Abstract: A method is provided for botting a tap hole of a shaft furnace using a botting gun fitted with a first hydraulic actuating cylinder holding the botting gun in bearing contact against the wall of the furnace, while a second actuating cylinder actuates a piston which injects the botting mass into the tap hole. In order to limit the contact pressures between the tip of the botting gun and the wall of the furnace, the supply pressure P.sub.1 of the first actuating cylinder is modulated as a function of the supply pressure P.sub.2 of the second actuating cylinder.

Abstract: The present invention provides a new process and a new apparatus for the treatment of steel-mill slag in a vessel which allows a wet granulation of the slag without the risk of explosions. The slag is caused to flow through a taphole at the bottom of the vessel, and the flow rate of the slag is determined by means of a continuous check of the weight of the vessel. One or more jets of granulating water, the flow rate of which is adjusted as a function of the slag flow rate, are directed onto the stream of slag flowing from the vessel. The apparatus comprises a vessel containing molten slag. This vessel is equipped with weighing means, with a taphole, with a device for shutting off the taphole, with means for maneuvering the shut-off device between an operating position and a stored or parked position away from the taphole and with a device for opening or freeing the taphole, engageable through the latter in order to initiate the flow of slag.

Abstract: The invention relates to a drive for an automatic lance-changing device, such as is used in the top-blowing steel-making process. Such a lance-changing device comprises two lance-receiving hooks pivotable about a horizontal axis of rotation, means for the synchronous vertical displacement of these hooks relative to the lance carriage and to the coupling head, means which, during this displacement of the hooks, cause these hooks to execute a pivoting movement about their said axis of rotation, and means for detecting by measurement the load acting on each hook, the latter being a function of the force with which the lance top part is pressed against said coupling head by the hooks. The drive of this invention is a lifting-spindle system, by means of which a vertically displaceable suspension ring for suspension hooks of the lance top part is driven.

Abstract: A device is presented for injecting preheated air into a shaft furnace and comprises of a plurality of tubular elements provided with a refractory lining, which are connected to each other by a ball-and-socket articulation and an expansion joint. The ball-and-socket articulations comprise a convex ball portion formed in the refractory material of the adjacent segment. They comprise a protective shell made of refractory steel which extends around the convex part up to the base of the ball portion. The radius of curvature of each ball-and-socket articulation is in the range of magnitude of half the diameter of the tubular elements.

Abstract: The device comprises a gripper with retractable claws which can engage through the tymp and control means which pass through the gripper and can be controlled from outside in order to spread or retract the claws radially with respect to the axis of the tymp. The gripper and its control means are carried by a yoke designed to be fitted onto the outer edge of the tuyere arch and to be associated with a conventional pneumatic explosive-actuated tool which can be fitted to the outside of the yoke, either onto extensions of the claws or onto the control means, in order to exert by its rotation and its bearing on the yoke a tractive force on the claws of the gripper.

Abstract: The device mounted at the end of an operating arm comprises one or more suckers for supporting objects, for example refractory bricks for the brick-lining of a metallurgical converter, means for linear and angular displacement of the suckers, sensors for monitoring and controlling automatically the means of displacement in order to grip and position the objects in a predetermined location, after immobilization of the operating arm. The suckers are provided on a sucker-carrying plate which in its turn is supported by a pair of blocks which can slide in transverse slide bars of a carriage which comprises a pair of longitudinal slide bars, perpendicular to the transverse slide bars and housed in sliding fashion in a central support attached to the end of the operating arm with a degree of angular freedom and a degree of linear freedom orthogonal to the axes of the longitudinal and transverse slide bars.

Abstract: A method for opening the taphole of a shaft furnace by withdrawing a rod, held in the hardened sealing compound of the taphole, includes engaging a coupling device onto the end of the rod, gripping the rod using a clamp longitudinally displaceable by a hydraulic jack, pulling out the rod by a length corresponding to the stroke of the jack and repeating this operation until the rod is completely withdrawn from the taphole.

Abstract: A device for automatically coupling a lance for injecting a fluid into a molten metal bath to a manifold for supplying the fluid to the lance includes means for hitching the lance rigidly to a lance-carrying carriage which can be displaced along a slide rail, and means ensuring the support of the manifold with respect to the lance-carrying carriage and enabling the manifold to be displaced vertically with respect to the lance-carrying carriage, or vice versa.

Abstract: A probe includes a probe foot which is suspended on a cable or a chain attached to a winding drum mounted in a sealed casing above the furnace and which communicates with the interior of the latter via a vertical sleeve passing through the upper wall of the furnace, an electric motor associated with a reducer for actuating the winding drum, and a device for detecting the unwinding and winding up of the winding drum in order to control the speed and torque of the motor. The motor is a servomotor, the speed and torque of which are controlled automatically as a function of the detection device by comparison of the actual speed of the motor with data of desired values dependent on the position of the probe foot.

Abstract: The probe comprises a probe arm provided with a series of orifices for simultaneously taking gas samples and measuring the heat at different locations of the charging surface and penetrating through an opening in the furnace. This opening is surrounded by a support hoop integrally connected to the wall of the furnace and provided with two diametrically opposite outer journals on which are articulated two parallel arms supporting between them the probe arm. This arm can move about the center of the said hoop under the action of at least one actuator mounted between the said hoop and the outer end of the probe arm, the arm comprising a circular sliding surface moving, sealingly, over the inner surface of the said hoop.

Abstract: The method consists in forming in a single metering device a pneumatic mixture comprising the powdered substances and the propellent gas, in propelling this mixture through a common main 18 into a distributor 20 in which the mixture is split into secondary currents which are sent to each of the injection points respectively through secondary pipes 22.sub.1, 22.sub.2, . . . 22.sub.n, in determining the flow rate in each of the secondary pipes 22.sub.1, 22.sub.2, . . . 22.sub.n by the tuyere 28.sub.1, 28.sub.2, . . . 28.sub.n flow cross-sections and in influencing the transport conditions in each secondary pipe 22.sub.1, 22.sub.2, . . . 22.sub.n by acting on the pressure P3 downstream from each tuyere 28.sub.1, 28.sub.2, . . . 28.sub.n in order to maintain this pressure at a determined value.The method is aimed more particularly at the injection of powdered coal into a blast furnace.

Abstract: The device comprises an oblique portion connected by a gooseneck, a nozzle, atuyere and a ball-and-socket joint to the wall of the furnace, in which the oblique portion comprises a tapered tube flange-mounted by its upper part onto an upper connection piece forming part of a bustle pipe and the lower part of which dips axially into a lower connection piece integral with the gooseneck, a bellows expansion joint and tension rods ensuring the mechanical connection between the tapered tube and the lower connection piece. The lower connection piece and the tapered tube can move mutually in the axial direction and have means for limiting their radial mobility.

Abstract: The probe comprises a support in the form of a sheath, a series of internal pipes, retained by spacers and connecting orifices distributed along the sheath to a device for measuring and for receiving the gas samples outside the furnace, and thermocouples arranged at the level of the said orifices. In order to enable the pipes to be replaced without disassembly of the probe, the said orifices are situated in steps provided in the sheath, while the internal pipes, for taking gas samples and heat measurements are all individual, straight and exchangeable elements housed in straight support and protection channels, each traversing the sheath from the outside as far as the respective step.

Abstract: The device comprises a housing with a circular passage orifice, a pivoting closing element in the form of a spherical dome and a circular gasket surrounding the said orifice and mounted on an annular support axially displacable towards the closing element under the action of a pneumatic fluid, the said annular support possessing for this purpose a passive annular surface exposed to the pressure in the said housing, the active surface of the support being larger than its passive surface.

Abstract: The device includes a chuck designed to be secured to a working tool and which has a front cavity for receiving an end of a drilling rod and a gripping device for fastening the end of the rod in this cavity. The gripping device is actuated by pneumatic or hydraulic pistons, sliding in a cylindrical chamber closed at the rear by a plug. In order to avoid rapid wear of this plug, a spring is arranged between the said plug and the adjacent face of the piston, the spring being strong enough to keep the piston away from the plug.

Abstract: The device includes a radar antenna mounted at the inside end of an arm which can be horizontally inserted through the wall of the furnace above the loading surface, an electronic control and measuring unit placed outside the furnace, and one or two waveguides connecting the said antenna to the electronic unit through the arm. The waveguide or waveguides are duplicated by two reference waveguides of the same nature and of the same length but not connected to the said antenna systems in order to provide a forward and return path for a reference signal generated by the electronic unit and which remains correlated with the measurment signal to allow a better identification of the reflected signal.

Abstract: The device includes a transmitting antenna which also serves as a receiving antenna and a separate receiving antenna for receiving the signals transmitted by the transmitting antenna and reflected at the point of reflection, and two data processing units, one for the signals picked up by the transmitting and receiving antenna and transmitted through a circulator and a first mixer, the other for the signals picked up by the receiving antenna and transmitted through a second mixer. The distance measurement is computed using the signals picked up by the transmitting and receiving antenna for distances less than a predetermined threshold and using the signals picked up by the receiving antenna for distances greater than the predetermined threshold.

Abstract: The installation comprises a chute for distributing the charging material, a skip transport system, a closed casing containing a device for the controlled sluicing of the charging material between the discharge by the skips and the distribution chute, a lower sealing valve and a proportioning valve opening symmetrically about a central axis, and a funnel-shaped hopper suspended rotatably within a sealed casing. A closing and material-deflecting plate is located in the hopper, this plate being movable vertically and axially within the hopper. A valve is associated with each of the skips in order to regulate the flow of material from the skips towards the hopper.

Abstract: A radar probe including several individual scanning antennas is mounted in the wall of the furnace above the loading surface and performs a two-dimensional scanning of the entire loading surface.

Abstract: A machine for opening tapholes has a conical guide and support head which is slidably mounted on a mount and which includes at least one hook equipped with two mutally opposite catching slots. The catching slots allow the hook to occupy two catching positions. In the first catching position, the head is secured to a sliding frame displacable by use of a sliding carriage. In the second catching position, the head is secured to the front end of the mount.