EP2882875B1 - Method for operating a blower lance arrangement, and blower lance arrangement itself - Google Patents

Description

The invention relates to a method for operating a Aufblaslanzenanordung (Heißwindlanzenanordnung), in which hot blast is blown onto a molten bath and / or a heap in a steelmaking reaction vessel, wherein the hot blast lance is fed via a hot blast line from a hot blast source, and a Aufblaslanzenanordnung (Heißwindlanzanordnung) with hot wind source itself, according to the preamble of claims 1 and 9.

It is known in the steel industry to supply oxygen to the steel bath. This process is called "freshness". The supply of oxygen can be done by bottom blowing and / or by inflation. When bottom blowing, the converter in the bottom area on one or more special floor nozzles, through which the oxygen is supplied. In the inflation process, the oxygen is blown onto the steel bath by means of a water-cooled lance.

From the EP 0 464 427 A2 is a generic method is known in which although a connection of lance and hot wind source is present, but this can be closed and solved only with the appropriate effort.

Steelmaking in converters uses both pig iron and scrap as a feedstock. In addition, however, also produced in the direct reduction process so-called sponge iron in the form of DRI (Direct Reduced Iron) or HBI (Hot Briquetted Iron) can be used. An example of this is from the EP 1 920 075 B1 known.

Another procedure is from the DE 43 43 957 A1 in which in the operating phase of the converter fuels, oxygen-containing gases and iron raw materials, scrap are also introduced, and the reaction gases above the melt in the gas space of the converter with oxidizing gases are post-combusted. The resulting heat is transferred to the melt. In addition, oxygen and / or fuels are supplied via floor jets.

Hot blast is understood to mean a heated oxygen-containing gas. The gas is typically composed of the main components oxygen, nitrogen and argon. The oxygen content is in the range of normal air (21%) and can reach levels of up to 50%, preferably 35%, by enrichment with oxygen. As a hot blast but can also be understood a synthesis gas, which is obtained, for example, from the exhaust gases of a combustion reaction of a fuel such as blast furnace gas, coke gas, converter gas, natural gas or a gaseous or liquid hydrocarbon with air. The O 2 content of the synthesis gas can be adjusted by the air ratio of the combustion and, if appropriate, simultaneous enrichment of the combustion air with oxygen and / or the mixing of the combustion exhaust gases with pure oxygen. Such a synthesis gas produced in addition to the above

Components additionally contain CO2 and water as combustion products.

All in all, therefore, two advantages can be combined with each other, namely on the one hand to adjust the possibility of introducing larger amounts of scrap in the melting of the steel on the one hand and a better Abgasnachverbrennung on the other hand.

Depending on the amount of scrap introduced and the energy required to melt the steel scrap, there is still an appropriate contribution from the increased energy input due to the blowing in of the hot air in order to achieve better afterburning of the exhaust gases.

A disadvantage of known lance arrangements is that they are only rigidly executable because of the high temperature level during operation.

The invention is therefore based on the object to further develop the method for operating a Aufblaslanzenanordnung, as well as a Aufblaslanzenanordnung further to the effect that the Aufblaslanzenanordnung (Heißwindlanzenanordnung) from the process in a rest position is movable.

The stated object is achieved according to the invention in a method of the generic type by the characterizing features of claim 1.

Further advantageous embodiments of the method are specified in the dependent claims 2 to 8.

With regard to a Aufblaslanze the task is solved by the characterizing features of claim 9.

Further related embodiments are given in the remaining dependent claims.

The core of the inventive method is that the hot blast lance with the hot blast source is releasably connected, such that for each batch. between the batches the connection can be automatically released and closed again.

With hot blast closure is thus meant an outwardly dense, hot blast passing connection between hot blast lance and hot blast line.

With the invention, the positioning movement of the hot blast lance is now connected to the converter with the lowering movement to the hot blast closure. This happens at the same time, making the process very effective and easy.
This means that optimum hot-air lance positions can be achieved for the process, which must not be blocked during the break times of the process, for example between batches.
It can also be achieved that the lance can be brought into a resting and / or waiting position.

In a further advantageous embodiment, it is indicated that the Aufblaslanze is movable in height and relative to the stationary hot blast via a lance carriage, and the Aufblaslanze with the hot blast the hot air cap with automatic adjustable Renkverschlussmitteln connected and the Renkverschluss is automatically locked upon reaching the connecting Renkendposition automatically by means of a plurality of Hydraulikzylinderzylindervorläungen. Thus, the hot-air shutter is automatically closed and opened.

Renkverschlusselemente are, for example, the well-known bayonet lock. There are the steps joining together and then twisting (renken) to secure the connection.

However, it is surprising in the present case that a closure similar to the bayonet closure can be used in this case in a hot-wind closure. However, it is important in this use according to the invention that the rotation takes place according to the invention automatically via hydraulic means. In addition to the actual Renkverschluss, but this invention, the interlocked Renkelemente are additionally secured hydraulically. That The mechanical closure is achieved as described above by the hydraulics, or possibly by motor or pneumatics. The gas-tight connection of the hot blast lance with is ensured by the sealing air.

For the definition "hot wind", the following has to be done. Hot air is understood as meaning an oxygen-containing gas heated to 500 ° C. to 1400 ° C., preferably 1200 ° C. The gas is typically composed of the main components oxygen, nitrogen and argon. The oxygen content is in the range of normal air (21%) and can by enrichment with oxygen but levels up to 35% or up to 50%.

However, a hot blast could also be a synthesis gas obtained, for example, from the flue gases of a combustion reaction of a fuel such as blast furnace gas, coke gas, converter gas or natural gas or other gaseous or liquid hydrocarbon with air. The O 2 content of the synthesis gas can be adjusted by the air ratio of the combustion and a possibly simultaneous enrichment of the combustion air with oxygen and / or mixing of the combustion exhaust gases with pure oxygen.

In contrast to normal hot blast, hot blast generated as described above has carbon dioxide and water as products of combustion.

The proposed inventive operation of a hot blast lance, as well as a corresponding hot blast lance itself makes all the above gases as hot blast handled.

In accordance with the invention is therefore advantageously further configured that the Heißwindschlüssigen connection of the hot blast lance with the hot blast, the connection of the hot blast lance is provided with a Renkverschlusselement and is lowered onto the complementary counter element of the Renkverbindung on the hot blast line, and that upon reaching the end position, the two complementary Renkverbindungselemente are automatically rotated relative to each other, until reaching the Renkendposition with subsequent locking.

In a further advantageous embodiment, it is therefore provided that the working cylinder for locking the Renkverbindung via a pressure accumulator in the event of an accident are obvious. This is of considerable importance for safety reasons.

In an advantageous embodiment, it is stated that a gap formed between the inner and outer sealing region of the hot-air shutter is subjected to blocking air after locking of the Renk connecting elements. In this case, nitrogen, or a gas containing essentially nitrogen, is used as barrier air. This sealing air chamber results as a circular ring chamber between the bearing surfaces of the flanges of the hot blast closure. This sealing air chamber in the manner of a labyrinth seal will be contained between two concentric grooves, preferably trapezoidal grooves, in one of the two opposite flanges in the hot blast closure. In this a sealing cord can be inserted. In the "twisted" secured end position of the two complementary closure elements, each containing a flange, these sealing cords are then sealingly.

In a further very advantageous manner is configured that a plurality of clamping connections of the Renkverbindungselemente are distributed to the annular configuration of the hot blast closure, and that the acted upon locking hydraulic cylinder are dimensioned so that a maximum of two working cylinders the entire weight of the Aufblaslanze (hot blast lance) if necessary can carry with the lance cart.

In a further advantageous embodiment, it is provided that the hot blast closure before and after connection with the Aufblaslanze (hot blast lance) is covered with an automatically openable and closable hood, so that before or after connection to the Aufblaslanze (hot blast lance) no residual heat from the hot blast line exits.

It is thus an inflatable or hot blast lance created with such a hot-wind connection that a height-adjustable hot blast lance over the hot blast seal with a hot blast line and a fixed hot blast source is connectable.

This simplifies the operation of a hot blast lance so that an effective use thereof is provided.

The invention supports the use of such a hot blast lance. The operation of the hot blast lance results from the knowledge that when using hot blast a higher and more energetically effective afterburning can be achieved than with the use of pure oxygen. This then leads to more energy being available in the conversion of pig iron to steel in the converter while maintaining the same material balance. With the present invention it is achieved that now a higher proportion of the otherwise lost in the process gas carbon monoxide in the converter afterburning and this released heat is transferred to the molten bath. There is thus a higher energy available for the process.

This said additional amount of energy can then be used to allow larger amounts of scrap to be melted. Also other coolants for the melt is possible. Also, for example, the use of sponge iron can also be increased, or economically sensible ever sponge iron be supplied.

As is known, the heat balance of the converter is determined from the tapping temperature. A high tapping temperature indicates a low coolant rate and a low tapping temperature indicates a high coolant rate.
Thus, from the chemical composition of the pig iron in conjunction with the desired tapping temperature and the amount of coolant used targeted an operating point, which is called the autothermal point of the process.

This autothermal point can be influenced by an afterburning of the process gases in the reaction vessel, for example in the converter, is realized.
This afterburning can be operated particularly advantageously by hot blast.

Optimum process control therefore depends very much on the optimized gas-coupled coupling of the hot blast source to the hot blast lance. The reliability and reproducible tightness of the hot blast closure according to the invention contributes to the fact that the entire combustion process in the converter can be regulated by supplying the cold air into the hot-wind generator.

It is further stated that the hot blast lance is fed via the hot blast line of a stationary Pebble Heater, in which heated, if necessary with Oxygen-enriched hot blast is generated.

In this embodiment, it proves to be advantageous that no flexible connecting lines must be present, via which the lance the hot air is supplied. This proves to be advantageous in view of the high temperatures of the hot air and the associated material stress. The durability of flexible materials for hoses to keep the lance permanently connected in the different positions is not given at these high temperatures.

By the method according to the invention this problem is solved by the lance is connected only in its operating position. The use of flexible materials is then no longer necessary. If the lance is not in its operating position, the connection element is open.

In a particularly advantageous embodiment, it is provided that the hot blast lance is provided with a first coolant circuit, and the hot blast closure is provided with a second coolant circuit, and that the two coolant circuits are thermally coupled to each other, or are interconnected by coolant, such that hot blast lance and hot blast closure at least are at least approximately the same temperature during operation. In this way, thermal stresses are avoided, and the hot blast operation runs optimally.

With respect to the inflatable or hot wind lance arrangement itself, the gist of the invention is the hot blast lance can be connected to a stationary hot-wire generator or a Pebble Heater via a stationary hot blast line, and that the connection between hot-blast lance and hot-blast line takes place via an automatically detachable hot blast closure provided with flanges.

In a further advantageous embodiment, it is stated that the hot blast lance is connected via a fixed hot blast line with a stationary Pebble Heater, and that the connection between the hot blast lance and hot blast line via an automatically releasable provided with flanges hot blast closure. Instead of a Pebble Heater, a cowper or a recuperator can be used as a regenerator.

Since this hot-air shutter is automatically actuated, the reduction to the end position of the hot blast lance can then be done with the direct Aufschließ the flange of the hot blast line to the flange of the hot blast lance. This is done by one and the same lowering movement. The flange of the hot blast lance is located on a 180 ° bent pipe socket of the hot blast lance, so that it can unlock at all by lowering the flange of the hot blast line.

In order to preheat the feed line to the hot-air closure before the hot air is conveyed through the lance into the converter, an exhaust pipe is first connected, for example, before the connection of the lance to the connection element, via which the hot air is led out of the workshop for preheating the feed line. It can also be connected in the region of the connecting element an exhaust pipe, which with a closure device - for example a slide - can be opened or closed. The hot blast connection must then also have another closure element which must be closed when the closure device is open to the exhaust air pipe. In this position, the preheating of the supply line can be done. After preheating, the closure device (hot-air closure) is correspondingly closed to the exhaust pipe and the closure element is opened again. After connecting the lance to the hot-air cap, the hot air can then be introduced via the lance into the converter.

In a further advantageous embodiment of the Aufblas- or Heißwindlanzenanordnung is proposed that hot blast closure and a connecting piece of the hot blast lance is provided with a complementary flange, which in turn is provided with automatic adjustable Renkverschlussmitteln, such that when closing the successive flanges, the Renkverschlusselemente a gas-tight and form mechanically fixed connection of hot blast lance and hot blast line.

Furthermore, it is advantageously configured that the Renkverschluss the hot blast closure is automatically locked upon reaching the connecting Renkendposition automatically by means of a plurality of hydraulic working cylinder.

It is of considerable advantage if the Renkverschlusselemente by means of hydraulic or motor drive are automatically rotated.

It is also advantageous that the blown-in hot blast amount can be controlled exclusively via adjusting means for the controlled supply of the cold air quantity fed into the Pebble Heater. This is ultimately possible by the hot blast closure according to the invention in a simple and secure manner.

In the last advantageous embodiment, the flange of the hot blast line, which is the subject of the hot blast closure, additionally provided with a closable and openable hood to heat the hot blast line as such either in the manner described above, or to avoid cooling thereof in the unconnected case ,

Another great advantage is that the working cylinder for locking the Renkverbindung on a pressure accumulator in the event of malfunction are obvious, and the pressure accumulator is located directly on the hot blast closure.

Furthermore, it is advantageously configured that the pressure medium connections to the working cylinders via pipes instead of tubes, as far as the recessed connection of the closure remains movable through the said piping. The use of a piping instead of a tubing is that it is significantly more temperature resistant.

The invention is illustrated in the drawing and described in more detail below.

Figur 1:

Gesamtaufbau mit verfahrensmäßigem Bezug

Figur 2:

Heißwindverschluss, offen

Figur 3:

Heißwindverschluss geschlossen

Figur 4:

Seitenschnittansicht des geschlossen Heißwindverschlusses

It shows:

FIG. 1:

Overall structure with procedural reference

FIG. 2:

Hot air cap, open

FIG. 3:

Hot air shutter closed

FIG. 4:

Side sectional view of the closed hot-air shutter

FIG. 1 shows the most important components for the process implementation of the connection of the hot blast lance to the hot blast line.
The hot blast line and the downwardly bent connecting pipe of the hot blast lance are each provided with a flange 5. The flanges 5 are formed complementary in such a way that they interlock, as will be described in more detail below, and form two complementary connecting elements which form the hot blast closure according to the invention.

FIG. 1 shows individual components such as hot blast line 6, hot blast lance 3, Pebble Heater 10 and converter in a functional context. The downward movement of the hot blast lance 3 generated by the lancet into the converter closes the two complementary flanges 5 of the hot blast lance 3 and the hot blast line 6 in the desired end position.

Within the tiltable about the tilt axis 2 converter 1 is an iron melt. Through bottom nozzles or bottom openings in the converter 1, oxygen, nitrogen, argon and natural gas, as well as and carbon (coal) and lime are fed to the molten bath. The respective controlled quantities are determined by a control device 20 and given corresponding control signals to the associated actuator 21, 22 and 23. From above the molten pool, hot wind is over a hot blast lance 3 is blown into the converter 1. The hot blast lance 3 is arranged on a lance carriage 4, which is also controlled by the control device 20. The hot blast lance 3 is connected to the flanges, as well as with Renkverschlusselementen complete with automatic twisting and locking means hot blast closure 5, which can be separated by a lifting movement of the lance carriage 4 together with hot blast lance 3 of the fixed hot blast 6 with open, ie unlocked hot blast closure, or by a Lowering movement with the hot blast line 6 gas-tight can be reconnected.

The hot blast closure is an automatically controlled device with which the gas-dynamic coherent, and gas-tight connection of hot blast line and hot blast lance can be made by means of said automatic coupling means.

The hot blast line 6 is fed by a so-called Pebble Heater 10, which generates hot blast from cold blast in the Blasphase. The cold wind is generated in a fan 13, and optionally can be additionally enriched with oxygen.

The heat balance in the converter, and thus also the heat supplied via the hot blast lance, is advantageously controlled or regulated exclusively via the control of the supply of cold air to the Pebble Heater. This is precisely where the control of the supplied hot blast takes place, and precisely above this the combustion rate and the total allothermal heat contributions in the reaction vessel or in the steel converter are optimally controlled.

FIG. 2 shows the upper portion of the hot blast lance 3, and the hot blast closure 5. The hot blast lance of course continues down and is not shown here. The connecting pipe is designed as a 180 ° pipe bend, so that a downward movement of the hot blast lance 3 also closes the flange 5 'of the hot blast lance down onto the complementary flange 5 "of the hot blast line The hot blast line likewise runs downwards and is not shown here any further.
The flange 5 'of the hot blast lance 3 has distributed on its outer circumference projecting guide fingers 5''' on. These guide fingers 5 '''engage in the guide chambers 9 of the hot blast closure during lowering.

In this illustration, the lower flange 5 "together with the guide chambers 9 is in a position rotated by about 30.degree .. In the desired retraction position, of course, the guide chambers 9 and the guide fingers 5 '" are directly aligned with one another!

By lowering the hot blast lance 3, the guide fingers then penetrate into the guide chambers 9 and lower further.
In the end position then the ring together with the guide chambers 9 is rotated by about 30 °, so that the guide fingers 5 '''are locked.

For this purpose, the lower flange 5 "has hydraulic adjusting means in the form of working cylinders 7 with which the ring on which the guide chambers 9 are placed can be rotated Hydraulic cylinder 8 is actuated so that they keep the Renkverbindung thus given positionally secured, and the flanges 5 'and 5 "also press together sealingly .In addition, there are sealing means, as shown below.

FIG. 3 shows the closed, twisted and secured hot-air lock from the perspective from above.

FIG. 4 shows in a side sectional view of the closed hot-air shutter 3. It can be seen that the upper flange, namely the flange 5 'includes integral sealing grooves 14, in which sealing cords can be inserted. There is an inner seal groove and an outer seal groove. The seal is designed in the manner of a labyrinth seal. In between, a barrier air volume is enclosed in closed flanges, which is acted upon in the closed state of the flanges with blocking air.

The system is designed so that in case of failure or power failure via an emergency power supply (eg 24 volts) all functions for opening and pivoting of the hot air shutter can be done.
The hydraulic cylinders are powered by a hydraulic system with a residual pressure of 200 bar. All hydraulic cylinders are separately monitored by suitable switching elements.

reference numeral

1

steel converter

2

Konverterkippeinrichtung

3

Hot blast lance
3 'connecting pipe of the hot blast lance

4

Lanz car

5

Hot blast closure, flanges of hot blast closure
5 'flange on the connection pipe of the hot blast lance
5 "counterflange on the hot blast line
5 '''guide fingers
5 '''' connections for cooling water

6

Hot air line

7

Adjusting means, torsional means

8th

lock cylinders

9

guide chambers

10

Pebble Heater

11

burning chamber

12

Sauerstoffdosierer

13

fan

14

seal grooves

15

Sealing air chamber
20 control device
21 actuators for oxygen floor nozzles
22 actuators for nitrogen floor nozzles
23 adjusters for coal feed

Claims (15)

1. Method for operating a blower lance arrangement (hot blast lance arrangement), in which a hot blast is blown onto the molten pool and/or the aggregate material in a converter, the hot blast lance being fed by a hot blast source via a hot blast line, the hot blast lance being connected releasably to the hot blast source in such a way that the connection can be automatically opened and closed again for each batch, that is to say between the batches, characterized in that the hot blast lance can be moved vertically and relative to the stationary hot blast line via a lance carriage, and the hot blast lance is connected to the hot blast line via the hot blast closure by way of automatic actuable bayonet closure means, and the bayonet closure is locked automatically by means of a plurality of hydraulic operating cylinder loads when the connecting bayonet end position is reached.
2. Method according to Claim 1, characterized in that, in the case of a converter which is prepared for the melting operation, the hot blast lance is lowered into the converter into an operating position in such a way that the hot blast lance is at the same time closed onto a hot blast closure for connection to the hot blast line by way of the lowering movement.
3. Method according to either of the preceding claims, characterized in that, in order to connect the hot blast lance to the hot blast line in a manner which is locked in terms of the hot blast, the connector of the hot blast lance is provided with a bayonet closure and is lowered onto the hot blast line onto the complementary corresponding element of the bayonet connection, and in that, when the end position is reached, the two complementary bayonet connecting elements are automatically rotated relative to one another until the bayonet end position is reached with subsequent locking.
4. Method according to one of the preceding claims, characterized in that the operating cylinders can be opened even in the case of a disruption in order to lock the bayonet connection via a pressure accumulator.
5. Method according to one of the preceding claims, characterized in that an intermediate space which is formed between the inner and outer seal region of the hot blast closure is loaded with sealing air after the locking of the bayonet connecting elements.
6. Method according to one of the preceding claims, characterized in that a plurality of bayonet connecting elements are arranged in a distributed manner on the circularly annular configuration of the hot blast closure, and in that the hydraulic operating cylinders which are loaded for locking purposes are dimensioned in such a way that at most two operating cylinders can support the entire weight of the hot blast lance including the lance carriage.
7. Method according to one of the preceding claims, characterized in that the hot blast closure is covered with an automatically openable and closable hood before and after the connection to the hot blast lance, with the result that no residual heat exits from the hot blast line before or after the connection to the hot blast lance.
8. Method according to one of the preceding claims, characterized in that the hot blast lance is provided with a first coolant circuit, and the hot blast closure is provided with a second coolant circuit, and in that the two coolant circuits are coupled thermally to one another, or are connected to one another in a manner which is locked in terms of the coolant, in such a way that the hot blast lance and hot blast closure are at least approximately the same temperature at least during operation.
9. Blower lance arrangement having a lance pipe, the height of which can be adjusted with respect to the converter (1) via a lance carriage (4), in which blower lance arrangement hot blast is blown onto the molten pool and/or the aggregate material in a converter (1), the hot blast lance (3) being fed by a hot blast source via a hot blast line (6), it being possible for the hot blast lance (3) to be connected via a stationary hot blast line (6) to a stationary hot blast generator or a pebble heater (10), and the connection between the hot blast lance (3) and the hot blast line (6) taking place via a hot blast closure (5) which can be released automatically and is provided with a flange, and the hot blast closure (5) and a connector piece (3') of the hot blast lance (3) being provided with in each case one complementary flange element (5', 5") which is in turn provided with automatically actuable bayonet closure means (7, 8, 9, 5'''), in such a way that, when the flanges (5', 5") which are moved onto one another are closed, the bayonet closure elements form a connection of the hot blast lance (3) and the hot blast line (6), which connection is fixed mechanically and is locked in terms of the gas.
10. Blower lance arrangement according to Claim 9, characterized in that the bayonet closure of the hot blast closure (5) can be mechanically locked automatically by means of a plurality of hydraulic operating cylinders (8) when the connecting bayonet end position is reached.
11. Blower lance arrangement according to one of the preceding claims, characterized in that the bayonet closure elements can be rotated automatically by means of a hydraulic or motor drive.
12. Blower lance arrangement according to one of the preceding claims, characterized in that the operating cylinders (8) can be opened even in the case of a disruption in order to lock the bayonet connection via a pressure accumulator, and the pressure accumulator is arranged directly on the hot blast closure (5).
13. Blower lance arrangement according to one of the preceding claims, characterized in that the pressure medium connections to the operating cylinders (7, 8) takes place via pipes instead of via hoses, to the extent that the bayonet connection of the closure remains movable by way of the said pipework.
14. Blower lance arrangement according to one of the preceding claims, characterized in that the hot blast quantity which is blown in can be regulated exclusively via actuating means (12, 13) for the regulated feed of the cold air quantity which is fed into the pebble heater (10).
15. Blower lance arrangement according to one of the preceding claims, characterized in that the flange (5") of the hot blast line (6) which is the subject of the hot blast closure (5) is also additionally provided with a closable and openable hood, in order either to heat the hot blast line (6) per se in the above-described way or to avoid cooling thereof in the non-connected case.

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