Museum display case with improved relative humidity control and related control method

Abstract

A display case for preserving and displaying objects in a protected environment. The display case includes: a display space, delimited by separating walls including a lower plane, side walls and a ceiling; and means for adjusting and controlling air climate in the display space. The means for adjusting and controlling include: a hygrometric probe for detecting the relative humidity inside the display space: a control unit, connected to the hygrometric probe and a first relative humidity control electrolytic membrane, located in a first opening formed in one of the separating walls, activated by the control unit.

Claims

1. A display case for preserving and displaying objects in a protected environment, comprising a display space, delimited by separating walls comprising a lower plane and side walls, and means for adjusting and controlling air climate in the display space, comprising: a hygrometric probe for detecting the relative humidity inside the display space, a control unit connected to the hygrometric probe, and a first relative humidity control electrolytic membrane, located in one first opening formed in one of the separating walls, activated by the control unit; wherein: the means for adjusting and controlling further comprises a second relative humidity control electrolytic membrane located in a second opening formed in one of the separating walls and activated by the control unit, the first electrolytic membrane is mounted in the first opening with a dry side thereof inwardly oriented in the display space while the second electrolytic membrane is mounted in the second opening with a humid side inwardly oriented in the display space, the first electrolytic membrane and the second electrolytic membrane are alternatively activated by the control unit for determined time ranges based on relative humidity values detected by the hygrometric probe, and each of the two openings is provided with a shutter movable between a closed position wherein the shutter closes the opening when the electrolytic membrane in such opening is not activated and an open position wherein the shutter leaves the opening open when the electrolytic membrane in such opening is activated.

2. The display case according to claim 1, wherein the two openings are placed adjacent to each other and the shutter is only one for the two openings and is movable between the two positions, each of which is a closed position for one of the two openings and simultaneously an open position for the other of the two openings.

3. The display case according to claim 1, wherein the first opening and the second opening are formed on the side walls of the display case.

4. The display case according to claim 1, comprising at least two climatic zones within the display space having set relative humidity conditions different from each other.

5. The display case according to claim 4, wherein said at least two climatic zones comprise a general climatic zone and one or several particular climatic zones, the display case comprising at least one electrolytic membrane of relative humidity control and a hygrometric probe at each particular climatic zone.

6. A method for preserving and displaying objects in a display space, comprising detecting relative humidity inside the display space, and adjusting the relative humidity inside the display space by providing at least one first relative humidity control electrolytic membrane, facing the display space, activating and deactivating the first electrolytic membrane according to the relative humidity detected inside the display space, providing a second relative humidity control electrolytic membrane facing the display space opposite-oriented with respect to the first relative humidity control electrolytic membrane, activating and deactivating the first and the second electrolytic membrane according to the relative humidity detected inside the display space, and closing by a shutter each of the first and the second electrolytic membrane when deactivated.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further characteristics and advantages of a display case according to the present disclosure will be more evident from the following description of a preferred embodiment thereof, made with reference to the appended drawings. In such drawings:

(2) FIG. 1 is a schematic plan view of a display case according to the present disclosure, in a first operating condition;

(3) FIG. 2 is a schematic plan view of a display of FIG. 1 case according to the invention; in a second operating condition;

(4) FIG. 3 is a diagram illustrating the operation of the display case according to the invention.

DETAILED DESCRIPTION

(5) in FIG. 1, a display case according to the present disclosure is generally indicated with 10. The display case 10 comprises a base surmounted by a case; the case is formed by separating walls that isolate an internal display space 30 from the external environment. The separating walls comprise in particular a lower plane 22, side walls 23 and a ceiling (not visible in the figures). The separating walls are coupled together by sealing and at least one of them (typically a side wall) can be opened in a per se conventional manner; in the figures, neither the openable walls nor the sealing means are highlighted, since they are extraneous to the invention; moreover, at least some of the side walls 23 and possibly the ceiling are at least partly made of transparent material, typically glass.

(6) The display case 10 comprises a particular climatic zone 31 in the display space 30. The climatic zone 31 is defined by specific differentiated (or differentiable) climatic conditions; the climatic zone 31 is partially separated from the rest of the display space 30 by means of a septum 32 which however does not isolate the climatic zone 31.

(7) The display case 10 also comprises means for adjusting and controlling the air in the display space 30. These adjusting and control means comprise relative humidity control electrolytic membranes 41, 42, in the particular climatic zone 31 which membranes are mounted in respective openings 51, 52 formed in one of the separating walls of the case 21, in particular in one of the side walls 23, so as to be facing the display space 30.

(8) The display case 10 further comprises, in the particular climatic zone 31, a hygrometric probe 61, capable of measuring the relative humidity in the same particular climatic zone 31. A control unit 25 is connected to the membranes 41, 42 and to the probe 61, to receive signals and process and transmit commands.

(9) The control unit 25 is set to feed each of the membranes 41, 42 so that in the climatic zone 31 the desired relative humidity conditions are established; the hygrometric probe 61 allows a feedback control, so as to obtain an accurate adjustment of the relative humidity conditions in the climatic zone 31, The membranes of a same climatic zone are clearly all fed in the same way, independently of how the membranes of the other climatic zones are fed.

(10) The membranes 41, 42 are mounted in an opposite way: the membrane 41 is mounted with its dry side oriented towards the display space 30 inside the display case 10 and its humid side is oriented outwardly of the display case 10, while vice versa the membrane 42 is mounted with its humid side oriented towards the display space 30 inside the display case 10 and its dry side oriented outwardly of the display case 10. Therefore, as shown graphically schematically by the arrows in FIGS. 1 and 2, the membrane 41 is able—when activated—to subtract humidity from the inside of the display space 30, while the membrane 42 is able—when activated—to increase the humidity inside the display space 30.

(11) The operating unit 25 operates so as to alternately activate the membrane 41 or the membrane 42, based on the relative humidity value measured by the probe 61.

(12) In the display case 10, no general air conditioning system is shown; however, it is possible that the display case is also provided with such a conventional system, in order to set average climatic conditions, which are then changed locally (as regards relative humidity) in the particular climatic zone 31 by means of the membranes 41, 42.

(13) In use, the membranes 41, 42 exert an influence in the climatic zone 31, in the sense of increasing or decreasing the relative humidity therein, depending on how they are controlled by the control unit 25. The influence extends starting from the membranes 41, 42 and is clearly attenuated as the distance from the membranes 41, 42 increases, but—with a suitable sizing—it is sufficient to ensure the climatic zone 31 to have an extension suitable for the correct housing of objects to be displayed in the display case 10. At a certain distance with respect to the membranes 41, 42 it is possible that the membranes does not exert any influence, and that therefore a general climatic zone 34 remains, different from the particular climatic zone 31 and not provided with relative humidity control electrolytic membrane. The climatic conditions and in particular the relative humidity of the general climatic zone 34 are caused by the environmental conditions, by the possible general air-conditioning system (which might also be of a conventional, active and/or passive type) of the display case, as well as—to a certain extent—even by the influence of the particular climatic zone 31. However, it is possible to size and arrange the membranes 41, 42 so that there is no general climatic zone, since the climatic zone 31 extends throughout the display space 30.

(14) In the display case 10, the two openings 51, 52 are placed adjacent to each other and the shutter 44 is envisaged on the two openings 51, 52 so as to be movable—with respect to each of the openings 51, 52—between a closed position wherein it closes the opening 51, 52 when the electrolytic membrane 41, 42 in such opening is not activated and an open position wherein it leaves the opening 51, 52 open when the electrolytic membrane 41, 42 in such opening is activated. The shutter 44 is only one for the two openings 51, 52 and is therefore movable between two positions, each of which is a closed position for one of the two openings and simultaneously an open position for the other of the two openings. In a variant, not shown, two distinct shutters could be provided, one for each of the openings 51, 52.

(15) FIG. 3 shows in a graph the operation of the display case 10. To obtain this graph, a display case 10 has been prepared with an internal volume of 1 m.sup.3, without any septum 32 inside the display space 30, arranged in a laboratory under environmental conditions of temperature equal to about 20-23° C. and relative humidity equal to around 22-25%; the control unit was set to obtain a relative humidity (HR) value of 30% in the display space 30.

(16) FIG. 3 shows the time on the abscissa, while the states of activation and non-activation of the two membranes 41 and 42 are represented on the ordinate as well as the relative humidity value detected by the probe 61. It is clear that thanks to several embodiments of the present disclosure it is possible to guarantee an almost perfect maintenance of the set relative humidity value, with variations well below 1% of relative humidity value.

(17) Of course, many variants are possible, for example, to provide for several particular climatic zones, variously arranged in the display space.