JPS6037386B2 - Heat recovery device from molten slag - Google Patents

Description

[Detailed description of the invention] The present invention relates to an apparatus for recovering heat from molten slag.

Conventionally, high-temperature molten slag discharged from steelmaking equipment such as blast furnaces and converters is generally cooled naturally or with water spray in a slag pit, etc., and then crushed and dumped in a landfill. The retained thermal energy was wasted.

The prior art to solve this technical problem is to charge molten slag into a saucer, arrange heat transfer tubes above the saucer to face the molten slag, and conduct mirror heat transfer from the molten slag to the heat transfer tubes. This system collects high-temperature steam and cools the molten slag. In this prior art, when the molten slag charged into the saucer is cooled, only the vicinity of the surface of the molten slag facing the heat transfer tube is rapidly cooled and solidified.
This is because the thermal conductivity of the molten slag is extremely low, so the cooling rate inside the molten slag does not follow the cooling rate near the surface of the molten slag. Therefore, although the temperature inside the molten slag is high, a phenomenon occurs in which the temperature decreases only near the surface of the molten slag. As the molten slag surface temperature decreases, the amount of radiant heat transferred to the heat transfer tube decreases, making it difficult to effectively recover heat from the molten slag. Therefore, an object of the present invention is to solve the above-mentioned technical problems and to
An object of the present invention is to provide a heat recovery device that can effectively recover heat from molten slag.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a partially cutaway plan view of an embodiment of the present invention. High temperature discharged from blast furnaces, converters, etc., e.g. 1500q
The molten slag of about 0 is transported to the position of the charging device 3 by the pot truck 2 running on the rails, and is transferred from the gutter 3a of the charging device 3 to the loading section of the trough 4a by rotating the pan 2a of the pan truck 2. 5 is poured into the stream. The plurality of independent troughs 4a are arranged in a rectangular shape in a horizontal plane, and the trough driving means 6a to
6d, it is rotated (moved) in the bridge direction of arrows 7a to 7d. The molten slag is sent in the rotational directions 7a to 7d as the trough 4a rotates, and is cooled by giving its sensible heat to a cooling medium in a heat transfer 12, which will be described later, by radiation heat transfer.
Then, the molten slag is crushed by the rope frame device 24 to become granular solid slag, and is discharged to the outside of the rotary trough 4 by the discharge device 44 via the hopper 45. A furnace shell 8 is provided to cover the trough 4a and the heat transfer tubes 12.

Heat exchanger tubes 12 are provided on the inner wall of the furnace shell 8 over the entire inner wall.
can be established. The heat exchanger tube 12 is connected to the charging device 3 as well as the rotating trough 4.
It is arranged above the trough 4a in front of the rotation direction 7a to 7d. The heat exchanger tubes 12 extend in an inverted U-shape in a vertical plane, straddling the troughs 4a to 4d. Both ends of the heat exchanger tube 12 are connected to the second
As shown in the figure, it is connected to headers 13 and 14 to constitute a heat transfer unit 15. A plurality of heat transfer units 15 are provided in a plurality of directions in the moving direction of the trough, and each heat transfer unit 15 is connected in series or in parallel, and a cooling medium is introduced from a circulation pump, a water supply pump, or the like. FIG. 2 shows an example in which heat transfer units 15 are connected in series. The independent trough 4a is moved in the direction of arrow 7a by trough drive means 6a and then in the direction of arrow 7 by trough drive means 6b.
is moved in the direction b.

These troughs 4a are moved, for example, by a chain drive. This trough 4a has a double truck structure, and only the upper truck can move in the direction 7b. 7
Movement in the c direction is performed by the trough drive means 6c.

In this case, only the trough 4a moves. The slag is moved in the direction 7d to the slag charging position by the trough driving means 6d.

Similarly to the movement in the direction 7b, the movement is performed only by the upper carriage.
A plurality of agglomeration devices 24 are provided in front of the immersion device 3 in the rotational direction 7a to 7c of the trough 4a in the circumferential direction of the rotating trough.

The fly clothing layer 24 includes a shaft portion extending over the entire width in the radial direction of the trough 4a above the trough 4a, penetrating the side wall of the furnace shell 8, and having a cooling medium passage therein, and a shaft portion protruding outward in the radial direction of the drain portion. Cooling medium passages 27a, 27 are provided integrally with the shaft part at intervals in the axial direction of the part and are suitable for the inside of Fujito.
3 to 5, and a flywheel drive means provided outside the furnace shell 8 that rotates the shaft around its axis, and cooling medium passages 27a and 27b. A cooling medium supply means for supplying a medium such as water is provided. The rope protrusion 28 has a length that allows it to penetrate into the loading portion of the trough 4a and effectively eel. A partition pipe 31 is inserted into the coolant passage of the koji part and the coolant passages 27a and 27b of the rope ridge 28. The cooling medium passage 27 is partitioned into a double pipe shape by the partition pipe 31, forming an inner passage 27a and a passage 27b. The partition pipe 31 is opened toward the tip of the rope protrusion 28, and the inner passage 27a and the outer passage 27b are opened. The cooling medium supply means includes a water supply pipe and a drain pipe connected to the inner passage and the outer passage of the shaft portion through a rotary pipe joint outside the furnace shell 8. Western rope clothing layer 2
4 damages or crushes the slag loaded on the loading portion 5 of the trough 4a.

The molten slag surface area and the interior of the molten slag are affected by the turbulent action of the sea bream coating layer 24, and it is possible to prevent only the molten slag surface area from being rapidly cooled. Therefore, the amount of radiation heat transferred from the molten slag to the heat transfer tube 12 increases, and effective heat transfer is performed. Further, the slag that has been cooled and solidified is crushed into particles by the crushing action of the rope slag device 24. The cooled and solidified slag is discharged from the trough 4a by a discharge device 44 provided ahead of the fly gear straight 24 of the rotary trough 4a in the rotation direction 7a to 7c.

By configuring the agitation protrusion 28 of the porcelain slag 24 so that its tip has a length that digs into the upper layer of the slag 45, the entire amount of molten slag is sufficiently absorbed.

Therefore, it is possible to prevent molten slag from adhering to the inner surface of the trough 4a. The discharge device 44 discharges not only the slag on the bedding but also the solid slag in the upper layer of the bedding. 1st again
Referring to the figure, the rotation direction 7 of the trough 4a from the charging device 3
Along a to 7c, in rotation angle range A, the high temperature molten slag is in a fluid state.

In the next rotation angle range B, the molten slag is in a transition state from a fluid state to a solid state, and is in a starch syrup-like high viscosity state of about 1250 to 1150 oo. In the last rotation angle range C,
The slag is solidified, and in this range C, the
The slag becomes granular due to the grinding or crushing action in step 4.
In the rotation angle range A to B, the surface of the pseudo-protrusion part 28 of the punch-breaking device 24 is cooled by water flowing from the inner passage 27a to the outer passage 27b.

Therefore, the molten slag in contact with the surface of the fly ridge 28 is rapidly cooled, becomes glassy, and adheres to the surface of the fly ridge 28 as shown in FIG. 3. Since the adhered slag is glassy, it is easily peeled off from the surface of the fly frame protrusion 28, and does not interfere with the driving of the Iso-Western pupil 24. Also, attached slag 4
0 protects the surface of the protrusion 28. Incidentally, in order to make it easier to peel off the adhered slag 40 from the surface of the fly-cattle protrusion 28, the surface of the fly-cattle protrusion 28 is made to be a smooth surface. In the rotation angle range C, the surface of the granular solidified slag has a relatively high hardness, so the coagulation protrusion 28 that contacts the granular slag
There is a risk of surface wear.

Therefore, on the outer circumferential surface of the crane azusa protrusion 28, as shown in FIGS.
As shown in the figure, a cylindrical round protection member 43 is fixed. The protective member 41 is made of a wear-resistant material, such as high manganese steel. Since the protective member 43 runs along the longitudinal direction of the rope punch projection 28 and has a circular cross section at right angles to the ball, a joint for welding with the rope punch projection 28 is formed, making the welding work easier. It can be done easily. In addition, molten slag discharged from a blast furnace and molten slag discharged from a converter are
Since the solidification temperature differs, the rotation angle range C differs depending on the molten slag to be treated, and the protection member 43 is attached to the flywheel protrusion 28 of the clearing layer 24 provided within this range C.
need to be installed.

The cooling medium passages 25 and 27 of the fly trap device 24 in the rotation angle range A to B' are preferably supplied with water as a cooling medium, or with relatively low temperature, for example, saturated water or boiled water, so that the molten slag By making a relatively large temperature difference between the cooling medium and the cooling medium, the amount of radiation heat transfer can be increased.

Furthermore, since the solidification temperature of molten slag discharged from a blast furnace and molten slag discharged from a converter is different,
The rotation angle range C varies depending on the molten slag to be treated, and it is necessary to attach the protection member 43 to the fly azure protrusion 28 of the fly calendar 24 provided within this range C. Cooling medium passage 2 of the condenser layer 24 in the rotation angle range A to B
5 and 27, it is preferable to supply water or relatively low temperature saturated water or a boiler as a cooling medium.If the temperature difference between the molten slag and the cooling medium is made relatively large in this way, the amount of radiation heat transfer can be reduced. can be increased.

As described above, according to the present invention, the molten slag is charged by the charging device into the trough driven by the trough driving means, and the slag is caused to transfer heat from the slag to the heat transfer tube disposed above the trough. The heat recovery equipment of the present invention is capable of continuously cooling, solidifying, pulverizing, and pulverizing molten slag into granules.

In addition, the vicinity of the surface of the slag loaded in the loading section of the trough and the inside of the slag are sufficiently covered by the rope layer, so
It is possible to prevent only the vicinity of the slag surface from being rapidly cooled, and therefore the amount of heat transferred to the heat transfer tube can be increased. Furthermore, the molten slag can be taken out as granular solid slag that is easy to handle. Furthermore, since a cooling medium is introduced into the cooling medium passage of the rope azusa device to cool the fly azure protrusion, it is possible to prevent the fly azure protrusion from overheating, and the cooling medium is heated to increase the amount of heat recovery. You can also do that. Since each trough is independent, the material can be discharged, for example, into a hopper by rotating the trough, and the discharge device can be simplified. In addition, especially when space is limited, a compact layout becomes possible. Since the trough is independent, maintenance and replacement are easy.

This trough can be moved rectangularly in the horizontal plane, so
The configuration of the means for driving the trough can be simplified. In the range where the slag is in a fluid state, the outer periphery of the slag protrusion is smooth, and therefore the slag easily separates from the slag protrusion, preventing unnecessary amounts of sag from adhering to the slag protrusion. I can escape.

In the range where the slag is in a solid state, the protective member is fixed along the longitudinal direction of the Nada-azusu projection, so it is easy to sufficiently damage the slag, and the protective member is attached to the Nada-azusu projection. Thermal stress due to thermal expansion is alleviated, preventing deformation and cracking of both.

This especially serves to prevent the cooling medium from leaking into the slag, as the cooling medium is passed through the fly ridge. In addition, the cylindrical protection member and the surface of the rope rope member form a space through which the joint during welding can be passed, making it possible to easily perform the welding work.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway plan view of an embodiment of the present invention, Fig. 2 is a simplified developed view of the heat exchanger tubes 12 in the circumferential direction of the trough 4a, and Fig. 3 is a diagram showing the area A to B'. FIG. 4 is a front view of the vicinity of the foot azure protrusion 28, FIG. 4 is a front view of the vicinity of the foot azure protrusion 28 in range C, and FIG. 5 is a sectional view taken along the line KK in FIG. 3... Input device, 4a... Trough, 5
...Loading section, 6a, 6b, 6c, 6d...
Trough drive means, 7a, 7b, 7c, 7d...
Movement direction, 8...furnace shell, 12...transmission pipe,
24...Fly frame device, 27...Cooling medium passage, 27a...Inner passage, 27b...Outer road, 28
...Rope punch protrusion, 31...Partition pipe, 44...
Ejection device, 43... protection member. Figure 2 Figure 3 Figure 4 Figure 5 Figure 1

Claims (1)

[Scope of Claims] 1. A plurality of independent troughs movable in a rectangular shape within a horizontal plane, trough driving means for driving the troughs, a charging device for charging molten slag into the trough, and movement of the troughs relative to the charging device. heat exchanger tubes disposed above the trough in the forward direction; a furnace shell covering the trough and the heat exchanger tubes; a shaft having a cooling medium passage; a cooling member that projects radially outward from the shaft and has a length that allows it to enter the loading area of the trough, is provided integrally with the shaft and communicates with the cooling medium passage within the shaft; It is equipped with a stirring protrusion having a medium passage, a stirring driving means provided outside the furnace shell for rotating a shaft part around its axis, and a means for supplying a cooling medium to the cooling medium passage, A plurality of stirring devices are provided at intervals in the direction of movement of the trough in front of the trough in order to stir the slag and increase the amount of radiant heat transferred to the heat transfer tube, and a plurality of stirring devices are provided in front of the stirring device of the trough in the direction of movement. The trough includes a discharge device for discharging slag from the trough, and a partition pipe inserted into a cooling medium passage between the shaft and the stirring protrusion and opening toward the tip of the stirring protrusion allows the shaft and the stirring protrusion to be separated. and are each partitioned into a double tubular shape, the cooling medium from the cooling medium supply means is supplied to either the inside or outside of the double tubular passage, and the cooling medium is discharged from either the inside or outside of the double tubular passage. However, the outer periphery of the stirring protrusion is smooth in the range of the trough movement direction where the slag loaded on the trough is in a fluid state, and the stirring protrusion is smooth in the range of the trough movement direction where the slag loaded on the trough is in a solid state. A heat recovery device from molten slag, characterized in that a cylindrical protection member made of a wear-resistant material is fixed to the outer periphery of the stirring projection of the device along the longitudinal direction of the stirring projection.