CN106793879B

CN106793879B - Door, in particular for a refrigerator and/or freezer

Info

Publication number: CN106793879B
Application number: CN201580055598.7A
Authority: CN
Inventors: N·瓦格纳; L·赵; D·格里贝尔; P·齐尔克
Original assignee: Rehau AG and Co
Current assignee: Ruihao Automobile Europe Co ltd; Ruihao Industrial Europe Co ltd
Priority date: 2014-10-13
Filing date: 2015-10-05
Publication date: 2021-02-09
Anticipated expiration: 2035-10-05
Also published as: DE202014104855U1; EP3207318A1; WO2016058671A1; CN106793879A

Abstract

The invention relates to a door, in particular for a refrigerator and/or freezer, comprising a door frame (1) having a polymeric door frame profile (2) and at least two transparent plates (3, 4, 5), which are arranged at a distance from one another parallel to the door frame plane and which together with the door frame profile (2) form at least one flat cavity (7, 8) filled with a gas (6), wherein the plates (3, 4, 5) consist of a polymeric material.

Description

Door, in particular for a refrigerator and/or freezer

Technical Field

The invention relates to a door, in particular for a refrigerator and/or freezer, having a door frame with a door frame profile and at least two transparent plates which are arranged at a distance from one another parallel to the door frame plane and in this case form at least one flat, gas-filled cavity.

Background

Such doors are used in particular in refrigeration appliances for retail food consumption. Such a door should on the one hand keep the energy consumption of the refrigerating or freezing appliance low by good thermal insulation and on the other hand allow a customer to directly see the contents of the appliance even with the door closed. It is particularly interesting in this case that the transparent plate is not covered by condensation water, whereby the visibility of the goods and the overall appearance of the goods supply are influenced. There is a risk of condensate formation, in particular on the relatively cold surfaces on the outside of the door, on which water vapor contained in the ambient air can deposit in liquid form. At high temperatures in the first place, the ambient air absorbs large amounts of water vapor, so that undesirable condensate formation occurs in cold-storage or refrigeration appliances which are exposed in particular to warm regions. Therefore, also under defined extreme ambient air conditions (i.e. high external temperature and at the same time high air humidity), it is often mandatory for the equipment manufacturer to keep the door free of condensation water by means of a configuration of the corresponding structure. In particular, at low internal device temperatures, high costs are required in order to meet these requirements. This often results in practice in that, in order to avoid condensate formation, the door is provided with a heating device which is disadvantageous for the purpose of the installation, wherein the heating power here is generally in the range of 100W or even more. Furthermore, the heating device disadvantageously increases the structural complexity of the door.

DE 3419977 a1 discloses a door for a refrigerator or freezer, in which three transparent panels are provided, spaced apart from one another. The plates are surrounded by a frame, wherein the spacing between the plates is determined by individual spacer bars. These spacer elements impair the insulation of the door, since they lead to undesirable thermal bridge formation. Such a spacer element is also known from the freezer door described in DE 102005059145 a 1.

Furthermore, it is known from the prior art to use plates made of glass, which are spaced apart from one another, in a corresponding door, wherein the cavity formed by these plates is filled with dry, i.e. water-vapor-free, argon gas for improved thermal insulation. Argon has a low thermal conductivity lambda relative to air_Ar＝0.018W/mK(λ_Luft0.026W/mK). Filling the cavity with pure inert gas is cumbersome and expensive.

Disclosure of Invention

The object of the present invention is to provide a door, in particular for a refrigerator and/or freezer, which has a low tendency for condensate formation, can be produced cost-effectively and moreover ensures a low energy consumption of the device.

According to the invention, this object is achieved by a door, in particular for a refrigerator and/or freezer, having a door

-a door frame having a polymeric door frame profile, and

at least two transparent plates which are arranged at a distance from one another parallel to the door frame plane and which together with the door frame profile form at least one flat, gas-filled cavity,

-wherein the plates are composed of a polymeric material.

According to the invention, i.e. using polymeric door frame profiles, said door frame profiles constitute a significant advantage in terms of thermal insulation due to the lower thermal conductivity of the polymeric material compared to metal solutions (e.g. aluminium profiles). By means of the polymeric door frame profile, the formation of thermal bridges between the interior of the device and the outside of the door is prevented, whereby the risk of condensate formation on the outside of the door is permanently reduced. Furthermore, according to the invention, the low thermal conductivity of the polymeric material also serves to increase the thermal insulation effect of the panel according to the invention. By using polymeric materials for the plates (polymeric materials generally having a molecular weight at λ)_KuHeat conductivity in the range of 0.15-0.3W/mK), corresponding heat resistance coefficient ω 1/λ vs glass plate (λ ≈ 1/λ)_Glas0.75W/mK) was significantly improved. Transparent in the context of the present invention means, in particular, that the individual plates each have a transmission of at least 70%, preferably at least 80%, particularly preferably at least 90%, for visible light.

According to a preferred embodiment of the invention, at least 70% by volume of the gas filling the at least one flat cavity consists of nitrogen. In particular, the cavity can be filled with atmospheric air, since no special, costly argon filling is required due to the improved insulation properties of the door frame profiles and panels. Air in the earth's atmosphere typically has a nitrogen content of 77-79 vol%, an oxygen content of 20-22 vol% and other gases (water vapor, argon, CO)₂And other trace gases). The water vapor content in atmospheric air is generally 1-2 (volume) depending on the stateProduct)%. This value can also be lower in very cold air and higher in very hot air. In order to reliably avoid the formation of condensation water in the cavity, it is therefore advantageous to dry the atmospheric air before filling the cavity with atmospheric air. The at least one cavity is advantageously sealed from the external environment prior to its filling, so that virtually no moisture can penetrate into the cavity from the outside in a refrigerator or freezer in operation.

Advantageously, at least three transparent plates are provided, which respectively form at least two flat cavities. The three-plate structure is advantageous in terms of thermal insulation. According to a preferred embodiment of the invention, at least two plates consist of polymethyl methacrylate (PMMA). PMMA is a polymer that can be processed well into panels with particularly good thermal insulation properties. PMMA has a significantly smaller thermal conductivity factor lambda relative to glass_PMMA0.19W/mK, so that the heat resistance coefficient ω of PMMA is approximately four times that of glass. It is also within the scope of the invention to use Polycarbonate (PC), Cyclic Olefin Copolymer (COC), Polystyrene (PS) or polyacrylate imide (PMMI) as the plate material. The aforementioned materials can also be used in a freely combined manner for the different plates (for example, the inner plate is composed of PMMA and the outer plate is composed of PC). All the aforementioned materials have the advantage that they also ensure a high degree of transmission for visible light with a plate thickness of a few millimeters, in particular>90％。

Another great advantage according to the principles of the present invention is that the plates made of polymeric material have a relatively low weight. This advantage can be used according to a preferred embodiment of the invention to keep the plates spaced apart from one another without separate spacer elements, wherein for this purpose all the plates are connected directly to the door frame, preferably glued. As a result, the spacer element can avoid the formation of thermal bridges and thus further reduce the tendency for condensate formation on the outside of the door.

In particular, it is within the scope of the invention for at least one plate to be connected to the door frame by a connecting plate arranged, preferably integrally formed, on the door frame profile. Preferably, at least one connecting plate connects the inner plate, which is surrounded on both sides by the other plates, to the door frame.

Advantageously, the plates have a thickness δ of at most 6mm, preferably at most 3mm_S. This weight and material saving configuration is possible in particular in the correspondingly thick dimensions of the cavity. The at least one flat cavity preferably has a thickness δ of from 10mm to 30mm_H. This ensures, on the one hand, a high specific heat resistance w in the cavity_λ＝δ_H/λ_HAnd on the other hand the cavity thickness delta_HIn this case, the dimensions are also so small that the adverse effect of free convection in the cavity is small or negligible. Within the scope of the invention, in particular, the plate thickness δ_SThickness delta from flat cavity_HIs at least 5, such as at least 6, such as at least 8. Within the scope of the invention, it is also possible, in particular, for all the plates to have the same thickness δ_SAnd/or all flat cavities have the same thickness delta_H。

The polymeric door frame profile may be composed of polyvinyl chloride (PVC). Alternatively, it is also possible, however, for the door frame profile to be produced, for example, from polypropylene (PP) or Polyamide (PA). It is also within the scope of the invention for the door frame profile to have at least one cavity. In this case, it is advantageous if the door frame profile has openings in the cavity wall, which connect at least two cavities to one another in a hydrodynamic manner via the cavity, in order to avoid condensation processes in the cavity. The hydrodynamic connection can optionally be supported by a hose arranged in the cavity, which is coupled to the openings on the end side. By means of these openings, a small air flow can be generated between two such cavities connected to one another, which air flow advantageously passes as close as possible on the surface of the plate corresponding to the closest refrigerated goods and in this movement can carry moisture away from this surface. This measure thus makes it possible to initiate the heating of the door in a defined frame condition, although the insulating properties of the door are slightly impaired.

Alternatively or additionally, toCondensation water formation between the plates is avoided, and a hygroscopic substance, for example in the form of dry beads, is also arranged in the at least one cavity, wherein the substance advantageously comprises or consists of silica gel. Furthermore, the substance may have an indicator characteristic with respect to its moisture content, for example in the form of a color indicator. The indicator shows in which range the receiving capacity of the substance for other moisture has been exhausted. Such substances are, for example, obtained from the Pasteur plant

Orange

Provided is a method. In this way, it can be additionally ensured that condensation water is prevented from forming in the at least one cavity. As long as the substance, via the color indicator, shows a gradually increasing depletion of its receiving capacity for further moisture, the gas filling of the at least one cavity can be renewed, for example, with fresh dry air within the scope of the maintenance of the device.

Finally, the plate on the outside of the door can be configured in a light-conducting manner. If the narrow side of the panel is illuminated with a light source, the entire panel correspondingly glows, whereby the appearance of the door can be further improved. Within the scope of the invention, in particular, this plate on the outside of the door has a greater thickness (for example 4-6mm) than the other plates, for example a maximum thickness of 3 mm. This optional measure is based on the fact that a certain minimum thickness is also required in order to achieve the desired optical effect when the outer plate is illuminated accordingly.

The invention further relates to a refrigerator having a door according to the invention according to claim 15.

Drawings

The invention is explained below on the basis of the figures, which show only one embodiment. It schematically shows:

figure 1 shows a door according to the prior art fixed to a cold-storage or freezer appliance,

figures 2a and 2b show a door according to the invention in a front or rear view,

figure 3 shows a three-dimensional view of section a-a in figure 2b,

figures 4a and 4B show the section B-B in figure 2B in two different embodiments of the invention,

fig. 5a, 5b show cross-sectional views corresponding to fig. 4a, b according to the prior art.

Detailed Description

Fig. 1 shows a refrigeration system assembly in cross section, as is described in the prior art according to DE 102005059145 a 1. The freezer assembly 50 is a component of a freezer cabinet, which is not further shown. The freezer assembly 50 has a glass door, generally indicated at 51. In the closed state, the glass door rests with a flexible seal 52 against a door column 53. The glass door 51 comprises, as a plurality of insulating glass panes, a pane complex 54 with three glass panes, namely an inner pane 3 ', an intermediate pane 4 ' and an outer pane 5 ', which are spaced apart from one another by means of spacer elements 55, namely an inner chamber 56 close to the freezer cabinet. The intermediate plate 4 ' is located between the inner plate 3 ' and the outer plate 5 '. The plate composite 54 is received on the edge side by the vertically oriented door frame profile 2'. In this receiving region, the door frame profile 2' is designed as a substantially U-shaped receiving groove 57 for the plate composite 54. The spacer elements 55 are connected to the plates 3 ', 4 ', 5 ' by means of an adhesive layer 58. Between the floor 59 of the receiving groove 57 and the spacer element 55, a sealing element 60 made of polyurethane is arranged as a secondary sealing material, which seals off the cavities 7 ', 8 ' formed by the webs 3 ', 4 ', 5 ' of the plate composite 54 from the environment. In order to avoid the formation of condensation water within the cavities 7 ', 8 ', a heat-conducting metal film 61 made of aluminum is glued to the base 59 by means of an adhesion promoter between the sealing element 60 and the door frame profile 2 '. The membrane 61 extends between the inner plate 3 'and the outer plate 5' in the receiving recess 57.

The door frame profile 2' is configured as a hollow-chamber profile. It has a plastic profile base 62 made of polyvinyl chloride (PVC). The plastic profile base 62 is coated on its visible side (in fig. 1, i.e. on the left lower side) with a decorative layer in the form of a decorative metal film 63 made of aluminum, which should prevent the formation of condensation water in this region. The plastic profile base 62 is covered above by a cover 63a which snaps into an upper snap-in reception of the plastic profile base 62. A flexible seal 52 is arranged between an inner wall 64 of the cover 63a and an outer wall 65 of the door column 53 facing the inner wall 64. The seal 52 is composed of three elastic sealing walls, an inner wall 66 facing the interior chamber 56, an intermediate wall 67 and an outer wall 68. The sealing

walls

66, 67, 68 of the integrated seal 52 consist of a plastic which is relatively soft with respect to the material of the door frame profile 2', for example of soft PVC. The sealing element 52 has a latching profile section 69 which latches into a receiving chamber 70 of the cover plate 63 a. In fig. 1, above the intermediate wall 67 and the outer wall 68, the seal 52 has a receiving chamber 71 for a magnet 72. The magnet cooperates with a metal section 73 of the lower wall 65 of the door post 53 in the closed state of the glass door. Viewed from the interior 56, the sealing element 66 is offset outward to such an extent that an intermediate space 74 is formed adjacent to the sealing element 66 between the door post 53 and the edge of the plate composite 54. The intermediate chamber is partially filled by a profile element 75. The latter being the separation between the seal 66 and the cavity 56. The profile element 75 is designed as a hollow-chamber profile. In the closed state of the glass door 51, a channel 76 of defined width is maintained between the profile element 75 and the door column 53, thereby ensuring that, in the closed state, the profile element 75 does not contact the glass door 51 and the door column 53 at the same time and in this way undesirably influences the closed state. The profile element 75 is formed integrally with the cover 63 a.

Fig. 2a, 2b and 3 show a door according to the invention for a refrigerator or freezer, having a door frame 1 with a polymeric door frame profile 2 with a door handle 100 attached thereto. The door may be hinged (e.g. similar to fig. 1) to a door post of the respective device. The door frame profile 2 is produced by an extrusion process and (as can be seen from fig. 2a, which shows the front side of the door, and fig. 2b, which shows the rear side of the door) is joined together in the form of four individual profile frames which are cut into an oblique angle. The door in turn has three transparent plates, namely an inner plate 3, an intermediate plate 4 and an outer plate 5, which are arranged at a distance from one another parallel to the door frame plane and which together with the door frame profile 2 form two flat cavities filled with gas 6, namely an inner cavity 7 and an outer cavity 8 (see fig. 2)Fig. 3). The intermediate plate 4 is correspondingly arranged between an inner plate 3 facing the interior of the apparatus and an outer plate 5 facing the surroundings U. The

plates

3, 4, 5 consist of the polymeric material PMMA. The gas 6 filling the two

flat cavities

7, 8 consists of atmospheric air which is dried by means of a drying process before filling the

cavities

7, 8. As can be seen from fig. 3, the

plates

3, 4, 5 are spaced apart from one another without separate spacer elements (see position 55 in fig. 1) and are for this purpose all bonded directly to the door-frame profile 2 by means of an adhesive 80. Both the inner plate 3 of the composite body facing the device and the intermediate plate 4 of the composite body are connected to the door frame 1 by connecting plates 9 which are integrally formed on the door frame profile 2. As can be seen from FIGS. 4a, 4b, the inner plate 3 and the intermediate plate 4 each have a thickness δ of 2mm_S. And the outer panel 5 is formed with a greater thickness delta_SA5mm, as will be discussed later. While the

flat cavities

7, 8 have a thickness delta of 14mm (fig. 4a) or 16mm (fig. 4b), respectively_H. In the exemplary embodiment according to fig. 4a, the ratio of the cavity thickness to the plate thickness is accordingly δ_H/δ _S7 and in fig. 4b 8.

The door frame profile 2 is made of PVC and (as can be seen from fig. 3) has a cavity 10. Furthermore, it is advantageous in the case of specific applications to provide

openings

11, 12 in the cavity walls of the door frame profile 2, which connect the two

cavities

7, 8 to one another in a hydrodynamic manner via the cavity 10. By means of this hydrodynamic connection, the warmer gas 6 is conveyed from the outer cavity 8 into the cooler inner cavity 7 to a lesser extent, wherein the small gas flow indicated by the arrows 13 passes directly over the cold outer surface 14 of the inner plate 3 through the corresponding arrangement of the

openings

11, 12 and in this way transports moisture away from the surface 14, so that condensation on this surface 14 is avoided. It is of course within the scope of the invention that the

openings

11, 12 are not provided so that the

cavities

7, 8, respectively, are completely sealed. It can also be seen that the outer panel 5 of the door facing the outside environment U is glued flat to the door frame profile 2 by means of the adhesive 80 and flush with it. Thereby, the appearance of the door is further improved. The outer panel 5 is furthermore light-conducting and can be illuminated by a light source 15 arranged on the narrow side of the outer panel 5, so that the entire outer panel 5 emits light slightly. The light-guiding properties require a certain minimum thickness of the respective plate. In order to achieve the optical effect described, the outer plate 5 is therefore thicker than the two

other plates

3, 4.

Fig. 5a, 5b show a cross section of a door according to the prior art, similar to the views of fig. 4a, 4 b. In these doors, the plates 3 ', 4', 5 'are made of glass and the cavities 7', 8 'are filled with argon 6'. The plates 3 ', 4 ', 5 ' are relatively thick and therefore have a high weight. The poor thermal insulation properties of the glass are compensated for by using argon gas 6'.

Claims

1. A door, the door having

-a door frame (1) with a polymeric door frame profile (2),

at least three transparent plates (3, 4, 5) which are arranged at a distance from one another parallel to the door frame plane and which together with the door frame profile (2) form at least two flat cavities (7, 8) filled with gas,

-wherein the door frame profile (2) is provided with openings (11, 12) in the cavity walls, which openings connect the cavities (7, 8) to each other in a fluid-dynamic manner,

-wherein the plates (3, 4, 5) consist of a polymeric material.

2. The door according to claim 1, wherein the door is a door for a refrigerating and/or freezing apparatus.

3. A door according to claim 1, characterized in that the gas (6) filling the at least one flat cavity (7, 8) consists of nitrogen for at least 70% by volume.

4. A door according to any one of claims 1-3, characterized in that at least three transparent plates (3, 4, 5) are provided, which correspondingly form at least two cavities (7, 8).

5. A door according to any one of claims 1-3, characterized in that the plates (3, 4, 5) are made of polymethylmethacrylate, PMMA, polycarbonate, PC, cyclic olefin copolymer, COC, polystyrene, PS or polyacrylate imide, PMMI.

6. A door according to any one of claims 1-3, characterized in that the plates (3, 4, 5) are kept spaced apart from each other without separate spacing elements (55) and for this purpose are all directly connected with the door frame profile (2).

7. A door according to any one of claims 1-3, characterized in that the plates (3, 4, 5) are kept spaced apart from each other without separate spacing elements (55) and for this purpose are all glued directly to the door frame profile (2).

8. A door according to any one of claims 1-3, characterized in that at least one plate (3, 4) is connected to the door frame (1) by means of a connecting plate (9) arranged on the door frame profile (2).

9. A door according to any one of claims 1-3, characterized in that at least one plate (3, 4) is connected to the door frame (1) by means of a connecting plate (9) integrally formed on the door frame profile (2).

10. A door according to claim 9, characterized in that the connection plate (9) connects an inner plate (4) surrounded on both sides by further plates (3, 5) with the door frame (1).

11. A door according to any one of claims 1-3, characterized in that the plates (3, 4, 5) have a thickness δ of at most 6mm_S。

12. A door according to any one of claims 1-3, characterized in that the panel (3, 3,4. 5) has a thickness delta of at most 3mm_S。

13. A door according to any one of claims 1-3, characterized in that said at least one flat cavity (7, 8) has a thickness δ from 10mm to 30mm_H。

14. Door according to any of claims 1-3, characterized in that the thickness δ of the cavity is_HRelative to the thickness delta of the plate_SIs at least 5.

15. Door according to any of claims 1-3, characterized in that the thickness δ of the cavity is_HRelative to the thickness delta of the plate_SIs at least 6.

16. A door according to any one of claims 1-3, characterized in that the door frame profile (2) consists of polyvinyl chloride, PVC.

17. A door according to any one of claims 1-3, characterized in that the door frame profile (2) has at least one cavity (10).

18. Door according to claim 17, characterized in that the opening connects at least two flat cavities (7, 8) to each other in a fluid-dynamic manner through the cavity (10).

19. A door according to any one of claims 1-3, characterized in that the first panel (5) seen from the outside of the door is structured light-conducting.

20. An apparatus for refrigerating articles, having

-a housing for accommodating an article,

-a refrigeration unit for cooling the interior of the housing, and

-a door according to any of claims 1-14 for closing the housing.

21. The apparatus of claim 20, wherein the item is a food item.

22. The apparatus of claim 20 or 21, wherein the refrigeration unit is an electric refrigeration unit.