WO1997044497A1

WO1997044497A1 - Pressure vessel with adjustable conduit for feeding flowable materials and application to ironmaking in cyclone type smelt-reduction reactor

Info

Publication number: WO1997044497A1
Application number: PCT/NL1997/000293
Authority: WO
Inventors: Hendrikus Koenraad Albertus Meijer
Original assignee: Hoogovens Staal BV
Current assignee: Tata Steel Ijmuiden BV
Priority date: 1996-05-23
Filing date: 1997-05-23
Publication date: 1997-11-27
Anticipated expiration: 1998-11-23
Also published as: NL1003186C2; AU2915497A

Abstract

Pressure vessel that can be coupled via supply and/or discharge pipes to peripheral auxiliary systems, which pressure vessel is suitable for containing a substance which is preferably pourable and preferably at a temperature of at least approximately 500 °C and with a pipe opening out in the pressure vessel for supplying to that substance a flowable, pourable processing agent such as a fluid, a gas or a powder, for which that pipe is coupled to a source situated outside that pressure vessel and which pipe is made such that the mouth of that pipe is adjustable while the pressure vessel is operating, in order at will to bring the level of the operation of that mouth higher or lower in the vessel.

Description

PRESSURE VESSEL WITH ADJUSTABLE CONDUIT FOR FEEDING FLOWABLE MATERIALS ANDAPPLICATION TOIRONMAKING IN CYCLONETYPE SMELT-REDUCTIONREACTOR

The invention addresses the area of supplying a flowable, pourable processing agent such as a gas, fluid or solid substance such as powder to a preferably hot substance present in a pressure vessel. More particularly, yet not exclusively, the invention addresses the area of either fully or partly reducing or prereducing iron oxide or prereduced iron or crude iron in a pressure vessel. The invention will be clarified in the following by reference to the full or partial reduction of iron oxide. To the specialist it will be clear that the invention is also applicable to other fields, whereby a hot substance is exposed under overpressure to a process gas or fluid or solid substance. In for example NL-A-7607352, US-A-3607224, US-A-2540593, NL-A-9401103, EP-A-0347126 installations are described for the so- called direct reduction and/or prereduction of iron compounds. Contrary to the usual blast furnace processes, in the case of the so- called direct reduction of iron compounds there is no need to use coke. The iron compounds to be reduced are simply smelted or at least made sufficiently soft by heating after which the melt is brought into contact with means of reduction in order to reduce the iron compounds. To this end carbon and oxygen are supplied. During the smelting or softening of the iron compounds a so-called prereduction can take place. To this end those iron compounds are normally heated and possibly even smelted in for example a fluidised bed reactor or in a so called smelting cyclone. When a fluidized bed reactor is used, the prereduced iron compounds are transferred still in solid state into a metallurgical vessel, the so-called smelting reactor. In the smelting reactor the prereduced iron compounds are smelted and then further reduction takes place. As is also described in NL-A-257692, when a smelting cyclone is used, the prereduced iron compounds leave the smelting cyclone already in molten state, so that the further reduction can take place in the metallurgical vessel immediately. In order to reduce the melt carbon is supplied and a gas of virtually pure oxygen is injected with great force onto the fluid bath in one or more jets. Normally a slag layer floats on top of the melt in which the reduction of the iron compounds takes place. The object of the invention is to make available arrangements with which a processing agent (such as, in the case of the reduction of iron compounds, virtually pure oxygen or pulverised coal) can be used as effectively as possible for a preferably hot substance to be processed such as a melt of iron compounds, possibly prereduced. To this end an apparatus of the type illustrated in Claim 1 is proposed. This permits the process conditions to be kept as close to optimum as possible while the pressure vessel is operating.

Preferably the operation of the mouth should be harmonised with the conditions in the pressure vessel in such a way that the pressure vessel is reliably leakage proof during its operation. This is because any loss in pressure and/or substances from the pressure vessel has a disadvantageous effect on the effectiveness of the process.

A further object of the invention is to propose arrangements with which the pipe for supplying the processing agent (solid, fluid or gaseous) to the interior of the pressure vessel can be relatively easily removed, for example for repair, preferably in such a way that the operation of the pressure vessel is not interrupted or negligibly.

Another object of the invention is to attain a solution applying the least possible amount of material and/or work. Yet another object of the invention is to make available arrangements with which a long lasting, reliable and essentially uninterrupted operation can be attained. Yet another object of the invention is to make available arrangements which are of simple construction yet still fulfil their functions reliably. In this context the words "flowable, pourable" are taken to describe a fluid or a gas, but also a solid material having a make-up enabling it to flow, such as pulverised or granular solid material. The invention is illustrated in more detail by reference to the following description and description of the accompanying drawings which illustrate different non-limitative embodiments of the present invention. In the drawings: - Fig. 1 shows schematically a cross-sectional side view of an apparatus for the manufacture of crude iron with a smelting cyclone which is included to illustrate the general operation of such an apparatus;

Fig. 2 shows a view corresponding to that of Fig. 1, whereby a modified embodiment is given showing more details of the invention;

Fig. 3 shows the detail III of Fig. 2 in a cross-sectional side view;

Fig. 4 shows a view corresponding to that of Fig. 3 of an alternative embodiment variant;

Fig. 5 shows a view corresponding to that of Fig. 2, partly cut away, of another embodiment variant;

Fig. 6 shows an alternative for the detail III of Fig. 2, in side view and partly cut away; - Fig. 7 shows a side view corresponding to that of Fig. 3 of yet another variant of the present invention;

Fig. 8 shows a side view of yet another variant for the embodiment given in Fig. 6;

Fig. 9 shows a side view corresponding to that of Fig. 1 of yet another variant of the invention.

Iron compounds are introduced into smelting cyclone (1) of Fig. 1 at (2). The iron compounds are prereduced in smelting cyclone (1) and drip along wall (3) of the smelting cyclone (1) into metallurgical vessel (4), for example a converter. In this the iron compounds with oxygen being supplied through opening (6) by means of lance (5₎ and means of reduction, for example coal, are further reduced into iron that is tapped off together with the formed slag through opening (7). As the iron compounds further reduce in metallurgical vessel (4₎ a hot gas containing CO (and H2) occurs that is conveyed to smelting cyclone (1) in which, with oxygen being supplied through openings (8₎, a reaction takes place resulting in the iron compounds being heated to above the smelting temperature and being subjected to a prereduction. The gas is then taken off through opening (9) at the top of smelting cyclone (1). Also shown is the possibility of stirring the melt down at the bottom of metallurgical vessel (4) by bottom bubbling by introducing an inert gas such as argon through openings (10) in the bottom of metallurgical vessel (4). Smelting cyclone (1) and metallurgical vessel (4) are shown in direct connection with each other. With the exception of supply and discharge pipes, they are essentially completely sealed off from the surroundings. The processes in the smelting cyclone and metallurgical vessel (4) take place at a pressure increased by 1 to 10 bar relative to the surroundings. Preferably the pressure increase relative to the atmospheric ambient pressure is approximately 2 to 5 bar, more particularly approximately 3 bar. The gases in smelting cyclone (1) and metallurgical vessel (4) contain CO2, H2, O2, H2O and CO. Temperatures of over approximately 500 °C, preferably over 1000 °C in particular temperatures of approximately 1100 °C to 1800 °c, more particularly approximately 1500 °C to 1600 °C prevail. The virtually pure oxygen which is supplied with force with the lance or pipe (5) onto slag layer (11) floating on the melt (12) causes vigorous reactions and motions of the melt in the metallurgical vessel (4), so that the melt (12) splashes up a great height. Consequently the metallurgical vessel (4) is high enough to keep the melt at sufficient distance from the smelting cyclone (1).

Fig. 1 has a single central lance (5) extending downward through smelting cyclone (1) and ending a little distance above the melt (12) in a mouth (13). Lance (5) runs essentially coaxially to the central longitudinal axis of the essentially rotation symmetrical metallurgical vessel (4) and smelting cyclone (1). In the embodiment of Fig. 1 lance (5) is therefore exposed to the processes occurring in smelting cyclone (1).

Fig. 2 shows an alternative for arranging the lance (5). Thereby lance (5) is arranged obliquely relative to the vertical. As is shown in more detail in Fig. 3 lance (5) extends below smelting cyclone (1) via a sealing structure (14) through the side wall of metallurgical vessel (4). On the side of lance (5) projecting out of metallurgical vessel (4) lance (5) is coupled to a powered displacement element (15) free to move along a straight rail (16), so that lance (5) is free to move back and forth in its longitudinal direction. Consequently the level of mouth (13) in metallurgical vessel (4) can be harmonised with the prevailing level of melt (12). During the process the level of the melt in metallurgical vessel (4) varies continually or at intervals by a height of for example approximately 1 metre. This is caused for example by tapping off at intervals or essentially continually a part of melt (12) via tap opening (7). Experiments have shown that the manner in which the virtually pure oxygen is injected via lance (5) onto melt (12) has a significant effect on the running of the processes in metallurgical vessel (4) and in smelting cyclone (1). The invention therefore proposes to make the level of mouth (13) capable of harmonising with the level of the melt (12) by means of making lance (5) capable of being adjusted in length.

Displacement element (15) can also be used to withdraw or introduce a lance (5) out of or into metallurgical vessel (4). The dashed lines in Fig. 3 show how a lance (5) present as spare component outside metallurgical vessel (4) can be kept available in a changeover installation.

In the embodiment in accordance with Fig. 2 lance (5) is significantly screened from the processes occurring in smelting cyclone (1), so that there is little risk of for example attack of the surface of that lance by the effect of one or more substances in the vessel. By way of variation to Fig. 2 lance (5) with sealing structure (14) as detailed in Fig. 3 can be arranged as shown by dashed lines at the top of Fig. 2 to correspond with the central, essentially vertical lance arrangement of Fig. 1. In this way lance (5) extends through a branch (17) of gas discharge (9). Though it is not shown, that gas discharge (9) runs to for example cooling, filtering and treatment installations in order for example to recoup the gas, or in order for example to supply the still active components from that gas (for example CO) to an installation for further processing, for example current generation. As a consequence of this the gas discharge pipe (9) is sealed from the surroundings by suitable sealing elements (not shown) in such a way that the desired overpressure can maintain itself in metallurgical vessel (4) and smelting cyclone (1). Any iron compounds, coal and/or means of reduction and other products necessary for the process are supplied to smelting cyclone (1) and/or metallurgical vessel (4) under a pressure that is at least equal to the pressure prevailing in metallurgical vessel (4) and smelting cyclone (1). Supplying via opening (6) can also be under pressure, but for example suitable locking arrangements (not shown) may also be provided in order to maintain the prevailing pressure in metallurgical vessel (4) and smelting cyclone (1). While melt (12) is being tapped off via tap opening (7) care is taken to ensure that the level of melt (12) nearly always stays above the top edge of the tap opening so that this guarantees the suitable sealing of metallurgical vessel (4) and smelting cyclone (1) relative to the surroundings.

The obliquely arranged lance (5) in accordance with Fig. 2, yet also others below smelting cyclone (1), or another reactor for pretreating the materials to be supplied to the melt, offer a number of advantages compared to a lance in accordance with Fig. 1, namely it is not necessary to run lance (5) through discharge (9) so that discharge (9) can be placed directly above reactor (1). Lance (5) is run through the wall outside the main flow in vessel (4) and therefore becomes less loaded. Lance (5) can be made shorter and is consequently easier to handle, less heavy and can be changed more quickly. Different lances (5) can extend into vessel (4) at the same time. Fig. 3 shows in more detail the sealing structure (14) for lance (5) which is free to move back and forth in its longitudinal direction. To this end the part of lance (5) extending outside metallurgical vessel (4) (or branch (17) in Fig. 2) runs in a housing (18) placed on wall (19) of smelting cyclone (1), metallurgical vessel (4) or branch (17) and which, with the exception of supply and/or discharge pipes, is sealed relative to the surroundings and relative to metallurgical vessel (4). To this end lance (5) extends through a seal (2) in the bottom side wall of housing (18). In the enclosed space (21) of housing (18) an inert gas for example such as nitrogen gas is used to maintain a slight overpressure relative to the pressure prevailing in metallurgical vessel (4). As a consequence of this no products can penetrate from smelting cyclone (1) and/or metallurgical vessel (4) into that space (21). This guarantees that the part of lance (5) situated inside space (21) does not become attacked and/or encrusted. Neither can the sealing passage (22) in the top wall of housing (18) in the drawing of Fig. 3 become attacked by products from metallurgical vessel (4) and/or smelting cyclone (1). As a consequence of this the sealing effect of passage (22) for lance (5) is reliably guaranteed. Also forming part of housing (18) is a connecting stub (24) projecting below passage (20) in the drawing of Fig. 3, which stub (24) connects to the rest of housing (18) sealed by a bayonet closure (25) or other suitable connection. This stub (24) carries a compensator element (23), for example for compensating differences in temperature expansion. For example a pneumatically operated slide valve (26) activates in stub (24) in order to guarantee a good seal when lance (5) is fully removed from metallurgical vessel (4) and/or smelting cyclone (1). Once attachment (25) has been undone, lance (5) can be removed in its entirety. In another variant (not shown) relative to Fig. 3 lance (5) ends within housing (18). A flexible tube runs in space (21) on the one hand opening out at the outer wall of housing (18) and on the other hand opening out in lance (5) and provides the supply to mouth (13₎. The mechanism for moving lance (5) up and down is then likewise incorporated in space (21).

A stop (27), for example suitable for coacting in blocking with passage (20), prevents under all circumstances that part of lance (5) which coacts with passage (22) from going into the space below passage

(20) and there becoming exposed to the products from metallurgical vessel (4) and/or smelting cyclone (1).

Fig. 4 shows an alternative for reliably adjusting the operation of mouth (13) while maintaining the suitable sealing of the smelting cyclone and metallurgical vessel (4). To this end lance (5) comprises a hollow pipe (28) free to move back and forth in its longitudinal direction. In lance (5) pipe (28) is surrounded by an annular duct (29). Hollow pipe (28) and annular duct (29) both open out at mouth (13) of lance (5). At mouth (13) hollow pipe (28) has a thickening (30) and the shape of that thickening (30) as well as the shape of the mouth of duct (29) are harmonised to one another such that by moving hollow pipe (28) up and down it is possible to adjust the injecting angle a and/or the injecting force of a processing substance leaving duct (29) at mouth (13). This means that lance (5) does not need to be free to move in its entire longitudinal direction so that its sealed passage through wall (19) is considerably easier compared to the embodiment of for example Fig. 3. It will be clear that the distance over which hollow pipe (28) is free to move back and forth can be limited. Therefore the level of mouth (13) does not need to be harmonised with that extent which is equal to the extent to which the level of the melt in metallurgical vessel (4) alters during the process. Furthermore Fig. 4 also shows couplings (31), for example for water cooling. Further it is also possible for example to supply oxygen via coupling (32) to hollow pipe (28) at a higher pressure and/or delivery compared to the supply of oxygen to duct (29) via coupling (33) or vice versa. It is also possible to conceive regulating the oxygen pressure and/or delivery to coupling points (32) and/or (33) . Fig. 5 shows yet another variant for harmonising the operation of mouth (13) of lance (5). To this end lance (5) is attached to the wall of metallurgical vessel (4), here partly shown, and free to swing essentially in its vertical plane. In all active swing positions of lance (5), mouth (13) remains essentially central relative to the central longitudinal axis of metallurgical vessel (4). Mouth (13) is placed obliquely relative to the longitudinal axis of lance (5) so that oxygen is blown in an essentially vertical direction down onto the melt (12). The position of mouth (13) may possibly be made adjustable relative to the longitudinal axis of lance (5) in order to enable the direction of operation of mouth (13) to be selected to depend on the swing position of lance (5).

Fig. 6 shows a variant whereby mouth (13) of lance (5) carries along its longitudinal direction blowing openings (34) located at a distance from one another. This enables process substance to flow out at different levels along mouth (13) as seen in the longitudinal direction of lance (5). This lance (5) can work in the two following manners:

In accordance with a first manner, at one or two of those levels, but not at all levels, openings (34) are coupled to primary supply (32). The other openings (34) are coupled to secondary supply (35) in such a way that it should preferably only be ensured that the openings not supplied out of primary supply (32) remain open and do not close up because of encrustations from, for example splashing fluid material from melt (12). In the example of Fig. 6 openings (34) are located at four levels of mouth (13). In each case the openings at one level are coupled to primary supply (32). The remaining 3 levels are coupled to secondary supply (35). Supplies (32) and (35) are regulable. In this embodiment of Fig. 6 lance (5) does not otherwise need to be movable while the system is operating. This allows its sealed passage through wall (19) to be ensured simply.

In accordance with a second manner in each case the bottom openings (34) are coupled to supply (32) for primary oxygen. Openings (34) at the other levels are coupled to supply (35) for secondary oxygen. Instead of secondary oxygen, air can also be supplied via supply (35) to those openings (34). Supply via couplings (32) and ₍35₎ is regulable. With this manner too the operation of the mouth of lance (5) can be harmonised with the level of the melt.

Furthermore the embodiment in accordance with Fig. 6 just as all other embodiments described and shown here may carry arrangements for screening from the great heat of the lance, such as a watercooled jacket. Fig. 7 further shows an embodiment whereby lance (5) is adjustable back and forth in its longitudinal direction. Lance (5) is surrounded at a distance by jacket (36). This jacket (36) encloses lance (5) preferably along a length which is at least equal to the length along which the lance is moved up and down during operation. Jacket (36) is sealably and detachably secured to wall (19), for example with the aid of a compliant coupling for taking up for example differences in expansion. After removing jacket (36) and lance (5), a valve (26) (here a pneumatically or hydraulically operated slide valve) can be used to seal wall (19). Beyond wall (19) jacket (36) transfers into a lateral coupling stub (41) for a supply (40) for coal, preferably pulverised coal. Lance (5) projects through sealing structure (14) fitted at the top of jacket (36) as shown in the drawing, which sealing structure (14) bears a close resemblance to the sealing structure (14) shown in Fig. 3. Corresponding numbers indicate components corresponding with Fig. 3. Nitrogen gas is supplied to space (21) of sealing structure (14) in order to prevent pulverised coal from jacket (36) from penetrating space (18) and damaging seal (22). Instead of nitrogen gas, oxygen or air for example may also be supplied to space (21). In that case it is even possible to omit seal (20). The supply of air and oxygen to space (18) must be such that any penetration of pulverised coal from the jacket into space (18) is prevented. In addition to the supply of oxygen via lance (5) a small supply of oxygen mixed with pulverised coal also takes place via jacket (36). The flow through jacket (36) and along the outside of lance (5) ensures that substances from vessel (4) do not go into the jacket and attack the outer wall of lance (5) in the area where they pass through wall (19). The pulverised coal flowing through jacket (36) along the outer wall of lance (5) also has a cleaning and scouring effect on that outer wall.

The embodiment in accordance with Fig. 7 has the advantage that for the injection of coal and oxygen the number of passages through wall (19) is kept to a minimum. In addition the dosing of coal and oxygen takes place close together, possibly directly above the slag floating on the melt. Often there are different combinations of jacket (36) and lance (5) extending into vessel (4). Each coal supply then has its own oxygen supply, and for example in the event of malfunction such a combination may be closed off in its entirety and taken out of vessel (4) for replacement or repair.

Based on Fig. 7 yet another variant is possible without application of a combined coal/oxygen injection. Jacket (36) is then used for allowing secondary air or oxygen flow to the outside along lance (5). Possibly jacket (36) may enclose lance (5) with a little clearance. Jacket (36) may also enclose lance (5) along such a length that lance (5) only projects out of jacket (36) for a length roughly corresponding to its length of travel during operation. The purpose of the air or secondary oxygen is to prevent substances from vessel (4) from penetrating jacket (36) and attacking the outside of lance (5) and/or seals (20) and/or (22). The rate of flow of the air or secondary oxygen from jacket (36) may be set just low enough to counter penetration by those substances. The farther jacket (36) encloses lance (5), the better seals (20) and/or (22) are protected from damage. In this way jacket (36) may be supplied continually but also in a pulsating manner from secondary source (38). Instead of a jacket (26) close-fitting around lance (5) it is also possible with a jacket (26) amply surrounding lance (5) to opt for filling the intermediate space with a porous material which has been chosen in accordance with the application. It is important that, from the vicinity of the wall of the pressure vessel, lance (5) is protected along a great part of its length extending into the pressure vessel from the content of the pressure vessel in such a way that one or more substances from the content of the pressure vessel cannot or can only slightly reach the area of the lance in the vicinity of the wall of the pressure vessel. To this end in a preferred embodiment the lance is enclosed by a protective medium such as pulsing gas in an annular gap between lance (5) and enclosing jacket (26). In these examples based on Fig. 7, when lance (5) is withdrawn with the jacket (36) from vessel (4), lance (5) but also seals (21) and (22) are protected from damage by for example rough handling.

Furthermore with these embodiments based on Fig. 7 it is possible to withdraw lance (5) while jacket (36) remains in its place. To facilitate the withdrawal, lance (5) can be thickened in its longitudinal area that coacts with its seals. When lance (5) is withdrawn it is situated beyond the thickened area and at a good distance from vulnerable seals (21), (22) so as to avoid damaging them. Thanks to this and because of the lack of the necessity to detach a coupling before being able to fully withdraw lance (5) from vessel (4) while jacket (36) remains behind, changing a lance can be carried out rapidly and reliably. To the specialist it will be clear how, for jacket (36), a valve, for example one corresponding to slide valve (26), can be achieved for the withdrawal of the jacket with lance (5) absent.

Furthermore, with the embodiments based on Fig. 7, instead of a lance adjustable in its length surrounded by jacket (36), a lance (5) permanently fixed within jacket (36) can also be used, the mouth of which is adjustable in correspondence with for example the embodiments in accordance with Figs. 4 or 6. Another possibility is to equip the lance in accordance with Fig. 5 with a jacket in order to achieve a combined coal/oxygen supply. Fig. 8 offers a further alternative for introducing process substance into vessel (4). This variant is largely based on the embodiment in accordance with Fig 6. At three levels the mouth carries outflow openings (42), (43) and (44). Care is taken to ensure that openings (43) and (44) open out in the slag layer (11) while openings (42) open out above it. Coal, preferably pulverised coal is supplied via openings (44). Primary oxygen is supplied via openings (43). Secondary oxygen is supplied via openings (42). Injecting the coal deep in the slag layer causes a low content of FeO to occur, little substance is formed and good combustion of the volatile parts occurs. By injecting primary oxygen in the top part of the slag layer less CO forms in the bottom part of the slag layer and there will be less foaming. The lance is for example adjustable in length as described by reference to Figs. 2, 3 or 7. Finally Figure 9 shows schematically an embodiment with different lances (5) for example arranged in a circular pattern. Here it is ensured in each case that lances (5) including their mouths are kept outside smelting cyclone (1) and its vertical imaginary continuation. Lances (5) are then protected as well as possible from any hot drips coming from smelting cyclone (1). Such lances (5) can also be made corresponding to the above described examples in order to harmonise the operation of mouth (13) with the level of melt (12) in metallurgical vessel (4).

Self-evidently the invention is not limited to the embodiments described and shown here. For example combinations are also possible of one or more components from one or more of the embodiments described and shown here. Of importance is that the invention achieves the effect that the operation of the mouth of the lance while the installation is in operation is capable of being harmonised continually or at intervals, preferably without causing harm to the sealing of the system relative to the surroundings. For example it is also not necessary for the smelting cyclone and/or metallurgical vessel (4) to be made rotation symmetrical. It is also not necessary to arrange smelting cyclone (1) centrally relative to metallurgical vessel (4). Furthermore, embodiments on the basis of combinations of one or more details from one or more of the embodiment variants described and/or shown here belong to the invention.

Claims

1. Pressure vessel that can be coupled via supply and/or discharge pipes to peripheral auxiliary systems, which pressure vessel is suitable for containing a substance which is preferably pourable and preferably at a temperature of at least approximately 500 °C and with a pipe opening out in the pressure vessel for supplying to that substance a flowable, pourable processing agent such as a fluid, a gas or a powder, for which that pipe is coupled to a source situated outside that pressure vessel and which pipe is made such that the mouth of that pipe is adjustable while the pressure vessel is operating, in order at will to bring the level of the operation of that mouth higher or lower in the vessel.

2. Pressure vessel in accordance with Claim 1, whereby an upper part of the pressure vessel is provided with a reactor such as a smelting cyclone (1) or a fluidised bed for preprocessing in it one or more materials to be supplied to the substance.

3. Pressure vessel in accordance with Claims 1 or 2, whereby the pipe is arranged essentially centrally relative to the part of the pressure vessel that, while that pressure vessel is operating, contains the substance and is aligned essentially vertically.

4. Pressure vessel in accordance with Claim 3, in the combination with Claim 2, whereby that pipe runs through that upper part of the pressure vessel.

5. Pressure vessel in accordance with Claim 2, whereby a pipe part running within the pressure vessel opposite its mouth is situated beyond the upper part of the pressure vessel and the imaginary, vertical continuation of the walls of that upper part downward.

Pressure vessel in accordance with one of the preceding Claims and with additional pipes for supplying to the substance a flowable, pourable processing agent for which those additional pipes are each coupled to a source situated outside that vessel and which additional pipes are each made such that the mouth of each of those pipes is adjustable while the pressure vessel is operating in order at will to bring the level of the operation of that mouth higher or lower in the pressure vessel.

Pressure vessel in accordance with one of the preceding Claims, whereby the pipe is adjustable essentially in its longitudinal direction.

8. Pressure vessel in accordance with one of the preceding Claims, whereby the pipe is adjustably free to swing.

9. Pressure vessel in accordance with one of the preceding Claims, whereby the mouth area of the pipe is adjustable.

10. Pressure vessel in accordance with Claim 9, whereby, as seen in the longitudinal direction of the pipe the mouth has one or more blowing openings situated at a distance from one another, which can be supplied at will with a processing agent.

11. Pressure vessel in accordance with Claim 10, whereby one or more, yet not all blowing openings may be coupled at will to a source with a high delivery and/or pressure and at the same time the remaining blowing openings can be coupled to a source of considerably lower delivery and/or pressure.

12. Pressure vessel in accordance with one of the preceding Claims, whereby one or more of the blowing openings of the mouth piece are suitable for issuing a jet of gas, powder or fluid, whose rate of outflow and/or quantity of outflow is adjustable per unit of time and/or direction of outflow.

13. Pressure vessel in accordance with one of the preceding Claims, whereby the pipe comprises two ducts running with mutual intermediate spaces within each other, and both ducts open out in the pressure vessel, whereby the two ducts are arranged and operated such that while the pressure vessel is operating any constituent from the pressure vessel is comprehensively prevented from penetrating the outer duct which would disadvantage the reliable operation of the pipe.

14. Pressure vessel in accordance with Claim 13, whereby the inner duct supplies a primary and the outer duct supplies a secondary processing agent.

15. Pressure vessel in accordance with Claim 13, whereby the outer duct supplies another material than the inner duct.

16. Pressure vessel in accordance with Claim 15, whereby one of the ducts supplies pulverised coal.

17. Pressure vessel in accordance with one of the preceding Claims 13 through 16, whereby the inner duct runs on past the outer duct on the mouth side.

18. Pressure vessel in accordance with one of the preceding Claims 13 through 17, whereby the outer duct extends within the pressure vessel over a length which is at least a considerable part of the length over which the inner duct extends into the pressure vessel.

19. Pressure vessel in accordance with one of the preceding Claims 13 through 18, whereby a narrow gap is determined between the outer and inner ducts.

20. Pressure vessel in accordance with one of the preceding Claims with the pipe led sealably and adjustably through the outer wall of the pressure vessel and with means for sealing off the passage opening for the pipe in the pressure vessel following removal of the pipe from the pressure vessel.

21. Pressure vessel in accordance with one of the preceding Claims and with the pipe led sealably and free to slide through the outer wall of the pressure vessel and whereby the pipe, in the area directly bordering the outer wall of the pressure vessel, is surrounded by a housing situated outside the pressure vessel which, apart from supply and/or discharge pipes and one or more passages for the pipe, is enclosed and which housing is made to be maintained at overpressure relative to the pressure prevailing in the pressure vessel while it is operating, in order to prevent any constituent from the pressure vessel from penetrating that housing.

22. Pressure vessel in accordance with Claim 21, whereby that pipe ends within the housing and a flexible tube for supplying processing agent to the pipe runs within that housing between the pipe and the housing wall.

23. Application of the pressure vessel in accordance with one of the preceding Claims in a method for the full or partial reduction or prereduction of iron ore or crude iron, whereby molten, unreduced, prereduced or crude iron collects down at the bottom of the pressure vessel and supplies a flowable, pourable processing agent from the pipe to that substance, for example a gas containing oxygen is blown with force onto or into that substance, and continually or at intervals pourable material is tapped off and the mouth of the pipe is adjusted continually or at intervals in order to bring about a harmonisation of the supply via that pipe to a changing of the level of that substance in the pressure vessel.

24. Application of the pressure vessel in accordance with Claim 23, whereby a pressure of at least approximately 3 bar and/or a temperature of at least 1000 °C prevails in the pressure vessel.

25. Application of the pressure vessel in accordance with Claims 23 or 24, whereby in the upper part of the pressure vessel there is a reactor such as a smelting cyclone (1) for pretreating in it a material to be supplied to the substance.

26. Application of the pressure vessel in accordance with one of the preceding Claims 23 through 25, whereby care is taken to ensure that the end of the pipe projecting in the pressure vessel is submerged in the molten crude iron or in the slag floating on it.

27. Application of the pressure vessel in accordance with Claim 26, whereby the pipe carries openings opening out both in and above the molten crude iron or the slag.

28. Pipe, evidently suitable for application in a pressure vessel in accordance with one of the preceding Claims 1 through 22.