JPH04365725A - Powder feeder - Google Patents

Abstract

PURPOSE:To suppress the compaction of powder in a hopper so as to stably supply powder to an air stream transport pipe in the case of intermittently discharging powder from a hopper and transporting the same with air stream. CONSTITUTION:Powder storing containers 5 each having a stirring blade 6 are respectively provided below plural powder blowing hoppers 4 arranged side by side below a powder tank. There are provided structures 11, 12 for always blowing gas for fluidizing powder in the storing containers 5 and structures 13, 14 for blowing gas for assisting the transport for an intermittently discharged powder in an intermittent discharge ports of the storing containers 5. Thus, the starting resistance in the lower portion of the powder blowing hopper can be decreased, the capacity of a driving motor can be reduced, and abrasion of parts can be lessened. Furthermore, the mixture of powder and air stream can be promoted so as to stably supply the power continuously.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is applicable to the transportation of powder (indicating granules or a mixture thereof) in fields such as cement, as well as the injection of pulverized coal or pulverized ore into blast furnaces. This relates to a supply device.

0002

2. Description of the Related Art Generally speaking, a powder supply device is placed below a hopper for storing powder, and the weight of the powder is applied to the powder supply device. Immediately after being charged into the hopper, the powder is mixed with air and other gases, so even if it is initially fluid, the longer it is stored for a longer time after being charged, the more gas will escape from the powder layer and it will become compacted. It's coming. Furthermore, since the lower part of the hopper generally has an inverted conical shape, as the powder layer moves downward due to discharge, compaction increases, making it difficult to smoothly introduce the powder into the powder supply device.

[0003] Conventionally, therefore, powder is fluidized by blowing gas into the hopper in order to alleviate or prevent compaction. It is not equipped with a function to promote fluidization, and is forced to approach a fluidized state by moving stirring blades.

[0004] In this method, the resistance applied to the stirring blade is large, and the capacity of the electric motor for driving the stirring blade becomes large, and at the same time, the stirring blade itself and mechanical parts such as the shaft are also required to be large. Particularly, when starting the powder supply device from a stopped state in a state where the powder is compacted, a large amount of resistance is encountered and the device cannot be started, which may lead to damage to the device. The initial cutting amount at startup varies greatly depending on the compaction state of the powder. Therefore, it becomes difficult to stably and continuously supply powder. For this reason, an increase in the capacity of the motor and mechanical strength of the stirring blades and the like are required only for the start-up, which increases the cost of the equipment (Japanese Unexamined Patent Publication No. 169315/1983).

[0005]

[Problems to be Solved by the Invention] In order to alternately switch between a plurality of powder blowing hoppers arranged in parallel, continuously discharge powder, and continuously transport the powder, the conventional powder supply device requires the following steps. Since the powder blowing hopper that is on standby has a long storage time, the compaction of the powder in the blowing hopper increases, and a large amount of power is required to start the stirring blades at the time of discharge. Due to large fluctuations in the output amount, smooth switching between the blow hoppers is not possible, and stable continuous supply is also not possible.

[0006] The present invention particularly provides a powder feeding device that is capable of reducing the power required to cut out powder from a powder blowing hopper, and smoothly switching between the blowing hoppers, and capable of stably and continuously supplying powder. This is what we provide.

[0007]

[Means for Solving the Problems] The present invention provides a powder storage container each equipped with a stirring blade at the lower part of a plurality of powder blowing hoppers arranged in parallel below a powder storage tank. A powder supply device characterized by having a structure for constantly blowing gas for fluidizing the powder and for blowing gas for assisting the conveyance of the cut powder into the cutting opening of the storage container. be.

[0008]

[Operation] The present invention maintains the powder in the powder storage container at the bottom of the powder blowing hopper in a fluid state by blowing gas and rotating the stirring blade, and when cutting out the powder from the blowing hopper. By blowing the transport auxiliary gas into the cut-out port of the blow hopper, the powder can be smoothly cut out from the blow hopper into the powder transport pipe.

[0009]

[Embodiment] An embodiment of the present invention will be described below.

FIGS. 1 and 2 are diagrams showing an example in which the present invention is applied as a pulverized coal supply device for injecting pulverized coal into a blast furnace.

[0011] Pulverized coal C adjusted in advance to a predetermined particle size range
Powder blowing hoppers 4, 4' are connected to the lower part of the pulverized coal storage tank 1, which stores pulverized coal, through filling pipes 2, 2' and filling valves 3, 3'.

Powder storage containers 5, 5' are provided at the bottom of the powder injection hoppers 4, 4'.
Stirring blades 6, 6' are rotatably provided in '.
The stirring blades 6, 6' are rotated via rotary tables 7, 7' by drive devices M, M'.

The weight measurement values from the load cells 8, 8' for measuring the weight of the pulverized coal in the powder injection hoppers 4, 4' are transmitted to the control devices 18, 18'.
8' controls the driving of the drive devices M and M' to drive the stirring blades 6.
, 6'.

The powder blowing hoppers 4, 4' are provided with pressurized gas blowing pipes 9, 9' for adjusting the pressure inside the blowing hoppers.
is installed, and the pressure regulating valves 10, 10' are controlled according to the pressure values of the blowing hoppers 4, 4' measured by the pressure gauges P, P' to control the pressurized gas from the pressurized gas blowing pipes 9, 9'. Control the blowing flow rate.

Stirring blades 6, 6' inside the powder storage containers 5, 5'
A fluidizing gas blowing pipe 11, 11' having a plurality of outlets 110, 1101 for fluidizing the pulverized coal in the storage containers 5, 5' is attached to the upper part of the storage container 5, 5'. Pressurized gas is blown into the storage container 5,
The pulverized coal in 5' is maintained in a fluid state. Reference numerals 12 and 12' designate blow regulating valves.

Powder cutting holes 50 in the powder storage containers 5, 5'
, 50' are equipped with transport auxiliary gas blowing pipes 13, 13', which blow pressurized gas when cutting the pulverized coal from the containers 5, 5' to assist in cutting and transporting the pulverized coal. Reference numerals 14 and 14' indicate transport auxiliary gas on-off valves.

Since the powder injection hoppers 4 and 4' are used in a switched manner, when pulverized coal is being supplied from one powder injection hopper, the conveyance auxiliary gas injection pipe 13 on the other pulverized coal injection hopper side is The auxiliary gas on-off valve 14 may be closed.

Cutting tube 15 from powder storage container 5, 5',
15' is connected to a powder conveying pipe 17 to the blast furnace via cut-off valves 16, 16'. The powdered coal cut into the powder transport pipe 17 is blown into the blast furnace by the transport gas.

For convenience, the injection of pulverized coal from, for example, the powder injection hopper 4 side will be explained. Filling pipe 2 from powder storage tank 1 into powder storage container 5 and powder blowing hopper 4;
Pulverized coal C is supplied and filled through the filling valve 3, and pressurized gas is supplied from the gas outlet 110 of the fluidizing gas blowing pipe 11 by the fluidizing gas blowing control valve 12 so that the superficial velocity is constant. The pulverized coal in the powder storage container 5 and the powder blowing hopper 4 is fluidized. In this state, the stirring blade drive motor M is driven to rotate the rotary table 7 and the stirring blade 6 to rotate. In this state, the pulverized coal in the powder storage container 5 is fluidized by the pressurized gas, so the starting resistance to the stirring blade drive motor M is very small. Therefore, the capacity of the agitating blade drive motor M may be small; for example, a capacity of about 50% of that of the conventional example is sufficient.

At the same time as the stirring blade drive motor M is started, the auxiliary transport gas on-off valve 14 is operated to blow out the auxiliary transport gas to the powder discharge port 50 so that the superficial velocity is constant. When the powder cutting valve 16 is opened, the pulverized coal is cut into the powder conveying pipe 17 while maintaining a good mixing state with the air flow due to the synergistic effect with the action of the fluidizing pressurized gas, and the powder is pulverized by the conveying gas. It is blown into the blast furnace from the tuyere through the conveying pipe 17.

Normally, while pulverized coal is being supplied from one powder injection hopper 4 to the powder transport pipe 17, pulverized coal is not supplied from the other powder injection hopper 4'.
The inside of the powder blowing hopper 4' is filled with pulverized coal, and pressurized gas is constantly blown into the coal from the fluidizing gas blowing pipe 11' to maintain the fluidized state. Then, at the end of the injection of pulverized coal from the powder injection hopper 4, the stirring blades 6' are rotated to stir the pulverized coal and the air flow, uniformly mixing them, and the air flow is delivered to the discharge port of the powder injection hopper 4'. A conveyance auxiliary gas is blown in to further fluidize the coal, and at the same time as the powder coal cutting from the powder blowing hopper 4 is finished, the powder cutting valve 16' is opened to cut the pulverized coal from the powder blowing hopper 4' into the powder conveying pipe 17. , can be continuously blown into the blast furnace.

Note that this embodiment is applied to the injection of pulverized coal into a blast furnace, and two powder injection hoppers are provided below one powder storage tank so that they can be switched alternately. It is not limited to this example, and its application can also be applied to powder supply such as conveying and blowing of ore powder, cement, or cement raw materials in addition to pulverized coal, and its structure is also applicable. It may be changed as appropriate depending on the subject.

[0023]

Effects of the Invention In the present invention, pressurized gas is blown into the powder blowing hopper to fluidize the powder, and the starting resistance to the powder stirring blades in the lower part of the hopper can be reduced.
The capacity of the stirring blade drive motor can be reduced, and damage to various mechanical parts of the stirring blade can be reduced. Furthermore, by blowing a conveyance auxiliary gas into the discharge port, the powder is stirred and the airflow is sufficiently mixed with the powder, making the switching transition extremely smooth even when switching between multiple powder blowing hoppers. This enables stable and continuous supply of powder.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a lower structure of an embodiment of a powder supply device of the present invention.

FIG. 2 is a diagram showing an embodiment of the powder supply device of the present invention.

[Explanation of symbols]

1 Powder storage tank 2 Filling tube 3 Filling valve 4 Powder injection hopper 5 Powder storage container 6 Stirring blade 7 Rotary table 8 Load cell 9 Pressurized gas blowing pipe 10 Pressure regulating valve 11 Fluidization gas blowing pipe 12　Blow regulating valve 13 Transport auxiliary gas blowing pipe 14 Transport auxiliary gas on-off valve 15 Cutting tube 16 Cutoff valve 17 Powder conveyance pipe 18 Control device

Claims (1)

[Claims] Claim 1: Powder storage containers each equipped with stirring blades are provided at the bottom of a plurality of powder blowing hoppers arranged in parallel below a powder storage tank, and a powder storage container is provided for fluidizing the powder in the storage container. A powder supply device characterized by having a structure for constantly blowing gas and for blowing gas into the cut-out port of the storage container to assist in transporting the cut-out powder.