JPH0347721Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a powder supply device for continuous casting.

(Prior art) During continuous casting of steel, powder containing SiO ₂ , CaO, etc. is added to the surface of the molten steel poured into the mold to prevent oxidation of the surface, retain heat, absorb inclusions in the steel, and It provides lubrication between the mold wall and molten steel. In recent years, automatic powder feeding devices have been developed to replace manual powder feeding, and powder feeding has come to be carried out mechanically.

Various methods have been proposed as conventional powder feeding devices. For example, Japanese Patent Application Laid-open No. 159951/1987 proposes a powder feeding nozzle placed above the molten steel surface at a position equal to or slightly higher than the thickness of a predetermined powder layer. A technique has been disclosed in which powder is continuously supplied by installing the supply nozzle in a permanently open state.

(Problems to be Solved by the Invention) However, the prior art has the following problems.

(b) Since the powder supply nozzle is fixed, the powder supply amount changes due to fluctuations in the molten metal level (for example, due to rising, the supply nozzle is buried in the powder layer and the supply amount decreases), and a constant amount of supply is not possible. Have difficulty.

(b) The powder supply amount is proportional to the powder consumption rate, and the powder supply speed cannot be freely controlled. (c) It is difficult to uniformly disperse the powder over the entire surface of the mold.

(Means for Solving the Problems) The present invention has been made to advantageously solve the problems of the prior art, and its gist is as follows.

(1) In a powder supply device, a powder supply nozzle is placed above a continuous casting mold at a certain distance from the molten steel surface, and the powder is continuously supplied from the nozzle. A sloped part with an inclination angle θ smaller than θ ₀ is provided, and the horizontal length L of the sloped part is defined as the maximum horizontal distance that the powder can reach when at rest within the sloped part L ₀ , L ₀ exceeds L ₀ Powder supply for continuous casting, characterized in that the value is less than the value obtained by adding twice the inner diameter D of the inclined part, the upstream side of the inclined part is communicated with a hopper, and a vibration device is provided in the hopper or the inclined part. Device.

(2) The device according to item 1 above, characterized in that a downward nozzle is communicated with the lower end of the inclined portion.

(3) The apparatus according to the above item 1 or 2, wherein the vibration device is a continuous casting mold.

(Example) The present invention will be explained below based on the drawings.

FIG. 1 is a diagram showing an embodiment of the present invention.

As shown in Fig. 1, the present invention includes a powder supply nozzle 3 that is placed at a certain distance H from a continuous casting mold (hereinafter referred to as mold) 6, and powder 2 is continuously supplied from this nozzle 3. In the powder supply device, the nozzle 3 is provided with an inclined portion 3B having an inclination angle θ smaller than the repose angle θ ₀ of the powder 2, and the horizontal length L (mm) of this inclined portion 3B.
L ₀ < L < L ₀ + 2D, where L ₀ is the maximum horizontal distance (mm) that the powder reaches when it is at rest within the slope, and D is the inner diameter of the slope (mm), and the upstream side of slope 3B is It is characterized in that it is connected to a powder hopper 8, and that the hopper 8 is further provided with a vibration device 9.

In the figure, reference numeral 4 denotes a height controller that is provided by mechanically connecting the mold and the sloped part of the nozzle 3, and this height controller 4 controls the vibration of the mold 6 to the sloped part 3.
can be transmitted to Note that the nozzle 3 and the mold 6 may be connected separately from this height meter.

Further, it is desirable that the lower end 3A of the nozzle 3 is provided facing downward, so that the powder 2 can be stored at a height h within the lower end 3A of the nozzle.

In the figure, numeral 5 denotes a molten metal level detection device installed above the molten steel surface 1A in the mold 6. This molten steel level detection device 5 detects vertical fluctuations of the molten steel surface 1A, and inputs the measured value to the control device 7. The control device 7 compares the measured value with a desired set value that is input in advance to the set value, and according to the difference between the measured value and the set value, the control device 7 issues a vertical movement command to the height controller 4 to correct the difference. The height is adjusted by adjusting the powder supply nozzle 3 to be positioned at a predetermined height. In this case, the fixed distance H may be within the range of 50 mm to 300 mm, and the powder used is
A spherical hollow body disclosed in Publication No. 20069 is suitable.

(Operation) FIGS. 2A and 2B are diagrams explaining the operation of the present invention.

When the vibration device 9 according to the present invention is not activated,
As shown in Figure 3 A, powder 2 is on the molten steel surface 1A.
It is not fed upward, and its tip 10 remains within the slope 3B of the nozzle 3.

However, when the vibration device 9 is activated, the particles of the powder 2 in the slope part 3B roll due to vibration, and the angle of repose becomes smaller than the angle of inclination of the slope part 3B. Maximum distance reached by
L ₀ exceeds the length L of the slope, the lower end 3 of the nozzle 3
It is supplied onto the molten steel surface 1A via A. In this way, the powder 2 is supplied when the maximum distance L ₀ exceeds the length _L of the inclined portion 3B due to the vibration of the nozzle 3 by the vibration excitation device 9. It varies depending on the inner diameter D, and the length changes within twice the inner diameter or 100 mm. However, if the diameter exceeds twice this diameter or 100 mm, there will be no further change even if vibration is applied. Therefore, in the present invention, the difference between L and L ₀ is calculated as 2 of the inner diameter D of the inclined portion 3B.
It needs to be twice or less than 100mm.

If this difference is more than twice the inner diameter D, powder 2 will not be supplied even if the vibration is applied, and the relationship between L and L ₀ is L ₀ ≧L.
In this state, powder is constantly supplied, which may lead to oversupply.

In addition, in the present invention, it is possible to use the vibration device as the mold 6 which is constantly vibrating, and in this case, there is an advantage that there is no need to provide a separate vibration device. When the vibration device 9 is provided, it is advantageous in that the powder supply rate can be adjusted by changing the strength of the vibration.

(Effects of the invention) As described above, according to the invention, powder can always be supplied at a constant rate, and furthermore, the supply rate can be adjusted as necessary, so the required amount of powder can be supplied, and the powder can be supplied at a constant rate. It has remarkable effects such as being able to prevent deterioration in the quality of steel products caused by excess or deficiency in supply, and also helping to prevent operational troubles.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an embodiment of the present invention, and FIGS. 2A and 2B are explanatory diagrams showing the operation of the present invention. 1... Molten steel, 1A... Molten steel surface, 2... Powder, 3... Nozzle, 3A... Lower part, 3B... Inclined part, 4... Height controller, 6... Mold, 8...
Hopper.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) In a powder supply device that has a powder supply nozzle that is placed above a continuous casting mold at a certain distance from the molten steel surface, and that continuously supplies powder from the nozzle. , the nozzle is provided with an inclined part having an inclination angle θ smaller than the angle of repose θ ₀ of the powder, and the horizontal length L of the inclined part is defined as L ₀ , which is the maximum horizontal distance that the powder reaches when it is at rest within the inclined part. When _L0 is greater than _L0 , it is less than the value obtained by adding twice the inner diameter D of the sloped part, the upstream side of the sloped part is communicated with the hopper, and the hopper or the sloped part is provided with an excitation device. Features: Powder supply device for continuous casting. (2) The powder supply device for continuous casting according to claim 1, which is characterized in that a downward nozzle is communicated with the lower end of the inclined portion. (3) A powder supply device for continuous casting according to claim 1 or 2, wherein the vibration device is a mold for continuous casting.