WO2012042366A1

WO2012042366A1 - Airtight container for conserving delicate objects

Info

Publication number: WO2012042366A1
Application number: PCT/IB2011/002304
Authority: WO
Inventors: Alessandro Goppion
Original assignee: Goppion S.P.A.
Priority date: 2010-10-01
Filing date: 2011-09-30
Publication date: 2012-04-05
Also published as: ITMI20101802A1

Abstract

This airtight container comprises a main space (13) for housing the objects, an auxiliary space (14) for housing a hygroscopic material, a communication path (27,28,31,32,33) between the auxiliary space and the main space, and it is characterised in that it comprises means (17) for checking the hygroscopic functionality of the hygroscopic material (15) and means for adjusting (21,22,23) the hygroscopic functionality of the hygroscopic material. The normal operation of the container is that typical of a container with a passive system, but the control and the adjustment of the functionality of the hygroscopic material substantially improve its performance. Indeed, the hygroscopic functionality is kept under control, so as to always have the optimal protection for the objects conserved in the container.

Description

Airtight container for conserving delicate objects

DESCRIPTION

The present invention concerns an airtight container for conserving delicate objects, such as works of art, scientific finds, cultural heritage objects or the like.

It is well know that there are objects whose conservation over time . depends upon climatic conditions in which they are conserved and in particular upon the relative level of humidity in the environment, in addition to the temperature and to other factors such as the cleanliness of the environment in which they are conserved (i.e. absence of substances which could be potentially dangerous for the object), absence of vibrations, limitation of light exposure, etcetera. These types of objects include works of art, cultural heritage objects and scientific findings having value which can also be very high, if not even priceless. It is also known to conserve and possibly display these objects in containers that are suitable for ensuring that the optimal conditions are kept.

In particular, the relative humidity is responsible, with its variations, of the exchange of water mass between the environment and the objects being displayed. This continuous exchange makes the objects undergo dangerous stress, since they generate local tension which can lead to very serious damage.

In order to keep the optimal hygrometric conditions (i.e. relative humidity of the environment comprised in a tolerance range) so called passive and active systems are known.

Passive systems are based upon the use of hygroscopic substances, which are capable of subtracting water vapour from the environment or more precisely subtracting it and providing it, according to the conditions. In particular, silica gel or colloidal silica or more appropriately (Si0₂)n_/ a polymer of silica dioxide, are well known. Although its action is normally indicated as a "drying agent", in reality the chemical-physical process with which the water vapour is subtracted from the air consists of an absorption operation: the molecules of water vapour bond to the surface of the silica gel, where by surface all the surface is meant that is in contact with the environment, which is much greater than the outer surface due to a considerable porosity of this material; this results in a greater overall area available for material exchange, i.e. a speed of the humidifying/dehumidifying process which is rather high. It should also be noted that, even though -as mentioned- especially the desiccant action is known, silica gel can also produce an opposite action, i.e. a humidifying action: when it is in a very dry environment, it releases molecules of water vapour adsorbed on its own surface thereto.

Active systems are, on the other hand, based upon the use of refrigerating machines with a compressor or Peltier cell and of vaporizers: the former thermally treat the air so as to subtract, from it, undesired water vapour with lowering of the temperature below the dew-point, the latter add controlled amounts of water vapour so as to increase the relative humidity value.

As known, active systems ensure a better efficacy, at the expense, however, of a greater constructive complexity and of higher operating costs. Moreover, with active systems it is necessary to be particularly careful to avoid that the refrigerating machines introduce foreign substances into the container or into the external environment, such as for example traces of lubricants when there are compressors, which can damage the objects instead of protecting them.

There are also mixed systems, which combine the characteristics of passive systems with those of active systems. These are of course complex systems, which are used to protect objects that are particularly precious, in which the passive system acts as a damper of the active system.

The present invention proposes to provide a container for conserving delicate objects which is effective and reasonably cost-effective.

Consequently, the invention concerns a container according to claim 1; preferred characteristics are then given in the dependent claims.

In particular, an airtight container according to the invention comprises a main space for housing the objects, an auxiliary space for housing a hygroscopic material, a communication path of the auxiliary space with the main space, and it is characterised in that it comprises means for checking the hygroscopic functionality of the hygroscopic material and means for adjusting the hygroscopic functionality of the hygroscopic material.

By "hygroscopic functionality", here and in the rest of the description, the capability is meant of the hygroscopic material of capturing water vapour from the environment (thus lowering its relative -humidity value) or rather, releasing water vapour to the environment (thus increasing its relative humidity . value) , according to whether the relative humidity of the environment is greater than a maximum value, or rather lower than a minimum value. Therefore, according to the invention the normal operation of the container is that which is typical of a container with a passive system, but the control and the adjustment of the functionality of the hygroscopic material substantially improves its performance. Indeed, thanks to the invention, the hygroscopic functionality is kept under control, so as to always have the optimal protection for the objects conserved inside the container. Moreover, there is no need to periodically replace the hygroscopic material: by avoiding having to access the container so as to replace the hygroscopic material, it is also possible to avoid interrupting the best conditions in which to conserve the objects, thus reducing the risk of damage.

Preferably, the means for checking the hygroscopic functionality comprise a weighing device that detects the weight variations of the hygroscopic material. This characteristic makes it possible to control, in a simple and reliable manner, the amount of water vapour held by the hygroscopic material and thus its capability of exchanging more vapour with the environment, thus varying the relative humidity of the environment itself. Preferably, the means for adjusting the hygroscopic functionality comprise a dehumidifying device for removing water vapour from the hygroscopic material and a humidifying device for adding water vapour to the hygroscopic material. These devices can be respectively a heater, acting on the hygroscopic material, and a steam generator, capable of directing a flow of steam towards the hygroscopic material. The steam generator can simply be a tray full of water, with heating means so as to make the water evaporate. As it should be understood, the adjustment of the hygroscopic functionality is obtained in a simple manner, therefore cost-effective and reliable, without using complex refrigerating machines, with a compressor or Peltier cells. Preferably, the container also comprises means for selectively closing the communication path between the auxiliary space and the main space, controlled so as to interrupt said communication when any one of the dehumidifying and humidifying devices is activated. In such a way, when it is necessary for there to be a variation of the content of water vapour of the hygroscopic material, the auxiliary space remains separate from the main space, so that the operation of the dehumidifying or humidifying devices does not lead to sudden variations of the conditions of relative humidity of the environment of the main space, where the object is being conserved.

According to one particularly preferred embodiment, the means for checking the hygroscopic functionality comprise a weighing device that detects the weight variations of the hygroscopic material, and the means for. adjusting the hygroscopic functionality comprise a dehumidifying device to remove water from the hygroscopic material and a humidifying device to add water to the hygroscopic material; moreover, the container comprises means for selectively closing the communication path between the auxiliary space and the main space, controlled so as to interrupt said communication when any one of the dehumidifying and humidifying devices is activated, and a control unit, operatively connected to the means for checking the hygroscopic functionality, to the means for adjusting the hygroscopic functionality, and to the means for selectively closing the communication path between the auxiliary space and the main space.

In such a manner, the hygrometric conditions inside the container are automatically kept, ensuring the best protection for the objects contained in the main space.

The container can be used only to conserve objects can also be used to display them. In such a case, the container will be a display case, in which the main space is defined by at least one transparent wall through which the delicate objects housed in it can be seen. The advantages of the invention are particularly advantageous in the case of a display case, in which the requirement of ensuring visibility makes keeping the optimal hygrometric conditions even more critical; indeed, the relative humidity of the environment, in which the display case is, can also vary in a very strong manner according to the number of people present around the display case or to the radiation conditions due to external lighting, either natural or artificial.

Further characteristics and advantages of the invention shall become clearer from the following description of one of its preferred embodiments, given with reference to the attached drawing. In such a drawing: fig. 1 is a schematic view of a container according to the invention. In the figures, an airtight container for delicate objects, in particular a display case intended for both displaying and conserving objects is wholly indicated with reference numeral 10.

The display case 10 comprises a display part 11 and a technical part 12. In the display part 11, a main space 13 is provided, intended to house the delicate objects; the space 13 is airtight, according to methods that are well known in the art. In the technical part 12, an auxiliary space 14 is provided, which is also airtight, in which hygroscopic material 15, carried by a support 16, is housed; preferably, such a material 15 is silica gel.

The main and auxiliary spaces 13, 14 are connected (again airtight) through a communication path, which shall be described in the rest of the description.

The display case 10 comprises means for checking the hygroscopic functionality of the hygroscopic material 15. Said means preferably comprise a weighing device 17, which supports the support 16 on which the hygroscopic material 15 rests. Said weighing device 17 can for example be made with a suitable system of load cells or with another equivalent system, be it in traction or compression or other.

The display case 10 also comprises means for adjusting the hygroscopic functionality of the hygroscopic material 15. Said means preferably comprise a dehumidifying device to remove water from the hygroscopic material 15 and humidifying device to add water to the hygroscopic material 15.

Preferably, the dehumidifying device is formed by heating elements 21, for example electric resistors, arranged in the auxiliary space 14, near to the hygroscopic material 15. Preferably, the humidifying device comprises a simple steam generator, formed by a tray 22 that is suitable for containing water and is provided with heating elements 23 (for example electric resistors).

Preferably, the display case 10 then comprises means for selectively closing the communication path between the auxiliary space 14 and the main space 13, controlled so as to interrupt said communication when any one of the dehumidifying 21 and humidifying 22, 23 devices is activated. Said selective closing means comprise two three- way valves, 25 and 26. The first three-way valve 25 is connected to the main space 13 through a duct 27, to the auxiliary space 14 through a duct 28 and to the outside environment through a suction fan 29, provided with a filter 30 for the sucked air. The second three-way valve 26 is connected to the main space through a duct 31 provided with a fan 32, to the auxiliary space 14 through a duct 33 and to the outside environment through a duct 34. The ducts 27, 28, 31, 33, together with the valves 25, 26 and with the fan 32, form the communication path between the main space 13 and the auxiliary space 14.

Moreover, in its technical part 12, the display case 10 is preferably provided with a system for managing the water in the tank 42, wholly indicated with reference numeral 41. The system 41 comprises a tank 42 for the water, with a pipe system 43 for delivering and returning towards the tray 22, provided with a pump 44. The system 41 also comprises a minimum level sensor 46, for checking the presence of a correct quantity of water in the tank 42, and a sensor 48 for checking the presence of water in the tray 22.

Finally, the display case 10 preferably comprises, in its technical part 12, a control unit 50 (for example a microprocessor) , operatively connected to the weighing device 17, to the heating elements 21 and 23, to the valves 25 and 26, to the fans 29 and 32, to the water pump 44, to the sensors 46 and 48, as well as to a temperature sensor 51 facing onto the duct 33. In operation, different modes are provided, which are controlled and adjusted by the control unit 50.

In normal operation mode, the heating elements 21 and 23 are not supplied with power; the valve 25 is in a position such as to connect the duct 27 to the duct 28 excluding the fan 29, which is still; the valve 26 is in a position such as to connect the duct 33 to the duct 31, closing the duct 34 towards the environment; the pump 44 is still, the fan 32 is operative. There is thus a circulation of air in a closed circuit between the main space 13 and the auxiliary space 14, through the ducts 27, 28, 33 and 31 of the communication path; in this circulation, air continues to come into contact with the hygroscopic material 15, which adjusts its water vapour content, i.e. the relative humidity.

This mode is kept until the weighing device 17 indicates that the hygroscopic material 15 has exceeded a minimum threshold or a maximum threshold of weight and that it is not therefore capable of continuing to suitably adjust the relative humidity of the air that circulates.

If the weighing device 17 indicates that the weight has dropped below the minimum threshold, it means that the hygroscopic material 15 is too dry and it may not be able to compensate for the relative humidity of the air circulating in the main space 13 if this is too dry. In this case, the normal operation mode is interrupted and the humidifying mode begins.

In this mode, first of all the fan 32 is stopped and the two valves 25 and 26 are switched: the valve 25 is actuated so that the duct 27 is closed towards the main space 13 and that the fan 29 is thus placed in communication with the duct 28 towards the auxiliary space 14; the valve 26 is actuated so that the duct 31 is closed and that the duct 33 is placed in communication with the duct 34. After this, the pump 44 and the heating elements 23 are activated and in this way the water that has been drawn to the tray 22 is heated, thus generating vapour in the auxiliary space 14. This water vapour is adsorbed to the hygroscopic material 15, restoring the optimal operation conditions. It should be noted that the air introduced in this step inside the auxiliary space 14 is in any case filtered by the filter 30. When the weighing device 17 then detects that the weight of the hygroscopic material 15 has returned to the foreseen values, the display case 10 returns to the normal operation mode. Possible excess water left over in the tray 22 at the end of the cycle is preferably collected by the pipe system 43 and is taken into the tank 42, through the inversion of the pumping direction of the pump 44; in this operating mode, water is thus prevented from remaining in the auxiliary space 14, which could easily alter the desired hygrometric conditions. If vice versa the weighing device 17 indicates that the weight has risen beyond the maximum threshold, it means that the hygroscopic material 15 is too humid and the relative humidity of the air circulating in the main space 12 could rise too much. In this case, the normal operation mode is interrupted and the dehumidifying mode begins.

In this mode, just like in the humidifying mode, first of all the fan 32 is stopped and the two valves 25 and 26 are switched: the valve 25 is actuated so that the duct 27 is closed towards the main space 13 and so that the fan 29 is thus placed in communication with the duct 28 towards the auxiliary space 14; the valve 26 is actuated so that the duct 31 is closed and that the duct 33 is placed in communication with the duct 34.. After this, the heating elements 21 are activated and hence the air, which hits the hygroscopic material 15 in the auxiliary space 14, is heated, thus subtracting water vapour therefrom, which is discharged to the outside through the air that comes out from the duct 34, pushed by the fan 29 with predetermined cycles. It should also be noted that the air introduced in this step in the auxiliary space 14 is in any case filtered by the filter 30. Furthermore, when the weighing device 17 detects that the weight of the hygroscopic material 15 has returned to the predetermined values, the display case 10 returns to the normal operation mode. The amount of water in the tray 22 necessary for the operation in the humidifying mode is maintained thanks to the system 41 for managing the water. When (at the beginning of the operation in humidifying mode or in any case during such an operation) the emptying out of the tray 22 is detected through the sensor 48, the pump 44 is activated so as to introduce water in the same tray 22. Moreover, if an anomaly is detected in the level of water inside the tank 42 (through the sensor 46), an alarm signal is emitted, so as to alert human controlling operators, which will then have to add or remove water from the tank 42; preferably, the water used will be demineralised water.

It should also be noted that, both in the humidifying mode and in the dehumidifying mode, the main space 13 remains separate from the auxiliary space 14 where operations on the hygroscopic material 15 occur. Thus, the objects present in the main space 13 are not disturbed by momentary humidity jumps due to the dehumidification and to the humidification of the hygroscopic material 15. It should finally be noted that in the humidifying or dehumidifying operation it is possible for the temperature of the air in the auxiliary space 14 to vary, to an extent such as to stray outside of the tolerance limits for objects in the main space 13; in such a case, it is worth avoiding that such a temperature variation disturbs the conditions of conservation of the delicate objects in the main space 13. For such a purpose, the temperature sensor 51 provides the control unit 50 with a signal that is used so as to give consent for the complete restoration of the operation mode (with switching of the valves 25 and 26 and actuation of the fan 32, so as to restore the circulation of air between the main space 13 and the auxiliary space 14) only when the high temperature has returned within a predetermined range, that is suitable for the requirement optimal conservation of the objects present in the ma ce 13.

Claims

1. Airtight container for conserving delicate objects that require environmental humidity control, comprising a main space (13) for housing the objects, an auxiliary space (14) for housing a hygroscopic material (15), a communication path (25, 26, 27, 28, 31, 32, 33) between the auxiliary space (14) and the main space (13), characterised in that it comprises means (17) for checking the hygroscopic functionality of the hygroscopic material (15) and means (21, 22, 23) for adjusting the hygroscopic functionality of the hygroscopic material (15).

2. Container according to claim 1, wherein the means for checking the hygroscopic functionality comprise a weighing device (17) that detects the weight variations of the hygroscopic material (15) .

3. Container according to claim 1 or 2, wherein the means for adjusting the hygroscopic functionality comprise a dehumidifying device (21) to remove water from the hygroscopic material (15) and a humidifying device (22, 23) to add water to the hygroscopic material (15).

4. Container according to claim 3, wherein the dehumidifying device comprises a heater (21), acting on the hygroscopic material (15).

5. Container according to claim 3, wherein the humidifying device comprises a steam generator (22, 23) , capable of directing a flow of steam towards the hygroscopic material (15) .

6. Container according to claim 3, comprising means (25, 26) for selectively closing the communication path between the auxiliary space (14) and the main space (13), controlled so as to interrupt said communication -when any one of the dehumidifying (21) and humidifying (22, 23) devices is activated.

7. Container according to claim 1, wherein: the means for checking the hygroscopic functionality comprise a weighing device (17) that detects weight variations of the hygroscopic material (15),

the means for adjusting the hygroscopic functionality comprise a dehumidifying device (21) to remove water from the hygroscopic material (15) and a humidifying device (22, 23) to add water to the hygroscopic material ( 15 ) ;

also comprising:

means (25, 26) for selectively closing the communication path between the auxiliary space (14) and the main space (13), controlled so as to interrupt said communication when any one of the dehumidifying (21) and humidifying (22, 23) devices is activated,

a control unit (50), operatively connected to the means (17) for checking the hygroscopic functionality, to the means (21, 22, 23) for adjusting the hygroscopic functionality, and to the means (25, 26) for selectively closing the communication route between the auxiliary space (14) and the main space (13).

8. Container according to any one of claims 1 to 7, wherein the container is a display case (10), in which the main space (13) is defined by at least one transparent wall through which the delicate objects housed in it can be seen .