JPH09194921A - Connecting tube for fluidized bed reduction furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a connecting tube, in which particles are not intruded, as the connecting tube for a fluidized bed reduction furnace. SOLUTION: The tip end part of the connecting tube 12 inside the fluidized bed reduction furnace is formed as a cylindrical shape sealing porous state tip part, and a flange 17 is arranged outside the furnace of the connecting tube 12, and this connecting tube is connected with a connecting tube 18 at the outside of the furnace. In the connecting tube 18 at the outside of the furnace, a purge pipe 20 for purging the tip end is arranged and a stop valve 21b for shutting off a pressure sensor at the time of purging to constitute the connecting tube in the fluidized bed reduction furnace.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluidized bed reduction apparatus for reducing ore, reduction of iron making dust, dezincification, etc., and more particularly to a pressure guiding tube of a pressure sensor of a furnace.

[0002]

BACKGROUND ART A smelting reduction method has been developed as an alternative to the conventional iron making technique using a blast furnace or the like. This method
In order to effectively use the exhaust gas generated in the smelting reduction furnace,
The exhaust gas is injected as a fluidizing gas into a fluidized bed reduction furnace to preheat or pre-reduce the ore (JP-A-56-105).
No. 409).

Further, it has been proposed to treat iron-making dust in a fluidized bed reduction furnace in order to remove zinc, lead and the like in the iron-making dust that adversely affects refractory materials in the smelting furnace in iron and steel making and the like. (See JP-A-7-18346).

FIG. 3 is an explanatory view of a conventional circulating fluidized bed reduction apparatus. The fluidized bed reduction apparatus includes a fluidized bed reduction furnace 1, a raw material supply section 3 for ores and iron-making dust from a raw material hopper 2, and discharge of products. A section 4 and a reducing gas blowing section 5 are provided. The external particle circulation device 7 provided at the gas outlet 6 of the fluidized bed reduction furnace 1 is provided with a primary cyclone 8 at the front stage and a secondary cyclone 9 at the rear stage, and each cyclone is provided with a down-match pipe 10a, 10b in a new match feeder. It is connected to 11a and 11b.

The raw materials such as ore and iron-making dust supplied from the raw material hopper 2 to the fluidized bed reduction furnace 1 are reduced by the injection of the reducing gas supplied from the bottom of the fluidized bed reduction furnace 1 to form a fluidized bed. While rising, it rises with the gas and moves to the primary cyclone 8. In the primary cyclone 8, the reduced particles are separated from the gas, descended through the downcomer 10a, and returned to the fluidized bed reduction furnace 1 through the pneumatic feeder 11a. The gas leaving the primary cyclone 8 is the secondary cyclone 9
Is separated into reduced particles and gas, and the reduced particles are collected in the downcomer 10.
b, sent to the downcomer 10a of the primary cyclone 8 via the pneumatic feeder 11b, and the gas is guided to the exhaust gas treatment facility.

In the fluidized bed reduction furnace, the differential pressure control is a main operating factor of the operation. Therefore, a pressure guiding tube is provided in the through hole of the furnace wall, but since the particle concentration in the furnace is large and the particles vibrate in the entire furnace at high speed, as shown in FIG. The inside of 13 is penetrated at an angle of about 60 degrees.

[0007]

However, since the pressure inside the furnace is high and the fluctuations in pressure are severe, the concentration of particles in the furnace is high, and the particles are repeatedly invaded and discharged into the pressure guiding tube to reduce the powder. Since the particulate particles have a high adhesiveness, they adhere to the wall of the pressure guiding tube, and eventually block the pressure guiding tube, and the density of the iron-based particles is large and the adhesiveness is large even when backwashing and purging. , It was difficult to clear the blockage. As a result, the pressure cannot be measured and the differential pressure of the furnace cannot be controlled.

Further, since the pressure guiding tube is installed at an inclination, not only the equipment becomes complicated, but also the pressure measurement accuracy is poor.

Therefore, the present invention provides a pressure guiding tube for a fluidized bed reduction furnace in which particles are prevented from entering the tube.

[0010]

According to the present invention, the tip of the pressure guiding tube inside the fluidized bed reduction furnace is made into a cylindrical shape with a porous tip closed, and a flange is provided outside the pressure guiding tube outside the furnace. It is characterized in that it is connected to a pressure guiding pipe, a purge pipe for purging the tip of the pressure guiding pipe outside the furnace is provided, and a stop valve for shutting off the pressure sensor at the time of purging is provided.

By making the tip of the pressure guiding tube porous, even particles of the order of μm can be prevented from entering, and clogging and clogging of the pressure guiding tube can be prevented.

A purge pipe for purging the tip of the pressure guiding pipe is provided, and a stop valve on the pressure sensor side is periodically closed to introduce a purge gas to purge the tip portion to prevent adhesion of fine powder to the porous portion. To do.

[0013]

1 is a vertical cross-sectional view of a pressure guiding tube according to the present invention. A furnace wall 13 of a fluidized bed reduction furnace is made of a refractory wall whose outer periphery is covered with a steel shell 14. Has a pressure guiding tube 12 with a flange inserted in the through hole, and an insertion tube 15 is inserted into the pressure guiding tube. The insertion tube 15 has a flange 16 of the pressure guiding tube 12 and a pressure guiding tube 18 communicating with a pressure sensor. It is fixed and held between the flange 19 and the flange 19.

The tip of the inner tube 15 is made of a porous material and has a closed shape. As the porous material, for example, a material obtained by stacking and sintering a plurality of stainless steel wire nets is used (for example, product names "Poremet" and "New Poremet" manufactured by Central Filter Industry Co., Ltd.).

The pressure guiding pipe 18 outside the furnace is provided with a purge pipe 20 for purging the tip, and stop valves 21a and 21b are provided in the pressure guiding pipe and the purge pipe, and at the time of purging, the stop valve 21a of the purge pipe 20 is opened to conduct. Stop valve 21 of pressure pipe 18
b is closed, the purge pipe and the pressure sensor are shut off, and the tip of the pressure guiding pipe 12 is purged to remove the reducing particles.

[0016]

【The invention's effect】

(1) Since the pressure guiding tube is not clogged or blocked, stable operation is possible.

(2) Since it is not necessary to mount the pressure guiding pipe in an inclined manner with respect to the furnace wall, the complexity of equipment is eliminated.

(3) If a porous metal material is used, only the tip of the pressure guiding tube can be made porous and the other pressure guiding tubes can be pipes, which improves the pressure measurement accuracy and reduces the cost. .

[Brief description of the drawings]

FIG. 1 is a vertical sectional view of a pressure guiding tube according to the present invention.

FIG. 2 is an explanatory view of a fluidized bed reduction furnace.

FIG. 3 is a vertical cross-sectional view showing attachment of a conventional pressure guiding tube.

[Explanation of symbols]

1 fluidized bed reduction furnace, 2 raw material hopper, 3 raw material supply section, 4 product discharge section, 5 reducing gas injection section,
6 gas outlet, 7 external particle circulation device, 8 1st cyclone, 9 2nd cyclone, 10a, 10b downcomer, 11a, 11b new match feeder, 1
2 pressure guiding pipes, 13 furnace walls, 14 iron skins, 15 insertion pipes, 16 flanges, 17 flanges, 18 pressure guiding pipes, 19 flanges, 20 purge pipes, 21a,
21b stop valve

Claims (1)

[Claims] 1. A tip of a pressure guiding tube inside a fluidized bed reduction furnace is formed into a cylindrical shape with a porous tip closed, a flange is provided on the outside of the pressure guiding tube, and the flange is connected to the pressure guiding tube outside the furnace. A pressure guiding tube in a fluidized bed reduction furnace characterized in that a pressure guiding tube is provided with a purge tube for purging the tip, and a stop valve for blocking the pressure sensor at the time of purging is provided.