Furnaces – Refuse incinerator – With means for advancing or handling refuse or residue
Patent
1996-04-10
1998-04-07
Lazarus, Ira S.
Furnaces
Refuse incinerator
With means for advancing or handling refuse or residue
110165R, 110255, 110257, 110258, F23G 500
Patent
active
057352240
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
The present invention relates to a thermal dechlorinating apparatus and method for collected ash, and particularly to a thermal dechlorinating apparatus and method for decomposing and removing harmful chlorine compounds contained in ash which is collected from a treatment apparatus or the like for treating exhaust gas released from waste incineration facilities for burning municipal waste and industrial waste.
BACKGROUND OF THE INVENTION
Organic chlorine compounds are contained in collected ash which is ejected from dust removing apparatus including electrostatic precipitators (EPs) and bag filters (BFs) installed in waste incineration facilities. Of these organic chlorine compounds, aromatic chlorine compounds such as polychlorinated dibenzodioxin (PCDD) and polychlorinated dibenzofuran (PCDF) are of particular interest because of their high toxicity. Thus, the development of an apparatus for treating them is desired.
An apparatus for reducing organic chlorine compounds in collected ash ejected from waste incineration facilities exists, for example, in the form of a horizontal thermal dechlorinating apparatus for collected ash provided with a rotary screw shaft.
FIG. 2 is a view illustrating a conventional thermal dechlorinating apparatus for collected ash. The apparatus comprises a horizontally elongated apparatus body 51, a feed port 52 for collected ash A and a discharge port 53 for treated ash B which are provided on the apparatus body 51 and spaced in an axial direction thereof, a rotary shaft 56 provided in the apparatus body 51, a feeding-portion screw 54, an ejecting-portion screw 55 and rotary vanes 57 fixed on the rotary shaft 56, and band heaters 58 disposed on the surface of the apparatus body 51. The collected ash A to be treated is charged into the apparatus body 51 through the feed port 52 and moves toward the discharge port 53 under action of the feeding-portion screw 54 of the rotary shaft 56. During this movement, the collected ash A is stirred and mixed by stirring vanes 57 and heated by the band heaters 58 to a temperature of 400.degree. C., for example. Thus, organic chlorine compounds contained in the collected ash A decompose. The collected ash A from which organic chlorine compounds have been removed by decomposition, i.e. the treated ash B, is ejected from a system through the discharge port 53.
However, it is difficult for the prior art apparatus described above to be run so as to always maintain the filling rate of ash therein at high levels. When the filling rate drops, air blows through the apparatus, or part of the fed ash is ejected in a short time in an insufficiently heated state, thus causing a problem of deterioration in the efficiency of treatment. Also, combustibles remaining in the ash cannot be burned completely; hence, when collected ash containing an adsorbent such as activated charcoal or the like is treated, there arises a problem that combustibles remain in the treated ash.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a thermal dechlorinating apparatus and method for collected ash which solves the aforesaid problems involved in the prior art and which has a high filling rate of ash to be treated and is capable of efficiently performing both complete combustion of combustibles remaining in the ash and decomposition of chlorine compounds.
To attain the aforesaid objective, the present invention provides the following:
(1) A thermal dechlorinating apparatus for collected ash, comprising a vertically elongated cylindrical apparatus body, a collected ash inlet and a collected ash outlet which are provided on the apparatus body spaced in a vertical direction thereof, an inlet port for heated air provided on the portion of the apparatus body between the collected ash inlet and the collected ash outlet, an exhaust gas outlet provided on the portion of the apparatus body above the collected ash inlet, a rotary shaft provided along the axial direction of the apparatus body, a screw provided on the rotary shaft, an
REFERENCES:
patent: 999698 (1911-08-01), Chapman
patent: 3916807 (1975-11-01), Eiki
patent: 4105397 (1978-08-01), Jasper et al.
patent: 4255129 (1981-03-01), Reed et al.
patent: 4306506 (1981-12-01), Rotter
Itaya Mazumi
Takasuka Gentaro
Lam Nhat-Hang H.
Lazarus Ira S.
Mitsui Engineering & Shipbuilding Co. Ltd.
LandOfFree
Thermal dechlorinating apparatus and method for collected ash does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Thermal dechlorinating apparatus and method for collected ash, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Thermal dechlorinating apparatus and method for collected ash will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-4918