Processes and plants for producing cement clinker, wherein no recirculation of preheater exhaust gases occurs and the ratio of solid fed in to exhaust gas in the preheater is set to greater than 1.0 kg of solid to gas.

Processes and plants for producing cement clinker, wherein no recirculation of preheater exhaust gases occurs and the ratio of solid fed in to exhaust gas in the preheater is set to greater than 1.0 kg of solid to gas.

A cement kiln burner device includes a powdered-solid-fuel flow channel having means for swirling a powdered-solid-fuel flow; a first air flow channel placed inside the powdered-solid-fuel flow channel to be adjacent to the powdered-solid-fuel flow channel having means for swirling an air flow; a second air flow channel placed in an outermost side outside the powdered-solid-fuel flow channel having means for straightly forwarding an air flow; and a combustible-solid-waste flow channel placed inside the first air flow channel. The second air flow channel is divided in a circumferential direction into four or more opening portions adapted to form ports for injecting air flows, and is configured to control flow rates of the air flows ejected from the opening portions, independently for each opening portion.

Processes and plants for producing cement clinker, wherein no recirculation of preheater exhaust gases occurs and the ratio of solid fed in to exhaust gas in the preheater is set to greater than 1.0 kg of solid to gas.

Processes and plants for producing cement clinker, wherein no recirculation of preheater exhaust gases occurs and the ratio of solid fed in to exhaust gas in the preheater is set to greater than 1.0 kg of solid to gas.

A cement kiln burner device includes a powdered-solid-fuel flow channel having means for swirling a powdered-solid-fuel flow; a first air flow channel placed outside the powdered-solid- fuel flow channel having means for swirling an air flow; a second air flow channel placed outside the first air flow channel having means for straightly forwarding an air flow; a third air flow channel placed inside the powdered-solid-fuel flow channel having means for swirling an air flow; and a combustible-solid-waste flow channel placed inside the third air flow channel. The second air flow channel includes an opening portion forming a port for injecting an air flow, and a closed portion covered for preventing an air flow from passing therethrough. The opening portion and the closed portion are alternately arranged in a circumferential direction.

A cement kiln burner device includes a powdered-solid-fuel flow channel having means for swirling a powdered-solid-fuel flow; a first air flow channel placed outside the powdered-solid- fuel flow channel having means for swirling an air flow; a second air flow channel placed outside the first air flow channel having means for straightly forwarding an air flow; a third air flow channel placed inside the powdered-solid-fuel flow channel having means for swirling an air flow; and a combustible-solid-waste flow channel placed inside the third air flow channel. The second air flow channel includes an opening portion forming a port for injecting an air flow, and a closed portion covered for preventing an air flow from passing therethrough. The opening portion and the closed portion are alternately arranged in a circumferential direction.

There are provided a cement kiln burner device capable of intensively bringing a combustible solid waste into a floating state within a cement kiln and easily causing ignition of the combustible solid waste in the floating state, and a method for operating the same. According to the present invention, there are provided: a powdered-solid-fuel flow channel including means for swirling a powdered-solid-fuel flow; a first air flow channel placed inside the powdered-solid-fuel flow channel to be adjacent to the powdered-solid-fuel flow channel, the first air flow channel including means for swirling an air flow; a second air flow channel placed in an outermost side outside the powdered-solid-fuel flow channel, the second air flow channel including means for straightly forwarding an air flow; and a combustible-solid-waste flow channel placed inside the first air flow channel. The second air flow channel is divided in a circumferential direction into four or more opening portions adapted to form ports for injecting air flows, and is configured to control flow rates of the air flows ejected from the opening portions, independently for each opening portion.

A process for reforming the fly ash by heating a raw fly ash powder that contains the unburned carbon and thereby decreasing the content of the unburned carbon, characterized in that (a) as means for heating the raw fly ash powder, use is made of a heating unit that heats the raw fly ash powder by passing it through a heated medium-fluidized bed, (b) a high-temperature gas stream is passed through the heating unit to form the heated medium-fluidized bed and to fluidize and convey the raw fly ash powder that is thrown into the medium-fluidized bed, (c) the flow rate of the high-temperature gas stream is so set that the raw fly ash powder thrown into the heating unit is all heated in the medium-fluidized bed and is taken out from a take-out port provided at an upper part of the heating unit but that the particulate medium forming the medium-fluidized bed is not discharged from the take-out port, (d) the fly ash powder after heated and discharged from the take-out port of the heating unit is introduced into an air classifier where it is separated into a fine powder and a coarse powder, (e) the fine powder separated by the air classifier is recovered as the reformed fly ash, and (f) the coarse powder separated by the air classifier is measured for its content of the unburned carbon and when the measured value is larger than a predetermined threshold value, the coarse powder is introduced again into the heating unit so as to be heated again and when the measured value is smaller than the threshold value, the powder is recovered as the reformed fly ash.

A process for reforming the fly ash by heating a raw fly ash powder that contains the unburned carbon and thereby decreasing the content of the unburned carbon, characterized in that (a) as means for heating the raw fly ash powder, use is made of a heating unit that heats the raw fly ash powder by passing it through a heated medium-fluidized bed, (b) a high-temperature gas stream is passed through the heating unit to form the heated medium-fluidized bed and to fluidize and convey the raw fly ash powder that is thrown into the medium-fluidized bed, (c) the flow rate of the high-temperature gas stream is so set that the raw fly ash powder thrown into the heating unit is all heated in the medium-fluidized bed and is taken out from a take-out port provided at an upper part of the heating unit but that the particulate medium forming the medium-fluidized bed is not discharged from the take-out port, (d) the fly ash powder after heated and discharged from the take-out port of the heating unit is introduced into an air classifier where it is separated into a fine powder and a coarse powder, (e) the fine powder separated by the air classifier is recovered as the reformed fly ash, and (f) the coarse powder separated by the air classifier is measured for its content of the unburned carbon and when the measured value is larger than a predetermined threshold value, the coarse powder is introduced again into the heating unit so as to be heated again and when the measured value is smaller than the threshold value, the powder is recovered as the reformed fly ash.