Stopper control device
A control device ( 1 ) for a stopper ( 3 ) comprises: —an outer casing ( 10 ), —a control rod ( 6 ) sliding through the casing ( 10 ), rigidly attachable to the stopper ( 3 ), —a hydraulic circuit ( 20 ) including a double-acting hydraulic cylinder ( 21 ) and a reversible hydraulic pump ( 9 ), the hydraulic cylinder ( 21 ) having a first and a second chamber ( 21 a, b ) between which a piston ( 22 ) slides, the hydraulic pump ( 9 ) being connected directly to the first and second chamber ( 21 a, b ) by means of a first branch and a second branch ( 20 a, b ) of said hydraulic circuit ( 20 , respectively, the piston being rigidly attached to the control rod ( 6 ), the hydraulic circuit ( 20 ) being entirely housed in the outer casing ( 10 ), —a control circuit ( 30 ) connected to the hydraulic circuit ( 20 ) to control the position of the piston ( 22 ).
1. A control device for a stopper being usable to adjust an outflow of liquid steel from a vessel, said device comprising:
a containing frame,
a control rod sliding through said frame, rigidly attachable to said stopper,
a hydraulic circuit including a double-acting hydraulic cylinder and a reversible hydraulic pump, said double-acting hydraulic cylinder having a first chamber and a second chamber between which a piston slides, said reversible hydraulic pump being connected to said first chamber and second chamber in such a way that a rotation of the reversible pump in one sense of rotation sends fluid directly to the first chamber, thus determining a movement of the piston in a first direction and a rotation of the reversible pump in the other sense of rotation sends fluid directly to the second chamber, thus determining a movement of the piston in a second direction opposite the first direction, said piston being attached to said control rod,
a control circuit connected to said hydraulic circuit to control a position of said piston, characterized in that said reversible hydraulic pump is directly connected to said first chamber and second chamber of said double-acting hydraulic cylinder, respectively by means of a first branch and a second branch of said hydraulic circuit wherein said hydraulic circuit and pump are entirely housed in said containing frame.
2. A control device according to claim 1 , wherein said reversible hydraulic pump is actuated by means of an electric motor connected to said control circuit.
3. A control device according to claim 2 , wherein said reversible hydraulic pump and said electric motor are corrected to each other in a fixed manner.
4. A control device according to claim 2 , wherein said reversible hydraulic pump and said electric motor are connected to each other by means of a quick connector.
5. A control device according to claim 1 , wherein said control circuit is feedback-controlled.
6. A control device according to claim 5 , wherein said control circuit comprises a position transducer to detect the position of the piston, said position transducer being housed in said frame.
7. A control device according to claim 6 , wherein said control circuit comprises a control unit connected to said electric motor and to said position transducer.
8. A control device according to claim 5 , wherein the control circuit comprises a level sensor to measure a level of liquid steel in an ingot mold, said level sensor being connected to said control unit.
9. A control device according to claim 6 , wherein the control circuit comprises a level sensor to measure a level of liquid steel in an ingot mold said level sensor being connected to said control unit.
10. A control device according to claim 7 , wherein the control circuit comprises a level sensor to measure a level of liquid steel in an ingot mold, said level sensor being connected to said control unit.
11. A control device according to claim 1 , wherein said hydraulic circuit includes a bypass valve to put said first chamber and second chamber of said double-acting hydraulic cylinder into communication to each other.
12. An apparatus comprising:
a vessel for molten, steel including a drain hole for, an outflow of said molten steel,
a stopper working on said drain hole to adjust said outflow,
a control device for said stopper comprising:
a frame,
a control rod sliding through said frame, and rigidly attachable to said stopper,
a hydraulic circuit including a double-acting hydraulic cylinder and a reversible hydraulic pump, said double-acting hydraulic cylinder having a first chamber and a second chamber between which a piston slides, said reversible hydraulic, pump being connected to said first chamber and second chamber in such a way that a rotation of the reversible pump in one sense of rotation sends fluid directly to the first chamber, thus determining a movement of the piston in a first direction and a rotation of the reversible pump in the other sense of rotation sends fluid directly to the second chamber, thus determining a movement of the piston in a second direction opposite the first direction, said piston being attached to said control rod,
a control circuit connected, to said hydraulic circuit to control a position of said piston, characterized in that said reversible hydraulic pump is directly connected to said first chamber and second chamber of said doable-acting hydraulic cylinder, respectively by means of a first branch and a second branch of said hydraulic circuit wherein said hydraulic circuit and pump are entirely housed in said containing frame.