JPH0820181B2 - Circulating non-ferrous metal scrap melting furnace - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention quickly dissolves non-ferrous metal scraps such as aluminum and non-ferrous metal scraps such as aluminum empty cans generated by machining and recycles them with good yield. The present invention relates to a non-ferrous metal scrap melting furnace with a small amount.

[0002]

2. Description of the Related Art Conventionally, in order to recover metal scraps of non-ferrous metals such as aluminum generated by machining from aluminum scraps and aluminum empty cans with a good yield, as a melting furnace that quickly melts metal scraps while preventing oxidation, It supplies metal scraps into a cylindrical container with holes and pours the melt from the top with a pump such as a precision melt pump or electromagnetic pump to create a vortex and melt the metal scraps. It has upper and lower open ends. There is a vertical cylindrical vortex chamber in which a molten metal vortex is formed by a complicated impeller provided in the lower part of the chamber to entrain metal scraps, and other mechanically dipping metal scraps in the melt.

However, among the above-mentioned conventional devices, those equipped with a pump have a low yield and low thermal efficiency because the molten metal is easily oxidized, and those equipped with an impeller have a complicated structure and damage to the impeller in contact with metal scraps. There is a problem that the maintenance load is large, such as being large.

[0004]

The problem to be solved is that the above-mentioned conventional ones have problems in performance and maintenance.

[0005]

The present invention is directed to a burner 31.
9d of the molten metal heating chamber 30 having the above is taken out and passed through the upper open swirl chamber 20.
In a circulation type non-ferrous metal melting furnace configured so that the low temperature molten metal 9e having melted 0 and lowered in temperature is again introduced into the molten metal heating chamber 30 to raise the temperature, the inner wall 41 of the pump housing 40 having the bottom 42 formed in a horizontal plane is represented by polar coordinates. When viewed, the radius vector Rx rotates around the pole Q and the minimum radius vector Rb slightly longer than the radius Ra of the impeller is used as the starting point Pb. Vertical side walls 44 and 45 of the discharge port 43 are constituted by a tangent line Sd extending from the end point Pd of the vortex line having the same diameter Rd and a line Sb gradually increasing the distance from the starting point Pb with respect to the tangent line Sd. A horizontal intermediate wall 52 having a circular hole 51 centered on a vertical center line passing through the pole Q and having the same radius as the minimum radius vector Rb is formed on the pump housing 40 and is larger than the minimum radius vector Rb of the vortex line. Maximum motion An inner peripheral wall 21 for a swirl chamber having a cylindrical inner peripheral surface having a radius Rc smaller than Rd is formed on a horizontal intermediate wall 52, is arranged concentrically with the vertical center line, and is provided at the lower end of an impeller shaft 61 which is descended and inserted from above. The minimum radius Rb
A disc 62 having a slightly shorter radius Ra is provided, and blades 63 are provided upright on the disc 62 to form an impeller 60.
Moreover, when the impeller 60 is inserted into the lowermost position from above, a slight gap H is maintained between the lower surface of the disk 62 and the bottom 42 of the pump housing.
The upper surface of the molten metal 11 is configured to be substantially flush with the upper surface, and the upper limit 11 of the molten metal surface 11 changes above the peripheral wall 21 of the swirl chamber 20.
According to the position between d and the lower limit 11e, the rotation speed control device 8 is provided to increase the rotation speed of the impeller shaft 61 when the molten metal surface 11 is high, and to decrease the rotation speed of the impeller shaft 61 when the molten metal surface is low.

[0006]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
Reference numeral 0 denotes a substantially vertical cylindrical swirl chamber in which the metal scrap 10 supplied from above is wound around the high-temperature molten metal 9d and guided downward, the upper part of which is opened so that the high-temperature molten metal 9d can flow in, and the lower part has a horizontal middle portion. An impeller in which a pump housing 40 having a discharge port 43 in a tangential direction is provided with a wall 52 therebetween, and a plurality of blades 63 are radially mounted on a horizontal disk 62 where a vortex is formed in the pump housing 40. 60 are arranged. Reference numeral 30 denotes a molten metal heating chamber, which is formed in a reverse taper shape so that a portion to be immersed in the high temperature molten metal 9d becomes wider downward, and a burner 31 for heating the high temperature molten metal 9d is provided above. Also, the swirl chamber 20 is the weir 1
They are separated by 2, but communicate with the swirl chamber 20 below the molten metal surface. Reference numeral 13 denotes the molten metal heating chamber 30 to the swirl chamber 2
0 is a runner that guides the high-temperature molten metal 9d to the upper part, and a slag scraper 14 is inserted into the high-temperature molten metal 9d from the upper side at the boundary with the molten-metal heating chamber 30 so that the slag scraper 14 can be vertically moved to prevent the slag floating on the molten metal surface from entering. There is. The swirl chamber 20 and the molten metal heating chamber 3
0 and the runway 13 are separated by the refractory wall 15, but are surrounded by the refractory wall 15 as a whole and integrated, and the swirl chamber 20 and the swirl chamber 20 are provided on one side of the molten metal heating chamber 30. The runners 13 are arranged side by side, and the door 1 for operation and maintenance is provided on the other side.
6 is provided to form a molten metal circulation path. In addition, 17 is an up-and-down movable motor for driving the impeller, and 22 is a metal scrap supply conveyor. Further, 18 is a molten metal level meter, which enables the molten metal level to be optimally controlled, and
The rotation speed of the impeller 60 can be controlled via the rotation speed control device 8 so as to form an optimum vortex shape depending on the molten metal level.

The essential part of the present invention for melting the thrown metal scrap 10 by a vortex will be described in detail.

When the inner wall 41 of the pump housing 40 having the bottom 42 formed in a horizontal plane is viewed in polar coordinates, the radius vector Rx rotates around the pole Q and the minimum radius vector Rb slightly longer than the radius Ra of the impeller is set as the starting point Pb. A tangent line Sd extending from the end point Pd of the vortex line having the maximum diameter Rd, and a straight line Sb gradually increasing the distance from the starting point Pb to the tangent line Sd. Thus, the vertical side walls 44 and 45 of the discharge port 43 are formed.

A horizontal intermediate wall 52 having a circular hole 51 centered on a vertical center line passing through the pole Q and having the same radius as the minimum radius vector Rb is formed on the pump housing 40.

An inner peripheral wall 21 for a swirl chamber is formed having a cylindrical inner peripheral surface having a radius Rc which is larger than the minimum radius Rb of the vortex line and smaller than the maximum radius Rd.

A disc 62 having a radius Ra slightly shorter than the minimum moving radius Rb is provided at the lower end of an impeller shaft 61 which is arranged concentrically with the vertical center line and is inserted downward from above, and blades 63 are provided on the disc 62. The impeller 60 is erected vertically, and when the impeller 60 is inserted from the uppermost position to the lowermost position, a horizontal space 52 is formed so as to maintain a slight distance H between the lower surface of the disk 62 and the bottom 42 of the pump housing. The lower surface and the upper surface of the blade 63 are configured to be substantially flush with each other.

Further, when the molten metal surface 11 is high depending on the position between the upper limit 11d and the lower limit 11e of the molten metal surface 11 which changes above the inner peripheral wall 21 of the swirl chamber 20, the rotation speed of the impeller shaft 61 is increased to increase the molten metal surface. There is provided a rotation speed control device 8 for slowing the rotation speed of the impeller shaft 61 when is low.

The operation will be described. First, the door 16 is opened and the same metal material as the metal scrap is inserted into the burner 3
In step 1, heating is performed to melt the metal material and prepare a molten metal. Subsequently, when the motor 17 is started and the impeller 60 is rotated, the pump action thereof causes the discharge port 43, the weir 12, the molten metal heating chamber 30, the runner 13, the swirl chamber 20, and the impeller 60.
A molten metal circulation path is formed. Then, the metal scrap 10 is thrown into the upper open swirl chamber 20 and is almost melted when passing through the impeller 60, so that the impeller is not damaged.

[0014]

According to the present invention, the high temperature molten metal 9d in the molten metal heating chamber 30 equipped with the burner 31 is taken out and passed through the upper open swirl chamber 20 into which the metal scrap 10 is introduced, and the metal scrap 10 is melted in the swirl chamber 20. In the circulation type non-ferrous metal melting furnace configured to guide the temperature of the low temperature molten metal 9e, whose temperature has been lowered, to the molten metal heating chamber 30 again to raise the temperature, the molten metal level meter 18 detects the molten metal level to enable optimum control. At the same time, the rotation speed of the impeller 60 can be controlled so as to form an optimum vortex shape depending on the level of the molten metal, and the supplied metal scrap 10 can be instantly wound into the vortex and melted, resulting in good yield and thermal efficiency. Well, it can be recycled and recovered, and the structures of the swirl chamber 20 and the impeller 60 are simple, they are hard to be damaged, have a long life, and the maintenance load is remarkably reduced.

[Brief description of drawings]

FIG. 1 is a partially cutaway vertical cut front view showing an embodiment of the present invention.

FIG. 2 is a plan view of the HH section of FIG.

FIG. 3 is a side view of the JJ section of FIG.

FIG. 4 is an enlarged plan view of a main part.

FIG. 5 is an enlarged front view of a main part.

FIG. 6 is a bottom view of KK in FIG.

[Explanation of symbols]

 8 Rotation speed control device 9d High temperature molten metal 9e Low temperature molten metal 10 Metal scrap 11 Molten metal surface 11d Upper limit of molten metal surface 11e Lower limit of molten metal surface 12 Weir 13 Runway 14 Slag scraper 15 Refractory wall 16 Door 17 Motor 18 Level meter 19 Thermometer 20 Vortex chamber 21 Inner wall of vortex chamber 22 Metal scrap supply conveyor 30 Molten metal heating chamber 31 Burner 40 Pump housing 41 Pump housing inner wall 42 Pump housing bottom 43 Discharge port 44 Discharge port side wall starting from the end of vortex line 45 Vortex line Side wall of discharge port starting from the starting point 51 Circular hole 52 Horizontal intermediate wall 60 Impeller 61 Impeller shaft 62 Disc 63 Blade H H Gap between disc and bottom of pump housing Pb Start point of vortex line Pd End point of vortex line Q pole Ra disc Radius Rb Minimum radius of vortex line Rc Radius of inner wall of vortex chamber Tangent of the end point of the straight line Sd vortex line starting from the start point of the maximum radius Rx radius Sb vortex line d circumvolution

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Noboru Tajiri 1-12-1 Higashisenta-cho, Naka-ku, Hiroshima-shi, Hiroshima Sanken Sangyo Co., Ltd. (72) Tokura Okuda 2 Asahi-cho, Kariya, Aichi 1-chome Aisin Seiki Co., Ltd.

Claims (1)

[Claims] 1. A high-temperature molten metal (9d) in a molten metal heating chamber (30) equipped with a burner (31) is taken out to form an upper open swirl chamber (2).
0), and the metal scrap (1
In a circulation type non-ferrous metal melting furnace configured so that the low temperature molten metal (9e) which is melted from (0) and is cooled down is introduced again to the molten metal heating chamber (30) to raise the temperature, a pump housing having a bottom (42) formed in a horizontal plane. (4
When the inner wall (41) of (0) is viewed in polar coordinates, the radius vector (Rx) rotates around the pole (Q) and the minimum radius vector (Rb) slightly longer than the radius (Ra) of the impeller is set as the starting point (P
b), a tangential line (Sd) extending from the end point (Pd) of the vortex line having the maximum radius vector (Rd), and the tangent line (Sd). On the other hand, a line (Sb) gradually increasing the distance from the starting point (Pb) constitutes vertical side walls (44, 45) of the discharge port (43), and a vertical center line passing through the pole (Q) is formed. A horizontal intermediate wall (52) having a circular hole (51) as a center and having the same radius as the minimum radius vector (Rb) is formed on the pump housing (40) and is larger than the minimum radius vector (Rb) of the vortex line. An inner peripheral wall (21) for a swirl chamber having a cylindrical inner peripheral surface having a radius (Rc) smaller than the maximum radius vector (Rd) is formed on the horizontal intermediate wall (52) and arranged concentrically with the vertical center line. , The lower limit of the radial vector (R
b) A disc (62) having a radius (Ra) slightly shorter than that of b) is provided, and the vanes (63) are erected on the disc (62) to form an impeller (60). The lower surface of the horizontal intermediate wall (52) and the upper surface of the blades (63) are maintained so that a slight gap (H) is maintained between the lower surface of the disc (62) and the bottom (42) of the pump housing when inserted from above into the lower position. And the upper surface (11d) of the molten metal surface (11) and the lower limit (11e) of the molten metal surface (11) that change above the inner peripheral wall (21) of the swirl chamber (20).
A rotation speed control device (8) for increasing the rotation speed of the impeller shaft (61) when the molten metal surface (11) is high, and for decreasing the rotation speed of the impeller shaft when the molten metal surface is low. A circulating type non-ferrous metal melting furnace.