JP2014117714A - Preheater for ladle - Google Patents

Abstract

【Task】
A ladle preheating device that effectively uses energy and does not pollute the work environment is provided.
[Solution]
A ladle body 1 having a pouring spout and an opening at the top, a lid 2 that closes and insulates the opening of the ladle body, and an electric resistance heating heater 3 that heats the inside of the ladle body are provided. A ladle preheating device comprising an electric resistance heating heater that heats the inside of the ladle body as a heating means.
[Selection] Figure 1

Description

  The present invention relates to an apparatus for preheating or keeping warm a ladle used in a casting workshop.

  The ladle is used as a container for conveying a molten metal for producing a cast product to a casting mold.

  The pre-heating of the ladle is performed because the molten metal is not rapidly cooled in the ladle when the hot molten metal is transferred from the furnace into the ladle. The preheating of the ladle is preferably as high as possible, but is performed so that the temperature of the outer wall of the ladle becomes 300 ° C. or more from the viewpoint of economy.

  Conventionally, there has been known a method of preheating a ladle by turning the ladle sideways or turning it over and heating the inside using a burner such as gas or heavy oil.

  However, in the preheating method using this burner, the warmed gas does not stay inside the ladle and always escapes to the outside, so that the thermal efficiency is poor. Further, since the combustion gas is always supplied into the ladle, the ladle cannot be sealed and insulated with the lid, and the heated combustion gas pollutes the working environment.

  In order to solve these problems, Patent Document 1 discloses a ladle preheating device that includes a ladle body and a sealing lid, inserts bipolar electrodes that penetrate the sealing lid, and heats the inside of the ladle body by arc discharge. Has been proposed.

JP 2012-55908 A

  According to the invention described in Patent Document 1, since the opening of the ladle is sealed with a lid without using a burner, there is no contamination of the working environment by combustion gas. However, since an arc is used as a heat source, it is desirable to introduce an inert gas in order to prevent arc stability and oxidation of the electrode surface, and it is difficult to use in the atmosphere.

  The problem to be solved by the present invention is to provide a ladle preheating device that effectively uses energy and does not contaminate the work environment.

  In order to solve the above problems, the ladle preheating device of the present invention includes a ladle body having a molten metal spout and an opening at the top, a lid for insulating the ladle body by closing the opening, and the inside of the ladle body. An electric resistance heating heater for heating the ladle is provided, and an electric resistance heating heater for heating the inside of the ladle body by energizing the heater is provided as a heating means.

  In order to preheat the ladle using the ladle preheating device of the present invention, the lid provided with the electric resistance preheating heater or the ladle body is moved up and down, the electric resistance heating heater is set, and then the electric resistance heating is performed. Energize the type heater to heat the ladle body from the inside.

  According to the present invention, the ladle opening can be covered and insulated by heating with electricity, so there is no contamination of the work environment and the energy saving effect is high. Further, since the heating by the electric resistance heater is not necessary, it is possible to heat the ladle in the atmosphere without needing to put an inert gas into the ladle unlike the arc heating.

  Since the lid is for preventing the heat preheated by the electric resistance heater, it does not need to be a structure for sealing the ladle body. In order to effectively use the thermal energy input in the preheating, the lid is preferably a two-layer structure having a heat insulating layer having excellent heat insulating properties. As a material excellent in heat insulation, a material having low thermal conductivity and low bulk specific gravity is preferable. Examples of the heat insulating layer include those made of a material having a thermal conductivity at 600 ° C. of 0.3 W / m · K or less and a bulk specific gravity of 0.5 or less. Examples of the material having a thermal conductivity at 600 ° C. of 0.3 W / m · K or less include alumina ceramic fiber board, calcium silicate ceramic fiber board, JIS A class refractory heat-insulating brick and the like.

  Furthermore, it is also easy to heat the pouring spout which is difficult to warm by throwing an electric resistance heating heater matched to its diameter into the pouring spout of the ladle.

  The electric resistance heating heater of the present invention is a heating means that generates heat by Joule heat by energizing an electric resistor, and examples thereof include a metal heater and a ceramic heater. By using a ceramic heater rather than a metal heater, the calorific value per unit area can be increased. Therefore, it is more preferable for an application where the opening area is limited such as a ladle.

  The ceramic heater in the present invention is, for example, a silicon carbide heating element or a molybdenum disilicide heating element, which directly heats ceramics and generates heat to 1,000 ° C. or more by Joule heat.

  In order to install the electric resistance heating type heater, as shown in FIG. 1 and FIG.

  In order to preheat the ladle, first the lid or ladle body provided with the electric resistance heating heater is moved up and down, and the electric resistance heating heater is set. The ladle body may be preheated by energizing an electric resistance heating heater, and the preheating temperature of the ladle may be controlled by measuring the temperature of the ladle body with a thermocouple provided outside the ladle.

  As described above, according to the ladle preheating apparatus according to the present invention, the heat energy can be effectively utilized by heating by the electric resistance heater and closing the opening of the ladle to insulate the work environment. There is no pollution. Since there is no consumption of the electrode, which is a concern with arc heating, it can be used in the atmosphere and there is no need to inject an inert gas.

It is a figure which shows typically the structure of the ladle preheating apparatus of this invention. It is a figure which shows typically one Embodiment of the structure of the cover of the ladle preheating apparatus of this invention.

  Hereinafter, a ladle preheating apparatus according to the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram schematically showing the configuration of a ladle preheating apparatus of the present invention.

  The ladle preheating device of the present invention comprises a ladle body 1, a lid 2 for closing and insulating the ladle opening, and an electric resistance heater 3. Since the atmosphere in the ladle may be in the air, it is not necessary to press and seal the lid 2 and the ladle body 1 as in arc discharge.

  The ladle may be provided with ceramic wool or a ceramic blanket between the lid 2 and the ladle 1 because the upper end of the ladle body is chipped or slag adheres due to handling.

  In order to warm the pouring spout 6 of the molten metal in the ladle 1, it is also preferable to heat the pouring spout electric resistance heater 4 in the inner diameter portion of the pouring spout 6.

  Control of the electric resistance heating heater may be performed by measuring the temperature with a thermocouple or the like provided outside the ladle and adjusting the electric power supplied to the heater.

  As described above, according to the ladle preheating device according to the present embodiment, the upper opening of the ladle 1 is covered with the lid 2 to insulate, so that the heat energy is not released to the outside, and the energy saving effect is achieved. In addition, since the electric resistance heater 3 is used as a heat source, the work environment is not contaminated.

  Since the electric resistance heaters 3 and 4 are not consumed in the atmosphere, there is no need to replace the ladle with an inert gas, and no pressing is required.

  Drawing 2 is a figure showing typically one embodiment of the structure of the lid of a ladle preheating device.

  The lid 2 is for preventing the heat preheated by the electric resistance heater 3 from escaping, and it is not necessary to seal the ladle body. As a preferable embodiment of the lid 2, as shown in FIG. 2, there may be mentioned one having a heat insulating layer 2-1 on the side in contact with the ladle body. The heat insulation layer 2-1 is made of a material having a thermal conductivity at 600 ° C. of 0.3 W / m · K or less and a bulk specific gravity of 0.5 or less, and may have a thickness of about 20 to 60 mm. A specific example of the electric resistance heater is a ceramic heater. The ceramic heater includes an end portion 3-2 for supplying electricity and a heat generating portion 3-1 for generating heat by the supplied electricity. Yes, the end 3-2 may be passed through the lid 2.

  The ladle preheating apparatus according to the present invention has been described above based on the embodiment, but the present invention is not limited thereto, and the object of the present invention can be achieved and within the scope of the invention. Various design changes are possible, all of which are included within the scope of the present invention.

  The present invention can be used as a preheating heat retaining device for a ladle used in a foundry.

1: Ladle 2: Lid 2-1: Thermal insulation layer 3: Electric resistance heating type heater 3-1: Heat generating part 3-2: End part 4: Electric resistance heating type heater for inlet 5: Power cable 6 for heater: Spout

Claims (4)

A ladle body having a molten metal spout and an opening at the top;
A lid that closes the opening of the ladle body and insulates it;
A ladle preheating apparatus comprising: an electric resistance heating heater for heating the inside of the ladle body, and an electric resistance heating heater for heating the inside of the ladle body by energizing the heater.   The lid has a heat insulating layer made of a material having a thermal conductivity at 600 ° C. of 0.3 W / m · K or less and a bulk specific gravity of 0.5 or less on a side in contact with the ladle body. The ladle preheating apparatus described in Item 1.   The ladle preheating device according to claim 1 or 2, wherein an electric resistance heating heater is also installed inside the spout of the ladle.   The ladle preheating device according to any one of claims 1 to 3, wherein the electric resistance heating heater is a ceramic heater.

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