DE20311833U1 - Goods transport container for perishable products has forced ventilation system to remove cooling medium from interior of container - Google Patents

Abstract

A goods transport container for perishable products, especially a truck container, comprises a coolant tank (1), a forced ventilation unit and an interior divider (2) to reduce the temperature and to expel cooling medium ( nitrogen) from the container to ensure a coolant-free interior during loading and unloading.

Description

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ANDREJEWSKI, HONKE & SOZIEN

PATENT ATTORNEYS EUROPEAN PATENT AND TRADEMARK ATTORNEYS

Attorney file:

97 443/Srb/Nu Graduate Physicist

DR. WALTER ANDREJEWSKI (-1996)

Graduate engineer DR.-ING. MANFRED HONKE Graduate physicist DR. KARL GERHARD MASCH Graduate engineer DR.-ING. RAINER ALBRECHT Graduate physicist

DR. JÖRG NUNNENKAMP, qualified chemist DR. MICHAEL ROHMANN, qualified physicist DR. ANDREAS VON DEM BORNE

D 45127 Essen, Theaterplatz D 45002 Essen, P.O. Box IO 02

July 25, 2003

Utility model application

Aldi GmbH & Co. KG Burgstrasse 37

45476 Mülheim / Ruhr

Goods transport containers

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Andrej ewski, Honke & Sozien, patent attorneys in Essen

Description:

The invention relates to a goods transport container for perishable products such as foodstuffs, etc., in particular a truck trailer or truck box, with a tank for holding a cooling medium, and with a distribution unit inside the container for the targeted discharge of the cooling medium and thus reducing the temperature inside the container.

A goods transport container of the design described above is described in DE 195 31 122 A1. Similar containers are known from practice. Nitrogen is generally used as the cooling medium, which is usually stored in the tank in liquid form and then flows into the interior of the container as a cool gas. This cooling gas usually has temperatures well below minus 100 ⁰ C, so the targeted supply of the cooled nitrogen gas ensures that the interior of the container is cooled down. For example, temperatures of minus 20 ⁰ C and even more can be easily generated inside the container in this way.

The atmospheric air that is initially present there is displaced to the outside by the nitrogen supply. Nitrogen has a higher specific weight than most other air components, so that these are expelled from the goods transport container. This can happen through the ventilation slots that are already present.

A goods transport container with the cooling device described is significantly superior to conventional cooling systems.

Andrejewski, Honke & Sozien, patent attorneys in Essen

which, for example, rely on external cooling units and function in the manner of a refrigerator. In addition, there are also inerting devices for transport containers, as described for example in EP 0 120 271 A1 or EP 0 357 949 Bl. The idea here is to create a certain atmosphere from an inert medium, usually nitrogen, in the goods transport container in order to protect the food usually contained there from spoiling. In this context, simultaneous cooling is also mentioned. However, this is again provided by a separate cooling unit within the framework of EP 0 357 949 Bl.

Such cooling units have the fundamental disadvantage that they produce exhaust gases and, in particular, noise emissions. This significantly limits the use of such goods transport containers, particularly for supplying shops in residential areas. These days, such noise and exhaust emissions are hardly tolerated.

For this reason, the described flushing of the goods transport container or truck trailer with the cooling medium, in particular the cooled nitrogen gas, is an effective means of protecting the food inside from spoiling and doing so with practically no emissions. In order to supply the cooling medium to the inside of the container, it is only necessary to open a shut-off device between the tank and the distribution unit at certain intervals, so that the liquid cooling medium evaporating in the tank can be discharged via the

Andrejewski, Honke & Sozien, patent attorneys in Essen

Shut-off device into the distribution unit and from there into the interior of the container.

The shut-off device can be operated electrically and remotely using the existing vehicle battery. An external unit is not required. In addition, the cooling medium flows almost silently from the distribution unit into the interior of the container, so that there is practically no indication on the outside of the goods transport container of the cooling taking place inside.

The known goods transport container on which the invention is based has proven itself in principle. However, problems can arise when loading and unloading the food stored in the transport container. These result from the fact that the cooling medium, in particular cooled nitrogen gas, cannot be inhaled by an operator or may be dangerous for such a person. In the past, attempts were made to solve this problem by only starting loading and unloading after a certain time with the goods transport container open in order to allow the cooling medium inside to escape to the outside. The ventilation time naturally depends on the external conditions, in particular the ambient temperature, wind conditions, etc. In addition, the ventilation time cannot be used advantageously for other purposes and must instead be waited for. The invention aims to remedy this situation.

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Andrej ewski, Honke & Sozien, patent attorneys in Essen

The invention is based on the technical problem of further developing a goods transport container for perishable products such as foodstuffs, etc., in particular a truck trailer or a truck box trailer, of the design described at the beginning in such a way that safe loading and unloading is possible and the ventilation of the goods transport container required for this takes place in the shortest possible time.

To solve this technical problem, a generic goods transport container is characterized within the scope of the invention in that a forced ventilation unit is provided to ensure that the interior of the container is largely free of cooling medium, at least for loading and unloading. The forced ventilation unit is therefore located next to the ventilation slots already present in the goods transport container, which ensure that the cooling medium emerging from the distribution unit can transport the displaced air to the outside. This process occurs almost continuously, at least as long as the cooling medium flows out of the distribution unit or there is a temperature gradient between the inside and outside.

In contrast, the forced ventilation unit primarily works during loading and unloading or during a preceding work step. In contrast to the ventilation slots, it ensures that air is actively introduced into the container from the outside in order to expel the cooling medium located there. Of course, this usually involves much larger volume flows than is the case when the cooling medium is supplied and the air is discharged.

Andrejewski, Honke & Sozien, patent attorneys in Essen

from the goods transport container. In this way, the invention ensures that the interior of the container is largely free of cooling medium during the upstream work step before loading and unloading. This means that health-endangering concentrations of the cooling medium inside the container can be excluded after forced ventilation. The invention achieves this by using an air quality measuring device inside the container, which is provided for controlling the forced ventilation unit.

The air quality measuring device can be arranged in the head area and thus takes into account the fact that layers of the cooling medium filling close to the bottom are initially removed from the inside of the container. The air quality measuring device usually has a sensor that measures the oxygen content.

The forced ventilation unit is controlled depending on how high this oxygen content is. In the simplest case, this can mean that a fan in the forced ventilation unit is operated at maximum or adjustable speed until the oxygen content has exceeded a specified target value (for example, more than 15 vol.%). This is because it can then be assumed that an operator can enter the interior of the container without any problem. There is therefore no longer any risk of suffocation.

In this context, it has proven useful to implement a control unit for actuating the forced ventilation unit and evaluating the air quality measuring device.

Andrejewski, Honke & Sozien, patent attorneys in Essen

This control unit may ensure the described control process in the sense that the forced ventilation unit and in particular the fan provided works until the air quality measuring device or the sensor for measuring the oxygen content detects a sufficient oxygen concentration inside the container. This state is usually accompanied by a visual and/or acoustic display which allows an operator to access the inside of the container. This can be implemented in detail by a light signal, a horn signal, etc.

For safety reasons, a recording unit is also provided which records and documents individual parameters such as air quality measurements, temperature measurements, etc. This makes it possible to determine without a doubt after what time the goods transport container can be entered for loading and unloading without any problems following forced ventilation. In addition, the recording unit provides complete documentation for quality assurance. This is because the recorded temperature measurements provide reliable information on whether the perishable products transported inside were ever exposed to a temperature that was harmful to them. At the same time, the documented air quality measurements can be used to prove that when nitrogen was used inside the container, not only was the desired temperature maintained, but also the inerting effect described in the relevant European preliminary applications EP 0 120 271 Al and EP 0 357 949 Bl was maintained.

Andrejewski, Honke & Sozien, patent attorneys in Essen

The goods transport container has at least one shut-off device with a position sensor. In the simplest case, this shut-off device is a rear flap that is opened for loading and unloading and supports the forced ventilation. It is advantageous to use a roller door or sectional door here, which can be stored inside the container to save space and does not require any space in the rear area to open. The position sensor assigned to the shut-off device now controls the forced ventilation unit in such a way that an opening signal sent to the roller door or shut-off device is immediately detected by the position sensor and, if necessary, starts the forced ventilation unit with the control unit interposed so that the forced ventilation can begin.

In addition, a shut-off unit is provided between the tank and the distribution unit. The shut-off unit has at least one solenoid valve for the controlled supply of the cooling medium. As a rule, at least two solenoid valves are used here to ensure a redundant design. This means that even if one solenoid valve fails, the cooling medium still flows through the distribution unit into the interior of the tank via the second solenoid valve, which is then (still) open.

Finally, at least one temperature sensor is provided inside the container, which, like the air quality measuring device, is located in the head area. This is also to protect the sensors from possible damage.

Andrejewski, Honke & Sozien, patent attorneys in Essen

protect. The temperature sensor can be used to control the amount of cooling medium fed into the tank and, in conjunction with the recording unit, to document the continuous cooling. To do this, the temperature is recorded by the control unit as already described and recorded by the recording unit. Depending on the temperature required inside the tank, the control unit opens the solenoid valves for a certain time until the desired temperature is reached inside the tank as part of a control process.

As a result, a goods transport container is provided which is designed in particular, but not limited to, as a truck trailer or truck box trailer. In principle, containers can also be equipped according to the invention. Low-emission cooling is always provided which has a high level of efficiency. This is achieved with a simple and low-maintenance 0 structure.

In addition, the goods transport container can be constructed in a modular manner. This means that not only will a shut-off device be provided at the rear, but additional shut-off devices will also be provided inside to separate individual chambers from one another. In conjunction with the shut-off devices, this makes it possible to achieve different temperatures in the respective chambers.

Andrejewski, Honke & Sozien, patent attorneys in Essen

For example, a three-part division is conceivable, with one freezer chamber storing frozen products such as ice cream, frozen vegetables, pizzas, etc., while another chamber is used for the so-called fresh service and stores fresh fruit and vegetables at higher temperatures than in the freezer chamber. Finally, a third chamber may be used for normal products that are not cooled or are only cooled slightly.

Another advantage is that the cooling implemented in the goods transport container according to the invention can start almost instantly and in particular does not require any pre-cooling. This can be achieved by the amount of cooling medium supplied with the help of the respective shut-off unit. In addition to fast and cost-effective cooling, safe loading and unloading is also achieved because the forced ventilation unit and an associated warning device only ensure that the interior of the container is released when an operator can stay there safely. These are the main advantages.

In the following, the invention is explained in more detail with reference to a drawing which merely represents an exemplary embodiment; in the drawings:

Fig. 1 shows a goods transport container according to the invention in the embodiment of a truck trailer,

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Andrej ewski, Honke & Sozien, patent attorneys in Essen

Fig. 2 a view of the interior of the goods transport container according to the invention and

Fig. 3 to 5 Detailed views of the container interior.
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The figures show a goods transport container in the form of a truck trailer. This is used to distribute perishable products such as food from a logistics center to individual stores, for example. For this purpose, a tank 1 is provided for holding a cooling medium, which, as shown in Fig. 1, is arranged below the goods transport container between the rear axle of a towing vehicle and the front axle of the trailer. Of course, other mounting locations are also conceivable.

Tank 1 is used to store liquid or gaseous nitrogen. Of course, other cooling media can also be used. However, for cost reasons, liquid nitrogen is usually used.

Inside the tank 1 or on the way into the interior of the goods transport container, the liquid nitrogen changes into the gaseous state and is introduced into the interior of the container with the help of a distribution unit 2. From Fig. 3 it can be seen that the distribution unit 2 consists of several pipes, made of stainless steel in particular, which are attached to the ceiling of the goods transport container and are equipped with individual outlet holes 3 for the cooling medium. So that the nitrogen from the tank 1 does not escape unhindered through

Andrejewski, Honke & Sozien, patent attorneys in Essen

the distribution unit 2 can exit, an intermediate shut-off unit 4 is provided, which can be seen in Fig. 4. In the exemplary embodiment, the shut-off unit 4 consists of two redundantly designed and electrically actuated solenoid valves. At the same time, in terms of flow, a siphon 5 can be seen in Fig. 4 behind the shut-off unit 4, in which any condensate that may form inside the distribution unit 2 collects.

With the help of the shut-off unit 4, the cooling medium can be specifically expelled from the distribution unit 2. This means that the inside of the container is increasingly filled with the cooling medium, starting from the floor to the ceiling (in the case of nitrogen). This reduces the temperature inside the container. At the same time, the cooled nitrogen gas that is regularly used at this point ensures that an inert atmosphere is provided inside the container for the foodstuffs transported there.

This so-called inerting of the container interior ensures that the goods or foodstuffs stored therein are protected from the harmful effects of atmospheric oxygen. At the same time, a certain residual concentration of oxygen can be maintained inside the container, with this concentration value being kept constant for a longer period of time. Overall, inerting reduces the respiratory activity of perishable foodstuffs in an atmosphere with 0 reduced oxygen content and consequently the

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Andrej ewski, Honke & Sozien, patent attorneys in Essen

Decomposition of food or wilting of flowers or plants can be delayed.

By using cooled nitrogen gas, the goods transport container is filled - as described - from the floor to the ceiling, so that the atmospheric air previously present there must escape. For this purpose, one or more ventilation devices 6 are provided at the head. The example in Fig. 3 shows such a ventilation device 6 in the form of a flap 6 that can be pivoted outwards.

In order to achieve safe loading and unloading, the interior of the container must be set up so that it is largely free of cooling medium. For this purpose, according to the invention, a forced ventilation unit 7 is provided, as shown in Fig. 3. This is located at the head of the truck trailer, in the ceiling area. In the exemplary embodiment, the forced ventilation unit 7 essentially has an indicated roller fan 8, which has longitudinal slats that rotate about a largely horizontally arranged axis 9. Like the solenoid valves or the shut-off unit 4, the roller fan 8 can be operated electrically, in each case powered by the vehicle battery that is already present or by an external or internal additional accumulator.

The roller fan 8, like the solenoid valves or the shut-off unit 4, receives its switch-on signals from a control unit 10. The control unit 10 thus acts on the forced ventilation unit 7, depending on

Andrejewski, Honke & Sozien, patent attorneys in Essen

Measured values that it receives from an air quality measuring device 11. In the exemplary embodiment, the air quality measuring device 11 essentially comprises a sensor for measuring the oxygen content inside the container. Depending on how high the oxygen content inside the container is, the control unit 10 controls the forced ventilation unit 7 accordingly, and does so until a certain minimum value of the oxygen concentration is reached. In the exemplary embodiment, this is approximately 20 vol.%, i.e. the oxygen content that is also present in the air atmosphere.

In addition, a recording unit 12 integrated in the control unit 10 or externally is provided, which records and documents the air quality measurement values provided by the air quality measuring device 11.

At the same time, the recording unit 12 is also able to record temperature measurements as well as the date, time 0, etc. The temperature measurements are provided by one or more temperature sensors 13 provided inside the container.

Based on the temperature determined inside the container using the temperature sensor 13, the control unit 10 controls the shut-off unit 4 accordingly. It goes without saying that a corresponding and desired temperature can be set on the control unit 10. The lower this temperature is, the more often the shut-off unit 4 must be opened in order to let the cooling medium into the container. This means that with the help of the temperature sensor 13, the cooling medium can be cooled.

Andrejewski, Honke & Sozien, patent attorneys in Essen

Sensor 13 controls the amount of cooling medium supplied to the tank interior.

Finally, a shut-off device 14 is implemented at the rear of the goods transport container. This is a roller door or sectional door 14. To load and unload the goods transport container, the roller door 14 is opened, for example from the driver's cab 15. This opening movement is detected by a position sensor 16, which is only indicated and is assigned to the shut-off device 14. The position sensor 16 is connected to the control unit 10. Based on its signal, the control unit 10 ensures that the forced ventilation unit 7 is immediately put into operation. This then works until the air quality measuring device 11 determines the desired oxygen concentration (20 vol. %) inside the container. This can be the case after just 20 to 30 seconds.

The air sucked in from the outside via the forced ventilation unit 7 in the ceiling area at the front is pressed into the interior of the container so that the gaseous cooling medium leaves the goods transport container at the rear via the now fully opened shut-off device 14.

Finally, Fig. 2 shows that the goods transport container can be divided into different chambers 17, 18. Each chamber 17, 18 can be separated from the other chambers 17, 18 by means of its own shut-off device 14 with position sensor 16, which is a swing gate inside the container.

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Andrejewski, Honke & Sozien, patent attorneys in Essen

In order to be able to set the temperature in each chamber 17, 18 differently if necessary, each chamber 17, 18 has its own distribution unit 2 and shut-off unit 4. Of course, separate sensors 11, 13 and 16 must then be implemented for each chamber 17, 18. This is only shown in outline.

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Claims (10)

1. Goods transport container for perishable products such as foodstuffs etc., in particular truck trailers, with a tank ( 1 ) for holding a cooling medium, and with a distribution unit ( 2 ) in the interior of the container for the targeted discharge of the cooling medium and thus reducing the interior temperature of the container, characterized in that a forced ventilation unit ( 7 ) is provided in order to ensure a largely cooling medium-free interior of the container at least for loading and unloading. 2. Goods transport container according to claim 1, characterized in that an air quality measuring device ( 11 ) is provided in the interior of the container for controlling the forced ventilation unit ( 7 ). 3. Goods transport container according to claim 1 or 2, characterized in that the air quality measuring device ( 11 ) is arranged in the head region. 4. Goods transport container according to one of claims 1 to 3, characterized in that the air quality measuring device ( 11 ) has a sensor for measuring the oxygen content. 5. Goods transport container according to one of claims 1 to 4, characterized in that a control unit ( 10 ) is implemented for actuating the forced ventilation unit ( 7 ) and evaluating the air quality measuring device ( 11 ). 6. Goods transport container according to one of claims 1 to 5, characterized in that a recording unit ( 12 ) records and documents individual parameters such as air quality measurements, temperature measurements, etc. 7. Goods transport container according to one of claims 1 to 6, characterized in that at least one shut-off device ( 14 ) is equipped with a position sensor ( 16 ) which controls the forced ventilation unit ( 7 ). 8. Goods transport container according to one of claims 1 to 7, characterized in that the distribution unit ( 2 ) has at least one solenoid valve for the controlled supply of the cooling medium. 9. Goods transport container according to one of claims 1 to 8, characterized in that two solenoid valves each form a redundant shut-off unit ( 4 ). 10. Goods transport container according to one of claims 1 to 9, characterized in that the supply quantity of cooling medium into the interior of the container is controlled with the aid of at least one temperature sensor ( 13 ).