GB2385116A

GB2385116A - A refrigerator with a bacteria removal device

Info

Publication number: GB2385116A
Application number: GB0228688A
Authority: GB
Inventors: Paolo Marega
Original assignee: Electrolux Home Products Inc
Current assignee: Electrolux Home Products Inc
Priority date: 2001-12-19
Filing date: 2002-12-09
Publication date: 2003-08-13
Anticipated expiration: 2022-12-09
Also published as: GB0228688D0; ITPN20010050U1; GB2385116B; FR2834555B3; ES1053423U; DE20218153U1; FR2834555A3; ES1053423Y

Abstract

A refrigerator comprises compartments 1, 2 separated by a wall 5 and in flow communication with channel 6 which has a fan 8 and an ultraviolet lamp 11 emitting radiation at a wavelength of 250 nm to remove bacteria from the air passing into both compartments 1, 2 via the fan 8. The ultraviolet lamp 11 is contained in a housing (12, fig 2) which prevents the emitted radiation from striking the walls of the compartments 1, 2 and/or the channel 6. The housing (12) maybe a metal box provided with apertures to allow the air to flow through the housing (12), and may have a plurality of deflecting fins (16, figs 3-6). The fins (16) may be straight (figs 3, 4) or bent (figs 5, 6). Inner walls of the housing (12) may be reflective so that the air may absorb the radiation more efficiently and the fins (16) may be treated such that they absorb the radiation. The lamp 11 and fan 8 may be connected in parallel and operate simultaneously or a control unit may be provided such that the lamp only operates when the fan is operated. The bacteria removal device may also be used in single compartment refrigerators.

Description

REFRIGERATOR WITH IMPROVED AIR PURIFYING DEVICE The invention relates to an improved type of refrigerator having two refrigerated compartments located one above the other and cooled by a single evaporator with an air-cooled assembly, and a device having a bactericidal action on the air contained in the said compartments. In particular, the present invention relates to the connecting channel between the said two compartments in a refrigerator of the type described in an Italian patent application for an industrial invention, No. PN2001A000060, filed on 12 September 2001 on behalf of the present applicant.

It is known that, when items are stored at a temperature in the range from OOC to 100C approximately, the development of particular moulds, yeasts and bacterial spores in the storage compartment is reduced, but is not completely prevented, and the preservation of foods or other articles is therefore adversely affected.

It is known that an excellent method for eliminating moulds, yeasts and bacteria is that of subjecting them and other organisms to the action of ultraviolet radiation, produced, for example, by ordinary commercially available lamps.

Patent US-A-2906104 describes a refrigerator comprising an ultraviolet lamp located in a housing, within which is installed a rotating disc which has an aperture positioned away from the centre of the said disc, in such a way that, as the disc rotates, a beam of radiation sweeps over the articles stored in the compartment.

The housing also comprises apertures located in the path of a flow of air created in the compartment of the refrigerator, in such a way that the bacteria drawn in by the air are also subjected to the radiation.

However, such UV lamps cannot be used in a direct way for irradiating the compartment of a refrigerator, since with the passage of time the ultraviolet rays have a devastating effect on the appearance and structure of the materials-mainly plastic materials-from which the components of the storage compartment are normally made.

The patent FR-A-1141573 describes a refrigerator comprising means for circulating the air drawn from the refrigerating compartment in a closed circuit in which a UV lamp is installed to irradiate the said circulating air. This document does not describe any structural details.

The patent DE 3708390AI describes a cooling compartment through which a forced flow of refrigerated air passes; a UV radiating lamp for the bactericidal treatment of germs contained in the said air is positioned in the air flow.

However, this configuration presents a problem in that the lamp can directly irradiate the wall of the channel, giving rise to the well-known problems when this wall is made of plastic; furthermore, the emitted radiation power is generally absorbed to a lesser extent by the air, but to a greater extent by the said walls of the channel, if these are not suitably treated.

The upper refrigerating compartment of the cited Italian patent (application) is clearly affected by the problem described above, but the known solutions of applying a suitable dedicated device for producing and circulating a flow of air suitably subjected to the radiation of an ultraviolet lamp having a bactericidal action are costly in terms of the accessory components to be provided, particularly an appropriate fan, and also in terms of the space required; in this respect, it should be noted that the principal object of the cited Italian patent application was precisely to make savings in the amount of space to be occupied.

It would therefore be desirable, and it is the object of the present invention, to provide a refrigerator, preferably of the domestic type, having one or more refrigerating compartments, preferably positioned one above the other and cooled by a single evaporator, and connected by an air-flow channel, in which the requirement to include a device having a bactericidal action on the circulating air is met in an efficient manner.

According to the present invention there is provided a refrigerator comprising at least one inner compartment, a channel for the ventilation of the latter and a fan wherein there is positioned in the channel a housing capable of allowing the passage of the flow of air and containing radiant bactericidal means, the housing being capable of preventing the radiation from the radiant bactericidal means from filtering and irradiating the channel and/or portions of the inner compartment.

The invention will be further described by way of non-limitative example with reference to the accompanying drawings, in which :- Fig. 1 shows a schematic front view of a refrigerator according to the invention; Fig. 2 shows a transverse median vertical section through the refrigerator of Fig. 1 ;

Fig. 3 shows a perspective view of a principal component of a refrigerator according to the invention; Fig. 4 shows a transverse vertical section through the component of Fig. 3; Fig. 5 shows a perspective view of an improved embodiment of the principal component of the refrigerator according to the invention; Fig. 6 shows a transverse vertical section through the component of Fig. 5.

A refrigerator which can be provided with the invention comprises an upper compartment 1, a lower compartment 2, a separating wall 5, a vertical channel 6 positioned near the back wall 7 of the upper compartment 1 and connecting the said two compartments, and a fan 8 positioned in the inlet 9 of the said channel, this inlet being positioned in the upper area of the said upper compartment 1.

The outlet 10 of the said channel is directed towards an evaporator 11, preferably of the finned assembly type.

Clearly, the invention can also be applied to a simpler refrigerator, for example one having a single compartment and provided with devices for circulating the air within this single compartment only, but the following description will make it clear that an optimal solution can be achieved with the refrigerator configuration specified above.

Additionally, it is well known that the ultraviolet radiation which has a bactericidal action is that which is in the wave band from 200 to 280 nm (UV-C).

It is therefore highly preferable to use a lamp having a radiation spectrum comprising at least the radiation band identified above.

Given these facts, the invention consists in fitting an ultraviolet lamp 11, preferably of the UV-C type, in the channel 6 through which the air flow passes, and in making and fitting in the same channel a housing 12 which is suitably equipped to contain the said lamp, but which prevents the radiation emitted by the lamp from striking the walls of the compartment, and from entering the food storage compartment, which would have even worse effects.

The advantage of this solution lies in the fact that it makes use of the existing fan for circulating the air between the two compartments, and therefore with this solution a single fan, which is already advantageously used for performing two independent and different functions, namely: efficiently drawing cold air from the evaporator, which is preferably of the assembly type; and

circulating the air between the two separate compartments, is additionally used for a bactericidal action on the circulating air, without this action, carried out by a UV lamp, compromising and/or damaging by direct radiation either the stored foods or the plastic walls of the compartment containing the lamp.

In particular, the preferred embodiment consists in making the said housing 12 in the form of a metal box structure 13, made in such a way as to completely screen the lamp and therefore prevent its radiation from being propagated around it.

Clearly, the said structure 13 must allow the normal passage of the ventilation flow, and for this purpose it is provided with two apertures, namely an upper aperture 14 and a lower aperture 15, which are, clearly, joined in a suitable way to the said channel 6.

To enable the ventilation flow to pass through correctly, while also providing efficient screening of the UV radiation but without excessively increasing the horizontal section of the housing, the said structure is preferably provided with a plurality of deflecting fins 16, suitably sized and distributed, as shown schematically in Figure 4.

However, in this solution the housing 12 and the corresponding metal structure 13 have to be rather deep, as shown in Figure 4, in which the said structure 13 has to have an outwardly projecting area 17, even when provided with the said fins 16, to provide a convenient housing for the lamp 6.

In order to achieve a further reduction of the horizontal section of the said structure and of the corresponding housing, it is preferable for the said fins 16 to be bent at an angle"s"which is less than a right angle, thus achieving an acceptable compromise which still allows the forced air flow to pass, which efficiently screens the UV radiation, and which does not require the said structure 13 and the corresponding housing 12 to be of excessive size.

An advantageous fundamental improvement of the invention consists in making the inner walls of the said structure from a material such that they are as reflective as possible, so that the radiation emitted by the UV lamp is repeatedly reflected by the said walls and is essentially absorbed by the air and/or by the said deflecting fins 16.

As regards these fins 16, they must oppose the passage of radiation to the exterior as efficiently as possible, even if any radiation which may escape is the result of the multiple reflection of the radiation between the walls of the said fins.

It is therefore preferable for the said fins to be capable of capturing as much radiation as possible (the exact opposite of what is required for the walls of the structure 13), and for this purpose they must be treated in such a way, or be made from such materials, that they have the greatest possible efficiency of absorption of UV radiation.

The nature of the materials to be used and of the treatments applied to these fins for this purpose are well known in the prior art and will therefore not be repeated.

Additionally, given that the efficiency of action of the UV lamp is closely related to and dependent on the ventilation flow and consequently on the operation of the fan, a useful and simple improvement of the invention consists in connecting the fan and the lamp in parallel, in such a way that these devices operate simultaneously, or providing a control unit (not shown) and an operating mode such that the lamp can operate only if the fan is put into operation, although it is also possible to provide modes in which the lamp can remain switched off even while the fan is in operation.

Claims

CLAIMS 1. A refrigerator comprising at least one inner compartment, a channel for the ventilation of the latter and a fan wherein there is positioned in the channel a housing capable of allowing the passage of the flow of air and containing radiant bactericidal means, the housing being capable of preventing the radiation from the radiant bactericidal means from filtering and irradiating the channel and/or portions of the inner compartment.
2. A refrigerator according to Claim 1, wherein the radiant bactericidal means comprise an ultraviolet lamp operating in a wave band including radiation at a wavelength of 250 nm.
3. A refrigerator according to Claim 2, wherein the housing comprises a box structure, and the ultraviolet lamp is positioned within the structure, which is shaped in such a way that the radiation of the lamp cannot escape from it.
4. A refrigerator according to Claim 3, wherein the box structure has a plurality of deflecting fins for allowing the forced air flow to pass through the channel.
5. A refrigerator according to Claim 4, wherein the inner surfaces of the box structure reflect UV radiation.
6. A refrigerator according to Claim 4 or 5, wherein the deflecting fins are made from UV-radiation-absorbent materials or at least treated in such a way that they essentially absorb the radiation.
7. A refrigerator according to any one of claims 3 to 6 wherein the box structure is made of metal.
8. A refrigerator according to any one of Claims 2 to 7, wherein the ultraviolet lamp is activated in synchronism with the fan, in such a way that the lamp can be activated only if and when the fan is also in operation.

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9. A refrigerator according to any one of the preceding claims wherein the fan is positioned in the inlet of the channel.
10. A dual-temperature refrigerator according to any one of the preceding claims, wherein the inner compartment comprises at least one upper inner refrigerating compartment, at least one lower inner compartment which, in use, is maintained at a lower temperature than the upper compartment and comprising a separating wall between the compartments and at least one aperture in the separating wall, wherein a channel is vertical and positioned on the back wall and connecting the compartments and an evaporator positioned in front of the lower outlet of the channel.
11. A refrigerator constructed and arranged to operate substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.