Description:TECHNICAL FIELD:

Present disclosure relates in general to a field of metallurgy. Particularly, but not exclusively, the present disclosure relates to hot gas generators in coal grinding plants. Further embodiments of the present disclosure disclose an igniter for a pilot burner for the hot gas generators.

BACKGROUND OF THE DISCLOSURE:

In order to begin a combustion process inside a fossil fuel fired combustion chamber, such as the one found in industrial and utility furnaces, an energy source, such as a pilot burner is required. The pilot burner helps to begin a self-sustaining combustion reaction of main fuel. Pilot burners generally have a dedicated fuel supply, a flame ignition source, and a flame detector. In operation, fuel is introduced to an ignition chamber through the dedicated fuel supply portion and the ignition source provides a spark to begin a combustion process.

In a combustion chamber, for example a tangential or a wall fired boiler, ignitors can be mounted to structural elements. For example, in a tangential boiler, pulverized coal and air are introduced into a furnace through fuel-air admission assemblies disposed in structural elements called wind boxes located in the corners of the furnace. Auxiliary fuel burners, which includes the pilot burners disposed within a moveable nozzle, are also located in the wind boxes, proximate to the fuel-air assemblies. The auxiliary fuel burners and fuel-air assemblies are aimed tangentially to an imaginary circle in the middle of the furnace to create a fireball, which serves as source of ignition for the incoming coal or inflammable coke oven or blast furnace gas.

The conventional pilot burners include the flame ignition source such as ignitors. Ignitors play a major role in igniting the fuel in the combustion chamber to produce a steady flame. The said ignitors generally consist of an electrode disposed within a housing. Further, insulating materials such as ceramic materials such as ceramic beads are disposed within the housing. Ceramic beads have enjoyed great success as insulators in the igniters used in gas-fired furnaces, stoves, and the like. However, over a period of time the ceramic materials such the beads deteriorate due to condensation of moisture in the fuel supplied. In addition to the moisture content, the ceramic beads are also affected by high temperature near the combustion chamber. Due to the said factors the insulation properties of the beads deteriorate more than usual. Once the insulation properties of the beads deteriorate, they may have to be changed. These deteriorated beads have to be changed on regular basis to maintain the life of igniter which adds up to the cost of maintenance. In case, the beads are not available, the entire igniter have to be replaced. Replacing the igniter is costly and would require the plant operations to be shut down which will also affect the production of the plant.

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

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, an igniter for a pilot burner of a hot gas generator in coal grinding plant is disclosed. The igniter includes an elongated tube defining a housing. A flexible cable is accommodated within the elongated tube. The flexible cable extends along a length of the elongated tube. The flexible cable is electrically conductive, and one end of the flexible cable is connected to a power source. Further, an insulating sheath is accommodated in a space defined between the flexible cable and the elongated tube. An igniter tip is fixedly connected to the other free end of the flexible cable. The igniter tip is structured to generate spark when a voltage of pre-determined intensity is passed through the flexible cable.

In an embodiment of the disclosure, the elongated tube is made of high carbon steel.

In an embodiment of the disclosure, the igniter tip is made of molybdenum.

In an embodiment of the disclosure, the flexible cable includes a core made of at least one of copper. Also, the flexible cable includes a cladding surrounding the core. The cladding is made of at least one of silicon, polyvinyl chloride, and cross-linked polyethylene. The flexible cable is a high voltage cable of rating 15kV. The voltage of the power source is 6000 volts. Cross section of the core of the flexible cable ranges from 1mm2 to 3mm2.

In an embodiment of the disclosure, the insulating sheath is at least one of high temperature sheath and heat resistant tape. Operating temperature range of the insulating sheath ranges from -60°C to 180°C. Optimum temperature of the insulating sheath ranges from 950°C to 1100°C. Di-electric strength of the insulating sheath is 15kV/mm.

In an embodiment of the disclosure, the igniter tip is crimped to the free end of the elongated tube.

In an embodiment of the disclosure, the igniter tip is encapsulated by a fire-retardant paste. The fire-retardant paste is capable of withstanding flame of 4 to 6 inches.

In another non-limiting embodiment of the disclosure, a pilot burner for a hot gas generator in a coal grinding plant is disclosed. The pilot burner includes an igniter having an elongated tube defining a housing. The igniter includes a flexible cable which is accommodated within the elongated tube and extending along a length of the elongated tube. The flexible cable is electrically conductive, and one end of the flexible cable is connected to a power source. The electric arc is generated by supplying a pre-determined range of electrical current. Further, an insulating sheath is accommodated in a space defined between the flexible cable and the elongated tube. An igniter tip is fixedly connected to the other free end of the flexible cable. The igniter tip is structured to generate spark when a voltage of pre-determined intensity is passed through the flexible cable. The pilot burner further includes a conduit positioned adjacent to the igniter and configured to channelize pilot gas from a source to a chamber in the hot gas generator. The pilot gas in combination with the spark generated by the igniter generates steady flame in the hot gas generator.

In an embodiment of the disclosure, the igniter and the conduit are supported adjacent to each other by a flange.

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 characteristic 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 embodiments 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 schematic view of a pilot burner for a hot gas generator in a coke oven plant, in accordance with an embodiment of the present disclosure.

FIG.2 illustrates a sectional side view of the pilot burner of FIG.1.

FIG.3 illustrates a schematic rear view of the pilot burner of FIG.1.

FIGS.4a and 4b illustrates schematic views of a rear portion and a tip portion of igniter for the pilot burner of FIG.1, respectively.

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 scope of the disclosure as set forth in the appended claims. The novel features which are believed to be characteristics 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 an igniter for a pilot burner of hot gas generator of coal grinding plant. The igniter according to the present disclosure eliminates the need of ceramic beads, thereby increasing the health of the igniter. The igniter of the present disclosure may require minimum maintenance than the conventional igniters which employ ceramic beads.

According to embodiments of the disclosure, igniter for the pilot burner used in a hot gas generator in a coal grinding plan is disclosed. The pilot burner along with the igniter may include a conduit positioned adjacent to the igniter. The conduit may be configured to channelize pilot gas from a source to a chamber in the hot gas generator. In an embodiment, the pilot gas may be at least one of a liquid petroleum gas [LPG] and the like. The pilot gas channelized into the chamber of the hot gas generator in combination with the spark generated by the igniter may generate a steady flame in the hot gas generator. The igniter of the present disclosure may include an elongated tube which may define a housing. The elongated tube may be made of materials such as but not limiting to high carbon steel. The elongated tube may accommodate a flexible cable. In an embodiment, the flexible cable is electrically conductive. The flexible cable may include a core made of materials such as but not limiting to copper and aluminum, and a cladding made of materials such as silicon, polyvinyl chloride, cross-linked polymer, and the like may be surrounded around the core. In an embodiment, the flexible cable may extend along an entire length of the elongated tube.

Further, an insulating sheath may be accommodated in the housing in a space defined between the flexible cable and an inner surface of the elongated tube. The insulating sheath may be at least one of a high temperature sheath and heat resistance tape. In an embodiment, operating temperature of the insulating sheath may range from -60°C to 180°C and the optimum temperature of the insulating sheath ranges from 950°C to 1100°C. Further, di-electric strength of the insulating sheath may be 15kV/mm. The igniter further includes an igniter tip which may be fixedly connected to a free end of the elongated tube. The igniter tip may be made of materials such as but not limiting to molybdenum. In an embodiment, the igniter tip may be crimped to the free end of the flexible cable. The igniter tip may be structured to generate the spark which is required to generate steady flame when a current of pre-determined intensity is passed through the flexible cable.

The terms “comprises…. a”, “comprising”, or any other variations thereof used in the specification, are intended to cover a non-exclusive inclusion, such that a system 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 4b. 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 of “adjacent,” “juxtaposed,” “substantially”, “above”, “right,” “along”, or “left” and other terms containing these specific terms and 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.

As an initial matter it should be noted that the term “hot gas generator” may be used in various industries such as metallurgical [including mineral drying], chemical and the like to depict a combustion chamber. The hot gas generator may be used to produce gases at different temperatures starting from combustion of different fuels such as natural gas, fuel oil and the like. In an embodiment, the hot gas generator may be a fossil fuel firing combustion, such as, for example pulverized coal firing furnace. The hot gas generator includes a pilot burner, generally designated by referral numeral 10 as shown in FIG.1. Hereinafter, the pilot burner (10) and its configuration may be elucidated with the aid of FIG(s) 1 to 3 in conjunction. The pilot burner (10) of the present disclosure may include an igniter (2) and a conduit (4). As shown in FIG.1, the conduit (4) may be juxtaposed/positioned adjacent to the igniter (2). In an embodiment, the pilot burner (10) includes a flange (3) with one or more holes to accommodate the igniter (2) and the conduit (4). The conduit (4) and the igniter (2) may be ingressed into respective holes of the one or more holes in the flange (3) [as shown in FIG.3] to hold them in close proximity to each other.

The igniter (2) of the present disclosure among other components may include an elongated tube (5). The elongated tube (5) may be made of materials such as but not limiting to high carbon steel. In an embodiment, the elongated tube (5) may be hollow tube defining a housing. The elongated tube (5) may be structured to accommodate a flexible harness also referred to as “flexible cable (6)” [the flexible cable is best shown in FIG.2]. The flexible cable (6) may run along entire length of the elongated tube (5). The flexible cable (6) may be disposed at a substantially central portion of the elongated tube (5). In an embodiment, the flexible cable (6) may include a core and a cladding. The core of the flexible cable (6) may be made of electrically conductive materials including material such as but not limiting to copper and aluminum. Any materials which are electrically conductive maybe used as the core and the above materials should not be construed as a limitation of the present disclosure. The core is further encompassed by the cladding. The term cladding here refers to is the application of one material over another to provide a skin or layer. The cladding may be made of materials such as but not limiting to silicon, polyvinyl chloride, and cross-linked polyethylene. The cladding may be configured to electrically isolate the core from the elongated tube (5). In an embodiment, one end of the flexible cable (6) may be connectable to a power supply system including a power source, the voltage of the power source is 6000 volts. In an embodiment, the flexible cable (6) may be a high voltage cable of rating of 15kV. The cross section of the flexible cable (6) ranges from 1mm2 and 3mm2. The terms “flexible harness” and “flexible cable” are often used interchangeably. Generally, in the following description, the “flexible harness” may be used to define an electrically conductive cable. However, in some instances the term “flexible cable” may be used herein to describe the electrically conductive cable. In any event, the context of which the terms are used herein will sufficiently explain how the terms are used.

Once the flexible harness (6) is positioned within the elongated tube (6), a space may be defined between the flexible harness (6) and an inner circumference of the elongated tube (5). The space defined between the flexible harness (6) and the elongated tubes (6) may be filled with an insulating sheath (7) [shown in FIG.4a]. The insulating sheath (7) may be configured to isolate the flexible cable (6) from the elongated tube (5). The insulating sheath (7) may be high temperature sheath and heat resistant tape. In an embodiment, the insulating material (7) may be a power seal tape made from specifically treated fabric coated with one side adhesive and another side may be laminated with liner. The insulating sheath (7) may be structured to continuously operate at a temperature range from -60°C to 180°C. Peak temperature of the insulating sheath (7) may range 950°C to 1100°C. Further, di-electric strength of the insulating sheath (7) may be 15kV/mm. The di-electric strength and other properties are illustrated above, the ranges should not be construed as a limitation of the present disclosure. A person skilled in the art may subtly vary the properties of the insulating sheath (7) to achieve similar results and the same should be interpreted within the scope of the present disclosure. The terms referred to hereinabove such as operating temperature, peak temperature and di-electric strength refer to properties of the insulating sheath (7). For instance, di-electric strength refers to maximum electric field that a material can withstand without experiencing failure of its insulating properties.

Further, an igniter tip (1) [shown in FIG.4b] may be connected to the elongated tube (5) towards the free end of the flexible cable (6). The igniter tip (1) may be crimped to the free end of the flexible cable (6) forming a crimp joint (8). In an embodiment, the igniter tip (1) may be made of molybdenum but not limiting to the same. Other materials such as silicon carbide, silicon nitride, nickel alloy and the like may be used for the igniter tip (1). The igniter tip (1) may be designed to generate spark when a current of pre-determined intensity is passed through the flexible cable (6). In an embodiment, the igniter tip (1) may generate spark. In an embodiment, the igniter tip (1) may be encapsulated by a fire-retardant paste (9) which may be capable of withstanding flame of 4 inches to 6 inches. The spark generated by the igniter tip (1) of the igniter (2) may be used to ignite pilot gas within a chamber of the hot gas generator to generate steady flame. The pilot gas may be channelized to the chamber in the hot gas generator through the conduit (4). In some embodiments, the pilot gas may be at least one of liquid petroleum gas but not limiting to the same. In an embodiment, the conduit (4) may be made of materials such as but not limiting to high carbon steel. One end of the conduit (4) may be connected to a gas source and free end of the conduit (4) may be disposed within the chamber and arranged proximal to the igniter tip (1). The pilot gas may be supplied from the source to the chamber through the conduit (4) and the pilot gas may be ignited at the entry of the chamber by the igniter (2) to generate a steady flame in the hot gas generator.

In an embodiment, the igniter (2) used in the pilot burner (10) of the hot gas generator in the coal grinding plant advantageously eliminates the requirement of ceramic beads and problems associated with use of such beads in the igniter (2). As the use of ceramic beads are eliminated, the life of the igniter (2) is significantly improved. Further, the igniter (2) of the present disclosure may require minimum maintenance than the conventional igniters.

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 invention. 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
Pilot burner assembly 10
Igniter tip 1
Igniter Assembly 2
Flange 3
Pilot Gas tube 4
Igniter tube 5
High Voltage Flexible cable 6
High temperature sheath 7
Crimp joint 8
Fire retardant paste 9

Claims:1. An igniter (2) for a pilot burner of a hot gas generator of a coal grinding plant, the igniter (2) comprising:
an elongated tube (5) defining a housing;
a flexible cable (6) is accommodated within the elongated tube (5) and extending along a length of the elongated tube (5), wherein the flexible cable (6) is electrically conductive, and one end of the flexible cable (6) is connected to a power source;
an insulating sheath (7) is accommodated in a space defined between the flexible cable (6) and the elongated tube (5); and
an igniter tip (1) fixedly connected to a free end of the flexible cable (6), wherein the igniter tip (1) is structured to generate spark when a voltage of pre-determined intensity is passed through the flexible cable (6).

2. The igniter (2) as claimed in claim 1, wherein the elongated tube (5) is made of high carbon steel.

3. The igniter (2) as claimed in claim 1, wherein the igniter tip (1) is made of molybdenum.

4. The igniter (2) as claimed in claim 1, wherein the flexible cable (6) includes a core made of at least one of copper and aluminum and a cladding surrounding the core.

5. The igniter (2) as claimed in claim 4, wherein the cladding is made of at least one of silicon, polyvinyl chloride, and cross-linked polyethylene.

6. The igniter (2) as claimed in claim 1, wherein the flexible cable (6) is a high voltage cable of rating 15kV.

7. The igniter (2) as claimed in claim 1, wherein the voltage of the power source is 6000 volts.

8. The igniter (2) as claimed in claim 1, wherein cross section of the core of the flexible cable (6) ranges from 1mm2 to 3 mm2.

9. The igniter (2) as claimed in claim 1, wherein the insulating sheath (7) is at least one of high temperature sheath and heat resistance tapes.

10. The igniter (2) as claimed in claim 1, wherein operating temperature range of the insulating sheath (7) ranges from -60 to 180°C.

11. The igniter (2) as claimed in claim 1, wherein optimum temperature of the insulating sheath (7) ranges from 950°C to 1100°C.

12. The igniter (2) as claimed in claim 1, wherein di-electric strength of the insulating sheath (7) is 15kV/mm.

13. The igniter (2) as claimed in claim 1, wherein the igniter tip (1) is crimped to the free end of the elongated tube (5).

14. The igniter (2) as claimed in claim 1, wherein the igniter tip (1) is encapsulated by a fire-retardant paste (9).

15. The igniter (2) as claimed in claim 14, wherein the fire-retardant paste (9) is capable of withstanding flame of 4-6 inches.

16. A pilot burner assembly (10) for a hot gas generator in a coal grinding plant, the assembly (10) comprising:
an igniter (2) comprises:
an elongated tube (5) defining a housing;
a flexible cable (6) is accommodated within the elongated tube (5) and extending along a length of the elongated tube (5), wherein the flexible cable (6) is electrically conductive, and one end of the flexible cable (6) is connected to a power source;
an insulating sheath (7) is accommodated in a space defined between the flexible cable (6) and the elongated tube (5); and
an igniter tip (1) fixedly connected to a free end of the flexible cable (6), wherein the igniter tip (1) is structured to generate spark when a voltage of pre-determined intensity is passed through the flexible cable (6); and
a conduit (4) positioned adjacent to the igniter (2) and configured to channelize pilot gas from a source to a chamber in the hot gas generator,
wherein, the pilot gas in combination with the spark generated by the igniter (2) generates steady flame in the hot gas generator.

17. The assembly (10) as claimed in claim 16, wherein the igniter (2) and the conduit (4) are held adjacent to each other by a flange (3).

18. The assembly (10) as claimed in claim 16, wherein the elongated tube (5) of the igniter (2) and the conduit (4) are made of high carbon steel.