JP2532722B2 - Decompressor - Google Patents

Description

TECHNICAL FIELD The present invention relates to a thawing device, and more particularly to a thawing device provided with a catalyst body.

2. Description of the Related Art Conventionally, an electric heater, particularly a ceramic far-infrared radiation type electric heater or an electric heater using an organic resin film as a substrate has been used as a defroster for defrosting frozen foods and the like. When frozen meat and fish are thawed with these electric heaters, water evaporates and at the same time gas of organic decomposition components from food is generated, and this gas turns into a foul odor and fills the thaw and the refrigerator, which causes discomfort. At the same time, this malodor sometimes adheres to other stored foods. Therefore, there is a proposal to provide a deodorizer using activated carbon or zeolite.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in a deodorizer that removes a bad odor by adsorption, the deodorizing ability sharply decreases when the adsorption capacity is saturated.
In addition, there is also a disadvantage that moisture generated during thawing hinders adsorption of odorous component gas. Further, the adsorbed odor may be re-evaporated by irradiation with warm air. Therefore, it must be replaced early.

It is an object of the present invention to provide a decompressor that eliminates the above inconveniences and can purify odorous gas for a long period of time.

Means for Solving the Problems The thaw device of the present invention comprises a thaw heating element in which a catalyst coating layer made of at least activated alumina, silica and platinum group metal is formed on the surface of a quartz tube containing an electric resistor. It is a thing.

The catalyst coating layer preferably covers an area larger than the half circumference of the outer peripheral surface of the quartz tube.

Effect According to the defroster of the present invention, the malodorous gas generated during the heat thawing of frozen foods is transformed into a harmless and odorless component by the catalytic oxidative decomposition action of the catalyst coating layer activated by the electric heating during the thawing. Therefore, the user does not feel uncomfortable and the bad odor does not adhere to other foods stored in the freezer or the refrigerator.

Further, since the catalyst for oxidatively decomposing a bad odor is activated by energization at the time of thawing, it is not necessary to replace it with a conventional deodorizer. Furthermore, since the catalyst layer contains silica, it has a strong adhesive strength with the quartz tube containing the electric resistor, and can be used for a long period of time without being peeled off by a thermal cycle.

Further, since the catalyst layer emits far infrared rays when heated,
It also contributes to improve the thawing efficiency.

Embodiment FIG. 1 shows the basic configuration of a decompressor according to an embodiment of the present invention.
That is, the thawing heating element 2 disposed in the thawing chamber 1
Has a catalyst coating layer 3 on its surface. Then, the malodor generated from the frozen food in the thawing chamber 1 is decomposed into an odorless component by the catalyst coating layer 3 which is heated by the heating element 2 and activated.

 Specific examples of the present invention will be shown below.

(Example-1) With the defroster having the configuration shown in FIG.
It is called a catalyst heater. ) Has the configuration shown in FIG. That is, both ends of the quartz tube 11 are melt-sealed after charging with argon gas with a catalyst heater consisting of a quartz tube 11 having a diameter of 10 mm containing a 300 W nichrome heater wire 10 and a catalyst coating layer 12 on the surface of the quartz tube 11. ing. 13 and 14 are insulators. The composition and forming method of the catalyst coating layer 12 are shown below.

Activated alumina powder 1000g, colloidal alumina 100g with alumina content 10wt%, aluminum nitrate 9-hydrate 100
g, silica content 20 wt% colloidal silica 1000 g, water
1200 g and 30 g of chloroplatinic acid as Pt and 15 g of palladium chloride as Pd were added, and mixed sufficiently by using a ball mill to prepare a slurry. This slurry is applied to the surface of a quartz tube having an outer diameter of 10 mm, an inner diameter of 9 mm and a length of 15 cm by a spray method, dried at 100 ° C. for 2 hours, and then calcined at 500 ° C. for 1 hour to form a quartz tube having a catalyst coating layer. The catalyst heater of the present invention was prepared using this, and a nichrome wire as an electric resistor and an insulator. The catalyst coating layer amount was 0.2 g, and the platinum group metal contents were Pt5.12 mg and Pd2.56 mg.

When the Nichrome heater wire 10 is energized, the Nichrome heater wire is
Heat rays are radiated from 10 in all directions. At this time, since the catalyst coating layer 12 is installed so as to cover the entire outer circumference of the quartz tube 11, all the heat rays radiated from the nichrome heater wire 10 in the entire circumferential direction are radiated to the catalyst coating layer 12, and the catalyst coating layer 12 is covered. Radiant heating of the layer 12 is efficiently performed, the catalyst is heated to its activation temperature in a short time, and the temperature of the catalyst coating layer can be increased.

This catalyst heater also heats the air in the vicinity, so that a convective air flow is generated. And this air flow is the nichrome heater wire.
When coming into contact with the catalyst coating layer 12 heated to the activation temperature by heating from 10 or diffusing into the coating layer, the malodorous component contained in the air near the catalyst heater is purified by the catalytic action. Therefore, the unpleasant odor at the time of thawing is decomposed in the defroster in which the catalyst heater is arranged, and a clean atmosphere is always maintained.

As the electric resistor used for the heating element, a coiled metal wire such as a nichrome wire or a kanthal wire may be used as it is, or a tungsten wire may be enclosed in a quartz tube together with an inert gas such as argon. The quartz tube of the present invention is glass containing 95% or more of silica.

The catalyst coating layer contains silica. By including silica in the catalyst coating layer, the adhesion of the catalyst coating layer to the quartz tube can be strengthened.

The content of silica is preferably 6-40 wt% in the catalyst coating layer. When the content of silica exceeds 40 wt%, the catalyst coating layer is likely to be cracked, resulting in poor adhesion. Also
If it is less than 6% by weight, the sufficient effect of improving the adhesion property of silica cannot be obtained.

The catalyst coating layer also contains activated alumina. This activated alumina not only acts as a catalyst carrier, but also improves the adhesion of the catalyst coating layer to the quartz tube.

The specific surface area of the catalyst coating layer is preferably 10 m ² / g or more. This is because as the specific surface area of the catalyst coating layer increases, the far-infrared radiation amount ratio compared to the amount of near-infrared radiation emitted increases, but the specific surface area is 10 m ² / g or more and a sufficient far-infrared radiation ratio is This is because it can be obtained.

It is desirable to include cerium oxide in the catalyst coating layer. By including cerium oxide in the catalyst coating layer, the heat resistance of the catalyst layer can be improved, and the catalytic oxidation activity for hydrocarbon compounds can be improved.

The content of cerium oxide is preferably 5 to 30 wt% in the catalyst coating layer. When the content of cerium oxide exceeds 30 wt%, the heat resistance of the catalyst coating layer deteriorates, and when it is less than 5 wt%, a sufficient effect of adding cerium oxide cannot be obtained.

It is desirable to include barium oxide in the catalyst coating layer. By including barium oxide in the catalyst coating layer, the heat resistance of the catalyst layer can be improved.

The content of barium oxide is preferably 1 to 10 wt% in the catalyst coating layer. When the content of barium oxide exceeds 10 wt%, the adhesion property of the catalyst coating layer deteriorates, and when it is less than 1 wt%, a sufficient addition effect of barium oxide cannot be obtained.

Further, the same addition effect can be obtained by using barium carbonate instead of barium oxide. The desirable addition amount of barium carbonate is 1 to 10 wt% in terms of barium oxide amount.

It is desirable that the catalyst coating layer contains titanium oxide. By including titanium oxide in the catalyst coating layer, the catalytic oxidation activity for nitrogen compounds such as ammonia can be improved.

The content of titanium oxide is preferably 4 to 30 wt% in the catalyst coating layer. When the content of titanium oxide exceeds 30 wt%, the adhesion property of the catalyst coating layer deteriorates, and when it is less than 4 wt%, a sufficient effect of adding titanium oxide cannot be obtained.

The specific surface area of the catalyst coating layer is preferably 10 m ² / g or more. This is because as the specific surface area of the catalyst coating layer increases, the far-infrared radiation amount ratio compared to the amount of near-infrared radiation emitted increases, but the specific surface area is 10 m ² / g or more and a sufficient far-infrared radiation ratio is This is because it can be obtained.

Further, when forming the catalyst coating layer, it is desirable to provide the catalyst coating layer after roughening the surface of the quartz tube, or after sufficiently degreasing the surface of the quartz tube. With this manufacturing method, the adhesion between the heating element and the catalyst coating layer can be improved.

Various methods can be used for forming the catalyst coating layer. For example, spray painting, dip painting, electrostatic painting,
There are roll coating method, screen printing method and the like.

The median particle size of the particles in the mixed slurry is 1 μm or more, 9 μm
It is preferably m or less. If it exceeds 9 μm, the coating layer becomes soft, and if it is thinner than 1 μm, the coating layer tends to crack.

Silica is silicon dioxide, but silicic acid may be used instead.

EFFECTS OF THE INVENTION As described above, according to the present invention, it is possible to always keep the room clean in order to remove the malodor generated during thawing of frozen foods by catalytic oxidation, and at the same time, attach the malodor to other stored foods. Nor.

Further, the thawing heating element used here can withstand long-term use.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a defroster according to an embodiment of the present invention, and FIG. 2 is a perspective view of a catalyst heater in the defroster. 1 ... Thaw chamber, 2 ... Heating element, 3 ... Catalyst coating layer, 4 ...
… Food.

Front page continued (72) Inventor Koichi Tachibana 1006, Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. 56) References JP-A-63-202366 (JP, A) JP-A-62-127022 (JP, A) Actually developed JP-A-62-160888 (JP, U)

Claims (2)

(57) [Claims] 1. A defroster comprising a defrosting heating element in which a catalyst coating layer comprising at least activated alumina, silica and a platinum group metal is formed on the surface of a quartz tube containing an electric resistor. 2. The defroster according to claim 1, wherein the catalyst coating layer covers an area larger than a half circumference of the outer peripheral surface of the quartz tube.