JP2893278B2 - Temperature level detector for heating furnace - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an aluminum-based metal ingot (hereinafter, referred to as an ingot).
(Referred to as an aluminum ingot) for use in instantaneous melting devices.

[Prior art] Melting of aluminum-based metal by die casting
When molding by casting as a member of electrical equipment, etc., there is an instant melting device as a device that continuously and quickly melts an aluminum ingot, raises the temperature of the molten metal to an appropriate temperature, and discharges the molten metal. The heating furnace used for the above will be described with reference to FIG.

FIG. 2 shows the entire instantaneous melting apparatus. In this figure, reference numeral 1 denotes a cold material insertion guide, and an aluminum ingot (hereinafter, referred to as a cold material) 2 as a material is guided into a melting furnace 3 in an upright state. The molten metal melted in the melting furnace 3 is prevented from scattering outside. The melting furnace 3 is a furnace body 31 made of a refractory material and having an upright hollow cylindrical shape with a bottom and capable of storing the cold material 2 therein in an upright state, and a furnace body for heating and melting the cold material from its surface.
It comprises an induction coil 32 provided on the outer periphery of 31 and an outlet 33 opened on the bottom wall of the furnace body 31. Reference numeral 4 denotes a heating furnace which is coaxially arranged below the melting furnace 3 and is a furnace body 41 made of a refractory material and having an upright hollow cylindrical shape with a bottom, and a furnace body for raising the temperature of the melt inside to an appropriate temperature.
It comprises an induction coil 42 provided on the outer periphery of 41 and an outlet 43 opened on the bottom wall of the furnace body 41. Reference numeral 5 denotes a hollow tubular tapping pipe which extends downward from the outside around the outlet 43 and communicates with the heating furnace 4, and a tap 51 is provided below the tapping pipe. 6
Is an electromagnetic pump arranged on the outer periphery of the tapping pipe 5 and above the tapping port 51, and is capable of giving an upward thrust to the molten metal in the tapping pipe 5.

Then, the cold material 2 sent into the melting furnace 3 in an upright state by the guide of the cold material insertion guide 1 is heated by the action of the induction coil 32 and melted from its surface to become molten metal. Outflow from 33 to heating furnace 4 and outflow
After passing through 43, it flows into the tapping pipe 5. Then, the electromagnetic pump 6 is operated to apply an upward thrust to the molten metal flowing into the tapping tube 5 so that the molten metal does not flow out of the tap hole 51. If the induction coil 42 is energized, the molten metal rises. Accumulated in the furnace 4 and maintained at an appropriate temperature. Further, when pouring the molten metal into a die casting machine or the like, if the operation of the electromagnetic pump 6 is stopped and the upward thrust given to the molten metal in the tapping pipe 5 is eliminated, the molten metal descends by its own weight, Hot water is supplied from the hot water outlet 51 to a die casting machine or the like (not shown).

Next, an apparatus for detecting the level of the molten metal in the heating furnace 4 will be described with reference to FIG. In FIG. 3,
Components having the same reference numerals as those of the heating furnace shown in FIG. 2 have the same configuration as that of FIG.

In FIG. 3, reference numeral 71 denotes a bottom electrode, which is provided near the outlet 43 of the heating furnace 4 so as to be in contact with the molten metal 44. Reference numerals 72 and 73 denote level detection electrodes, which are provided above the inner wall of the furnace body 41 (upper limit line of the melt level) and below the inner wall (lower limit line of the melt level) so as to be in contact with the molten metal 44, respectively. Reference numerals 82 and 83 are detection lamps provided outside the heating furnace 4 and are electrically connected to the surface level detection electrodes 72 and 83, respectively. Reference numeral 9 denotes a power source. One pole is connected to each of the detection lamps 82 and 83, and the other pole is connected to the bottom electrode 71.

Before the melting of the cold material 2 in the melting furnace 3 shown in FIG. 2, or in a state in which the molten metal has flowed out of the outlet 43 and the molten metal is hardly accumulated in the heating furnace 4, , Power supply 9, bottom electrode 71 and molten metal level detection electrode 72
Alternatively, since the circuits composed of the molten metal level detection electrodes 73 are all closed, both the detection lamps 82 and 83 are turned off. Next, the melting of the cold material 2 proceeds in the melting furnace 3 shown in FIG. 2, and the amount of the molten metal 44 accumulated in the heating furnace 4 increases, and the surface of the molten metal 44 in the heating furnace 4 Rises, and when the molten metal 44 contacts the molten metal level detection electrode 73, the bottom electrode 71 of the molten metal level detection electrode 73 is energized by the molten metal, and is configured by the power supply 9, the bottom electrode 71, and the molten metal level detection electrode 73. Since the circuit is closed, a current flows through the detection lamp 83, and the detection lamp 83 is turned on. Then, when the molten metal level further rises and the molten metal contacts the molten metal level detection electrode 72, the molten metal level detection electrode 72 and the bottom electrode 71 are energized by the molten metal 44, and the power source 9, the bottom electrode 71 and the molten metal level detection are performed. Since the circuit including the electrode 72 is closed, a current flows through the detection lamp 82, and the detection lamp 82 is turned on.

[Problems to be solved by the invention]

By the way, in the heating furnace provided with the above-mentioned level detector, the molten metal adheres to the furnace wall and solidifies, and often a slag is formed. If the molten metal level is lower than the molten metal level detection electrode, the molten metal level detection electrode and the molten metal level will be electrically connected by a slag. And a circuit is formed between the bottom electrode and
There has been an inconvenience that the detection lamp corresponding to this level detection electrode is turned on. That is, in the conventional level detector, there is a problem in that the sticking action adheres to the level detecting electrode and the detection operation becomes inaccurate.

According to the present invention, experience has shown that the sticking of the slag to the inner wall of the heating furnace is biased, and in particular, the sticking of the slag hardly adheres to the inner wall of the inner wall to which the slag is attached in the radial direction. It is an object of the present invention to provide a device that can accurately detect the level of a molten metal based on the above.

[Means for solving the problem]

In order to achieve the above-mentioned object, a device for detecting the level of a metal surface of a heating furnace according to the present invention is provided. And a first electrode provided at a position corresponding to the first electrode so as to be able to come into contact with the molten metal in the heating furnace, and a first electrode disposed on an inner wall radially opposed to an inner wall of the heating furnace in which the first electrode is disposed. A second electrode provided so as to be able to come into contact with the molten metal in the heating furnace at each position, and a detection device disposed outside the heating furnace and connected to a circuit connecting the first electrode and the second electrode. And a power supply for applying a voltage to a circuit connecting the first electrode, the detector, and the second electrode, and detecting a level of the molten metal level by energizing the first electrode and the second power supply. The first electrode and the second electrode Each of the electrodes, the relative inner wall recess formed in the heating furnace, the tip of each electrode is configured to be inserted and arranged so as not to protrude from the bottom surface of the recess.

[Operation] In the above configuration, when the level of the molten metal in the heating furnace rises due to the supply of the molten metal and the molten metal comes into contact with both of the pair of molten metal level detection electrodes, a circuit formed by these electrodes is formed. Since the circuit is closed, current flows from the power supply to the detector via the transformer. For example, when the detector includes a lamp, the detector is turned on. Therefore, it can be seen that the molten metal surface is above the pair of molten metal level detection electrodes. Also, when the molten metal flows down and the molten metal level drops so as not to come into contact with both of the pair of molten metal level detection electrodes, a circuit constituted by these electrodes is opened, so that no current flows to the detector. If the detector is a lamp, it is turned off.
Therefore, it can be seen that the molten metal level is below the molten metal level detection electrode. In addition, even if a slag adheres to one of the pair of molten metal level detection electrodes and the electrode and the molten metal level are electrically connected regardless of the molten metal level, the inner wall is opposed to the inner wall in the radial direction. Since the slag hardly adheres, the slag hardly adheres to the other electrode.Therefore, the pair of electrodes are not electrically connected, and the detector malfunctions even if the slag adheres to one of the electrodes. There is very little to do.

If the tip of the electrode is arranged so as not to protrude from the bottom surface of the concave portion, the stick becomes less likely to adhere to the electrode, so that the malfunction of the detector is almost completely eliminated.

Next, an embodiment of the present invention will be described with reference to FIG. In FIG. 1, components denoted by the same reference numerals as those of the heating furnace shown in FIG. 2 have the same configuration as that of FIG.

In FIG. 1, reference numerals 10a and 11a denote first electrodes for detecting the level of the molten metal, which are formed above the inner wall of the furnace 41 (upper limit line of the molten metal surface) and below the inner wall (lower line of the molten metal surface), respectively. The tips are inserted into the recesses 12a, 13a so that their tips do not protrude from the bottom surfaces of the recesses 12a, 13a, and can come into contact with the molten metal 44. Reference numerals 10b and 11b denote second electrodes for detecting the level of the molten metal, respectively. Depressed portions 12b and 13b are formed on inner walls radially opposed to the concave portions 12a and 13a, respectively.
It is inserted so as not to protrude from the bottom surface of 3b and to be in contact with the molten metal 44. Then, each first electrode 10
The detection lamps 14a, 14b and the insulation transformers 15a, 15b provided outside the heating furnace 4 are connected in series between the a, 11a and the second electrodes 10b, 11b, and each of the insulation transformers 15a, 15b is The power supply 9 is connected in parallel.

Next, the operation in the case where the heating furnace having the molten metal level detecting device having the above configuration is used for the instantaneous melting device will be described.

Before the melting of the cold material 2 in the melting furnace 3, or
In a state where the molten metal flows out from the outlet 43 and the molten metal is hardly accumulated in the heating furnace 4, the first electrode 10
a, the circuit composed of the second electrode 10b and the detection lamp 14a, and the circuit composed of the first electrode 11a, the second electrode 11b and the detection lamp 14b are all open, so that the detection lamps 14a and 14b are open.
b is off. Next, the melting of the cold material 2 proceeds in the melting furnace 3 shown in FIG. 2, and the amount of the molten metal 44 accumulated in the heating furnace 4 increases, and the surface of the molten metal 44 in the heating furnace 4 Rises, and when the molten metal 44 contacts the first electrode 11a and the second electrode 11b, the first electrode 11a and the second electrode 11b are energized by the molten metal, and the first electrode 11a, the second electrode 11b, and the detection lamp 14b. Is closed, a voltage is applied to this circuit from the power supply 9 via the insulating transformer 15b, and the detection lamp 1
Current flows through 4b, and this detection lamp 14b is turned on. Then, when the molten metal surface further rises and the molten metal 44 contacts the first electrode 10a and the second electrode 10b, the first electrode 10a and the second electrode
b is energized by the molten metal, and the circuit composed of the first electrode 10a, the second electrode 10b and the detection lamp 14a is closed, so that a voltage is applied to this circuit from the power supply 9 via the insulating transformer 15a, Current flows through 14a, and this detection lamp 1
4a lights up.

Here, since the first electrode 10a and the second electrode 10b are set to the upper limit line of the molten metal surface, and the first electrode 11a and the second electrode 11b are set to the lower limit line of the molten metal surface, the detection lamps 14a and 14b
The following is clarified by the lighting / extinguishing state of.

Both the detection lamps 14a and 14b are turned off: the level of the molten metal in the heating furnace 4 is below the lower limit line, and it is necessary to start melting the cold material 2 in the melting furnace 3 shown in FIG.

Only the detection lamp 14b is turned on: the surface of the heating furnace 4 is between the lower limit line and the upper limit line.

Both the detection lamps 14a and 14b are turned on: the surface of the hot water in the heating furnace 4 is above the upper limit line, and it is necessary to stop melting the cold material 2 in the melting furnace 3 shown in FIG.

Then, the level of the molten metal 44 repeatedly rises and falls, but the first electrodes 10a, 11a and the second electrodes 10b, 11b do not protrude from the bottom surfaces of the recesses 12a, 13a, 12b, 13b, respectively, because their tips do not protrude. Then, the molten metal 44 is caught by these electrodes and solidified, so that no slag is formed. However, for example, when a slag is formed on the inner wall around the first electrode 10a and the molten metal surface is below the first electrode 10a, the first electrode 10a and the molten metal 44 may be electrically connected. However, since no slag is formed on the second electrode 10b corresponding to the first electrode 10a, the first electrode 10a and the second electrode 10b
Is not energized, and the detection lamp 14a does not light up by mistake.

In the above embodiment, the first electrode and the second electrode corresponding to the first electrode are used.
Although a pair of electrodes for detecting the level of the molten metal are provided on the upper and lower lines, they may be provided on the inner wall corresponding to another level at which the level of the molten metal is to be detected.

[Effect of the Invention] The molten metal level detecting device of the temperature rising furnace of the present invention includes the first electrode and the second electrode for detecting the molten metal level provided on the inner wall of the temperature rising furnace as described above, Since the tip of each electrode is inserted and arranged in the recess formed on the inner wall of the heating furnace so as not to protrude from the bottom of the recess, the slag hardly adheres to the electrode, and therefore the detector Has an excellent effect that it is appropriately prevented from malfunctioning.

[Brief description of the drawings]

FIG. 1 is a vertical side view of a heating furnace having a level detector according to the present invention, FIG. 2 is a vertical side view of an instantaneous melting apparatus, and FIG. 3 is a heating furnace having a conventional level detector. It is a vertical side view. 4 ... heating furnace, 9 ... power supply, 44 ... molten metal 10a, 11a ... first electrode 10b, 11b ... second electrode 12a, 12b, 13a, 13b ... recess 14a, 14b ... detector 15a , 15b …… Insulation transformer

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A 56-49495 (JP, U) JP-A 63-5229 (JP, U) (58) Fields surveyed (Int.Cl. ⁶ , DB name) G01F 23/24 C22B 9/16 F27B 1/28 F27D 21/00 F27D 21/04

Claims (1)

(57) [Claims] An inner wall of a heating furnace for maintaining the temperature of a molten metal such as an aluminum-based metal ingot and raising the temperature of the molten metal to an appropriate temperature; A first electrode provided so as to obtain the first electrode, and a first electrode disposed on an inner wall radially opposed to an inner wall of the heating furnace in which the first electrode is disposed. A second electrode, a detector disposed outside the heating furnace and connected in a circuit connecting the first electrode and the second electrode, and connecting the first electrode to the detector and the second electrode. A power supply provided in a circuit, wherein the first electrode and the second
In the apparatus for detecting the level of a molten metal in a heating furnace, the level of the molten metal is detected by energizing with a power supply, wherein each of the first electrode and the second electrode is provided in a recess formed in an inner wall of the heating furnace. On the other hand, an apparatus for detecting the level of a molten metal level in a heating furnace, wherein each of the electrodes is inserted and arranged so that the tip of each electrode does not protrude from the bottom surface of the recess.