CN209537548U - A kind of RH purifier promoting the decarburization of molten steel depth - Google Patents
A kind of RH purifier promoting the decarburization of molten steel depth Download PDFInfo
- Publication number
- CN209537548U CN209537548U CN201822253729.6U CN201822253729U CN209537548U CN 209537548 U CN209537548 U CN 209537548U CN 201822253729 U CN201822253729 U CN 201822253729U CN 209537548 U CN209537548 U CN 209537548U
- Authority
- CN
- China
- Prior art keywords
- dip pipe
- molten steel
- wall
- vacuum chamber
- weir wall
- 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.)
- Active
Links
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 65
- 239000010959 steel Substances 0.000 title claims abstract description 65
- 238000005261 decarburization Methods 0.000 title claims abstract description 25
- 230000001737 promoting effect Effects 0.000 title claims abstract description 8
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims abstract description 28
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 25
- 239000001301 oxygen Substances 0.000 claims abstract description 25
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 25
- 230000007423 decrease Effects 0.000 claims abstract description 15
- 229910052786 argon Inorganic materials 0.000 claims abstract description 14
- 238000007664 blowing Methods 0.000 claims abstract description 10
- 230000000630 rising effect Effects 0.000 claims abstract description 8
- 239000007789 gas Substances 0.000 claims abstract description 7
- 230000037431 insertion Effects 0.000 claims abstract 2
- 238000003780 insertion Methods 0.000 claims abstract 2
- 239000011449 brick Substances 0.000 claims description 3
- NACUKFIFISCLOQ-UHFFFAOYSA-N [Mg].[Cr] Chemical compound [Mg].[Cr] NACUKFIFISCLOQ-UHFFFAOYSA-N 0.000 claims description 2
- 238000007670 refining Methods 0.000 abstract description 22
- 238000006243 chemical reaction Methods 0.000 description 24
- 229910052799 carbon Inorganic materials 0.000 description 20
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 19
- 238000005516 engineering process Methods 0.000 description 13
- 238000000034 method Methods 0.000 description 11
- 239000010410 layer Substances 0.000 description 10
- 238000005262 decarbonization Methods 0.000 description 8
- 239000007788 liquid Substances 0.000 description 6
- 229910001209 Low-carbon steel Inorganic materials 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 238000004519 manufacturing process Methods 0.000 description 4
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 3
- 229910052782 aluminium Inorganic materials 0.000 description 3
- 238000011161 development Methods 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 238000012545 processing Methods 0.000 description 3
- 238000003723 Smelting Methods 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000004615 ingredient Substances 0.000 description 2
- CSJDCSCTVDEHRN-UHFFFAOYSA-N methane;molecular oxygen Chemical compound C.O=O CSJDCSCTVDEHRN-UHFFFAOYSA-N 0.000 description 2
- 230000003068 static effect Effects 0.000 description 2
- 238000012546 transfer Methods 0.000 description 2
- 230000009466 transformation Effects 0.000 description 2
- 238000010792 warming Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 229910000975 Carbon steel Inorganic materials 0.000 description 1
- 229910000976 Electrical steel Inorganic materials 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 239000004411 aluminium Substances 0.000 description 1
- 229910001563 bainite Inorganic materials 0.000 description 1
- 238000003763 carbonization Methods 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000005097 cold rolling Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000006477 desulfuration reaction Methods 0.000 description 1
- 230000023556 desulfurization Effects 0.000 description 1
- 238000007598 dipping method Methods 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 229910001608 iron mineral Inorganic materials 0.000 description 1
- 238000002386 leaching Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000036284 oxygen consumption Effects 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000012827 research and development Methods 0.000 description 1
- 230000033764 rhythmic process Effects 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 238000009628 steelmaking Methods 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- 229910000859 α-Fe Inorganic materials 0.000 description 1
Landscapes
- Treatment Of Steel In Its Molten State (AREA)
Abstract
A kind of RH purifier promoting the decarburization of molten steel depth, molten steel furnace external refining technical field.Device includes: vacuum chamber, rises dip pipe, decline dip pipe, ladle, Yan Qiang, argon blowing tube, top blow oxygen lance.Top blow oxygen lance is assembled at the top of vacuum chamber, bottom is connected with rising dip pipe and decline dip pipe respectively, rises dip pipe exit in vacuum chamber bottom and installs weir wall.Rise and argon blowing tube is housed on dip pipe, is communicated with gas.Rise in dip pipe and decline dip pipe insertion molten steel ladle, molten steel is recycled between vacuum chamber and ladle by rising dip pipe and decline dip pipe.The advantage is that being conducive to implement, weir wall is maintained easily, can be promoted the use of in factory, has good Practical significance.
Description
Technical field
The utility model relates to molten steel furnace external refining technical field, in particular to a kind of RH refining for promoting the decarburization of molten steel depth
Device.
Background technique
RH refining techniques is developed jointly successfully by German Rheinstahl and Hutlenwerke company, because by vacuum fine
Refining technology is effectively combined with Circulating Flow of Molten Steel technology, and RH is provided simultaneously with that the refining treatment period is short, decarburization effect is good, steel
The series of advantages such as water degree of purity height, therefore be used widely in smelting the BOF steelmaking shop that rhythm is fast, production capacity is big,
As important external refining facility.With the development of technology, RH can be used for deaerating, decarburization, desulfurization, removal are mingled with, uniformly
A variety of refining purposes such as temperature and ingredient.Domestic steel mills numerous at present have been equipped with RH refining equipment.
Internationalization market is increasing substantially to mild steel demand, with functions such as excellent in toughness, processability, deep drawabilities
The ultra-low-carbon steels such as ultra-low-carbon bainite steel, non-directional cold-rolling silicon steel, super-purity ferrite stainless steel series is successively developed, simultaneously
Requirement of the steel grade to carbon content is also higher and higher.RH is the important refining equipment of molten steel decarburization, domestic more to improve production efficiency
Steel mill, family successively develops on the basis of traditional RH refinery practice increases a series of advanced works such as circular flow, rapid vacuumizing
Skill technology, and attempt that the structure of RH is improved and optimized.In recent years, RH development has entered exploitation close to threshold of reaction technology
The SECONDARY REFINING IN A VACUUM CHAMBER stage.Influence of the vacuum degree to reaction reduces after carbon content is less than 0.002%, the shadow of molten steel static pressure
It rings and increases.When carbon content is very low, and carbon and oxygen balance partial pressure can not overcome static pressure, bubble will be difficult to be formed, reaction between carbon and oxygen
It is suppressed, as a result molten steel decarbonization rate is greatly reduced, and the efficiency for producing ultra-low-carbon steel is lower.Due to reacting only in molten steel
Reaction layer occurs, and decarbonization rate reduces rapidly, and decarburizing reaction is close to stagnating, and researcher is by introducing the general of decarburizing reaction layer
It reads to conduct further research and technological development.Reaction layer thickness is related from the different stages of reaction and carbon oxygen level, in life
The reaction layer thickness for producing decarburization in the usual processing route of ultra-low-carbon steel is gradually reduced, and is much larger than 200mm from decarburization thickness early period,
100~200mm then is reduced to, finally molten steel reacts undulated layer in 0~50mm after [C]≤0.002%.
Many producers take the extension processing time to increase reaction carry out degree to reach the qualified ingredient of Ultra-low carbon, or
Increase oxygen content come the problem of increasing the method for reaction layer depth, but inefficiency and molten steel too high oxygen level can be brought in this way.
There is researcher to improve decarbonization rate using hydrogen is blown into RH furnace dip pipe, or increases decarburization in molten steel surface blowing-iron mineral powder
The methods of reaction interface obtains certain decarburization effect, but these methods is used to require to carry out biggish transformation to equipment,
It is not easy to realize and safeguard[1][2].Only being continually striving to development innovation technological transformation and technology upgrading just can more effectively improve refining
Technical level.The purpose of this utility model is to find to be easily achieved and effective deep decarbonization method.The utility model is from anti-
It answers a layer angle to set out, improves refining ultra-low-carbon steel by improving the flowing velocity of molten steel and the update efficiency of molten steel in conversion zone
Efficiency.
Summary of the invention
The purpose of this utility model is to provide a kind of RH purifiers for promoting the decarburization of molten steel depth, from raising reaction efficiency
Angle set out, change steel liquid flow state by improving refining equipment, find that a kind of production efficiency is higher, and quality of molten steel is purer
Net molten steel depth decarbonization device and process.
The utility model proposes new RH equipment improved method-improvement RH device bottom construction, forcibly changing enters vacuum
The molten steel height of room makes the molten steel for being in conversion zone lower part enter conversion zone surface layer, improves reaction effect of the molten steel in conversion zone
Rate and carbon and oxygen balance are horizontal.It is deep to be suitable for RH refining using the technical measures for changing molten steel flow characteristic for the utility model technology
Carbonization treatment shortens RH depth decarburization time, and then shortens refining cycle, realizes the process goal quickly refined.Be conducive to simultaneously
It reduces and uses oxygen consumption, improve the degree of purity of molten steel, this is the meaning of the utility model technology.
The vacuum refining of liquid steel depth decarbonization device of the utility model includes: vacuum chamber 1, rises dip pipe 21, decline dipping
Pipe 22, ladle 3, weir wall 4, argon blowing tube 5, top blow oxygen lance 6.Top blow oxygen lance 6 is assembled at the top of vacuum chamber 1, bottom is soaked with rising respectively
Stain pipe 21 is connected with decline dip pipe 22, rises 21 exit of dip pipe in 1 bottom of vacuum chamber and installs weir wall 4.Rise dip pipe
Argon blowing tube 5 is housed on 21, is communicated with gas.Rise dip pipe 21 and decline dip pipe 22 is inserted into ladle 3 in molten steel, molten steel is logical
It crosses rising dip pipe 21 and decline dip pipe 22 recycles between vacuum chamber and ladle.
The utility model proposes improving to RH furnace vacuum chamber, increase circle (arc) shape weir wall together in vacuum chamber bottom.
The position of weir wall is located at the outlet port that vacuum chamber bottom rises dip pipe, and overlooking weir wall (see Fig. 3 and Fig. 4) is part circle (arc)
Shape.The inner wall of weir wall 4 is concordant with the inner wall of dip pipe is risen, i.e., rectilinear weir wall；Or it can be made into slope weir wall, weir wall bottom
Portion's inner wall radius is equal with the inner wall radius of dip pipe is risen, and weir wall top inner wall radius is greater than bottom, increasing simultaneously molten steel
Into being that gradually deflecting is bottom horizontal flow sheet by rising flowing during vacuum chamber.4 200~400mm of thickness of weir wall, height 100
~200mm.Weir wall 4 uses magnesium chromium matter or other material fire resisting brick masonries.
The utility model includes the following steps: for the method for vacuum refining of liquid steel depth decarburization
(1) inserted after ladle enters the station by jacking ladle or decline vacuum chamber adjustment deep, it is desirable that guarantee to insert it is deep be greater than conventional value,
It can be controlled in 600~800mm；
(2) forvacuum is wanted before handling, starts vacuum pump evacuation after starting refining, promotes molten steel liquid in vacuum chamber
Position h to 500mm~600mm；Promotion argon gas is blown by rising dip pipe simultaneously, the molten steel normal circulation stream under lift gas effect
It is dynamic.
(3) start oxygen blast when being evacuated down to 8~15KPa and force decarburization, while being warming up to target temperature, forced until reaching
Stop oxygen blast after the target carbon content of decarburization；
(4) after stopping oxygen, the indoor vacuum degree of vacuum is stepped up, the pressure in vacuum chamber is finally dropped into 67Pa, simultaneously
Argon intensity incrementally increases design maximum, and (range under different technology conditions is in 0.012~0.015Nm3/ (t.min)),
Good reaction between carbon and oxygen mass transfer condition is provided；
(5) carbon content drops to 20 × 10 in molten steel-6~30 × 10-6When, it adjusts and inserts deeply, make under vacuum chamber molten steel height h
It is down to 300~400mm, Argon intensity keeps maximum, starts to carry out molten steel deep decarburization.
(6) carbon content reaches target (< 10 × 10-6) after, aluminum deoxidation is outbound after 3~10min of weak circulation.
Utility model has the advantages that
The utility model improves vacuum chamber, improves molten steel and enters the flow behavior after vacuum chamber, sees attached drawing 5 and attached
Fig. 6.In common RH, lower layer's molten steel is difficult to participate in reaction in vacuum chamber when carbon content is very low, invalid circulation is carried out, after improvement
Whole molten steel directly from upper layer, flow through by (being less than 200mm or 300mm apart from molten steel surface, depending on the height on weir), then water
Advection stock flows into after converging as main flow and other stream stocks declines dip pipe, and part molten steel can turn back along weir wall again into
Enter molten steel upper layer to converge with main level stream stock.While guaranteeing that circular flow is not suffered a loss in this way, substantially increase reaction between carbon and oxygen machine
Rate.
After the utility model technology, reaction between carbon and oxygen efficiency is improved, and molten steel oxygen consuming amount and aluminium consumption reduce, the folder of generation
Sundries is reduced, therefore production cost can reduce, and molten steel is purer.
The utility model technology is to improve on the basis of existing RH conventional structure to vacuum trench bottom, and technology is conducive to
Implement, weir wall maintains easily, therefore technology can be promoted the use of in factory, has good Practical significance.
Detailed description of the invention
Fig. 1 is the rectilinear weir wall of schematic view of facade structure-of the utility model.
Fig. 2 is the schematic view of facade structure-slope weir wall of the utility model.
Fig. 3 is rectilinear weir wall schematic top plan view.
Fig. 4 is slope weir wall schematic top plan view.
Fig. 5 is common RH vacuum chamber molten steel flow schematic diagram.
Fig. 6 is to add weir wall vacuum chamber molten steel flow schematic diagram.
In figure, vacuum chamber 1 rises dip pipe 21, decline dip pipe 22, ladle 3, weir wall 4, argon blowing tube 5, top blow oxygen lance 6.
Specific embodiment
It is described further referring to device of the attached drawing to the utility model.
As depicted in figs. 1 and 2, the vacuum refining of liquid steel depth decarbonization device of the utility model includes: vacuum chamber 1, rises leaching
Stain pipe 21, decline dip pipe 22, ladle 3, weir wall 4, argon blowing tube 5, top blow oxygen lance 6.
Former common RH impregnates bore 550m, vacuum chamber internal diameter 1860mm.Vacuum chamber bottom rise dip pipe just on
Fang Zengjia circular weir wall, the inner wall of weir wall is concordant with the inner wall of dip pipe is risen, and flows directly into molten steel in uphill process very
The top of empty room.Weir wall is built using electric smelting recombined magnesia-chrome brick, weir wall thickness 300mm, height 200mm.
Described device be produce ultra-low-carbon steel use vacuum refining depth decarburization method as follows:
(1) slotting deep by jacking ladle or decline vacuum chamber adjustment after ladle enters the station, it is increased to by common 500mm
700mm；
(2) forvacuum before handling starts evacuation after starting refining, promotes molten steel liquid level h in vacuum chamber and arrives
600mm；Promotion argon gas is blown by rising dip pipe simultaneously, molten steel normal circulation flows under lift gas effect.
(3) start oxygen blast when being evacuated down to 15KPa and force decarburization, while being warming up to target temperature, reach and force decarburization
Stop oxygen blast after target carbon content 0.02%；
(4) the indoor vacuum degree of vacuum is stepped up, the indoor pressure of vacuum is dropped into 67Pa, while Argon intensity is gradually
Increase to design maximum 0.012Nm3/ (t.min) provides good reaction between carbon and oxygen mass transfer condition；
(5) when in molten steel carbon content drop to 30 × 10-6When, it adjusts and inserts deeply, drop to vacuum chamber molten steel height h
400mm, Argon intensity keep maximum, start to carry out molten steel deep decarburization.
(6) carbon content reaches target 10 × 10-6Afterwards, aluminum deoxidation, it is outbound after weak circulation 5min.
By using the utility model, this example still ensure that identical under the conditions of prometaphase same technological parameter
Horizontal circular flow and processing capacity, and the deep decarburizing phase decarburization efficiency of middle and later periods is increased to original 2 times or more.Work as carbon
After content is less than 0.01%, DECARBONIZATION REACTION RATE constant Kc can increase 25~50%.It can reduce simultaneously and force oxygen supply stage oxygen
Over-blowing amount, molten steel oxygen consuming amount reduce, and substantially increase the carbon oxygen controlled level and molten steel cleanness of molten steel.
Above example is one kind of the preferred embodiments of the present invention, is merely to illustrate the technical solution of the utility model
Rather than it limits.It will be understood by those skilled in the art that the usual variations in detail, the shape that are carried out within the scope of technical solutions of the utility model
Formula variations and alternatives should all contain within the protection scope of the present utility model.
Claims (3)
1. a kind of RH purifier for promoting the decarburization of molten steel depth characterized by comprising vacuum chamber (1) rises dip pipe
(21), decline dip pipe (22), ladle (3), weir wall (4), argon blowing tube (5), top blow oxygen lance (6)；Assembly top at the top of vacuum chamber (1)
Oxygen-blowing gun (6), bottom are connected with rising dip pipe (21) and decline dip pipe (22) respectively, rise in vacuum chamber (1) bottom and soak
Stain pipe (21) exit is installed by weir wall (4)；Rise and argon blowing tube (5) are housed on dip pipe (21), is communicated with gas；Rise dip pipe
(21) and in decline dip pipe (22) insertion ladle (3) interior molten steel.
2. the RH purifier according to claim 1 for promoting the decarburization of molten steel depth, which is characterized in that increase in vacuum chamber bottom
Add one of circle or curved weir wall；The position of weir wall is located at the outlet port that vacuum chamber bottom rises dip pipe, and vertical view weir wall is portion
Cyclotomy or arc；The inner wall of weir wall (4) is concordant with the inner wall of dip pipe is risen, i.e., rectilinear weir wall or sloping formula weir wall,
Weir wall bottom interior wall radius is equal with the inner wall radius of dip pipe is risen, and weir wall top inner wall radius is greater than bottom.
3. the RH purifier according to claim 1 or 2 for promoting the decarburization of molten steel depth, which is characterized in that weir wall (4) thickness
200~400mm, 100~200mm of height；Weir wall (4) uses magnesium chromium matter fire resisting brick masonry.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201822253729.6U CN209537548U (en) | 2018-12-29 | 2018-12-29 | A kind of RH purifier promoting the decarburization of molten steel depth |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201822253729.6U CN209537548U (en) | 2018-12-29 | 2018-12-29 | A kind of RH purifier promoting the decarburization of molten steel depth |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN209537548U true CN209537548U (en) | 2019-10-25 |
Family
ID=68267773
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201822253729.6U Active CN209537548U (en) | 2018-12-29 | 2018-12-29 | A kind of RH purifier promoting the decarburization of molten steel depth |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN209537548U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109576447A (en) * | 2018-12-29 | 2019-04-05 | 钢铁研究总院 | A kind of RH purifier and method promoting the decarburization of molten steel depth |
-
2018
- 2018-12-29 CN CN201822253729.6U patent/CN209537548U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109576447A (en) * | 2018-12-29 | 2019-04-05 | 钢铁研究总院 | A kind of RH purifier and method promoting the decarburization of molten steel depth |
| CN109576447B (en) * | 2018-12-29 | 2024-06-04 | 钢铁研究总院 | RH refining device and method for promoting deep decarburization of molten steel |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108148948B (en) | A high-efficiency single nozzle refining furnace and special steel smelting process | |
| CN108866277B (en) | A single-nozzle refining furnace and refining process for smelting ultra-low carbon stainless steel | |
| CN102127618B (en) | Device and method for refining, oxygenating and deeply decarbonizing molten steel in vacuum | |
| CN101792845A (en) | Method for smelting ultra-low-carbon steel by using single-nozzle refining furnace | |
| CN102559983A (en) | Method for preventing nitrogen increase of molten steel in converter tapping process | |
| CN109576447A (en) | A kind of RH purifier and method promoting the decarburization of molten steel depth | |
| CN209537548U (en) | A kind of RH purifier promoting the decarburization of molten steel depth | |
| CN109234489A (en) | The control method of catch carbon stage nitrogen increased amount is reduced when a kind of converter smelting mild steel | |
| US9809868B2 (en) | Straight barrel type vacuum refining device and method for use the same | |
| CN207958424U (en) | A kind of efficient single-mouth refining furnace | |
| CN101805817B (en) | Method for smelting ultra-low hydrogen steel by using single-nozzle refining furnace | |
| CN108148945B (en) | A kind of blowing process that RH refining furnace second-time burning efficiency can be improved | |
| CN112111625B (en) | RH vacuum powder injection refining device and powder injection method thereof | |
| CN102031328A (en) | Converter charging method | |
| CN103305655B (en) | Method for manufacturing ultra low carbon steel by melting techniques using vacuum-degassing system | |
| CN207498409U (en) | A kind of RH refining furnaces dip pipe | |
| CN105734198B (en) | A kind of preparation method of the phosphorous weathering steel of electricity converter smelting | |
| CN201883107U (en) | Refining furnace with single snorkel | |
| CN205933887U (en) | Keep still device of originality of RH ladle top sediment | |
| CN103233097B (en) | Argon oxygen decarburization (AOD) furnace capable of shortening stainless steel refining time and method of furnace | |
| CN207738801U (en) | A kind of dual channel design RH refining furnace top blast nozzles | |
| CN107043844B (en) | An intermediate frequency induction melting furnace system and method | |
| CN206352150U (en) | A kind of RH purifiers | |
| CN106119465B (en) | A kind of device and method of holding RH ladle top slag reproducibilities | |
| CN217103964U (en) | Slag blocking cone for reducing slag discharge of converter |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |