other exemplary method described herein, such as the above referenced methods. Figure 4 The method 400 is described. In some examples, the controlled atmosphere container 10 , the atmosphere control system 16 , the controller 20 , the remote controller 30 , and / or any other suitable controller includes a non-transitory computer-readable storage medium 600 .

[0107] Figure 7An exemplary method 700 of configuring a controlled atmosphere container 10 to perform an air leak test is shown. The method 500 is applicable when the controlled atmosphere container 10 includes a membrane 21 and a pump 22, but does not include, for example, a valve 25 or a controller 20, or when the controller 20 is not properly configured to perform an air leak test. The method includes coupling 710 the valve 25 to the pump 22 in parallel with the membrane 21. That is, the method can be used to retrofit an existing container 10 with a valve 25 to allow the pump 22 to reduce the pressure in the cargo space 11 to a greater extent than through the membrane 21, thereby enabling the container to perform an air leak test, and / or improving the accuracy of the air leak test.

[0108] In some examples, the method 700 includes connecting 720 a valve and / or pump to the controlled atmosphere container controller 20. In some examples, the method 700 includes providing 730 and / or installing 740 a controlled atmosphere container controller 20 in the controlled atmosphere container 10, such as by providing a kit of parts 500. Optionally, the method 700 includes configuring an existing controller of the controlled atmosphere container 10 to perform an air leak test, such as the controller 20 is already installed in the controlled atmosphere container 10. This can include configuring 750 a processor of the existing controller 20 to execute instructions that cause the processor to perform the test, such as by Figure 4 In some such examples, the method 700 includes installing 760 the non-transitory computer readable storage medium 600 described above in the controlled atmosphere container 10, which may include connecting 761 a processor of the existing controller 20 to the non-transitory computer readable storage medium 600.

[0109] Exemplary embodiments of the invention have been discussed with particular reference to the examples illustrated. However, it will be appreciated that changes and modifications may be made without departing from the scope of the invention as defined in the appended claims.

Claims

1. A controlled atmosphere container controller for a controlled atmosphere container, the controlled atmosphere container comprising a cargo space for storing cargo, the controlled atmosphere container controller being configured to perform an air leakage test on the controlled atmosphere container, the test comprising the controlled atmosphere container controller: causing a first property of the atmosphere in the cargo space to have a first value; ceasing to cause the characteristic to have the first value; receiving, within a time period after the stopping, a signal from a sensor configured to sense a second characteristic of the atmosphere in the cargo space, the signal representing a value of the second characteristic of the atmosphere in the cargo space during the time period; and Actions are performed based on the signal to allow determination of an air leak in the controlled atmosphere container.

2. The controlled atmosphere container controller of claim 1, comprising a filter configured to allow fluid to flow therethrough to adjust a composition of the atmosphere in the cargo space.

3. The controlled atmosphere container controller of claim 2, wherein the filter is a membrane.

4. A controlled atmosphere container controller according to any one of claims 1 to 3, comprising a valve configurable to open access to the cargo space.

5. A controlled atmosphere container controller according to claim 4 and claim 2 or claim 3, comprising a pump arranged to fluidly connect both the filter and the valve to an external atmosphere outside the cargo space, wherein the valve is fluidly connected or connectable to the pump in parallel with the filter.

6. The controlled atmosphere container controller of claim 5, wherein the controlled atmosphere container controller causing the first characteristic of the atmosphere in the cargo space to have the first value comprises the controlled atmosphere container controller causing the valve to open to the cargo space and / or causing the pump to operate.

7. The controlled atmosphere container controller of claim 6, wherein the controlled atmosphere container controller stopping causing the first characteristic to have the first value comprises the controlled atmosphere container controller causing the valve to close and / or causing the pump to cease operation.

8. A controlled atmosphere container controller according to any one of claims 1 to 7, wherein the first characteristic comprises a pressure, a temperature and / or a composition of the atmosphere in the cargo space.

9. A controlled atmosphere container controller according to any one of claims 1 to 8, wherein the second characteristic comprises the first characteristic.

10. The controlled atmosphere container controller of claim 9, wherein the controlled atmosphere container controller performing the action comprises the controlled atmosphere container controller comparing the value of the second characteristic during the time period to the first value.

11. A controlled atmosphere container controller according to any one of claims 1 to 10, wherein the testing comprises the controlled atmosphere container controller receiving, during the testing, a further signal from the sensor or a further sensor, the further signal representing a further value of the second characteristic during the testing; and The performing of the action comprises comparing the value of the second characteristic during the time period with the further value of the second characteristic during the testing period.

12. A controlled atmosphere container comprising the controlled atmosphere container controller according to any one of claims 1 to 11 and the cargo space for storing cargo.

13. A controlled atmosphere container according to claim 12, when dependent on claim 5, comprising said filter, said valve and said pump.

14. A kit of parts for performing air leak testing on a controlled atmosphere container, the kit of parts comprising: The controlled atmosphere container controller according to any one of claims 1 to 11, wherein the controlled atmosphere container includes the cargo space for storing cargo; as well as A valve is configurable to selectively fluidly couple the cargo space with an external atmosphere outside the cargo space.

15. A method of performing an air leak test on a controlled atmosphere container, the controlled atmosphere container comprising a controller and a cargo space for storing cargo, the method comprising the controller: causing a first property of the atmosphere in the cargo space to have a first value; ceasing to cause the characteristic to have the first value; receiving, within a time period after the stopping, a signal from a sensor configured to sense a second characteristic of the atmosphere in the cargo space, the signal representing a value of the second characteristic of the atmosphere in the cargo space during the time period; and Actions are performed based on the signal to allow determination of an air leak in the controlled atmosphere container.

16. The method of claim 15, wherein the controlled atmosphere container comprises: a filter configured to allow a fluid to flow therethrough to adjust a composition of the atmosphere in the cargo space; a valve configurable to open access to the space; and A pump is arranged to fluidly couple both the filter and the valve to an external atmosphere outside the cargo space, wherein the valve is fluidly connected or connectable to the pump in parallel with the filter.

17. The method of claim 16, wherein the filter is a membrane.

18. The method of claim 16 or claim 17, wherein the controller causing the first characteristic of the atmosphere in the cargo space to have the first value comprises the controller causing the valve to open and / or causing the pump to operate; and Wherein the controller ceasing to cause the first characteristic to have the first value comprises the controller causing the valve to close and / or causing the pump to cease operation.

19. A non-transitory computer-readable storage medium storing instructions that, when executed by a processor of a controlled atmosphere container controller, cause the processor to perform the method of any one of claims 15 to 18.

20. A vessel comprising a controlled atmosphere container controller according to any one of claims 1 to 11, a controlled atmosphere container according to claim 12 or claim 13, a kit of parts according to claim 14, or a non-transitory computer readable storage medium according to claim 19.

Images