Method and device for determining the consumption of electrode material during the operation of an electric furnace

Abstract

A method determines the consumption of electrode material during the operation of an electric furnace, particularly an arc furnace for producing steel. The method determines a weight of an electrode column, which is arranged in the electric furnace or is to be introduced into the electric furnace, using a weighing device. A device for determining the consumption of electrode material of an electric furnace, particularly an arc furnace for producing steel, is provided for performing the method. The device contains a weighing device for determining the weight of at least one electrode column which is arranged in the electric furnace or is to be introduced into the electric furnace, wherein the weighing device is integrated in an operating device of a system containing the electric furnace. Vibration conditions of the electrode column during operation of the electric furnace can also be determined with the method and with the device.

Claims

1. A method for determining consumption of electrode material during a production of steel in an electric arc furnace, the method comprises the step of: determining a weight of at least one electrode column disposed inside the electric arc furnace or to be introduced into the electric arc furnace, without removing the electrode column from the electric arc furnace, by using at least one weighing device carrying out a continuous or quasi-continuous determination of the weight of the electrode column with a temporal resolution of from 1 to 500 Hz without having to modify an operating procedure of the electric furnace and without additional electrode column movements having to be carried out.

2. The method according to claim 1, which further comprises automatically determining the weight of the at least one electrode column.

3. The method according to claim 1, which further comprises determining the weight of the at least one electrode column at at least two different points in time.

4. The method according to claim 3, which further comprises determining the weight of the at least one electrode column before and after a melt operation interval of the electric furnace.

5. The method according to claim 1, which further comprises: integrating the weighing device in an operating device of a system containing the electric furnace, and integrating the weighing device in a transport device with which the electrode column disposed inside the electric furnace and held in the electric furnace by a holding device, is received and transported in the electric furnace and/or transported out of the electric furnace, and/or with which the electrode column disposed outside of the electric furnace is transported into the electric furnace, and/or the weighing device is integrated in the holding device by which the electrode column is held in position during the operation of the electric furnace, in an adjusting device of the holding device, with which the holding device is adjustable, including being height-adjustable.

6. The method according to claim 1, which further comprises determining the weight of the at least one electrode column using at least one strain gauge, at least one force transducer and/or at least one pressure measuring element disposed in a hydraulic system for adjusting a holding device for the electrode column.

7. The method according to claim 1, which further comprises providing an arc furnace as the electric furnace.

8. The method according to claim 6, which further comprises selecting the strain gauge from the group consisting of a metallic strain gauge and an optical strain gauge.

9. A device for determining consumption of electrode material during a production of steel in an electric arc furnace, the device comprising: at least one weighing device for a continuous or quasi-continuous determination of a weight of at least one electrode column disposed in the electric arc furnace during a production of steel in the electric arc furnace without having to modify an operating procedure of the electric arc furnace and without additional electrode column movements having to be carried out, said weighing device being integrated in a transport device for transporting and holding the electrode column.

10. The device according to claim 9, wherein said weighing device determines the weight of the electrode column automatically.

11. The device according to claim 9, wherein said transport device is configured to receive the electrode column that is disposed inside the electric furnace and held in the electric furnace by a holding device and to transport the electrode column inside the electric furnace and/or transport the electrode column out of the electric furnace and/or to transport the electrode column disposed outside of the electric furnace into the electric furnace.

12. The device according to claim 9, wherein said weighing device is integrated in a holding device which is configured to hold the electrode column during a melt operation of the electric furnace.

13. The device according to claim 12, wherein said weighing device is integrated in a support arm of the holding device.

14. The device according to claim 12, wherein said weighing device has at least one of a strain gauge, at least one force transducer or at least one pressure measuring element disposed in a hydraulic system for adjusting the holding device for the electrode column.

15. The device according to claim 14, wherein said strain gauge is selected from the group consisting of a metallic strain gauge and an optical strain gauge.

16. The device according to claim 9, wherein said weighing device is configured such that said weighting device determines the weight of the at least one electrode column continuously or at least quasi-continuously with a temporal resolution of from 1 to 500 Hz.

17. The device according to claim 9, wherein the electric furnace is an arc furnace for producing steel.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

(1) FIG. 1 is an illustration of a system containing an electric furnace and a device for determining a consumption of electrode material of the electric furnace according to a first embodiment of the invention; and

(2) FIG. 2 is an illustration of a device for determining the consumption of electrode material of the electric furnace according to a second embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

(3) Referring now to the figures of the drawings in detail and first, particularly to FIG. 1 thereof, there is shown a system containing an electric arc furnace 10, which receives for example steel scrap and optionally further additives as an input material, which is melted down in the arc furnace 10 by the thermal energy of arcs struck in the arc furnace 10.

(4) In order to strike the arcs, the system has a bottom electrode (not shown in FIG. 1) which is arranged in the arc furnace 10 and is in direct electrical contact with the input material of the arc furnace 10, as well as an electrode column 12, which is composed of a plurality of elongate graphite electrodes 14, which are screwed together via threaded nipples 16 at their respective longitudinal ends. In practice, a plurality, in particular three, electrode columns 12 arranged parallel to one another can be used, in particular dispensing with the bottom electrode, only one electrode column 12 being shown in FIG. 1 for better clarity.

(5) Furthermore, the system contains a holding device 18, on which the electrode column 12 is hung and starting from which the electrode column 12 extends from above into the arc furnace 10 in a substantially vertical direction through a hole in the furnace lid 20. The holding device 18 contains a substantially horizontal support arm 22, which is supported by a substantially vertical pillar 24. On its end on the furnace side, a support arm 22 has a clamp 26, in which the electrode column 12 is received and which can, for example, contain one or more clamping jaws by which the electrode column 12 is fixed in the clamp 26 or can be released from the clamp 26.

(6) The electrode column 12 is held by the holding device 18 in a position in which the tip, arranged inside the arc furnace 10, of the electrode column 12 is located above the input material of the arc furnace 10 at a defined distance from the input material. By applying an electric voltage between the bottom electrode and the electrode column 12, arcs can be struck between the electrode column 12 and the input material of the arc furnace 10 and the input material can be melted due to the thermal energy released by the arc. The electrode column 12 is energized via the support arm 22, which is produced from an electrically conductive material for this purpose and is connected to a power source via cables (not shown in FIG. 1).

(7) In order to be able to adjust the height of the electrode column 12, and in particular to facilitate feeding of the electrode column 12 necessary as a result of the burn-off of the electrode 12 during the melt operation of the arc furnace 10, the holding device 18 is height-adjustable, i.e. movable in the direction of the arrow 28. Furthermore, the holding device 18 can be raised together with the electrode column 12 and preferably together with the furnace lid 20 relative to the arc furnace 10 and is pivotable about a vertical axis 30 in order to be able to open the arc furnace 10, for example after it has been tapped, and in order to be able to charge the arc furnace 10 with new input material through the opening of the arc furnace 10 assigned to the furnace lid 20.

(8) Furthermore, the system contains a transport device 32, which is constructed as a crane device with a substantially horizontal crane track 34, a crane carriage 36 movable along the crane track 34 in the direction of arrow 35 and a crane hook 40, which is hung on the crane carriage 36 by a cable 38 and can be raised and lowered in a vertical direction relative to the crane carriage 36 along the arrow 39. The positions and paths of movement of the transport device 32 and the holding device 18 are aligned such that the crane carriage 36 is movable into a position vertically above the position of the clamp 26 of the holding device 18 in which the electrode column 12 received in the clamp 26 is hung on the transport device 32 or can be removed from it. For this purpose, the electrode column 12 can have a loop (not shown specifically in FIG. 1) or the transport device 32 can have a suitable coupling apparatus for hanging the electrode column 12 on it. New electrodes 14 can be transported by the transport device 32 to the electrode column 12 and connected thereto and the electrode column 12 can be removed from the holding device 18 if necessary or fed to the holding device 18.

(9) Furthermore, the system contains a weighing device 42, which in the present embodiment contains a strain gauge 44 attached to the upper side of the support arm 22, which measures a strain caused in the support arm 22 by the weight of the electrode column 12, as well as a load cell 46, which is attached in the region of the connection between the support arm 22 and the pillar 24 and is connected to the support arm 22 and the pillar 24 such that it can perform measurements effectively and crane scales 48 hung on the crane carriage 36 of the transport device 32 and arranged between the crane carriage 36 and the crane hook 40.

(10) The strain gauge 44 and the load cell 46 each serve to measure the weight of the electrode column 12 while it is held by the holding device 18, for example between two consecutive melt operation intervals of the arc furnace 10. Whereas the crane scales 48 serve to measure the weight of the electrode column 12 while it is hanging from the transport device 32, for example while the electrode column 12 is being lowered relative to the arc furnace 10 and the holding device 18 by the transport device 32, for example after a new electrode 14 has been fixed to the electrode column 12 by the nipple.

(11) The determination of the weight of the electrode column 12 carried out by the weighing device 42 facilitates the precise determination of the consumption of electrode material of the arc furnace 10, the determination of consumption being integrated in the operation of the arc furnace 10 such that it can be carried out at minimal additional cost. In practice, the weighing device 42 can, of course, also contain just two or one of the various components strain gauge 44, load cell 46 and crane scales 48 illustrated in FIG. 1.

(12) FIG. 2 shows a detailed view of a device for determining the consumption of electrode material of the electric furnace according to a second embodiment, which device contains the crane scales 48, which have a hook 50 on one end for coupling with the electrode column 12 and which have an eye 52 on their other end for hanging the crane scales 48 on a crane hook 40 of a transport device 32, which is configured as shown in FIG. 1.

(13) The following is a summary list of reference numerals and the corresponding structure used in the above description of the invention: 10 Electric furnace/arc furnace 12 Electrode column 14 (Graphite) electrode 16 Threaded nipple 18 Holding device 20 Furnace lid 22 Support arm 24 Pillar 26 Clamp 28 Arrow 30 Vertical axis 32 Transport device 34 Crane track 35 Arrow 36 Crane carriage 38 Cable 39 Arrow 40 Crane hook 42 Weighing device 44 Strain gauge 46 Load cell 48 Crane scales 50 Hook 52 Eye