, Description:TECHNICAL FIELD:
Present disclosure relates in general to a field of metallurgy. Particularly, but not exclusively, the present disclosure relates metallurgical furnaces. Further embodiments of the present disclosure disclose a tuyere for a tuyere stock arrangement in the metallurgical furnace.

BACKGROUND OF THE DISCLOSURE:

Generally, an iron making process is a process in which coke is used as a fuel and an iron ore is used as a raw material. The raw materials are charged into an iron making furnace or a metallurgical furnace through a charging inlet and hot air is introduced into the furnace through a blast passage of a tuyere. The tuyere is provided in a lower part of the furnace. The hot air is supplied so that the charged coke burns, and the iron ore is reduced and smelted, and thereby producing molten iron that is a hot melt.

In a conventional steel making furnace, the tuyere for introducing hot air into the furnace is typically made of pure copper. Although the melting point of pure copper is 1,083° C, which is a somewhat low melting point, coolant such as water is circulated in the copper tuyere. The coolant is circulated at a high speed so that the copper tuyere can resist the heat of the hot air. The hot air may have a high temperature of about 1,200° C, which is being introduced into the iron making furnace through the tuyere.

To introduce hot air into the iron making furnace, tuyere is provided in the wall of the furnace. Here, to realize a desired airtight structure of the tuyere regardless of the internal pressure of the furnace, the tuyere is typically installed to protrude inwards into the furnace after being combined with a tuyere cooler. Because the tuyere has an inward protruding structure as mentioned above, the tuyere must be prevented from being fused or damaged by heat inside the furnace. Conventionally, the tuyere is typically provided with a water-cooling system, in which cooling water is introduced into the tuyere through an inlet and circulates through a cooling passage while cooling the tuyere prior to being discharged from the tuyere through an outlet.

Since the end portion of the tuyere projects inside the furnace it is exposed to severe circumstances in the furnace. For instance, the inner and outer walls of the front end of the tuyere is damaged easily. This is due to extreme thermal load, mechanical abrasion caused the charge during its descending or distributed coal powder and contact with liquid iron and slag. Thereby the working life of the tuyere is significantly reduced. The capital expenditure to replace the tuyere would also be significantly higher and may affect the production capacity of the plant.

The present disclosure is directed to overcome one or more limitations stated above or any other limitations associated with the conventional arts.

The information disclosed in this background of the disclosure section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

SUMMARY OF THE DISCLOSURE

One or more shortcomings of the conventional arts are overcome by an apparatus and a method as claimed and additional advantages are provided through the provision of apparatus and the method as claimed in the present disclosure.

Additional features and advantages are realized through the techniques of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered a part of the claimed disclosure.

In one non-limiting embodiment of the disclosure, a tuyere for a metallurgical furnace is disclosed. The tuyere includes a tuyere body defining a front-end receivable in an interior of the metallurgical furnace and a rear end opposite to the front end. The tuyere body is defined with a passage extending from the rear end to the front end. At least a portion of an outer surface of the tuyere body at the front end is coated with a refractory layer of pre-determined thickness to improve wear resistance of the tuyere body at high temperatures in the interior of the metallurgical furnace.

In an embodiment of the disclosure, the tuyere body is made of at least one of copper and copper alloy.

In an embodiment of the disclosure, the rear end of the tuyere body is fluidly connected to a blow pipe which is configured to channelize hot blast air from a hot blast air supply unit to the metallurgical furnace.

In an embodiment of the disclosure, the pre-determined thickness of the refractory layer ranges from 4mm to 7mm. The refractory layer is made of 99.99% Al2O3 powder with inevitable impurities. The Al2O3 powder is mixed with liquid including water to prepare pulp.

In an embodiment of the disclosure, the pulp is anchored to the portion of the outer surface of the tuyere body facing the interior of the metallurgical furnace through a plurality of anchors. The plurality of anchors is made of nickel (Ni)-chromium (Cr) wires and each of the plurality of anchors is defined with a “C” shaped cross section.

In an embodiment of the disclosure, each of the plurality of anchors is joined to the portion of the outer surface of the tuyere body by thermal joining methods.

In an embodiment of the disclosure, the pulp is pasted on to the plurality of anchors and the plurality of anchors is configured to hold the pulp.

In an embodiment of the disclosure, the outer surface of the tuyere body is coated with an alloy of nickel-chromium [Ni-Cr]. The composition of Nickel is 80% by wt. and chromium of 20% by wt. the thickness of the coat ranges from 2mm to 3mm.

In an embodiment of the disclosure, the surface of the refractory layer is encompassed by a sacrificial metal coating. The sacrificial metal coating is made of nickel and chromium. The sacrificial metal coating is structured to prevent damage to the refractory layer.

It is to be understood that the aspects and embodiments of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiments may be combined to form a further embodiment of the disclosure.

The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

BRIEF DESCRIPTION OF THE ACCOMPANYING FIGURES

The novel features and characteristics of the disclosure are set forth in the appended claims. The disclosure itself, however, as well as a preferred mode of use, further objectives, and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying figures. One or more embodiments are now described, by way of example only, with reference to the accompanying figures wherein like reference numerals represent like elements and in which:

FIG.1 illustrates an exemplary schematic view of a tuyere for a metallurgical furnace, in accordance with an embodiment of the present disclosure.

FIG.2 illustrates an exemplary schematic view of the tuyere of FIG.1 with refractory layer, in accordance with an embodiment of the present disclosure.

FIG.3 illustrates impact of temperature on the tuyere due to provision the refractory layer (R) over the outer surface of the tuyere body, in accordance with an embodiment of the present disclosure.
The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION

The foregoing has broadly outlined the features and technical advantages of the present disclosure in order that the detailed description of the disclosure that follows may be better understood. Additional features and advantages of the disclosure will be described hereinafter which form the subject of the claims of the disclosure. It should be appreciated by those skilled in the art that the conception and specific embodiments disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure. It should also be realized by those skilled in the art that such equivalent processes do not depart from the spirit and scope of the disclosure as set forth in the appended claims. The novel features which are believed to be characteristic of the disclosure, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present disclosure. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, can be arranged, substituted, combined, and designed in a wide variety of different configurations, all of which are explicitly contemplated and make part of this disclosure.

Embodiments of the present disclosure discloses a tuyere for a tuyere stock arrangement in a metallurgical furnace. The tuyere of the present disclosure may retain significantly improved wear resistance than the conventional tuyeres. The tuyere of the present disclosure ensures significantly improved mechanical properties. Further, the average life of the tuyere is increased significantly. The configuration of the tuyere of the present disclosure to obtain the said advantage is set forth hereinafter.

The tuyere for the tuyere stock arrangement for the metallurgical furnace may include a tuyere body. The tuyere body may define a front end and a rear end opposite to the front end. The tuyere body may be defined with a passage extending from the rear end to the front end. In an embodiment, the front end may be receivable in an interior of the metallurgical furnace. The outer surface of the tuyere body is structured such that at least a portion of its outer surface may be coated with an alloy of Nickel and Chromium [Ni-Cr]. The nickel composition of 80 wt.% and chromium of 20 wt.%. In an embodiment, the thickness of the coating of Ni-Cr may range from 2mm to 3mm. Further, a portion of the outer surface of the tuyere body may be defined with a plurality of anchors. Each of the plurality of anchors may be joined to the portion of the outer surface by thermal joining means such as but not limiting to spot welding. The plurality of anchors may be made of nickel-chromium wires. The plurality of anchors may be defined with a “C” shaped cross section, each end of the “C” shaped cross section is joined to the surface of the tuyere body.

Once the plurality of anchors is joined to the outer surface of the tuyere body, a refractory layer of pre-determines thickness may be anchored to the plurality of anchors. The refractory layer may be made of 99.99% aluminum oxide [Al2O3] with inevitable impurities. In an embodiment, the refractory layer may be made of Al2O3 powder mixed with liquid including water to prepare pulp. The pulp obtained may be anchored to the portion of the outer surface of the tuyere body facing the interior of the metallurgical furnace through a plurality of anchors. That is the pulp may be pasted on to the outer surface of the tuyere body defined with the plurality of anchors. The pulp may be pasted layer by layer until a desired thickness may be achieved. Once the refractory layer of desired thickness is achieved a sacrificial metal layer/coating may be provided onto the refractory layer. The sacrificial metal coating may be designed to prevent damage to the refractory layer. The tuyere configuration may be explained in detail with the aid of figures hereinafter.

The terms “comprises…. a”, “comprising”, or any other variations thereof used in the specification, are intended to cover a non-exclusive inclusion, such that an assembly that comprises a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such setup or method. In other words, one or more elements in an assembly proceeded by “comprises… a” does not, without more constraints, preclude the existence of other elements or additional elements in the assembly.

Henceforth, the present disclosure is explained with the help of one or more figures of exemplary embodiments. However, such exemplary embodiments should not be construed as limitation of the present disclosure.

The following paragraphs describe the present disclosure with reference to FIG(s) 1 to 3. In the figures, the same element or elements which have similar functions are indicated by the same reference signs. For the purposes of promoting an understanding of the principles of the disclosure, reference will now be made to specific embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated methods, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention pertains.

The following detailed description is merely exemplary in nature and is not intended to limit application and uses. Furthermore, there is no intention to be bound by any theory presented in the preceding background or summary or the following detailed description. It is to be understood that the disclosure may assume various alternative orientations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices or components illustrated in the attached drawings and described in the following specification are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions or other physical characteristics relating to the embodiments that may be disclosed are not to be considered as limiting, unless the claims expressly state otherwise. Hereinafter, preferred embodiments of the present disclosure will be described referring to the accompanying drawings. While some specific terms directed to a specific direction will be used, the purpose of usage of these terms or words is merely to facilitate understanding of the present invention referring to the drawings. Accordingly, it should be noted that the meanings of these terms or words should not improperly limit the technical scope of the present invention.

Embodiments of the disclosure discloses a tuyere (10) for a tuyere stock arrangement of a metallurgical furnace. It should be noted that neither the entire tuyere stock arrangement nor the metallurgical furnace is depicted in the figures of the present disclosure to simplify and enable better understanding of the present disclosure.

In an embodiment, the tuyere stock arrangement [not shown] may be designed for feeding hot blast air to an interior of the metallurgical furnace through the metallurgical furnace wall. In an embodiment, the tuyere body (3) may be of converging nozzle shape. The tuyere (10) may be maintained in position by a tuyere cooler and a tuyere cooler holder. Referring now to FIG.1, the tuyere (10) may include a tuyere body (3). The tuyere body (3) may be made of materials such as but not limiting to copper and alloys of copper. The tuyere body (3) is defined with a front end (1) and a rear end (4) opposite to the front end (1). In an embodiment, a passage (C) may be defined at a substantially central portion of the tuyere body (3). The passage (C) may extend from the rear end (4) to the front end (1) of the tuyere body (3) The passage (C) may define an inner surface of the tuyere body (3) and the tuyere body (3) may be include an outer surface. The rear end (4) of the tuyere body (3) may be configured to receive a blow pipe. In an embodiment, the rear end (4) of the tuyere body (3) may be fluidly connected to the blow pipe and may be configured to channelize hot blast air from a hot blast air supply unit to the interior of the metallurgical furnace.

The front end (1) of the tuyere body (3) may be receivable in the interior of the metallurgical furnace. Since, a portion of the front end (1) of the tuyere body (3) may be damaged easily due to extreme thermal loads, mechanical abrasion caused by the charge during its descending or distributed coal powder and contact with liquid iron and slag, thereby affecting the life of the tuyere (10). Specifically, the portion of the outer circumference of the front end (1) may be subjected to such challenges. The tuyere body (3) of the present disclosure may be designed in way that the tuyere body (3) may be capable of withstanding the extreme conditions within the metallurgical furnace.

The portion of the outer surface of the tuyere body (3) facing the interior of the metallurgical furnace may be designed to accommodate one or more coatings or layers which may be set forth in detail hereinafter. The portion of the outer surface of the tuyere body (3) may be initially provided with Inconel® coating. Inconel® are alloys capable of resisting oxidation, corrosion, and the like. Inconel® coating may include nickel-chromium [Ni-Cr] based super alloys. In an embodiment, composition of nickel and chromium used in the Inconel® coating according to present disclosure may be 80% by weight and 20% by weight, respectively. The range disclosed above should not be construed as a limitations for the present disclosure. In an embodiment, the Ni-Cr based coating may be provided on the entire outer surface of the tuyere body (3). In another embodiment, the coating provided may be of pre-determined thickness. The thickness of the coating may range from 2mm to 3mm [millimeters].

Upon coating the outer surface of the tuyere body (3) with the Ni-Cr coating, the portion of the outer surface of the tuyere body (3) facing the interior of the metallurgical furnace may be defined with a plurality of anchors (2) [shown in FIG.1]. The plurality of anchors (2) may be made of Nickel-Chromium [Ni-Cr] wires but not limiting to the same. The plurality of anchors (2) may be joined to the outer surface by thermal joining methods. The thermal joining method may include welding such as spot welding/local welding but not limiting to the same. The plurality of anchors (2) may be of “C” shaped cross section. Either ends of the plurality of anchors (2) may be welded to the outer surface of the tuyere body (3). The plurality of anchors (3) may be joined in a pre-defined order along the entire circumferential surface of the tuyere body (3) on the outer surface [facing the interior of the blast furnace]. The plurality of anchors (2) may be designed to hold a refractory layer (R) that may be pasted over the portion of the outer surface of the tuyere body (3) [as shown in FIG.2].

The refractory layer (R) may be anchored to the outer surface of the tuyere body (3) with the aid of the plurality of anchors (2) as mentioned above. In an embodiment, the refractory layer (R) of the present disclosure may be made of oxides of aluminum. The refractory layer (R) according to the present disclosure may be made of aluminum oxide (Al2O3). Al2O3 i.e., the aluminum oxide used may be 99.99% of Al2O3. The aluminum oxide may be in the form of powder and along with 99.99% Al2O3 powder there may be other inevitable impurities. The powder may be mixed with liquid such as water to prepare pulp. Once the pulp is formed, the pulp [i.e., mixture of Al2O3 and water] may be pasted on to the portion of the outer surface of the tuyere body (3). In an embodiment, the pulp may be pasted over the plurality of anchors (2). The pulp may be pasted over the portion of the outer surface until a desired thickness may be achieved to form the refractory layer (R). In an embodiment, the pulp may be pasted onto the outer surface until the thickness of range 4mm to 7mm is obtained. Upon achieving the desired thickness, the refractory layer (R) [i.e., made of pulp] may be sintered at high temperature. This arrangement may minimize the difference of thermal expansion between the refractory layer (R) and the Ni-Cr coating, thereby reducing the difference between linear expansion to avoid crack generation due to thermal stress. In some embodiments, the refractory layer (R) may be manufactured corresponding to the shape of the outer surface of the tuyere body (R) and then may be placed over the tuyere body (3) and the same should be within the scope of the present disclosure.

Further, the refractory layer (R) provided over the portion of the outer surface of the tuyere body (3) may be shielded with a sacrificial metal coating. The sacrificial metal coating may be provided over the refractory layer (R) to ensure that the refractory layer (R) may not be dislodged from the outer surface during the installation of tuyere (10) in the metallurgical furnace. The sacrificial metal coating may be provided along the entire circumferential surface of the refractory layer (R) and the shape of the sacrificial metal coating may conform to the shape of the refractory layer (R). In an embodiment, the sacrificial metal coating may be made of nickel-chromium [Ni-Cr] material. The sacrificial metal coating may be in form of plates and may be cased around the refractory layer (R). The sacrificial metal coating may be sacrificial in nature as it may melt during the operation of the metallurgical furnace. As shown in FIG.3, the impact of providing the refractory layer (R) over the outer surface of the tuyere body (3) facing the interior of the metallurgical furnace is depicted. FIG.3 indicates temperature distribution in the tuyere body (3) made of copper or alloys of copper. Flow and thermal analysis of tuyere (10) with the described configuration may be conducted. Temperature in case of tuyere body (3) with refractory layer (3) [in FIG.3 depicted by B] may be significantly lower when compared to the temperature of tuyere without refractory [in FIG,3 depicted by A].

In an embodiment, the tuyere (10) of the present disclosure may possess significantly improved wear resistance than the conventional tuyeres. The tuyere (10) of the present disclosure ensures significantly improved mechanical properties including mechanical abrasion. Further, the average life of the tuyere is increased significantly due the structure and configuration of the tuyere (10) as described above.

It is to be understood that a person of ordinary skill in the art may develop a system of similar configuration without deviating from the scope of the present disclosure. Such modifications and variations may be made without departing from the scope of the present disclosure. Therefore, it is intended that the present disclosure covers such modifications and variations provided they come within the ambit of the appended claims and their equivalents.

Equivalents

With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.

It will be understood by those within the art that, in general, terms used herein, are generally intended as "open" terms (e.g., the term "including" should be interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," the term "includes" should be interpreted as "includes but is not limited to," etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding the description may contain usage of the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles "a" or "an" limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases "one or more" or "at least one" and indefinite articles such as "a" or "an" (e.g., "a" and/or "an" should typically be interpreted to mean "at least one" or "one or more"); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of "two recitations," without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to "at least one of A, B, and C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, and C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to "at least one of A, B, or C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, or C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase "A or B" will be understood to include the possibilities of "A" or "B" or "A and B."

While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated in the description.

Referral Numerals:
Description Reference number
Tuyere 10
Front face 1
Anchor 2
Tuyere body 3
Rear face 4
Passage C

Claims:We claim:

1. A tuyere (10) for a metallurgical furnace, the tuyere (10) comprising:
a tuyere body (3) defining a front end (1) receivable in an interior of the metallurgical furnace and a rear end (4) opposite to the front end (1), wherein the tuyere body (3) is defined with a passage (C) extending from the rear end (4) to the front end (1);
wherein, at least a portion of an outer surface of the tuyere body (3) at the front end (1) is coated with a refractory layer (R) of pre-determined thickness to improve wear resistance of the tuyere body (3) at high temperatures in the interior of the metallurgical furnace.

2. The tuyere (10) as claimed in claim 1, wherein the tuyere body (3) is made of at least one of copper and copper alloy.

3. The tuyere (10) as claimed in claim 1, wherein the rear end (4) of the tuyere body (3) is fluidly connected to a blow pipe which is configured to channelize hot blast air from a hot blast air supply unit to the metallurgical furnace.

4. The tuyere (10) as claimed in claim 1, wherein the pre-determined thickness of the refractory layer (R) ranges from 4mm to 7mm.

5. The tuyere (10) as claimed in claim 1, wherein the refractory layer (R) is made of 99.99% Al2O3 powder with inevitable impurities.

6. The tuyere (10) as claimed in claim 5, wherein the Al2O3 powder is mixed with liquid including water to prepare pulp.

7. The tuyere (10) as claimed in claim 1 and 6, wherein the pulp is anchored to the portion of the outer surface of the tuyere body (3) facing the interior of the metallurgical furnace through a plurality of anchors (2).

8. The tuyere (10) as claimed in claim 1, wherein the plurality of anchors (2) is made of Nickle [Ni]-chromium [Cr] wires.

9. The tuyere (10) as claimed in claim 1, wherein each of the plurality of anchors (2) is defined with a “C” shaped cross section.

10. The tuyere (10) as claimed in claim 1, wherein each of the plurality of anchors (2) is joined to the portion of the outer surface of the tuyere body (3) by thermal joining methods.

11. The tuyere (10) as claimed in claim 6 and 8, wherein the pulp is pasted on to the plurality of anchors (2) and the plurality of anchors (2) is configured to hold the pulp.

12. The tuyere (10) as claimed in claim 1, wherein the outer surface of the tuyere body (3) is coated with an alloy of nickel-chromium [Ni-Cr] of thickness ranging from 2mm to 3mm.

13. The tuyere (10) as claimed in claim 1, wherein the surface of the refractory layer (R) is encompassed by a sacrificial metal coating.

14. The tuyere (10) as claimed in claim 13, wherein the sacrificial metal coating is made of nickel (Ni)-chromium (Cr) material.

15. The tuyere (10) as claimed in claim 13, wherein the sacrificial metal coating is structured to prevent damage to the refractory layer (R).

16. A tuyere stock arrangement of a metallurgical furnace comprising a tuyere (10) as claimed in claim 1.