JPH08230981A - Powder discharging apparatus - Google Patents

Abstract

PURPOSE: To continuously discharge powder deposited in a horizontal pipe by providing an L-shaped valve pipe at a discharging port on a bottom of a reservoir and blowing carrier gas with a gas blowing pipe into the horizontal pipe through a bent end face of the L-shaped valve pipe. CONSTITUTION: A reservoir 1 with its bottom in an inverted cone shape is mounted and fixed on a plurality of weighing devices 20 such as load cells, while a vertical pipe 4 of an L-shaped valve pipe 3 comprising the vertical pipe 4 and a horizontal pipe 5 is connected to a discharging port 2 of the reservoir 1. In this case, two gas blowing pipes 13, for example, for blowing carrier gas are inserted in parallel into the horizontal pipe 5 through a bent end face of the horizontal pipe 5 bending in a horizontal direction from a lower end of the vertical pipe 4. An amount of discharged powder per unit time is calculated by a controller 10, while difference in a set flow rate from a flow rate setting device 9 is obtained, and an amount of blown carrier gas into the gas blowing pipes 13 is controlled by an adjust valve 12 to realize a predetermined discharged amount.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for continuously and controllably discharging powder particles such as powdered ore, powdered coal and cement contained in a storage tank. .

[0002]

2. Description of the Related Art As an apparatus for controllably discharging powder particles of various particle sizes such as powdered ore, coal powder, and cement contained in a storage tank from a storage tank, for example,
In Japanese Patent Laid-Open No. 1-130725, the bottom discharge port of the storage tank is
Connect the L-shaped valve pipe consisting of the vertical pipe part and the horizontal pipe part,
An apparatus (hereinafter referred to as prior art 1) is disclosed in which powder particles discharged through the vertical pipe portion and discharged into the horizontal pipe portion are discharged by a carrier gas such as nitrogen gas blown into the horizontal pipe portion. ing.

FIG. 3 is a schematic vertical sectional view of a device of Prior Art 1. As shown in FIG. 3, the storage tank 1 having the inverted conical bottom portion in which the powder A is contained is like a plurality of load cells arranged at equal intervals in the circumferential direction in the horizontal plane. It is placed and fixed on the weighing device 20. A discharge port 2 for the granular material is provided at the bottom of the storage tank 1, and the discharge port 2 includes a vertical pipe portion 4 and a horizontal pipe portion 5 that bends in the horizontal direction from the lower end of the vertical pipe portion 4. The upper end of the L-shaped valve pipe 3 provided with the discharge pipe 6 is connected to the downstream end of the horizontal pipe portion 5.

The diameter d of the discharge port 2 and the inner diameter of the vertical pipe portion 4 are substantially the same, and the diameter of the powder particles having the maximum particle size accommodated in the storage tank 1 can be smoothly passed. . The inner diameter and the length of the horizontal pipe portion 5 of the L-shaped valve pipe 3 are such that the granular material discharged from the discharge port 2 through the vertical pipe portion 4 accumulates in the horizontal pipe portion 5 and has an inclined surface of repose angle α. Are dimensioned to be formed.

A nozzle 7 for injecting a carrier gas such as nitrogen gas into the horizontal pipe portion 5 is provided at the bent end of the L-shaped valve pipe 3. The nozzle 7 is attached to the tip of the gas blowing pipe 8, and the gas blowing pipe 8 is
It is connected to a carrier gas supplier 21 via a pulse valve 19 whose opening interval can be controlled. Reference numeral 19 'is a pulse valve controller, which adjusts the opening interval of the pulse valve 19 based on the change in the amount of decrease in the powder or granular material in the storage tank 1 detected by the metering device 20, to inject the carrier gas, Controls the amount of powder delivered.

According to the above-mentioned apparatus, the granular material discharged from the discharge port 2 of the storage tank 1 through the vertical pipe portion 4 and accumulated in the horizontal pipe portion 5 while maintaining the inclined surface of the angle of repose α. A is destroyed by the carrier gas blown from the nozzle 7 through the gas blowing pipe 8, is transferred in the horizontal pipe portion 5 toward the downstream end thereof, and is discharged through the discharge pipe 6. The amount of powder or granules corresponding to the amount discharged is L from the discharge port 2 of the storage tank 1.
It passes through the vertical pipe portion 4 of the mold valve pipe 3 and falls into the horizontal pipe portion 5 to accumulate.

By blowing the carrier gas into the horizontal pipe portion of the L-shaped valve pipe connected to the bottom outlet of the storage tank,
As another example of the device that discharges the powder or granular material that drops from the storage tank and accumulates in the horizontal pipe portion, a device shown in a schematic vertical sectional view in FIG. 4 (hereinafter referred to as prior art 2) is known. In the device of Prior Art 2, two gas injection nozzles 7a, 7b connected to the gas injection pipe 8 are arranged near the bent end of the L-shaped valve pipe 3. In the middle of the gas injection pipe 8,
A flow rate detector 11 and a control valve 12 are provided, and a controller 10 connected to the flow rate setting device 9 is connected to the flow rate detector 11 and the control valve 12.

The above-mentioned device is simpler than the device of the prior art 1, and based on the gas flow rate set by the flow rate setting device 9, the amount of carrier gas blown from the gas blowing nozzles 7a, 7b is determined. It is adjusted by the control valve 12, whereby the granular material is transferred in the horizontal pipe portion 5 of the L-shaped valve pipe 3 toward its downstream end, and is discharged through the discharge pipe 6.

[0009]

The prior art 1 has the following problems. That is, in the device of the prior art 1, since the discharging speed of the granular material is controlled by controlling the opening interval of the pulse valve 18, the discharging of the granular material has to be discontinuous. Therefore, it is not suitable when highly accurate control is required or when transferring a large amount of powder or granules.

Prior art 2 has the following problems.
That is, according to the device of the prior art 2, although it is possible to continuously control the dispensing of the powdery particles, the L-shaped valve tube 3
Between the gas injection nozzles 7a, 7b attached to the bent end of the powder particle and the sloped surface of the powder particles, frictional resistance is generated between the powder particles and the inner surface of the L-shaped valve tube 3, which results in powder particles. It impedes the driving force that breaks down the body deposition slope.

That is, the frictional resistance is extremely increased depending on the specific gravity, surface texture and particle size distribution of the powder or granular material. Therefore, in order to move the powder or granular material in the L-shaped valve tube 3 from the stationary state, Excessive driving force or a large amount of carrier gas is required. As a result, the powder or granular material in the L-shaped valve tube 3 is in a state of flowing in at a large flow rate after the transfer is started, and the flow rate cannot be controlled. Furthermore, when the particle size distribution of the powder particles accumulated in the L-shaped valve tube 3 is non-uniform,
As a result of the carrier gas channeling, the inclined surface of the deposited powder and granules does not work effectively, and as a result, even if a large amount of carrier gas is blown, the powder and granules cannot be transferred.

Therefore, the object of the present invention is to solve the above-mentioned problems and to continuously control the powder or granular material in the storage tank regardless of the material such as the specific gravity and surface texture of the powder or granular material and the particle size distribution thereof. It is to provide a device that can dispense as stably as possible.

[0013]

The apparatus of the present invention has a vertical pipe portion whose upper end is connected to a discharge port of the bottom of a storage tank in which the granular material is stored, and a horizontal direction from a lower end of the vertical pipe portion. An L-shaped valve pipe having a discharge pipe provided at a downstream end of the horizontal pipe portion, and a horizontal pipe portion that bends in a horizontal direction, and a horizontal portion for a predetermined length in the horizontal pipe portion through a bent end surface of the L-shaped valve pipe. And a gas blowing pipe that is charged into the gas discharging pipe, the gas blowing pipe is discharged from the discharge port, passes through the vertical pipe portion, falls into the horizontal pipe portion, and accumulates in the accumulated layer of the granular material. It is characterized in that the powder particles accumulated in the horizontal pipe portion are transferred by blowing a carrier gas of a predetermined flow rate therethrough, and the powder particles are continuously discharged from the discharge pipe.

If a plurality of the gas blowing pipes are charged in parallel in the granular material deposit layer in the horizontal pipe portion, the granular materials can be transferred more efficiently. Further, it is preferable to insert a metal rod through the bent end surface of the L-shaped valve tube so as to be movable along the axis of the gas injection tube, and thereby the gas injection tube can be prevented from being blocked.

[0015]

According to the apparatus of the present invention, the gas blowing pipe is inserted through the bent end face of the L-shaped valve pipe into the granular material deposit layer in the horizontal pipe portion with the open end being close to the inclined face of the deposit layer. Is
A predetermined amount of carrier gas is blown from the gas blowing pipe toward the inclined surface of the deposited layer. As a result, the granular material deposit layer that has fallen from the storage tank through the vertical pipe portion of the L-shaped valve pipe and accumulated in the horizontal pipe portion is destroyed, and the granular material is transferred toward the downstream end of the horizontal pipe portion, Then, it is discharged from the discharge pipe.

At this time, since the angle of repose of the powder or granules is directly destroyed by the carrier gas, the powder or granules are irrespective of the material such as the specific gravity and surface texture of the powder or granules and the particle size distribution thereof.
It can be continuously and controllably and stably dispensed. Further, by inserting a metal rod into the gas blowing pipe so as to be movable along its axis, it is possible to prevent the powder and granular material from entering the gas blowing pipe and blocking it. Even in this case, the metal rod can be easily removed by moving it along the axis of the gas blowing pipe.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the device of the present invention will be described with reference to the drawings. FIG. 1 is a schematic vertical sectional view showing an embodiment of the device of the present invention. As shown in the drawing, a storage tank 1 in which powder and granules are stored and whose bottom portion is an inverted conical shape is a weighing tank like a plurality of load cells arranged at equal intervals in a circumferential direction in a horizontal plane. The vertical pipe portion 4 of the L-shaped valve pipe 3 including the vertical pipe portion 4 and the horizontal pipe portion 5 is connected to the discharge port 2 of the storage tank 1 fixed on the device 20, and the horizontal pipe portion. A discharge pipe 6 is connected to the end portion of 5 as in the conventional device.

In this embodiment, the diameter of the discharge port 2 of the storage tank 1, the vertical pipe portion 4 of the L-shaped valve pipe 3, the horizontal pipe portion 5 and the discharge pipe 6 are all 140 mm. The diameter is the same, and the distance a from the central axis of the vertical pipe portion 4 to the central axis of the discharge pipe 6 is 593 mm.

A gas injection pipe 13 having an inner diameter of 10 mm for injecting a carrier gas is provided in the horizontal pipe portion 5 through a bent end surface of a horizontal pipe portion 5 which is bent horizontally from a lower end of the vertical pipe portion 4 of the L-shaped valve pipe 3. Two are installed in parallel with. The charging length of the gas blowing pipe 13 into the horizontal pipe portion 5 is set to an appropriate value in accordance with the required maximum transfer amount of the granular material and the control accuracy.

When the distance from the tip of the gas blowing pipe 13 to the accumulation slope of the powder or granules is too short, the carrier gas such as nitrogen gas blown from the gas blowing pipe 13 blows out to form the powder or granules. Becomes difficult to be transferred. As the distance to the deposition slope becomes longer, the transfer amount of the powdery particles increases, but the controllability of the transfer amount decreases. When the distance of the gas injection pipe 13 to the deposition slope is the longest, that is, when the charging length into the horizontal pipe portion 5 is zero, the characteristics are almost the same as those of the prior art 2. In this embodiment, the distance l from the tip of the gas blowing pipe 13 to the slope of accumulation of the powder and granules is 150 to 200 mm.

The number of gas injection pipes 13 charged in the horizontal pipe portion 5 is selected according to the transfer ability of the powder or granular material. In general,
As the number of gas blowing pipes 13 charged increases, the transfer capacity of powder particles increases, but there is a limit to the transfer capacity depending on the diameter of the L-shaped valve pipe 3. Therefore, it is necessary to determine the optimum number of the gas injection pipes 13 according to the diameter of the L-shaped valve pipe 3.

A flow rate detector 11 and a control valve 12 are provided in the middle of the gas injection pipe 13, and the flow rate detector 11 and the control valve 12 are connected to a controller 10 connected to a flow rate setting device 9. Has been done. In the controller 10, the discharge amount of the granular material per unit time is calculated from the total weight of the storage tank 1 measured by the measuring device 20 and the granular material A accommodated therein, and the flow rate setting device The difference from the set flow rate from 9 is calculated,
The amount of carrier gas blown into the gas blow-in pipe 13 is controlled by the control valve 12 so as to obtain a predetermined discharge amount.

In order to prevent the inside of each of the gas blowing pipes 13 from being invaded by powdery particles and particles,
As shown in the enlarged vertical sectional view of FIG. 2, a wear-resistant metal rod 14 is inserted along the axis of the gas injection pipe 13. The carrier gas flows through the annular gap between the inner surface of the gas blowing pipe 13 and the metal rod 14, while the metal rod 14 prevents the intrusion of the particulate material into the gas blowing pipe 13. The metal rod 14 is provided with a seal fitting 15, a holding fitting 16 and a seal rubber 17 for preventing the carrier gas supplied into the gas blowing pipe 13 from leaking out.

A handle 18 is attached to the base end of the metal rod 14, and in the case where the granular material enters the annular gap between the gas blowing pipe 13 and the metal rod 14 to cause blockage, The blockage is removed by moving the metal rod 14 back and forth along the axis of the gas injection pipe 13 by 18.

In this way, the water is discharged from the discharge port 2 of the storage tank 1 through the vertical pipe portion 5 and the angle of repose α in the horizontal pipe portion 5.
The granular material A deposited while maintaining the inclined surface of the
A predetermined amount of the carrier gas is transferred toward the downstream end of the horizontal pipe portion 5 by the carrier gas blown through the gas blowing pipe 13 having its open end brought close to the inclined surface of the deposit layer, and It is discharged from the discharge pipe 6.

FIG. 5 shows the case where the carrier gas is blown into the horizontal pipe portion 5 of the L-shaped valve pipe 3 from the two gas blowing pipes 13 and the case where the carrier gas is blown from the single gas blowing pipe 13. 3 is a graph showing the relationship between the total amount of carrier gas blown in and the amount of powder or granular material transferred. As is apparent from FIG. 5, even if the total amount of carrier gas blown is the same, the number of gas injection pipes is more efficient than the case of one gas injection pipe, compared to the case of one gas injection pipe. I was able to.

In FIG. 6, the distance l from the tip of the horizontal pipe portion 5 of the L-shaped valve pipe 3 to the slope of accumulation of powder is 15
FIG. 7 is a graph showing the relationship between the set value of the granular material transfer amount and the actual transfer amount when the carrier gas is blown from the two gas blowing pipes 13 charged as 0 mm, and FIG. 6 is a graph showing the relationship between the set value of powder and granular material transfer amount and the actual transfer amount. As is clear from comparing FIG. 6 and FIG. 7, the gas injection pipe with l set to 150 mm.
When 13 is charged, the upper limit of the amount of powder or granular material transferred within ± 20% of the set value is about 180 Kg / min, whereas
When the gas injection pipe 13 is charged with the value of 200 mm, the upper limit of the amount of powder or granular material transferred within ± 20% of the set value is about 250K.
It was g / min, and it was possible to transfer a larger amount of powder.

[0028]

As described above, according to the present invention,
Regardless of the material such as the specific gravity and surface properties of the granular material and its particle size distribution, the industrially useful effect that the granular material in the storage tank can be continuously and controllably and stably dispensed is brought about. .

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional view showing an embodiment of the device of the present invention.

FIG. 2 is an enlarged vertical sectional view of a gas injection pipe portion in the device of the present invention.

FIG. 3 is a schematic vertical sectional view of a device of Prior Art 1.

FIG. 4 is a schematic vertical sectional view of a device of Prior Art 2.

FIG. 5 is a graph showing the relationship between the amount of carrier gas blown and the amount of powder or granular material transferred when two gas blowing pipes are used and when one gas blowing pipe is used.

[Fig. 6] Distance l from the tip to the slope of accumulation of powder
6 is a graph showing the relationship between the set amount of powder and granular material transfer amount and the actual transfer amount when carrier gas is blown from a gas injection pipe charged in the horizontal pipe portion at a distance of 150 mm.

FIG. 7: Distance l from the tip to the slope of accumulation of powder
6 is a graph showing the relationship between the set value of powder and granular material transfer amount and the actual transfer amount when carrier gas is blown from a gas injection pipe charged into the horizontal pipe portion at a distance of 200 mm.

[Explanation of symbols]

 A Powder / granule 1 Storage tank 2 Discharge port 3 L-type valve pipe 4 Vertical pipe part 5 Horizontal pipe part 6 Discharge pipe 7 Nozzle 8 Gas injection pipe 9 Flow rate setter 10 Flow rate controller 11 Flow rate detector 12 Flow rate control valve 13 Gas Blow-up pipe 14 Metal rod 15 Seal metal fitting 16 Holding metal fitting 17 Seal rubber 18 Handle 19 Pulse valve 19 'Pulse valve controller 20 Metering device 21 Carrier gas supply device

Claims (3)

[Claims] 1. A vertical pipe part, whose upper end is connected to an outlet of a bottom of a storage tank in which the granular material is stored, and a horizontal pipe part that bends in a horizontal direction from a lower end of the vertical pipe part. An L-shaped valve pipe having a discharge pipe provided at a downstream end of the horizontal pipe portion, and a gas blowing pipe horizontally inserted into the horizontal pipe portion for a predetermined length through a bent end surface of the L-shaped valve pipe. And blowing a carrier gas at a predetermined flow rate through the gas blowing pipe into the deposited layer of the particulate material discharged from the discharge port, passing through the vertical pipe portion and falling into the horizontal pipe portion. According to the present invention, the powdery or granular material depositing device is transferred to continuously discharge the powdery or granular material from the discharge pipe. 2. The powdery or granular material discharging device according to claim 1, wherein a plurality of the gas blowing pipes are charged in parallel in the powdery or granular material deposition layer in the horizontal pipe portion. 3. A metal rod for preventing the obstruction of the gas injection pipe along the axis of the gas injection pipe,
The powder or granular material dispensing device according to claim 1, which is movably inserted.