JPH06298376A - Powder material storage tank structure - Google Patents

Abstract

PURPOSE:To prevent a bridge from being made in a storage container for enabling quantitative feed or discharge to be achieved by utilizing a porous material for the inner wall surface of a storage container and/or a discharge pipe in a powder storage tank, mounting a pressure reducing device and a pressure air device onto the porous material, and installing a controller for controlling the valves of the respective devices. CONSTITUTION:This powder material storage tank 1 is composed of a storage container 2 and a discharge pipe 3. The inner wall surface 4 at the lower part of the storage container 2 is provided with a porous material 5 made from artificial graphite or the like and with a connection port 6 connected to the porous material 5. A pressure air device 7 and a pressure reducing device 8 are connected respectively. To the connection port 6 through valves. The valves of the pressure air device 7 and the pressure reducing device 8 are switched to each other by a controller 9. Owing to miss structure possible to include gas in a powder material in the inner wall surface 4 on the lower part of the storage container 2 by air pulse-like by air pulse or continuous pressurization through the porous material and to repeat deairing operation by pressure reducing so as to prevent any bridge from being generated in the storage tank.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a powder storage tank structure, and more specifically, to a porous material on the lower inner wall surface of a storage container and / or the inner wall surface of its discharge pipe, and a decompression device and pressurized air on the porous material. The present invention relates to a powder storage tank structure for controlling powder of a storage container and / or a discharge pipe without providing a mechanical operation by providing a device and a control device for controlling the valves of the pressure reducing device and the pressure air device.

[0002]

2. Description of the Related Art Conventionally, a powder storage tank has a structure in which powder is supplied to a storage container from the upper part and the powder is discharged from a lower discharge pipe. In such a storage tank structure, the fluidity is poor depending on the particle size of the powder, the structure of the storage tank, etc., so that a bridge is formed in the storage container or the discharge pipe is clogged to efficiently discharge the powder from the storage container. I couldn't do that.

As a method of preventing the formation of bridges in the storage container of the storage tank, there is a method of mechanically applying vibration to the powder or the storage tank. However, this method vibrates only the powder near the vibrator and has little effect in the distant place, and if the vibration is applied too much, the powder hardens conversely, and it is installed inside the storage container. However, there is a problem in that the powder flow is obstructed, it is easy to break down, it is expensive, and noise is generated.

There is also a method of continuously supplying pressurized air into the storage container of the powder storage tank. However, the pressurized air and the like become excessive and dust is generated, and the bulk density is lowered, resulting in an increase in size of the storage container. There was a problem.

On the other hand, in order to control the amount of powder discharged from the storage container of the storage tank, there is a method in which a rotary valve is used and the movement of the fluid is controlled by the mechanical opening / closing operation of this valve. . This method has many constituent parts, is less reliable, has a large resistance to the passage of powder, needs to have a large diameter discharge pipe, and has a rotary supply when quantitatively supplying and discharging a fixed amount. -There was a problem that the gap remained in the valve due to its structure, and leakage was likely to occur in fine powder particles.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems. Specifically, a porous material is used for the inner wall surface of the storage container of the powder storage tank and / or the discharge pipe. A powder storage tank structure that can be equipped with decompression and pressure air devices on the quality material and a control device that controls the valves of each device to prevent the formation of bridges in the storage container and to supply or discharge a fixed amount. The purpose is to propose.

[0007]

That is, according to the present invention, in a powder storage tank in which powder is supplied to a storage container from the upper portion and the powder is discharged from a discharge pipe below the storage container, the inner wall surface of the lower portion of the storage container and / or Provided on the inner wall surface of the discharge pipe are a porous material, a decompression device connected to the porous material by a pipe and a pressure air device, and a control device for controlling opening and closing of these valves, and a lower inner wall surface of the storage container and / or It is characterized in that the inner wall of the discharge pipe is configured to repeatedly give fluidity and deaeration by pulsed or continuous pressurization of air through the porous material, and is expressed by the following formula of the porous material. It is characterized in that the value of the gas permeability (K) is 0.1 cm ² / sec or more. However, the symbols in the formulas are shown below. ΔP: Pressure drop Q: Air flow rate (atm · cm ³ / sec) L: Thickness of sample (cm) A: Cross-sectional area of sample (cm ² )

The structure and operation of the means of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a vertical sectional view showing an example of an apparatus used for carrying out the present invention, FIG. 2 is a plan view of FIG. 1, and FIG. 3 is a discharge used for carrying out the present invention. FIG. 4 is a vertical cross-sectional view showing an example of a tube, FIG. 4 is a horizontal cross-sectional view taken along the line AA of FIG. 3, and FIG. 5 is an explanation seen from a vertical cross-section showing an example of an apparatus used for carrying out the present invention. FIG. 6 is an explanatory view seen from a vertical section, showing an example of an apparatus used for carrying out the present invention.

First, a method for preventing bridge formation in the storage container of the powder storage tank will be described.

As shown in FIGS. 1 and 2, the powder storage tank 1 of the present invention comprises a storage container 2 and a discharge pipe 3. A porous material 5 made of, for example, artificial graphite and a connection port 6 connected to the porous material 5 are provided on an inner wall surface 4 below the storage container 2. This connection port 6 is shown in FIG.
As shown in FIG. 5, the pressure air device 7 and the pressure reducing device 8 such as a vacuum pump are connected via valves, respectively, and the control device 9 is further configured to switch the valves of the pressure air device 7 and the pressure reducing device 8. .

With the above structure, the gas is contained in the powder by the pulsed or continuous pressurization of air through the porous material on the inner wall surface 4 of the lower part of the storage container 2, while the degassing is performed by the depressurization. It can be repeated and bridge formation in the reservoir is prevented. Conventionally, the generated bridge was destroyed by vibration, but the device of the present invention can prevent the generation of the bridge. However, it is less effective after the bridge is formed, and is also effective in increasing the bulk density of the powder.

The porous material is preferably provided over the entire inner wall surface of the lower portion of the storage container, but even if there is a fan-shaped gap as shown in FIG. 2, the effect is not so much affected.

The pressure can be applied by pulsed or continuous pressurization, but pulsed pressurization is effective.

Next, the valve mechanism of the powder discharge pipe under the storage container will be described.

The valve mechanism of the powder discharge pipe can control the powder with a simple and small device without opening and closing mechanically. The structure of this device may be the same as that of the structure in which the porous material 5 and the depressurizing and pressurized air devices are provided on the inner wall surface 4 of the lower portion of the storage container 2 of the storage tank 1.

That is, as shown in FIGS. 3 and 4, a pipe made of a porous material 5 is formed in the lower portion of the storage container 2, and piping screws 12 and 13 are cut in the upper and lower portions of the pipe, and a pressure is applied between the upper and lower portions of the pipe. It has a structure in which piping for air and pressure reduction is attached by a sleeve 14 and a ring retainer 15. This method utilizes the fact that the powder hardens due to depressurization in the piping.While keeping the powder below atmospheric pressure to stop the flow of the powder, when fluidizing it, raise it above atmospheric pressure with pressurized air, etc. The powder flow rate can be controlled depending on the degree (time, pressure).

Example 1. As shown in FIG. 5, an artificial graphite porous material 5 having an air permeability (K) = 25 cm ² / sec is arranged in a fan shape on the inner wall surface 4 of the storage container 2 of the storage tank. A pressure reducing device 8 and a pressure air device 7, which are
The discharge amount was adjusted by the conventional discharge pipe and valve except that the switching valve of the pressure reducing device 8 and the pressure air device 7 was opened and closed by the timer. In the storage container 2 of the storage tank, coal powder (D50, 18 μm,
True specific gravity of 1.5 to 1.6, 16 μm or less (45% or less) is charged, and the pressure is reduced to 410 Torr by the pressure reducing device 8 from the porous material 5 on the inner wall surface of the lower portion of the storage container 2 to 2 kg / cm ² N _2.
The gas was pulse-pressurized for 1 second every 2-3 seconds by opening and closing the valve controller 9. At this time, the porous material 5 to 10 m
The pressure in the powder separated by about / m was negative and no bridge was formed. Further, Table 1 shows changes in bulk specific gravity at the time of charging coal powder and after 10 minutes in a stationary state, and changes in bulk specific gravity at the time of charging coal powder and after 10 minutes by the above method.
According to the examples, it was found that the bulk specific gravity of the powder can be increased, which contributes to downsizing of the storage tank.

[0019]

[Table 1]

Example 2. In the valve mechanism of the discharge pipe shown in FIG. 6, the air permeability (K) = 30c
A porous material 5 of m ² / sec, a decompression device 8 composed of a vacuum pump and the like and a pressure air device 7 are connected by piping, and an auxiliary valve 11 (a resistance of a ball valve or the like is provided below the valve mechanism). A small number of valves) are provided, and the control device 9 controls the opening / closing of the switching valve between the pressure air device 7 and the auxiliary valve 11.

The same coal powder as in Example 1 was used in the storage container 2 of the storage tank, and the quantitative supply or quantitative discharge of the valve mechanism 10 was operated under the following conditions. That is, the degree of pressure reduction 410
After continuously reducing the pressure with Torr, 2 kg / cm ² ,
When it was carried out under a pressurizing condition of 7 kg / cm ² , quantitative discharge could be easily carried out as shown in Table 2.

[0022]

[Table 2]

Example 3. The decompression device 8 and the pressure air device 7 were used for the storage container 2 and the discharge pipe made of the porous material shown in FIGS. 5 and 6, respectively. When this apparatus was operated under the same conditions as in Example 1 and the powder was discharged, a fixed amount could be discharged smoothly as shown in Table 3 without generation of bridges.

[0024]

[Table 3]

[0025]

As described above in detail, according to the present invention, in the powder storage tank in which the powder is supplied from the upper portion to the storage container tank and the powder is discharged from the discharge tube below the storage container tank, the lower inner wall surface of the storage container and A porous material is provided on the inner wall surface of the discharge pipe, a decompression device and a pressure air device connected to the porous material by a pipe, and a control device for controlling the opening and closing of these valves. And / or is characterized in that it is configured to repeatedly give fluidity and deaeration by pulsed or continuous pressurization of air to the inner wall surface of the discharge pipe through a porous material. By providing a porous material, a pressure reducing device, and a pressure air device in the valve mechanism of the pipe, it is possible to prevent the formation of a bridge in the storage tank, and to supply a fixed amount or perform a smooth discharge.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an example of an apparatus used for carrying out the present invention.

FIG. 2 is a plan view of FIG.

FIG. 3 is a vertical cross-sectional view showing an example of a discharge pipe used when carrying out the present invention.

4 is a cross-sectional view taken along the line AA of FIG.

FIG. 5 is an explanatory view seen from a vertical cross section, showing an example of an apparatus used for carrying out the present invention.

FIG. 6 is an explanatory view seen from a vertical section, showing an example of an apparatus used for carrying out the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Powder storage tank 2 Storage container 3 Discharge pipe 4 Inner wall surface 5 Porous material 6 Connection port 7 Pressure air device 8 Pressure reducing device 9 Control device 10 Valve mechanism 11 Auxiliary valve 12 Screw 13 Screw 14 Sleeve 13 Ring presser

Claims (2)

[Claims] 1. A powder storage tank in which powder is supplied from the upper part to a storage container of a storage tank, and the powder is discharged from a discharge pipe below the storage container, wherein a lower inner wall surface of the storage container and / or an inner wall surface of the discharge pipe. Is provided with a porous material, a decompression device connected to the porous material by a pipe and a pressure air device, and a control device for controlling the opening and closing of these valves, and the lower inner wall surface of the storage container and / or the discharge pipe are provided. A powder storage tank structure, characterized in that the inner wall surface is repeatedly provided with fluidity and deaeration by pulsed or continuous pressurization of air through the porous material. 2. The powder storage tank structure according to claim 1, wherein the value of the air permeability (K) represented by the following formula of the porous material is 0.1 cm ² / sec or more. However, the symbols in the formulas are shown below. ΔP: Pressure drop Q: Air flow rate (atm · cm ³ / sec) L: Thickness of sample (cm) A: Cross-sectional area of sample (cm ² )