Gas Supply Equipment

Abstract

To provide a gas feed device capable of blowing gas of a prescribed flow rate without requiring adjustment.SOLUTION: A gas feed device 1 comprises: a first gas flow passage 2 receiving the feed of gas from a gas socket 21 to feed the gas to a gas suction plug P attached to a ladle; a second gas flow passage 3 having a pressure accumulation cylinder T storing gas and receiving the feed of the gas from the gas socket 21 to feed the gas to the pressure accumulation cylinder T; and a third gas flow passage 4 feeding a small amount of gas from the pressure accumulation cylinder T to the gas suction plug P. The third gas flow passage 4 has an orifice plate 44 through which an orifice hole 46 with an inside diameter reduced compared to the inside diameter of the third gas flow passage 4, 40 passes.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a gas supply device. [Background technology]

[0002] Traditionally, ladles are used to handle molten metal (molten metal). A ladle stores or contains molten metal. A ladle is equipped with a gas injection plug (hereinafter also referred to as an injection plug) that injects gas into the stored or contained molten metal. The injection plug is typically installed at the bottom of a tank-shaped ladle. The injection plug injects gases such as argon or nitrogen into the molten metal. This serves to stir the molten metal, regulate its temperature, and promote the removal reaction of nonmetallic components. The injection plug can be a porous plug with a porous, molded refractory layer with continuous pores, or a slit plug with a dense, unmolded refractory layer with slits (slit-like pores). The injection plug injects gas into the molten metal by passing it through the porous or slit-like pores.

[0003] When the ladle is moved after the gas injection process, it is disconnected from the gas piping. At this time, since the gas injection is stopped, molten metal enters the inside of the pores of the blowing plug. The molten metal that has entered the inside of the pores solidifies over time. Even if the ladle is subsequently used again, the pores of the blowing plug are clogged with the entered metal. For this reason, it was necessary to remove the entered metal before the ladle could be reused.

[0004] To address this problem, Patent Document 1 proposes a gas supply device in which a pressurized gas cylinder (hereinafter also referred to as a cylinder) that stores gas under pressure is attached to the ladle, and when the gas piping is disconnected from the gas supply source, gas is supplied from this cylinder to the blowing plug.

[0005] Patent Document 1 describes a pressure-accumulator gas injection device (gas supply device) detachably mounted on a ladle. This pressure-accumulator gas injection device includes a main pipe, a pressure-accumulator cylinder that accumulates gas through the main pipe, and a control unit that accumulates gas in the pressure-accumulator cylinder simultaneously with the start of gas injection through the main pipe or during gas injection, and switches to injection of the gas accumulated in the pressure-accumulator cylinder simultaneously with the end of gas injection through the main pipe. The device also includes a flow control valve for adjusting the gas flow rate when releasing the gas from the pressure-accumulator cylinder. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-239010 Summary of the Invention [Problem to be solved by the invention]

[0007] In conventional gas supply systems, the flow rate of gas flowing from the accumulator cylinder toward the blowing plug is adjusted by a flow control valve. A movable valve device such as a needle valve is used as the flow control valve. The movable valve device has the problem that the valve opening changes due to vibrations caused by the ladle moving, which causes the gas flow rate to change. If the gas flow rate changes, the blowing plug will no longer be able to blow out the gas at the specified flow rate, and there is a risk that the pores in the blowing plug will become clogged. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a gas supply device that can blow out gas at a predetermined flow rate without requiring adjustment. [Means for solving the problem]

[0008] The gas supply device of the present invention, which solves the above-mentioned problems, comprises: a first gas flow path having a gas receiving port for receiving a supply of gas during refining of molten steel contained in a ladle, and receiving the supply of gas from the gas receiving port and supplying the gas to a gas injection plug attached to the ladle; a second gas flow path having a pressure accumulator cylinder for storing gas, and receiving the supply of gas from the gas receiving port and supplying the gas to the pressure accumulator cylinder; and a third gas flow path for supplying a small amount of gas from the pressure accumulator cylinder to the gas injection plug, wherein the third gas flow path has an orifice plate therethrough through which an orifice hole having an inner diameter smaller than that of the third gas flow path passes.

[0009] The gas supply device of the present invention is provided with an orifice plate having orifice holes therethrough, thereby making it possible to maintain a constant flow rate of the gas flowing through the third gas flow path (specifically, the gas flowing from the accumulator cylinder toward the gas injection plug). Furthermore, since there are no moving parts for adjusting the flow rate, the gas flow rate does not change even if the ladle vibrates. Furthermore, since there are no moving parts for adjusting the flow rate, the space required for moving parts in conventional configurations is no longer necessary, making it possible to reduce the overall size of the gas supply device. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a front view showing a configuration of a gas supply device according to an embodiment. [Figure 2] FIG. 2 is a diagram showing the configuration of an orifice plate. [Figure 3] FIG. 2 is a configuration diagram showing a gas flow in the gas supply device of the embodiment. [Figure 4] FIG. 2 is a configuration diagram showing a gas flow in the gas supply device of the embodiment. [Figure 5] FIG. 2 is a configuration diagram showing a gas flow in the gas supply device of the embodiment. [Figure 6] FIG. 1 is a diagram showing a needle valve of a conventional gas supply device. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention will be described below using embodiments. Note that the embodiments are one form of specifically implementing the present invention, and the present invention is not limited to these forms. Furthermore, configurations and materials not specifically mentioned in the embodiments can be the same as those of conventional gas supply devices.

[0012] [Embodiment] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A gas supply device according to an embodiment of the present invention will be described below with reference to the drawings. A gas supply device 1 according to this embodiment is mounted on a ladle containing molten steel.

[0013] (Gas supply equipment) As shown in FIG. 1, the gas supply device 1 of this embodiment includes a first gas flow path 2, a second gas flow path 3, a third gas flow path 4, and a case 5. The first gas flow path 2 is divided into a first pipe 20. The first pipe 20 is formed of a pipe. The first pipe 20 has a gas supply port 21, a gas discharge port 22, a check valve 23, and a strainer 24.

[0014] During refining with molten steel contained in a ladle, the gas supply port 21 of the first piping 20 is connected to a gas supply source G as shown in FIG. 1, and a large amount of gas is supplied from the gas supply source G. The large amount of gas supplied to the gas supply port 21 is supplied to the blowing plug P through the first piping 20. The gas supply port 21 is disconnected from the gas supply source G when refining is completed. The gas supply port 21 corresponds to a gas receiving port.

[0015] The gas outlet 22 of the first pipe 20 is connected to a blowing plug P. The blowing plug P is used to blow gas into the molten steel contained in the ladle. The blowing plug P is made of a refractory material and has a truncated cone shape. The blowing plug P corresponds to a gas blowing plug.

[0016] The check valve 23 of the first pipe 20 allows gas to flow from the gas supply port 21 of the first pipe 20 toward the gas discharge port 22 (second pipe 30) and regulates the flow of gas in the opposite direction. A conventional check valve can be used as the check valve 23 as long as it is a valve that can restrict the flow of gas in the first pipe 20 to only a predetermined direction.

[0017] The strainer 24 of the first pipe 20 is a member that removes foreign matter contained in the gas flowing through the first gas flow path 2 (inside the first pipe 20). The specific configuration of the strainer 24 is not limited. In this embodiment, the strainer 24 is a Y-shaped strainer in which a cylindrical filter material is pressed from below onto the first pipe 20 in a state inclined with respect to the gas flow direction.

[0018] The second gas flow path 3 is divided into a second pipe 30. The second pipe 30 is formed by a pipe. The second pipe 30 has a first connection part 31 connected to the first pipe 20, a second connection part 32 connected to the accumulator cylinder T, two filters 33 and 34, a check valve 35 provided between the two filters 33 and 34, and a safety valve 36 provided between the second connection part 32 and the filter 33.

[0019] The filters 33 and 34 of the second pipe 30 are members that remove foreign matter contained in the gas flowing through the second gas flow path 3 (inside the second pipe 30). The specific configuration of the filters 33 and 34 is not limited. In this embodiment, the filters are made of a metal mesh.

[0020] The check valve 35 of the second piping 30 allows gas to flow from the first connection part 31 of the second piping 30 toward the accumulator cylinder T (second connection part 32) and regulates the flow of gas in the reverse direction. A conventional check valve can be used as the check valve 35 as long as it is a valve that can restrict the flow of gas in the second piping 30 to only a predetermined direction.

[0021] The safety valve 36 of the second pipe 30 is a valve device that releases gas when the pressure of the gas inside the second pipe 30 and the accumulator cylinder T exceeds a predetermined value. The safety valve 36 can be any conventional valve device that can reduce the pressure of the gas inside the second pipe 30 and the accumulator cylinder T to a predetermined pressure or lower. In this embodiment, the safety valve 36 is a relief valve.

[0022] The third gas flow path 4 is divided into a third pipe 40. The third pipe 40 is formed of a pipe. The third pipe 40 has a first connector 41 connected to the second pipe 30, a second connector 42 connected to the first pipe 20, a filter 43, and an orifice plate 44 provided between the filter 43 and the second connector 42. The filter 43 of the third pipe 40 is a member that removes foreign matter contained in the gas flowing through the third gas flow path 4 (inside the third pipe 40). The specific configuration of the filter 43 is not limited. In this embodiment, it is a metal mesh.

[0023] 2, the orifice plate 44 of the third pipe 40 is connected to the third pipe 40 by joints 45, 45 formed on both ends thereof. The orifice plate 44 of this embodiment is a circular plate with a thickness of 1.52 mm, and has small holes 46 with a diameter of 0.8 mm formed therein.

[0024] In this embodiment, the first pipe 20, the second pipe 30, and the third pipe 40 all use pipes with the same inner diameter. That is, in the gas supply device 1 of this embodiment, the gas flow path is defined by pipes with a substantially constant inner diameter. The inner diameter of the third pipe 40 decreases at the orifice plate 44.

[0025] The case 5 is a member that houses and fixes the first pipe 20, the second pipe 30, and the third pipe 40. The case 5 of this embodiment houses the first pipe 20 and the second pipe 30 inside with the gas supply port 21 and the gas discharge port 22 of the first pipe 20 and the second connection part 32 of the second pipe 30 located outside the case 5. The case 5 in this embodiment has a box shape that is covered on all sides. The case 5 has a heat insulating material 50 disposed on the inner peripheral surface thereof. The materials of the case 5 and the heat insulating material 50 are not limited.

[0026] The gas supply device 1 of this embodiment is installed in a ladle. The gas supply device 1 of this embodiment (i.e., the case 5) is installed and fixed to the outer circumferential surface of the ladle. The ladle is a member in which a blowing plug P is provided, and is a tank-like container made of a refractory material capable of containing high-temperature molten steel. The ladle has the blowing plug P provided at its bottom.

[0027] The blow plug P can be a conventionally known blow plug. The blow plug P of this embodiment has a refractory material in the shape of a truncated cone. The tip surface of this refractory material corresponds to the inner surface of the ladle (the surface that contacts the molten steel when the ladle contains the molten steel). The blow plug P has a plurality of slits formed therein as gas flow paths for passing gas. The slits penetrate the interior of the blow plug P, forming slit-like pores. Gas supplied to the blow plug P passes through the slits and is blown into the ladle through the blow hole.

[0028] Specifically, during refining of molten steel, a large amount of gas is supplied from the gas supply source G to the blow plug P via the first piping 20, and the large amount of gas is blown into the molten steel from the blowing port of the blow plug P, thereby refining the molten steel. The blown gas may be an inert gas such as argon gas. Note that, although the blow plug P uses a refractory material having slits in it in this embodiment, a refractory material having a porous material may also be used.

[0029] [Operation of this mode] Next, the operation of the gas supply device 1 of this embodiment will be described in more detail. The gas supply device 1 of this embodiment is assembled and fixed to a ladle. High-temperature molten steel is stored in the ladle. In this state, the gas supply port 21 is connected to a gas supply source G, and a large amount of gas is supplied from the gas supply source G. The gas supplied from the gas supply port 21 flows through the first piping 20 to the first connecting part 31, as shown by the arrow in FIG. 3. 3, the gas supplied from the gas supply port 21 passes through the first pipe 20 and is sent to the blow plug P via the gas outlet port 22. At the same time, the gas is supplied from the first connection part 31 through the second pipe 30 and via the second connection part 32 to the pressure accumulator cylinder T. The gas supplied to the pressure accumulator cylinder T accumulates under pressure in the pressure accumulator cylinder T.

[0030] When a sufficient amount of gas is stored in the accumulator cylinder T, the gas pressure in the second piping 30 and the accumulator cylinder T increases, making it difficult for the gas to flow into the second piping 30. This causes the gas to flow only toward the blowing plug P. Specifically, as shown by the arrows in FIG. 4 , the gas flows through the first piping 20 without flowing into the second piping 30. The gas flowing through the first piping 20 is supplied to the blowing plug P via the gas outlet 22 and is blown from the blowing plug P into the molten steel contained in the ladle, where refining and other processes are carried out.

[0031] When refining or the like is completed or the ladle is moved, the gas supply device 1 disconnects the gas supply port 21 from the gas supply source G. In this state, the supply of gas from the gas supply source G to the first piping 20 is stopped. This causes a relative increase in gas pressure downstream of the first piping 20, and the gas in the gas supply device 1 tends to blow out from the gas supply port 21. In this case, the check valve 23 of the first piping 20 and the check valve 35 of the second piping 30 regulate the backflow of gas. As a result, the discharge (leakage) of gas in the gas supply device 1 from the gas supply port 21 is suppressed.

[0032] Then, the gas pressure in the pressure accumulator cylinder T becomes relatively high, and gas starts to flow out of the pressure accumulator cylinder T. The gas in the pressure accumulator cylinder T flows through the second pipe 30 from the second connection part 32 of the second pipe 30, as shown by the arrows in Figure 5. The gas that has flowed through the second pipe 30 flows through the second connection part 42 to the third pipe 40.

[0033] An orifice plate 44 is provided in the third piping 40, and a small amount of gas flows downstream (toward the second connecting part 42) of the orifice plate 44. The small amount of gas that flows through the third piping 40 passes through the first connecting part 41 and the first piping 20, and is supplied to the blowing plug P via the gas outlet 22, and is blown from the blowing plug P into the molten steel contained in the ladle.

[0034] In this way, by blowing a small amount of the gas stored in the accumulator cylinder T from the blow plug P, molten steel does not enter the slit in the blow plug P through which the gas flows, and this prevents the gas permeability of the blow plug P from deteriorating and interfering with gas blowing, and prevents the blow plug P from suffering excessive wear during oxygen cleaning, and prevents a decrease in the number of times it can be reused.

[0035] [Effects of this form] As described above, the gas supply device 1 of this embodiment has the first gas flow path 2 (first piping 20), the second gas flow path 3 (second piping 30) that receives gas from the gas supply port 21 and supplies the gas to the accumulator cylinder T, and the third gas flow path 4 (third piping 40) that supplies a small amount of gas from the accumulator cylinder T to the blow plug P. The third gas flow path 3 has an orifice plate 44 therein, through which an orifice hole having an inner diameter smaller than the inner diameter of the third gas flow path passes. In the gas supply device 1 of this embodiment, the orifice plate 44 regulates the flow rate of the gas flowing through the third gas flow path 4 (third piping 40) to a predetermined flow rate. That is, the flow rate of the gas is regulated so that a small amount of gas flows.

[0036] In this embodiment, the orifice plate 44, which has no moving parts, regulates the flow rate of the gas flowing through the third gas flow path 4 (third piping 40), and the gas flow rate does not change even if the ladle (and the gas supply device 1) vibrates when the ladle is moved. In other words, there is no need for a process such as readjusting the flow rate of the gas flowing through the third gas flow path 4 (third piping 40).

[0037] Furthermore, as shown in Fig. 6, a conventional needle valve has a protruding handle for adjusting the valve opening, and requires space for operating the handle. On the other hand, as shown in Fig. 2, the orifice plate 44 has an overall size that is approximately the same as that of the third pipe 40. As a result, the overall size of the gas supply device 1 of this embodiment can be made smaller than that of conventional devices.

[0038] In the gas supply device 1 of this embodiment, the size of each gas flow path 2, 3, 4 is reduced, so that more insulating material 50 (thicker insulating material 50) can be arranged on the inner surface of the case 5 (similar in size to the case of a conventional gas supply device). In particular, the insulating material 50 can be arranged on the surface of the case 5 that contacts the ladle, which prevents the gas flow paths 2, 3, 4 from being damaged by heat from the ladle. As a result, the life of the gas supply device 1 of this embodiment is extended. In this embodiment, the size of the case 5 is set to be the same as that of the case of a conventional gas supply device, and more insulating material 50 is arranged, but this configuration is not limiting. The size of the case 5 may also be reduced.

[0039] Alternatively, a thin tube with a small inner diameter may be used instead of the orifice plate 44 as a configuration for adjusting the flow rate of gas flowing through the third gas flow path 4 (third piping 40). In this case, adjusting the flow rate of gas requires adjusting not only the inner diameter of the thin tube but also its length. In contrast, the thickness of the orifice plate 44 does not need to be adjusted, and the flow rate of gas can be adjusted simply by adjusting the inner diameter of the pores 46.

[0040] Furthermore, the outer diameter of the thin tubes is also small (they become pipes with thin walls). This makes them more susceptible to the effects of ambient heat. In other words, the effects of heat during use must be taken into consideration. In addition, thin tubes are prone to deformation. For example, they may be deformed (specifically, bent) by the vibration of the ladle. When the thin tubes are deformed, the inner diameter changes in parts, which changes the flow rate of the gas flowing inside, making it difficult for the gas to flow at a specified flow rate. In contrast, the orifice plate 44 does not require consideration of such effects of heat or deformation.

[0041] A thin tube having an inner diameter similar to that of the orifice plate 44 of this embodiment is very expensive. In contrast, the orifice plate 44 can be manufactured simply by drilling the holes 46 in a circular plate (or a commercially available orifice plate can be used), and can be prepared inexpensively.

[0042] As described above, the gas supply device 1 of this embodiment can maintain the flow rate of the gas flowing through the third gas flow path 4 (third piping 40) at a predetermined flow rate. Furthermore, since there are no moving parts for adjusting the flow rate, the gas flow rate does not change even when the ladle vibrates. Furthermore, the absence of moving parts for adjusting the flow rate eliminates the need for the space required for moving parts in conventional configurations, allowing the overall size of the gas supply device to be reduced. As a result, more insulating material 50 can be arranged (especially between each gas flow path 2, 3, 4 and the ladle), which can reduce the impact of heat from the ladle and result in a longer lifespan. [Explanation of symbols]

[0043] 1: gas supply device, 2: first gas flow path, 20: first piping, 21: gas supply port, 22: gas exhaust port, 23: check valve, 24: strainer, 3: second gas flow path, 30: second piping, 31: first connection part, 32: second connection part, 33, 34: filter, 35: check valve, 36: safety valve, 4: third gas flow path, 40: third piping, 41: first connection part, 42: second connection part, 43: filter, 44: orifice plate, 45: joint, 46: pore, 5: case, 50 insulation material.

Claims

1. It is fixed to the outer surface of the ladle, a first gas flow path having a gas receiving port connected to a gas supply source to receive a supply of gas during refining of molten steel contained in the ladle, the first gas flow path receiving the supply of gas from the gas receiving port and supplying the gas to a gas injection plug attached to the ladle; a second gas flow path having a pressure accumulator cylinder for accumulating gas, receiving the gas from the gas receiving port and supplying the gas to the pressure accumulator cylinder; a third gas flow path that supplies a small amount of gas from the pressure accumulator cylinder to the gas injection plug; the third gas flow path has an orifice plate therein through which an orifice hole having an inner diameter smaller than an inner diameter of the third gas flow path penetrates, the gas supplied from the gas receiving port immediately after the start of gas supply is supplied to the gas injection plug via the first gas flow path, and is supplied to the pressure accumulator cylinder via the second gas flow path; When a sufficient amount of gas is stored in the pressure accumulator cylinder and the gas pressure in the second gas flow path and the pressure accumulator cylinder increases, gas does not easily flow through the second gas flow path, and the gas is mainly supplied to the gas injection plug via the first gas flow path, a gas supply device characterized in that, when the gas receiving port is disconnected from the gas supply source, the gas pressure in the pressure accumulator cylinder becomes relatively high, and the gas flows from inside the pressure accumulator cylinder through the second gas flow path into the third gas flow path and is supplied to the gas injection plug with the flow rate reduced by the orifice plate (excluding the case where the third gas flow path has a control valve in the flow path that closes when the pressure accumulator cylinder accumulates the gas and opens when the gas accumulated in the pressure accumulator cylinder is allowed to flow to the gas injection plug in the small amount of gas).

2. The gas supply device according to claim 1 , further comprising a case that houses the first gas flow path, the second gas flow path, the third gas flow path, and a heat insulating material therein.

Images