Paul Wurth S.a.

Georges Stamatakis

Paul Goedert

Louis Schmit

Yvan Kroemmer

Bernard Cauwenberghs

Guy Junk

Markus Mayer

Junk Guy

Method for producing pulverized coal, the method comprising the steps of heating a drying gas, preferably an inert gas, in a hot gas generator () to a predefined temperature; feeding the heated drying gas into a pulverizer (); introducing raw coal into the pulverizer (), the pulverizer () grinding the raw coal to pulverized coal; collecting a mixture of drying gas and pulverized coal from the pulverizer () and feeding the mixture to a filter (), the filter () separating the dried pulverized coal from the drying gas; and collecting the dried pulverized coal for further use and feeding part of the drying gas from the filter to a recirculation line () for returning at least part of the drying gas to the hot gas generator (). According to an important aspect of the present invention, the method comprises the further step of controlling an exit temperature of the mixture of drying gas and pulverized coal exiting the pulverizer () by controlling a volume of water injected into the heated drying gas before feeding it into the pulverizer ().

Method for producing pulverized coal

A method for producing pulverized coal including the steps of providing a drying gas heated to a predefined temperature in a hot gas generator; feeding the heated drying gas into a pulverizer; introducing raw coal into the pulverizer, the pulverizer grinding the raw coal into pulverized coal; collecting a mixture of drying gas and pulverized coal from the pulverizer and feeding the mixture to a filter, the filter separating the dried pulverized coal from the drying gas; collecting the dried pulverized coal for further use and feeding the drying gas from the filter to an exhaust line; and collecting the drying gas exiting the filter and feeding part of the collected drying gas to a recirculation line for feeding recirculation drying gas to the hot gas generator. According to an important aspect of the present invention, the step of providing the drying gas includes feeding a variable flow rate of hot stove waste gas to the hot gas generator through a hot stove waste gas line so as to maximize the amount of hot stove waste gas used as drying gas. A pressure of the drying gas at a pulverizer gas inlet is controlled by regulating a flow rate of the hot stove waste gas through the hot stove waste gas line.

Method of producing pulverized coal

The present invention proposes a pulverized coal injection lance () for feeding pulverized coal from a rear end of the lance () to a front end () of the lance (). The lance () comprises an outer pipe () for conveying combustive gas, and an inner pipe (), coaxially arranged within the outer pipe (), for conveying pulverized coal. The inner pipe () forms a separation wall for separating the pulverized coal from the combustive gas. The separation wall is at least partially discontinued in a region near the front end () of the lance (), thereby forming a mixing region () within the pulverized coal injection lance (). According to an important aspect of the invention, the outer pipe () and the inner pipe () have substantially the same length and wherein the inner pipe () comprises at least one lateral opening () for allowing pulverized coal and combustive gas to come into contact within the pulverized coal injection lance () near the front end ().

Pulverized coal injection lance

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Canach, Luxembourg

Georges Stamatakis