By a News Reporter-Staff News Editor at Journal of Engineering -- From Alexandria, Virginia, VerticalNews journalists report that a patent by the inventors Colannino, Joseph (Bellevue, WA); Karkow, Douglas W. (Des Moines, WA); Wiklof, Christopher A. (Everett, WA), filed on August 11, 2015, was published online on November 28, 2017.
The patent's assignee for patent number 9828288 is Clearsign Combustion Corporation (Seattle, WA).
News editors obtained the following quote from the background information supplied by the inventors: "Rotary kilns, or calciners, are used to cause thermal decomposition, phase transition, or removal of volatile fractions from ores and other solid materials in the presence of air. The most familiar calcine (a word that refers to any product produced by the process) is Portland cement, which is produced from limestone (calcium carbonate) as the decomposition product calcium oxide.
"Typically, temperature vs. time should be carefully controlled in rotary kilns to provide sufficient energy without exceeding a melting point of the product. Lime kilns (as Portland cement-producing rotary kilns may be commonly referred to) tend to be somewhat tricky to operate for producing optimum product. Temperatures that are too high or too low, or treatment times that are too long or too short can result in sub-par product that does not yield favorable market demand or price. Operation of rotary kilns may be complicated by variations in co-fired fuels (such as tires) that are introduced into the kilns along with raw materials for producing the product.
"What is needed is a technology that can maintain consistent desirable kiln conditions and/or adapt to changing operating conditions, while minimizing undesirable flue gases such as oxides of nitrogen (NOx) and carbon monoxide (CO)."
As a supplement to the background information on this patent, VerticalNews correspondents also obtained the inventors' summary information for this patent: "One embodiment is a rotary kiln including a stationary fuel nozzle, a perforated flame holder spaced a selected distance from the stationary nozzle, and a rotating inclined kiln shell rotating around the fuel nozzle and the perforated flame holder. The perforated flame holder includes an input surface facing the fuel nozzle, an output surface, and a plurality of perforations extending between the input and output surfaces. A heating mechanism is positioned adjacent the perforated flame holder. An inclined rotating kiln shell includes an upper end and a lower end and rotates around the stationary fuel nozzle and the perforated flame holder.
"In one embodiment the heating mechanism applies heat to the perforated flame holder before the fuel nozzle outputs fuel onto the perforated flame holder. After the heating mechanism heats the perforated flame holder, the fuel nozzle outputs fuel onto the perforated flame holder. The elevated temperature of the perforated flame holder causes a combustion reaction of the fuel within the perforations of the flame holder. The combustion reaction is confined primarily to the immediate vicinity of the perforated flame holder.
"According to an embodiment, the inclined rotating shell conveys a feedstock, reaction intermediates, and a calcined product along the inside of the inclined rotary shell from the upper end to the lower end, and outputs a calcined product at the lower end. The combustion reaction is substantially confined to the perforated flame holder. The perforated flame holder is designed and positioned to maintain a desired flame characteristic and/or a desired time vs. temperature profile in the reactants and products conveyed through the rotary kiln."
For additional information on this patent, see: Colannino, Joseph; Karkow, Douglas W.; Wiklof, Christopher A.. Perforated Burner for a Rotary Kiln. U.S. Patent Number 9828288, filed August 11, 2015, and published online on November 28, 2017. Patent URL: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=9828288.PN.&OS=PN/9828288RS=PN/9828288
Keywords for this news article include: Clearsign Combustion Corporation.
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