JP2912651B2 - Cooking device - Google Patents

Description

The present invention relates to an oily smoke generated when cooking an oven or grill,
The present invention relates to a cooker having a function of decomposing and removing odors.

2. Description of the Related Art For purifying oily smoke and odor generated during cooking, a method using a catalyst using a box-shaped oven has been put to practical use. The configuration is roughly classified into the following two.

First, a honeycomb supporting a catalyst and a heater for heating the honeycomb are provided in an exhaust hole, and cooking exhaust gas is sucked by a fan and passed through the catalyst-supporting honeycomb to catalytically oxidize and decompose the exhaust gas.

Secondly, as shown in FIG. 3, an exhaust hole 3 is provided in a part of the top plate 2 of the cooking chamber 1, and an exhaust passage 5 is further provided between the top plate 2 and the heat insulating material 4 to form an upper surface of the exhaust passage. An inorganic fiber porous body 6 carrying an oxidation catalyst dispersed therein is arranged. A means has been proposed in which oil smoke generated from the cooking product 7 is oxidatively decomposed by the inorganic fiber porous body 6 heated by a heater 8 through an exhaust hole 3 and an exhaust passage 5 by natural convection, and is discharged from the exhaust hole 9.

Since there is no need for an auxiliary heater for heating the catalyst because the residual heat of the heater for cooking is used, there is an advantage that the purification performance is high because the exhaust passage is wide and the contact time with the catalyst is long.

Problems to be Solved by the Invention However, the above-mentioned prior art has the following problems.

In the first method using a honeycomb supporting a catalyst, if the shape and the number of cells of the honeycomb are increased in order to extend the contact time between the catalyst and the exhaust gas, the pressure loss becomes large, so that the exhaust gas is difficult to pass and the cost is high. Becomes Recent ovens allow full-fledged cooking at higher temperatures, so the honeycomb method has a lower processing capacity, especially for cooking with a large amount of oil smoke, such as fish and meat, and the cost is high for that There is a disadvantage that.

In the second natural exhaust method using an inorganic fiber porous body, it is necessary to make a part of an exhaust passage hollow to reduce exhaust resistance. Usually, the inside of the exhaust passage has a high temperature of 400 ° C. or more, so that the oil smoke passes through the upper surface of the exhaust passage. Therefore, if a plate-like inorganic fiber porous body is fixed on the upper surface of the exhaust passage, the oil smoke is oxidized and decomposed there.

However, as described above, in the case of a double-sided baking where the power is alternately concentrated and applied to the upper and lower heaters in a full-fledged grilled cooker, when the lower heater is energized and the temperature of the oxidation catalyst falls, the oil smoke is oxidized and decomposed. There is a drawback that they pass through the cavity as it is.

Means for Solving the Problems In order to solve the above problems, in the present invention, a heating chamber for heating food, a heater provided inside a top plate of the heating chamber, and a heater provided outside the top plate are provided. A heat insulating material, an exhaust passage provided between the top plate and the heat insulating material, and a composite oxide made of cerium, copper, and manganese having an area slightly smaller than the top plate disposed throughout the exhaust passage are dispersed. A porous inorganic body carried, an opening provided at the rear of the top plate for communicating the heating chamber with the exhaust passage, and a fan provided at the rear of the exhaust passage, during cooking; The exhaust gas is sucked by the fan, and the cooking exhaust gas is treated by the oxidation catalyst heated by the heat of the heater in the exhaust passage. As a result, when the upper heater is energized, the soot is catalytically oxidized and decomposed by the heat of the heater, and when the temperature of the catalyst is lowered by energizing the lower heater, the inorganic fiber porous material acts as a filter for the soot and a considerable percentage of it. The oily smoke is adsorbed and held in the inorganic fiber porous body, and is subsequently purified when the upper heater is turned on. It is also easy to mix activated carbon fibers or the like into the inorganic fiber porous material in order to increase the adsorptive power.

Operation The operation of the above means will be described.

In the present invention, as a method for heating the inorganic fiber porous body as a catalyst, a cooking heater provided inside a top plate of a heating chamber is used. Therefore, the heat wasted due to the heat loss can be effectively used, and it is not necessary to newly provide a heater for heating the catalyst. In addition, since the catalyst is dispersed and supported on an inorganic fiber porous body having a very high porosity and disposed throughout the exhaust passage, the contact time between the exhaust gas and the catalyst is set as an exhaust passage with an area slightly smaller than the area of the cooking chamber top plate. Is extremely long and high purification performance is obtained. When the temperature of the catalyst is lowered by turning off the upper heater, the filter absorbs oily smoke, so that the purification characteristics at low temperatures are good.

According to the present invention, oil smoke and odor during cooking can be easily decomposed and removed in the present invention.

Embodiment An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a simple cross-sectional view of an embodiment of a cooking device incorporating an oil and smoke purifying means according to the present invention, and FIG. 2 is a conceptual cross-sectional view of a porous inorganic fiber body carrying a catalyst. An exhaust hole 3 is opened by punching at the rear of the top plate 2 of the cooking chamber 1, and an exhaust passage 5 provided between the top plate 2 and the heat insulating material 4.
Is connected to In the exhaust passage 5, a bulk inorganic fiber porous body 6 (in the present invention, SiO ₂ / Al ₂
O ₃ non-woven fabric) is fixed. Oil smoke generated from the cooked food 7 is sucked by the fan 11, passes through the exhaust hole 3, passes through the inorganic fiber porous body 6, and is discharged from the exhaust hole 9. In this example, the height of the exhaust passage 5 was set to 10 mm. During this time, oily smoke or odor components in the exhaust gas are decomposed and removed by the catalyst heated by the upper heater 8. In addition, when the temperature of the inorganic fiber porous body 6 decreases when the lower heater 10 is energized, the inorganic fiber porous body 6 acts as a filter for oil smoke, adsorbs a considerable amount of oil smoke, and the temperature is again increased. You can bake when you rise. In the present invention, the exhaust gas is sucked not by natural exhaust but by the fan 11, so that even if the exhaust passage 5 is filled with the inorganic fiber porous body 6 at a considerably high density, resistance is hardly generated and the adsorption characteristics are improved. FIG. 2 is a conceptual cross-sectional view of the inorganic fiber porous body dispersedly supported with the oxidation catalyst 12. As shown in FIG. Actually, the mackerel, saury, poultry, etc. were burned on both sides by alternately energizing the upper and lower heaters in the cooker having the configuration shown in FIG. 1. Oil smoke and odor components generated when both heaters were energized were completely purified. There was no leakage of oil smoke from the cooker. On the other hand, when the inorganic fiber porous body 6 was removed in the same configuration as in FIG. 1, oil smoke and odor leaked were severe. From this, it is clear that the effectiveness of the present invention and that the purification is not simply based on the heat of the heater.

Next, the catalyst will be described. The catalyst used in the present invention,
Any of a white metal element, a transition metal oxide (including a composite oxide), and a rare earth oxide may be used, but a transition metal oxide is preferable in terms of cost.

Among these catalyst systems, in particular, a combination of a rare earth element cerium oxide and a transition metal oxide has an excellent effect on oil and smoke purification. The reason is considered as follows.
That is, as cooking progresses, oil smoke is rapidly generated from a certain time. At this time, the oxygen concentration in the refrigerator temporarily decreases slightly. In addition, when the oil smoke comes into contact with the oxidation catalyst, it acts as a reducing agent, and desorbs oxygen adsorbed on the surface of the oxidation catalyst. Therefore, the oxidation ability is reduced, so that the oil smoke cannot be purified and the oil smoke leaks. On the other hand, when coexisting with cell oxide, cerium oxide functions as an oxygen donor, replenishes the surface of the oxidation catalyst with adsorbed oxygen, and regenerates the catalytic activity.
Therefore, by the coexistence of both, an effective purifying effect can be obtained in a situation where the load of the oil smoke of the cooking appliance is maximized. In particular, as a combination of cerium oxide and transition metal oxide,
A composite oxide of copper and manganese oxide is highly active. Although the reason is not clear, it is considered to be related to the electronic state of the composite oxide. In the present invention, Ce, Cu, Mn composite oxide
_{CeO 2 · CuxMn 3 - x O} 4 (O <X <1.5), Fe 2 O 3 · Mn 2 O 3 · Cu
O, La _1-X CexCoO ₃ (0 <X ≦ 0.2) was used. The support on the inorganic fiber nonwoven fabric was performed simultaneously with the production of the nonwoven fabric. On the other hand, the support on the woven fabric was performed by the impregnation method in the liquid phase. The salad oil is decomposed at 250 ° C. regardless of whether the catalyst is carried on non-woven fabric or woven fabric. (The salad oil was used as a tracer for fats and oils.) Next, the conditions for oil smoke and odor treatment will be described. First, regarding the particle size of oil smoke, the particle diameter of oil smoke from horse mackerel, mackerel, saury, poultry, and salad oil was in the range of about 0.1 to 5 μm. Therefore, in order to capture and decompose these particles, a porous body having a larger pore diameter is preferable. However, the inorganic fiber porous body used in the present invention has a pore diameter of several μm to several hundred μm and is suitable as a catalyst carrier. In order to further promote the oxidation reaction, it is necessary to supply oxygen.However, the inorganic fiber porous material has a porosity of tens of percent, and as large as 80 to 90%, it is optimal for taking in oxygen from the air. Yes, this has a significant effect on the point at which the reaction is advanced.

Next, the correlation between the porosity of the porous inorganic fiber and the purification properties of the oil will be described.

FIG. 4 shows the decomposition time of the salad oil at 300 ° C. with respect to the change in the porosity. 1mm thick, size 50mm x 5 as sample
0 mm 25% by weight SiO ₂ / Al ₂ O ₃ nonwoven catalyst CeO ₂ · CuxMn
_{Use 3-X} O ₄ (x = 0.9) supported and 0.5g salad oil
It was dropped. From FIG. 4, it is considered that the porosity is preferably 40% or more, but at a higher temperature, about 30% is sufficient. The supported amount of the catalyst is shown in Fig. 5 with a porosity of 60%, a thickness of 1mm, and a size of 5cm.
5cm SiO ₂ -Al ₂ O ₃ nonwoven catalyst La _1-X CexCoO ₃ of (x = 0.
1) Loading amount (wt%) when supporting and 300g of salad oil 0.5g
As shown in the decomposition time in ° C., it is considered that 10% or more is preferable, but this also naturally changes depending on the temperature.

Next, in the structure shown in FIG. 1, the height of the exhaust passage 5 (that is, the height of the inorganic fiber porous body 6) is appropriate in relation to the exhaust speed by suction of the fan 11, the pressure loss, and the reaction temperature (porous body temperature). There is a height. The height of the exhaust passage 5 is set to 5 mm, 10 mm, 15 mm, 20 mm, and 30 mm in the configuration shown in FIG.
The evaluation was made using smoke of g salad oil. As a result, if the diameter is 5 mm, the resistance to ventilation is large, and the suction force of the fan is too strong, so that it is difficult to fix the inorganic fiber porous body. On the other hand, when the thickness is 30 mm, a temperature gradient is formed between the upper and lower portions of the inorganic fiber porous body, and the cost is disadvantageous. Therefore, the height is preferably 10 to 20 mm. In this case, the temperature of the porous body was 400 ° C. or higher in most parts.

Next, the temperature required for decomposing the oil smoke will be described. This will also use the cooker Figure 1 configuration, salad oil and to generate several times the smoke of oxidative decomposition while actual cooking cooking chamber, SiO ₂ -Al ₂ O while changing the output of the heater ₃ fiber nonwoven fabric Was evaluated at different temperatures. The size of the porous body is 200m
m × 150 mm, the heater also has uneven temperature, so the temperature can not be uniform as a whole, but a K-type thermocouple was placed 5 cm before and after in the exhaust flow direction from the center of the porous body and the temperature was measured. . The heater input was controlled so that the temperature was about 350 ° C, 400 ° C, and 450 ° C. As a result, it was possible to visually judge that the smoke had disappeared at about 400 ° C.
The same was true for the odor. Therefore, as described above, when the height of the inorganic fiber porous body is set to 10 to 20 mm in the configuration of FIG. 1, since the temperature of the porous body was 400 ° C. or higher, the porous body was brought to a temperature sufficient for purification. It can be said that it has become.

In the above embodiment uses a SiO ₂ -Al ₂ O ₃ fiber nonwoven fabric as the inorganic fibrous porous material. The preferred non-woven material SiO ₂ -Al
_In addition to ₂ O ₃ , SiO ₂ alone or ZrO ₂ may be used. Since the necessary condition is basically whether or not the porosity can be obtained, the present invention is not particularly limited in terms of the material. However, the SiO ₂ —Al ₂ O ₃ system is preferred from the viewpoint of cost. On the other hand, woven fabrics containing SiC as a main component are on the market, but Al ₂ O ₃ or S
A woven fabric made of iO ₂ or ZrO ₂ may be used. Fiber diameter is usually several μm
It is about 10 μm, but it is necessary to provide voids between the fibers so as to capture oil and smoke particles, and woven fabric to increase the porosity.

The cooker having means effective for purifying oily smoke and odor in oven cooking, particularly during double-sided baking, has been described above. However, the means according to the present invention is not limited to a cooker because of its configuration, and its application field is wide and simple. It is thought that it is something.

Effects of the Invention As described above, according to the present invention, the following effects can be obtained.

(1) The use of a highly active catalyst and a porous material with a high porosity makes it highly effective in purifying oily smoke generated during cooking and can process a large amount of smoke. . Further, since the residual heat of the cooking heater is utilized, it is not necessary to newly provide an auxiliary heater for heating the catalyst, so that the cost is low.

(2) Since the exhaust passage is widened, the inside is filled with an inorganic fiber porous material containing an oxidation catalyst, and the air is exhausted by suction with a fan, the temperature of the catalyst can be reduced by double-sided baking cooking by alternately energizing the upper heater. When the temperature drops, oil fumes and odors can be prevented from leaking from the oven chamber even at a low temperature because oil fumes can be adsorbed.

[Brief description of the drawings]

FIG. 1 is a sectional view of a cooker incorporating an oil and smoke purifying means according to one embodiment of the present invention, FIG. 2 is a conceptual sectional view of a porous inorganic fiber body carrying the catalyst, and FIG. FIG. 4 is a characteristic diagram showing the correlation between the porosity of the inorganic fiber porous body and the oil burning-off time, and FIG. 5 is a diagram showing the amount of catalyst carried on the inorganic fiber porous body. FIG. 4 is a characteristic diagram showing a correlation with an oil burning time. DESCRIPTION OF SYMBOLS 1 ... Heating chamber, 3 ... Opening part, 4 ... Heat insulation material, 5 ... Exhaust passage, 6 ... Inorganic porous material, 8, 10 ... Heater, 11
... fans, 12 ... oxidation catalysts.

Continued on the front page (72) Inventor Yasunori Kaneko 1006 Kazuma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (72) Inventor Akio Fukuda 1006 Okadoma Kazuma Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. (56 ) References JP-A-55-6132 (JP, A) JP-A-64-54128 (JP, A) JP-A-52-39475 (JP, A) Japanese Utility Model Showa 55-159913 (JP, U) (58) Field surveyed (Int. Cl. ⁶ , DB name) F24C 15/20 F24C 14/00

Claims (2)

(57) [Claims] 1. A heating chamber for heating food, a heater provided inside a top plate of the heating chamber, a heat insulating material provided outside the top plate, and a heat insulating material provided between the top plate and the heat insulating material. An exhaust passage provided therebetween, an inorganic fiber porous body dispersing and supporting a composite oxide made of cerium, copper, and manganese having an area slightly smaller than the top plate provided in the entire exhaust passage, and the heating chamber; An opening provided in a rear portion of the top plate for communicating with the exhaust passage, and a fan provided behind the exhaust passage, wherein the fan sucks oil smoke generated during cooking with the fan; A cooking device having cooking exhaust processing means for oxidizing and decomposing by the oxidation catalyst heated by the heat of the heater. 2. The inorganic transition porous material is made of SiO ₂ , Al ₂ O ₃ , ZrO.
_2. The cooking device according to claim 1, wherein the cooking device is a non-woven fabric or woven fabric of a fiber composed of any one or more of the _two , or a woven fabric of a fiber mainly composed of SiC.