JPS5939153Y2 - Blast furnace top pressure power recovery device using dry dust remover - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a blast furnace top pressure power recovery device using a dry dust remover.

The conventional blast furnace top pressure power recovery device is as shown in Figure 1.
B at approximately 130°C to 150°C discharged from the top of blast furnace 1
The gas passes through a coarse dust remover (dust catcher) 3 installed in the gas path 2 and is then sent to a venturi scrubber or wet EP.
(electrostatic precipitator) or other wet type dust remover 4.

After the furnace top pressure is adjusted by a septum valve (furnace top pressure adjustment valve) 5, it is led to a gas holder 6.

Reference numeral 7 denotes a power generation facility installed in parallel with the septum valve 5, which is always connected to the in-house power grid and has a heavy load. B gas is supplied to the inlet cutoff valve 10j through the vane 4f11, and after driving the gas turbine 9, the B gas is returned to the outlet side of the septum valve 5 through the outlet cutoff valve 12.

Such conventional devices are used in the following two ways.

0 Moist B gas at 40°C to 60°C from wet dust remover 4 is heated to about 120°C to 140°C for partial combustion of B gas.
to raise the temperature and guide it to the turbine 9.

This raises the gas temperature sufficiently to prevent moisture condensation within the turbine 9 and prevents dust from accumulating on the turbine blades.

0 The wet B gas from the wet dust remover 4 is guided directly to the turbine 9.

The idea is to wash away the dust with water droplets, so
In order to prevent water droplets from attacking the blade material, considerations are taken such as eliminating stationary blades in a radial flow turbine, although this is less efficient, and using multiple stages in an axial flow turbine, although it is more expensive, to reduce the relative speed. .

In any of the above-mentioned embodiments, since power is recovered from the B gas after passing through the wet dust remover 4, the B gas has already been cooled, so it cannot be said to be an effective power recovery method.

As mentioned above, B gas is discharged from the top of the furnace at a temperature of 130°C to 150°C, so if it can be guided to turbine 9 at this temperature, the recovered power at this turbine 9 will be 2.
Increases from 0 to 35%.

Therefore, instead of the wet type dust remover 4 shown in Fig. 1, a dry type EP
It is possible to use a dry dust remover such as a bag filter or a bag filter.

However, such dry dust removers are generally not suitable for high temperatures;
The blowing waves of the blast furnace 1 cannot withstand the high temperatures (gas temperature rises from 500°C to 7'O0°C).

Another dry dust removal method uses granular solids such as sand as a filtration layer, but there are considerable technical problems in filtering fine and sticky dust such as blast furnace dust. .

Therefore, the present invention provides a blast furnace top pressure power recovery device that can solve the above problems while using a dry dust remover such as a dry EP or a bag filter. 〜Explained based on FIG. 6.

In FIG. 2, the same reference numerals as in the conventional example (FIG. 1) indicate the same components.

In other words, 1 is a blast furnace 3 is a coarse dust remover, 5 is a septum valve, 6 is a gas holder, 7 is a power generation equipment, 8 is a generator, 9 is a gas turbine, 10 is an inlet shutoff valve, 11 is a turbine cabana valve, and 12 is a Each outlet isolation valve is shown.

In the present invention, a dry dust remover 13 such as a dry EP or a bag filter is provided in place of the conventional wet dust remover.

A cooling fluid supply path 15 having a valve 14 is provided, and a sensor 16 for detecting abnormal temperature is provided near the gas outlet of the dry dust remover 13.

This abnormal temperature detection sensor 16 emits a signal 17 when the B gas discharged from the dry dust remover 13 reaches a set temperature or higher, and the pulp 14 is thereby activated and the solid line shown in Figures 2 and 3 is activated. As shown in FIG.
8, or from the first cooling fluid injector 19 installed at the blast furnace top 1A as shown in the phantom line in FIG. The cooling fluid 20 is injected toward the.

As shown in FIGS. 2 and 4, a passage 18B is provided in the piping 18 near the entrance to the dry dust remover 13, in which the B gas travels or flows straight from the top to the bottom and then reverses. , a second cooling fluid injector 21 is provided upstream of this gas reversal location A.

Simultaneously with the aforementioned opening movement of the pulp 14, the cooling fluid 20 is injected from the second cooling fluid injector 21.

The B gas is cooled by the cooling fluid 20 injected from both injectors 19,21.

The reason why the button abnormal temperature detection sensor 16 is provided downstream of the dry dust remover 13 is to prevent the sensor 16 from being covered with dust and causing a time delay in abnormal temperature detection.

That is, for example, if the amount of dust upstream of the dry dust remover 13 is 3 to 10? At 1Nm3, the amount of dust downstream is 10 mVNm3 or less.

In addition, as shown in FIG. 5, the pipe 2 from the dry dust remover 13
The temperature measuring section 23 of the sensor 16 provided in the sensor 2 is directly exposed to the B gas so that there is no time delay in temperature detection.

The time delay (within 2 seconds) caused by providing the sensor 16 after the dry dust remover 13 does not substantially pose any problem.

That is, since the time delay in cooling fluid injection 1 from below the set temperature is also within 1 second, the total time delay is about 3 seconds.

In addition, the initial temperature rise in the atrium is at most 15°C/second,
During a total time delay of approximately 3 seconds, the gas temperature increases by only 45°C.

Now let's consider a bag filter with a maximum operating temperature of 240°C.

When the set temperature is 170°C, the gas temperature when injecting the cooling fluid 20 is the highest, [170°C + 45°C = 215°C]
This is a value sufficiently lower than the maximum operating temperature.

When the temperature detected by the sensor 16 becomes lower than the set temperature, the signal 17 will no longer be generated, the valve 14 will close, and the injection of the cooling fluid 20 will be stopped.

As the cooling fluid 20, a cooling gas using sensible heat and a cooling liquid using latent heat are used.

Cooling gas has the advantage that there is no need to worry about B gas becoming wet, and (a) water vapor of 3 to 6 atg, (b) H2,
Inert gas such as CO2, reducing gas such as (c) B gas, C gas (coke oven gas), etc. are used.

In addition, the cooling liquid must be completely evaporated in the B gas before it reaches the dry dust remover 13 in order to prevent the dust from caking. Fuel, etc. are used.

In the case of (e), when both fuels are used, the injected fuel evaporates and mixes with the B gas, temporarily increasing the calorific value of the B gas and causing no loss.

In this case, the piping is smaller and the power required for injection is smaller than in the case of cooling with cooling gas.

The positions of the two cooling fluid injectors 19 and 21 are such that, for example, the injected droplets roar on the wall of the pipe 18 and become coarse, and enter the dry dust remover 13 unevaporated, causing dust to stick to the dust remover element. Care must be taken not to cause damage or deterioration of the element material.

From this point of view, the most desirable option is to attach the injector 19 to the base 18A1 of the blast furnace riser pipe as shown by the solid line in FIG. 3 or to the blast furnace top 1A as shown by the phantom line in FIG. shall be.

In this way, the coarse droplets fall onto raw materials such as coke and ore and evaporate naturally.

This type is suitable when the distance from the top of the blast furnace to the dry dust remover 131 is relatively short.

Generally, as shown in Fig. 4, B gas flows downward in the upper area in a pipe 18 leading to the single blast furnace dry type dust remover 13, and then reverses and flows upward.
B is provided, and an injector 21 is provided above the location A where the B gas starts to reverse, so that coarse droplets are separated by the inertia of the droplets at the location A where the B gas begins to reverse. Look.

In this way, coarse droplets will not be scattered downstream,
It is stored at the bottom of the reversal location A and gradually falls naturally.

As shown in FIG. 6, the position of the abnormal temperature detection sensor 16 is as shown in FIG.
The car is heavy to position 3.

According to the present invention described above, the following effects can be expected.

(b) The fine dust remover is a dry type and does not use cleaning water for dust removal, so the thermal energy of the blast furnace gas generated from the top of the blast furnace is hardly lost during dust removal, and the The high temperature gas discharged from the turbine can be guided to the turbine 11, increasing the amount of energy recovered by the turbine on the downstream side.

Moreover, even after dust removal, clean gas (even though it is called clean, it is 5m9/N)
Contains about m3 of dust.

) is dry, so it does not cause corrosion to the various equipment installed on the downstream side (turbine, valves, piping, various detectors, etc.). Since it does not adhere to the turbine blades, troubles can be minimized.

(b) Since the dust remover is a dry type, the dust can be removed, eliminating the need for large and expensive thickeners and water treatment equipment that would be required in the case of a wet type that generates a large amount of sewage.

(c) When the gas temperature becomes abnormally high due to a blow-through of the blast furnace, a sensor detects the initial temperature of the abnormally high temperature, and cooling fluid is supplied into the blast furnace to cool the gas from the blast furnace. After that, the temperature will be lowered, and an adverse effect on the dry dust remover can be prevented.

2) Since the gas is not cooled during normal blast furnace operation, the high-temperature gas discharged from the top of the furnace can be directly guided to the turbine, increasing the amount of energy recovered by the turbine.

(e) By installing the abnormal temperature detection sensor near the gas outlet of the dry dust remover, there is no wear due to dust, so the temperature measuring part can be directly exposed to the blast furnace gas without a protection tube, and therefore there is less detection delay. Be accurate.

Furthermore, as mentioned above, since the blast furnace gas is dry, even the slightest fine dust in the gas will not adhere to the temperature measurement unit, making it possible to accurately detect abnormal temperatures (quickly) without time delay. can.

(f) Since the first cooling fluid injector is installed at the top of the blast furnace or at the base of the rising tube plate, and the injection direction is directed into the blast furnace, the coarse droplets of the cooling fluid used for cooling the high-temperature gas, for example, are The droplets fall onto raw materials such as ores and evaporate naturally, which causes the droplets to become coarse and unevaporated 11
This prevents dust entering the dry dust remover from sticking to the dust remover element and deteriorating the element material, and also prevents the gas from flowing downward in the upper area in a circular or straight direction through the second cooling fluid injector. Since it is provided on the upstream side of the place where it will be turned over later, the droplets will be separated by inertia, and therefore, an adverse effect on the dry type dust remover can be prevented.

Furthermore, since it evaporates naturally, inexpensive water can be easily used as the cooling fluid.

[Brief explanation of the drawing]

Fig. 1 is a system diagram showing a conventional example, Figs. 2 to 6 show an embodiment of the present invention, Fig. 2 is a system diagram, Fig. 3 is an enlarged view of the injector installation part, The figure is an enlarged view of the dry dust remover, Figure 5.
FIG. 6 is an enlarged view of each sensor arrangement section. DESCRIPTION OF SYMBOLS 1... Blast furnace, 1A... Blast furnace top, 7... Power generation equipment, 9... Gas turbine, 13... Dry dust remover, 15
...Cooling fluid supply path, 16...Sensor for detecting abnormal temperature, 18A...Rising tube machine base, 18B...
Passage, 19... First cooling fluid injector, 21... Second cooling fluid injector, 20... Cooling fluid, A... Gas reversal location.

Claims (1)

[Scope of utility model registration request] 11 The pressure of the gas coming out of the blast furnace was kept almost constant.
A first cooling fluid injector is provided at the top of the blast furnace or at the base of the rising tube plate, and the blast furnace In the gas path including the coarse dust remover leading to the Eri dry type dust remover, a path is provided in which the gas flows downward from above, swirling or going straight, and then reverses. Two cooling fluid injectors are provided, and an abnormal temperature detection sensor is provided near the gas outlet of the dry dust remover, and when the abnormal temperature detection sensor detects a temperature equal to or higher than a set temperature, cooling fluid is injected from both injectors. A blast furnace top pressure power recovery device using a dry dust remover characterized by the following configuration.