JPH05223464A - High frequency crucible type induction furnace having muffling device - Google Patents

Abstract

PURPOSE:To simplify the shape of any sound absorbing material and to simplify molding and mounting by a method wherein the sound absorbeing material is caused to respond to a diffusion passage for noise. CONSTITUTION:A yoke 3 is arranged to the outside of an induction coil 2 wound around a crucible 1 and a brick 4 is placed on a bottom. The yoke and the brick are held by a furnace frame 5 and an upper furnace frame 6 is coupled to the upper part thereof. A deck plate 7 is placed on the upper furnace body 6 and continued to a working floor. An openable furnace cover 8 is arranged on the crucible 1. A whole is arranged on a floor 9. The outer periphery of the furnace frame 5 is covered with a cylindrical sound absorbing material 14. Similarly, the bottom of the furnace frame 5 is covered with a bottom sound absorbing material 15. The outer periphery of the upper furnace frame 6 is covered with an upper sound absorbing material 13, the upper surface of the deck plate 7 is covered with a deck sound absorbing material 12, and the shoulder of the crucible 1 above the deck plate 7 is covered with a shoulder sound absorbing material 11. The sound absorbing material is a porous material, such as a castable material, cow wool, and rock wool.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high frequency crucible induction furnace equipped with a silencer.

[0002]

2. Description of the Related Art The load of a high frequency crucible induction furnace is several kg.
To 20t, the frequency is in the range of 100Hz to 3000Hz. Especially, from 0.5t to 5t, the frequency is often 500Hz. A conventional example will be described with reference to FIG. 1, which shows an embodiment of the present invention, in which there is no sound absorbing material from the shoulder sound absorbing material 11 to the bottom sound absorbing material. As is well known, a yoke 3 is placed outside the induction coil 2 wound around the crucible 1, bricks 4 are placed on the bottom, these are held by a furnace frame 5, and an upper furnace frame 6 is joined to the upper part thereof. To do. The deck plate 7 is placed on the upper furnace frame 6 and is connected to the work floor (not shown). An openable / closable furnace lid 8 is arranged on the crucible 1. The whole is arranged on the floor surface 9. The alternating current of the induction coil 2 gives an alternating magnetic field to the object to be heated (not shown) in the crucible 1, and the object to be heated is melted by the induced current and the Joule heat due to the resistance of the object to be heated.

[0003]

According to the conventional example described above, the induction coil 2, the yoke 3 and the like vibrate due to electromagnetic force and magnetostrictive vibration due to the alternating magnetic field and the magnetic field generated in the furnace. Is generated and diffuses outside from the furnace frame 5 and the like. FIG. 2 is a frequency analysis diagram of the conventional example and the example, and is data obtained by the noise meter 10 for frequency analysis of 1/3 octave placed at a distance of 1 m diagonally above the shoulder of the furnace. In the figure, the data of “no sound absorbing material” indicates data of 500 Hz and 5 t in the conventional example. Since the power supply is 500 Hz, vibration and noise are 100
It has a peak at 0 Hz. Data noise is shown in Fig. 1.
It is considered to follow the path of arrows A, B, C and D.

An object of the present invention is to provide a high-frequency crucible induction furnace having a sound absorbing material corresponding to respective noise diffusion paths, each sound absorbing material having a simple shape, and having a sound deadening device which can be easily molded and mounted. Especially.

[0005]

A high-frequency crucible induction furnace equipped with a muffler of the present invention comprises a muffler for an induction furnace held by an upper furnace frame on the lower surface of a deck plate and a furnace frame below the deck. A cylindrical sound absorbing material that covers the outer circumference of the furnace frame, a bottom sound absorbing material that covers the bottom surface of the furnace frame, an upper sound absorbing material that covers the outer circumference of the upper furnace frame, and a deck sound absorbing material that covers the upper surface of the deck plate. Divided into a shoulder sound absorbing material covering the shoulder of the crucible above the deck board,
At least one of these sound absorbing materials constitutes the sound deadening device.

[0006]

Operation: Referring to FIG. Each sound absorbing material 11, 12, 13, 14 or 1 corresponding to the noise diffusion paths A, B, C and D
No. 5 absorbs noise to reduce the noise of the high frequency crucible induction furnace. All the sound absorbing materials are simple in shape and easy to mold and mount.

[0007]

FIG. 1 is a front view showing a cross-sectional view of the outside of the embodiment. Although there is a part that overlaps with the description of the conventional technology section,
In the figure, a yoke 3 is placed outside an induction coil 2 wound around a crucible 1, bricks 4 are placed on the bottom, these are held by a furnace frame 5, and an upper furnace frame 6 is joined to the upper part thereof. Upper furnace frame 6
The deck board 7 is placed on top of and is continued to the work floor (not shown). An openable / closable furnace lid 8 is arranged on the crucible 1. The whole is arranged on the floor surface 9. As a characteristic structure of the embodiment, the outer periphery of the furnace frame 5 is covered with a cylindrical sound absorbing material 14. Similarly, the bottom surface of the furnace frame 5 is covered with the bottom sound absorbing material 15, the outer periphery of the upper furnace frame 6 is covered with the upper sound absorbing material 13, the upper surface of the deck plate 7 is covered with the deck sound absorbing material 12, and the deck plate 7 A shoulder sound absorbing material 11 covers the shoulder of the crucible 1 above. These sound absorbing materials are castable materials and porous materials such as kao wool and rock wool.

According to this structure, the noise on the path A is the shoulder sound absorbing material 11, the noise on the path B is the deck sound absorbing material 12 and the upper sound absorbing material 13, and the noise on the path C is the cylindrical sound absorbing material 14. The noise of the route D is absorbed by the bottom sound absorbing material 15 and is silenced. FIG. 2 is a frequency analysis diagram of the conventional example and the example, and is data obtained by the noise meter 10 for frequency analysis of 1/3 octave placed at a distance of 1 m diagonally above the shoulder of the furnace. In the figure, the data "with all sound absorbing materials" is the same as the above-mentioned conventional example of 500 Hz and 5 t, and shows the case where rock wool is used as the sound absorbing material. As can be seen from the comparison, the noise value decreases at each frequency, but the decrease at frequencies above 60 Hz is remarkable, and 96 dB (A) is 81 dB in the overall case.
It became (A) and the noise was reduced by 15 dB (A).
Although each of the sound absorbing materials can be applied individually, the effect of the cylindrical sound absorbing material 14 covering most of the yoke 3 is great.

[0009]

According to the high-frequency crucible type induction furnace equipped with the silencer of the present invention, each sound absorbing material corresponding to the noise diffusion path absorbs the noise of each path and reduces the noise of the induction furnace. Each of the sound absorbing materials has a simple shape and is easy to mold and mount.

[Brief description of drawings]

FIG. 1 is a front view showing a cross section of the outside of an embodiment.

FIG. 2 is a frequency analysis diagram of a conventional example and an example.

[Explanation of symbols]

 5 furnace frame 6 upper furnace frame 7 deck plate 8 furnace lid 11 shoulder sound absorbing material 12 deck sound absorbing material 13 upper sound absorbing material 14 tubular sound absorbing material 15 bottom sound absorbing material

Claims (1)

[Claims] 1. A silencer for an induction furnace, which is held by an upper furnace frame on a lower surface of a deck plate and a furnace frame below the drum frame, a cylindrical sound absorbing material covering an outer periphery of the furnace frame, and a bottom surface of the furnace frame. A bottom sound absorbing material that covers the upper furnace frame, a top sound absorbing material that covers the outer periphery of the upper furnace frame, a deck sound absorbing material that covers the upper surface of the deck plate, and a shoulder sound absorbing material that covers the shoulder of the crucible above the deck plate. A high-frequency crucible-type induction furnace having a sound deadening device, characterized in that the sound deadening device is constituted by at least one of these sound absorbing materials.