TWI557230B - From the blast furnace nozzle blowing oxygen equipment, and blast furnace operating methods - Google Patents

Description

Equipment for blowing oxygen from a blast furnace tuyere, and blast furnace operation method

The present invention relates to an apparatus for blowing oxygen from a blast furnace tuyere and a blast furnace operation method, the blast furnace tuyere having a nozzle for blowing fine pulverized coal into a blast furnace from a blast furnace tuyere, and capable of being blown from the pulverized coal Blow in oxygen near the entry position.

In recent years, global warming caused by an increase in the amount of carbon dioxide emissions has become a problem, and suppression of CO ₂ emissions has become an important issue in the iron making industry. Therefore, in the recent blast furnace operation, the low-reduction material ratio operation (also referred to as low-RAR operation) in which the reduction material is blown from the blast furnace tuyere is strongly promoted, and RAR is the abbreviation of "Reducing Agent Ratio", which means reducing the manufacturing of 1t milling iron. At the time of the operation of the combined reduction material from the blast furnace tuyere and the coke charged from the top of the furnace. Micro-powder coal is mainly used in the reducing material blown from the blast furnace tuyere. In order to improve the combustibility of the pulverized coal injected into the blast furnace from the blast furnace tuyere and reduce the ratio of the reducing material, it is conceivable to blow oxygen into the vicinity of the blowing position of the pulverized coal from the nozzle into which the pulverized coal is blown.

On the other hand, in the iron-making institute, fuel gas such as blast furnace gas or coke oven gas, and combustion-supporting gas, that is, oxygen, are generally generated therein. Gas such as gas or an inert gas such as nitrogen is supplied by piping equipment. In this case, basically, it is designed to flow one gas in one pipe, and the portion where the gas is mixed with the heterogeneous gas is limited to a device such as a combustion torch or a gas mixing device. The reason for this is that, since the pipes of different types of gases are always connected to each other, as a result, problems such as abnormal combustion and a decrease in gas purity occur in the pipes due to the type of gas. Therefore, it is necessary to avoid mixing two or more kinds of gases in one pipe. For example, in the case where the supply of oxygen to the piping for supplying oxygen to the nozzle is stopped, after the oxygen supply is stopped, if the furnace gas of the blast furnace flows into the oxygen piping, there is an abnormal combustion. Therefore, after the oxygen supply to the oxygen piping is stopped, the oxygen piping must be flushed with an inert gas such as nitrogen (instead of an inert gas).

In the method of replacing the gas in the pipe, a pipe for the inert gas such as nitrogen gas is connected to the pipe to be replaced to supply the inert gas, and the gas concentration in the pipe is confirmed to be in a range where abnormal combustion does not occur, and then piping is constructed. A method of supplying a new type of gas such as air into a pipe in an internal working environment. In this method, in consideration of work efficiency, it is preferable to carry out gas replacement in the piping in a safe and short time. For example, as described in Patent Document 1, a method in which a region having a high inert gas concentration is locally formed in a pipe and air is supplied so as not to come into contact with a gas remaining in the pipe is used. In addition, in order to prevent the gas concentration in the pipe from being abnormally burned, the gas holder is provided in the middle of the pipe for the gas use target, and the gas to be used for the gas is temporarily cut off in an emergency. The gas holder has a method of storing a gas so that the gas does not flow to the downstream side.

Any of the above methods performs gas substitution. In this case, it is known that a shutoff valve is provided on the most downstream side (connection end side) of the connected piping. The opening and closing operation of the shutoff valve is controlled based on state information such as gas pressure or flow rate flowing through the pipe flowing into the object. For example, as disclosed in Patent Document 3 or Patent Document 4, a pipe for flushing a nitrogen gas pipe for flushing is proposed, and a shutoff valve and a flow rate adjusting valve are provided in the nitrogen pipe. And a method of controlling the shutoff valve and the flow regulating valve.

Advanced technical literature Patent literature

Patent Document 1: Japanese Patent No. 4781032

Patent Document 2: JP-A-2011-6576

Patent Document 3: Japanese Patent Publication No. 50-40085

Patent Document 4: Japanese Patent No. 4744349

However, in the gas replacement method described in Patent Document 1 or Patent Document 2, the gas is replaced by the state in which the gas supply is stopped by one shutoff valve. Therefore, when the power source of the shutoff valve is collapsed due to a power failure or a large earthquake, There will be a hindrance to the smooth replacement of the gas. For example, supplying pulverized coal and oxygen from a nozzle to a blast furnace tuyere as described above When the oxygen supply to the oxygen pipe is stopped, the oxygen pipe must first be flushed with an inert gas such as nitrogen, but the trapping valve of the inert gas cannot be opened because the valve power source is lost, so that the inert gas cannot be sent to the oxygen pipe. The gas in the blast furnace furnace is mixed into the oxygen piping, and there is a possibility of abnormal combustion. In particular, in the blast furnace operation in which the pulverized coal and oxygen are blown from the blast furnace tuyere into the blast furnace using a nozzle, even if the supply of oxygen is stopped, the oxygen remaining in the oxygen piping must be rapidly replaced with an inert gas such as nitrogen to remove oxygen. . The reason for this is that when the blast furnace gas containing CO flows back to the oxygen piping and reacts with the residual oxygen, there is a possibility of causing abnormal combustion.

In the method described in Patent Document 3 or Patent Document 4, the valve configuration of the nitrogen gas pipe for flushing which is always connected to the piping of the fuel-based gas is one cut by one flow rate adjusting valve and the most downstream side (connecting end side). When the valve is closed or damaged due to some reason, or the pressure in the piping of the fuel gas is always higher than the pressure in the piping for flushing nitrogen, the fuel gas is mixed into the nitrogen piping. On the other side, in this state, for example, if air is replaced on the nitrogen piping side for maintenance, abnormal combustion may occur. In other words, in the apparatus in which the pulverized coal is blown into the blast furnace tuyere by the nozzle and the oxygen is blown from the nozzle in the vicinity of the blowing position, the piping for flushing nitrogen is always connected to the oxygen piping and is 1 When the shut-off valve controls the flow of nitrogen, there is a concern that the gas in the blast furnace furnace is mixed into the oxygen piping, or the gas or oxygen in the blast furnace furnace is mixed into the nitrogen piping.

The present invention has been made in view of the above problems, and an object thereof is to provide an apparatus for blowing oxygen into a blast furnace from a blast furnace tuyere and The blast furnace operation method is capable of reliably preventing the pulverized coal from being blown into the blast furnace tuyere by the nozzle and similarly blowing oxygen from the nozzle near the blowing position, and stopping the oxygen supply in the blast furnace The gas is mixed into the oxygen piping, or the gas or oxygen in the blast furnace furnace is mixed into the nitrogen piping. Further, in the present invention, the apparatus for blowing oxygen into the blast furnace from the blast furnace tuyere and the blast furnace operation method are capable of preventing the oxygen piping from being trapped even when the valve power source is lost during the operation of blowing the fine coal and oxygen through the nozzle. Mix the gas into the blast furnace.

The gist of the present invention for solving the above problems is as follows.

(1) A device for blowing oxygen from a blast furnace tuyere, comprising: a nozzle capable of blowing fine coal and oxygen into a blast furnace from a blast furnace tuyere; and connecting the nozzle to supply oxygen to the nozzle An oxygen pipe; a flow rate adjusting valve provided in the oxygen pipe; a nitrogen pipe connected to the oxygen pipe and having a nitrogen shutoff valve upstream of the flow rate adjusting valve; and a connection upstream of the oxygen pipe and the nitrogen pipe An oxygen shutoff valve disposed in the oxygen pipe; and a control device for performing opening and closing control of the oxygen shutoff valve and the nitrogen shutoff valve; wherein the control device closes the nitrogen shutoff valve when the oxygen shutoff valve is opened, and the oxygen shutoff valve Open the aforementioned nitrogen shutoff valve when closed.

(2) An apparatus for blowing oxygen from a blast furnace tuyere, comprising: a nozzle capable of blowing fine coal and oxygen into the blast furnace from a blast furnace tuyere; and connecting the nozzle to supply oxygen to the nozzle An oxygen pipe; a flow regulating valve disposed in the oxygen pipe; and connected upstream of the flow regulating valve a nitrogen gas pipe for the oxygen pipe; two oxygen shutoff valves disposed upstream of the oxygen pipe and the nitrogen gas pipe; and a gas pipe disposed between the two oxygen shutoff valves Oxygen vent valve.

(3) The apparatus for injecting oxygen from a blast furnace tuyere according to the second aspect of the invention, wherein the nitrogen gas piping includes: a check valve; and two disposed upstream of the check valve A nitrogen shut-off valve and a nitrogen gas discharge valve disposed between the two nitrogen shut-off valves.

(4) The apparatus for injecting oxygen from a blast furnace tuyere according to the above (3), comprising: a control device for performing opening and closing control of the two oxygen shutoff valves and the two nitrogen shutoff valves, wherein the control device is When the two oxygen shut-off valves are opened, the two nitrogen shut-off valves are closed, and the two nitrogen shut-off valves are opened when the two oxygen shut-off valves are closed.

(5) An apparatus for blowing oxygen from a blast furnace tuyere, comprising: a nozzle capable of blowing fine coal and oxygen into the blast furnace from a blast furnace tuyere; and connecting the nozzle to supply oxygen to the nozzle An oxygen piping; a flow regulating valve disposed in the oxygen pipe; a nitrogen pipe connected to the oxygen pipe upstream of the flow regulating valve; and an oxygen flow cutting mechanism upstream of a connection position of the oxygen pipe and the nitrogen pipe The oxygen pipe is disposed in the foregoing oxygen pipe to cut off the oxygen flow of the oxygen pipe when the power source is lost.

(6) The apparatus for injecting oxygen from a blast furnace tuyere according to the above (5), wherein the nitrogen gas pipe includes: a check valve; and a nitrogen gas flow opening and closing mechanism disposed upstream of the check valve to be powered When the source is lost, nitrogen gas is caused to flow to the aforementioned nitrogen piping.

(7) The apparatus for blowing oxygen into a blast furnace tuyere according to the above (6), wherein the nitrogen gas flow opening and closing mechanism includes two nitrogen shutoff valves that perform an opening operation when the power source is lost, and two nitrogen gas disposed in the nitrogen gas A nitrogen discharge valve that closes between valves and closes when the power source is lost.

(8) The apparatus for injecting oxygen from a blast furnace tuyere according to any one of (5) to (7), wherein the oxygen flow shutoff mechanism has two oxygen cutoffs that perform a closing operation when the power source is lost a valve; and an oxygen discharge valve that is disposed between the two oxygen shutoff valves of the oxygen pipe and that is opened when the power source is lost.

(9) The apparatus for blowing oxygen from a blast furnace tuyere according to any one of claims 1, 3, 4, and 6 to 8 is provided with a receiving tank which is larger than the nitrogen shutoff valve or the nitrogen gas The flow opening and closing mechanism is further connected upstream to the nitrogen gas pipe, and has a volume of 3 to 5 times the volume of the pipe from the receiving groove to the blast furnace tuyere; and a nitrogen main pipe shutoff valve is disposed on the upstream side of the receiving groove. The power is turned off when the power source is lost.

(10) A blast furnace operation method in which a pulverized coal and oxygen are blown into a blast furnace by using an apparatus for blowing oxygen from a blast furnace tuyere according to any one of the above (1) to (9).

According to the apparatus for injecting oxygen from the blast furnace tuyere and the blast furnace operation method according to the present invention, only nitrogen gas is supplied downstream of the connection position of the nitrogen gas pipe and the oxygen gas pipe, and the oxygen pipe can be flushed with nitrogen gas even if the supply of oxygen or the valve power is stopped. When the source is lost, the gas in the blast furnace furnace can still be reliably prevented. Mix in oxygen piping.

1‧‧‧ blast furnace

2‧‧‧Blowpipe

3‧‧‧Blast furnace tuyere

4‧‧‧ nozzle

5‧‧‧ Wind path

6‧‧‧Micro-powder flow adjustment valve

7‧‧‧Oxygen piping

8‧‧‧Nylon piping

11‧‧‧Oxygen Supervisor

12‧‧‧Oxygen collection head

13, 14‧‧‧ oxygen branch

15‧‧‧Flexible pipe

16‧‧‧Oxygen connection tube

17‧‧‧Connected pipe shut-off valve

18‧‧‧Connected pipe check valve

19‧‧‧Connecting pipe discharge valve

20‧‧‧Branch cut-off valve

21‧‧‧Oxygen flow adjustment valve

22‧‧‧Oxygen shut-off valve

23‧‧‧Oxygen discharge valve

24‧‧‧Nitrogen Supervisor

25‧‧‧Nitrogen collection head

26‧‧‧Nitrogen manifold

27‧‧‧Nitrogen check valve

28‧‧‧Nitrogen shut-off valve

29‧‧‧Nitrogen discharge valve

30‧‧‧Control device

31‧‧‧ receiving slot

32‧‧‧Nitrogen main control shut-off valve

33‧‧‧Safety valve

34‧‧‧Excretion

40‧‧‧Oxygen

50‧‧‧nitrogen

70‧‧‧Oxygen flow cutting mechanism

80‧‧‧Nitrogen flow opening and closing mechanism

100‧‧‧Oxygen blowing equipment

Fig. 1 is a longitudinal sectional view showing an embodiment of a blast furnace to which the blast furnace working method of the present invention is applied.

Fig. 2 is a schematic view showing an apparatus for blowing oxygen into a blast furnace from the blast furnace tuyere of Fig. 1.

Fig. 3 is an explanatory diagram of a program of the control device of Fig. 2;

Fig. 4 is an explanatory view showing a valve actuation state when the power source of the oxygen blowing device of Fig. 2 is lost.

Fig. 5 is an explanatory diagram of a procedure when the power source of the oxygen blowing device of Fig. 2 is lost.

Next, an embodiment of the blast furnace working method of the present invention will be described with reference to the drawings. Fig. 1 is a general view of a blast furnace to which the blast furnace working method of the present embodiment is applied. A plurality of blast furnace tuyères 3 are installed in the circumferential direction of the side wall of the blast furnace 1, and a blowing pipe 2 for hot air blowing is connected to each blast furnace tuyere 3, and a nozzle 4 is provided through the blowing pipe 2. On the hot air blowing direction side of the blast furnace tuyere 3, a space called the wind path 5 formed by hot air supplied from the blow pipe 2 mainly burns carbon material in this space. The pulverized coal which is blown into the wind path 5 from the nozzle 4 through the blast furnace tuyere 3 is burned together with the coke, and the volatile matter and the fixed carbon are burned, and the remaining unburned is generally called pul coal. The carbon and ash collection system is discharged from the wind path as unburned coal.

The fine coal powder blown into the air path 5 from the blast furnace tuyere 3 heats the particles by radiation heat transfer from the flame in the wind path 5, and further heats up the particles by radiation heat transfer and conduction heat transfer. When the temperature rises to above 300 °C, thermal decomposition begins, and the volatiles are ignited to form a flame, and the combustion temperature reaches 1400 to 1700 °C. When the fine coal and oxygen are simultaneously blown from the nozzle 4, the fine coal is burned by contact with O _{2 ,} and the fine coal is heated and heated by the heat of combustion. Thereby, the pulverized coal starts to be burned at a position close to the nozzle, and the burning rate also rises.

In the present embodiment, in order to improve the combustibility of the pulverized coal, oxygen is blown into the vicinity of the blowing position of the pulverized coal by using a nozzle. The nozzle 4 is configured to blow fine coal and oxygen into the blast furnace tuyere 3. For example, in the case where the nozzle 4 is a so-called single-tube nozzle, the pulverized coal and oxygen are blown into the blast furnace tuyere 3 by two components of a nozzle for blowing fine pulverized coal and a nozzle for blowing oxygen. Further, in the case where the nozzle 4 is a so-called double-tube nozzle in which a small-diameter blowing pipe is inserted inside the large-diameter blowing pipe, for example, the pulverized coal is blown from the inner blowing pipe, and the pipe and the outer blowing pipe are blown from the inside. The gap is blown into the oxygen. The blowing of the pulverized coal and oxygen of the double pipe nozzle may also be reversed, so that it is preferable that the oxygen and the pulverized coal are close to each other to form a state in which combustion is more likely.

The so-called nozzle capable of blowing fine coal and oxygen means that in the nozzle tube, the fine coal and oxygen preferably flow in different flow paths, and supply the fine coal and oxygen from the outlet of the nozzle to the blast furnace tuyere. The pulverized coal and oxygen can be blown into the nozzle in the blast furnace. In the present embodiment, oxygen is blown into the vicinity of the blowing position of the pulverized coal by using two double-tube nozzles. In addition, In the present embodiment, in order to bring the pulverized coal and oxygen into close proximity, only oxygen is blown from the nozzle, and oxygen is not enriched during air blowing. However, it is also necessary to concentrate oxygen during the supply of air.

In the normal operation of the blast furnace, fine coal and oxygen are blown from the nozzle 4. When the operation is interrupted or the power supply of the pulverized coal blowing equipment is stopped due to an accident or the like, there is a case where the blowing of the pulverized coal is stopped. In this case, the supply of oxygen must also be stopped, and the residual oxygen is quickly removed from the oxygen piping supplying the oxygen to the nozzle 4, and replaced (flushed) into an inert gas such as nitrogen. The reason for this is that only the oxygen supply is stopped, and since the blast furnace gas containing CO flows back to the oxygen piping and reacts with the oxygen remaining in the oxygen piping, there is a possibility of causing abnormal combustion. It is assumed that in order to prevent the blast furnace gas from flowing back to the nozzle 4 in a countercurrent flow, there is a possibility that the metal is oxidized at a high temperature, and thus the equipment is not well preserved. This condition occurs not only when the usual pulverized coal is blown into the stop operation but also when the pulverized coal is blown in or the oxygen is blown in because of problems in the equipment. In particular, in the case where the pulverized coal and oxygen are supplied to the nozzle 4 at the same time, it is necessary to quickly and safely and reliably replace the oxygen piping with an inert gas such as nitrogen. In the present embodiment, the substitution can be performed, for example, by the following configuration.

Fig. 2 is a schematic view showing the apparatus for blowing fine coal and oxygen into the blast furnace from the blast furnace tuyere of Fig. 1. The oxygen insufflation device (the device that blows oxygen from the blast furnace tuyere) 100 includes a nozzle 4, an oxygen pipe 7 through which oxygen supplied to the nozzle 4 flows, and a nitrogen pipe 8 connected to the oxygen pipe 7 Oxygen flow shutoff mechanism 70 (various valves) of oxygen piping 7 and nitrogen flow opening and closing mechanism 80 provided in nitrogen piping 8 (various Valve), and control device 30 for controlling various valves. In the present embodiment, the oxygen pipe 7 means a pipe through which oxygen flows, and includes an oxygen main pipe 11, an oxygen collecting head 12, an oxygen branch pipe 13, an oxygen branch pipe 14, a flexible pipe 15, and an oxygen connecting pipe 16. The nitrogen gas pipe 8 means a pipe through which nitrogen gas flows, and has a nitrogen gas main pipe 24, a nitrogen gas collecting head 25, and a nitrogen gas branch pipe 26.

In the normal operation, oxygen 40 is supplied to the oxygen main pipe 11, and oxygen flows toward the blast furnace tuyere 3 at the oxygen pipe 7. In the present embodiment, in the oxygen pipe 7, the direction of the flow of oxygen toward the blast furnace tuyere 3 is taken as the downstream direction, and the reverse direction is taken as the upstream direction. Further, in the case where the oxygen supply is stopped, the nitrogen gas 50 is supplied to the nitrogen gas main pipe 24 and flows toward the oxygen gas pipe 7 at the nitrogen gas pipe 8. In the present embodiment, the direction in which the nitrogen gas flows toward the oxygen pipe 7 is the downstream direction in the nitrogen gas pipe 8, and the reverse direction is the upstream direction.

The pulverized coal PC system is supplied to the nozzle 4 from a pulverized coal storage tank (not shown) together with a high pressure gas (high pressure N ₂ ), and the amount of blowing is adjusted by the pulverized coal flow rate adjusting valve 6. In the blow pipe 2 (see Fig. 1), air is sent to a hot air furnace from a blast furnace (not shown), and hot air is supplied from there. If necessary, the addition of oxygen to the hot air is carried out in the air stream upstream of the hot blast stove.

The high-pressure oxygen disposed at the most upstream of the oxygen piping 7 is supplied to the piping (oxygen main pipe 11), which is connected to the oxygen branch pipe 13 by the number of oxygen collecting heads 12 of the blast furnace tuyere 3, and the oxygen 40 is supplied from the oxygen main pipe 11. It is distributed to each nozzle 4 (each blast furnace tuyere 3). example For example, when the number of the blast furnace tuyere 3 is 40, the oxygen branch pipe 13 has a total of 40 pieces. In this embodiment, since two nozzles 4 are used, each oxygen branch pipe 13 is branched into two oxygen branch pipes 14, and each oxygen branch pipe 14 is connected to the oxygen connecting pipe 16 through the flexible pipe 15, and oxygen is supplied from each oxygen connecting pipe 16. It is supplied to each double pipe nozzle 4. The oxygen insufflation device 100 includes a plurality of nozzles 4 corresponding to the blast furnace tuyere 3, and a plurality of oxygen branch pipes 13 for supplying oxygen to the pipes (oxygen mains 11) for supplying oxygen to the nozzles 4 The head 12 is branched from each of the blast furnace tuyeres 3, and each of the oxygen flow regulating valves 21 provided in the plurality of oxygen branch pipes 13 is connected to the oxygen branch pipes 13 on the upstream side of the oxygen flow rate adjusting valve 21.

The oxygen connecting pipe 16 is provided with two connecting pipe shutoff valves 17 on the downstream side of the oxygen pipe 16 on the side of the nozzle 4, and a connecting pipe check valve is interposed in the upstream side of the connecting pipe shutoff valve 17. 18. A connecting pipe discharge valve 19 is connected between the two connecting pipe shutoff valves 17. Further, a branch pipe shutoff valve 20 is interposed in the oxygen branch pipe 14 at the upstream end of the flexible pipe 15 side. The oxygen branch pipe 13 is provided with an oxygen flow shutoff mechanism 70, and the oxygen flow shutoff mechanism 70 functions to break the aforementioned oxygen flow in the oxygen pipe in the case where the power source is collapsed. As shown in Fig. 2, the oxygen branch pipe 13 is provided with an oxygen flow rate adjusting valve 21 on the side of the oxygen branch pipe 14 at the downstream side, and two oxygen shutoff valves 22 are interposed in the upstream side of the oxygen flow rate adjusting valve 21, An oxygen discharge valve 23 is connected between the two oxygen shutoff valves 22. The oxygen flow shutoff mechanism 70 includes two oxygen shutoff valves 22, an oxygen discharge valve 23, and a control device 30. The two oxygen shutoff valves 22 and the oxygen discharge valve 23 are opened and closed by a power source. When the power source is lost, the two oxygen shutoff valves 22 become closed, and the oxygen discharge valve 23 becomes open. It is an on-off valve that is always closed by an opening operation of the power source, and the oxygen discharge valve 23 is an on-off valve that is always opened by a power source to perform a closing operation.

In the oxygen blowing device 100, for example, in the oxygen branch pipe 14 and the oxygen connecting pipe 16, a nitrogen pipe 8 is connected in order to perform flushing with nitrogen gas of an inert gas. In the nitrogen gas pipe 8, nitrogen gas is distributed from the high-pressure nitrogen gas main pipe 24 to the oxygen branch pipe 13 through the nitrogen gas collecting head 25 and the nitrogen gas branch pipe 26. For example, in the case where the number of the blast furnace tuyere 3 is 40 and the oxygen branch pipe 13 is 40, the nitrogen branch pipe 26 is also 40. Each of the 40 nitrogen branch pipes 26 passes through a nitrogen check valve 27, and is connected between the oxygen flow regulating valve 21 and the downstream side oxygen shutoff valve 22, and is connected to the oxygen branch pipe 13 corresponding to each of the nitrogen branch pipes 26. Oxygen is prevented from flowing from the oxygen branch pipe 13 into the nitrogen branch pipe 26 by the nitrogen check valve 27.

The nitrogen gas branch pipe 26 is provided with a nitrogen gas flow opening and closing mechanism 80, and the nitrogen gas flow opening and closing mechanism 80 functions to cause nitrogen gas to flow into the nitrogen gas pipe 8 when the power source is lost. As shown in FIG. 2, in the nitrogen branch pipe 26, two nitrogen shutoff valves 28 are interposed in the nitrogen gas check valve 27 side, that is, on the connection side end portion of the oxygen branch pipe 13, between the two nitrogen cutoff valves 28. A nitrogen discharge valve 29 is connected. The nitrogen flow opening and closing mechanism 80 includes two nitrogen shutoff valves 28, a nitrogen gas discharge valve 29, and a control device 30. The two nitrogen shutoff valves 28 and the nitrogen gas discharge valve 29 are opening and closing valves that are opened and closed by a power source, and when the power source is collapsed. The two nitrogen shutoff valves 28 become open and the nitrogen discharge valve 29 becomes closed.

The oxygen insufflation device 100 preferably further includes a receiving tank 31 connected to the nitrogen piping 8 upstream of the nitrogen shutoff valve 28, and a nitrogen gas main shutoff valve 32 disposed upstream of the receiving tank 31. In the embodiment shown in Fig. 2, the receiving tank 31 is connected to the nitrogen main pipe 24, and the nitrogen main pipe 24 is provided with a nitrogen main pipe shut-off valve 32. The nitrogen main pipe shutoff valve 32 is a valve that is opened and closed by a power source, and is turned off when the power source is lost. The receiving tank 31 is filled with nitrogen gas, and the volume of the receiving tank 31 is 3 to 5 times larger than the piping volume from the downstream of the receiving tank 31 to the full height furnace tuyere 3.

According to the above configuration, when the power source is lost, nitrogen gas is supplied to all the pipes from the receiving tank 31 to the blast furnace tuyere 3. Further, the piping from the receiving tank 31 to the blast furnace tuyere 3 corresponds to the piping from the receiving tank 31 to the nozzle 4 of the blast furnace tuyere 3, and the piping of the oxygen piping 7 and the nitrogen piping 8. Further, the receiving groove 31 is provided with a pressure gauge PG in addition to the pressure gauge PT, and further preferably includes a safety valve 33 and a draining member 34.

The receiving tank 31 may be disposed in the nitrogen branch pipe 26 upstream of the nitrogen shutoff valve 28 downstream of the nitrogen collecting head 25 in the form shown in Fig. 2 . In this case, the volume of the receiving groove 31 is preferably 3 to 5 times the volume of the pipe from the downstream of the full height furnace tuyere 3, but it is necessary to receive the number corresponding to the number of the blast furnace tuyere 3 Slot 31. In the form shown in Fig. 2, the volume of the receiving groove 31 is increased, but one unit is sufficient.

During normal operation during the supply of power, various valves of the oxygen insufflation device 100 can be controlled by the control device 30, particularly the oxygen flow regulating valve 21, the oxygen shutoff valve 22, the oxygen discharge valve 23, and the nitrogen cutoff. The valve 28, the nitrogen gas discharge valve 29, and the nitrogen gas main shutoff valve 32 are controlled by the control device 30 for opening and closing control or opening degree control. In the normal operation of the blast furnace 1, that is, the milling operation, since oxygen must be blown from the nozzle 4 together with the pulverized coal, oxygen must be supplied on the downstream side of the oxygen branch pipe 14. Therefore, as shown in Fig. 3, it is set to open two oxygen shutoff valves 22, close the oxygen discharge valve 23, and set to close the two nitrogen shutoff valves 28, open the nitrogen discharge valve 29, and perform the oxygen flow regulating valve 21 as necessary. Openness control. In this state, nitrogen gas is not supplied from the nitrogen branch pipe 26 to the oxygen branch pipe 14, and only oxygen gas is supplied from the oxygen branch pipe 13 to the oxygen branch pipe 14.

In this state, when the supply of oxygen to the downstream side of the oxygen branch pipe 14 is stopped due to the stop of the blast furnace operation or the like, as shown in FIG. 3, the two oxygen shutoff valves 22 are closed, the oxygen discharge valve 23 is opened, and the oxygen gas discharge valve 23 is opened. The two nitrogen shutoff valves 28 are opened, and the nitrogen discharge valve 29 is closed. In this state, oxygen is not supplied from the oxygen branch pipe 13 to the oxygen branch pipe 14, and nitrogen gas is supplied from the nitrogen branch pipe 26 to the oxygen branch pipe 14, and the nitrogen gas is flushed further downstream than the connection position of the oxygen pipe 7 and the nitrogen gas pipe 8. At this time, for example, even if the oxygen shutoff valve 22 on the downstream side does not perform the closing operation at all, oxygen is discharged from the oxygen discharge valve 23 and replaced by nitrogen gas, and the supply of oxygen toward the downstream side is cut off. Further, in this state, even if the oxygen discharge valve 23 does not perform the opening operation at all, the oxygen supply to the downstream side is cut off by the oxygen shutoff valve 23 on the upstream side. In other words, if the oxygen insufflation device 100 is provided with two oxygen shutoff valves 22 and the oxygen discharge valve 23 provided in the oxygen pipe 7 between the two oxygen shutoff valves 22, the cutoff can be surely cut off. Oxygen supply to the downstream side. As a result, it is possible to prevent oxygen or the like from being mixed into the nitrogen branch pipe 26 side, and it is also possible to reduce the possibility that a problem arises due to a malfunction of the valve operation.

When the oxygen supply to the downstream side of the oxygen branch pipe 14 is again supplied from the state of stopping the supply of oxygen to the downstream side of the oxygen branch pipe 14, as shown in FIG. 3, the gas shut-off valve 22 is again set to open, and the oxygen gas is turned off. The discharge valve 23 is set to close the two nitrogen shutoff valves 28, open the nitrogen discharge valve 29, and control the opening degree of the oxygen flow rate adjusting valve 21 as necessary. Thereby, the nitrogen gas which is flushed on the downstream side of the oxygen branch pipe 14 is blown into the blast furnace tuyere 3 by the supplied oxygen, and then the oxygen gas is blown from the nozzle 4.

In this way, the oxygen insufflation device 100 of the present embodiment is connected to the nozzle 4, and the flow rate adjustment valve 21 is provided in the oxygen pipe 7 through which the oxygen supplied to the nozzle 4 flows, and the nitrogen gas is supplied to the upstream side of the flow rate adjustment valve 21. The piping 8 is connected to the oxygen piping 7, and two oxygen shutoff valves 22 are provided upstream of the connection position of the oxygen piping 7 and the nitrogen piping 8, and an oxygen discharge valve 23 is provided between the two oxygen shutoff valves 22 of the oxygen piping 7. . Therefore, when the oxygen of the oxygen piping 7 which is further downstream than the connection position is flushed by nitrogen, for example, the two oxygen shutoff valves 22 are closed and the oxygen discharge valve 23 is opened, only the nitrogen gas can be supplied to the oxygen piping 7 and The connection position of the nitrogen gas pipe 8 is flushed on the downstream side, and the gas in the blast furnace furnace can be prevented from being mixed into the oxygen pipe 7.

Further, the nitrogen gas pipe 8 includes a nitrogen check valve 27, two nitrogen shutoff valves 28 disposed on the upstream side of the nitrogen check valve 27, and A nitrogen vent valve 29 is placed between the two nitrogen shutoff valves 28. Therefore, for example, when the oxygen of the oxygen piping 7 on the downstream side of the connection position is flushed by nitrogen, if two oxygen shutoff valves 22 are set to be closed and the oxygen discharge valve 23 is opened, the two nitrogen shutoff valves are set to open. When the nitrogen gas discharge valve 29 is closed, the nitrogen gas can be supplied only to the downstream side of the connection position of the nitrogen gas pipe, and the gas in the blast furnace furnace can be prevented from being mixed into the oxygen gas pipe 7, or the gas or oxygen in the blast furnace furnace can be mixed. Nitrogen pipe 8 is used. Further, for example, in a state where the oxygen is supplied to a position further downstream than the connection position of the nitrogen gas pipe 8 from a state where the nitrogen purge is further downstream than the connection position, if it is set to close the two nitrogen gas shutoff valves 28 and set to open the nitrogen gas discharge The valve 29 is set to open the two oxygen shutoff valves 22 and is set to close the oxygen discharge valve 23, so that only oxygen can be supplied to the downstream of the connection position of the nitrogen gas pipe 8, and oxygen can be prevented from being mixed into the nitrogen gas pipe 8.

The control device 30 is set to close two nitrogen shutoff valves 28 when the two oxygen shutoff valves 22 are opened, and is set to open two nitrogen shutoff valves 28 when the two oxygen shutoff valves 22 are closed, and can supply oxygen to The gas is flushed into the oxygen pipe 7 or the gas or oxygen in the blast furnace furnace is mixed into the nitrogen gas pipe 8 at a downstream side of the connection position of the oxygen pipe 7 and the nitrogen gas pipe 8 or by nitrogen gas. That is, if the control device 30 is set to turn off at least one nitrogen shutoff valve 28 when all (2) of the oxygen shutoff valves 22 are open, and at least one oxygen shutoff valve 22 is closed to open the nitrogen shutoff valve 28 (2 ), oxygen can be supplied to the downstream side of the connection position, or flushed by nitrogen.

Next, Fig. 4 shows the valve operation of the oxygen shutoff valve 22, the oxygen discharge valve 23, the nitrogen shutoff valve 28, the nitrogen gas discharge valve 29, and the nitrogen gas main shutoff valve 32 when the power source is lost (downward in the figure). For example, when the power source of the valves is compressed air, the control device 30 detects that the valve power source, that is, the compressed air is lost. When the power source is detected, the oxygen shutoff valve 22 is closed, the oxygen discharge valve 23 is opened, and the nitrogen gas is turned on. The shutoff valve 28 closes the nitrogen discharge valve 29 to cause the nitrogen main pipe shutoff valve 32 to close. On the other hand, the power source of the valve is in the case of electric power, and depending on the situation, the control device 30 may also be inoperable. Even in this case, since the oxygen shutoff valve 22 is closed when there is no power source, the oxygen discharge valve 23 is opened when there is no power source, the nitrogen shutoff valve 28 is opened when there is no power source, and the nitrogen discharge valve 29 is closed when there is no power source. When the nitrogen main pipe shutoff valve 32 is closed when there is no power source, when the valve power source is lost, the valves are opened and closed as shown in FIG.

When the power source is lost, the oxygen flow shutoff mechanism 70 functions, and one of the upstream sides of the oxygen shutoff valve 22 is closed, and when the oxygen flow is cut off, the gas in the blast furnace furnace can be prevented from flowing into the piping on the upstream side of the oxygen shutoff valve 22. Come back. When the two oxygen shutoff valves 22 are closed and the oxygen discharge valve 23 is opened, the gas in the blast furnace furnace can be surely prevented from flowing back into the piping on the upstream side of the oxygen shutoff valve 22, and oxygen gas can be prevented from being mixed into the nitrogen gas pipe 8.

Further, the nitrogen flow opening and closing mechanism 80 functions, the two nitrogen shutoff valves 28 become open, and the nitrogen discharge valve 29 becomes closed, while the two oxygen shutoff valves 22 are closed and the oxygen discharge valve 23 is opened. Thereafter, the nitrogen gas is flushed further downstream than the connection position of the nitrogen gas pipe 8, and the gas in the blast furnace furnace can be prevented from entering the oxygen pipe 7. When two shut-off valves 22, 28 are provided in each of the oxygen piping 7 and the nitrogen piping 8, and the discharge valves 23, 29 are provided therebetween, even if the shut-off valve from one branch is made for some reason When a leak occurs, since the gas is mixed by the other shut-off valve and the gas leaking from the discharge valves 23, 29 is discharged together, the leak-preventing gas is filled between the two shut-off valves and pressurized to the source pressure. It can further reduce the mixing of different gases with each other.

Fig. 5 is a view showing the operation of each valve when the power source of the valve is lost and the temporal change of the pressure in the receiving groove 31. For example, in the normal operation state in which the fine coal and oxygen are blown from the nozzle 4 as described above, when the power source is lost, the action becomes that the oxygen shutoff valve 22 is closed, the oxygen discharge valve 23 is opened, and the nitrogen shutoff valve 28 is opened, nitrogen gas is turned off. The discharge valve 29 is closed and the nitrogen main control shutoff valve 32 is closed. Therefore, when the power source is lost, the oxygen supply from the oxygen branch pipe 13 to the oxygen branch pipe 14 is stopped, and the oxygen branch pipe 14 can be supplied with nitrogen gas from the nitrogen branch pipe 26. At this time, since the nitrogen main pipe shutoff valve 32 is closed, it is not expected to supply the nitrogen gas to the nitrogen gas main pipe 24, but the nitrogen gas stored in the receiving tank 31 is supplied to the oxygen branch pipe through the nitrogen gas main pipe 24, the nitrogen gas collecting head 25, and the nitrogen gas branch pipe 26. 14. As the supply causes the pressure in the receiving tank 31 to gradually decrease.

The inside of the blast furnace 1 is in a high pressure state as in the normal operation, and the capacity in the receiving tank 31 is equal to or slightly larger than the piping volume of the nozzle 4 of the blast furnace tuyere 3 on the downstream side of the receiving tank 31. can. However, when the valve power source is like electric power, it is also estimated that the valve power source The subsidence causes the blast furnace itself to become a state of stopping (stopping the air supply to the blast furnace). In the case where the blast furnace is stopped (stopping the air supply to the blast furnace), the pressure in the blast furnace may become zero (atmospheric pressure). In this case, since the nitrogen gas from the receiving tank 31 is blown into the blast furnace 1 through the oxygen branch pipe 13 or the oxygen branch pipe 14, it is preferable to set the tank capacity to 3 to 5 times the volume of the pipe to be replaced. Since the capacity is determined by the shape of the pipe such as the easiness of gas accumulation, the nitrogen gas is actually flowed from the receiving tank 31 to the nozzle 4 of the full-high furnace tuyere 3, depending on the relationship between the concentration of nitrogen in the piping and the cumulative flow rate. It can also be set. Further, in this manner, even when the valve power source is lost, the downstream side can be quickly flushed by the nitrogen gas from the connection position of the oxygen pipe 7 and the nitrogen gas pipe 8, thereby preventing the gas in the blast furnace furnace from being mixed into the oxygen pipe 7 Since the nitrogen gas which is necessary or more is not allowed to flow, the cooling of the excess blast furnace tuyere 3 can also be prevented.

2‧‧‧Blowpipe

3‧‧‧Blast furnace tuyere

4‧‧‧ nozzle

6‧‧‧Micro-powder flow adjustment valve

7‧‧‧Oxygen piping

8‧‧‧Nylon piping

11‧‧‧Oxygen Supervisor

12‧‧‧Oxygen collection head

13, 14‧‧‧ oxygen branch

15‧‧‧Flexible pipe

16‧‧‧Oxygen connection tube

17‧‧‧Connected pipe shut-off valve

18‧‧‧Connected pipe check valve

19‧‧‧Connecting pipe discharge valve

20‧‧‧Branch cut-off valve

21‧‧‧Oxygen flow adjustment valve

22‧‧‧Oxygen shut-off valve

23‧‧‧Oxygen discharge valve

24‧‧‧Nitrogen Supervisor

25‧‧‧Nitrogen collection head

26‧‧‧Nitrogen manifold

27‧‧‧Nitrogen check valve

28‧‧‧Nitrogen shut-off valve

29‧‧‧Nitrogen discharge valve

30‧‧‧Control device

32‧‧‧Nitrogen main control shut-off valve

34‧‧‧Excretion

40‧‧‧Oxygen

50‧‧‧nitrogen

70‧‧‧Oxygen flow cutting mechanism

80‧‧‧Nitrogen flow opening and closing mechanism

100‧‧‧Oxygen blowing equipment

PT‧‧‧ pressure gauge

PG‧‧‧pressure gauge

Claims (9)

An apparatus for blowing oxygen from a blast furnace tuyere, comprising: a nozzle capable of blowing fine coal and oxygen into the blast furnace from a blast furnace tuyere; and an oxygen piping connected to the nozzle for supplying oxygen to the nozzle; a flow rate adjusting valve provided in the oxygen pipe; a nitrogen pipe connected to the oxygen pipe and having a nitrogen shutoff valve upstream of the flow rate adjusting valve; and being disposed upstream of a connection position of the oxygen pipe and the nitrogen pipe An oxygen shut-off valve for an oxygen pipe; a control device for performing opening and closing control of the oxygen shutoff valve and the nitrogen shutoff valve; and a receiving groove connected to the nitrogen pipe upstream of the nitrogen shutoff valve and having a flow from the receiving groove to the foregoing The volume of the pipe volume of the blast furnace tuyere is 3 to 5 times; and the nitrogen main pipe shut-off valve is disposed on the upstream side of the receiving groove, and is closed when the power source is lost; the control device is when the oxygen shut-off valve is opened The nitrogen shut-off valve is closed to open the nitrogen shut-off valve when the oxygen shut-off valve is closed. An apparatus for blowing oxygen from a blast furnace tuyere, comprising: a nozzle capable of blowing fine coal and oxygen into the blast furnace from a blast furnace tuyere; and an oxygen piping connected to the nozzle for supplying oxygen to the nozzle; a flow rate adjustment valve provided in the oxygen pipe; a nitrogen pipe connected to the oxygen pipe upstream of the flow rate adjustment valve; and 2 oxygen gas disposed upstream of the oxygen pipe at a connection position of the oxygen pipe and the nitrogen pipe a shutoff valve; and an oxygen discharge valve provided to the oxygen pipe between the two oxygen shutoff valves. An apparatus for blowing oxygen into a blast furnace tuyere according to the second aspect of the invention, wherein the nitrogen piping includes: a check valve; two nitrogen shutoff valves disposed upstream of the check valve; and the second nitrogen shutoff valve A nitrogen purge valve between the nitrogen shutoff valves. An apparatus for blowing oxygen into a blast furnace tuyere according to the third aspect of the patent application, comprising: a control device for performing opening and closing control of the two oxygen shutoff valves and the two nitrogen shutoff valves, wherein the control device is the two When the oxygen shut-off valve is opened, the two nitrogen shut-off valves are closed, and when the two oxygen shut-off valves are closed, the two nitrogen shut-off valves are opened. An apparatus for blowing oxygen from a blast furnace tuyere, comprising: a nozzle capable of blowing fine coal and oxygen into the blast furnace from a blast furnace tuyere; and an oxygen piping connected to the nozzle for supplying oxygen to the nozzle; a flow regulating valve disposed in the oxygen pipe; and connected to the nitrogen of the oxygen pipe upstream of the flow regulating valve The gas piping; the oxygen flow cutting mechanism is disposed upstream of the oxygen piping and the nitrogen piping, and is disposed upstream of the oxygen piping, and cuts off the oxygen flow of the oxygen piping when the power source is lost; the nitrogen piping is provided with: a check valve And a nitrogen flow opening and closing mechanism disposed upstream of the check valve to allow nitrogen to flow to the nitrogen pipe when the power source is lost. An apparatus for blowing oxygen into a blast furnace tuyere according to the fifth aspect of the patent application, wherein the nitrogen flow opening and closing mechanism includes two nitrogen shutoff valves that perform an opening operation when the power source is lost; and the two nitrogen shutoff valves are disposed A nitrogen discharge valve that closes between when the power source is lost. An apparatus for blowing oxygen from a blast furnace tuyere according to the fifth or sixth aspect of the patent application, wherein the oxygen flow interruption mechanism has two oxygen shutoff valves that perform a closing operation when the power source is lost; and is disposed in the oxygen piping An oxygen discharge valve that opens between the two oxygen shutoff valves and opens when the power source is lost. An apparatus for blowing oxygen from a blast furnace tuyere according to any one of claims 3 to 6, further comprising: a receiving tank connected to the nitrogen gas pipe upstream of the nitrogen gas shutoff valve or the nitrogen gas flow opening and closing mechanism And having a volume of 3 to 5 times the volume of the piping from the receiving tank to the blast furnace tuyere; and a nitrogen main-stage shut-off valve disposed on the upstream side of the receiving tank to perform a closing operation when the power source is lost. A blast furnace operation method is used as the first patent application scope The equipment for blowing oxygen from the blast furnace tuyere to any of the eight items blows the pulverized coal and oxygen into the blast furnace.