U.S. patent number 3,788,243 [Application Number 05/230,283] was granted by the patent office on 1974-01-29 for domestic solid waste incinerator.
This patent grant is currently assigned to General Electric Company. Invention is credited to Christian A. Eff.
United States Patent |
3,788,243 |
Eff |
January 29, 1974 |
DOMESTIC SOLID WASTE INCINERATOR
Abstract
An incinerator for use in a residential kitchen with a box-like
housing enclosing a combustion chamber formed by an inner liner and
a top-opening access cover. The inner liner has a forwardly
inclined semi-cylindrical front wall and a bottom wall generally
perpendicular to the said front wall, as well as generally vertical
side and rear walls. A reversible, slow-motion, motor-driven
agitator is present in the bottom of the combustion chamber to
shift the position of the solid-combustible load, as well as to
break up the carbonized residue. The front wall of the incinerator
housing has a loading door that is connected by a linkage mechanism
to the access cover whereby they move in unison for ease in loading
the combustion chamber.
Inventors: |
Eff; Christian A. (Louisville,
KY) |
Assignee: |
General Electric Company
(Louisville, KY)
|
Family
ID: |
22864607 |
Appl.
No.: |
05/230,283 |
Filed: |
February 29, 1972 |
Current U.S.
Class: |
110/191;
110/173C; 110/216; 110/258; 110/210; 110/250 |
Current CPC
Class: |
F23G
5/10 (20130101); F23G 5/50 (20130101) |
Current International
Class: |
F23G
5/08 (20060101); F23G 5/10 (20060101); F23G
5/50 (20060101); F23g 003/04 () |
Field of
Search: |
;110/8R,173R,173C
;220/29 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Perlin; Meyer
Assistant Examiner: Capossela; Ronald C.
Attorney, Agent or Firm: Caslin; Richard L.
Claims
What is claimed as new and desired to be secured by Letters Patent
of the United States is:
1. An incinerator comprising a housing enclosing a combustion
chamber, an access cover for loading the chamber with solid
combustibles, and means for sealing the cover during the operating
cycle, heating means for igniting and degrading the combustibles,
the combustion chamber being formed by an inner liner means having
a forwardly inclined semi-cylindrical front wall means, and a
substantially imperforate bottom wall means in combination with a
slow-motion, motor-driven agitator in the bottom of the combustion
chamber for shifting the position of the solid combustible load,
said inner liner means serving to carry some of the weight of the
solid combustible load on the inclined front wall means so as to
reduce the load on the agitator and prevent it from becoming
jammed.
2. An incinerator as recited in claim 1 wherein the motor-driven
agitator has an alternately reversible motor means with short
operating cycles.
3. An incinerator as recited in claim 1 wherein the incinerator
housing is substantially box-like and the bottom wall of the inner
liner is arranged in a substantially perpendicular plane with
respect to the said forwardly inclined front wall, while the back
wall, opposite side walls, and the top wall of the inner liner are
substantially parallel with adjacent outer walls of the incinerator
housing, a portion of the said top wall being downwardly inclined
to substantially parallel the said bottom wall, the said access
cover being associated with the inclined portion of the top wall so
as to provide room for opening the cover and loading the combustion
chamber.
4. An incinerator for solid waste comprising an outer box-like
housing enclosing a combustion chamber formed by an inner liner
means and a top-opening access cover sealing means for rendering
the cover substantially airtight, the inner liner means having a
forwardly inclined semi-cylindrical front wall means, generally
vertical parallel side wall means, a substantially imperforate
bottom wall means that lies in a plane that is substantially
perpendicular to the said front wall means, a generally vertical
rear wall means, and a top wall means with a downwardly inclined
front portion which includes an access opening associated with the
said access cover for loading the waste into the combustion
chamber, and a slow-motion motor-driven agitator located adjacent
the said bottom wall means for shifting the position of the solid
waste load, said inner liner means serving to carry some of the
weight of the solid waste load on the inclined front wall means so
as to reduce the load on the agitator and prevent it from becoming
jammed.
5. An incinerator for solid waste as recited in claim 4 wherein the
motor-driven agitator is provided with alternately reversible motor
means with short cycles.
6. An incinerator as recited in claim 4 wherein the front wall of
the outer housing has a loading door connected by suitable linkage
to the said access cover whereby they move in concert, and locking
means associated with the loading door to insure that both the
loading door and access cover remain closed during the incinerating
cycle.
7. An incinerator as recited in claim 6 with panel means
substantially closing the space between the access opening in the
top wall of the inner liner and the adjacent walls of the outer
housing to form a loading compartment, the loading door being
hinged along its bottom edge to the outer housing and having inner
extension plates attached to the opposite sides of the door and
adapted to telescope with respect to the side walls of the loading
compartment to form a hopper leading to the access opening of the
combustion chamber.
8. A domestic incinerator comprising a box-like housing enclosing a
combustion chamber formed by an inner liner and a top-opening
access cover, sealing means for rendering the cover substantially
airtight, the front wall of the housing having a loading door, and
linkage means connected between the door and the access cover
whereby they move in concert, and locking means associated with the
loading door to insure that both the loading door and the access
cover remain closed during the incinerating cycle, the said linkage
means being provided with a compressible section such that if
excessive pressures were to build up in the combustion chamber, the
access cover would be allowed to open slightly and relieve the
pressure before it is automatically closed again by the
compressible linkage means.
9. A domestic incinerator as recited in claim 8 with hinging means
for mounting the access cover to the inner liner, the said linkage
means comprising a push rod connected to the loading door at one
end and to a first crank arm at the other end, the said first crank
arm being fixed to a movably supported shaft member, a second crank
arm fixed to the shaft member, and a link member connected at one
end to the second crank arm and at its other end to the access
cover, the closing action of the loading door tending to align the
second crank arm with the link member thereby applying a strong
closing and sealing force on the access cover.
10. A domestic incinerator as recited in claim 9 wherein the said
linkage means between the loading door and the access cover is
located on each side of the access cover.
Description
CROSS-REFERENCE TO RELATED APPLICATION
This application is related to a prior filed copending application
of the present inventor entitled, "Solid Waste Incinerator",
application Ser. No. 207,161, which was filed in the U.S. Patent
Office on Dec. 13, 1971, and issued on July 3, 1973 as Pat. No.
3,742,874. The prior application is based on the incinerating
process that is employed, while the present application is directed
to the construction and nature of the combustion chamber as well as
the loading and cover sealing means therefor. Many of the same
drawings of the prior application are utilized in this application
to illustrate this invention.
BACKGROUND OF THE INVENTION
The present invention relates to the art of solid waste
incinerators in general, and particularly to a domestic incinerator
which would be installed in the kitchen and would be able to
consume the amount of solid combustibles that accumulates in the
average-size household. There is an ever-growing trend to use more
packaged and prepared foods, disposable consumer items and obtain
more newspapers and other kinds of reading materials. The disposal
of this household waste and trash has become a major problem. In a
typical metropolitan area, residential waste accounts for almost 40
percent of all waste tonnage generated. The waste collection
agencies are severely overloaded in coping with the growing volume
of household trash accumulation, as well as grass clippings, leaves
and shrubbery trimmings that accumulate in the yard.
At the same time, air and water pollution are serious national
problems. Together, waste disposal and environmental pollution
present a dual problem that to date has defied adequate solutions.
Over the years, most solid waste has been burned in municipal
incinerators or used for land fill. Each method, however,
contributes to pollution. The principle alternative to
incineration, that is land fill, also faces increasingly severe
limitations. Some major metropolitan areas are running out of land
in which to dump solid waste. An estimated two-thirds of the cost
of waste disposal is in its collection. As labor costs increase and
per capita generation of waste increases, these costs are also due
to increase. Many local building codes require Class "A" flues for
domestic incinerators, and this has been a deterrent to the growth
of the market of such incinerators. Today, the concern over air
pollution also is an additional limiting factor. In working toward
a solution to the total problem of solid waste disposal, domestic
incinerators have so far played a minor role. Admittedly, a
domestic incinerator can only handle solid waste combustibles like
paper, cardboard and other cellulose materials, plastics, food
waste and the like, biodegradeable material, and cannot handle such
things as glass, metals, aerosol cans, liquid volatiles and the
like, which should be disposed of by some other method. The use of
domestic trash compactors installed in or near the kitchen is also
growing in acceptance as an aid to the trash collection process.
Moreover, the use of food waste disposers has been of significant
help in reducing the amount of waste, as it has been estimated that
food waste accounts for approximately 16 percent of the household
waste.
If the option of on-site domestic incineration is eliminated by
governmental ecology restrictions, future costs of waste disposal
would rise even higher. It behooves the major appliance industry to
perfect and offer a practical domestic incinerator that operates
efficiently and does not contribute to existing air pollution
problems.
BRIEF DESCRIPTION OF THE DRAWINGS
My invention will be better understood from the following
description taken in conjunction with the accompanying drawings and
its scope will be pointed out in the appended claims.
FIG. 1 is a front elevational view of an electric incinerator of
the present invention installed in a line of kitchen base
cabinets.
FIG. 2 is a right side, cross sectional elevational view on an
enlarged scale of the incinerator of FIG. 1, with some parts broken
away to show a large combustion chamber having a top-access cover
that is connected by a linkage mechanism to a front-loading door,
as well as showing the front wall of the combustion chamber as
being inclined forwardly at about 30.degree. to the vertical, and
an agitator mounted in the bottom of the combustion chamber to
shift the position of the solid combustible load as well as to
break up the carbonized residue. The agitator is powered by a
reversible motor and gearbox assembly to provide a slow-motion
reversible action for the agitator.
FIG. 3 is a top, cross sectional plan view taken generally along
the line 3--3 of FIG. 2 and looking down into the combustion
chamber at the left side to view the construction of the chamber as
well as the nature of the agitator mounted adjacent its bottom
wall. A group of four fly ash separators is shown in the lower
right-hand corner of the view, and a preheater is mounted directly
behind the separators. In the upper right-hand corner, there is a
single blower motor unit supporting on its through shaft three
blower wheels to provide the proper air flow patterns of primary,
secondary and tertiary air. Notice that FIG. 2 is taken on the line
2--2 of FIG. 3, generally through the center line of the combustion
chamber.
FIG. 4 is a cross sectional, elevational view of the back of the
incinerator taken generally on the line 4--4 of FIG. 3, and showing
the reversible motor and gearbox assembly mounted beneath the
combustion chamber.
FIG. 5 is a left side, cross sectional elevational view taken on
the line 5--5 of FIG. 3 generally through the center of the blower
motor unit and adjacent the first cyclone separator, showing the
loading door and the access cover both moved into an open
position.
FIG. 6 is a block flow diagram showing the main elements of the
incinerating process, as well as the various flow patterns for
primary, secondary and tertiary air streams.
FIG. 7 is a schematic circuit diagram to show primarily the circuit
for controlling the reversible agitator motor means, as well as the
electric heating means and, in a general way, the various control
components of the incinerator.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning now to a consideration of the drawings, and in particular
to FIG. 1, there is shown a domestic incinerator 10 embodying the
present invention that is a built-in appliance installed in a base
cabinet 11 beneath a kitchen countertop 14, somewhat in the same
manner as a built-in automatic dishwasher. The incinerator 10 is
adapted to be front loaded through a loading door 16 adjacent the
top portion of the front wall and generally near the left side
thereof. This door 16 is hinged along its bottom edge, and it is
adapted to be locked by a door handle 17 which may be operated for
unlocking the door and gaining access to the interior of the
incinerator. An ash removal door 18 is shown at the bottom for
emptying the ash collecting jars of the fly ash separators.
Referring now to the right side, cross sectional, elevational view
of FIG. 2, for a detailed explanation of some of the structural
aspects of the incinerator 10, there is an outer incinerator
housing 19 of sheet metal, box-like construction that defines the
outer limits of the appliance. It will be appreciated that an
incinerator is a high temperature apparatus reaching temperatures
of about 1,500.degree.F. in some areas, and that thermal insulating
means must be provided within the housing 19 to insure that the
external surface temperatures of the incinerator do not exceed the
temperature safety regulations of the Underwriters' Laboratories,
Inc., covering electric appliances that are to be installed in a
living area such as the kitchen or utility room, as distinguished
from the basement, the porch or the garage. An air space 21 is
first formed behind each outer wall of the housing 19 by means of
an insulation guard 22 which has assembled on its innermost side a
layer of thermal insulation 23 which substantially completely
surrounds the interior of the incinerator housing. The loading door
16 is likewise thermally insulated. This outer wall construction
allows for the circulation of relatively cool room air throughout
the entire air space 21 for restricting the external temperatures
of the housing 19. This air space 2 exhausts out through a duct
(not shown) in the vicinity of the exhaust duct 118 of the
incinerator at the back thereof.
The incinerator has a combustion chamber 25 formed by a drum-like
inner liner 27 and a removable top cover 29 for loading the
combustion chamber with solid waste combustibles through the
front-loading door 16. The inner liner 27 has a forwardly inclined,
semicylindrical front wall 30 that is inclined at about a
60.degree. angle, as is best seen in both FIGS. 2 and 3, and it has
a bottom wall 32 that is generally perpendicular to the inclined
front wall. There are generally parallel, vertical side walls 33
and 34, and a generally vertical rear wall 36, and finally a
horizontal top wall 37 that has a downwardly inclined front portion
38. The removable top cover 29 cooperates with an opening 40 in the
inclined top wall 38. Moreover, the removable cover 29 is provided
on its underside with a high temperature sealing gasket 42 which is
adapted to be compressed tightly against the peripheral flange of
the cover opening 40 for rendering the combustion chamber 25
generally airtight during operation, and precluding the escape of
heated gases, smoke, odors, vapors and the like into the
kitchen.
The bottom wall 32 of the inner liner 27 is furnished with an
agitator 80 which is formed in the shape of a circular flat plate
82 having a series of radial vanes 84 fixed to the top surface
thereof. The agitator 80 is mounted on a shaft 86 that extends down
through the bottom wall 32 and is in turn provided with two
electric drive motors 87 and 88 through a speed reducing gearbox
90. One motor 87 is for driving the shaft 86 in one direction and
the other motor 88 is for driving the shaft in the other direction.
It is appreciated that a single reversible motor could be
substituted for these two motors 87 and 88, but it would be much
more expensive than the two low cost motors that are employed, such
as are used widely in the cooking oven art for rotisserie drive
motors. The gearbox 90 is geared down to provide a slow motion
turning action of the agitator 80 within the combustion chamber 25,
on the order of one or two revolutions per minute. Each motor is a
shaded pole, fractional horsepower motor that may be stalled
without becoming overheated and inoperative. The gears of the
gearbox 90 are also capable of withstanding a stalled rotor
condition.
One advantage of having the inner liner 27 with a forwardly
inclined semi-cylindrical front wall 30 is that the entire weight
of the solid combustibles within the combustion chamber 25 does not
rest upon the agitator 80 as would be the case if the inner liner
were vertically disposed. Only some of the weight of the load is
carried on the agitator and, thus, some of the load tends to be
carried along by the agitator. This is especially true of the lower
portion of the load. When the combustion chamber is fully loaded,
the portion of the load near the top may tend to remain stationary,
and this varies as the portion of the load is spaced from the
agitator. The smooth surface of the semi-spherical front wall 30
tends to facilitate the turning action of the load and prevents
interference or jamming of irregularly shaped articles to be
burned. Moreover, the reversible action of the agitator tends to
free the agitator from being stalled due to jams and it also serves
to break up carbonized residue that forms toward the end of the
incinerating cycle.
The front-loading door 16 is connected by suitable linkage 45 to
the access cover 29 whereby they both move in unison. This means
that the opening of the loading door 16 causes the opening of the
access cover 29, and vice versa, for ease in loading the combustion
chamber. Locking means (not shown) is associated with the door
handle 17 of the loading door 16 to insure that both the loading
door 16 and hence the access cover 29 remain closed during the
incinerating cycle. The loading door 16 is hinged along its bottom
edge by means of hinge means 47 assembled between the lower edge of
the door 16 and the front panel of the incinerator housing 19. A
loading compartment 51 is formed within the incinerator housing 19
between the loading door 16 and the access cover 29 by an inclined
rear wall 53 which extends upwardly and forwardly from the rear
edge of the access opening 40 of the downwardly inclined top wall
38 to combine with the top insulation guard 22. Similarly, side
walls such as 55 are spaced away from the opposite sides of the
access opening 40, and they extend from the inclined top wall 38
generally vertically upwardly to cooperate with the top insulation
guard 22 to complete the loading compartment 51. The inner side of
the door 16 at each edge thereof has a vertical extension plate 49
so that when the door 16 is pivoted to its open position as seen in
FIG. 5, these extension plates serve to form a hopper leading to
the access opening 40 of the combustion chamber 25 so as to
discourage the spillage of waste as the incinerator is being
loaded.
The access cover 29 has a pair of generally parallel, integral
strap members 57 that are hinged to the back wall 53 of the loading
compartment by means of hinge pins 59 that engage in suitable
bracket members 60 behind the wall 53. Thus, the cover 29 is
capable of being raised or lowered within the loading compartment
51 by means of a pivotal action. The linkage mechanism 45 is
furnished between the loading door 16 and the access cover 29 so
that the door and the cover move in unison. This linkage mechanism
45 includes an elongated push rod 61 at each side of the access
cover outside the side walls 55, where each rod is connected at its
lower end to one of the side extension plates 49 near the bottom
edge of the front door 16 by means of a pivot pin 62. The upper end
of each push rod 61 is pivoted to a crank arm 64 by means of hinge
pin 65. The push rod 61 is provided with a compressible action
which is formed by two overlapping sections 167 and 168 having pin
and slot connections 162, 163, 162' and 163' between the two
sections. A coiled spring 165 is confined between the two pins 162,
162' which are arranged at the ends of each push rod section 167
and 168 thereby serving to extend the push rod sections to be as
long as possible. The function of the compressible push rods 61, 61
is to permit the access cover 29 to spring open without the
necessity of opening the loading door 16, in the event a small
explosion should occur in the combustion chamber thereby creating
excess pressures that might otherwise damage the internal structure
of the incinerator. This crank arm 64 is fixed to a shaft member 67
that is rotatably supported adjacent its ends by bearing members 69
that are fixed to the back side of the wall 53. A pair of crank
arms 71 are fixed to the shaft near the center thereof so as to
move therewith. A short link member 73 is pivoted to the end of
each crank arm 71 as at 74, and is attached at its other end to the
strap member 57 of the cover 29 as by pin 76. Thus, when the
loading door 16 is opened, this causes the push rod 61 to move
upwardly thereby causing the crank arm 64 to rotate in a clockwise
direction as seen in FIG. 2 thereby turning the shaft 67 and, in
turn, pivoting the crank arm 71 in a clockwise direction which
exerts a lifting force on the link member 73 thereby pulling the
strap member 57 of the access cover 29 up so that the cover pivots
about its hinge axis 59 to an open position as shown in FIG. 5.
Notice what happens when the loading door 16 is moved to its closed
position as shown in FIG. 2. This causes the push rod 61 to be
pulled downwardly by its lower pin 62 thereby causing the crank arm
64 to move in a counterclockwise direction which causes the second
crank arm 71 to move in the same direction thus putting a
compressive force on the link member 73 tending to straighten out
the link member 73 to be in general alignment with the crank arm 71
so that the three hinge points 67, 74 and 76 would be generally
within a single imaginary line drawn from pin 67 through pin 76.
This is not possible because the access cover 29 is seated and
sealed first, but this jackknife tendency exerts a continuing
compressive force on the cover to insure a good sealing action. A
suitable slot 78 is cut in the rear wall of the loading compartment
51 to permit each crank arm 71 and strap 57 to extend therethrough.
Thus, the crank arms 71 are allowed to move out of the loading
compartment 51 as is seen in FIG. 5 when the cover is opened.
The switching of the two counter-rotating motors 87 and 88 is
affected by a bimetal reversing switch 92 shown in the schematic
circuit diagram of FIG. 7. This switch 92 has a normally closed set
of switch contacts 94 that are connected in series with the motor
88 across line L1 and neutral conductor N. Arranged in parallel
with the motor winding 88 is a heater 95 such that when the circuit
is closed the first motor 88 will be energized at the same time as
the heater 95 until the heater reaches a temperature which causes
the bimetal switch 92 to snap to its alternate position. This would
cause the switch contacts 94 to open and result in the closing of a
second set of normally open switch contacts 97. This second set of
switch contacts 97 is arranged to be in series with the second
motor 87 so that the two motors 87 and 88 function alternately to
turn the agitator in counterrevolutions as a function of the heater
95 in cooperation with the bimetal switch actuator. Thus, there is
a cycle causing the bimetal operated switch 92 to function back and
forth every 2 to 3 minutes. Since the agitator turns at about one
revolution per minute, it will turn in one direction about two or
three revolutions and then it will stop and turn in the reverse
direction for about the same length of time.
The motor drive circuits for the agitator 80 of the present
invention are the only changes in the circuit diagram of FIG. 7
from the circuit diagram in the earlier filed application of the
same inventor, application Ser. No. 207,161 entitled, "Solid Waste
Incinerator" now Pat. No. 3,742,874. Rather than describe the
complete circuit diagram in detail here, mere reference will be
made to the principle elements of the circuit since the entire
circuit does not form part of the present invention, but is covered
in the prior application.
With reference to the circuit diagram of FIG. 7, this incinerator
model is provided with a three-wire electrical service; nominally,
of 230 volts, single phase, 60 cycle A.C., which is usually
available in the average residence having adequate wiring. This
voltage source has a pair of line wires L1 and L2 and a grounded
neutral conductor N, there being about 115 volts measured either
between line L1 or L2 and neutral N and 230 volts measured between
the two line wires L1 and L2. The heating means for the incinerator
is in the form of a preheater resistance element 100 and a main
resistance heater 101 which are connected in series across lines L1
and L2 at 230 volts by means of leads 103 and 105. A first door
interlock switch 106 is connected in lead 103 and a second door
interlock switch 107 is connected in lead 105. These two normally
open switches 106 and 107 are joined together to act in unison.
When the incinerator loading door 16 is closed and locked, the two
door interlock switches 106 and 107 will be closed to complete the
circuit through the heating means 100 and 101. The incinerator
loading door 16 has a door lock 17, with the lock mechanism not
shown, but its function is to insure that the incinerator cycle
cannot be initiated unless the door 16 is first closed and then
locked. The lock mechanism cooperates with the door interlock
switches 106 and 107 to close these switches when the door is fully
locked. Once the incinerator temperature rises above about
350.degree.F., a door interlock thermostat 110 operates to
de-energize a door latching solenoid 112 such that it is not
possible to unlock the door when the temperature within the
combustion chamber 25 is above 350.degree.F. This type of door
latch system would be similar to that taught in the Getman Pat. No.
Re. 26,944, which is assigned to the General Electric Company, the
assignee of the present invention. The door lock mechanism 17 has
an automatic locking bolt 114 that is shown diagrammatically in
FIG. 7. This automatic locking bolt is a pivoted, spring biased
member that automatically engages within a keeper 115 of a movable
rod 116 of the mechanism of the door lock 17 when it is in the
closed position. A momentary contact switch 117 serves to close the
solenoid circuit to deactivate the locking bolt 114 so that the
door lock mechanism can be operated.
There are two indicator lights 119 and 120 connected across line L1
and neutral conductor N. The first indicator light 119 or OPEN
light indicates when the loading door 16 is locked and the
incinerator is operating except that it is still possible to open
the door at will. The second indicator light 120 or LOCKED light
operates alternately with the first light such that it indicates
when the temperature in the incinerator combustion chamber 25
reaches above 350.degree.F. at which time it is not possible to
unlock and open the door 16 until such time as the temperature
drops below about 350.degree.F. This indicator lighting arrangement
119 and 120 is obtained by use of the door interlock thermostat 110
which functions at the preset temperature of about 350.degree.F.
This thermostat 110 has a normally closed switch 135 adapted to be
in series circuit with light 119 and an alternate normally open
switch 137 adapted to be in series circuit with the light 120.
A third motor is present in the circuit; that is, blower motor 122,
which is best seen in the cross sectional plan view of FIG. 3 for
driving a series of three blower wheels 123, 124 and 125, as will
be further explained with relation to the block flow diagram of
FIG. 6. The blower motor 122 is arranged to be connected in
parallel with the LOCKED light 120 and to be in series with the
door interlock thermostat 110 such that the blower motor 122 is
energized after the door interlock thermostat 110 operates at its
critical temperature of about 350.degree.F.
There is an over-temperature protective thermostat 125 arranged in
series with both the preheater 100 and the main heater 101. This
thermostat is normally closed and it opens when the temperature
within the main heater compartment reaches about 1,500.degree.F.
This protects the incinerator from runaway conditions and
de-energizes the heating elements 100 and 101 whenever the
temperatures become excessive.
A third thermostat, a logic thermostat 127, is utilized to control
a primary air inlet damper 129 that is located at the inlet of a
primary air duct 130, as is shown in the bottom rear of FIG. 2.
This logic thermostat 127 is calibrated to operate at a temperature
within the combustion chamber 25 of about 800.degree.F. When it
does trip, it energizes both a bimetal relay 131 and relay 132
which controls the damper 129.
It has been deemed preferable to locate the incinerator heating
means 101 so that it will not be in direct contact with the trash
or solid combustible load. The heating means could be located
within the combustion chamber 25 adjacent the top of the inner
liner 27 and away from the opening 40. However, in the preferred
embodiment, as best seen in FIG. 2, the heating means 101 is
located in a main heater compartment 135 which is positioned at the
front of the incinerator housing generally beneath the forwardly
inclined semispherical front wall 30 of the inner liner 27. This
heating means 101 is a resistance heating element of bare wire
form, such as nichrome wire that is supported on a series of
ceramic insulators or spools 136 in such a way that it is wound a
plurality of turns on each spool and then strung to the adjacent
spool 136 and again a plurality of turns are wound on that spool
before leading the wire 101 to the next spool. The wattage of this
heater wire 101 is about 3000 watts.
Turning attention to the gas flow block diagram of FIG. 6, primary
air enters the combustion chamber 25 through the open damper 129
after the chamber temperature rises above about 350.degree.F. This
primary air passes through duct 140 and it passes through the load
and is drawn into the first blower wheel 123 that is located
adjacent the top wall 37 of the combustion chamber. This blower
wheel 123 has a split scroll 142, as seen in FIG. 2, having a first
downwardly inclined discharge duct 144 within the combustion
chamber 25, and a second generally horizontal discharge duct 146
which leads out of the combustion chamber and discharges into a fly
ash separator 148 in the form of a series of four cyclone
separators for separating the fly ash from the flue gases. The
first discharge duct 144 is for sending a blast of air down into
the combustion chamber so that the air is able to reach the many
isolated air pockets within the solid combustibles so as to support
combustion thereof. The gas passes from the fly ash separator 148
to a preheater unit 150 which contains the supplementary heater
element 100 of about 3,000 watts for raising the temperature of the
gas to a maximum of about 1,100.degree.F. before the gas is
delivered to the main heater chamber 135 with its main heater 101
of another 3,000 watts for raising the gas temperature to a maximum
of about 1,500.degree.F. when most of the smoke, odors and vapors
are consumed.
From the main heater chamber 135, part of the gas is returned to
the combustion chamber 25 and recirculated. The remaining amount of
the gas is delivered to an afterburner unit 152 which is located
beneath the main heater compartment 135.
Since there is a reduced amount of oxygen in the gases discharging
from the main heater compartment 135, a supply of secondary air is
provided for the afterburner 152 so as to oxidize the combustibles
that might still be entrained in the flue gases. This secondary air
is brought into the incinerator housing by means of the second
blower wheel 124 shown in FIGS. 3 and 6. The function of the
secondary air is to cool the windings of the blower motor 122 as
well as to cool down the walls of the combustion chamber 25 and
finally to supply oxygen to the afterburner 152 for oxidizing the
combustibles in the flue gases.
A third blower wheel 125 is part of an exhaust system which is
arranged downstream of the afterburner 152. But first, it is well
to insure that there are no combustibles in the flue gases
exhausting from the afterburner 152 that might reach the blower
wheel 125. This assurance is provided by a flame box 154 that is
generally an elongated box-like construction that is formed up the
back side of the incinerator housing generally behind the preheater
150 and beneath the blower motor 122. It is also desirable to
provide a source of room air or tertiary air for the flame box.
This tertiary air is drawn into the flame box by means of the
exhaust blower 125 to further oxidize the combustibles in the flue
gases before they are returned to the outside atmosphere by means
of a suitable duct extending through a kitchen wall.
Modifications of this invention will occur to those skilled in this
art, therefore, it is to be understood that this invention is not
limited to the particular embodiments disclosed, but that it is
intended to cover all modifications which are within the true
spirit and scope of this invention as claimed.
* * * * *