APPARATUS FOR THE PRODUCTION AND STORAGE OF NITROGEN BY CHEMICAL ADSORPTION OF OXYGEN FROM AIR, FOR USE IN THE PRESERVATION OF FOODS

The present patent application for industrial invention relates to a device for nitrogen production and storage for food preservation using chemical reactions to remove oxygen from air.

The device of the invention is designed for domestic use, although it

5 can be used also in other fields, such as, for illustrative, not limiting purposes,

in the catering sector.

Devices are traditionally used to create environments with different sizes, with modified atmosphere for food preservation. In general, these devices are used for industrial uses (fruit preservation, beverage

10 preservation, food packaging).

The following devices are normally used to feed environments where air is replaced with nitrogen:

- high-pressure nitrogen cylinders;

- nitrogen generators using molecular filters;

15 - nitrogen generators using the PSA method;

- liquid nitrogen.

These nitrogen-administering systems are bulky, noisy and difficult to handle in domestic environments. Moreover, they produce an excess quantity of nitrogen with respect to family requirements.

20 JP 1 157368 discloses a food preservation chamber that uses an

oxygen-absorbing agent composed of a solution immersed in a bath.

GB 219 308 discloses oxygen-absorbing means to obtain inert atmospheres.

CN 201 194534 discloses an apparatus to extract oxygen.

25 JP 6 018152 discloses a refrigerator that removes oxygen to preserve

vegetable products.

JP 5 049460 discloses a food preservation chamber. CN 86 207235 discloses a food preservation device that uses oxygen combustion.

US 2005/034599 discloses a package of oxygen-absorbing products.

The purpose of the present invention is to eliminate the drawbacks of the prior art by providing a device for nitrogen production and storage that is effective, efficacious, versatile and practical.

This purpose is achieved according to the invention, with the characteristics claimed in independent claim 1 .

Advantageous embodiments appear from the dependent claims.

According to the device of the invention, nitrogen is obtained chemically, removing oxygen from the air in a closed environment. There are many chemical reactions that can be used to remove oxygen from a closed environment and they can all be used in the device of the invention, including combustions.

The possible use of different chemical reactions to produce nitrogen derives from the fact that the device is composed of two base elements: a preparation container and a storage tank.

In the preparation container oxygen is removed in a closed environment, controlling the purity of nitrogen and eliminating any undesired products that have been generated.

Nitrogen without oxygen is stored in the storage tank.

When the demand of nitrogen is little, the device according to the invention is provided with a storage tank integrated into the preparation container. The storage tank receives the nitrogen without oxygen and a compressor transfers the nitrogen from the storage tank to a bottle or container to be persevered with nitrogen.

The description of the device for nitrogen production and storage using chemical reactions to remove oxygen from air will be made based on a preferential hypothesis, without any limiting purposes, according to which the chemical reaction is obtained by using oxygen-absorbing agents that are normally produced and available on the market. The air introduced in the device may come from other processes (extraction of combustion gas) and may initially have an oxygen percentage lower than environmental air in normal conditions.

The device of the invention may receive an accessory that makes it possible to use combustions to remove oxygen from the air, eventually combined with suitable absorbing products to neutralize undesired products originated from combustion.

Oxygen absorbers may use various methods to remove oxygen from air, such as, for illustrative, not limiting purpose, oxidation of iron dust.

Normally oxygen absorbers are sold in bags of various sizes and each size corresponds to a quantity of oxygen that can be absorbed. Absorbing products take a long time to absorb the oxygen in the air. The quantity of nitrogen produced for time unit is not very high, but sufficient for domestic use. In particular, but not limitedly to this use, the nitrogen produced is sufficient to preserve beverages or liquid products and also solid products.

The use of oxygen absorbers makes it possible to create nitrogen generators with very small dimensions and reduced cost.

Further characteristics of the invention will appear clearly from the detailed description below, which refers to a merely illustrative, not limiting embodiment, illustrated in the attached drawings, wherein :

Fig. 1 is a perspective view of the device for nitrogen production and storage according to the invention ;

Fig. 2 is a top view of the device of Fig. 1 ;

Fig. 3 is a front elevation view of the device of Fig. 1 ;

Fig. 4 is a side elevation view of the device of Fig. 3;

Fig. 5 is a cross-sectional view along vertical plane V-V of Fig. 4;

Fig. 5A is an enlarged view of a detail of Fig. 5;

Figs. 6 and 7 are the same views as Figs. 1 and 3, except for they illustrate the device of the invention connected to a 5-liter wine bottle;

Figs. 8 and 9 are the same views as Figs. 6 and 7, except for they illustrate the device of the invention disconnected from the wine bottle; Fig. 1 0 is a perspective view of a second embodiment of the device of the invention,

Fig. 1 1 is a top view of the device of Fig. 1 0;

Fig. 1 2 is a front elevation view of the device of Fig. 1 0;

Fig. 1 3 is a cross-sectional view along vertical plane XI I l-XI 11 of Fig. 1 2;

Figs. 14A and 14B are two perspective views from different angles of a third embodiment of the device of the invention ;

Fig. 1 5 is a front elevation view of the device of Fig. 14A;

Fig. 1 6 is a cross-sectional view along vertical plane XVI-XVI of Fig. 15;

Figg. 1 7A, 1 7B, 16C and 1 7D are respectively a front elevation view, a lateral view a prospective view and a plant view of fourth embodiment of the device according to the invention ;

Referring to the figures, the device for nitrogen production and storage is disclosed, which is generally indicated with numeral (1 00).

The device (1 00) has a very simple structure composed of a substantially parallelepiped frame (101 ), which can be adjusted to different solutions according to the specific use: a recessed kitchen, a refrigerated cabinet for wine preservation, a container to be placed on a piece of furniture, and the like.

Referring to Fig. 5, the device (1 00) comprises a preparation container (1 ) wherein nitrogen is prepared and a storage tank (4) wherein nitrogen is stored. The container (1 ) and tank (4) are disposed inside the frame (101 ) of the device.

The container (1 ) comprises an upper receptacle (30) and a lower portion (31 ) ending with a bottom (32). In the upper receptacle (30) bags with oxygen absorbers (2) are contained. The upper receptacle (30) is provided with a hermetic seal cap (1 A) and a grid (1 B) whereon the bags with oxygen absorbers (2) are placed.

A fan (6) is provided under the grid (1 B) for air circulation inside the container (1 ). The fan (6) is mounted on a partition (1 C) provided with holes for air circulation in the lower portion (31 ) of the container. An oxygen detector (7) is positioned inside the container (1 ) and fixed to the partition (1 C) supporting the fan. The lower part (31 ) of the container is preferably, but not necessarily, composed of a bellows to realize a variable volume of the container (1 ), practically with constant pressure.

The device (100) comprises three position detectors (13, 15, 14) disposed at three different heights to detect the position of the bottom (32) of the container. Preferably, said position detectors (13, 15, 14) are proximity micro-switches. For instance, two proximity micro-switches (13, 15) are disposed at different heights in a lateral wall of the frame (101 ). A third proximity micro-switch is disposed in the base of the frame (101 ). Proximity micro-switches (13, 14, 15) are used to detect the volume of the container (1 ) in various operating conditions of the device (100).

In case of a fixed volume container, proximity micro-switches are replaced by a pressure detector inside the container (1 ).

Referring to Fig. 3, a valve (8) is mounted on the upper receptacle (30) of the container, which provides communication between the internal volume of the container (1 ) and the external environment to introduce air.

A compressor (3) transfers the produced nitrogen from the container (1 ) to the tank (4). A maximum pressure valve (17) is disposed on the compressor (3). At the inlet of the tank (4) a non-return valve (18) is provided for one-way flow from container to tank. At the outlet of the tank (4) a pressure regulator (16) and a condensation collector (16B) are provided.

The device (100) comprises an electrical power box (5) with an electronic board that manages the operating cycle of the device. On the electrical box (5) a control panel is provided, comprising a start button (5A), a switch-off button (5F), three indicator lights (5B, 5C, 5D) and one display (5E).

After introducing the bags with oxygen absorbers (2) in the upper receptacle (10) of the container (1 ) and closing the cap (1 A), the start button (5A) is pressed to start the automatic cycle. Consequently, the fan (6) is started; a clock provided on the electronic board is operated and the oxygen detector (7) detects the percentage of oxygen in the container (1 ), which is shown on the display (5E). When the oxygen detector (7) detects a correct oxygen concentration (which can be regulated on the electronic board), the compressor (3) is actuated and transfers nitrogen from the container (1 ) to the tank (4); the fan (6) stops and the clock on the electronic board resets.

The bottom (32) of the container (1 ) is raised and when the first proximity microswitch (13) is actuated by the bottom (32), the compressor (3) stops. Now the valve (8) is opened, providing communication between the inside of the container (1 ) and the external environment. So, the volume of the container (1 ) increases.

The third proximity microswitch (14) detects the bottom (32) and consequently the complete filling of the container (1 ). Consequently, the electrovalve (8) is closed and the cycle is restarted.

A first pressure gauge (20) reads the pressure inside the container (4) and a second pressure gauge (21 ) reads the output pressure from the tank (4) towards a device where the food to be preserved is positioned, such as, for example, a tapping device (10) like the one shown in Figs. 6 - 9.

The device (100) is provided with suitable safety systems.

The second proximity micro-switch (15), which is disposed in intermediate position between the first micro-switch and the second micro- switch, detects the volume reduction of the container (1 ) caused by the removal of oxygen. If the compressor (3) is not started after the actuation of the second proximity microswitch (15), it means that the oxygen detector (7) is exhausted and must be changed. In such a case a first red indicator light (5B) turns on.

The third proximity microswitch (14) detects the maximum volume of the container (1 ). If the second proximity microswitch (15) is not actuated after closing the electrovalve (8), it indicates that no oxygen has been removed and that, consequently, the oxygen absorber (2) in the bags is exhausted. So, a second red indicator light (5C) turns on.

When it is green, the third indicator light (5D) indicates that the start button (5A) has been actuated.

The button (5F) is used to switch off the device (100). When the device (100) is switched off and disconnected from the food preservation device, oxygen is removed from the container (1 ). Therefore, the oxygen absorber (2) contained in the bags is not consumed and the oxygen sensor (7) is protected.

Instead, nitrogen is stored in the storage tank (4), ready for use. The first pressure gauge (20) indirectly indicates the quantity of nitrogen available.

Figs. 5 and 5A show an accessory (22) that can be inserted in the container (1 ) to remove oxygen by means of combustion.

The accessory (22) is composed of a cup (22A), a lateral protection net (22B) and an upper protection disk (22C) mounted in such manner to vertically slide inside said cup (22A).

In order to use the accessory (22), a cotton flock imbued with alcohol is lit, the upper protection disk (22C) is raised and the lit cotton flock is placed in the cup (22A). The accessory (22) is inserted in one of the holes of the partition (1 C) supporting the fan (6) and the cap (1 A) of the container is closed. The start button (5A) is pressed. When the oxygen is consumed, the cotton flock is extinguished. The bags with oxygen absorber (2) neutralize the carbon monoxide and the remaining oxygen.

The advantage of using combustion is the acceleration of the oxygen removal process.

Figs. 6 - 9 show the device (100) connected to a 5-liter wine bottle (9). Supermarkets often sell this type of wine bottles.

A tapping device (10), such as the one disclosed in the Italian patent No. 0001364183, is mounted on the bottle. The tapping device (10) is mounted on the bottle (9) when the latter is full of wine. The tapping device (10) has a fast-coupling connection (1 1 ) coupled with a corresponding fast- coupling connection of the device (100) connected to a pipe used to extract nitrogen from the tank (4). Moreover, the tapping device (10) comprises a tap (10B) and a button (1 OA) to make wine come out of the tap (10B).

When the connection (1 1 ) of the tapping device is inserted into the connection (12) of the device (Figs. 6 and 7), a connection is created between the tapping device (10) and the device (100) for nitrogen production and storage for food preservation. By actuating the button (10A) of the tapping device, wine comes out of the tap (10B), being pushed by the nitrogen that enters the bottle (9).

When the connection (1 1 ) of the tapping device is separated from the connection (12) of the device (Figs. 8 and 9), each connection (1 1 , 12) guarantees the seal of the circuit to which it is connected. Consequently, the tank (4) of the device for nitrogen production and storage is not emptied and the bottle (9) is saturated with nitrogen, replacing the tapped wine and protecting the wine that is still contained in the bottle.

Likewise, the device (100) can be connected with the connection (12) to suitable devices for replacement of air contained in sealed containers, provided with a valve to introduce nitrogen for preservation of solid food (or solid substances) inside said sealed containers.

The device (100) is provided with a compressor (3) and does not need to be connected to an external pneumatic system. When it is necessary to protect the contents of smaller bottles, devices (100) with lower dimensions can be made.

Hereinafter elements that are identical or corresponding will be indicated with the same numerals, omitting their detailed description.

Referring to Figs. 10-14 a second embodiment of the device of the invention is described, which is generally indicated with numeral (200). In the device (200) the cap (1 A) of the container (1 ) is disposed in the front lower part of the device (200). In such a case, the receptacle (30) containing the bags of oxygen absorbers (2) is disposed in the bottom of the device (200). Instead, the bellows-like portion (31 ) is disposed above the receptacle (30) in the top of the device (200).

A spring (42) is disposed inside the bellows-like portion (31 ), which pushes the bellows-like portion (31 ) to the maximum volume configuration.

The upper wall (32) of the bellows-like portion is adapted to be detected by position sensors (14, 15, 13) disposed at different heights. The first position sensor (14) detects a maximum volume configuration of the bellows-like portion; the second position sensor (15) detects an intermediate volume configuration of the bellows-like portion and the third position sensor (13) detects a minimum volume configuration of the bellows-like portion.

Referring to Figs. 14A, 14B, 15 and 16 a third embodiment of the device of the invention is described, which is generally indicated with numeral (300). In the device (300) the container (1 ) is not provided with a bellows-like portion, but comprises a portion with rigid walls (50) with constant volume.

In such a case, no position sensors are provided and the filling condition of the container (1 ) is controlled with a detector or pressure transducer or, more inexpensively, with two vacuometers.

Figures 17A, 17B, 17C and 17D show a device (400) according to a fourth embodiment of the invention which is a simplified embodiment with respect to the preceding embodiments. The device (400) can be used when the demand of Nitrogen is little.

The device (400) comprises a preparation container (1 ) wherein the nitrogen is prepared removing the oxygen. The preparation container (1 ) is used also as storage tank (4) to receive the nitrogen without oxygen; i. e. the storage tank (4) is integrated into the preparation container (1 ).

In this case a compressor (3) transfers the nitrogen from the preparation container (1 ) directly to the bottle (9) or container to be persevered with nitrogen.