Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23Q—IGNITION; EXTINGUISHING-DEVICES
  • F23Q9/00—Pilot flame igniters
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23D—BURNERS
  • F23D14/00—Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid
  • F23D14/02—Premix gas burners, i.e. in which gaseous fuel is mixed with combustion air upstream of the combustion zone
  • F23D14/04—Premix gas burners, i.e. in which gaseous fuel is mixed with combustion air upstream of the combustion zone induction type, e.g. Bunsen burner
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23D—BURNERS
  • F23D14/00—Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid
  • F23D14/46—Details, e.g. noise reduction means
  • F23D14/72—Safety devices, e.g. operative in case of failure of gas supply
  • F23D14/725—Protection against flame failure by using flame detection devices
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23G—CREMATION FURNACES; CONSUMING WASTE PRODUCTS BY COMBUSTION
  • F23G7/00—Incinerators or other apparatus for consuming industrial waste, e.g. chemicals
  • F23G7/06—Incinerators or other apparatus for consuming industrial waste, e.g. chemicals of waste gases or noxious gases, e.g. exhaust gases
  • F23G7/08—Incinerators or other apparatus for consuming industrial waste, e.g. chemicals of waste gases or noxious gases, e.g. exhaust gases using flares, e.g. in stacks
  • F23G7/085—Incinerators or other apparatus for consuming industrial waste, e.g. chemicals of waste gases or noxious gases, e.g. exhaust gases using flares, e.g. in stacks in stacks
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23Q—IGNITION; EXTINGUISHING-DEVICES
  • F23Q7/00—Incandescent ignition; Igniters using electrically-produced heat, e.g. lighters for cigarettes; Electrically-heated glowing plugs
  • F23Q7/06—Incandescent ignition; Igniters using electrically-produced heat, e.g. lighters for cigarettes; Electrically-heated glowing plugs structurally associated with fluid-fuel burners
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23D—BURNERS
  • F23D2207/00—Ignition devices associated with burner
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23D—BURNERS
  • F23D2900/00—Special features of, or arrangements for burners using fluid fuels or solid fuels suspended in a carrier gas
  • F23D2900/00014—Pilot burners specially adapted for ignition of main burners in furnaces or gas turbines
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23N—REGULATING OR CONTROLLING COMBUSTION
  • F23N2227/00—Ignition or checking
  • F23N2227/22—Pilot burners
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23N—REGULATING OR CONTROLLING COMBUSTION
  • F23N2227/00—Ignition or checking
  • F23N2227/42—Ceramic glow ignition

Definitions

• the present invention relates to devices for igniting combustible waste gases, and more particularly, to a spark-less pilot igniter which uses induction heating to ignite combustible gas in an ignition system.
• the most commonly employed means of disposing of waste gases is generally by elevated flare stacks.
• the safety and effectiveness of disposing waste gas in an elevated flare is dependent on the ignition of these gases either through a continuous or intermittent pilot, or with constant or intermittent electric ignition.
• the present means of igniting waste gases at the end of a flare stack is with a constant burning pilot. Since a pilot uses natural gas or propane which is becoming more costly, a method of igniting either the pilot or a direct ignition of the flare gases by the use of an electrical ignitor is advantageous.
• the present method of ignition of a pilot at the top of a stack is mixing natural gas, propane, or other fuel gas and air at the ground level and igniting it and forcing this ignited gas up a long tube to a pilot at the top of the stack. This method, however, is not a positive method of ignition.
• an apparatus for igniting waste gases flowing from an exhaust exit of a flare gas stack.
• a pilot head is positioned proximally to the exhaust exit, wherein combustible pilot gas flows through the pilot head.
• a hot surface ignition assembly is positioned proximally to the pilot head, wherein the hot surface assembly passes electric current through a ceramic-insulated element in order to produce heat by induction sufficient to ignite the pilot gas.
• the hot surface ignition assembly can operate at or above temperatures of 2,100 °F.
• the combustible pilot gas is a different composition than the gas flowing through the flare gas stack. In yet other embodiments, the combustible pilot gas is the same composition as the gas flowing through the flare gas stack.
• thermocouple positioned proximally to the pilot head, wherein the thermocouple is able to sense heat from combusting pilot gas and, upon sensing the heat, reducing or eliminating the electric current passing through the ceramic-insulated element.
• the thermocouple is also able to sense the absence of heat from combusting pilot gas and, upon sensing the absence of heat, again passing said electric current through said ceramic-insulated element.
• FIG. 1 is a side view of a pipe flare tip with a pilot incorporating one embodiment of the hot surface igniter of the present invention
• FIG. 3 is a side view of a pilot as shown in FIG. 1 and FIG. 2;
• FIG. 4 is a perspective view of a flame front combustion chamber incorporating one embodiment of the hot surface igniter of the present invention
• FIG 6. is a side view of a flare tip combustion chamber mounted on a flare tip to ignite process gas and using one embodiment of the hot surface igniter of the present invention
• FIG. 8 is a perspective view of a flare tip combustion chamber hot surface igniter assembly as in FIG. 6 and FIG. 7 and
• FIG. 9 is a side view of a flare tip combustion chamber hot surface igniter assembly with a partial cross-sectional cutaway view of the internal wiring connection and tip.
• the present invention is directed to improved methods of igniting waste gas.
• the configuration and use of the presently preferred embodiments are discussed in detail below. It should be appreciated, however, that the present invention provides many applicable inventive concepts that can be embodied in a wide variety of contexts other than traditional waste gas combustion. Accordingly, the specific embodiments discussed are merely illustrative of specific ways to make and use the invention, and do not limit the scope of the invention.
• waste gases which must be disposed of either continuously or intermittently through flaring, thermal oxidation, or other means of process combustion and must be ignited so that the gases are disposed of safely and effectively.
• waste gases are process byproducts that are continuously produced at a relatively constant volumetric flow rate.
• large quantities of gases such as feed materials, intermediates, or products, must be disposed of quickly to prevent explosions and/or hazardous conditions from occurring in the plant.
• Flaring is a combustion control process in which volatile organic compounds (VOCs) are piped to a remote, usually elevated, location and burned in an open flame in the open air using a specially designed burner tip, auxiliary fuel, and steam or air to promote mixing for VOC destruction.
• VOCs volatile organic compounds
• the degree to which combustion is completed is governed by flame temperature, amount of time in the combustion zone, turbulence in the mixing of the components to complete the oxidation reaction, and available oxygen for free radical formation.
• the combustion is considered complete if all VOCs are converted to carbon dioxide and water. Incomplete combustion results in some of the VOC being unaltered or converted to other organic compounds such as aldehydes or acids.
• FIG. 1 in which a pipe flare tip 1 is shown with a pilot assembly 2 mounted to it by means of an upper mounting bracket 9 and a lower mounting bracket 10.
• the flare tip 1, or burner tip is designed to give environmentally acceptable combustion of the vent gas over the flare system's capacity range.
• the maximum and minimum capacity of a flare to burn a flared gas with a stable flame is a function of tip design.
• consideration is given to flame stability, ignition reliability, and noise suppression.
• Many flare tips are known in the art although they are often proprietary in design.
• the flare structure, pilot gas piping, and other upstream components have not been shown for clarity, since they are common amongst all flare systems and known to those familiar with the art.
• FIG. 2 and FIG. 3 illustrate one embodiment of a pilot assembly 2 with more clarity.
• a pilot head 3 is affixed to the top of pilot body 5.
• the pilot assembly 2 is secured to a supporting member (not shown) by means of a pilot gas connection flange 13.
• the pilot gas will first pass through a Y-strainer 12 in order to remove any debris from the gas stream.
• the gas then goes through an inspiratory 11 which may, for example, rely on a venturi effect to mix ambient air into the pilot gas stream, thereby creating a combustible mixture.
• This combustible mixture is delivered to the pilot head 3 by means of the pilot body 5.
• the hot surface ignition assembly, or HSI assembly 4 is affixed to the pilot head 3 by, for example, a threaded or welded fitting, but may be affixed thereto by any means known in Utility Patent Application
• thermocouple junction box 7 Once the control system receives confirmation of the flame via the thermocouple junction box 7, the power to the HSI assembly 4 will be stopped, the HSI assembly 4 will cool, and the pilot flame will continue to burn. In the event that the pilot flame is extinguished, the thermocouple 6 will send a signal that will cause the control system to turn the HSI assembly 4 on again, and within seconds it will be hot enough to reignite the combustible pilot gas, and the cycle continues.
• the HSI assembly 4 is built to be a drop-in replacement for existing sparking technology. As with spark rods in the prior art, the HSI assembly will be supported by means of HSI support brackets 14. At the base of the HSI assembly is an HSI junction box 8 which provides the means of connecting the HSI assembly 4 to the power source via the HSI power connection 15.
• FIG. 4 and FIG. 5 illustrate another embodiment of the present invention.
• a fire ball also known in the art as a flame Utility Patent Application
• the ignition gas is mixed with the ignition air in the combustion chamber throat 18 by means of turbulence.
• the combustible gas passes into the combustion chamber body 19, inside of which is installed an HSI element 24.
• This element upon initiation by the controls system, will rapidly heat to a temperature in excess of 2,100 °F, causing ignition of the combustible mixture present in the combustion chamber body 19.
• the combustion initiates a flame front which can then pass through the combustion chamber exit port 25 to continue through a pipe until it exits and ignites a flare or pilot.
• the items downstream of the exit port are not shown since they are understood by those familiar with the art.
• the flame front was initiated by means of a high voltage spark which would be installed in the ignition port 21.
• the sparking contacts of the prior art are replaced with a hot surface igniter, which consists of a ceramic body 22, an induction heating element 21, and a power connection 23.
• the controls system (not shown) connects to the power connection 23 and provides a simple on/off signal. Since the device is entirely enclosed, a sight glass 20 is provided so the operator may have visual confirmation of the status of the HSI element 24.
• the HSI element 24 may be Utility Patent Application
• Cody et al. Attorney Docket No.: 3112-700WOPT inserted, for example, by means of a threaded connection in the ignition port 21 for ease of servicing.
• FIG. 6 in which process gas flows through the flare tip 26 to be combusted once it exits into the atmosphere.
• a process gas ignitor assembly 27 is shown mounted to the flare tip 26 and the ignitor head 29 is inserted into the combustion chamber 28 that is filled with re-directed process gas by means of the process gas diverter 33 which extends into the flare tip.
• This arrangement allows for reliable flaring without the use of pilot gas, a practice commonly referred to as 'zero-flaring.'
• the HSI junction box 31 is electrically connected to a controller located at grade that can be powered by a range of both AC and DC power sources.
• Power is transmitted by a high temperature power cable 42 that is electrically isolated within the ignitor body 30.
• the ignitor body 30 is affixed to the ignitor head 29 in which the high temperature power cable 42 is connected to the HSI power connection 41.
• a conventional nut and screw connection assembly is depicted for the sake of clarity, however, other means of connectivity are often used.
• the HSI power connection 41 is electrically isolated from the ignitor head 29 by means of a high-strength, heat resistant ceramic insulator 40.
• the HSI power connection 41 transmits power to the HSI assembly 35 depicted in FIG. 8.
• the HSI assembly is comprised of the HSI body 39 and the ceramic insulator 40, depicted in FIG. 9, which is protected by an impact guard 36.
• the HSI element (not shown for the sake of clarity) located at the end of the ignitor head 29 is inserted into an opening located on the combustion chamber 28, in which gas is diverted as aforementioned.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Environmental & Geological Engineering (AREA)
• Incineration Of Waste (AREA)

Applications Claiming Priority (2)

Publications (1)

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• 2011
  • 2011-10-28 BR BR112013010455A patent/BR112013010455A2/pt not_active IP Right Cessation
  • 2011-10-28 US US13/284,393 patent/US20120282555A1/en not_active Abandoned
  • 2011-10-28 EP EP11837191.3A patent/EP2633237A2/de not_active Withdrawn
  • 2011-10-28 WO PCT/US2011/058377 patent/WO2012058587A2/en active Application Filing

Non-Patent Citations (1)

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