JPS6347313A - Smelting, reducing and refining equipment - Google Patents

Abstract

PURPOSE:To collect the dust contained in a high-temp. exhaust gas which contains a large amt. of dust and is discharged from the prereducing furnace of molten iron producing equipment consisting of the prereducing furnace and smelting and reducing furnace with high thermal efficiency without losing the sensible heat of the exhaust gas by passing the above- mentioned exhaust gas through a specific heat resistant massive material. CONSTITUTION:The exhaust gas which is of a high temp. and contains a large amt. of the dust 20 from the prereducing furnace 2 is passed through a dust collector 3 from an inlet 6 and subjected to dust collection at the time of producing a molten iron from iron ore with the equipment provided with the prereducing furnace 2 and the smelting and reducing furnace 1. The central part 8 of a dust collector body 5 has the diameter larger than the diameter of an inlet 6 and outlet 7 for the exhaust gas and is partitioned by grid materials 9, 10 made of ceramics, in which many latent heat balls 11 formed by using a stainless steel and packing a CaCl2-NaCl material into the stainless steel bars are moved from above and below. The dust 20 in the exhaust gas sticks to the balls 10 and simultaneously, the balls 11 absorbs the sensible heat of the exhaust gas by a phase change. The dust 20 sticking to the balls 11 is separated by a sieving device 19 and is recovered into a hopper 22. The balls are put into storage tanks 26-28 where compressed air is fed to the balls 11 to release the absorbed heat of the balls. the absorbed heat is used to drive a gas turbine 42.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention is a melting process in which iron ore is blown into molten pig iron in a smelting furnace together with coal and lime, and oxygen gas is blown into the molten pig iron through a lance and a bottom tuyere. The present invention relates to reduction refining equipment, and more specifically, relates to a smelting reduction refining equipment that can collect dust in exhaust gas discharged from a smelting reduction furnace with high thermal efficiency.

[Prior art] The smelting reduction refining method is an alternative to the blast furnace iron manufacturing method, and in order to eliminate the disadvantages of the blast furnace iron manufacturing method, such as the high cost of setting up a blast furnace and the need for a vast site. , which has been developed in recent years. In such a smelting reduction smelting method, pre-reduced ore, powdered coal and lime are injected into the hot metal in the smelting furnace through a tuyere provided at the bottom of the furnace, and oxygen gas is injected through another tuyere. As well as blowing into hot metal,
Oxygen gas is blown onto the hot metal from the top of the furnace through a lance inserted into the furnace. Then, the coal is dissolved in the hot metal, and the ore is reduced by the carbon in the coal. Co gas generated from hot metal is secondary combusted by oxygen gas blown from a lance and becomes CO2 gas. This CO
The sensible heat of the two gases is transferred to the forming slag covering the hot metal, and then returned to the hot metal.

[Problems to be Solved by the Invention] Incidentally, in this smelting reduction process, dust is discharged from the smelting reduction furnace along with high-temperature exhaust gas, so it is necessary to remove this dust. Moreover, since the dust is generated in large quantities, conventionally the dust is removed using a Venturi scrubber or the like, which has high dust collection efficiency, before wet dust collection. However, in the case of deep wet dust collection, there is a problem that the energy of the exhaust gas cannot be effectively recovered because the heat loss caused by the water supplied during the dust collection process of the exhaust gas is large. That is, in the high temperature section, the radiant heat of the exhaust gas can be recovered, but the thermal energy of the exhaust gas is consumed by the supplied water, and it is difficult to recover sensible heat other than the radiant heat in the downstream section. To avoid this problem, use a high-performance dry filter such as a bag filter! However, these dry type dust collectors have a low heat resistance of about 300° C. and cannot be used to collect dust from high-temperature exhaust gas.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a smelting reduction fil equipment having high dust collection efficiency, low heat loss, and a collection am that can withstand high temperatures.

[Means for Solving the Problems] The smelting and refining equipment according to the present invention is a smelting and refining equipment that includes a smelting and reducing furnace and a dust collector that collects dust in the exhaust gas generated from the smelting and reducing furnace. The above-mentioned arbor device includes a device main body having an exhaust gas passage, a plurality of heat-resistant lumps filled in the device main body to collect dust in the exhaust gas, and a heat-resistant lump material filled in the device main body. a supply means for continuously supplying the heat-resistant material; a discharge means for continuously discharging the heat-resistant mass from the Vll basic body; and a separation means for separating dust collected in the exhaust gas passage from the heat-resistant mass. ,
It is characterized by having a heat recovery means for recovering thermal energy possessed by the bulk heat-resistant material after separation. In this case, it is preferable that the cross-sectional area of the central part of the exhaust gas passage in the apparatus main body is larger than the cross-sectional areas of the inlet and outlet, and the bulk heat-resistant material compensates for the thermal energy of the exhaust gas. It is preferable to have a substance that stores latent heat during change.

[Function] In this invention, when collecting dust in the exhaust gas generated from the smelting reduction furnace, the device body of the dust collector is filled with a lumpy heat-resistant material, and the lumpy heat-resistant material is continuously supplied by the supply means. The exhaust gas is supplied to the exhaust gas passage, and is continuously discharged from the apparatus main body by the exhaust means. By colliding the exhaust gas with this lumpy heat-resistant material,
Continuously removes dust from exhaust gas. Thereafter, the separating means separates dust from the lumpy heat-resistant material, and the heat recovery means recovers the thermal energy possessed by the lumpy heat-resistant material. In this way, dust can be collected in a dry manner, and furthermore, since the thermal energy of the bulk heat-resistant material is recovered by the heat recovery means after separating the dust, heat loss is small. In addition, since the bulk heat-resistant material is continuously supplied to the equipment body and discharged from the equipment body,
Dust collection efficiency is high. Furthermore, since high-temperature dust is attached to two heat-resistant materials, the heat-resistant temperature is high.

[Example] Fig. 1 is a schematic diagram showing a dust collector of a smelting reduction refining equipment according to an embodiment of the present invention, and Fig. 2 is a block diagram showing a smelting reduction refining equipment according to this embodiment.

High-temperature exhaust gas generated in the melting reduction furnace 1 is sent to the preliminary reduction furnace 2 and used for preliminary reduction of ore.

This forecast! ! The exhaust gas discharged from the reduction furnace 2 is supplied to the pre-dust collection stage 3 and sent to the downstream stage 4 after being sent to the east.

The main body 5 of the dust collector 113 has an exhaust gas inlet 6 and an exhaust gas outlet 7, and exhaust gas flows therein. The main body 5 is configured such that the cross-sectional area of the central portion 8 thereof is larger than the cross-sectional areas of the exhaust gas inlet 6 and the exhaust gas outlet lower part. In the central part 8 of the main body 5, ceramic grid members 9 and 10 are provided on the exhaust gas inlet 6 side and the exhaust gas outlet lower side, respectively, and latent heat balls are provided between the grid members 9 and 10. 11 is filled. This latent heat ball 11 is
The outside is covered with stainless steel, and the inside is CaC12-NaC.
It is filled with I-based material and has a diameter of 20 to 25 mm.
[It is 1111. When the high temperature exhaust gas flowing through the main body 5 collides with the latent heat ball 11, the dust 2o in the exhaust gas is attached and removed.

In this case, if the composition of the substance filled inside the latent heat ball 11 is 68% by weight of CaCl2 and 32% by weight of NaCl, this substance undergoes a phase change at 500°C, and the heat amount of the exhaust gas is reduced by the phase change. It is designed to be stored as latent heat. In this case, the heat storage layer has a capacity of 240 kilojoules per 1 kg of material, for example, about 10 kilojoules of ceramic, which has a relatively large heat storage capacity.
It has twice the heat storage l.

A hopper 12 is installed above the main body 5, and this hopper 12 has a valve 13, a sub-hopper 14, and a valve 1.
5 to the upper end of the central portion 8 of the main body 5.

Then, by opening the valves 13° and 15, the latent heat balls 11 are continuously supplied from the main hopper 12 to the central portion 8. Further, a valve 16 is provided at the lower end of the central portion 8, and when the valve 16 is opened, the latent heat balls 11 are continuously discharged from the central portion 8. In this case, by adjusting the opening degrees of the valves 13, 15, and 16, the amount of supply and discharge of the latent heat balls 11 can be adjusted. Sieve II is below valve 16! ! 1
9 is installed, and this sieve device 19 is covered with a sieve coarser than the dust 20. Then, the latent heat ball 11 with the dust 20 attached thereto is dropped onto this @l device 19, and the part is vibrated by a vibrator (not shown), for example, so that only the dust 20 is passed through the sieve of the sieving device 19. pass. In addition, each sieve device has a heat insulating cover 21 above it.
is installed, and this moisturizing cover 21 covers the latent heat ball 1.
1 to keep it warm. A hopper 22 is installed below the sieve member 19, and the hopper 22 stores the dust 20 after passing through the sieve. A sub-hopper 24 is installed below this hopper 22 via a valve 23, and a valve 24 is installed at the lower end of this sub-hopper 24.
5 is provided. Then, by adjusting the opening degrees of the valves 23 and 25, a predetermined amount of dust 20 is supplied to a transport means such as a truck, and this dust 20 is transported to a destination. Further, the sieve device 19 is inclined to one side, so that the latent heat balls 11 that do not pass through the sieve roll on it. storage tanks 26, 27, and 28. The passages of the latent heat balls 11 leading to the storage tanks 26, 27, and 28 are provided with pulps 29, 30, 31, respectively, and each valve is closed after each storage tank is filled with the latent heat balls 11. It has become. In addition, valves 32, 33, and 34 are provided at the lower end of each storage tank, and the latent heat balls 11 in each storage tank are provided with valves 32, 33, and 34, respectively.
33 and 34 are opened, the liquid is discharged from each storage tank and supplied to a conveyor (not shown), which returns the liquid to the hopper 12.

Save lil! Air compressed to a high pressure by a near compressor 35 is supplied into the tanks 26, 27, and 28. The latent heat balls 11 in each storage tank are cooled by contact with this high-pressure compressed air, undergo a phase change at 500° C., return to the original phase, and release the stored latent heat. The compressed air is heated to a high temperature by the apparent and latent heat released by the latent heat ball 11. At this time, this compressed air is supplied to each storage tank with the flow m being divided by iJ by valves 36, 37, and 38. The air heated by the latent heat balls to a high temperature and high pressure is passed from each storage tank to a valve 39°40.41
is introduced into the gas turbine 42 via the gas turbine 4
Drive 2. A generator 43 and the drive shafts of the near compressor 35 are connected to the drive shaft of the gas turbine 42, and the near compressor 35 and the generator 43 are driven by the gas turbine 42. Air exiting the gas turbine 42 is introduced into a heat exchanger 44 and used to generate high-pressure steam, and then is discharged outside the system.

In the smelting reduction refining equipment configured in this manner, the high temperature exhaust gas generated in the smelting reduction furnace 1 is used for reducing ore in the preliminary reduction furnace 2 and then supplied to the dust collector 3. '
At Jmm3, exhaust gas is introduced from the exhaust gas inlet 6 of the main body 5 and is supplied via the grid member 9 to the central portion 8 of the main body 5 filled with latent heat balls 11. In this central portion 8, dust 20 in the exhaust gas collides with and adheres to the latent heat ball 11, and the heat of the exhaust gas is stored in the latent heat ball 11 as latent heat due to phase change. Thereafter, this exhaust gas flows out from the exhaust gas outlet lower via the grid member 10 and is supplied to the lower process. On the other hand, by adjusting the valves 13, 15, and 16, the amount of latent heat balls 11 supplied from the hopper 12 and the amount m discharged from the center section 8 are adjusted, so that the latent heat balls 11 are placed at a predetermined level in the center section 8. Flow at speed. The latent heat balls 11 with the dust 20 attached thereto, discharged through the valve 16, are supplied onto a sieve device 19, and the dust 20 passes through the sieve and is separated from the latent heat balls 11.

The separated dust 20 is transported to a destination via a hopper 22, 24 by a transport means such as a truck. In this case, since the dust 20 is collected in a dry manner, the main component of the dust 20 is FeO.

In conventional wet dust collection, water is used, so the main component of the dust is Fe3O4, which is discarded without being used, but this FeO is used in high-grade magnetic materials and the like.

The latent heat balls 11 discharged from the central part 8 are dust 20
After being separated, it rolls on the sieving device 19 and passes through the valve 29.
30.31 to the storage tank 26°27.28. In this case, the valves 32, 33, 34 are kept closed and each reservoir is filled with a latent heat ball 11. Each storage tank is then supplied with highly compressed air via valves 36, 37, 38, which compressed air
1 and is supplied to the gas turbine 42 through valves 39, 40, 41 at high temperature and pressure. The turbine 42 is driven by this high-temperature, high-pressure air, and the sensible heat of this high-temperature, high-pressure air is recovered as driving energy for the turbine. Gas turbine 42 drives near compressor 35 and generator 43. Then, this power generation 15143 recovers the sensible heat of the high-temperature, high-pressure air as electric power. Compressed air exiting the gas turbine 42 is supplied to a heat exchanger 44, and its sensible heat is recovered as high pressure steam.

Thereafter, valves 32, 33, 34 are opened and storage tank 26
．． 27. The cooled latent heat ball 11 is discharged from 28. The discharged latent heat balls 11 are returned to the hopper 12 by a conveyor (not shown) and are used for subsequent dust collection.

As described above, since the dust is collected in a dry manner and the thermal energy of the latent heat ball 11 is recovered as electric power and high-pressure steam, the heat loss of the exhaust gas is small. Furthermore, since a latent heat ball filled with a substance that undergoes a phase change at 500°C is used, a large amount of the thermal energy of the exhaust gas can be stored as latent heat during phase change, reducing thermal loss. . In addition, since the latent heat ball 11 continuously moves within the central portion 8 of the main body 5, dust 20 is always present at the exhaust gas collision portion within the central portion 8.
It is possible to supply latent heat balls 11 to which no particles are attached, and the dust collection efficiency is high. Moreover, since the cross-sectional area of the central part 8 is larger than the cross-sectional area of the exhaust gas population 6 and the outlet lower,
The flow velocity of the exhaust gas in the central portion 8 is reduced, and the dust collection efficiency can be further increased. Furthermore, since the high-temperature dust 20 is attached to the latent heat ball 11, which has a high heat-resistant temperature, the heat-resistant temperature is high.

In this embodiment, latent heat balls were used to collect dust in the exhaust gas, but the present invention is not limited to this, and any lumpy heat-resistant material such as ceramic balls may be used. Further, the substance to be filled inside the latent heat ball is not limited to that shown in this embodiment, and any substance may be used as long as it can store the thermal energy in the exhaust gas as latent heat accompanying a phase change.

[Effects of the Invention] According to the present invention, the device body of the dust collector is filled with a lumpy heat-resistant material, and the lumpy heat-resistant material is continuously supplied to the device main body by the supply means, and is continuously fed by the discharge device. After the dust in the exhaust gas is removed by colliding with the lumpy heat-resistant material in the device body, the dust is separated from the lumpy heat-resistant material by the separation means, and the heat of the lumpy heat-resistant material is removed by the heat recovery means. Recover energy. Therefore, the dust can be collected in a dry manner, and the heat energy of the bulk heat-resistant material can be recovered, so that the heat loss of the exhaust gas can be reduced. Further, since the bulk heat-resistant material is continuously supplied to the apparatus main body and discharged from the apparatus main body, dust collection efficiency can be improved.

Furthermore, since the high-temperature deaf is attached to a heat-resistant material, the heat resistance is high.

Since the collected dust has FeO as its main component, this dust can be effectively used as a highly tractable magnetic material.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing a dust collector in a smelting reduction refining facility according to an embodiment of the present invention, and Fig. 2 is an actual tM of the present invention.
It is a block diagram showing the smelting reduction refining equipment concerning PiII. 1; Melting reduction furnace, 3; Collection Wfl, 5; Main body, 6: Exhaust gas inlet, 7; Exhaust gas outlet, 11: Latent heat ball, 12.14
, 22.24; Hopper, 13, 15° 16.23.25
．． 29, 30.31, 32° 33.34, 36.37,
38, 39.40° 41; Valve, 19; Sieve device, 26
, 27. 28; storage tank, 35; near compressor, 42
Gas turbine, 43; Generator, 44; Heat exchanger Applicant's representative Patent attorney Takehiko Suzue Figure 1 Figure 2

Claims (3)

[Claims] (1) In a smelting reduction refining facility that includes a smelting reduction furnace and a dust collector that collects dust in the exhaust gas generated from the smelting reduction furnace, the dust collector has an equipment main body that has an exhaust gas passage. , a plurality of heat-resistant lumps filled inside the apparatus main body to collect dust in exhaust gas; a supply means for continuously supplying the heat-resistant lumps to the apparatus main body; and a supply means for continuously supplying the heat-resistant lumps to the apparatus main body. a separation means for separating dust collected in the exhaust gas passage from the bulk heat-resistant material; and a heat recovery means for recovering thermal energy possessed by the bulk heat-resistant material after separation. A smelting reduction refining facility characterized by having. (2) The apparatus main body is characterized in that the cross-sectional area of the central part of the exhaust gas flow path is larger than the cross-sectional area of the inlet and outlet thereof. Refining equipment. (3) The smelting reduction refining equipment according to claim 1 or 2, wherein the bulk heat-resistant material includes a material that stores thermal energy of exhaust gas as latent heat during phase change.