JPS5810672B2 - Scrap preheating device using high-temperature exhaust gas from an electric furnace - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for preheating scrap supplied to an electric furnace using exhaust gas from the electric furnace.

Preheating of scrap to be supplied to an electric furnace has been conventionally carried out by utilizing combustion heat of fuel using a burner or the like.

For example, scrap is charged into a preheating packet with a burner placed at the top and preheated by blowing combustion gas from above, or the scrap is charged into an electric furnace and placed in a burner installed in the electric furnace. However, there is something to preheat it.

In these prior art techniques, a large amount of high-temperature exhaust gas (1200 to 1300 C) generated in the electric furnace during smelting is discharged into the atmosphere without being utilized at all, and on the other hand, a large amount of fuel is used to preheat the scrap.

In addition, since the exhaust gas contains a large amount of refining dust,
Dust must be removed before being released into the atmosphere, and for this reason the hot exhaust gas must be cooled before being introduced into the precipitator.

There is a point.

Therefore, means such as mixing cold air into the exhaust gas are added, and as the amount of emitted gas increases, the power of the induced blower increases, resulting in the disadvantage of energy dissipation and high consumption.

Therefore, the present invention aims to solve the above problems.

The purpose of the present invention is to provide a device that preheats scrap, which is a raw material for refining, using high-temperature exhaust gas discharged from an electric furnace.

FIG. 1 is a sectional view of an embodiment of the present invention.

An exhaust gas duct 11 and a damper 12 extend in a horizontal straight line for introducing exhaust gas from the electric furnace 1 shown in FIG.
, and a gas introduction means 3 consisting of a hood 13, as well as a damper 14 and an exhaust for discharging the cold gas after preheating the scrap.

A gas outlet means 4 consisting of a gas duct 15 is arranged at a position on the moving rail 7 of the scrap truck 5.

When the scrap cart 5 carrying the packet 2 charged with scrap moves on the rail 7 and reaches directly below the hood 13, the upper and lower parts of the packet 2 are connected to the gas introduction means 3 and the gas outlet. Means 4 includes first and second
They are connected airtightly through sealing means 6.9.

Thereafter, high-temperature exhaust gas is introduced into the packet 2 from the exhaust gas duct 11 to preheat the scrap, and the exhaust gas after the scrap preheating is led out from the exhaust gas duct 15.

FIG. 2 is a front view showing the lower part of the packet 2. FIG.

The packet 2 has a crumb 8 in its lower part.

This gram 8 has a two-part opening/closing structure, with a half part 8a and another half part 8b connected to a horizontal pin 16.
17 at the bottom of the packet 2, respectively.

When opening the crumb 8, the wires 18, 1 connected to the outer ends of the half portions 8a ab on one diameter line, respectively.
9, each half part 8a, 8b
are opened in directions away from each other around pins 16 and 17.

Thereby, the scraps in the packet 2 can be easily discharged.

When the crumb 8 is fully closed, the gas that has flowed between the scraps in the packet 2 is discharged through the plurality of conduction holes 20 bored in the bottom plate 8c of the half parts ga and gb, as shown in FIG. It is led out through the cylinder 21.

Note that the temperature of the exhaust gas is lowered in the lower part of the packet 2, so there is no fear of thermal deformation of the movable parts of the crumb 8.

FIG. 3 is a sectional view of the upper part of the packet 2 and the vicinity of the first sealing means 6.

A horizontal annular first seal box 22 that is open upward is provided on the upper outer periphery of the packet 2 .

The first seal box 22 is filled with a sealing material 23, such as sand.

Above the first seal box 22, a cylindrical first seal body 2 is provided.
4 are provided concentrically, and the upper part of this first seal body 24 is connected to a lifting means such as a piston rod 25a of a cylinder 25.
It is fixed to the tip of the

The cylinders 25 are pivotally supported at fixed positions on the frame 26 at intervals of, for example, 120 degrees in the circumferential direction of the first seal body 24, and are expandable and retractable in the vertical direction.

The inner circumferential surface of the first seal body 24 and the lower end of the hood 13 are airtightly connected by a cylindrical first expandable member 27 that is vertically expandable.

When connecting the upper part of the hood 13 and the packet 2,
The cylinder 25 is driven to extend and the first seal body 24 is inserted into the seal material 23 of the first seal box 22 as shown in FIG.

As a result, between the lower end of the hood 13 and the upper end of the packet 2, the inside of the packet 2 includes the first elastic member 27 and the first elastic member 27.
The packet 2 is isolated from the outside by the seal body 24, the seal material 23, and the first seal box 22, and cold air is prevented from entering the packet 2.

The second sealing means 9 has a similar mechanism to the first sealing means 6.

Directly below the exhaust pipe 21, a horizontal annular second seal box 28 that is open upward is provided.
8 is filled with a sealing material 29.

A tip of a piston rod 30a of a cylinder 30 is fixed to the lower end of the second seal box 28.

The cylinder 30 is pivotally supported at a fixed position of the gas deriving means 4 at intervals of, for example, 180 degrees in the circumferential direction of the second seal box 28, and is vertically expandable and retractable.

The inner circumferential surface of the second seal box 28 and the duct portion 14a of the gas deriving means 4 are connected by a cylindrical second telescopic member 31 that is vertically telescopic.

When connecting the lower part of the packet 2 and the gas deriving means 4, each cylinder 30 is driven to extend 7 to close the second seal box 28.
is pushed up so that the exhaust pipe 21 as the second seal body is inserted into the seal material 29 of the second seal box 28.

This prevents cold air from entering the lower part of the packet 2.

The exhaust pipe 21 has a half-cylindrical shape, and is attached to the lower part of each half portion 8a, 8b of the crumb 8 as shown in the figure.

The first and second sealing means 6, 9 are originally provided for the purpose of preventing the intrusion of cold air, but they are opened and closed at appropriate times to release cold air in order to prevent scraps with a large amount of impurities from melting. It can also be introduced.

The present scrap preheating device is operated as follows to preheat the scrap.

A scrap cart 5 carrying a packet 2 charged with scrap is moved onto a rail 7 and fixed at a position where a gas introducing means 3 and a gas deriving means 4 are arranged.

At the top of the packet 2, the first seal body 24 is lowered into the first seal box 22 by the cylinder 25, and at the bottom of the packet 2, the second seal box 28 is raised by the cylinder 30, the exhaust pipe 21 is inserted, and the gas An airtight flow path is formed.

Next, the damper 14 of the gas deriving means 4 and the damper 12 of the gas introducing means 3 are opened to supply high temperature exhaust gas from the electric furnace to the packet 2 to preheat the scrap.

The exhaust gas flow passes through the gap in the scrap from top to bottom, as indicated by the arrow in FIG. 1, and heat exchange takes place therein.

Once the scrap is preheated to a predetermined temperature, the dump 12,
14 is fully closed, the first seal body 24 is raised, the second seal box 28 is lowered, the packet 2, the gas introduction means 3, and the gas discharge means 4 are uncoupled, and the scrap cart 5 is moved to the preheated scrap discharge position. up to rail γ
move the top.

Then, the packet 2 is lifted up by a crane (not shown), and the scrap is charged into an electric furnace.

FIG. 4 shows a plurality of preheaters 41 (three shown) each consisting of the packet 2 and scrap cart 5 shown in FIGS. 1 to 3.
, 42, 43 is a simplified plan view of the preheating device.

The rail 7 shown in FIG. 1 is different from the rails 52, 53, 5 shown in FIG.
It corresponds to 4.

These rails 52, 53, 54 are connected to the gas introduction means 48.
Directly below each of the hoods 44, 45, and 46, the exhaust gas duct 47 extends perpendicularly to and intersects with a linear exhaust gas duct 47 corresponding to the exhaust gas duct 11 in FIG.

The dampers 49, 50° 51, which will be described later, are the same as the damper 12 in FIG.
It corresponds to

The hood 13 shown in the first figure corresponds to hoods 44, 45, 46, which are commonly connected to the exhaust gas duct 47 at intervals in the axial direction, and are connected to the gas introduction means 48. is configured.

Note that a damper 56 is interposed in the gas introduction means 48 upstream of the exhaust gas duct 47.

Dampers 49, 50, 51 are interposed between each hood 44, 45, 46 and the exhaust gas duct 47, respectively.

On each rail 52, 53, 54, a preheater 41, 42,
43 are arranged movably along the rail.

Further, below the rails 52, 53, 54, a gas deriving means 55 is provided with a damper (not shown) and connected to the lower part of each preheater 41, 42, 43, in parallel with the gas introducing means 48. provided.

Note that a part of the duct of the gas introducing means 48, in which the damper 56 is interposed downstream, is connected to the gas deriving means 55.

The upper part of the gas introduction means 48 and each preheater 41, 42.43, and the gas derivation means 55 and each preheater 41.4
2.43 are provided with sealing means similar to the first and second sealing means 6, 9 of the embodiment of FIGS. 1-3, respectively.

In FIG. 4, the preheater 43 is in the process of charging scrap or is on standby, the preheater 42 is in the process of preheating, and the preheater 41 has been moved to complete preheating and to charge the scrap into the electric furnace 1. state.

In this state, the dampers 49, 51 and the damper of the gas deriving means 55 corresponding to the preheater 41, 43 are closed,
The dampers of the gas deriving means 55 corresponding to the damper 50 and the preheater 42 are open.

High-temperature exhaust gas from the electric furnace 1 is introduced into the preheater 42 via the exhaust gas duct 47, and the scrap in the preheater 42 is preheated.

When the preheating of the scrap in the preheater 42 is completed,
In order to charge the scrap after preheating into the electric furnace 1, the preheater 42 is moved upward in FIG. After charging the scrap, the preheater 41 is moved to the lower part of FIG. 4 to input new scrap.

In this way, the scrap can be continuously preheated by sequentially introducing high temperature exhaust gas into each preheater 41, 42, 43.

In addition, when preheating operation is not required, the exhaust gas duct 4
Exhaust gas can be discharged through a bypass duct 57 which is arranged in parallel with the exhaust gas 7 and is equipped with a damper 56 .

Further, by adjusting the opening degree of the damper 56, the high-temperature exhaust gas from the electric furnace can be fed into the packet, and the remaining exhaust gas can be sent to the gas deriving means 55.

By performing such an operation, the high-temperature exhaust gas from the electric furnace can be mixed with the foul-smelling exhaust gas from the packet by the downstream gas deriving means, and the foul smell can be removed by combustion.

As described above, according to the present invention, the gas introducing means and the gas deriving means are connected to the packet charged with scrap through the first and second sealing means, and the high temperature exhaust gas from the electric furnace is introduced into the packet. This eliminates the need to use fuel to preheat the scrap.

Further, by preheating the scrap, the time for melting the scrap in the electric furnace can be shortened, and the power consumption of the electric furnace can be reduced.

Since the temperature of the exhaust gas after preheating the scrap is relatively low, it is possible to introduce the exhaust gas into the precipitator without mixing cold air into the exhaust gas as in the conventional case, and therefore the power of the induced blower is relatively small. Finish.

Furthermore, since high-temperature exhaust gas is sequentially introduced into multiple preheaters made up of packets loaded on a trolley, it is possible to provide flexibility in preheating operation, and adjust the amount of preheating scrap and preheating temperature accordingly. It is easy to adjust and allows efficient preheating operation.

Further, according to the present invention, a plurality of preheaters 41, 42, 43 are arranged on a rail 52 extending in a straight line at right angles to the exhaust gas duct 47.
, 53 and 54, and therefore the work of loading and unloading scrap into the packet 2 can be carried out at a position vertically away from the exhaust gas duct 47 in FIG. can be carried out in a relatively spacious place, improving work safety.

Furthermore, the first sealing means 6 provided between the upper part of the packet 2 and the gas introducing means 3, and the second sealing means 9 provided between the lower part of the packet 2 and the gas deriving means 4,
Seal material 23 in the first and second seal boxes 22.28.
29, the first and second seal bodies 24, 21 can be inserted and removed by the first and second elevating means 25, 30, and the airtightness is further improved by the first and second telescopic members 27, 31.

In this way, high-temperature exhaust gas is reliably prevented from leaking outside and deteriorating the working environment, and the thermal energy contained in the exhaust gas is prevented from dissipating, making it possible to preheat scrap with high efficiency. It becomes possible.

[Brief explanation of drawings]

1 is a sectional view of an embodiment of the present invention, FIG. 2 is a front view showing the lower part of the packet 2, FIG. 3 is a sectional view showing a part of the first sealing means 6, and FIG. 4 is a sectional view of the present invention FIG. 1...Electric furnace, 2...Packet, 3,
48...Gas introduction means, 4,55...
Gas derivation means, 5... Cart, 6... First sealing means, 8... Crumb, 9...
Second sealing means, 13, 44, 45, 46°61...
...Hood, 21...Exhaust pipe, 22...
・First seal box, 23, 29... Seal material, 2
4...First seal body, 25, 30...
Cylinder, 27... First telescopic member, 28...
...Second seal box, 31...Second telescopic member,
41,42.43... Preheater.

Claims (1)

[Scope of Claims] 1. A packet 2 into which scrap to be preheated is loaded is placed on a scrap truck 5, and a plurality of preheaters 41, 42.
43, respectively, and an exhaust gas duct 47 that guides high-temperature exhaust gas from the electric furnace 1 is arranged horizontally in a straight line above the preheaters 41, 42, and 43. Below the exhaust gas duct 47, a scrap trolley 5 is installed. Straight guiding rails 52, 53, 54 are laid extending at right angles to the exhaust gas duct 47, and the packet 2 has half parts 8a, 8b at its lower part that open and close downward around the horizontal axis. gas introduction means 3 fixedly provided above each packet 2 for introducing high temperature exhaust gas from the electric furnace 1 into the packets 2 from above, and below the packets 2. Gas deriving means 4 are fixedly provided to respectively derive the gas after heating the scrap from below the packet 2, and the upper part of the packet 2 and the gas introducing means 3 can be freely connected and disconnected to seal the gas. a first sealing means 6 for sealing the gas, and a second sealing means 9 for connecting and disconnecting the lower part of the packet 2 and the gas deriving means 4 and for sealing the gas, the first sealing means 6 is a horizontal annular first seal box 22 which is provided on the outer periphery of the upper part of the packet 2 and is filled with a sealing material 23 and opened upward; A cylindrical first seal body 24 that can be inserted into the seal box 22, a first elastic member 27 that airtightly connects the gas introduction means 3 and the first seal body 24 and is vertically expandable and contractible, and a first elastic member 27 that is provided at a fixed position. 1st
The second sealing means 9 includes a first elevating means 25 for elevating and lowering the sealing body 24, and the second sealing means 9 includes each half portion 8a of the crumb 8,
A second seal body 21 having a half-cylindrical shape provided at the lower part of 8b,
A sealing material 29 is provided concentrically below the second sealing body 21.
A horizontal annular second seal box 28 filled with gas and opened upwards into which the second seal body 21 can be inserted;
A scrub preheating device using high-temperature exhaust gas from an electric furnace, characterized in that it includes an expandable member 31 and a second elevating means 30 provided at a fixed position for elevating and lowering a second seal box.