U.S. patent number 3,791,697 [Application Number 05/251,183] was granted by the patent office on 1974-02-12 for method and apparatus for flame jet cutting.
Invention is credited to Zenjiro Hokao, Taiitsu Makajima.
United States Patent |
3,791,697 |
Hokao , et al. |
February 12, 1974 |
METHOD AND APPARATUS FOR FLAME JET CUTTING
Abstract
A cutter proper is provided with a burner having at its tip a
nozzle that injects a combustion flame of oxygen and kerosene at
supersonic speed. Thermit material is supplied to the flame jet
that is injected by burning the oxygen and kerosene at supersonic
speed whereby the concrete or stone material and the like is burnt
at such high temperatures where said material to be cut is melted.
The cutting body can be cut by melting without relying on
destruction of human work by injecting the flame jet toward the
cutting body.
Inventors: |
Hokao; Zenjiro (Saitama-ken,
JA), Makajima; Taiitsu (Tokyo, JA) |
Family
ID: |
27279055 |
Appl.
No.: |
05/251,183 |
Filed: |
May 8, 1972 |
Foreign Application Priority Data
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May 12, 1971 [JA] |
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46/32111 |
Oct 6, 1971 [JA] |
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46/79018 |
Jan 28, 1972 [JA] |
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47/10688 |
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Current U.S.
Class: |
299/14; 175/13;
431/114; 110/261; 431/4; 431/158 |
Current CPC
Class: |
E21C
37/16 (20130101); E21B 7/14 (20130101) |
Current International
Class: |
E21B
7/14 (20060101); E21C 37/00 (20060101); E21C
37/16 (20060101); E21c 021/00 () |
Field of
Search: |
;299/14 ;175/13,14
;431/4,114,158 ;110/22B |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Purser; Ernest R.
Attorney, Agent or Firm: Meyer, Tilberry & Body
Claims
Having thus described our invention, we now claim:
1. A method of cutting a stone or concrete-like material comprising
the steps of: providing a combustion jet flame comprised of oxygen
and kerosene in a burner; ejecting said jet flame from said burner
at supersonic velocity; supplying a thermit to said jet flame
following ejection from said burner; ejecting a cooling fluid about
the periphery of said jet flame; directing said jet flame and
thermit against an area of the material to be cut, and directing
said cooling fluid about the periphery of the area of the material
to be cut.
2. An apparatus for flame cutting stone or concrete-like material
comprising: a jet flame cutter head adapted to provide continuous
combustion of a mixture of oxygen and kerosene received therein to
form a jet flame; means to supply metered amounts of oxygen and
kerosene to said jet flame cutter head; means to ignite and sustain
combustion of said oxygen and kerosene to provide a jet flame in
said jet flame cutter head; means to eject said jet flame from said
flame cutter head at supersonic velocity; means to provide a
coolant about the periphery of said flame cutter head; means for
supplying thermit to said jet flame; and means to direct said
coolant about the periphery of said jet flame.
3. The apparatus defined in claim 2, including a thermit powder
supply pipe with a nozzle positioned adjacent the tip of said flame
cutter head; a thermit powder container; and thermit powder
pressure feeding means connected to said container to supply
thermit powder under pressure to said powder supply pipe
nozzle.
4. The apparatus of claim 2, wherein said jet flame cutter head
includes a combustion chamber having a nozzle at one end; injector
means for injecting a mixture of oxygen and kerosene into said
chamber, said injector means being disposed on the side of said
chamber opposed to said nozzle; an oxygen supply pipe connected at
one end to said injector means and at the opposite end to oxygen
supply means; a kerosene supply pipe connected at one end to said
injector means and at the opposite end to a kerosene supply means;
a thermit powder supply pipe secured at one end to the tip of said
jet flame cutter head and at the other and to a supply of thermit
powder; and a liquid cooling tube encircling said jet flame cutter
head connected to a supply of liquid coolant.
5. The apparatus of claim 4, including a plurality of liquid
coolant outlet ports in the tip of said flame cutter head
communicating with said liquid cooling tube and adapted to direct
coolant about the periphery of said jet flame and about the
periphery of impingement of said jet flame against said material to
be cut.
6. The apparatus of claim 2, including a noise muffler comprising
an elongated inner tube dimensioned to be slidably received
co-axially over said jet flame cutter head, said inner tube
including a plurality of axially spaced apart annular pockets
projecting radially outwardly from said tube; an outer tube
co-axially received over said inner tube and sealed to provide a
closed fluid chamber there between, port means in said annular
pockets to provide communication between said inner and outer
tubes; and means to introduce a fluid coolant under pressure into
said chamber to flow through said port means into said inner tube
to muffle the sound of, and impinge the periphery of, said jet
flame.
7. The apparatus defined in claim 6, including means to adjustably
position said muffler longitudinally along said jet flame cutter
head.
Description
This application pertains to the art of cutting and more
particularly to the cutting of stone-like materials.
The invention is particularly applicable to cutting concrete, stone
material and other materials similar to the concrete by a flame jet
and will be described with particular reference thereto; however,
the invention has broader application as will be more fully
appreciated by those skilled in the art.
Heretofore, concrete and stone materials have been cut generally by
means of "chipping work by hand" using hammer or chisel. This work
comprised cutting the concrete with the chisel by gradually
destroying it and the time and labor required for accomplishing the
work was tremendous with the resultant work efficiency being quite
low. Also, as the chipping work was being carried out, numerous
cracks were caused in the stone by the action of striking the
chisel. Because of this cracking, the remaining portion of the cut
concrete which was to be used following cutting frequently could
not be used due to severe cracks.
In cutting relatively thin concrete plates, mechanical machines
such as motor saw and the like have heretofore been utilized.
However, wear and tear of the component machine parts is
excessively great and in the case where the machines must be used
for extended time periods, valuable work time is required for
replacement and maintenance of the machine components. Further,
when cutting thick concrete blocks and the like, large cutting
machines have been required which, in turn, increased the costs and
operational difficulties thereof.
The present invention contemplates a new and improved method and
apparatus which overcame all of the above referred problems and
others and provides method and apparatus for flame jet cutting
which is simple, economical and readily adaptable to use with
different stone or concrete-like materials having various
thicknesses.
In accordance with the present invention, there is provided a
method of flame jet cutting particularly adapted for use in cutting
stone or concrete-like materials. The method comprises the steps of
providing a combustion flame jet comprised of oxygen and kerosene
in a burner; ejecting the jet from the burner at a supersonic
velocity; and, supplying a thermit to the jet following ejection
from the burner whereby the material is cut by the simultaneous
combustion of the oxygen, kerosene and thermit.
In accordance with a more limited aspect of the present invention,
the method further includes the step of cooling the burner by
injecting a cooling fluid onto the periphery of the flame jet.
In accordance with another aspect of the present invention, there
is provided an apparatus particularly adapted for use in flame jet
cutting of stone or concrete-like material. The apparatus includes
a cutter head having a burner therein for permitting desired
combustion of oxygen and kerosene therein to form a cutting flame
jet; means for supplying selected amounts of the oxygen and
kerosene to the burner; means for permitting escape of the jet from
the burner at high velocity; and, means for continuously directing
a cooling fluid at least around the outer periphery of the
burner.
In accordance with another aspect of the present invention, the
apparatus further includes means for directing a thermit material
to the flame jet adjacent the burner and means for continuously
supplying the thermit material to the directing means.
In accordance with still another aspect of the present invention,
means are provided to permit a continuous cooling fluid flow onto
the periphery of the flame jet at least from a position immediately
adjacent the burner during escape of jet from the burner.
In accordance with yet another aspect of the present invention, the
apparatus includes means for muffling the noise created by
apparatus operation.
The principal object of the present invention is the provision of a
method and apparatus for flame jet cutting stone or concrete-like
material.
Another object of the present invention is the provision of a
method and apparatus for flame jet cutting which is simple.
Another object of the present invention is the provision of a
method and apparatus for flame cutting which is efficient in
use.
Another object of the present invention is the provision of a
method and apparatus for flame jet cutting which is readily adapted
for use with stone or concrete-like materials of different types
and sizes.
Still another object of the present invention is the provision of a
method and apparatus for flame jet cutting which is inexpensive to
employ.
Still another object of the present invention is the provision of a
method and apparatus for flame jet cutting which provides improved
cuts in stone or concrete-like materials.
The invention may take form in certain parts and arrangements of
parts, a preferred embodiment of which will be described in detail
in the specification and illustrated in the accompanying drawings
which form a part hereof and wherein:
FIG. 1 is a flow sheet schematically showing a cutting device and a
fuel supply circuit according to the present invention;
FIG. 2 is a vertical cross-sectional view of a tip portion of the
burner;
FIG. 3 is a flow sheet schematically showing a cutting device and a
fuel supply circuit according to the present invention in which the
burner includes means for ejecting water from the burner tip so as
to surround the jet flame;
FIG. 4 is a vertical cross-sectional view of the tip portion of the
burner shown in FIG. 3;
FIG. 5 is an elevational view of the tip portion of the burner
shown in FIG. 4; and,
FIG. 6 is a vertical cross-sectional view of a muffler mounted at a
tip portion of the cutter head.
Referring now to the drawings wherein the showings are for purposes
of illustrating the preferred embodiment of the invention only and
not for purposes of limiting same, there is shown in FIG. 1 a
burner 2 provided at a tip of a cutter head 1. An oxygen cylinder 3
supplies oxygen under a pressure of generally between 40-45 psi to
burner 2 and a kerosene cylinder 4 supplies kerosene under a
pressure of generally between 40-45 psi to burner 2. A cylinder 5
of high pressure nitrogen is employed to cause the kerosene to flow
from cylinder 4 to burner 2. With reference to FIG. 2, it will be
seen that the tip portion of burner 2 is provided with a rubber
nozzle 6 and a combustion chamber 7 which is communicated with the
nozzle. At the end of combustion chamber 7 spaced remote from
nozzle 6, there is provided an injector 9 threaded to a holder 8. A
plurality of injecting outlets 10 bored on the central portion of
injector 9 are communicated with a central opening 11 in holder 8
and opening 11 is communicated with a kerosene supply pipe 12 for
injecting kerosene as will hereinafter become apparent. The
plurality of injecting outlets 13 bored on external peripheral
portion of injector 9 are communicated with an external peripheral
opening 14 of the holder 8 with opening 14 being communicated with
an oxygen supply pipe 15 which surrounds the external periphery of
kerosene supply pipe 12. The injected kerosene is mixed with the
oxygen through its atomization and is burned at high temperatures
in the range of 3,500.degree. to 8,800.degree.K in combustion
chamber 7 by its ignition at the tip of the burner 2. As the
mixture is ejected from nozzle 6, it is transformed to supersonic
flame jet of Mach number 5-6. Simultaneously therewith, the
external wall surface of combustion chamber 7 is heated to a high
temperature so that it is necessary to effect continuous cooling
thereof. In the preferred embodiment and for needed cooling, a
sleeve 17 is provided between the external peripheries of nozzle 6,
combustion chamber 7 and an outer tube 16. A through-hole 18 is
provided in sleeve 17 adjacent its base end and the other end is
disposed in a tight fitting contact with the external periphery of
holder 8. Also, the opposite end of holder 8 is connected to an
inner tube 19 which surrounds the external periphery of oxygen
supply pipe 15. Cooling fluid, which comprises water in the
preferred embodiment, is supplied under a pressure of approximately
10 liters per minute at a pressure of 4 to 6 psi to the space or
channel formed between oxygen supply pipe 15 and inner tube 19.
From there, it is introduced to the space or channel formed between
combustion chamber 7 and sleeve 17 through an opening 20 in holder
8 to cool the external wall of the combustion chamber. It is then
discharged to the outside by passing through hole 18 and thence
through the space or channel formed between sleeve 17 and outer
tube 16. In FIGS. 1 and 3 of the drawings, reference numeral 21
generally designates a tank for holding the cooling water and
numeral 22 generally designates a pump for pumping the water to the
cutter head.
A thermit powder supply pipe 23 is provided along the outside of
cutter head 1 and includes a tip formed with jetting port 24
generally directed toward the tip direction of the burner 2. The
thermit material or powder is conveniently stored in a thermit
powder container 25 and is supplied under pressure to the end of
burner 2 by pressurized air from a compressor 26 from where it is
jetted outwardly of port 24 toward the flame jet. When the flame
jet is directed against a body 27 which is to be cut, that is,
concrete material or the like, the thermit is burned on the surface
of the cut 28. The flame at that point becomes one of high
temperature so that body 27 is effectively melted at cut 28. The
molten material is caused by the melting or cutting action and is
removed from the area of the cut by the pressure, generally in the
range of from 10-15 psi, of the flame jet itself. The material from
the cut also acts to melt additional successive new surface of body
27 so that the area of the cut is rapidly melted. In practice, the
cutting speed is about 6-8 meters per hour when reinforced concrete
plate having a thickness of 10 cm is being cut. Although the
preferred embodiment of the invention employs thermit powder which
is supplied by means of a pipe, it will be understood that the
powder is not necessarily required and that a thermit rod may be
intermittently inserted into the cutting surface of the
concrete.
The concrete surface which has been cut in a manner as hereinabove
described eliminates the cracks which have heretofore occurred in
the case of the chiseling type of cutting work. Thus, the shape of
the concrete surface when using the subject invention may be
favorably maintained. Accordingly, regardless of the thickness and
the size of the concrete material, cutting can be effected so that
machining such as boring and the like, is made possible. Again, it
will be appreciated that the subject invention may be utilized not
only for the concrete but also for stones and other concrete-like
materials.
Since, body 27 is heated to high temperatures at the periphery of
that portion to be cut during the time of cutting, it is desirable
to provide means for cooling that peripheral area. In the situation
where the body to be cut is comprised of concrete, cooling is most
advantageous as concrete has properties of showing brittleness to
the heat which, of course, is not desired.
The device shown in FIGS. 3, 4 and 5 is designed to cut the body
while providing cooling to an extent that the thermal influence can
be ignored even if it is highly influenced by the heat.
In the device shown in FIG. 4, a flow passage 29 for the cooling
fluid is formed on the external peripheries of combustion chamber 7
and oxygen supply pipe 15. The cooling fluid is fed under pressure
from tank 21 by means of pump 22. The cooling fluid which has
cooled the external wall of combustion chamber 7 is jetted
outwardly from the tip of the cutter head through a plurality of
jetting out ports 30 formed on the periphery of the opening portion
of the tip of burner 2. By this arrangement, jetting cooling water
surrounds the periphery of the flame jet to thereby impinge the
cutting area to effect cooling and shields the sounds of the
operation of the flame jet.
As described hereinabove, the cutting body is cooled by the cooling
fluid at the periphery of the cutting area while it is being cut so
that the cutting action does not cause thermal influence on a
cutting body which has a tendency of thermal alteration. Thus, the
shape of the cut area in the body may be maintained as desired.
Since the cooling fluid is jetted outwardly from the tip of burner,
a continuous circulation circuit for the fluid is not required in
order that the device itself may be constructed in a light weight
and compact form. Further advantages are that the use of a special
heat resisting alloy is not required at the tip portion of burner 2
and that the noise caused by operation of the flame jet is shielded
so as to provide sound insulation.
The apparatus shown in FIG. 6 shows means for muffling the sound of
the flame jet. The jet cutter according of the present invention
has an extremely great injection sound of the flame jet. Because of
this, the noise level could cause problems with persons near the
apparatus during its operation. This is particularly true when the
apparatus is utilized in a residential area.
Therefore, and with reference to FIG. 6, a muffler 31 is provided
which is comprised of an inner tube 32 and an outer tube 34
disposed concentrically therearound so that there is a clearance or
channel 33 therebetween. Clearance 33 is sealed at both ends of
inner tube 32 and outer tube 34. The inner tube is formed so as to
include a plurality of bulged portions 35 along its periphery
which, in turn, include a plurality of water jetting out holes 36
on the sides thereof. A cylindrical mounting portion 37 is formed
on the base end of muffler 31 with a jet cutter 38 inserted
thereinto and affixed thereto by means of any convenient retaining
members 39 such as screws and the like. Also, a water feeding port
40 is formed on the muffler with a hose 42 leading from a pump 41
connected to port 40.
When jet cutter 38 is used, the ignition is carried out in the
condition where the tip of the jet cutter is caused to protrude to
the outside of muffler 31. After ignition and when the flame is
stabilized, the muffler is caused to move forward so that the tip
of jet cutter 38 is situated generally at the vicinity of mounting
portion 37 and retained in that position by means of retaining
members 39. In this condition, pump 41 is operated so that
pressurized fluid or water is introduced into the clearance or
channel 33 from water feeding port 40 such that the inside of
clearance 33 is filled with the fluid. The fluid is then caused to
jet outwardly from ports 36 of tube 32 to form a film of water on
the periphery of the flame. The noise of operation of the jet flame
is thereby shielded by the wall of water in clearance 33, the film
of water in the periphery of the jet flame and the irregular
surface formed by the bulged portions of the inner tube.
The invention has been described with reference to the preferred
embodiment. Obviously, modification and alteration will occur to
others upon the reading and understanding of this specification. It
is my intention to include all such modification and alterations
insofar as they come within the scope of the appended claims or the
equivalents thereof.
* * * * *