DE3109111A1 - "PLANT FOR INPUTING COAL IN METALLURGICAL PROCESSING VESSELS WITH A VARIETY OF INLAY POINTS AND METHOD FOR OPERATING THE PLANT" - Google Patents

Description

FRIED. KRUPP GESELLSCHAFT LIMITED LIABILITY

in food

Plant for feeding coal into metallurgical process vessels with a large number of injection points and procedures for operating the facility

The invention relates to a system according to the preamble of claim 1 and a method for operation this plant.

The one used in metallurgical processes, especially in the smelting of iron ores in blast furnaces Coke is being partially replaced by other cheaper fuels. It comes both with regard to the temporal course as well as on the local distribution essentially on the regular introduction of the substitute fuel at.

From DE-AS 26 52 510 a system for coal processing is and a corresponding transport device for introducing the pulverized coal into a blast furnace is known. In this known system, raw coal is fed into a mill and ground there to form coal dust. The coal dust is dried by a preheated air stream and conveyed to a separator from which the pulverized coal enters a storage container. When in grinding If wet carbon sorts are used, the downstream of the separator will be contaminated Filters, leading to malfunctions and thus interruptions

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the continuous fuel supply to the blast furnace leads. In addition, it can only be expelled after the marriage Moisture no longer removed separately are and therefore burdened the metallurgical process by blowing into the furnace.

Several batch or metering bunkers are connected downstream of the storage container of the known system, of which alternately one emptied with pressurized inert gas to feed coal dust into the blast furnace and another is replenished from the reservoir, the conduit paths from the reservoir to the dosing bunkers and from the dosing bunkers to the blast furnace released or interrupted by shut-off valves will. The shut-off valve of another dosing hopper closes - even if only for a small amount Period of time - to an interruption in the continuous flow of fuel into the blast furnace. About that In addition, the shut-off valves are because of the "they are located." Coal dust and the associated high friction are exposed to severe wear and tear, which requires early replacement of the valves and thus also to interruptions the continuous introduction of coal dust ^ into the blast furnace.

On their way from a common pneumatic line into the blast furnace, the pulverized coal arrives from the air flow a separate compressed air source is transported, in the known system via a distributor in a large number of feed lines leading to the "on the circumference" of the blast furnace ?;

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the nozzles located. Depending on their arrangement, these feed or injection lines have different ones Lengths and thus - in inverse proportion - different Line resistances, so that at one point of the blast furnace more coal dust is supplied than at another point. In terms of location, this means a deviation from a uniform fuel supply.

The known system requires two separate systems to convey the coal dust from the processing plant to the blast furnace Compressed air sources, a compressed gas source for inert gas and a preheater for air, creating a high expenditure of energy and the presence of inert gas is required.

The invention is based on the object of introducing fine-grain fuel into metallurgical process vessels to improve while avoiding irregularities and interruptions and at the same time the necessary effort of energy and auxiliary materials as well as the necessary scope of investment to lower.

This object is achieved by the features specified in claim 1. These features make it possible to use the fuel evenly on the circumference of the blast furnace, the operation of this part of the plant preferably according to the characteristics of claims 5 and 6 can be done.

With the Ausgestalton the system according to claim 2 can be determined will be whether the around the encircling blow mold geleaen ^ n Sufficient hot air flows to the burning point in the process vessel. In the event that the hot wind flow is not aeni-uond great, the coal rod is fed through the relevant irrigation line interrupted after the measure of claim 7.

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So that the new coal dust supply in the event that the relevant focal point assumes hot wind again, can take place without interference, the relevant injection line is also blown free according to the measure of claim 7. During the interruption of the pulverized coal supply in a combustion point, the remaining pulverized coal supply evenly distributed over the remaining burners.

In the case of a system that draws its coal dust from a dosing bunker and a storage bunker in front of it, it is possible to determine the mass flow of the coal dust fed to the blast furnace without interruption, even then who the dosing hopper is refilled from the storage container. Since there is no shut-off valve downstream of the dosing hopper, there is no possibility of premature wear of a valve here either. That between the reservoir and the dosing bunker arranged valve can be blown free by propellant gas after completion of the refilling process, so j that the closing of this valve also largely friction: can be done freely and thus with little wear.

An embodiment of the object of the invention is shown in the drawing \ and will be described in more detail below.

The system for processing and inputting fuel comprises a transfer tank 1, and a rotary kiln Beheizer [2 as well as a grinding unit 3. The rotary kiln Beheizer 2 has \ suitable for gaseous media feed line 4. and a chimney S. The filling of the rotary tube -Heater is connected to the transfer container 1 via a conveyor belt 6. The receiving opening of the grinding system 3 is connected to the exit opening of the rotary tube heater 2 via another conveyor belt 7. The grinding plant 3 has a feed line 8 which is connected to a CpIjI fir.o 9 annoschiosKon. A Ti nmiportloi fcuno 10 goes from the Mn hl plant to a vortex or separator 11. The separator 11 is

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line 12 with a filter system 13 and an outlet

κ carrying line 14 connected to a storage container 15. The filter system 13 has a vent line leading to the outside 16 and is via another discharge line 17 connected to the storage bunker 15. The storage bunker 15 is via a further line 18 with a filter 19, which in turn has a vent line 20 going into the open air. The discharge lines 14 and 17 and the Line 18 are each with a shut-off valve 14 'or 17', 18 'equipped.

The storage bunker 15 is connected via a discharge line 21 with a driving station 22, which in turn via a Refill line 23 equipped with a shut-off valve 23 'is connected to a metering hopper 24. The dosing hopper 24 has a discharge line 25, via which it is connected to a driving station 26 to which a Samireü line 27 connects.

The storage container 15 is assigned a weighing device 65 with a differentiation element, from which a signal about the time-related weight change dG ^ / dt of the storage container 15 (for example in kg / s) can be taken. A weighing device 74 with a differentiation element is assigned to the dosing hopper 24, from which a signal about the time-related weight change dG ₇ ./dt of the dosing hopper 24 can be taken

The system for introducing fine-grain fuels further comprises a line 28, that is at one end with a source 29 for a pneumatic conveying medium and at the other end via pin fruit iukeitsal-seh .: the 30 with a Verdi enter 31 is connected, at "the output side of which a distribution line 32 is connected. The line 28 has two branch lines, one of which communicates with the inlet i ΐυ, -. Σ 4 dos d - s Dr-hrohr- Tube ^:

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2 and the other branch line 9 'with the input side of the fan 9 is connected. The distributor line 32 is connected to a pressure accumulator 34 via a connecting line 33 tied together.

Two lines 35 and 36 branch off from the distributor line 32, each with a shut-off valve 35 'or 36' and one each Have flow meters 35 "or 36". The line 35 branches into a fluid that opens into the storage bunker 15 Sierungsleitung 37 and a drift line 38 leading into the driving station 22, each with a control valve 37 'and 38'. the Line 36 branches into a fluidization line 39 which opens into the dosing bunker 24 and into one to the propulsion station 26 leading drift line 40, each with a control valve 39 'or 40'. The upper area of the reservoir 15 is connected to the driving station 26 by a pressure equalization line 41. The upper area of the dosing hopper 24 is connected to the driving station 26 via a pressure equalization line 42.

The collecting line 27 opens into a distributor bottle 43, from which a large number of individual, evenly on the circumference in branch off the blast furnace 44 opening injection lines 45, j Each of these injection lines 45 is provided with two shut-off valves 46, 47 and a vent valve connected in between 4 8 equipped. Each of the injection lines! 45 also has a flow resistance regulator 49 and a measuring element 50 with an electrical transmitter 51 assigned to it The flow resistance regulators 49 have a symbolically indicated pairing of a cone and a conical seat, j where the flow resistance by changing the distance can be changed between the cone and the cone seat. ; Between the shut-off valve 4 7 and the flow resistance regulator 4 9 leads to a LeH.ung 52, which is connected to a compressed air source

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f 10

\ i 53 is connected and which contains a valve 54 / the

ji between the full passage cross section and the Sperrij position can be regulated. From the around the blast furnace 44 l. | arranged ring line 55 lead individual nozzle assemblies

I; 5 or connecting lines 56 to the blow molds 57 of the high-

''] Furnace 44. From the ring line 55 and a corresponding ¹ I oven near point of the nozzle assembly 56 performs respective control-'i line to an electrical differential pressure transmitter 58th

■ The encoders 51 and 58 are common to the inputs of a 10 all automatic control and regulation 59 connected, the output

^: Gears in turn with the actuators of the associated valves 46, 47, 48, 54 and the flow resistance regulator 49 are connected.

: How the system works

] 15 'The coal entered in the transfer container 1 is from conveyed by the conveyor belt 6 into the rotary kiln heater 2. Introduced into the rotary kiln heater 2 via the supply line 4 warm gaseous media flow around the coal, drying it in direct contact and leaving the pipe container 20 2 together with the moisture expelled from the coal through the chimney 5 into the free atmosphere.

This drying process can be made particularly economical if smoke or exhaust gases are used as the drying medium that arise as a waste product in other processes - e.g. a wind heater 25 or a boiler system.

The dried coal is conveyed by the conveyor belt 7 into the grinding system 3 and there ^{crushed 1} U of a grain size: v. ■ which, dispersed in a gaseous medium, can be transported through a conduit ·: = ·:. For this purpose, the fan 9 presses a gaseous medium at a pressure of 40 mbd, for example:

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into the grinding plant 3 and pushes the coal dust through & transport line 10 into the separator 11, in which a Separation between the coal and the gaseous medium is added, wherein the coal dust can get through the discharge line 14 into the storage container 15, wä; the gasfi, charged with a residue of coal dust Medium medium passes through the vent line 12 into the F system 13. In the filter system 13 the e: valid separation between the coal dust caused by öj Discharge line 17 enters the storage container 15 url the gaseous medium flowing through the ventilation duct. 16 reached the open air instead. The use of drier. Coal dust enables a reliable function de filter system 13, because the bag filter is not through fer Coal dust becomes sticky and dirty.

To avoid coal dust explosions and to keep things warm; To keep the conveyed goods warm, it is advantageous also in c Area for the extraction of coal dust from the Mahlan! 3 to the separator 11 or to the filter system 13 au The use of air from the free atmosphere to divert smoke or exhaust gases from other processes not only do not exclude the danger of a coal dust explosion but also the already dried coal sausage

add moisture again, and the use of Gii gas or inert gases requires to avoid the environment! loads a correspondingly operationally reliable and gas-tight coal filling sluice at the MaIj plant for over a long period of time. f

For the promotion of the pulverized coal from the hopper ι by the metering hopper 24 into the furnace 44, a he "] pressure of the pneumatic conveying medium, the risk of explosion is necessary to increase the pulverized coal corresponds ^. 'Do ph a Ib is in particular this Förderabsci' ⁵ ■ * "when using air

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a pneumatic conveying device that is as low in oxygen as possible is used. It is very beneficial here too from others Smoke or exhaust gases originating from processes, which also keep the heated coal dust warm, as propellants to use.

In this case, there is the further advantage that the second shut-off valve 4 7 in each injection line 45 and the vent valve 48, both of which are necessary for operation with furnace gas, can be omitted.

The propellant gas withdrawn from the line 29 is in the Feuchtic keitsabscheider 30 dried and from the compressor 31 with the required operating pressure of approximately 5 to 6 bar is printed in the distribution line 32. The required operating pressure depends on the pressure in the blast furnace 44 and the pressure losses in the conveyor system of the plant.

The coal dust entered into the dosing bunker 24 is stored

3 with a bulk density of about 500 kq / m. Around

To make a dense bed "flowable", the propellant gas passing through the fluidization line 39 loosens the coal 20_ dust by forming a dispersed coal dust / flue gas mixture with a density of about 320 kg / m 2 and conveys it through the discharge line 25 to the driving station 26. In the driving station the coal becomes relatively dense dust-smoke gas mixture of that through the driveline 40

arriving flue gas is diluted to a density of about 20 kg / m 2 and conveyed into the collecting line 27. The coal dust mass flow determined for the metallurgical process in kg / s, for example, corresponds to the decrease in weight of the. The amount of pulverized coal stored in the dosing bunker 24. This pulverized coal mass flow is essentially determined by the volume flow of the propellant gas flowing through the fluidization line 39, which in turn can be regulated by the control valve 39 '. The volume flow of the propellant gas passing through the driveline 40 can be controlled by the control valve 40 ' ¹

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If the coal supply in the metering bunker 24 falls below a predetermined value, the metering void is filled with the coal dust located in the storage container 15. For this refilling process, the grinding system 3 is first shut down so that the valves 14 ', 17' and II can be closed. Then the balance f is set in action, the pressure in the reservoir 15 de pressure in the metering hopper 24 is equalized and the shut-off valve 23 'in the refill line 23 is opened. By opening '.

of the shut-off valve 35 ', the propellant gas passes through the Le device 35 and the fluidization line 37 in the storage container 15, from where there is the coal dust to the propellant station 22 promotes, while propellant gas dilutes incoming coal dust stream through the drift line 38 c at the propellant station 22 to the dosing hopper 24 promotes. The coal dust mass flow conveyed by the propellant 22 for refilling the Dosing bunker 24 is generally larger than the coal j conveyed into the collecting line 27 by the propellant station 26 dust mass flow, so that the weighing device 74 would last!

of the refilling process an increase in weight per unit of time recorded. The total in the blast furnace 44 conveyed coal dust mass flow dm ../ dt results from that of Weighing device 65 emitted signal of the time-related

Change in weight of the storage container 15 dG _g5 / dt and dera? from the weighing device 74 emitted signal of the time | increased weight change of the dosing hopper 24 dG _{? 4} / dt

_{? 4}

dm ₄₄ / dt = - (dG ₆₅ / dt

dG ₇₄ / dt)

wherein a weight decrease with a negative value and ^: a weight increase with a positive n value is included in the FOt.

A - not necessarily typical - numerical example may clarify the connection: the weighing device 65 gives a ze ί tbozononn weight loss dos storage tank ^ V- '

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31 09 1Ί.1

of 30 kg / s Cdm ₆₅ / dt = - 30 kg / s) and the weighing device 74 of the dosing hopper 24 shows a time-related weight increase of 22 kg / s. The resulting coal dust mass flow dm,. / Dt results in this case as

dm ₄₄ / dt = - C-30 kg / s + 22 kg / s) = 8 kg / s.

The coal dust mass flow dm ../ dt conveyed into the blast furnace 44 is transmitted via the signal from the weighing device 65 and controlled via the signal of the weighing device 74 in that the control valves 37 'and 39' accordingly more or less opened. When the dosing hopper 24 is sufficiently filled, the control valve is activated first 37 'closed so that no more coal dust from the storage container 15 is removed and fed to the driving station 22. The propellant gas now flows out of the line 35 only through the control valve 38 'and blows the shut-off valve 23' above the dosing hopper 24 so that the closing and subsequent reopening of this valve can be done with little wear. Simultaneously with switching off of the control valve 37 'is the signal of the weighing device 65 with regard to the change in weight of the storage container 15 to regulate the coal dust mass flow dm. ^ / Dt eliminated, which is now exclusively from the Signal of the weighing device 74 results.

Before the emptied reservoir 15 is again supplied with pulverized coal from the grinding plant 3, the check valve 23 are 'and the control valves 37' and 38 'geschlofron The ¹ S prevailing in the tank 1 overpressure -is through the open valve 18', the line 18 and vented the filter to the open atmosphere. After the shut-off valves 14 'and 17' have been opened, the storage container 15 is again supplied with coal dust from the grinding plant 3.

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The partial flow of propellant gas arrives during the refilling process through line 35 via the pressure compensation line 4; into the collecting line 27 and is there with the propellant gas! Partial flow from line 36 combined. So that the flow! ming speed of the coal dust / propellant gas mixture in the collecting line 27 not impermissibly high values with premature signs of wear to downstream: Apparatus is reached at the flow meters 35 "uäj 36 "the propellant gas flow is measured and monitored as a total;

The coal dust mass flowing through the collecting line 27 flows from the distributor bottle 43 through the injector tion lines 45 and is thus divided into a large number - for example 30 - partial flows. Since the distributor fl standing on one side of the blast furnace have the injection lines 45 necessarily different lengths and there; different flow resistances. This is conditioned lead to different partial flows and thus to an inadequate introduction of coal dust into the blast furnace, be avoided according to the object of the invention s. This is done with everyone in the injection lines 45 built-in measuring device 50 of the respective carbon mass flow measured and as a measured value from the assigned? electrical transmitter 51 forwarded to the control and regulation unit 59. By adding up all of the electrical ones Transmitters 51 received measured values and division by the number of measuring points is given to the flow resistance regulators 49 An impulse is given that regulates the flow resistance in such a way! that the coal flow in all injection lines 45 is the same; is.

An even distribution of the coal dust on the one individual blow molds 57 of the blast furnace 4 4 is only useful if the from the Rinaleitunq 55 through the

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Hot air reaching the blast furnace nozzle assemblies 56 each has a sufficient partial flow or throughput. To control these partial flows, the difference between the pressure on the ring line 55 and the pressure determined on the nozzle assembly 56 in the vicinity of the blow mold 57 and with the electrical differential pressure transmitter 58 as a signal forwarded to the control and regulation unit 59. If the differential pressure is sufficiently large, this also results a sufficiently large flow of hot air or hot blast.

If the pressure difference is too low, however, it must be assumed that there is not enough hot air through the relevant Nozzle assembly 56 arrives. It is therefore provided that the control and regulation unit 59 falls below a certain Pressure difference in a nozzle assembly 56 signals to close the shut-off valves 46, 47 of the corresponding In-. jection line 45 and to open the associated valve 54 gives. Through these valve adjustments, the coal dust flow from the distribution bottle 4 3 into the corresponding-: Injection line stopped and the compressed air from the compressed air source 53 can pass through line 52 and the

Blow out the flow resistance regulator 49 and the injection line 4 5 from coal dust and cool the tip of the injection lance. If the burning point around the corresponding blow mold 57 allows the inflow of hot air again, the valve 54 is closed again and the shut-off valves 46, 47 are opened again so that the ΒΊ arüte.l ¹ ev / i odor coal dust is fed.

The invention is not based on the exemplary embodiment described limited. So the described aniaue can take place the blast furnace 4 4 can be upstream of another metallurgical process vessel, for example a converter.

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It is also possible, for example, to build a system with two \ advisory containers 15, each with zx ^ ei. to equip subsequent dosing bunkers 24, which is sufficient in an advantageous manner to operate the grinding system 3 uninterrupted.

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Claims (1)

Claims 1. Annex to. Placing coal in metallurgical process vessels with a variety of inlet parts and one corresponding number of injection lines leading to the injection points, thereby marked ei chne t that the injection lines (45) each have a measuring element (50) with an associated transmitter (51) and a flow resistance regulator that can be changed by the transmitter (51) via an automatic regulating and control system (59) (49) have. 2. Plant according to claim 1 with one arranged around the process vessel Ring line with leading to the inlet parts ■ Connection lines for the supply of combustion air into the process vessel, thus marked Ei chne t that for each injection point (57) one measuring line from the ring line (55) and one from the nozzle assembly (56) near the injection point leads to a differential pressure transducer (58) that each injection line (45) in its access part at least one shut-off valve (46, 47) and one equipped with a further shut-off valve (54) Has line connection (52) to a compressed air source (53), and that the individual line parts associated shut-off valves (46, 47; 54) alternately from the lüfferenzdruokgeber (58) via the control Control automatic (59) are lockable. 3. An] age according to one of claims 1 or 2 with at least one ;: storage container and at least one dosing tank assigned to the or each storage container and separable from this by a shut-off valve, wherein the or each storage container and de.r hy \ · :. that dosing valve with a - 1 - BATH ORIGINAL known per se V / iegeeinrichtung with a differentiation element iond - for controlling the coal mass flow to be discharged - an upstream fluidization line is equipped with a control valve, characterized in that the control valve (39 ¹ ) of the fluidization line (39) of the dosing hopper (24) and the Control valve (37 ¹ ) of the fluidization line (37) of the storage container (15) can be regulated by the weighing device (65, 74-) of the dosing hopper (24) and the associated storage container (15). 4. Plant according to claim 3, characterized in that that the gate container (15) over at least a line connection (14) is connected to a Kahlanlage (3), which is preceded by a Vox warming system (2) is. 5. A method for operating the system according to one of the claims 1 to 4, characterized in that that the flow resistance regulator (49) arranged in the injection lines (45) from the transmitters (51) of the Measuring elements (50) changed via the automatic control system (59) as a function of the measured flow rate will. 6. The method of claim 5 ₅ wherein the particular for riio flow Widerstanäsregler (49) controlled variable after summing all v.'ird obtained from the sensors (51) values and division by the number of encoder output (51). 7. The method according to any one of claims 5 or 6, characterized ge ken η draws t that if a given; Fourth gate, from the Idffererizoruckrob & r (58) the - 2 - ORIGINAL Valves (46, 47) closed and valve (54) opened will. Method according to one of Claims 5 to 7, characterized characterized / that the control valve located in the fluidization line (39) leading to the dosing bunker (24) (39 ') and the one in the storage tank (15) the control valve (37 ') j located in the fluidization line (37) for determining the total coal mass flow that has reached the blast furnace (4 4) by means of the output signals of the j Weighing devices (65, 74) of the storage container (15) and> of the dosing hopper (24) can be controlled. ; Method according to claim 8, characterized in that simultaneously with the interruption of the refill line (23) between the storage container (15) and the dosing hopper (24) the influence of the weighing device output (65) of the storage container (15) for controlling the regulating valve tils (39 ') is excluded. 'I. 10. The method according to any one of claims 8 or 9, characterized ge-) indicates that for interrupting the replenishing line (23) · first the points of the reservoir (15) leading .j Fluidisierungsleitung (37) control valve (37 ^1), then the shut-off valve (23 ') in the refill line (23) and finally the control valve (38') in the driveline (38) is closed. 11. The method according to any one of claims 5 to 10, characterized in, that the coal is dried before grinding. 12. The method according to any one of claims 5 to 11, characterized in that for drying the coal, for conveying the coal from the grinding plant to the storage container and as a propellant for Fön.wrn dor coal from Voiτηΐ; -.!><-Hol! it can be used up in the blast furnace waijno Rnnch- odtr Abn ^ se from other processes. BATH ORIGINAL