JPH07284948A - Plasma cutting device - Google Patents

Abstract

PURPOSE:To rapidly cut a steel shell of a thick wall vessel having a lining layer of a refractory material on the internal face by a required width in the horizontal position, continuously in a long time, without erosion of a plasma torch caused by cutting slag, and without requiring a skillful cutting technique. CONSTITUTION:In a plasma cutting equipment to cut a steel shell of a thick wall vessel having a lining layer of a refractory material on the internal face, two plasma torches 1, 2 are attached on a holding device 30 whose position is adjustable freely by bridging on a cutting groove in almost right angle against the cutting groove, and on the almost central rear side of the plasma torches 1, 2, two auxiliary blow nozzles 3, 4 pointing toward the cutting groove are held parallel to the cutting groove with the holding device 30 whose position is made freely adjustable. The holding device 30 is held with arms 20, 22 freely adjustable in the horizontal direction and height direction attached on a running carriage 23 freely moving along the cutting groove.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma cutting device for disassembling a thick plate container such as a blast furnace, a converter or a molten steel ladle which has a refractory lining on the inner surface of a steel shell.

[0002]

2. Description of the Related Art A container with a refractory lining on the inner surface of a steel shell is usually cut by a gas cutter or a jet lance, but the cutting slag does not penetrate the refractory and stays inside the cutting groove. However, there is a possibility that re-fusion may not be performed and cutting may not be completely performed, and not only a skill is required for cutting, but also manual cutting, which is a heavy work.

Further, in gas cutting, a large amount of oxygen is used and the gas is cut by an oxidation reaction with iron, so that a large amount of smoke is generated and the working environment is deteriorated.

In view of the above, the iron shell is melted and cut by the plasma arc, and oxygen is blown into the cutting groove in the traveling direction by the auxiliary blow nozzle attached to the plasma torch, and the cutting slag is moved to the outside of the cutting groove by the oxygen pressure. The applicant has invented and developed the plasma cutting method of Japanese Patent Application No. 263106/1993, which is characterized in that it is caused to flow out, and the problem was solved.

In the dismantling work of a cylindrical container, since the inside of the container is cut off after the iron shell is cut, if the cutting is performed perpendicularly to the iron shell, the cutting corresponding to the curvature and the plate thickness is caused by the difference in the inside and outside diameters. If the width is not secured, the outer diameter corner interferes with the remaining steel skin corner.

However, in the method of the present invention, since the cutting width is 10 to 12 mm, the cutting width required for dismantling cannot be secured in one run, and it becomes difficult to cut off the cutting end portion. There was a problem that there is. That is, it is necessary to change the torch position and repeat traveling in order to secure a cutting width that can be cut off with one torch.

As a cutting method using a plurality of torches,
There is a plasma arc cutting machine disclosed in Japanese Unexamined Patent Publication No. 2-217174, which connects two plasma torches for cutting to separate power sources through a switch, and when drilling, a plasma torch for drilling The purpose of the invention is to provide an economical plasma arc cutting machine in which the power source is shared for cutting and drilling by connecting to the power source through the switch of, and the cutting width is not adjusted. Absent.

[0008]

DISCLOSURE OF THE INVENTION The present invention does not require a skilled cutting technique in order to quickly secure a cutting width that allows the cutting end portion to be cut off, and the plasma is produced by the rebound of the cutting slag. It is an object of the present invention to provide a plasma cutting device capable of continuously cutting a thick plate container lined with a refractory with a required width without melting the torch.

[0009]

In order to achieve the above-mentioned object, the present invention is a plasma cutting apparatus for cutting the iron shell of a thick plate container having a refractory lining on the inner surface thereof, which is cut at a substantially right angle to a cutting groove. The two plasma torches are mounted on a holding device whose position can be adjusted across the groove, and two auxiliary blow nozzles are positioned parallel to the cutting groove toward the cutting groove in the rear of the center of the plasma torch. The refractory is lined by holding it on the holding device so that it can be adjusted, and holding the holding device on a horizontally and vertically adjustable arm mounted on a traveling carriage that can move along the cutting groove. It is possible to continuously cut a thick plate container with a required width for a long time.

[0010]

According to the apparatus of the present invention, two plasma torches are aligned in parallel to each other at right angles to the cutting direction and are directed to the cutting groove through the chuck capable of adjusting the angle, and the auxiliary blow is made parallel to the cutting direction and rearward of the plasma torch moving direction. Attach two nozzles to a support arm that can be adjusted vertically and horizontally with respect to the cutting direction,
Each of the adjusting functions can be used to adjust the position between each plasma torch and the auxiliary nozzle.

Thus, the arcs of the two plasma torches can be directed to the optimum position in parallel with the cutting groove with respect to the iron skin thickness and the cutting width to be cut.

Further, the two auxiliary blow nozzles can blow oxygen in the cutting direction inside the cutting groove in a cutting direction at a high speed and in a large amount, and a large amount is generated by the arc of the two plasma torches. It becomes possible to oxidize the cutting slag to make it brittle and to flow it out of the cutting groove.

As a result, the refractory is lined so that the cutting width at which the end of cutting can be cut off does not require a skillful cutting skill, and there is no melting loss of the plasma torch due to rebound of the cutting noro. A plasma cutting method capable of cutting a thick plate container continuously for a long time with a required width is achieved.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to FIGS. 1 (a) is an elevational view of an embodiment of the plasma cutting apparatus, FIG. 1 (b) is a side view of FIG. 1 (a), and FIG.
FIG. 2A is a vertical sectional view of the plasma torch overall position adjusting section (AA sectional view of FIG. 1A), and FIG. 2B is a transverse sectional view of the plasma torch overall position adjusting section (FIG. a) B-
FIG. 3 is a plan view of the position adjusting portion of the plasma torch and the auxiliary blow nozzle.

A device configuration of an embodiment of the present invention will be described with reference to FIG. The apparatus is roughly configured by a holding device 30 that holds two plasma torches 1 and 2 in a positionally adjustable manner, and an arm 31 that holds the entire holding device 30 in a positionally adjustable manner.

A holding device 30 for holding two plasma torches 1 and 2 in a positionally adjustable manner includes a plasma torch angle adjusting shaft 10 and 11 which swings to the left and right, vertical arm supporting chucks 18 and 19 which slide to the left and right, and a vertical arm supporting chuck. It is composed of vertical arms 5, 6 and the like supporting the torch that are moved up and down.

The arm 31 for holding the entire holding device 30 in a positionally adjustable manner includes a horizontal arm 20 to which the holding device 30 is fixed via vertical arm support chucks 18 and 19, and an up / down / left / right adjusting chuck 21 for allowing position adjustment. And the vertical arm 22 and the like provided on the traveling carriage 23.

Explaining in detail, the plasma torches 1, 2
Are supported by chucks 8 and 9 at right angles to and parallel to the cutting groove, and the angle can be adjusted by plasma torch angle adjusting shafts 10 and 11 of chucks 8 and 9. The chucks 8 and 9 are fixed to the plasma torch supporting vertical arms 5 and 6, and have a structure capable of vertical movement adjustment by the plasma torch vertical adjustment knobs 12 and 13 and racks 14 and 15.

As shown in the plan view of FIG. 3, the auxiliary blow nozzles 3 and 4 are passed through the holes of the auxiliary blow nozzle support base 7, the vertical level is adjusted in advance, and the auxiliary blow nozzles 3 and 4 are parallel to the cutting groove and rearward in the plasma torch advancing direction. Are supported in series,
The structure is such that the left and right can be adjusted by the slide base 16 and the knob 17. The slide base 16 is fixed to one of the chucks 8 and 9, and has a structure in which the vertical movement can be adjusted by following the plasma torches 1 and 2.

The plasma torch supporting vertical arms 5 and 6 are
After adjusting the left and right positions of the plasma torches 1 and 2 in advance, the horizontal arm 2 is moved by the vertical arm support chucks 18 and 19.
It is fixed at 0.

The horizontal arm 20 is fixed to the vertical arm 22 by a vertical / horizontal adjustment chuck 21.

The vertical arm 22 is attached to a traveling carriage 23, and has a structure capable of traveling along a cutting groove by a rail 24 and a rail mount 25 which are attached to an iron skin in advance.

The overall vertical and horizontal adjustment structure of the plasma torch will be described in detail with reference to FIGS. Regarding the upper and lower sides, the structure is such that a horizontal arm vertical adjustment rack 27 attached to the vertical arm 22 and a knob 26 can adjust the vertical direction. Horizontal arm 20
The structure is such that the horizontal arm left / right adjustment rack 29 and the knob 28 attached to the can be adjusted.

The cutting conditions of the embodiment are shown below.

Plasma current, voltage 300 A, 160 V Plasma gas H ₂ + Ar Cutting speed 100 to 300 mm / min Auxiliary blow nozzle diameter 2.0 mm Auxiliary blow oxygen pressure 5 kg / cm ² Tilt angle θ 5 ° Workpiece Iron skin thickness 75 mm Back refractory thickness 100 mm

In the above-mentioned embodiment, during cutting, the cutting slag flows out from the cutting groove, is fixed to the iron shell, and is oxidized by oxygen blown from the auxiliary blow nozzle to become brittle, so that re-fusion of the cutting portion does not occur, The cut portion was completely separated, and the required cutting width of 30 mm could be secured.

The cutting length is 2.1 m per time,
Even if the cutting was continued for 15 minutes, the plasma torch was not melted or the tip of the plasma torch was not clogged, and continuous automatic cutting was possible for a long time.

[0028]

According to the present invention, the following effects can be obtained.

(1) By using 2 torches, 1
A wide cutting width can be secured by running.

(2) By using the two torches, the cutting speed can be increased and the cutting efficiency is improved.

(3) Even if the cutting slag does not penetrate the refractory by cutting the iron shell of the container lined with the refractory,
It does not require the skill required for gas cutting, enables automatic cutting, and eliminates heavy work.

[Brief description of drawings]

FIG. 1 is an example of a plasma cutting device, and FIG.
Is an elevation view and FIG. 1B is a side view.

2 is a plasma torch overall position adjusting unit, and FIG.
2A is a vertical sectional view, and FIG. 2B is a horizontal sectional view.

FIG. 3 is a plan view of a position adjusting portion of a plasma torch and an auxiliary blow nozzle.

[Explanation of symbols]

 1, 2 Plasma torch 3, 4 Auxiliary blow nozzle 5, 6 Torch support vertical arm 7 Auxiliary blow nozzle support base 8, 9 Chuck 10, 11 Plasma torch angle adjusting shaft 12, 13 Knob 14, 15 Rack 16 Slide base 17 Knob 18 , 19 Vertical arm support chuck 20 Horizontal arm 21 Vertical / horizontal adjustment chuck 22 Vertical arm 23 Traveling carriage 24 Rail 25 Rail mount 26 Knob 27 Rack 28 Knob 29 Rack 30 Holding device 31 Arm

Claims (1)

[Claims] 1. A plasma cutting device for cutting an iron skin of a thick plate container having a refractory lining on its inner surface. A holding device that can position two plasma torches across the cutting groove at a substantially right angle to the cutting groove. And two auxiliary blow nozzles directed to the cutting groove, parallel to the cutting groove, and substantially in the rear of the center of the plasma torch and held by the holding device so that the position of the holding device can be adjusted. A plasma cutting device, characterized in that it holds a horizontally adjustable and vertically adjustable arm mounted on a traveling carriage that can move along.