U.S. patent number 3,838,974 [Application Number 05/274,406] was granted by the patent office on 1974-10-01 for rich fume incinerator.
This patent grant is currently assigned to Midland-Ross Corporation. Invention is credited to Klaus Heinrich Hemsath, Arvind Chhotalal Thekdi.
United States Patent |
3,838,974 |
Hemsath , et al. |
October 1, 1974 |
RICH FUME INCINERATOR
Abstract
An incineration system for incinerating flue gases which contain
varying quantities of combustibles therein. Means is provided for
controlling combustion air added to the flue gases when they
contain combustible matter and means is provided for sensing the
temperature of the combusting waste gases. When a preset
temperature is exceeded, additional air is added to reduce the
temperature of the gas, but when the temperature falls below the
preset point, the burner firing rate is increased and the added air
is cut off to insure proper incineration and achieve fuel
efficiency.
Inventors: |
Hemsath; Klaus Heinrich
(Sylvania, OH), Thekdi; Arvind Chhotalal (Toledo, OH) |
Assignee: |
Midland-Ross Corporation
(Cleveland, OH)
|
Family
ID: |
23048050 |
Appl.
No.: |
05/274,406 |
Filed: |
July 24, 1972 |
Current U.S.
Class: |
422/111; 423/210;
431/173; 422/168; 423/246; 431/174 |
Current CPC
Class: |
F23G
7/065 (20130101); F23G 2207/30 (20130101); F23G
2207/101 (20130101) |
Current International
Class: |
F23G
7/06 (20060101); F23c 005/00 (); F23c 009/04 ();
F23q 007/06 () |
Field of
Search: |
;23/277C ;423/210,246
;110/8A ;431/5,202,352,173 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Scovronek; Joseph
Assistant Examiner: Marcas; Michael S.
Attorney, Agent or Firm: Vrahotes; Peter Nawalanic; Frank
J.
Claims
What is claimed is:
1. In an incineration system for exhaust gases emitting from a
stack, the combination comprising: a housing confluent with and
located over the upper portion of the stack, means defining a
restricted annular passageway immediately surrounding the exit
opening of the stack and confluent with the lower portion of the
housing, means for supplying air from the said annular passageway
and into said housing to produce an annular stream of air effective
through its aspirating action to enhance the egress of the exhaust
gases from said stack into said housing and entrain them in said
air stream, at least one burner located within said housing
adjacent and laterally outward of the exit end of said annular
passageway, means for sensing the temperature in said housing,
means responsive to said sensing means for controlling the quantity
of air from said passageway and controlling the quantity of air and
fuel to said burners.
2. The incineration system of claim 1 wherein said housing is
provided with a plurality of tangential burners located therein
immediately above the exit end of the stack and laterally outward
of the exit end of said annular passageway.
3. In an incineration system for exhaust gases emitting from a
stack, the combination comprising: a housing having an upper
chamber, a lower chamber, and a reduced section therebetween of
essentially cylindrical form, the stack being received within said
housing with its exhaust end located within the reduced section of
said housing to define therewith a restricted annular passageway
communicating with both said upper and lower chambers and
immediately surrounding the exit opening of the stack, means for
supplying air to said lower chamber to produce an annular stream of
air exiting from said annular passageway into said upper chamber
and effective through its aspirating action to enhance the egress
of the exhaust gases from said stack into said upper chamber and
entrain them in said air stream, burner means located within said
upper chamber adjacent and laterally outward of the exit end of
said annular passageway, means for sensing the temperature in said
upper chamber, and means responsive to said temperature sensing
means for controlling said air supply means and said burner
means.
4. The incineration system of claim 3 wherein said burner means
comprises a plurality of burners located adjacent and laterally
outward of the exit end of said annular passageway with their
longitudinal axes directed generally tangentially relative to the
stack.
5. An incinerator for exhaust gases emitting from a stack and
containing combustibles but insufficient oxygen to support the
substantially complete combustion thereof, said incinerator
comprising a housing having an upper chamber, a lower chamber, and
a reduced passageway section therebetween of essentially
cylindrical form, the stack being received within said housing with
its exhaust end located within the reduced passageway section of
said housing to define therewith a restricted annular passageway
communicating with both said upper and lower chambers and
immediately surrounding the exit opening of the stack, means for
supplying air to said lower chamber to produce an annular stream of
air exiting from said annular passageway into said upper chamber
and effective through its aspirating action to enhance the egress
of the exhaust gases from said stack into said upper chamber and
entrain them in said air stream, an upwardly facing lateral
shoulder in said upper chamber forming the lower end thereof and
located immediately above and surrounding the exit end of said
stack for stabilizing thereat the flame of the burning exhaust
gases in the upper housing, and burner means in said upper housing
located adjacent and laterally outward of the exit end of said
annular passageway.
6. An incinerator as specified in claim 5 wherein the inside wall
of said stack is flared out at its upper end to approximately meet
with the outside wall of the stack.
7. An incinerator as specified in claim 5 wherein said burner means
comprises a plurality of burners located with their longitudinal
axes directed generally tangentially relative to the stack.
Description
BACKGROUND OF THE INVENTION
Industrial fumes containing common air pollutants, such as
hydrocarbons, alcohols, ethers, soot and other combustibles, are
frequently encountered. These fumes can be broadly divided into two
types. The first type of fumes contains relatively insignificant
quantities of combustible pollutants and there is an ample supply
of oxygen for the combustion of the pollutants. Standard types of
incinerators are readily available on the market which can be used
for the incineration of such fumes.
The other type of fumes contains mainly a mixture of combustibles
(hydrocarbons, soot particles, etc.) and other inert gases. The
oxygen content of such fumes is relatively small. When a source of
ignition, such as a premix pilot or a burner operating at
stoichiometric air/fuel ratio, is placed in the fume stream, the
fume cannot continue to burn because of insufficient oxygen.
Presently available incinerators, as a rule, are not able to
complete combustion of the exhausts; thereby yielding exhaust gases
with high quantities of pollutants.
It is, therefore, an object of this invention to provide an
incineration system for incinerating industrial waste gases which
contain varying amounts of combustibles therein.
It is another object of this invention to provide means for
incinerating waste gases and maintaining the temperature of the
combustion uniform.
It is a further object of this invention to provide apparatus to
incinerate rich fumes.
It is still another object of this invention to provide means for
incinerating rich fumes that achieve high fuel efficiency.
Other objects, purposes and advantages will be apparent from a
consideration of the following description and the accompanying
drawing in which:
FIG. 1 is a vertical cross-sectional view, partially schematic, of
an incineration system incorporating the features of this
invention; and
FIG. 2 is a cross-sectional view taken along line 2--2 of FIG.
1.
SUMMARY OF THE INVENTION
A double chambered system is added to a stack emitting industrial
waste gases which contain various amounts of combustibles therein.
The first chamber terminates at the exit end of the stack in an
annular passage, or restriction, so that air at high velocity is
directed longitudinally relative the stack. This air acts as an air
pump to enhance egress of the flue gases. These gases then enter
into the second chamber of the housing, which chamber includes a
plurality of burners. Within the second housing is a thermocouple
which senses the temperature of the waste gases. A preset
temperature is achieved by varying the quantities of air emitted
from the first chamber as opposed to the amount of fuel and air
supplied to the burners in the second chamber. In this way a
constant temperature may be maintained despite the variance of
combustibles within the exhaust gas.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
It has been found with regard to the explosion of a gas mixture
containing combustibles, such as hydrocarbons, inert gases and air,
that if the oxygen content of the mixture is less than 3 percent,
the mixture cannot combust merely by increasing its temperature.
Such mixtures are considered as above the upper combustion limit,
and they are generally referred to as "rich fumes."
For proper and efficient incineration of rich fumes, it is
necessary to mix air with the combustibles in the fumes, and the
temperature of the air/-fume mixture should be raised to a level
where the reaction rates are very rapid. Thus, addition of air,
proper mixing of the air with the fumes, and heating of the fumes
to incineration temperature are the three most important
requirements for the incineration of rich fumes. In case of very
rich fumes containing combustibles which have a heating value in
excess of approximately 40 Btu/ft..sup.3, it is necessary to supply
excess air, in addition to the combustion air, to reduce the
temperature of combustion products to the practical incineration
temperature, which is between 1,500.degree.-1,800.degree.F. The
amount of excess air, of course, depends on the selected
incineration temperature, the heating value of the fumes and the
oxygen content of the fumes. By controlling the incineration
temperature, the refractory materials in the incinerator are
protected.
In case of a batch type process, the fume composition, volume and
temperature can vary considerably with time. For the maximum fuel
economy, air and fuel supply to the incinerator must be controlled
very carefully and independently.
Referring now to the drawing, an incineration system is shown
generally at 10 and is adapted to incinerate exhaust fumes coming
from a stack 12. The stack 12 has refractory bricks 14 lined on the
inside thereof in order to preserve its heat and, as shown, has its
inner wall flared out at its upper end at a shallow angle to its
axis to approximately meet with its outer wall. Disposed about and
above the stack 12 is a housing 16 having a lower chamber 18 and an
upper chamber 20, the housing also being lined with refractory
material 21. The lower chamber 18 terminates at the upper end of
the stack 12 and has a restricted channel 22 portion. The lower
chamber 18 also has an opening 24 therein which receives an air
pipe 26.
The upper chamber 20 which, as shown, is formed of appreciably
wider cross-sectional size than the restricted channel portion 22
to form within the chamber an upwardly facing flame stabilization
shoulder or step located just above the upper end of the stack 12,
is supplied with tangential burners 28 that are received within
openings 30 in the refractory 21 and are located laterally outward
of the exit end of the annular passageway 22 and immediately above
the exit end of the stack 12. Gas lines 32 are attached to the
burners 28 as are air lines 34. The air lines 26 and 34 are in
communication with an air control unit 36.
Received within the upper portion of the upper chamber 20 is a
thermocouple 38 which has a lead 40 communicating with a
temperature measuring and recording instrument 42. The temperature
measuring instrument 42 in turn has a lead 44 that communicates
with the air controller 36.
In operation, the rich fumes are emitted from the stack 12 into the
upper chamber 20. Initially, the burners 28 are fired in order to
provide the heat of combustion necessary for the exhaust gases.
Simultaneously, a quantity of air is supplied to the lower chamber
18 from the air line 26 and passes through the channel 22 about the
exit end of the stack 12. This air passing through the channel 22
acts as an air pump to aspirate and thereby enhance the discharge,
or emission, of the exhaust gases from the stack 12. Additionally,
the annular stream of air from channel 22 promotes uniform mixing
of the gases within upper chamber 20.
The combustion products will ignite in the upper chamber 20 and the
temperature thereof is sensed by thermocouple 38. The measuring
instrument 42 will set a given temperature for the combustion
products and will control the amount of air supplied to the lower
chamber 18 and the upper chamber 20 in response to this
temperature. When the temperature is low, additional air will be
supplied to the burners 28 in order to raise the temperature and
assures complete incineration of the waste gases. The burners 28
may be of the type that gas is supplied thereto in proportional
response to the amount of air supplied to the burners. If the
temperature becomes too high, the supply of air to the burners is
discontinued and the temperature is controlled by air supplied
through the air pipe 26 into the housing 16. So long as the
temperature can be maintained at the set point through the
supplying of air to the exhaust gases, the burners 28 need not be
operated. This obviously means that the exhaust gases have a
sufficient quantity of combustibles therein to independently
support combustion. If the amount of combustibles in the exhaust
gases are so high that the preset temperature is exceeded, an
excess amount of air will be added through pipe 26 in order to
lower the temperature of the combusting exhaust gases. Thus, an
incineration system is provided which is operative to completely
combust waste gases emitted from a stack, regardless of the amount
or percentage of combustibles contained in the gases.
* * * * *