U.S. patent number 3,776,151 [Application Number 05/229,659] was granted by the patent office on 1973-12-04 for method and apparatus for eliminating smoke emissions from incinerators.
Invention is credited to Wallace C. Wilson.
United States Patent |
3,776,151 |
Wilson |
December 4, 1973 |
METHOD AND APPARATUS FOR ELIMINATING SMOKE EMISSIONS FROM
INCINERATORS
Abstract
Smoke emissions are eliminated from an incinerator by admitting
cool air into a stack arranged to receive smoke from a combustion
chamber for inducing a draft in the stack which opposes a natural
draft therein. Smoke is carried along by the induced draft and
returned to the combustion chamber, so that only gases free of
particulate matter are emitted from the stack. The induced draft
returning to the combustion chamber as overfire air has sufficient
pressure for creating turbulence in the combustion chamber for
retaining the smoke in the combustion chamber a time sufficient to
ensure complete combustion thereof. The cool air is admitted into
the stack by a louvered portion provided in the stack and arranged
adjacent the combustion chamber, and, alternatively, one or more
louvered elements connected to the combustion chamber and the stack
so as to be in parallel with the louvered portion. Ducts are
connected to the louvered portion and louvered elements to return
smoke to the combustion chamber.
Inventors: |
Wilson; Wallace C. (Yakima,
WA) |
Family
ID: |
22862179 |
Appl.
No.: |
05/229,659 |
Filed: |
February 28, 1972 |
Current U.S.
Class: |
110/204 |
Current CPC
Class: |
F23G
5/24 (20130101); F23B 7/007 (20130101) |
Current International
Class: |
F23G
5/24 (20060101); F23g 005/00 () |
Field of
Search: |
;110/8R,18R,49,119 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Sprague; Kenneth W.
Claims
1. An incinerator comprising in combination:
a. a stack arranged to receive smoke, and including means for
admitting cool air into the stack for inducing a draft therein
which opposes a natural draft in the stack;
b. means connected to said stack for returning smoke carried along
by the induced draft, so that only gases free of particulate matter
are emitted from said stack; and
c. container means having wall defining a combustion chamber, and
wherein said stack is connected to said container means and
arranged in communication with the combustion chamber for receiving
smoke therefrom, said means for admitting including a louvered
portion formed in said stack and arranged adjacent to the
combustion chamber, the means for returning including a duct
connected to said container means and arranged in communication
with the combustion chamber so as to provide an overfire air supply
for creating sufficient turbulence in the combustion chamber for
retaining the smoke in the combustion chamber a time sufficient to
ensure complete combustion thereof, and at least one louvered
element connected to said container means and arranged in
communications with the combustion chamber for receiving smoke
therefrom, and connected to said stack in parallel with the
louvered portion of said stack, a duct connected to said louvered
element and said container means for returning smoke from said
louvered element to the combustion chamber.
2. An incinerator comprising in combination:
a. a stack arranged to receive smoke, and including means for
admitting cool air into the stack for inducing a draft therein
which opposes a natural draft in the stack;
b. means connected to said stack for returning smoke carried along
by the induced draft, so that only gases free of particulate matter
are emitted from said stack; and
c. container means having walls defining a combustion chamber, and
wherein said stack is connected to said container means and
arranged in communication with the combustion chamber for receiving
smoke therefrom, at least one louvered element connected to said
container means and arranged in communication with the combustion
chamber for receiving smoke therefrom, and connected to said stack
in parallel with the louvered portion of said stack, a duct
connected to said louvered element and said container means for
returning smoke from said louvered element to the combustion
chamber.
3. A structure as defined in claim 2, wherein the means for
returning includes a duct connected to the louvered member, and to
said container means and arranged in communication with the
combustion chamber.
4. A structure as defined in claim 1, wherein the means for
returning includes a duct connected to the louvered member, and to
said container means and arranged in communication with the
combustion chamber.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to apparatus for eliminating smoke
emissions from incinerators, and, more specifically, to such a
apparatus for incinerators primarily intended to burn paper.
2. Description of the Prior Art
Incinerators have long been used to burn trash, and particularly
paper, both for large buildings and individual residences. In
recent years, however, the problem of air pollution has resulted in
the use of such incinerators to be either eliminated by legislation
or effectively eliminated by strict emission control standards.
The most objectionable air pollutant normally emitted from an
incinerator is smoke. Smoke is gasborne particles resulting from
incomplete combustion of the materials being burned. It has long
been known that if these particles, or particulate matter, can be
either recycled to the combustion chamber or further burned in an
additional combustion chamber, they can theoretically be eventually
eliminated by complete combustion. In the past, attempts have been
made to recycle this particulate matter to the combustion chamber
by running a duct from the stack to the middle or lower portion of
the combustion chamber so as to employ the draft created in the
combustion chamber to draw the particulate matter through the duct
and combustion chamber and back to the stack.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved
apparatus for eliminating smoke emissions from incinerators. It is
a further object of the present invention to provide apparatus
which will return smoke laden air through the combustion chamber in
the form of overfire air for creating turbulence in the combustion
chamber.
It is yet another object of the present invention to provide an
incinerator which meets air pollution control emission standards,
while remaining simple in construction and inexpensive in cost of
fabrication and maintenance.
These and other objects are achieved according to the present
invention by admitting cool air into a stack arranged to receive
smoke from a combustion chamber for inducing a draft in the stack
which opposes a natural draft therein, and returning to the
combustion chamber smoke carried along by the induced draft so that
only gases free of particulate matter are emitted from the stack.
The step of returning includes the steps of returning the induced
draft as overfire air and providing sufficient pressure in the
induced draft for creating turbulence in the combustion chamber for
retaining the smoke in the combustion chamber a time sufficient to
ensure complete combustion thereof.
Apparatus for carrying out the method according to the present
invention has a stack arranged to receive smoke and with means for
admitting cool air into the stack for inducing a draft therein
which opposes a natural draft in the stack, and means connected to
the stack for returning smoke carried along by the induced draft so
that only gases free of particulate matter are emitted from the
stack. Container means may be provided having walls defining a
combustion chamber. The stack is connected to the container means
and arranged in communication with the combustion chamber for
receiving smoke therefrom.
In a preferred embodiment of apparatus according to the present
invention, the means for admitting is a louvered portion formed in
the stack and arranged adjacent the combustion chamber. The means
for returning may include a duct connected to the container means
and arranged in communication with the combustion chamber so as to
provide the overfire air supply for creating sufficient turbulence
in the combustion chamber for retaining the smoke in the combustion
chamber a time sufficient to ensure complete combustion
thereof.
A preferred embodiment of the present invention has at least one
louvered element connected to the container means and arranged in
communication with the combustion chamber for receiving smoke
therefrom, and connected to the stack and in parallel with the
louvered portion of the stack. A duct is connected to the louvered
element and to the container means for returning smoke from the
louvered element to the combustion chamber.
These together with other objects and advantages which will become
substantially apparent reside in the details of construction and
operation as more fully hereinafter described and claimed,
reference being had to the accompanying drawings forming a part
hereof, wherein like numerals refer to like parts throughout.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front elevational view showing an incinerator according
to the present invention.
FIG. 2 is a top plan view showing the incinerator of FIG. 1.
FIG. 3 is a sectional view taken generally along the line 3 --3 of
FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, FIG. 1 shows an incinerator 10
according to the present invention having a stack 12 with a pipe
portion 13 and means 14 for admitting cool air into stack 12 for
inducing a draft therein which opposes a natural draft in stack 12.
Means 16 is connected to stack 12 for returning smoke carried along
by the induced draft, so that only gases free of particulate matter
are emitted from stack 12.
A container means 18 is provided to which stack 12 is connected.
Container means 18 may be a barrel 20 provided with access openings
21, 22 (FIG. 3). Doors 23, 24 are hinged as at 26, 28,
respectively, to cover access openings 21, 22, respectively. Hinges
26, 28 may be of any suitable, known type, such as piano hinges.
Bar and keeper assemblies 30, 32 are provided to retain doors 23,
24, respectively, in their closed position with respect to access
openings 21, 22, respectively. Barrel 20 is provided with a vent 34
in door 23, a vent 36 (FIG. 2) having a pivotally mounted cover
member 37, vents 38 and 40, and vent 41 in door 24. Vents 39, 41
are not shown in FIG. 3. Vent 36 is arranged in a top wall 42 (FIG.
2) and vents 38, 40 are arranged in a cylindrical side wall 44.
Walls 42, 44 are combined with a bottom wall 45 (FIG. 3) to define
a combustion chamber 46 (FIG. 3). Stack 12, by means of being
connected to container means 18, is in communication with
combustion chamber 46 by means of opening 47 for receiving smoke
therefrom.
Means 14 has a louvered portion 48 formed in stack 12 and arranged
adjacent combustion chamber 46. Portion 48 is formed by a plurality
of fins 50 arranged about the periphery of stack 12. Fins 50 are
formed in a suitable, known manner, such as by stamping. Means 16
has a duct 52 (FIG. 3) connected to stack 12 and in communication
therewith by means of an opening 54 provided in louvered portion
48, and is connected to container means 18 and arranged in
communication with combustion chamber 46 by means of an opening 55
provided in top wall 42. In this manner, the induced draft
returning through duct 52 is designed so as to provide an overfire
air supply for creating sufficient turbulence in combustion chamber
46 for retaining the smoke in combustion chamber 46 a time
sufficient to ensure complete combustion thereof. Duct 52 has an
elbow portion 56 connecting same to louvered portion 48 at opening
54. A screen 57 may be arranged at the outlet of pipe portion 13 to
catch any ashes or other particles that may allude the induced
draft in louvered portion 48 and pass up the stack 12.
Although it is to be understood that an incinerator according to
the present invention may have only stack 12 with a louvered
portion 48, the particular embodiment shown in the drawings has a
pair of louvered elements 58 connected to container means 18 and
arranged in communication with combustion chamber 46 via openings
60 formed in top wall 42 and in communication with stack 12 for
receiving smoke therefrom. Elements 58 are also connected to stack
12 for communication therewith by means of openings 62. The
elements 58 are connected to stack 12 in parallel with louvered
portion 48. Fins 50 are also formed in pipe portions 63 of elements
58. A duct 64 is connected to a respective louvered element 58 and
is in communication therewith by means of an opening 66. Ducts 64
are also connected to container means 18 and are in communication
with combustion chamber 46 by means of opening 68 provided in wall
44 by returning smoke from louvered element 58 to combustion
chamber 46. Each louvered element 58 has an elbow 70 and a pipe 72
as a part thereof. Each duct 64 has a pair of elbows 74 and
connecting portions 76, 78. A pipe 80 completes each duct 64.
In operation, trash, preferably paper 82, is firmly packed and
evenly distributed in barrel 20 by passing same through access
opening 21 with door 23 pivoted out of the way (not shown). Paper
82 may be packed into combustion chamber 46 up to barrel ring 84.
Vent 36 is left open at all times. Vent 34 is preferably left
partially open for regulation of the oxygen required for
combustion. After a fire is started in combustion chamber 46, cold
air from the atmosphere enters louver portion 48 and louver
elements 58 through fins 50 therof. This cold air sets up an
induced draft which forces hot air and other gases carrying
particulate matter into the return duct 52, 64 and into combustion
chamber 46 as overfire air. With proper design, the pressure of the
induced draft entering into combustion chamber 46 provides
sufficient overfire pressure for creating turbulence in combustion
chamber 46 for retaining the smoke in combustion chamber 46 a time
sufficient to ensure complete combustion thereof. The arrows in
FIG. 3 of the drawings show the various flow paths. Access opening
22 may be used, when door 24 is swung open, for cleaning the
residue ash from combustion chamber 46 of barrel 20. Incinerator 10
is intended to reduce the entire composition of paper 82 into
ashes. These ashes can be used as, for example, fertilizer which
will be beneficial to the environment. When properly operated,
incinerator 10 will emit smoke, or carbons, in an amount not to
exceed three-quarters of one ringleman - a value taken from a
standard Ringleman Chart -- and then only will it emit such an
amount for less than 30 seconds.
The cold air will cause the induced draft due to its tendency to
settle when mixed with warm air. The foregoing is considered as
illustrative only of the principles of the invention. Further,
since numerous modifications and changes will readily occur to
those skilled in the art, it is not desired to limit the invention
to the exact construction and operation shown and described, and
accordingly all suitable modifications and equivalents may be
resorted to, falling within the scope of the invention. What is
claimed as new is as follows:
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