JP2000111271A - Metal melting furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a part of a dust collecting hood exposed to high temperature capable of bearing the high temperature and having long life without being oxidized. SOLUTION: A dust collecting hood 6 is provided above the opening part of a crucible 1, which comprises a dust collecting part 6a made of a fire-proof material for sucking exhaust gas and powder dust due to the combustion of materials adhering to a metal material when it is melted and a duct 6c connected to the dust collecting part 6a to exhaust the sucked gas to a treatment device in a post-stage.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal melting furnace provided with a device for collecting gas and dust discharged by a metal melting furnace during melting.

[0002]

2. Description of the Related Art FIG. 2 shows the structure of a conventional example, in which (a) is a view of a metal melting furnace viewed from above, and (b) is a sectional view taken along line AA of (a). In FIG. 2, reference numeral 1 denotes a crucible of an induction furnace which is formed of a refractory material and receives a metal material therein, 2 is a molten metal in which a metal material is melted, 3 is wound around the outer periphery of the crucible 1, and An induction coil for inductively melting a metal material, a reference numeral 4 denotes an outer shell of the induction furnace, and a reference numeral 5 denotes a gas discharged by the induction furnace during melting and a dust collecting hood for collecting dust. In FIG. 2, the crucible 1, the induction coil 3, and the outer cover 4 constitute a crucible-type induction furnace. The crucible-type induction furnace is provided at an upper portion of the crucible 1 for melting a molten metal charged into the crucible 1 into a molten metal 2 having a predetermined temperature and component, and then casting the molten metal 2 into a mold (not shown). This is a device for tapping water from a tap hole to a not-shown pan. When the molten metal 2 is, for example, a molten metal for cast iron, the metal material to be melted in this crucible-type induction furnace is a steel scrap obtained by collecting pieces of steel and the like, a return material of a casting such as a gate and a weir that does not become a product at the time of casting, Chips, such as shavings of castings, additives containing carbon and silicon for component adjustment, etc., such as oil and grease adhering to steel chips and chips, and casting sand adhering to returned materials of castings, etc. are burned during melting. Exhaust gas and dust. If this gas and dust are left undisturbed, not only the inside of the factory will be contaminated but also the health of workers will be impaired.
(For example, a ring hood that cuts the inner surface of a hollow steel plate formed into a ring along the upper edge of the crucible into a slit shape and collects dust from the cutout) After collecting dust through a dust collector such as a bag filter (not shown), the dust is collected and released into the atmosphere.

[0003]

By the way, in the conventional construction, the dust collecting hood is made of a steel plate and is disposed along the upper edge of the crucible, so that the dust collecting hood is heated by radiation from the molten metal in the crucible, or is not heated by the induction coil. The steel sheet is exposed to a high temperature due to induction heating due to leakage magnetic flux of the steel sheet, so that the steel sheet is oxidized and cannot be used for a long time.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a dust collecting hood having a portion exposed to a high temperature and having a long life without being oxidized by withstanding the high temperature. is there.

[0005]

Means for Solving the Problems In order to solve the above problems, the invention according to claim 1 is directed to a metal melting furnace in which a metal material is charged into a crucible formed of a refractory and having an opening at an upper part and melted. Above the opening of the crucible, a dust collecting section made of a refractory material for sucking exhaust gas and dust generated by burning of deposits and the like adhered to the metal material during melting, and a gas connected to the dust collecting section and sucked in the latter stage And a dust collecting hood having a duct for discharging to the processing apparatus.

In the metal melting furnace according to the first aspect, the dust collecting portion can be formed along the upper edge of the opening of the crucible.

Further, as in the third aspect of the present invention, in the metal melting furnace according to the first or second aspect, the dust collecting portion forms a substantially vertical surface on the inner surface, and is substantially horizontal from the vertical surface. A plurality of dust collecting holes can be provided radially.

According to the first to third aspects of the present invention, the portion receiving the radiation from the molten metal is made of a refractory material, and the dust collecting holes for dust collection are divided into a plurality of pieces and provided radially. It is formed as a steel plate duct that collects surrounding gas and dust, so it receives radiant heat from the molten metal, but is not heated by leakage magnetic flux from the induction coil, so the dust collection surface oxidizes and has a short life Can be prevented, and the mechanical strength of the dust collecting portion made of a refractory can be prevented from being reduced by dividing the dust collecting hole into a plurality.

[0009]

FIG. 1 shows the structure of a main part of an embodiment of the present invention. FIG. 1 (a) is a cross-sectional view of a crucible-shaped induction furnace cut at a height substantially at the center of a dust collecting hole. b) shows a longitudinal section. In FIG. 1, members denoted by the same reference numerals as those of the conventional example have approximately the same functions, and therefore description thereof will be omitted. In FIG. 1, reference numeral 1 denotes a crucible of an induction furnace which is formed of a refractory and receives a metal material therein, 2 is a molten metal in which a metal material is melted, 3 is wound around the outer periphery of the crucible 1, and a crucible 1 is provided.
An induction coil for inductively melting the metal material inside, an outer shell 4 of the induction furnace, a gas exhaust hole 6 when the induction furnace is melted, and a dust collecting hole 6b for collecting dust, have a refractory (for example, alumina and silica door). And the like, and a dust collecting hood including a dust collecting portion 6a formed by a dust collecting portion and a duct 6c made of a steel plate that collects and collects gas and dust on the exit side of the dust collecting hole 6b. Here, the dust collecting portion 6a forms a vertical surface 6d perpendicular to the inner surface, and a plurality of dust collecting holes 6b are formed radially in a substantially horizontal direction from the vertical surface 6b. The duct 6c is a ring-shaped hollow body made of a steel plate, and has a notch 6e formed by cutting the inner surface thereof, and the notch 6e is formed in the dust collecting hole 6a of the dust collecting part 6a.
b (outer peripheral side). In FIG. 1, the crucible 1, the induction coil 3, and the outer cover 4 constitute a crucible-type induction furnace. The crucible-type induction furnace converts a molten metal charged into a crucible 1 into a molten metal 2 of a predetermined temperature and component.
After pouring the molten metal 2 into a casting mold (not shown), the molten metal is poured from a tapping hole provided at the top of the crucible 1 to a not-shown pan. When the molten metal 2 is, for example, a molten metal for cast iron, the metal material to be melted in this crucible-type induction furnace is a steel scrap obtained by collecting pieces of steel and the like, a return material of a casting such as a gate and a weir that does not become a product at the time of casting, Chips, such as shavings of castings, additives containing carbon and silicon for component adjustment, etc.The oils and fats attached to steel chips and chips, foundry sand attached to returned materials of castings, etc. are burned during melting. Exhaust gas and dust.

The gas and the dust are collected by a dust collecting portion 6a having a dust collecting hole 6b and formed of a refractory material, and a duct 6c made of a steel plate collectively collecting the gas and the dust on the exit side of the dust collecting hole 6b. The dust is collected by a dust collection hood 6 and guided to a dust collector such as a bag filter (not shown) to collect the dust, and then discharged to the atmosphere.

[0011]

According to the present invention, since the dust collecting portion of the dust collecting hood is formed of a refractory material, there is no thermal deterioration of the dust collecting portion due to radiant heat from the molten metal, and the life of the dust collecting hood is extended. There is. Further, since the dust collecting portion is not heated by the leakage magnetic flux of the induction coil, the electric efficiency of the induction coil is improved accordingly.

[Brief description of the drawings]

FIG. 1 shows a configuration of a main part of an embodiment of the present invention,
(a) is a cross-sectional view of the crucible-type induction furnace cut at a height substantially at the center of the dust collecting hole, and (b) is a vertical cross-sectional view.

2A and 2B show a configuration of a conventional example, in which FIG. 2A is a view of a metal melting furnace as viewed from above, and FIG.

[Explanation of symbols]

 6 Dust collecting hood 6a Dust collecting part 6b Dust collecting hole 6c Duct

Claims (3)

[Claims] 1. A metal melting furnace for charging a metal material into a crucible formed of a refractory and having an opening at an upper portion, and melting the metal material.
Above the opening of the crucible, suck the exhaust gas and dust due to the combustion of the deposits and the like attached to the metal material during melting,
A metal melting furnace, comprising: a dust collecting portion formed of a refractory; and a dust collecting hood having a duct connected to the dust collecting portion and discharging a sucked gas to a subsequent processing device. 2. The metal melting furnace according to claim 1, wherein the dust collecting portion is formed along the upper edge of the opening of the crucible. 3. The metal melting furnace according to claim 1, wherein the dust collecting portion has a substantially vertical surface formed on an inner surface thereof, and a plurality of dust collecting holes are formed radially substantially horizontally from the vertical surface. A metal melting furnace characterized by being provided.