CA2022622A1 - Electrode water ring - Google Patents
Electrode water ringInfo
- Publication number
- CA2022622A1 CA2022622A1 CA 2022622 CA2022622A CA2022622A1 CA 2022622 A1 CA2022622 A1 CA 2022622A1 CA 2022622 CA2022622 CA 2022622 CA 2022622 A CA2022622 A CA 2022622A CA 2022622 A1 CA2022622 A1 CA 2022622A1
- Authority
- CA
- Canada
- Prior art keywords
- water
- electrode
- ring
- spray
- water ring
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 title claims abstract description 81
- 239000007921 spray Substances 0.000 claims abstract description 18
- 238000010891 electric arc Methods 0.000 claims abstract description 10
- 239000008400 supply water Substances 0.000 claims 3
- 238000005260 corrosion Methods 0.000 abstract description 7
- 230000007797 corrosion Effects 0.000 abstract description 7
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 abstract description 5
- 229910002804 graphite Inorganic materials 0.000 abstract description 5
- 239000010439 graphite Substances 0.000 abstract description 5
- 230000008016 vaporization Effects 0.000 abstract description 4
- 238000009834 vaporization Methods 0.000 abstract description 4
- 238000005507 spraying Methods 0.000 abstract 1
- 231100001261 hazardous Toxicity 0.000 description 4
- 238000000034 method Methods 0.000 description 4
- 239000007789 gas Substances 0.000 description 3
- 230000003647 oxidation Effects 0.000 description 3
- 238000007254 oxidation reaction Methods 0.000 description 3
- PNEYBMLMFCGWSK-UHFFFAOYSA-N Alumina Chemical class [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 2
- 230000003628 erosive effect Effects 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 230000001105 regulatory effect Effects 0.000 description 2
- 241001062472 Stokellia anisodon Species 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 239000000498 cooling water Substances 0.000 description 1
- 230000002950 deficient Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000007772 electrode material Substances 0.000 description 1
- 238000004880 explosion Methods 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000012768 molten material Substances 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 230000002028 premature Effects 0.000 description 1
Landscapes
- Vertical, Hearth, Or Arc Furnaces (AREA)
- Furnace Details (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
In an electric arc furnace corrosion and consumption of the graphite electrodes can be reduced by spraying water on the region above the molten bath. This can be more effectively done by the present application which provides a water ring mounted on the electrode holder and substantially surrounding the elec-trode having nozzles which direct the spray of water onto the electrode. The water ring has in inlet and an outlet so that there is a constant flow of water in excess of that required to emit a spray from the nozzles thereby providing cooler water and control pressure and avoiding vaporization of the water in the ring and enabling better control of the water spray.
In an electric arc furnace corrosion and consumption of the graphite electrodes can be reduced by spraying water on the region above the molten bath. This can be more effectively done by the present application which provides a water ring mounted on the electrode holder and substantially surrounding the elec-trode having nozzles which direct the spray of water onto the electrode. The water ring has in inlet and an outlet so that there is a constant flow of water in excess of that required to emit a spray from the nozzles thereby providing cooler water and control pressure and avoiding vaporization of the water in the ring and enabling better control of the water spray.
Description
'~Q2~22 This invention relates to improvements ln electrlc arc furnaces. ln partlcular, it relates to improved apparatus whereby graphite electrodes of an electric arc furnace may be protected against costly loss and wasteful consumption due to oxidation corrosion.
Typical electric arc furnaces use one or more graphite electrodes which are suspended, by means of an electrode holder, above a batch of ore or metal to be melted or smelted.
Heat is generated by energizing the electrodes so that an arc is created between the electrodes and the ore or metal in the batch contained in the furnace.
Of course, the constant electric discharge, the heat of the furnace and the atmosphere of the hot gases above the bath contribute to gradual erosion and consumption of the electrodes and constitute a substantial cost in the process of operating an electric arc furnace.
Although some of this consumption is necessary and inevitable, a large portion is due to oxidation of the sides of the electrode above the bath which is unrelated and unnecessary to the creation of the arc or the generation of heat. In fact, the erosion and severe pencilling of the lower portion often consumes in excess of 50% of the electrode material, especially in regions where the temperatures are above 400 Fahrenheit.
It has long been recognized that the heat of the atmosphere and the availability of oxygen or other corrosive gases will cause the sides of the electrode well above the point to become eaten away and consumed wastefully, thus contributing to costs.
20'~2622 Various attempts to overcome this problem have been tried with some success. One such technique involves the positioning of a jacket around the upper parts of the electrode extending down from the electrode holder. Another involves the use of inert gases to protect the electrode from corrosion.
A third involves the use of coated electrodes which shield the graphite from corrosion.
One of the most successful techniques has been to direct a stream of water on the upper reaches of the electrode stalk just below the electrode holder and allow it to run down to nearly the bottom of the electrode where it vaporizes.
This stream of water cools and shields the upper reaches of the electrode against contact with hot gases and the consequent corrosion.
One of the problems associated with the use of a cooling water to protect electrodes is the fact that water is considered difficult to manage and dangerous in some operations.
In particular, the melting of aluminum oxides are a problem because of the extremely high heats generated which accelerate the rate of oxidation corrosion. In addition, water has always been considered hazardous because any excessive amount of water which runs down the electrode into the bath is likely to create dangerous explosions in the crust at the top of the bath. Therefore, it has been found that although water is effective to prevent wasteful loss of graphite electrodes in the high temperature and corrosive atmosphere of an electric arc furnace used to smelt aluminum oxides, it is very important to control the flow of water so that it does not reach the bath and create hazardous conditions.
Typical electric arc furnaces use one or more graphite electrodes which are suspended, by means of an electrode holder, above a batch of ore or metal to be melted or smelted.
Heat is generated by energizing the electrodes so that an arc is created between the electrodes and the ore or metal in the batch contained in the furnace.
Of course, the constant electric discharge, the heat of the furnace and the atmosphere of the hot gases above the bath contribute to gradual erosion and consumption of the electrodes and constitute a substantial cost in the process of operating an electric arc furnace.
Although some of this consumption is necessary and inevitable, a large portion is due to oxidation of the sides of the electrode above the bath which is unrelated and unnecessary to the creation of the arc or the generation of heat. In fact, the erosion and severe pencilling of the lower portion often consumes in excess of 50% of the electrode material, especially in regions where the temperatures are above 400 Fahrenheit.
It has long been recognized that the heat of the atmosphere and the availability of oxygen or other corrosive gases will cause the sides of the electrode well above the point to become eaten away and consumed wastefully, thus contributing to costs.
20'~2622 Various attempts to overcome this problem have been tried with some success. One such technique involves the positioning of a jacket around the upper parts of the electrode extending down from the electrode holder. Another involves the use of inert gases to protect the electrode from corrosion.
A third involves the use of coated electrodes which shield the graphite from corrosion.
One of the most successful techniques has been to direct a stream of water on the upper reaches of the electrode stalk just below the electrode holder and allow it to run down to nearly the bottom of the electrode where it vaporizes.
This stream of water cools and shields the upper reaches of the electrode against contact with hot gases and the consequent corrosion.
One of the problems associated with the use of a cooling water to protect electrodes is the fact that water is considered difficult to manage and dangerous in some operations.
In particular, the melting of aluminum oxides are a problem because of the extremely high heats generated which accelerate the rate of oxidation corrosion. In addition, water has always been considered hazardous because any excessive amount of water which runs down the electrode into the bath is likely to create dangerous explosions in the crust at the top of the bath. Therefore, it has been found that although water is effective to prevent wasteful loss of graphite electrodes in the high temperature and corrosive atmosphere of an electric arc furnace used to smelt aluminum oxides, it is very important to control the flow of water so that it does not reach the bath and create hazardous conditions.
2~22~2~
It is therefore the object of this invention to provide means for directing a stream of water on an electrode in such a way that the flow of water is well regulated and controllable.
This objective is achieved by means of the present invention which provides a water ring surrounding the electrode in the region immediately beneath the electrode holder having nozzles at spaced intervals around the ring directed onto the adjacent surface of the electrode and having an inlet whereby water may be conducted to the water ring and an outlet whereby water flowing through the ring may be drawn off.
Ideally, the nozzles of the water ring proviae a shaped spray designed to cover a wide sector of the periphery of the electrode.
Preferably the source of water to the inlet may be controlled by pressure or adjustable valves to effect the flow in the water ring and the amount of water emitted by the nozzles.
The invention may be best understood by a description of one embodiment thereof with reference to the drawings in which:
Figure 1 is a perspective view of an electric arc furnace incorporating the present invention;
Figure 2 is a cross sectional view of an electric arc electrode having a water ring of the present invention;
Figure 3 is a detailed elevation view of the water ring in Figure 2;
Figure 4 is a plan view of the water ring shown in Figures 1, 2 and 3;
~i)22~22 Figure 5 is an elevation view of the nozzle in Figure 3;
Figure 6 ls a plan view of the nozzle in Figure 3;
Figure 7 is a schematic view of the water supply system associated with the water ring shown in Figure 1.
Figure 1 illustrates simplistically the typical arrangement of an electric arc furnace in which a shell 2 contains a bath of molten material 4 which is being heated by electrical energy arced to the bath from the electrode 6 which is held above the bath by the electrode holder 8 having a central aperture 10 through which the electrode 6 is placed and clamped. As the electrode becomes consumed at the lower end adjacent to the bath, the electrode holder is lowered to maintain the desired proximity to the bath.
However, periodically it is necessary to loosen the grip on the electrode and slip the electrode downward or advance it within the holder.
Also shown in Figure 1 is a water ring 12 which is suspended beneath the electrode holder 8 and substantially surrounds the circumference of the electrode 6.
Figure 2 is an enlarged cross sectional view of the electrode 6 and the electrode holder 8 showing in greater detail the water ring 12 which is supported by brackets 14 fastened to the underside of the holder at spaced intervals around the electrode. Also shown in Figure 2 are nozzles 16 which extend downward and inward at about 45 degrees from the horizontal and adapted to direct a spray 18 onto the wall of the electrode 6.
2~22~22 Figure 3 illustrates a sectional view of the water ring 12 and the nozzle 16 supported by the bracket 14 fastened to the underside of the electrode holder 8.
Figure 4 illustrates the water ring alone with the brackets 14 attached at four intervals around the periphery.
Note that the water ring 12 has an inlet line 20 and an outlet line 22 so that water may flow into the ring around the circular course of the ring and out the outlet 22.
Figure 5 is one cross sectional view of a typical nozzle 16 having a threaded male end 24 and an outlet 26, a V notch 28 designed to create a spray 18 which is narrow in the dimension parallel to the axis of the electrode.
Figure 6 is a cross sectional view at right angles to that in Figure 5 and illustrates the same nozzle showing the spray 18 with a wider angle in a direction perpendicular to the axis of the electrode 6 so that the water spray from a number of spaced nozzles will cover the entire circumference of the electrode.
Figure 7 illustrates schematically the electrode holder 8 having brackets 14 depending therefrom to support the ring 12 with four nozzles 16 directed toward the electrode~
In Figure 7 the water supply to the water ring 12 is shown schematically and comprises a reservoir tank 30 containing a supply of relatively cool makeup water to the inlet line 32 which is fed by a pump 34 monitored by pressure valve 36 and adjusted by a valve 38. The water supplied under pressure to the water ring 12 is then returned by the line 40 to the reservoir 30. The return line 40 may also be monitored by a gauge 37 and a control valve 39 which may be either manual or automatic depending on the degree of automation for which it is designed.
2022~2~ 1 By means of the illustrated apparatus, the electrode of an electric arc furnace may be protected from corrosion by a spray of water which is directed onto the electrode from the nozzles 16. Although four are shown, any number may be selected but preferably should be numerous enough to cover the entire circumference of the electrode with water.
As previously mentioned, it is important, especially in some processes, to adequately control the amount of water that is delivered to the electrode by spray so that adequate protection is provided without delivering excess water which may reach the bath and create hazardous conditions.
To this end, the pump 34 may deliver the water to the water ring at whatever pressure is desired (which can be monitored by the gauge 36 and controlled by the valve 38. The amount of pressure in the water ring 12 can then be controlled by the back pressure and restriction adjusted at the valve 39 so that the pressure in the ring 12 provides a spray which is adequate but not excessive.
Although the water ring could be supplied with an inlet line only and the spray regulated by means of the pressure of the supply line, this configuration creates difficulty, especially in high temperature operations because the excessive temperature causes vaporization of the water in the water line before it reaches the spray nozzles or the electrode.
This can result in a deficient water spray or even worse, may result in an attempt to supply an adequate water spray by increasing the pressure and the flow which may then result in excessive water resulting in the hazardous conditions mentioned above.
20'~2622 By means of the present inventlon and the arrangement illustrated in Figures 4 and 7, the flow of water through the water ring may be maintained which may be well in excess of the amount of water required or dispensed through the nozzles 16 and the surplus is taken out through the return line 40 and returned to the make up reservoir 30. In this way sufficient volume of cool water is maintained so that vaporization does not take place in the water ring, even under high temperature conditions. Thus premature vaporization of the water is eliminated and a measured and controllable flow of water from the nozzles can be maintained to ensure coverage of the electrode without excessive water reaching the molten bath.
Because of the large volume of flow through the ring, the water supplied to the nozzles and therefor to the electrodes, will be cooler than would otherwise be the case.
Although the foregoing description contains numerous details of the apparatus thought to be preferred in the embodiment illustrated, it will be realized that numerous modifications and variations might be employed without departing from the inventive concept herein.
It is therefore the object of this invention to provide means for directing a stream of water on an electrode in such a way that the flow of water is well regulated and controllable.
This objective is achieved by means of the present invention which provides a water ring surrounding the electrode in the region immediately beneath the electrode holder having nozzles at spaced intervals around the ring directed onto the adjacent surface of the electrode and having an inlet whereby water may be conducted to the water ring and an outlet whereby water flowing through the ring may be drawn off.
Ideally, the nozzles of the water ring proviae a shaped spray designed to cover a wide sector of the periphery of the electrode.
Preferably the source of water to the inlet may be controlled by pressure or adjustable valves to effect the flow in the water ring and the amount of water emitted by the nozzles.
The invention may be best understood by a description of one embodiment thereof with reference to the drawings in which:
Figure 1 is a perspective view of an electric arc furnace incorporating the present invention;
Figure 2 is a cross sectional view of an electric arc electrode having a water ring of the present invention;
Figure 3 is a detailed elevation view of the water ring in Figure 2;
Figure 4 is a plan view of the water ring shown in Figures 1, 2 and 3;
~i)22~22 Figure 5 is an elevation view of the nozzle in Figure 3;
Figure 6 ls a plan view of the nozzle in Figure 3;
Figure 7 is a schematic view of the water supply system associated with the water ring shown in Figure 1.
Figure 1 illustrates simplistically the typical arrangement of an electric arc furnace in which a shell 2 contains a bath of molten material 4 which is being heated by electrical energy arced to the bath from the electrode 6 which is held above the bath by the electrode holder 8 having a central aperture 10 through which the electrode 6 is placed and clamped. As the electrode becomes consumed at the lower end adjacent to the bath, the electrode holder is lowered to maintain the desired proximity to the bath.
However, periodically it is necessary to loosen the grip on the electrode and slip the electrode downward or advance it within the holder.
Also shown in Figure 1 is a water ring 12 which is suspended beneath the electrode holder 8 and substantially surrounds the circumference of the electrode 6.
Figure 2 is an enlarged cross sectional view of the electrode 6 and the electrode holder 8 showing in greater detail the water ring 12 which is supported by brackets 14 fastened to the underside of the holder at spaced intervals around the electrode. Also shown in Figure 2 are nozzles 16 which extend downward and inward at about 45 degrees from the horizontal and adapted to direct a spray 18 onto the wall of the electrode 6.
2~22~22 Figure 3 illustrates a sectional view of the water ring 12 and the nozzle 16 supported by the bracket 14 fastened to the underside of the electrode holder 8.
Figure 4 illustrates the water ring alone with the brackets 14 attached at four intervals around the periphery.
Note that the water ring 12 has an inlet line 20 and an outlet line 22 so that water may flow into the ring around the circular course of the ring and out the outlet 22.
Figure 5 is one cross sectional view of a typical nozzle 16 having a threaded male end 24 and an outlet 26, a V notch 28 designed to create a spray 18 which is narrow in the dimension parallel to the axis of the electrode.
Figure 6 is a cross sectional view at right angles to that in Figure 5 and illustrates the same nozzle showing the spray 18 with a wider angle in a direction perpendicular to the axis of the electrode 6 so that the water spray from a number of spaced nozzles will cover the entire circumference of the electrode.
Figure 7 illustrates schematically the electrode holder 8 having brackets 14 depending therefrom to support the ring 12 with four nozzles 16 directed toward the electrode~
In Figure 7 the water supply to the water ring 12 is shown schematically and comprises a reservoir tank 30 containing a supply of relatively cool makeup water to the inlet line 32 which is fed by a pump 34 monitored by pressure valve 36 and adjusted by a valve 38. The water supplied under pressure to the water ring 12 is then returned by the line 40 to the reservoir 30. The return line 40 may also be monitored by a gauge 37 and a control valve 39 which may be either manual or automatic depending on the degree of automation for which it is designed.
2022~2~ 1 By means of the illustrated apparatus, the electrode of an electric arc furnace may be protected from corrosion by a spray of water which is directed onto the electrode from the nozzles 16. Although four are shown, any number may be selected but preferably should be numerous enough to cover the entire circumference of the electrode with water.
As previously mentioned, it is important, especially in some processes, to adequately control the amount of water that is delivered to the electrode by spray so that adequate protection is provided without delivering excess water which may reach the bath and create hazardous conditions.
To this end, the pump 34 may deliver the water to the water ring at whatever pressure is desired (which can be monitored by the gauge 36 and controlled by the valve 38. The amount of pressure in the water ring 12 can then be controlled by the back pressure and restriction adjusted at the valve 39 so that the pressure in the ring 12 provides a spray which is adequate but not excessive.
Although the water ring could be supplied with an inlet line only and the spray regulated by means of the pressure of the supply line, this configuration creates difficulty, especially in high temperature operations because the excessive temperature causes vaporization of the water in the water line before it reaches the spray nozzles or the electrode.
This can result in a deficient water spray or even worse, may result in an attempt to supply an adequate water spray by increasing the pressure and the flow which may then result in excessive water resulting in the hazardous conditions mentioned above.
20'~2622 By means of the present inventlon and the arrangement illustrated in Figures 4 and 7, the flow of water through the water ring may be maintained which may be well in excess of the amount of water required or dispensed through the nozzles 16 and the surplus is taken out through the return line 40 and returned to the make up reservoir 30. In this way sufficient volume of cool water is maintained so that vaporization does not take place in the water ring, even under high temperature conditions. Thus premature vaporization of the water is eliminated and a measured and controllable flow of water from the nozzles can be maintained to ensure coverage of the electrode without excessive water reaching the molten bath.
Because of the large volume of flow through the ring, the water supplied to the nozzles and therefor to the electrodes, will be cooler than would otherwise be the case.
Although the foregoing description contains numerous details of the apparatus thought to be preferred in the embodiment illustrated, it will be realized that numerous modifications and variations might be employed without departing from the inventive concept herein.
Claims (4)
1. In an electric arc furnace having an electrode, suspended by an electrode holder, a water ring mounted to substantially surround said electrode, having nozzle means to spray water on said electrode, said water ring having an inlet end and an outlet end and means to supply water under pressure to said inlet end whereby a volume of water flows through said water ring which is in excess of the water which flows through said nozzle.
2. The invention as claimed in claim 1 in which said water ring is mounted by suspending it from and beneath said electrode holder.
3. The invention as claimed in claim 2 in which said water ring has nozzles with the spray having a wide lateral dimension and a small vertical dimension and said nozzles are spaced so as to spray water on the entire circumference of said electrode.
4. The invention as claimed in claims 1, 2 or 3 in which the means to supply water to said water ring comprises a reservoir of water, a pump means to supply water under pressure to the inlet of said water ring, a return line to convey water from the outlet end of said water ring to said reservoir, and means to monitor and control the flow of water through said water ring.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2022622 CA2022622A1 (en) | 1990-08-03 | 1990-08-03 | Electrode water ring |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2022622 CA2022622A1 (en) | 1990-08-03 | 1990-08-03 | Electrode water ring |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2022622A1 true CA2022622A1 (en) | 1992-02-04 |
Family
ID=4145640
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2022622 Abandoned CA2022622A1 (en) | 1990-08-03 | 1990-08-03 | Electrode water ring |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2022622A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103922562A (en) * | 2014-04-11 | 2014-07-16 | 抚顺科盛霞石微晶材料设备制造有限公司 | Electrode cooler for bottom-plug electrode melting furnace |
-
1990
- 1990-08-03 CA CA 2022622 patent/CA2022622A1/en not_active Abandoned
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103922562A (en) * | 2014-04-11 | 2014-07-16 | 抚顺科盛霞石微晶材料设备制造有限公司 | Electrode cooler for bottom-plug electrode melting furnace |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Dead |