EP1399597B1 - Device for loading a shaft furnace - Google Patents

Abstract

A loading device for a shaft furnace comprises a chute supported by a suspension rotor (28) in a fixed housing. The rotor (28) is fitted with a cooling circuit, supplied with liquid coolant via a rotating annular joint (44). The latter comprises a fixed ring (60) and a rotating ring (62), and is fitted in an annular leak collecting tank (46) formed by the suspension rotor (28). Fixed ring (60) is supported by the housing (12). Rotating ring (62) is supported entirely by fixed ring (60) via a bearing (64). Selective coupling means (65, 66) connect the rotating ring (62) to the suspension rotor (28) in such a way as to transmit a rotary moment of rotor (28) to rotating ring (62) selectively, while at the same time preventing other forces from rotor (28) being transmitted to rotating ring (62).

Description

TECHNICAL FIELD TO WHICH THE INVENTION RELATES

The present invention relates to a loading device for a tank. It relates more particularly to the cooling of a device for loading for a shaft furnace, such as a blast furnace, which includes a casing to be mounted on the head of the shaft furnace, a suspended suspension rotor of rotating way in this housing, a loading chute suspended in the suspension rotor and at least one cooling circuit carried by the rotor suspension.

STATE OF THE ART

In 1978 the company Paul Wurth S.A. proposed such a loading device, which is described in detail in US Patent 4,273,492. The rotor of suspension of this device is provided with a lower protective screen which surrounds the feed channel of the chute and protects the drive devices housed in the housing, particularly against heat radiation at inside the shaft oven. To this end, the lower screen includes a circuit for coolant which is supplied with coolant through a annular rotary fitting arranged around the feed channel of the chute. This rotary connector includes a rotary ferrule and a fixed ring. The ferrule rotary extends the suspension rotor, of which it forms an integral part, outside the housing. The fixed ring is fixed on the casing and the rotary ferrule is adjusted with play in the fixed ring. Two cylindrical roller bearings are intended to center the rotating ferrule in the fixed ring. In the fixed ring two superimposed annular grooves are arranged so as to face the external cylindrical surface of the rotating shell. Connection channels of the cooling system define mouths in the cylindrical surface outer of the rotating shell opposite the two grooves. Toppings sealing, which are mounted along the two edges of each groove, rely on the external cylindrical surface of the rotating shell for the purpose sealing between the rotating ferrule and the fixed ring. In practice, it It turned out that this type of swivel fitting is hardly suitable for a loading of a shaft furnace. Indeed, in order to avoid leaks of cooling water in the housing, it is necessary to ensure a good seal between the ferrule rotary and fixed ring. However, in a shaft oven, the efficiency of the fillings seal of the swivel joint deteriorates rapidly. They are indeed contact with a fairly hot shell, which is hardly favorable for their duration of life. In addition, following differential thermal expansions, the radial clearance between the rotating ferrule and the fixed ring is highly variable, which is also detrimental to the life of the seals, and may even cause seizure and complete destruction of the swivel joint. So you have to note that the life of the swivel fitting is still affected by violent shocks that are inevitably absorbed by the suspension rotor of the chute. Finally, it should be noted that such a large diameter swivel joint which is fitted with watertight seals has significant friction, which significantly increases the power required to drive the chute rotation. In conclusion, it turned out that a swivel fitting of the type described in US Patent 4,273,492 has far too many disadvantages to be a reliable solution to supply a cooling circuit carried by equipment rotary loading of a shaft furnace.

To avoid all these inconveniences, the company Paul Wurth S.A. proposed already in 1982 a device for cooling a loading installation a blast furnace without watertight fittings. This cooling device, which is described in detail in US Patent 4,526,536, has been installed in numerous blast furnace loading facilities across the world. It is characterized by an upper annular tank, which is carried by a upper sleeve of the suspension rotor and which is gravity fed with cooling water. To this end, a water supply line from cooling is integrated in the housing and present above the tank annular at least one mouth allowing gravity flow of the cooling water in the upper annular tank rotating with the suspension rotor. The upper ring tray is connected to several cooling coils fitted to the suspension rotor. These streamers have discharge lines discharging into a lower annular tank, which is stationary in rotation since it is carried by the lower edge of the casing. The water therefore flows by gravity from a supply line stationary in rotation, in the upper annular tank of the suspension rotor, passes by gravity through the cooling coils mounted on the rotor suspension, to then be collected in the annular tank of the housing and be evacuated outside the housing. Water level measurements in two annular tanks allow to control the circulation of cooling water. In the upper annular tank, the level is adjusted so as to constantly find between a minimum level and a maximum level. If the level goes down to the minimum level, the feed rate is increased of the annular tank to ensure proper supply of the coils. If the level rises to the maximum level, the feed rate is reduced of the annular tank to avoid overflow of the annular tank.

A first disadvantage of the cooling device of 1982 is that the pressure available to pass the cooling water through the cooling circuits is essentially determined by the difference of height between the annular tank and the lower collector. It is therefore necessary to equip the rotor for cooling circuits with low pressure drop, which is a considerable disadvantage from the standpoint of space and / or cooling efficiency. There is in particular a risk of local overheating due to the low cooling water circulation speeds in the cooling circuits. Another disadvantage of the cooling device from 1982 is that blast furnace gases come into contact with water from cooling already in the upper annular tank. Like these tall gases furnaces are heavily loaded with dust, large quantities of dust inevitably passes into the cooling water. These dusts form sludge in the upper annular tank, which cross the cooling coils and risk blocking them. Moreover, the blast furnace gases make the cooling water acidic, which promotes corrosion of the cooling circuits.

In order to be able to realize pressure drop cooling circuits higher, it was proposed in patent application DE 3342572 to equip these circuits with an auxiliary pump carried by the suspension rotor. This auxiliary pump is rotated by a mechanism which transforms one rotation of the suspension rotor in one rotation of a shaft pump drive. As a result, the auxiliary pump works only when the rotor is rotating. In addition, such an auxiliary pump is quite sensitive to sludge passing through the cooling coils.

Patent application WO 99/28510 presents a method for cooling a loading device of the kind described above which is equipped with a swivel fitting. Contrary to the teachings of the state of the art, no attempt is made to ensure the perfect tightness of the swivel joint, as recommended for example in US patent 4,273,492, or to avoid leaks in outside the swivel joint by a level control system, such as recommended for example in US patent 4,526,536. We rather suggest supply coolant to the swivel joint of so that a leakage flow passes through an annular separation gap between the rotary part and the fixed part of the rotary union to form a joint liquid that prevents dust from entering the swivel joint. This leakage flow is then collected and discharged outside the housing, without passing by the cooling circuit. As a result, dust sludge does not also do not pass through the cooling circuit and do not risk then not to plug the latter.

Patent application WO 99/28510 proposes several embodiments for the annular rotary union. In a first execution, the fixed part is a annular block which is adjusted with clearance in an annular channel of the rotor of suspension, so as to be separated from each of the two cylindrical walls of this channel through a radial annular slot. To reduce the leakage rate through these two radial annular slots, patent application WO 99/28510 suggests either providing at least one lip seal in each annular slot, or to design each annular slot in the form of a labyrinth seal. A disadvantage of this execution is that the annular channel in the rotor of suspension requires very precise machining, therefore very expensive. Moreover, the adjustment of the annular block in the annular channel of the suspension rotor must be very specific. It also follows that this execution is very sensitive to centering defects in the rotation of the suspension rotor as well as violent shocks absorbed by the suspension rotor. Another disadvantage is that the entire suspension rotor must be disassembled to repair a channel damaged ring finger. In an alternative version, the fixed part of the fitting rotating comprises a stationary rotating ring which is axially supported, using two tight seals, on a ring housed in an annular channel of the suspension rotor. The fixed rotating ring can be slid vertically, so that it can be pressed against the ring housed in the annular channel of the suspension rotor. This execution is relatively sensitive to defects in flatness of the rotation of the suspension rotor. However, such flatness defects of rotation of the suspension rotor is difficult to avoid because the bearing ring load supporting the suspension rotor in the casing is generally not symmetrical with respect to the axis of this bearing and varies with the angular position of the loading chute.

In conclusion, more than twenty years after the patent filing date US 4,273,492, we still do not have a satisfactory solution to supply with pressurized coolant rotary equipment of a device loading for a shaft furnace.

OBJECT OF THE INVENTION

Therefore, it will be highly appreciated that the charging device defined in the first claim, finally constitutes a satisfactory solution to the above problem.

STATEMENT OF THE INVENTION

It must first be remembered that a charging device according to the invention is of the type comprising a casing to be mounted on the head of the shaft furnace, a rotor suspension suspended rotatably in this housing, a loading chute suspended in the suspension rotor and at least one circuit of cooling carried by the suspension rotor. This cooling circuit is supplied with coolant through a fitting annular turn which is of the type comprising: a fixed ring carried by the housing, a rotating ring in rotation with the suspension rotor and rolling means between the fixed ring and the rotating ring. In this fitting rotating, the fixed ring and the rotating ring cooperate so as to define a cylindrical interface in which at least one annular groove provides a transfer of pressurized coolant between the fixed ring and the rotating ring. Transfer of coolant from the rotating ring the suspension rotor is then provided by connected connection means between the rotating ring and the suspension rotor. A device according to the invention stands out in particular for the following characteristics. The fitting annular turn is mounted inside the housing in an annular tank of collection of leaks which is formed by the suspension rotor. In addition, the ring of this rotating union is supported exclusively by the fixed ring by means of the rolling means. Mating means then couple this rotating ring, freely supported by the fixed ring, to the suspension rotor so as to selectively transmit a moment of rotation of the suspension rotor to the rotating ring, while preventing transmission of other forces from the suspension rotor to the ring press. The connection means finally comprise at least one element deformable tubular, so that the connection means form a non-rigid connection between the rotating ring and the suspension rotor. He will be appreciated that these characteristics finally provide, after more than twenty years of research, a reliable solution to supply with coolant under pressure rotary equipment of a loading device for an oven to tank. In fact, in the solution according to the invention, the rotary connector does not cause neither sealing problems nor excessive friction problems nor seal life issues or problems with differential thermal expansions or seizure problems. The fitting turning is insensitive to severe shocks which are inevitably absorbed by the chute suspension rotor. It is also insensitive to faults centering of the rotor and to flatness of the rotation of the rotor of suspension. Special machining of the rotor suspension rotor is not required. The swivel joint can be easily replaced without removing the suspension rotor.

It will also be appreciated that the device according to the invention allows easily to integrate a cooling circuit carried by the suspension rotor in a closed cooling circuit. To this end it is sufficient to provide a first annular groove in the cylindrical interface to ensure transfer coolant from the fixed ring to the rotating ring, and a second annular groove in the cylindrical interface to ensure transfer of coolant from the rotating ring to the fixed ring. Of this way we can get the coolant going back and forth through the annular swivel joint.

Alternatively, the cooling circuit (s) may include at least one open discharge line. In this case, the housing includes advantageously a fixed annular tank for collecting the coolant, in which the discharge line (s) open out during the rotation of the suspension rotor. Evacuation means are associated with the tank fixed ring to discharge coolant in a controlled manner outside of the housing.

Drainage means are advantageously connected to the annular tank of leakage collection to evacuate the leakage rate collected by it from controlled way outside the housing.

In a preferred embodiment of the device according to the invention, the fixed ring of the swivel fitting is carried by an annular flange which is fixed on the casing. The annular leakage collecting tank then includes upper edges which cooperate with this annular flange to define labyrinth seals. he As a result, the swivel joint is relatively well insulated from the rest of the housing.

The connection means advantageously comprise at least one connection flexible and axially compressible coupling, which is advantageously carried by the rotating ring and includes a coupling head. At this coupling coupling is then associated with a coupling seat, which is arranged in the annular leakage collecting tank, so that the head coupling seat on the coupling seat when the coupling annular turn is mounted in the annular leakage collecting tank. He will be appreciated that this embodiment in particular makes assembly very easy and disassembly of the annular rotary union.

The aforementioned coupling means advantageously comprise a simple radial cross member mounted in the annular collection tank for suspension rotor leaks and a notch in the rotating ring. This notch then engages the radial cross member when the annular rotary coupling is arranged in the annular leakage collecting tank.

The connection means advantageously open into a collector ring arranged below the annular leakage collecting tank. Many cooling circuits carried by the suspension rotor are then connected to the annular collector.

In a preferred embodiment, a pair of spaced packings axially is arranged in the cylindrical interface between a groove annular and the rolling means, respectively between two grooves adjacent annulars. A drainage channel drains the interface area cylindrical between the two packings of a pair of packings in the annular leakage collecting tank.

BRIEF DESCRIPTION OF THE FIGURES

Fig.1:

est une coupe verticale d'une première exécution d'un dispositif de chargement d'un four à cuve selon l'invention;

Fig.2:

est une coupe verticale d'un raccord tournant annulaire équipant le dispositif de chargement d'un four à cuve de la Figure 1;

Fig.3:

est une autre coupe verticale du raccord tournant annulaire équipant le dispositif de chargement d'un four à cuve de la Figure 1;

Fig.4:

est encore une autre coupe verticale du raccord tournant annulaire équipant le dispositif de chargement d'un four à cuve de la Figure 1;

Fig.5:

est une coupe selon la ligne de coupe 5-5 dans la FIG. 4 ; et

Fig.6:

est une coupe verticale d'une deuxième exécution d'un dispositif de chargement d'un four à cuve selon l'invention.

Other features and characteristics of the invention will emerge from the detailed description of some advantageous embodiments presented below, by way of illustration, with reference to the accompanying drawings. These show:

Fig.1:

is a vertical section of a first embodiment of a device for loading a shaft furnace according to the invention;

Fig.2:

is a vertical section of an annular rotary connector fitted to the loading device of a shaft furnace of Figure 1;

Fig.3:

is another vertical section of the annular rotary coupling fitted to the loading device of a shaft furnace of FIG. 1;

Fig.4:

is yet another vertical section of the annular rotary connector fitted to the loading device of a shaft furnace of Figure 1;

Fig.5:

is a section along section line 5-5 in FIG. 4; and

Fig.6:

is a vertical section of a second embodiment of a device for loading a shaft furnace according to the invention.

DETAILED DESCRIPTION OF SOME EMBODIMENTS ADVANTAGES OF THE INVENTION

In the figures, the same references designate identical elements or the like.

Figure 1 shows schematically a loading device with a rotary chute 10 which is intended to equip a shaft furnace, such as for example a blast furnace.

This device comprises a casing 12 with an annular flange 14 at its end lower, a support plate 16 at its upper end, and a side casing 18. The annular flange 14 serves to connect the casing 12 of tight to a counter flange (not shown) of a shaft furnace. To the plate support 16 is tightly connected the lower end of a hopper or valve housing (not shown). The lateral envelope 18 connects the flange 14 sealingly to the support plate 16. A sleeve fixed supply 20 is fixed using an annular flange 22 in a central opening of the support plate 16. This fixed supply sleeve 20 enters the casing 12 to define a supply channel 24 for the material to be loaded in the shaft furnace. This supply channel 24 has an axis central 26 which is normally confused with the central axis of the shaft furnace.

In the casing 12 is mounted a suspension rotor 28 for the chute 10. The upper end of this suspension rotor 28 forms a sleeve suspension 30, which surrounds the fixed supply sleeve 20 and is suspended from using a large diameter bearing ring 32 in the casing 12. The lower end of the suspension rotor 28 forms a screen box 34 in the central opening of the lower flange 14 of the casing 12. It supports in in addition to the bearings of the suspensions 36 for the chute 10.

A ring gear 38 of the suspension sleeve 34 cooperates with a motor (not shown) to drive the suspension rotor 28, and therefore the chute 10 suspended therein, rotating about the axis 26. The most often, the chute 10 is further equipped with a pivoting device (not shown), which allows you to vary its angle of inclination by rotating it in its suspension bearings 36 around an axis 40 which is perpendicular to the axis of rotation 26 (in FIG. 1, the axis 40 is perpendicular to the plane of the leaf).

To protect the screen casing 34 from high temperatures in the shaft furnace and to prevent them from transmitting heat inside the casing 12, the screen casing 34 is provided with cooling circuits 42 ₁ , 42 ₂ , 42 ₃ , 42 ₄ in which a coolant, for example water, is circulated. These cooling circuits 42 ₁ , 42 ₂ , 42 ₃ , 42 ₄ advantageously contain baffles or tubes (not shown) circulating the cooling water along a predetermined path along the walls of the screen box 34. They are connected to a coolant distribution circuit using an annular rotary connection, which is generally identified by the reference numeral 44. The latter is mounted inside the casing 12 in an annular leakage collecting tank 46, which is formed by the upper end of the suspension sleeve 30 of the suspension rotor 28. Referring to FIG. 2, it will be noted that the two upper edges 48, 50 of the annular leakage collecting tank 46 cooperate with the annular flange 22 to define labyrinth seals 52, 54. A sort of chamber is thus defined inside the casing 12 separate 56, in which for the annular rotary connection 44 is well protected from the fumes which penetrate into the casing 12. To further reinforce this protection, it is possible to inject a clean gas into this separate chamber 56, so as to maintain the latter in overpressure by compared to the oven.

• FIG. 2, le transfert du liquide de refroidissement à travers le raccord tournant annulaire 44 au rotor de suspension 28;
• FIG. 3, le retour du liquide de refroidissement du rotor de suspension à travers le raccord tournant annulaire 44 ;
• FIG. 4, l'accouplement mécanique du raccord tournant annulaire 44 au rotor de suspension, son graissage et la gestion des débits de fuite.

The annular rotary union 44 will now be described in more detail with the aid of FIGS. 2 to 5. It will be noted that FIG. 2 to 4 represent vertical sections of the annular rotary union 44 of FIG. 1 at three different locations, illustrating respectively:

• FIG. 2, the transfer of the coolant through the annular rotary connector 44 to the suspension rotor 28;
• FIG. 3, the return of the coolant from the suspension rotor through the annular rotary connector 44;
• FIG. 4, the mechanical coupling of the annular rotary coupling 44 to the suspension rotor, its lubrication and the management of the leakage rates.

Referring first to FIG. 4, the mechanical design of the fitting annular turn 44 will be briefly described. The latter includes a ring fixed 60, which is screwed onto the lower surface of the flange 22, as well as a rotary ring 62, which is mounted with radial clearance in the fixed ring 60. It It is important to note that the rotating ring 62 is supported exclusively by the fixed ring 60 by means of a bearing 64. Indeed, there is no rigid connection between the rotating ring 62 and the suspension rotor 28, however selective coupling means couple the rotating ring 62 to the suspension rotor 28 so as to selectively transmit a moment of rotation of the suspension rotor 28 to the rotating ring 62, while preventing transmission of other forces from the suspension rotor 28 to the rotating ring 62. A particularly simple execution of these coupling means is illustrated using FIG. 4 and 5. It is a radial cross member 65 which is fixed in the annular leakage collecting tank 46 and which engages a notch 66 in the rotary ring 62 when the annular rotary connector 44 is fixed in the annular leakage collecting tank 46. It will be appreciated that the radial cross member 65 and the notch 66 cooperate so as to transmit a moment of rotation of the suspension rotor 28 to the rotating ring 62, while nevertheless allowing relative vertical and radial displacements of the two elements. This makes the annular rotary union 44 almost insensitive to thermal expansion, shocks, vibrations and layout faults experienced by the suspension rotor 28. Remain to note that the reference 68 globally marks a lubrication circuit under bearing pressure 64. The excess grease is discharged below of the bearing 64 through a drainage channel 69 in the loading channel 24.

Referring now to FIG. 2, the transfer of coolant to the suspension rotor 28 by the annular rotary union 44 will described in more detail. Reference 70 identifies a fitting for a pipe supply of pressurized coolant. An internal channel 72 of the fixed ring 60 connects this fitting 70 to an annular groove 74 which is arranged in a concave cylindrical surface 76 of the fixed ring 60. A internal channel 78 of the rotating ring 62 is connected to a mouth 80, which is arranged in a convex cylindrical surface 82 of the rotating ring 62 opposite the annular groove 74. This internal channel 78 opens into the lower front surface of the rotating ring 62 in a fitting coupling 84.

In summary, the pressurized coolant supplied to the fitting 70 passes through the fixed ring 60 through the internal channel 72 in the annular groove 74, to be transferred through a cylindrical interface, formed by the two cylindrical surfaces 76, 82, and the first mouth 80 in the rotating ring 62. In this, the coolant flows to through the internal channel 78 in the coupling fitting 84.

Referring again to FIG. 2, it will be noted that the fitting coupling 84 is axially projecting from the front surface bottom of the rotating ring 62. It comprises a flexible tubular element 100 laterally and axially compressible, which is embedded with one end in the lower front surface of the rotating ring 62. The other end carries a coupling head 102. The tubular element 100 comprises a bellows compensator 104 surrounded by a helical compression spring 106. The coupling head 102 is associated with a coupling seat 108, which is arranged on the bottom of the annular leakage collecting tank 46 so as to what the coupling head 102 sits on the coupling seat when the annular rotary union 44 is mounted in the annular collection tank for leaks 46. It will be noted that the compression spring 106 then provides sufficient contact pressure between coupling head 102 and seat coupling 108, so that a seal 110, which is carried either by a spherical convex crown 111 of the coupling head 102 either by a conical concave crown 112 of the coupling seat 108 can seal between the two coupling elements. It remains to be noted that the coupling seat 108 could also be carried by the rotating ring 62. In this case, the coupling fitting 84 would be axially projecting by relative to the bottom of the annular leakage collecting tank 46. Finally, the head coupling 102 could be fitted with a conical concave crown and the coupling seat of a spherical convex crown, which cooperate with or without a gasket to ensure watertightness during their coupling.

From the first coupling fitting 84, the pressurized coolant enters through the coupling seat 108 into an annular supply manifold 114. The latter is arranged immediately below the annular tank 46. At this supply manifold 114 of the suspension rotor 28 are connected supply tubes of the cooling circuits 42 ₁ , 42 ₂ , 42 ₃ , 42 ₄ carried by the suspension rotor 28. In FIG. 1, there is shown by way of example the supply tube 116 which supplies the cooling circuit 42 ₁ .

In FIG. 1 it can be seen that the coolant leaves the cooling circuit 42 ₁ through a return tube 118 which opens into a second annular manifold 120. The latter is arranged just below the first annular manifold 114.

Referring now to FIG. 3, the return of the coolant through the annular rotary connector 44 will be described in more detail. The second annular collector 120 serves as a collector for all the returns from the cooling circuits 42 ₁ , 42 ₂ , 42 ₃ , 42 ₄ . It is connected through a coupling fitting 84 '/ coupling seat 108' assembly, which is of the same type as the assembly 84/108 described above, to an internal channel 78 'of the rotating ring 62. From this channel 78 ′ the coolant passes, in the opposite direction to that described above, through a mouth 80 ′ and the cylindrical interface 76, 82 in a second annular groove 74 ′ arranged in the concave cylindrical surface 76 of the fixed ring 60. In this fixed ring 60 the coolant is led through an internal channel 72 'in the fixed connector 70' for a return line of the coolant under pressure.

Referring again to FIG. 4, the management of leakage rates will be now described in more detail. It will first be noted that the radial clearance between the fixed ring 60 and the rotating ring 62 is relatively important, to reduce the risk of seizure of the two rings 60, 62. Thus, the axial leakage flow in the cylindrical interface 76, 82 is quite large. This leak rate is however controlled by gaskets and drainage channels. A first pair of seals 121 ', 121 "is arranged in the cylindrical interface 76, 82 between the first groove 74 and the bearing 64. These two seals 121 ′, 121 ″ are axially spaced one of the other, and the zone 122 of the cylindrical interface 76, 82 situated between the two seals 121 ', 121 "is drained by a drainage channel 124 in the annular leakage collecting tank 46. Since the pressure in the circuit pressure lubrication 68 is higher than in zone 122 of the cylindrical interface 76, 82, it is guaranteed that the coolant does not can enter bearing 64. A second pair of seals 126 ', 126 "is arranged in the cylindrical interface 76, 82 between the first groove 74 and the second groove 74 '. Interface area 128 cylindrical 76, 82 located between the two seals 126 ', 126 "east drained by a drainage channel 130 in the annular collection tank for leaks 46. Since the pressure in zone 128 of the cylindrical interface 76, 82 is lower than the pressures in the second groove 74 ′, it is guaranteed that the coolant cannot be short-circuited through the interface cylindrical 76, 82 of the first groove 74, where the pressure prevails supply, in the second groove 74 ′, where the return pressure prevails which is significantly lower than the supply pressure. A last seal 132 is arranged in the cylindrical interface 76, 82 in below the second groove 74 '. The leakage rate flowing through this seal 132 is drained through the cylindrical interface 76, 82 in the annular leakage collecting tank 46. In summary, the linings sealing 121 ', 121 ", 126', 126" and 132 are not intended to completely cancel leakage rates but to limit them to reasonable values and to channel them in a controlled manner into the annular leakage collecting tank 46. It it follows that the seals 121 ', 121 ", 126', 126" and 132 are always well cooled and lubricated, which significantly increases their life of life and avoids seizures. In addition, the power required to make turning the rotary ring 62 in the fixed ring 60 is thus considerably scaled down.

Reference 134 locates a drainage pipe which allows the evacuation of leakage rates collected in the annular leakage collecting tank 46. On the FIG. 1 we see that this drainage pipe 134 opens into an annular tank fixed 136, which is arranged in the lower end of the casing 12. When the suspension rotor is rotating, the free end of the drainage pipe 134 moves in the fixed annular tank 136. Remains to be noted that means evacuation are associated with the fixed annular tank 136 to evacuate the liquid of controlled cooling outside the housing 12. In FIG. 1, these evacuation means are represented schematically by pipes 138.

FIG. 6 shows a simplified embodiment of the device of FIG. 1. In this simplified embodiment, the return of the coolant from the cooling circuits 42 ₁ , 42 ₂ , 42 ₃ , 42 ₄ does not pass through the annular rotary union 44 ′, but is evacuated through open discharge pipes in the fixed annular tank 136 which is arranged in the lower end of the casing 12. In FIG. 6, for example the discharge line 140 of the cooling circuit 42 _{1 has been shown} . It follows that the annular rotary connector 44 'must only have an annular groove and internal channels to ensure the transfer of the coolant under pressure between the fixed ring and the rotary ring. The disadvantage of this system is that in the fixed annular tank 136, the coolant is exposed to the atmosphere prevailing in the casing 12. This requires a more expensive treatment of the cooling water before its recirculation in the cooling system .

Claims (9)

1. Loading device for a shaft furnace, comprising:

   a housing (12) to be mounted on the head of the shaft furnace;

   a suspension rotor (28) rotatingly suspended within said housing (12);

   a loading chute (10) suspended in said suspension rotor (28);

   at least one cooling circuit (42) supported by said suspension rotor (28);

   an annular rotating joint (44) to supply said cooling circuit (42) with a liquid coolant, said annular rotating joint (44) comprising a fixed ring (60), supported by said housing (12), a rotating ring (62) which rotates with said suspension rotor (28), and bearing means (32) between said fixed ring (60) and said rotating ring (62), said fixed ring (60) and said rotating ring (62) interacting to form a cylindrical interface in which at least one annular groove (74, 74') serves to transfer pressurised liquid coolant between said fixed ring (60) and said rotating ring (62); and

   connecting means (84, 108, 84', 108') connected between said rotating ring (62) and said suspension rotor (28) to transfer liquid coolant from said rotating ring (62) to said suspension rotor (28);

   characterised in that:

   said annular rotating joint (44) is mounted inside the housing (12) in an annular leak collecting tank (46) which is formed by said suspension rotor (28);

   said rotating ring (62) is supported exclusively by said fixed ring (60) by way of said bearing means (64);

   selective coupling means (65, 66) couple said rotating ring (62) to said suspension rotor (28) in such a way as to selectively transmit the rotary motion of said suspension rotor (28) to said rotating ring (62), while at the same time preventing the transmission of other forces from said suspension rotor (28) to said rotating ring (62); and

   said connecting means (84, 108, 84', 108'), comprising at least one deformable tubular component, such that said connecting means (84, 108, 84', 108') forms a non-rigid connection between said rotating ring (62) and said suspension rotor (28).
2. Device as claimed in claim 1, characterised by :

   a first annular groove (74) in said cylindrical interface to transfer liquid coolant from said fixed ring (60) to said rotating ring (62); and

   a second annular groove (74') in said cylindrical interface to transfer liquid coolant from said rotating ring (62) to said fixed ring (60).
3. Device as claimed in claim 1, characterised in that:

   said at least one cooling circuit (42) comprises at least one outlet pipe;

   said housing (12) comprises a fixed annular tank (136) for collecting liquid coolant;

   said outlet pipe (140) leads into said fixed annular tank (136) when said suspension rotor (28) is rotating; and

   drainage means are associated with said fixed annular tank to drain the liquid coolant out of the housing (12).
4. Device as claimed in any one of claims 1 to 3, characterised by drainage means (134, 136, 138) that are connected to said annular leak collecting tank (46) to drain the leaks which the latter collects in a controlled fashion out of said housing (12).
5. Device as claimed in anyone of claims 1 to 4, characterised in that:

   said fixed ring (60) is supported by an annular flange (22) fixed to said housing (12); and

   said annular leak collecting tank (46) comprises top ends (48, 50) which interact with said annular flange (22) to form labyrinth joints (52, 54).
6. Device as claimed in anyone of claims 1 to 5, characterised in that said connecting means (84, 108, 84', 108') comprises :

   at least one flexible, axially compressible coupling connection (84, 84') which is supported by said rotating ring (62) and comprises a coupling head (102); and

   a coupling seat (108, 108') which is arranged in said annular leak collecting tank (46), in such a way that said coupling head sits on said coupling seat (102) when said rotating annular joint (44) is mounted in said leak collecting tank (46).
7. Device as claimed in any one of claims 1 to 6, characterised in that said coupling means (65, 66) comprises :

   a radial cross member (65) mounted in said annular leak collecting tank (46) of the suspension rotor (28); and

   a notch (66) in said rotating ring (62) which engages with said radial cross member (65) when said rotating annular joint (44) is fitted in said annular leak collecting tank (46).
8. Device as claimed in anyone of claims 1 to 7, characterised in that:

   said connecting means (84, 108, 84', 108') leads into an annular collector (114, 120) fitted above said annular leak collecting tank (46); and

   a number of cooling circuits (42) supported by said suspension rotor (28) are connected to said annular collector.
9. Device as claimed in anyone of claims 1 to 8, characterised by :

   a pair of axially spaced watertight fittings (121', 121") (126', 126"), said pair of watertight fittings being fitted in said cylindrical interface between an annular groove (74) and said bearing means (64) or between two adjacent annular grooves (74, 74'); and

   a drainage channel (124, 130) capable of draining the cylindrical interface (122, 128) between the two watertight fittings of a pair of watertight fittings in said annular leak collecting tank (46)

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