JP3554008B2 - Gas cutting crater - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a gas cutting crater for hot cutting, and more particularly to a gas cutting crater capable of shortening a preheating time when starting cutting.
[0002]
[Prior art]
In steel mills and steel mills, relatively thick steel materials and billets are cut in a hot state by a cutting crater. This cutting is performed by preheating a steel material or a steel piece to be cut by a flame formed in the gas cutting crater, and thereafter moving the crater in the cutting direction while injecting cutting oxygen.
[0003]
Generally, when a material to be cut is preheated by a flame, a flame formed by mixing a predetermined amount of fuel gas and an amount of oxygen necessary for burning the gas in advance and ejecting the mixed gas from a preheating hole of a gas cutting crater. It is most efficient to use (neutral flame).
[0004]
However, the gas cutting crater used for hot cutting and the torch to which the crater is attached are heated by radiant heat from a steel material or a steel slab, so that the preheated oxygen and the fuel gas are mixed inside the torch as described above. In the case of the type or the chip mixing type in which mixing is performed inside the crater, a flashback accident may occur.
[0005]
For this reason, the gas cutting crater used for hot cutting is an out-mixing type that mixes preheated oxygen and fuel gas outside the crater, or mixes both in a groove formed at the tip of the crater. Generally, it is configured as a front mixing type.
[0006]
On the other hand, in a cutting device for continuous casting that requires hot cutting, it is required to further reduce the time required for cutting a billet. In order to satisfy this requirement, it is necessary to reduce the cutting time and the preheating time by increasing the cutting speed.
[0007]
Here, the preheating time generally refers to the time from when the material to be cut is approached to the material to be cut and preheated in a state where a flame is formed at the crater, and when cutting oxygen is jetted, cutting can be started. However, in the case of hot cutting, a so-called running cutting is generally performed in which a steel slab is continuously moved while a flame is formed at the crater to cut a steel slab. Therefore, shortening the preheating time in hot cutting is synonymous with increasing the cutting speed.
[0008]
When attention is paid to shortening the preheating time, it is difficult to sufficiently mix the preheating oxygen and the fuel gas with the external mixing type gas cutting crater, and the preheating power of the flame formed in the gas cutting crater is small. For this reason, in the gas cutting crater, the cutting oxygen is ejected at the time of preheating and a part of the cutting oxygen jet is used as preheating oxygen, so that a neutral flame-like flame is formed around the jet and the preheating power is increased. Have improved.
[0009]
The present applicant has already developed and proposed a front-mixing type gas cutting crater which has solved the above problem (Japanese Utility Model Publication No. 1-12525). The gas cutting crater has a sub-preheating hole for ejecting preheating oxygen and a fuel gas hole for ejecting fuel gas alternately on the same circumference on the outer periphery of the hole for ejecting cutting oxygen and between the secondary preheating oxygen holes. It is arranged.
[0010]
According to the above technology, it is possible to promote the mixing of the sub-preheating oxygen and the fuel gas in the groove formed at the tip of the crater, and it is possible to form a stronger flame when preheating the steel material and the billet. . Therefore, it is possible to shorten the preheating time (improve the cutting speed) as compared with the gas cutting crater in which only the fuel gas holes are arranged between the cutting oxygen holes and the secondary preheating oxygen holes.
[0011]
[Problems to be solved by the invention]
In a cutting apparatus incorporated as a part of a comprehensive plant such as a continuous casting line or a rolling line, reduction of cycle time has always been a demand.
[0012]
Even with the above-described front-mixing type gas cutting crater, the flame formed at the crater is a so-called carbonized flame, and there is a problem that there is a limit in increasing the cutting speed.
[0013]
An object of the present invention is to provide a front mixing type gas cutting crater which can make a formed flame closer to a neutral flame.
[0014]
[Means for Solving the Problems]
In order to solve the above problems, a gas cutting crater according to the present invention is a gas cutting crater having a groove for mixing preheating oxygen and fuel gas at its tip, wherein a cutting oxygen hole arranged at the center, A primary preheating oxygen hole disposed around the cutting oxygen hole, a sub-preheating oxygen hole disposed on a circumference surrounding the primary preheating oxygen hole, and the sub-preheating on the same circumference as the sub-preheating oxygen hole. A fuel gas hole disposed between oxygen holes, and a secondary preheating oxygen hole disposed around a circumference in which the auxiliary preheating oxygen holes and the fuel gas holes are alternately arranged, and at least the auxiliary preheating oxygen The hole, the fuel gas hole, and the secondary preheating oxygen hole are opened in a groove formed at the tip, and the sub-preheating oxygen hole and the secondary preheating oxygen hole are electrically connected inside.

[0015]
[Action]
In the gas cutting crater (hereinafter simply referred to as "crater"), sub-preheating oxygen holes and fuel gas holes are alternately formed on the same circumference, and primary preheating holes are formed on the inner peripheral side of the fuel gas holes. At the same time, a secondary preheating oxygen hole is formed on the outer peripheral side. Therefore, the preheated oxygen jet exists over the entire circumference of the fuel gas ejected from the fuel gas hole.
[0016]
Further, since at least the fuel gas hole, the auxiliary preheating oxygen hole, and the secondary preheating oxygen hole open in the groove formed at the tip, mixing of the fuel gas and the preheating oxygen ejected from each hole is promoted inside the groove. In addition, since preheated oxygen ejected from the primary preheated oxygen holes is present outside the groove, a flame similar to that in the case of ejecting cut oxygen can be formed. For this reason, the formed preheating flame approaches the neutral flame more, and the preheating power is improved.
[0017]
【Example】
Hereinafter, one embodiment of the crater will be described with reference to the drawings. FIG. 1 is a sectional view of the crater, and FIG. 2 is a front view of the crater.
[0018]
In the figure, a crater A has a primary preheating oxygen hole 12 formed between a nozzle member 1 having a cut oxygen hole 11 formed at the center thereof and the nozzle member 1 fitted with the nozzle member 1 and fitted. A distributing member 2 having a sub-preheating oxygen hole 13 and a fuel gas hole 14 therein, a fixing member 3 for fixing the nozzle member 1 fitted to the distributing member 2, and a distributing member fitted and fitted to the distributing member 2 2 and a cap 4 that forms a secondary preheated oxygen hole 15 therebetween.
[0019]
The nozzle member 1 is disposed at the center of the crater A, and a cutting oxygen hole 11 for ejecting cutting oxygen is formed at the center. A step portion 1a is formed on the rear end (left side in FIG. 1, the same applies hereinafter) of the nozzle member 1 and on the outer periphery thereof, which abuts against the shoulder 2a of the distribution member 2 to seal oxygen. . In addition, when the nozzle member 1 is fitted to the distribution member 2, the nozzle member 1 comes into contact with the inner peripheral wall of the distribution member 2 at a predetermined position on the front side (the right side in FIG. 1, the same applies hereinafter) of the nozzle member 1. A slit 1b is formed to ensure concentricity of the nozzle member 1 and the nozzle member 1 and to allow the primary preheating oxygen to flow.
[0020]
The distributing member 2 has the nozzle member 1 fitted therein to form a primary oxygen chamber 12a communicating with the primary preheating oxygen hole 12 therebetween, and abuts a distributing portion formed at the tip of a torch (not shown). The cutting oxygen, the primary preheating oxygen, the fuel gas, the auxiliary preheating oxygen, and the secondary preheating oxygen supplied to the distribution section are distributed to the corresponding portions of the crater A, and are further fitted to the cap 4 so as to be interposed between the two. The oxygen chamber 16 communicates with the preheating oxygen holes 13 and the secondary preheating oxygen holes 15.
[0021]
A shoulder 2a is formed inside the distribution member 2 at a predetermined position on the rear side, and a screw 2b is formed at an end of the distribution member 2 so as to be continuous with the shoulder 2a. Then, the nozzle member 1 is fitted to the distribution member 2 and the fixing member 3 is screwed to the screw portion 2b, so that the nozzle member 1 fitted to the distribution member 2 is integrated so as not to be detached. I have.
[0022]
When the nozzle member 1 fitted to the distribution member 2 is fixed by the fixing member 3, the step portion 1a and the shoulder portion 2a of the nozzle member 1 come into contact with each other to seal the gap between the cut oxygen hole 11 and the primary oxygen chamber 12a, Cutting oxygen supplied at a high pressure is prevented from leaking to the primary oxygen chamber 12a.
[0023]
At the rear end of the distribution member 2, a first seal portion 2c, a second seal portion 2d, a third seal portion 2e, and a fourth seal portion 2f that are in contact with the distribution portion formed on the torch are formed, respectively. In addition, these seal portions 2c to 2f prevent each gas supplied from the distribution portion of the torch from leaking to another flow path.
[0024]
At a predetermined position on the outer periphery on the front side of the distribution member 2, a slit 2 g is formed to contact the inner peripheral surface of the cap 4 to ensure concentricity of the distribution member 2 and to allow secondary preheating oxygen to flow. When the distribution member 2 is fitted to the cap 4, a ring-shaped oxygen chamber 16 having a substantially equal gap is formed between the two.
[0025]
In the first groove 17 formed between the first seal portion 2c and the second seal portion 2d, a through hole 12b penetrating inside the distribution member 2 and communicating with the primary oxygen chamber 12a is formed. .
[0026]
The fuel gas hole 14 is formed to penetrate between the second groove 18 formed between the second seal portion 2d and the third seal portion 2e and the front end face of the distribution member 2. Further, a sub-preheating oxygen hole 13 having a predetermined depth is formed from the front end surface of the distribution member 2 toward the rear side of the member 2, and an oxygen chamber 16 is formed near the bottom of the sub-preheating oxygen hole 13. There is formed a through hole 13a which communicates with the air.
[0027]
The auxiliary preheating oxygen holes 13 and the fuel gas holes 14 are alternately formed on the same circumference on the front end face of the distribution member 2 as shown in FIG.
[0028]
In the third groove 19 formed between the third seal portion 2e and the fourth seal portion 2f, a through hole 16a penetrating toward the oxygen chamber 16 is formed.
[0029]
The cap 4 is formed to have a dimension larger than the length of the front end face 2h and the front end face of the fourth seal portion 2f of the distribution member 2. Therefore, when the distribution member 2 is fitted to the cap 4, the groove 20 is formed on the front side of the crater A. The groove 20 has a fuel gas hole 14, a sub-preheating oxygen hole 13, and a secondary preheating oxygen hole 15, each of which is capable of promoting the mixing of each gas ejected from each hole.
[0030]
In the crater A configured as described above, the primary preheated oxygen supplied through the torch is supplied to the primary oxygen chamber 12a from the through hole 12b formed in the first groove 17, and is ejected from the primary preheated oxygen hole 12 to the outside. The secondary preheated oxygen is supplied to the oxygen chamber 16 from the through hole 16a formed in the third groove 19, and passes through the oxygen chamber 16 from the secondary preheated oxygen hole 15 to the groove 20 formed at the tip of the crater A. At the same time, the gas is ejected from the oxygen chamber 16 through the through hole 13a to the groove 20 from the auxiliary preheating oxygen hole 13. The fuel gas is ejected from the second groove 18 through the fuel gas hole 14 toward the groove 20 formed at the tip of the crater A.
[0031]
Accordingly, the primary preheating oxygen, the secondary preheating oxygen, and the secondary preheating oxygen are present around the fuel gas jet ejected from the groove 20 to the outside of the crater A, and the mixing of the fuel gas and the oxygen is promoted, and the preheating power is reduced. An enhanced flame is formed.
[0032]
For this reason, when cutting a steel material by running, it is possible to cut reliably by ejecting the cutting oxygen immediately before the start of cutting, and it is possible to prevent the cooling of the steel material by the cutting oxygen jet and improve the cutting speed It is.
[0033]
【The invention's effect】
As described above in detail, in the gas cutting crater according to the present invention, the fuel gas is ejected by arranging the primary preheating oxygen hole, the secondary preheating oxygen hole, and the secondary preheating oxygen hole around the fuel gas hole for ejecting the fuel gas. Mixing of fuel gas and oxygen can be promoted. For this reason, the formed flame approaches the neutral flame more, and the preheating power can be improved.
[Brief description of the drawings]
FIG. 1 is a sectional view of a crater.
FIG. 2 is a front view of a crater.
[Explanation of symbols]
A Tinder 1 Nozzle member 1a Steps 1b, 2g Slit 2 Distributing member 2a Shoulder 2b Screw 2c First seal 2d Second seal 2e Third seal 2f Fourth seal 3 Fixing member 4 Cap 11 Cutting oxygen hole 12 Primary preheating oxygen hole 12a Primary oxygen chamber 12b Through hole 13 Secondary preheating oxygen hole 13a Through hole 14 Fuel gas hole 15 Secondary preheating oxygen hole 16 Oxygen chamber 16a Through hole 17 First groove 18 Second groove 19 Third groove 20 Groove

Claims (1)

In a gas cutting crater having a groove for mixing preheating oxygen and fuel gas at its tip, a cutting oxygen hole arranged at the center, a primary preheating oxygen hole arranged around the cutting oxygen hole, A sub-preheating oxygen hole disposed on a circumference surrounding the primary preheating oxygen hole; a fuel gas hole disposed on the same circumference as the sub-preheating oxygen hole and between the sub-preheating oxygen holes; A secondary preheating oxygen hole arranged around a circumference in which the oxygen holes and the fuel gas holes are alternately arranged, and at least the auxiliary preheating oxygen hole, the fuel gas hole, and the secondary preheating oxygen hole are formed at the tip. A gas cutting crater, wherein the gas is opened in the groove and the secondary preheating oxygen hole and the secondary preheating oxygen hole are electrically connected inside.

Images