JP2009179816A - Carburizing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a carburizing apparatus for performing the carburization by feeding carrier gas mainly consisting of CO gas and enriched gas mainly consisting of hydrocarbon gas in a carburization chamber with a workpiece being led therein, which is capable of reducing the amount of carrier gas to be fed in the carburization chamber by adequately exhausting hydrogen gas contained in atmospheric gas in the carburization chamber and suppressing generation of CO<SB>2</SB>gas associated with combustion of carrier gas. <P>SOLUTION: A carburizing apparatus includes a carburization chamber 3 for carburizing a workpiece A, and gas feeding devices 4, 5 for feeding carrier gas mainly consisting of CO gas and enriched gas mainly consisting of hydrocarbon gas into the carburization chamber, and further includes a circulation passage 10 for taking out atmospheric gas in the carburization chamber and circulating the gas therein. A hydrogen gas separation device 20 is provided in the circulation passage, which separates and takes out hydrogen gas contained in the atmospheric gas. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to a carburizing apparatus for carburizing a processing material such as steel parts, and in particular, a carburizing chamber for carburizing the processing material, a carrier gas mainly composed of CO gas, and a hydrocarbon in the carburizing chamber. In a carburizing apparatus having a gas supply device that supplies an enriched gas containing gas as a main component, a carrier gas that appropriately discharges hydrogen gas contained in the atmospheric gas in the carburizing chamber and supplies it to the carburizing chamber This is characterized in that the amount of carbon dioxide is reduced and the generation of CO ₂ gas accompanying the combustion of the carrier gas is suppressed.

  Conventionally, in order to increase the strength of treatment materials made of steel parts such as low carbon steel and low alloy steel, carburization treatment for diffusing and penetrating carbon from the surface of these treatment materials has been performed.

  And when carburizing the processing materials such as steel parts in this way, various carburizing apparatuses have been used conventionally.

  Here, for example, in the carburizing apparatus shown in FIG. 1, the first door 1a is opened to guide the processing material A into the introduction chamber 2, and the first door 1a is closed to adjust the atmosphere in the introduction chamber 2. After that, the treatment material A introduced into the introduction chamber 2 in this way is opened into the carburizing treatment chamber 3 by opening the second door 1b, and the second door 1b is closed.

Then, with the treatment material A introduced into the carburizing chamber 3 as described above, the carrier gas containing CO gas as a main component is adjusted into the carburizing chamber 3 while adjusting the flow rate by the flow rate adjusting valve 4a. In addition to being led through the gas supply pipe 4, the enriched gas mainly composed of hydrocarbon gas C _n H _{2n + 2} such as propane gas or butane gas is led through the enriched gas supply pipe 5 while adjusting the flow rate by the flow rate regulating valve 5a. In the carburizing chamber 3, the carrier gas and the enriched gas are agitated by the agitating fan 6, and the treating material A introduced into the carburizing treatment chamber 3 is heated so that the surface of the treating material A has carbon. Thus, the carbon applied to the surface of the treatment material A is diffused into the treatment material A and carburized.

Here, when carbon is added to the treatment material A and carburized in the carburizing chamber 3 supplied with the carrier gas and the enriched gas, generally 2CO → CO ₂ + (C), C _n H _{2n + 2} + nCO ₂ → 2nCO + (n + 1) H ₂ reaction occurs to generate hydrogen gas in the carburizing chamber 3, and the hydrogen concentration thus generated causes the relative concentration of CO in the carburizing chamber 3 to be relatively high. There is a problem that the control of the carburizing atmosphere by the carbon potential is distorted.

  For this reason, conventionally, as shown in Patent Document 1 and the like, excess carrier gas is supplied into the carburizing chamber 3 through the carrier gas supply pipe 4, and the hydrogen gas generated in the carburizing chamber 3 is supplied as described above. Together with the carrier gas, the gas is introduced into the introduction chamber 2 through the gap of the second door 1b between the carburizing chamber 3 and the introduction chamber 2, and the gas thus introduced into the introduction chamber 2 is introduced into the introduction chamber 2. 2 is conducted to the exhaust passage 2a provided in the combustion chamber 2 and burned.

However, since the carrier gas containing CO gas as a main component is excessively supplied into the carburizing chamber 3 as described above, the running cost is high and the gas introduced into the introduction chamber 2 as described above is exhausted from the exhaust path. When led to 2a and burned, there was a problem that a lot of CO ₂ was generated and the environment was harmed.
JP 2001-214255 A

  This invention makes it a subject to solve the above problems in the carburizing apparatus which carburizes a process material.

That is, in the present invention, a carburizing chamber for carburizing the processing material, and a gas supply device for supplying a carrier gas mainly composed of CO gas and an enriched gas mainly composed of hydrocarbon gas into the carburizing chamber. In the carburizing apparatus provided with the above, the hydrogen gas contained in the atmospheric gas in the carburizing chamber is appropriately discharged, the amount of carrier gas supplied to the carburizing chamber is reduced, and CO ₂ gas is generated. It is a problem to suppress.

  In the present invention, in order to solve the above-described problems, a carburizing chamber for carburizing a treatment material, and an enrichment mainly composed of a carrier gas mainly composed of CO gas and a hydrocarbon gas in the carburizing chamber. In the carburizing apparatus having a gas supply device for supplying gas, a circulation path for taking out and circulating the atmospheric gas containing hydrogen gas in the carburizing process chamber from the carburizing process chamber is provided, and A hydrogen gas separation device for separating and taking out hydrogen gas contained in the atmospheric gas was provided.

  Here, in the hydrogen gas separation device, for example, a hydrogen permeation filter that selectively permeates hydrogen gas can be used, and a suction device is connected to the hydrogen gas separation device using the hydrogen permeation filter, The hydrogen gas contained in the atmospheric gas guided to the hydrogen gas separation device can be separated and taken out.

  In the carburizing apparatus according to the present invention, a circulation path for extracting and circulating the atmospheric gas containing hydrogen gas in the carburizing chamber is provided and separated from the hydrogen gas contained in the atmospheric gas in the circulation path. Since the hydrogen gas separation device to be taken out is provided, the atmospheric gas containing the hydrogen gas generated in the carburizing chamber during the carburizing process as described above is led to the hydrogen gas separation device through the circulation path, and this hydrogen gas separation device Thus, the hydrogen gas is separated from the atmospheric gas and taken out, while the remaining atmospheric gas is returned to the carburizing chamber.

For this reason, in the carburizing apparatus according to the present invention, it is not necessary to supply excess carrier gas into the carburizing chamber in order to discharge the hydrogen gas generated during the carburizing process from the carburizing chamber as in the prior art. In addition, as in the case where atmospheric gas containing hydrogen gas is introduced into the exhaust passage and burned, a large amount of CO ₂ is not generated to harm the environment.

  Hereinafter, a carburizing apparatus according to an embodiment of the present invention will be specifically described with reference to the accompanying drawings. Note that the carburizing apparatus according to the present invention is not limited to the one shown in the following embodiments, and can be implemented with appropriate modifications within a range not changing the gist of the invention.

  In the carburizing apparatus in this embodiment, as shown in FIGS. 2 to 4, the vacuum pump 30 is provided via exhaust pipes 32 a and 32 b provided with opening / closing valves 31 a and 31 b in the introduction chamber 2 and the carburizing chamber 3, respectively. Is attached.

  And in the carburizing apparatus in this embodiment, as shown in FIG. 2, in the state which closed the 1st door 1a and the 2nd door 1b, the on-off valve 31b in the exhaust pipe 32b connected to the carburizing process chamber 3 is provided. Opened, the atmospheric gas in the carburizing chamber 3 is sucked by the vacuum pump 30 to bring the carburizing chamber 3 into a state close to a vacuum, and then the first door as shown in FIG. After opening 1a and introducing the processing material A into the introduction chamber 2, the first door 1a is closed.

  Then, after the treatment material A is guided into the introduction chamber 2 in this way, the on-off valve 31a in the exhaust pipe 32a connected to the introduction chamber 2 is opened, and the atmospheric gas in the introduction chamber 2 is caused to flow by the vacuum pump 30. Suction is performed to bring the inside of the introduction chamber 2 close to a vacuum, and in this state, the second door 1b is opened, and the processing material A introduced into the introduction chamber 2 is introduced into the carburizing treatment chamber 3. After the second door 1b is closed, the on-off valve 31b in the exhaust pipe 32b connected to the carburizing chamber 3 is closed.

Then, with the treatment material A introduced into the carburizing chamber 3 and the on-off valve 31b closed as shown in FIG. 4, the carburizing chamber 3 has a carrier mainly composed of CO gas as shown in FIG. The gas is guided through the carrier gas supply pipe 4 while adjusting the flow rate by the flow rate adjusting valve 4a, and the enriched gas mainly composed of hydrocarbon gas C _n H _{2n + 2} such as propane gas or butane gas is flowed by the flow rate adjusting valve 5a. The gas is guided through the enriched gas supply pipe 5 while adjusting the above.

  Then, the carrier gas and the enriched gas thus supplied into the carburizing chamber 3 are stirred in the carburizing chamber 3 by the stirring fan 6 and the processing material A is heated in the carburizing chamber 3. Thus, carbon is imparted to the surface of the treatment material A, and the carbon thus imparted to the surface of the treatment material A is diffused into the treatment material A to be carburized. When the treatment material A is carburized in this way, hydrogen gas is generated in the carburizing chamber 3 as described above.

  Here, in the carburizing apparatus according to this embodiment, a circulation path 10 is provided for extracting and circulating the atmospheric gas containing hydrogen gas generated in the carburizing process chamber 3 from the carburizing process chamber 3, and this circulation path. 10 is provided with a circulation pump 11 that sucks and circulates the atmospheric gas in the carburizing chamber 3, and opens an extraction valve 12 provided on the upstream side of the circulation path 10 for extracting the atmospheric gas from the carburizing chamber 3. Thus, the atmospheric gas containing hydrogen gas in the carburizing chamber 3 is guided into the circulation path 10.

  Then, after the atmospheric gas including the hydrogen gas introduced into the circulation path 10 is guided to the cooling device 13 and cooled, the atmospheric gas including the hydrogen gas thus cooled is supplied to the hydrogen gas separation device 20. Thus, the hydrogen gas separation device 20 separates and takes out the hydrogen gas contained in the atmospheric gas.

  Here, in this hydrogen gas separation device 20, as shown in FIG. 5, a hydrogen permeation filter 22 formed into a cylindrical shape using a hollow fiber that selectively permeates hydrogen gas is used. , (B), a pair of holding plates 25 provided with a plurality of vent holes 25a in the container 21 of the hydrogen gas separation device 20 are provided at a required interval, and between the pair of holding plates 25. A plurality of the hydrogen permeable filters 22 having the above-described cylindrical shape are provided so as to communicate with the vent holes 25a.

The atmosphere gas containing the hydrogen gas is guided to the inside of the hydrogen permeable filter 22 formed in a cylindrical shape, and a suction device 24 including a vacuum pump is connected to the hydrogen gas separation device 20 through a hydrogen gas guide tube 23. The atmospheric gas introduced into the hydrogen permeable filter 22 is sucked from the periphery of the hydrogen permeable filter 22 by the suction device 24, and the hydrogen gas contained in the atmospheric gas is selectively permeated to the hydrogen. The hydrogen gas is guided through the filter 22 to the hydrogen gas guide tube 23, and the hydrogen gas is discharged through the hydrogen gas guide tube 23. The hydrogen gas discharged through the hydrogen gas guide tube 23 can be burned or used as a hydrogen gas raw material. In addition, since the content of CO gas or the like is very small in the hydrogen gas, almost all water is produced when it is burned, and CO ₂ gas or the like is generated. Is prevented.

  Then, the atmospheric gas from which the hydrogen gas has been removed by the hydrogen gas separation device 20 as described above is guided to return to the carburizing chamber 3 through the circulation path 10, and the return gas provided on the return side of the circulation path 10. The valve 14 is opened to return the atmospheric gas from which the hydrogen gas has been removed as described above to the carburizing chamber 3.

  Thus, the atmosphere gas containing a large amount of CO gas or the like is removed from the hydrogen gas and returned to the carburizing chamber 3, and the carrier is supplied into the carburizing chamber 3 through the carrier gas supply pipe 4. The amount of gas can be greatly reduced, the running cost is greatly reduced, and the atmosphere that leaks to the outside from the carburizing chamber 3 with the inside of the carburizing chamber 3 in a sealed state or close to a sealed state. The amount of gas can be greatly reduced.

  Also, the inside of the carburizing chamber 3 is in a sealed state or close to a sealed state, and the inside of the carburizing chamber 3 is in a vacuum state as described above. When the carburizing chamber 3 is not exposed to the atmosphere, the carburizing chamber 3 is brought into a vacuum state as described above at the start of the next operation. Carrier gas and enriched gas can be supplied into the processing chamber 3. For this reason, it is not necessary to perform a troublesome operation (so-called seasoning) of supplying all the atmospheric gas in the carburizing chamber 3 by supplying new gas into the carburizing chamber 3, and the time at the start of the next operation Can be shortened.

  The method for preventing the atmospheric gas in the carburizing chamber 3 from leaking from the second door 1b is not particularly limited. For example, a heat-resistant packing (not shown) or the like is provided on the second door 1b. Can be provided.

Further, in order to efficiently perform the carburizing treatment of the treatment material A in the carburizing treatment chamber 3, when the carrier gas or the like is excessively supplied into the carburizing treatment chamber 3, as shown in FIG. An exhaust pipe 7 provided with a flow rate adjusting valve 7a in the carburizing chamber 3 is provided in the carburizing chamber 3 so that a part of the atmosphere gas containing hydrogen gas in the carburizing chamber 3 is discharged from the carburizing chamber 3 to the outside. It is also possible to burn a part of the atmospheric gas including hydrogen gas provided to the exhaust pipe 7. Even when a part of the atmospheric gas including the hydrogen gas guided to the exhaust pipe 7 is burned as described above, the amount of the atmospheric gas including the hydrogen gas guided to the exhaust pipe 7 is much higher than that of the conventional case. Therefore, the amount of generated CO ₂ gas is greatly reduced.

Here, while using the hydrogen gas separation apparatus using a plurality of hydrogen permeation filters as described above, as shown in Table 1 below, the CO gas is 24.13 vol% and the CO ₂ gas is 0.398 vol. %, CH ₄ gas 0.497% by volume, hydrogen gas 32.0% by volume, and the atmospheric gas flow adjusted to the above gas composition is used. An experiment was conducted in which the flow rate of the permeated gas guided through the hydrogen permeation filter was changed as shown in Table 1 below, the gas composition in each permeate gas was examined, and the results are shown in Table 1. .

  As is clear from this result, when the hydrogen gas is separated from the atmospheric gas using the hydrogen gas separation device, the hydrogen gas selectively permeates the hydrogen permeation filter and the hydrogen permeation is achieved. The ratio of hydrogen gas in the permeated gas that passed through the filter was very high, and the ratio of CO gas and the like was very small. In particular, as the flow rate of the atmospheric gas guided to the hydrogen gas separation device and the flow rate of the permeated gas guided through the hydrogen permeation filter are increased, the proportion of hydrogen gas contained in the permeated gas is extremely high. It was.

  In the above embodiment, an example of a batch type carburizing apparatus has been shown. However, the carburizing apparatus of the present invention is not limited to such a batch type carburizing apparatus and is not shown in the drawing. It may be a continuous carburizing apparatus that sequentially guides the material to a heating chamber, a carburizing chamber, and a diffusion chamber and continuously carburizes.

It is the schematic explanatory drawing which showed the conventional carburizing processing apparatus used in carburizing a process material. In the carburizing apparatus according to one embodiment of the present invention, it is a schematic explanatory view showing a state before introducing a treatment material into an introduction chamber. In the carburizing apparatus which concerns on the embodiment, it is the schematic explanatory drawing which showed the state which introduced the processing material in the introduction chamber. In the carburizing apparatus which concerns on the embodiment, it is the schematic explanatory drawing which showed the state which introduce | transduces a processing material into a carburizing process chamber and performs a carburizing process. It is a schematic perspective view of the hydrogen permeable filter used for the hydrogen gas separation apparatus in the carburizing apparatus according to the above embodiment. It is a schematic sectional drawing of the hydrogen gas separation apparatus used for the carburizing processing apparatus which concerns on said embodiment. In the carburizing apparatus according to the above-described embodiment, it is a schematic explanatory diagram of a modified example in which an exhaust pipe provided with a flow rate adjusting valve is provided in the carburizing chamber.

Explanation of symbols

A processing material 1a 1st door 1b 2nd door 2 Introduction chamber 3 Carburizing chamber 4 Carrier gas supply pipe 4a Flow rate adjustment valve 5 Enriched gas supply pipe 5a Flow rate adjustment valve 6 Stirring fan 7 Exhaust pipe 7a Flow rate adjustment valve 10 Circulation path 11 Circulation pump 12 Extraction valve 13 Cooling device 14 Return valve 20 Hydrogen gas separation device 21 Container 22 Hydrogen permeation filter 23 Hydrogen gas guide tube 24 Suction device 25 Holding plate 25a Ventilation hole 30 Vacuum pumps 31a, 31b On-off valve 32a, 32b Exhaust tube

Claims (4)

  A carburizing treatment apparatus comprising a carburizing treatment chamber for carburizing a treatment material, and a gas supply device for supplying a carrier gas containing CO gas as a main component and an enriched gas containing hydrocarbon gas as a main component into the carburizing treatment chamber. In addition, a circulation path is provided for extracting and circulating the atmospheric gas containing hydrogen gas in the carburizing chamber from the carburizing chamber, and the hydrogen gas contained in the atmospheric gas is separated into the circulating path and extracted. A carburizing apparatus characterized in that a separation apparatus is provided.   2. The carburizing apparatus according to claim 1, wherein a hydrogen permeation filter that selectively permeates hydrogen gas is used in the hydrogen gas separator.   3. The carburizing apparatus according to claim 2, wherein a suction device is connected to the hydrogen gas separation device using the hydrogen permeation filter to separate hydrogen gas contained in the atmospheric gas introduced to the hydrogen gas separation device. A carburizing apparatus characterized by being removed.   The carburizing apparatus according to any one of claims 1 to 3, wherein the carburizing chamber is sealed during the carburizing process.

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