JPS5814259B2 - Chiyouriki - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION An object of the present invention is to eliminate, in various types of cooking appliances, the odor generated during cooking that fills the room and pollutes the indoor air, and also eliminates the nuisance to the neighbors due to outdoor exhaust.

Cookers are generally designed for the purpose of cooking food, and are not intended to eliminate cooking odors.

The present invention makes it possible to eliminate cooking odors using the cooker itself, and prevents the odor from emitting indoors as well as outdoors and causing harm, which is fundamentally different from those that are exhausted outdoors using ventilation fans, etc. It is something.

The principle of deodorizing cooking odors in the present invention is based on the fact that the main odor substance is a hydrocarbon consisting of carbon and hydrogen.
It oxidizes to 2+n/2H20 to form odorless carbon dioxide and water, making it odorless.

In addition, if the odorous substance contains something with a very strong odor such as 1N- (nitrogen) or -SHλ group (mercapta group), 1N1 is replaced by an N2 (nitrogen) molecule, and -
In the case of an SH group, SO2 and H20 are odorless.

Although the principle is as described above, simply installing an oxidation catalyst does not have a sufficient effect.

That is, oxidation catalysts that exhibit excellent effects include platinum (Pt) catalysts, manganese-based catalysts containing manganese dioxide as a main component (details will be described later), and metal oxide-based catalysts.

Furthermore, in order for these catalysts to fully exhibit their effects, cooking odors cannot be removed unless various conditions are met, such as heating at a high temperature above a certain temperature and the method of installing the catalyst.

In order to be installed in this external home cooker, the catalyst must be ■
The following conditions are required: 1) it should be inexpensive; 2) it should not cause any pollution during production, use, or disposal; 2) it should be easy to manufacture; and 2) it should have catalytic activity at as low a temperature as possible.

The results of various studies to satisfy the various conditions described above in the present invention are shown below.

First, in order to examine the catalytic activity, pt (platinum) ■, Mn-based catalyst ■ (details will be described later), and γ-MnO2 ■ CO alone (
Figure 1 shows the carbon monoxide purification ability.

This shows that the pt,Mn-based catalyst has superior oxidation ability compared to γ-Mn02 alone.

However, PT is expensive and has a major drawback in that it is difficult to obtain in large quantities.

Therefore, as the catalyst used in the present invention, a Mn-based catalyst mainly composed of γ-MnO2, which is inexpensive and easily available, is suitable.

Next, the composition of the Mn-based catalyst used in the present invention will be explained in detail.

The composition of the Mn-based catalyst is manganese dioxide, lime aluminate,
Contains iron oxide and basic copper carbonate.

Lime aluminate acts as a heat-resistant binder in the catalyst.

As the aluminate lime, commercially available alumina cement or high alumina cement can be used.

Compared to Bortland cement, lime aluminate has
It has excellent heat resistance and cures at room temperature, and mechanical strength can be obtained without sintering in the production of catalysts.

The composition ratio of lime aluminate required for the catalyst is 40 to 15% by weight.

If it is less than 15% by weight, the mechanical strength is weak, and if it is less than 40% by weight,
In the above, the composition of other necessary components described later becomes smaller,
The activity of the catalyst becomes smaller.

Manganese dioxide is the main catalyst used in the present invention.

Manganese dioxide includes γ-Mn02, β-Mn02, α-
In addition to Mn02 and ρ-Mn02, there are various chemically synthesized manganese dioxides, but γ-MnO2 was particularly excellent.

In addition, using γ-Mn 0 2 and heat treatment, β-Mn 0
0 2 showed almost the same performance as γ-Mn 0 2.

However, naturally occurring β-MnO2, α-Mn02, etc. were all inferior in performance to γ-Mn02.

The preferred composition ratio of manganese dioxide is 45 to 75% by weight.

Manganese dioxide is the main catalyst, and the initial performance is satisfactory to some extent even if it is less than 45% by weight.
45% by weight or more is required to satisfy a long life of more than 1,000 hours.

Moreover, if it exceeds 75% by weight, it becomes impossible to add necessary amounts of other components.

Next, let's talk about iron oxide.

As iron oxides, iron oxyhydroxide and anhydrous iron oxide were investigated, but iron oxyhydroxide was superior in terms of mechanical strength and catalytic activity.

The reason for this is that iron oxyhydroxide has acicular crystals and has excellent miscibility with other powders, especially lime aluminate, and when molded, a three-dimensional lattice-like network of iron oxyhydroxide is formed. it is conceivable that.

The most effective effect is obtained when the amount of iron oxyhydroxide added to the catalyst is 8 to 10% by weight.

Next is basic copper carbonate, which is also called verdigris.
It is relatively stable at room temperature, and turns into copper oxide at high temperatures of 500°C or higher.

However, patina is highly active against carbon monoxide and hydrocarbons at low temperatures due to the coexistence of manganese dioxide, and remains catalytically active even after changing to oxidized steel at high temperatures.

If you want to use oxidized steel as the main component as a finished catalyst, use copper nitrate,
There is a method using cuprous oxide or cupric oxide as raw materials.

Among these methods, the method of adding copper nitrate not only generates nitrogen oxides during production and is expensive to treat, but also has a problem in that the activity is tactilely low until heat treatment is performed.

Furthermore, when copper oxide is added from the beginning, verdigris is much more active than verdigris even if the same stoichiometric amount is added.

Therefore, to obtain a catalytic activity equivalent to that of verdigris, several times or more copper oxide must be added.

Since copper is expensive, it is preferable to use a small amount of copper.

Therefore, the main features obtained by adding verdigris as a promoter as described above are as follows.

(2) Catalytic activity is maintained at the stage where the curing of the catalyst body is completed, that is, even without or after firing.

■Since no heat treatment is required, it is possible to reduce costs and reduce pollution during manufacturing.

■Since no calcination step is required during the manufacturing process, the mechanical strength and abrasion resistance of the catalyst body during transportation are significantly improved.
Especially when it is incorporated as a part for household cooking equipment, its high mechanical strength is a great advantage.

■By adding patina, it is economical because it exhibits an accompaniment effect with a small amount.

When the amount of patina added to the catalyst is less than 2% by weight, no significant accelerator effect is observed.

Furthermore, adding more than 10% by weight not only increases cost, but also reduces mechanical strength, especially mechanical strength at high temperatures, and reduces the promoter effect on manganese oxides and iron oxides.

Therefore, the preferred amount of basic copper carbonate to be added is 2 to 10
Weight%.

FIG. 2 compares the catalytic abilities of catalysts having typical composition ratios (wt%) shown in Table 1.

As is clear from these results, the γ-MnO2, lime aluminate, iron oxyhydroxide, and basic carbonate steel exhibit excellent oxidation activity.

Further, FIG. 3 shows the amount of this catalyst used.

Here 5S. The V value is S. V=(processing gas amount/hr)/
Catalyst volume = hr-, heating temperature is 110℃ for A, B
is 200°C and C is 500°C.

From the above results, the operating temperature range of the catalyst is approximately 110℃~
300℃, and one with a separate heating source for the catalyst
It has been confirmed through experiments that it can be used at temperatures of 10 to 700°C, while S. The V value was in the range of 1000-30000 hr-.

Next, the results of actual odor removal are shown in FIG.

In addition, the implementation conditions are calorie 2500Kcal/h
Hydrocarbon (H.C) is used to remove the odor that occurs when grilling sardines with salad oil on a frying pan in a gas range.
This is seen in terms of its purifying ability.

Also, the amount of catalyst is S. V20,000hr-, and was placed in the odor exhaust passage in a state where it was heated by combustion gas.

Examining, organizing and re-describing the conditions for using the catalyst mentioned above, 1. The tactile material used is manganese-based oxidation catalyst2. The amount of catalyst used is S. ■1000~30000 hr-3 Heating temperature is 110~700℃ 4. Manganese oxidation catalyst is manganese dioxide 45-75w
t%, lime aluminate 15-25 wt%, iron oxyhydroxide 5-15 wt% and basic carbon, acid copper 2-10 wt%
If a Mn-based oxidation catalyst designed to satisfy the above-mentioned conditions is installed in the odor exhaust path of various cooking appliances, odors generated during cooking can be removed.

This Mn-based oxidation catalyst can be installed, for example, in an electric wrench shown in FIG.

In the figure, 1 is a time switch, 2 is a temperature setting knob, 3 is a door, and 4 is an exhaust port.

An oxidation catalyst is provided in the odor exhaust path that reaches this exhaust port.

Of course, the same applies to gas ranges.

FIG. 7 shows a wrench that uses both a gas burner 5 and an electric heater 6. Food 8 such as fish placed on a shelf 7 is heated and cooked, and combustion exhaust gas containing odor is generated in the internal space 9 of the range. The hot air 10 passes through an oxidation catalyst in the exhaust path and is discharged to the outside from the exhaust port 4.

FIG. 8 is a partially cutaway view when this hot air 10 is discharged from the exhaust port 4, and the exhaust path P is provided with a catalyst layer 11, the internal space 9 is provided with an inlet 12, and Inside the discharge passage P itself, a large number of oxidation catalysts 13 are provided in layers.

Therefore, the combustion exhaust gas and the odor associated with cooking enter the exhaust path P through the inlet 12, and the oxidation catalyst 13 in the exhaust path is heated by the exhaust gas, oxidizes and removes the passing odor, and discharges the gas in a nearly odorless state. can.

The oxidation catalyst is preferably arranged in a structure that has good air permeability and a large contact area with the gas, such as a honeycomb shape, so as not to impede the passage of exhaust gas and odor, and the heat of the exhaust gas alone is insufficient to heat the catalyst. In this case, as shown in FIGS. 9 and 10, an electric heater or a gas burner may be provided as the auxiliary heat source 14 to heat the catalyst to a desired temperature within the range of 110 DEG C. to 700 DEG C.

Furthermore, if the catalyst has a multilayer structure and is difficult to exhaust through natural ventilation alone, an exhaust fan 16 may be provided as shown in FIG. 10 to perform forced exhaust.

The heating temperature of the oxidation catalyst was set at 110°C to 700°C. This is because at temperatures lower than 110°C, water vapor generated by the reaction on the catalyst surface condenses, wetting the catalyst and degrading the catalytic performance. This is because the catalyst will undergo thermal deterioration at temperatures higher than °C.

Further, the catalyst may be provided at the top, side, or bottom of the cooking space as long as it is in the odor exhaust path of the cooking device, or it may be provided separately from the cooking device main body and connected with a connecting pipe or the like.

Furthermore, a distance plate or the like may be interposed to prevent oil components of the food to be cooked from adhering to the catalyst or catalyst powder from adhering to the food to be cooked.

Next, as a specific example, two electric open ovens and two gas ovens are prepared, and each one is equipped with the aforementioned oxidation catalyst in the odor discharge path in an amount of S, V 10,000 hr-1, and the remaining one is
Table 2 below shows the results of comparing three sardines baked at 300°C in a total of four ovens, with no oxidation catalyst applied to the ovens.

Table 3 shows the presence or absence of odor when four sliced onions were roasted in butter using these four ovens.

In addition, when three sardines and one onion were roasted in butter, the amount of hydrocarbons (H.C) generated was measured at both the inlet and outlet of the catalyst layer, and the results are shown in Figure 5. More than 80% of the odor was removed, and the odor was almost unnoticeable.

Furthermore, I cooked 3 sardines in a microwave oven using both a gas burner and an electric heater.
The odor produced when the fish was roasted in butter was evaluated by 16 testers, depending on the presence or absence of an oxidation catalyst, and the results were as shown in Table 4 below.

In this way, in the cooking device of the present invention, since an oxidation catalyst mainly composed of heated manganese dioxide is placed in the odor discharge path, most of the odors generated during cooking can be removed. Therefore, it is possible to prevent harmful effects caused by the release of odors indoors and outdoors.

Moreover, since such an oxidation catalyst mainly composed of manganese dioxide is cheap and easily available, it can be molded into any shape and installed in a cooking appliance, and due to the characteristics of manganese dioxide, it can also purify smoke as well as odor. This has the advantage of keeping a good cooking environment.

[Brief explanation of drawings]

Figure 1 shows the carbon monoxide (CO) purification rate of various oxidation catalysts, Figure 2 shows the relationship between heating temperature and CO purification rate of manganese dioxide-based oxidation catalysts, and Figure 3 shows the amount of oxidation catalyst. Figure 4 is a diagram showing the relationship between the heating temperature of the oxidation catalyst and the hydrocarbon (HC) purification rate, and Figure 5 is a diagram showing the HC concentration before and after the purification reaction by the catalyst. , Fig. 6 is a perspective view of an electric wrench according to an embodiment of the present invention, Fig. 7 is a diagram showing the operation of a range using both an electric heater and a gas burner, and Fig. 8 shows the movement of odor generated during cooking and its treatment. 9 and 10 are explanatory diagrams showing the odor discharge path. P...Odor exhaust path, 13...Oxidation catalyst.

Claims (1)

[Claims] 1. A cooking appliance in which a manganese-based oxidation catalyst containing at least manganese dioxide, lime aluminate, iron oxyhydroxide, and basic copper carbonate is installed in an odor exhaust path at a temperature of 110°C to 700°C.