JPH0147219B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for purifying oil smoke that can be kept clean by removing oil smoke generated in a kitchen or the like.

Various seasonings and cooking oils used in cooking are often attached to areas around cooking tables and ventilation fans in ordinary homes and restaurants, which is undesirable from the viewpoint of hygiene management of cooking tables. At present, to remove deposits generated during these various cooking processes, wiping with cloth or paper, cleaning with chemical detergent, etc. are performed regularly by hand. These tasks are performed directly by humans, and not only do they require long hours of work throughout the year, but they also have the disadvantage that if the regular intervals are too long, oil droplets may drip, causing discomfort. It was hot.

The present invention uses an oil smoke gasification and decomposition catalyst to purify oil smoke, a ceramic resistance heating element is provided to heat the oil smoke gasification and decomposition catalyst, and an inorganic polymer is used as a binder for the oil smoke gasification and decomposition catalyst. The oil smoke is catalytically purified by coating the surface of a ceramic resistance heating element as a catalyst, and bringing the air containing oil smoke sent by a blower into contact with the catalyst coating layer on the honeycomb-shaped ceramic resistance heating element.

Traditionally, manganese,
Metal oxides such as iron, copper, and cobalt, oxides of rare earth elements, and precious metal catalysts are used. All of these catalysts are catalysts for oxidation reactions, and since they make little contribution to completely oxidizing oil smoke and are thought to have the effect of promoting the formation of tar in attached oils and fats, the inventors decided to use conventional A new catalyst, different from oxidation reaction catalysts, was proposed as a catalyst that suppresses the taring of oil and exhibits a self-cleaning effect.

This catalyst is known to have a weak partial oxidation reaction, and it is assumed that the decomposition mechanism for the thermal decomposition of unsaturated fatty acids, which are the main components of salad oil, is through intermediates of partially oxidized compounds. It is thought that catalysts with these weak partial oxidation reactions activate this reaction and decompose and evaporate the oil before the hydrogen abstraction polymerization reaction that proceeds in parallel.
Therefore, it has a self-cleaning effect by inhibiting oil from turning into tar, and compared to oxidation reaction catalysts, it has excellent low-temperature activity below 200°C, and begins to decompose oil at around 120°C.

In order to purify oil smoke, the catalyst is heated with a heating element to the temperature range required for purification. In this configuration, a heating element is brought into contact with a catalyst body in the form of a woven fabric, a honeycomb shape, or a pellet shape.
Because of the planar shape, the catalyst body had the disadvantage that it was not uniformly heated by the heating element. In addition, when placing a catalyst in an air flow path, it is necessary to reduce the pressure loss of the catalyst, and if the pressure loss is high, the air volume will be low, and the capacity of the blower must be increased to increase the air volume. The following problem arises. A honeycomb body is a shape of the catalyst body with low pressure loss, but the configuration in which the catalyst body is shaped like a honeycomb and a heating element is placed in contact with it provides high oil and fat purification performance because the surface temperature of the catalyst body is non-uniform. However, the shape of the heating element is restricted, and depending on the state of contact, the efficiency of heat transfer from the heating element to the catalyst becomes poor, leading to increased heat loss, which is an inconvenience. In particular, non-uniformity in surface temperature greatly affects oil purification performance.The temperature in the area that is in contact with the heating element is high, so high purification performance can be obtained, but the temperature is low in the area that is not in contact, resulting in low purification. All I could get was performance. Therefore, it has been desired to have a configuration of a heating element and a catalyst body that has a small pressure loss, has good heat transfer efficiency from the heating element to the catalyst body, and can uniformly heat the catalyst body to achieve high oil and fat purification performance.

The present invention provides a method for purifying oil smoke using a structure in which when oil smoke is purified using a catalyst body, pressure loss due to the catalyst body is small and high purification performance can be obtained.

In addition, by using an inorganic polymer as a binder, we have created a coating layer structure that has good adhesion to the ceramic resistance heating element and does not cause abnormalities such as peeling off from the ceramic resistance heating element due to steam or rapid heating and cooling. It also provides.

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

Figure 1 shows an example of a configuration for purifying cooking oil smoke, in which a ceramic resistance heating element with a coating layer formed on its surface in which a catalyst for gasification and decomposition of oil smoke is dispersed using an inorganic polymer as a binder, and a blower are arranged. There is.
1 is an air flow path, 2 is a blower, 3 is a ceramic resistance heating element with a coating layer formed thereon, 4 is a lead wire, 5 is a flame, 6 is a cooking container, and 7 is oil smoke.

FIG. 2 shows a front view in the thickness direction of a ceramic resistance heating element with a coating layer formed thereon. 8 is a ceramic resistance heating element, 9 is a coating layer in which a gasification and decomposition catalyst for oil smoke is dispersed, and an air flow path 1 is provided with a blower 2 and a ceramic resistance heating element 3 having a coating layer 9 formed thereon. The ceramic resistance heating element 3 on which the coating layer 9 is formed is energized by a lead wire 4. The oil smoke 7 generated from the cooking container 6 placed on the flame 5 adheres to the coating layer 9 in which the oil smoke gasification and decomposition catalyst is dispersed using an inorganic polymer as a binder.
It is catalytically purified by the heat generated by the ceramic resistance heating element 8.

The oil smoke gasification dispersion catalyst is an oxide _of Group _1A or Group 2A of the periodic table, or a compound represented by _{the formula (} M _{A )} 2A
M _B : element of group 3B or group 4B, O: oxygen, x, y, z: integer). The inorganic polymers are acidic metal phosphates and alkali metal silicates, which are used together with pigments to form phosphate-based inorganic paints and silicate-based inorganic paints.

The coating layer 9 is a phosphate-based inorganic paint containing an oil smoke gasification decomposition catalyst and an acidic metal phosphate as a binder;
Alternatively, it is dispersed in a silicate-based inorganic paint containing an alkali metal silicate as a binder and applied to the surface of the ceramic resistance heating element 7.

The coating layer 9 is obtained by dispersing silicone varnish, methanol, surfactant, and water together with a gasification decomposition catalyst in a heat-resistant paint, and drying and baking the mixture.
These additives make the coating layer porous to enhance the contact between the catalyst and the oil smoke, and also prevent a decrease in coating film adhesion caused by the addition of the catalyst through the adhesive strength of the silicone varnish.

The ceramic resistance heating element 7 is made of PTC ceramics with many through holes formed into a honeycomb shape. Electrodes are attached to both end faces of the through hole partition walls, and when air is sent through the through hole while electricity is applied, hot air is emitted from the outlet. come out.

The oil smoke 7 adheres to the coating layer 9 in which a catalyst for gasification and decomposition of oil smoke is dispersed, raises the temperature of the ceramic resistance heating element 7, and causes the catalyst for gasification and decomposition of oil smoke to have a catalytic action. removed.
The air that has come into contact with the coating layer 9 has the oil smoke 7 removed, passes through a honeycomb-shaped ceramic resistance heating element 7, and is exhausted by the blower 2.

A coating layer in which zeolite and activated clay are used as gasification and decomposition catalysts for oil smoke, and acidic metal phosphates are dispersed in a phosphate-based inorganic paint (Sumitomo Chemical Co., Ltd. P-300B) as a binder for inorganic polymers. was formed to determine the effect of the present invention.

Phosphate-based inorganic paint (Sumitomo Chemical Co., Ltd. P-
300B) To 100 parts, add an oil smoke gasification decomposition catalyst consisting of 8 parts of zeolite and 2 parts of activated Shiraki, and add 6 parts of silicone varnish (containing 50% xylene) and 2 parts of methanol.
1 part, 0.5 parts of surfactant, and 10 parts of water for 60 minutes using a ball mill. La1−xCaxCrO ₃
A ceramic resistance heating element consisting of was immersed in the milled paint, air-dried for 60 minutes, and then baked at 300°C for 30 minutes to form a coating layer on the surface of the ceramic resistance heating element. The ceramic resistance heating element is a honeycomb-shaped molded product with holes of 2 mm in diameter evenly drilled in the thickness direction. When forming a coating layer on the surface of a ceramic resistance heating element, the procedure was optimized to ensure that the 2 mm diameter hole drilled in the thickness direction was not closed by the coating layer and that peeling and pinholes did not occur. Ta. A ceramic resistance heating element with a coating layer formed thereon was arranged as shown in FIG. 1, and the purification properties of salad oil were measured. During the experiment, salad oil was placed in a cooking container over a flame and brought to a boil. The distance between the cooking container and the ceramic resistance heating element on which the coating layer was formed was 1 m. In addition, the temperature of the ceramic resistance heating element that formed the coating layer was 200℃.
The amount of air was adjusted in advance so that In the experiment, air containing oil smoke was applied to the coating layer, and the weight of oil adhering to the ceramic resistance heating element on which the coating layer was formed was measured. If the amount of oil adhering to the ceramic resistance heating element is 1 when the current is applied to the element for 0, then if the current is applied for a for 20 minutes, b for 40 minutes, and c for 60 minutes, the adhesion ratio for each of a, b, and c is 0.77 and 0.65. , 0.60
The amount has become extremely small. On the other hand, in the above experiment, when similar measurements were performed using a ceramic resistance heating element without a coating layer, the oil adhesion ratio was 0.95 for a, 0.90 for b, and 0.88 for c.
It was hot.

FIG. 3 shows the oil adhesion ratio measured by the above method. Furthermore, FIG. 4 shows the results of measuring the amount of oily mist in the air that passed through the honeycomb-shaped ceramic resistance heating element. From the above results, it can be seen that oil smoke has been removed.

That is, the coating layer of the present invention (heat-resistant paint with a gasification decomposition catalyst, silicone varnish, methanol, surfactant, and water dispersed and dried and fired) can be used without a coating layer or with the conventional coating layer (heat-resistant paint with a gasification decomposition catalyst dispersed and fired). The oil smoke is effectively removed compared to the conventional method (dispersing and drying).

In addition, a coating layer is formed by dispersing an oil smoke gasification and decomposition catalyst consisting of lime aluminate and calcium silicate in a silicate-based inorganic paint (Ceramitite, manufactured by Shikoku Kaken Co., Ltd.) that uses an alkali metal silicate as a binder for an inorganic polymer. When the film was formed and its effects were evaluated, the characteristics shown in FIGS. 3 and 4 were obtained. Potassium carbonate, magnesium oxide, and the like were also effective as gasification and decomposition catalysts for oil smoke dispersed in silicate-based inorganic paints.

The method for forming a coating layer on the surface of a ceramic resistance heating element is to apply a coating containing an inorganic polymer as a binder and a catalyst for gasification and decomposition of oil smoke dispersed onto the surface of the ceramic resistance heating element using a spray gun. method is also possible.

By contacting the oil smoke with the coating layer and catalytically purifying it, a smoke-free environmental atmosphere is obtained. In other words, (1) When dispersing the gasification decomposition catalyst in the heat-resistant paint, silicone varnish methanol, surfactant, and water are simultaneously dispersed, which makes the paint film porous and improves the contact between the catalyst and oil smoke. .
Therefore, it has superior oil smoke purification performance compared to a coating layer containing only a catalyst.

(2) When fixing the gasification decomposition catalyst to the surface of the resistance heating element, the catalyst is dispersed in the heat-resistant paint.
The adhesive action of the silicone varnish prevents the adhesion of the coating film from decreasing due to the addition of a catalyst. Therefore, the adhesion of the heat-resistant coating film does not decrease due to the addition of the catalyst, and a catalytically functional coating layer with excellent adhesion can be obtained.

(3) When the present invention is applied to, for example, a ventilation fan, oil smoke is decomposed by the coating layer in which the gasification and decomposition catalyst is dispersed, and the dirt on the ventilation fan is reduced. Therefore, the number of times the ventilation fan is cleaned and removed is reduced. Further, when the present invention is applied to, for example, a cooking appliance, oil smoke generated inside the cooking appliance is decomposed by the coating layer in which the gasification and decomposition catalyst is dispersed, and clean air is discharged to the outside of the cooking appliance. Therefore, you can always have a clean kitchen environment.

The present invention is not limited to the dimensions and shapes described in the detailed description, and the ceramic component of the ceramic resistance heating element and the shape of the honeycomb can also be used as long as the temperature rises sufficiently and the shape is breathable. be.

[Brief explanation of drawings]

Fig. 1 is a principle block diagram for purifying oil smoke according to the present invention, Fig. 2 A and B are an enlarged front view and a front view of main parts in the thickness direction of a ceramic resistance heating element with a coating layer formed thereon, and Fig. 3 , FIG. 4 is a characteristic diagram of the present invention. DESCRIPTION OF SYMBOLS 1...Air flow path, 2...Blower, 3...Ceramic resistance heating element with a coating layer formed thereon, 4...Lead wire, 5...Flame, 6...Cooking container, 7...Oil smoke, 8... Ceramic resistance heating element, 9... Coating layer in which oil smoke gasification and decomposition catalyst is dispersed.

Claims (1)

[Claims] 1. A honeycomb-shaped ceramic resistance heating element is disposed in the air flow path of a device having a blower, and the surface of the ceramic resistance heating element is coated with acidic metal phosphate or alkali metal silicate. Add at least one gasification decomposition catalyst selected from the following groups (A) and (B), silicone varnish, methanol, surfactant, and water to a heat-resistant paint using an inorganic polymer as a binder, and then dry and bake. A method for purifying oil smoke, comprising: forming a coating layer obtained by doing this, and bringing the coating layer into contact with the coating layer. (A) Na ₂ O, K ₂ O, CaO, MgO (B) Compound represented by formula (M _A ) _X (M _B ) _Y (O) _Z However, M _A :Na, K, Ca, Mg M _B :C, Si, Al O: Oxygen x, y, z: Indicates an integer