JPS59211513A - Blowing device for fine powder fuel to blast furnace - Google Patents

Abstract

PURPOSE:To use effectively the space around a blast furnace by installing a fine grinding, classifying and capturing installation, the 1st storage tank and a feed tank in the place apart from the blast furnace and installing a distributor and succeeding apparatus around the body of the blast furnace. CONSTITUTION:A fine grinding, classifying, and capturing installation 1, the 1st storage tank, 3 and a feed tank 17 are installed within a zone (1) apart from a blast furnace 15 by averting the narrow space around the furnace 15. The succeeding distributor 27, the 2nd storage tanks 29A, B, intermediate tanks 31A, B, feed tanks 33A, B, diffusers 35A, B, etc. are installed around the body of the furnace 15 to use deffectively the space around the furnace 15.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pulverized fuel handling device, and more particularly to a pulverized fuel handling device that is capable of injecting pulverized coal into a blast furnace to replace a portion of the normally used coke. The present invention relates to a feeding device.

Figure 1 is a conceptual diagram of a conventional pulverized fuel feeding device to a blast furnace disclosed in Japanese Patent Publication No. 51-29684, which feeds an equal amount of pulverized fuel to multiple blast tuyeres of a blast furnace. This is a device that can do this.

This device will be briefly explained with reference to FIG. First, the coal pulverization equipment and the fine powder classification and collection equipment are collectively indicated by the reference numeral 1 in this figure. The coal is pulverized into one classification, and the fuel is pulverized in the collection equipment 1, which passes through a valve 2 and is stored in a storage tank 3.
By opening the valve 4A in one of the supply tanks (5A or 5B) (usually 2 or 3) (temporarily set to 5A in this case), the pulverized fuel can be discharged by its own weight. Use and supply. Next, the valve 4A is closed and high-pressure inert gas is introduced into the supply tank 5A (not shown in this figure), and the pressure inside the supply tank 5A is increased to a pressure adjusted according to the blowing pressure to the blast furnace 15. . When the supply of pulverized fuel from another supply tank (5B here) to the blast furnace 15 is completed, the valve 6A is opened, and the pulverized fuel in the supply tank 5A is fluidized and the dense phase is transferred by pressure. It is then cut out and introduced into the disperser 7. On the other hand, the high-pressure conveying gas is communicated through the valve 8 to the distributor 7, where the pulverized fuel is mixed and diluted with the conveying gas to form a solid-gas two-phase flow, and the distributor is installed near the blast furnace. It is transported through a single transport pipe 9 up to lo. A mixed flow of pulverized fuel and gas enters the distributor 1o from the lower end thereof and is diffused within the distributor 10 in a manner corresponding to the number of blowing tuyeres of the blast furnace 15 disposed on the same plane of the cylindrical portion of the distributor 1o. The mixed flow of pulverized fuel and gas distributed to each tuyere line IIA-lln is distributed to each tuyere line 11A.

11B, -1In through the blowing tuyere 12A, 1
2B.

. . 12n, and is mixed with high temperature air supplied through the hot air annular pipe 13, the blower branch pipes 14A, 14B, . . . 14n at the core, and burned.

This method uses multiple air tuyeres 12A, 12B...1
It is an extremely reliable and rational method because it is possible to feed an equal amount of pulverized fuel to 2n and does not use a mechanical distribution device that involves rotation or the like.

However, multiple air tuyeres 12A, 12B...1
In order to feed an equal amount of pulverized fuel to 2n, each tuyere line 11A after the distributor 10.

It is a prerequisite that the pressure drop of the solid-gas two-phase flow within 11B...lln be approximately the same.

Generally, the space around a blast furnace is narrow due to the furnace body cooling piping (not shown), various in-furnace detection devices, casthouse building, etc., and the tuyere lines IIA, IIB...11n, which feed pulverized fuel, are used to completely absorb the pressure drop. Tuyere line 11A.

Designed to be almost the same as 11B...lln.

It is extremely difficult to construct. Further, the problem is complicated by the fact that the pressure at the tips of the blast tuyeres in the blast furnace 15 is not constant at all the tuyeres. On the other hand, with the remarkable progress in blast furnace operating technology in recent years, various attempts have been made to improve productivity by controlling the circumferential heat balance within the blast furnace.

Under these circumstances, the amount of pulverized fuel supplied to the tuyeres 11
If it is possible to control each of A, IIB...lln independently, the system can be achieved by equally distributing to all the air tuyeres 11A, 11B...11n and changing the blowing amount for each air tuyere. This is an extremely effective method since it is possible to control the heat balance in the circumferential direction within the blast furnace 15.

For this reason, the present invention provides an apparatus that can easily and reliably control the amount of pulverized fuel supplied for each blowing operation.

The content of the present invention will be explained below with reference to FIG. First, the coal pulverization equipment, fine powder classification, and collection equipment are collectively shown as 1 in this figure. The coal is pulverized into one classification and the fuel pulverized in the collection equipment 1 passes through a valve 2 and is stored in a first storage tank 3.

Next, when the weighing device 25 attached to the feed tank 17 detects that the pulverized fuel in the feed tank 17 has reached the lower limit level, the exhaust pressure valve 22 opens and the pressure in the feed tank is reduced to atmospheric pressure. Then, the vent valve 16 opens and the pulverized fuel is supplied to the feed tank using its own weight. When the scale 25 detects that the pulverized fuel has reached the upper limit level of the feed tank, the valve 23 opens the furnace and the pressure inside the feed tank is increased to a predetermined value using inert gas. While fluidizing with active gas, the valve 18 is opened to cut out the pulverized fuel in a dense phase state and guide it to the first disperser 19. A distributor installed near the blast furnace in which high-pressure conveying air is communicated through the one-way valve 20 to the first distributor 19, where the pulverized fuel is mixed with the conveying gas and diluted to form a solid-gas two-phase flow. Single conveyor pipe 26 to 27
Transport inside.

A mixed flow of pulverized fuel and gas enters the distributor 27 from its lower end and is diffused within the distributor 27. The branch pipe corresponds to the number of blast tuyeres of the blast furnace 15 arranged on the same plane of the cylindrical portion of the distributor 270. It is distributed to 28A, 28B...28n. The distributed pulverized fuel is stored together with the conveying air in second storage tanks 29A, 29B, .
Sent to 9n, bag filter-38A, 38B...3
Solid-gas separation is performed at 8n, and the conveyed air is released into the atmosphere, and only the pulverized fuel is stored in the second storage tanks 29A, 29B...29n.
can be stored in Next, intermediate tanks 31A, 31B...3
A weighing device 44A, 44B, . . . , 44 attached to the intermediate tank indicates that the pulverized fuel in 1n has reached the lower limit level.
When detected by n, the exhaust pressure valves 39A and 39B-39n open to lower the pressure inside the intermediate tank to atmospheric pressure, and the exhaust valve 30
A, 30B...30n are opened and pulverized fuel is supplied to intermediate tanks 31A, 31B...31n using their own weight. The pulverized fuel is in the intermediate tank 31A.

When the scales 44A, 44B-44n detect that the upper limit level of 31B...31n has been reached, the valve 40
A.

40B...40n is opened and the intermediate tank 3 is filled with inert gas.
1A, 31B...31n supply tank 33A
, 33B...raise to the same value as in 33n, valves 41A, 4
1B...The intermediate tank 31A is fluidized with an inert gas introduced through 41n.

Supply tank 33 installed at the bottom of 31B...31n
A, 33B... When the fine powder fuel in 33n falls below a preset level, the valves 32A, 32B...
32n and pour the pulverized fuel into the intermediate tank 31A.

31B...31n to supply tanks 33A, 33B...
・Supply to 33n. Supply tanks 33A, 33B...
33n is maintained at a pressure corresponding to a preset amount of pulverized fuel injected by introducing inert gas through valves 42A, 42B, . . . , 42n, and valve 43A.

The pulverized fuel is cut out in a dense phase state through the valves 34A, 34B...34n while being fluidized with an inert gas introduced through the valves 43B...43n, and the second disperser 35A
, leading to 35B-35n. Valve 36A.

36B...36n to communicate high-pressure conveying air to the disperser, where the pulverized fuel is mixed with the conveying air,
The tuyere lines 37A, 3 are diluted and made into a solid-gas two-phase flow state.
7B...37n is conveyed, and the ventilation tuyere part no burner 12
Blow into the blast furnace 15 from A, 12B...12n.

By employing such a device, it is possible to arbitrarily change the amount of pulverized fuel blown into a specific blower.

For example, if it is desired to increase the amount of air blown into the air tuyeres of the A system compared to other tuyeres, this can be done by increasing the pressure in the supply tank 33A to a pressure corresponding to the predetermined amount of blown air. The amount of pulverized fuel blown into the blower can be detected by the rate of weight loss measured by a weighing device 45A attached to the supply tank 33A.

Alternatively, in the process of supplying pulverized fuel from the intermediate tank 31A to the supply tank 33A, the sum of the values measured by the weighing device 44A attached to the intermediate tank 31A and the weighing device 45A attached to the supply tank 33A. It can be detected by the rate of weight loss.

When controlling the blowing amount for each blowing tuyere, the amount of pulverized fuel stored in the second storage tanks 29A, 29B, . . . , 29n may differ between the storage tanks. There is no operational problem if the capacity of the second storage tanks 29A, 29B, . In such a case, a level meter is installed in the second storage tank, and for the tuyere system in which pulverized fuel is stored up to a predetermined level, valve 46A installed in the branch pipe (for example, 28A) of that system is closed to remove the pulverized fuel. It is also possible to cut off the fuel supply. In addition, a second storage tank 29 after the distributor 27, an intermediate tank 31,
The system of the supply tank 33 and the second distributor 35 is connected to the blast furnace 150.
The explanation was given by providing the same number of tuyeres as the number of tuyeres, but considering the economic efficiency of equipment costs, multiple tuyeres were installed together (for example, 2 to 4 tuyeres).
second storage tank 29 with a corresponding number of systems;
It is also possible to provide an intermediate tank 31 and a supply tank 33 and branch them to each tuyere in the middle of the tuyere inlet 37 after the disperser 35.

This device performs fine pulverization as shown in zone ■ in Figure 2.

The classification and collection equipment, the first storage tank 3, and the feed tank 17 can be installed in a place away from the blast furnace to avoid the narrow space around the blast furnace 15. By installing it around the furnace body of No. 15, the space around the blast furnace can be used effectively, which is an extremely excellent effect.

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram of a conventional system for feeding pulverized fuel to a blast furnace, and FIG. 2 is a conceptual diagram of an apparatus according to the present invention. Patent applicant Nippon Steel Corporation

Claims (1)

[Claims] A first storage tank stores solid fuel that has been pulverized by a crusher, classified, and collected, and a pulverized fuel that is intermittently cut out by gravity from the second storage tank and is turned into an inert gas. a feed tank that pressurizes and cuts the fuel while fluidizing it; a first disperser that dilutes and conveys the pulverized fuel cut out from the feed tank with air; a distributor that conveys the pulverized fuel in a solid-gas two-phase flow state in a conveying pipe and evenly distributes the pulverized fuel to each blowing section of the blast furnace; a second storage tank that stores the pulverized fuel distributed by the distributor; A second storage tank is intermittently evacuated to receive pulverized fuel;
Furthermore, there is an intermediate tank that fluidizes and pressurizes with inert gas in order to cut into the supply tank, a supply tank that supplies pulverized fuel with a predetermined sound level to the blast furnace, and a second disperser that dilutes and conveys it with air. A device for injecting pulverized fuel into a blast furnace, characterized by comprising: