JPS6130768Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to an ingot preheating device that preheats ingots that are carried into a melting furnace such as a casting machine pot. The present invention relates to a device for preheating ingots.

In general, it is desirable to heat ingots before they are carried into a melting furnace such as a casting machine pot in order to prevent the adverse effects of a sudden drop in temperature of the molten metal in the melting furnace. It is conceivable that the ingot may be preheated using an independent heating source, but this is expected to have drawbacks such as a relatively high cost for ingot preheating.

On the other hand, the present applicant has previously proposed an ingot having a rolling surface such as a ball shape, which facilitates transportation and handling.

Taking the above points into consideration, this idea utilizes the temperature of the combustion gas discharged from the melting furnace and the rolling properties of the ingot to effectively and inexpensively preheat the ingot, thereby preventing and reliably reducing the temperature inside the melting furnace. It is an object of the present invention to provide an ingot preheating device which can prevent such problems and reduce fuel costs.

Hereinafter, a first embodiment of the ingot preheating device according to the invention will be described with reference to the accompanying drawings.

In FIG. 1, reference numeral 10 indicates a furnace body of a melting furnace such as a casting machine pot, and a tundish 11 of this furnace body 10.
For example, molten metal 12 heated to 420℃ or higher
is stored, and this molten metal 12 is used for casting such as die casting. A chimney 13 is installed in the furnace body 10, and this chimney 13 communicates with a flue 14 formed inside the furnace body 10, and the inside of the chimney is filled with combustion gas obtained by heating and melting the molten metal in the hot water tank 11. Formed as a flue for exhaust.

A cylindrical cover is provided around a portion of the chimney 13 adjacent to the flue, and a relatively closed annular space S is formed around the chimney 13. In this annular space S, a conveying pipe 46 is spirally wound around the chimney 13, so that the ingot 17 can roll therein. The ingot 17 has a rolling surface that rolls and moves like a ball ingot, while the lower end of the conveying pipe 46 opens into the molten metal 12 of the melting furnace. In addition, the supply side (upper end) of the conveying pipe 46
is connected to a delivery pipe of an elevator-type parts feeder (not shown), and an ingot 17 rolls out from the parts feeder through the delivery pipe.
The conveyor pipe 4 rolls in an inclined direction due to gravity.
6.

If a plurality of heat exchange fins 18, 18 are attached to the conveying pipe 46 at appropriate intervals in the axial direction within the annular space S, the heat exchange area can be increased and the ingot 17 can be effectively preheated.

In addition, the escape 20 is installed at the bottom of the chimney 13.
is provided. The escape 20 includes a pair of upper stopper 21 and lower stopper 22 that project into the conveyance path at a distance of one ingot such as a ball ingot. These upper and lower stoppers 21 and 22 are connected by a swing lever 23, which swings by an actuation device such as an actuation cylinder 25 controlled by a solenoid valve. As the swing lever 23 swings, the stoppers 21 and 22 alternately move the conveyor pipe 4.
The ingot 17 protrudes into the molten metal 12 of the melting furnace and adjusts the rolling fall of the ingot 17 into the molten metal 12 of the melting furnace. The actuating cylinder 25 is actuated by a detection signal from a hot water level position detector (not shown), etc., and adjusts and controls the actuation of the upper and lower stoppers 21 and 22 so that the amount of molten metal stored in the hot water tank 11 is constant. There is.

Next, the operation of the ingot preheating device of this invention will be explained.

The ingots 17 rolled out of the elevator type parts feeder are rolled within the conveying pipe 46 by their own weight, and when they reach the conveying pipe 46 in the annular space S, they are temporarily stored in this part by the escape 20. The ingots 17 stored in the annular space S are preheated by the combustion gases discharged through the chimney 13. This preheating temperature is, for example, 120°C when the ingot 17 is stored in the annular space S for about 10 minutes, and 150°C for 20 minutes.
It reaches about ℃.

When the amount of molten metal 12 in the melting furnace becomes less than a predetermined amount of preheated ingots 17, the actuating cylinder 25 is activated to swing the escape 20 and carry the required amount of ingots 17 into the molten metal 12. When the ingot 17 is carried into the molten metal 12, the discharge end of the conveying pipe 46 opens into the molten metal 12, so that the molten metal 12 can be prevented from scattering. Further, since the ingot 17 is sufficiently heated in advance, a sudden drop in temperature of the molten metal 12 can be reliably prevented.

Generally, a 10kg ingot without preheating is
Melting furnace heated to over 420℃, (molten volume 250
Kg), a sudden temperature drop of approximately 15°C will occur, so this adverse effect must be prevented. In this case, compensation for the temperature drop in the molten metal is achieved by automatically igniting and heating the fuel supplied into the melting furnace, but conventionally, the amount of fuel used due to the repetition of the above heating is greater than necessary. There were flaws. In contrast, in this invention, the ingot is effectively preheated, so the amount of fuel used can be reduced.

In this case, by spirally winding the conveying pipe 46, the length of the heat exchange section can be increased, and the preheating efficiency of the ingot can be increased.

2 and 3 show an ingot preheating device according to a second embodiment.

A cylindrical cover is provided around a portion of the chimney 13 adjacent to the flue, and a relatively closed annular space is formed around the chimney 13. In this annular space, a conveying pipe 56 is spirally wound around the chimney 13, so that the ingot 17 can roll therein. On the inner peripheral wall of the spirally formed conveying pipe 56,
The ingot 17 is further provided with a spiral guide 57 and is rolled within the conveying pipe 56.
Since it is guided spirally along the guide 57, the effective heat exchange length is expanded compared to the first embodiment. Further, a rectifier plate 58 having a cross-shaped cross section is inserted into the flue of the chimney 13, and the rectifier plate 58 allows the combustion gas discharged through the chimney 13 to be uniformly distributed and flowed. There is. Further, the conveying pipe 56 is supported by a support bracket 56A.
It is supported by a rectifier plate 58 at appropriate locations via.

Furthermore, FIG. 4 shows a third embodiment of the ingot preheating device.

In this ingot preheating device, a rectifying plate 58 having a cross-shaped cross section is provided in the flue of the chimney 13 to uniformly disperse and flow the combustion gas, and the rectifying plate 58
A guide wire 60 is spirally wound on the top, and the space between the guide wires 60 is formed as an ingot conveyance path. Thus, the ingots carried into the chimney 13 from a conveying pipe (not shown) are rolled spirally in this flue by a guide wire 60, and are carried into a casting machine pot, etc. from a discharge port (not shown). . In this case, since the ingot rolling in the flue of the chimney 13 comes into direct contact with the combustion gas and undergoes heat exchange, the ingot is effectively preheated. Another advantage is that equipment costs are low.

As described above, in the ingot preheating device according to the present invention, the temperature of the combustion gas discharged from the melting furnace is used to preheat the ingot, so that the ingot can be preheated at low cost. At the same time, since the ingot is effectively and efficiently preheated by heat exchange with the combustion gas, a sudden drop in temperature of the molten metal in the melting furnace can be prevented, and the necessary temperature for melting the ingot can be prevented. It also has the effect of saving fuel.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a first embodiment of the ingot preheating device according to the invention, FIG. 2 is a sectional view showing a second embodiment of the ingot preheating device, and FIG. FIG. 4 is an enlarged sectional view taken along the line, and a perspective view showing the ingot preheating device of the third embodiment. 10...furnace body, 11...tank, 12...molten metal,
13... Chimney, 14... Flue, 45, 46... Conveying pipe, 17... Ingot, 20... Escape, 60... Guide wire.

Claims (1)

[Scope of utility model registration request] A conveying path capable of guiding balls or similar rollable ingots into a tundish of a melting furnace, and a passage opening/closing mechanism provided in the conveying path so as to control passage of the ingots, A bent portion is formed in the conveyance path within a chimney connected to the flue of the melting furnace or in a relatively closed space around the chimney, so that the conveyance path has a sufficiently long path within the chimney or the space. A preheating device for ingots.