TECHNICAL FIELD
[001] Present disclosure generally relates to the field of Metallurgy. Particularly, but not exclusively, the present disclosure relates to a pilot burner for a lime kiln associated with the steel making process. Further, embodiments of the disclosure disclose a system and a method for igniting pilot burner assembly in the lime kiln.
BACKGROUND OF THE DISCLOSURE
[002] Lime, also known as Calcium oxide which is represented by chemical notation CaO is one of the vital raw materials used in manufacturing industries. Lime making is an important part of steel-making process, especially through the Basic Oxidation Furnace (BOF) route in the blast furnaces. Lime is added after the beginning of the oxygen “blow”, where it reacts with impurities (primarily Silica) to form slag, which is later removed. For example, approximately 70 kilograms of lime is required for every ton of steel in the metallurgical industry. Limestone i.e., calcium carbonate represented by the chemical notation CaCO3 is the main raw material for preparing lime. The basic mechanism for preparing lime is to decompose the calcium carbonate present in limestone into calcium oxide and carbon dioxide by means of heating. The decomposition is illustrated by the reaction formula: CaCO3 + heat = CaO + CO2 (in which 42.5 Kcal heat is required for the reaction), i.e., the reaction is endothermic. The process of lime preparation may include several phases such as preheating, calcining, cooling, and discharging, each phase being carried out a predetermined temperature range.
[003] Production of lime from limestone conventionally takes place in a lime kiln where limestone and fuel [either a solid fuel loaded directly into the kiln, or a gaseous fuel fed through a pipeline] are combusted by a burner. The limestone undergoes preheating, calcining, and cooling phases which are accompanied by the final discharge phase where released CO2 is discharged appropriately. Lime kilns may be vertical, rotary, sleeve type, double chambered and the like depending on the operating capacity and requirements. Typical fuels employed are coke, coke powders, coal, etc., in case of solid fuels, and high-coke mixed gas, coke oven gas, converter gas, calcium carbide waste, producer gas, natural gas, etc., in case of gaseous fuels. Conventional lime kilns face a number of problems which may be detrimental to the personnel as well as the plant or manufacturing set-up, especially due to involvement large quantities of fuels and other

combustible substances. Light-up or ignition of the heating unit i.e., burner and ignitor has been a challenge, and in some cases, hazardous from the safety point of view, be it blast furnace stoves, or sinter plants or lime kilns. One of the existing techniques makes use of fireballs (cloth soaked in oil and then ignited) to ignite a Coke Oven gas torch which raises the surrounding refractory lining temperature inside the kiln. This enables the heating unit to be fired with any other gas that is less combustible. But this process has always been fraught with safety issues mostly because of backfiring due to inadvertent extinguishing of the flame, and then re-igniting without proper purging. For instance, if due to some reason the pilot burner flame extinguishes, then the combustible gas would be kept accumulating inside the kiln. The reason could be improper air to gas ratio, technical glitches, faulty components, and so on. This unburnt, accumulated gas needs to be purged properly before re-ignition. In some instances, even after purging, there may be chances of backfire during ignition as fireball insertion, by itself, is a hazardous task which requires utmost attention, skills, and care. This makes it mandatory for the personnel to have a close watch and continuous monitoring of the pilot burner flame. Another problem is the complications associated with regulation of temperatures inside the kiln, which may also prove hazardous in certain situations.
[004] Present disclosure is directed to overcome one or more limitations stated above or any other limitations associated with the prior arts.
SUMMARY OF THE DISCLOSURE
[005] One or more shortcomings of the prior arts are overcome by the system, the assembly and the method as disclosed in the present disclosure and additional advantages are provided through the system, the assembly and the method. 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.
[006] In one non-limiting embodiment of the present disclosure, a system for igniting a pilot burner in a lime kiln is disclosed. The system includes an ignition torch supported by a first closure concealing an opening in the lime kiln, where the ignition torch comprises a spark plug. Then, the system includes a first flame sensor supported by the first closure, the first flame sensor is configured to detect flame of the ignition torch in the lime kiln. Further, the system has a supply

unit supported by a second closure concealing another opening in the lime kiln, the supply unit is configured to direct coke oven gas and air to the pilot burner inside the lime kiln. The system then includes a control unit configured to actuate at least one first valve to supply an auxiliary fuel and air to the ignition torch. Then the control unit activates the spark plug to ignite the ignition torch and actuates at least one second valve to direct the coke oven gas and the air into the pilot burner based on detection of the flame of the ignition torch, to ignite the pilot burner by the flame of the ignition torch.
[007] In an embodiment, the ignition torch is electrically powered. Further, the auxiliary fuel source is a liquid petroleum gas (LPG) source.
[008] In an embodiment, the supply unit is fluidly connected to a coke oven gas source and an air source.
[009] In an embodiment, the first flame sensor is at least one of an ionization electrode flame sensor, ultraviolet (UV) flame sensor, an infrared flame (IR) sensor or an integrated UV and IR flame sensor. Further, the system includes a second flame sensor supported by the second closure, the second flame sensor is configured to detect burning of the pilot burner in the lime kiln. The second flame sensor is a UV sensor communicatively coupled to the control unit to indicate a burning condition of the pilot burner to the control unit.
[0010] In an embodiment, the control unit is configured to close the at least one second valve to cut-off supply of the coke oven gas and the air to the pilot burner inside the lime kiln based on detection of an extinguished condition of the pilot burner by the second flame sensor.
[0011] In an embodiment, the system includes at least one thermal sensor communicatively coupled to the control unit, wherein the at least one thermal sensor is configured to detect temperature of the pilot burner.
[0012] In another non-limiting embodiment, a pilot burner assembly for a lime kiln associated with steel making process is disclosed. The assembly includes a pilot burner extending inside a refractory lining of the lime kiln, where the pilot burner is configured to burn to heat the refractory lining. The pilot burner assembly then includes a system for igniting the pilot burner in the lime
4

kiln. The system includes an ignition torch supported by a first closure concealing an opening in the lime kiln, where the ignition torch comprises a spark plug. Then, the system includes a first flame sensor supported by the first closure, the first flame sensor is configured to detect flame of the ignition torch in the lime kiln. Further, the system has a supply unit supported by a second closure concealing another opening in the lime kiln, the supply unit is configured to direct coke oven gas and air to the pilot burner inside the lime kiln. The system then includes a control unit configured to actuate at least one first valve to supply an auxiliary fuel and air to the ignition torch. Then the control unit activates the spark plug to ignite the ignition torch and actuates at least one second valve to direct the coke oven gas and the air into the pilot burner based on detection of the flame of the ignition torch, to ignite the pilot burner by the flame of the ignition torch.
[0013] In an embodiment, the assembly includes at least one thermal sensor communicatively coupled to the control unit, the at least one thermal sensor configured to detect temperature of the pilot burner.
[0014] In another non-limiting embodiment, a method for igniting a pilot burner in a lime kiln associated with steel making process is disclosed. The method includes actuating, by a control unit, at least one first valve to supply an auxiliary fuel and air to the ignition torch, where the ignition torch is supported by a first closure concealing an opening in the lime kiln. The method then includes activating, by the control unit, a spark plug to ignite the ignition torch, and then, actuating at least one second valve to direct coke oven gas and air into the pilot burner through a supply unit based on detection of flame of the ignition torch, to ignite the pilot burner by the flame of the ignition torch. The flame of the ignition torch is detected by a first flame sensor supported by the first closure in the lime kiln.
[0015] In an embodiment, the method includes detecting burning of the pilot burner by a second flame sensor, the second flame sensor is supported by a second closure fluidly coupled with the lime kiln.
[0016] In an embodiment, the method includes closing, by the control unit, the at least one second valve to cut-off supply of the coke oven gas and the air to the pilot burner based on detection of an extinguished condition of the pilot burner by the second flame sensor.

[0017] 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 together to form a further embodiment of the disclosure.
[0018] 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
[0019] The novel features and characteristics of the disclosure are set forth in the appended description. 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:
[0020] FIG. 1 illustrates a schematic of a portion of the lime kiln having a pilot burner assembly along with a system for igniting the pilot burner, according to an embodiment of the present disclosure;
[0021] FIG. 2 is a flowchart depicting the method for igniting a pilot burner in a lime kiln shown FIG. 1; and
[0022] FIG. 3 illustrates a schematic block diagram of the pilot burner assembly having the system for igniting the pilot burner, according to an embodiment of the present disclosure.
[0023] 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 system, the assembly and the method illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION
[0024] 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 description of the disclosure. It should also be realized by those skilled in the art that such equivalent methods do not depart from the scope of the disclosure. The novel features which are believed to be characteristic of the disclosure, as to 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.
[0025] In the present disclosure, the word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any embodiment or implementation of the present subject matter described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.
[0026] While the disclosure is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and will be described in detail below. It should be understood, however that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternative falling within the scope of the disclosure.
[0027] The terms “comprises”, “comprising”, or any other variations thereof, are intended to cover non-exclusive inclusions, such that a system, an assembly, or a method that comprises a list of acts does not include only those acts but may include other acts not expressly listed or inherent to such a system or an assembly or a method. In other words, one or more acts in a method proceeded by “comprises… a” does not, without more constraints, preclude the existence of other acts or additional acts in the system or the assembly or the method.
[0028] Embodiments of the present disclosure disclose a system for igniting a pilot burner in lime kilns. The system includes an ignition torch supported by a first closure concealing an opening in

the lime kiln, where the ignition torch comprises a spark plug. The ignition torch containing the spark plug is powered electrically, so that the spark plug generates sparks to ignite the air-fuel mixture discharged into the ignition torch. In an embodiment, the ignition torch is supplied with an auxiliary fuel, such as LPG, along with air for combustion. Then, the system includes a first flame sensor supported by the first closure, the first flame sensor is configured to detect flame of the ignition torch in the lime kiln. Further, the system has a supply unit supported by a second closure concealing another opening in the lime kiln, the supply unit is configured to direct coke oven gas and air to the pilot burner inside the lime kiln. For this, the supply unit is connected to a coke oven gas source and an air source. In an embodiment, the first flame sensor is at least one of an ionization electrode flame sensor, ultraviolet (UV) flame sensor, an infrared flame (IR) sensor or an integrated UV and IR flame sensor. The system also includes a second flame sensor supported by the second closure and associated with the detection of the flame in the pilot burner inside the lime kiln. The system then includes a control unit configured to actuate at least one first valve to supply an auxiliary fuel and air to the ignition torch. Then the control unit activates the spark plug to ignite the ignition torch. This is followed by control unit actuating at least one second valve to direct the coke oven gas and the air into the pilot burner based on detection of the flame of the ignition torch, to ignite the pilot burner by the flame of the ignition torch. Further, the second flame sensor is a UV sensor communicatively coupled to the control unit to indicate a burning condition of the pilot burner to the control unit.
[0029] In an embodiment, the control unit is configured to close the at least one second valve to cut-off supply of the coke oven gas and the air to the pilot burner inside the lime kiln based on detection of an extinguished condition of the pilot burner by the second flame sensor. The system also includes at least one thermal sensor communicatively coupled to the control unit, the at least one thermal sensor is configured to detect temperature of the pilot burner.
[0030] Present disclosure also discloses a pilot burner assembly having a pilot burner extending inside a refractory lining of the lime kiln, where the pilot burner is configured to burn to heat the refractory lining. The assembly, in addition to pilot burner, includes the system discussed in the above paragraphs.

[0031] Further, the present disclosure embodies a method for igniting a pilot burner in a lime kiln associated with steel making process. The method includes actuating, by a control unit, at least one first valve to supply an auxiliary fuel and air to the ignition torch, where the ignition torch is supported by a first closure concealing an opening in the lime kiln. This is followed by activating, by the control unit, a spark plug to ignite the ignition torch, and then, actuating at least one second valve to direct coke oven gas and air into the pilot burner through a supply unit based on detection of flame of the ignition torch for ignition of the ignition torch. The flame of the ignition torch is detected by a first flame sensor supported by the first closure in the lime kiln. The method involves detecting burning of the pilot burner by a second flame sensor that is supported by a second closure. The second closure remains in fluid connection with the lime kiln. Based on detection of the extinguished condition , the control unit closes the at least one second valve to cut-off supply of the coke oven gas and the air to the pilot burner.
[0032] The present disclosure is explained with the help of figures. However, such exemplary embodiments should not be construed as limitations of the present disclosure since the system, the assembly and the method disclosed may be used or employed for any manufacturing process or any metallurgical facility. A person skilled in the art may envisage various such embodiments without deviating from scope of the present disclosure.
[0033] FIG. 1 illustrates a schematic of a portion of a lime kiln (100) having a system (50) for igniting a pilot burner (3) associated with the lime kiln (100). Modern lime kilns (100) as shown may have one or more vertical towers or chambers having an outer wall or a structure (1). For example, a lime kiln (100) may be of a single shaft or a twin shaft configuration. The outer wall or structure (1) may include several layers or sections including, but not limited to refractory linings, cooling layers, coatings and so on, which are not discussed in detail. The refractory lining, for example, a lining of refractory bricks, is intended to withstand high temperatures and provide structural stability, thermal insulation and robustness to the lime kiln (100). As shown, the lime kiln (100) is associated with the system (50) intended to ignite the pilot burner (3) and monitor some of the parameters associated with the lime kiln (100) operation. The pilot burner (3) may be positioned at an optimal position, for instance, in a connecting channel [not shown] inside a twin shaft lime kiln. The pilot burner (3) may be fed with air-fuel mixture, including but not limited to coke oven gas plus air mixture for combustion, and consequently, for heating the refractory lining

of the lime kiln (100). In an embodiment, burning of the pilot burner (3) may increase the temperature of the refractory lining to about 600-700 degree Celsius. In another embodiment, the refractory lining may be defined or equipped with a plurality of lances [not shown] through which combustible gases may be charged. The gases charged through the lances may catch fire due to high temperature of the refractory lining previously heated up by the pilot burner (3). This results in burning of the gases charged from the lances within the space (2) inside the lime kiln (100) to perform calcination of the limestone. In an embodiment, the calcination process may be accompanied with cooling and discharging phases, which are not discussed. Further, the position and orientation of the pilot burner (3) shown in FIG. 1 is for the purpose of illustration only, and the pilot burner (3) may be positioned and oriented in any manner inside the lime kiln (100) depending on the requirement.
[0034] The pilot burner (3), as shown, may be supported by a supply unit (17). For example, the pilot burner (3) may be inserted into the space (2) through the supply unit (17). The supply unit (17) may in turn be supported by a second closure (18) which conceals an opening (P2) in the lime kiln (100). In an embodiment, the supply unit (17) may be integral with the second closure (18) or may be joined by any of the known joining means. In another embodiment, the supply unit (17) may be in the form of a conduit, a chamber, a closure, a duct, a pipe, or of any other configuration. In an embodiment, the second closure (18) may support a second flame sensor (16) which may be associated with the detection of a flame (3F) in the pilot burner (3) inside the lime kiln (100). The supply unit (17) may direct or channelize the fuel and air to the pilot burner (3) for burning. In an embodiment, the pilot burner (3) may be cylindrical in shape with internal channels/passages [not shown] for directing the air and the fuel. The pilot burner (3) may have an extremity (3N) which defines a nozzle like end for enhancing discharging characteristics of the flame (3F). In an embodiment, the supply unit (17) may receive air from an air conduit (19), and the fuel from a fuel conduit (22). The air conduit (19) and the fuel conduit (22) may be fluidly connected to an air source (3AI) and a fuel source (3CO), respectively. The air source (3AI) and the fuel source (3CO) are not shown. In an embodiment, the fuel is a coke oven gas, although other fuels may be readily used for burning the pilot burner (3). The fuel conduit (22) in fluid connection with the fuel source (3CO) [coke oven gas source] may be provided with one or more second valves, including but not limited to direction, pressure and flow regulating valves. One or more second valves are

interchangeably referred to as at least one second valve throughout the specification. For example, the valve (22A) may be a direction control valve which may allow or restrict flow of the fuel into the supply unit (17), or a pressure/flow control valve (22B) which may regulate pressure and flow rates of the fuel. The air conduit (19) may be provided with a similar valve (19A). The valves associated with the fuel conduit (22) and the air conduit (19) are collectively termed as one or more second valves throughout the specification. In an embodiment, the conduits (19) and (22) may be equipped with sensors (20, 21) which may detect flow conditions, including but not limited to direction, pressure and flow characteristics of the fuel and the air inside their respective conduits (19) and (22). The supply unit (17) may have internal arrangements to channelize the air-fuel mixture inside the pilot burner (3).
[0035] Further, the system (50) as shown may include an ignition torch (4) supported by a first closure (8). The first closure (8) is positioned so as to conceal another opening (P1) in the lime kiln (100). In an embodiment, the opening (P1) may be a poking hole in the lime kiln (100). The ignition torch (4), as shown, may be equipped with a spark plug (5) [or a lighter]. In an embodiment, the spark plug (5) may be powered electrically or mechanically, so that the spark plug (5) may generate sparks to aid in ignition of the ignition torch (4). In an embodiment, the ignition torch (4) may be supplied with an auxiliary fuel, such as LPG or other gases, along with air for combustion. The first closure (8) as shown may be provided with air inlet (14) for directing air from an air source (4AI), and a fuel inlet (13) for supplying the auxiliary fuel (LPG) from a fuel source (4FI). Like the second closure (18), the first closure (8) may also have internal arrangements (not shown) to direct the air and fuel mixture into the ignition torch (4) towards the spark plug (5) for combustion and ignition. Further, as shown, first closure (8) may support a first flame sensor (7) in the vicinity or proximity (6) of the spark plug (5). The first flame sensor (7) may detect a condition of flame (4F) of the ignition torch (4) effected by the spark plug (5). For example, the first flame sensor (7) may detect presence or absence of the flame (4F) of the ignition torch (4). In some embodiments, the first flame sensor (7) may detect other characteristics of the flame (4F), such as but not limited to intensity, spectral properties, luminance, etc., of the flame (4F). Ignition mechanism of the fuel (LPG) and air mixture by the spark plug (5) may be similar to conventional spark plugs or lighters. In an embodiment, the first flame sensor (7) is at least one of an ionization electrode flame sensor or other alternatives. The first flame sensor (7) may detect

spectral properties such as wavelength, frequency, energy, or other radiation characteristics of the flame (4F), depending on the nature and type of flame sensor employed.
[0036] In an embodiment of the disclosure, the ignition torch (4) may be optionally enclosed and/or supported by a shell-like enclosure (9) which may partially or fully surround the ignition torch (4). The sparks (5S) produced by the spark plug (5) of the ignition torch (4) may take part in igniting the pilot burner (3). For instance, the spark plug (5) may be activated to produce sparks whenever the pilot burner (3) needs to be set in operation to heat the refractory lining of the lime kiln (100). In an embodiment, the nozzle (3N) portion of the pilot burner (3) may be spaced apart from the vicinity of the spark plug (5) by a predefined distance. In such a scenario, the ignition torch (4) may produce flame (4F) of sufficient length that may easily ignite the pilot burner (3). In an embodiment, the spark plug (5) may be activated or ignited to effect ignition of the pilot burner (3).
[0037] Referring back to the fuel inlet (13) and the air inlet (14), one or more first valves (13A, 14A) may be provided in each of these inlets. One or more first valves are interchangeably referred to as at least one first valve throughout the specification. The one or more first valves (13A, 14A) may include but not limited to direction, pressure and flow regulating valves. For example, the valves (13A, 14A) may be direction control valves which may allow or restrict flow of the auxiliary fuel and the air into the inlets (13) and (14), respectively. In other embodiments, the one or more first valves (13A, 14A) may include pressure/flow control valve in addition to direction control valves which may regulate pressure and flow rates of the auxiliary fuel and the air. The valves (13A, 14A) associated with the fuel inlet (13) and the air inlet (14) are collectively termed as one or more first valves throughout the specification. In an embodiment, the inlets (13) and (14) may be equipped with sensors (15) which may detect flow characteristics, including but not limited to direction, pressure and flow rates of the auxiliary fuel and the air inside their respective inlets (13) and (14). In an embodiment, the one or more first valves, the one or more second valves, the spark plug (5), the first flame sensor (7), the second flame sensor (16), the sensors (15, 20, 21) are communicatively interfaced with a control unit (25) [depicted by dotted lines]. The control unit (25) may regulate and coordinate the operations of the one or more first valves, the one or more second valves, the spark plug (5), the first flame sensor (7), the second flame sensor (16), and the sensors (15, 20, 21), which will be explained in detail below.

[0038] Reference is now made to FIG. 2 which illustrates a flowchart depicting a method embodiment of the present disclosure. FIG. 1 is also referred in conjunction with FIG. 2. The method is intended for igniting the pilot burner (3) in the lime kiln (100) through the ignition torch (4). The method includes a first step (201) of actuating at least one first valve (13A, 14A) to supply the auxiliary fuel and air to the ignition torch (4). Once the auxiliary fuel and the air mixture reach the spark plug (5) in the ignition torch (4), the control unit (25) may activate the spark plug (5) to ignite the ignition torch (4), i.e., by producing sparks (5S) which combust the incoming auxiliary fuel and air mixture. The sensors (15) may give feedback to the control unit (25) regarding flow characteristics of both auxiliary fuel and air as they enter into the ignition torch (4). Activation of the spark plug (5) by the control unit (25) is depicted by step (202). The control unit (25), upon activating the spark plug (5), actuates the at least one second valve (19A, 22A) to direct the coke oven gas and the air into the pilot burner (3) through the conduits (22) and (19) respectively, and the supply unit (17). Actuation of the second valves (19A, 22A) is based on detection of the flame (4F) of the ignition torch (4) by the first flame sensor (7). The first flame sensor (7) may send signals to the control unit (25) corresponding to conditions of the flame (4F) of the ignition torch (4), as depicted by step (203). The control unit (25) may decide regarding actuation of the second valves (19A, 22A) on the basis of whether the ignition torch (4) is burning or not, based on signals received from the first flame sensor (7). Once the coke oven gas and air mixture enters the pilot burner (3) through opened second valves (19A, 22A), and if the ignition torch (4) is burning, then the pilot burner (3) gets ignited by the ignition torch (4) due to combustion of the coke oven gas and air mixture. The flame (3F) emanating from the pilot burner (3) raises the temperature of the refractory lining which may aid in firing up of supplemental air fuel mixture necessary for calcination of the limestone. Actuation of the second valves (19A, 22A) by the control unit (25) is depicted by step (204), while ignition of the pilot burner (205) by the ignition torch (4) is depicted by the step (205). In an embodiment, if the first flame sensor (7) detects an extinguished condition of the flame (4F) of the ignition torch (4), then the first flame sensor (7) may indicate the control unit (25) about absence of the flame (4F). The control unit (25) may check the first valves (13A, 14A) for conditions, such as malfunctional issues, opening conditions, etc., to make sure that the auxiliary fuel and air are appropriately directed towards the ignition torch (4). The control unit (25) may also receive feedback from sensors (15) regarding flow characteristics of the auxiliary

fuel and air. Once proper flow of the auxiliary fuel and the air is ensured, the control unit (25) may activate the spark plug (5) to ignite the ignition torch. In an embodiment, the control unit (25) may have a timing and control module which may regulate and monitor the timing of ignition and non-ignition of the spark plug (5).
[0039] FIG. 3 illustrates a block diagram depicting the pilot burner assembly (200) having the system (50) outlined in the above paragraphs, according to some embodiments of the disclosure. The assembly (200), alongside system (50) components, may include a second flame sensor (16) communicatively associated with the pilot burner (3) [also shown in FIG. 1] as well as the control unit (25). In an embodiment, the second flame sensor (16) may be an ultraviolet (UV) sensor or other alternatives which may detect characteristics of the flame (3F) of the pilot burner (3), such as but not limited to presence or absence of the flame (3F), intensity, spectral properties, luminance, etc. In an embodiment, the second flame sensor (16) may detect spectral properties such as wavelength, frequency, energy, or other radiation characteristics of the flame (3F), depending on the type of flame sensor employed.
[0040] Now, if due to some issues the pilot burner (3) goes off, i.e., the flame (3F) extinguishes, the second flame sensor (16) gives signals to the control unit (25) regarding the extinguished condition. The control unit (25), in response, may close the second valves (19A, 22A) to cut¬off/inhibit coke oven gas and air from entering into the pilot burner (3). This prevents unintended accumulation of the coke oven gas and air inside the lime kiln in the absence of the flame (3F) of the pilot burner (3). As shown in FIG. 3, a thermal sensor (80) such as, but not limited to pyrometer or a thermostat may also be integrated in the lime kiln (100). The thermal sensor (80) may be interfaced with the control unit (25) so that it may indicate the temperature of refractory lining or the gases of combustion or any components in the kiln (100) to the control unit (25), which may be beneficial in preventing hazards due to overheating.
[0041] In an embodiment of the disclosure, the control unit (25) (like an electronic control unit) may be a centralized control unit, or a dedicated control unit associated with the lime kiln (100) components. The control unit (25) may be implemented by any computing systems that is utilized to implement the features of the present disclosure. The control unit may be comprised of a processing unit. The processing unit may comprise at least one data processor for executing

program components for executing user- or system-generated requests. The processing unit may be a specialized processing unit such as integrated system (bus) controllers, memory management control units, floating point units, graphics processing units, digital signal processing units, etc. The processing unit may include a microprocessor, such as AMD Athlon, Duron or Opteron, ARM’s application, embedded or secure processors, IBM PowerPC, Intel’s Core, Itanium, Xeon, Celeron or other line of processors, etc. The processing unit may be implemented using a mainframe, distributed processor, multi-core, parallel, grid, or other architectures. Some embodiments may utilize embedded technologies like application-specific integrated circuits (ASICs), digital signal processors (DSPs), Field Programmable Gate Arrays (FPGAs), etc.
[0042] In some embodiments, the control unit may be disposed in communication with one or more memory devices (e.g., RAM, ROM etc.) via a storage interface. The storage interface may connect to memory devices including, without limitation, memory drives, removable disc drives, etc., employing connection protocols such as serial advanced technology attachment (SATA), integrated drive electronics (IDE), IEEE-1394, universal serial bus (USB), fiber channel, small computing system interface (SCSI), etc. The memory drives may further include a drum, magnetic disc drive, magneto-optical drive, optical drive, redundant array of independent discs (RAID), solid-state memory devices, solid-state drives, etc.
[0043] The system, assembly and method disclosed in the present disclosure have several inherent advantages. One advantage is that the potential hazards due to inadvertent ignition or combustion of pilot burner may be eliminated. This not only prevents hazards but is also beneficial in saving the fuel and inadvertent increase in temperature of the lime kiln. Another advantage is that the presence of thermal sensors interfaced with the control unit assists in monitoring the temperatures inside the lime kiln, thereby eliminating the hazards due to uncontrolled/undesired rise in temperatures. Yet another advantage is that the flame sensors may give indications regarding characteristics of the flame [pilot burner and ignition torch] which may be beneficial in precise monitoring and regulation of air-fuel mixture flow into the pilot burner, as well as the ignition torch.

Equivalents:
[0044] 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.
[0045] It will be understood by those within the art that, in general, terms used herein, and
especially in the appended claims (e.g., bodies of the appended claims) 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 following appended claims 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, claims, 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."
[0046] 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 being indicated by the following claims.

Table of reference numerals
Component/Step Numeral
Lime kiln 100
System 50
Outer wall or structure 1
Space/volume inside the lime kiln 2
Pilot burner 3
Extremity/Nozzle 3N
Flame of the pilot burner 3F
Coke oven gas source 3CO
Air source to pilot burner 3AI
Ignition torch 4

Flame of ignition torch 4F
Air source to ignition torch 4AI
Auxiliary fuel source 4FI
Spark plug 5
Sparks of spark plug 5S
Vicinity/Proximity of spark plug 6
First flame sensor 7
First closure 8
Shell like enclosure 9
Auxiliary Fuel inlet 13
Air inlet 14
First valves 13A, 14A
Sensors 15, 20, 21
Second flame sensor 16
Supply unit 17
Second closure 18
Air conduit 19
Fuel conduit 22
Second valves 19A, 22A, 22B
Control unit 25
Openings in the kiln P1, P2
Horizontal and vertical spacings H, W
Method steps 201-205
Pilot burner Assembly 200
Memory unit 60

Thermal sensor 80

We claim:
1. A system (50) for igniting a pilot burner (3) in a lime kiln (100), the system (50)
comprising:
an ignition torch (4) supported by a first closure (8) concealing an opening (P1) in the lime kiln (100), wherein the ignition torch (4) comprises a spark plug (5);
a first flame sensor (7) supported by the first closure (8), the first flame sensor (7) is configured to detect flame (4F) of the ignition torch (4) in the lime kiln (100);
a supply unit (17) supported by a second closure (18) concealing another opening (P2) in the lime kiln (100), the supply unit (17) is configured to direct coke oven gas and air to the pilot burner (3) inside the lime kiln (100);
and
a control unit (25), configured to:
actuate at least one first valve (13A, 14A) to supply an auxiliary fuel and
air to the ignition torch (4),
activate the spark plug (5) to ignite the ignition torch (4), and
actuate at least one second valve (19A, 22A) to direct the coke oven gas and
the air into the pilot burner (3) based on detection of the flame (4F) of the ignition
torch (4), to ignite the pilot burner (3) by the flame (4F) of the ignition torch (4).
2. The system (50) as claimed in claim 1, wherein the ignition torch (4) is electrically powered.
3. The system (50) as claimed in claim 1, wherein the auxiliary fuel is liquid petroleum gas (LPG).
4. The system (50) as claimed in claim 1, wherein the supply unit (17) is fluidly connected to a coke oven gas source (3CO) and an air source (3AI).
5. The system (50) as claimed in claim 1, wherein the first flame sensor (7) is at least one of an ionization electrode flame sensor.

6. The system (50) as claimed in claim 1 comprises a second flame sensor (16) supported by the second closure (18), the second flame sensor (16) is configured to detect burning of the pilot burner (3) in the lime kiln (100).
7. The system (50) as claimed in claim 6, wherein the second flame sensor (16) is a UV sensor communicatively coupled to the control unit (25) to indicate a burning condition of the pilot burner (3) to the control unit (25).
8. The system (50) as claimed in claims 1 and 6, wherein the control unit (25) is configured to close the at least one second valve (19A, 22A) to cut-off supply of the coke oven gas and the air to the pilot burner (3) inside the lime kiln (100) based on detection of an extinguished condition of the pilot burner (3) by the second flame sensor (16).
9. The system (50) as claimed in claim 1 comprises at least one thermal sensor (80) communicatively coupled to the control unit (25), wherein the at least one thermal sensor (80) is configured to detect temperature of the pilot burner (3).
10. A pilot burner assembly (200) for a lime kiln (100), the assembly (200) comprising:
a pilot burner (3) extending inside a refractory lining of the lime kiln (100), wherein the pilot burner (3) is configured to heat the limestone in the lime kiln (100) to fire the burden through main lances; and a system (50) for igniting the pilot burner (3), the system (50) comprising:
an ignition torch (4) supported by a first closure (8) concealing an opening (P1) in the lime kiln (100), wherein the ignition torch (4) comprises a spark plug (5);
a first flame sensor (7) supported by the first closure (8), the first flame sensor (7) is configured to detect flame (4F) of the ignition torch (4) in the lime kiln (100);
a supply unit (17) supported by a second closure (18) concealing another opening (P2) in the lime kiln (100), the supply unit (17) is configured to direct coke oven gas and air to the pilot burner (3) inside the lime kiln (100);

and
a control unit (25), configured to:
actuate at least one first valve (13A, 14A) to supply an auxiliary fuel
and air to the ignition torch (4),
activate the spark plug (5) to ignite the ignition torch (4), and actuate at least one second valve (19A, 22A) to direct the coke oven
gas and the air into the pilot burner (3) based on detection of the flame (4F)
of the ignition torch (4), to ignite the pilot burner (3) by the flame (4F) of
the ignition torch (4).
11. The assembly (200) as claimed in claim 10 comprises at least one thermal sensor (80) communicatively coupled to the control unit (25), wherein the at least one thermal sensor (80) is configured to detect temperature of the pilot burner (3).
12. A method for igniting a pilot burner (3) in a lime kiln (100) associated with steel making process, the method comprising:
actuating, by a control unit (25), at least one first valve (13A, 14A) to supply an auxiliary fuel and air to the ignition torch (4), wherein the ignition torch (4) is supported by a first closure (8) concealing an opening (P1) in the lime kiln (100),
activating, by the control unit (25), a spark plug (5) to ignite the ignition torch (4), and
actuating, by the control unit (25), at least one second valve (19A, 22A) to direct coke oven gas and air into the pilot burner (3) through a supply unit (17) based on detection of flame (4F) of the ignition torch (4), to ignite the pilot burner (3) by the flame (4F) of the ignition torch (4),
wherein, the flame (4F) of the ignition torch (4) is detected by a first flame sensor (7) supported by the first closure (8) in the lime kiln (100).
13. The method as claimed in claim 12, comprises detecting burning of the pilot burner (3) by
a second flame sensor (16), wherein the second flame sensor (16) is supported by a second
closure (18).

14. The method as claimed in claim 12 comprises closing, by the control unit (25), the at least one second valve (19A, 22A) to cut-off supply of the coke oven gas and the air to the pilot burner (3) based on detection of an extinguished condition of the pilot burner (3) by the second flame sensor (16).