[0001 ] The present invention generally relates to a rotary charging device for charging and distributing charge material (burden) in a metallurgical reactor e.g. a blast furnace or a melter-gasifier used in pig iron production.

[0002] Nowadays such charging devices typically have the following construction. They comprise a stationary housing forming a closure on the top opening (throat) of the reactor. The housing has an upper housing part, usually in the form of a connecting hopper or valve casing, which has one or more burden inlets and is mounted on top of a lower housing part, usually configured as a gear casing. An annular rotor is rotatably arranged inside this lower housing part (gear casing) and supports a distribution member, mostly a pivotable distribution chute, for distributing charge material circumferentially inside the reactor. A feeder spout is arranged centrally in the lower housing part and forms an open channel that channels charge material through a central passage in the rotor and onto the distribution member. An early example of this typical type of charging device is disclosed in U.S. patent no 3,693,812.

[0003] As is well known in the field, supply of working fluids to the rotary parts of the charging device enables various improvements such as water-cooling, hydraulic powering or controlled lubrication. The present invention relates more particularly to an improved charging device, which is equipped with a conduit- connecting rotary joint for fluid supply to rotating components of the charging device, e.g. to the rotor and/or the distribution member. Accordingly, the rotary joint connects at least one stationary conduit to at least one rotary conduit that rotates with the rotor. Examples of such charging devices are discussed below.

Background art

[0004] For instance, in U.S. patent no 4,273,492 PAUL WURTH proposed water-cooling of exposed parts of the charging device (see FIG.8 of this patent). In this device, the rotor has a screen equipped with a cooling circuit to protect against radiant heat from inside the furnace. This circuit is supplied with coolant via an annular rotary joint arranged coaxially around the central passage in the rotor. To avoid leakage and to allow pressurizing the circuit for forced circulation, the rotary joint has watertight seals. These seals deteriorate quite rapidly due to wear caused by considerable circumferential speed of relative motion of the seals resulting from the large diameter of the rotary joint.

[0005] In U.S. patent no 4,526,536, PAUL WURTH proposed a cooling system with a kind of "open rotary joint" that works without watertight seals. This kind of system now equips numerous blast furnace charging devices throughout the world. It includes an upper annular trough mounted coaxially on the upper circumference of the rotor to rotate therewith. Stationary ports supply cooling water into the upper rotary trough that is connected to cooling coils on the rotor. The coils have outlet pipes discharging into a fixed annular trough mounted on the stationary housing around a lower portion of the rotor. Whilst avoiding wear-prone seals, a disadvantage of this gravity-driven cooling system is that the available pressure is limited by the difference in height between the troughs and that cooling liquid is exposed to the dust laden furnace atmosphere. Due to limited pressure, high velocities of coolant flow, as required to avoid detrimental film boiling, are difficult if not impossible to achieve. This approach is therefore not viable where pressurized forced circulation is required, e.g. for achieving high velocities of coolant flow, as is the case especially in high temperature reactors.

[0006] As another cooling application requiring inert gas or water to be supplied to the rotor and to the distribution chute, PAUL WURTH proposed a chute equipped with water or inert gas cooling channels in U.S. patent no. 5,252,063. This system also uses an "open rotary joint" similar to that of US 4,526,536, which does not permit pressurizing.

[0007] International patent application WO 03/002770 by PAUL WURTH on the other presents a rotary joint designed for a pressurized cooling circuit on the rotating components of a charging device. The design of WO 03/002770 is an improvement over the design of U.S. 4,273,492, in that the rotary part of the joint is supported in floating manner by the stationary part and in that seals, which are less tight i.e. not entirely watertight, are used (i.e. a small amount of leakage is foreseen). Therefore, these seals are less subject to problems of excessive wear. Whilst allowing pressurized forced circulation and increasing the seal service-live, large-diameter watertight seals arranged between the stationary and rotary parts of the joint are still required. Even though less rapidly, these seals still wear off due to the large diameter of the joint.

[0008] In U.S. patent 6,481 ,946, PAUL WURTH proposed a charging device, in which a hydraulic cylinder is arranged on the rotor for pivoting the distribution chute. Accordingly, US 6,481 ,946 proposes two kinds rotary joints (see FIG.3 & FIG.6 of this patent) suitable for this specific application. However, similar to the rotary joints discussed above, the rotary joints disclosed in US 6'481 '946 are also arranged annularly around the rotor and thus have a considerable diameter. Consequently, the seals used in the joint are also prone to wear.

[0009] International patent application WO 97/37047 discloses a charging device for a shaft furnace, which differs substantially from the above-described typical design. In the device according to WO 97/37047, a cover and a special type of seal form the top closure of the furnace. A conventional stationary housing with drive components and the typical rotor are not provided. The rotor's function is assumed by the intermediate storage hopper that, contrary to common practice, is rotatably mounted relative to the furnace and supports the cover. Thus, in contrast to typical design, the rotatable hopper supports the distribution chute. Besides being rotatable and supporting the cover and the chute, the intermediate hopper also assumes its typical function of providing intermediate storage and acting as a sluice chamber, i.e. a gas-tight lock. To this end, it has upper and lower sealing valves and material gate valves.

[0010] The installation of WO 97/37047 requires cables for electric power supply and conduits for hydraulic power supply and for water-cooling to pass onto the rotary hopper, among others for actuating the lower material gate valve, the lower sealing valve and the chute. Accordingly, WO 97/37047 proposes to arrange those conduits through a central pipe-shaped member, which passes through a bell, and via spokes connecting the pipe-shaped member to a feed hopper in the upper portion of the rotary hopper. By virtue of its unusual configuration, the device of WO 97/37047 enables the use of a small diameter rotary joint arranged on top of the pipe-shaped member. However, this device has among others the drawbacks of involving considerable rotating masses, including that of the intermediate hopper and its payload of charge material, and that of not being compatible with conventional designs of charging device components, especially of the gear casing comprising the drive mechanism for rotating the distribution chute. Moreover, due to the water lute type seal at the top closure, an installation according to WO 97/37047 can only practically be used with low-pressure reactors that operate at no more than 0.1 - 0.2 bar overpressure.

Technical problem

[001 1 ] It is a first object of the presently claimed invention to provide a charging device for a shaft furnace, which enables the use of a small diameter conduit- connecting rotary joint, while avoiding or at least reducing the extent of the aforementioned disadvantages of a device according to WO 97/37047.

General description of the invention

[0012] As opposed to the device of WO 97/37047, the invention, as presently claimed in independent claim 1 , relates to a charging device for a metallurgical reactor that may employ a standard-type drive mechanism. The proposed charging device thus comprises a stationary housing with a lower housing part having an annular rotor arranged therein. In known manner, the rotor is rotatable about an axis of rotation and has a central passage coaxial with the axis of rotation. The housing has an upper housing part with at least one charge material inlet offset from the axis of rotation, through which the charging device can be connected to upstream devices of a complete charging installation, e.g. to a stationary intermediate storage hopper.

[0013] For distributing charge material inside the reactor in known manner, a distribution member, e.g. a pivotally mounted distribution chute, is supported by the rotor to rotate together with the rotor, which can be driven by a typical drive mechanism.

[0014] The charging device also comprises a feeder spout arranged centrally in the stationary housing. The feeder spout provides an open channel that channels charge material through the central passage onto the distribution member. [0015] Furthermore, charging device has at least one stationary conduit, at least one rotary conduit that rotates together with the rotor, and a conduit-connecting rotary joint that has a stationary part and a rotary part and connects the stationary conduit to the rotary conduit for fluid supply to the rotor and/or to the distribution member.

[0016] In order to overcome the above-mentioned problem, the charging device according to independent claim 1 has a feeder spout:

- that has an inlet section in the upper housing part and an outlet section protruding into the lower housing part;

- that is rotatably supported;

- that is coupled to the rotor to rotate together with the rotor; and

- that comprises a support configured to support the rotary part of the rotary joint at a position that is coaxial with the longitudinal axis and that is located above the outlet section of the feeder spout.

[0017] The rotary conduit can thus conveniently pass from the rotary part of the rotary joint via the support and via the outside of the feeder spout to any rotary component of the charging device that requires fluid supply.

[0018] This configuration provides an installation with a small-diameter rotary joint, i.e. a joint having a diameter substantially smaller than the passage inside the rotor, that can be readily installed in order to connect the stationary supply circuit to the rotary conduit(s). Thus the need for a custom-made hollow, large and wear-prone rotary joint is eliminated. As will be understood, in the present context, the expression "joint diameter" refers to the decisive diameter of (a virtual cylinder through) the interface between the stationary part and the rotary part of the joint. The width of the passage as measure of comparison refers to the smallest diameter of free passage within the rotor, i.e. the width required for receiving the feeder spout and/or permitting a nominal charge material flow. Compared to prior art, the invention thus enables use of a rotary joint with substantially smaller diameter. The joint diameter may even be smaller than the internal diameter of the outlet of the feeder spout, i.e. smaller in diameter than the minimum required flow cross-section. [0019] As will also be appreciated, the proposed configuration solution requires modifications merely at the level of the feeder spout. No other substantial modifications in the charging device components, in particular at the level of the drive mechanism for driving the distribution member, are necessary for putting into practice the proposed solution.

[0020] In a first embodiment, the support comprises an axle fixed to the one or more spoke members and a dedicated auxiliary roller bearing supporting both the axle and the feeder spout in rotation. In this embodiment, the feeder spout preferably has an associated mechanical coupling, e.g. an axially slideable coupling, connecting the feeder spout in rotation to the rotor so that they rotate synchronously despite the independent bearing of the feeder spout.

[0021 ] In a different second embodiment, the feeder spout is fixedly attached to the rotor i.e. the former is supported in unison with the latter. Since the rotor is rotatably supported on a main roller bearing, the main roller bearing thus also supports the feeder spout in this embodiment. The spout can be fixedly attached to the rotor by one or more transverse beams extending radially in the central passage so as to allow any charge material falling incidentally outside the spout to pass through the central passage. In this embodiment, the stationary part of the joint is preferably flexibly attached to the upper housing part so as to allow radial movement of the rotary joint relative to the housing, e.g. by means of a flexible member and at least two articulated tie rods.

[0022] As will be understood, whereas it may be provided no axle is required in the second alternative. For instance, the rotary joint may be mounted directly onto the spoke member(s). Irrespective of which embodiment, if an axle is provided it is preferably hollow and coaxial with the longitudinal spout axis. Most preferably, it has a lower axle portion that is fixed to the spoke member(s) at a level above the spout outlet section and an upper axle portion arranged at a level above the spout inlet section. Accordingly, neither the axle nor the rotary joint suffer from impacts if the joint is sheltered at a distal and safe position on the upper portion of the axle.

[0023] In both of the above alternatives, the feeder spout preferably comprises at least two spoke members fixed to the inlet section and an annular flow-shaping ring fixed coaxially with the longitudinal axis to the spoke members. The flow- shaping ring allows retaining and circumferentially distributing charge material inside the feeder spout to reduce adverse reduction of flow rate when the spoke members cross the incoming flow during rotation of the spout.

[0024] In case a closed-loop cooling circuit is arranged on the rotor and/or on the chute supported by the rotor, the conduits are connected by means of the rotary joint. On their section starting from the rotary joint and ending at the rotor or at the distribution member (and vice versa), they preferably pass via the spout support, ideally inside thereof, and via the outside of the feeder spout so as to be sheltered from any material impact.

[0025] As another preferred feature, the housing may comprise a circumferential dust protection skirt surrounding the feeder spout and protruding into the rotor passage with sufficient interspace to permit charge material that drops besides the spout to descend nevertheless into the passage of the rotor. This avoids blocking rotation of the feeder spout. Preferably, the spout protrudes into the rotor passage with annular clearance and so as to shield the rotor from charge material, ideally over an axial distance of at least 50% of the passage height. In a simple configuration, the feeder spout is funnel-shaped, preferably with an outlet section of cylindrical or downwardly tapering shape, and with a frusto-conical inlet section.

[0026] As will be understood, the proposed configurations are particularly suited for a charging device with rotating and pivoting distribution chute and also permit coolant supply of a distribution chute equipped with a water-cooled jacket. In one possible embodiment, the charging device, more specifically its stationary upper housing part, has at least two charge material inlets offset from the rotation axis. In this case, for minimizing impact on the material flow rate, it is preferred to arrange the inlets in radially opposite position and to equip the feeder spout with two radially opposite spoke members. Even though three spoke members would provide a statically better support of the spout, the proposed design minimizes undesirable interruptions while avoiding non-simultaneous interruptions of both incoming flows when feeding through both inlets at the same time. Generally speaking, the number of spokes and their geometrical arrangement preferably corresponds to the number and geometric arrangement of material inlets. Brief Description of the Drawings

[0027] Further details and advantages will be apparent from the following non- limiting description of preferred embodiments with reference to the accompanying drawings, in which:

FIG.1 is a vertical cross-sectional view schematically illustrating a first embodiment of a charging device;

FIG.2 is a horizontal cross-section according to line ll-ll of FIG.1 illustrating a support for a rotary joint of the charging device of FIG.1 ;

FIG.3 is a horizontal cross-section according to line Ill-Ill of FIG.1 illustrating a connection of rotary conduits to a rotor of the charging device of FIG.1 ;

FIG.4 is a partially broken horizontal cross-section according to line IV-IV of FIG.1 , illustrating a connection of rotary conduits to a distribution chute and to chute suspension shafts of the charging device of FIG.1 ;

FIG.5 is a vertical cross-sectional view schematically illustrating a second embodiment of a charging device;

FIG.6 is a partially broken horizontal cross-section according to line VI-VI of FIG.5, illustrating a connection of rotary conduits to a distribution chute and to chute suspension shafts of the charging device of FIG.5.

FIG.7 is a partial view in vertical cross-section schematically illustrating a third embodiment of a charging device, which corresponds to a variant of FIG.1 ;

FIG.8 is a partial view in vertical cross-section schematically illustrating a fourth embodiment of a charging device, which corresponds to a variant of FIG.5.

Throughout these drawings, identical reference numerals and reference numerals with incremented hundreds digit identify identical or similar parts.

Detailed Description with respect to the Drawings

[0028] FIG.1 partially illustrates a charging installation for a metallurgical reactor, e.g. a blast furnace or a melter gasifier. The installation comprises a charging device, generally identified by reference numeral 100. The rotary charging device 100 comprises a stationary housing 102 that has a lower housing part 104 and an upper housing part 106. In FIG.1 , the upper and lower housing parts 104, 106 are adjacent separate casings connected in gas-tight manner at flange 107. The lower housing part 104 is attached to a flange at the top opening (throat) of the reactor. Since the reactor typically operates at overpressure, e.g. at 2 to 5 bar, the housing 102 is configured as a gas-tight enclosure, through which furnace gas cannot leak and which connects the top opening to material feeding devices (not shown) of the charging installation.

[0029] The charging device 100 is of the rotary type to enable distribution of bulk charge material, e.g. lump ore, sinter, pellets, direct reduced iron (DRI), compacted DRI or coke, inside the reactor. To this effect, an annular supporting structure, hereinafter called rotor 108, is rotatably arranged inside the lower housing part 104. The rotor 108 is supported on a main roller bearing 109 that is fixed to the structure of the lower housing part 104. Accordingly, the rotor 108 is rotatable about a rotation axis A, which is normally vertical and typically coincides with the central axis of the reactor. The rotor 108 supports a distribution member 1 16, typically a trough-shaped or conically tubular elongated distribution chute, so that the distribution member 1 16 rotates in unison with the rotor 108 about axis A. The annular rotor 108 has an internal substantially cylindrical wall 1 1 1 that delimits a central passage 1 10, through which charge material drops onto the distribution chute 1 16.

[0030] The distribution chute 1 16 is attached to the rotor 108 by means of a mechanism configured for pivoting, i.e. varying the tilt angle of the distribution chute 1 16, about a pivoting axis C (see FIG.4) perpendicular to axis A. Various well-known components of the charging device 100, such as drive and gear components for rotating and pivoting the distribution chute 1 16, which are not essential to the present invention, are not shown. Suitable configurations are known, e.g. from U.S. patent 3'880'302. In a well-known mode of operation, the distribution chute 1 16 distributes charge material in targeted manner radially and circumferentially inside the reactor in accordance with its tilting and rotational motion. As will be understood, other types of rotary distribution members, e.g. a non-pivoting chute according to WO 2007/039339, and corresponding drive mechanisms may be used. [0031 ] As seen in FIG.1 , the upper housing part 106 has two radially opposite charge material inlets 1 12, 1 14 that are offset from the axis of rotation A and connected in sealed manner to a respective feed pipe. Depending on the type of charging installation and reactor, charge material is supplied through the inlets 1 12, 1 14 from any suitable source such as, for instance upstream intermediate storage hoppers or directly from conveyor belts. As illustrated in FIG.1 , the charging device 100 is configured to direct and center a flow of charge material 1 15 centrally along axis A onto the distribution chute 1 16.

[0032] To this effect, a feeder spout 120 is arranged with its longitudinal axis B centrally inside the stationary housing 102. The feeder spout 120 is configured as an upwardly and downwardly unrestricted open channel for channeling a free falling flow of charge material received from the inlets 1 12, 1 14 through the central passage 1 10 onto the distribution member 1 16. While other funnel-shaped configurations are not excluded, in a simple and rotationally balanced construction, the feeder spout 120 has an upper inlet section 122 formed of a hollow frusto- conical mantle that is attached in smooth transition to a lower outlet section 124 made of a shell or tube of cylindrical or downwardly tapering tubular shape. Irrespectively of shape, the inlet section 122 has an inlet of large cross-section adapted for receiving bulk material from both inlets 1 12, 1 14, whereas the outlet section 124 has an outlet of small cross-section for centering the flow 1 15.

[0033] For collecting charge material directly from the inlets 1 12, 1 14, the upwardly widening inlet section 122 is arranged inside the upper housing part 106. The outlet section 124 is arranged at least partially in the lower housing part 104. While shorter forms of outlet sections are possible, the outlet section 124 of the feeder spout 120 preferably protrudes into the central passage 1 10 with an annular clearance toward the cylindrical wall 1 1 1 so as to shield the rotor 108 from charge material. As seen in FIG.1 , the outlet section 124 protrudes into the central passage 1 10, preferably on an axial distance of at least 50% of the height of the central passage 1 10 for reliable shielding and improved centering of the flow 1 15 onto the distribution chute 1 16.

[0034] As further seen in FIG.1 , the upper housing part 106 has a lower portion conjugated in shape to the frusto-conical inlet section 122 of the feeder spout 120. A cylindrical sleeve 125 and the lower portion of the upper housing part 106 form a circumferential dust protection skirt surrounding the feeder spout 120. The cylindrical sleeve 125 also protrudes into the passage 1 10 and may be water- cooled. The upper housing part 106 and the sleeve 125 are configured to leave a circumferential interspace toward the feeder spout that permits charge material accidentally dropping past the inlet section 122 to descend through the passage 1 10 into the reactor.

[0035] As will be noted, besides providing a channeling function, the feeder spout 120 is rotatably supported relative the stationary housing 102 and coupled in rotation to the rotor 108. Rotatably supporting the feeder spout 120 enables it to support a conduit-connecting rotary joint 130 (also called swivel joint or revolving joint), and more specifically its rotary part 132 that is connected in fluid tight manner to a stationary part 134 of the rotary joint 130. In the embodiment of FIG.1 , the feeder spout 120 is supported by means of an auxiliary roller bearing 129 that is arranged on the top cover of the upper housing part 106. FIG.1 merely exemplarily illustrates a two-path radial type rotary joint 130 for forward and return connection. Depending on the application, the rotary joint 130 may be of the axial or radial type and of a single-path or multi-path configuration.

[0036] As will be appreciated, the feeder spout 120 comprises a support 140 that has two radially opposite spoke members 142, 144, which extend generally radially, e.g. transversely upward at an angle to axis B, from the upper inlet section 122 toward the axis B. Suitable spoke members 142, 144 are e.g. hollow profiles of rectangular or inverted U-shape. At their outer ends, the spoke members 142, 144 are fixed to the feeder spout 120. At their inner ends, the spoke members 142, 144 are fixed to a central axle 146, more specifically, to a lower portion of the axle 146. The axle 146 is hollow and extends coaxially with axis B. In the embodiment of FIG.1 , the axle 146 extends through a seal at the top cover of the upper housing part 106 and has an upper portion outside the housing 102, to which the rotary part 132 of the rotary joint 130 is fixedly mounted in order to rotate with the feeder spout 120. As will be noted, the support 140 supports the rotary joint 130 above the outlet section 124, and preferably above the inlet section 122, to avoid impact of material. Arranging the rotary joint 130 centrally on or approximately on the axis A and above the region through which the flow 1 15 passes, has the major benefit of enabling the use of a small-diameter standard type rotary joint 130. Thereby, a considerable increase in joint life-time and at the same time reduced cost of the rotary joint 130 is achieved. Furthermore, even though the rotary joint 130 could be mounted immediately above the feeder spout 120, mounting the rotary joint 130 outside and above the housing 102 facilitates maintenance. Furthermore, the auxiliary roller bearing 129 on the upper portion of the axle 146 is also arranged outside the housing 102, thus avoiding exposure to the reactor atmosphere.

[0037] In the embodiment of FIG.1 , the axle 146 has its lower end arranged significantly above the outlet section 124 of the rotatable feeder spout 120 in order to further minimize the risk of material impact. Other configurations for supporting the rotary part 132 of the rotary joint 130 coaxially with the longitudinal axis B of the feeder spout 120 are not excluded however. Preferably, the hollow axle 146 is water-cooled, e.g. by means of a cooling serpentine (not shown) connected to the rotary part 132 of the rotary joint 130 and arranged inwardly on the cylindrical wall of the axle 146.

[0038] As schematically illustrated in FIG.1 , conduits connected to the rotary part 132 are arranged to pass from the rotary part 132 via the support 140 and via the outside surface of the feeder spout 120 toward the rotating components that require fluid supply, e.g. the rotor 108 and/or the distribution member 1 16. In the specific embodiment of FIGS.1 -4, respective water-cooling circuits, e.g. cooling serpentines, are provided on both the rotor 108, for cooling the heat-exposed cylindrical wall 1 1 1 , and on the distribution chute 1 16, which is also directly exposed to the heat inside the reactor.

[0039] Accordingly, as best illustrated in FIGS.1 -2, a rotary forward conduit 152 and a rotary return conduit 153 pass inside the hollow axle 146, inside the spoke members 142, 144 and downwardly along the outside of inlet and outlet sections 122, 124 into the central passage 1 10. Within the central passage 1 10, as best seen in FIG.3, the rotary forward and return conduits 152, 153 are respectively connected to an inlet and an outlet of a cooling circuit arranged on the rotor 108, e.g. to cool the cylindrical wall 1 1 1 . Furthermore, as illustrated in FIG.4, the rotary forward and return conduits 152, 153 are respectively connected to a coolant inlet and outlet of the distribution chute 1 16, which has a water-cooled jacket. In addition, the return conduits 152, 153 are also connected to two cooling arrangements for cooling two pivotally actuated chute suspension shafts 156, 158. The suspension shafts 156, 158 support and pivot the chute 1 16 about axis C and are thus also exposed to heat from inside the reactor. The mentioned connections are made e.g. using heat and wear resistant flexible hoses, whereas the rotary forward and return conduits 152, 153 themselves are preferably made of standard tubes that are mounted in floating manner to allow axial dilatation, e.g. with suitable pipe clips. Since the outlet section 124 is arranged at least partially in the lower housing part 104, the outlet section 124 shields the rotary conduits 152, 153 from bulk material flowing inside the feeder spout 120. To enhance this effect, a significant extent of vertical protrusion of the outlet section 124 inside the central passage 1 1 1 is preferred, as shown in FIG.1 .

[0040] In order to avoid rupture of the rotary conduits 152, 153 or their connections, the feeder spout 120 is coupled in rotation to the rotor 108 to rotate synchronously therewith. In the embodiment of FIG.1 , this is achieved by means of a mechanical coupling 160, preferably an axially slideable coupling. The mechanical coupling 160 may be a suitable articulated rod linkage or any other drive type fastening, e.g. an inverted U-shaped tappet engaging respective axially oriented tappet holes on the rotor 108 and the outlet section 124. The coupling 160 fixes the feeder spout 120 in rotation to the rotor 108 so that both rotate in unison despite being independently supported by respective roller bearings 109, 129. As will be appreciated, an independent rotational support avoids the risk of radial motion of the rotary joint 130 off the axis. To further reduce such risk, the auxiliary roller bearing 129 is mounted close to or preferably adjacent the rotary joint 130 as best seen in FIG.1 . While mechanical coupling is preferred, other means of coupling the rotor 108 and the feeder spout 120 in rotation, such as a synchronized auxiliary drive driving the feeder spout 120 are not excluded. Furthermore, a rotary electric connector, e.g. of the slip ring type, can be integrated in or provided adjacent to the rotary joint 130 for powering electric components on the rotating parts of the charging device 100, e.g. on the rotor 108. [0041 ] As further seen in FIG.1 , the rotary joint 130 connects the rotary conduits 152, 153 respectively to a stationary forward conduit 154 and a stationary return conduit 155 of any suitable stationary cooling circuit (not shown). Whereas FIGS.1 -4 illustrate a preferred embodiment for connecting cooling circuits on rotating parts of the charging device 100, it will be understood, that the rotary joint 130 may alternatively or in addition be used for connecting other types of circuits, e.g. a hydraulic power circuit for actuating a hydraulic actuator for pivoting the chute according to US 6,481 ,946, and/or a lubrication circuit.

[0042] As another remarkable feature, the feeder spout 120 is equipped with an annular flow-shaping ring 170 that is fixed coaxially with axis B to the spoke members 142, 144, e.g. downstream, upstream or at the level of the spoke member 142, 144 (when seen relative to the flow 1 15). The flow-shaping ring 170 is configured as a so-called "stone box", i.e. as a material retaining ring, in which a layer of charge material is retained in order to avoid wear-off. To this effect, the flow-shaping ring 170 has any suitable cross-section that is concave in the flow direction of flow 1 15, e.g. a simple L-shaped cross-section as illustrated in FIG.1 . As seen in FIG.2, the flow-shaping ring 170 is configured as a closed ring covering 360° in circumference so as to continuously obstruct inflow from the inlets 1 12, 1 14, irrespectively of the rotational position of the feeder spout 120.

[0043] A first function of the flow-shaping ring 170 is to reduce the extent of interruption of the flow 1 15 when the rotating spoke members 142, 144 cross the flow 1 15. To this effect, the annular flow-shaping ring 170 is positioned centrally within the flow path of material falling into the feeder spout 120. Thereby, the flow- shaping ring 170 acts as a "spreader" and causes circumferential distribution of material about axis B, i.e. broadening of the flow. Since the flow-shaping ring 170 broadens the flow, it reduces the flow interruption when the spoke members 142, 144 cross the flow 1 15. As a second function, the flow-shaping ring 170 reduces eccentric impact of the flow 1 15 on the distribution chute 1 16, especially in case of low flow-rates. As illustrated in FIG.1 , it radially divides the flow into an inward partial flow and an outward partial flow. At low flow rates, these partial flows collide above or within the outlet section 124 into a recombined flow having reduced horizontal velocity. As a third function, the annular flow-shaping ring 170 enhances mixing of materials, in case two different types of material are dropped simultaneously from each inlet 1 12, 1 14 respectively. Enhanced mixing downstream the flow-shaping ring 170 is another consequence of circumferentially spreading and radially dividing each of the inflows as described above.

[0044] FIGS.5-6 illustrate a second embodiment of a charging device 200. In FIGS.5-6, reference signs with incremented hundreds digit refer to structurally and/or functionally identical parts with respect to FIGS.1 -4. Therefore, only the main differences and notable common features will be detailed below.

[0045] As in the first embodiment, the charging device 200 has a stationary housing 202 with a lower housing part 204 fixed immediately on the top opening of the reactor. The upper housing part 206 also forms a gas gas-tight connection to upstream installation devices via inlets 212, 214. In the charging device 200 however, the housing 202 is of unitary construction with the upper and lower housing parts 204, 206 forming a single enclosure.

[0046] The charging device 200 also has a feeder spout 220 of particular design arranged inside the housing 202. That is to say the feeder spout 220 is also rotatable about its longitudinal axis B and comprises a support 240 configured for supporting the rotary part 234 of a conduit connecting rotary joint 230 coaxially with axis B and above the lower housing part 202. The support 240 also has an axle 246 with an upper portion carrying the rotary joint 230 above the housing 202. A flow-shaping ring 270 is also fixed to the spoke members 242, 244 of the support 240.

[0047] As opposed to FIGS.1 -4 however, the feeder spout 220 is fixedly attached to the rotor 208 by means of one or more transverse beams, e.g. two radially opposite transverse beams 262, 264, as best seen in FIG.6. The transverse beams 262, 264 extend radially through the passage 210 and are circumferentially spaced in order to allow charge material, which accidentally passes outside of the feeder spout 220, to pass between them and drop into the reactor. The transverse beams 262, 264 have their respective ends rigidly fixed to the outlet section 224 and to the rotor 208, e.g. to a lower region of the cylindrical wall 21 1 . Preferably, the transverse beams 262, 264 are arranged in the lowermost region of the passage 210 in order to provide additional heat shielding. Being rigidly connected by the transverse beams 262, 264, the feeder spout 220 and the rotor 208 form a unitary structure that rotates in unison. Consequently, no separate roller bearing is required. The main roller bearing 209 of the rotor 208 also supports the feeder spout 220 with its longitudinally axis B coinciding with rotation axis A.

[0048] In order to allow minor radial movement of the rotary joint 230, which may occur due to its axial distance from the roller bearing 209 and due to play of the roller bearing 209, the stationary part 234 of the rotary joint 230 is attached to the top cover of the upper housing part 206 by means of a flexible member 280. The flexible member 280 is preferably a gas-tight bellows, i.e. a corrugated expansion joint (often called compensator), sealingly connecting the rotary joint 230 to the top opening in the upper housing part 206, in order to avoid gas leakage. For fastening the stationary part 234 axially to the stationary housing 202, i.e. for limiting pressure-induced expansion of the flexible member 280, two or more articulated tie rods 282 fasten a mounting flange to the top cover of the upper housing part 206. The stationary part 234 is fixed on this mounting flange, as illustrated in FIG.1 . In case protecting the flexible member 280 against torsional load is desirable, one or more tangential tie rods (not shown) are preferably provided for fixing the stationary part 234 in rotation to the upper housing part 206. A gas-tight seal is preferably provided in between the stationary part 234 and the axle 246 of the support 240, e.g. at the mounting flange, in order to isolate the rotary joint 230 from the reactor atmosphere inside the housing 202.

[0049] FIG.7 illustrates a charging device 300 according to a third embodiment, which is a variant of FIGS.1 -4. Its central feeder spout 320 is also supported rotatably about its longitudinal axis B by means of an independent auxiliary roller bearing 329. The auxiliary roller bearing 329 is also mounted on top of the upper housing part 306 shortly below the conduit connecting rotary joint 330. Thus the roller bearing 329 and the rotary joint are easily accessible and protected from impact of material. They are further protected from furnace gases by means of a seal or gasket between the top cover of the upper housing part 306 and the axle 347 that supports the feeder spout 320. Whereas it has independent bearing, the funnel-shaped feeder spout 320 is also coupled in rotation to the rotor in the lower housing part (not shown). Accordingly, the lower portion of the charging device 300, at the level of the lower housing part (not shown), has components and functions configured as described above by reference to FIGS.1 -4, in particular any kind of desired fluid-supplied circuit on the rotor and/or on the distribution member. FIG.7 illustrates only modifications in the upper housing part 306.

[0050] As seen in FIG.7, the support 341 has a modified configuration. It has radially opposite spoke members 343, 345 that extend transversely upwards toward axis B to a higher level, i.e. over a longer extent and at steeper angle. The flow-shaping ring 370 has identical configuration and function as in FIG.1 -4. Only its attachment to the steeper spoke members 343, 345 is adapted. Using longer spoke members 343, 345, the axle 347 that carries the feeder spout 320 and the rotary joint 330 can have considerably shorter length when compared to FIGS.1 -4. This configuration may be preferred, e.g. in case the diameter of the axle 347 and its roller bearing 329 has to be larger, e.g. for increasing stability of the rotatable feeder spout 320. Even with a large-diameter axle 347 and bearing 329, a small- diameter rotary joint 330 of suitable commercially available type can be used. In fact, the rotary joint 330 that connects one or more required conduits to the rotor does not necessarily have the same larger diameter as the axle 347, as seen in FIGS.1 &7. In particular, the rotary joint 330 may have a smaller rotary part 332 mounted centrally within the top front end of the axle 347. Other parts, especially conduit connections, structurally and/or functionally identical to those of FIGS.1 -4 are not repeatedly described and indicated by corresponding reference signs with incremented hundreds digit.

[0051 ] FIG.8 in turn illustrates another embodiment of charging device 400. This charging device 400 is a variant of the device 200 of FIG.5 with modifications in the arrangement of the small-diameter rotary joint 430 for conduit connection. More specifically, FIG.8 shows another possible configuration for supporting the rotary part 432. In contrast to the preceding embodiments, the rotary joint 430 is mounted inside the upper part 406 of the housing 402. This allows eliminating the axle and the seal used, mainly for gas-tightness, in preceding embodiments. As seen in FIG.8, the rotary joint 430 is mounted immediately on top of steep spoke members 443, 445 configured identical to those of FIG.7, at an angle of less than 45° with the vertical axis A or B. Accordingly, despite the absence of an axle, the rotary joint 430 is still arranged in an uppermost position in the housing 402 where it is relatively sheltered. The housing 402 can be of unitary or assembled construction, although an assembled construction is seen in FIG.8. By means identical to those described above in relation to FIG.5, the feeder spout 420 is fixedly attached to the rotor (not shown in FIG.8) to allow eliminating the auxiliary roller bearing. Consequently, whereas no separate roller bearing is required, minor radial movement of the rotary joint 430 with respect to the housing 402 should be allowed due to the axial distance towards and play in the main roller bearing of the rotor (see FIG.5). Using a similar albeit inverted arrangement as that in FIG.5, the stationary part 434 of the rotary joint 430 is therefore flexibly attached to the upper flange around a top opening in the upper housing part 406. As seen in FIG.8, a flexible member 480 connects the immobile upper housing part 406 to a separate mounting flange or mounting plate 481 that supports and fixes the stationary part 434 in rotation with respect to the housing 402. As in FIG.5, the flexible member 480 may be a compensator. Two or more articulated tie rods 482 fasten the mounting plate 481 and therewith the stationary part 434 of the rotary joint 430 axially to the housing 402. One or more tangential tie rods (not shown) can be provided for blocking any potential rotation of the stationary part 434. The rotary part 432 however, is mounted directly onto the spoke members 452, 453 in order to rotate in unison with the feeder spout 420 and thus with the rotor that requires supply in fluid. The stationary forward conduit 454 and the stationary return conduit 455 pass from the stationary part 434 through sealed openings in the mounting plates 481 outside the housing 402. Whereas exposing the rotary joint 430 to the less friendly atmosphere inside the housing 402, this embodiment may reduce investment cost by avoiding a wear-prone gas-tight seal, an additional axle and an additional auxiliary bearing. Due to a special configuration of steep spoke members 452, 453 and of the housing 402, the rotary joint 430 is nevertheless in a relatively sheltered position and easily accessible for maintenance, by simple removal of the mounting plate 481 . However, the embodiments of FIGS.1 -7, which do have a sealed axle 146; 246; 347, obviously have the additional benefit of permitting maintenance without depressurizing the furnace. [0052] In conclusion, several advantages will be summarized. Both embodiments discussed above enable the use of a small-diameter rotary joint for supplying fluid to the rotary parts of the charging in any desired kind of circuit, e.g. a water-cooling circuit, a hydraulic powering circuit, a lubrication circuit. In particular, the proposed configuration enables high velocity / high-pressure force circuit water-cooling of heat exposed parts of the charging device by means of a standard type low-wear rotary joint. Moreover, the proposed configurations avoid exposing the rotary joint to the reactor atmosphere thus further increasing the joint life-time.

Legend:

FIG.1 FIG.5-

100 charging device 200 charging device

102 stationary housing 202 stationary housing

104 lower housing part 204 lower housing part

106 upper housing part 206 upper housing part

107 connection flange 208 annular rotor

108 annular rotor 209 main roller bearing

109 main roller bearing 210 central passage

1 10 central passage 21 1 cylindrical wall

1 1 1 cylindrical wall 212,

charge material inlets

214

1 12,

charge material inlets

114 215 flow of charge material

1 15 flow of charge material 216 distribution member

1 16 distribution member 220 feeder spout

120 feeder spout 222 inlet section

122 inlet section 224 outlet section

124 outlet section 227 protection skirt

125 cylindrical sleeve 230 rotary joint

129 auxiliary roller bearing 232 rotary part

130 rotary joint 234 stationary part

132 rotary part 240 support

134 stationary part 242,

spoke members

244

140 support

246 axle

142,

spoke members

144 252 rotary forward conduit

146 axle 253 rotary return conduit

152 rotary forward conduit 254 stationary forward conduit

153 rotary return conduit 255 stationary return conduit

154 stationary forward conduit 256,

chute suspension shafts

258

155 stationary return conduit

262,

156, transverse beams

chute suspension shafts 264

158

270 flow-shaping ring

160 mechanical coupling

280 flexible member

170 flow-shaping ring

282 articulated tie rods

A axis of rotation

axis of rotation = longitudinal axis (of

B longitudinal axis (of feeder spout) A=B

feeder spout)

C pivoting axis

C pivoting axis FIG.7 FIG.8

300 charging device 400 charging device

302 stationary housing 402 stationary housing

306 upper housing part 406 upper housing part

307 connection flange 407 connection flange

312, 412,

charge material inlets charge material inlets

314 414

320 feeder spout 420 feeder spout

322 inlet section 422 inlet section

329 auxiliary roller bearing

330 rotary joint 430 rotary joint

332 rotary part 432 rotary part

334 stationary part 434 stationary part

341 support 441 support

343, 443,

spoke members spoke members

345 445

347 axle

352 rotary forward conduit 452 rotary forward conduit

353 rotary return conduit 453 rotary return conduit

354 stationary forward conduit 454 stationary forward conduit

355 stationary return conduit 455 stationary return conduit

370 flow-shaping ring 470 flow-shaping ring

B longitudinal axis (of feeder spout) 480 flexible member

481 mounting plate

482 articulated tie rods axis of rotation = longitudinal axis (of feeder spout)