JPH05283083A - Method for washing carbon material parts - Google Patents

Abstract

PURPOSE:To provide the excellent method for washing carbon material parts to improve the electrode performance of a fuel cell and prolong the lifetime by preventing the burning at the time of burning catalyzer of a ribbed electrode of a fuel cell, and improving the gas permeability of the ribbed electrode to enable the even distribution of the electrolyte such as phosphoric acid. CONSTITUTION:Ozonized gas, which includes the ozone generated by an ozone generator 11, is fed to a diffusion cylinder 13 provided in the bottom of an ozone absorbing tower 12, and is poured as fine bubble in the water filled inside of the ozone absorbing tower 12 to obtain the ozone included water. The ozone included water inside of the ozone absorbing tower 12 is fed by a liquid feeding pump 14, and is blown from a nozzle 15 to the surface of the ribbed electrode 2 to contact to the ribbed electrode 2. The structure, in which the ozone absorbing tower 12 is omitted, or the structure, in which the ribbed electrode 2 is impregnated with the ozone included water, is possible.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a fuel cell, and more particularly to a pretreatment method for a ribbed electrode of a fuel cell which can improve the electrode performance of a phosphoric acid fuel cell.

[0002]

2. Description of the Related Art Conventionally, a fuel cell has been known as a device for directly converting the energy of fuel into electric energy. In this fuel cell, usually, a pair of porous electrodes are arranged with an electrolyte-impregnated matrix sandwiched between them, and a fluid fuel such as hydrogen is brought into contact with the back surface of one of the electrodes, and oxygen is fed to the back surface of the other electrode. Contact with the fluid oxidant of the
The electric energy is taken out from between the electrodes. In this type of fuel cell, electric energy can be extracted with high conversion efficiency as long as the fuel and the oxidant are supplied.

Among such fuel cells, a unit cell of a fuel cell using phosphoric acid as an electrolyte is constructed as shown in FIG. In this case, FIG. 12 is a vertical cross-sectional perspective view showing the unit cell. That is, in FIG. 12, a pair of ribbed electrodes 2 are arranged to sandwich a matrix 1 impregnated with phosphoric acid as an electrolyte, and a unit cell 3 is formed. In this case, the pair of ribbed electrodes 2 is usually formed of a porous material made of a carbon material, and a catalyst is added to the front surface facing the matrix 1. Further, flow passages 2a for the fluid fuel and the fluid oxidant are formed on the back surfaces of the pair of ribbed electrodes 2 which are the surfaces opposite to the catalyst application surface. Then, the unit cell 3 configured in this way
Are alternately stacked via the gas separation plate 4 to form a fuel cell stack.

By the way, the ribbed electrode 2 is usually made of a mixture of carbon fiber and carbonizable resin, and is carbonized.
After being graphitized, it becomes an electrode substrate for fuel cells. And
After such carbonization and graphitization, one or both sides are polished to make the thickness uniform, and then catalyst addition and firing, groove processing, matrix coating, and phosphoric acid impregnation are sequentially performed. After that, finally, the anode and cathode ribbed electrode plates 2 are integrated to form a unit cell 3 as shown in FIG.

[0005]

However, the conventional ribbed electrode formed as described above has a problem that a part of the catalyst burns when it is fired after the catalyst is added. There is also a problem that the gas permeability is poor and the variation of phosphoric acid is large.

Among these problems, it is considered that the cause of the catalyst burning is the organic stain on the surface of the ribbed electrode.
Organic stains are oils and fats from the skin oils of the human body during processing,
Oils and fats from cosmetics, oils and fats that are scattered in the air from motors, pumps and the like and are floating, or machine oils that are attached during processing such as cutting and polishing are considered. Then, these organic stains on the ribbed electrode plate surface are
The catalyst burns at a relatively low temperature.

Further, as a result of investigating the cause of the poor gas permeability, it was found that it was caused by clogging of polishing debris when polishing one or both surfaces of the ribbed electrode to make the thickness uniform. That is, the ribbed electrode is polished while being sucked by the vacuum chuck, but the polishing residue is
It was found that, while passing through the comparatively large pores of the ribbed electrode, it failed to pass through the small pores and caused clogging, resulting in poor gas permeability of the ribbed electrode and variation. And if the gas permeability is poor like this,
The power generation characteristics of the fuel cell will deteriorate.

By the way, in the ribbed electrode, the portion that is clogged due to the above-mentioned causes has a higher density and a smaller average pore diameter than the portion that is not clogged. As a result, phosphoric acid preferentially penetrates into the area with a small average pore size (clogging area) due to the capillary phenomenon.
Uneven distribution of phosphoric acid occurs. When the vehicle is operated for a long time in this state, even if there is an amount of phosphoric acid that does not hinder the operation as a whole, a phosphoric acid deficiency occurs locally, and eventually operation becomes impossible.

Further, the above-mentioned problems are not limited to the fuel cell rib-equipped electrode, but similarly exist in general carbon material parts that are subjected to a certain processing such as polishing.

The present invention has been proposed in order to solve the above problems, and its purpose is to prevent combustion at the time of burning a catalyst in a fuel cell rib electrode and to prevent gas in the rib electrode. Providing an excellent method for cleaning carbon material parts that improves the electrode performance of fuel cells and contributes to a longer life by improving the permeability and allowing the uniform distribution of electrolytes such as phosphoric acid It is to be.

Another object of the present invention is not only to provide an electrode with ribs for a fuel cell, but also to provide an excellent cleaning method that is effective for cleaning general carbon material parts that are similarly subjected to certain processing such as polishing. Is.

[0012]

A method according to claim 1, wherein the carbon material component is washed with ozone-containing water containing dissolved ozone or ozonized gas bubbles, and the method according to claim 2 is characterized. Is characterized in that the carbon material component is cleaned with an oxidizing solution, and the method according to claim 3 is characterized in that the carbon material component is contacted with an oxidizing gas and then washed with water. ..

These methods of the present invention are generally applicable to carbon material parts which are formed from a carbon material and which have been subjected to a certain processing treatment. In particular, the fuel cell rib according to claim 4 is used. It is used as a method of cleaning attached electrodes.

[0014]

The operation of each of the methods of the present invention will be described below, particularly when it is used as a method for cleaning a ribbed electrode for a fuel cell.

First, in each method of the present invention, organic stains on the surface of the ribbed electrode are oxidized by ozone (claim 1), an oxidizing solution (claim 2), or an oxidizing gas (claim 3). At the same time as disassembling, it is possible to remove the polishing debris clogged in the ribbed electrode.

That is, the removal of organic stains on the surface of the ribbed electrode in the liquid phase or vapor phase in each method of the present invention does not require complete decomposition of the organic stains, and partial oxidation is sufficient for oxidation. That is, in the method of the present invention, the organic stain on the surface of the ribbed electrode is oxidized by ozone in water, an oxidizing solution, or an oxidizing gas to form a moderate oxide such as an aldehyde, a ketone, or a carboxylic acid. Since these oxides are washed and removed using water as a medium, organic stains can be easily and surely removed. Then, stains of inorganic substances, such as various salts, can be removed by dissolving or suspending them in water.

In each of the methods of the present invention, the polishing dust clogged in the ribbed electrode is cleaned by ozone-containing water (Claim 1), cleaned by an oxidizing solution (Claim 2), or oxidized. It can be removed by the contact with a volatile gas and the cleaning effect by cleaning with water (claim 3). In particular, when cleaning with ozone-containing water (Claim 1),
Not only the removal effect by water, but also the cleaning effect by the coexistence of ozonized gas. That is, in this method, since ozone is injected into the water as fine bubbles, a mechanical cleaning effect due to the fine bubbles is added, and polishing debris can be easily and surely removed, and even extremely fine polishing debris is removed. be able to. In this case, as a method of injecting ozone, generally, a method of injecting ozonized air into water through a scattering cylinder having fine pores is adopted.

Further, in each method of the present invention, the impregnation property of the ribbed electrode with the electrolyte can be improved. On the surface of the carbon fiber or the like which is the base material of the ribbed electrode, oxidation of ozone (Claim 1), an oxidizing solution (Claim 2), or an oxidizing gas (Claim 3) causes the formation of hydroxyl groups, carboxyl groups, etc. Hydrophilic groups can be added. By the added hydrophilic group, the hydrophilicity of the surface is improved and the impregnating property of the electrolyte such as phosphoric acid can be improved.

The methods of the present invention can be widely applied not only to the fuel cell ribbed electrode but also to a general cleaning method for carbon material parts which are formed of a carbon material and are subjected to a certain processing treatment. Similarly, an excellent effect can be obtained.

[0020]

EXAMPLES Hereinafter, a plurality of examples for cleaning a fuel cell ribbed electrode according to the method of the present invention will be described with reference to FIG.
It will be specifically described with reference to FIGS. In this case, FIGS. 1 to 5 are process flows showing the first to fifth embodiments according to the method of claim 1, and FIGS. 6 to 9 are
Processing flows showing sixth to ninth embodiments according to the method of claim 2, respectively, and FIG. 10 and FIG. 11 are processing flows showing respectively tenth embodiment and eleventh embodiment according to the method of claim 3. ..

(1) First Embodiment (Washing with Ozone-Containing Water) ... FIG. 1 In the first embodiment shown in FIG. 1, ozone-containing water containing dissolved ozone or ozonized gas bubbles is sprayed on the ribbed electrode. It is an embodiment configured as follows. That is, in FIG.
The ozonized gas containing ozone generated by the ozone generator 11 is dispersed in the cylinder 13 provided at the bottom of the ozone absorption tower 12.
And is injected into the ozone absorption tower 12 as fine bubbles from the dispersion cylinder 13. Most of the injected ozonized gas moves to water by gas-liquid contact and becomes dissolved ozone.

The ozone-containing water containing dissolved ozone or ozonized gas bubbles obtained in this way is delivered from the ozone absorption tower 12 by the liquid delivery pump 14, and is a nozzle arranged above the ribbed electrode 2. 15 to the ribbed electrode 2
Is sprayed on the surface of the and contacts the electrode 2 with ribs. In this case, the ribbed electrode 2 is placed on the mesh-shaped conveyor 16, and is stopped at a predetermined cleaning position facing the nozzle 15 for a certain time required for cleaning, and then sent to the next step. It is designed to be used. Note that, from the viewpoint of simplification of the drawing, the conveyors in the front and rear steps are not shown.

As described above, the ozone-containing water containing the dissolved ozone or the ozonized gas bubbles is sprayed from the nozzle 15 onto the surface of the ribbed electrode 2 for a certain period of time to bring it into contact with the surface of the ribbed electrode 2. Organic stains and polishing debris are removed by the oxidation effect of ozone and the cleaning effect of ozone-containing water.

Further, the ozone-containing water containing the ozonized gas bubbles, which has contacted the ribbed electrode 2 and consumed most of the dissolved ozone, is recovered as follows, and the ozone absorption tower 12 is again used.
It is sent inside and reused. That is, a water receiving tank 17 is disposed below the conveyor 16 facing the nozzle 15, and is sprayed from the nozzle 15 onto the ribbed electrode 2 to come into contact with the ribbed electrode 2 to remove most of the dissolved ozone. The ozone-containing water containing the consumed ozonized gas bubbles falls into the water receiving tank 17. In this case, the water receiving tank 17 is partitioned by a partition plate 18 and divided into a settling section 19 and a supernatant section 20. With this configuration, among oxides and polishing dust mixed in the ozone-containing water due to cleaning, relatively large polishing dust particles stay in the settling section 19 of the water receiving tank 17 and settle at the bottom thereof, and the sediment discharge valve 21. It is discharged from and treated separately.

After removing the relatively large polishing dust as described above, the ozone-containing water in the water receiving tank 17 is sent out from the supernatant portion 20 and passed through the filter 22 so that small polishing dust particles and oxides can be obtained. The contaminants such as particles are removed.
Further, the ozone-containing water filtered by the filter 22 is sprayed from the upper part of the ozone absorption tower 12 by the circulation pump 23,
Again, it is contacted with ozonated gas containing ozone. Reference numeral 24 in the drawing denotes a hood arranged above the nozzle 15, and is provided to collect a small amount of ozone generated when the ozone-containing water is sprayed onto the ribbed electrode 2. Then, the ozone that has not been absorbed by the ozone absorption tower 12 is decomposed by the exhaust ozone decomposing tube 25 together with the ozone recovered by the hood 24, and then released into the atmosphere by the exhaust gas blower 26.

The method of this embodiment is preferably carried out under the following conditions. First, the dissolved ozone concentration for contacting the ribbed electrode 2 to oxidize organic dirt and washing and removing polishing dust or ozone-containing water containing ozonized gas bubbles is at least 0.5 mg / l or more. It is necessary to set it, and more preferably about 0.5 to 2 mg / l. That is,
If the concentration is 0.5 mg / l or more, the higher the concentration, the better the reactivity and the faster the reaction rate, but the amount of ozone discharged increases. preferable. On the other hand, if it is less than 0.5 mg / l,
There is a possibility that the organic stain is not sufficiently oxidized and the organic stain cannot be reliably removed.

Next, the contact time between the ribbed electrode 2 and the ozone-containing water, which is the time for spraying the ozone-containing water containing the ozonized gas bubbles to the ribbed electrode 2, should be at least 5 minutes or longer. Necessary, and preferably,
It takes about 5 to 15 minutes. That is, the longer the contact time,
Although it is possible to completely carry out the reaction, the oxidation in the liquid phase in this example is a partial oxidation, and the aldehyde,
Moderate oxides such as ketones and carboxylic acids are produced,
Since these oxides are washed and removed using water as a medium, a relatively short contact time of about 5 to 15 minutes
The organic dirt can be removed sufficiently. Further, also for the removal of the polishing dust clogged in the ribbed electrode 2, the purpose can be sufficiently achieved by the relatively short contact time of about 5 to 15 minutes.

Further, as in the present embodiment, the method of spraying the ozone-containing water to the ribbed electrode 2 using the nozzle 15 is performed by dissolving the ozone-containing water containing dissolved ozone or ozonized gas bubbles in the ribbed electrode 2. It is extremely effective as a method for supplying effectively, but more specifically, the nozzle 1
The ozone-containing water can be supplied most efficiently by arranging 5 as close as possible to the ribbed electrode 2 and arranging them evenly. More desirably, by spraying ozone-containing water under pressure from the nozzle to the ribbed electrode,
More effective cleaning can be performed. In addition, it is more effective if the ribbed electrode 2 is inverted and double-sided.

As described above, in the present embodiment, the ozone-containing water containing dissolved ozone or ozonized gas bubbles was sprayed onto the ribbed electrode by using the nozzle to adhere to the surface of the ribbed electrode. Organic stains
Partial oxidation in the liquid phase by contact with dissolved ozone,
It is easily or reliably removed by dissolving or suspending in ozone-containing water. At the same time, the polishing debris clogged in the ribbed electrode not only has the effect of cleaning with ozone-containing water,
The mechanical cleaning effect of fine ozonized gas bubbles is added, and it flows out together with ozone-containing water and is easily and surely removed.

As described above, according to the cleaning method of this embodiment,
Since the organic dirt adhering to the surface of the ribbed electrode can be sufficiently removed, in the thus cleaned ribbed electrode, combustion of the catalyst at the time of catalyst burning does not occur unlike the conventional case. Specifically, the number of catalytic combustion occurrences for 1000 electrode treatments in the cleaned ribbed electrode of the present example and the conventional non-cleaned ribbed electrode of the present example was examined. The results shown in Table 1 were obtained. That is, as shown in Table 1, none of the cleaned electrodes with ribs of the present example generated catalytic combustion even after the electrode treatment of 1000 sheets.

[0031]

[Table 1] Further, since the clogged polishing dust is sufficiently removed by the cleaning effect of the ozone-containing water, the gas permeability is improved. Specifically, under a certain condition, the average value of the gas permeability of the cleaned ribbed electrode of the present example and the conventional ribbed electrode of the present example that was not cleaned was examined,
The results shown in Table 2 below were obtained. That is, as shown in Table 2, the ribbed electrode of the present example was improved in transparency by about 14% on average as compared with the conventional ribbed electrode.

[0032]

[Table 2] In addition to the above effects, it was confirmed that in the cleaned ribbed electrode of this example, the surface hydrophilicity was improved and the phosphoric acid wettability was improved. It is presumed that this is because the cleaning performed in the present example resulted in surface oxidation of carbon fibers, which are the base material of the ribbed electrode, by ozone, and addition of hydrophilic groups such as hydroxyl groups and carboxyl groups to the surface. Specifically, when the phosphoric acid wettability of the cleaned ribbed electrode of this example and the conventional non-cleaned ribbed electrode of this example was examined, the results shown in Table 3 below were obtained. was gotten. In addition, the values in Table 3 are obtained by using a sample (20 ×
200 m) is cut out, and about 5 mm at the tip is vertically set so as to be immersed in an 85% phosphoric acid solution, left standing at room temperature, and the permeation amount of phosphoric acid per hour is examined. That is, as shown in Table 3, the ribbed electrode of the present example, which has been subjected to the cleaning, has improved phosphoric acid wettability by about 17% as compared with the conventional ribbed electrode.

[0033]

[Table 3] Further, as described above, in the cleaned ribbed electrode of this example, the clogged polishing residue is sufficiently removed by the ozone-containing water, so that the distribution of phosphoric acid impregnated in the ribbed electrode is also It was confirmed that the phosphoric acid was improved and was almost uniformly present. That is, as described above, in the conventional ribbed electrode, there is a difference in the average pore diameter between the portion where the polishing residue is clogged and the portion where the polishing residue is not clogged, resulting in uneven distribution of phosphoric acid. By performing the cleaning of this embodiment, the polishing dust is sufficiently removed, so that the average pore diameter is made uniform, and as a result, the phosphoric acid can be uniformly distributed.

(2) Second Embodiment (Washing with Ozone-Containing Water) ... FIG. 2 The second embodiment shown in FIG. 2 contains dissolved ozone or ozone containing ozone-containing gas bubbles as in the first embodiment. Unlike the first embodiment, water is sprayed on the ribbed electrodes, and the ozone absorption tower is omitted to simplify the structure. In FIG. 2, the same parts as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

That is, in FIG. 2, the ozone generator 1
Ozonized gas containing ozone generated in 1 is received in the water receiving tank 2
The water is sent to a dispersion cylinder 13 provided at the bottom of No. 1 and is injected as fine bubbles into the water filled in the water receiving tank 21 from the dispersion cylinder 13. Most of the injected ozonized gas moves to water by gas-liquid contact and becomes dissolved ozone. The ozone-containing water containing dissolved ozone or ozonized gas bubbles in the water receiving tank 17 is sent from the supernatant section 20 and passed through the filter 22 to remove contaminants such as small polishing dust particles and oxide particles. To be done. in this way,
The ozone-containing water filtered by the filter 22 is delivered by the circulation pump 23, sprayed onto the surface of the ribbed electrode 2 from the nozzle 15 arranged above the ribbed electrode 2, and contacts the ribbed electrode 2.

Further, the large abrasive dust particles settled in the settling section 19 of the water receiving tank 17 were treated by the sediment discharge valve 21 as in the first embodiment, and were not absorbed by water in the water receiving tank 17. As in the first embodiment, ozone is collected by the hood 24 arranged above the nozzle 15, decomposed by the exhaust ozone decomposing tube 25, and then released into the atmosphere by the exhaust gas blower 26.

In the present embodiment having the above-mentioned structure, in addition to obtaining the same effects as the first embodiment, the ozone absorption tower 12 and the liquid sending used in the first embodiment are obtained. Since the pump 14 is omitted and the dissolved ozone is generated by direct gas-liquid contact in the water receiving tank 17, there is an advantage that the system is simple. Since the ozone absorption efficiency in water due to the gas-liquid contact in the water receiving tank 17 is lower than that in the case where the ozone absorption tower 12 is used, it is necessary to make the water depth of the water receiving tank deeper accordingly.

(3) Third Example (Washing with Ozone-Containing Water) ... FIG. 3 In the third example shown in FIG. 3, dissolved ozone is produced using an ozone absorption tower, as in the first example. On the other hand, unlike the first embodiment, this is an embodiment in which the ribbed electrode is directly immersed in ozone-containing water containing dissolved ozone or ozonized gas bubbles. In addition, in FIG.
The same parts as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

That is, referring to FIG. 3, the ribbed electrode 2
Is fixed to the upper part of the reaction tank 27 filled with ozone-containing water containing dissolved ozone or ozonized gas bubbles. In this case, the ribbed electrode 2 is weak in mechanical strength and cannot be fixed as it is, and therefore, the ribbed electrode 2 is fixed by being sandwiched between coarse meshes. Further, the periphery of the ribbed electrode 2 is sealed with a sealing material 28 so as to prevent a short pass of the ozone-containing water from the periphery thereof. And in the ozone absorption tower 12,
The ozone-containing water containing dissolved ozone or ozonized gas bubbles is delivered by the liquid delivery pump 14, flows in from the bottom of the reaction tank 27, and comes into contact with the ribbed electrode 2 fixed to the upper portion of the reaction tank 27, It passes through the gap between the attached electrodes 2.
At this time, the organic stains on the ribbed electrode 2 are oxidized by ozone, and the polishing dust is removed by the cleaning effect of the ozone-containing water and the mechanical cleaning effect of the fine ozonized gas bubbles.

The ozone-containing water that has passed through the gap between the ribbed electrodes 2 in this manner is sent out from the upper portion of the reaction tank 27,
After the filter 22 removes contaminants such as small polishing dust and oxide particles, it is sprayed from the upper part of the ozone absorption tower 12 by the circulation pump 23 and again brought into contact with ozone-containing gas containing ozone. Although not shown,
When a relatively large amount of polishing debris and other contaminants are present, the load on the filter 22 increases, so the reaction tank 27
It is desirable that a part of the above is used as a settling section, or that a settling tank is separately provided before the filter 22 to remove large polishing dust in advance.

In the present embodiment having the above-mentioned structure, since ozone-containing water containing dissolved ozone or ozonized gas bubbles always passes through the gap between the ribbed electrodes 2,
There is an advantage that ozone cleaning can be surely performed. Further, in the configuration of the present embodiment, it is important to properly control the flow velocity of ozone-containing water that passes through the gap between the ribbed electrodes 2. Further, in the present embodiment, the flow direction of the ozone-containing water in the reaction tank 27 is configured to be an upward flow, but conversely, the ozone-containing water is made to flow in from the upper part of the reaction tank 27 and sent out from the bottom part. It is also possible that the flow direction of the ozone-containing water in the reaction tank 27 is a downward flow. In this case, the cleaning effect by the ozone-containing water tends to be slightly lower than that in the case of using the upward flow, but there is an advantage that the ozone absorption efficiency is improved and the organic dirt is easily decomposed.

(4) Fourth Embodiment (Washing with Ozone-Containing Water) ... FIG. 4 The fourth embodiment shown in FIG. 4 is an embodiment in which an ultraviolet lamp is installed in addition to the configuration of the third embodiment. .. That is,
In FIG. 4, an ultraviolet lamp 29 is installed below the ribbed electrode 2 fixed to the upper part of the reaction tank 27 and is irradiated with ultraviolet rays. When configured in this way, the third
In addition to the action and effect of the example, further, by irradiation of ultraviolet rays, the self-decomposition of ozone in water is promoted, and oxygen radicals, hydroxyl radicals, and hydrogen peroxide radicals having stronger oxidizing power are generated. This accelerates the decomposition of organic dirt. In this case, the radicals have a high activity and a short life, so that the ultraviolet lamp 29
Is preferably installed as close to the surface of the ribbed electrode 2 as possible.

(5) Fifth Embodiment (Washing with Ozone-Containing Water) ... FIG. 5 The fifth embodiment shown in FIG. 5 is similar to the third embodiment, and contains ozone containing dissolved ozone or ozonized gas bubbles. Unlike the third embodiment, the electrode with ribs is directly immersed in water, but the ozone absorption tower 12 is omitted to simplify the structure. The cylinder 13 is provided at the bottom of the reaction tank 27.
Is configured to directly inject the ozonized gas into the reaction tank 27. With such a configuration, there is an advantage that the system can be simplified.

(6) Sixth Embodiment (Washing with Oxidizing Solution) ... FIG. 6 The sixth embodiment shown in FIG. 6 is an embodiment in which the oxidizing solution is sprayed on the ribbed electrodes. That is, the oxidizing solution in the supernatant portion 20 of the water receiving tank 17 is filtered by the filter 22 to remove contaminants such as small polishing dust particles and oxide particles, and then sent out by the circulation pump 23, so that the ribbed electrode 2 of the ribbed electrode 2 is discharged. From the nozzle 15 arranged on the upper portion, the surface of the ribbed electrode 2 is sprayed for a certain period of time and comes into contact with the ribbed electrode 2.

As described above, by spraying the oxidizing solution from the nozzle 15 onto the surface of the ribbed electrode 2 for a certain period of time and bringing them into contact with each other, organic stains and polishing debris on the ribbed electrode 2 are caused by the oxidizing solution. It is removed by the effect of oxidation and washing.

Further, the oxidizing solution which has come into contact with the ribbed electrode 2 and whose oxidizing ability has been lowered falls into the water receiving tank 17, and out of oxides and polishing dust mixed in the oxidizing solution by washing,
The relatively large abrasive dust particles are collected in the settling portion 19 of the water receiving tank 17.
Accumulated on the bottom of the tank and settles on the bottom of the tank, and is discharged from the precipitate discharge valve 21 and separately processed. After removing the relatively large polishing dust, the oxidizing solution in the water receiving tank 17 is
By being sent out from the supernatant portion 20 and passed through the filter 22, contaminants such as small polishing dust particles and oxide particles are removed. Further, the oxidizing solution filtered by the filter 22 is sent to the nozzle 15 by the circulation pump 23 and is again sprayed on the surface of the ribbed electrode 2. Due to such contact between the oxidizing solution and the ribbed electrode 2, a small amount of mist and oxidizing gas of the oxidizing solution are generated. These mist and gas are generated in the hood 2 arranged above the nozzle 15.
4, is decomposed in the exhaust gas processing cylinder 31, and then is discharged into the atmosphere by the blower 26.

Further, in order to compensate for the decrease in the oxidizing ability of the oxidizing solution, the highly concentrated oxidizing solution is supplied from the oxidizing solution tank 32 to the supernatant part 20 of the water receiving tank 17 at a constant flow rate by the chemical injection pump 33. Injected. As a result, the oxidative solution with reduced oxidative capacity, depending on the injection amount of the high-concentration oxidative solution,
From the settling part 19 side of the water receiving tank 17, the overflow pipe 34
And then discharged to the outside of the system.

Although not shown, if necessary, the oxidizing solution adhering to the surface of the ribbed electrode 2 is removed by washing with water in the subsequent step.

The method of this embodiment is preferably carried out under the following conditions. First, an oxidizing solution for contacting the ribbed electrode 2 to oxidize organic stains and washing and removing polishing dust is hydrogen peroxide, hypochlorous acid, permanganic acid, hydrofluoric acid or nitric acid. At least 1
Seed, more preferably hydrogen peroxide. In other words, hydrogen peroxide has the strongest oxidizing power next to hydrofluoric acid in the above-mentioned oxidizing solution, and is easily decomposed even if it adheres to and remains on the surface of the ribbed electrode, making it harmless. There is an advantage that it does not adversely affect the fuel cell. On the other hand, hydrofluoric acid has the strongest oxidizing power, but is difficult to handle. In addition, hypochlorous acid is usually used as a sodium salt, and since sodium remains, it is necessary to wash with water in a subsequent step, and the number of steps increases accordingly. Similarly, permanganate requires washing with water. On the other hand, since nitric acid has a weak oxidizing power, it takes a long time to oxidize and the treatment time becomes long.

Next, the time for spraying the oxidizing solution onto the ribbed electrode 2, that is, the contact time between the ribbed electrode 2 and the oxidizing solution, is the case when dissolved ozone or ozone-containing water containing ozonized gas bubbles is used. As in the case of the first embodiment, it is necessary to set at least 5 minutes or more, and preferably about 5 to 15 minutes. That is, the longer the contact time, the more completely the reaction can be carried out, but the oxidation in the liquid phase in this example is partial oxidation, and a medium-grade oxide such as an aldehyde, a ketone or a carboxylic acid is used. Are generated and these oxides are washed and removed using water as a medium, so that the organic stains can be sufficiently removed by a relatively short contact time of about 5 to 15 minutes. In addition, regarding the removal of the polishing dust clogging the ribbed electrode 2,
A relatively short contact time of about 15 minutes can sufficiently achieve the purpose.

Further, the method of spraying the oxidizing solution onto the ribbed electrode 2 using the nozzle 15 as in this embodiment is a method for effectively supplying the oxidizing solution to the ribbed electrode 2. It is extremely effective, but more specifically, the nozzle 15 is brought as close as possible to the ribbed electrode 2, and
By arranging them evenly, ozone-containing water can be supplied most efficiently. In addition, it is more effective if the ribbed electrode 2 is inverted and double-sided.

As described above, in this embodiment, the oxidizing solution is sprayed onto the ribbed electrode using the nozzle so that the organic stains adhering to the surface of the ribbed electrode are treated with the oxidizing solution. Upon contact, it is partially oxidized in the liquid phase and dissolved or suspended in an oxidizing solution to be easily and surely removed. At the same time, the polishing debris clogged in the ribbed electrode is due to the cleaning effect of the oxidizing solution,
It flows out with the oxidizing solution and is easily and reliably removed. Further, by spraying the oxidizing solution on the ribbed electrode from the nozzle in a pressurized state, more effective cleaning can be performed.

As described above, according to the cleaning method of this embodiment,
Since the organic dirt adhering to the surface of the ribbed electrode can be sufficiently removed, in the thus cleaned ribbed electrode, combustion of the catalyst at the time of catalyst burning does not occur unlike the conventional case. Specifically, the number of occurrences of catalytic combustion for 1000 electrode treatments of the cleaned ribbed electrode of this example and the conventional non-cleaned ribbed electrode of this example was examined. The same result as the result of the first embodiment shown in Table 1 was obtained. That is, in the cleaned ribbed electrode of this example, no catalytic combustion occurred even after the treatment of 1000 electrodes.

Further, since the clogged polishing dust is sufficiently removed by the cleaning effect of the oxidizing solution, the gas permeability is improved. Specifically, under a certain condition, the average value of the gas permeability of the cleaned ribbed electrode of the present example and the conventional ribbed electrode of the present example which was not cleaned was examined, Results similar to those of the first embodiment shown in Table 2 were obtained. That is, the cleaned ribbed electrode of this example is about 1 on average as compared with the conventional ribbed electrode.
The transparency was improved by 4%.

In addition to the above effects, it was confirmed that in the cleaned ribbed electrode of this example, surface hydrophilicity was improved and phosphoric acid wettability was improved. It is presumed that this is because the cleaning performed in the present example caused surface oxidation of the carbon fiber, which is the base material of the ribbed electrode, by the oxidizing solution, and the addition of hydrophilic groups such as hydroxyl groups and carboxyl groups to the surface. Specifically, the ribbed electrode of the present example,
Phosphoric acid wettability of the conventional non-cleaned ribbed electrode of this example was examined under the same conditions as in the first example, and the results of the first example shown in Table 3 above were obtained. Similar results were obtained. That is, the cleaned ribbed electrode of the present embodiment is about 1 compared to the conventional ribbed electrode.
The wettability of phosphoric acid was improved by 7%.

Further, as described above, in the cleaned ribbed electrode of this embodiment, the clogged polishing residue is sufficiently removed by the oxidizing solution, so that the phosphoric acid impregnated in the ribbed electrode is removed. Was also improved, and it was confirmed that phosphoric acid was present almost uniformly. That is, by performing the cleaning of this example, the polishing dust is sufficiently removed, so that the average pore diameter of the ribbed electrode is made uniform, and as a result, the phosphoric acid can be uniformly distributed.

(7) Seventh Embodiment (Washing with Oxidizing Solution) ... FIG. 7 The seventh embodiment shown in FIG. 7 is different from the sixth embodiment.
This is an example in which the ribbed electrode is directly immersed in an oxidizing solution. That is, in FIG. 7, the ribbed electrode 2 is fixed to the upper part of the reaction tank 27 filled with the oxidizing solution. In this case, the ribbed electrode 2 has weak mechanical strength,
Since it cannot be fixed as it is, it is fixed, for example, by sandwiching it with a coarse mesh. Further, the periphery of the ribbed electrode 2 is sealed so as to prevent a short pass of the oxidizing solution from the periphery thereof.

Then, the oxidizing solution in the reaction tank 27 is sent out from the upper part of the reaction tank 27, and by the filter 22,
After the contaminants such as polishing dust and oxide particles are removed, the circulating pump 23 flows in from the lower part of the reaction tank 27, and the reaction tank 2
While passing through the ribbed electrode fixed to the upper portion of the rib 7, the ribbed electrode 2 passes through the gap. At this time, the organic stains on the ribbed electrode 2 are oxidized by the oxidizing solution, and the polishing dust is removed by the cleaning effect of the oxidizing solution.

The ozone-containing water that has passed through the gaps between the ribbed electrodes 2 in this way is filtered by the filter 22 to remove small polishing debris and oxide particles, and then the circulation pump 2
Then, it is re-injected into the reaction tank 27 again. Although not shown, the load of the filter 22 increases when a relatively large amount of polishing debris and other contaminants are present. Therefore, a part of the reaction tank 27 is used as a sedimentation section or the filter 22 is used. It is desirable that a separate settling tank be provided before the above, and that large polishing debris be removed in advance.

In the present embodiment having the above-mentioned structure, the oxidizing solution always passes through the gap between the ribbed electrodes 2, so that there is an advantage that the cleaning can be surely performed. Further, in the configuration of the present embodiment, it is important to properly control the flow rate of the oxidizing solution passing through the gap between the ribbed electrodes 2. Furthermore, in the present embodiment, the oxidizing solution is configured to flow upward in the reaction tank 27, but conversely, the oxidizing solution is introduced from the upper portion of the reaction tank 27 and discharged from the bottom portion. The flow direction of the oxidizing solution in the reaction tank 27 may be a downward flow.

(8) Eighth Embodiment (Washing with Oxidizing Solution) ... FIG. 8 In addition to the configuration of the seventh embodiment, the eighth embodiment shown in FIG. 8 is designed to inject bubbles into the reaction tank. It is an embodiment configured as follows. That is, in FIG. 8, the scattering cylinder 13 having fine pores is installed at the bottom of the reaction tank 27.
The pressurized air generated by the external compressor 35 is injected into the oxidizing solution as fine bubbles from the scattering cylinder 13, and the ribbed electrode 2 fixed to the upper portion of the reaction tank 27 is used.
Contact with. In this case, the mechanical cleaning effect of fine air bubbles is added to the cleaning effect of the oxidizing solution passing through the gaps between the ribbed electrodes 2, so that more effective cleaning is performed and even finer polishing residue is obtained. It becomes possible to remove it sufficiently. In this configuration, in order to obtain the most effective cleaning effect, the scattering cylinders 13 should be installed as close as possible to the surface of the ribbed electrode 2 so that the ribbed electrode 2 is brought into contact with the ribbed electrode 2 in the form of finer bubbles. desirable.

(9) Ninth Embodiment (Washing with Oxidizing Solution) ... FIG. 9 In addition to the configuration of the seventh embodiment, the ninth embodiment shown in FIG. This is an example in which a sound wave oscillator 36 is installed. In the case of such a configuration, the ultrasonic cleaning effect of the ultrasonic waves generated by the ultrasonic transducer 36 is added to the cleaning effect of the oxidizing solution that passes through the gaps of the ribbed electrode 2, and Cavitation phenomenon occurs. Therefore, since the organic dirt and the polishing dust can be reliably peeled from the ribbed electrode 2, the organic dirt and the finer polishing dust can be sufficiently removed more effectively and in a shorter time.

(10) Tenth Embodiment (Contact with Oxidizing Gas and Water Cleaning) ... FIG. 10 In the tenth embodiment shown in FIG. 10, ozone is used as the oxidizing gas and ozone is brought into contact with the ribbed electrode. In this embodiment, the cleaning is performed with water after the cleaning. That is, FIG.
In the above, the ozonized gas containing ozone generated by the ozone generator 11 is pressurized by the pressure increasing device 41, and is applied to the surface of the ribbed electrode 2 from the gas ejection nozzle 42 arranged above the ribbed electrode 2. It is sprayed and comes into contact with the ribbed electrode 2. In this case, the ribbed electrode 2 is placed on the mesh-shaped gas contacting conveyor 16a, and after stopping at a predetermined cleaning position facing the gas ejection nozzle 42 for a certain time required for cleaning. , Sent to the next step. Then, by contacting the ribbed electrode 2 with the ozonized gas for a certain period of time, the organic stains on the ribbed electrode 2 are subjected to moderate oxidation to generate aldehydes, ketones, carboxylic acids, and the like, These products and polishing debris are removed by the cleaning effect of gas blowing.

In addition, on the upper part of the gas jet nozzle 42,
A hood 24 for collecting the ozonized gas after contacting the ribbed electrode 2 is arranged. That is, most of the ozonized gas after contacting the ribbed electrode 2 still has a sufficient oxidizing ability, and is collected by the hood 24, and after fine dust of polishing dust is removed by the gas filter 43. After being returned to the pipe in front of the booster 41 by the circulation blower 44 and joined with the ozonized gas, it is pressurized again by the booster 41 and is circulated for use. On the other hand, the ozonized gas, which has passed through the gap between the ribbed electrodes 2 and has a reduced oxidizing ability, flows into the receiving tank 45 arranged below the gas contacting conveyor 16a together with the polishing dust. Here, the exhaust gas filter 46 removes the fine dust of the polishing dust from the ozonized gas having the reduced oxidizing ability, and the exhaust ozone is decomposed by the exhaust ozone decomposing tube 25, and then the ozonized gas is exhausted to the atmosphere by the exhaust gas blower 26. Is released to. Further, the polishing residue removed from the ribbed electrode 2 by spraying the ozonized gas is the polishing residue storage unit 4 provided at the bottom of the receiving tank 45.
Dropped to 7 and discarded separately.

The ribbed electrode 2 that has been subjected to the gas contact treatment as described above is sent from the gas contact conveyor 16a to the water cleaning conveyor 16b and faces the water cleaning nozzle 48 at a predetermined cleaning position. Then, water is sprayed from the water washing nozzle 48 for a certain period of time. By this water washing, the intermediate oxidation products remaining on the ribbed electrode 2, that is, aldehydes, ketones, carboxylic acids and the like are washed and removed using water as a medium. Further, polishing debris remaining on the ribbed electrode 22 is similarly removed.

In this case, the water after water washing falls into the water receiving tank 17 arranged below the water washing conveyor 16b.
Then, among the oxides and polishing dust mixed in the water due to the cleaning, relatively large polishing dust particles stay in the settling section 19 of the water receiving tank 17 and settle at the bottom thereof, and are discharged from the precipitate discharge valve 21. It is processed separately. After removing the relatively large abrasive dust particles, the water in the water receiving tank 17 is sent from the supernatant section 20, filtered by the filter 22, and further sent to the water washing nozzle 48 by the circulation pump 23. , Is again sprayed on the surface of the ribbed electrode 2.

The method of this embodiment is preferably carried out under the following conditions. First, the oxidizing gas for contacting with the ribbed electrode 2 to oxidize organic stains and for cleaning the polishing dust by gas blowing is at least one of ozone, fluorine and chlorine, and more preferably ozone gas. Is. That is, ozone gas is
Among the above-mentioned oxidizing gases, it has the strongest oxidizing power next to fluorine, and the concentration can be easily controlled by changing the voltage of the ozone generator. Even though it is easily decomposed and rendered harmless, there is an advantage that it does not adversely affect the completed fuel cell. On the other hand, although fluorine gas has the strongest oxidizing power, it is difficult to handle. Also, chlorine gas is
Since it has a weak oxidizing power, it requires long-term treatment with a large amount of gas.

When an ozonized gas is used as the oxidizing gas as in this embodiment, the ozone concentration is
It is preferably at least 1 ppm or more. That is, when the concentration is 1 ppm or more, the higher the concentration, the more excellent the reactivity and the faster the reaction rate. However, if the concentration is too high, the amount of unreacted ozone increases and the efficiency deteriorates. Therefore, it is necessary to select an appropriate concentration in consideration of this point.

The contact time between the ribbed electrode 2 and the oxidizing gas, which is the time for blowing the oxidizing gas onto the ribbed electrode 2, must be at least 0.5 minutes, and is more preferable. Is about 1 to 5 minutes. That is, the longer the contact time, the more completely the reaction can be carried out, but the oxidation in the gas phase in this example is partial oxidation, which is a medium-grade oxide such as aldehyde, ketone and carboxylic acid. Are produced, and these oxides are washed and removed using water as a medium in the subsequent water washing step. Therefore, by a relatively short contact time of about 1 to 5 minutes,
The required moderate oxidation can be carried out. In addition, regarding the removal of the polishing dust clogging the ribbed electrode 2,
A relatively short contact time of about 5 minutes can sufficiently achieve the purpose.

Further, as in this embodiment, the method of spraying the oxidizing gas under pressure to the ribbed electrode 2 using the gas jet nozzle 42 and the booster 41 is the ribbed electrode 2
It is extremely effective as a method for effectively supplying an oxidizing gas to the above, and as described above, it is possible to obtain the cleaning effect by the gas, but more specifically, the gas jet nozzle 42 can be used as much as possible. By providing the ribbed electrode 2 close to and evenly disposing it, the oxidizing gas can be supplied most efficiently and a high cleaning effect can be obtained. In addition, it is more effective if the ribbed electrode 2 is inverted and double-sided.

The contact time between the ribbed electrode 2 and water, which is the time for spraying water on the ribbed electrode 2 in the subsequent water washing step, is similarly 1-5.
Minutes are desirable. By this contact time, it is possible to dissolve or suspend an acid such as an aldehyde, a ketone, or a carboxylic acid or an intermediate product generated in the gas contacting step of the first stage, and surely remove it. As a cleaning method in this water cleaning step, a method of spraying water on the ribbed electrode 2 by using the water cleaning nozzle 48 as in the present embodiment is extremely effective, but more specifically, By arranging the water washing nozzle 48 as close as possible to the ribbed electrode 2 and evenly arranging the ribbed electrode 2, washing can be performed most efficiently. More desirably, by spraying water on the ribbed electrode 2 from the water cleaning nozzle 48 in a pressurized state, more effective cleaning can be performed. In addition, it is more effective to invert the ribbed electrode 2 and wash both surfaces with water.

As described above, in the present embodiment, the oxidizing gas is sprayed onto the ribbed electrode by using the nozzle so that the organic dirt attached to the surface of the ribbed electrode is converted into oxidizing gas. The organic soil that has been partially oxidized in the gas phase due to the contact and partially oxidized is dissolved or suspended in water by the subsequent water washing step, and is easily and reliably removed. At the same time, the polishing dust clogged in the ribbed electrode is easily and surely removed by the cleaning effect by the gas spraying and the water cleaning effect.

As described above, according to the cleaning method of this embodiment,
Since the organic dirt adhering to the surface of the ribbed electrode can be sufficiently removed, in the thus cleaned ribbed electrode, combustion of the catalyst at the time of catalyst burning does not occur unlike the conventional case. Specifically, the number of occurrences of catalytic combustion for 1000 electrode treatments of the cleaned ribbed electrode of this example and the conventional non-cleaned ribbed electrode of this example was examined. The same result as the result of the first embodiment shown in Table 1 was obtained. That is, in the cleaned ribbed electrode of this example, no catalytic combustion occurred even after the treatment of 1000 electrodes.

Further, since the clogged polishing residue is sufficiently removed by the cleaning effect of the oxidizing gas and water,
Gas permeability is improved. Specifically, under a certain condition, the average value of the gas permeability of the cleaned ribbed electrode of the present example and the conventional ribbed electrode of the present example which was not cleaned was examined, Results similar to those of the first embodiment shown in Table 2 were obtained. That is, the cleaned ribbed electrode of this example had an improved transparency of about 14% on average as compared with the conventional ribbed electrode.

In addition to the above effects, it was confirmed that in the cleaned electrode with ribs of this example, surface hydrophilicity was improved and phosphoric acid wettability was improved. It is presumed that this is because the cleaning of the present example caused the surface of the carbon fiber, which is the base material of the ribbed electrode, to be oxidized by the oxidizing gas, so that hydrophilic groups such as hydroxyl groups and carboxyl groups were added to the surface. Specifically, the ribbed electrode of the present example,
Phosphoric acid wettability of the conventional non-cleaned ribbed electrode of this example was examined under the same conditions as in the first example, and the results of the first example shown in Table 3 above were obtained. Similar results were obtained. That is, the cleaned ribbed electrode of the present embodiment is about 1 compared to the conventional ribbed electrode.
The wettability of phosphoric acid was improved by 7%.

Further, as described above, in the cleaned ribbed electrode of this embodiment, the clogged polishing debris is sufficiently removed by the cleaning effect of the oxidizing gas and water. The distribution of phosphoric acid impregnated in was also improved, and it was confirmed that phosphoric acid was present almost uniformly.
That is, by performing the cleaning of this example, the polishing dust is sufficiently removed, so that the average pore diameter of the ribbed electrode is made uniform, and as a result, the phosphoric acid can be uniformly distributed.

(11) Eleventh embodiment (contact with oxidizing gas and washing with water) ... FIG. 11 In the eleventh embodiment shown in FIG. 11, an ultraviolet lamp is installed in addition to the structure of the tenth embodiment. This is an example. That is, in FIG. 11, an ultraviolet lamp 29 is installed between the gas ejection nozzle 42 and the ribbed electrode 2, and ultraviolet rays are emitted. When configured in this way, the first
In addition to the action and effect of Example 0, further, the irradiation of ultraviolet rays promotes the self-decomposition of ozone in the air to generate radicals such as oxygen radicals having a stronger oxidizing power,
These radicals accelerate the decomposition of organic stains. In this case, as described above, the radicals have a high activity and a short life. Therefore, it is desirable that the ultraviolet lamp 29 is installed as close to the surface of the ribbed electrode 2 as possible.

(12) Other Examples In each of the above examples, the method for cleaning the electrode with the fuel cell rib has been described, but the object of the present invention is:
The electrode is not limited to the fuel cell rib-equipped electrode, and is widely applicable as a general cleaning method for carbon material parts formed of a carbon material and subjected to a certain processing treatment. Is what you get.

[0079]

As described above, according to the method of the present invention, the carbon material part is washed with dissolved ozone or ozone-containing water containing ozonized gas bubbles or an oxidizing solution, or is oxidized. After contacting with a reactive gas, by washing with water, in particular, to prevent combustion at the time of catalyst burning in the ribbed electrode, to improve the gas permeability of the ribbed electrode,
Since the electrolyte such as phosphoric acid can be uniformly distributed, the electrode performance of the fuel cell can be improved and the life can be extended.

Further, the method of the present invention is not limited to electrodes with fuel cell ribs, but can be widely applied as a general cleaning method for carbon material parts that are subjected to a certain processing such as polishing. Also, it is possible to obtain an excellent effect.

[Brief description of drawings]

FIG. 1 is a process flow showing a first embodiment of a method for cleaning a carbon material component according to the present invention.

FIG. 2 is a processing flow showing a second embodiment of the method for cleaning a carbon material component according to the present invention.

FIG. 3 is a processing flow showing a third embodiment of the cleaning method for carbon material parts according to the present invention.

FIG. 4 is a processing flow showing a fourth embodiment of the cleaning method for carbon material parts according to the present invention.

FIG. 5 is a process flow showing a fifth embodiment of the method for cleaning a carbon material component according to the present invention.

FIG. 6 is a processing flow showing a sixth embodiment of the method for cleaning a carbon material component according to the present invention.

FIG. 7 is a processing flow showing a seventh embodiment of the cleaning method for carbon material parts according to the present invention.

FIG. 8 is a processing flow showing an eighth embodiment of the cleaning method for carbon material parts according to the present invention.

FIG. 9 is a processing flow showing a ninth embodiment of the cleaning method for carbon material parts according to the present invention.

FIG. 10 is a first method of cleaning a carbon material component according to the present invention.
The processing flow which shows 0 Example.

FIG. 11 is a first method of cleaning a carbon material component according to the present invention.
The process flow which shows 1 Example.

FIG. 12 is a vertical cross-sectional perspective view showing a unit cell of a fuel cell including a ribbed electrode.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Matrix 2 ... Rib electrode 2a ... Flow path 3 ... Unit cell 4 ... Gas separation plate 11 ... Ozone generator 12 ... Ozone absorption tower 13 ... Dispersion cylinder 14 ... Liquid feed pump 15 ... Nozzle 16, 16a, 16b ... Conveyor 17 ... Water tank 18 ... Partition plate 19 ... Sedimentation part 20 ... Supernatant part 21 ... Sediment discharge valve 22 ... Filter 23 ... Circulation pump 24 ... Hood 25 ... Exhaust ozone decomposition cylinder 26 ... Exhaust gas blower 27 ... Reaction tank 28 ... Sealing material 29 ... Ultraviolet lamp 31 ... Exhaust gas treatment cylinder 32 ... Oxidizing solution tank 33 ... Chemical injection pump 34 ... Overflow pipe 35 ... Compressor 36 ... Ultrasonic transducer 41 ... Booster device 42 ... Gas ejection nozzle 43 ... Gas filter 44 ... Circulation blower 45 ... Receiving tank 46 ... Exhaust gas filter 47 ... Abrasive waste storage 48 ... Water cleaning nozzle

Claims (4)

[Claims] 1. A method for cleaning a carbon material part formed of a carbon material and subjected to a certain processing treatment, wherein the carbon material part is cleaned with ozone-containing water containing dissolved ozone or ozonized gas bubbles. And a method for cleaning a carbon material component. 2. A method of cleaning a carbon material part, which is formed of a carbon material and which has been subjected to a certain processing treatment, wherein the carbon material part is cleaned with an oxidizing solution. Method. 3. A method of cleaning a carbon material part formed of a carbon material and subjected to a certain processing treatment, wherein the carbon material part is brought into contact with an oxidizing gas and then washed with water. Cleaning method for carbon material parts. 4. The carbon material component is a fuel cell rib-equipped electrode that constitutes a unit cell of a fuel cell by arranging a pair of electrodes with a matrix containing an electrolyte interposed therebetween. The method for cleaning a carbon material component according to claim 1, 2 or 3, wherein each of the cleaning agents has a groove for flowing the agent.