Abstract: A rotary charging device for a shaft furnace, in particular a blast furnace, is disclosed. The charging device is equipped with a cooling system. The rotary charging device includes a rotatable support for rotary distribution means as well as a stationary housing for the rotatable support. The cooling system includes a rotary cooling circuit fixed in rotation with the rotatable support as well as a stationary cooling circuit on the stationary housing. A heat transfer device is provided which includes a stationary heat transfer element configured to be cooled by a cooling fluid flowing through the stationary cooling circuit and which includes a rotary heat transfer element configured to be heated by a separate cooling fluid circulated in the rotary cooling circuit.

Abstract: A rabble arm for a furnace includes an elongated metallic support core, at least one rabble tooth having a rabble portion and a fixing portion and a fixing device co-operating with the fixing portion for fixing the rabble tooth to the elongated metallic support core. The fixing portion includes a through hole through which the elongated metallic support core axially passes. The fixing device co-operates with the fixing portion around the through hole for fixing the rabble tooth to the elongated metallic support core.

Abstract: A method of operating a multiple hearth furnace with a plurality of vertically aligned hearth floors includes feeding a first material onto the uppermost hearth floor and moving it over the hearth floor before it falls through a drop hole onto the next lower hearth floor. The first material is processed in this way from hearth floor to hearth floor to the lowermost hearth floor. A second material is fed onto one of the hearth floors to be mixed into the first material. This second material is moved separately from the first material in a separate annular zone of the hearth floor onto which it is fed before it is mixed into the first material, providing an efficient thermal preconditioning of the second material prior to mixing it with the first material without requiring any supplemental equipment.

Abstract: A multiple hearth furnace includes an upright cylindrical furnace housing divided into a plurality of vertically aligned hearth chambers. A cleaning lance inlet port is sealingly connected to the cylindrical furnace housing and radially leads into one of the hearth chambers. A cleaning lance assembly is provided and includes an elongated mount arranged outside the furnace housing and the cleaning lance is slidably mounted on the elongated mount. The cleaning lance includes a cleaning nozzle and can be sealingly introduced through the lance inlet port along a radial trajectory into the hearth chamber by moving it along the elongated mount. The cleaning nozzle is arranged on the cleaning lance, so as to be capable of directing a jet of cleaning fluid onto a rabble arm that is positioned in a cleaning position in the vicinity of the radial trajectory when the cleaning lance is slidably moved along the elongate mount.

Abstract: A gas tight shut-off valve for a material charging or discharging lock includes a valve closing element that is movable relative to a valve a seat, between a first position which the valve closing element and the annular valve seat can be axially pressed together, and a second position in which the valve closing element is located laterally of the discharge opening in the valve seat. A soft sealing element is associated either with the annular valve seat or with the valve closing element. The valve further includes a heat protecting element which is movable between a first position in which it covers the soft sealing element when the valve closing element is in its second position, and a second position in which it uncovers the soft sealing element.

Abstract: A multiple hearth furnace comprises at least one cleaning lance inlet port (52, 54) radially leading into one of its hearth chambers (24). A cleaning lance assembly (40′, 40″) includes an elongated mount (42) and at least one cleaning lance (48, 50) slidably mounted on the elongated mount (42). Each cleaning lance (48, 50) is connected to a cleaning fluid distribution system (56) and comprises at least one cleaning nozzle (58, 60). It can be sealingly introduced through the lance inlet port (52, 54) along a radial trajectory into the hearth chamber (24) by moving it along the elongated mount (42). The at least one cleaning nozzle (58, 60) is capable of directing a jet of cleaning fluid onto a rabble arm (34) positioned in a cleaning position in the vicinity of the radial trajectory when the cleaning lance (48, 50) is slidably moved along the elongate mount (42).

Abstract: A rabble arm for a furnace, as e.g. a multiple hearth furnace, comprises an elongated metallic support core (10), at least one rabble tooth having a rabble portion and a fixing portion and fixing means co-operating with the fixing portion for fixing the rabble tooth (14) to the elongated metallic support core. The fixing portion (48) includes a through hole through (50) which said elongated metallic support core axially passes; and the fixing means co-operates with the fixing portion (48) around the through hole for fixing said rabble tooth (14) to said elongated metallic support core (10).

Abstract: A method of operating multiple hearth furnace (10) with a plurality of vertically aligned hearth floors (361, 362, 363, 364, 365), comprises in particular following steps. A first material is fed onto the uppermost hearth floor and moved over this uppermost hearth floor (361) before it falls through a drop hole (40) onto the next lower hearth floor. This first material is processed in this way from hearth floor to hearth floor down to the lowermost hearth floor (366). A second material is fed onto one of the hearth floors to be mixed into the first material. This second material (64) is moved separately from the first material in a separate annular zone (68) of the hearth floor onto which it is fed before it is mixed into the first material. The method allows to provide an efficient thermal preconditioning of the second material prior to mixing it into the first material without requiring any supplementary equipment therefore.

Abstract: A gas-tight shut-off valve (14) for a material charging or discharging lock (10) comprises a valve closing element (26) that is movable relative to a valve seat (22), between a first position, in which the valve closing element (26) and the annular valve seat (22) can be axially pressed together, and a second position, in which the valve closing element (26) is located laterally of the discharge opening (24) in the valve seat (22). A soft sealing means (28) is associated either with the annular valve seat (22) or with the valve closing element (26). The valve (14) further comprises a heat protecting element (30), which is movable between a first position, in which it covers the soft sealing means (28) when the valve closing element (26) is in its second position, and a second position, in which it uncovers the soft sealing means (28).

Abstract: The invention relates to a charging device for creating superimposed layers of fine-grained bulk material on a rotating hearth (2). For each layer of bulk material to be charged, said charging device comprises a discharge hopper (22) having an outflow slot (36) and a discharge roller (42) positioned ahead of each outflow slot (26). Said outflow slot (36) and discharge roller (42) extend essentially at a right angle to the direction of rotation of the rotating hearth and the discharge roller (42) has a drive (44), the rotational frequency of which can be controlled.

Abstract: A device for the discharge of bulk material (96) from a pressure vessel (2) is proposed, which comprises at least one sluice bin (24, 26) with a bottom (42, 44) and a top (40) sluice gate. The sluice bin (24, 26) is arranged under a plate (76, 76'), into which it forms an orifice (28, 30) for the bulk material (96). The top sluice gate (40) has a sealing plate (66), which is arranged above this plate (76, 76') in such a way that it can be positioned above the orifice (28, 30) of the sluice bin (24, 26) and, after a sealing connection to the edge of the orifice (28, 30) has been made, can be forced against this edge by overpressure in the pressure vessel (2).