US 8,127,931 B2Granted

Apparatus for removing unburned carbon in fly ash

AssigneeMitsui Engineering & Shipbuilding Co., Ltd.

InventorsKazuyoshi Matsuo, Kazuo Abe, Hitoshi Koyama, Toshio Yamaki

Life of this patent

Estimating the term…

Loading patent…

Abstract

Unburned carbon is efficiently separated according to the properties of fly ash. An apparatus is provided which comprises: a slurry preparation tank (10) in which water (c) is added to fly ash (a) to produce a slurry (d); a scavenger addition device (20) for adding a scavenger (e) to the slurry (d); a vertical surface-modification device (30) in which the slurry after addition of the scavenger is stirred at a high speed to impart shear force thereto and thereby cause the scavenger (e) to adhere to the surface of unburned carbon (b) contained in the slurry; a regulating tank (60) in which a blowing agent (f) is added to the slurry (d′) which has undergone surface modification with the surface modification device; and a flotation machine (70) with which the unburned carbon (b) is floated together with bubbles (n) and separated from the slurry containing the blowing agent.

Claims3

Dependent claims

An apparatus for removing unburned carbon from fly ash, comprising

a slurry adjusting tank in which a slurry is generated with the addition of water to fly ash,
a collector addition device in which a collector is added to the above-mentioned slurry,
a vertical high speed stirring tank in which the slurry with added collector is stirred at high speed and through the application of a shearing force and the collector is attached to the surface of the unburned carbon in the slurry,
an adjusting tank in which a frother is added to the slurry having its surface modified by the high speed stirring tank, and
a flotation unit in which the unburned carbon is floated and separated along with the air bubbles from the slurry after the frother has been added,
wherein a plurality of the high speed stirring tanks are connected in series by connecting tubes and have a bypass channel arranged to bypass a predetermined high speed stirring tank connected by said connecting tubes.

3 more elements

Dependencies are inferred from the claim text.

Facts

Application: 12/448,565Filed 26 Dec 2006
Published: US 2010/0051516 A14 Mar 2010
Granted: 6 Mar 2012
Term ends: Not estimatedThe source records don’t support an estimate.

Classification15 codes

B01F 27/191
Stirrers with two or more mixing elements mounted in sequence on the same axis: with similar elements
B01F 27/0724
Characterised by the disposition of the stirrers with respect to the rotating axis: directly mounted on the rotating axis
B01F 27/0726
Characterised by the disposition of the stirrers with respect to the rotating axis: having stirring elements connected to the stirrer shaft each…
B01F 27/707
With paddles, blades or arms: the paddles co-operating, e.g. intermeshing, with elements on the receptacle wall