DE2054722A1 - Refrigerated shipping container - Google Patents

Description

DR.ING. F. WtTBSTHOFF _{o A} DIPL. ING. G. ^{PULSE 8 MÜIICH1! N 8O}

SCHWiIGERSTRASSE S DR. ING. D. BEHRENS " ^l " ^{ol (} «Οββι

PATmAKWlLT ₁ "": _ο "τρ" ™ ΓΓ "'

1A-38785

Description of the patent application

ELECTRONIC ASSISTANCE CORPORATION, Fair Lawn, New Jersey, U.S.A.

regarding refrigerated shipping containers.

The invention relates to coolable shipping containers or so-called refrigerated containers, and in particular it relates to novel and very useful ones with cooling devices equipped shipping containers that make it possible to store the shipping goods in a first place where a source for an electric current with a first frequency is available, as well as at a second place where a source is available is available for an electric current with a second frequency

When sending perishable goods such as fruit, vegetables, dairy products ^ eggs, meat and from the sea Chilled food is necessary to prevent spoilage of the transported goods. For short-term or long-term storage as well as for quick freezing different temperatures have to be used for a particular product. For example, with short-term A temperature of around 4.5 ° C is advisable for storing asparagus, while a temperature of around 0 ° C is recommended for long-term storage of asparagus. The freezing point of Asparagus is around -1.1 ° E, while with quick freezing

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- 2-tone asparagus a temperature of about -54-, 4 ° C is appropriate.

Often certain temperature ranges are prescribed for the various purposes. For example, strawberries are stored briefly at temperatures in the range from 5 »5 to 7.2 ° C and for a long time at temperatures in the range from -0.55 to ⁰ ° C .; the freezing point is around -1.1 ° C, while the quick freezing temperature is around -9 »5 ° C.

Controlling the humidity is also important. For example, with cauliflower a relative humidity of 85% to 90 $ must be maintained, while the relative humidity moisture in melons should be in the range of 7% to 85%.

It can thus be seen that with regard to the optimal control of the temperature and the humidity during the Shipping of perishable food and the like strict requirements must be met. A fact that makes it extremely difficult to make these claims meet, is that during shipping the electrical power sources available in different places are not standardized.

If goods are to be transported by plane, there is a likelihood that the electrical power grid At the airport where the goods to be transported are stored before being loaded onto an aircraft, an alternating current with a frequency of about 60 Hz. Once the cargo has been put on an airplane, there is a likelihood that the only available electrical power source supplies an alternating current with a frequency of 400 Hz. At the destination or arrival airport, where it may be necessary to store the load again for a longer period of time, there is again the probability that a power source is available, which supplies an alternating current with a frequency of 60 Hs.

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Up to now known devices for controlling the Temperature of perishable food during transport have not proven to be expedient in every respect proven.

One way of regulating the temperature is to use, for example, frozen carbon dioxide or dry ice is used, which enables temporary cooling without the transport container being connected to a power source needs to be. However, this solution is unsatisfactory, since it is not possible to determine the temperature of the transported goods to regulate sufficiently, and since the dry ice evaporates fairly quickly, so that the transported goods do not during one can be cooled for a longer period of time.

A slightly more complicated option is to use practically two different ΣηΤΠ devices, one of which can be fed with an alternating current with a frequency of 60 Hz, while the other is operational is when you connect them to a source for an alternating current with a frequency of 400 Hz. However, this option also proves to be unsatisfactory because it provides a requires a certain amount of time, and since the personnel handling the transported goods must be trained to ensure that the correct connections are made in the course of the transport; in addition, the ones to be used here Facilities quite expensive.

Another possibility is to provide a cooling device to be carried by the vehicle concerned, which is designed so that it can be fed with an alternating current of 60 Hz at the loading area, and also a to provide a cooling device which responds to frequency changes and which is connected to the electrical system of the vehicle when the vehicle is in motion. The drive mechanism of the vehicle is designed so that the output frequency of the alternator is in

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Depending on the driving speed or the engine speed changes, and switching means are provided through which the Pole arrangement of the motor on one between the ends of his Speed range is changed. In this way, the chiller motor speed range in kept an optimal speed range for the compressor. Here, changeover switches must be operated by hand to activate the To select the operating mode of the cooling device during storage of the goods to be transported or during transport. Switching between the two pole arrangements of the motor can be effected by a frequency-sensitive relay. Such However, the arrangement leaves much to be desired, since the operation of the cooling device is directly dependent on the speed of the vehicle in which the cooling device is installed.

Furthermore, it is already known to provide a portable cooling device that can be connected to a normal power supply system can be connected to an alternating current of 60 Hz, or to a 6 volt direct current source, as in Motor vehicles is encountered. Here, the connector is connected inside in such a way that the required switching is effected in that the plug is connected to the relevant power source. In modern distribution systems where planes in large Be used extensively to transport food items to markets is proven (but also such a system only to a limited extent as useful.

Furthermore, it is known to provide a transportable cooling device, which is connected to a dock wall, for example provided power supply can be connected while it is calibrated on a vehicle, this facility serves to freeze a certain amount of a eutectic fluid on the spot. Here leaves one that can be connected to the electrical system Fan circulate air over the eutectic fluid to maintain temperature. Such an arrangement also offers

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no complete solution of the problem posed, d% she insufficient choice of temperature offers, and since the cooling device only remains effective for a limited period of time, the IPlud again after this period has expired must be brought to freeze.

The invention is based on the object of the above-described disadvantages of the prior art and Avoiding arrangements. In particular, the invention provides measures which make it possible to remove highly perishable goods how to move food from any source to any market, and that! to keep the entire transport process at an optimal temperature. Furthermore, the invention provides measures that make it possible to carry out the transport process in such a way that only minimal loss of time occurs and the personnel handling the consignments are only trained to a minimal extent needs to be.

For the stated purpose, the invention provides a trans, portable housing for receiving the transported goods and a fluid circuit firmly connected to this housing. With In this fluid circuit, a compressor, an evaporator and a condenser are connected in series, and there is a connection which can be connected to electrical power sources operating at two different frequencies. A the compressor motor driving the compressor can be switched to a first operating mode in which it is connected to a desired speed works when it is supplied with an alternating current at one of the two frequencies; this compressor motor can be switched to a second operating mode, with 4 it essentially at the same speed runs when it is fed with an alternating current with the second of the two frequencies. Here one generates with the Connection connected frequency-sensitive device an output signal, which varies according to the frequency of the alternating current directs the connection from the relevant power source

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is fed out. One by the frequency-sensitive Device actuatable device switches the compressor motor to the operating mode coming into embossing, so that the Compressor motor always at the desired speed regardless of the frequency of the alternating current supplied to it is working.

fan drive motors are also provided which drive an evaporator fan and a condenser fan. Even these motors can each be switched to one of two modes of operation, and they will operate on that Operating mode switched automatically by detecting the frequency of the alternating current which the motors is supplied via the connection mentioned.

The invention and advantageous details of the invention are illustrated below with reference to schematic drawings explained in more detail using an exemplary embodiment.

Figure 1 is a front perspective view of part of a device according to the invention.

Fig. 2 shows schematically the circuit of certain electrical switching elements of the device according to the invention.

flg. 5 is a schematic representation of certain electrical line means according to the invention and a sludge line arrangement.

In Fig. 1 can be seen a total of 10 designated device according to the invention. The device 10 comprises a rectangular bottom 12, a generally rectangular left side wall 14, and a generally rectangular right side wall 16. The apparatus further comprises a left rectangular sloping ceiling section 18 and a right rectangular one inclined ceiling section 20k which go into a rectangular ceiling section 22 of the device. It also includes Device a closing the rear end of the container

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Rear wall 24 and a front wall, not shown, which is removable to facilitate filling and emptying of the container facilitate.

A cooling device 26 for cooling the interior of the container is arranged in the container. This cooling device 26 includes a plurality of hoses 28 for distributing cooled air throughout the container such that the products stored therein are effectively cooled. In a typical refrigeration facility eight hoses are provided, of which, however, only two are shown in FIG. 1 for the sake of clarity.

The overall design of the container described is such that it can be easily transported in an airplane can, wherein the to the wall surfaces 12, 14, 16, 18, 20 and 22 parallel and to the rear wall 24 and to the front wall at right angles The axis of the container runs parallel to the axis of the aircraft fuselage. The container consists of one or several materials that have good thermal insulation properties have in order to reduce the load on the cooling device 26.

The cooling device 26 can be connected to a power source 30 according to FIG. 2 with the aid of a plug 32, which supplies an alternating current with a frequency of 60 Hz or a frequency of 400 Hz. The plug 32 is according to FIG. 2 connected to five branch lines 34, 36, 38, 40 and 42. The branch lines 38, 40 and 42 can be operated with electric motors 44, 46 and 48 are connected. Each of these electric motors of known type can work with two different modes of operation, as with respect to engine 44 at 44-1 and 44-2 of the motor 46 at 46-1 and 46-2 and with respect to the motor 48 at 48 »1 and 48-2 is only indicated schematically. In the The first operating mode of each motor is the operating mode in which the motor is connected to an alternating current a frequency of 60 Hz, while the motor in • the second operating mode with an alternating current with a

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Frequency iron 400 Hs is fed, with the motor at both Modes of operation essentially bit the same speed works.

According to FIG. 2, the motors 44, 46 and 48 are assigned switching means 50 and 52 and 54, respectively, which make it possible to connect the motors to the power source 30 as required so that they are operated according to one or the other of their two modes of operation. In that shown in FIG The position of this switching means is the line 38 with the motor 44 connected by a line 56 so that it is with a AC current of 60 Hz can work · ', the line 40 is with the motor 46 is connected by a line 58 so that it is with an alternating current of 60 Hz, and the line 42 is connected to the motor 48 via a line 60 so that the motor is operated with alternating current of 60 Hz can be. If switches 50, 52 and 54 are toggled, the line 39 is connected to the motor 44 via a line 62 so connected that this motor can be operated with alternating current of 400 Hz, the line 40 is connected to the motor connected via a line 64 so that this motor is fed with alternating current of 400 Hz, and the line 42 is connected to the motor 48 via a line 66 so that it operates on alternating current of 400 Hz.

The switches 50, 52 and 54 are dropped through as R-1 and R-2. (Switch 50) relays R-3 and R-4 (switch 52) and relays R-5 and R-6 (switch 54) are controlled. You Heiais R-1, RB and R-5 sigd connected to a common line 66, that with the Leitugg? 34 is connected via a transmission filter for 60 ms, and the relay R-2, R-4 and R-6 are connected to a common line 72, the door 74 400 Hz is connected to the line via a pass filter. The 60 Hz filter 70 allows an alternating current to pass through, the frequency of which is in the range from, for example, slightly less than 50 Hz to approximately «over 60 Hs, ie the alternating current which is available in practically all airports around the world.

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In the United States, a frequency of 60 Hz is common, while in Europe, for example, a frequency of 50 Hz is common. However, the 60 Hz filter does not pass an alternating current whose frequency is close to 400 Hz.

On the other hand, the 400 Hz filter 74 leaves an alternating current the frequency of which is 400 Hz, while it does not allow any alternating current to pass through, the frequency of which is in the vicinity of 60 Hz.

The circuit according to Pig. 2 works as follows; The connector 32 is used at an airport or on board an airplane connected to the respectively available power supply device, regardless of whether the supplied AC current has a frequency of 60 or 400 Hz. Initially, switches 50, 52 and 54 are in the position shown in FIG Fig. 2 position shown or in the last described opposite position. In either case, only the odd ones will be used Eelais E-1, E-3 and E-5 or only the even-numbered relays R-2, R-4 and £ -6 energized. This is due to, that only one of the filters 70 and 74 · that of the relevant Current drawn from the power source lets through *

The electrical energy is supplied to the motors 44, 46 and 48 so that the motors are fed with 60-period alternating current or with 400-period alternating current, whichever depends on whether the odd-numbered relays or the even-numbered relays are energized via the filters 70 and 74 will. If the odd-numbered relays E-1, E-3 and E-5 are energized, the motors 44 ₉ 46 and 48 are switched in the manner shown in FIG. 2 for operation with 60-period alternating current. If the even numbers R-2, E-4 and £ -6 are excited, the three motors can be fed with 400-period · »alternating current.

Si ·, motors 44, 46 and 48 are · ο designed that their · Operating speeds at 60 Hs are essentially the same • ind as with 400 Hs. Such · operational behavior can be

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s.B. by having two poles at 60 Ea and at 400 Hz brings twelve poles to effect. In the H.nbliwk on the The usual slip at full load can result in a motor shaft speed of about 3450 rpm at full load and 60 Hs bsw. a speed τοη about 3700 rpm at full load and 40QhHz result.

The motors 44, 46 and 48 serve sram according to the invention Driving a compressor 80 or an evaporator fan 82 or a capacitor fan 84. (According to the above Description, these three units run essentially at the same speed, regardless of the frequency of the current that is suggested to them via the connector 32.

3 shows how the compressor 80, the The evaporator 82 ′ and the condenser 84 are switched on in a line circuit 86. The compressor 80 compresses a refrigerant substantially adiabatically so that the temperature dee Coolant increases rapidly. The refrigerant is compressed fed via a line 88 to the capacitor 84 *, in which a heat exchange takes place. With this heat exchange In the condenser 84 *, heat is released from the coolant to the ambient air, since the coolant is on a higher temperature than the ambient air. The condenser fan 84 allows ambient air through the condenser 84 * flow away to facilitate the heat exchange · Bas Coolant then flows in the cooled state through a line 90 to a throttle valve 92, which acts as a two-way valve is formed and can be controlled by an electromagnet 95 so that the coolant either a line 96 or a line 98 is supplied.

The electromagnet 94 is controlled by a thermostat 100 connected to a power source 102 · You Power source 102, as shown in Jig * 3, may be a battery or the electricity can be taken from the electricity grid «

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- 11 to which the plug 32 is connected.

The thermostat, constructed in a known manner, is adjusted so that it receives a desired temperature. As long as the thermostat 100 senses a temperature deviating from the setpoint temperature, the electromagnet 94 operates. that the two-way throttle valve 92 establishes a connection between the line 90 and the line 96. Here it can Flow refrigerant via line 96 to the evaporator 82 ', in which it is under a low pressure, so that it evaporates. The evaporation is a cooling process, so that the one arranged in the container 10 according to FIG Evaporator absorbs heat from inside the container. This heat exchange is carried out according to Pig. 2 through the Evaporator fan 82 supported. The coolant then flows through a line 104 back to the compressor 80, whereupon the work cycle described is repeated.

When the thermostat 100 senses the set temperature, it controls the solenoid 94 so that the valve 92 the Flows refrigerant to a bypass conduit 98 which bypasses the evaporator 82 'while the compressor 80 can still be operated with his Hennlast

In the context of the invention it is possible to use devices which make it unnecessary to bring the supplied current, which can be three-phase, for example, into phase, e.g. a Phase reversal switches can also be used with capacitors Correcting the power factor and other devices Provide, e.g. magnetic-hydraulic circuit breakers for overcurrent protection, a transformer for disconnecting the supplied alternating currents to a lower voltage of e.g. 28 V as well as display means, e.g. a lamp for displaying wrong phase of the supplied current. Furthermore, rectifier means are contemplated within the scope of the invention provide that convert the supplied alternating current into direct current, and instead of the filters described, others

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Provide devices, e.g., frequency sensitive relay means, responsive to the high and low frequencies, respectively to switch on the motor control devices in question

Furthermore, according to the invention, automatic defrosting means can be provided which have one associated with the hot gas Electromagnets include when the liquid falls off associated electromagnet is excited, as well as an electrical ear that controls deg defrosting. During a defrost, the evaporator fan is turned off and the evaporator is exposed to hot gas to defrost the evaporator coil

The invention thus provides novel and very useful methods and devices that transport this facilitate perishable goods by air The device according to the invention is designed so that it can be connected for the purpose of operation to a normal electricity network, for example a three-phase network in which the voltage in the range from 200 to 250 V and the frequency is in the range of 50 to 60 Hs, or at which the frequency 400 Hz. The invention enables transport delays during transport as well as at the point of departure as well to be avoided at the place of destination, so that perishable products are protected against spoilage during transport will.

For those skilled in the art, it is obvious that the device according to the invention can be used in a wide variety of modifications and variations.For example, the device according to the invention can be designed in such a way that it automatically adjusts to one of more than two frequency ranges when it is switched on Is connected to the power grid. Furthermore, one of the frequency ranges can be provided for direct current, wherein a direct current can be regarded as an alternating current _v with the frequency zero. Furthermore

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you can use a power source e.g. a gasoline engine Provide a drivable power generator or a solid-state inverter that works with a fixed frequency

Claims :

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Claims (7)

DR. ING. F. WUESTHOFF ₈ MUNICHKN ΘΟ DIPL. ING. G. PULS - 14 · - 8CHWHOEB8TRA8SE S DR.ETPKCHMANN
DR. ING. D. BEHRBNS PATENTANWÄLTE raoTSOTPATBMT «βίο» » 1J.-38 785 EXPECTATIONS Λ · / Device for storing clay products to be kept cool at a first location at which a power source operating at a first frequency is available, and at a second location at which a power source operating at a wide frequency is available, characterized by portable housing means (10) for receiving the products, fluid circuit means (86) attached to the housing means, compressor means (80) connected in series with the fluid circuit means, evaporator means (82 *) and condenser means (84 *), plug means (32) to connect the device to a with one of the two frequencies working power source (30), to the connector means connected compressor motor means (44) for driving the compressor means, wherein the compressor motor means can be brought into a first switching position in which they operate at a desired speed when they are an alternating current with the first Frequeni is supplied, and can be brought into a second switching position, at d when they operate at substantially the same speed when they are supplied with an alternating current at the second frequency, frequency sensitive supply means (70, 74) connected to the connector means for generating an output signal which is dependent on the frequency of the electrical power source to which the connector means are connected, as well as switching means (B-1, B-2, 50) which are actuated by the frequency-sensitive supply means in order to bring the compressor motor means into their first switching position when the plug means are connected or connected to a power source operating at the first frequency. around 109823/1155 to bring the compressor motor means into its second switching position when the plug means to one with the second Frequency operating power source can be connected. 2. Apparatus according to claim 1, characterized by evaporator fan means (82) for one-way blowing of air over the evaporator means (82 ¹ ) »to facilitate the exchange of heat, evaporator fan motor means (46) connected to the connector means (32) for driving the evaporator fan means, the evaporator fan motor means Can be brought into a first switching position, in which they work at a desired speed when you are supplied with an alternating current at the first frequency, and can be brought into a second switching position, in which they work essentially at the same speed when they are a AC current is supplied at the second frequency, as well as by switching means (B-3, H-4-t 52), which are actuated by the frequency-sensitive supply means (70, 74-) to bring the evaporator fan motor means in its first switch position when the Plug means are connected to a power source operating with the first frequency, and in a zw Second switch position when the plug means are connected to a power source operating at the second frequency. 3 · Device according to claim 1, characterized by condenser fan means (84) for blowing air over the ondemsator means (84 *) for heat exchange to facilitate condenser fan motor means (48) connected to the connector means (32) for driving the Condenser fan means, wherein the condenser fan motor means can be brought into a first switching position in which they operate at a desired speed when they are supplied with an alternating current at the first frequency, and in a second switching position, in which the work at substantially the same speed when they receive an alternating current 'is supplied with the second frequency j as well as by switching * 109823/1155 means (R-5, R-6.54), those at K _o ligands sator fan motor means to bring by the frequency sensitive Zufülirungßmittel (70, 74) are actuated into its first switching position when the plug means is connected to a working at the first frequency current source and into the second switching position when the plug means are connected to a power source operating at the second frequency. 4. Apparatus according to claim 1, characterized by shunt means (98) which are connected in parallel with the evaporation means (82 ') in the case of the flow circuit means (86), as well as switched on in the flow circuit means Valve means (92) so that the fluid flowing through the fluid circuit means during operation of the compressor means (80) can be made to flow through the evaporator means or to flow through the bypass means as required and so bypassing the vaporizer means. 5 * Device according to claim 4, characterized by in the housing means (10) arranged thermostat means (100) for displaying whether the temperature in the Housing means is below a predetermined! Temperature, as well as by electromagnetic means (94), which by the thermostat « means can be operated to adjust the valve means (92) so that the flow circuit means (86) Flowing fluid around the evaporator means (82 *) is only diverted when the temperature in the housing means is below the predetermined temperature. 6. Device for storing goods at a storage location, where a power source operating at a first frequency is available, and in a vehicle in which one is available with a power source second frequency working power source is available to me, characterized by center of housing J. (10) «around Picking up the stored goods, fastened in the housing means » Flux circle means (86), with this flow circle means in leg switched compressor means (80), evaporator means (82 ') and Capacitor means (84 *), plug means (32) for connection ".., i..1 0 9 823/1155 BATH ORIGINAL of the device to any one of the two power sources operating at two different frequencies, compressor motor means (44) connected to the plug means for driving the compressor means, the compressor motor means being able to be brought into a first switching position in which they work at a desired speed when they receive an alternating current is supplied at the first frequency, and in a second switching position, in which they work essentially at the same speed when they are supplied with an alternating current at the second frequency, frequency-sensitive supply means connected to the _{connector means for E 1} , -generating an output signal, which depends on the frequency with which the power source to which the plug means are connected operates, switching means (E-1, R-2, 50) which can be actuated by the frequency-sensitive supply means and which bring the compressor motor means into their first switching position when the disturbances .cker means with one with the first frequency operating power source are connected, and in the second switch position, when the plug means are connected to a power source operating at the second frequency, evaporator fan means (82) for blowing air over the evaporator means to facilitate the heat exchange, evaporator fan motor means connected to the connector means (46), which can be brought into a first switching position, in which they work at a desired speed if an alternating current with the first frequency is suggested to them, and in a second switching position, in which they work essentially at the same speed, if iimen an alternating current with the white frequency 2ug3fiihr ⁺ . ^: W \ rd, curch the frequency sensitive Zufülirj.'ogsmittel operable Schaltlaittel (RJ, H-4, 52), the dis ^ Verdampfergebläsemc oraii l-bel in their first Schaltatellutg brirc ■ - ■■ '■ .: if the Steokana.ittel an'i silt d-ar ^ gtea J? r «c ■ * ·; ■;» 2 >. ' ' βινί.ώ özro ^ ou'.llo «.ώ + .. θ- : ι * "ί Ä γ, ■%% ί * · _λ - ^ ti ■" * ^ rti ■ '-. - i Steck «; ? Kd: - ^ l sch ein «lait dar BATH ORIGINAL (84) for blowing air over the condenser means, in order to facilitate the exchange of heat, condenser fan motor means (48) connected to the connector means and shown in FIG a first switching division can be brought, in which they work at a desired speed when they are connected to an alternating current the first frequency is supplied, and in a second switching position in which they are essentially at the same speed operate when they are supplied with an alternating current at the second frequency through the frequency sensitive supply means actuatable switching means (R-5, B-6, 54), the the capacitor fan motor means in their first switch position bring when the connector means to one with the first. Frequency operating power source can be connected, and into the second switching position when the plug means are connected to a power source operating at the second frequency, Shunt means (98) connected in parallel, which form a component of the fluid circuit means and determine with the evaporator, which make it possible to induce the fluid circulated by the compressor means in the fluid circuit means as required, to flow through the vaporizer means or bypassing the vaporizer means through the lift lock means, in the housing arranged thermostat means (100) which indicate oh the temperature in the housing means below a predetermined Temperature, as well as solenoid means (94) which can be actuated by the thermostat means and which adjust the valve means so that the fluid flowing through the fluid circle means only then around the evaporator means is indicated when the temperature in the housing center is below the predetermined temperature. 7. Method for transporting perishable goods by air, characterized in that the goods to be transported are placed in transportable insulated housing means, that a refrigeration device is attached to the device, the refrigeration device in alternating current with a frequency of 3/1155 _ßAD original about 60 Hz is supplied when the housing means is on an airport located that the refrigeration device is supplied with an alternating current with a frequency of about 400 Hz when-calibrated the housing means on board a plug-in tool find that the frequency of the supplied alternating current is sensed, that an electrical signal is generated, which depends on the frequency of the alternating current supplied, and that the refrigeration device in Depending on this electrical signal is brought into one of two possible switching positions, so that the operating speed the Ealtevrzeugungsvorrichtung from the frequency of the alternating current supplied to it essentially independent is. 1 0 9 8 2 3 '' 1 1 b 5 ORIGINAL INSPECTED