U.S. patent application number 09/756689 was filed with the patent office on 2002-07-11 for molten metal holding furnace baffle/heater system.
Invention is credited to Denning, Scott, Hale, Russell.
Application Number | 20020089099 09/756689 |
Document ID | / |
Family ID | 25044628 |
Filed Date | 2002-07-11 |
United States Patent
Application |
20020089099 |
Kind Code |
A1 |
Denning, Scott ; et
al. |
July 11, 2002 |
Molten metal holding furnace baffle/heater system
Abstract
Disclosed is a molten metal holding furnace system and a baffle
and/or heater for use therein. The baffle/heater includes, among
other things, a heat conductive body, at least one heater apertures
and at least one passageways from a first side of the baffle body
to the second side of the baffle body. Heaters within the heater
apertures are isolated within the baffle body from the molten
metal.
Inventors: |
Denning, Scott; (Ft. Wayne,
IN) ; Hale, Russell; (Dyer, TN) |
Correspondence
Address: |
WELLS ST. JOHN P.S.
601 W. FIRST
SUITE 1300
SPOKANE
WA
99201-3828
US
|
Family ID: |
25044628 |
Appl. No.: |
09/756689 |
Filed: |
January 9, 2001 |
Current U.S.
Class: |
266/229 |
Current CPC
Class: |
F27D 1/1808 20130101;
F27B 3/045 20130101; C22B 21/0084 20130101; F27D 2099/0036
20130101; F27B 14/02 20130101; F27B 14/14 20130101 |
Class at
Publication: |
266/229 |
International
Class: |
C21B 007/14 |
Claims
I/we claim:
1. A baffle for use in a molten metal holding furnace with an
interior cavity for holding molten metal, the baffle comprising: a
heat conductive baffle body with a first end, a second end, a first
side, a second side, a top side and a bottom side, the baffle body
being configured to span substantially across an interior cavity of
a molten metal holding furnace at an intermediate location in the
holding furnace; at least one heater aperture in the top side of
the baffle body configured to receive at least one heater; such
that the at least one heater is isolated from molten metal in the
holding furnace; and at least one passageway between the first side
and the second side of the baffle body, said at least one
passageway being positioned through the baffle body such that when
the baffle body is positioned within the holding furnace, molten
metal may flow from one side of the baffle body to another side of
the baffle body.
2. A baffle as recited in claim 1, and further wherein the at least
one passageway is located below an intended level of the surface of
molten metal in the holding furnace.
3. A baffle as recited in claim 1 and wherein the baffle body is
comprised of graphite.
4. A baffle as recited in claim 1 and wherein the at least one
apertures have a heater therein.
5. A baffle as recited in claim 1 and further wherein there are two
spaced-apart passageways through the baffle body.
6. A molten metal holding furnace comprised of: an insulated shell
having bottom and side walls for containing molten metal and an
internal cavity; a baffle comprised of: a heat conductive baffle
body with a first end, a second end, a first side, a second side, a
top side and a bottom side, the baffle body being configured to
span substantially across the interior cavity of the insulated
shell at an intermediate location in the holding furnace; at least
one heater aperture in the top side of the baffle body configured
to receive at least one heater; such that the at least one heater
is isolated from molten metal in the holding furnace; and at least
one passageway between the first side and the second side of the
baffle body, said at least one passageway being positioned through
the baffle body such that when the baffle body is positioned within
the holding furnace, molten metal may flow from one side of the
baffle body to another side of the baffle body.
7. A molten metal holding furnace as recited in claim 6, and
further wherein the baffle body is graphite.
8. A molten metal holding furnace as recited in claim 6, and
further comprising at least one heater in at least one heater
aperture in the baffle body.
9. A molten metal holding furnace as recited in claim 6, and
further comprising a lid over the top of the internal cavity of the
insulated shell, the lid substantially sealing the internal cavity
from the outside air.
Description
TECHNICAL FIELD
[0001] This invention pertains to a molten metal melting or holding
furnace baffle and heater system.
BACKGROUND OF THE INVENTION
[0002] Metal castparts such as aluminum castparts are typically
manufactured by first smelting the raw components and then
transferring the metal for casting. The casting process generally
includes a melting or holding furnace, a degassing unit, filtration
of the molten metal and then the casting of the metal into a
desired shape. The metal may later be recast or shaped in its later
handling. There may also be a secondary or scrap smelter to prepare
the material to be placed in the melting or holding furnace.
[0003] In the melting or holding furnace, the material is either
melted if it is not already in the desired molten state, or it is
held, while heat is applied to maintain it in a desired molten
state.
[0004] Molten metal from the melting or holding furnace may then be
degassed in a degassing unit. In the degassing unit, impurities are
removed from the molten metal through several known processes. The
degassed molten metal is typically then filtered by known means
before being cast into a desired solidified shape.
[0005] Molten metal may be one of the more difficult environments
in which to maintain equipment such as heaters and pumps, due to
the heat and the corrosive factors within the molten metal. The
components of various systems which are submerged in the molten
metal must therefore be specially designed to withstand the heat
and corrosive effects of the molten metal environment.
[0006] In some typical holding furnaces, heat is applied through a
plurality of smaller immersible heating units which are immersed
into the top surface of the metal. Due to the difficult operating
environment, the immersible heating units generally require
frequent maintenance or replacement. Utilizing a plurality of these
typical immersion heaters at or near the top of the surface level
of the molten metal is also not as efficient as it could be in the
heating of the metal or maintenance of the holding furnace.
Further, typical immersion heaters intended to operate in this
environment are substantially more expensive than heaters which may
be used with this baffle system.
[0007] In other holding furnaces, radiant heaters are located in
the furnace lid and radiate heat downward to the molten metal.
These types of furnaces typically have excess oxide buildup both on
the bath surface and on the furnace walls, which is detrimental to
both metal quality and furnace life. Additionally, these types of
furnaces may limit the practical depth of the molten metal in the
furnace due to compensation for thermal losses. In some situations,
the depth may be limited to eighteen inches despite a desire for a
deeper furnace.
[0008] This invention is intended for use in the holding furnace or
melting furnace and provides a new system through which heat may be
applied to the metal being heated or melted, and/or which provides
baffling.
[0009] It is therefore an object of this invention to provide an
improved molten metal melting or holding furnace system.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Preferred embodiments of the invention are described below
with reference to the following accompanying drawings.
[0011] FIG. 1 is top view of one embodiment of a holding furnace
system as contemplated by this invention;
[0012] FIG. 2 is a front elevation view of the embodiment of the
holding furnace system shown in FIG. 1;
[0013] FIG. 3 is a side elevation view of the embodiment of the
holding furnace system shown in FIG. 1;
[0014] FIG. 4 is a perspective view of the block/baffle utilized in
the embodiment of the holding furnace system shown in FIG. 1;
[0015] FIG. 5 is a perspective view of another example of an
alternative block/baffle which may be utilized in the embodiment of
the holding furnace system shown in FIG. 1;
[0016] FIG. 6 is a side elevation view of the embodiment of the
holding furnace system shown in FIG. 1, only with yet another
example of an alternative block/baffle which may be utilized in
combination therewith; and
[0017] FIG. 7 is a front elevation view of the embodiment of the
holding furnace system shown in FIG. 1, with the holding furnace
tilted to allow molten metal to be poured out of the holding
furnace.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] Many of the fastening, connection, manufacturing and other
means and components utilized in this invention are widely known
and used in the field of the invention described, their exact
nature or type is not necessary for an understanding and use of the
invention by a person skilled in the art or science, and they will
not therefore be discussed in significant detail. Furthermore, the
various components shown or described herein for any specific
application of this invention can be varied or altered as
anticipated by this invention and the practice of a specific
application of any element may already be widely known or used in
the art, or by persons skilled in the art or science, and each will
not therefore be discussed in significant detail.
[0019] The terms "a", "an" and "the" as used in the claims herein
are used in conformance with longstanding claim drafting practice
and interpretation and not in a limiting way. Unless specifically
set forth herein, the aforementioned terms are not limited to one
of such items but instead are intended to mean "at least one".
[0020] While references may be made herein to molten aluminum, this
is only used to give an example and not to limit the invention to
molten aluminum systems since the invention disclosed herein may be
used for other molten metals as well.
[0021] FIG. 1 is ta op view of one embodiment of a holding furnace
system as contemplated by this invention, illustrating holding
furnace 100, furnace containment walls 101, refractory or furnace
lining 102, bottom furnace lining surface 102a, side furnace lining
walls 102b, baffle 104 with baffle top side 104a, baffle first side
104b, baffle second side 104c, heater apertures 105 in baffle 104,
dip well 106 with dip well walls 103, charge well 107 shown with
under pour funnel, and the interior cavity 108 of the holding
furnace 100. Holding furnaces 100 are well known in the art.
[0022] FIG. 2 is a front elevation view of the embodiment of the
holding furnace system shown in FIG. 1, illustrating holding
furnace 100, furnace containment walls 101, side furnace lining
walls 102b, baffle, furnace lid 110, heater 117, heater apertures
105 in baffle 104, dip well 106 with dip well walls 103, charge
well 107 shown with under pour funnel, spout 122, furnace base 120
and axis 121 about which the furnace may be rotated to pour or
discharge molten metal (as shown more fully in FIG. 7).
[0023] The heater 117 may be any one of a number of different types
of heaters known in the trade and depending on the specific
circumstances of the furnace, preferably a radiant heater or a gas
fired heater. No one type or kind of heater is required to practice
the invention.
[0024] While the use of the furnace lid 110 is not necessary to
practice this invention it is preferred as it assists in the
control of the gases in the furnace.
[0025] FIG. 3 is a side elevation view of the embodiment of the
holding furnace system shown in FIG. 1, illustrating heating
furnace 100, furnace base 120, lid 110, furnace lining 102, heater
apertures 105, insulation 125, baffle 104, first passageway 126a
and second passageway 126b in baffle 104. It will be noted that
while two passageways 126a and 126b are shown, one or more may be
utilized in the practice of this invention, with no specific number
required. As shown in FIG. 6 for example, there is only one
passageway which spans across the entire span of the baffle
104.
[0026] It will further be noted that three heater apertures 105 are
illustrated, one or more may be utilized in the practice of this
invention, with no specific number required.
[0027] FIG. 4 is a perspective view of the block/baffle utilized in
the embodiment of the holding furnace system shown in FIG. 1, and
shows baffle 104 with top side 104a, bottom side 104f, first end
104d, second end 104e, first side 104b, first passageway 126a, and
second passageway 126b. In this embodiment, three heater apertures
105 are shown, first heater aperture 105a, second heater aperture
105b and third heater aperture 105c, with second heater aperture
105b being longer or deeper than the other two. It will be noted
that there are numerous variations of heater aperture 105 sizes and
configuration.
[0028] The baffle body 104 is preferably made of synthetic
graphite, a manmade material which is made from petroleum coke for
use in aluminum, an example of which may be grade CS114 available
from Union Carbide. No one type of material or composition is
required to practice the invention, and numerous types may be used,
such as technical ceramics, silicon carbides, silicon nitrides, and
others, all within the contemplation of this invention.
[0029] The baffle 104 will be sized to fit the application and may
be in any one of a number of different external and internal shapes
and configurations. One example of a size is wherein the baffle 104
is twenty nine inches high, thirty six and three-quarters inches
long and ten and one-half inches thick. There is likewise no
particular number of passageways or shapes of passageways are
required to practice the invention.
[0030] FIG. 5 is a perspective view of another example of an
alternative block/baffle which may be utilized in the embodiment of
the holding furnace system shown in FIG. 1, showing a single
passageway 126a which only extends partially across the span of the
baffle 104. All other components and items are as shown and
described above with respect to FIG. 4.
[0031] FIG. 6 is a side elevation view of the embodiment of the
holding furnace system shown in FIG. 1, only with yet another
example of an alternative block/baffle which may be utilized in
combination therewith. FIG. 6 shows a baffle 104 for a holding
furnace 100, the baffle having one passageway 140 which spans the
entire length of the baffle 104. FIG. 6 also shows heater apertures
105 in the heating block or baffle 104.
[0032] FIG. 7 is a front elevation view of the embodiment of the
holding furnace 100 system shown in FIG. 1, with the holding
furnace 100 tilted about tilt axis 121 to allow molten metal to be
poured out of the holding furnace 100 through spout 122. Also shown
in FIG. 7 are furnace containment wall 101, furnace lid 110 and
furnace base 120.
[0033] As will be appreciated by those of reasonable skill in the
art, there are numerous embodiments to this invention, and
variations of elements and components which may be used, all within
the scope of this invention.
[0034] One embodiment of this invention for example is a baffle for
use in a molten metal holding furnace with an interior cavity for
holding molten metal, the baffle comprising: a heat conductive
baffle body with a first end, a second end, a first side, a second
side, a top side and a bottom side, the baffle body being
configured to span substantially across an interior cavity of a
molten metal holding furnace at an intermediate location in the
holding furnace; at least one heater aperture in the top side of
the baffle body configured to receive at least one heater; such
that the at least one heater is isolated from molten metal in the
holding furnace; and at least one passageway between the first side
and the second side of the baffle body, said at least one
passageway being positioned through the baffle body such that when
the baffle body is positioned within the holding furnace, molten
metal may flow from one side of the baffle body to another side of
the baffle body.
[0035] In addition to the foregoing, examples of further
embodiments of the baffle would be for instance: wherein the at
least one passageway is located below an intended level of the
surface of molten metal in the holding furnace; wherein the baffle
body is comprised of graphite; wherein the at least one apertures
have a heater therein; and/or wherein there are two spaced apart
passageways through the baffle body.
[0036] It will also be appreciated that there are molten metal
holding furnace embodiments of the invention, such as wherein the
molten metal holding furnace is comprised of: an insulated shell
having bottom and side walls for containing molten metal and an
internal cavity; a baffle comprised of: a heat conductive baffle
body with a first end, a second end, a first side, a second side, a
top side and a bottom side, the baffle body being configured to
span substantially across the interior cavity of the insulated
shell at an intermediate location in the holding furnace; at least
one heater aperture in the top side of the baffle body configured
to receive at least one heater; such that the at least one heater
is isolated from molten metal in the holding furnace; and at least
one passageway between the first side and the second side of the
baffle body, said at least one passageway being positioned through
the baffle body such that when the baffle body is positioned within
the holding furnace, molten metal may flow from one side of the
baffle body to another side of the baffle body.
[0037] In addition to the foregoing and similar to the examples
given for the baffle, examples of further embodiments of the molten
metal holding furnace include embodiments in which the baffle would
be: wherein the at least one passageway is located below an
intended level of the surface of molten metal in the holding
furnace; wherein the baffle body is comprised of graphite; wherein
the at least one apertures have a heater therein; and/or wherein
there are two spaced-apart passageways through the baffle body.
[0038] Another embodiment is one in which the molten metal holding
furnace further includes a lid over the top of the internal cavity
of the insulated shell, the lid substantially sealing the internal
cavity from the outside air.
[0039] In compliance with the statute, the invention has been
described in language more or less specific as to structural and
methodical features. It is to be understood, however, that the
invention is not limited to the specific features shown and
described, since the means herein disclosed comprise preferred
forms of putting the invention into effect. The invention is,
therefore, claimed in any of its forms or modifications within the
proper scope of the appended claims appropriately interpreted in
accordance with the doctrine of equivalents.
* * * * *