JP2504842B2 - Crucible furnace equipment - Google Patents

Description

TECHNICAL FIELD The present invention relates to a crucible furnace apparatus used for holding and melting aluminum.

(Prior Art and Problems) In FIG. 4, a state in which a refractory material b is lined on the inner surface of the crucible furnace main body a, and the crucible c is kept inside the refractory material b at a constant distance. It is installed in. Crucible c
An object to be heated d such as a lump of aluminum is contained in the inside of. A burner e is installed tangentially on the side wall of the crucible furnace body a, and the burner e is mainly a high-speed injection burner.

The high-temperature combustion gas f burned by the burner e is injected into the furnace at high speed, swirls at a high speed in the annular path g between the crucible c and the refractory material b, and the heated object d inside the crucible c is made as uniform as possible by forced convection. Consideration is given to heating the outer surface of the crucible c.

Combustion gas f rising while swirling in an annular path g between crucible c and refractory material b is exhausted from an exhaust port h in the upper part of the furnace body.

Further, there is also one in which an air preheater is provided at the exhaust port to preheat combustion air to recover heat.

In such a conventional technique, a normal burner is used, and high-load combustion is required to melt aluminum lumps and the like. Therefore, it is difficult to reduce the NO _x in the exhaust gas below a certain value due to the large noise caused by combustion noise, and the limit is usually about 60 to 100 ppm.

Further, the combustion gas burned by the burner is jetted into the furnace at a high speed in order to uniformly and rapidly heat the crucible. For this reason, the high-temperature and high-speed combustion gas directly contacts the crucible and causes the life of the crucible (half a year to 1 year) to be shortened.

An object of the present invention is to solve the above-mentioned problems, namely, high noise, difficulty in reducing NO _x , short life of crucible, and the like.

(Means for Solving the Problem) In FIG. 1, reference numeral 1 is a primary air-fuel mixture chamber and 2
Is the on-panel catalyst layer provided on the downstream side. At the center of the panel-shaped catalyst layer 2, a secondary mixture pipe 4 having a jet hole 3 at its tip is projected to form a combustion section 5. The combustion unit 5 having such a configuration is provided on the side wall 7 of the crucible furnace 6 in a single or plural number.

A second aspect of the present invention corresponds to FIG. 2, in which the entire combustion section 5 is made small, and the combustion section 5 is mounted in a combustion completion chamber 9 having a tapered ejection port 8. The temperature of the panel-shaped catalyst layer 2 can be controlled by introducing the jet port 8 into the crucible furnace 6 and opening the jet port 8 in the crucible furnace 6.
The composition is maintained at 600 to 1000 ° C., the composition according to claim 4 is a composition in which the primary mixture passage 10 is provided on the outer periphery of the primary mixture chamber 1, and the composition according to claim 5 is the secondary mixture. This is a configuration in which the ejection holes 3 provided in the trachea 4 are provided in the lateral direction. The above-mentioned panel-shaped catalyst layer 2 may be made of platinum, palladium, or a mixture thereof, for example.

(Operation) In FIG. 1, when the primary air-fuel mixture chamber of the fuel gas and air is introduced into the primary air-fuel mixture chamber 1 from the primary air-fuel mixture inlet 13 and reaches the panel-shaped catalyst layer 2, the primary air-fuel mixture is It is ignited by the igniter 11 to form a flame on the entire surface of the panel-shaped catalyst layer 2, and the temperature of the catalyst layer 2 is maintained in the range of 600 to 1000 ° C. The temperature is maintained by detecting the temperature of the catalyst layer 2 by the temperature detector 14 and controlling the combustion amount. In this state, when the secondary mixer is introduced into the secondary mixer pipe 4 and ejected laterally from the ejection hole 3 at the tip thereof, the temperature of the panel-shaped catalyst layer 2 reaches 600 to 1000 ° C. , The heat immediately reacts and starts combustion.

According to the present invention described above, since lean fuel combustion is performed in the panel-shaped catalyst layer 2, there is no local overheating, and 600 to 1
Since the low temperature combustion of 000 ° C. is performed, the generation of nitrogen oxides (NO _x ) can be suppressed to a minimum, and at the same time, low noise combustion can be realized by the lean fuel combustion. Further, since the combustion with the secondary air-fuel mixture is the combustion surrounded by the catalyst layer 2, that is, the combustion performed in the atmosphere in the temperature range, firstly, the combustion is stabilized and the generated flame is generated. Is a very short flame. Secondly, since the combustion is performed by injecting secondary air from the ejection holes 3 to the periphery thereof, diffusion of the air-fuel mixture can achieve low NO _x combustion without local overheating and low noise combustion.

Further, since the crucible 12 is mainly heated by the radiant heat from the panel-shaped catalyst layer 2, the crucible 12 can be uniformly heated by the radiant heating from a large area and does not directly hit the flame, so that the life of the crucible 12 is improved. It can be significantly improved. The amount of heat required for the crucible 12 differs depending on whether the crucible 12 is melted or held, but in the case of holding the molten metal, for example, is the injection of the secondary mixture from the secondary mixer pipe 4 stopped? However, it is only necessary to control the injection amount, and the device of the present invention can be used for both melting and holding. As a result, the temperature of the catalyst layer 2 may be maintained at a temperature (600 to 1000 ° C.) required to maintain combustion in the catalyst layer 2, and it is not necessary to unnecessarily raise the temperature of the catalyst layer 2 and the catalyst life There is an advantage that can be extended.

FIG. 2 shows another embodiment of the combustion unit 5
Is configured as a whole and is inserted into a combustion completion chamber 9 having an ejection port 8 so that the ejection port 8 is connected to the crucible furnace 6
It is a structure that is opened inside. In this embodiment, the combustion gas generated in the combustion section 5 as described above is completely combusted in the combustion completion chamber 9 and ejected from the ejection port 8 to circulate around the crucible 12 to heat the crucible 12. Since the circulating gas is a heat flow that has completed combustion, the flame does not hit the crucible 12 as it is, and the life of the crucible 12 can be extended. Due to the structure, the embodiment having such a structure can provide the above-mentioned various advantages only by replacing the burner attached to the conventional crucible furnace apparatus.

FIG. 3 is an enlarged explanatory view of the combustion section, which is an embodiment in which the primary mixture channel 13 is provided on the outer periphery of the primary mixture chamber 1 of the combustion section 5, and the preheating of the primary mixture is achieved by this configuration. You can

(Effects of the Invention) Since the present invention is as described above, it is possible to suppress the generation of nitrogen oxides to a minimum with a low noise and to prevent the flame from directly hitting the crucible by the unique configuration, It has various effects such as a drastic improvement in the life of the crucible.

[Brief description of drawings]

FIG. 1 is a cross-sectional explanatory view of the present invention, FIG. 2 is a cross-sectional explanatory view of another embodiment of the present invention, and FIG. 3 (A) is a cross-sectional explanatory view showing an example of a combustion part. ) Is an explanatory front view. FIG. 4 is a cross-sectional explanatory view of a conventional crucible furnace. Reference numeral 1 ... Primary air-fuel mixture chamber, 2 ... Panel-shaped catalyst layer, 3 ... Injection hole, 4 ... Secondary air-fuel mixture tube, 5 ... Combustion section, 6 ... Crucible furnace, 7
... Side wall, 8 ... Jet port, 9 ... Combustion completion chamber, 10 ... Primary mixture passage, 11 ... Ignition device, 12 ... Crucible, 13 ... Primary mixture introduction section, 14 ... Temperature detector. 15 ... Current plate

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Yoshiyuki Sano 1-48-6-1101 Higashiikebukuro, Toshima-ku, Tokyo (72) Inventor Hideo Yoshikawa 5-3-9 Higashi-Kojiya, Ota-ku, Tokyo (72) Inventor Hiroshi Ichiyanagi 6-9 Takaracho, Kure-shi, Hiroshima (72) Nobuo Matsuo 6-9 Takaracho, Kure-shi, Hiroshima (72) Inventor Mitsuo Imamura 6-9 Takaracho, Kure-shi, Hiroshima (72) Masayuki Matsuda Takaracho, Kure-shi, Hiroshima 6-9

Claims (5)

(57) [Claims] 1. A combustion section constituted by providing a panel-shaped catalyst layer on the downstream side of a primary air-fuel mixture chamber, and projecting a secondary air-fuel mixture tube having an injection hole at its tip in the central portion of the panel-shaped catalyst layer. A crucible furnace device in which one or more are provided on the side wall of the crucible furnace. 2. The crucible furnace apparatus according to claim 1, wherein the combustion section is inserted into a combustion completion chamber having a tapered jet outlet, and the jet outlet is opened in the crucible furnace. 3. The temperature of the panel-shaped catalyst layer is 600 to 1000 ° C.
The crucible furnace apparatus according to claim 1 or 2, wherein the crucible furnace apparatus is held within the range. 4. The crucible furnace apparatus according to claim 1, 2 or 3, wherein a primary air-fuel mixture passage is provided on the outer periphery of the primary air-fuel mixture chamber. 5. The crucible furnace apparatus according to claim 1, 2, 3 or 4, wherein the ejection holes provided in the secondary air-fuel mixture tube are provided so as to eject the secondary air-fuel mixture laterally.