FR2755045A1 - Pneumatic device to facilitate or create a liquid metal flow from a vessel, especially liquid steel ladles - Google Patents

Abstract

A pneumatic device is claimed for facilitating or creating the flow of liquid metal when opening a stopper system protected by a refractory element in vessels with gravity, pressure or vacuum flow. The device comprises one or two complementary elements and uses the natural movement of the stopper system in order to make it function. It is lodged in the flow elements and is used in the nominal conditions of the process without inducing pollution. It is made up of a propulsion/percussion system placed in the mobile part after the opening of the stopper system and essentially an insert placed in the fixed part of the stopper system. The insert comprises a shaft which extends the propellant which creates a flow orifice in the refractory protection. The propellant is armed on being put in place and functions with the movement of the mobile part of the stopper system. The mode of propulsion can be by compressed gas, mechanical compression or any other source of energy able to activate a piston. The device may combine different dimensions to enable it to be adapted for particular thermal, dimensional or mechanical conditions of the casting process, notably the diameters of the casting orifices.

Description

 The present invention relates to a pneumatic device for creating or facilitating flow when opening the closure system of a container containing metal in the liquid state.

 The closure system is traditionally protected from liquid metal by refractory sand. This sand flows by gravity when the closure system is opened.

Incidents
Sometimes the refractory sand agglomerates to form grains of a different particle size or sintered in contact with the liquid metal to form a hard and compact crust. The gravimetric flow of sand and / or metal then becomes difficult, if not impossible.

The cure
During these incidents, the movable orifice of the closure system is vented and an attempt is made to manually drill the drain hole using a mechanical tool.

 The device according to the invention makes it possible to remedy the consequences of incidents.

 According to a first characteristic, it comprises a propellant / striker which is placed in the flow channel of the lower movable part of the closure system.

 According to a second characteristic, it includes an insert possibly placed in the upper part of the closure system. This insert is placed in the refractory sand.

 The main feature is the use of the movement of the closing system to activate the percussion of the sand or the propulsion of the insert in order to cause a sufficient opening to allow the flow of the metal.

According to the particular embodiments
- the device can be made with different types of material in order not to pollute the liquid metal or to obtain particular characteristics
- the insert can be made of different lengths and dimensions in order to adapt to the nominal dimensions and to the wear of the closure system or of the coatings of the capacity
- the propellant can be used without the insert
The only percussion function of the thruster is used.

- the propellant can use different propulsion modes (hydraulic, gaseous, etc.) adapted to the closure system and to the process conditions
- the propellant can use materials which participate during their propulsion in chemical and / or physical reactions in order to perfect the functioning of the device
- the thruster / striker is put in place after the observation of the non-flow of the metal
- the thruster / striker can be fitted without operating pressure. The handling system then ensures the placement and filling of propellant in situ during positioning. Armament is then useless.

 The accompanying drawings illustrate the device.

 Figure 1 shows the insert in position in the fixed part of the closure system.

 FIG. 2 represents the thruster in position in the movable part of the closure system.

 Figure 3 shows the entire device ready to operate.

The fixed part (9) of the capacity closure system generally comprises an inlet channel (1) and a flow channel (2). These channels are filled with refractory sand. The insert consists of an arrow (3) sliding in a conduit (5). The upper end can be protected by a refractory cement which ensures the sealing of the duct and the thermal protection. The arrow is held in the conduit by a pin (6)
The insert is held and positioned in the center of the channels by upper flexible elements (4) and lower fixed wedges (8). The lower zone of the arrow (7) receives the propellant piston. The insert is positioned relative to the fixed part of the closure system (9).

 The movable part of the closure system (21) also includes a flow channel (10). The propellant is maintained in the closing system by jacks (11) also providing a centering function. The body (14) contains the piston propulsion system (15). The body is filled by means of a valve (12). The piston is held on the base (17) of the body by a set of eccentric balls (16). A pin (18) provided with a ring (19) arms the propellant. A warranty seal locks the pin. A safety pin locks the piston (15).

 The complete system is shown in Figure 3. The closure system consists of two elements sliding against each other. The opening is obtained by matching the two orifices (2) and (10).

 During the matching of the two orifices, the propellant piston ejects the arrow through its conduit and creates a sufficient orifice to allow the flow of liquid metal. At the end of propulsion, the cylinders lose their bearing load and the propellant falls by gravity.

 According to variants not illustrated, the device can combine different dimensions to adapt to the thermal, dimensional, mechanical conditions of the process, in particular the diameters of the orifices.

 According to variants not illustrated, the propulsion mode can use gas compression, mechanical compression or any other source of energy necessary for the movement of the piston.

 The device according to the invention is particularly intended to facilitate the opening of pockets of liquid metal in the steel industry.

 According to variants not illustrated, the device can use only the percussion force of the piston (15) to break the surface layer of the sand and create a flow. The insert is not used in this case.

Claims (8)

 1) Device for facilitating or creating the flow of liquid metal during the opening of a closure system protected by a refractory element in gravity flow capacities, under pressure or under vacuum. This device is characterized in that it comprises one or two complementary elements, that it uses the proper movement of the closure system to perform its function, that it is housed in the flow elements and that it is used under the nominal conditions of the process without inducing pollution.  2) Device according to claim 1 characterized in that the insert consists of a sealed protective conduit (5) containing an arrow (6)  3) Device according to claim 2 characterized in that the insert is held in the center of the channel by flexible elements (4) compensating for the wear of the channel  4) Device according to claim 2 characterized in that the insert is held substantially in the center of the channel by fixed inclined wedges (8) ensuring the circulation of the propellant piston.  5) Device according to claim 1 characterized in that the propellant consists of a body (4) and a piston (5)  6) Device according to claim 1 characterized in that this propellant can be installed after discovery of an incident  Device according to claim 1 characterized in that this propellant is provided with a circular holding system ensuring centering and locking in place  8) Device according to claim 1 characterized in that the propulsion is provided by any pneumatic, mechanical, electrical or other means, individually or combined.  9) Device according to claim 1 characterized in that the propellant is armed or filled with gas while it is in place in the orifice of the movable part of the closure system