JPH04281177A - refrigerator - Google Patents

Abstract

PURPOSE:To defrost a heat exchanger and remove the constituent of smell existing in a refrigerator especially in the refrigerator provided with deodorizing function. CONSTITUTION:Smell in a refrigerator 7 is sucked usually by a fan through an air suction port 9 to adsorb the smell by a catalyst coating layer 3 and/or another catalyst coating layer 4 containing zeolite while cooling is effected by a heat exchanger 6. When frost is adhered to the heat exchanger 6 and a cooling capacity is dropped, a catalyst is activated by conducting electric current through a heat generating body 2 to decompose the small, adsorbed by the catalyst coating layer 3 and the catalyst coating layer 4, and eliminate the smell thereof. At the same time, frost, adhered to the heat exchanger 6, is removed by the ascending of heated air. Water drops will never be hitted against the heat generating body 2 by a water drop protecting plate 5. After the frost, adhered to the heat exchanger 6, is removed and the adsorbing capacity of the catalyst layer 3 and/or the catalyst layer 4 is restored again, the conduction of the electric current is stopped again to adsorb the constituents of smell. The adsorption of the smell and the decomposition of the smell are repeated alternately in such a manner.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerator with a deodorizing function that can defrost a heat exchanger and remove odor components present in the refrigerator over a long period of time.

0002

2. Description of the Related Art Generally, there are various bad odors inside a refrigerator. These malodorous components are mainly mercaptans, amines, etc., and are caused by foods.

[0003] Conventionally, as a means for deodorizing the interior of the refrigerator, a method has been mainly used in which activated carbon is placed inside the refrigerator to adsorb and deodorize component gases that cause odors. Recently, a method has also been taken in which equipment equipped with an ozone generation function is placed indoors to oxidize and decompose malodorous components using ozone gas.

0004

[Problems to be Solved by the Invention] Since such conventional adsorption means using activated carbon has a limited adsorption capacity,
Activated carbon had to be replaced periodically. Further, there was a problem that moisture in the atmosphere interfered with gas adsorption. On the other hand, methods that use ozone to decompose odors require special equipment to control the generation of ozone at the optimal concentration for deodorization, and there are odor components that are difficult to decompose.
Further, there was a problem that the ozone generator had a limited lifespan.

[0005] The present invention solves the above problems, and provides a refrigerator that has a simple configuration and can remove frost adhering to a heat exchanger, as well as completely eliminate odors and harmful gases inside the refrigerator over a long life. is intended to provide.

[0006]

[Means for Solving the Problems] In order to achieve the above object, the present invention includes a refrigerator compartment, a fan, a heat exchanger, a water droplet protection plate provided substantially below the heat exchanger, and a water droplet protection plate provided substantially below the heat exchanger. a heating element provided close to the bottom of the plate, a catalyst coating layer is provided on at least one of the water droplet protection plate and the heating element, and the catalyst coating layer contains at least activated alumina, silica, and a platinum group metal. It is composed of zeolite.

[0007]

[Function] With the above-described configuration, the present invention normally circulates the air inside the refrigerator from below the heating element to the top using a fan, and removes the odor components in the refrigerator from the water droplet protection plate and/or the heating element covered with the water droplet protection plate and/or the heating element. A catalyst layer containing zeolite as an adsorbent performs adsorption and deodorization, and a heat exchanger cools the inside of the refrigerator.

[0008] When frost forms on the heat exchanger and the cooling capacity drops to a certain level, the fan is stopped and the heating element is energized to reduce the water droplet protection plate and/or the catalyst layer coated on the heating element. The catalyst substance is activated and the odor components adsorbed on the catalyst coating layer are oxidized and decomposed by chemical action to make them odorless. At the same time, the air heated by the heating element rises to remove frost adhering to the heat exchanger. Heated frost falls as water droplets, but the water droplet protection plate prevents them from falling onto the heating element.

[0009] After the frost adhering to the heat exchanger is removed by heating from the heating element and the adsorption capacity of the catalyst coating layer is restored again, the power supply to the heating element is stopped, and the odor component is removed by the catalyst coating layer again. Perform adsorption.

[0010] In this way, by alternately repeating the adsorption of odor components by the catalyst coating layer and the oxidative decomposition of the odor components by energizing the heating element, it is possible to remove the odor in the refrigerator over a long period of time.

Further, the catalyst coating layer formed on the surfaces of the water droplet protection plate and the heating element is formed using a catalytic material of a platinum group metal supported on alumina together with a noble metal as a catalytic material and silica sol as a binder. By including silica in the catalyst coating layer, the adhesion of the catalyst coating layer to the heating element outer tube such as a quartz tube can be strengthened. Furthermore, the amount of odorous substances adsorbed can be increased by adding zeolite to the catalyst coating layer. Further, the zeolite contained in the catalyst layer is preferably Cu ion exchange type A zeolite. By including Cu ion-exchanged type A zeolite, the adsorption properties of methyl mercaptan, which is the main cause of refrigerator odor, can be increased compared to other zeolites such as MS5A and 10X.

0012

Embodiment An embodiment of the present invention will be described below with reference to FIG.

[0013] 1000 g of activated alumina powder, 1000 g of colloidal alumina with alumina content of 10 wt%, 100 g of aluminum nitrate nonahydrate, and silica content of 20 wt%.
1000 g of colloidal silica, 1200 g of water, 30 g of chloroplatinic acid as Pt, and 15 g of palladium chloride as Pd were added and thoroughly mixed using a ball mill to prepare a slurry. To 150 g of this slurry, 31 g of Cu ion exchange type A zeolite and 38 g of colloidal silica.
and 94 g of water were added and thoroughly mixed using a ball mill to prepare slurry A.

[0014] This slurry A has an outer diameter of 10 mm and an inner diameter of 9 m.
277 mm at the center of the quartz tube surface with a length of 330 mm.
was applied by spraying, dried at room temperature, and then
A quartz tube with a catalyst coating layer is obtained by firing at 0°C for 1 hour,
A heating element 2 was prepared using this, a nichrome wire as an electric resistor, and an insulator. The amount of catalyst coated was 0.6 g.

Further, 1.2 g of the catalyst was coated on the concave surface of the water droplet protection plate 5 having a concave cross section and a length of 380 mm using the slurry A by a spray method.

The heating element 2 and the water droplet protection plate 5 were attached to a refrigerator as shown in FIG. In FIG. 1, 1 is a fan, 2 is a heating element, 3 is a catalyst layer coated on the heating element 2, 4 is a catalyst layer coated on a water droplet protection plate 5, 5 is a water droplet protection plate, 6 is a heat exchanger, and 7 is a Refrigerator room, 8 is the opening/closing door, 9 is the air intake port, 1
0 is an air outlet.

When the switch (not shown) of the refrigerator is turned on, the inside of the refrigerator starts to be cooled, and the air inside the refrigerator compartment 7, which is sucked in through the air intake port 9 by the activated fan 1, is passed through the heating element 2 as shown by the arrow. and is sent to the water droplet protection plate 5.

Here, since the heating element 2 is not energized, the heating element 2 and the catalyst coating layers 3 and 4 of the water droplet protection plate 5 contain Cu ion-exchanged type A zeolite which has a high adsorption capacity at low temperatures.
Odor components in the air are adsorbed and removed. The purified air is turned into cold air by the heat exchanger 6 and sent into the refrigerator compartment 7 again, and this air circulation is repeated.

When frost forms on the heat exchanger 6 and the cooling capacity drops to a certain level, the fan 1 is stopped by a signal from a timer or a temperature sensor (not shown), and the heating element 2 is turned off. When electricity is applied, the frost on the heat exchanger 6 is defrosted. At the same time, the heating element 2 heats the catalyst layer 3 coated on the surface, activates the catalyst metal, oxidizes and decomposes the odor component adsorbed on the catalyst coat layer 13, and regenerates the catalyst coat layer 3. In addition, the heating element 2 heats the water droplet protection plate 5 disposed above, activates the catalyst metal of the catalyst coating layer 4 coated on the surface of the water droplet protection plate 5, and causes the catalyst metal to be adsorbed to the catalyst coating layer 4. The catalyst coating layer 4 is regenerated by oxidatively decomposing the odor components.

The water droplet protection plate 5 is provided to prevent water droplets generated by melting of frost from falling directly onto the surface of the heating element 2 when the heat exchanger 6 is defrosted. After the frost adhering to the heat exchanger 6 is removed and the adsorption capacity of the catalyst coating layers 3 and 4 is restored, the electricity supply to the heating element 2 is stopped, and the catalyst layers 3 and 4 are allowed to adsorb the odor components again. conduct.

As described above, according to the refrigerator of the embodiment of the present invention, the catalyst coating layers 3 and 4 alternately adsorb odor components and oxidize and decompose the adsorbed odor components, thereby removing the odor components. It has the effect of being able to perform frosting and deodorization for a long time. .

[0022]

As is clear from the description of the embodiments above, according to the present invention, a catalyst coating layer is provided on at least one of the water droplet protection plate and the heating element, and the catalyst coating layer is made of at least activated alumina. By containing silica, platinum group metals, and zeolite, the catalyst coating layer alternately adsorbs odor components and oxidizes and decomposes the adsorbed odor components while the refrigerator is operating, resulting in long-term deodorizing performance. We can provide a refrigerator that can perform the following functions.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing the configuration of a refrigerator according to an embodiment of the present invention.

[Explanation of symbols]

1 Fan 2 Heating element 3 Catalyst coating layer coated on the heating element 4 Catalyst coating layer coated on the water droplet protection plate 5 Water droplet protection plate 6 Heat exchanger 7 Refrigeration room

Claims (1)

[Claims] Claim 1: A refrigerator comprising a refrigerator, a fan, a heat exchanger, a water droplet protection plate provided substantially below the heat exchanger, and a heating element provided close to and below the water droplet protection plate, A refrigerator, wherein a catalyst coating layer is provided on at least one of the water droplet protection plate and the heating element, and the catalyst coating layer contains at least activated alumina, silica, a platinum group metal, and zeolite.