Technical Field

[0001 ] The present invention generally relates to a charging installation of a shaft furnace, comprising in particular two storage hoppers and a receiving hopper for feeding material into the storage hoppers. The present invention further relates to a method for charging a shaft furnace using such a charging installation.

Background Art

[0002] At least one storage hopper is provided in the charging installation for receiving material, such as e.g. coke or sinter, from a skip or conveyor belt and temporarily storing the material therein before it is fed to the shaft furnace. If more than one storage hopper (generally two, sometimes three) is provided, these are arranged in parallel and allow a sequential charging of the shaft furnace. Material is fed into one storage hopper, while another storage hopper has its material emptied into the shaft furnace. Thus, any material fed into the shaft furnace is first stored in such a storage hopper. The material must therefore be distributed into one or the other of the storage hoppers. This distribution may be achieved by means of a distribution rocker which has a central pivot and is actuated to either feed the material into the first storage hopper or the second storage hopper. Alternatively a horizontal translating receiving hopper may be provided for guiding the material into the correct storage hopper.

[0003] In cases where the shaft furnace installation does not allow enough space for a distribution rocker or a horizontal translating receiving hopper, a pivoting receiving hopper may be used. Such a pivoting receiving hopper is arranged to pivot about a pivot axis and thereby align its outlet with either one of the inlets of the storage hoppers.

[0004] In operation, some material may be retained in the receiving hopper even after the filling sequence has finished. As the receiving hopper is moved from one storage hopper to the other, this material may fall out of the receiving hopper and fall either between the two storage hoppers or onto a still closed sealing valve of the next storage hopper. The sealing valve or the safe operation thereof may be compromised by such material.

Technical Problem

[0005] It is an object of the present invention to provide an improved charging installation of a shaft furnace. This object is achieved by a charging installation as claimed in claim 1 .

General Description of the Invention

[0006] A charging installation of a shaft furnace comprises a first storage hopper and a second storage hopper, arranged in parallel with respect to each other; each of the first and second storage hoppers having an inlet for receiving material and an outlet for feeding material into the shaft furnace. A receiving hopper is arranged upstream of the first and second storage hoppers, the receiving hopper being pivotably arranged about a horizontal pivoting axis and configured for receiving material therein and for distributing the material to one of the first and second storage hoppers. The receiving hopper comprises an inlet for receiving material from a feed apparatus and an outlet for feeding the material to the first and second storage hoppers, the receiving hopper being pivotable at least between two transfer positions, wherein, in a first transfer position the outlet of the receiving hopper is in alignment with the inlet of the first storage hopper and, in a second transfer position, the outlet of the receiving hopper is in alignment with the inlet of the second storage hopper. A rest position is arranged between the first and second transfer positions.

[0007] According to an aspect of the present invention, the charging installation further comprises a material gate associated with the outlet of the receiving hopper; and an actuating mechanism associated with the material gate for opening and closing the outlet of the receiving hopper, the actuating mechanism being configured so as to actuate the material gate through the pivoting movement of the receiving hopper. The actuating mechanism is configured so as to essentially close the outlet of the receiving hopper when the receiving hopper is in the rest position and so as to essentially open the outlet of the receiving hopper when the receiving hopper is in either of the first and second transfer positions. [0008] The material gate prevents any rest of material - coke, sinter, or other - that may be remaining in the receiving hopper from falling onto a closed sealing valve of one of the storage hoppers or from falling between the two storage hoppers. The actuating mechanism of the material gate causes the latter to be self-closing, i.e. there is no need for a separate actuator for the material gate. The material gate is actuated by the pivoting movement of the receiving hopper. Thus, no activation or control of the material gate has to be foreseen in the shaft furnace sequence; there is no risk of failure of the material gate.

[0009] The actuating mechanism advantageously comprises a first link element and a second link element. The first link element has a first end and a second end, wherein a pivot point is located between the first and second end, the first link element being pivotably connected with the pivot point to the receiving hopper, the material gate being connected to the first end of the first link element. The second link element has a first end and a second end, the first end of the second link element being rotatably connected to the second end of the first link element, the second end of the second link element being rotatably connected to a support structure that houses the charging installation.

[0010] The first link element may comprise a first portion and a second portion, the first and second portions of the first link element being arranged in an angled configuration, the pivot point being arranged at a meeting point between the first and second portions.

[001 1 ] The first and second portions of the first link element are preferably rigidly connected to each other or formed in one piece.

[0012] The first link element is preferably pivotably mounted on the receiving hopper about an axis parallel to the pivoting axis of the receiving hopper.

[0013] The movement of the material gate about its pivot point is preferably in a direction opposite to the direction of the receiving hopper about the pivoting axis of the receiving hopper.

[0014] Advantageously, the actuating mechanism comprises a first set of first and second link elements on a first side of the receiving hopper and a second set of first and second link elements on a second side of the receiving hopper, opposite to the first side. [0015] The charging installation preferably further comprises an actuator, preferably a hydraulic cylinder, for moving the receiving hopper between the two transfer positions.

[0016] The present invention further relates to a method for charging a shaft furnace, wherein the method comprises:

providing a charging installation as described above;

opening a seal valve associated with the inlet of the first or second storage hopper;

moving the receiving hopper from its rest position into its first or second transfer position so as to align the outlet of the receiving hopper with the inlet of the first or second storage hopper, wherein the movement of the receiving hopper into its first or second transfer position moves the material gate away from the outlet of the receiving hopper;

feeding material into the receiving hopper and allowing the material to be transferred via the open outlet of the receiving hopper into the first or second storage hopper; stopping the feed of material into the receiving hopper;

moving the receiving hopper away from its first or second transfer position into its rest position, thus moving the material gate over the outlet of the receiving hopper, thereby essentially closing the outlet of the receiving hopper;

closing the seal valve associated with the inlet of the first or second storage hopper.

[0017] The method comprises placing the receiving hopper into a rest position wherein the material gate of the receiving hopper essentially closes the outlet of the receiving hopper before opening or closing the seal valves associated with the inlets of both the first and second storage hoppers. Thus, after feeding material into the first storage hopper, the receiving hopper is moved into its rest position and the outlet of the receiving hopper is closed. Once the receiving hopper is in its rest position, the first seal valve associated with the inlet of the first storage hopper can be closed and the second seal valve associated with the inlet of the second storage hopper can be opened. The receiving hopper can now be placed into its second transfer position so as to align the outlet of the receiving hopper with the inlet of the second storage hopper. It should be noted that, while the seal valves are operated, the receiving hopper is in its rest position and the outlet is closed. Thus, no material can escape from the receiving hopper and land on a closed seal valve.

Brief Description of the Drawings

[0018] Preferred embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which:

Fig. 1 is a schematic view of a charging installation according to the invention;

Fig. 2 is an enlarged view of the receiving hopper of Fig.1 in the first transfer position;

Fig. 3 is an enlarged view of the receiving hopper of Fig.1 in the second transfer position; and

Fig. 4 is an enlarged view of the receiving hopper of Fig.1 in the rest position. Description of Preferred Embodiments

[0019] Figure 1 shows a charging installation 10 of a shaft furnace with a first storage hopper 12 and a second storage hopper 12', arranged in parallel with respect to each other. Each storage hopper 12, 12' has an inlet 14, 14' for receiving material and an outlet 16, 16' for feeding material into said shaft furnace (not shown).

[0020] The storage hoppers 12, 12' are generally fed in sequence, i.e. while material is fed into one storage hopper 12, 12', the other storage hopper 12, 12' is emptied. While the feeding of material into the storage hopper 12, 12' is carried out under atmospheric pressure, the emptying of material out of the storage hopper 12, 12' must be carried out at furnace pressure. Thus, the storage hopper 12, 12' must be pressurized before the material contained therein can be fed into the shaft furnace.

[0021 ] Before a storage hopper can be emptied, it has to be brought to furnace pressure. Thus, each hopper inlet 14, 14' of the storage hoppers 12, 12' is provided with a sealing valve (not shown), which in cooperation with a sealing valve associated with the outlet 16, 16' ensures that the storage hopper 12, 12' is gas tight and can thus be pressurized. [0022] A receiving hopper 18 is arranged upstream of the storage hoppers 12, 12' for distributing material from a skip 20, or any other appropriate feed apparatus, to one or the other of the storage hoppers 12, 12'. Such a receiving hopper 18 comprises an inlet 24 for receiving material from the skip 20 and an outlet 26 for feeding the material to the first or second storage hopper 12, 12'. The receiving hopper 18 is pivotably arranged about a horizontal pivoting axis 22 and can be moved between a first transfer position, a second transfer position and a rest position. An actuator 28 is provided for moving the receiving hopper 18 about its pivoting axis 22.

[0023] In Fig.1 , the receiving hopper 18 is arranged in its first transfer position in order to feed material into the first storage hopper 12. In this first transfer position, the outlet 26 of the receiving hopper 18 is in alignment with the inlet 14 of the first storage hopper 12.

[0024] The charging installation 10 further comprises a material gate 30 associated with the outlet 26 of the receiving hopper 18 and an actuating mechanism 32 associated with the material gate 30. The actuating mechanism 32 is configured to move the material gate 30 so as to close the outlet 26 when the receiving hopper 18 is in its rest position and to open the outlet 26 when the receiving hopper 18 is in the first or second transfer positions. The mechanism 32 is in particular configured to actuate the material gate 30 based on the pivoting movement of the receiving hopper 18, i.e. without the need of an additional electric or hydraulic actuator.

[0025] The actuating mechanism 32 can be more closely described by referring to Figs 2, 3 and 4, which show an enlarged view of a receiving hopper in three positions.

[0026] In Fig.2, the receiving hopper is in its first transfer position, i.e. the outlet 26 is open and communicates with the inlet 14 of the first storage hopper 12. The actuating mechanism 32 comprises a first link element 34 and a second link element 36. The first link element 34 has a first end 38, a second end 40 and a pivot point 42 located between the first and second ends 38, 40. The first link element 34 preferably comprises a first portion 44 and a second portion 46 arranged in an angled configuration, the pivot point 42 being arranged at a meeting point between the first and second portions 44, 46. The material gate 30 is connected to the first end 38 of the first link element 34. The first link element 34 is pivotably connected with the pivot point 42 to the receiving hopper 18.

[0027] The second link element 36 has a first end 48 rotatably connected to the second end 40 of the first link element 34 and a second end 50 rotatably connected to a support structure (not shown) that houses the charging installation 10. Thus, the second end 50 of the second link element 36 forms a fixed point and, with the movement of the receiving hopper 18 and the pivot point 42 about pivoting axis 22, the actuating mechanism 32 moves the material gate 30 with respect to the receiving hopper 18 without the need for an additional actuator. The movement of the receiving hopper 18 into the desired position causes the material gate 30 to also move in its appropriate position. With the actuating mechanism 32 shown in the figures, the material gate 30 is moved about the pivot point 42 in a direction opposite to the direction of movement of the receiving hopper 18 about its pivoting axis 22.

[0028] Once the first storage hopper 12 has been filled, the receiving hopper 18 is moved clockwise into a rest position. This movement causes the material gate 30 to move anticlockwise and close the outlet 26 of the receiving hopper 18. The rest position of the receiving hopper 18 is illustrated in Fig.4. Once the receiving hopper 18 has reached its rest position, the first sealing valve of the first storage hopper 12 may be closed and the first storage hopper 12 can be pressurized in order to feed the material contained therein into the shaft furnace. At the same time, the second sealing valve of the second storage hopper 12' may be opened to prepare the second storage hopper 12' for receiving material.

[0029] Once the second storage hopper 12' is available, the receiving hopper 18 is moved clockwise into the second transfer position. This movement causes the material gate 30 to move anticlockwise and open the outlet 26 of the receiving hopper 18. The second transfer position of the receiving hopper 18 is illustrated in Fig.3. Once the receiving hopper 18 is in its second transfer position, material can be charged into the second storage hopper 12'.

Legend of Reference Numbers:

10 charging installation 12 first storage hopper ' second storage hopper 34 first link element

, 14' inlet of storage hopper 36 second link element

, 16' outlet of storage hopper 38 first end of first link element receiving hopper 40 second end of first link element skip 42 pivot point

pivoting axis 44 first portion

inlet of receiving hopper 46 second portion

outlet of receiving hopper 48 first end of second link element actuator 50 second end of second link material gate element

actuating mechanism