JPH0889732A - Regenerating method of heat resistant filter with metallic frame - Google Patents

Abstract

PURPOSE: To reduce the regeneration cost, to prevent the oxidation of a metallic frame and consequently to unnecessitate polishing of a metallic frame after regenerating a heat resistant filter and to surely regenerate the heat resistant filter. CONSTITUTION: The regenerating method of the heat resistant filter Ml with the metallic frame is for regenerating the used heat resistant filter 13, to which mat and fat stick, by heating in the state mounted in the inside of the metallic frame 11. The heat resistant filter 13 is placed in a hot regeneration furnace setted to a reducing atmosphere or inert atmosphere in the inside and heated up to the temp., at which oils and fats are decomposed, to decompose under heating and remove those from the heat resistant filter 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for remanufacturing a heat resistant filter with a metal frame used in a kitchen or the like.

[0002]

2. Description of the Related Art Conventionally, an exhaust device such as a kitchen using a heat-resistant filter as shown in FIG. 5 is known. The exhaust device 100 includes a hood 10 having an opening facing a heating jig 200 such as a gas stove above the cooking table 300.
1, the hood 101 and the exhaust port W formed in the wall surface W
1 and the duct 102 disposed between the exhaust port W1 and
It is composed of an electric fan 400 provided inside.

A heat-resistant filter 500 is installed inside the duct 102, and the cooking container 2 heated by the gas stove 200 is heated by the heat-resistant filter 500.
The high temperature oily smoke generated from 01 and the fine dust rising with water vapor are captured.

The heat resistant filter 500 is usually formed by laminating a heat resistant material such as glass wool in a state where the air permeability is not impaired, and the laminated body is mounted in the duct 102 while being kept in the shape of a metal frame. There is. When the heat-resistant filter 500 is used for a long period of time, the glass wool or the like inside is clogged due to the accumulation of oily smoke or the like, and as a result, the pressure loss increases, so the oily smoke or the like is sufficiently sucked by the electric fan 400. Can't do it.

Therefore, when the heat-resistant filter 500 becomes dirty due to adhesion of oily smoke or the like, it is removed from the inside of the duct 102 to remove oily smoke or the like, so-called regeneration processing is performed.

Conventionally, as the above-mentioned regeneration treatment, the heat resistant filter 500 removed from the metal frame is immersed in an alkaline cleaning agent such as sodium hydroxide solution (concentration about 3%) heated to 80 ° C to 90 ° C. For example, a method of cleaning by heating and a method of heating the heat resistant filter 500 to burn off oily smoke and the like have been adopted.

[0007]

By the way, in the method of cleaning the heat resistant filter with the above alkaline cleaning solution,
First, the oily smoke captured by the heat-resistant filter is in an oxidatively fixed state due to the high temperature during cooking, and even if a high temperature alkaline cleaning solution is used, the oil and fat such as oily smoke should be completely dissolved in the cleaning solution. Has a problem that a good cleaning effect cannot be obtained.

Further, since a high temperature alkaline cleaner is used, the alkaline cleaner may be scattered during the cleaning operation, resulting in a bad working environment. In addition, there is a problem in that the residual cleaning solution that remains after cleaning must be processed, which results in additional processing costs.

Further, in order to perform the cleaning treatment, the heat resistant filter must be removed from the metal frame and mounted again on the metal frame after the cleaning treatment is completed. Such an operation is very complicated and often Therefore, there is a problem that the cleaning process costs increase because of the time and labor required.

On the other hand, in the method of heating the heat-resistant filter to burn off oily smoke and the like, the heat-resistant filter can be processed with the metal frame mounted on the heat-resistant filter.
In addition, even if the oil smoke captured by the heat-resistant filter is oxidized and fixed due to high temperature during cooking, it can be burned without any problems. Is not worse, and is generally superior to the above cleaning method.

However, in this combustion-based regeneration method, the metal frame together with the heat-resistant filter is exposed to high temperature in the air or in an oxidizing atmosphere, so that the surface of the metal frame is oxidized and discolored, resulting in an appearance. There is a problem that it becomes unsightly and the product value falls.

The present invention has been made in order to solve the above problems, and on the premise that the heat-resistant filter is regenerated while being mounted on a metal frame, the regeneration cost is low, Since the metal frame is not oxidized, there is no need to polish the metal frame after the heat-resistant filter has been regenerated, and as a result, the heat-resistant filter with a metal frame can be surely regenerated at low cost. Is intended to provide.

[0013]

According to a first aspect of the present invention, there is provided a method for regenerating a heat-resistant filter with a metal frame, in which a used heat-resistant filter having oils and fats and the like attached is heated in a state of being mounted in the metal frame. A method for regenerating a heat-resistant filter with a metal frame to be regenerated, wherein the inside is set to a reducing atmosphere or an inert atmosphere, and the temperature is raised to a temperature at which fats and oils decompose, It is characterized in that a heat resistant filter is loaded, and the above oils and fats are decomposed by heating and removed from the heat resistant filter.

According to a second aspect of the present invention, there is provided a method for regenerating a heat-resistant filter with a metal frame, in which a used heat-resistant filter having oils and fats and the like attached thereto is heated and regenerated in a state of being mounted in the frame of the metal frame. A method for regenerating a heat-resistant filter with a heat-resistant filter, wherein the inside is first set to an oxidizing atmosphere, and the heat-resistant filter is loaded into a heating regeneration furnace heated to a temperature at which oils and fats decompose, and then the inside. Is set to a reducing atmosphere, and a heat-resistant filter derived from the heating / regeneration furnace is loaded into a reducing furnace heated to a predetermined temperature, and oils and fats attached to the heat-resistant filter in the heating / regeneration furnace are loaded. And the like are removed by heating and decomposition, and the oxidized surface portion of the metal frame is reduced in the regeneration furnace.

[0015]

According to the method for regenerating a heat-resistant filter with a metal frame according to claim 1, the heat-resistant filter is loaded into a heating / regeneration furnace while being mounted on the metal frame, and is heated to be captured in the heat-resistant filter. The oils and fats and the like that have been generated undergo thermal decomposition, are gasified, and are removed from the heat resistant filter. Since the inside of the heating / regeneration furnace is set to a reducing atmosphere or an inert atmosphere, the surface of the metal frame is not oxidized even at a high temperature.

According to the method of regenerating a heat resistant filter with a metal frame according to claim 2, the heat resistant filter mounted on the metal frame is heated in the first stage heating and regenerating furnace in an oxidizing atmosphere. As a result, oils and fats and the like trapped inside the heat resistant filter are combusted and removed as combustion waste gas. A discolored oxide layer is simultaneously formed on the surface of the metal frame by the heat treatment in the first stage, but the reducing furnace in the second stage is set to a reducing atmosphere,
By heating in this atmosphere, the oxide layer on the surface of the metal frame is reduced, and the discoloration is eliminated.

[0017]

First, a heat resistant filter to which the method of the present invention is applied will be described. FIG. 1 is a partially cutaway perspective view showing an example of the heat resistant filter. As shown in this figure, the filter device 1 includes a metal C-shaped member, a metal frame 11 formed in a rectangular shape such that the opening of the groove 11 a is located inside, and a metal frame 11 of the metal frame 11. A rectangular support frame 12 fitted in the groove 11 a and a groove 11 of the metal frame 11 similarly.
a rectangular wire mesh 14 fitted in a, and this wire mesh 14
-Resistant filter 13 sandwiched between the metal frame 11 and the metal frame 11
It consists of and.

Such a filter device 1 is provided with a wire mesh 14 in a duct for sucking exhaust gas containing oils and fats.
Mounted in a state of facing the upstream side, receives the exhaust flow supplied from the direction indicated by the white arrow, and oils and fats contained therein are captured by the heat resistant filter 13.

The metal frame 11 is a kind of shape-retaining material for facilitating the attachment of the heat-resistant filter 13 to the duct or the like. In this embodiment, the metal frame 11 made of stainless steel having an excellent rust preventive function is used. ing. However, the metal frame 11 of the filter device 1 according to the present invention is not limited to the one made of stainless steel, and may be made of iron, aluminum alloy, brass or the like.

The support frame 12 and the wire mesh 14 are members for holding the heat-resistant filter 13 on the respective shafts in the metal frame 11, and particularly the support frame 12 on the downstream side is pushed by the exhaust flow and is heat-resistant filter 13. Since a force is applied in the direction of coming out of the metal frame 11, it is formed of a sturdy frame body to prevent it.

In the case of the present embodiment, the heat-resistant filter 13 has a large number of continuous long glass fibers that are independently bent at random, and the contact portions between the fibers are alkali metal silicate-based inorganic adhesive. Which has a so-called random structure joined by an inorganic binder such as an agent,
A unit weight of 600 g / m ² is applied,
The heat-resistant filter 13 according to the present invention is not limited to the one having the above-mentioned random structure, and may be a laminate of woven products of heat-resistant fibers. Further, a heat-resistant and breathable nonwoven fabric is used. May be.

The material of the filter is not limited to glass fiber, but may be silica fiber, alumina fiber, aluminosilicate fiber, zirconia fiber, silicon carbide fiber, carbon fiber or the like.

The filter device 1 does not necessarily have the metal frame 11, the support frame 12 and the heat resistant filter 1 as shown in FIG.
However, the support frame 12 and the wire netting 14 may be omitted depending on the mode of use. Further, the support frame 12 may be composed of a wire rod.

When such a filter device 1 is used for a long period of time, oils and fats are trapped inside the heat-resistant filter 13 to cause clogging, and the metal frame 11, which is a metal product, and the support frame. Oils and fats and the like adhere to the surfaces of the wire mesh 12 and the wire net 14 and become extremely contaminated. And
The method for regenerating a heat-resistant filter with a metal frame according to the present invention regenerates the filter device 1 contaminated with such oils and fats by heating.

FIG. 2 is an explanatory view showing a first embodiment of a heat-resistant filter regenerating apparatus with a metal frame to which the method of the present invention is applied. As shown in this figure, the regeneration device 2 includes a long heating regeneration furnace 3 having a heating chamber 3a therein, and a filter device 1
And a conveyor belt 4 for longitudinally penetrating the heating chamber 3a for conveying the gas into the heating chamber 3a, and an inert gas supply means for supplying an inert gas to the upstream side in the heating chamber 3a. 5 and a decomposed gas suction means 6 for sucking and removing the decomposed gas generated inside the heating chamber 3a from the downstream side.

In the heating chamber 3a of the heating / regenerating furnace 3, a plurality of energization heating elements 31 are arranged at appropriate places. By energizing the heating elements 31, the inside of the heating chamber 3a is heated to a predetermined temperature (in this embodiment). The case is set to 500 ° C.). An inlet 32 for introducing the filter device 1 into the heating chamber 3a is opened at the upstream end of the heating / regeneration furnace 3, and the filter device 1 is provided at the downstream end of the heating / regeneration furnace 3.
A lead-out port 33 for leading out from the inside of the heating chamber 3a is opened.

The conveyor belt 4 is stretched around a plurality of rollers 41 provided outside the heating / regenerating furnace 3,
The layout is set so that the upper portion thereof penetrates the inlet 32 and the outlet 33. Any one of the plurality of rollers 41 serves as a drive roller, and the conveyor belt 4 is rotated by rotationally driving the drive roller. Such a conveyor belt 4 is formed of a mesh belt, and the mounting surface of the filter device 1 on the conveyor belt 4 can contact the atmospheric gas in the heating chamber 3a through a mesh.

A carry-in portion 42 of a predetermined length is formed on the upstream side of the inlet 32 of the conveyor belt 4, and
A carry-out section 43 of a predetermined length is formed on the downstream side of the outlet 33 of the conveyor belt 4, and the filter device 1 has the carry-in section 4 described above.
The filter device 1 introduced into the heating chamber 3a through the inlet 32 by being sequentially placed on the second substrate 2 and led out of the heating chamber 3a through the outlet 33 is the unloading unit 4
From 3 to the next step.

The inert gas supply means 5 includes an inert gas source 51, a pressure feed pump 52 for supplying the inert gas from the inert gas source 51 into the heating chamber 3a, and the pressure feed pump 5.
2 and the heating chamber 3a. Therefore, by driving the pressure pump 52, the inert gas from the inert gas source 51 is supplied into the heating chamber 3 a through the gas supply pipe 53. In this embodiment, an air separation device is used as the inert gas source 51, and nitrogen gas obtained from this air separation device is used as the inert gas.

In this embodiment, the gas supplied to the heating chamber 3a is an inert gas (nitrogen gas). However, in the present invention, the gas supplied to the heating chamber 3a is inert. The gas is not limited to the gas, but may be a reducing gas such as hydrogen.

The decomposition gas suction means 6 sucks the decomposition gas in the heating chamber 3a, and a gas discharge pipe 62 connecting the suction pump 61 and the downstream side of the heating / regeneration furnace 3.
It consists of and. By operating the suction pump 61, the decomposed gas in the heating chamber 3a is discharged into the gas exhaust pipe 62.
It is sucked through and discharged out of the system.

The heating and regenerating furnace 3 is provided with a thermometer 34, a pressure gauge 35 and an oxygen concentration meter 36, which detect the temperature, pressure and oxygen concentration in the heating chamber 3a and The detection result of is input to a controller (not shown). Then, in the control device, the detected value is compared and calculated with a preset value input in advance, and when the detected value as a result of the comparison calculation is different from the set value, the heating element 31, the pressure feed pump 52 and the suction pump 61 are controlled. A signal is output, and the amount of power supplied to the heating element 31, the amount of inert gas pressure fed by the pressure feed pump 52, and the amount of decomposed gas suctioned by the suction pump 61 are controlled to appropriate values.

In particular, the pressure in the heating chamber 3a is controlled so as to be the same as the atmospheric pressure or slightly higher than the atmospheric pressure. The reason is that an inert atmosphere must be maintained by supplying an inert gas in the heating chamber 3a, but if the inside of the heating chamber 3a is lower than atmospheric pressure, the inlet 3
2 and the outlet 33 causes air to enter the heating chamber 3a,
This is because the inert atmosphere in the heating chamber 3a cannot be maintained. Further, when the pressure in the heating chamber 3a is too high than the atmospheric pressure, the inert gas or the decomposition gas is introduced from the inlet 32 or the outlet 33. This is because it leaks to the outside and pollutes the work environment.

A method of regenerating the heat resistant filter with a metal frame of the present invention using the regenerating apparatus 2 of the first embodiment will be described below. First, the heating element 31 in the heating / regeneration furnace 3 is energized to start heating in the heating chamber 3a. Simultaneously with the start of heating, the pressure feed pump 52 and the suction pump 61 are operated, the inert gas from the inert gas source 51 is supplied into the heating chamber 3a through the gas supply pipe 53, and the atmosphere inside the heating chamber 3a is increased. The gas (initially a mixed gas of an inert gas and air) is led out of the system through the gas discharge pipe 62.

The oxygen concentration meter 36 detects that oxygen is not present in the heating chamber 3a and the atmosphere is inactive, and the temperature of the heating chamber 3a is preset based on the detection result of the thermometer 34. When it is confirmed that the temperature in the heating chamber 3a has been raised to the above temperature and the air in the heating chamber 3a is completely replaced by the inert gas based on the detection result of the oxygen concentration meter 36, the conveyor belt 4 Is orbitally driven, and the used filter device 1 is sequentially mounted on the carry-in section 42.

The used filter device 1 placed on the carry-in section 42 is sequentially introduced into the heating chamber 3a through the inlet 32 by the circulating drive of the conveyor belt 4. Then, since the inside of the heating chamber 3a is heated to a temperature sufficient for decomposing oils and fats, the oils and fats trapped inside the heat resistant filter 13 of the filter device 1 and the metal frame 1
1, the oils and fats attached to the surfaces of the support frame 12 and the wire net 14 are thermally decomposed in the high temperature environment to be decomposed gas or the like, which is led out of the system through the gas discharge pipe 62.

Since the inside of the heating chamber 3a is an inert atmosphere of an inert gas, the metal frame 1 made of metal is used.
1. The surfaces of the support frame 12 and the wire netting 14 are not oxidized to form an oxide film. Therefore, the outlet 3
Filter device 1 led out of the heating / regeneration furnace 3 via
Is in a regenerated state in which oils and fats trapped in the heat-resistant filter 13 are removed, and the metal frame 11 made of metal is
No discoloration due to the formation of an oxide film has occurred, and the appearance is beautiful.

FIG. 3 is an explanatory view showing a second embodiment of a regenerating apparatus for a heat resistant filter with a metal frame to which the method of the present invention is applied. As shown in this figure, in the case of this example, the playback device 2
a is a heating / regeneration furnace 30 for performing a heating / regeneration treatment of the filter device 1 in an oxidizing atmosphere, a reduction furnace 7 connected to the downstream side of the heating / regeneration furnace 30 in a reducing atmosphere, and heating / regeneration of these. Conveyor belt 4 passing through the furnace 30 and the reduction furnace 7.
It consists of and. Then, the filter device 1 conveyed by the conveyor belt 4 is first subjected to a heat regeneration treatment in the heating regeneration furnace 30 in an oxidizing atmosphere, and then subjected to a reduction treatment in the reduction furnace 7.

The structure of the heating and regenerating furnace 30 is almost the same as that of the regenerating apparatus 2 of the first embodiment described above. However, since the inside of the heating / regeneration furnace 30 is in an oxidizing atmosphere, the inert gas supply means 5 as in the previous example is not provided. In this embodiment, air is introduced through the opening for loading and unloading the filter device 1 in order to make the inside of the heating / regeneration furnace 30 an oxidizing atmosphere.

In order to introduce air into the heating / regeneration furnace 30,
Further, in order to guide the decomposition gas generated in the heating / regeneration furnace 30 to the outside of the system, a decomposition gas suction means 6a is provided on the downstream side of the heating / regeneration furnace 30. This decomposed gas suction means 6a
Is a gas exhaust pipe 62a provided in the heating / regeneration furnace 30 and a suction pump 6 provided downstream of the gas exhaust pipe 62a.
1a, the suction pump 61a is operated to suck the decomposition gas in the heating / regeneration furnace 30, and the suction amount is adjusted so that the inside of the heating / regeneration furnace 30 is in a negative pressure environment. It is adapted to be taken into the heating / regeneration furnace 30 through the opening.

The reduction furnace 7 also has the same structure as the heating and regeneration furnace 3 of the previous example. That is, an inlet 72 for introducing the filter device 1 into the reducing chamber 7a is provided at the upstream end of the reducing furnace 7, and an outlet 73 for leading out the filter device 1 from the reducing chamber 7a is provided at the downstream end. The conveyor belt 4 is arranged so as to penetrate through the inlet 72 and the outlet 73. Further, a plurality of electrothermal heating elements 71 are installed inside the reduction chamber 7a of the reduction furnace 7.

A reducing gas supply means 5a is provided on the upstream side of the reduction chamber 7a. This reducing gas supply means 5a
Is composed of a reducing gas source 51a, a pressure feed pump 52a for pressure-feeding the reducing gas from the gas source 51a into the reduction chamber 7a, and a gas supply pipe 53a connecting the pressure feed pump 52a and the reduction chamber 7a. ing. In this embodiment, hydrogen gas is used as the reducing gas. The reduction furnace 7 is not provided with a forced exhaust means for forcibly exhausting the atmospheric gas in the reduction chamber 7a to the outside of the system.

The reducing furnace 7 is provided with a thermometer 74, a pressure gauge 75, and a hydrogen concentration meter 76, and the atmosphere of the temperature, pressure and hydrogen concentration in the reduction chamber 7a is controlled based on the detected values. It is supposed to be. In particular, the pressure inside the reducing chamber 7a is set to be equal to or slightly higher than the atmospheric pressure to prevent air from entering the reducing chamber 7a.

The reproducing apparatus 2a according to the second embodiment will be described below.
A method of regenerating the heat resistant filter with a metal frame of the present invention using the above will be described. First, the heating element in the heating / regeneration furnace 30 and the heating element 71 in the reduction furnace 7 are energized to
Heating of the inside and the inside of the reduction chamber 7a is started. Simultaneously with the start of heating, the suction pump 61a and the pressure feed pump 52a are operated, the atmospheric gas (initially only air) in the heating chamber 3a is led out of the system through the gas discharge pipe 62a, and the reducing gas source 51a Reducing gas is supplied into the heating chamber 3a through the gas supply pipe 53a.

As a result, the temperature inside the heating / regeneration furnace 30 is raised to a predetermined temperature, the inside of the reducing chamber 7a of the reducing furnace 7 is in a reducing atmosphere, and the temperature is raised to a preset temperature. When it is confirmed that the conveyor belt 4 is rotated, the used filter device 1 is sequentially mounted on the conveyor belt 4 on the most upstream side.

Then, the filter device 1 introduced into the heating and regenerating furnace 30 is heated, and the oil and fat trapped in the heat resistant filter 13 and the oil and fat attached to the metal frame 11 and the like are thermally decomposed. It is removed and the filter device 1 is regenerated. Since the inside of the heating / regeneration furnace 30 is in an oxidizing atmosphere, a thin oxide film is formed on the surface of the regenerated metal frame 11 and the like, which is in a slightly discolored state. The decomposed gas generated at this time is supplied to the gas exhaust pipe 62a by the suction pump 61a.
Through the heating and regenerating furnace 30 to the outside of the system, and a predetermined gas treatment is performed in the subsequent gas treatment equipment.

Then, the filter device 1 for which the regeneration processing has been completed
Is passed through the inlet 72 by the conveyor belt 4 and the reduction furnace 7
Since it is introduced into the interior and exposed to a reducing atmosphere at a predetermined temperature in the reducing chamber 7a, the oxide film formed on the surface of the metal frame 11 or the like is reduced, the discolored state of the surface is eliminated, and the outlet 73 is Through the system. Note that the reducing gas (hydrogen) is consumed only for reducing the metal oxide on the surface of the metal frame 11, etc., and an amount of reducing gas commensurate with the consumption amount is supplied from the reducing gas source 51a via the pressure feed pump 52a. Is supplied to the return chamber 7a.

Since the reducing chamber 7a is in an inert atmosphere of an inert gas, the metal frame 1 made of metal is used.
1. The surfaces of the support frame 12 and the wire netting 14 are not oxidized to form an oxide film. Therefore, the outlet 7
Filter device 1 led out of the heating / regeneration furnace 3 via
Is in a regenerated state in which oils and fats trapped in the heat-resistant filter 13 are removed, and the metal frame 11 made of metal is
No discoloration due to the formation of an oxide film has occurred, and the appearance is beautiful.

Each of the regeneration devices 2 and 2a of the above-mentioned embodiments employs a tunnel type heating regeneration furnace or a reduction furnace, and the filter device to be regenerated is continuously transferred to the heating regeneration furnace or the reduction furnace by a conveyor belt. It is supposed to be introduced,
The method of the present invention is not limited to the use of the continuous apparatus as described above, but the lid is opened, a predetermined number of filter devices are loaded in an inert atmosphere and high temperature furnace, and the lid is closed. A so-called batch type regenerating furnace may be employed in which the filter device is left for a predetermined time after being closed to regenerate the filter device, and after the regeneration is completed, the lid is opened and the regenerated filter device is taken out.

(Test Example) The following effect confirmation test was carried out in order to confirm the effect of the method for regenerating the heat resistant filter with a metal frame of the present invention. First, the salad oil is applied to the surface of the metal frame of the filter device, and the salad oil is charged into an electric furnace having an oxidizing atmosphere inside and heated at 200 ° C. for 30 minutes to oxidize the salad oil to obtain an actual filter device. The state in which oil smoke adhered to the metal frame of was reproduced. Then, the filter device to which the oily smoke had adhered was loaded into a batch-type regeneration furnace to perform regeneration treatment. The reproduction conditions are as follows.

Temperature rising rate: 10 ° C./min Heat treatment temperature: 500 ° C. Treatment time: 40 minutes (after reaching 500 ° C.) Adhesion amount of oils and fats: 20% by weight of glass fiber heat resistant filter Under the same conditions, in Example 1, a metal frame using stainless steel (SUS304) was adopted, and the regeneration environment of the regenerator was an inert atmosphere using nitrogen gas. In Example 2, the metal frame was used. Was made of stainless steel (SUS304), and the regenerating environment of the regenerating furnace was a reducing atmosphere using hydrogen gas. Further, in Example 3, the metal frame is made of copper, and the regeneration environment of the regenerator is an inert atmosphere using nitrogen gas. In Example 4, while the metal frame is made of copper, The regenerating environment of the regenerating furnace was set to a reducing atmosphere using hydrogen gas.

In Comparative Example 1, the same regeneration conditions were used in common, a metal frame of SUS304 was used, and the regeneration environment of the regeneration furnace was an oxidizing atmosphere (air), and as Comparative Example 2, Playback conditions are common,
A test was conducted using a metal frame made of copper and setting the regenerating environment of the regenerating furnace to an oxidizing atmosphere (air).

The flow rates of nitrogen gas and hydrogen gas supplied to the regenerator were set to 8 liters / minute for the above tests. After performing such a regeneration test, the state of the surface of the metal frame was visually observed. The observation result is
As shown in Table 1.

[0054]

[Table 1]

As can be seen from Table 1, in the case of the embodiment, regardless of the material of the metal frame, it adhered whether the regeneration environment was an inert environment by nitrogen gas or a reducing environment by hydrogen gas. The soot was completely removed and no discoloration was observed on the surface.

On the other hand, in the case of the comparative example, since the regenerating environment is an oxidizing environment due to air, a brown oxide film is formed on the surface after the regeneration when the metal frame is stainless steel, and When the metal frame was copper, a dark green oxide film was formed on the surface.

From the above, it can be seen that by setting the regeneration environment to an inert environment or a reducing environment, it is possible to satisfactorily heat and regenerate the filter device with the heat resistant filter mounted on the metal frame.

FIG. 4 is a graph showing the pressure loss of a new heat resistant filter and a heat resistant filter regenerated by the method of the present invention. In this graph, the wind speed of the suction gas passing through the heat-resistant filter is graduated on a logarithmic scale on the horizontal axis,
The vertical axis is a logarithmic scale of pressure loss when the suction gas passes through the heat resistant filter. And, the horizontal axis is 0.
A wind speed value in the range of 3 to 10 m / sec is set, and a pressure loss value in the range of 0.05 to 10 mmAq is set on the vertical axis.

When the pressure loss value of the new heat-resistant filter for each predetermined wind speed was actually measured and plotted on this graph, the relationship shown by the solid line was obtained. On the other hand, when the pressure loss value for each predetermined wind speed was actually measured and plotted for the heat resistant filter of the recycled product, the relationship shown by the dotted line was obtained. The solid line and the dotted line almost coincide with each other, and it can be seen that there is no difference in pressure loss between the heat resistant filter and the new product.

[0060]

In the method for regenerating a heat-resistant filter with a metal frame according to claim 1 of the present invention, the inside is set to a reducing atmosphere or an inert atmosphere, and the temperature is raised to a temperature at which oils and fats decompose. In addition, the heat-resistant filter mounted on the metal frame is loaded into the heating and regenerating furnace.

Therefore, by loading the heat-resistant filter equipped with the metal frame into the high temperature heating and regenerating furnace, the oils and fats and the like trapped in the heat-resistant filter are thermally decomposed and gasified to be heat-resistant filter. Removed from within.

Since the inside of the heating and regenerating furnace is set to a reducing atmosphere or an inert atmosphere, the surface of the metal frame is not oxidized even if the atmosphere temperature is high, and as a result, the conventional atmosphere is not obtained. As described above, the surface of the metal frame does not undergo oxidative discoloration that occurs when it is heat-treated in an oxidizing atmosphere, and is extremely effective in maintaining a beautiful appearance of the metal frame. Further, conventionally, in order to remove the oxidative discoloration, a post-treatment such as polishing was required, but such polishing is not necessary, and it is possible to reduce the reproduction cost accordingly. It is possible to avoid such an inconvenience that the metal frame is damaged due to repeated polishing and the like, and the appearance is impaired.

Further, since oils and fats and the like attached to the heat resistant filter are thermally decomposed in the heating and regenerating furnace without being oxidized, this thermally decomposed gas can be used as a fuel gas, which is an effective resource resource. It is convenient in terms of utilization.

In the method for regenerating a heat-resistant filter with a metal frame according to claim 2 of the present invention, first, the inside is set to an oxidizing atmosphere, and the inside of the heating regeneration furnace is heated to a temperature at which fats and oils are decomposed. Is configured to be loaded with the heat-resistant filter, then the inside is set to a reducing atmosphere, and the heat-resistant filter derived from the heating regeneration furnace is loaded into the reducing furnace heated to a predetermined temperature. It will be.

Therefore, the heat-resistant filter mounted on the metal frame is heated in the first-stage heating / regeneration furnace in an oxidizing atmosphere, so that oils and fats trapped inside the heat-resistant filter are removed. It is burnt and removed as combustion waste gas. By this first stage heat treatment, a discolored oxide layer is simultaneously formed on the surface of the metal frame, but the reducing furnace in the second stage is set to a reducing atmosphere. By heating, the oxide layer on the surface of the metal frame is reduced and the above discoloration is eliminated.Therefore, compared with the case of performing heat treatment only in the conventional oxidizing atmosphere, the metal frame does not require the subsequent troublesome polishing treatment. Therefore, it is effective in reducing the processing cost.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view showing an example of a heat-resistant filter which is a target of a regeneration method of the present invention.

FIG. 2 is a process chart showing a first regeneration method of the present invention.

FIG. 3 is a process chart showing a second regeneration method of the present invention.

FIG. 4 is a graph showing the pressure loss of a new heat resistant filter and a heat resistant filter regenerated by the method of the present invention.

FIG. 5 is a cross-sectional view illustrating a usage state of the heat resistant filter.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Filter device 11 Metal frame 12 Support frame 13 Heat-resistant filter 14 Wire mesh 2,2a Regeneration device 3,30 Heating regeneration furnace 31 Electric heating element 32 Inlet port 33 Outlet port 34 Thermometer 35 Pressure gauge 36 Oxygen concentration meter 4 Conveyor belt 41 Roller 42 carry-in section 43 carry-out section 5 inert gas supply means 51 inert gas source 52 pressure pump 53 gas supply pipe 6,6a decomposition gas suction means 61,61a suction pump 62,62a gas discharge pipe 7 reduction furnace 7a reduction chamber 71 energization Heating element 72 Inlet 73 Outlet 74 Thermometer 75 Pressure gauge 76 Hydrogen concentration meter

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tomohiko Matsunaga 100-1 Urakawachi, Miyamae, Fujisawa-shi, Kanagawa Stock Company Fuji Steel Works, Fujisawa Works

Claims (2)

[Claims] 1. A method for regenerating a heat-resistant filter with a metal frame, in which a used heat-resistant filter having oils and fats and the like attached thereto is heated and regenerated in a state where the heat-resistant filter is attached to the inside of the metal frame. The atmosphere is set to an inert atmosphere, and
Regeneration of a heat-resistant filter with a metal frame, characterized in that the heat-resistant filter is loaded in a heating regeneration furnace heated to a temperature at which oils and fats are decomposed, and the oils and fats are thermally decomposed and removed from the heat-resistant filter. Method. 2. A method for regenerating a heat-resistant filter with a metal frame, in which a used heat-resistant filter to which oils and fats have adhered is heated and regenerated in a state of being mounted in the frame of a metal frame, wherein the inside is an oxidizing atmosphere. The heat-resistant filter is loaded into a heating and regeneration furnace whose temperature is set to a temperature that decomposes oils and fats, and then the inside is set to a reducing atmosphere and the temperature is raised to a predetermined temperature. The heat reduction filter derived from the heating regeneration furnace is loaded into the reduced reduction furnace, and oils and fats and the like adhering to the heat reduction filter in the heating regeneration furnace are thermally decomposed and removed, and the metal frame is used in the regeneration furnace. A method for regenerating a heat-resistant filter with a metal frame, characterized in that the surface portion in the oxidized state is reduced.