DE102012016045B3 - Method for operating a Aufblaslanzenanordnung, and Aufblaslanzenanordnung itself - Google Patents

Abstract

The invention relates to a method for operating a Aufblaslanzenanordnung in which hot blast is blown onto the molten bath and / or the heap in a converter, wherein the hot blast lance is fed via a hot blast from a hot blast source, according to the preamble of claims 1 and 8. In this case achieve that the Aufblasverfahren more effective and the inflation lance is improved with respect to the coupling with the hot blast source, the invention proposes that the hot blast lance with the hot blast source is detachably connected, such that for each batch d. H. between the batches the connection can be automatically released and closed again.

Description

The invention relates to a method for operating a Aufblaslanzenanordung, in particular Heißwindlanzenanordnung in which hot blast is blown onto a molten bath and / or a heap in a reaction vessel steelmaking, wherein the hot blast lance is fed via a hot blast line from a hot blast source, and a Aufblaslanzenanordnung, in particular Heißwindlanzen Arrangement 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.

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, and scrap are 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 a possibly 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 o. G.

Components additionally contain CO2 and water as combustion products. From the DE 36 07 777 A1 and the DE 602 04 675 T2 are hot blast lances that blow hot air of up to 1400 ° C in a melting vessel known. From the DE 42 40 666 C1 It is also known that the media lines of the lance are aligned with the supply lines. From the EP 441 767 A2 are releasable media connections of the lance known. 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.

Core of the inventive method is that the hot blast lance with the hot blast source is detachably connected, so that for each batch ie between the batches, the compound can be automatically released and closed again, and that with a lowering the hot blast lance on a hot blast closure for connection to the hot blast line is closed. 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 will now be the Positioning movement of the hot blast lance in the converter with the lowering movement connected to the hot blast closure. This happens at the same time, making the process very effective and easy. Ie. It is possible to achieve optimal positions of the hot blast lance for the process, which must not be blocked during the pauses of the process, for example between the 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 stated that the Aufblaslanze in height and relative to the stationary hot blast via a lance carriage is movable, and the Aufblaslanze with the hot blast, the hot blast with automatically adjustable Renkverschlussmitteln connected and the Renkverschluss upon reaching the connecting Renkendposition automatically by means of a plurality hydraulic cylinder actuation locks is locked. Thus, the hot-air shutter is automatically closed and opened.

Renkverschlusselemente are, for example. The well-known bayonet closure. 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. Ie. 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 be up to 35% or up to 50% by enrichment with oxygen.

However, a hot blast could also be a synthesis gas obtained, for example, from the exhaust 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 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 are openable even in case of failure. 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 such that a plurality of clamping connections of the Renkverbindungselemente are distributed to the annular configuration of the hot blast closure, and that acted upon for locking hydraulic cylinder are dimensioned so that a maximum of two working cylinders If necessary, you can carry the entire weight of the lance (hot blast lance) together with the lance carriage.

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 exits before or after connection to the Aufblaslanze (hot blast lance) no residual heat from the hot blast line.

It is thus an inflatable or hot blast lance created with such a hot-wind connection that a höhenerfahrbare hot blast lance on the hot blast seal with a hot blast 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. Other coolants for the melt are possible. Also, for example, the use of sponge iron can also be increased, or economically sensible ever supplied sponge iron.

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, eg. 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, possibly. Enriched with oxygen hot air 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 Aufblas- or Heißwindlanzenanordnung itself, the essence of the invention is that the hot blast lance over a fixed hot blast line with a stationary Heißwinderzeuger or a Pebble Heater is connectable, and that the connection between the hot blast lance and hot blast via an automatic detachable flanged hot blast closure takes place.

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.

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, for example, an exhaust pipe is first connected to the connection element before the connection of the lance, 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 can be opened or closed with a closure device - for example, a slide. 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 ,

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

It shows:

1 : Overall structure with procedural reference

2 : Hot air cap, open

3 : Hot air shutter closed

4 : Side sectional view of the closed hot-air shutter

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 bent down connecting pipe of the hot blast lance are each with a flange 5 Mistake. The flanges 5 are complementary formed in such a way that they interlock, as will be described in more detail below, and form two complementary connecting elements that form the hot blast closure according to the invention.

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

Within the around the tilt axis 2 tiltable converter 1 there is an iron melt. Through floor nozzles or bottom openings in the converter 1 For example, oxygen, nitrogen, argon and natural gas, as well as carbon and coal are added to the molten bath. The thereby controlled respective quantities are from a control device 20 determined and corresponding control signals to the associated actuator 21 . 22 and 23 given. From above the molten bath, hot air is released via a hot blast lance 3 in the converter 1 blown. The hot blast lance 3 is on a lance cart 4 arranged, which is also from the control device 20 is controlled. The hot blast lance 3 is equipped with the flanges made of flanges, as well as with Renkverschlusselementen complete with automatic twisting means and locking means 5 connected, which by a lifting movement of the lance wagon 4 including hot blast lance 3 from the fixed hot blast line 6 can be disconnected with open, ie unlocked hot-air shutter, or by a lowering movement with the hot blast line 6 can be reconnected gas-tight.

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 wind in the blowing phase. The cold wind is in a fan 13 produced, and optionally can also be supplemented 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 the control of the supplied hot blast, and just above the combustion rate and the total allothermal heat contributions in the reaction vessel or in the steel converter is optimally controlled.

2 shows the upper section of the hot blast lance 3 , as well as the hot wind closure 5 , Of course, the hot blast lance 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 the flange 5 ' the hot blast lance down on the complementary flange 5 '' the hot blast line closes. The hot blast line also runs down and is not shown here. The flange 5 ' the hot blast lance 3 has distributed on its outer circumference protruding guide fingers 5 ''' on. These leadership fingers 5 ''' grab it in the leadership chambers 9 the hot-wind closure when lowering a.

In this illustration, the lower flange 5 '' including the management chambers 9 in a position rotated by about 30 °. In the desired retraction position are of course the guide chambers 9 and the guide fingers 5 ''' directly aligned with each other!

By lowering the hot blast lance 3 The guide fingers then penetrate into the guide chambers 9 and continue to lower. In the end position then the ring including the guide chambers 9 twisted by about 30 °, leaving the guide fingers 5 ''' are locked.

For this purpose, the lower flange 5 '' hydraulic actuating means in the form of working cylinders 7 on, with which the ring on the the guide chambers 9 are placed, can be twisted. In the position of the closed hot-air shutter, which will be described below, the hydraulic cylinders will then additionally be used 8th actuated so that they keep the thus given Renkverbindung secured, and the flanges 5 ' and 5 '' also press together sealingly. In between are also sealants, as shown below.

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

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 ' integral sealing grooves 14 contains, 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.

LIST OF REFERENCE NUMBERS

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

Steller for oxygen floor nozzles

22

Adjusters for nitrogen bottom nozzles

23

Steller for coal feed

Claims (15)

A method of operating an inflation lance assembly in which hot blast is blown onto the molten bath and / or the debris in a converter, the hot blast lance being fed via a hot blast line from a hot blast source, characterized in that the hot blast lance is releasably connected to the hot blast source, that for each batch ie between the batches, the compound is automatically solvable and re-closable, and that is closed with a lowering the hot blast lance on a hot blast closure for connection to the hot blast line. A method according to claim 1, characterized in that the hot blast lance is lowered at a prepared for the melting process converter in the converter at the same time in an operating position. A method according to claim 1 or 2, characterized in that the hot blast lance is movable in height and relative to the stationary hot blast via a lance carriage, and the hot blast lance with the hot blast line the hot blast closure with automatic adjustable Renkverschlussmitteln connected and the Renkverschluss on reaching the connecting Renkendposition automatically means a plurality of hydraulic Arbeitzylinderbeaufschlagungen is locked. Method according to one of the preceding claims, characterized in that the Heißwindschluss the hot blast lance with the hot blast, the connection of the hot blast lance is provided with a Renkverschluss 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 automatically rotated relative to each other until reaching the Renkendposition with subsequent locking. Method according to one of the preceding claims, characterized in that the working cylinder for locking the Renkverbindung via a pressure accumulator are openable even in case of failure. Method according to one of the preceding claims, characterized in that a gap formed between the inner and outer sealing region of the hot blast closure is subjected to blocking air after locking the Renkverbindungselemente. Method according to one of the preceding claims, characterized in that the hot blast closure is concealed before and after connection with the hot blast lance with an automatically openable and closable hood, so that exits before or after connection to the hot blast lance no residual heat from the hot blast line. 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 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 during operation at at least approximately the same temperature. Aufblaslanzenanordnung, in particular Heißwindlanzenanordnung, with a height adjustable via a lance carriage relative to the converter lance tube, wherein hot blast is blown onto the molten bath and / or the debris in a converter, wherein the hot blast lance is fed via a hot blast line from a hot blast source, characterized in that the Hot blast lance via a fixed hot blast line with a stationary Heißwinderzeuger or a Pebble Heater is connectable, and that the connection between hot blast lance and hot blast line via an automatically releasable provided with flanges hot blast closure. Aufblaslanzenanordung, in particular Heißwindlanzenanordnung, according to claim 9, characterized in that the 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 flanged flanges, the Renkverschlusselemente a gas-tight and form mechanically fixed connection of hot blast lance and hot blast line. Aufblaslanzenanordnung in particular Heißwindlanzenanordnung, according to claim 10, characterized in that the Renkverschluss the hot blast closure upon reaching the connecting Renkendposition automatically by means of a plurality of hydraulic working cylinder are mechanically locked. Aufblaslanzenanordnung in particular Heißwindlanzenanordnung, according to any one of the preceding claims, characterized in that the Renkverschlusselemente by means of hydraulic or motor drive are automatically rotated. Aufblaslanzenanordnung in particular Heißwindlanzenanordnung, according to any one of the preceding claims, characterized in that the injected hot blast amount is controlled exclusively by adjusting means for controlled supply of the fed into the Pebble Heater amount of cold air. Aufblaslanzenanordnung in particular Heißwindlanzenanordnung, according to any one of the preceding claims, characterized in that 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, in the unconnected case, to avoid cooling down. Aufblaslanzenanordnung in particular Heißwindlanzenanordnung, according to any one of the preceding claims, characterized in that a plurality of Renkverbindungselementen are distributed to the annular configuration of the hot blast closure, and in that the acted upon locking hydraulic cylinder are dimensioned so that a maximum of two working cylinders, the total weight of the hot blast lance can carry the lance car.

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