KR100770166B1 - Apparatus for manufacturing source particles of separator for fuel cell and method of manufacturing source particles of separator for fuel cell by using the same - Google Patents

Abstract

An apparatus for preparing starting material powder for a bipolar plate for a fuel cell is provided to maximize the mixing efficiency in a mixing assembly, thereby improving particle size uniformity of the starting material powder and minimizing agglomeration of particles, and to impart improved durability to a bipolar plate. An apparatus for preparing starting material powder for a bipolar plate for a fuel cell comprises: a processing chamber(100) for receiving a mixed solution containing starting materials for a bipolar plate for a fuel cell and a solvent, and for transferring heat to the mixed solution; a mixing assembly(300) connected to a region of the processing chamber and including at least two rotatable agitators(330,350); and a depressurizing unit(500) connected to the processing chamber so as to reduce the pressure in the processing chamber.

Description

Apparatus for manufacturing source particles of separator for fuel cell and method of manufacturing source particles of separator for fuel cell by using the same}

1 is a conceptual cross-sectional view showing an apparatus for preparing a raw material powder for a separator plate for a fuel cell according to an embodiment of the present invention.

FIG. 2 is a perspective view illustrating the first stirrer of FIG. 1.

3 is a perspective view illustrating the second stirrer of FIG. 1.

Figure 4 is a graph showing the results of reaction heat analysis using a differential scanning calorimetry of Examples and Comparative Examples.

<Short description of the symbols in the drawings>

100: process chamber 110: first chamber

120: second chamber 300: mixing assembly

330: first stirrer 332: fixed portion

334: connection portion 337: stirring portion

350: second stirrer 500: pressure reducing device

600: temperature control device 700: rotation speed control device

1000: raw material powder manufacturing apparatus for fuel cells

The present invention relates to a fuel cell separator raw material powder manufacturing apparatus and a fuel cell separator plate raw material powder manufacturing method using the same, and more particularly, to simplify the powder manufacturing process and improve the particle size uniformity of the raw material powder produced. The present invention relates to a fuel cell separator plate raw material powder production apparatus and a fuel cell separator plate raw material powder manufacturing method using the same.

In general, a fuel cell can produce a high power by stacking unit cells in multiple layers to produce a stack, which is composed of a polymer solid electrolyte, a gas diffusion layer, a catalyst layer, and a separator. do. In order to obtain high power, a large number of unit cells must be stacked, and the bending strength of the separator must be excellent for stable stack fastening.

To this end, the particle size uniformity of the raw material powder used in forming the separator plate should be ensured.

Meanwhile, as the raw material for the separator, a mixed material made of a polymer resin, a carbon material, and other additives is used.

Conventionally, the raw material powder was prepared by dissolving the raw materials in a solvent, mixing them using a mixer, and then drying the mixed solution in a vacuum oven and then grinding.

However, in the drying process using a vacuum oven as described above, due to the separation of the layer between the carbon material and the polymer solution, the solution may not only be mixed unevenly, but also due to the loss of the sample and the inflow of impurities through various processes. Pollution may result.

The object of the present invention is to account for the above-described problems, it is possible to manufacture the raw material powder for fuel cell separator plate excellent in particle size uniformity and can be processed by a batch process to reduce the process time and to prevent the loss and contamination of raw materials It is to provide a fuel cell separator plate raw material powder production apparatus that can be.

Another object of the present invention relates to a method for producing a separator plate raw material powder for a fuel cell capable of ensuring particle size uniformity of the separator plate raw material powder.

The separator raw material powder manufacturing apparatus for a fuel cell according to an aspect of the present invention includes a process chamber for accommodating a mixed solution consisting of a separator material for fuel cells and a solvent and transferring heat to the mixed solution, in one region of the process chamber. A mixing assembly connected to the process chamber, the mixing assembly comprising at least two rotatable agitators, and a pressure reducing device connected to the process chamber to reduce pressure within the process chamber.

The process chamber is constituted by a combination of two subchambers having a separate structure, and the process chamber is insulated.

The mixing assembly is directly connected to the process chamber and includes a main rotational portion that is rotatable relative to the process chamber, and the stirrer is connected to the main rotational portion so as to be rotatable with respect to the main rotational portion.

The first stirrer was designed primarily for the agitation of the mixed solution (for wet mixing), and the second stirrer was designed primarily for the agitation of the residue, the solids from which solvent components were removed from the mixed solution (for dry mixing).

Each of the mixing assemblies may include a pair of first and second stirrers, and a water-sealed pump is used as the decompression device.

The manufacturing apparatus may further include a temperature control device for adjusting the temperature of the process chamber, and a rotational speed control device for adjusting the rotational speed of the mixing assembly and the stirrer.

In order to produce a fuel cell separator raw material powder according to an aspect of the present invention, first, a mixed solution composed of a fuel cell separator raw material and a solvent is prepared. The mixed solution is stirred first under heating and reduced pressure using a first stirrer to volatilize the solvent component of the mixed solution. Subsequently, when the solvent component starts to volatilize while the first stirring is continued, the second stirring is performed while preventing the agglomeration of the raw materials by using a second stirrer different from the first stirrer. Through the above process, the mixed solution is transformed into a separator raw material powder having a uniform particle size distribution.

The first and second stirring may be separated in time, or alternatively, the two stirring steps may be made to overlap each other in time.

Hereinafter, with reference to the accompanying drawings will be described an apparatus and a method for manufacturing a raw material powder for a separator cell according to an embodiment of the present invention.

1 is a conceptual cross-sectional view showing an apparatus for preparing a raw material powder for a separator plate for a fuel cell according to an embodiment of the present invention. FIG. 2 is a perspective view illustrating the first stirrer of FIG. 1. 3 is a perspective view illustrating the second stirrer of FIG. 1.

Referring to FIG. 1, a separator plate raw material powder manufacturing apparatus 1000 for a fuel cell may include a process chamber 100, a mixing assembly 300, a pressure reduction device 500, a temperature control device 600, and a rotation speed control device 700. It includes.

The process chamber 100 accommodates a mixed solution composed of a raw material material and a solvent for a fuel cell, and provides a space in which the mixed solution is powdered. The mixed solution may be premixed outside the process chamber 100, but may be initially mixed in the process chamber 100 by supplying raw materials and a solvent to the process chamber 100, respectively. have.

The mixed solution contained in the process chamber 100 is powdered by a batch process under heating and depressurizing conditions.

The process chamber 100 is substantially coupled to the first chamber 110 containing the mixed solution and the first chamber 110 so that the process chamber 100 can be isolated from the external gas. 120.

The first chamber 110 and the second chamber 120 are firmly coupled to each other so that gas is introduced from the outside during the powdering process so as not to dilute the reduced pressure inside.

The first chamber 110 has a triple structure consisting of an inner wall, an outer wall, and a heat medium jacket disposed between the inner wall and the outer wall. The inner wall and the outer wall is preferably made of a material such as stainless steel having a high corrosion resistance in order to prevent corrosion from the mixed solution or the influence of the outside.

The heat medium jacket contains a material having a large heat capacity such as mineral oil type or synthetic oil type (alkylbenzene) heat medium oil, thereby preventing heat inside the process chamber 100 from being released to the outside. That is, the process chamber 100 is maintained insulated as a whole.

In addition, in the present exemplary embodiment, the first chamber 110 has a structure in which the width of the first chamber 110 does not change even if it goes toward the bottom surface (lower side). Alternatively, the first chamber 110 has a width narrowing toward the bottom surface. May have various shapes.

That is, at the level of those skilled in the art, the structure of the first chamber 110 may be variously modified so that the separator raw material material in the mixed solution may be dispersed in the solution as a whole.

In the present embodiment, since only the first chamber 110 has a thermal contact relationship with the mixed solution substantially, it has a triple structure. Alternatively, the second chamber 120 may also have a triple structure.

The mixing assembly 300 is rotatably connected to the ceiling surface of the second chamber 120. The mixing assembly 300 sufficiently mixes the mixed solution contained in the process chamber 100 and the residue after the solvent component is volatilized by heating / decompression and further prevents agglomeration of the residue. The mixing assembly 300 rotates at a predetermined speed with respect to the ceiling surface of the second chamber 120 during the process.

Therefore, the particle size uniformity of the raw material powder for the fuel cell separator, which is the final product, can be greatly improved.

The mixing assembly 300 is connected to the main rotating part 310 so as to be rotatable with respect to the main rotating part 310 and the main rotating part 310 which is rotatably connected to the ceiling surface of the second chamber 120. It includes a first stirrer 330 and a second stirrer 350 connected to the main rotator 310 so as to be rotatable about the main rotator 310. The first stirrer 330 and the second stirrer 350 have a different form and have a difference in a main function performed.

The first stirrer 330 induces uniform dispersion of the raw material powder of the separator plate in the mixed solution. The first stirrer 330 may be rotated at a predetermined speed with respect to the main rotating unit 310 while the main rotating unit 310 rotates, thereby maximizing uniform dispersion of the mixed solution.

Referring to FIG. 2, the first stirrer 330 includes a fixing part 332, a stirring part 337, and a connecting part 334.

The fixing part 332 is rotatably connected to the main rotating part 310, and the connecting part 334 is fixed to both ends of the fixing part 332, respectively. In addition, the connecting portion 334 is composed of two and are arranged to be staggered (twisted) to each other are coupled to both ends of the stirring portion (337).

The stirring unit 337 serves to substantially agitate the mixed solution. However, the two twisted connections 337 also help induce uniform dispersion of the mixed solution.

In the present embodiment, a structure in which the fixing part 332 and the stirring part 337 are connected by the connecting parts 337 disposed to cross each other is described, but the first stirrer 330 provides uniform dispersion of the mixed solution. As long as it can be efficiently derived, it may have various forms different from the above structure. That is, the first stirrer 330 may be referred to as a wet mixing stirrer used for uniform dispersion of the mixed solution.

The second stirrer 350 promotes solids floating while the solids are dried, thereby preventing aggregation of the solids. Thus, the resulting separator raw material powder particles have a uniform particle size distribution.

Referring to FIG. 3, the second stirrer 350 has a spiral impeller shape.

Therefore, as described above, the residues of the mixed solution in which the solvent is volatilized can be effectively suspended, thereby effectively blocking the aggregation of the residues. Specifically, by moving the lower residue to the upper and falling back down, the aggregated residue can be spaced apart from each other.

Although the second stirrer 350 having a spiral impeller shape is illustrated in the present embodiment, various forms may be employed as the second stirrer 350 as long as the second stirrer 350 has an effective structure for preventing aggregation of solid content.

As such, the second stirrer 350 mainly operates to prevent aggregation of dried solids. That is, the second stirrer 350 may be referred to as a dry mixing stirrer unlike the first stirrer 330 described above. The second stirrer 350 may also exhibit a dual rotational effect by rotating the mixing assembly 300 as well as rotating as a whole.

In this embodiment, the first stirrer 330 is mainly used continuously during the process, and the second stirrer 350 is used after the solvent component in the mixed solution starts to volatilize (just after the water pump operation).

Although not shown, the mixing assembly 300 according to the present embodiment includes two first stirrers 350 and second stirrers 350, respectively. That is, each stirrer 330, 350 is provided in pairs.

In addition, the same stirrer 330 or 350 is arrange | positioned so that it may mutually not face each other. This is to maximize the stirring efficiency.

In the present embodiment, the first stirrer 330 in the mixed solution state, the second stirrer 350 is operated in the solid state state, but the temporal operating range of each of the stirrers 330 and 350 is determined by the operator's intention. It can vary accordingly. In addition, the rotation (idle) of the entire mixing assembly 300 may also be continuously made during the entire powdering process, and may be variously changed according to the intention of the operator such as pausing at a specific stage.

That is, the revolution of the mixing assembly 300 and the rotation of the respective agitators 330 and 350 may be designed in various operation combinations and applied to the powdering process.

In particular, in the time zone mainly between the first stirring step by the first stirrer 330 and the second stirring step by the second stirrer 350, the first stirrer 330 and the second stirrer 350 are simultaneously It is desirable to work.

In order to dry the mixed solution, a vacuum drying method is used. That is, while reducing the pressure in the process chamber 100 and at the same time heating can effectively volatilize the solvent component in the mixed solution.

Referring back to FIG. 1, the separator cell raw material powder production apparatus for a fuel cell according to the present embodiment includes a decompression device 500. The decompression device 500 is connected to the process chamber 100 to lower the pressure in the process chamber 100, thereby lowering the vapor pressure of the mixed solution so that vaporization can occur easily at a relatively low temperature. do.

 The decompression device 500 is connected to one region of the second chamber 120 of the process chamber 100. This is because the generated volatile solvent moves to the top of the process chamber 100.

In this embodiment, a water-sealed (vacuum) pump is used as the decompression device 500.

The water-sealed pump has been mainly used as a vacuum pump or a compressor in a pressure range near atmospheric pressure together with a vane pump, a ROOTS pump, and the like. It pumps by turning the water in the casing and pumps it. It has the advantage that there is no risk of failure in liquids or powders such as water, aqueous solution, and oil contained in the intake gas, and it is widely used in the paper industry, the labor industry, and the cement industry. Is used. It also plays an important role as a lake pump for large centrifugal pumps.

Particularly the above-mentioned water-sealed pump is suitable because a large amount of volatile solvent is discharged during the raw material powdering process of the separator plate for fuel cell. The submersible pump is very useful for discharging such a large amount of gas.

 The raw material powder manufacturing apparatus 1000 according to the present embodiment includes a temperature control device 600 and a rotation speed control device 700.

The temperature control device 600 and the rotational speed control device 700 are each disposed outside the process chamber 100.

The temperature control device 600 may variably control the temperature inside the process chamber 100, for example, to allow the operator to easily control the temperature through a computer screen.

In addition, the rotation speed adjusting device 700 allows the operator to remotely control the process speed of the mixing assembly 300, the rotation speed of the first stirrer 330, and the rotation speed of the second stirrer 350.

Hereinafter, a result of actually manufacturing a raw material powder for a separator for a fuel cell by a manufacturing apparatus and a manufacturing method according to the present invention will be described. However, the technical spirit of the present invention is not limited by the following examples. In addition, to compare with the present invention will also be described with the raw material powder production results by a conventional apparatus and method.

Example

The above-described artificial graphite powder having an average particle diameter of 75 μm and an aspect ratio of particles of 1.5 and carbon having a surface area of 50 to 100 m ² / g using the separator raw material powder manufacturing apparatus for fuel cell according to the present invention. Using a black, liquid epoxy / phenol resin and a release agent, the mixing weight ratio was mixed at a ratio of 75% of a carbon material and 25% of a polymer resin. The average particle diameter of the final obtained powder prepared using the above production apparatus was about 150 µm, and the particle size distribution uniformity was about 0.3, thereby obtaining a very uniform raw material powder. As a result of analysis using differential scanning calorimetry (DSC), it was confirmed that the mixture uniformity of the carbon material and the polymer resin was excellent because of excellent reactivity of about 40 ~ 50 J / g. (See Figure 4)

When the separator was formed at 175 ° C., 14.2 MPa, and 10 minutes using the raw material powder thus prepared, the thickness of the separator was found to be suitable for fuel cell stack production within 50 μm.

Comparative example

After wet mixing with the same composition as in the above embodiment, drying was carried out in a vacuum oven, and raw material powder was prepared by a process of grinding using a universal mill. The average particle diameter of the powder thus prepared was about 70 μm, and the uniformity of the particle size distribution was about 0.8, which showed very uneven particle size distribution. DSC analysis showed a weak reactivity of about 15-25 J / g, indicating that the mixing uniformity of the raw material powder was low. (See Figure 4)

As a result of the separation plate molding under the same conditions as in the above example using the raw material powder prepared as described above, it was confirmed that there is a possibility of causing a problem in manufacturing the fuel cell stack with a thickness variation of about 100 to 120 μm.

As described above, the raw material powder manufacturing apparatus for fuel cells according to the present invention is not only designed to operate in accordance with the characteristics of each process step by providing a heterogeneous stirrer, but also the mixing efficiency due to the revolution of the mixing assembly and the rotation of each stirrer. It can be maximized, it is possible to improve the particle size uniformity of the raw material powder to be produced and to minimize the aggregation between the particles.

In addition, according to the above apparatus, the raw material powder manufacturing process can be collectively processed to increase the process efficiency, as well as to significantly reduce the loss and contamination of the raw material powder during the process.

The raw material powder produced by the manufacturing apparatus and the manufacturing method according to the present invention has excellent particle characteristics, and thus, it is possible to improve the durability of the separator for fuel cell, which is a final molded product.

As described above, the present invention has been described by way of limited embodiments and drawings, but the present invention is not limited to the above embodiments, and those skilled in the art to which the present invention pertains various modifications and variations from such descriptions. This is possible. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the claims below but also by the equivalents of the claims.

Claims (12)

A process chamber for receiving a mixed solution composed of a raw material material and a solvent for a fuel cell and transferring heat to the mixed solution; A mixing assembly connected to one region of the process chamber and including at least two rotatable agitators; And And a decompression device connected to the process chamber to reduce the pressure in the process chamber. According to claim 1, The process chamber comprises a first chamber for containing a mixed solution and a second chamber coupled to the first chamber to block the process chamber from the outside, characterized in that the fuel cell separator plate raw material powder manufacturing apparatus. The method of claim 1, The mixing assembly is connected directly to the process chamber and includes a main rotational part rotatable with respect to the process chamber, wherein the stirrer is connected to the main rotational part so as to be rotatable with respect to the main rotational part Separator raw material powder manufacturing device. The method of claim 1, The mixing assembly, Separator raw material powder production apparatus for a fuel cell comprising a wet stirrer and a dry stirrer a second stirrer. The method of claim 4, wherein The first stirrer, A fixed part directly connected to the main rotating part to be rotatable; An agitator disposed parallel to the bottom surface of the process chamber and configured to stir the mixed solution; And Separator raw material powder manufacturing apparatus for a fuel cell, characterized in that it comprises a connecting portion of the two strands connected to the fixing portion and the agitator and twisted with each other. The method of claim 4, wherein Separator raw material powder production apparatus for a fuel cell, characterized in that the second stirrer has a spiral impeller (impeller) shape. The method of claim 4, wherein The mixing assembly is a fuel cell separation plate raw material powder manufacturing apparatus, characterized in that each comprises a pair of first stirrer and a pair of stirrers. The method of claim 7, wherein Separator raw material powder manufacturing apparatus for a fuel cell, characterized in that the first stirrers are connected to the main rotating part to face each other. The method of claim 1, Separator raw material powder production apparatus for a fuel cell, characterized in that the decompression device is a water-sealed pump. Preparing a mixed solution comprising a raw material and a solvent for a separator plate for a fuel cell; A first stirring step of volatilizing the solvent component of the mixed solution by stirring the mixed solution under heating and reduced pressure using a first stirrer; And And a second stirring step of preventing agglomeration of the raw materials by stirring immediately after the solvent component begins to volatilize using a first stirrer and a second stirrer. The method of claim 10, The first stirring step is a fuel cell separation plate raw material powder manufacturing method, characterized in that the continuing during the powder manufacturing process. The method of claim 10, The second stirrer has a spiral impeller (impeller) shape, characterized in that the fuel cell separation plate raw material powder manufacturing method.

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