JPS59104293A - Method and device for producing fused flux for submerged arc welding - Google Patents

Abstract

PURPOSE:To produce a fused flux contg. no water with less driving power in such a way that the grain size thereof can be adjusted by running downward the molten flux, bringing the flux into collision against a flow regulating plate consisting of a cooled rotary circular truncated cone, and granulating the flux. CONSTITUTION:A cooled granulator 3 is provided with a granulating plate 13 consisting of a rotary circular truncated cone body supported by a revolving shaft core 26, a revolution transmission pipe 27, a suspension hook 12, etc., a water sprayer 18 which ejects cooling water from many sprinkling ports 38 and cools said plate 13 from the rear, a water recoverer 36 which collects and discharges the cooling water, and a flux receiver 20 which rotates and has an annular and sectionally recessed shape. The molten flux charged from a melting furnace 1 into a charging furnace 2 in such a device 3 is dropped onto the plate 13 through a feed port 2a by tilting the furnace 2 to bring the flux into collision against said plate, whereby the flux is cooled and granulated. The grain size thereof can be easily adjusted by the position of the melt falling onto the plate 13, the rotating speed of the plate, etc. The scattering of the granules is prevented by an anti-scattering plate 19 and the granules are dropped into the receiver 20, from which the granules are taken out through a suction pipe 37.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for producing a flux for fusion type submerged arc welding, in which a molten flux raw material is air-cooled and pulverized into a product.

In general, melt-type flux for welding (hereinafter referred to as melt flux) is a mixture of raw materials consisting of various natural oxides, carbonates, alumina salt ores, and various industrial products that are mixed to achieve the desired quality characteristics and heated in an electric furnace at high temperature. After melting, it is cooled with water, dried, crushed, sieved, and sized (to obtain the desired particle size distribution) to produce a product. In this method, the high-temperature molten material is cooled by putting it into water or jet water, so it is unavoidable that the product flux contains moisture, and the subsequent drying process not only requires thermal energy. ,
There is a problem in that it is difficult to completely dehydrate the water once taken in. The moisture content of the melt flux used when welding high-strength steel is a major cause of hydrogen cracking in the weld, so it is desirable to keep it as low as possible. Recently, in order to prevent this hydrogen cracking, an air cooling method has been developed in which cooling with water is stopped, and the material is air cooled and solidified in the atmosphere, followed by crushing and sieving to obtain the desired particle size distribution.

Air cooling methods include cooling and solidifying molten flux on a water-cooled iron plate, and dropping it onto a water-cooled cylinder. When cooled and solidified on a water-cooled iron plate, the coagulated material becomes a large lump, and in order to obtain the desired particle size distribution as a welding flux, it requires labor to grind and the yield of grinding and sieving is poor. Furthermore, it is necessary to control the cooling rate so as not to form highly hygroscopic crystalline materials. The method of dropping into a water-cooled cylinder yields relatively thin particles, but they are mostly uniform particles, and in order to achieve the desired particle size distribution for welding flux, large-diameter particles must be made and then crushed. It is necessary that
Depending on the desired particle size distribution, it was necessary to pulverize one part under one condition, the remaining part under another condition, and mix them.

Due to these obstacles, although the air cooling method is an innovative method for reducing the hydrogen content of melt flux, it has not become a mainstream method for producing melt flux.

The present invention was achieved as a result of intensive research aimed at eliminating these obstacles to the air cooling method. That is, the object of the present invention is to provide a manufacturing method capable of rapidly air cooling, obtaining a desired particle size distribution as a welding flux, that is, grading the particles, and achieving a high yield. This method was achieved by focusing on the fact that the circumferential speed of a rotating body differs depending on the location or rotational speed. The present invention will be explained in detail below.

FIG. 1 is a partially sectional side view of a melting furnace, and FIG. 2 is a partially sectional side view showing an apparatus according to an embodiment of the present invention. 1 is a melt flux melting furnace, 2 is an injection furnace, 6
3 is a crane, and 3 is a cooling sizing device. The molten material 5 melted in the melt flux melting furnace 1 is transferred to the injection furnace 2 and poured into the cooling/sizing device 3. The melt flux melting furnace 1 is lined with graphite bricks 4 to prevent reaction with the melt 5 as much as possible, and is tiltable. The injection furnace 2 is suspended by a crane 6 having a traveling motor 7 and a tilting motor 9. The tilting chain 1 is locked by a locking part 11 provided at the bottom of the furnace on the lifting side, and is hoisted up by the driving motor 9 at around 1. As a result, the injection furnace 2 connects the rotatable joint 10 provided at the top of the furnace. Tilt to the center. The poured melt falls into the cooling/sizing device 3. The injection furnace 2 is also lined with bricks 2b.

The cooling grading device 3 includes a grading plate 13 made of a rotating cone (umbrella-shaped body). Water sprinkler system to cool it from inside18. Water recovery device 369 Melt flux scattering prevention plate in the shape of a cylindrical body 192 Rotating ring-shaped melt flux receiver with a concave cross section 20. It is equipped with a melt flux suction tube 37 and a pedestal 33 for fixing the above-mentioned device. The grain size regulating plate 13 is composed of a detachable hanging piece 121, a cylindrical body-shaped water-scattering prevention skirt 14, and a pipe-shaped rotating shaft core 26. The shaft core 26 is fixed to a rotation transmission pipe 27 by a bolt 15, and the rotation transmission pipe 27 is connected to a ball bearing 2.
9,298 and a roller 24 arranged in a ring shape on the bottom of the pipe, and a pulley 3 at the bottom.
1 is fixed and this pulley is connected to motor 3 via a belt.
It rotates by being driven by 2. The ball bearings 29 and 298 are fixed to the base 33 by the support body 23.

The water sprinkler 18 also has a conical shape, and forms a double conical structure together with the grain regulating plate 13. The grain regulating plate 13 faces the rear surface thereof with a gap therebetween, and its conical outer plate is provided with a large number of water sprinkling ports 38 for spouting water. The interior of the water sprinkling device 18 is hollow, and water is supplied from a water inlet path 34, and water is sprayed from a large number of water sprinkling ports 38. The water recovery device 36 is in the shape of a ring-shaped gutter or a round dish, and receives the sprayed water that has fallen against the back surface of the grading plate 13 and drains it through the drainage path 35. The water sprinkler 18 is attached to the support 1
It is fixed to the base 33 through 6. The flux catcher 20 is provided with a ring-shaped rack 202 on its outer periphery, and at one diametrical end this rank engages with a gear 21, and at the other end it is pushed by a spring roller 22 to ensure this engagement. Ru. The receiver 20 is supported by a ball bearing 24a arranged in a ring shape, and the ball bearing is fixed to a pedestal 33 through a support 28.

Like the rotation transmission pipe 27, the shaft 39 of the gear 21 is supported by ball bearings 29b, 29C, t:l-ra 25, and a bearing support 30, and is fixed to a pedestal 33. Further, a pulley 31a is attached to the lower part of the shaft 39, and the pulley is rotated by being driven by a motor 40 via a belt.

This cooling and sizing device is constructed as described above and operates as follows. That is, the crane 6 moves to the melting furnace 1 side and injects the molten material 5 in the melting furnace 1 into the injection amount 2 . Thereafter, the crane 6 moves to the upper part of the cooling and grading device 3 so that the pouring amount 2 of the melt 5 in the pouring chamber 2a can be dropped onto a predetermined position on the grading plate 13. The crane 6 stops at this position, and the motor 9 winds up the chain 8 to fill the injection amount 2, causing the melt to flow out from the spout 2a and drop onto the grading plate 13. The grading tli 13 is umbrella-shaped and is rotated at high speed by the motor 32, so when the melt is poured, it collides with the grading plate 13, scatters, and is scattered by centrifugal force, and is prevented from dissipating by the prevention plate 19. The receiver is blocked and falls into the container 20.

The molten material is cooled and granulated by this collision and scattering, and the particle size can be easily changed and adjusted by changing the position on the grading plate 13 where the molten material falls, the rotation speed of the grading plate 13, etc. Since the granules that have fallen into the receiver 2o are rotated by the motor 40, they eventually reach the lower part of the suction pipe 37, where they are sucked into the pipe and taken out.

The results of a granulation experiment performed using the cooling/granulating device 3 will be described in detail below. The components of the melt are shown in Table 1.

Table 1 Melt Components The injection rate of the melt was 50 kg/min by appropriately changing the inclination speed of the injection amount, and the total injection amount was 250 kg.

The temperature of the melt falling from the injection volume was measured with an optical pyrometer. Figure 3 shows the temperature change. 1420℃ in melting furnace 1
The initial temperature of the injection amount is 14
The temperature was adjusted to 00°C. Curve A shows the temperature time change in this case. The number of revolutions of the cooling/grading plate 13 is 11,000.
Two types were used: rp and 50 rpm, and three types of peripheral speed were set with three falling positions. Table 2 shows the particle size distribution of the flux produced under these conditions.

Table 2 □ □ Next, as shown in curve B in Figure 3, the initial injection temperature was set to 130°C.
The temperature is 0°C, and the rotational speed of the cooling grain plate 13 is 11000 rpm.
Table 3 shows the particle size distribution when the peripheral speed of the falling part was 1884 m/sec.

20x, 48 48x 65 65x 100 100
x 200 200x D Furthermore, injection temperature condition 1400
Table 4 shows the flux particle size distribution when the cooling plate rotation speed was 101,000 rpm and the peripheral speed of the falling part was changed from 942 m/min to 2,826 m/min in 20 seconds per cycle.

Table 4 (%) According to the above experiment, when the injection amount and injection speed are fixed, the particle size distribution of the flux is regulated by the circumferential speed of the melt falling part of the cooling/grading plate 13, as shown in Table 2. I understand. The faster the circumferential speed, the finer the particles. Further, as shown in Tables 2 and 3, the higher the injection temperature, the finer the particles. Further, as shown in Tables 2 and 4, when the falling area is changed by changing the injection amount, an average particle size distribution of the particle size distribution obtained at the circumferential speed of each falling area can be obtained. These results show that the larger the centrifugal force, the more fine particles are formed. Therefore, when the injection amount is constant, the slower the injection speed, the finer the particles will be.
When the injection rate is constant, it can be expected that the larger the injection amount, the wider the particle size distribution due to cooling during injection. The following factors can be considered as further factors for controlling the particle size and particle size distribution of the flux produced by this apparatus.

■The operation of the injection amount, that is, the position and the tilting speed, etc., are not constant, but are patterned to match the desired particle size distribution.■The surface of the particle size regulating plate 13 is roughened (providing irregularities), and runs in the vertical direction of the slope. The surface properties are changed by providing protrusions, etc.; 1. The atmospheric temperature is lowered by introducing cold air; 2. The anti-scattering plate 19 is also cooled and rotated, for example, in the opposite direction to the grain size regulating plate 13 without being fixed.

It is also conceivable that the flux receiver container 20 is integrated with the grain regulating plate 13, and in this case, the support and rotation mechanism for the flux receiver become unnecessary and can be simplified. Further, although the scattering prevention plate 19 has vertical side walls and an open top in the embodiment, the side walls may be inclined toward the particle size regulating plate 13 and the top may be closed. Of course, the injection port should be secured so that there is no problem in injecting the dissolved material. It is also possible to stop using the injection amount 2 and directly inject from the melting furnace 1.

As explained above, according to the present invention, since it is not a granulated type, moisture is not introduced into the fluff, and the melt collides with the fluff, scatters due to the addition of centrifugal force, and becomes particles due to cooling at that time, so it is agglomerated and then crushed. Compared to the conventional method, less power is required for particleization, and since there are many adjustable parameters, it is possible to obtain a method and apparatus for producing melt flanks in which particle size and distribution can be easily adjusted.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a melting furnace, FIG. 2 is an explanatory diagram showing an example apparatus of the present invention, and FIG. 3 is a graph showing temperature-time characteristics. In the drawing, 5 is a melted fluff, 13 is a rotating cone,
2 is an injection amount, 20 is a flux receiver, and 18 is a water sprinkler.

Claims (1)

[Claims] +11 A method for producing a frank for fusion-type submerged arc welding, characterized in that the molten flux is made to collide with a cooled rotating cone to be scattered and granulated. (2) An injection furnace for injecting molten flux, a rotating cone with which the molten flux collides, a franks receiver that receives the granulated flux that has been blown and scattered by the cone, and the rotating cone. A franks manufacturing device for fusion type submerged arc welding, characterized in that it is equipped with a water sprinkler device that cools the franks from the back side.