Note : Les revendications sont présentées dans la langue officielle dans laquelle elles ont été soumises.
THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A method for heat treating a casting having a sand core,
the sand core comprising, at least, sand particles bound
together by a binder material, and the sand core defining
a cavity within the casting, the method comprising the
steps of:
introducing the metal casting, with the sand core
therein, into a furnace;
heating the furnace to a temperature in excess of the
combustion temperature of the binder material;
providing an oxygenated atmosphere within the heated
furnace;
containing the metal casting, with the sand core
therein, within the heated furnace in the
oxygenated atmosphere to permit the binder material
to combust, whereby sand particles of the sand core
are loosened from the sand core;
removing the loosened sand particles from the cavity;
capturing clumps of sand core material which become
dislodged from the casting prior to the binder
material being combusted therefrom; and retaining
the dislodged clumps of sand core material within
the furnace to permit the binder material to be
combusted therefrom.
2. The method of claim 1, wherein the step of removing the
loosened sand particles from the cavity includes, at least,
continuously removing the loosened sand particles from the
cavity as the binder material is combusted.
3. The method of claim 1, wherein the step of removing the
loosened sand particles from the cavity includes, at least,
directing a flow of air against the casting as the casting is
contained within the furnace such that the flow of air
dislodges loosened sand particles from the cavity.
4. The method of claim 3, wherein the step of directing a
flow of air against the casting as the casting is contained
within the furnace includes, at least, a step of directing a
flow of air against the casting at an airflow velocity in
excess of 3,000 feet per minute.
5. The method of claim 1, further comprising a step of
collecting the portion of the sand particles dislodged from
the casting and conveying it out of the furnace.
6. The method of claim 5, wherein the step of collecting the
portion of the sand particles dislodged from the casting
includes, at least, the step of continuously collecting
portions of the sand particles as the portions of the sand
particles are dislodged from the casting and conveying the
portions of the sand particles out of the furnace.
7. The method of claim 1, wherein the step of heating the
furnace includes, at least, heating the furnace to a
temperature in excess of approximately 850°F.
8. The method of claim 1, wherein the steps of capturing and
retaining the dislodged clumps of sand core material include,
at least, a step of providing a screen disposed beneath the
casting, the screen having openings therein which are not
sufficiently large to pass clumps of sand core material of
predetermined size.
9. The method of claim 8, further comprising a step of
causing clumps of sand core material smaller than the
predetermined size which pass through the screen to impact
upon a surface so as to break up the clumps.
10. A method for heat treating a casting having a sand core
which comprises, at least, sand particles bound together by a
binder material, the sand core defining a cavity within the
casting, and the method comprising the following steps:
introducing the casting with at least a portion of sand
core therein into a furnace;
heating the furnace to a temperature in excess of the
combustion temperature of the binder material;
providing an oxygenated atmosphere within the furnace;
containing the casting, with the sand core therein,
within the oxygenated atmosphere in the heated
furnace to permit the binder material to combust,
whereby portions of the sand core are loosened from the
sand core and fall from the cavity while the casting
is in the furnace; and
suspending, within the oxygenated atmosphere in the
furnace, portions of the sand core which become
dislodged from the casting prior to the binder being
combusted therefrom; and
releasing the suspended portions of the sand core once
the binder is combusted therefrom.
11. A method for heat treating a casting having a sand core
which comprises, at least, sand particles bound together by a
binder material, the sand core defining a cavity within the
casting, and the method comprising the following steps:
introducing the casting with at least a portion of sand
core therein into a furnace;
heating the furnace to a temperature in excess of the
combustion temperature of the binder material;
providing an oxygenated atmosphere within the furnace;
containing the casting, with the sand core therein,
within the oxygenated atmosphere in the heated
furnace to permit the binder material to combust,
whereby portions of the sand core are loosened from the
sand core and fall from the cavity while the casting
is in the furnace; and
providing a screen disposed beneath the casting and
within the oxygenated atmosphere of the furnace,
wherein the screen has openings therein which are
not sufficiently large to pass portions of the sand
core of a predetermined size, and wherein the
openings are sufficiently large to pass portions of
the sand core which are less than the predetermined
size; and
suspending on the screen portions of the sand core
which are larger than the predetermined size, to
allow further combustion of binder material
therefrom.
12. The method of claim 11, further comprising the step of
releasing the suspended portions of the sand core once the
binder is combusted therefrom.
13. The method of claim 11, further comprising, at least, a
step of causing portions of the sand core which pass through
the screen to impact upon a surface so as to break up the
portions of the sand core which pass through the screen.
14. The method of claim 11, further comprising a step of
directing airflow against the casting, while the casting is in
the furnace, so as to dislodge portions of the sand core from
the casting.
15. The method of claim 14, wherein the step of directing
airflow against the casting, while the casting is in the
furnace, includes, at least, directing, from a plurality of
directions, airflow against the casting so as to dislodge
portions of the sand core from the casting.
16. The method of claim 14, wherein the step of directing
airflow against the casting, while the casting is in the
furnace, includes, at least, directing airflow against the
casting at an airflow velocity in excess of 3,000 feet per
minute.
17. The method of claim 11, wherein the step of providing an
oxygenated atmosphere within the furnace comprises, at least,
the step of controlling the oxygen content in the furnace so
that a higher percent of oxygen is maintained where a higher
percentage of the binder material combusts.
18. The method of claim 17, wherein the step of providing an
oxygenated atmosphere within the furnace includes, at least,
conveying the casting through a plurality of zones
within the furnace,
controlling the oxygen content within the furnace to
provide 13-17% oxygen in zones of the plurality of
zones in which a major portion of binder combustion
takes place, and
controlling the oxygen content within the furnace to
provide 10-13% oxygen in zones of the plurality of
zones in which a major portion of binder combustion
does not take place.
19. The method of claim 11, further comprising the steps of
collecting and conveying the loosened portions of sand core
out of the furnace.
20. The method of claim 11, wherein the step of heating the
furnace includes, at least, heating the furnace to a
temperature of approximately 980°F.
21. A method for manufacturing a casting comprising the
following steps:
producing a casting having a sand core,
wherein the sand core includes, at least, sand
particles bound together by a combustible
binder material, and
wherein the sand core defines a cavity within
the casting;
introducing the casting into a furnace prior to any
substantial destruction to the sand core, wherein
the furnace is heated to a temperature in excess of
the combustion temperature of the binder material;
providing an oxygenated atmosphere within the furnace;
containing the casting, with the sand core therein,
within the furnace to permit the binder material to
combust, whereby sand particles of the sand core
are loosened from the sand core and fall from the
cavity while the casting is in the furnace; and
suspending, within the oxygenated atmosphere in the
furnace, portions of the sand core which become
dislodged from the casting prior to the binder being
combusted therefrom; and
releasing the suspended portions of the sand core once
the binder is combusted therefrom.
22. The method of claim 21, wherein the step of
introducing the casting into the furnace is performed prior to
any mechanical shaking intended to remove meaningful portions
of the sand core, whereby mechanical shaking for core removal
is avoided.
23. A method for heat treating a casting having a sand core
which comprises, at least, sand particles bound together by a
binder material, the sand core defining a cavity within the
casting, and the method comprising the following steps:
introducing the casting with at least a portion of sand
core therein into a furnace, wherein the furnace
defines a plurality of zones that are spatially
displaced from one another;
heating the furnace to a temperature in excess of the
combustion temperature of the binder material;
providing an oxygenated atmosphere in at least one zone
of the plurality of zones;
conveying the casting along a path through the
plurality of zones,
whereby the casting, with the sand core therein, is
exposed to the oxygenated atmosphere within the
heated furnace to permit the binder material to
combust,
whereby portions of the sand core are loosened from the
sand core and fall from the cavity while the casting
is in the furnace;
suspending, within the oxygenated atmosphere in the
furnace, portions of the sand core which become
dislodged from the casting prior to the binder being
combusted therefrom; and
releasing the suspended portions of the sand core once
the binder is combusted therefrom.
24. The method of claim 23, wherein the step of introducing
the casting into the furnace is performed prior to any
mechanical shaking intended to remove substantial portions of
the sand core, whereby mechanical shaking for core removal is
avoided.
25. The method of claim 24, further comprising the steps of:
providing a screen disposed beneath the casting and
within the oxygenated atmosphere of the furnace,
wherein the screen has openings therein which are
not sufficiently large to pass portions of the sand
core of a predetermined size, and wherein the
openings are sufficiently large to pass portions of
the sand core which are less than the predetermined
size; and
suspending on the screen portions of the sand core
which are larger than the predetermined size, to
allow further combustion of binder material
therefrom.
26. The method of claim 23, further comprising the steps of:
providing a screen disposed beneath the casting and
within the oxygenated atmosphere of the furnace,
wherein the screen has openings therein which are
not sufficiently large to pass portions of the sand
core of a predetermined size, and wherein the
openings are sufficiently large to pass portions of
the sand core which are less than the predetermined
size; and
suspending on the screen portions of the sand core
which are larger than the
predetermined size, to allow further
combustion of binder material
therefrom.
27. The method of claim 26, further comprising, at least, a
step of causing portions of the sand core which pass through
the screen to impact upon a surface so as to break up the
portions of the sand core which pass through the screen.
28. The method of claim 23, further comprising a step of
directing airflow against the casting, while the casting is in
the furnace, so as to dislodge portions of the sand core from
the casting.
29. The method of claim 28, wherein the step of directing
airflow against the
casting, while the casting is in the furnace, includes, at
least, directing, from a plurality of directions, airflow
against the casting so as to dislodge portions of the sand
core from the casting.
30. The method of claim 23, wherein the step of providing an
oxygenated atmosphere further includes, at least,
controlling the oxygen content within the furnace to
provide 13-17% oxygen in the zones of the plurality
of zones in which a higher percentage of the binder
material combusts, and
controlling the oxygen content within the furnace to
provide 10-13% oxygen in the zones of the plurality
of zones in which a lesser percentage of the binder
material combusts.
31. The method of claim 23, further comprising the step of
angling the casting within the furnace such that at least a
portion of the loosened portions of the sand core will fall
out of the casting under the force of gravity.
32. The method of claim 23, further comprising the steps of
collecting and conveying the loosened portions of sand core
out of the furnace.
33. The method of claim 23, wherein the step of heating the
furnace includes, at least, heating the furnace to a
temperature of approximately 980°F.
34. A method for manufacturing a casting comprising the
following steps:
producing a casting having a sand core,
wherein the sand core includes, at least, sand
particles bound together by a combustible
binder material, and
wherein the sand core defines a cavity within
the casting;
introducing the casting with at least a portion of
sand core therein into a furnace,
wherein the furnace is heated to a temperature
in excess of the combustion temperature of
the binder material, and
wherein the furnace defines a plurality of zones
that are spatially displaced from one
another;
providing an oxygenated atmosphere in at least one
zone of the plurality of zones;
conveying the casting along a path through the
plurality of zones,
whereby the casting, with the sand core therein, is
exposed to the oxygenated atmosphere within the
heated furnace to permit the binder material to
combust,
whereby portions of the sand core are loosened from
the sand core and fall from the cavity while the
casting is in the furnace; and
suspending, within the oxygenated atmosphere in the
furnace, portions of the sand core which become
dislodged from the casting prior to the binder being
combusted therefrom; and
releasing the suspended portions of the sand core once
the binder is combusted therefrom.
35. The method of claim 34, wherein the step of introducing
the casting into the furnace is performed prior to any
mechanical shaking intended to remove substantial portions of
the sand core, whereby mechanical shaking for core removal is
avoided.
36. The method of claim 34, further comprising the steps of:
providing a screen disposed beneath the casting and
within the oxygenated atmosphere of the furnace,
wherein the screen has openings therein which are
not sufficiently large to pass portions of the sand
core of a predetermined size, and wherein the
openings are sufficiently large to pass portions of
the sand core which are less than the predetermined
size; and
suspending on the screen portions of the sand core
which are larger than the predetermined size, to
allow further combustion of binder material
therefrom.
37. The method of claim 36, further comprising a step of
causing portions of the sand core which pass through the
screen to impact upon a surface so as to break up the portions
of the sand core which pass through the screen.
38. The method of claim 34, further comprising a step of
directing airflow against the casting, while the casting is in
the furnace, so as to dislodge portions of the sand core from
the casting.
39. The method of claim 38, wherein the step of directing
airflow against the casting, while the casting is in the
furnace, includes, at least, directing, from a plurality of
directions, airflow against the casting so as to dislodge
portions of the sand core from the casting.
40. The method of claim 38, wherein the step of directing
airflow against the casting, while the casting is in the
furnace, includes, at least, directing airflow against the
casting at an airflow velocity in excess of 3,000 feet per
minute.
41. The method of claim 34, wherein the step of providing an
oxygenated atmosphere further includes, at least,
controlling the oxygen content within the furnace to
provide 13-17% oxygen in the zones of the plurality
of zones in which a higher percentage of the binder
material combusts , and
controlling the oxygen content within the furnace to
provide 10-13% oxygen in the zones of the plurality
of zones in which a lesser percentage of the binder
material combusts.
42. The method of claim 34, further comprising steps of
collecting and conveying the loosened portions of sand core
out of the furnace.
43. The method of claim 34, wherein the step of heating the
furnace includes, at least, heating the furnace to a
temperature of approximately 980°F.
44. A method for heat treating a casting having a sand core
which comprises, at least, sand particles bound together by a
binder material, the sand core defining a cavity within the
casting, and the method comprising the following steps:
introducing the casting, with the sand core therein,
into a furnace;
heating the furnace to a temperature in excess of the
combustion temperature of the binder material;
providing an oxygenated atmosphere within the furnace;
containing the casting, with the sand core therein,
within the oxygenated atmosphere in the heated
furnace to permit binder material to combust,
whereby portions of the sand core are loosened from
the sand core and fall from the cavity while the
casting is in the furnace; and
suspending within the oxygenated atmosphere in the
furnace portions of the sand core that have fallen
from the casting.
45. The method of claim 44, wherein the step of suspending
includes, at least,
capturing at least some of the portions of the sand
core that have fallen from the casting,
retaining the captured portions of the sand core
within the furnace in a manner that permits binder
material to be combusted therefrom, and
releasing the retained portions of the sand core
subsequent to the combustion of binder material
therefrom.
46. The method of claim 45,
wherein the furnace defines a plurality of zones that
are spatially displaced from one another, and
wherein the method further comprises the step of
conveying the casting along a path through the
plurality of zones.
47. An apparatus for heat treating a metal casting having a
sand core comprising sand bound by a binder, wherein the
sand core defines a cavity within the casting, and
wherein the apparatus comprises:
a work chamber for receiving the casting therewithin;
a heating means for heating an atmosphere within said
work chamber such that the casting and the sand
core are heated to a temperature sufficient to
combust the binder of the sand core, whereby the
binder is burned off, so as to dislodge
portions of the sand core from the casting; and
retaining means operatively associated within said
work chamber
for capturing portions of the sand core which
become dislodged from the casting prior to the
binder being combusted therefrom, and retaining
the captured portions of the sand core within
said work chamber atmosphere, until the binder
has been substantially combusted therefrom.
48. The apparatus of claim 47, further comprising collection
means formed in a lower portion of said work chamber for
collecting the portion of the sand dislodged from the casting,
where said retaining means is disposed above said collection
means.
49. The apparatus of claim 47 or 48, wherein said retaining
means includes, at least, a screen.
50. The apparatus of claim 47 or 48, wherein said retaining
means is a broad member defining a plurality of apertures
therethrough.
51. The apparatus of claim 48, further comprising hearth
means for supporting the casting within said work chamber,
wherein said hearth means is disposed above said collection
means.
52. The apparatus of one of claims 47-51, wherein said
retaining means is constructed and arranged to release
captured and retained portions of the sand core once the
binder has been substantially combusted therefrom, wherein the
released portions of the sand core are reduced to a size
smaller than one-quarter inch.
53. The apparatus of claim 48, wherein said collection means
includes, at least, a trough.
54. The apparatus of claim 47, further comprising baffle means
disposed beneath said retaining means for contacting portions
of sand core released from said capturing means.
55. The apparatus of claim 47, further comprising a discharge
means for discharging the sand from said collection means and
said work chamber.
56. An apparatus for heat treating a casting having a sand
core comprising sand bound by a binder, wherein the sand core
defines a cavity within the casting, and wherein the apparatus
comprises:
a work chamber for receiving the casting therewithin;
a heating means for heating said work chamber such that
the casting and the sand core are heated to a
temperature sufficient to combust the binder of the
sand core, whereby binder is burned and portions of
the sand core are dislodged from the costing; and
suspension means in heat and gaseous communication with
said work
chamber fosuspending portions of the sand core and
substantially
promoting further combustion of the binder of the
suspended portions of the sand core.
57. The apparatus of claim 56, wherein said suspension means
includes, at least, a screen.
58. The apparatus of claim 56, further comprising baffle means
disposed beneath said suspension means for contacting portions
of sand core released from said suspension means.
59. The apparatus of claim 58, wherein said suspension means
is constructed and arranged to release suspended portions of
the sand core once the binder has been substantially combusted
therefrom.
60. The apparatus of claim 59, wherein the released portions
of the sand core are reduced to a size smaller than
one-quarter inch.
61. The apparatus of claim 60, further comprising means for
directing airflow over the suspended portions of the sand core
so as to promote combustion of the binder therefrom.
62. The apparatus of any one of claims 56-61, further
comprising:
hearth means for supporting the casting within said
work chamber, wherein said suspension means is
disposed below said hearth means.
63. The apparatus of claim 56, wherein said suspension means
is disposed within said work chamber.
64. The apparatus of claim 63, further comprising collection
means formed in a lower portion of said work chamber for
collecting portions of the sand core dislodged from the
casting, wherein said suspension means is disposed above said
collection means.
65. The apparatus of claim 64, further comprising a hearth
means for supporting the casting within said work chamber,
wherein said hearth means is disposed above said collection
means and said suspension means is interposed between said
hearth means and said collection means.
66. The apparatus of claim 65, wherein said suspension means,
said hearth means, and said collection means are vertically
aligned.
67. The apparatus of claim 66, further comprising a discharge
means for discharging the sand from said collection means and
said work chamber.
68. A method for heat treating a casting having a sand core
which comprises, at least, sand particles bound together by a
binder material, the sand core defining a cavity within the
casting, and the method comprising the following steps:
providing a flow of oxygenated air;
heating the flow of oxygenated air to a temperature in
excess of the combustion temperature of the binder
material;
introducing the casting into a furnace, wherein the
casting is exposed within the furnace to the flow
of oxygenated and heated air to permit binder
material to combust, whereby portions of the sand
core are loosened from and fall from the cavity of
the casting while the casting is within the
furnace;
collecting, distant from the casting, the portions of
the sand core which fall from the cavity of the
casting prior to the binder being combusted
therefrom;
maintaining the collected portions of the sand core
within the flow of oxygenated air to permit binder
to be combusted therefrom, whereby the flow of
oxygenated air is heated and sand is at least
partially reclaimed from the collected portions of
the sand core; and
conveying the at least partially reclaimed sand away
from the furnace.
69. The method of claim 68, wherein the step of
maintaining the collected portions of sand core within the
flow of oxygenated air includes, at least, suspending the
collected portions of sand core within the flow of oxygenated
air to permit binder to be combusted therefrom.
70. The method of claim 69, wherein any clumps of portions of
sand core transported away from the furnace with the at least
partially reclaimed sand have been disintegrated to a size
smaller than one-quarter inch.
71. The method of claim 69, wherein the step of suspending the
collected portions of sand core is carried out within the
furnace.
72. The method of claim 71, wherein the step of suspending
includes, at least,
providing a screen disposed beneath the casting and
within the furnace,suspending on the screen portions
of the sand core which are larger than a predetermined
size, to allow further combustion of binder material
therefrom, and
releasing the suspended portions of the sand core
subsequent to the combustion of binder therefrom.
73. The method of claim 69,
wherein the furnace defines a plurality of zones that
are spatially displaced from one another, and
wherein the method further comprises the steps of,
conveying the casting along a path through the
plurality of zones, and
directing the flow of oxygenated air from a
plurality of directions against the casting,
while the casting is in the furnace, so as to
dislodge portions of the sand core from the
casting, wherein the step of directing
airflow includes, at least,
directing a flow of air in a first
direction in a first zone of the
plurality of zones, and
directing a flow of air in a second
direction in a second zone of the
plurality of zones, and
wherein the step of conveying includes, at least,
conveying the casting sequentially through the
first zone and the second zone.
74. A method for heat treating a casting having a sand core
which comprises, at least, sand particles bound together by a
binder material, the sand core defining a cavity within the
casting, and the method comprising the following steps:
introducing the casting into a furnace, wherein the
furnace defines a plurality of zones that are
spatially displaced from one another;
heating the furnace to a temperature in excess of the
combustion temperature of the binder material;
providing an oxygenated atmosphere in at least one zone
of the plurality of zones;
conveying the casting along a path through the
plurality of zones, whereby the casting, with the
sand core therein, is exposed to the oxygenated
atmosphere within the heated furnace to permit the
binder material to combust;
directing airflow at the casting while the casting is
in the furnace so as to dislodge portions of the
sand core from the casting, wherein the step of
directing airflow includes, at least, varying the
direction from which airflow is directed at the
casting as the casting is conveyed through the
furnace; and
suspending, within the oxygenated atmosphere in the
furnace, portions of the sand core which become
dislodged from the casting prior to the binder being
combusted therefrom such that binder is combusted
from the suspended portions of the sand core.
75. The method of claim 74, Wherein the step of varying the
direction from which airflow is directed at the casting
includes, at least,
directing a flow of air in a first direction in
a first zone of the plurality of zones, and
directing a flow of air in a second direction in
a second zone of the plurality of zones, and
wherein the step of conveying includes, at least,
conveying the casting sequentially through the
first zone and the second zone.
76. The method of claim 75, wherein the step of varying the
direction from which airflow is directed at the casting
includes, at least, operating a fan in each of the first zone
and the second zone, and providing ductwork in each of the
first zone and the second zone such that the direction of
airflow in the first zone differs from the direction of
airflow in the second zone.
77. The method of claim 75, wherein the step of directing a
flow of air against the casting as the casting is contained
within the furnace includes, at least, a step of directing a
flow of air against the casting at an airflow velocity in
excess of 3,000 feet per minute.
78. The method of claim 75,
wherein the step of varying the direction from which
airflow is directed at the casting further
includes, at least, directing a flow of air
horizontally through a third zone of the plurality
of zones,
wherein the step of conveying further includes, at
least, conveying the casting through the third
zone, and
wherein the first direction and the second direction
are vertical directions.
79. A method of processing a casting having a sand core, which
sand core comprises, at least, sand particles bound together
by a binder material, which sand core defines a cavity within
the casting, the method comprising the steps of:
introducing a casting with at least some sand core
therein into a furnace;
heating the furnace to a temperature sufficient to
heat treat the casting and sufficient to combust
the binder of the sand core;
burning binder of the sand core within the furnace to
release core portions of varying sizes from the
casting;
reducing the size of at least larger portions of the
released sand core portion within the furnace,
which reducing is accomplished through additional
burning of binder in the larger portions of the
released sand core portions; and
thereafter conveying sand and any attached binder away
from the furnace,
thereby accomplishing heat treatment, core removal,
and at least partial sand reclamation in an
integrated process associated with a single
furnace.
80. The method of claim 79, wherein the step of introducing
the casting into the furnace is performed prior to any
mechanical shaking intended to remove substantial portions of
the sand core, whereby mechanical shaking for core removal is
avoided.
81. The method of claim 79, further comprising the steps of:
conveying the casting along an elongated path through
a plurality of adjacent zones, wherein the path and
the plurality of adjacent zones are defined by the
furnace; and
cooling the casting at some point in time after the
casting has been conveyed through the plurality of
adjacent zones; and
wherein the heating step includes, at least, the step
of heating all zones of the plurality of adjacent
zones; and
wherein the burning step includes, at least, the steps
of introducing oxygen to zones of the plurality of
adjacent zones and controlling the introduction of
oxygen to introduce larger amounts of oxygen in
certain zones encountered by the casting and
smaller amounts of oxygen in the zones encountered
by the casting later than said certain zones,
whereby core portions in varying amounts and varying
sizes are released in more than one zone of the
plurality of adjacent zones.
82. The method of claim 81, wherein the reducing step
includes, at least, the step of reexposing the larger portions
of the released sand core portions to heated and oxygenated
air associated with at least one of the zones of the plurality
of adjacent zones.
83. The method of claim 81,
wherein the method further comprises a step of
directing airflow from a plurality of directions
against the casting, while the casting is in the
furnace, so as to dislodge portions of the sand
core from the casting, wherein the step of
directing airflow includes, at least,
directing a flow of air in a first direction in
a first zone of the plurality of zones, and
directing a flow of air in a second direction in
a second zone of the plurality of zones, and
wherein the step of conveying includes, at least,
conveying the casting sequentially through the
first zone and the second zone.
84. A method for heat treating a casting having a sand core
which comprises, at least, sand particles bound together by a
binder material, the sand core defining a cavity within the
casting, and the method comprising the following steps:
providing an oxygenated atmosphere;
heating the oxygenated atmosphere to a temperature in
excess of the combustion temperature of the binder
material;
introducing the casting, with at least a portion of
the sand core therein, into a furnace,
wherein the furnace includes a support assembly
for supporting the casting within the
furnace,
wherein the introducing step includes a step of
placing the casting upon the support
assembly,
wherein the casting is exposed within the
furnace to the oxygenated and heated
atmosphere to permit binder material to
combust, and
wherein portions of the sand core are loosened
from and fall from the cavity of the casting
and the support assembly while the casting is
within the furnace;
collecting, distant from the casting and the support
assembly, the portions of the sand core which fall
from the support assembly prior to the binder being
combusted therefrom;
maintaining the collected portions of the sand core
within the oxygenated atmosphere in a manner that
permits binder to be combusted therefrom such that
sand is at least partially reclaimed from the
collected portions of the sand core; and
conveying the at least partially reclaimed sand away
from the furnace.
85. The method of claim 84, wherein the step of
maintaining the collected portions of the sand core within the
oxygenated atmosphere includes a step of suspending the
collected portions of the sand core within the oxygenated
atmosphere to permit binder to be combusted therefrom.
86. The method of claim 85, wherein the maintaining step
includes a step of sizing the collected portions of the sand
core and any clumps of portions of the sand core transported
away from the furnace with the at least partially reclaimed
sand have been disintegrated to a size smaller than
one-quarter inch.
87. The method of claim 85 or 86, wherein the step of
suspending the collected portions of the sand core is carried
out within the furnace.
88. The method of claim 85, wherein the step of suspending
includes steps of
providing a screen disposed beneath the casting and
within the furnace,
suspending on the screen portions of the sand core
which are larger than apertures defined by the
screen, to allow further combustion of binder
material therefrom, and
releasing the suspended portions of the sand core
subsequent to the combustion of binder therefrom.
89. The method of claim 88, wherein the released portions of
the sand core fall into a hopper disposed within the furnace.
90. The method of claim 85,
wherein the furnace defines a plurality of zones that
are spatially displaced from one another, and
wherein the method further comprises a step of
conveying the casting along a path through the
plurality of zones
91. The method of claim 90,
wherein the method further comprises a step of
directing the oxygenated atmosphere from a
plurality of directions against the casting, while
the casting is in the furnace, so as to dislodge
portions of the sand core from the casting, wherein
the directing step includes steps of
directing a flow of air in a first direction in
a first zone of the plurality of zones, and
directing a flow of air in a second direction in
a second zone of the plurality of zones, and
wherein the step of conveying includes a step of
conveying the casting sequentially through the
first zone and the second zone.
92. A method of processing a casting having a sand core,
which sand core comprises, at least, sand particles bound
together by a binder material, which sand core defines a
cavity within the casting, the method comprising steps of:
introducing a casting with at least some sand core
therein into a furnace,
wherein the furnace includes a support assembly
for supporting the casting within the
furnace, and
wherein the introducing step includes a step of
placing the casting upon the support
assembly;
heating the furnace to a temperature sufficient to
heat treat the casting and sufficient to combust
the binder of the sand core;
burning binder of the sand core within the furnace to
release core portions of varying sizes from the
casting, wherein the released sand core portions
fall from the cavity of the casting and the support
assembly while the casting is within the furnace;
reducing, at a reclaiming region distant from the
casting and the support assembly, the size of at
least larger portions of the fallen sand core
portions to at least partially reclaim sand from
larger portions of the fallen sand core portions,
which reducing is accomplished through
additional burning of binder in the larger
portions of the released sand core portions,
and
wherein the reclaiming region and the furnace
are proximately located such that heat passes
between the reclaiming region and the
furnace; and
thereafter conveying sand and any attached binder away
from the furnace,
thereby accomplishing heat treatment, core removal,
and at least partial sand reclamation in an
integrated process associated with a single
furnace.
93. The method of claim 92, wherein gasses are transferred
between the reclaiming region and the furnace.
94. The method of claim 92, wherein the method further
comprises a step of maintaining the larger portions of the
released sand core portions in a heated state during the time
between the step of burning binder and the step of reducing.
95. The method of claim 92, wherein the step of reducing is
carried out prior to any activity intended to substantially
cool the larger portions of the released sand core portions.
96. The method of claim 92, wherein the reclaiming region is
below the support assembly such that the released sand core
potions fall, under the force of gravity, from the support
assembly to the reclaiming region.
97. The method of claim 96, wherein the reclaiming region is
disposed within the furnace.
98. The method of claim 97, wherein the reducing step includes
a step of suspending upon a screen disposed within the heated
atmosphere of the furnace at least the larger portions of the
fallen sand core portions.
99. The method of claim 92, further comprising steps of:
conveying the casting along an elongated path through
a plurality of adjacent zones, wherein the path and
the plurality of adjacent zones are defined by the
furnace; and
cooling the casting at some point in time after the
casting has been conveyed through the plurality of
adjacent zones; and
wherein the heating step includes a step of heating
all zones of the plurality of adjacent zones; and
wherein the burning step includes steps of
introducing oxygen to zones of the plurality of
adjacent zones, and
controlling the introduction of oxygen to
introduce larger amounts of oxygen in certain
zones, and smaller amounts of oxygen in those
zones encountered by the casting later than
said certain zones,
whereby core portions in varying amounts and varying
sizes are released in more than one zone of the
plurality of adjacent zones.
100. The method of claim 99, wherein the reducing step
includes a step of reexposing the larger portions of the
released sand core portions to heated and oxygenated air
associated with at least one of the zones of the plurality of
adjacent zones.
101. The method of claim 91,
wherein the method further comprises a step of
directing airflow from a plurality of directions
against the casting, while the casting is in the
furnace, so as to dislodge portions of the sand
core from the casting, wherein the step of
directing airflow includes steps of
directing a flow of air in a first direction in
a first zone of the plurality of zones, and
directing a flow of air in a second direction in
a second zone of the plurality of zones, and
wherein the step of conveying includes a step of
conveying the casting sequentially through the
first zone and the second zone.
102. A method for heat treating a casting having a sand core
and reclaiming sand from the sand core, wherein the sand
core comprises sand particles bound together by a binder
material, the sand core defining a cavity within the
casting, and the method comprising the following steps:
introducing the casting, with at least a portion of
the sand core therein, into a furnace system
containing an oxygenated and heated atmosphere,
wherein the furnace system defines
a heat treating region, and
a reclaiming region disposed below the
heat treating region and in heat and
gaseous communication with the heat
treating region,
wherein the furnace system includes a support
assembly for supporting the casting within
the heat treating region, and
wherein the introducing step includes a step of
placing the casting upon the support
assembly;
heat treating the casting while the casting is
disposed within the heat treating region;
dislodging portions of the sand core from the casting
while the casting is disposed within the heat
treating region,
wherein the dislodging step includes a step of
combusting binder material of the portions of
the sand core, and
wherein the dislodged portions of the sand core
fall from the casting and the support
assembly into the reclaiming region;
reclaiming, at least partially and within the
reclaiming region, sand from the fallen portions of
the sand core, wherein the reclaiming step includes
a step of further combusting binder material of the
fallen portions of the sand core; and
conveying the reclaimed sand away from the furnace
system,
thereby accomplishing heat treatment, core removal,
and at least partial sand reclamation in an
integrated process associated with a single furnace
system.
103. The method of claim 102, wherein the method further
comprises a step of maintaining the released sand core
portions in a heated state during the time between the
dislodging step and the reclaiming step.
104. The method of claim 102, wherein the step of reclaiming
is carried out prior to any activity intended to substantially
cool the dislodged portions of the sand core.
105. The method of claim 102, wherein the heat treating region
and the reclaiming region are vertically aligned.
106. The method of claim 102, wherein the dislodged portions
of the sand core free fall from casting and the support
assembly into the reclaiming region.
107. The method of claim 102, wherein the heat treating region
and the reclaiming region are both disposed within a single
furnace.
108. The method of claim 102, wherein the combusting step of
the dislodging step includes a step of exposing the casting
and at least a portion of the sand core therein to the
oxygenated and heated atmosphere.
109. The method of one of the claims 102-108, wherein the
further combusting step of the reclaiming step includes a step
of suspending, within the oxygenated and heated atmosphere, at
least some of the fallen portions of the sand core such that
binder is combusted from the suspended portions of the sand
core.
110. A method for heat treating a casting having a sand core
which comprises sand particles bound together by a combustible
binder material, the sand core defining a cavity within the
casting, and the method comprising steps of:
introducing the casting, with at least a portion of the
sand core therein, into a furnace;
heating the furnace to a temperature sufficient to heat
treat the casting and in excess of the combustion
temperature of the binder material;
providing an oxygenated atmosphere in the furnace,
whereby the casting and the sand core therein are
exposed to the oxygenated atmosphere within the
heated furnace to permit binder material of the sand
core to combust;
directing airflow at the casting while the casting is
in the furnace so as to dislodge portions of the
sand core from the casting, wherein the directing
step includes a step of varying the direction from
which airflow is directed at the casting while the
casting is in the furnace; and
suspending, within the oxygenated atmosphere of the
furnace, the fallen portions of the sand core.
111. The method of claim 110, further comprising steps of
supporting the casting upon a support assembly within
the furnace, wherein the dislodged portions of the
sand core fall from the casting and the support
assembly, and
forcing the oxygenated atmosphere to flow across the
suspended portions of the sand core, whereby
combustion of the binder material of the suspended
portions of the sand core is enhanced.
112. The method of claim 111, further comprising a step of
releasing the suspended portions of the sand core subsequent
to the combustion of binder material therefrom.
113. The method of claim 110,
wherein the furnace defines a plurality of zones that
are spatially displaced from one another, and
wherein the method further comprises a step of
conveying the casting along a path through the
plurality of zones.
114. The method of claim 113,
wherein the step of varying the direction from which
airflow is directed at the casting includes steps
of
directing a flow of air in a first direction in
a first zone of the plurality of zones, and
directing a flow of air in a second direction in
a second zone of the plurality of zones, and
wherein the step of conveying includes a step of
conveying the casting sequentially through the
first zone and the second zone.
115. The method of claim 114,
wherein the step of varying the direction from which
airflow is directed at the casting further includes
a step of directing a flow of air horizontally
through a third zone of the plurality of zones,
wherein the step of conveying further includes a step
of conveying the casting through the third zone,
and
wherein the first direction and the second direction
are vertical directions.
116. The method of claim 114, wherein the step of varying
the direction from which airflow is directed at the casting
includes a step of operating a fan in each of the first zone
and the second zone of the plurality of zones.
117. The method of claim 114, wherein the step of varying the
direction from which airflow is directed at the casting
further includes a step providing ductwork in each of the
first zone and the second zone.
118. The method of claim 114, further comprising a step of
suspending, within the oxygenated atmosphere in the furnace,
portions of the sand core which become dislodged from the
casting prior to the binder being combusted therefrom such
that binder material is combusted from the suspended portions
of the sand core.
119. The method of claim 114, including a step of sizing the
suspended portions of the sand core and releasing portions of
the sand core smaller than one-quarter inch.
120. The method of claim 114, wherein the step of suspending
includes steps of
providing a screen disposed beneath the casting and
within the oxygenated atmosphere of the furnace,
wherein the screen has openings therein which are
not sufficiently large to pass portions of the sand
core of a predetermined size, and wherein the
openings are sufficiently large to pass portions of
the sand core which are less than the predetermined
size, and
suspending on the screen portions of the sand core
which are larger than the predetermined size, to
allow further combustion of binder material
therefrom.
121. The method of claim 110, wherein the predetermined size
is one-quarter inch.
122. A method for heat treating a casting having a sand core
which comprises sand particles bound together by a binder
material, the sand core defining a cavity within the casting,
and the method comprising steps of:
introducing the casting, with at least a portion of
the sand core therein, into a furnace that defines
a plurality of zones that are spatially displaced
from one another;
heating at least a plurality of zones of the plurality
of zones to a temperature sufficient to heat treat
the casting and in excess of the combustion
temperature of the binder material;
conveying the casting along a path through the
plurality of zones;
providing an oxygenated atmosphere including steps of
introducing a larger amount of oxygen into
certain zones of the heated plurality of
zones, and
introducing a smaller amount of oxygen into
zones of the heated plurality of zones
encountered by the casting later than said
certain zones,
whereby the casting and the sand core therein are
exposed to the oxygenated atmosphere within the
heated furnace to permit binder material of the
sand core to combust so that portions of the sand
core are loosened from the sand core and fall from
the cavity while the casting is in the furnace; and
suspending within the oxygenated atmosphere of the
furnace, the fallen portions of the sand core.
123. The method of claim 112, wherein the step of providing an
oxygenated atmosphere further includes steps of
controlling the oxygen content within the furnace to
provide 13-17% oxygen in the zones of the plurality
of zones in which a higher percentage of the binder
material combusts , and
controlling the oxygen content within the furnace to
provide 10-13% oxygen in the zones of the plurality
of zones in which a lesser percentage of the binder
material combusts.
124. A method for heat treating a casting having a sand core
which comprises sand particles bound together by a combustible
binder material, the sand core defining a cavity within the
casting, and the method comprising steps of:
introducing the casting, with at least a portion of
the sand core therein, into a furnace, and placing
the casting upon a support assembly within the
furnace;
providing an oxygenated atmosphere in the furnace;
heating the oxygenated atmosphere in the furnace to a
temperature sufficient to heat treat the casting
and in excess of the combustion temperature of the
binder material, wherein the casting and the sand
core therein are exposed to the heated and
oxygenated atmosphere within the furnace so that
binder material of the sand core combusts and
portions of the sand core fall from the casting and
the support assembly; and
further reclaiming sand from the fallen portions of
the sand core, by further exposing the fallen
portions of the sand core to the heated and
oxygenated atmosphere, wherein the further
reclaiming step includes a step of sizing the
fallen portions of the sand core so that any clumps
of portions of sand core that are with the
reclaimed sand have been disintegrated to a size
smaller than one-quarter inch.
25. The method of claim 114, wherein the reclaiming step
includes a step of suspending the fallen portions of the sand
core within the heated and oxygenated atmosphere.
126. The method of claim 114, wherein the reclaiming step is
carried out within the furance.
127. The method of claim 114, further comprising a step of
conveying the reclaimed sand away from the furnace, wherein
the reclaiming step is carried out such that any clumps of
portions of sand core that are conveyed away from the furnace
with the reclaimed sand have been disintegrated to a size
smaller than one-quarter inch.
128. A method for heat treating a casting having a sand core
which comprises sand particiles bound together by a
combustible binder material, the sand core defining a cavity
within the casting, and the method comprising steps of:
introducing the casting, with at least a portion of the
sand core therein, into a furnace;
heating the furnace to a temperature sufficient to
heat treat the casting and in excess of the
combustion temperature of the binder material;
providing an oxygenated atmosphere in the furnace,
whereby the casting and the sand core therein are
exposed to the oxygenated atmosphere within the
heated furnace to permit binder material of the sand
core to combust;
directing airflow, at an airflow velocity in excess of
3,000 feet per minute, at the casting while the
casting is in the furnace, whereby portions of the
sand core are dislodged from the casting; and
suspending, within the oxygenated atmosphere of the
furnace, the fallen portions of the sand core.
129. A method for heat treating a casting having a sand core
which comprises sand particles bound together by a binder
material, the sand core defining a cavity within the casting,
and the method comprising steps of:
providing a flow of oxygenated air;
heating the flow of oxygenated air to a temperature in
excess of the combustion temperature of the binder
material;
introducing the casting into a furnace, wherein the
casting is exposed within the furnace to the flow
of oxygenated and heated air to permit binder
material to combust, whereby portions of the sand
core are loosened from and fall from the cavity of
the casting while the casting is within the
furnace;
collecting, distant from the casting, the portions of
the sand core which fall from the cavity of the
casting prior to the binder being combusted
therefrom;
maintaining the collected portions of the sand core
within the flow of oxygenated air to permit binder
to be combusted therefrom, whereby sand is at least
partially reclaimed from the collected portions of
the sand core; and
conveying the at least partially reclaimed sand away
from the furnace, wherein the maintaining step
includes a step of sizing the collected portions of
the sand core so that any clumps of portions of
sand core transported away from the furnace with
the at least partially reclaimed sand have been
disintegrated to a size smaller than one-quarter
inch.
130. An apparatus for heat treating a casting having a sand
core comprising sand bound by a binder, wherein the sand core
defines a cavity within the casting, and wherein the apparatus
comprises:
a furnace defining a work chamber for receiving the
casting therewithin;
a support assembly for supporting the casting within
said work chamber;
a heating means for heating said work chamber to a
temperature sufficient to combust the binder of the
sand core, whereby binder material is burned and
portions of the sand core fall from both the
casting and the support assembly;
suspension means for suspending within said work
chamber portions of the sand core that fall from
the casting and the support assembly prior to the
binder being combusted therefrom, wherein said
suspension means includes a broad member defining
apertures therethrough; and
airflow means for directing airflow through said
apertures and over the suspended portions of the
sand core so as to promote combustion of the binder
therefrom.