U.S. patent application number 09/389851 was filed with the patent office on 2002-03-28 for apparatus and method for fractionating alternative solid fuels.
Invention is credited to BERRUN-CASTANON, JORGE, CANTU-MARTINEZ, HECTOR-AGUSTIN, CUEVAS-MARTINEZ, ANGEL, FARIAS-MARTINEZ, LUIS-RAMON, GARCIA-SECOVIA, ARMANDO, GARZA-ONDARZA, JOSE-JAVIER.
Application Number | 20020035804 09/389851 |
Document ID | / |
Family ID | 23540011 |
Filed Date | 2002-03-28 |
United States Patent
Application |
20020035804 |
Kind Code |
A1 |
GARCIA-SECOVIA, ARMANDO ; et
al. |
March 28, 2002 |
APPARATUS AND METHOD FOR FRACTIONATING ALTERNATIVE SOLID FUELS
Abstract
An apparatus and a method for fractionating alternative solid
fuels, specially whole tires, into volatiles and coal, to be used
as alternative fuels, and metal, the apparatus comprising: a
feeding zone wherein the solid fuels are feed to the apparatus, a
gasifying zone into which the solid fuels are processed, obtaining
a gaseous fraction, coal and metal; cooled grills controlling the
bed permeability and permanence time of the solid fuels at the
gasifying zone; and a discharging zone into which the resultant
coal and metal are discharged.
Inventors: |
GARCIA-SECOVIA, ARMANDO;
(NUEVO LEON, MX) ; FARIAS-MARTINEZ, LUIS-RAMON;
(NUEVO LEON, MX) ; GARZA-ONDARZA, JOSE-JAVIER;
(LEON, MX) ; BERRUN-CASTANON, JORGE; (NUEVO LEON,
MX) ; CANTU-MARTINEZ, HECTOR-AGUSTIN; (NUEVO LEON,
MX) ; CUEVAS-MARTINEZ, ANGEL; (LEON, MX) |
Correspondence
Address: |
ABELMAN FRAYNE & SCHWAB
150 EAST 42ND STREET
NEW YORK
NY
100175612
|
Family ID: |
23540011 |
Appl. No.: |
09/389851 |
Filed: |
September 2, 1999 |
Current U.S.
Class: |
48/197R ;
110/248; 110/346 |
Current CPC
Class: |
Y02P 20/143 20151101;
Y02P 20/144 20151101; C10J 3/16 20130101; F23G 7/12 20130101; F23H
3/02 20130101; F23G 2207/112 20130101; F23G 5/50 20130101; C10J
3/30 20130101; F23G 2209/281 20130101; C10J 2300/1223 20130101;
F23G 5/027 20130101; F23G 2207/113 20130101 |
Class at
Publication: |
48/197.00R ;
110/346; 110/248 |
International
Class: |
C10J 001/00; C10K
001/00; F23G 005/00 |
Claims
What is claimed is:
1. An apparatus for fractionating alternative solid fuels, into a
gaseous fraction, a coal fraction, and a solid fraction,
comprising: gasifying means into which the solid fuels are
processed, including a first end and a second end; a feeding zone
at the first end of the gasifying means; feeding means, operatively
placed at the feeding zone of the gasifying means, in order to
control feeding of solid fuels; a gasifying zone next the feeding
zone, wherein the partial combustion of the solid fuels will take
place; air feeding means connected to the gasifying zone for
feeding air for the combustion of the solid fuel; mesh means at the
gasifying zone, controlling the permeability and permanence time of
the solid fuels at the gasifying zone; cooling means associated
with the mesh means, in order to control the temperature of the
mesh means; driving means for the mesh means which open or close
said mesh means, for discharging the coal fraction and the solid
fraction, after a complete separation of the gaseous fraction of
said solid fuels in order to avoid the formation of agglomerates
into the gasifying means; gas exhaust means, into which the gaseous
fraction is discharged from the gasifying zone for further use; a
discharging zone next the gasifying zone; and discharging means at
the discharging zone which receive the coal fraction and the solid
fraction from the gasifying zone.
2. The apparatus according to claim 1, wherein the gasifying means
comprise a vertical column.
3. The apparatus according to claim 1, wherein the gasifying means
comprise a horizontal chamber.
4. The apparatus according to claim 1, wherein the feeding means
comprise feeding valve means including driving means to open and
close said feeding valve means.
5. The apparatus according to claim 1, wherein the feeding valve
means comprise a plurality of gates in which the solid fuels are
fed.
6. The apparatus according to claim 1, wherein the driving means
for the feeding valves means comprises hydraulic motors which lift
and lower said feeding valve means.
7. The apparatus according to claim 1, wherein the air feeding
means comprise an air pump to feed air at ambient temperature.
8. The apparatus according to claim 1, wherein the air feeding
means further including a hot air input from a suitable source at
the gasifying zone in order to control the temperature thereof.
9 The apparatus according to claim 1, wherein the mesh means
comprise a plurality of grills.
10. The apparatus according to claim 1, wherein the cooling means
of the mesh means including internal pipes inside said mesh means,
into which cool water is circulated by means of a pump.
11. The apparatus according to claim 1, wherein the cooling means
of the mesh means including internal pipes inside said mesh means,
into which cool air is circulated by means of a pump.
12. The apparatus according to claim 1, wherein the driving means
for the mesh means comprise hydraulic motors for alternately
introduce or withdraw said mesh means.
13. The apparatus according to claim 1, wherein the discharging
means comprise a plurality of gates.
14. The apparatus according to claim 1, wherein the discharging
means include driving means.
15. The apparatus according to claim 1, wherein the driving means
of the discharging means comprises hydraulic motors which lift and
lower said discharging valve means.
16. The apparatus according to claim 1, wherein the feeding means
feed the solid fuel to the gasifying zone, by gravity.
17. The apparatus according to claim 1, wherein the feeding means
feed the solid fuel to the gasifying zone, by an hydraulic piston
and cylinder assembly
18. The apparatus according to claim 1, wherein the discharging
means discharge the coal fraction and the solid fraction from the
gasifying zone to the discharging zone, by gravity.
19. The apparatus according to claim 1, wherein the discharging
means discharge the coal fraction and the solid fraction from the
gasifying zone, by an hydraulic piston and cylinder assembly.
20. The apparatus according to claim 1, wherein the discharging
means discharge the coal fraction and the solid fraction from the
discharging zone to the outside of the apparatus, by gravity.
21. The apparatus according to claim 1, wherein the discharging
means discharge the coal fraction and the solid fraction from the
discharging zone to the outside of the apparatus, by an hydraulic
piston and cylinder assembly.
22. The apparatus according to claim 1, wherein the discharging
means discharge valve means including driving means which open and
close said discharging valve means in order to discharge the coal
fraction and the solid fraction from the apparatus.
23. The apparatus according to claim 1, wherein gasifying means are
placed at a back end of a kiln for producing cement, the hot air
input is taken from a tertiary air duct of the kiln, the
discharging means discharge the gaseous fraction to a pre-calciner
or calciner section of the kiln to substitute primary fuel, and the
discharge means discharge the coal fraction to a kiln input to
substitute primary fuel and the solid fraction is integrated to a
cement clinker, substituting part of iron required in the form of
an oxide.
24. The apparatus according to claim 1, wherein the discharging
means discharge the solid fraction to a feeding conveyor belt of a
kiln for the production of cement..
25. The apparatus according to claim 1, wherein the discharging
means discharge the coal fraction to a main burner of a kiln for
the production of cement.
26. The apparatus according to claim 1, wherein the hot air input
comes from residual air from a cement clinker cooler and the
discharge means discharge the solid fraction outside of the
gasifying means, to containers for an application to a recuperator
of a kiln for the production of cement having no pre-calciner.
27. The apparatus according to claim 1, wherein the discharging
means discharge the coal fraction a main burner of a kiln fro the
production of cement. having no pre-calciner.
28. A method for fractionating alternative solid fuel, into a
gaseous fraction, a coal fraction, and a solid fraction comprising
the steps of: providing an apparatus including a gasifying zone
wherein the solid fuels will be partially burned and the volatiles
will be emitted; feeding the alternative solid fuel to the
gasifying zone; providing an air input to the gasifying zone;
partially burning the alternative solid fuels into the gasifying
zone until most of the volatiles have been emmitted, coal with a
minimum content of volatiles is obtained, and the non combustible
solids are separated; discharging the volatiles from the gasifier
for further use; discharging the resultant coal and solids from the
gasifying zone for further use.
29. A method according to claim 7, further comprising providing hot
air from a suitable source to the gasifying zone in order to
control the temperature in the gasifying zone.
30. A method according to claim 7, wherein the discharging of the
resulting coal and solids from the gasifying zone is carried out by
gravity.
31. A method according to claim 7, wherein the discharging of the
resulting coal and solids from the gasifying zone is carried out by
mechanical means.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to an apparatus and a method for the
recovery of energy from solid waste, by combustion of the solid
waste in industrial kilns and more particularly to an apparatus and
a method for fractionating alternative solid fuels, such as tires,
into volatile gases and coal to be used as alternative fuels, and
metal.
[0003] 2. Description of the Related Art
[0004] Since 1980, hazardous solid waste, such as discarded tires
from all kind of vehicles, has been used as an alternative or
supplemental fuel in kilns for the production of cement.
[0005] The necessity to reduce total fuel costs through the
substitution of waste-derived fuels instead the normal fossil
fuels, primarily coal, has been the main driving force behind the
desirability of cheap alternative fuels to fire industrial kilns
such as kilns for producing cement.
[0006] One of the most readily useable and highest heat content
non-hazardous wastes, consist of discarded tires. It is estimated
that there are about 36 cement plants in the United States
utilizing tire derived fuel.
[0007] Whole tires, tires ground into "crumb" and tire chips are
used as fuel with essentially similar results.
[0008] Tires ground into "crumb" have the following advantages: 1)
allows the steel in the bead and radial bands to be removed via air
classification, 2) The crumb can then be blown in together with
powdered coal fuel, substituting a part of the powdered coal as the
main fuel source, and 2) the transportation storage and management
of the crumb is very similar to the managing of coal fines.
[0009] There are however some disadvantages in the use of crumb
tires in the kilns for producing cement:: 1) the removal of the
steel is from the crumb tires is very difficult, notwithstanding
that cement has a need for iron in its process; and 2) the
production} of the crumb is quite expensive, making the crumb as
costly as the coal or coke.
[0010] Tire "chips" of varying size are routinely used as fuel in
kilns for producing cement. These chips range in sizes varying from
2 cm.times.2 cm to 15 cm.times.15 cm. In all cases, the
transportation, storage and management is essentially the same.
Transportation is via truck and storage is generally carried out in
an open air pile similar to the storage of coal or limestone. The
feeding of the chips into the kiln is via a conveyor fed from a
hopper. A front end loader is used to load the hopper from the
storage pile.
[0011] The use of tire chips as fuel has some advantages: 1) the
feed rate can be continuous and carefully regulated; 2) there is
very little manual labor involved in handling chips versus whole
tires.
[0012] There are, however, some disadvantages in the use of tire
chips: 1) similarly to the tire "crumb", the production of chips
from whole tires is also expensive, certainly not as costly as the
production of crumb, but often represent a half the cost of
acquiring and delivering the supplemental fuel; 2) the steel wire
from the bead and radial belts of the tires do not shear smoothly
when the tires are chipped and consequently, the chips are ragged
and the steel wires protruding the chips, hook everything they come
into contact with, making difficult the operation of the plant.
[0013] Finally, the use of whole tires as fuel in kilns for
producing cement, is also common in the cement industry. In this
case, trucks loaded with whole tires, deliver their charge at the
end of a conveyor. Tires are manually unloaded from the truck onto
the conveyor. The conveyor feeds the tires to a mechanism that
inserts one tire at a time into the kiln at specified time
intervals. The main advantage of using whole tires, is that there
is no processing costs in addition to the acquisition costs. Also,
unlike tire chips, the whole tires do not migrate throughout the
facility nor, like the crumb, they are not subjected to possible
"dust fires".
[0014] However, despite the above advantages the use of hole tires
present some problems related to the removal of steel wire from the
gasifier section of the kiln, which tends to get entangled into of
the gasifier forming a great tangle of wire, affecting the flow of
volatiles from the combustion chamber to the kiln or calciner,
decreasing the fuel substitution percentage and limiting the use of
whole tires as supplemental fuel.
[0015] Therefore, being the use of the whole tires the most
reliable and economic alternative fuel, it would be highly
desirable to have a method and an apparatus which could avoid the
above referred problems in the use of whole tires.
[0016] In recent years, there have been developed a number of
methods and apparatuses for the recovery of energy from wastes,
specially for kilns for producing cement, which are specially
adapted to use tires (both grounded or whole tires) as a fuel
substitution in the range of 5% to 25% at best, depending on the
type of kiln, fuel and feeding points.
[0017] U.S. Pat. No. 4,627,877 of Ogawa et al. discloses a method
and apparatus for continuously producing a cement clinker by using
a waste material as a fuel for preheating or calcining a cement
material, by using an apparatus comprising a cement material
feeder, a preheater or calcinator, a rotary kiln, a cooler and
means for flowing an exhaust gas from the rotary kiln to the
preheater or calcinator. Said apparatus is characterized by
including a heat-decomposer which is located between the preheater
or calcinator and the rotary kiln, in which a combustible material
is heat decomposed by a hot gas exhausted from the rotary kiln and
the resultant combustible gas is burnt in the preheater or
calcinator substituting a part of the primary fuel therein. Ogawa's
method has the limitation that it is only able to use grounded
tires since it does not have any means to prevent entanglements of
wire or means to remove the wire which is released when using whole
tires. Furthermore, Ogawa's method does not show any means to
control the bed permeability and permanence of the grounded tire at
the calcination point which would be highly desirable since, by
controlling the permanence time and permeability of the bed will
allow a complete calcination of the tire and an adequate production
and flow of the volatiles to the point of combustion.
[0018] U.S. Pat. No. 4,640,681 of Steinbiss et al. discloses a
method and apparatus for the disposition of hazardous and waste
materials of low heat content, for example, refuse, by means of a
combustion process which is carried out in a furnace, by the
presence of added hot combustion air at a sufficient temperature so
that the combustion and/or flue gas temperatures are at least
1,250.degree. C. In a preferred embodiment of the invention, the
combustion process is combined with a process for the production of
cement clinker and is carried out parallel to the same, wherein air
at about 800.degree. C. is branched off for combustion of the
hazardous substances from the cooler air of the cement clinker
installation and introduced into the furnace. The hot flue gas of
the combustion in the furnace is directed into the cement clinker
installation. Although in Steinbiss patent it is possible to
control the permanence time of the waste materials in the furnace,
this method and apparatus is not intended for whole tires and it is
a fluidized bed gasifier. Therefore it can not gasify whole tires
and discharge the wire. Furthermore, since the main objective of
this invention is the disposition of hazardous and waste materials,
it is designed to use only waste materials of low heat content,
therefore the quality and quantity of volatile produced is very low
and can not be considered as a suitable supplemental fuel for
industrial kilns.
[0019] U.S. Pat. No. 4,256,503, of Tsuda et al., discloses a method
for effectively utilizing waste tires in an apparatus for burning
cement by means of a rotary kiln, comprising the steps of; charging
waste tires crushed or without crushing as fuel directly into the
back end of the kiln, to a position in said kiln wherein the gas
temperature is 600.degree. C. to 1,400.degree. C., in an amount not
exceeding 60% of the total fuel calculated as heat energy. The main
disadvantage of this method is that the heat released by the
combustion of volatiles would overheat the back end of the kiln and
would induce the formation of very hard agglomerates which are very
difficult to remove.
[0020] U.S. Pat. No. 4,110,121 of Rechmeir et al. discloses a
process for producing cement clinker in which raw meal is fed to a
heat exchanger, heat is supplied to the heat exchanger from a
downstream kiln, the raw meal is heated in the heat exchanger and
the heated raw meal is conveyed to the kiln and sintered therein by
the use of a fuel to form the cement clinker, the improvement
comprises using high grade waste fuel formed from organic waste in
the form of tires, rubber scrap, or plastics scrap and wherein the
waste fuel is processed before combustion by pyrolysis to form
pyrolysis gases and a pyrolyzed residue and said pyrolyzed residue
is comminuted or gasified. Although Rechmeir process discloses the
separation of the residual carbon form tires, it does not disclose
the separation of the wire or the management of the wire into the
pyrolyzer, which would limit the use of whole tires.
[0021] U.S. Pat. No. 5,226,774 of Tutt et al., discloses an
apparatus for controlling the input of combustible solids through a
port formed in a wall of a rotary kiln cylinder of an operating
cement kiln at a location between an upper end and a lower fired
end thereof, the kiln containing hot mineral material for
combustion of said combustible solids in contact with said mineral
material. In Tutt's apparatus, the tires are directly feed into the
kiln, and therefore the disadvantages are similar to those of
Tsuda's method.
[0022] Considering the above referred problems, applicants
developed an apparatus and a method for fractionating alternative
solid fuels, specially whole tires, into volatiles and coal, to be
used as alternative fuels, and metal.
[0023] Applicant apparatus and method provide means to separate the
residual carbon and volatile of burned solid fuels, as well as the
wire produced by the combustion of the whole tires. Furthermore,
there are included means to control the permanence time of the
solid fuel at the gasifying zone of the apparatus, which can be
optimized for each type of solid fuel.
[0024] Applicant apparatus comprises a main column having a feeding
zone, including one or more feeding valves; driving means are
provided for opening and closing said feeding valves, a gasifying
zone located below the feeding zone, having a cool air input coming
from a suitable source such as an air pump; If possible an input
for hot air which is used for the combustion of the solid fuels,
coming from a suitable source; one or more alternately introduced
and withdrawn cooled grills controlling the permeability and
permanence time of the solid fuels at the gasifying zone; a
gasifier duct in which the volatiles are discharged from the
gasifying zone to the main burner or other suitable zone of the
kiln or pre-heater wherein the apparatus of the present invention
will be used; a discharging zone located below the gasifying zone
having one ore more discharging valves which receive the coal and
solids coming from the gasifier and which are opened at a
convenient time in order to discharge the coal and solids from the
apparatus; and a discharging opening situated below the discharging
valves.
[0025] Applicant method comprises: providing an apparatus including
a gasifier wherein the solid fuels will be partially burned and the
volatiles will be emitted; feeding the alternative solid fuel to
the gasifying zone of the apparatus; providing cool air to the
gasifier and if possible hot air from a suitable source; partially
burning the alternative solid fuels into the gasifying zone until
most of the volatiles have been emitted, coal with a minimum
content of volatiles is obtained, and the non combustible solids
are separated; discharging the volatiles from the gasifier for
further use; and discharging the resultant coal and solids from the
gasifier by gravity or any other known means.
[0026] With Applicant's apparatus and method, the fuel substitution
percentage achieved can be higher than 40%, which is higher than
the fuel substitution percentages achieved by the actual known
methods and apparatuses.
SUMMARY OF THE INVENTION
[0027] It is therefore a main objective of the present invention,
to provide an apparatus and a method for fractionating alternative
solid fuels.
[0028] It is also a main objective of the present invention to
provide an apparatus and method for fractionating alternative solid
fuels, of the above disclosed nature, which provide means to
separate the volatiles and the residual coal, to be used as
alternative fuels, and the non combustible solids, produced by the
partial combustion of the solid fuels.
[0029] It is another objective of the present invention to provide
an apparatus and method for fractionating alternative solid fuels,
of the above disclosed nature, which provide means to separate the
wire produced by the combustion of whole tires.
[0030] It is also a main objective of the present invention to
provide an apparatus and method for fractionating alternative solid
fuels, of the above disclosed nature, which include means to
control the permanence time of the solid fuel at the calcination
point, to be optimized for each type of solid fuel.
[0031] It is still another objective of the present invention to
provide an apparatus and method for fractionating alternative solid
fuels, of the above disclosed nature which includes means for
controlling permeability.
[0032] It is still a main objective of the present invention to
provide an apparatus and method for fractionating alternative solid
fuels, of the above disclosed nature, in which fuel substitution
percentage achieved is higher than 40%, which is higher than the
fuel substitution percentages achieved by the actual methods and
apparatuses.
[0033] These and other objects and advantages of the apparatus and
method for fractionating alternative solid fuels, of the present
invention will become apparent to those persons having an ordinary
skill in the art, from the following detailed description of the
embodiments of the invention which will be made with reference to
the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] FIG. 1 is a front view of the apparatus for fractionating
alternative solid fuels of the present invention;
[0035] FIG. 2 is a diagram of a cement plant, including the
apparatus for fractionating alternative solid fuels of the present
invention in a first embodiment of use;
[0036] FIG. 3 is a diagram of a cement plant, including the
apparatus for fractionating alternative solid fuels of the present
invention in a second embodiment of use;
[0037] FIG. 4 is a diagram of a cement plant, including the
apparatus for fractionating alternative solid fuels of the present
invention in a third embodiment of use;
[0038] FIG. 5 is a diagram of a cement plant, including the
apparatus for fractionating alternative solid fuels of the present
invention in a fourth embodiment of use;
[0039] FIG. 6 is a diagram of a cement plant, including the
apparatus for fractionating alternative solid fuels of the present
invention in a fifth embodiment of use;
[0040] FIG. 7 is a diagram of a thermoelectrical plant, including
the apparatus for fractionating alternative solid fuels of the
present invention as another embodiment of use;
DETAILED DESCRIPTION OF THE INVENTION
[0041] The invention will now be described referring to a preferred
embodiment thereof, illustrated in the accompanying drawings
wherein the same signs and numbers, refer to the same parts of the
shown figures.
[0042] Referring to FIG. 1, the apparatus for fractionating
alternative solid fuel comprises:
[0043] gasifying means consisting of a main column 1 having a first
end 2 and a second end 3, and including:
[0044] a feeding zone F, having:
[0045] valve means including one or more feeding valves
[0046] comprising gates 4, 4', located at the feeding zone F, in
which the solid fuels S are fed, and which are opened and closed
for a convenient time and sequence in order to feed the solid fuels
S to the place wherein the combustion will take place;
[0047] driving means for the feeding valves (not shown) which could
be hydraulic motors, to open (lifting) and close (lowering) said
feeding valves 4,4';
[0048] a gasifying zone G located below the feeding zone F,
having:
[0049] input means for hot air 5 which is used for the combustion
of the solid fuels S.sub.1 coming from a suitable source (not
illustrated) which could be, in case of applying the present
invention to a rotary kiln for producing cement, the tertiary air
duct or the clinker cooler;
[0050] input means 6 for cool air coming from a suitable source
such as an air pump;
[0051] mesh means comprising one or more alternately introduced and
withdrawn cooled grills 7, 7', 7" having internal pipes (not
shown), into which cool air or water is circulated by means of a
pump, said cooled grills controlling the bed permeability and
permanence time of the solid fuels S at the gasifying zone G and
are able to be withdrawn in order to discharge the coal and solids,
after the separation of volatile and solids is achieved, to a
discharging zone D avoiding the formation of very hard agglomerates
which are very difficult to remove;
[0052] driving means for the cooled grills (not shown) which
operatively introduce or withdraw said cooled grills 7, 7', 7";
[0053] a duct 8 into which the volatiles are discharged from the
gasifying zone G for further use, said volatiles serving as
supplemental fuel;
[0054] a discharging zone D located below the gasifying zone G
having:
[0055] valve means including one ore more discharging valves
comprising gates 9, 9' which receive the coal C and solids, such as
wire W, coming from the gasifier G and which are opened at a
convenient time in order to discharge the coal and solids C from
the apparatus; and
[0056] a discharging opening H located below the discharging valves
9, 9' to discharge the coal C and solids, such as wire W, from the
apparatus.
[0057] It is to be understood that, the gasifying means can be a
vertical column wherein the feeding zone, the gasifying zone and
the discharging zone are placed in a downwardly sequence, or else,
it can be a horizontal chamber wherein the feeding zone, the
gasifying zone and the discharging zone are placed in a side by
side fashion, and in this embodiment it would be needed a
mechanical feeding device including an hydraulic cylinder and
piston assembly (not shown).
[0058] The apparatus of the present invention can be used for
fractionating continuously batches of supplemental fuel, such as
whole tires, so that when a first batch of burning material is
placed at the feeding valves 4,4' which are initially closed, a
second batch may be already at the gasifying zone G, wherein the
cooled grills 7, 7', 7" are sequentially opened at predetermined
times, depending on the characteristics--such as size--of the
supplemental fuel being processed, thus controlling the bed
permeability and permanence time, and avoiding the formation of
agglomerates inside the apparatus. The grill cooling means (not
shown) avoid that the pipes forming the grill lose mechanical
properties due to overheating or corrosion.
[0059] When the last cooled grill is opened 7"--if the apparatus
has more than one grill--, the resultant coal C and solids, such as
wire W, are discharged to the discharge valve 9, which is opened at
a convenient time as well as the other discharge valves 9'--in case
that the apparatus has more than one discharge valve--, when a
predetermined amount of coal C and solids W are obtained.
[0060] The last feeding valve 4' is opened discharging the
supplemental fuel to the first cooled grill 7, as soon as this is
emptied.
[0061] Therefore, the apparatus of the present invention can be fed
with whole tires, without problems such as wire entangling,
obtaining a complete separation of volatile, coal and wire.
[0062] Although it was mentioned that the apparatus of the present
invention has an input of hot air 5, it is also suitable to operate
without a hot air input when there is not available.
[0063] As it was mentioned, one of the applications of the present
invention is at the cement industry, in which the installation of
the present apparatus is at a rotary cement kiln or calciner, using
whole or shredded tires as supplemental fuel.
[0064] Referring to FIG. 2, a first possible embodiment of use of
the apparatus of the present invention R, at a rotary cement kiln,
is by installing the apparatus at the back end of the cement kiln,
feeding the apparatus with whole or shredded tires T, injecting air
form the atmosphere A, taking hot air from the tertiary air duct
9--if the kiln has a tertiary air duct--, and discharging the
volatiles V to the pre-calciner or calciner 10 to substitute
primary fuel M, and discharging wire W and tire coal C to the kiln
input 11 to substitute primary fuel. The wire is integrated to the
clinker K, substituting part of the iron required in the form of an
oxide. The main advantages of this form of use are that the
volatiles are burned where it is required. Therefore there is less
tendency to form hot points and agglomerates at the input of the
kiln, than in the case in which all the alternative fuel is
directly fed to the kiln.
[0065] Referring to FIG. 3, a second possible embodiment of use, is
as described in the first one, but additionally discharging the
wire W to the outside of the apparatus and of the rotary kiln 12,
to containers or to a conveyor belt (not shown). This way of use is
suitable for the production of white cement in which the iron oxide
content is less than in the normal cement.
[0066] Referring to FIG. 4 a third possible embodiment of use, is
as described in the second one, but discharging the tire coal C to
the main burner 13. The main advantage of discharging the tire coal
C to the main burner 13 is that a higher percentage of primary fuel
substitution can be achieved mainly because the tire coal C is
burned in the main burner 13 after reaching the limit of energy
amount substituted at the pre-calciner.
[0067] Referring to FIG. 5, a fourth possible embodiment of use
consists on using the residual air from the clinker cooler 14 which
is hotter than the atmosphere air, instead of using hot air from
the tertiary air duct 9. The volatiles V are discharged and burned
in the main burner 13 and the tire coal C is discharged to the
calciner 10, achieving a higher percentage of primary fuel
substitution. In this case, the wire W is discharged outside of the
apparatus and of the rotary kiln 12, to containers or to a conveyor
belt (not shown). Therefore it is possible the application of the
recuperator R of the present invention at kilns without a
pre-calciner.
[0068] Referring to FIG. 6, a fifth possible embodiment of use is
as described in the fourth one, but discharging the tire coal C to
the main burner 13. Therefore it is also possible the application
of the recuperator R of the present invention at kilns without a
pre-calciner.
[0069] Referring again to FIG. 1, a sixth possible embodiment of
use is as described in the first one, but, instead of using whole
or shredded tires, alternative solid fuels having similar or the
same properties of the tires, are used, i.e., so that a residue
similar to coal be obtained.
[0070] Although it has been mentioned that the apparatus of the
present invention can be used at the cement industry, it can be
used at any kind of industry having industrial kilns. For example,
referring to the FIG. 7, it can be used at a thermoelectrical plant
or any other industrial kiln, discharging the volatiles V and tire
coal C to the main burner 15, and discharging the wire W to outside
of the apparatus.
[0071] The method for fractionating alternative solid fuels,
specially whole tires, according to the present invention comprises
the steps of:
[0072] providing an apparatus including a gasifier wherein the
solid fuels will be partially burned and the volatiles will be
emitted;
[0073] feeding the alternative solid fuel to the gasifying zone of
the apparatus;
[0074] providing cool air to the gasifier from the atmosphere and
if possible hot air from a suitable source;
[0075] partially burning the alternative solid fuels into the
gasyfing zone until most of the volatiles have been emitted, coal
with a minimum content of volatiles is obtained, and the non
combustible solids are separated;
[0076] discharging the volatiles from the gasifier to an industrial
kiln wherein the substitution of primary fuel will be made;
[0077] discharging the resultant coal and solids from the gasifier
by gravity or any other known means to an industrial kiln wherein
the substitution of primary fuel will be made or to a conveyor belt
or to a container for further use.
[0078] Although it was described that it is provided hot air to the
gasifier from a suitable source, it is suitable to make the
combustion with cool air only.
[0079] Finally it must be understood that the apparatus and method
for fractionating alternative solid fuels of the present invention,
is not limited exclusively to the above described and illustrated
embodiments and that the persons having ordinary skill in the art
can, with the teaching provided by this invention, to make
modifications to the design and component distribution of the,
apparatus and method for fractionating alternative solid fuels of
the present invention, which will clearly be within the true
inventive concept and scope of the invention which is claimed in
the following claims.
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