U.S. patent application number 13/924825 was filed with the patent office on 2013-10-24 for methods of using tires and scrap rubber in the manufacture and melting of steel and other metals.
The applicant listed for this patent is Rex Enterprises, LLC. Invention is credited to Franklin Leroy Stebbing.
Application Number | 20130276581 13/924825 |
Document ID | / |
Family ID | 35094909 |
Filed Date | 2013-10-24 |
United States Patent
Application |
20130276581 |
Kind Code |
A1 |
Stebbing; Franklin Leroy |
October 24, 2013 |
Methods of Using Tires and Scrap Rubber in the Manufacture and
Melting of Steel and Other Metals
Abstract
A method of using scrap rubber and other scrap materials, such
as tires or parts or pieces of tires, to manufacture or melt steel
and other metals in a furnace is disclosed. The scrap rubber may be
used as a carbon source for the manufacture of steel and other
metals, and may be used as an energy source to melt the scrap metal
used to make the steel and other metals. The net benefit of this
method includes reducing the amount of scrap rubber, such as tires,
to be sent to a waste disposal facility or landfill, thereby
improving the environment. In addition, by increasing the use of
scrap rubber as a source of energy for steel or metal production,
less energy is required from other sources.
Inventors: |
Stebbing; Franklin Leroy;
(Norfolk, NE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Rex Enterprises, LLC |
Norfolk |
NE |
US |
|
|
Family ID: |
35094909 |
Appl. No.: |
13/924825 |
Filed: |
June 24, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13439654 |
Apr 4, 2012 |
8470069 |
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13924825 |
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13022741 |
Feb 8, 2011 |
8152894 |
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13439654 |
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12719586 |
Mar 8, 2010 |
7883566 |
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13022741 |
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Current U.S.
Class: |
75/10.65 ;
75/414 |
Current CPC
Class: |
C21C 5/565 20130101;
C21C 2005/5282 20130101; Y02P 10/216 20151101; C21C 2300/02
20130101; Y02P 10/20 20151101; C22B 5/00 20130101; C22B 4/00
20130101; C21C 5/5211 20130101; C21C 5/527 20130101 |
Class at
Publication: |
75/10.65 ;
75/414 |
International
Class: |
C22B 5/00 20060101
C22B005/00; C22B 4/00 20060101 C22B004/00 |
Claims
1. A steel or metal alloy product made from a process comprising
the steps of: applying a quantity of metal into a furnace; applying
a quantity of an energy source into the same furnace, wherein the
quantity of an energy source is selected from the group consisting
of whole tires, tire pieces, tire parts, tire sections, tire bales,
tire powder, tire particles, tire chunks, waste hoses, carbon-based
rubber materials, rubber pieces, rubber parts, rubber sections,
rubber powder, rubber particles, rubber chunks, carbon-based waste
materials and carbon-based scrap materials, wherein the quantity of
an energy source combusts in the furnace, wherein the combustion of
the quantity of an energy source in the furnace aids in forming
liquid metal in the furnace, wherein the quantity of an energy
source aids in converting the carbon monoxide gas to carbon dioxide
gas in the furnace, and wherein the quantity of an energy source
increases the carbon level of the liquid metal.
2. The product of claim 1 wherein the step of applying the quantity
of metal and the step of applying the quantity of an energy source
are performed at the same time.
3. The product of claim 1 wherein the step of applying the quantity
of metal is performed prior to the step of applying the quantity of
an energy source.
4. The product of claim 1 wherein the step of applying the quantity
of metal is performed after the step of applying the quantity of an
energy source.
5. The product of claim 1 further comprising the step of applying
coal or coke to the furnace.
6. The product of claim 5 wherein the coal or coke is mixed with
the quantity of an energy source prior to being applied to the
furnace.
7. The product of claim 2 wherein the furnace is an electric arc
furnace.
8. The product of claim 7 wherein the quantity of metal and the
quantity of an energy source are placed in a charge bucket prior to
being applied to the furnace.
9. The product of claim 3 wherein the quantity of metal is placed
in a charge bucket prior to being applied to the furnace.
10. The product of claim 3 wherein the quantity of an energy source
is placed in a charge bucket prior to being applied to the
furnace.
11. The product of claim 2 wherein the quantity of metal and the
quantity of an energy source are placed on a conveyor prior to
being applied to the furnace.
12. The product of claim 4 wherein the quantity of metal and the
quantity of an energy source are placed on a conveyor prior to
being applied to the furnace.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of U.S. application Ser.
No. 13/439,654, filed Apr. 4, 2012, now U.S. Pat. No. 8,470,069,
which is a continuation of U.S. application Ser. No. 13/022,741,
filed Feb. 8, 2011, now U.S. Pat. No. 8,152,894, which is a
continuation of U.S. application Ser. No. 12/719,586, filed Mar. 8,
2010, now U.S. Pat. No. 7,883,566, which is a continuation of U.S.
application Ser. No. 12/489,837, filed Jun. 23, 2009, now U.S. Pat.
No. 7,674,317, which is a continuation of U.S. application Ser. No.
12/165,002, filed Jun. 30, 2008, now U.S. Pat. No. 7,553,351, which
is a continuation of U.S. application Ser. No. 11/108,950, filed
Apr. 19, 2005, now U.S. Pat. No. 7,393,379, which claims benefit to
U.S. Provisional Application Ser. No. 60/563,701, filed Apr. 20,
2004, now expired.
FIELD OF THE INVENTION
[0002] The invention relates generally to the melting of scrap
metal in a furnace using rubber tires, or parts of rubber tires, as
an additional energy source. The invention also relates generally
to the inclusion of rubber tires, or parts of rubber tires, as a
carbon component for the making of steel and other metals.
BACKGROUND OF THE INVENTION
[0003] It is known to use scrap tires, or parts of tires, as a
supplemental fuel source and carbon source for steel melting in an
electric arc furnace. The techniques and methods of such use are
described in U.S. Pat. No. 5,322,544 and U.S. patent application
Ser. No. 09/974,199 (now U.S. Pat. Nos. 7,674,318 and 8,114,185),
all of which are in the name of Franklin Leroy Stebbing and all of
which are incorporated herein by reference in their entirety. As
described in U.S. Pat. No. 5,322,544, recycling scrap tires into
steel or using them as a heat source improves the environment by
removing the tires from landfills where they do not degrade but do
create a fire hazard. Additionally, a single scrap tire, weighing
about 20 pounds, has about the same heating value of coke,
approximately 15,000 BTU's per pound, or approximately, 300,000
BTU's per tire. In the manufacture of steel, scrap tires, which are
so plentiful that they have a near zero cost, can be used as a
substitute to coal or coke as the heating source, thereby
significantly reducing the costs to manufacture the steel. As
described in U.S. patent application Ser. No. 09/974,199, the scrap
tires can be bundled with scrap steel in a charging bucket and then
the contents of the bucket placed in the furnace where the bundled
tires and scrap steel are recycled into steel. The present
invention described herein builds upon the known techniques and
methods of using scrap tires or scrap rubber in the manufacture of
steel, as set forth in U.S. Pat. No. 5,322,544 and U.S. patent
application Ser. No. 09/974,199.
BRIEF SUMMARY OF THE INVENTION
[0004] The present invention provides a system that permits the use
of the many forms of tires and scrap rubber in the furnace. The
invention allows the tires to be inserted into the furnace at a
more precise and controlled rate, time, and location. To this end,
for example, by inserting the tires at a slower rate into the
furnace and separate from the scrap steel, as compared to batch
feeding them or feeding them as tires and scrap steel bundles, it
is possible to use larger quantities of tires at a specific
controlled location and time. In an exemplary application, four
tires or the equivalent of four tires may be added per ton of steel
to be produced, as compared to two tires per ton ordinarily
expected. A benefit with the increase in the amount of tires that
can be used is the decrease in the number and amount of tires to be
sent to a waste tire disposal facility or landfill, thereby
improving the environment, and putting more scrap tires to
beneficial use. In addition, by increasing the use of tires as a
source of energy for steel or the metal production, less energy is
required from other sources for such steel or metal production.
[0005] The invention further allows the use of tires in many forms,
so that the tires can be more readily handled and stored before
they are put into the furnace. Also, the present invention allows
the tires to be put into the furnace separate from the scrap metal
that is also to be put into the furnace. Unlike previous methods
and techniques, the invention does not require the combining of the
tires with the steel or scrap metal prior to the placement of the
tires and scrap metal into the furnace. By eliminating the tires
from the charge bucket, more available space for the scrap metal is
created in the charge bucket. This can be especially valuable in
some melt shops where headroom or other factors limit charge bucket
size. Also, it is no longer necessary to transport the charging
buckets to a location where the tires are stored, as is the case in
many electric arc furnace shops.
[0006] The invention also allows the tires to be injected into the
furnace at very elevated temperatures, thereby increasing the
efficiency of the combustion of the tires. Moreover, the invention
allows the tires to be injected into the furnace continuously and
in a location most advantageous, such as while a foamy slag process
is taking place. This allows the carbon monoxide that is being
formed by the foamy slag process to convert to carbon dioxide with
additional heat generation inside of the furnace--a result of the
catalytic effect of the tires. With the invention, the tires may be
placed or injected into the molten metal bath in the furnace so as
to increase the carbon level in the liquid steel or metal to the
desired level for the type and grade being produced.
[0007] Other features and advantages of the invention will become
apparent to those skilled in the art upon review of the following
detailed description, claims and drawings in which like numerals
are used to designate like features.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 shows a schematic view of exemplary techniques for
inserting tires or parts of tires into a furnace for the
manufacture of steel or other metals.
[0009] Before the embodiments of the invention are explained in
detail, it is to be understood that the invention is not limited in
its application to the details of construction and the arrangement
of the components set forth in the following description or
illustrated in the drawings. The invention is capable of other
embodiments and of being practiced or being carried out in various
ways. Also, it is to be understood that the phraseology and
terminology used herein are for the purpose of description and
should not be regarded as limiting. The use of "including" and
"comprising" and variations thereof is meant to encompass the items
listed thereafter and equivalents thereof as well as additional
items and equivalents thereof.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0010] The invention is generally depicted in FIG. 1, but may be
embodied in various forms. As used herein, the term "tires" is to
be broadly interpreted to include whole tires, tire pieces, parts,
sections, bales, powder, particles, chunks, and the like. With the
teachings and principles of the present invention, the term "tires"
is also to be understood to encompass other types of rubber or
rubber products, such as waste hoses, scrap rubber materials,
rubber pieces, parts, sections, powder, particles, chunks, and the
like, or any other similar product or material that is suitable for
use as carbon or fuel in a steel or metal making furnace.
[0011] Referring to FIG. 1, the invention includes a furnace 10
that has an opening 12 positioned above or in the roof of the
furnace 10 for inserting tires, or parts of tires. The furnace 10
may be an arc furnace or any other furnace used for melting steel
or metal. It should be understood that the invention is not limited
to the type of furnace used for melting steel, that the teachings
and principles of the invention may be applied to all types of
furnaces that permit the use of tires as either fuel or a carbon
source.
[0012] To transport to and place the scrap steel or metal into the
furnace 10, a number of devices and techniques are possible. The
device might be a conventional charging bucket that is filled with
scrap steel and is moved to a location above the furnace where the
contents can be emptied into the furnace. The device may include a
conveyor that is used to convey the scrap steel directly into the
furnace in a continuous or semi-continuous mode. A similar device
includes a shaft that is filled with scrap metal, and through
gravity, the scrap metal moves toward and into the furnace.
Typically, the previously mentioned conveyor and shaft have a dual
purpose. The conveyor or shaft is enclosed and this enclosure is
also used to provide a duct for the removal of the hot exhaust
gases from the furnace operation. These hot gases come in contact
with the steel or metal scrap to preheat the steel or metal scrap
before it enters the furnace.
[0013] The aforementioned devices and techniques to transport and
place the scrap steel or metal into the furnace 10 may also be used
to transport and place the tires, or parts of tires, into the
furnace 10 separately from the scrap steel or metal. That is, a
conveyor may be used to transport and deposit the tires into the
furnace 10, a charging bucket or box may be used to transport and
charge the tires into the furnace, or a hopper may be located in
proximity to the furnace 10 and used as a feeder to introduce the
tires into the furnace 10.
[0014] Alternatively, the opening 12 in the furnace 10 roof or
sidewall may be used to permit any size tire or tire bales or
pieces of tires to be inserted or dropped into the furnace interior
and at any desired time and rate so as to maximize the benefits of
the melting and refining processes taking place within the furnace
10. The opening 12 can also include a chute to direct the tires
into a desired position within the furnace 10. When used with a
conveyor fed furnace such as Consteel.RTM., the tires can be
dropped into the furnace and the heat from the tires will be drawn
through the Consteel.RTM. conveyor enclosure by the exhaust fans,
thereby providing additional heat to the scrap metal on the
conveyor. The tires can be added in a location opposite the
conveyor opening to maximize the travel distance from the point of
deposit to the conveyor entrance thus maximizing residence time in
the furnace for best heat transfer to the scrap in the furnace but
also to allow the tires sufficient time to more fully combust
before the heat is drawn into the Consteel.RTM. enclosure to
preheat the scrap. When used with a shaft furnace such as that
manufactured by Fuchs, the tires would likewise be deposited to
fully maximize the combustion and to gain contact time with the
scrap in the furnace. In some instances, it is advantageous to
combust the tires alone, prior to adding the scrap steel. This heat
energy is drawn through the scrap metal in the shaft or the feeding
conveyor, thus preheating it before it is moved into the furnace
proper.
[0015] As another exemplary alternative, a pneumatic powered gun 14
may be used to put the tires into the furnace 10. In this
embodiment, the tires are in a granulated or powdered form or
suitable pieces and are blown through a tube or pipe 16 and into
the furnace 10. The gun 14 can use compressed air or other gases to
propel the tires or tire pieces through the pipe 16. Alternatively,
the gun 14 may simply be a tube for inserting the tires and tire
pieces into the furnace 10. The gun could be used through the door
to "cut in" scrap like a conventional carbon lance and also to
provide the added benefit of CO conversion. In a similar fashion,
tire pieces can be used to augment or replace carbon in the
sidewall burners found in most electric arc furnaces to gain the
advantages accruing from the use of tires in place of coal.
[0016] The gun 14 can also function as a burner, with the tires or
tire pieces serving as the fuel and using air and/or oxygen for
combustion. In this embodiment, the tires serve as an additional
energy source for the furnace 10. The air can be conveyed by the
same pipe as the tires or by a separate pipe 18, as would likely be
the case if oxygen were used to promote or enhance the combustion
of the tires.
[0017] Yet another alternative device or technique for inserting
the tires into the furnace 10 includes the use of a thrower device
to throw the desired amount of tires into the opening 12 in the
furnace 10, or through a door or other suitable opening (not
shown). The thrower device would be used as an alternative to the
gun in the situations where the tire pieces were not suitable for
gunning into the furnace because of the size or shape of the
pieces, or if the tires contained wire or bead materials from the
tires that were interfering with the operation of the gun. The
thrower device may be configured to work in conjunction with the
specific size and configuration of tires being used. That is, the
thrower device may be configured to accommodate any size tire or
combination of tire sizes, along with any size of tire particles,
large or small.
[0018] By adding the tires separately to the furnace 10, the
conventional technique of first combining the metal scrap and the
tires, and then putting the combined metal scrap and tires into the
furnace is eliminated, thus saving time, effort, and resources.
Moreover, this allows the tires to be added separately and directly
to the furnace 10 in controlled quantities and at the correct time
and location inside of the furnace to obtain maximum benefit. Also
more space is created in the charging buckets for additional scrap
metal.
[0019] More particularly, the objective in operating the furnace is
to add energy at the maximum rate possible without causing damage
to the furnace, or wasting energy that cannot be absorbed by the
scrap metal quickly enough. This is desirable because of the large
energy losses that occur to the water cooled furnace walls and roof
and also to the furnace fume exhaust duct, combustion chamber, and
dust collector. The longer the time taken to bring the scrap to
tapping temperature, and/or holding at this temperature, the
greater the heat losses. Because of the heat lost through
radiation, equipment water cooling, and exhaust gases, the amount
of total heat lost is proportional to the time spent in heating the
scrap to molten temperature and holding at this temperature before
tapping. The higher the rate of heat input, the lower the heat lost
to the surroundings because of the time factor. Through the
modulated, controlled, insertion of tires to the furnace, separate
from the scrap steel, the heat lost is better controlled.
[0020] Apart from the heat lost, the cost of energy is also a major
consideration, with electricity the most expensive, followed by
natural gas, coke, coal and finally scrap tires, which have a
negative cost (because they provide a disposal fee for consuming
them along with some gain in the scrap steel which they contain).
By replacing the traditional heat sources, such as electricity,
with scrap tires, significant cost savings can be achieved. More
specifically, the cost of electricity is highest at the early
stages of the melting cycle because this is the time when the
maximum amount of energy can be transferred to the scrap because it
is cold and can accept heat more readily and also because the
electric arc is shielded by the scrap, reducing damage to the
furnace walls and roof. There is a power company "demand charge"
for this rapidly consumed electrical energy--a charge that is
established by the maximum rate of electrical power used during
perhaps a fifteen-minute period in perhaps a twelve-month cycle.
Different power companies have differing schedules. With the
technique of applying the tires to the furnace separately from the
scrap steel, this is also the time when the energy from the scrap
tires can be used to reduce the demand charges and replace all or
part of the electrical energy consumed during the initial and early
stages of the melting cycle, while the scrap is still solid and
relatively cold and able to accept the energy from the tire flames
as it passes through the scrap. Thus, the use of a modulated,
controlled, throttled flow of energy from the tires to replace
electricity, (as well as gas, coke or coal) can result in
significant cost savings.
[0021] Tire energy can be the major source of energy in the early
stages of the heating cycle, with natural gas consumption then in a
reduced rate and electricity gradually increased as the cycle
progress but at a diminished rate at the beginning stages of the
heat to save on demand charges. As the scrap metal is turned to
molten metal the amount of energy that can be added to the metal
bath from sources other than electricity is decreased because the
liquid bath surface tends to reflect energy rather than absorb it.
Also the bath is protected and covered by the insulating effects of
the foamy slag. The solid tire parts can be dropped into or added
to the bath, however, increasing carbon content or reacted with
oxygen for additional energy in the bath.
[0022] The trend in this industry is to reduce electrical energy by
adding more chemical energy in the form of natural gas burners and
coal because it is cheaper. There are differences in the equipment
being used and the melting practices followed, so the results vary
from mill to mill. It is clear however, that low cost chemical
energy is a very desirable commodity. It should therefore be
appreciated that scrap tires clearly supply this need. The rate of
energy added to the furnace by electricity, natural gas or coal
injection is controlled. The rate of tire energy input needs to be
controlled for the same reasons. This further allows the rate of
energy release to be reduced so that the tires are not burning at a
less controlled rate and consumed before the steel scrap can
capture the available heat energy, as can occur if the tires are
bundled with the scrap steel prior to insertion into the
furnace.
[0023] Also, in another aspect of the invention, with the use of
tires separate from the scrap steel, the other forms of energy
being applied to the furnace may be reduced or regulated in a more
precise and controlled manner. As indicated above, these energy
inputs are usually natural gas or fuel oil with combustion air or
oxygen, electricity, coal or coke. These other energy inputs into
the furnace can be more precisely adjusted to correspond to the
rate of tire energy input since the tire energy can now be
controlled at a desired rate, as opposed to the known techniques of
batch feeding the tires with scrap steel. In this invention, the
tire energy is the primary source with the other energies filling
the gaps not taken care of by tire energy.
[0024] Because the tires enhance the conversion of carbon monoxide
to carbon dioxide, the tires can be injected into the furnace slag
area in a location where this conversion can be most beneficial.
The slag having been made from the addition of lime and/or other
slag forming materials having the desired flux and foaming
properties. The tire injection location is chosen so that the
carbon monoxide released from the foamy slag can be converted to
carbon dioxide before it enters, or while it is moving through the
scrap metal. The carbon monoxide bubbles are formed in the slag by
the use of a lance that injects carbon, usually coal particles,
along with oxygen gas, directly or indirectly into the slag which
is floating on the molten steel puddle in the bottom of the furnace
vessel. The foamed slag is in contact with, and partially envelopes
and engulfs the steel scrap above it. The carbon monoxide bubbles
continually burst and this gas flows through the scrap metal and
finally is exhausted out through an exhaust port, usually a hole
the furnace roof, often referred to as a "fourth hole." A large
percentage of the available energy in this gas is lost because it
exits the furnace as CO rather than converting to CO2. In one
method of the invention, the tires or tire pieces would be added to
the coal mix during, or prior to, injecting into the slag, or the
tires may be added independently of the coal mix. The added tires
facilitate the conversion from CO to CO2. The ratio and timing may
be adjusted to allow the slag to form CO and then convert to CO2
after the foam had done its job, releasing the conversion energy
while it was passing through the scrap metal, thus heating the
scrap metal. In another method, the tire or tire pieces would be
injected at a location above the slag but low in the scrap layer so
there would be sufficient mixing time for the tire fume to react
the CO to CO2. While the tires or tire pieces are burning in the
scrap metal zone in the furnace, the heat from this exothermic
reaction has a chance to contact and transfer to the scrap as it
passes through it, thereby improving the rate of melting of the
scrap metal. In another method, the tires are used to replace
substantially all of the coal for slag foaming. Thus saving the
cost of the coal and assisting the CO conversion.
[0025] Similarly, the tires can be injected directly into the
furnace while steel scrap is being fed by a shaft or conveyor
system. The tires are burned in the furnace while the hot gases
generated from the tire fire are withdrawn by the fume collection
system. This hot exhaust is pulled through the enclosure
surrounding the shaft or scrap conveyor, which causes it to be in
close contact with the scrap metal. The hot gases will heat the
metal as the gases move through the scrap in a counter-flow
direction to the direction of travel for the scrap. This greatly
enhances the purpose and value for having shaft or conveyor fed
furnaces because the amount of available heat captured by them will
be much greater. This also increases the efficiency of using tires
because the contact time for the flames in these enclosures is even
greater because the tires are gradually placed in the furnace so as
to burn at a slower, controlled rate, giving the scrap metal more
time to absorb the heat. This also allows any remnants of the CO to
CO2 conversion to take place in the shaft or conveyor enclosure
before it escapes.
[0026] By using tires in forms other than whole tires some of the
more valuable components of the tires can be removed before the
residue from the tires is used for furnace feed. For example, crumb
rubber particles have value as raw material for other products. The
crumb rubber and other materials can be removed from the tires
first, before the residue is used as a carbon, fuel and scrap metal
source for steel or metal manufacturing, thus, increasing the value
of the scrap tires and helping to convert them from a waste
material to valuable assets.
[0027] Also, when the rubber material is removed from the tires the
remaining tire material has a higher scrap metal content, which can
increase its value as a charge material for the furnace.
Additionally, having a higher metal content can permit the tire
pieces to be handled with a scrap-handling magnet--a device
typically found in steel scrap handling facilities and melt
shops.
[0028] Injecting rubber from the tires directly into a hot furnace,
separate from the scrap steel or metal, allows the rubber to be
exposed to, and achieve a very high temperature almost
instantaneously. This allows the rubber to be incinerated very
rapidly with more complete combustion taking place inside of the
furnace.
[0029] As stated above, the tires can be injected or placed
directly into the metal bath so that the carbon from the tire is
added directly to the metal. The tires provide a source of carbon,
replacing coal or coke. The tires can be injected in controlled
amounts so that the level of carbon in the bath can be more
precisely adjusted according to the type or grade of steel being
produced. This provides a more exact carbon level to be achieved in
the finished product. The amount of tires that may be added may
vary depending on the level of carbon required for the steel.
[0030] In summary, with various aspects of the present invention,
the known step of combining the tires together with the metal scrap
before introduction into the furnace is eliminated. The efficiency
for the use of tires as an energy source is increased, since the
energy is consumed gradually, instead of all at once with known
batch-feeding techniques, and also the efficient use of the energy
from the conversion of CO to CO2 is enhanced because the catalytic
effect is not wasted in a rapid release from the furnace before it
has time to act. A larger total quantity of tires can be converted
to a useful function, greatly improving the environment. Total
emissions from the process are improved on a more or less
continuous basis. An emission "spike" is eliminated because of the
more uniform application of the catalytic effect of the scrap
tires. Also, other forms of energy now used in the furnaces can be
reduced and replaced by scrap tire energy. With the principles and
teachings of the invention, the production of many types of metal
products including various steel alloys, iron alloys and the like
can be improved.
[0031] The above described invention provides several advancements
over the art in the use of tires, or parts of tires, as a fuel
source for steel or other metal melting, and as a carbon component
for the making of steel or other metals. First, the invention
improves air emissions from steel melting. Second, the invention
provides a way to convert additional waste materials, i.e., scrap
tires or tire parts, to a valuable commodity. Third, the invention
provides a method for increasing scrap tire consumption by the
steel industry. Fourth, the invention eliminates the step of
combining the scrap rubber from tires, or tire parts, with scrap
metal prior to placing the scrap rubber in the furnace. Fifth, the
invention provides a technique of injecting and placing the rubber
into the furnace so that the rubber can be put into the furnace in
the desired amounts, at the desired times, and in the best
location. Sixth, the invention allows the use of the many forms of
tires or scrap rubber, e.g., bales, pieces, crumbs, shredded
pieces, and the like, as a feed for the furnace. Seventh, the
invention allows the reduction of "electrical demand" charges and
other electrical consumption charges. Eighth, the invention
enhances the scrap preheating aspects of shaft and conveyor fed
furnaces, such as Consteel.RTM. by increasing the energy for
preheating as a result of burning the tires and/or increasing CO to
CO2 conversion in the furnace or in the shaft or conveyor. Finally,
the invention produces steel or other metals by injecting carbon
directly into the liquid metal using scrap rubber as a carbon
source for the steel whether the liquid metal is in the furnace or
afterward when in the ladle. One skilled in the art will appreciate
that the invention provides still other advancements over the art
as it pertains to the use of tires, or parts of tires, as a fuel
source for steel or other metal melting, and as a carbon component
for the making of steel or other metals.
[0032] Variations and modifications of the foregoing are within the
scope of the present invention. It should be understood that the
invention disclosed and defined herein extends to all alternative
combinations of two or more of the individual features mentioned or
evident from the text and/or drawings. All of these different
combinations constitute various alternative aspects of the present
invention. The embodiments described herein explain the best modes
known for practicing the invention and will enable others skilled
in the art to utilize the invention. The claims are to be construed
to include alternative embodiments to the extent permitted by the
prior art.
[0033] Various features of the invention are set forth in the
following claims.
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