DE102007010981A1 - Cooling element for cooling a transport box is hermetically surrounded by a gas-tight multiple layer film to enclose a regulating unit, a steam passage and a vaporizer - Google Patents

Abstract

Cooling element is hermetically surrounded by a gas-tight multiple layer film to enclose a regulating unit (3), a steam passage (4) and a vaporizer (2). The vaporizer and the steam passage are flexible and the steam is only able to pass via the regulating unit to an absorbent (1). An independent claim is also included for a method for evacuating a cooling element. Preferred Features: The regulating unit contains a valve (6) which is operated by deforming the multiple layer film and a thermostatic valve. The thermostatic valve contains a regulating body made from a bimetal and is in thermal contact with the steam.

Description

The The invention relates to a sorption cooling element with a Control element and with a gas-tight multi-layer film for cooling in which by evaporation of a working fluid and subsequent Sorption of the working medium vapor in a sorbent below Vacuum cold is generated. The evaporator is flexible in this case, to be adapted to various cooling tasks.

Sorption cooling elements are apparatus in which a solid adsorbent is a second, at lower temperatures boiling agent, the working medium, vapor sorbed under heat release (sorption phase). The work equipment evaporates in an evaporator while absorbing heat. After the adsorbent is saturated, it can pass through Heat supply at higher temperature desorbed again become (desorption phase). In the process, working fluid evaporates from the adsorbent from. The working fluid vapor can be reliquefied and then evaporate again.

Adsorption apparatus for cooling with solid sorbents are from EP 0 368 111 and the DE-OS 34 25 419 known. Sorbent container, filled with sorbents, thereby absorb working agent vapor, which is produced in an evaporator, and sorb it under heat release. The heat of sorption must be removed from the sorbent. The chillers can be used to cool and keep food warm in thermally insulated boxes.

The WO 01/10738 A1 describes a self-cooling beverage can with an evaporator inside and a sorber outside the can. The cooling is started by opening a steam channel between evaporator and sorber. The cold generated in the evaporator is discharged through the surfaces of the drink to be cooled within the can. The heat generated in the sorbent is stored in a heat buffer. The self-cooling beverage can is heavily modified over an ordinary can and expensive to manufacture.

Further theoretical refinements of self-cooling containers are in the WO 99/37958 A1 compiled. Cost effective is none of the devices implement and manufacture.

The US Pat. No. 6,474,100 B1 finally describes a self-cooling cooling element on the outside of a bag for liquids or bulk materials. The sorbent is enclosed in a flexible, multi-layered film. The contact to the hot sorption filling is reduced to a minimum by insulation and flow materials as well as by intervening heat storage masses. The temperature compensation between the hot sorber filling and the cold evaporator, which are opposed over a large area, must be reduced by an elaborate insulation.

The DE 10 2005 034 297 A1 describes a sorption cooling element with gas-tight film in which a sorbent is filled in a gas-tight sorbent bag, which is cut to start the cooling function by means of cutting tool. A regulation of the cooling capacity is not possible.

task The invention relates to low-cost sorption cooling elements for single use in which the cooling adjustable is.

Solved This object is achieved by the characterizing features of the claims 1 and 19. The dependent claims show further inventive cooling elements.

According to the invention the individual components of a cooling element in a gas-tight, flexible multi-layer film sealed under vacuum so that the working fluid vapor flowing out of the liquid working fluid only to flow through the working medium vapor channel and the control element to the sorbent can. The generated by the external air pressure Deformation forces must be sufficient, the multi-layer film so to nestle the individual components that for the Working medium steam no side path remains open, the control device to bypass. The individual components do not need to be together be connected gas-tight. They are only in one of the multi-layer film insert bag and fix it until the Place bag under vacuum tightly around the components and only the Working medium steam channel remains open.

According to the invention the control element is easily opened by deforming the multilayer film and be closed. Elaborate vacuum feedthroughs are therefore not necessary.

Especially Advantageously, the control element of a valve seat and an on it matched sealing surface are formed. about a lever mechanism can pass through the multilayer film the regulator is opened and closed and if necessary also be used for power control.

Around to press the sealing surface on the valve seat are not further spring elements necessary if the flexible film so on the sealing surface abuts that of the outer Air pressure can act on the valve.

Advantageous it is hoses for the working medium steam channels to use, although the external pressure withstand, but not an additional pressure, z. B. generated by a tool that is externally applied to the multilayer film acts and squeezes the hose so strong that the flow path blocks becomes.

One another very inexpensive control organ is then formed, when the sorbent is sealed within a separate bag is. If this bag at the contact point to the working medium vapor channel pierced by sharp-edged cutting tool is also open the control organ. The cutting tool can of course also between multi-layer film and a separate bag. For the triggering must then the outer foil at the relevant point be deformable without being leaking yourself.

The Control element can in addition to the actual closure element and order a thermostatic valve will be extended. With the help of the thermostatic valve can the temperature of the evaporator is maintained at a control temperature become. At higher temperatures, the thermostatic valve gives the way the working medium vapor to the sorbent free, too deep Temperatures, the thermostatic valve closes the way.

When Thermostat are all known elements that are used in a temperature change a change of direction. Best known are here stretchers and bi-metals. Also memory alloys can be used advantageously. Especially inexpensive Bi-metal spirals can be used for the control organ. This temperature variations of less than 0.1 Kelvin can be achieved.

By the installation of a thermostatic valve, the cooling elements particularly advantageous for temperature-controlled cooling be used by transport isolation containers. isolated Transport containers serve z. B. for shipping temperature sensitive Food or pharmaceutical goods between +2 and + 8 ° C. Equipped with cooling elements according to the invention isolated transport containers are arbitrary storable for a long period of time. To start the cooling function all you have to do is open the regulator and cool it Product packed in the interior. The thermostatic valve regulates then the interior in a narrow temperature window, regardless from the currently prevailing outside temperature multiple days. As well as the insulation container of inexpensive material (eg polystyrene) can be made on one often expensive return transport be waived.

According to the invention all inner walls of an insulated container with evaporator surfaces be occupied. The interior temperature is then also at strongly fluctuating Outdoor temperatures very homogeneous. Since the evaporator constructed flexible according to the invention is, at least one evaporator area can be designed hinged. This area can be opened if necessary and the full Grant access to the internal volume.

Under Vacuum must all flow channels to Sorbents are retained. For this purpose are spacers provided that the working fluid vapor from the liquid Allow working fluid to flow freely and at the same time the cold surfaces conduct heat well with the foil to contact.

According to the invention this flexible plastic spacers used, which are adapted to the respective cooling task. requirement However, that is the plastic spacer during the storage time does not outgas and worsen the vacuum. From Advantage is when used as plastic polycarbonate, polyamide or polypropylene is used because these materials before or during the Production process heated to higher temperatures and can be degassed.

spacer made of plastic can according to known manufacturing processes such as deep drawing, extruding or thermoblowing cost getting produced. Advantageously, in the manufacturing process put emphasis on that no later outgassing substances such as plasticizers are added.

at the thermal transport containers in use today The goods are cooled by means of ice packs, which are within the Container must be arranged. Because these ice packs a multiple of the volume of an inventive Take evaporator, on the one hand, the internal volume clearly reduced, or on the other hand, a larger insulated container necessary. Larger containers have in turn more external surfaces over the more heat in the interior flows in, in turn, over larger Ice packs must be compensated.

The Areas of application are not on isolated containers limited. In principle, any object with inventive Cooling elements are equipped. It is advantageous z. B. the cooling of tents, in which even entire tent walls replaced by cooling elements according to the invention can be. Cooling of patients or Injured in a hot environment or to reduce it Body temperature is just as possible as a use as a cooling vest or cooling suit.

In principle, the place of use is everywhere be found where today cooling batteries or ice rechargeable batteries are used. The cooling elements according to the invention can be stored for any length of time relative to the cooling and ice accumulators and can be adapted to the task to be cooled, since the evaporator is designed to be flexible.

sorbents can reach temperatures of over sorption during the sorption process Reach 100 ° C. For such high temperatures are the ones commonly used in the packaging sector Multi-layer films are not always suitable. In particular, the for The sealing used polyethylene layers are already soft at 80 ° C and leave the sheath under vacuum be leaking. A sealing layer of polypropylene, however, can withstand significantly higher temperatures. Your melting point is over 150 ° C.

In Combination with high temperatures can cause sharp edges, Corners and tips on sorbent granules impermissible Cause leaks. This risk may be due to at least one polyester or polyamide layer can be met within the multilayer film. Polyamide films are particularly tear and puncture resistant. The actual gas barrier is characterized by a layer of a thin Metal foil or a metallized layer ensured. proven have this thin aluminum foils with a Layer thickness from 8 μm. Less tight are metallized Plastic films. Nevertheless, with short storage periods also the use of these metallized films possible, especially as they produce cheaper compared to the metal foils are.

The individual layers of a multilayer film are bonded together by adhesive connected. Commercially available adhesives contain solvents which not be completely removed from the adhesive layer during bonding. about longer periods of time, these solvents diffuse then through the inner layers, and affect the vacuum inside the cooling element. The diffusion is at higher temperatures, as in the sorption and manufacturing process the cooling elements occur, amplified. The to Use coming glue must therefore also for be designed for high temperatures.

Advantageous come multi-layer films with a polyamide layer thickness of 12 up to 50 μm, an aluminum layer thickness of 6 to 12 μm and a polypropylene layer thickness of 50 to 100 μm Commitment. Use find such films z. B. for packaging of foods that are added after preserving for preservation Temperatures of over 120 ° C are sterilized.

invention Multilayer films are z. B. on the company Wipf AG in Volketswil, Switzerland. When using such films are cooling elements with a leakage rate of less than 1 × 10 high -8 mbarl / sec possible. The shelf life thus achieves several years without the cooling readiness is impaired.

The Welding (sealing) multi-layer films to bags and the filling of bulk material and the subsequent Evacuation is state of the art in the food industry.

countless Bag sizes and shapes are in use there. Particularly noteworthy are stand-up pouches, bags with pouring openings, Bag with cardboard reinforcement, tear-open bag, Pouch with peel effect for easier opening and bag with valves. They all can with their specific characteristics for the cooling elements according to the invention be beneficial.

At the Filling of solid sorbent in bags is created Dust, which deposits on the inside of the film. Dust on the later seal points can lead to leaks, when the dust layer is opposite to the polypropylene layer is too thick. Polypropylene layer thicknesses of 50 to 100 microns are sufficient to ensure fine dust particles in the polypropylene layer safely and melt vacuum-tight.

at Use of films according to the invention makes it possible to hot, sharp-edged and dust-releasing sorbent without further protective liners directly under vacuum to envelop and over a perennial To store the period without the foil material itself or pass through this foreign gases into the cooling element, which impair the sorption reaction or even completely prevention.

When Sorbent is advantageous zeolite used. This one can in its regular crystal structure up to Sorb reversibly 36% by mass of water. In the inventive Application is the technically feasible water absorption 20 to 25%. Zeolites also have at relatively high temperatures (over 100 ° C) still a considerable water vapor sorption capacity and are therefore particularly suitable for the use according to the invention.

zeolite is a crystalline mineral that is in a framework structure Contains silicon and aluminum oxides. This very regular Scaffold structure contains cavities, in which water molecules with heat release can be sorbed. Within the framework structure the water molecules are exposed to strong field forces, their strength from that already in the framework structure contained amount of water and the temperature of the zeolite depends.

Naturally occurring, natural Zeo Lith types absorb significantly less water. Per 100 g of natural zeolite, only 7 to 11 g of water are sorbed. This reduced water absorption capacity is due on the one hand to their specific crystal structures and on the other hand to non-active impurities of the natural product. For cooling elements, which also have the opportunity during a longer cooling period to release the heat of sorption via the shell, synthetic zeolites with their greater sorption capacity are therefore to be preferred. For cooling elements with high cooling capacity and / or short cooling time, in which the sorbent remains relatively hot, according to the invention also natural zeolites are used. At high sorbent temperatures, synthetic zeolites are no longer at an advantage over the natural ones. Typically, with inhibited release of the heat of sorption and concomitant high sorbent temperatures of over 100 ° C, both types can sorb only 4 to 5 g of water vapor per 100 g of dry sorbent mass. Economically, even the natural representatives are clearly in the advantage for this application, since the price is considerably lower.

natural Zeolites have another advantage. The non-active admixtures typically 10 to 30%. You are not active involved in refrigeration, yet they are by the with adjacent zeolite crystals heated. They work with it like an additionally installed, inexpensive heat buffer. The result is that the zeolite filling gets less hot and thus at lower temperatures additional water vapor can sorb.

natural Zeolite granules consist of broken or crushed fragments and therefore has sharp and pointed geometric shapes that under vacuum and elevated temperatures, the multi-layer films puncture or cut through.

Under which are about 30 different, natural zeolites the following for the invention Advantageous to use cooling elements: clinoptilolite, chabazite, Mordenite and Phillipsite.

In naturally occurring substances can also be used without environmental requirements be returned to nature. natural Zeolites can after their use in cooling elements z. B. as a soil conditioner, as a liquid binder or to improve water quality in stagnant water be used.

From The synthetic zeolite types are types A, X and Y, respectively to be recommended in their inexpensive Na form.

Next The combination of zeolite / water are also other solid sorption pairings for use in the invention Cooling elements possible. Especially mentioned be bentonites and salts, which are also water with the working fluid represent suitable combinations. Activated carbon can also be used in combination provide a beneficial solution with alcohols. There too These fabric pairings work in negative pressure, they can Welded in multilayer films according to the invention become.

According to the invention to sizing the amount of sorbent and arrange so that for the incoming water vapor only a minimal Pressure drop to be overcome within the sorbent got to. In this case, the pressure drop should especially in water as a working fluid less than 5 mbar. In addition, the sorbent has the inflowing agent vapor sufficient surface to provide attachment. For a uniform sorption within the sorbent and a low pressure drop too ensure sorbent granules have proven particularly useful. Granule diameters between 2 and 10 mm show the best Results. These are easy to unpack and form after the Evacuate a hard, pressure and dimensionally stable sorbent molding, which maintains the form imposed during evacuation. Around nevertheless with the dimensionally stable sorbent moldings To be able to represent variable geometries, according to the invention Sorbent in several, only via steam flow channels filled connected areas. The single solid areas can be, if the steam channel continues to be flexible is, move against each other, fold and stack at z. For example, cramped Space to satisfy and yet to allow a good air circulation.

Advantageous are also preformed from zeolite powder, dimensionally stable Zeolite blocks, already in the flow channels can be incorporated and de ren shaping the desired Cooling element geometry is adjusted. The stable zeolite blocks can in the area of the working medium vapor channels cavities have, in order not to hinder the flow.

at The sorption reaction releases heat of sorption which causes the Heated sorbent. The capacity for Water increases strongly at higher sorbent temperatures from. For a high cooling capacity over a longer To maintain period, it makes sense to use the sorbent to cool.

In direct contact of the sorbent with the multi-layer film resulting heat of sorption can be dissipated unhindered through the film to the outside. As a rule, the heat be derived from the surrounding air. It is also very efficient to cool the sorption container with water.

There the heat transfer to an air flow from the outside of the sorbent bag in the same Magnitude is like the heat transfer a sorbent granules to the inside of the bag, In principle, large film surfaces are recommended without ribbing, such as cylinder, plate or tube geometries. There in particular zeolite granules a low heat conduction have the sorption containers are designed so that the average heat conduction path within the sorbent Does not exceed 5 cm.

All Applications are characterized in that a cooling element over stored indefinitely at any temperatures becomes. At the start of the cooling effect, the control organ open. Arbeitsmitteldampf can from this time to Sorbents flow and are deposited by this. The sorbent gets hot as it releases the steam inside its crystal structure liquefied and adsorbed. Of the Evaporator cools down and can be used as a source of cold be used. For fast-running cooling tasks (eg. B. cooling a liquid) is usually the Not enough time to cool the sorbent appreciably. The absorption capacity for agent vapor is therefore limited because of the hot sorbent temperatures be, if not admixtures act as a heat buffer.

at Cooling elements with longer cooling time is the Sorbent heat over the multilayer film can give off and depending on the application, this heat at a higher temperature level also to a warm to keep Product can transfer.

at Applications in the deep-freeze sector are also sufficiently dimensioned Flow channels and optionally freezing point-lowering additives to be considered in the work equipment. With these additions can also evaporate at the working water evaporation temperatures be achieved below zero ° C without the water iced.

Especially in temperature-controlled transport applications it can Occur that the ambient temperatures below the control temperature of the thermostat. When temperatures drop, first the thermostat close and the active cooling of the cooling element. Once the temperature is in Evaporator drops below 0 ° C would be in use of pure water this solidifies and the solidification heat deliver to the interior at 0 ° C. Unless the water filling is sufficiently dimensioned, then the interior temperature is not fall below freezing.

For Transport tasks where 0 ° C is too low, may be in place of pure water an aqueous, eutectic mixture for Use come their conversion point slightly below the control temperature of the thermostat is set (eg conversion point 3 to 4 ° C and a thermostat control temperature of 5 ° C). In this constellation is thus, as long as the temperature of the Interior is above the control temperature of the thermostat, Vapor from the aqueous mixture evaporate and cool the interior. At temperatures below the Normally the thermostat closes the steam channel. Sinks now the outside temperature is below the transformation point and flows from the mixture continues to heat to the environment decreases the temperature in the evaporator until the mixture reaches the transformation point below. The mixture is now changing and giving off heat to the interior. With appropriate dimensioning can therefore an inventive cooling element not Cool only at a constant temperature but at Below this temperature provide conversion heat and keep the transported goods at least at the transformation temperature.

For Applications where no increase in the evaporator volume desired by additional eutectic mixtures is, according to the invention also between evaporator and tank insulation a separate heat source to be ordered. This heat source does not need its own regulation, because their excess heat from the evaporator is dissipated by the thermostatic control before the higher temperatures reach the cargo. The Power output of this heat source should be such that their heat dissipation is sufficient, the insulated container at least at the lowest expected ambient temperatures to keep at the required indoor temperature. According to the invention the heat source also not homogeneous within the insulated container be arranged. Rather, it is sufficient a selective heat release, because the evaporator acts like a steam heater, which the of the Heat source absorbed amount of heat distributes and regulates the entire evaporator surface. Water, that evaporated in thermal contact with the heat source, condensed within the evaporator structure on cooler surfaces and heats them to the level of the evaporating site. The temperature of the entire evaporator thus remains homogeneous. As soon as the temperature at the thermostat exceeds its control temperature, opens the control organ and leaves as long as working medium steam in The sorbent will flow up to the control temperature again is reached.

When separate heat sources are in principle all known exothermic running chemical reactions suitable for keeping warm be used by bodies (eg open flame, catalytic Combustion, etc.). Particularly advantageous is the oxidation of iron powder with atmospheric oxygen in the presence of water, salts and activated carbon. These slow-running oxidation consumes only little oxygen, the either through the generally porous insulation walls diffused into the interior or via appropriately sized openings is directed from the outside to the heat source.

Of course are also excellent electrical heating elements that are made supplied with batteries or rechargeable batteries. at This type of heat source can also heat the heating element additional, electrical thermostats are regulated.

Just in rare cases, the working fluid in the evaporator can exist in unbound form. Mostly it will distributed in an absorbent fleece and by hygroscopic Forces fixed. Particularly inexpensive materials are absorbent papers, as they are in great variety for household and industry for the absorption of liquids be used. The water-storing fleeces may as well like the spacers made of plastic or more natural Zeolite, do not outgas under vacuum and higher temperatures. Particularly suitable for this commercial Microfibres made of polypropylene. These fibers are prepared for water absorption and do not give off the vacuum interfering gases.

advantageously, is the evaporator in the area of the heat source a something assigned larger fleece amount, so there too more liquid working fluid for steam heating is available. In addition, the fleece geometry can be designed that a decreasing amount of working fluid on the suction effect the nonwoven material is refilled.

A Another solution opens the fixation of the working fluid in organic binders such. B. Water Lock from Grain Processing Corp. USA. Advantageously, the combination of several o. g. Be action.

Around the necessary steam channel cross section between evaporator and sorbent filling upright despite the outside air pressure obtained according to the invention, the steam passage through several layers of a plastic network are formed and stabilized. Between the network structure remains sufficient cross section for the flow. When using polypropylene nets can higher temperatures are allowed without gas release. Due to the flexible structure of the nets, they also fit optimally to the respective geometries.

Of the Evaporator can according to the invention any shapes and be made of different materials. Technically, it is necessary that during the cooling process a sufficiently large opening to escape the water vapor remains in the working medium vapor channel, Working fluid in the liquid state at the point to be cooled remains, prevents entrainment of liquid components will and good thermal connection to be cooled Object is possible.

The Sealing the multi-layer films is usually thermal by pressing hot sealing bars on the outside Film surfaces to the superimposed sealing layers become soft and merge together. The welding process can be done within a vacuum chamber under vacuum. Advantageous But it is also, the bag at an open point of the sealed seam to evacuate by means of a suction device. To the suction channel To keep it open, there is a spacer between the foil surfaces of polypropylene, advantageously analogous to the structural material, that the flow channel in the interior of the cooling element spans, loaded. Once the evacuation is complete, become the foil surfaces including the spacer heated by sealing bar until the sealing layer and the identical Material of the spacer merge into each other and after the To make a gas-tight connection.

The Drawing shows in:

1 an inventive, still lying flat cooling element for cooling an insulated transport box,

2 the flexible evaporator 1 in perspective and in section,

3 the cooling element after 1 together with an insulated transport box,

4 a thermostatic valve,

5 a regulatory organ,

6 a further embodiment of an evaporator in a sectional view and

7 a sorbent section with three sorbent pockets.

This in 1 has shown cooling element nor its flat shape, as dictated by the manufacturing process. Two tailored multi-layer films 7 are stacked with their opposite sealing layers and equipped with the individual components of the cooling element. In the drawing is the upper multilayer film 7 displayed transparently to show the position of the components. The two multi-layer films 7 consist of four individual layers glued together. Over the innermost polypropylene layer are the films at the peripheral edges 23 hermetically sealed (welded). A gas-tight aluminum layer is enveloped in each case by two polyamide layers, which in turn protect the aluminum layer against destruction and allow a graphic printing of the multi-layer film. The evaporator 2 contains two superimposed one-piece spacers 11 on which six fleece plates 10 are hung up. The fleece 10 consists of several layers of a hydrophilic microfiber mat made of polypropylene. It is soaked with the working fluid water. The maximum water absorption is limited because of the external pressure on the capillary structure of the microfiber. The amount of water added is more than can be absorbed by the amount of sorbent. At low ambient temperatures, the surplus water mass can freeze and keep the interior of the insulation box at 0 ° C during icing. The six fleece plates 10 are at given bend lines 24 spaced. Under a fleece is a thermostatic valve 8th inserted, from which a Arbeitsmitteldampfkanal 4 to a regulatory organ 3 and from there into the sorbent 1 leads. The working medium steam channel 4 is from a flexible hose line 24 made of plastic clamped, which withstands the external overpressure and is not squeezed when kinking. Under vacuum, the multi-layer film nestles 7 so around the internals that the way to the sorbent 1 for the water vapor only through the thermostatic valve 8th , the hose line 24 and the governing body 3 is possible.

For the production of the cooling element according to the invention, the cut multi-layer films 7 pre-sealed in segments, equipped with the individual components and then down to a small suction opening 40 in the area of a sealed seam 23 welded. To the suction opening 40 a vacuum pump is docked, which sucks the air and possibly released gases from the cooling element. Following this, the suction opening, 40 through which, in order to keep the suction channel open, a part of a spacer 11 protrudes, heated by means of suitable welding bar so far that the material of the spacer 11 merges with the sealing layer. Under certain geometric conditions, it may be advantageous if the evaporator 2 and the sorbent 1 be evacuated separately.

2 shows the evaporator 2 according to 1 cut along the line AA and in perspective view. Along the fold lines 24 is the evaporator 2 been folded into its cubic shape. At the cut surfaces is the spacer 11 and the water-soaked nonwovens 10 to see. Everything comes together from the multilayer film 7 envelops. In the area of kinks 24 there is no fleece 10 so that the upper multi-layer film 7 except for the spacer 11 can compress to compensate for the resulting over the outer film length contraction. In this way, a slight deformation of the evaporator 2 can be achieved without wrinkling. On the left wall of the evaporator 2 is the thermostatic valve 8th between fleece 10 and spacers 11 inserted. About the spacer 11 stand all areas of the fleece 10 with the thermostatic valve 8th in connection.

3 shows the cooling element according to 1 in the folded state before insertion in an insulated transport box 12 with a lid 25 can be covered. The transport box 12 has a free space on one edge 26 in which the working medium steam channel 4 can be used. The regulatory organ 3 and the sorbent 1 thus come in the outer area of the transport box 12 lying on a side wall, the six folded into a cuboid surfaces of the evaporator 2 clothe the six inner surfaces of the transport box 12 , The resulting interior serves to accommodate the cargo. The upper evaporator plate 5 is foldable. About them the interior is accessible in full cross section. On two inner walls of the transport box 12 there are recesses 27 each having a heat source 18 be able to record. The heat sources 18 contained in an air-permeable shell, a mixture of iron powder, water, salt, cellulose and activated carbon. When exposed to air, the iron powder oxidizes exothermically. The atmospheric oxygen passes through the porous Styrofoam insulation of the transport box 12 to iron powder and / or additional, thin air channels 28 in the recesses 27 , The heat sources 18 ensure a heating of the interior in the event that the transport box 12 in a respect to the control temperature of the thermostat 8th stands too cold environment. The heat development of the heat sources 18 even remains unregulated. When the heat sources 18 Provide more heat than is needed for the interior, opens the thermostatic valve 8th and lets so much steam into the sorbent 1 flow out until the evaporator temperature is within the control range again. Because the evaporator 2 contains only water and water vapor, the temperature remains throughout the evaporator 2 homogeneous. Of evaporator lots in the, z. B. from the heat sources 18 , more heat is incident, water evaporates under heat absorption and in portions from which heat flows off to the environment, steam will flow and condense exothermically. Due to the capillary suction effect of the nonwoven material, the water concentration can equalize again.

4 shows a thermostatic valve 8th in cross section. A bi-metal strip rolled up into a spiral 9 is at its inner end 41 fixed with a housing open on one side 29 connected during the free end 42 a sealing washer 30 contains the opening at the control temperature 31 of the working medium vapor channel 4 closes. The opening 31 gets from one into the case 29 gastight pipe section 38 formed, on the other end of a plastic hose 14 is deferred. To the hose 14 in turn, the multi-layer film nestles 7 on the edges 23 sealed gas-tight. The multi-layer film 7 and the hose 14 can in the further course by engaging from outside squeezing 15 (not shown) are pressed so strong that the working medium vapor channel 4 can be blocked from the outside. To start the cooling, the squeezing elements are removed. Due to the restoring forces of the plastic hose 14 now opens the flow path for the working medium vapor. The control element according to the invention is in this embodiment by the thermostatic valve 8th and formed the squeezing. Under the case 29 of the thermostatic valve 8th there is a layer of a plastic net 43 , As the threads 39 of the network 43 Overlay at the crossing points, remain working medium vapor channels also within the network level. The best results are achieved with nets that have a thread thickness of about 2 mm with a thread spacing of about 3 mm. Although on the plastic net 43 from one side of the mesh the microfiber of the web and from the other side the flexible multilayer film are pressed, remains sufficient cross section for the working medium vapor. If the cross-section of individual areas is too short, z. B. in the inflow to the thermostatic valve 8th , can use multiple layers of the plastic net 43 be layered on top of each other. The inventive flexibility of the evaporator 2 it is still preserved.

5 shows a control organ 3 in a sectional view, which is kept closed by the outer air pressure of the multilayer film 7 deformed so far that a disc-shaped sealing surface 16 on a sealing seat 17 is pressed. The seal seat 17 in turn will be from a piece of pipe 32 formed on the second end of a flexible corrugated hose 13 is plugged. On the right angle continuation 44 of the working medium vapor channel 4 also becomes a corrugated hose 13 made of plastic. The continuation 44 starts in a plastic case 33 in which the sealing surface 16 from the seal seat 17 can be lifted or unfolded. The necessary leverage for folding is via a with the sealing surface 16 connected lever rod 34 applied. The lever rod 34 is in a suitably tailored side pocket 45 the multi-layer film 7 embedded. Also this side pocket 45 is on the edges 23 sealed in a vacuum-tight manner. Under vacuum, the sealing surface 16 by means of the multi-layer film 7 and lever rod 34 on the seal seat 17 pressed. A slight tilting movement on the lever rod 34 from the plane of the drawing deforms the multilayer film 7 so far that the way for the working medium vapor can be fully or dosed released. With optimal structure of the control element 3 closes the sealing surface 16 automatically as soon as the tipping force on the lever rod 34 eliminated.

6 shows a further embodiment of a cut and perspective illustrated evaporator 2 which absorbs heat from a stream of air to be cooled. The flow channel 37 for the air flow is from the evaporator 2 self formed and spanned. For this purpose, the originally flat produced evaporator 2 to a centrally applied working medium vapor channel, in this embodiment of a perforated corrugated hose 13 is formed folded after evacuation by 180 °. The originally widely spaced seal seams 35 and 36 are now directly opposite. Since the inner foil ends are cut shorter than the outer, the outer ends can 22 the multi-layer film 7 be welded again and in this way the hermetically closed flow channel 37 form for the air flow. At the far end 46 of the flow channel 37 The flat air flow is converted into a round flow geometry.

In the embodiment shown, the working medium vapor channel is formed by two layers of a reticulated spacer 11 educated. The fleeces 10 are in thermal contact with the flow channel 37 ,

7 finally shows a sketch of the filled with sorbent area of a cooling element. The multi-layer film 7 is in three pockets 19 divided only by the working medium steam channel 4 communicate with each other. The working medium steam channel 4 is formed by a perforated corrugated hose (not shown), which is extremely pressure-stable and flexible at the same time by its corrugation. The three sorbent bags 19 contain a Zeolithschüttung which is pressure-stable under vacuum but inflexible. In the overflow areas 39 where no zeolite is filled, the structure remains flexible thanks to the flexible corrugated hose. At these overflow areas 39 the entire cooling element can be folded in order to be able to optimally adapt to the task required in each case.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• EP 0368111 [0003]
• - DE 3425419 [0003]
• WO 01/10738 A1 [0004]
• WO 99/37958 A1 [0005]
• - US 6474100 B1 [0006]
• DE 102005034297 A1 [0007]

Claims (19)

Cooling element with a sorbent ( 1 ) which is capable of sorbing, under vacuum, a vaporous working fluid which is produced by a liquid working medium in an evaporator ( 2 ) evaporates and with a control element ( 3 ) in a working medium vapor channel ( 4 ) between sorbent ( 1 ) and evaporators ( 2 ), characterized in that the entire cooling element of a gas-tight multi-layer film ( 7 ) is hermetically encased, the multilayer film ( 7 ) is designed to be flexible and under vacuum so the regulatory body ( 3 ), the working medium vapor channel ( 4 ) and the evaporator ( 2 ) encloses that evaporator ( 2 ) and working medium steam channel ( 4 ) remain flexible and the working medium vapor only via the control element ( 3 ) can flow to the sorbent. Cooling element according to claim 1, characterized in that the control element ( 3 ) a valve ( 6 ) obtained by deforming the multilayer film ( 7 ) is operable. Cooling element according to one of the preceding claims, characterized in that the control element ( 3 ) a thermostatic valve ( 8th ) contains. Cooling element according to one of the preceding claims, characterized in that the thermostatic valve ( 8th ) in the evaporator ( 2 ) is arranged. Cooling element according to one of the preceding claims, characterized in that the thermostatic valve ( 8th ) a bi-metal body ( 9 ) and is in thermal contact with the liquid working fluid. Cooling element according to one of the preceding claims, characterized in that the sorbent ( 1 ) Zeolite and the working fluid contains water. Cooling element according to one of the preceding claims, characterized in that the evaporator ( 2 ) a fleece ( 10 ) from which the working fluid can evaporate and a spacer ( 11 ), which between fleece ( 10 ) and multilayer film ( 7 ) Working medium steam channels ( 4 ). Cooling element according to one of the preceding claims, characterized in that the flexible evaporator ( 2 ) several inner walls of a thermally insulated container ( 12 ) covered. Cooling element according to claim 8, characterized in that at least one surface of the evaporator ( 2 ) is foldable and allows access to the interior. Cooling element according to one of the preceding claims, characterized in that the liquid working medium Contains substances that change the conversion point to +2 to + 4 ° C move. Cooling element according to one of the preceding claims, characterized in that the working medium vapor channel ( 4 ) a flexible and in suitable places porous corrugated hose ( 13 ) contains. Cooling element according to one of the preceding claims, characterized in that the working medium vapor channel ( 4 ) a piece of tubing ( 14 ), which can be squeezed by external crimping elements to prevent the flow of the working medium vapor. Cooling element according to one of the preceding claims, characterized in that the control element ( 3 ) a sealing surface ( 16 ) obtained from the multilayer film ( 7 ) to a sealing seat ( 17 ) is pressed. Cooling element according to claim 8, characterized in that a thermally insulated container ( 12 ) via a heat source ( 18 ) has its interior at lower ambient temperatures to the control temperature level of the thermostatic valve ( 8th ) is heated. Cooling element according to claim 14, characterized in that the heat source ( 18 ) Contains iron powder, which maintains an exothermic reaction in the presence of atmospheric oxygen. Cooling element according to one of the preceding claims, characterized in that the sorbent ( 1 ) in several lots ( 19 ) within the multilayer film ( 7 ) and the games ( 19 ) remain movable against each other and yet via flexible Arbeitsmitteldampfkanäle ( 4 ) are accessible from the working medium steam. Cooling element according to one of the preceding claims, characterized in that the working medium vapor channel ( 4 ) made of flexible plastic nets ( 20 ) is formed, which are superimposed in several layers and keep a sufficient cross section for the working medium vapor flow open. Cooling element according to one of the preceding claims, characterized in that on the multilayer film ( 7 ) in the exterior of the evaporator ( 2 ) an air duct ( 21 ) is provided, via which in the evaporator ( 2 ) Heat can be absorbed. Method for evacuating a cooling element according to one of the preceding claims, characterized in that the multilayer film ( 7 ) in the region of a sealed seam a spacer ( 11 ) consists of polypropylene via a vacuum pump evacuated the interior of the cooling element and that after evacuation of the spacer ( 11 ) is heated to such an extent that it reacts with the sealing layer of the multilayer film ( 7 ) merges and forms a gas-tight, evacuated cooling element.