Abstract:
Bei einem Verfahren zum Reduzieren der NOx-Emissionen eines Drehrohrofens einer Klinkerherstellungsanlage wird durch einen Brenner des Drehrohrofens zugeführter Brennstoff mit durch den Brenner zugeführter Primärluft verbrannt, wobei die Primärluft einen gegenüber der Umgebungsluft geringeren Sauerstoffgehalt und eine gegenüber der Umgebungsluft erhöhte Temperatur aufweist und die Primärluft durch Vermischen von Umgebungsluft mit Abgas aus dem Drehrohrofen oder aus einem an den Drehrohrofen angeschlossenen, dem Vorwärmen von Rohmehl dienenden Wärmetauscher erhalten wird. Die Primärluft wird weiters durch Vermischen mit Warmluft, insbesondere Abluft eines Klinkerkühlers, erhalten.
Abstract:
A method is described for reducing NOx emissions and improving energy efficiency during mineral processing in a rotary kiln (12). The method comprises injection of air (32) with high velocity/high kinetic energy into the kiln to reduce or eliminate stratification of kiln gases. The method can be applied to mix gases in a rotary kiln vessel or in a preheater/pecalciner vessel.
Abstract:
A method is described for reducing NOx emissions and improving energy efficiency during mineral processing in a rotary kiln. The method comprises injection of air with high velocity/high kinetic energy into the kiln to reduce or eliminate stratification of kiln gases. The method can be applied to mix gases in a rotary kiln vessel or in a preheater/pecalciner vessel.
Abstract:
The present invention is directed to a method and apparatus for controlling the kiln gas stream (90, 138) in a conventional long wet or dry process cement kiln (10). A portion of the kiln gas stream (90) can be withdrawn from the rotary kiln vessel (17) at a point upstream, relative to kiln gas flow of the chain system in the mineral drying zone (24). Alternatively, or in conjuction with bypass formation, the apparatus (256) can be used to add tertiary air to the kiln gas stream (90) to promote combustion efficiency downstream of the clinkering zone (28). Use of the present apparatus (56, 156) to form a kiln gas bypass stream (64) enhances operating efficiencies of long kilns by reducing dust loss, by facilitating isolation of high alkali by-product streams, by reducing alkali content of collected kiln dust, by increasing energy efficiency of long kiln operation, and by allowing greater overall control in the cement manufacturing process.
Abstract:
A high organic concurrent decoating kiln includes a low-oxygen zone and a high-oxygen zone. The disclosed kiln allows a gas low in free oxygen to be used in the initial stages of decoating, while a gas higher in free oxygen can be used in the final stages. The total amount of free oxygen used throughout the kiln, in particular at the upstream portion of the kiln, is kept low. Exhaust gas can be recirculated for use in a burner-fired chamber that provides the initial low-oxygen gas to the kiln.
Abstract:
In a kiln whose interior is heated by combustion with oxidant having a higher oxygen content than air, streams of staging oxidant are fed into the space between the combustion zone and the inner surface of the kiln, and the stoichiometric ratios and amounts of oxygen in the combustion zone and in the overall operation of the kiln are adjusted to provide control or reduction of NOx formation while maintaining or increasing productivity of the kiln.
Abstract:
A method for feeding lime mud into a lime kiln including a rotary kiln shell having an interior between a first end wall and a second end wall, the method including: feeding the lime mud into a flue gas flow in the interior of the rotary kiln shell or in close proximity to the shell to pretreat the lime mud; separating the pretreated lime mud from the flue gas flow; conveying the separated lime mud into the lime kiln, and calcining the separated lime mud in the lime kiln.
Abstract:
The invention relates to a device for burning solid matter, especially for producing quicklime, dolomite lime or cement, said device comprising a rotary kiln (1), and a cooling section (4) located downstream of said kiln (1). The inventive device is characterised in that a flume (3a) contains means for separating the rising cooling air stream (4d) from the burnt combustion product (2*) that leaves the kiln (1) and is deposited on the bottom (4a) of the cooling section (4). The flume (3a) in the kiln hood comprises at least one mobile wall (6) for controlling the flow course of the rising heated cooling air stream, said wall being located above the outlet (1a) of the rotary kiln.