EP3070425B1 - Freeze dryer having a viewing window - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION

The invention relates to a freeze dryer. Furthermore, the invention relates to a new use of a material.

STATE OF THE ART

Freeze dryers are used for gentle drying of a high-quality, thermally sensitive drying material, in particular a pharmaceutical or biochemical drying material. In this case, the material to be dried contains liquid which is to be eliminated by freeze-drying and which is preferably high-purity water or a solvent. Usually, such a drying material is freeze-dried in containers. Any container, in particular a drying vessel, a vial, an ampoule, a bowl or a so-called vial, with the drying material arranged therein is also referred to below as a product.

In a product chamber of a freeze dryer several shelves are arranged one above the other for many known embodiments. A closable by a door opening products can be introduced into the product chamber and placed on the shelves. In the freeze drying process, the product is then first frozen in the product chamber of the freeze dryer. In the following step, a so-called primary drying is carried out by sublimated in the product chamber at low pressure or technical vacuum and low temperature, the solvent contained in the Trocknungsgut without intermediate occurrence of a liquid phase directly from the frozen state to the gaseous state. In an ice condenser chamber connected to or integrally formed with the product chamber, for example on a refrigerated cold trap of the ice condenser chamber, the previously sublimated solvent precipitates as ice. At the explained primary drying can be followed by a secondary drying, in which by a pressure reduction and / or further heating more strongly bound solvent is removed. In the products in the product chamber remains in the container dried Trocknungsgut, which is also referred to as lyophilisate. In the freeze-drying process, the pressure, temperature and other parameters are controlled or controlled according to a product-specific sublimation pressure curve to achieve good and reproducible drying results. Freeze dryers are often operated discontinuously.

Whilst freeze dryers are well known in which the housing incl. The door is formed opaque, for example. With a door made of stainless steel, freeze dryer are also known in which a door is formed with a disc of inorganic glass or acrylic glass, so that the door a window forms through which the interior of the freeze dryer is visible even when the door is closed (see, for example, the embodiments "Epsilon" pilot freeze drying plants and the different production facilities of the applicant, as this on the website www.martinchrist.de [as of filing the present patent application] are described and shown).

The publication EP 1 412 686 B1 describes the need to produce in the product chamber of a freeze dryer a uniform water vapor partial pressure with uniform pressure distribution also in the area of the chamber walls and any door. The document describes the observation that in the area of the chamber walls and the door the temperature of the products depends not only on the temperature of the cooled control panels. Rather, the temperature of the inner walls of the product chamber also influences the temperature of the products by means of heat radiation. If, for example, the steam leaving the product has a temperature of -40.degree. C., this temperature increases on the control panels to, for example, -20.degree. C., while under certain circumstances the steam in the vicinity of the walls may increase, for example. B. can reach 20 ° C. Due to these temperature differences, pressure differences of more than 10% can occur. As a result of the pressure and temperature differences, undesirable inhomogeneities result in the quality of the freeze-drying process of the products. In order to avoid the influence of a chamber wall temperature on the temperature of the products is described as known that the control panels are equipped with an outer edge, which protects or shields the product against an emanating from the chamber walls heat radiation. The publication EP 1 412 686 B1 suggests in addition Prior to lining the product chamber including the door with components which are to ensure a shield which is intended to prevent heating of the control panels and the products arranged thereon by a heat radiation of the chamber walls. For this purpose, the shielding components are tempered by these are flowed through by a heating / cooling medium.

To ensure homogenous freeze-drying conditions and to avoid a layer of ice that may cover shelves and products placed thereon, the document suggests DE 10 2007 049 278 B4 to arrange a thermally insulating screen between the underside of a cold radiating footprint and a further footprint arranged thereunder with products arranged thereon. By means of the thermally insulating screen, a shield should be such that a cold transfer from the bottom of the upper footprint to the underlying further footprint with products arranged thereon is avoided, thus allowing a more accurate control of the temporal freezing profile of the products.

CN 203 231 613 U discloses a viewing window of a freeze dryer made of crystal glass.

OBJECT OF THE INVENTION

• die Gefriertrocknungsbedingungen der Produkte in vergrößertem Ausmaß homogenisiert sind,
• eine Ausbreitung einer elektromagnetischen Anregung für einen Sensor und/oder eines elektromagnetischen Messsignals in dem Gefriertrockner verbessert ist und/oder
• die elektromagnetische Verträglichkeit des Gefriertrockners verbessert ist.

It is an object of the present invention to propose a freeze dryer in which

• the freeze-drying conditions of the products are homogenized to an increased extent,
• a propagation of an electromagnetic excitation for a sensor and / or an electromagnetic measuring signal is improved in the freeze dryer and / or
• the electromagnetic compatibility of the freeze dryer is improved.

SOLUTION

The object of the invention is achieved with the features of the independent claims. Further preferred embodiments according to the invention can be found in the dependent claims.

DESCRIPTION OF THE INVENTION

1. a) Untersuchungen haben gezeigt, dass trotz der Bemühungen zur Homogenisierung der Prozessbedingungen für die gleichzeitige Gefriertrocknung einer Vielzahl von Produkten in einem Gefriertrockner Inhomogenitäten auftreten. Bei weiteren Untersuchungen konnte eine Korrelation der Prozessbedingungen mit der Position der Produkte auf Stellflächen in dem Gefriertrockner festgestellt werden. Schließlich hat sich herausgestellt, dass offensichtlich die Produkte in dem Gefriertrockner, welche im Einfallbereich von durch ein Sichtfenster des Gefriertrockners hindurchtretendem Licht, insbesondere Sonnenlicht, angeordnet sind, einer höheren Temperatur ausgesetzt sind als Produkte, welche in abgeschatteten Bereichen des Gefriertrockners angeordnet sind. Quantitative Erfassungen dieser Temperaturunterschiede haben gezeigt, dass hierbei Produkte im Einstrahlungsbereich durch das Sichtfenster infolge der Einstrahlung von Licht bis zu 6 K wärmer sind als Produkte in abgeschatteten Bereichen.
   Um ein zuverlässiges Gefrieren sämtlicher Produkte zu gewährleisten, ist somit erforderlich, dass die Temperaturbedingungen in dem Gefriertrockner derart gestaltet werden, dass auch für die im Einstrahlungsbereich angeordneten Produkte die Gefriertemperatur erreicht wird, was zur Folge hat, dass in abgeschatteten Bereichen angeordnete Produkte auf eine Temperatur heruntergekühlt werden, welche bis hin zu 6 K unterhalb der an sich erforderlichen Temperatur liegt. Dies erhöht den Energieaufwand. Andererseits ist in einigen Fällen für die Herbeiführung der Sublimation gewünscht, dass die Temperatur möglichst gering unterhalb der Gefriertemperatur liegt und/oder ein schneller Sublimationsvorgang mit einem kleinen Temperaturgradienten herbeigeführt wird, was angesichts der erläuterten Temperaturunterschiede nur begrenzt möglich ist.
2. b) Möglich ist, dass in dem Gefriertrockner und/oder in den Produkten Sensoren angeordnet sind, welche ein kabelloses elektromagnetisches Messsignal zu einem ebenfalls in dem Gefriertrockner angeordneten Empfänger aussenden. Möglich ist auch, dass ein derartiger Sensor ohne eigene Energieversorgung ausgebildet ist und von einem Sender zwecks Energieversorgung angeregt wird und dann wiederum ein bspw. temperaturabhängiges Signal absendet. Hierbei finden (insbesondere hochfrequente) elektromagnetische Schwingungen oder Strahlungen Einsatz. Beispielsweise findet für die Anregung und/oder das Messsignal eine Frequenz im Bereich von 2,4 GHz Einsatz, wobei hierbei insbesondere auch Frequenzen mit im Bereich von ± 10 % oder ± 20 % von der genannten Frequenz Einsatz finden können. Unter Umständen beträgt die Intensität des von dem Sensor ausgesendeten Messsignals lediglich 100-stel bis 1000-stel der Anregungsintensität. Soll die Intensität des ausgesendeten Messsignals so bemessen werden, dass von jedem Ort in dem Gefriertrockner, in welchem der Sensor angeordnet werden kann, noch das Messsignal durch einen Empfänger empfangen werden kann, muss die Anregungsfrequenz hinreichend groß bemessen werden. Hierbei ist insbesondere die Zahl der Reflektionen der Strahlung einerseits für die Anregung und andererseits für das Messsignal zu berücksichtigen. Ergänzend sind Verluste der Strahlung nach außen zu minimieren, welche letztendlich die Anregung und/oder das Messsignal schwächen. Der Erfindung zugrunde liegende Untersuchungen haben gezeigt, dass signifikante Verluste auftreten im Bereich eines Sichtfensters des Gefriertrockners, im Bereich dessen lediglich eine eingeschränkte Reflektion erfolgt, während ein Teil der Strahlung von dem Sichtfenster absorbiert oder durchgelassen wird.
3. c) Schließlich ist festgestellt worden, dass die unter b) erläuterte Strahlung und die Durchlässigkeit des Sichtfensters für die Strahlung zu dem Ergebnis führen kann, dass die elektromagnetische Verträglichkeit des Gefriertrockners nicht gewährleistet ist. Beispielsweise kann es zu Störungen von elektronischen Geräten, insbesondere Mobiltelefonen, kommen, welche im Umgebungsbereich des Gefriertrockners angeordnet sind.

The invention is based in particular on the following findings:

1. a) Investigations have shown that in spite of efforts to homogenize the process conditions for simultaneous freeze drying of a variety of products in a freeze dryer inhomogeneities occur. In further investigations, a correlation of the process conditions with the position of the products on shelves in the freeze dryer was found. Finally, it has been found that, apparently, the products in the freeze drier located in the area of incidence of light passing through a viewing window of the freeze dryer, in particular sunlight, are exposed to a higher temperature than products placed in shaded areas of the freeze dryer. Quantitative observations of these temperature differences have shown that products in the irradiation area through the viewing window due to the irradiation of light are up to 6 K warmer than products in shaded areas.
   Thus, in order to ensure reliable freezing of all products, it is necessary that the temperature conditions in the freeze drier be such as to reach the freezing temperature also for the products placed in the irradiation area, resulting in products placed in shaded areas at a temperature be cooled down, which is up to 6 K below the temperature required per se. This increases the energy expenditure. On the other hand, in some cases it is desired for the sublimation to be achieved that the temperature is as low as possible below the freezing temperature and / or a rapid sublimation process is brought about with a small temperature gradient, which is only limitedly possible in view of the temperature differences explained.
2. b) It is possible for sensors to be arranged in the freeze dryer and / or in the products which emit a wireless electromagnetic measuring signal to a receiver likewise arranged in the freeze dryer. It is also possible that such a sensor is designed without its own power supply and is excited by a transmitter for the purpose of power supply and then in turn sends a, for example, temperature-dependent signal. Here are (in particular high-frequency) electromagnetic oscillations or radiation use. For example, for the Excitation and / or the measurement signal a frequency in the range of 2.4 GHz use, in which case, in particular, frequencies in the range of ± 10% or ± 20% of the said frequency can be used. Under certain circumstances, the intensity of the measurement signal emitted by the sensor is only 100ths to 1000ths of the excitation intensity. If the intensity of the emitted measurement signal is to be so dimensioned that the measurement signal can still be received by a receiver from any location in the freeze dryer in which the sensor can be arranged, the excitation frequency must be sufficiently large. In this case, in particular the number of reflections of the radiation on the one hand for the excitation and on the other hand for the measurement signal to be considered. In addition, losses of the radiation to the outside are to be minimized, which ultimately weaken the excitation and / or the measurement signal. Investigations based on the invention have shown that significant losses occur in the region of a viewing window of the freeze dryer, in the area of which only a limited reflection takes place, while a part of the radiation is absorbed or transmitted by the viewing window.
3. c) Finally, it has been found that the radiation explained under b) and the permeability of the viewing window for the radiation can lead to the result that the electromagnetic compatibility of the freeze-dryer is not guaranteed. For example, it may cause interference of electronic devices, in particular mobile phones, which are arranged in the vicinity of the freeze-dryer.

According to the invention it is proposed that the viewing window is formed with a reduced radiation transmission. If, for example, a viewing window of inorganic glass (or of organic glass, in particular an acrylic glass or transparent plastic glass of materials such as PMMA, PC, PET, SAN, PVC, etc.) is used, measures are taken in the context of the invention that the radiation transmission of the viewing window used according to the invention is smaller (for example, in the entire frequency range or only in the relevant frequency range 10%, 20%, 30%, 50% or even 70% smaller) than the radiation transmissibility of a viewing window of the same dimensions of the same inorganic glass ( or from the same organic glass, in particular from a transparent plastic glass) without the additional measures according to the invention for reducing the radiation permeability.

At least one of the previously explained problems a) to c) can be at least reduced by the reduction of the radiation transmissibility according to the invention, ie a heating of products in the irradiation range of light in the region of the viewing window (see a)) or a reduction of the reflection of electromagnetic radiation in the region the viewing window (see b) and c)) are reduced or avoided altogether (the measures according to the invention being not limited to the purpose of eliminating these problems exemplified).

For a first variant of the invention, the viewing window is formed with a layer or coating with reduced radiation transmission. Thus, the viewing window can be formed, for example, with other layers or a base body of a "conventional material" of the viewing window, for example. Organic glass such as transparent plastic glass or inorganic glass. The layer or the coating can then additionally be used to reduce the radiation permeability, it being possible to influence the extent of the reduction of the radiation permeability by dimensioning the layer or coating and selecting the material of the layer or coating. In this case, the layer or coating should be selected such that the viewing window also remains transparent through the layer or coating, whereby a certain impairment of the transparency (such as a slight darkening and / or a specular effect at particular viewing angles through the viewing window) may be present can. It is also possible to retrofit an existing viewing window with such a layer or coating.

Basically, there are many possibilities for the construction of the viewing window with a layer or coating. To name just a few non-limiting examples, the viewing window can be formed with a base body, for example of inorganic glass or transparent plastic glass, on which the layer or coating is applied on the inside with respect to the freeze dryer or the outside. Quite possible is also a multi-layer structure of the body with different materials, whereby a layer or coating with reduced radiation transmission in the interior of the viewing window, ie between adjacent layers of another material, may be arranged. It is also possible that several layers or coatings are used with reduced radiation transmission.

In the context of the invention it is possible that the radiation transmission is reduced to the same extent over the surface of the viewing window. For another embodiment, the Viewing windows have areas of different reductions in radiation transmissivity, for example, a central field with a reduced extent of reduction of radiation transmissibility, for example, to limit the viewing only limited or not, and an outboard of the central area arranged edge area with increasing the extent of reduction of radiation transmission.

As exemplary embodiments may be used as a coating with reduced radiation transmission, a film which may be adhered to a base body or an adjacent layer. It is possible that such a film is formed as a kind of film. There are many possibilities for the design of the film. For example, a film with an amorphous cobalt alloy can be used here. As another example, a layer with reduced radiation transmission may be formed with a lacquer. It is also possible that a layer vapor-deposited onto a main body or adjacent layers is used as the layer with reduced radiation permeability. It is also possible that a layer or coating with reduced radiation transmission is formed with a fabric, mesh or mesh, wherein here as the fabric, mesh or mesh-forming material any materials, in particular polyester, metal, stainless steel, silver-polyamide fibers u. Ä. Can be used. It is also possible that the layer formed with the fabric, mesh or grid is interspersed with a material of an adjacent layer or a base body, with which the fabric, mesh or grid is "embedded" in the material of the adjacent layer or the base body. To mention only a further non-limiting example of the formation of the layer or coating with reduced radiation permeability, it is also possible to use a nonwoven (for example a carbonized polyester nonwoven) which can also be penetrated by a material of an adjacent layer or a base body.

For a further variant of the invention, the viewing window is formed with a conventional material for the formation of a viewing window, in particular inorganic glass, mineral glass, crystal glass, organic glass, acrylic glass or transparent plastic glass. For this proposal, this material of the viewing window is accompanied by an additive with reduced radiation permeability, which, for example, can be dissolved in said material or which may, for example, be particles added to said material, which are then distributed locally in said material without resolution in this. On the choice of the additive and the dimensioning of the additive, in particular the mass fraction of the additive in the material, it is possible to influence the extent of the reduction of the radiation permeability.

While it is generally possible that the viewing window and in particular the layer or coating with reduced radiation transmission is formed without grounding, for some embodiments, in particular for reducing the radiation transmission in a low-frequency range, may be advantageous if the viewing window (here in particular the layer or Coating with reduced radiation transmission) has a ground. In this case, the reduction in the radiation permeability in the low-frequency or high-frequency range may depend primarily on the type of grounding, in particular whether the grounding is punctual or flat.

In the context of the invention, any thicknesses of the viewing window (and possibly the layer or coating with reduced radiation permeability) are possible. Preferably, a viewing window with a thickness in the range of 4 cm to 6 cm use. It is possible here that a layer or coating with reduced radiation permeability has only a very small thickness, for example less than 100 μm, less than 50 μm or even less than 10 μm or 5 μm.

In the context of the invention, a reduction of the radiation transmissibility can take place in any relevant frequency range. For a proposal according to the invention the viewing window has a reduced radiation transmission for light in a frequency range of 300 GHz and 400 THz, which corresponds to the infrared spectrum of solar radiation. Here, for example, in the context of the invention, a reduction of the radiation permeability in the mentioned frequency range by 10%, 20%, 30%, 50% or even 70%. This embodiment is based on the finding that the explained undesired effect of the heating of the products in the irradiation area through the viewing window arises primarily from the infrared spectrum of the sunlight.

For a further embodiment of a freeze dryer according to the invention (at least) a sensor is arranged in the interior of the freeze dryer, which is excited with an excitation frequency of an external excitation to power the sensor and / or a measurement signal frequency for wireless transmission of a measurement signal to a remote inside the Freeze-dryer arranged receiver. For this embodiment It is advantageous if the viewing window has a reduced radiation transmission in the range of the excitation frequency and / or the measurement signal frequency, ie the choice of measures taken to reduce the radiation transmission of the viewing window is adapted to the excitation frequency and / or the measurement signal frequency. To name but a non-limiting example, may be in choosing a freeze-dryer, as this in the document DE 10 2006 019 641 B4 a reduction of the radiation transmission in a frequency range of 1.5 GHz to 3 GHz, preferably in a frequency range of 2.0 to 2.8 GHz or 2.2 to 2.6 GHz, carried out. It is also possible that a transmitting antenna of the sensor is multifunctional designed as a receiving antenna.

For a further embodiment, the viewing window has a reduced radiation transmission in a frequency range of 500 MHz, 1800 MHz and / or 1900 MHz (it should also be understood that deviations from these frequencies by ± 5%, ± 10% or ± 20%). are available). A reduction of the radiation transmission in this frequency range has been found to be particularly effective in order to increase the electromagnetic compatibility, in particular in connection with arranged in the surrounding area of the freeze dryer cell phones or wireless technology transmitters.

Within the scope of the invention, it is quite possible for a reduced radiation transmittance to be brought about in the various different aforementioned frequency ranges mentioned above, wherein it is also possible for different layers or coatings or additives to be used on the same viewing window for different frequency ranges.

The transmittance of electromagnetic radiation, as well as the detection of radiation transmission reduction, is specifically defined in the standards ASTM D4935-10, IEEE Std 299-2006, IEEEE Std 1128-1998 and ASTM A698 / A698M-07. Here, the radiation transmission can be defined with a so-called screen attenuation, with respect to which reference is made to the aforementioned standards. In a particular embodiment of the invention, the viewing window (in at least one of the frequency ranges mentioned here or in the entire frequency range) has a screen attenuation according to standard IEEE 299-2006 of 20 dB, preferably at least 25 dB or in the range of 25 dB to 32 dB.

• ein- oder mehrstückig ausgebildet sein kann und/oder
• sich in einem Randbereich des Sichtfensters erstreckt oder umlaufend den Grundkörper des Sichtfensters umschließt.

Another aspect of the invention pays attention to an edge region of the coating or layer with reduced radiation transmission. Under certain circumstances, the layer or coating is exposed to special stresses in such an edge region. For example, in the edge region during operation of the freeze dryer, as a result of mechanical stresses, the temperatures and pressures acting, a coating can be released. Under certain circumstances, an undesired optical behavior of the viewing window, for example with changing tinting, transparency and refraction, also results in the edge region. In a particular embodiment of the invention, the layer or coating, which has the reduced radiation transmission, covered with a cover. The cover can be, for example, local cover or fastening elements, a cover strip or a cover ensuring a profile which surrounds a base body of a viewing window, to name but a few examples. It is also possible that the cover serves as a fastening, by means of which (possibly in addition to, for example, adhesive agents) a fixation of the layer or coating takes place on a base body of the viewing window. In extreme cases, such a cover or attachment may be formed as a kind of frame of the viewing window, which

• may be formed one or more pieces and / or
• extends in an edge region of the viewing window or circumferentially surrounds the main body of the viewing window.

In this case, it is also possible for the frame to serve further tasks, for example to fasten the viewing window to other housing parts of the freeze dryer or to hold a hinge.

Within the scope of the invention, there are many possibilities for the type of construction of the viewing window. Thus, for example, a window can form a portion of the housing of the freeze-dryer. For a particular proposal of the invention, the viewing window is formed by a door or flap of the freeze dryer, which, for example, can be closed and opened for loading and unloading the freeze dryer. This embodiment makes use in particular of the fact that usually a door or flap for loading or unloading the freeze drier is arranged at a central region of the housing of the freeze dryer at a small distance to the shelves of the freeze drier, so that when the viewing window in the area the door or flap is also ensured at the same time that a good Insight into the interior of the freeze dryer and on the products through the viewing window is guaranteed.

While in principle per se with the use of the viewing window with reduced radiation transmission are given advantages, the invention uses according to a further proposal caused by the viewing window with reduced radiation transmission homogenization of the temperature of the products in the freeze dryer. For this purpose, a control unit of the freeze dryer is equipped with control logic. The control logic introduces in the freeze dryer a temperature which is a differential temperature below the freezing temperature of the products freeze-dried in the freeze dryer. Here, the differential temperature is adapted to a screen attenuation of the viewing window. This will be clarified by means of a simplified embodiment:
If a freezing temperature is about 0 ° C., the temperature of the products should be at least -4 ° C. before initiation of the primary drying, and if the radiation transparency of the viewing window is not reduced in accordance with the invention, the temperature gradient of the samples in the freeze drier 6K must be as shown in FIG In the prior art, a control unit of the freeze dryer ensure a temperature of the samples, which is at -10 ° C for non-irradiated by the radiation of light samples. By means of the inventive design of the viewing window with reduced radiation transmission results due to the irradiation of light only a temperature deviation of 1 K (in particular 0.7 K or 0.5 K) between products in the irradiation of light and products in the shaded area. According to the invention, in this case, the control logic of the control unit of the freeze dryer only a temperature of - 5 C (or - 4.7 ° C or - 4.5 ° C) aussteuern, which is nevertheless ensured by the inventive measures that all samples a maximum temperature of -4 ° C. As a result of the increased screening attenuation of the viewing window according to the invention, an adaptation of the differential temperature is thus possible, which reduces the energy input and allows rapid, gradual sublimation, under certain circumstances also with a reduced temperature gradient.

In a further embodiment of the invention, (also) one end face of the viewing window is provided with a layer or coating with reduced radiation permeability. This embodiment of the invention is based on the knowledge that under certain circumstances in the edge region of the viewing window, a radiation exchange between the interior and the exterior of the Freeze-dryer (in one direction or in both directions), which can be reduced by the layer or coating with reduced radiation transmission in the region of the front side of the viewing window. Here, the invention comprises both embodiments in which only a portion of the end face of the viewing window is equipped with the layer or coating with reduced radiation transmission as well as embodiments in which the end face of the viewing window is continuously and circumferentially equipped with such a layer or coating.

For a further embodiment according to the invention, a housing wall of a product chamber of the freeze dryer forms the viewing window. Here, the product chamber formed by the housing wall is formed separately from an outer housing of the freeze dryer and removable from the outer housing. It is possible that the outer housing forms another window. The arranged in the product chamber products are thus visible in the product chamber in the removed state from the outer housing and visible even through the second-mentioned window when the product chamber is inserted into the outer housing. For example, such product chambers according to the there referred to as "drying chambers" transparent product chambers for the embodiments ALPHA to DELTA website www.martinchrist.de be removed, which are here as a hollow cylindrical, closed with a lid transparent containers, for example. Made of transparent plastic glass and which inside the products can absorb.

It is also possible for a basic module of a freeze dryer which forms an ice condenser chamber to be used in different variants. In a two-chamber principle, the base module is separated by a valve-equipped intermediate plate of a hood-like housing, which then forms the product chamber. On the other hand, in a single-chamber principle, the footprint for the products may be formed inside the ice condenser chamber formed by the base module, and the closure of the base module may be through a lid. In these cases, the lid or the housing limiting the product chamber is formed with the viewing window, wherein preferably the entire lid or the entire housing can be made of any glass and the previously described measures can be taken to reduce the radiation transmission.

Basically, the use of a fabric, a layer, a coating, a fleece, a paint, a film, a grid and / or a network, which or which reduces a radiation transmission, for different applications, especially for windows of buildings, for clothing, Curtains, curtains, canopies, protective suits, medical equipment, desiccators, microbiological incubators, data center shields and the like. Ä., Known. According to the invention, the use of such a fabric, a layer, a coating, a fleece, a lacquer, a foil, a grid and / or mesh with reduced radiation permeability or addition for a viewing window of a freeze dryer is proposed for the first time.

In particular, it is also possible to use the coating (s) or the layer (s) as a specially adapted filter, which transmits visible radiation but at the same time reflects or absorbs electromagnetic radiation in a predetermined wavelength range. By way of example only, in the predetermined wavelength range for the product, a noxious wavelength or a wavelength range may be selectively filtered out, e.g. for markers in medicine that are sensitive to specific wavelengths.

Alternatively or cumulatively to the shielding of a heat radiation and / or an RF radiation, it is also possible to shield at least one specific frequency, which has a significant influence on the function of the product. By way of non-limiting example, the products may be fluorescent cancer cell markers activated by electromagnetic waves of a specific frequency. During the manufacturing process, which includes the freeze-drying step, the product must be protected against electromagnetic radiation of that frequency to ensure the later functioning of the product. Manufacturers of such products are, for example, ROTOP PHARMAKA GmbH, Bautzner Landstr. 400 01328 Dresden and Naradowe Centrum Badan Jadrowych, Osrodek Radioizotopow POLATOM ul. Andrzeja Soltana 7 05-400 Otwock-Swierk Polska.

Advantageous developments of the invention will become apparent from the claims, the description and the drawings. The advantages of features and of combinations of several features mentioned in the description are merely exemplary and can come into effect alternatively or cumulatively, without the advantages necessarily being required by the invention Embodiments must be achieved. Without thereby altering the subject matter of the appended claims, as regards the disclosure of the original application documents and the patent, the following applies: Further features can be found in the drawings - in particular the illustrated geometries and the relative dimensions of several components relative to one another and their relative arrangement and operative connection. The combination of features of different embodiments of the invention or of features of different claims is also possible deviating from the chosen relationships of the claims and is hereby stimulated. This also applies to those features which are shown in separate drawings or are mentioned in their description. These features can also be combined with features of different claims. Likewise, in the claims listed features for further embodiments of the invention can be omitted.

The features mentioned in the patent claims and the description are to be understood in terms of their number that exactly this number or a greater number than the said number is present, without requiring an explicit use of the adverb "at least". Thus, for example, when talking about a layer or coating, it is to be understood that there is exactly one layer or coating, two layers or coatings, or more layers or coatings. These features may be supplemented by other features or be the only characteristics that make up the product in question.

The reference numerals contained in the claims do not limit the scope of the objects protected by the claims. They are for the sole purpose of making the claims easier to understand.

BRIEF DESCRIPTION OF THE FIGURES

Fig. 1 bis 5

zeigen stark schematisiert unterschiedliche Ausführungsformen eines Gefriertrockners.

Fig. 6

zeigt in einer Vorderansicht eine Tür eines Gefriertrockners, welche ein Sichtfenster besitzt.

Fig. 7

zeigt einen Schnitt VII-VII der Tür gemäß Fig. 6.

Fig. 8

zeigt ein Detail VIII des Schnitts VII-VII gemäß Fig. 7.

Fig. 9

zeigt in einer Vorderansicht eine weitere Tür eines Gefriertrockners, welche ein Sichtfenster besitzt.

Fig. 10

zeigt einen Schnitt X-X der Tür gemäß Fig. 9.

Fig. 11

zeigt ein Detail XI des Schnitts X-X gemäß Fig. 10.

Fig. 12 bis 14

zeigen stark schematisiert die Nutzung eines Grundmoduls mit einer Eis-Kondensatorkammer für unterschiedliche Bauformen eines Gefriertrockners.

In the following the invention will be further explained and described with reference to preferred embodiments shown in the figures.

Fig. 1 to 5

show highly schematic different embodiments of a freeze dryer.

Fig. 6

shows in a front view of a door of a freeze dryer, which has a viewing window.

Fig. 7

shows a section VII-VII of the door according to Fig. 6 ,

Fig. 8

shows a detail VIII of section VII-VII according to Fig. 7 ,

Fig. 9

shows in a front view another door of a freeze dryer, which has a viewing window.

Fig. 10

shows a section XX of the door according to Fig. 9 ,

Fig. 11

shows a detail XI of the section XX according to Fig. 10 ,

Fig. 12 to 14

show very schematically the use of a basic module with an ice condenser chamber for different designs of a freeze dryer.

DESCRIPTION OF THE FIGURES

Fig. 1 shows a highly schematic of a freeze dryer 1. The freeze dryer 1 has a housing 2. In the housing 2, a product chamber 3 (which may also be referred to as a drying chamber) and an ice condenser chamber 4 are formed. The product chamber 3 and the ice condenser chamber 4 are connected to each other via an opening 5, wherein the opening 5 is closed by a valve 6. For the illustrated embodiment, the product chamber 3 and the ice condenser chamber 4 are separated by a partition 7, which forms the opening 5. Quite possible, however, are different embodiments, in which the product chamber 3 and the ice condenser chamber 4 are permanently fluidly connected to each other or even formed as a common chamber. In the ice condenser chamber 4 there is a cooling device 12, in particular a cold-end, on which moisture removed from the products during freeze-drying can be deposited as ice. For the illustrated embodiment, a pump 8 (here with the interposition of a valve 9) is connected to the ice condenser chamber 4, by means of which the pressure conditions in the product chamber 3 and the ice condenser chamber 4 can be predetermined, in particular with the bringing about a technical Vacuum. In the product chamber 3 are a plurality of shelves 10a, 10b, ..., which are arranged parallel and one above the other. On the shelves 10, a plurality of products 11, in particular vials, are arranged (which is shown for simplicity of illustration only for a footprint 10d). The needs-based design of the pressure and temperature conditions in the product chamber 3 and the ice condenser chamber 4 via the pump 8, possibly further pumps or connections to a pressure source and / or pressure sink, the cooling device 12 and possibly further cooling and / or Heating devices and in particular by the passage of a tempering fluid through the shelves 10. The shelves 10 may be fixed in the freeze dryer 1 or be adjustable in height, which may be the case in particular for automated loading and unloading. With regard to the structural design details, constructive design variants, the formation of the pressure control devices, heating and cooling devices and the process control of the freeze dryer 1 is on the skilled worker known embodiments, the relevant, documented by patent applications and industrial property rights to freeze-dryers and in particular the embodiments of freeze-dryers , as these are the website www.martinchrist.de refer referenced. In the context of the invention, a "freeze dryer" also includes a freeze-drying plant, in which (in contrast to the embodiments shown here), an automated loading and unloading takes place.

The housing 2 is basically opaque and electromagnetically shielded. For example, the housing 2 is basically made of stainless steel or at least equipped with a sheath and / or lining made of stainless steel. The housing 2 has an opening 13, which is arranged here in the region of the product chamber 3 and over which the shelves 10 are accessible from the outside, so that via the opening 13 a (automated or manual) loading and unloading of the freeze dryer 1 is possible. The opening 13 is (manually or automatically) closed by a door or flap 14. The door or flap 14 forms a viewing window 15 through which the interior of the freeze dryer 1, here the interior of the product chamber 3, is visible and the footprint 10 with the products 11 are visible.

In Fig. 1 an example of a door 14 is shown, which is pivotable about a vertical axis for opening and pressure-tight closing of the opening 13. The door 14 has this an at least partially transparent viewing window 15, via which the interior of the product chamber 3 with the shelves 10 and the products 11 is visible from the outside.

In the Fig. 1 to 4 For example, a base body 16 of the door 14 is shown as a white surface, while a layer or coating 17 is shown as a black surface. In this case, the base body 16 is formed with a transparent material (in particular inorganic glass or crystal glass or organic glass, in particular transparent plastic glass made of materials such as PMMA, PC, PET, SAN, PVC and the like, customary for such doors 14. On the base body 16 is according to Fig. 1 on the outer side of the layer or coating 17 is arranged, wherein, for example, the layer 17 may be molded onto the base body 16 (or vice versa), the layer 17 and the base 16 may be glued together or a coating 17 is glued to the base body 16 , In this case, the layer or coating 17 can also be formed with a woven, nonwoven, lacquer, a film or a film, a grid and / or a net.

For the in Fig. 2 illustrated embodiment, the layer or coating 17 is applied to the inside of the door 14 on the base body 16 or connected on this side with the base body 16.

For the in Fig. 3 illustrated embodiment, the main body 16 of the door 14 is provided both on the inside and on the outside with a layer or coating 17a, 17b.

For the in Fig. 4 illustrated embodiment, the door on the outside and on the inside with a layer or a base body 16a, 16b formed, in which case the layer or coating 17 between the main bodies or layers 16a, 16b is arranged and preferably cohesively or via an adhesive with two basic bodies 16a, 16b is connected.

For the in Fig. 5 illustrated embodiment, the material of the base body 16 of the door 14 is provided with an additive 18, in which it may be in the material of the base body 16 is not resolved, but may be stochastically distributed particles 19 act.

In the Fig. 6 to 8 a concrete embodiment of a door 14 is shown. The door 14 here has a viewing window 15, which is square with rounded corners. In the edge region, the door 14 has a cover or a frame 20 (hereinafter also referred to as "cover 20"), which is preferably non-transparent. In Fig. 6 On the one hand, a closure mechanism 21 formed here with a lever can be seen, via which a gas-tight closed position of the door 14 can be brought about and secured. On the other hand, the door 14 has in the lateral edge region via hinge elements 22, 23, via which the door 14 can be hinged to the housing 2 of the freeze dryer 1 to allow the pivoting of the door 14 about a vertical axis from the open position to the closed position and vice versa. For the exemplary embodiment, the main body 16 of the door 14 is formed with a glass pane 24, in particular made of transparent plastic glass and / or with a thickness in the range of 4 to 6 cm. At least in the region of the viewing window 15, the layer or coating 17 is applied on the outside to the glass pane 24. In the in Fig. 8 illustrated detail VIII of the cross section according to Fig. 7 the cover 20 is L-shaped. A leg 25 of the L is on the side on which the layer or coating 17 is disposed on the glass pane 24 at. The other leg 26 of the L is located on an outer end face 27 of the base body 16 (here the glass pane 24). The leg 25 of the cover 20 forms on the outside of the door 14 surrounding the viewing window 15 and this outwardly bounding frame, while the leg 26 forms a kind of enclosure of the base body 16. For the illustrated embodiment, the cover 20 is formed in one piece, without this necessarily being the case. The cover 20 is screwed by screws 28, 29 with the base body 16, wherein the screws 29 from the front of the door 14 vertical to the plane according to Fig. 6 are screwed into the base body 16 and the screws 28 are screwed vertically to the end faces 27 of the base body 16. For the illustrated embodiment, the leg 25 of the cover 20 overlaps the layer or coating 17, wherein a possible coating 17 may also be clamped between the leg 25 of the cover 20 and the base body 16 and / or the leg 25 of the cover 20, the edge region of the layering or coating 17 protects. Possible (deviating from the detail VIII according to Fig. 8 ) but also that the leg 25 of the cover 20 directly adjoins the layer or coating 17 without overlapping. Preferably, the shutter mechanism 21 and the hinge members 22, 23 are supported by the frame-shaped cover 20. On the frame-shaped cover 20, the base body 16 is held with layer or coating 17 via the screws 28, 29.

For the embodiment according to Fig. 9 to 11 the frame or cover 20 is not integrally formed. Rather, here to form the cover or the frame 20 a plurality of segments 30a, 30b, 30c, 30d use. The segments 30 are formed as U-profiles. The base legs 31 of the segments 30 are each bolted to the associated end face 27 of the base body 16. Between the side legs 32, 33, the outer edge regions of the base body 16 are added. Preferably, the edge areas of the base body 16 received between the side legs 32, 33 are machined with the production of cutouts 34, 35 to the clear dimension between the side legs 32, 33, in particular with a clearance fit, press fit or transition fit. In this way it can be made possible that, apart from the cutouts 35, the base body 16 is produced with a thickness having a relatively large tolerance, for example as a result of a casting process with tolerances of up to several millimeters. It is possible that as in Fig. 9 it can be seen that the segments 30a, 30b and 30b, 30c form a miter. In this case, preferably, the shutter mechanism 21 is supported by the segment 30b, while the hinge members 22, 23 may be supported by the segment 30d. For the embodiment according to Fig. 9 to 11 is, for example, the base body 16 made of a transparent plastic glass with an addition 18. It is alternatively or cumulatively possible that the base body 16 is provided with a coating or layer 17.

The cover or frame 20 or segments 30 are preferably made of stainless steel. For the base body 16, any materials can be used, provided that they are at least partially transparent. PMMA, PET or PC or glass can be used here in particular. Notwithstanding the illustrated embodiment, accordingly, a viewing window 15 may not be formed in a door or flap 14. Rather, for example, can also drying chamber containers, as can be seen from the Internet page www.martinchrist.de form the viewing window 15 and thus be equipped with a layer or coating 17 and / or an additive 18 to reduce the radiation transmission.

Fig. 12 shows a highly schematic of a further embodiment of a freeze dryer 1, in which the ice condenser chamber 4 is formed with a base module 36 which has a trough or cup-like housing 37 with arranged therein cooling device 12. On the housing, the necessary connections for pressurization and venting and generation of the vacuum are provided. The housing 37 is open at the top. On the housing 37 is under sealing by means of a sealing element 38, an intermediate plate 39th supported, which in particular in the region of a central through bore, the valve 6 has. On the intermediate plate 39 is supported (in a manner not shown here), a frame with shelves 10a, 10b ... from. The shelves 10 are received in a housing 40 open in the direction of the base module 36 and the intermediate plate 39. The housing 40 is sealed by a sealing element 41 with respect to the intermediate plate 39. According to the illustrated embodiment Fig. 12 the freeze dryer 1 is designed as a two-chamber freeze dryer, wherein the base module 36 forms the ice condenser chamber 4, while the housing 40 limits the product chamber 3 and a separation of the ice condenser chamber 4 and the product chamber 3 through the intermediate plate 39 and the valve 6 takes place. The housing 37 is cuboidal or cylindrical, so that the in Fig. 12 illustrated cross section corresponding to an upside-down U results. The housing 40 is in this case partially or preferably completely formed of inorganic glass or organic glass with the above-mentioned materials. In this case, the housing is formed with reduced radiation transmission, which by means of in Fig. 12 17, wherein the coating 17 can be formed on the outside, inside or as an intermediate layer of the housing 40. It is also possible that a wall of the housing 40 is provided with the radiation permitting reducing particles 19 or an otherwise additive 18, wherein in principle all the above measures for reducing the radiation transmission can also be used for the housing 40.

Fig. 13 shows a different embodiment of a freeze dryer 1, but in which the same basic module 36 is used as in Fig. 12 , In this case, no intermediate plate 39 and no U-shaped housing 40 is used. Rather, a lid 42 is supported by a sealing element 38 on the housing 37 of the basic module 36. Here, the lid 42 is made of any glass with the implementation of the previously described measures to reduce the radiation transmission. For the in Fig. 13 illustrated embodiment, the lid 42 is equipped on its outside with a coating 17. In this case, the footprint 10 is located directly in the ice condenser chamber 4 and the product chamber 3 and the ice condenser chamber 4 are formed as an integral chamber, so that here is a single-chamber principle application.

While according to Fig. 13 the footprint 10 in a manner not shown, for example via a frame, is supported directly on the housing 37, disclosed Fig. 14 an embodiment, in which likewise a single-chamber principle is used and the same basic module 36 is used as in the Fig. 12 and 13 , Again, a lid 42 is supported on the housing 37 via a sealing element 38 and suitable measures for reducing the radiation permeability of the lid 42 are taken. In this case, however, the footprint 10 is fixed to the cover 42, which can be done via struts 43, which, distributed over the circumference, extend from the edge of the footprint 10 in the vertical direction up to the cover 40. It is possible that the struts also include lines 44, which the supply and removal of measurement signals and / or for supplying electrical voltage for heating and / or cooling and / or the supply and / or discharge of a fluid for cooling and / or Heating the footprint 10 can serve. This supply and / or supply and discharge can also take place via the cover 42, via the intermediate plate 39 or the housing 37.

In the simplest case, the fixation of the housing 40, the intermediate plate 39 and the lid 42 to the housing 37 for the embodiment according to Fig. 12 to 14 on the pressure conditions, so that automatically with the venting of the ice-condenser chamber 4 and / or the product chamber 3, the contact force between said components is increased and removal of the technical vacuum easy assembly and disassembly is possible. It is understood that any complementary connection and fastening measures can be taken. According to the embodiments according to Fig. 12 to 14 the housing 40 or the cover 42 forms the viewing window 15.

• Möglich ist der Einsatz einer selbstklebenden Folie, welche eine Schirmdämpfung von mehr als 20 dB oder mehr als 30 dB besitzt und eine Materialstärke von mehr als 35 µm oder mehr als 75 µm besitzt, wobei eine selbstklebende Wirkung der Folie herbeigeführt ist durch einen rückseitigen wasser- und druckaktivierbaren Kleber. Eine derartige Folie ist bspw. kommerziell verfügbar unter der Kennzeichnung "RDF62" oder "RDF72" des Unternehmens YSHIELD (vgl. www.yshield.com), wobei diese Folien eine Lichtdurchlässigkeit von 62 % bzw. 72 % besitzen.
• Möglich ist, dass eine Schicht oder Beschichtung 17 im Randbereich mit einer Randversiegelung, bspw. mit Silikon (z. B. Kennzeichnung "DOW Corning 796") ausgestattet ist.
• Einsatz finden kann ein sogenannter Sonnenschutzfilm, welcher unter der Kennzeichnung "3M" (eingetragene Marke) sowie "Plastic S15" von dem Unternehmen 3M Deutschland GmbH vertrieben wird.
• Möglich ist, dass ein abschirmendes Gewebe aus Edelstahl Einsatz findet, welches bei 1 kHz eine Dämpfung von zumindest 100 dB, bei 1 MHz von zumindest 95 dB, bei 100 MHz zumindest 55 dB, bei 1 GHz zumindest 40 dB und bei 10 GHz zumindest 25 dB herbeiführt. Dieses kann bspw. eine Maschenweite im Bereich von 0,08 bis 0,12 mm besitzen und ein Gewicht von 380 bis 420 g/m² besitzen. Ein derartiges Abschirmgewebe wird bspw. von dem Unternehmen Aaronia AG unter der Kennzeichnung "Aaronia Mesh" vertrieben, vgl. das Datenblatt "Feuerfestes Abschirmgewebe Aaronia Mesh" Rev. 1.1, 19.09.2014, s. a. www.aaronia.de .
• Möglich ist auch der Einsatz eines Abschirmgewebes aus einem Gewebematerial mit einem Silber/Polyamid-Gemisch (20 % / 80 %). Ein derartiges Gewebe kann eine Maschenweite im Bereich von 0,5 bis 0,9 mm besitzen mit einer Stärke von 0,08 mm bis 0,12 mm und einem Gewicht von 15 g/m² ± 20 %. Hiermit kann eine Abschirmung von mehr als 40 dB bei 10 GHz und mehr als 45 dB bei mehr als 1 GHz herbeigeführt werden. Ein derartiges Gewebe wird beispielsweise von dem Unternehmen Aaronia AG unter der Kennzeichnung "Aaronia-Shield" (eingetragene Marke) vertrieben, vgl. das Datenblatt "50 dB EMV Abschirmung Abschirmstoff Aaronia-Shield", Rev. 1.7, 19.09.2014, s. a. www.aaronia.de .
• Einsatz finden können auch beliebige Drahtgewebe nach DIN ISO 9044, vgl. die in der Norm festgelegten Maschenweiten, Drahtdurchmesser, Teilungen, Ketten, Schüsse, offene Siebflächen, Bindungen und Webarten, Maschenzahlen je Längeneinheit, Werkstoffe, Maschenformen mit Quadratmasche, Langmasche oder Breitmasche, Webarten mit Drahtgewebe und Drahtgitter, Leinwand-(glatter)Bindung, Form A, Drahtgewebe mit Körperbindung, Wellengitter, Form C, DOKA-Gitter, Form D, EGLA-Gitter, Form E. Derartige Drahtgewebe werden insbesondere von dem Unternehmen HAVER & BOECKER vertrieben, vgl. www.diedrahtweber.com.
• Möglich ist auch eine abschirmende Oberflächenbeschichtung, wie diese bspw. von dem Unternehmen GfO Gesellschaft für Oberflächentechnik mbH unter der Kennzeichnung "ELAMET" (eingetragene Marke) vertrieben werden (s. a. www.gfo-online.com). Derartige Beschichtungen können im Rahmen der Erfindung auf organische Glasflächen in einem Vakuum aus einem Dampf aufgebracht werden und bspw. Aluminium und/oder Indium-Zinn-Oxyd beinhalten. Eine derartige Beschichtung kann eine Dicke weniger als 2,5 µm, 4 µm oder 5 µm besitzen. Möglich ist auch, dass eine derartige Beschichtung mit einem Kupfer-Blei-Bestandteil und/oder Kupfer-Nickel-Bestandteil oder Kupfer-NiCR-Bestandteil oder Kupfer-Stahl-Bestandteil gebildet ist.
• Möglich ist auch der Einsatz eines metallisierten Polyestergewebes, welches vorzugsweise eine Schirmdämpfung von zumindest 75 dB bei einem Flächengewicht von 70 bis 90 g/m² und einer Dicke im Bereich von 0,05 bis 0,1 mm besitzt, wobei das Gewebe mit Polyester, Kupfer, Nickel und einer Schutzschicht gebildet sein kann. Ein derartiges metallisiertes Polyestergewebe ist bspw. von dem Unternehmen YSHIELD unter der Kennzeichnung HNG80 bekannt, vgl. www.yshield.com. Alternativ kann ein metallisiertes Polyestergewebe HNG100, ein metallisiertes Nylonvlies HNV80, ein feinmaschiges metallisiertes Polyesternetz HNO60, ein Edelstahlgewebe HEG10 oder HEG03, ein carbonisiertes Polyestervlies NCV95, eine Schirmfolie MCL61, eine Schirmfolie MCF5 des Unternehmens YSHIELD Einsatz finden, vgl. ebenfalls www.yshield.com.

Below, by way of example, usable layers or coatings 17 and / or additives 18, by means of which a reduction in the radiation permeability can be brought about, are mentioned, without the invention being restricted to these exemplary embodiments:

• It is possible to use a self-adhesive film which has a screen attenuation of more than 20 dB or more than 30 dB and has a material thickness of more than 35 μm or more than 75 μm, wherein a self-adhesive effect of the film is brought about by a water-side coating. and pressure-activated adhesive. Such a film is, for example, commercially available under the designation "RDF62" or "RDF72" of the company YSHIELD (see www.yshield.com), which films have a light transmittance of 62% and 72%, respectively.
• It is possible for a layer or coating 17 in the edge region to be provided with an edge seal, for example with silicone (eg "DOW Corning 796" marking).
• A so-called sun protection film can be used, which is marketed under the designation "3M" (registered trademark) as well as "Plastic S15" by the company 3M Deutschland GmbH.
• It is possible that a shielding fabric made of stainless steel is used, which at 1 kHz attenuation of at least 100 dB at 1 MHz of at least 95 dB at 100 MHz at least 55 dB, at 1 GHz at least 40 dB and 10 GHz at least 25th dB induced. This may, for example, have a mesh size in the range of 0.08 to 0.12 mm and have a weight of 380 to 420 g / m ² . Such a shielding fabric is marketed, for example, by the company Aaronia AG under the name "Aaronia Mesh", cf. the Data sheet "Fireproof shielding fabric Aaronia Mesh" Rev. 1.1, 19.09.2014, sa www.aaronia.de ,
• It is also possible to use a shielding fabric made of a fabric material with a silver / polyamide mixture (20% / 80%). Such a fabric may have a mesh size in the range of 0.5 to 0.9 mm with a thickness of 0.08 mm to 0.12 mm and a weight of 15 g / m ² ± 20%. This can provide a shield of more than 40 dB at 10 GHz and more than 45 dB at more than 1 GHz. Such a fabric is sold for example by the company Aaronia AG under the name "Aaronia-Shield" (registered trademark), cf. the Data sheet "50 dB EMC Shielding Substance Aaronia-Shield", Rev. 1.7, 19.09.2014, sa www.aaronia.de ,
• Any wire mesh according to DIN ISO 9044 can also be used, cf. the mesh sizes specified in the standard, wire diameters, pitches, chains, shots, open screen surfaces, weaves and weaves, mesh counts per unit length, materials, square mesh, long mesh or wide mesh weave, wire weave and wire mesh weave, canvas (plain) weave, shape A, wire weave with body weave, wave mesh, form C, DOKA lattice, form D, EGLA lattice, form E. Such Woven wire fabrics are marketed especially by the company HAVER & BOECKER, cf. www.diedrahtweber.com.
• Also possible is a shielding surface coating, such as these, for example, by the company GfO Gesellschaft fur Oberflächentechnik mbH under the label "ELAMET" (registered trademark) are sold (sa www.gfo-online.com). Such coatings can be applied in the context of the invention on organic glass surfaces in a vacuum from a vapor and include, for example, aluminum and / or indium-tin-oxide. Such a coating may have a thickness less than 2.5 μm, 4 μm or 5 μm. It is also possible that such a coating is formed with a copper-lead component and / or copper-nickel component or copper-NiCR component or copper-steel component.
• It is also possible to use a metallized polyester fabric, which preferably has a screen attenuation of at least 75 dB at a basis weight of 70 to 90 g / m ² and a thickness in the range of 0.05 to 0.1 mm, wherein the fabric with polyester, Copper, nickel and a protective layer may be formed. Such a metallized polyester fabric is known, for example, from the company YSHIELD under the designation HNG80, cf. www.yshield.com. Alternatively, a metallised polyester fabric HNG100, a metallized nylon nonwoven HNV80, a fine mesh metallised polyester net HNO60, a stainless steel mesh HEG10 or HEG03, a carbonized polyester nonwoven NCV95, a screen sheet MCL61, a screen sheet MCF5 from YSHIELD can be used. also www.yshield.com.

The arrangement of a layer or coating on an inner side of the viewing window is particularly advantageous if it is to be avoided that the electromagnetic radiation should pass from the interior of the housing of the freeze dryer to the outside. If, on the other hand, the coating or layer is arranged on the outside, the electromagnetic radiation propagates from the interior of the freeze dryer through the transparent plastic glass. In this case, it may be disadvantageous that the electromagnetic radiation is also transmitted to the edge region of the transparent plastic glass and there "bypasses" the coating or layer. In particular, in this case is advantageous if the front side of the transparent plastic glass is also equipped with a layer or coating. On the other hand, it is disadvantageous in the arrangement of the coating or layer on the inside the viewing window that the infrared radiation through the transparent plastic glass rode up to the inner coating or layer, where it is then reflected. By passing through the transparent plastic glass and the reflection is already an undesirable heating of the transparent plastic glass. This can be avoided if the outside of the transparent plastic glass is provided with the coating or the radiation-transmitting reduction layer. If the layer or coating is arranged on the inside, this must meet the strict requirements for the materials of the interior of the freeze dryer, for example, regulations of the FDA. Furthermore, u. U. be exposed in this case, the layer or coating during operation of the freeze dryer and the technical vacuum acting there and the temperatures occurring elevated stresses.

Preferably, no electromagnetic wave or microwave based heater is used in the freeze dryer.

In the context of the invention, an at least partially transparent or transparent layer or coating is also used in order to be able to observe changes in the product during the process progress.

It is possible that the measures according to the invention influence reflection, absorption, emission and / or transmission, which on the one hand can apply to radiation from the inside to the outside and on the other hand to radiation from outside to inside.

The global radiation of the sun, for example for the midday sun in the Mediterranean in the summer, has relative radiation intensities above 20% in the wavelength range UVA (315-380 nm), in the range of visible light (380-780 nm) and in the range infrared A (ER -A; 780-1400 nm). In addition, it is possible that the material used also reduces the radiation transmission for radiation in the wavelength range infrared B (IR-B, 1400-300 nm). According to the invention, for example, a reduced radiation permeability can be brought about in one, several or all of the areas mentioned.

By doing Prospectus EVONIK Industries: Polymer & Laser Laser Application Center, February 2008, on page 17 Materials called, which a reduced transmittance, which describes the proportion of the incident beam flux or luminous flux, which is a transparent Component completely penetrates, or describes the quotient between the radiation flux of the exiting or transmitting light beam and the radiation flux of the incident light beam cause. These are, in particular, nanomodified PMMA marked "PLEXIGLAS GS 0Z01" and nanomodified TROGAMID marked "TROGAMID RS 6047", with "PLEXIGLAS" and "TROGAMID" being registered Trademarks acts. These materials are also usable within the scope of the invention. Another usable material for reducing the radiation transmission is borosilicate glass, which is also marketed under the name "Duran" (registered trademark).

LIST OF REFERENCE NUMBERS

1

freeze dryer

2

casing

3

product chamber

4

Ice condenser chamber

5

opening

6

Valve

7

partition wall

8th

pump

9

Valve

10

footprint

11

product

12

cooling device

13

opening

14

Door or flap

15

window

16

body

17

Layer, coating

18

additive

19

particle

20

Cover, frame

21

locking mechanism

22

hinge element

23

hinge element

24

pane

25

leg

26

leg

27

front

28

screw

29

screw

30

segment

31

base leg

32

side leg

33

side leg

34

countersink

35

countersink

36

basic module

37

casing

38

sealing element

39

intermediate plate

40

casing

41

sealing element

42

cover

43

strut

44

management

Claims (16)

1. Freeze dryer (1) comprising a viewing window (15) of an organic glass or an inorganic glass, characterised in that the viewing window (15) has a reduced transmissibility for radiation by comprising a layer or coating (17) having a reduced transmissibility for radiation and/or by comprising a material with an additive (18) having a reduced transmissibility for radiation, the reduced transmissibility for radiation of the viewing window (15) with the additive (18), the layer or the coating (17) being smaller than the transmissibility for radiation of the viewing window (15) without the layer or coating (17) or the additive (18).
2. Freeze dryer (1) of claim 1, characterised in that the viewing window (15) comprises a grounding.
3. Freeze dryer (1) of one of the preceding claims, characterised in that the viewing window (15) comprises an inorganic glass, mineral glass or crystal glass.
4. Freeze dryer (1) of one of the preceding claims, characterised in that the viewing window (15) comprises an organic glass, in particular transparent PMMA, PC, PET, SAN, PVC.
5. Freeze dryer (1) of one of the preceding claims, characterised in that the viewing window (15) comprises a thickness in the range of 4 cm to 6 cm.
6. Freeze dryer (1) of one of the preceding claims, characterised in that the viewing window (15) comprises a reduced transmissibility for radiation for light in the frequency region of 380 THz and 790 THz.
7. Freeze dryer (1) of one of the preceding claims, characterised in that

   a) in the interior of the freeze dryer (1) a sensor having an excitation frequency and/or a measurement signal frequency is arranged and

   b) the viewing window (15) comprises a reduced transmissibility for radiation in the region of the excitation frequency and/or the measurement signal frequency.
8. Freeze dryer (1) of one of the preceding claims, characterised in that the viewing window (15) comprises a reduced transmissibility for radiation in a frequency region of 900 MHz, 1800 MHz and/or 1900 MHz.
9. Freeze dryer (1) of one of the preceding claims, characterised in that the viewing window (15) comprises a shielding effectiveness according to the standard IEEE 299-2006 of at least 20 dB.
10. Freeze dryer (1) of one of the preceding claims, characterised in that the layer or coating (17) with the reduced transmissibility for radiation is covered and/or fixed in the edge region by a cover or a frame (20).
11. Freeze dryer (1) of one of the preceding claims, characterised in that the viewing window (15) is formed by a door or flap (14) of the freeze dryer.
12. Freeze dryer (1) of one of the preceding claims, characterised in that a control unit of the freeze dryer (1) comprises control logic which induces a temperature in the freeze dryer (1) which is by a difference temperature below the freezing temperature of the products (11) which shall be freeze dried in the freeze dryer (1), the difference temperature being adapted to the increased shielding effectiveness of the viewing window (15).
13. Freeze dryer (1) of one of the preceding claims, characterised in that a front side (27) of the viewing window (15) is equipped with a layer or coating (17) comprising a reduced transmissibility for radiation.
14. Freeze dryer (1) of one of the preceding claims, characterised in that a lid (42) and/or a housing (40) which or which limits a product chamber (3) and/or an ice condensator chamber (4) together with a base module (36) of a freeze dryer (1) or a housing of a product chamber of the freeze dryer (1) being formed separately from an outer housing of the freeze dryer and being uncaseable from the outer housing forms the viewing window (15).
15. Use of a layer or coating (17) or an additive (18) which reduces a transmissibility for radiation for a viewing window (15) of a freeze dryer (1), the viewing window (15) being formed with the layer or coating (17) or with a material comprising the additive (18) comprises a transmissibility for radiation being smaller than the transmissibility of the viewing window (15) without the layer or coating (17) or the additive (18).
16. Use of claim 15 wherein a layer or coating (17) is used which filters a predetermined wave length region, the wave length region covering the wave length or a wave length region to which at least one component contained in the product, in particular a marker material or substance, is responsive.

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