KR102240460B1 - A system of nitriding furnace) - Google Patents

Abstract

The present invention is a nitriding furnace; A storage tank for supplying ammonia gas to the nitridation furnace; An electromagnetic flow meter for measuring the flow rate of the input ammonia gas input from the storage tank to the nitriding furnace; An ammonia flow rate measuring unit for measuring a flow rate of residual ammonia gas remaining in the nitridation furnace; And a gas injection line for introducing gas from the nitriding furnace to the ammonia flow rate measuring unit from the nitriding furnace _{, excluding expensive nitrogen potential (K N} ) measuring equipment, and controlling the flow rate of ammonia gas in the nitriding furnace. It is possible to provide a nitridation furnace system capable of controlling the nitrogen potential (K _{N) by measuring in real time.}

Description

Nitriding furnace system {A SYSTEM OF NITRIDING FURNACE)}

The present invention relates to a nitriding furnace system, and more particularly, to a nitriding furnace system capable of measuring a flow rate of ammonia gas in a nitriding furnace in real time.

Nitriding is a surface treatment technique in which activated nitrogen is diffused into steel to obtain a high-hardness nitride layer on the steel surface.

When such nitriding is performed on steel, it is widely used in precision parts, automobile parts, and molds because it improves abrasion resistance, fatigue resistance, high temperature strength and corrosion resistance, and can be treated at a low temperature below the transformation point, so that heat deformation is small.

In addition, nitriding improves the adhesion of the coating layer and exhibits excellent properties in hardening of the underlying layer, and thus the application to complex treatment is increasing.

On the other hand, nitriding has a wide range of applied steel types compared to carburizing, and the treatment temperature is also carried out at 850 to 950°C in the case of carburizing, but nitriding is performed in the range of 460 to 600°C, and additional heat treatment and post treatment are not required.

In the case of carburization, the hardening depth is 0.4~1.5mm, but the nitriding is thin, 0.01~0.03mm, and the impact resistance (toughness) is also weak, but the nitriding is normal.

In particular, the deformation is large due to carburization, while nitriding is minimal due to the low-temperature process, and the corrosion resistance is normal due to the high carbon content in the case of carburizing, causing stress corrosion cracking, but it is excellent due to the improvement of corrosion resistance of low-carbon steel and abrasion resistance. It is also superior to carburizing.

Nitriding is largely divided into gas nitriding, salt bath nitriding, and ion nitriding.

In the case of gas nitridation, there are advantages of high hardness, wear resistance, fatigue strength, large capacity, and limited shape, but there are disadvantages in that it is difficult to control the use of ammonia (toxic gas), takes a long time, and requires a dedicated steel type.

The salt bath nitriding has the advantage of short time, sintering resistance, fatigue strength, no restrictions on steel grade, less equipment, and applicable to any shape, but it is possible to apply CN-removal measures in drainage treatment, environmental pollution and a porous layer on the white layer. This excessive problem, there is a problem that the hardness of the material decreases during repeated nitriding.

The ion nitriding has the advantages of good nitridation, ease of process control and phase control, and the use of N2 gas, but it is difficult to nitrate into fine holes due to electric field effect between products (nitride targets), temperature uniformity problem, arc generation, and nitridation of fine holes. There are drawbacks.

Meanwhile, the product is nitrated using a nitridation heat treatment furnace. At this time, in the nitriding process, the nitrogen potential (K _N ) in the heat treatment furnace corresponds to a major factor in the nitridation process.

In the conventional case, _{in measuring the nitrogen potential (K N} ), this was measured through a separate nitrogen potential (K _N ) measuring equipment, but the nitrogen potential (K _N ) measuring equipment has a problem corresponding to high cost. .

Korean Patent Publication No. 10-414542

The problem to be solved by the present invention is to provide a nitriding furnace system capable of controlling _{the nitrogen potential (K N ) by excluding expensive nitrogen potential (K N} ) measuring equipment and measuring the flow rate of ammonia gas in the nitriding furnace in real time. There is a purpose.

The objects of the present invention are not limited to the objects mentioned above, and other objects that are not mentioned will be clearly understood by those skilled in the art from the following description.

In order to solve the above-noted problems, the present invention provides a nitriding furnace; A storage tank for supplying ammonia gas to the nitridation furnace; An electromagnetic flow meter for measuring the flow rate of the input ammonia gas input from the storage tank to the nitriding furnace; An ammonia flow rate measuring unit for measuring a flow rate of residual ammonia gas remaining in the nitridation furnace; And a gas injection line for injecting gas from the nitriding furnace into the ammonia flow rate measuring unit.

In addition, the present invention provides a nitriding furnace system, characterized in that the residual ammonia gas flow rate is the flow rate of undecomposed ammonia gas among the input ammonia gas inputted from the storage tank to the nitriding furnace.

In addition, the present invention, the ammonia flow rate measurement unit, the reaction tank; A solvent storage tank for introducing a solvent into the reaction tank; And a discharge tank for discharging the reactants reacted in the reaction tank, wherein the reaction tank includes: an inlet located at one side of the reaction tank; An outlet located on the other side of the reaction tank; A first valve positioned between the inlet and the solvent storage tank; And a second valve positioned between the discharge port and the discharge tank.

In addition, the present invention provides a nitridation furnace system further comprising a third valve positioned between the inlet and the gas injection line.

In addition, the present invention provides a nitridation furnace system, further comprising a plurality of flow meters positioned between the storage tank and the electromagnetic flow meter.

In addition, in the present invention, the plurality of flow meters include a first flow meter, a second flow meter, and a third flow meter, the first flow meter is a flow meter with a capacity of 0.5 rubes (㎥) to 1 rube (㎥), and the second flow meter Is a flow meter with a capacity of 1 to 3 rubes, and the third flow meter is a flow meter with a capacity of 3 to 7 rubes.

In addition, the present invention provides a first solenoid valve located between the storage tank and the first flow meter, a second solenoid valve located between the storage tank and the second flow meter, and the storage tank and the third flow meter. It provides a nitridation furnace system further comprising a third solenoid valve positioned therebetween.

According to the present invention as described above, it is possible to provide a nitriding furnace system capable of controlling _{the nitrogen potential (K N ) by excluding expensive nitrogen potential (K N} ) measuring equipment and measuring the flow rate of ammonia gas in the nitriding furnace in real time. I can.

More specifically, in the present invention, an ammonia flow rate measuring unit for measuring the "remaining ammonia gas flow rate" remaining in the nitridation furnace; And by including a gas injection line for introducing the gas from the nitriding furnace from the nitriding furnace 1400 to the ammonia flow rate measuring unit, it is possible to replace the _{expensive nitrogen potential (K N) measuring equipment, through which,} Potential (K _N ) can be measured.

1 is a schematic cross-sectional view showing a nitriding furnace according to the present invention.
2 is a schematic system diagram for explaining a nitridation furnace system including an ammonia gas flow rate measurement unit according to the present invention.
3A to 3C are schematic diagrams for explaining a method of measuring a flow rate of ammonia gas through an ammonia flow rate measuring unit.

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms different from each other, and only these embodiments make the disclosure of the present invention complete, and common knowledge in the technical field to which the present invention pertains. It is provided to completely inform the scope of the invention to the possessor, and the invention is only defined by the scope of the claims.

With reference to the accompanying drawings below will be described in detail for the implementation of the present invention. Regardless of the drawings, the same reference numerals refer to the same elements, and "and/or" includes each and all combinations of one or more of the recited items.

Although the first, second, and the like are used to describe various components, it goes without saying that these components are not limited by these terms. These terms are only used to distinguish one component from another component. Therefore, it goes without saying that the first component mentioned below may be the second component within the technical idea of the present invention.

The terms used in the present specification are for describing exemplary embodiments and are not intended to limit the present invention. In this specification, the singular form also includes the plural form unless specifically stated in the phrase. As used herein, “comprises” and/or “comprising” do not exclude the presence or addition of one or more other elements other than the mentioned elements.

Unless otherwise defined, all terms (including technical and scientific terms) used in the present specification may be used with meanings that can be commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, terms defined in a commonly used dictionary are not interpreted ideally or excessively unless explicitly defined specifically.

Spatially relative terms "below", "beneath", "lower", "above", "upper", etc. It can be used to easily describe the correlation between a component and other components. Spatially relative terms should be understood as terms including different directions of components during use or operation in addition to the directions shown in the drawings. For example, if a component shown in a drawing is turned over, a component described as "below" or "beneath" of another component will be placed "above" the other component. I can. Accordingly, the exemplary term “below” may include both directions below and above. Components may be oriented in other directions, and thus spatially relative terms may be interpreted according to the orientation.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic cross-sectional view showing a nitriding furnace according to the present invention. However, the nitridation furnace according to the present invention in FIG. 1 is only an example, and the structure of the nitridation furnace is not limited in the present invention.

Referring to Fig. 1, the nitridation furnace 1 according to the present invention includes an outcasing unit 10; A port 20 located inside the outcasing part 10; And an incasing portion 30 positioned inside the port 20.

The outcasing portion 10 includes an outcasing 11 having an open top, and a lid 12 opening and closing an upper portion of the opened outcasing 11.

In addition, the port 20 is located inside the outcasing 11 to form a space 21 between the outcasing 11 and the outer casing 11.

In addition, the port 20 has an open upper portion, and the upper portion of the opened port may be opened and closed by a lid of the out casing portion 10.

The incasing part 30 is connected to the incasing 31 and the lid 12 in which the upper and lower portions are opened to communicate with the inside of the port 20, and the nitriding object 100 is accommodated therein. And, it includes an auxiliary lid (32) for opening and closing the upper portion of the incasing (31).

However, in the present invention, the presence or absence of the incasing part 30 is not limited.

On the other hand, the nitriding treatment object 100 may be understood as a metal material for hardening the surface by infiltrating nitrogen, and it is preferable to maintain the cleaned state before the nitriding treatment.

Here, it is preferable to be understood that the nitridation treatment object 100 is positioned inside the incasing 31 while being seated on the inner bottom surface of the port 20.

However, when the incasing part 30 is excluded from the present invention, it is understood that the nitridation treatment object 100 is located inside the port 20 while being seated on the inner bottom surface of the port 20 It is desirable to be.

Subsequently, referring to FIG. 1, the nitridation furnace 1 according to the present invention includes a circulation fan part 13 located under the outcasing part 10, and the circulation fan part 13 is the port 20 ) And a motor part 13b for driving the circulation fan 13a, and located outside the outcasing part 10 and a circulation fan 13a located at the lower side of the inside of the circulating fan 13a.

In addition, the nitridation furnace 1 according to the present invention includes a nitrogen gas supply unit 16 for supplying nitrogen to the port 20, and the nitrogen gas supply unit 16 has one end inside the port 20. And a nitrogen gas supply control valve 16b for controlling the nitrogen supplied to the nitrogen gas supply pipe 16a and the nitrogen gas supply pipe 16a located at.

In addition, the nitridation furnace 1 according to the present invention includes a process gas supply unit 17 for supplying a process gas to the port 20, and the process gas supply unit 16 has one end of the port 20 It includes a process gas supply pipe (17a) located inside and a process gas supply control valve (17b) for controlling the process gas supplied to the process gas supply pipe (17a).

At this time, nitrogen gas of N ₂ , N ₂ +CO _{2 may be supplied to the nitrogen gas supply unit 16, and ammonia (NH 3} ) gas may be supplied to the process gas supply unit 17.

Meanwhile, as shown in the drawing, one end of the nitrogen gas supply pipe 16a and one end of the process gas supply pipe 17a are preferably located under the circulation fan 13a, through which the The nitrogen gas supplied through the nitrogen gas supply pipe 16a and the process gas supplied through the process gas supply pipe 17a can be easily circulated by the circulation fan 13a.

Subsequently, referring to FIG. 1, the nitriding furnace 1 according to the present invention may further include an opening/closing device 15 for opening and closing the lid 12.

That is, the nitriding furnace 1 can open the lid 12 by operating the opening and closing device 15, and also, while opening the lid 12, the auxiliary lid 32 can be opened at the same time.

Accordingly, after opening the lid 12 and the auxiliary lid 32, the nitriding treatment object 100 may be accommodated in the incasing 31 in the port 20.

Thereafter, when the nitriding treatment object 100 is accommodated in the incasing 31, the auxiliary top lid 32 and the lid 12 may be closed by operating the opening and closing device 15.

Since the sequence of the nitriding heat treatment in the opening and closing device 15 and the nitridation furnace 1 is obvious in the art, a detailed description thereof will be omitted.

Subsequently, referring to FIG. 1, the nitridation furnace 1 according to the present invention may further include an air exhaust unit 40 for sucking air remaining in the port 20 and discharging it to the outside before the nitriding heat treatment operation. have.

The air exhaust unit 40 has an exhaust pipe 41 connected to one end to communicate with the port 20 through the outcasing 11 and a vacuum pump 42 connected to the other end of the exhaust pipe 41 Includes.

The vacuum pump 42 has a general form driven by receiving power from the outside.

The air exhaust unit 40 drives the vacuum pump 42 to suck the air remaining in the port 20 and discharge it to the outside.

For example, the air exhaust unit 40 drives the vacuum pump 42 for about 10 to 15 minutes to remove air remaining in the port 20.

At this time, the air exhaust unit 40 sucks the air remaining inside the port 20 and the incasing 31 while the auxiliary lid 32 is driven with the incasing 31 open. And can be discharged to the outside.

In addition, the nitridation furnace 1 may start the nitriding heat treatment after removing the air remaining in the port 20 and filling the inside with nitrogen at a predetermined pressure.

Meanwhile, the air exhaust unit 40 may further include a release valve 43 for controlling the removal of air remaining in the port 20 by the vacuum pump 42.

For this reason, since the port 20 maintains a vacuum state in which no air remains, oxidation of the heat treatment object 100 may be prevented.

Subsequently, referring to FIG. 1, the nitridation furnace 1 according to the present invention may further include a pressure discharge part 50 for maintaining a constant pressure in the port 20.

At this time, the pressurized discharge unit 50, a pressurized discharge pipe 51 having one end passing through the lid 12 and communicating with the port 20, and a pressurization connected to a predetermined area of the pressurized discharge pipe 51 It includes a discharge valve (52).

The pressurized release valve 52 maintains a constant pressure in the port 20 and rapidly discharges the undecomposed gas generated in the port 20 to the outside.

In other words, since the pressure release valve 52 must prevent air penetration into the port 20 during nitriding heat treatment, the pressure in the port 20 is kept constant from the beginning to the end of the work, and the inside of the port 20 Undecomposed gas generated from is quickly discharged to the outside so that the proper pressure is maintained.

As a result, the nitriding furnace 1 can prevent the inflow of air into the port 20 and shorten the nitriding treatment time for the nitriding object 100.

Subsequently, referring to FIG. 1, the nitridation furnace 1 according to the present invention further includes a cooling unit 60 for cooling the nitrogen heated in the port 20 and resupplying it to the port 20. I can.

The cooling unit 60 cools the nitrogen heated during the heat treatment in the port 20 and resupplies it to the port 20, so that a rapid cooling effect of the nitridation treatment object 100 can be expected.

The cooling part 60 is connected to a first cooling pipe 61 having one end passing through the outcasing 11 and communicating with the inside of the port 20, and the other end of the first cooling pipe 61 A vacuum blower 62, a heat exchanger 63 connected between both ends of the first cooling pipe 61, and both ends, one end connected to the vacuum blower 62, and the other end of the exhaust pipe 41 ) And a second cooling pipe 64 connected to communicate with each other.

The vacuum blower 62 has a general form driven by receiving power from the outside, and sucks nitrogen accommodated in the port 20 to obtain the first cooling tube 61, the heat exchanger 63, and the The second cooling pipe 64 and, again, the circulation to the port 20 can be sequentially performed.

In addition, the heat exchanger 63 may be air-cooled or water-cooled, and the type of the heat exchanger is not limited in the present invention.

In this case, the heat exchanger 63 may include a first heat exchanger 63a and a second heat exchanger 63b, but the number of heat exchangers 63 is not limited in the present invention.

In addition, the cooling unit 60 is located between the heat exchanger 63 and the vacuum blower 62, the first flow rate control valve 65 connected to the first cooling pipe 61 and the A second flow rate control valve 66 connected between the second cooling pipe 64 and the exhaust pipe 41 may be further included.

The first flow rate control valve 65 and the second flow rate control valve 66 control the amount of nitrogen re-inflow into the vacuum blower 62 and the port 20, respectively, to appropriately adjust the flow rate. It can be understood as controlling.

That is, in the nitridation furnace 1 according to the present invention, the nitrogen heated in the port 20 is cooled while passing through the heat exchanger 63 as the vacuum blower 62 is driven, and then returned to the port 20. As it can be resupplied, a rapid cooling effect of the nitridation treatment object 100 can be expected.

In addition, since the nitrogen is circulated in a vacuum state, oxidation of the nitridation object 100 due to the inflow of air can be prevented.

Subsequently, referring to FIG. 1, the nitridation furnace 1 according to the present invention may further include an air supply unit 70 for cooling the nitridation object 100 by receiving air from the outside.

The air supply unit 70 may include a cooling fan (not shown) for supplying external air to the space unit 21, and is connected to the cooling fan (not shown) to supply external air. It may include a supply pipe 71 and a discharge pipe 72 for discharging the air supplied to the space 21 to the outside.

At this time, in the present invention, the supply pipe 71 is connected to the lower portion of the outcasing 11 so as to communicate with the space part 21, and the discharge pipe 72 is the outcasing so as to communicate with the space part 21. It is preferable to be connected to the top of (11).

Therefore, in the present invention, external air may be supplied to the lower side of the outcasing 11 and discharged to the upper side of the outcasing 11, and in this process, the nitridation treatment object 100 may be cooled. I can.

That is, in the nitridation furnace 1 according to the present invention, when the cooling fan (not shown) is driven to cool the nitridation treatment object 100 that has been subjected to nitridation heat treatment in the incasing unit 30, external air cooled from the outside is It flows into the space 21 from the lower side of the outcasing 11.

The air introduced into the space part 21 rotates and passes along the space part 21 to cool the port 20 and the outcasing 11.

Therefore, the nitriding treatment object 100 accommodated in the incasing part 30 is naturally cooled as the port 20 and the out casing 11 are cooled, and the port 20 and The air that has cooled the outcasing part 10 is discharged to the outside through the discharge pipe 72 connected to the upper part of the outcasing 11 in a state of high-temperature air absorbing heat.

As described above, the nitridation furnace 1 according to the present invention includes an outcasing portion 10; A port 20 located inside the outcasing part 10; And an incasing portion 30 positioned inside the port 20.

At this time, the outcasing portion 10 includes an outcasing 11 having an upper opening, a lid 12 opening and closing the upper portion of the opened outcasing 11, and the outcasing portion 10 It includes a circulation fan part 14 located at the bottom of ).

In addition, the circulation fan part 13 is located outside the circulation fan 13a located at the inner lower side of the port 20 and the outcasing part 10, and a motor part for driving the circulation fan 13a Includes (13b).

In addition, the nitridation furnace 1 according to the present invention includes a nitrogen gas supply unit 16 for supplying nitrogen to the port 20, and the nitrogen gas supply unit 16 has one end inside the port 20. It includes a nitrogen gas supply pipe (16a) located at, and also includes a process gas supply unit 17 for supplying the process gas to the port 20, the process gas supply unit 16 has one end of the port It includes a process gas supply pipe (17a) located inside the (20).

At this time, one end of the nitrogen gas supply pipe (16a) and one end of the process gas supply pipe (17a) are preferably located under the circulation fan (13a), therefore, in the present invention, the nitrogen gas supply pipe (16a) ) And the process gas supplied through the process gas supply pipe 17a can be easily circulated by the circulation fan 13a.

As described above, the nitridation furnace according to the present invention has been described with reference to FIG. 1, but as described above, the nitridation furnace according to the present invention in FIG. .

Hereinafter, a nitridation furnace system including an ammonia gas flow rate measurement unit according to the present invention through the nitridation furnace as described above will be described.

2 is a schematic system diagram for explaining a nitridation furnace system including an ammonia gas flow rate measurement unit according to the present invention.

Referring to FIG. 2, the nitridation furnace system including the ammonia gas flow rate measurement unit according to the present invention includes the nitridation furnace 1400 as in FIG. 1 described above, but the type of the nitridation furnace 1400 is limited in the present invention. It is not.

In addition, the nitridation furnace system including the ammonia gas flow rate measurement unit according to the present invention includes an ammonia storage tank (1100, hereinafter referred to as "storage tank") for supplying ammonia gas to the nitridation furnace 1400; An electromagnetic flow meter (1300) for measuring the flow rate of "input ammonia gas" inputted from the storage tank (1100) to the nitriding furnace (1400); An ammonia flow rate measuring unit 1500 for measuring the “remaining ammonia gas flow rate” remaining in the nitridation furnace 1400; And a gas injection line 1410 for injecting gas from the nitriding furnace 1400 into the ammonia flow rate measuring unit 1500.

In this case, the residual ammonia gas flow rate may be defined as an undecomposed ammonia gas among "input ammonia gas" inputted from the storage tank 1100 to the nitridation furnace 1400.

More specifically, "input ammonia gas" inputted from the storage tank 1100 to the nitriding furnace 1400 causes a decomposition reaction as shown in Formula (1) below in the nitriding furnace 1400.

NH ₃ -> N ₂ + 3H ₂ ... Formula (1)

Nitriding proceeds through various processes by _{the N 2} generated by the decomposition reaction of the “input ammonia gas”.

The various processes may include, for example, a first nitriding step (S60), a second nitriding step (S70), a cooling step (S80), etc. disclosed in Korean Patent Registration No. 10-1830221, but in the present invention It does not limit the type of step in which the nitriding is performed.

On the other hand, under the control of the potential of nitrogen _(N K) in these various processes and nitriding proceeds, the nitrogen potential (K _N) is to be expressed as Equation (1).

Nitrogen potential (K _N ) = p[NH ₃ ]Rest/p[H ₂ ^3/2 ] ... Equation (1)

In Equation (1), p[NH ₃ ]Rest refers to the partial pressure of the undecomposed ammonia gas among the ammonia gas introduced into the nitridation furnace, and p[H ₂ ^3/2 ] refers to the partial pressure of the hydrogen gas generated after decomposition. , In the above-described various processes, the nitrogen potential (K _N ) is controlled to 1.0 to 10, or the nitrogen potential (K _N ) is controlled to 0.4 to 1.0, however, in the present invention, the nitrogen potential (K _N ) Does not limit the number of.

For example, in the nitriding furnace, ammonia gas (NH ₃ ) is gradually decomposed into nitrogen (N ₂ ) and hydrogen (H ₂ ), and the ammonia gas (NH ₃ ) reacts with the surface of the material to form a nitrogen compound layer. Hydrogen (H ₂ ) gas is generated, and in this process, the nitrogen potential (K _N ) may be decreased or increased, and in each step, the nitrogen potential (K _N ) is controlled to proceed with the nitridation process.

Therefore, the value of the nitrogen potential (K _N) in the nitriding process corresponds to a key factor, in the case of the prior art, in the measurement of the nitrogen potential (K _N), measuring them through separate nitrogen potential (K _N) measurement equipment However, in the case of the nitrogen potential (K _N ) measuring equipment, there is a problem corresponding to the high price.

However, in the present invention, an ammonia flow rate measuring unit 1500 for measuring the "remaining ammonia gas flow rate" remaining in the nitriding furnace 1400; And by including a gas injection line 1410 for injecting the gas of the nitriding furnace from the nitriding furnace 1400 to the ammonia flow rate measuring unit 1500, it is possible to replace the _{above-described expensive nitrogen potential (K N) measuring equipment.} And, through this, it is possible to measure _{the nitrogen potential (K N) inside the nitridation furnace 1400.}

More specifically, according to Equation (1) described above, since the nitrogen potential (K _N ) value corresponds to p[NH ₃ ]Rest/p[H ₂ ^3/2 ], the nitriding furnace which is the value of _{p[NH 3 ]Rest} In the case of measuring the partial pressure of undecomposed ammonia gas among the ammonia gas injected into the inside and the partial pressure _{of hydrogen gas generated after decomposition, which is the p[H 2} ^3/2 ] value, the above-described nitrogen potential (K _N ) value can be measured in real time. _{In consideration of the nitrogen potential (K N} ) value measured in real time, through the flow rate of the "input ammonia gas" inputted from the storage tank 1100 to the nitriding furnace 1400 or temperature control of the nitriding furnace, each _{By controlling the nitrogen potential (K N} ) value required in the step, it is possible to proceed with the nitriding process.

At this time, measuring the partial pressure of the undecomposed ammonia gas among the ammonia gas introduced into the nitridation furnace, which is the value of _{p[NH 3 ]Rest, can be measured through the ammonia flow measurement unit 1500 described above, and also, p[H 2} ^{3 /2} ] Since the partial pressure of hydrogen gas generated after decomposition, which is a value, corresponds to the partial pressure of hydrogen gas generated by the above-described formula (1), "input ammonia injected from the storage tank 1100 to the nitriding furnace 1400 When measuring the flow rate of "gas" and the flow rate of undecomposed ammonia gas among the input ammonia gas, the partial pressure of hydrogen gas generated after decomposition can also be measured.

For example, assuming that 100% of the "input ammonia gas" input to the nitriding furnace 1400 from the storage tank 1100 is decomposed in the nitriding furnace, according to Formula (1), ammonia gas (NH ₃ ) Is decomposed to _{form a mixed gas decomposed in a volume ratio of nitrogen (N 2} ) gas 25% and hydrogen (H ₂ ) gas 75%, and the volume of hydrogen (H ₂ ) gas at this time is p compared to the volume of the nitriding furnace It constitutes the partial pressure of hydrogen gas generated after decomposition, which is the value of [H ₂ ^{3/2 ].}

In addition, assuming that 50% of the "input ammonia gas" injected into the nitriding furnace 1400 from the storage tank 1100 is decomposed in the nitriding furnace, according to the formula (1), ammonia gas (NH ₃ ) is It is decomposed to form a mixed gas decomposed in a volume ratio of 25%*0.5 of nitrogen (N _{2 ) gas and 75%*0.5 of hydrogen (H 2} ) gas, and 50% of the undecomposed "input ammonia gas" is undecomposed ammonia. Corresponding to the gas, the undecomposed ammonia gas constitutes the partial pressure of the undecomposed ammonia gas among the ammonia gas introduced into the nitridation furnace having a value _{of p[NH 3 ]Rest.}

After all, according to the same principle, when the content of the undecomposed ammonia gas in the "input ammonia gas" inputted from the storage tank 1100 to the nitriding furnace 1400 can be measured, the above-described nitrogen potential (K _N ) An ammonia flow rate measuring unit 1500 for measuring a value and, more specifically, a "remaining ammonia gas flow rate" remaining in the nitridation furnace 1400; And through a gas injection line 1410 for injecting the gas of the nitriding furnace from the nitriding furnace 1400 to the ammonia flow rate measuring unit 1500, the content of the undecomposed ammonia gas is measured, through which p[NH ₃ ]It is possible to measure the partial pressure of undecomposed ammonia gas among the ammonia gas introduced into the nitriding furnace, which is the value of Rest.

Hereinafter, the ammonia flow rate measurement unit 1500 according to the present invention will be described in more detail.

3A to 3C are schematic diagrams for explaining a method of measuring a flow rate of ammonia gas through an ammonia flow rate measuring unit. At this time, in the present invention, the ammonia flow rate measurement unit may be a known ammonia decomposition rate measurement device, and the ammonia decomposition rate measurement unit may be configured as described below, but the configuration of the ammonia flow rate measurement unit in the present invention is not limited.

First, referring to Figure 3a, the ammonia flow rate measurement unit 1500 according to the present invention, the reaction tank 1510; A solvent storage tank 1520 for introducing a solvent into the reaction tank 1510; And a discharge tank 1600 for discharging the reactants reacted in the reaction tank 1510.

More specifically, the reaction tank 1510 includes an inlet 1511 located at one side of the reaction tank 1510; And a first valve 1530 disposed between the inlet 1511 and the solvent storage tank 1520 including an outlet 1512 located on the other side of the reaction tank 1510; And a second valve 1540 positioned between the discharge port 1512 and the discharge tank 1600.

Meanwhile, as described above, the reaction tank 1510 is connected to a gas injection line 1410 for introducing gas from the nitriding furnace 1400 to the ammonia flow rate measuring unit 1500, that is, the The gas of the nitriding furnace is discharged through the gas injection line 1410, and the gas of the nitriding furnace may be injected into the ammonia flow rate measuring unit 1500, more specifically, the reaction tank 1510.

In addition, in order to control whether or not the gas from the nitriding furnace is injected into the reaction tank 1510 through the gas injection line 1410, a third valve ( 1411) may be further included.

On the other hand, through the gas injection line 1410, the ammonia flow rate measuring unit 1500, more specifically, in the case of the gas of the nitriding furnace injected into the reaction tank 1510, contains various gases.

For example, in the case of the gas of the nitriding furnace, nitrogen (N ₂ ) gas, hydrogen (H ₂ ) gas, etc. may be included, and in particular, ammonia gas (NH ₃ ) to be measured in the present invention, that is, in the nitriding furnace It contains undissolved ammonia gas among the input ammonia gas.

In this case, the ammonia gas has a property of being soluble in water, and when the ammonia gas is dissolved in water, the aqueous solution constitutes alkaline aqueous ammonia.

That is, among nitrogen (N ₂ ) gas, hydrogen (H ₂ ) gas and ammonia gas (NH ₃ ) constituting the gas of the nitriding furnace, the ammonia gas is well soluble in water, _{When measuring the content of the dissolved gas, the ammonia gas (NH 3} ) in the gas of the nitridation furnace, that is, the content of the undecomposed ammonia gas in the ammonia gas introduced into the nitriding furnace may be measured.

Therefore, in the present invention, the solvent stored in the solvent storage tank 1520 may be water, provided that the solvent stored in the solvent storage tank 1520 corresponds to a material capable of dissolving the ammonia gas, the present invention Does not limit the type of the solvent.

Hereinafter, a method of measuring the flow rate of ammonia gas through the ammonia flow rate measurement unit will be described.

First, referring to FIG. 3B, by turning on the third valve 1411 described above, the gas from the nitriding furnace is discharged through the gas injection line 1410, and the ammonia flow rate measurement unit 1500, more specifically, , Gas from the nitriding furnace is introduced into the reaction tank 1510.

At this time, the first valve 1530 and the second valve 1540 correspond to the OFF state.

When the gas from the nitriding furnace is introduced into the reaction tank 1510 and the reaction tank 1510 is fully filled with the nitriding furnace gas, the gas from the nitriding furnace is no longer introduced into the reaction tank 1510.

When the gas from the nitriding furnace is no longer supplied to the reaction tank 1510, the third valve 1411 is turned off.

_{That is, in a state in which the nitridation furnace gas including nitrogen (N 2} ) gas, hydrogen (H ₂ ) gas, and ammonia gas (NH ₃ ) in the reaction tank 1510 is fully filled, the third valve 1411 is turned off. By doing so, the gas from the nitriding furnace is no longer introduced into the reaction tank 1510.

Thereafter, referring to FIG. 3C, by turning on the first valve 1530, the solvent stored in the solvent storage tank 1520, that is, water is introduced into the reaction tank 1510.

At this time, in the case of the reaction tank 1510, since it is fully filled with the gas of the nitriding furnace, the solvent stored in the solvent storage tank 1520, that is, water, is transferred to the reaction tank 1510 by the pressure of the reaction tank 1510. However, in the present invention, ammonia gas (NH ₃ ) is included in the gas of the nitridation furnace, and in the case of the ammonia gas (NH ₃ ), it is dissolved by the water, so that the ammonia gas (NH ₃ ) Water may be added to the reaction tank 1510 from the solvent storage tank 1520 as much as is dissolved.

That is, the water of the water level h1 as in FIG. 3B is lowered to the water level h2 as in FIG. 3C, and the water whose water level is lowered is introduced into the reaction tank 1510 to dissolve the ammonia gas. , The aqueous solution constitutes alkaline aqueous ammonia.

Consequently, in the present invention, it is possible to measure the flow rate of ammonia gas in the gas of the nitridation furnace using the property that ammonia gas is well soluble in water.

For example, when the amount of the solvent, that is, water added to the reaction tank 1510 is 10 cc, the “input ammonia gas” that is not decomposed compared to 100% of the “input ammonia gas” introduced from the storage tank 1100 to the nitriding furnace 1400 Gas" may be measured as 10%, which may vary depending on the capacity of the reaction tank 1510, and does not limit such a measurement value in the present invention.

In addition, for example, when the "input ammonia gas" that is not decomposed compared to 100% of the "input ammonia gas" injected into the nitriding furnace 1400 from the storage tank 1100 is measured as 10%, in the nitriding furnace, It means that 90% of the "input ammonia gas" has been decomposed, and as described above, according to Formula (1), ammonia gas (NH ₃ ) is decomposed to nitrogen (N ₂ ) gas 25% * 0.9, hydrogen (H ₂ ) It constitutes a mixed gas decomposed at a volume ratio of 75%*0.9 of gas, and 10% of the undecomposed "input ammonia gas" corresponds to undecomposed ammonia gas, and the undecomposed ammonia gas is p[NH ₃ ] It constitutes the partial pressure of undecomposed ammonia gas among the ammonia gas injected into the nitriding furnace, which is the value of Rest.

According to this principle, when the content of the undecomposed ammonia gas in the "input ammonia gas" input from the storage tank 1100 to the nitriding furnace 1400 can be measured, the above-described nitrogen potential (K _N ) value Ammonia flow rate measuring unit 1500 for measuring the "remaining ammonia gas flow rate" remaining in the nitridation furnace 1400; And through a gas injection line 1410 for injecting the gas of the nitriding furnace from the nitriding furnace 1400 to the ammonia flow rate measuring unit 1500, the content of the undecomposed ammonia gas is measured, through which p[NH ₃ ]It is possible to measure the partial pressure of undecomposed ammonia gas among the ammonia gas introduced into the nitriding furnace, which is the value of Rest.

Meanwhile, after the reaction is completed, the first valve 1530 is turned off and the second valve 1540 is turned on, so that the reactants reacted in the reaction tank 1510 are transferred to the discharge tank 1600. Will be discharged.

_{As described above, in the present invention, the nitrogen potential (K N} ) value is measured by measuring the content of the undecomposed ammonia gas in the "input ammonia gas" inputted from the storage tank 1100 to the nitriding furnace 1400, It is possible to replace the expensive nitrogen potential (K _N ) measuring equipment described above, and through this, it is possible to measure _{the nitrogen potential (K N) inside the nitridation furnace 1400.}

At this time, in the present invention, it is important to measure the flow rate of the "input ammonia gas" inputted from the storage tank 1100 to the nitridation furnace 1400 together with the flow rate of the undecomposed ammonia gas.

Therefore, in the present invention, through the electromagnetic flow meter 1300, it is possible to measure the flow rate of the "input ammonia gas" inputted from the storage tank 1100 to the nitriding furnace 1400.

_{On the other hand, by controlling the nitrogen potential (K N} ) value required in each step by controlling the flow rate of the "input ammonia gas" inputted into the nitriding furnace 1400 from the storage tank 1100 or the temperature of the nitriding furnace, In order to proceed, it is necessary to control the flow rate of the "input ammonia gas".

Accordingly, as shown in FIG. 2, the nitridation furnace system including the ammonia gas flow rate measurement unit according to the present invention includes a plurality of flow meters 1210 and 1220 located between the storage tank 1100 and the electromagnetic flow meter 1300. , 1230).

For example, the plurality of flow meters 1210, 1220, 1230 may include a first flow meter 1210, a second flow meter 1220, and a third flow meter 1230, and the first flow meter 1210 is It is a flow meter with a capacity of 0.5 to 1 rube (cubic meter, ㎥), and the second flow meter 1220 is a flow meter with a capacity of 1 to 3 rubes (cubic meter, ㎥) And, the third flow meter 1230 may be a flow meter with a capacity of 3 rubes (cubic meter, ㎥) to 7 rubes (cubic meter, ㎥), however, the capacity of the plurality of flow meters in the present invention is not limited .

In addition, the nitridation furnace system including the ammonia gas flow rate measurement unit according to the present invention includes a first solenoid valve 1110 positioned between the storage tank 1100 and the first flow meter 1210, and the storage tank 1100. And a second solenoid valve 1120 positioned between the second flow meter 1220 and a third solenoid valve 1130 positioned between the storage tank 1100 and the third flow meter 1230 can do.

For example, the first flow meter 1210 is a flow meter with a capacity of 0.5 rubes (m 3 ), the second flow meter 1220 is a flow meter with a capacity of 3 rubes (㎥), and the third flow meter 1230 is a flow meter with a capacity of 7 rubes. (㎥) Assuming that it is a flow meter of capacity, when the first solenoid valve 1110 and the second solenoid valve 1120 are turned on, "input ammonia injected from the storage tank 1100 to the nitriding furnace 1400" The flow rate of "gas" is 3.5 rubes (㎥), and at this time, the flow rate of "input ammonia gas" displayed on the electromagnetic flow meter 1300 corresponds to 3.5 rubes (㎥).

That is, the flow rate of the “input ammonia gas” can be controlled through the plurality of flow meters 1210, 1220, and 1230 as described above and the solenoid valves that turn on/off the same.

Although the embodiments of the present invention have been described with reference to the above and the accompanying drawings, those of ordinary skill in the art to which the present invention pertains can be implemented in other specific forms without changing the technical spirit or essential features of the present invention. You can understand that there is. Therefore, it should be understood that the embodiments described above are illustrative in all respects and are not limiting.

Claims (7)

Nitriding furnace;
A storage tank for supplying ammonia gas to the nitridation furnace;
An electromagnetic flow meter for measuring the flow rate of the input ammonia gas input from the storage tank to the nitriding furnace;
An ammonia flow rate measuring unit for measuring a flow rate of residual ammonia gas remaining in the nitriding furnace; And
And a gas injection line for introducing gas from the nitridation furnace to the ammonia flow rate measurement unit,
The residual ammonia gas flow rate is a flow rate of undecomposed ammonia gas among the input ammonia gas, which is input from the storage tank to the nitridation furnace,
The ammonia flow rate measuring unit, the reaction tank; A solvent storage tank for introducing a solvent into the reaction tank; And a discharge tank for discharging the reactants reacted in the reaction tank,
The reaction tank, an inlet located at one side of the reaction tank; An outlet located on the other side of the reaction tank; A first valve located between the inlet and the solvent storage tank; And a second valve positioned between the discharge port and the discharge tank. delete delete The method of claim 1,
Nitriding furnace system further comprising a third valve positioned between the inlet and the gas injection line. The method of claim 1,
Nitriding furnace system, characterized in that it further comprises a plurality of flow meters positioned between the storage tank and the electromagnetic flow meter. The method of claim 5,
The plurality of flow meters include a first flow meter, a second flow meter, and a third flow meter,
The first flow meter is a flow meter with a capacity of 0.5 to 1 rube (㎥), the second flow meter is a flow meter with a capacity of 1 to 3 rubes (㎥), and the third flow meter is a 3 rube ( A nitriding furnace system, characterized in that it is a flow meter with a capacity of ㎥) to 7 rubes. The method of claim 6,
A first solenoid valve located between the storage tank and the first flow meter, a second solenoid valve located between the storage tank and the second flow meter, and a first solenoid valve located between the storage tank and the third flow meter. Nitriding furnace system further comprising 3 solenoid valves.

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