CN103045807A - Vacuum circulation degassing insert tube - Google Patents

Vacuum circulation degassing insert tube Download PDF

Info

Publication number
CN103045807A
CN103045807A CN2011103075383A CN201110307538A CN103045807A CN 103045807 A CN103045807 A CN 103045807A CN 2011103075383 A CN2011103075383 A CN 2011103075383A CN 201110307538 A CN201110307538 A CN 201110307538A CN 103045807 A CN103045807 A CN 103045807A
Authority
CN
China
Prior art keywords
brick
vacuum circulation
tubular stinger
circulation degassing
annular recesses
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.)
Granted
Application number
CN2011103075383A
Other languages
Chinese (zh)
Other versions
CN103045807B (en
Inventor
李龙
陈炼
戈文荪
曾建华
陈永
杨森祥
杜利华
王文刚
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Pangang Group Panzhihua Iron and Steel Research Institute Co Ltd
Original Assignee
Pangang Group Panzhihua Iron and Steel Research Institute Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Pangang Group Panzhihua Iron and Steel Research Institute Co Ltd filed Critical Pangang Group Panzhihua Iron and Steel Research Institute Co Ltd
Priority to CN201110307538.3A priority Critical patent/CN103045807B/en
Publication of CN103045807A publication Critical patent/CN103045807A/en
Application granted granted Critical
Publication of CN103045807B publication Critical patent/CN103045807B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Landscapes

  • Treatment Of Steel In Its Molten State (AREA)

Abstract

The invention discloses a vacuum circulation degassing insert tube used for external refining RH devices; an annular groove is disposed on the outer wall of the insert tube; Al2O3-C bricks (4) are disposed in the annular groove. With the characteristic that the Al2O3-C refractory material is not easy to be moisturized by slag, the erosion of the vacuum circulation degassing insert tube caused by slag is reduced, and the purpose of bonded slag reduction is realized; therefore, the service life of the vacuum circulation degassing insert tube is prolonged.

Description

The vacuum circulation degassing tubular stinger
Technical field
The present invention relates to a kind of vacuum circulation degassing tubular stinger, relate in particular a kind of vacuum circulation degassing tubular stinger for external refining RH device.
Background technology
Nitrogen in steel, protium have a negative impact to its performance, and nitrogen makes steel generation blue shortness and timeliness embrittlement, and hydrogen makes steel generation hydrogen embrittlement and corrosion.Therefore, in smelting process, must carry out degassed processing to molten steel.Existing vacuum processing method has: the RH method, namely nineteen fifty-seven Thyssen Iron And Steel Company invention vacuum circulation degassing method; The RH-OB method is the new technology that nippon obtained at RH method basis increase heating function in 1978; The RH-KTB method also is Kawasaki top blowing oxygen vacuum outgas method, is invented in 1988 by Kawasaki, Japan company; The RH-PB method, the circulating degasification powder injection process.Along with the raising of RH apparatus function and the continuous expansion of refining steel grade scope, the RH device has occupied dominant position in external refining.Facts have proved, the RH SECONDARY REFINING IN A VACUUM CHAMBER is to improve the quality of products, reduce production costs, enlarge the important means of kind.Domestic and international most steel mill has all configured the RH a refining unit, and still, the RH a refining unit is in use very harsh to the working conditions of RH tubular stinger.In the RH treating processes, structure reason owing to tubular stinger, make easily glutinous slag of tubular stinger, when especially producing the ultra low-carbon steels such as IF, dry slag is more serious, the erosion of slag is so that the refractory materials of RH tubular stinger is easily damaged, and the work-ing life of RH tubular stinger is short causes the vacuum chamber maintenance of rolling off the production line in advance, therefore so that the RH tubular stinger becomes the weak link of RH refining unit and the production efficiency that has directly determined the RH refining unit work-ing life of RH tubular stinger.
At present, the method for minimizing dry slag mainly contains: coating is processed, and specifically adopts coating that slag is not directly contacted with mould material, to reach the purpose that reduces dry slag, still in treating processes, because slag has limited the ability of coating inhibition dry slag to the erosion of coating; Residue adjustment is processed, and is to process the later stage at RH to carry out the slag modification, reduces the viscosity of slag, thereby makes slag be difficult for sticking on the tubular stinger, but the erosion of mould material and ladle liner is aggravated; Air blowing treatment is to be blown into argon gas by the porous refractory that is contained in the mould material, forms air curtain at slag lining, and slag is not contacted with refractory materials, thereby realizes few dry slag, but the deficiency that exists ventilated element easily to stop up and damage.Clinker removal method to dry slag on the tubular stinger mainly is to adopt mechanical doctor, but owing to having cold steel in the dry slag, mechanical removal is easy to make mould material to damage, and has greatly shortened the work-ing life of tubular stinger.Therefore, effectively reduce the tubular stinger dry slag, help to prolong the work-ing life of tubular stinger, thereby improve the production efficiency of RH device, play the effect of cost efficiency.
Summary of the invention
The objective of the invention is to overcome short shortcoming of the easy dry slag of existing vacuum circulation degassing tubular stinger, work-ing life, provide a kind of that be difficult for dry slag and have long-life vacuum circulation degassing tubular stinger.
Have annular recesses on the outer wall according to vacuum circulation degassing tubular stinger of the present invention, in this annular recesses, be provided with Al 2O 3-C brick.
Preferably, described Al 2O 3The composition of-C brick comprises Al 2O 3And C, and Al 2O 3With the weight percent of C be: 3.7-5: 1.
Preferably, described tubular stinger comprises the steel construction structure of cast, has Al on the outside surface of this steel construction 2O 3Pouring layer, described annular recesses is formed at described Al 2O 3On the outer wall of pouring layer.
Preferably, has the riveting part on the outside surface of described steel construction, described Al 2O 3Have the through hole corresponding with described riveting part on the-C brick, described riveting part is inserted in the described through hole.
Preferably, be embedded into described Al in the described annular recesses 2O 3Al is adopted in the outer end of the through hole of-C brick 2O 3The mixture shutoff of-C and pitch.
Preferably, be embedded into described Al in the described annular recesses 2O 3Described Al is adopted in slit between the-C brick 2O 3The mixture of-C and pitch is filled.
Preferably, the material of described riveting part adopts 20G, and a plurality of described riveting parts are distributed on the excircle of described steel construction.
Preferably, dark 100～120 millimeters of described annular recesses, and described annular recesses is 300～400 millimeters along the length of the length direction of this vacuum circulation degassing tubular stinger.
Preferably, the internal surface of described steel construction is coated with Mg-Cr brick layer, and the lower end of this Mg-Cr brick layer extends to the lower end mouth of pipe of described tubular stinger, the Cr of Mg-Cr brick in this Mg-Cr brick layer 2O 3Content be 24～28% (heavy part).
Preferably, described Al 2O 3The composition of pouring layer contains Al 2O 3, and optionally contain SiO 2, FeO and Na 2O, wherein, with respect to the Al of 100 weight parts 2O 3, SiO 2Content be that the content of 0～0.5, FeO is 0～0.5, Na 2The content of O is 0～0.55.
As mentioned above, according to the Al of vacuum circulation degassing tubular stinger of the present invention 2O 3Pouring layer has annular recesses, embeds Al in this annular recesses 2O 3-C brick is because Al 2O 3-C refractory materials is difficult for wetting by slag, thereby can reduce the dry slag of this vacuum circulation degassing tubular stinger, and is embedded into the Al in the annular recesses 2O 3Al is adopted in the outer end of the through hole of-C brick 2O 3The mixture shutoff of-C and pitch is embedded into the Al in the annular recesses 2O 3Al is also adopted in slit between the-C brick 2O 3The mixture of-C and pitch is filled, and is difficult for by the wetting characteristics of slag therefore can take full advantage of carbonaceous material, reduces slag by the erosion to this vacuum circulation degassing tubular stinger of described through hole and described slit.Therefore, adopt technical scheme of the present invention, can reduce the dry slag of vacuum outgas tubular stinger, and then prolong its work-ing life, improve the production efficiency of RH device external refining.
Other features and advantages of the present invention will partly be described in detail in embodiment subsequently.
Description of drawings
Accompanying drawing is to be used to provide a further understanding of the present invention, and consists of the part of specification sheets, is used from explanation the present invention with following embodiment one, but is not construed as limiting the invention.
Fig. 1 is the longitudinal sectional drawing according to vacuum circulation degassing tubular stinger of the present invention.
Description of reference numerals
1 flange, 2 steel construction
3Al 2O 3Pouring layer 4Al 2O 3-C brick
5Mg-Cr brick layer 6 riveting part
7 anchor flukes
Embodiment
Below in conjunction with accompanying drawing the specific embodiment of the present invention is elaborated.Should be understood that, embodiment described herein only is used for description and interpretation the present invention, is not limited to the present invention.
In the present invention, for the convenience of describing, used some nouns of locality, such as " upper end ", " lower end ", " top ", " bottom " etc. usually all for direction shown in the drawings, or for each parts mutual alignment relationship description word of vertical or gravity direction.
Fig. 1 is the longitudinal sectional drawing according to vacuum circulation degassing tubular stinger of the present invention.
As shown in Figure 1, the vacuum circulation degassing tubular stinger according to present embodiment comprises flange 1, steel construction 2, Al 2O 3Pouring layer 3, Al 2O 3-C brick 4, Mg-Cr brick layer 5, riveting part 6 and anchor fluke 7.
Described flange 1 is connected in the upper end of steel construction 2, is used for the vacuum circulation degassing tubular stinger being connected with the vacuum chamber of the RH device that is located thereon section and fixing.
Described steel construction 2 is cast, and material adopts 20G, in the present embodiment, and for guaranteeing steel construction 2 and inner Mg-Cr brick layer 5, outside Al 2O 3The coefficient of expansion between the pouring layer 3 is complementary to prevent Mg-Cr brick layer 5 and Al 2O 3Pouring layer 3 cracks, and the thickness of steel construction 2 is 24～27 millimeters.
Described Mg-Cr brick layer 5 covers on the internal surface of steel construction 2, adopts Cr 2O 3Content is the Mg-Cr brick of 24～28% (heavy parts), can resist washing away of the molten steel that flows through in the passage that Mg-Cr brick layer 5 forms, and, in the present embodiment, Mg-Cr brick layer 5 extends to the mouth of pipe of vacuum circulation degassing tubular stinger, in order to prevent the Al that thermal shock causes 2O 3Al in the pouring layer 3 2O 3Peeling off of mould material.
Described Al 2O 3Pouring layer 3 covers on the outside surface of steel construction 2, extends to the lower end mouth of pipe of vacuum circulation degassing tubular stinger, Al 2O 3The Al that pouring layer 3 adopts 2O 3The composition of mould material contains Al 2O 3, and optionally contain SiO 2, FeO and Na 2O, wherein, with respect to the Al of 100 weight parts 2O 3, SiO 2Content be that the content of 0～0.5, FeO is 0～0.5, Na 2The content of O is 0～0.55.Wherein, present embodiment improves Al 2O 3Al in the mould material 2O 3The content of composition helps to improve Al 2O 3The thermostability of mould material.In addition, according to the Al of vacuum circulation degassing tubular stinger of the present invention 2O 3Pouring layer 3 has annular recesses, and when this vacuum circulation degassing tubular stinger being installed on the RH device when processing molten steel, described annular recesses is in this vacuum circulation degassing pipe and the ladle and covers the position that the slag on the molten steel face contacts.Particularly, in the present embodiment, dark 100～200 millimeters of annular recesses, be 300～400 millimeters along the length of the length direction of vacuum circulation degassing tubular stinger, and in annular recesses, build Al is arranged 2O 3-C brick 4.
At above-mentioned Al 2O 3In the pouring layer 3, Al 2O 3Mould material is cast in anchor fluke 7, and this anchor fluke 7 is welded on the steel construction 2 in each mode on oppositely that is distributed in steel construction 2, and anchor fluke 7 can be eliminated stress that all directions produce to prevent Al 2O 3Pouring layer 3 cracks or peels off, and the material of the anchor fluke in the present embodiment adopts the thickness matching of 20G and length and pouring layer.
In the present embodiment, Al 2O 3-C brick 4 is by 6 connections of riveting part and be fixed in Al 2O 3In the annular recesses of pouring layer 3, particularly, Al 2O 3The composition of-C brick comprises Al 2O 3And C, and Al 2O 3With the weight percent of C be: 3.7-5: 1, in addition, this Al 2O 3-C brick 4 also contains a small amount of additive and resin.In addition, at Al 2O 3Have the through hole that matches well mutually with riveting part 6 on the-C brick 4, make Al thereby riveting part 6 passes this through hole 2O 3-C brick 4 is fixed in the annular recesses.
Particularly, a plurality of riveting parts 6 in the present embodiment are welded on the slag lining of steel construction 2 and evenly arrange around the outside surface of steel construction 2, riveting part 6 materials are 20G, and specification is 18～22 millimeters of diameters, long 70～90 millimeters, and the spacing between two riveting parts 6 is 90～110 millimeters up and down.
The embedding Al of vacuum circulation degassing tubular stinger according to the present invention in the annular recesses of slag lining 2O 3-C brick 4 is because slag touches Al 2O 3The wetting angle of-C refractory materials is less than 90 °, so that Al 2O 3-C brick 4 is not easy by slag wetting, thereby has reduced the erosion of slag to the vacuum circulation degassing tubular stinger, realizes reducing simultaneously the purpose of dry slag, and then improves the production efficiency of external refining.
In addition, be embedded into Al in the annular recesses 2O 3Al is adopted in the outer end of the through hole of-C brick 2O 3The mixture shutoff of-C and pitch is embedded into the Al in the annular recesses 2O 3Al is also adopted in slit between the-C brick 2O 3The mixture of-C and pitch is filled, and is difficult for by the wetting characteristics of slag thereby take full advantage of carbonaceous material, reduces slag by the erosion to this vacuum circulation degassing tubular stinger of described through hole and described slit.
Manufacture craft according to the vacuum circulation degassing tubular stinger of present embodiment is: flange 1, a plurality of riveting part 6 and a plurality of anchor fluke 7 are welded on the steel construction 2, wherein, flange 1 is connected in the top of steel construction 2, a plurality of riveting parts 6 are welded on the slag lining of steel construction 2, particularly, it is the slag lining welding multi-turn riveting part 6 on the outside surface of steel construction 2 in the present embodiment, spacing between the riveting part 6 is 100 millimeters up and down, a plurality of anchor flukes 7 are welded on the outside surface of steel construction 2 except the position that is welded with riveting part 6, guarantee during welding that a plurality of anchor flukes 7 are towards different directions; With the brick inside at steel construction 2 of Mg-Cr; Carry out Al 2O 3The mould material cast after the cast, forms Al 2O 3Pouring layer 3, and this Al 2O 3Have one dark 100～200 millimeters on the pouring layer 3, be 300～400 millimeters annular recesses along the length of the length direction of vacuum circulation degassing tubular stinger, pour into a mould and carry out demoulding maintenance after one day, and the time of demoulding maintenance is not less than 2 days, then processes about 55～70 hours in high dry temperature is 400～450 ℃ ring mirror; After drying is complete, will have the Al of the through hole that mates with riveting part 6 2O 3-C brick 4 is embedded in the annular recesses by riveting part 6; To be embedded into the Al in the annular recesses 2O 3Al is adopted in the outer end of the through hole of-C brick 2O 3The mixture shutoff of-C and pitch is embedded into the Al in the annular recesses 2O 3Al is also adopted in slit between the-C brick 2O 3The mixture of-C and pitch is filled; At last, the vacuum circulation degassing tubular stinger is connected with vacuum chamber by flange 1, toasts online, temperature is not less than 1000 ℃.
Below describe by reference to the accompanying drawings preferred implementation of the present invention in detail; but; the present invention is not limited to the detail in the above-mentioned embodiment; in technical conceive scope of the present invention; can carry out multiple simple variant to technical scheme of the present invention, these simple variant all belong to protection scope of the present invention.In addition, each the concrete technical characterictic described in above-mentioned embodiment in reconcilable situation, can make up by any suitable mode, as long as it is without prejudice to thought of the present invention, it should be considered as content disclosed in this invention equally.

Claims (10)

1. a vacuum circulation degassing tubular stinger is characterized in that, has annular recesses on the outer wall of this tubular stinger, is provided with Al in this annular recesses 2O 3-C brick (4).
2. vacuum circulation degassing tubular stinger according to claim 1, wherein, described Al 2O 3The composition of-C brick (4) comprises Al 2O 3And C, and Al 2O 3With the weight percent of C be: 3.7-5: 1.
3. vacuum circulation degassing tubular stinger according to claim 1, wherein, described tubular stinger comprises the steel construction (2) of cast, has Al on the outside surface of this steel construction (2) 2O 3Pouring layer (3), described annular recesses is formed at described Al 2O 3On the outer wall of pouring layer (3).
4. vacuum circulation degassing tubular stinger according to claim 3 wherein, has riveting part (6), described Al on the outside surface of described steel construction (2) 2O 3Have the through hole corresponding with described riveting part (6) on-C brick (4), described riveting part (6) is inserted in the described through hole.
5. vacuum circulation degassing tubular stinger according to claim 4 wherein, is embedded into the described Al in the described annular recesses 2O 3Al is adopted in the outer end of the through hole of-C brick (4) 2O 3The mixture shutoff of-C and pitch.
6. according to claim 1 or 3 described vacuum circulation degassing tubular stingers, wherein, be embedded into the described Al in the described annular recesses 2O 3Described Al is adopted in slit between the-C brick (4) 2O 3The mixture of-C and pitch is filled.
7. vacuum circulation degassing tubular stinger according to claim 4, wherein, the material of described riveting part (6) adopts 20G, and a plurality of described riveting parts (6) are distributed on the excircle of described steel construction (2).
8. according to claim 1 or 3 described vacuum circulation degassing tubular stingers, wherein, dark 100～120 millimeters of described annular recesses, and described annular recesses is 300～400 millimeters along the length of the length direction of this vacuum circulation degassing tubular stinger.
9. vacuum circulation degassing tubular stinger according to claim 3, wherein, the internal surface of described steel construction (2) is coated with Mg-Cr brick layer (5), and the lower end of this Mg-Cr brick layer (5) extends to the lower end mouth of pipe of described tubular stinger, the Cr of the Mg-Cr brick in this Mg-Cr brick layer (5) 2O 3Content be 24～28% (heavy part).
10. vacuum circulation degassing tubular stinger according to claim 3, wherein, described Al 2O 3The composition of pouring layer (3) contains Al 2O 3, and optionally contain SiO 2, FeO and Na 2O, wherein, with respect to the Al of 100 weight parts 2O 3, SiO 2Content be that the content of 0～0.5, FeO is 0～0.5, Na 2The content of O is 0～0.55.
CN201110307538.3A 2011-10-12 2011-10-12 Vacuum circulation degassing insert tube Active CN103045807B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201110307538.3A CN103045807B (en) 2011-10-12 2011-10-12 Vacuum circulation degassing insert tube

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201110307538.3A CN103045807B (en) 2011-10-12 2011-10-12 Vacuum circulation degassing insert tube

Publications (2)

Publication Number Publication Date
CN103045807A true CN103045807A (en) 2013-04-17
CN103045807B CN103045807B (en) 2014-05-07

Family

ID=48058666

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201110307538.3A Active CN103045807B (en) 2011-10-12 2011-10-12 Vacuum circulation degassing insert tube

Country Status (1)

Country Link
CN (1) CN103045807B (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104032097A (en) * 2014-07-02 2014-09-10 攀钢集团攀枝花钢铁研究院有限公司 Inserting pipe used for vacuum circulating degasification furnace and manufacturing method of inserting pipe

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH10263339A (en) * 1997-03-21 1998-10-06 Toyono Ceratec Kk Ceramic filter
JPH10310816A (en) * 1997-05-07 1998-11-24 Nippon Steel Corp Immersion tube
CN201525862U (en) * 2009-11-20 2010-07-14 武汉钢铁(集团)公司 Novel insert tube for RH vacuum device
CN201534865U (en) * 2009-09-30 2010-07-28 鞍钢股份有限公司 Insert tube for RH refining
CN201648450U (en) * 2010-04-22 2010-11-24 武汉钢铁(集团)公司 Vacuum treatment inserting pipe

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH10263339A (en) * 1997-03-21 1998-10-06 Toyono Ceratec Kk Ceramic filter
JPH10310816A (en) * 1997-05-07 1998-11-24 Nippon Steel Corp Immersion tube
CN201534865U (en) * 2009-09-30 2010-07-28 鞍钢股份有限公司 Insert tube for RH refining
CN201525862U (en) * 2009-11-20 2010-07-14 武汉钢铁(集团)公司 Novel insert tube for RH vacuum device
CN201648450U (en) * 2010-04-22 2010-11-24 武汉钢铁(集团)公司 Vacuum treatment inserting pipe

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
周斌: "攀钢RH真空精炼炉用耐火材料的长寿化实践", 《耐火材料》, vol. 43, no. 4, 31 August 2009 (2009-08-31), pages 300 - 302 *
徐国涛等: "RH真空处理装置用耐火材料初探", 《钢铁研究》, no. 2, 31 March 1994 (1994-03-31), pages 45 - 50 *
朱伯铨: "RH插入管刚玉-尖晶石浇注料研制与应用", 《炼钢》, vol. 16, no. 1, 29 February 2000 (2000-02-29), pages 20 - 22 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104032097A (en) * 2014-07-02 2014-09-10 攀钢集团攀枝花钢铁研究院有限公司 Inserting pipe used for vacuum circulating degasification furnace and manufacturing method of inserting pipe
CN104032097B (en) * 2014-07-02 2016-03-30 攀钢集团攀枝花钢铁研究院有限公司 A kind of insert pipe for vacuum circulation degassing furnaces and preparation method thereof

Also Published As

Publication number Publication date
CN103045807B (en) 2014-05-07

Similar Documents

Publication Publication Date Title
CN104327881B (en) Liquid continuous slag-removal fixed bed gasification furnace and gasification method thereof
CN101748246B (en) Method for improving service life of insert tube of vacuum degassing furnace
CN204174222U (en) The repair structure of iron-making heat wind furnace hot air duct and repairing mould thereof
CN110918967A (en) Repairing method for inner liner of torpedo hot metal mixer car
CN104529485B (en) Two-layer compound refractory material and two-layer compound refractory material ditch cover and its manufacture method and application
CN103045807B (en) Vacuum circulation degassing insert tube
CN106702073A (en) Hot replacement method for converter bottom blowing element
CN205300256U (en) Metallurgical stove brickwork structure
CN109439825B (en) Method for prolonging service life of blast furnace main channel
CN201867070U (en) Furnace door water-cooled end wall of roller hearth soaking furnace
CN203559063U (en) Blast furnace thin-wall lining
CN212720899U (en) Furnace body structure of ore-smelting electric furnace
CN201560196U (en) Blast-furnace novel tuyere-belt cooling wall
JP5489568B2 (en) Gas injection nozzle
CN205270840U (en) Air brick core for ladle
CN210916131U (en) Novel composite iron notch structure
CN203396231U (en) Combined structure of ore heat furnace inner liner
CN203700416U (en) High thermal shock resistant desulfurizing device
CN110722143B (en) Method for improving continuous casting efficiency of tundish
CN213388767U (en) RH dip pipe structure
CN105779676A (en) Blast furnace molten iron runner flow nozzle
CN211645297U (en) Blast furnace slag hole protection structure for vanadium titano-magnetite smelting
CN216192472U (en) Sectional type composite desulfurization spray gun
CN212025389U (en) Novel composite air-cooled durable silicomanganese furnace
CN207280199U (en) A kind of smelting furnace bell for installing copper cooling water pipe additional

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C14 Grant of patent or utility model
GR01 Patent grant