JPS5915714A - Concentric type burner for gas-cutting - Google Patents

Abstract

PURPOSE:To economize the quantity of a gas, and to reduce the adhesion of slag by continuously or discontinuously forming an opening in a symmetric type region extending over bilateral one part of the rear half section in the direction of progress of the burner while forming one opening at the central section of the rear half section in the direction of progress of the burner. CONSTITUTION:Around a cutting oxygen opening 1a opening at the center of a gas ejecting surface 3, preheating gas openings are arranged on a concentric circle in a bilateral symmetric shape as 2a, 2a... by nine in front half on viewing in the direction of progress X of the burner, as 2b, 2b' at every one in the left and right of a rear half section and as 2c by one at the central section of the rear half section. A region Y containing the nine openings 2a, 2a... and the openings 2b, 2b' of bilateral one pair corresponds to an angle of spread of a reaction region B in which a steel material is being melted and oxidized on gas cutting. One opening 2c, on the other hand, is positioned at a section corresponding to a groove 5 formed to a steel plate on gas cutting. Accordingly, the quantity of the gas can be economized and the adhesion of slag can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gas cutting nozzle for cutting steel plates, etc., and more specifically, a cutting oxygen hole is opened in the center of a gas ejection surface, while a preheating gas hole is provided on the circumference of the cutting oxygen hole. This invention relates to a so-called concentric crater that is opened continuously or intermittently.

Figure 1 shows the main parts of a well-known concentric crater A. As shown in the figure, the concentric crater A has a cut oxygen hole in its center.
Also, a preheating gas hole 2 is provided around the cutting oxygen hole 1. The preheating gas holes 2 are opened on the gas ejection surface 3 on a circle surrounding the opening of the cutting oxygen hole 1, and the openings are ring-shaped as shown in FIG. The star type shown in Figure 2) and the gear type shown in Fig. 2 are known, and are used depending on the type of preheating gas used. In any case, conventionally, as described above, the opening 2a of the preheating gas hole 2 is the same as the opening 2a of the cutting oxygen hole 1.
They are evenly distributed on a circle around a. This is to prevent the inflow of air by surrounding the oxygen jet 0 with the preheated gas flow 11, thereby keeping the purity of the cutting oxygen high during gas cutting. If the purity of cutting oxygen decreases, the cutting speed will drop significantly or the condition of the cut surface of the steel plate will deteriorate, causing slag to occur at the edges of the cut surface.

By the way, in gas cutting, there are currently two major problems to be solved. One is to reduce the consumption of cutting oxygen and preheating gas from the perspective of energy conservation, and the other is to concentrically gas cut steel sheets whose surfaces are coated with rust-preventing zinc-containing paint called zinc primer. It is to be carried out efficiently in a type crater.

The latter problem can be explained as follows with reference to FIG. That is, the steel plate 4 having the zinc primer 4a on its surface is exposed to the heat of the preheating flame 2a of the crater A, the cutting oxygen 1a, and the steel plate 4.
The zinc primer on the surface of the steel sheet melts and becomes liquid (the melting point of zinc is 420℃).
), cutting oxygen is injected into the molten zinc primer, so some of the burnt material (slag) of the zinc primer tends to scatter upward. On the other hand, most of the cutting oxygen flows outward, but since the injected cutting oxygen is entirely surrounded by the preheating gas, a portion of it circulates within the preheating gas wall as shown in the figure. Under these conditions.''
The second slag is "pushed to one side" and adheres to the gas injection surface 3 of the crater A, and as a result, the openings of the preheating gas hole and the cutting oxygen hole are immediately clogged, and in practice, the concentric type crater is Sink zureimer: Cannot be used for cutting steel plates. Therefore, conventionally, in order to cut zinc primer and steel plates, an eccentric type nozzle with a preheating gas nozzle and a cutting oxygen nozzle [1] installed side by side has been used, or a zinc primer treatment torch has been provided separately. . However, due to the nature of the crater, the eccentric crater has the disadvantage that the opening of the crater must be placed extremely close to the steel plate, making it extremely difficult to adjust the distance between the crater and the steel plate. If used separately, there is naturally a problem that gas consumption will increase significantly.

In order to solve the former problem, the present inventors first considered the mechanism of gas cutting, and found that the front part of the crater (
The preheating gas at the front of the cutting direction is necessary to sustain the combustion reaction with the steel plate (Fe), but the preheating gas at the rear of the cutting direction can be reduced to some extent. Experiments have shown that it is not only possible to reduce the consumption of cutting oxygen and preheating gas without significantly reducing the cutting speed and maintaining the good cutting condition of the steel plate, but also to solve the latter problem. I found out.

The gist of the present invention is that the preheating gas holes open continuously or intermittently in a symmetrical region extending from the first half in the direction of crater movement to the left and right parts of the latter half in the direction of movement of the crater. This invention consists in a concentric type crater for gas cutting, which is characterized by having several openings in the center.

The present invention will be specifically described below with reference to the illustrated embodiments.

FIG. 4 shows the opening of the crater A according to the present invention. Note that the figure shows a gear-shaped crater as an example.

In the figure, reference numeral 1a denotes a cut oxygen hole opening that opens at the center of the gas ejection surface 3, and around the opening 1a, there are nine preheating gas hole openings in the front half when viewed in the crater traveling direction X, as shown in the figure. ,
2a, 2a..., 1 piece on the left and right of the rear half 2b, 2
Furthermore, 1 piece 2C is arranged concentrically and symmetrically in the center of the rear half. 9 openings 2a, 2a
...and the area Y including the pair of left and right openings 2b and 2b' is,
This roughly corresponds to the spread angle of reaction zone B (blacked out area in the figure) where the steel material is melting and oxidizing during gas cutting. On the other hand, one opening 2C is located opposite to the groove 5 formed in the steel plate during gas cutting. In the figure, C indicates a molten base material, D indicates a resolidified base material, and E indicates a solidified oxide.

According to the crater having the above configuration, not only the amount of preheating gas consumed is reduced in response to the reduced number of preheating gas hole openings compared to the conventional crater, but also the consumption of cutting oxygen can be reduced at the same time. Furthermore, the cutting speed is approximately the same as that of the conventional method, and the roughness of the cut surface of the steel plate is also very good, and no 70 cracks occur at the edges of the cut surface. Further, even when cutting a steel plate coated with a zinc primer, upward scattering of slag is effectively prevented, and the amount of adhesion to the gas injection surface of the crater is extremely reduced. This is because the preheating gas holes are not open in most of the latter half of the crater in the direction of propagation, so the amount of heat input by the preheating gas is small, and as a result, the zinc primer is not sufficiently melted, resulting in a state of steaming. Even if the zinc ply 7 melts, the reflux of cutting oxygen as shown in FIG. 3 does not occur, and all of the cutting oxygen flows outward, so it is thought that it is unlikely to adhere to the gas ejection surface of the crater.

One opening 2C of the preheating gas holes has a great influence on the state of the cut surface of the steel plate. By providing this opening 2C, the entrainment of air into the cutting oxygen from the rear side in the direction of travel is extremely effectively prevented, that is, the purity of the cutting oxygen is prevented from decreasing, and the energy of the cutting oxygen jet is reduced. is prevented. Also, by providing this opening [12C,
If this opening 2C does not exist, the rapid cooling of the slag N (Fig. 4) on the steel plate that would otherwise occur is prevented, and the molten slag is blown away by the ejection energy of the preheated gas from the opening 2C. Therefore, the cut steel plate is
, f does not appear and a good cut surface can be obtained.

Incidentally, when using the crater according to the present invention, it is important to move the crater in a forward tilted position (for example, about 10 degrees) as in the case shown in FIG.

When the crater is moved perpendicularly to the steel plate, the amount of slag deposited on the gas ejection surface of the fire 10 increases slightly, and
If the crater is moved in a backward tilted position, top slag will occur on the steel plate.

The above-mentioned effects of the crater according to the present invention were confirmed by the following comparative experimental examples.

This experiment was carried out by blocking the preheating gas hole opening of the conventional gear torch +11 in various ways, as shown in Figures 6 (I) to M.
They created a crater and conducted experiments on each crater.

FIG. 6 (Il shows a conventional gear type crater.

Figure 6 (Company) shows that three openings on the left and right in the rear half of the crater in the direction of crater movement in Figure 6 (I) are closed, while two openings on both sides of the center of the latter half [1 and 1 in the front half] are closed. The crater is shown with all openings open.

Figure 6 (IIT) shows that the four openings on the left and right in the rear half of the crater in the direction of crater movement in Figure 6 (I) are closed, while one opening in the center of the latter half and all openings in the front half are closed. The crater is shown in an open state.

Figure 6 (IV) shows one opening on the left and right in Figure 6 (perpendicular to the direction of travel of the crater in Il), one opening on the front side adjacent to them, and two openings on the left and right in the rear half. The crater is shown with two openings closed, one opening between the closed openings, two openings corresponding to the center of the rear half, and other openings in the front half open.

FIG. 6M shows a crater according to the invention.

” - When a steel plate was actually cut using each crater, the craters shown in Figure 6 (Sha), (■), and ■ were as shown in Figure 6 (
Compared to the case of the conventional crater shown in I), the cutting speed is very slow and it is difficult to put it into practical use.On the other hand, only the crater according to the present invention (FIG. 6 (V)) can provide a satisfactory cutting speed. Ta.

Comparative measurements of gas consumption between the conventional crater shown in Figure 6B) and the inventive crater shown in Figure 6M revealed that the inventive crater consumes approximately 5% of the cutting oxygen and approximately 5% of the preheating gas. We were able to save 25% each.

In addition, when we observed the state of slag adhesion to the gas ejection surfaces of the conventional crater and the inventive crater, we found that the amount of slag deposited on the conventional crater was extremely large and only about 8 mL could be cut, but the inventive crater According to the report, the amount of slag deposited was extremely small even after cutting 25 m.

As is clear from the results of the experiment described above, the present invention does not uniformly arrange the preheating gas hole openings around the cutting oxygen hole openings as in the conventional crater, but in the latter half of the crater advancing direction. By simply partially closing or not opening the area, the desired objectives such as saving gas amount and reducing slag adhesion can be achieved.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of the principle concentric crater, Figure 2 (Il, (
(3) and (III) are plan views of the gas ejection surface showing the types of conventional preheating gas hole openings, Figure 3 is an explanatory diagram showing the reflux state of cut oxygen in the conventional crater, and Figure 4 is the one according to the present invention. Fig. 5 is a plan view of the gas injection surface of the crater, and Fig. 6 is a sectional view of a steel plate showing the state of slag generation (Il is a plan view of the gas injection surface of the conventional crater, Fig. 6 (Company), ( III) and (Foundation) are respectively plan views of the gas ejection surface of deformed craters for comparison with the present invention crater, and FIG. 6M is a plan view of the gas ejection surface of the present invention crater. 1... Cutting oxygen Hole, 1a...Cut oxygen hole opening, 2.
・・Preheating gas hole, 2 a , 2 b , 2 b ,
2 c -, Preheating gas hole opening, A... Crater patent Applicant: Kawatetsu Koukai Kogyo Co., Ltd. Agent: Patent attorney Aoyama Ao and two others Figure 1 Figure 3 Figure 4 h Figure 6 (I) Figure 6 1) Figure 6 (I[I
) Figure 6 ■) Figure 6 a Force

Claims (1)

[Claims] (1) A concentric crater in which a cutting oxygen hole is opened in the center of the gas ejection surface, and preheating gas holes are continuously or intermittently opened in a circle around it, and the preheating gas hole is a crater. A gas cutting device characterized by opening continuously or intermittently in a symmetrical area extending from the first half in the direction of propagation to the left and right parts of the latter half in the direction of propagation of the crater, and having one opening in the center of the latter half in the direction of propagation of the crater. Concentric crater.