UA113509C2 - METHOD OF METALLURGY INSTALLATION AND METALLURGICAL INSTALLATION - Google Patents

Abstract

The metallurgical plant has a recovery plant (7) located in the steelmaking process before the steel production unit (8) and a gas-generating plant (1) that generates export gas (2). The carbon dioxide contained in the export gas (2) and the water in the separation device (3) are at least partially removed from the export gas (2). ) by combustion of combustible gas (11). The combustible gas (11) is supplied to the furnace device (6) in a volume that is much greater than that required to heat the generator gas (4). it is not used to heat the generator gas (4), off The use can be made inside the combustion device (6) for steam production and relative to the direction of the flue gas stream (12) that occurs during the combustion of combustible gas (11), after the combustion device (6). heating the flue gas (11) and by heating the oxidizing gas (10) used to burn the flue gas (11) and by heating and drying the feed materials (20, 21) supplied to the recovery plant (7) and to the gas generator well the installation (1).

Description

The invention relates to a method of operation of a metallurgical plant, which includes a recovery plant located in the steel production process before the steel production plant, and a gas generator plant that generates export gas - and carbon dioxide contained in the exported gas and water in the separator the device is at least partially separated from the export gas, and at the same time the received (generator) gas is heated in the combustion device by burning combustible (fuel) gas before being fed to the previously placed recovery unit - and the fuel gas is fed into the combustion device in a volume that is greater than required for heating generator gas.

The proposed invention also relates to a metallurgical plant, which is designed in such a way that it performs a similar method during operation.

Similar metallurgical installations and corresponding methods of operation are known from publication О5 5 846 268 А.

In metallurgical plants, especially in plants for the production of iron and steel, large amounts of thermal energy are required at high temperatures. In such installations, large amounts of waste heat are released as a by-product. Such obtained waste heat is partially already used to heat the intermediate products received inside the metallurgical plant or to be processed, especially process gases. The waste heat is partially already used to power the electric generator with the help of steam generating devices together with the turbine connected to them.

The task of the invention is to create opportunities for more efficient use of the metallurgical installation of the above-mentioned type.

This task is solved by the method of operation with the features of clause 1 of the claims.

Preferred variants of the implementation of the corresponding invention of the method of operation are the subject of dependent clauses 2-11.

In accordance with the invention, it is provided to implement a method of operating a metallurgical installation of the above-mentioned type in such a way that the thermal energy obtained during the combustion of flue gas, if it is not used for heating the generator gas, is thermally used inside the combustion device for the production of steam and/or relative to the direction of the gas flow of flue gas , which occurs during the combustion of fuel gas, is used after the combustion device for heating and/or drying the raw materials that are fed to the previously placed recovery unit and/or to the gas generator unit.

In the preferred form of implementation of the proposed invention, the flue gas produced during the combustion of fuel gas is first used to generate steam and only then to heat the generator gas.

In some cases, it is necessary to maintain the temperature of the generator gas basically constant at a given value. If this is the case and the temperature of the flue gas is very high, it is possible to mix cold air into the flue gas after it is used for steam generation and before heating the generator gas to set the temperature of the flue gas that heats the generator gas.

In a particularly preferred form of implementation of the proposed invention, it is provided that - the heating of the generator gas is limited to an intermediate temperature lower than the reaction temperature required for the use of the generator gas in the previously placed recovery unit, although the thermal energy required for this is obtained by burning the fuel gas, and - the heated generator gas the gas is heated from the intermediate temperature to the reaction temperature by partial oxidation of the generator gas.

If the thermal energy of the flue gas is large enough, it is possible that the thermal energy of the flue gas after the combustion device is used for heating the flue gas and for heating the oxidizing gas used for burning the flue gas and for heating the coolant oil.

It is possible that part of the export gas generated in the gas-generating unit is used as fuel gas. Alternatively or additionally, it is possible that the process gas enriched with carbon dioxide and water, which is obtained by removing carbon dioxide and water from export gas, is used as a furnace gas. If the mentioned process gas does not burn stably enough or does not contain the necessary thermal energy, then additional combustible gas may be mixed with the process gas, or the process gas may be burned together with the additional combustible gas.

The amount and composition of export gas received, and the related amount and composition of process gas received, are often subject to significant temporal fluctuations. Therefore, in many cases, it may be appropriate that the part of the export gas or process gas used as fuel gas is temporarily stored in a low-pressure gas storage located in front of the combustion device.

In many cases, combustible gas is produced during the operation of the previously placed installation. It is possible that the combustible gas is at least partially mixed with the export gas.

Alternatively or additionally, the combustible gas may be used as fuel gas.

In addition, it is possible that hot blast furnace gas is produced during the operation of the previously placed installation. In this case, it is possible that the thermal energy contained in the blast furnace gas is used to heat the generator gas before it is fed to the combustion device and before it is used to generate steam. The hot blast furnace gas may alternatively be a combustible or a non-combustible gas.

The previously placed reduction plant can be designed, for example, as a blast furnace, as a smelter-reduction plant, as a melting unit or as a direct reduction plant.

The gas generator plant can be designed, for example, as a coal gasification plant or as a metal smelting plant.

The specified task is also solved with the help of a metallurgical plant with the features of item 12 of the claims. According to the invention, it is provided that the metallurgical plant of the above-mentioned type is designed in such a way that during operation it performs the method of operation corresponding to the invention.

Other advantages and details emerge from the further description of the implementation examples in relation to the drawings, which depict:

Fig. 1 Scheme of the metallurgical plant

Fig. 2 Scheme of a fragment of a metallurgical plant according to fig. 1,

Fig. C Scheme of a possible form of implementation of the metallurgical installation in fig. 1.

According to fig. 1, the metallurgical plant has a gas generator unit 1. The gas generator unit 1 can, for example, be designed as a coal gasification unit or as a metal smelting unit. In case of implementation as a metal melting plant, it can be implemented, in particular, as an iron smelting plant - also as a blast furnace, in particular as an oxygen blast furnace - or as a smelting and reduction plant. An oxygen blast furnace is a blast furnace in which technically pure oxygen is used as the blasting gas, and the resulting blast gas can be returned to the blast furnace.

The gas generator unit 1 generates during operation gas 2, which is further referred to as export gas 2. Export gas 2 contains combustible components, as well as additionally carbon dioxide, water and, as a rule, also nitrogen. The presence of carbon dioxide and water in fig. 1 is represented by the fact that the designations "СОг" and "НгО" are indicated for export gas.

Export gas 2 - in whole or in part - is fed to the separation device 3. In the separation device C, export gas 2 is processed - if necessary, only a part of the export gas 2 is fed to the separation device 3. In particular, in the separation device C, the dioxide present in the export gas 2 carbon and the water present in the export gas 2 are completely or partially removed from the export gas 2. This creates, on the one hand, the generator gas 4, in which, compared to the export gas 2, the content of carbon dioxide and water is reduced. This is shown in fig. 1 by the designations "СО»-" and "НгО-". On the other hand, process gas 5 is obtained, which is often referred to as residual gas enriched with carbon dioxide and water. This is shown in fig. 1 with the designations "СОг" and "НО".

The generator gas 4 is supplied first to the combustion device 6 and from there to the previously placed reducing unit 7. The previously placed reducing unit 7 is a unit that in the process of steel production precedes the unit 8 for steel production. The previously placed reduction unit 7 can, for example, be made as a blast furnace, smelter-reduction unit, as a melting unit or as a direct reduction unit.

In the combustion device 6, the generator gas 4 is heated in the heat exchanger 9 of the generator gas. At the same time, the chemical composition of generator gas 4 remains at least largely unchanged. Only the temperature of the generator gas 4 changes.

During the operation of the combustion device 6, in the combustion device 6 using the oxidizing gas 10, the combustion gas 11 is burned to form flue gas 12. Both gases 10, 11 are fed to the combustion device 6. The oxidizing gas 10 can, in particular, be ordinary air.

Combustion gas 11 is supplied to the combustion device 6 in a volume that is much higher than that required for heating the generator gas 4. Therefore, a significant amount of excess thermal energy is produced in the combustion device 6. The produced thermal energy can, if it is excess, because - that is, it is not needed and is not used to heat generator gas 4, -

be used, for example, to produce steam with the help of the evaporator 13 and, thus, to activate the water-steam circulation circuit. The steam can, for example, drive the turbine 14, which in turn drives the electric generator 15. Alternatively, the steam can be used in another way.

If steam generation is carried out, the evaporator 13 - see especially clearly in fig. 2 - relative to the direction of the gas flow, flue gas 12 precedes the generator gas heat exchanger 9.

The flue gas 12 obtained by burning the fuel gas 11 is first used for steam generation and only after that - for heating the generator gas 4.

If necessary, with the help of flue gas 12, the generated steam can also be superheated. Perhaps the existing superheater (not shown in the figures) in this case precedes the heat exchanger 9 of the generator gas, if necessary also the evaporator 13, relative to the direction of the gas flow of the flue gas 12. In addition, the evaporated water can be heated. In this case, the corresponding heater (not shown in the figures) is located after the heat exchanger 9 of the generator gas relative to the direction of the gas flow of the flue gas 12.

Alternatively or additionally to the use for steam generation, it is possible to use the flue gas 12 in the units 16-19, which are located relative to the direction of the gas flow of the flue gas 12 behind the combustion device 6.

For example, the fuel gas 11 can be heated in the heat exchanger 16 of the fuel gas.

Alternatively or additionally to the heating of the fuel gas 11, the oxidizing gas 10 is heated in the heat exchanger 17 of the oxidizing gas. The heating of the fuel gas 11 and the oxidizing gas 10 is carried out, of course, before supplying the mentioned gases 10, 11 to the combustion device 6.

In addition, as an alternative or in addition to the heating of the fuel gas 11 and the oxidizing gas 10, in the device 18 for the preparation of raw materials (raw materials), drying and heating of the raw materials 20 can be carried out, which must be fed to the previously placed reduction unit 7. Similarly, in the additional device 18 preparation of raw materials - additionally or alternatively - drying and heating of raw materials 21 can be carried out, which must be fed to the gas generating unit 1. How can raw materials 21

To be used, in particular, iron ore or coking coal.

If, in addition, the excess thermal energy of flue gas 12 is available, then it is additionally possible to use the thermal energy of flue gas 12 behind the combustion device 6 in the oil heat exchanger 23 to heat the coolant oil 24.

In some cases, it may be rational to set the temperature of the flue gas 12, which heats the generator gas 4. For this purpose, to the flue gas 12 according to fig. 2, cold air 25 can be mixed in. In this case, cold air 25 is mixed in after using flue gas 12 to generate steam, but, of course, before heating generator gas 4.

It is possible to heat the generator gas 4 in the combustion device 6 to the temperature T of the reaction (usually above 800 "C, which the generator gas 4 must have in order to be able to be used in the previously placed recovery unit 7. In many cases, however, it is useful to limit the heating of the generator gas gas 4 to an intermediate temperature T", which is lower than the temperature T of the reaction. This is the case, although the combustion of the fuel gas 11 produces the necessary thermal energy for this (that is, for heating to the temperature T of the reaction). The intermediate temperature T can, for example, lie in the range from approximately 400 "C to approximately 600 "C. If the generator gas 4 in the combustion device 6 is heated only to an intermediate temperature T, then the generator gas 4 heated in the combustion device 6, according to Fig. 2, by partial oxidation of the generator gas 4 in the oxidizing device 26 is heated from the intermediate temperature HT to the reaction temperature T. As a rule, for this purpose, the oxidizing device 26 is additionally oxidizing gas 21 is supplied to generator gas 4, for example, technically pure oxygen (oxygen content at least 90 9b).

Fuel gas 11, which is burned in the combustion device 6, can be chosen in principle any. Combustion gas 11 can be supplied to the metallurgical plant from the outside. Alternatively, the combustible gas may be gas produced within the metallurgical plant. For example, it is possible that as fuel gas 11 according to fig. A part of the export gas 2 generated by the gas generator 1 is used. Alternatively or additionally, it is possible that the process gas 5 is used as a combustion gas 11. If necessary, an additional combustible gas 28 can be mixed with the process gas 5. Alternatively, if necessary, an additional combustible gas 28 can be burned in a separate burner of combustion device b together with process gas 5.

If a part of the export gas 2 or process gas 5 is used as the fuel gas 11, a low-pressure gas storage 29 is preferably placed in the supply line that brings the corresponding gas 2, 5 to the combustion device 6. The low-pressure gas storage 29 serves to equalize fluctuations in the amount or composition that occur during the generation of export gas 2 and process gas 5. In the low-pressure gas storage 29, there is a gas pressure p, which is slightly higher than atmospheric pressure.

In many cases, during the operation of the previously placed installation 7, gas 30 is released, which is hot and flammable. This gas 30 is often called blast furnace gas. If the blast furnace gas 30 is combustible, it can be - fully or partially - mixed with the export gas 2. Alternatively or additionally, the blast furnace gas 30 can be used as a furnace gas 11.

If necessary, it can be used together with export gas 2 and process gas 5. In particular, blast furnace gas 30 in this case is identical to the combustible gas 28 that is mixed with process gas 5 or burned together with it.

If the blast furnace gas 30 is hot, then it is possible to use the thermal energy available in the blast furnace gas 30 to heat the generator gas 4 before it is fed to the combustion device b and to produce steam (including superheating). This is also shown in fig. With a dotted line.

The proposed invention has many advantages. In particular, it is possible to effectively use the thermal energy produced in the metallurgical plant and the produced combustible gases in a relatively simple way.

The above description serves only to explain the proposed invention. The scope of legal protection of the proposed invention should be determined exclusively by the appended claims.

LIST OF POSITION DESIGNATIONS

1 gas generating plant 2 export gas

C separation device 4 combustion gas 5 process gas

From 6, the combustion device 7 previously housed a recovery plant 8 steel production plant 9 generator gas heat exchanger 10, 27 oxidizing gas 35 11 combustion gas 12 flue gas 13 evaporator 14 turbine 15 generator 40 16-19 aggregates 16 fuel gas heat exchanger 17 oxidizing gas heat exchanger 18 , 19 raw material preparation devices 20, 21 raw materials 45 23 oil heat exchanger 24 oil heat carrier 25 cold air 26 oxidation device 28 additional combustible gas 50 29 low pressure gas storage blast furnace gas p gas pressure

T is the reaction temperature

T is an intermediate temperature

Claims (16)

FORMULA OF THE INVENTION 1. The method of operation of a metallurgical plant, which contains a recovery plant (7), located in the process of steel production before a plant (8) for steel production, and a gas generator plant (1) that generates export gas (2), - and the carbon dioxide contained in the export gas (2) and/or water in the separator (3) is at least partially removed from the export gas (2), and at the same time, the generator gas (4) before being fed to the recovery unit (7) is heated in the combustion device (6) by burning fuel gas (11), - and the fuel gas (11) is fed into the combustion device (6) in a volume that is greater than that required for heating the generator gas (4), - and the obtained at combustion of fuel gas (11), thermal energy is used to heat the generator gas (4) and/or inside the combustion device (6) for the production of iMabo steam relative to the direction of the gas flow of flue gas (12), which occurs during the combustion of fuel gas (11), after combustion device (b) for heating the fuel gas (11) and/or for heating the oxidizing gas (10) used for burning the fuel gas (11), and/or for heating and/or drying the starting materials (20, 21), which served for one internal installation (7) and/or gas generator installation (1). 2. The method of operation according to claim 1, which is distinguished by the fact that the flue gas (12), which occurs during the combustion of the fuel gas (11), is first used for steam generation and only then - for heating the generator gas (4). 3. The method of operation according to claim 2, which differs in that in order to set the temperature of the flue gas (12) that heats the generator gas (4), cold air (25) is mixed into the flue gas (12) after it is used for steam generation and before heating generator gas (4). 4. The method of operation according to claims 1 or 2 or 3, which differs in that - the heating of the generator gas (4) is limited to an intermediate temperature (7), lower than the reaction temperature (Т) required for the use of the generator gas (4) in recovery unit (7), although the necessary thermal energy is produced during combustion of fuel gas (11), and - the heated generator gas (4) by partial oxidation of the generator gas (4) is heated from the intermediate temperature (7) to the reaction temperature (Т) . 5. The method according to any of the preceding points, which is characterized by the fact that the thermal energy of the flue gas (12) after the combustion device (6) is used for heating the combustion gas (11) and/or for heating the oxidizing gas (10) used for combustion of fuel gas (11), and/or for heating heat carrier oil (24). Zo 6. The method according to any of the previous clauses, which differs in that as fuel gas (11) a part of the export gas (2) generated in the gas generator unit (1) or obtained during the removal of carbon dioxide and water from the export gas is used (2), the process gas (5) enriched with carbon dioxide and water, and the process gas (5), if necessary, is mixed with the additional fuel gas (28) or burned together with the additional fuel gas (28). 7. The method of operation according to claim 6, which differs in that the part of export gas (2) or process gas (5) used as fuel gas (11) is temporarily stored in a low-pressure gas storage (29) located in front of the combustion device (6) . 8. The method according to any of the previous items, which is characterized by the fact that during the operation of the recovery unit (7) combustible blast furnace gas (30) is produced, and that the combustible blast furnace gas (30) is at least partially mixed with the export gas (2), and used as fuel gas (11). 9. The method according to any one of claims 1-7, which is characterized by the fact that during the operation of the recovery unit (7) combustible blast furnace gas (30) is produced, and that the thermal energy containing the blast furnace gas (30) is used to heat the generator of gas (4) before its supply to the combustion device (b) and/or for steam generation. 10. The method according to any of the previous items, which is characterized by the fact that the reduction unit (7) is designed as a blast furnace or as a melting-reduction unit, or as a melting unit, or as a direct reduction unit. 11. The method according to any of the preceding points, which is characterized by the fact that the gas generator unit (1) is designed as a coal gasification unit or as a metal smelting unit, in particular as a pig iron smelting unit, or as a smelting and reducing unit. 12. A metallurgical plant, made with the possibility of implementing the method according to any of the previous items during operation, which contains: - a plant (8) for the production of steel, - a recovery plant (7), located in front of the plant (8) for the production of steel, - a gas generator unit (1) that generates export gas (2), - a separation device (3) for at least partial removal of carbon dioxide and water contained in export gas (2) with the formation of generator gas (4), - combustion device (b) with a main line for supplying generator gas (4) from the separation device (3) to the combustion device (6) and with a main line connected to the recovery unit (7) for supplying generator gas heated in the combustion device (6) from the combustion device (b) to the recovery unit (7), - a main line for supplying fuel gas (11) to the combustion device (6), - a main line for supplying oxidizing gas (10) to the combustion device (6), and the installation contains at least one from the following devices: - placed inside the combustion device (b) the evaporator (13) for steam generation and - placed after the combustion device (b) relative to the direction of the gas flow of the flue gas (12) that occurs when the combustion gas (11) is burned, the device ( 18, 19) preparation of raw materials for heating and drying of raw materials (20, 21), which are fed to the recovery unit (7) and the gas generator unit (1). 13. A metallurgical plant according to claim 12, which is characterized by the fact that it contains a pipeline for supplying cold air to the flue gas (12). 14. A metallurgical installation according to claim 12 or 13, which differs in that it contains a low-pressure gas storage (29) for intermediate storage of export gas (2) or process gas (5), and the low-pressure gas storage (29) is located in front of the combustion device ( 6). 15. A metallurgical plant according to any one of claims 12-14, characterized in that the reduction plant (7) is a blast furnace, a melting-reduction plant, a melting unit or a direct reduction plant. 16. A metallurgical plant according to any of claims 12-15, which is characterized by the fact that the gas generating plant (1) is designed as a coal gasification plant, a metal smelting plant, in particular a pig iron smelting plant, or a smelting and reduction plant. and - - nin I M 24 |2z 16 . syu b -i z) -ShZ52 ee and p YIV tt Z r so», NeO) | ' that 4 (bbo-, No0-) 71 and pt In and | rya r 5 (Sat, Noah i) | roses t! | peri I B 1-10 I Il to Fig. 1 in i