KR20210032796A - Cutting apparatus and cutting method - Google Patents

Abstract

The cutting device according to the embodiment of the present invention injects combustion gas including hydrogen gas so that a flame is generated toward the base material and the first nozzle for injecting the first oxygen gas toward the base material, and at the end from which the combustion gas is discharged. It includes an injection unit having a second nozzle formed to be inclined to become closer to the first nozzle.
Accordingly, according to the embodiment of the present invention, the width of the flame can be reduced as compared to the prior art by using hydrogen gas as the combustion gas for generating the flame. Accordingly, it is possible to reduce the heating width of the base material due to the flame compared to the prior art, thereby reducing the amount of the base material lost by cutting.
In addition, since the hydrogen gas does not contain carbon (C), there is an effect of reducing the generation of fume due to carbon (C) as in the prior art.

Description

Cutting device and cutting method {CUTTING APPARATUS AND CUTTING METHOD}

The present invention relates to a cutting device and a cutting method, and more particularly, to a cutting device and a cutting method capable of reducing the loss of the base metal by cutting.

Cast slabs that are continuously cast from a casting facility are provided after being cut to a predetermined length at the request of a customer. To this end, a cutter is installed at the rear end of the secondary cooling table including a plurality of segments of the casting equipment.

In general, the cutting machine generates a flame to heat the cast steel and cuts the cast steel by rapidly oxidizing the cast steel by injecting high-pressure oxygen gas. At this time, LNG gas and oxygen gas are used as gases that generate flame.

However, when using LNG gas to generate a flame, the width of the flame (length in the longitudinal direction of the cast iron) is wide, and the area to be heated unnecessarily is large, resulting in a problem with a large amount of loss by cutting or a long loss length. have. This eventually leads to a decrease in the production rate of the product.

In addition, the cast steel is heated by a flame and cut while melting, and a cutting snow in which the melt is formed or fixed to the edge of the upper or lower part of the cut surface of the cast steel is generated. Accordingly, there is a problem in that the cutting snow is removed after the cutting operation, and since the cutting snow is also generated in a large area due to a wide flame, it is not easy to remove the cutting snow.

In addition, since LNG contains methane (CH ₄ ), there is a problem that a large amount of fume is generated by carbon (C) during the combustion reaction.

Korean Patent Registration KR1140278

The present invention provides a cutting device and a cutting method capable of reducing the amount of loss of the cut and discarded base material.

The present invention provides a cutting device and a cutting method capable of suppressing or preventing the generation of cutting snow and fume.

A cutting device according to an embodiment of the present invention includes a first nozzle for injecting a first oxygen gas toward a base material; And a second nozzle that injects combustion gas including hydrogen gas so as to generate a flame toward the base material, and is formed inclined to be closer to the first nozzle toward an end from which the combustion gas is discharged. .

One of both ends of the first nozzle is a first inlet through which the first oxygen gas is introduced, and the other end is a first injection port through which the first oxygen gas is discharged, and the first nozzle includes the first inlet and the first The first extension line, which is a virtual line connecting the injection hole, is provided so that an angle formed by a reference line, which is a virtual line parallel to the upper surface of the base material, is perpendicular.

The first nozzle may include a first passage having a constant diameter in an up-down direction; A second passage having one end connected to the first passage and having a smaller diameter toward the other end; A third passage having one end connected to the second passage and having a constant vertical diameter; And a fourth passage having one end connected to the third passage and increasing in diameter toward the other end, wherein one end of the first passage opposite to the other end connected to the second passage is the first inlet And, of both ends of the fourth passage, the other end, which is an opposite end connected to the third passage, is the first injection port.

The diameter of the first passage is larger than that of the third and fourth passages.

The vertically extending lengths of the first to fourth passages are formed longer in the order of a third passage, a first passage, a fourth passage, and a second passage.

Of both ends of the second nozzle, one end is a second inlet through which combustion gas is introduced, and the other end is a second injection port through which the combustion gas is discharged, and the second nozzle connects the second inlet and the second injection port. The second extension line, which is an imaginary line, is formed so that the angle formed by the first extension line is 3° to 14°.

The second nozzle is formed such that an angle between the second extension line and the first extension line is 5° to 9°.

The second nozzle may include a fifth passage through which the combustion gas can be moved; And a sixth passage having one end connected to the fifth passage and having a diameter larger than that of the fifth passage, and among both ends of the fifth passage, one end opposite to the other end connected to the sixth passage The second injection port is the second inlet, and the other end, which is an end opposite to one end connected to the fifth passage, among both ends of the sixth passage.

The extended length of the sixth passage is longer than that of the fifth passage.

The second nozzle is provided in plural and arranged in a row to surround the first nozzle.

_{The diameter (D 1} ) of the first injection port may be 2mm to 4mm.

The diameter of the second injection port (D ₂ ) is greater than or equal to the diameter of the second inlet (I _{2 ).}

_{The diameter (D 2} ) of the second injection port may be 0.7mm to 2.5mm.

And a third nozzle connected to the second nozzle to supply a second oxygen gas having a lower pressure than the first oxygen gas to the second nozzle, and the combustion gas is the hydrogen gas inside the second nozzle. And the second oxygen gas are mixed.

A cutting method according to an embodiment of the present invention includes an oxidation process of oxidizing the base material by injecting a first oxygen gas in a first injection direction toward a base material to be cut; Generating a flame by injecting combustion gas including hydrogen gas toward the base material in a second injection direction crossing the first injection direction; And cutting the base material by oxidation of the base material and heating by the flame.

The first oxygen gas and the combustion gas are injected so that the angle formed by the first injection direction and the second injection direction is 3° to 14°.

The injection is performed so that the flow rate of the first oxygen gas is greater than the flow rate of the combustion gas.

The pressure of the first oxygen gas may be 5 bar to 10 bar, and the pressure of the hydrogen gas may be 3 bar to 3.5 bar.

The combustion gas includes a second oxygen gas having a lower pressure than the first oxygen gas.

The pressure of the second oxygen gas may be 0.4 to 0.6 bar.

According to an embodiment of the present invention, by using hydrogen gas as a combustion gas for generating a flame, the width of the flame can be reduced compared to the conventional one. Accordingly, it is possible to reduce the heating width of the base material due to the flame compared to the prior art, thereby reducing the amount of the base material lost by cutting.

In addition, since the hydrogen gas does not contain carbon (C), there is an effect of reducing the generation of fume due to carbon (C) as in the prior art.

In addition, as hydrogen gas is used as the combustion gas, hydrogen gas and oxygen gas partially react to _{generate water (H 2} O). This water (H ₂ O) rapidly cools the melt melted by a flame. Functions. Accordingly, it is possible to reduce the bonding force that the melt adheres to the cutting surface, and there is an effect that it is easy to remove the cutting snow afterwards.

In addition, as the second nozzle for injecting the combustion gas is provided to be inclined and the inclination angle is optimized, the overlapping area between the base metal heating region by the flame and the base metal oxidation region by the high pressure first oxygen gas is increased, 1 It can prevent the diffusion of oxygen gas. Therefore, it is possible to prevent the occurrence of a cutting failure in which a part of the base material is not heated due to insufficient heating or insufficient oxidation.

In addition, by optimizing the diameter of the first injection port of the first nozzle, while sufficiently oxidizing the base material, the area lost by cutting can be reduced compared to the conventional one. In addition, by optimizing the diameter of the second injection port of the second nozzle, it is possible to prevent the occurrence of a problem that the flame does not reach the cast iron due to a small flow rate or flow rate of the combustion gas.

1 is a view showing a casting equipment having a cutting device according to an embodiment of the present invention.
2 is a view showing a cutting device according to an embodiment of the present invention.
3(a) is a result of measuring a cast steel with a thermal imaging camera when a flame is generated using LNG gas and oxygen gas as fuel gas.
3B is a result of measuring a cast steel with a thermal imaging camera when a flame is generated using hydrogen gas and oxygen gas as fuel gas.
4 is a view showing a cutting unit and a gas supply unit according to an embodiment of the present invention.
Figure 5 is a three-dimensional view viewed from the upper side of the injection unit according to an embodiment of the present invention, Figure 6 is a three-dimensional view viewed from the lower side.
7 is a cross-sectional view showing an injection unit according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in more detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, only the present embodiments make the disclosure of the present invention complete, and the scope of the invention to those of ordinary skill in the art It is provided to inform you. In order to describe the embodiments of the present invention, the drawings may be exaggerated, and the same reference numerals in the drawings refer to the same elements.

The present invention relates to a cutting device and a cutting method capable of reducing the amount of loss of the base material that is cut and discarded, and suppressing or preventing the generation of cutting snow and fume.

Hereinafter, as a base material that is an object to be cut, a cast steel manufactured by solidifying and casting molten steel will be described as an example. However, the base material is not limited to the cast steel, and various materials or products that can be cut by heat and oxidation by flame may be applied.

1 is a view showing a casting equipment having a cutting device according to an embodiment of the present invention.

Referring to FIG. 1, the casting equipment receives molten steel and initially solidifies it into a constant shape (mold) 30, which is provided in the lower part of the mold 30 and cools the unsolidified cast pieces drawn from the mold 30, while a series of Cutting provided with a cutting part for cutting the solidified cast slab into a predetermined length by being located at the rear end of the cooling table 40 and the cooling table 40 in which a plurality of segments 41 are continuously arranged to perform the molding operation Including device 5000.

In addition, the casting facility is a ladle 10 containing molten steel refined in the steel making process, a tundish 20, and a tundish that temporarily store molten steel through an injection nozzle connected to the ladle 10 and store the molten steel. It includes an immersion nozzle 22 for supplying the molten steel stored in the mold 30 to the mold (20).

2 is a view showing a cutting device according to an embodiment of the present invention.

Referring to Figure 2, the cutting device 5000 includes a cutting portion 5100 for generating a flame by injecting a gas toward the base material to be cut, that is, the cast (S), the cutting portion 5100 may be provided in plural. have.

In addition, the cutting device 5000 is mounted on the table 5200 and the table 5200 to horizontally move the cast piece transmitted from the cooling table 40 while supporting the length of the cast piece while supporting the cutting part 5100. And a gas supply unit 5400 having a traveling unit 5300 movable in the direction and a gas line for supplying gas for flame generation or cutting of cast iron to the cutting unit 5100.

First, the table 5200 and the traveling part 5300 of the cutting device 5000 will be described.

The table 5200 is a means for supporting a cast piece to be cut, and is positioned at the rear of the cooling table 40 to support the cast piece S continuously transmitted from the cooling table 40 while moving. These tables 5200, each extending in the longitudinal direction of the cast piece (S), a pair of guide members 5220 arranged in a row in the width direction of the cast piece (S) and a pair of guide members 5220 ) Is formed to extend in the alignment direction of the guide member 5220, is arranged in alignment in the extending direction of the guide member 5220, and includes a plurality of rollers 5210 on which the cast piece S is supported.

The pair of guide members 5220 are disposed to be spaced apart in the width direction of the cast piece S, and the separation distance between the pair of guide members 5220 is disposed to be greater than the length of the cast piece S in the width direction. The pair of guide members 5220 may be, for example, rails.

The plurality of rollers 5210 are arranged in a longitudinal direction of the cast steel S as described above to support the cast steel, and each of the rollers 5220 is installed to connect between the pair of guide members 5220 so as to be rotatable.

The running part 5300 is installed on the pair of guide members 5220 so as to be movable in the longitudinal direction of the cast piece. In other words, the running part 5300 is installed to slide on the pair of guide members 5220. The traveling part 5300 is formed extending from the upper side of the table 5200 in the arrangement direction of the pair of guide members 5220, and the traveling body 5310 protruding downward toward the table 5200 at both ends in the width direction. , It is formed to extend in the width direction of the cast piece S or in the extension direction of the traveling body 5310, and is mounted to be driven along the moving member 5320 and the moving member 5320 installed on the traveling body 5310, It includes a moving block 5330 on which the cutting portion 5100 is supported, and a traveling member 5340 installed at both ends of the traveling body 5310 so as to slide along the pair of guide members 5220.

The traveling body 5310 is in a downward direction in which the table 5200 is located from each of both ends of the first traveling body 5311 and the first traveling body 5311 extending in the arrangement direction of the pair of guide members 5220. It may include a pair of second traveling bodies 5312 which are formed to extend and have a traveling member 5340 mounted thereon. Here, for convenience of description, the traveling body 5310 is divided into a first traveling body 5311 and a second traveling body 5312, but it may be an integral means.

The traveling member 5340 is fastened to the lower portion of the traveling body 5310 protruding as described above, that is, the lower portion of the pair of second traveling bodies 5312 and slides along the guide member 5220. The driving member 5340 may be, for example, a wheel.

The moving member 5320 is a means for moving the cutting part 5100 in the width direction of the cast piece S, and may be a rail extending in the extending direction of the first traveling body 5311.

The moving block 5330 is a means for moving along the moving member 5320 while supporting the cutting portion 5100. The moving blocks 5330 are provided in a number corresponding to the cutting part 5100.

The cutting part 5100 is a means for oxidizing and cutting the cast steel S while heating and melting the cast steel S by generating a flame. That is, the cutting part 5100 is a means for injecting oxygen gas (hereinafter, referred to as first oxygen gas) for oxidizing the cast iron and combustion gas for generating a flame.

First, the combustion gas supplied to the cutting part 5100 will be described.

The combustion gas contains hydrogen gas. In addition, the combustion gas may further include oxygen gas (hereinafter, referred to as second oxygen gas), which is a gas that helps combustion of hydrogen gas. When the combustion gas includes hydrogen gas and second oxygen gas, the combustion gas may be described as a mixture of hydrogen gas and second oxygen gas. Here, the second oxygen gas is a gas having a lower pressure than the first oxygen gas.

Hydrogen gas is a gas having a calorific value of about 28,000 kcal/kg, which is more than twice as high as the heat amount (11,780 kcal/kg) of LNG gas used as a conventional combustion gas. Accordingly, when hydrogen gas is used as the combustion gas, a flame having a higher temperature can be generated than when using LNG gas under the same flow rate condition. In other words, the flow rate of hydrogen gas required to generate a flame of a target temperature or to heat a cast steel to a target temperature is less than that of the LNG gas. Accordingly, it is possible to reduce the flow rate of the combustion gas supplied to the cutting unit for cutting the cast steel compared to the conventional one.

In addition, as the flow rate of the combustion gas injected from the cutting portion 5100 decreases, the size of the flame, more specifically, the length of the flame in the longitudinal direction of the cast iron (hereinafter, the flame width) decreases. This can reduce the width of the cast steel heated by the flame.

3(a) is a result of measuring a cast steel with a thermal imaging camera when a flame is generated using LNG gas and oxygen gas as fuel gas. 3B is a result of measuring a cast steel with a thermal imaging camera when a flame is generated using hydrogen gas and oxygen gas as fuel gas. Here, (b) of FIG. 3 is shown by overlapping the captured image of FIG. 3 (a) for comparison of the heating width of the cast steel.

In addition, for the experiment, a cutting part having the same configuration and shape was used, and combustion gas was supplied at the same flow rate.

Referring to FIG. 3, the heating width HW _{2 of the} cast iron heated by the flame generated using hydrogen gas is narrower than the _{heating width HW 1} heated by the flame generated using the LNG gas.

From this, it can be seen that when hydrogen gas is used as the fuel gas, the heating width of the cast iron can be reduced compared to when the LNG gas is used, and the length or amount lost by cutting can be reduced.

In addition, since the hydrogen gas does not contain carbon (C), there is an effect of reducing the generation of fume due to carbon (C) as in the prior art.

Then, the function of the hydrogen gas and oxygen gas, some reactions there the water (H ₂ O) can be produced, the water (H ₂ O) has a melt quenching melt by the flame. Accordingly, it is possible to reduce the bonding force that the melt adheres to the cutting surface, and there is an effect that it is easy to remove the cutting snow afterwards.

Hereinafter, a cutting unit and a gas supply unit according to an exemplary embodiment of the present invention will be described with reference to FIGS. 4 to 7.

4 is a view showing a cutting unit and a gas supply unit according to an embodiment of the present invention. Figure 5 is a three-dimensional view viewed from the upper side of the injection unit according to an embodiment of the present invention, and Figure 6 is a three-dimensional view viewed from the lower side. 7 is a cross-sectional view showing an injection unit according to an embodiment of the present invention.

The cutting part 5100 is a means for oxidizing and cutting the cast steel S while heating and melting the cast steel S by generating a flame. As shown in FIG. 4, the cutting part 5100 includes an injection part 5120 for injecting a combustion gas for generating a flame and a first oxygen gas for oxidizing and cutting the cast steel S.

In addition, the cutting part 5100 may include a support part 5110 that is mounted on the moving block 5330 and supports the injection part 5120.

5 to 7, the injection part 5120 is formed to penetrate the injection body 5124 and the injection body 5124 mounted and installed under the support part 5110 in the vertical direction, and the first oxygen gas The first nozzle 5121 and each of the first nozzles 5121 are formed to pass through the injection body 5124 in the vertical direction from the outside of the first nozzle 5121, and are arranged to surround the first nozzle 5121, and are burned. It includes a plurality of second nozzles 5122 for injecting gas.

In addition, the injection unit 5120 may further include a third nozzle 5123 supplying the second oxygen gas to the second nozzle 5122.

The spray body 5124 is a configuration constituting the exterior of the spray part 5120 and is mounted under the support part 5110. The injection body 5124 according to the embodiment has a circular cross-section. However, the shape of the injection body 5124 is not limited thereto, and may be changed into various shapes in which a nozzle may be provided.

The first nozzle 5121 is a means for injecting a first oxygen gas that oxidizes the cast steel S for cutting, and the first oxygen gas may be a high-pressure gas.

The first nozzle 5121 is provided so as to be perpendicular to the cast piece S seated on the table 5200. For a more detailed description, an opening through which the first oxygen gas is introduced among the first nozzles 5121 (hereinafter, referred to as the first inlet 5121a) and an opening through which the introduced first oxygen gas is discharged (hereinafter, referred to as the first injection hole 5121b) The virtual line connecting )) is named as the first extension line (B _{1 ).} In addition, a virtual line parallel to the upper surface of the cast piece S seated on the table 5200 is referred _{to as a first reference line SL 1.}

Reflecting this, the first nozzle 5121 will be described again. In the first nozzle 5121, the first extension line B ₁ is the first reference line SL ₁ and the angle θ ₁ is perpendicular (or right angle). It is formed to achieve.

The flow of the first oxygen gas injected through the first nozzle 5121 may be referred to as “first injection direction”.

The first nozzle 5121 may have a different diameter in the extending direction. More specifically, the first nozzle 5121 has an inner space through which gas can pass, the first passage 5121-1 having a constant diameter in the vertical direction, and one end is connected to the first passage 5121-1, A second passage (5121-2) whose diameter decreases toward the other end, one end is connected to the second passage (5121-2), a third passage (5121-3) having a constant vertical diameter, and one end of the third passage (5121-3). A fourth passage 5121-4 connected to the passage 5121-3 and having a larger diameter toward the other end may be included.

Accordingly, the lower portion of the first nozzle 5121 may be described as a shape whose diameter increases toward the direction in which the first injection hole 5121b is located. In this way, as the lower part of the first nozzle 5121 or the fourth passage 5121-4 is provided in a shape whose diameter increases as it goes downward, there is an effect of increasing the injection pressure of the first oxygen gas due to the Venturi effect. .

Among both ends of the first passage 5121-1, one end opposite to the other end connected to the second passage 5121-2 is the first inlet 5121a through which the first oxygen gas is introduced. In addition, of both ends of the fourth passage 5121-4, the other end connected to the third passage 5121-3, which is the opposite end, is the first injection port 5121b through which the first oxygen gas is discharged. In this case, the _{diameter D 1} of the first injection port 5121b, which is the other end of the fourth passage 5121-4, is provided to be smaller _{than the first inlet I 1 which is one end of the first passage 5121-1.} .

Also, the diameter of the first passage 5121-1 may be larger than the diameter of the third and fourth passages 5121-3 and 5121-4. In addition, of both ends of the second passage 5121-2, one end may be the same as the diameter of the first passage 5121-1 and the other end may be the same as the diameter of the third passage 5121-3.

In addition, the vertical extension lengths of the first to fourth passages 5121-1, 5121-2, 5121-3, and 5121-4 are the third passage 5121-3, the first passage 5121-1, and the fourth passage. The passages 5121-4 and the second passages 5121-2 may be formed to be elongated in that order.

_{The first nozzle 5121 is provided such that the diameter D 1} of the first injection hole 5121b through which the first oxygen gas is discharged is 2mm to 4mm. This is to minimize the area lost by cutting while sufficiently spraying the first oxygen gas into the cast iron through the first injection hole 5121b.

On the other hand, when the diameter (D ₁ ) of the first injection hole 5121b is less than 2 mm, oxidation is insufficient due to insufficient first oxygen gas injected through the first injection hole 5121b, and thus, in the thickness direction of the cast plate (S). Cutting defects that are not partially cut may occur.

Conversely, when the diameter (D ₁ ) of the first injection hole 5121b exceeds 4mm, the first oxygen gas injected into the cast piece S through the first injection hole 5121b or reaching the cast piece S Since the area is large, there is a problem that the area oxidized by the first oxygen gas becomes unnecessarily large. In other words, the area of the cast iron exposed to the first oxygen gas injected through the first injection hole 5121b is large, and the cast iron S is oxidized to an excessive area. Accordingly, there is a problem in that the amount of loss due to cutting is large and the amount of product produced is reduced.

The second nozzle 5122 is a means for injecting combustion gas for generating a flame, and the combustion gas includes hydrogen gas. In the second nozzle 5122, of the openings at both ends, combustion gas flows into the opening at one end (hereinafter, referred to as the second inlet 5122a), and the opening at the other end (hereinafter, referred to as the second injection port 5122b) The combustion gas is injected through.

In addition, a plurality of second nozzles 5122 are provided and arranged in a circumferential direction of the spray body 5124 from the outside of the first nozzle 5121. Accordingly, the plurality of second nozzles 5122 are arranged to surround the first nozzle 5121. In this case, it is preferable that the plurality of second nozzles 5122 and the first nozzle 5121 are provided with the same separation distance.

In addition, the second nozzle 5122 is not parallel to the first nozzle 5121 and is provided to be inclined toward or have an inclination toward the first nozzle 5121. More specifically, the second nozzle 5122 is formed to be inclined to be closer to the first nozzle 5121 as it goes downward.

For a more detailed description, _{a virtual line parallel to the first extension line B 1} is named as a second reference line SL ₂ , and the second inlet 5122a and the second injection port 5122b of the second nozzle 5122 The imaginary line connected to is referred to as a second extension line (B _{2 ).}

Reflecting this, the second nozzle 5122 is provided so that the second extension line B ₂ is not parallel to the second reference line SL ₂ and is inclined to be closer to the first nozzle 5121 as it goes downward.

In addition, the second nozzle 5122 is provided so that the inclination angle formed with the first nozzle 5121 is 3° to 14°, more preferably 5° to 9°. In other words, the angle θ _{2 formed by the second extension line B 2} and the second reference line SL ₂ is 3° to 14°, more preferably 5° to 9°.

_{In this way, adjusting the inclination angle θ 2} of the second nozzle 5122 to 3° to 14° increases the heating area of the cast iron S unnecessarily, or the combustion gas injected through the second nozzle 5122 This is to suppress or prevent the flow or obstruction of the flow of the first oxygen gas injected through the first nozzle 5121.

The flow of the combustion gas injected through the second nozzle 5122 may be referred to as a'second injection direction'.

On the other hand, if the inclination angle θ ₂ of the second nozzle 5122 is provided so that it is less than 3° or exceeds 14°, a cutting failure may occur or a cast iron heating region may increase.

The injection unit 5100 is configured to be fastened to and detached from the lower portion of the support unit 5110. In addition, the first to third gas lines 5420a, 5420b, and 5420c of the gas supply unit 5400, which will be described later, pass through the support portion 5110 to be supported. At this time, the positions of the first to third gas lines 5420a, 5420b, and 5420c in the support part 5110 do not change and are fixed.

Accordingly, depending on the fastening structure of the support part 5110 and the injection part 5120, the positions of the first to third gas lines 5420a, 5420b, and 5420c installed to pass through the support part 5110, on the injection body 5124 The positions of the first to third inlets 5121a, 5122a, and 5123a are determined. That is, the positions of the first to third inlets 5121a, 5122a, and 5123a are determined for fastening and connection between the support part 5110 and the injection part 5120 and are not changed.

Thus, the fact that the inclination angle of the second nozzle 5122 is less than 3° or exceeds 14° does not change the position of the second inlet 5122a, and is provided by changing the position of the second injection port 5122b. I can.

On the other hand, the second nozzle 5122 has a shape inclined so that the second injection port 5122b is closer to the first nozzle 5121 than the second inlet 5122a, while the position of the second inlet 5122a is fixed, When the inclination angle of the second nozzle 5122 is decreased, the second injection hole 5122b gradually becomes farther away from the first injection hole 5121b.

In addition, the second nozzle 5122 has an inclined shape such that the second injection port 5122b is closer to the first nozzle 5121 than the second inlet 5122a, and the position of the second inlet 5122a is fixed, When the inclination angle of the second nozzle 5122 is increased, the second injection hole 5122b becomes closer to the first injection hole 5121b.

Accordingly, the second nozzle 5122 has an inclined shape such that the second injection port 5122b is closer to the first nozzle 5121 than the second inlet 5122a, and the position of the second inlet 5122a is fixed, When the inclination angle θ ₂ of the second nozzle 5122 is reduced to less than 3°, the separation distance SD between the second injection hole 5122b and the first injection hole 5121b becomes too large. Accordingly, the cast iron region (i.e., oxidation region) oxidized by the first oxygen gas injected from the first injection port 5121b and the flame generated by combustion of the combustion gas injected from the second injection port 5122b There is a problem that the overlapping area between the cast areas (ie, heating areas) becomes too small. In this case, even if the cast iron is heated, it is not oxidized, or if the oxidation is insufficient, it is not cut. Therefore, if the overlapping area between the oxidation region and the heating region is small, as described above, it is not possible to cut or a part of it is not cut. Can occur.

In order to increase the overlapping area between the heating region and the oxidation region of the cast steel S, the amount of hydrogen gas and the second oxygen gas supplied to the second nozzle 5122 may be increased, but due to this, the consumption amount of hydrogen and the second oxygen gas And there is a problem in that the cost is increased due to this.

In addition, as described above, when the inclination angle θ ₂ of the second nozzle 5122 is reduced to less than 3°, the separation distance between the plurality of second nozzles 5122 must be increased. In this case, since the combustion gas injection area from the plurality of second nozzles 5122 increases, there is a problem in that the area of the flame increases, and thus, the heating area of the cast iron unnecessarily increases.

Conversely, the second nozzle 5122 has an inclined shape so that the second injection port 5122b is closer to the first nozzle 5121 than the second inlet 5122a, while the position of the second inlet 5122a is fixed, When the inclination angle θ ₂ of the second nozzle 5122 is increased to exceed 14°, the separation distance SD between the second injection hole 5122b and the first injection hole 5121b becomes too close. The combustion gas injected through the second nozzle 5122 may interfere with the flow of the first oxygen gas injected through the first nozzle 5121. That is, when the inclination angle θ ₂ of the second nozzle 5122 exceeds 14°, a large amount of the first oxygen gas discharged from the first nozzle 5121 collides with the combustion gas. Accordingly, a large amount of the first oxygen gas discharged from the first nozzle 5121 is moved or changed in flow. Accordingly, diffusion of the first oxygen gas injected from the first nozzle 5121 may occur, resulting in insufficient oxidation of the heating region, resulting in failure to be cut or partly cut off.

The second nozzle 5122 is provided so that the diameter D ₂ of the second injection hole 5122b is greater than or equal to the diameter I _{2 of the second inlet 5122a.} In addition, the second injection port 5122b has a diameter D ₂ of 0.7 mm to 2.5 mm.

On the other hand, when the diameter (D ₂ ) of the second injection hole 5122b is less than 0.7mm or exceeds 2.5mm, the flow rate or flow rate of the combustion gas discharged from the second injection hole 5122b is small, so that the flame is not sufficiently formed. The flame may not reach the cast iron, or the temperature of the flame may be low. In this case, the cast piece (S) is not sufficiently heated to be cut, or a defect in which a part is not cut may occur.

The second nozzle 5122 may have a shape having a different diameter in the vertical direction. More specifically, the second nozzle 5122 has a passage having an inner space through which gas can be moved (hereinafter, referred to as the fifth passage 5122-5), and one end is connected to the fifth passage 5122-5, and the fifth passage It includes a passage having a larger diameter than the (5122-5) (hereinafter, the sixth passage (5122-6)). Here, the extended length of the sixth passage 5122-6 may be longer than that of the fifth passage 5122-5.

In addition, one end of the fifth passage 5122-5 is a second inlet 5122a through which hydrogen gas is introduced. In addition, the other end of the sixth passage 5122-6 opposite to one end connected to the second passage 5121-2 is the second injection port 5122b.

The combustion gas may include a second oxygen gas in addition to hydrogen gas, and the second oxygen gas may be supplied to the second nozzle 5122. Accordingly, a third nozzle 5123 for supplying the second oxygen gas to the second nozzle 5122 may be provided.

The third nozzle 5123 is a means for supplying the second oxygen gas to the second nozzle 5122, and the second oxygen gas is introduced into one of the openings at both ends (hereinafter, the third inlet 5123a). , The opening at the other end (hereinafter, the outlet 5123b) is connected to the second nozzle 5122 so as to communicate with the inner space of the second nozzle. Accordingly, when the second oxygen gas is supplied from the third nozzle 5123 to the second nozzle 5122, the hydrogen gas and the second oxygen gas are mixed in the second nozzle 5122.

The third nozzle 5123 may have a shape having a different diameter in the extending direction. More specifically, the third nozzle 5123 has a passage through which gas can be moved (hereinafter, the seventh passage 5123-7) and one end is connected to the seventh passage 5123-7, and the seventh passage 5123- It includes a passage having a smaller diameter than 7) (hereinafter, the eighth passage 5123-8).

Here, one end of the seventh passage 5123-7 is a third inlet 5123a through which the second oxygen gas is introduced. And, of the eighth passages 5123-8, the other end opposite to one end connected to the seventh passage 5123-7 is the discharge port 5123b.

The support part 5110 is a means for supporting the injection part 5120 and is mounted on the moving block 5330. Accordingly, the cutting part 5100 may be horizontally moved in the width direction of the cast piece S together with the moving block. In addition, the support part 5110 serves to support the gas lines 5420a, 5420b, and 5420c of the gas supply part 5400, which will be described later. That is, the gas lines 5420a, 5420b, and 5420c are formed to extend through the support portion 5110, and their ends are connected to the injection portion.

The gas supply unit 5400 is a means for supplying the first and second oxygen gas and hydrogen gas to the cutting unit 5100. More specifically, the gas supply unit 5400 supplies a first oxygen gas to the first nozzle 5121 of the injection unit 5120, a hydrogen gas to the second nozzle 5122, and a second oxygen gas to the third nozzle 5123. Supply.

The gas supply unit 5400 includes a first gas storage unit 5410a in which a first oxygen gas is stored, a second gas storage unit 5410b in which hydrogen gas is stored, a third gas storage unit 5410c in which the second oxygen gas is stored, One end is connected to the first gas storage unit (5410a), the other end is connected to the first gas line (5420a) connected to the first nozzle (5121) of the injection unit (5120), one end is connected to the second gas storage unit (5410b) The second gas line 5420b connected to the second nozzle 5122 of the injection unit 5120 and the other end connected to the third gas storage unit 5410c, and the other end of the injection unit 5120 And a third gas line 5420c connected to the nozzle 5123.

In addition, the gas supply unit 5400 is installed on the extension path of each of the first to third gas lines 5420a, 5420b, and 5420c to control the gas flow rate first to third flow control unit 5430a, 5430b, 5430c, cutting unit It is installed on the extension path of the first to third gas lines 5420a, 5420b, 5420c so as to be located between the 5100 and the flow control units 5430a, 5430b, 5430c, The first to third gas lines 5420a so as to be located between the backfire prevention parts 5440a, 5440b, and 5440c, the first to third backfire prevention parts 5440a, 5440b, and 5440c and the flow control parts 5430a, 5430b, and 5430c. , 5420b, 5420c), and may include fourth to sixth backfire prevention units 5450a, 5450b, and 5450c to prevent backfire of the flame.

The first gas storage unit 5410a is a means for providing a high-pressure first oxygen gas, and the pressure may be 5 bar to 10 bar. In addition, the second gas storage unit 5410b provides hydrogen gas, which is one of the combustion gases, and the pressure may be 3 bar to 3.5 bar. In addition, the third gas storage unit 5410c provides the second oxygen gas having a lower pressure than the first oxygen gas, and the pressure may be 0.4 to 0.6 bar.

The first gas line 5420a has its other end connected to the first inlet 5121a of the first nozzle 5121, and the second gas line 5420b has its other end connected to the second inlet ( 5122a), and the other end of the third gas line 5420c is connected to the third inlet 5123a of the third nozzle 5123. In addition, each of the first to third gas lines 5420a, 5420b, and 5420c may be a pipe or a hose through which gas can be moved.

The first to sixth backfire prevention units 5440a, 5440b, 5440c, 5450a, 5450b, and 5450c have a flame through the first to third gas lines 5120a, 5420b, and 5420c, and the first to third gas storage units ( 5410a, 5410b, 5410c) is a means to prevent accidents by blocking reverse flow.

That is, the first to third backfire prevention parts 5440a, 5440b, and 5440c are the first to third backfire prevention parts 5440a, 5440b, and 5440c and the fourth to sixth backfire prevention parts 5450a, 5450b, and 5450c. ) It is a means to prevent the flame from flowing back. In addition, the fourth to sixth backfire prevention units 5450a, 5450b, and 5450c include the first to third backfire prevention units 5440a, 5440b, and 5440c, and the flames passing through the fourth to sixth backfire prevention units 5450a, 5450b , 5450c) and the first to third gas storage units 5410a, 5410b, and 5410c.

These first to sixth backfire prevention parts 5440a, 5440b, 5440c, 5450a, 5450b, and 5450c are provided with a backfire prevention filter to prevent the backflow of the flame, so that the gas flows in only one direction. , It may be a means to block the flow of gas in the reverse direction. For example, the first to sixth backfire prevention units 5440a, 5440b, 5440c, 5450a, 5450b, and 5450c allow gas to flow only in the direction in which the cutting unit 5100 is located, and the first to third gas storage units ( 5410a, 5410b, 5410c) may be a means provided with a check valve for blocking the flow in the direction.

Of course, the first to sixth backfire prevention portions 5440a, 5440b, 5440c, 5450a, 5450b, and 5450c are not limited to the above-described examples, and allow gas to flow only in the direction of the cut portion 5100, and the reverse direction Various means can be applied to block the flow of gas.

Hereinafter, a method of cutting a cast piece using a cutting device according to an embodiment of the present invention will be described with reference to FIGS. 1, 2 and 4 to 7.

When the primary solidified cast piece S is drawn from the mold 30, the cast piece S is secondarily solidified while moving along the cooling zone 40 installed under the mold 30. Then, the cast piece S, which has passed through the cooling table 40 and has been solidified, is seated and supported on the roller 5210 of the cutting device 5000.

Thereafter, the cutting part 5100 cuts the cast piece S seated on the roller 5210 to a predetermined length. To this end, the gas supply unit 5400 supplies the first oxygen gas and the combustion gas to the injection unit 5120 of the cutting unit 5100.

That is, the first oxygen gas of the first gas storage unit 5410a is supplied to the first nozzle 5121 of the injection unit 5120 through the first gas line. At this time, the pressure of the first oxygen gas supplied to the first nozzle 5121 may be 5 bar to 10 bar, and the flow rate may be 23 Nm ³ /h to 27 Nm ³ /h. Accordingly, the first oxygen gas having a high pressure of 5 bar to 10 bar is injected from the first injection port 5121b of the first nozzle 5121.

In addition, fuel gas, that is, hydrogen gas of the second gas storage unit 5410b is supplied to the second nozzle 5122 through the second gas line 5420b. In this case, the hydrogen gas supplied to the second nozzle 5122 may have a pressure of 3 bar to 3.5 bar.

At this time, the second oxygen gas may be further used as the fuel gas. In this case, the second oxygen gas of the third gas storage portion 5410c is further supplied to the third nozzle 5123 through the third gas line 5420c. The second oxygen gas supplied to the third nozzle 5123 may have a pressure of 0.4 to 0.6 bar.

In this way, when hydrogen gas and second oxygen gas are used as the fuel gas, the flow rate of the hydrogen gas supplied to the second nozzle 5122 is supplied so that the flow rate of the second oxygen gas supplied to the third nozzle 5123 is greater than the flow rate of the second oxygen gas supplied to the third nozzle 5123. It is desirable. Further, the flow rate of the combustion gas injected from the second plurality of nozzles (5122) may be 12Nm ³ / h to 15Nm ³ / h. That is, the sum of the combustion gas flow is injected from each of the second plurality of nozzles (5122) may be 12Nm ³ / h to 15Nm ³ / h.

In this way, when hydrogen gas is supplied to the second nozzle 5122 and the second oxygen gas is supplied to the third nozzle 5123, the hydrogen gas and the second oxygen gas are supplied from the second injection port 5122b of the second nozzle 5122. The mixed combustion gas is injected.

In this way, when the combustion gas is injected from the second injection port 5122b, if the flame is ignited around the combustion gas using a separately provided igniter, the hydrogen gas and the second oxygen gas of the combustion gas are combusted to generate a flame. And, the cast (S) is heated and melted by the generated flame.

In addition, while a flame is generated and the cast steel S is heated, the cast steel heating region is rapidly oxidized and cut by the high-pressure first oxygen gas injected from the first injection port 5121b.

The cutting of the cast piece S is performed while horizontally moving the cut portion 5100 in the width direction of the cast piece. That is, the moving block 5330 on which the cutting part 5100 is mounted is cut while moving along the moving member 5320.

In addition, the cutting portions 5100 may be provided in a pair so as to face each other, and the cast pieces S may be cut by operating each of the pair of cutting portions 5100. That is, one of the pair of cut parts 5100 may be cut while moving from one edge of the cast piece S in the width direction to the center direction, and moving the other cut part 5100 from the other edge to the center direction.

In addition, by moving the driving part 5300 on which the cutting part 5100 is mounted in the longitudinal direction of the cast iron, the cutting length may be adjusted.

And, as the hydrogen gas is used as the combustion gas that generates the flame, the width of the flame (FW) can be reduced compared to the prior art. For this reason, it is possible to reduce the heating width of the cast piece (S) due to the flame compared to the prior art, it is possible to reduce the length or amount lost by cutting.

In addition, since the hydrogen gas does not contain carbon (C), there is an effect of reducing the generation of fume due to carbon (C) as in the prior art.

Then, the embodiment with use of hydrogen gas as combustion gas, there is hydrogen gas and oxygen gas may be some reaction with the water (H ₂ O) generated, the water (H ₂ O) has a melt molten by flame It functions to rapidly cool. Accordingly, it is possible to reduce the bonding force that the melt adheres to the cutting surface, and there is an effect that it is easy to remove the cutting snow afterwards.

In addition, the second nozzle 5122 is provided to be inclined to be closer to the first nozzle 5121 as it goes downward, and the angle θ ₂ formed with the first nozzle 5121 is optimized. Accordingly, it is possible to increase the overlapping area between the heating zone by the flame and the oxidation zone by the high pressure first oxygen gas, and to prevent the diffusion of the first oxygen gas, so that the first oxygen gas can be densely injected toward the cast steel. have. Accordingly, it is possible to prevent the occurrence of a cutting failure in which a part is not cut due to insufficient heating or insufficient oxidation of the cast steel.

_{In addition, by optimizing the diameter D 1} of the first injection hole 5121b of the first nozzle 5121, the cast steel S can be sufficiently oxidized and the area lost by cutting can be reduced.

_{In addition, by optimizing the diameter (D 2} ) of the second injection hole 5122b of the second nozzle 5122, the flame may sufficiently reach the cast iron. In other words, it is possible to prevent the occurrence of a problem that the flame does not reach the cast iron due to the small flow rate or flow rate of the combustion gas.

5120: injection unit 5124: injection body
5121: first nozzle 5122: second nozzle
5123: third nozzle

Claims (20)

A first nozzle for injecting a first oxygen gas toward the base material; And
A second nozzle that injects combustion gas including hydrogen gas so as to generate a flame toward the base material, and is formed to be inclined to be closer to the first nozzle toward an end from which the combustion gas is discharged;
Cutting device comprising an injection unit having a. The method according to claim 1,
One of both ends of the first nozzle is a first inlet through which the first oxygen gas is introduced, and the other end is a first injection port through which the first oxygen gas is discharged,
The first nozzle is a cutting device provided such that an angle formed by a first extension line, which is a virtual line connecting the first inlet and the first injection port, is perpendicular to a reference line, which is a virtual line parallel to an upper surface of the base material. The method according to claim 2,
The first nozzle,
A first passage having a constant diameter in the vertical direction;
A second passage having one end connected to the first passage and having a smaller diameter toward the other end;
A third passage having one end connected to the second passage and having a constant vertical diameter; And
A fourth passage having one end connected to the third passage and having a larger diameter toward the other end;
Including,
One end of both ends of the first passage that is opposite to the other end connected to the second passage is the first inlet,
A cutting device in which the other end of both ends of the fourth passage, opposite to one end connected to the third passage, is the first injection port. The method of claim 3,
A cutting device in which the diameter of the first passage is larger than that of the third and fourth passages. The method of claim 3,
A cutting device that extends vertically of the first to fourth passages in the order of a third passage, a first passage, a fourth passage, and a second passage. The method according to claim 1,
One of both ends of the second nozzle is a second inlet through which combustion gas is introduced, and the other end is a second injection port through which the combustion gas is discharged,
The second nozzle is a cutting device formed such that an angle formed by a second extension line, which is a virtual line connecting the second inlet and the second injection port, with the first extension line is 3° to 14°. The method of claim 6,
The second nozzle is a cutting device formed such that an angle between the second extension line and the first extension line is 5° to 9°. The method of claim 6,
The second nozzle,
A fifth passage through which the combustion gas can be moved; And
A sixth passage having one end connected to the fifth passage and having a larger diameter than the fifth passage;
Including,
Of both ends of the fifth passage, one end opposite to the other end connected to the sixth passage is the second inlet,
A cutting device in which the other end of both ends of the sixth passage, opposite to one end connected to the fifth passage, is the second injection port. The method of claim 8,
A cutting device in which the extended length of the sixth passage is longer than that of the fifth passage. The method according to claim 1,
A cutting device in which a plurality of the second nozzles are provided and arranged so as to surround the first nozzle. The method according to claim 2,
A cutting device having a diameter (D ₁ ) of 2mm to 4mm of the first injection port. The method of claim 6,
The diameter (D ₂₎ is a cutting device more than the diameter (I ₂₎ of the second inlet of the second nozzle. The method of claim 12,
A cutting device having a diameter (D ₂ ) of 0.7mm to 2.5mm of the second injection hole. The method according to any one of claims 1 to 13,
A third nozzle connected to the second nozzle and supplying a second oxygen gas having a lower pressure than the first oxygen gas to the second nozzle,
The combustion gas is a mixed gas in which the hydrogen gas and the second oxygen gas are mixed inside the second nozzle. An oxidation process of oxidizing the base material by injecting a first oxygen gas in a first injection direction so as to face the base material to be cut;
Generating a flame by injecting combustion gas including hydrogen gas toward the base material in a second injection direction crossing the first injection direction; And
Cutting the base material by oxidation of the base material and heating by the flame;
Cutting method comprising a. The method of claim 15,
A cutting method of injecting the first oxygen gas and the combustion gas so that the angle formed by the first injection direction and the second injection direction is 3° to 14°. The method of claim 15,
A cutting method for injecting such that the flow rate of the first oxygen gas is larger than the flow rate of the combustion gas. The method of claim 15,
A cutting method wherein the pressure of the first oxygen gas is 5 bar to 10 bar, and the pressure of the hydrogen gas is 3 bar to 3.5 bar. The method of claim 15,
The combustion gas is a cutting method comprising a second oxygen gas having a lower pressure than the first oxygen gas. The method of claim 19,
The pressure of the second oxygen gas is 0.4bar to 0.6bar cutting method.

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