JPH01111807A - Circulating fluidized bed prereduction apparatus - Google Patents

Abstract

PURPOSE:To facilitate control of circulating quantity of injection gas by standing a blowing nozzle for reduction gas at bottom of a reduction furnace and arranging a blowing nozzle for control gas as slidable from side part in horizontal zone of a settling toward. CONSTITUTION:An outer part grain circulating device is constituted by connecting the settling tower with the fluidized bed reduction furnace 6. The blowing nozzle 38 for reduction gas is standed at the bottom of the reduction furnace 6 and the blowing nozzle 12 for control gas is arranged from said part at the lower part of the settling toward 10. The blowing nozzle 12 for control gas is arranged so as to give lap length (l) in the horizontal zone 10 of the settling tower 10 and made to slidable in the settling toward 10 by horizontal driving device 16 to optionally control the circulating flow of the control gas. The fluidized bed is formed by blowing the reduction gas from the nozzle 38, and by generating reducting action, the filling layer is formed in the settling toward 10. By this method, the circulating control in the fluidized bed prereduction apparatus for fine powdery iron is facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a fluidized bed pre-reduction furnace for iron ore used in a smelting reduction process.

[Prior Art] In order to reduce iron ore to produce hot metal, methods such as using a blast furnace and melting iron ore reduced in a shaft furnace in an electric furnace have been adopted.

In the method using a blast furnace, a large amount of coke is used as a heat source and a reducing agent, and iron ore, which is an iron source, is usually sintered to improve air permeability and reducibility in the furnace.
It is charged into a blast furnace as sintered ore.

Therefore, the blast furnace method requires not only large equipment costs but also
It requires a lot of energy and labor.

On the other hand, the method of reducing iron ore using a shaft furnace requires pretreatment to pelletize the iron ore, and has the disadvantage that it consumes a large amount of reducing agent and expensive natural gas as a heat source.

As an alternative to such conventional hot metal production techniques, the smelting reduction method is attracting attention. The smelting reduction furnace used in this method was developed for the purpose of producing molten iron-based alloys using smaller-scale equipment without being restricted by the raw materials used.

The present inventors previously proposed one of such melt reduction methods in JP-A-61-64807.

Furthermore, the present inventors proposed a preliminary reduction device as shown in FIG. 3 in Japanese Patent Application No. 61-286599.

That is, the fluidized bed reduction furnace is attached to an external particle wi ring device,
In the configuration of this external particle circulation device, a cyclone 31 is connected to an outlet provided at the upper part of the fluidized bed reduction furnace 6, and fine particles that are scattered along with the reducing gas 11 are captured.

A hopper 32 for temporarily storing captured particles is connected to the lower part of the cyclone 31. The hopper 32 temporarily stores the captured particles, and a predetermined amount is returned to the fluidized bed reduction furnace 6 by a circulation cutting device 33.

On the other hand, there are a plurality of gas outlets 34 inside the fluidized bed reduction furnace 6.
．． 35 is formed. This gas outlet 34.35
A bubbling fluidized bed 36 is formed in the middle of the bubbling fluidized bed 7136, and a circulation outlet of the external particle circulation device is provided in this bubbling fluidized bed 7136.

In addition, a packed bed 37 is formed at the bottom of the fluidized bed reduction furnace 6,
A furnace bottom blowing nozzle 38 is provided within the packed bed 37 .

In the figure, 39 is a cut-off valve for charging the raw material 25 such as fine ore or limestone into the fluidized bed reduction furnace 6, and 40, 41, and 42 are valves for adjusting the amount of reducing gas blown out. J! ] Seben,
43 is a cutting valve for fine-grained reduced ore, and 44 is a cutting valve for group-sized reduced ore.

(Problems to be Solved by the Invention) The present invention provides a device that allows easy control of the circulation amount in a fluidized bed preliminary reduction device for finely powdered iron powder.

(Means for Solving the Problems) The present invention provides facilities for producing reduced ore, in which an external particle circulation device is attached to a fluidized bed reduction furnace, a sedimentation tower is provided in the external particle circulation device, and a horizontal A region is connected to the fluidized bed reduction furnace, and a reducing gas injection nozzle is erected at the bottom of the reduction furnace, and a control gas is provided in the horizontal region of the sedimentation tower with a lap length l with the horizontal region. This is a circulating fluidized bed pre-reduction device in which a blowing nozzle or a group of blowing nozzles are slidably installed horizontally.

The present invention will be explained below with reference to the drawings.

FIG. 1 is an overall view of the present invention, and FIG. 2 is an explanatory view of the main parts of the present invention. In FIG.

The upper part of the settling tower 6 communicates with the cyclone 31 and is provided with a system for separating gas and reduced iron powder.

The lower part of the settling tower 10 forms a horizontal region 13 and is integrated with the lower part of the fluidized bed reduction furnace 6 .

A reducing gas blowing nozzle 38 is installed upright at the bottom of the reduction furnace 6, and a control gas blowing nozzle 12 is installed horizontally at the bottom of the settling tower 1O.

As shown in FIG. 2, the control gas blowing nozzle 12 is provided with a wrap length l relative to the horizontal area 13 of the settling tower 10, and is slidable within the settling tower 10 by a horizontal drive device 16. 1
5 is a full hose, and 44 is a reduced iron powder outlet.

Therefore, according to the present invention, in the fluidized bed reduction furnace 6, reducing gas is blown from the reducing gas injection nozzle 38 to form a fluidized bed, which is subjected to a reducing action and filled into a settling column.
Form i45.

A packed layer of reduced iron powder is formed in the horizontal area of the settling tower, and a control gas is blown into the horizontal area from a control gas injection nozzle to provide a circulating flow.

Although only one control gas blowing nozzle is shown in FIGS. 1 and 2, the same applies to a case where a plurality of control gas blowing nozzles are used.

According to experiments, the circulating flow can be arbitrarily controlled by varying the lap length l with respect to the nozzle length in the horizontal region.

(Effect of the invention) The present invention provides a horizontal section at the lower part of the circulating fluidized bed (between the settling column and the reduction reaction column), and the horizontal section regulates the flow of the contents from the settling column to the reduction reaction column. A nozzle that ejects in the horizontal direction is installed in the horizontal part to provide a circulation force, and the length of insertion of this ejecting nozzle into the horizontal part can be varied, so the circulation amount can be controlled by the position of the ejecting nozzle and the amount of gas ejected. It is easy to do.

[Brief explanation of the drawing]

FIG. 1 is an overall explanatory diagram of the present invention, FIG. 2 is an explanatory diagram of the main part of FIG. 1, and FIG. 3 is an explanatory diagram of a conventional example. 6: Fluidized bed reduction furnace 10: Sedimentation tower, 13: Horizontal area, 12: Control gas blowing nozzle. Agent Patent Attorney Tate Chanogi Mistakes Figure 3 ＋＋ 71 17 Figure 1 Figure 2 ↑ Dynamic layer concentration source, 11 situation Descending tower 11Ja gas blowing nozzle horizontal area reducing gas blowing nozzle

Claims (1)

[Claims] In a facility for producing reduced ore, an external particle circulation device is attached to a fluidized bed reduction furnace, a settling tower is provided in the external particle circulation device, a horizontal area is provided at the bottom of the settling tower and connected to the fluidized bed reduction furnace, A circulating flow system in which a reducing gas blowing nozzle is erected at the bottom of the reduction furnace, and a control gas blowing nozzle having a wrap length l with the horizontal area of the settling tower is slidably installed horizontally in the horizontal area of the settling tower. Layer pre-reduction device.