JPS59139954A - Electric dust collecting apparatus - Google Patents

Abstract

PURPOSE:To attain to enhance oil soot removal capacity and to simplify the regeneration and maintenance thereof, in an elelctric dust collecting apparatus, by providing an oxide catalyst and mesh like flat heater to the surface opposed to a discharge wire. CONSTITUTION:When oil soot or an oil droplet is flowed into an electric dust collecting apparatus from the direction shown by the arrow B, oil soot is charged by corona discharge generated by high voltage applied between a discharge wire 2' and a mesh like flat heater 8 being an opposed electrode. An electric field is formed between the positively charged oil soot and the negative potential flat heater 8 and an oxide catalyst 7 is ionized to collect the charged oil soot. In addition, charged oil soot particles are mutually collided to be flocculated and collected by the adhesive or adsorbing action of the oxide catalyst 7 having filter effect. The oxide catalyst 7 is a pellet shaped molded body and formed by using a noble metal such as platinum or palladium. As the mesh like flat heater 8, a woven heater or ceramic heater is used and a noble metal catalyst is supported thereby.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an electrostatic precipitator having an oxide catalyst for removing oil smoke.

Conventional configurations and their problems In general, electrostatic precipitators use a parallel type where the flow runs parallel to the dust collection electrode, and an orthogonal type where the flow runs perpendicular to the dust collection electrode. The current situation is that the orthogonal formula is not used. However, when a dielectric filter is used together with the dust collecting electrode, the orthogonal method is very effective, and long-term maintenance is also possible by replacing the filter. On the other hand, the dielectric filter is mainly made of the filter itself or a non-woven fabric made of vinyl chloride, polyester, or rayon, and when targeting oil smoke and oil droplets, the filter gets clogged quickly due to oil adhesion, leading to rapid performance deterioration. It has drawbacks.

In order to eliminate the above-mentioned drawbacks, other filter media are available, such as filter media made by alternately layering fluororesin-coated wire mesh and oil-absorbent paper, or foamed metal coated with fluororesin. It has been considered to be applied as a filter medium, but even in the filter medium, stains caused by oil smoke and oil droplets can only be removed by washing, and it still has some disadvantages.

Purpose of the Invention The present invention is intended to solve the problems associated with regenerating the filter medium of an electrostatic precipitator (i.e., the maintenance required by filter replacement and cleaning), and to improve the removal performance of oil smoke and oil droplets. This is also an attempt to improve the results.

Structure of the Invention The electrostatic precipitator of the present invention includes a discharge wire and a counter electrode provided opposite to the discharge wire, and includes a particulate oxide catalyst for removing oil smoke on at least the surface facing the discharge wire. The desired purpose was achieved by providing a mesh-shaped sheet heater as a counter electrode that heats the catalyst and has a filter function.

Description of examples Examples thereof will be described below with reference to the accompanying drawings.

FIG. 1 shows the basic principle of an electrostatic precipitator to which the present invention is directed.

1 is the main body of the electrostatic precipitator, and 2 is a discharge wire, which is connected to the high voltage output of a DC high voltage power source 3 and attached to the main body 1 via an insulator such as an insulator. Reference numeral 4 denotes a filter material such as a dielectric filter provided downstream of the discharge line 2 across the ventilation path. Reference numeral 5 denotes an electrode having air permeability, which is provided downstream of the filter medium 4 and is connected to the low voltage output of the DC high voltage power supply 3.
is attached to.

In the above configuration, when dirty air such as oil smoke flows in from the direction of the arrow, the dust in the contaminated air is charged by corona discharge caused by the high voltage applied between the discharge wire 2 and the counter electrode 5. . When positively charged dust approaches the filter medium 4, an electric field is formed between the charged dust and the breathable electrode 5 with a negative potential, and this electric field ionizes the filter medium 4, such as a dielectric filter, and removes the charged dust. is collected electrically.

The present invention applies the basic principle of the electrostatic precipitator described above. Its characteristics are that instead of filter media such as dielectric filters,
It is possible to provide an oxide catalyst molded into pellets and use it as a counter electrode to heat the oxide catalyst for regeneration after cooking, and furthermore, it is possible to heat the oxide catalyst for regeneration after cooking. The purpose of this invention is to use a menoneue-shaped sheet heater that can collect and remove the catalyst together with the catalyst.

In the configuration shown in Figure 1, a non-woven fabric made of polyester, vinyl chloride, rayon, polypropylene, etc. is used as the filter material, or a dielectric filter is eliminated and the counter electrode is made of a material with a filter effect (wire mesh, foam, etc.). If you are targeting oil smoke during cooking, the amount of smoke generated is extremely large, so it is possible to use a filter that uses a counter electrode and a dust collection electrode. The oil and smoke removal performance deteriorates quickly.

Moreover, problems such as bad smells being emitted from the collected cooking oil smoke remain.

From the above, in the present invention, instead of the filter medium such as the dielectric filter shown in FIG. 1, an oxide catalyst formed in the shape of a pellet (7) is provided, and a mesh-like sheet heater is used as the counter electrode. The oxide catalyst can be heated and regenerated after cooking, and can also be used as a filter in the same way as the oxide catalyst in removing oil smoke, so the oil smoke removal performance can be further improved than in the case of using only the oxide catalyst.

To explain further based on the embodiment shown in FIG. 2, 1' is the main body of the electrostatic precipitator, 2' is the discharge line, and 3' is the DC high voltage power supply. Reference numeral 6 denotes a case made of an insulating material, and houses a pellet-shaped oxide catalyst 7 and a mesh-like sheet heater 8 that serves three roles as a heater, a filter, and a counter electrode. The planar heater 8 is completely insulated from the discharge wire 2' when performing electrostatic precipitate, and maintains the temperature required to have a catalytic function only when decomposing and regenerating the oil smoke deposited on the oxide catalyst 7. The structure is such that it can be electrically heated to a temperature of 250°C or higher. 9 is a suction fan that sucks in oil smoke.

In the above configuration, when oil smoke and oil droplets flow in from the direction of arrow B, the oil smoke is charged by corona discharge caused by the high voltage applied between the discharge wire 2' and the mesh-like sheet heater 8 of the counter electrode. An electric field is formed between the positively charged oil smoke and the planar heater 8 which has a negative potential, and this electric field ionizes the oxide catalyst 7, causing the charged oil smoke to be collected electrically and the charged oil smoke to collide. The particles aggregate and adhere to the oxide catalyst 7, which also has the effect of a filter, or are collected by adsorption.

Here, the oxide catalyst 7 is a pellet-shaped molded body,
Catalysts whose main components are noble metals such as platinum and palladium, or metal oxides such as manno1/copper are used. In such cases, it is compounded with a binder such as portland cement or alumina 7-ment. In addition, the performance can be improved by incorporating an adsorbent material such as aluminosilicate into the carrier and the latter catalyst molded body to improve the catalytic effect. It may be provided in a layered manner on the surface, and is limited to the examples.

The oil smoke and oil droplets flowing in from the direction of arrow B are the oxide catalyst 7.
However, the mesh-shaped sheet heater 8 used as a counter electrode also has an effect as a filter, and contributes to collecting the inflowing oil soot and oil droplets. Therefore, as for the removal performance of oil smoke and oil droplets, there are effects such as adhesion and adsorption collection to the oxide catalyst 7 and the effect of the mesh-shaped sheet heater 8 as a filter, and better removal performance can be obtained. Further, as the mesh-like planar heater 8, a planar beater such as a weave heater or a ceramic heater is used. A weave heater is made by weaving thin metal wires into a cloth made of glass fiber, and can be heated by applying electricity to the thin metal wires. Furthermore, since it is a glass fiber woven fabric, it also functions as a filter. Furthermore, by connecting the metal wire to the low voltage output side, it can also be used as a counter electrode. The ceramic heater is made of barium titanate or ceramic mixed with a conductive material, has a ventilation structure, and plays the same role as the weave heater described above.

The above-mentioned mesh/U-shaped planar heat 8 further supports a noble metal catalyst such as platinum or palladium, and the oil smoke collected as a filter during oil smoke removal is transferred to an oxide catalyst after cooking is completed. At the same time as heating and regeneration, desorption and purification are performed by the action of the noble metal catalyst.

Therefore, in the smoke collection part of the electrostatic precipitator of the present invention, that is, the mesh-like planar heater 8 carrying an oxide catalyst and a noble metal catalyst, the oil smoke removal performance in collecting cooking oil smoke may deteriorate early, and the odor may be reduced. The problem of generation can be solved by electrically heating the oxide catalyst 7 with a sheet metal heater having a noble metal catalyst. That is,
The action of the catalyst decomposes and regenerates the oil smoke and oil droplets.

In the present invention, in order to heat the oxide catalyst 7, a mesh-like planar heater 8 carrying a noble metal catalyst is used, or in general, a heating element such as a nichrome wire is replaced with a metal oxide such as a magnet 7a. It is usually heated using an insulated pipe sheathed with iron or stainless steel pipes. However, when heaters are used, they can be quite heavy depending on the number of heaters used, and heating points are concentrated locally, making it impossible to uniformly heat the entire oxide catalyst. As it does not function as a filter at all, its disadvantages include poor oil smoke removal performance.

Effects of the Invention As described above, in the present invention, by using an oxide catalyst and a mesh-like sheet heater in place of the conventional filter medium such as a dielectric filter and the counter electrode in the smoke collection part of the electrostatic precipitator,
In addition to improving the oil smoke removal performance, it can also have a great effect on simplifying and prolonging its regeneration and maintenance.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the basic principle of an electrostatic precipitator, and FIG. 2 is a schematic configuration diagram of an electrostatic precipitator showing an embodiment of the present invention. 2'...discharge wire, 7...oxide catalyst, 8...
・Metsuyu-shaped sheet heater.

Claims (4)

[Claims] (1) A discharge wire and a counter electrode provided opposite to the discharge wire are provided, an oxide catalyst for removing granular oil smoke is provided at least on the surface facing the discharge wire, and the catalyst is further heated. An electrostatic precipitator in which a mesh-shaped sheet heater with a filter function is used as a counter electrode. (2) As an oxide catalyst, the main components are noble metals such as platinum, radium, etc., and metal oxides such as aluminum, copper, etc., and adsorbent materials such as alumina silicate are used through a binder such as silica ment. Electrostatic precipitator 0 according to claim 1, which uses a pellet-shaped product. (3) Electrostatic precipitator Q according to claim 1, in which the mesh-like sheet heater is a weave heater or a ceramic heater. (4) The electrostatic precipitator according to claim 1, wherein the mesh-like sheet heater supports a precious metal catalyst such as platinum or noradium.