JP2005075359A - Method and apparatus for filling powder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for filling a powder which can fill stably and at a high speed the powder into a powder container, and an apparatus for it. <P>SOLUTION: The powder is fed into a powder fluidizing apparatus 11 to form and keep a powder fluidized layer 11a. Under this condition, pressurized air is fed from above the powder fluidized layer through an air feeding valve (automatic control valve) 32, and the powder for forming the powder fluidized layer is filled into the powder container 51 from a filling nozzle 44 through a conduit 42. In this case, an air pressure above the powder fluidized layer in the powder fluidizing apparatus 11 is detected by a pressure sensor 35, and this detected pressure is outputted to a controller 34. The air pressure above the powder fluidized layer is controlled within an appropriate range by controlling an aperture of the air feeding valve 32 based on a signal from this controller. It is possible thereby to keep a powder filling speed into the powder container within a required high-speed range. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a powder filling method and apparatus for filling a powder container with a fine powder such as a toner for developing an electrostatic latent image having a particle size of 20 μm or less at a high speed, and particularly in an electrophotographic copying machine. The present invention relates to a powder filling method and apparatus suitable for directly filling dry toner in a toner cartridge or a copier developing unit.

  Conventionally, a rotary valve, a screw feeder, an auger type filling device, and the like are known as powder filling devices for efficiently filling powder into a fixed volume filling container. When filling a container (powder container) with powder using these filling devices, place the powder container directly under the filling device, increase the bulk density of the powder in the filling device, and remove the extracted powder by gravity. In general, the powder container is filled with (self-weight).

  Also, in Patent Document 1 below, after introducing gas into the powder in the powder feeder to improve the fluidity, the powder is transported from the powder feeder to the vicinity of the receiving container by a subordinate pipe and removed. A method has been proposed in which after degassing the powder in the transport pipe by air piping, the container is filled with high density.

  Further, in Patent Document 2 below, gas is uniformly introduced into the powder to obtain a flow state of the powder controlled with a minimum amount of gas, and the depth of a small-diameter filling container or a complicated-shaped filling container or A powder filling technique is disclosed in which fluidized powder flows into the bottom, is small and portable, is easy to operate, and can be degassed from the filled powder and filled with high density and no dust.

  In this powder filling technique, each of a gas introduction part for introducing a powder fluidizing gas into a powder fluidizer and a gas discharge part downstream of a filling nozzle for filling a powder container with powder In addition, a powder-gas separation sieve that allows gas to pass but does not allow powder to pass therethrough is provided, and the opening area of the powder-gas separation sieve in the gas introduction part is defined as the opening of the powder-gas separation sieve in the gas discharge part. The fluidized powder is fluidized from the powder fluidizer by maintaining the gas flow rate of the gas discharge unit higher than the gas flow rate of the gas introduction unit by setting the area to 1.002 times or more of the area. It is configured to spontaneously discharge to a filling container (powder container) via a powder path and a filling nozzle.

  However, the various powder filling techniques described above have the disadvantage that it is relatively easy to fill the powder with high density and no dust, but it is difficult to stably fill the powder at a high speed. It was.

  That is, in the powder filling apparatus described in Patent Document 2 below, the powder filling operation is performed as follows. A predetermined amount of powder is put into the powder fluidizing apparatus, and the apparatus is sealed. Next, air is continuously supplied from the lower side of the device to form a fluidized bed. In this state, pressurized air is supplied from the upper side of the device to increase the pressure to a predetermined level, and then the pressurized air is supplied. The operation is stopped and the powder container is filled with the powder through the conduit. In this filling operation, the pressurized air in the powder fluidizer is transported to the powder container together with the powder. Also, during this filling operation, pressurized air is not supplied to the powder fluidizer until the amount of residual powder is reduced to a predetermined value. In addition, the amount of air for powder fluidization is considerably smaller than the amount of pressurized air. Therefore, the air for powder fluidization has almost no function of conveying powder to a powder container. Absent. As a result, as the powder filling operation is continued, the air pressure in the powder fluidizing device is lowered, and the powder filling rate into the powder container is gradually lowered.

JP-A-9-193902 JP 2002-293301 A

  The present invention has been made in view of the above-described problems of the prior art. The purpose of the present invention is to fluidize a powder to be filled in a powder container in a powder fluidizer and to increase the fluidized powder. It is an object of the present invention to provide a powder filling method and apparatus capable of stably filling at high speed with high density and no dust.

The invention according to claim 1
Powder is introduced into the powder fluidizer and gas is introduced into the powder fluidizer from the lower part to form and maintain the powder fluidized bed. In this state, pressure is applied from above the powder fluidized bed. A method of filling a powder container with a powder through a conduit by supplying a gas and forming the powder fluidized bed by the pressure of the pressurized gas;
By controlling the pressure above the powder fluidized bed in the powder fluidizer within the appropriate range, the powder filling rate (powder filling amount per unit time) in the powder container is within the desired range. It is a powder filling method characterized by maintaining.

  The invention according to claim 2 is characterized in that the pressure (gauge pressure) above the powder fluidized bed in the powder fluidizer is controlled within a range of 4.0 to 20.0 kPa. It is the powder filling method described.

The invention according to claim 3
A powder fluidizing device, a gas introducing means for introducing a gas for forming a powder fluidized bed from a lower portion of the powder fluidizing device, and a pressurized gas in an upper part of the powder fluidizing device. A powder filling apparatus comprising: a pressurized gas supply means for supplying; and a powder conveying conduit having one end opened in the powder fluidizing apparatus and the other end provided with a powder filling nozzle. Because
The pressurized gas supply means has one end opened to an upper portion in the powder fluidizer, the other end connected to a pressurized gas supply source, and an automatic control valve (pressurized gas supply valve). A pressurized gas supply pipe, a control means for controlling the opening degree of the automatic control valve, and a pressure sensor having a pressure detection end inserted in an upper part in the powder fluidizer, the pressure sensor, The powder filling apparatus is characterized in that a feedback control system capable of appropriately controlling the pressure of the upper part in the powder fluidizer within a range by the control means and the automatic control valve.

  In the powder filling method according to the first aspect of the present invention, the pressure above the powder fluidized bed in the powder fluidizer is controlled within a suitable range, and the powder in the powder fluidizer is pressure controlled. Because it is configured to pump with pressurized gas, the powder filling speed in the powder container can be maintained within the desired high speed range, and the powder container is filled with powder with high density and no dust. can do.

  In the powder filling method according to the second aspect of the present invention, by controlling the pressure above the powder fluidized bed in the powder fluidizing apparatus to 4.0 kPa or more, the powder is smoothly and rapidly put into the powder container. Can be filled. In addition, the powder fluidizing device preferably has a simple structure and a low cost (for example, a plastic molded product) like other components. In this case, the pressure resistance of the powder fluidizing device is about 20%. 0.0 kPa is the limit. For this reason, when the atmospheric pressure exceeds 20.0 kPa, breakage or air leakage is likely to occur.

  In the powder filling apparatus according to the third aspect of the present invention, the atmospheric pressure in the upper part of the powder fluidization apparatus is controlled within a desired range by a feedback control system including a pressure sensor, a control means, and an automatic control valve. Therefore, with a simple and inexpensive configuration, it is possible to maintain the powder filling rate in the powder container at a high value and to fill the powder container with powder with high density and no dust. Become.

  In this powder filling device, it is preferable to provide a pressure release valve (relief valve) for discharging the pressurized gas at the upper part in the powder fluidizing device to the outside. Troubles can be avoided when the atmospheric pressure at the site rises abnormally due to unforeseen reasons.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic explanatory view showing the overall structure of the powder filling apparatus.
First, the structure of this powder filling apparatus will be described. The powder filling device 10 is constituted by a powder fluidizing device 11 and various attached means arranged around the powder fluidizing device 11. The powder fluidizing device 11 is a molded product of, for example, a soft plastic, and can be sealed / opened by opening and closing a lid body 13 to which a pressure release valve (relief valve) 12 is attached.

  That is, as the attachment means, (1) gas introduction means 21 for introducing a powder fluidized bed forming gas from the bottom into the powder fluidizer 11, and (2) the powder fluidizer 11 Pressurized gas supply means 31 for supplying pressurized gas to the upper space, and (3) a powder lead-out pipe 43 connected to one end of the conduit 42 and a powder filling nozzle (hereinafter referred to as a filling nozzle) to the other end. ) 44 and a powder conveying means 41 comprising a powder conveying conduit (hereinafter referred to as a conduit) 42 provided. The powder lead-out tube 43 is inserted into the powder fluidizer 11 and its open end is positioned near the bottom of the powder fluidizer 11.

  In the gas introducing means 21, an air pump 23 driven by a motor 22, a vent pipe 26 provided with a check valve 24 on the upstream side (discharge side of the air pump 23) and an introduction gas regulating valve 25 on the downstream side, The air header 27, the gas distribution plate 28, and the gas-powder separation sieve (ventilated perforated plate) 29, which are respectively disposed in the lower part of the powder fluidizing device 11, are disposed. The perforated porous plate 29 is formed by forming a large number of air holes through which gas passes but does not allow powder to pass, for example, a sintered metal plate, a sintered resin plate, or a fine metal mesh.

  In the pressurized gas supply means 31, one end opens to an upper part in the powder fluidizer 11, the other end is connected to a pressurized gas supply source (for example, an air compressor or a blower) not shown, and automatically. A pressurized air supply pipe 33 provided with an air supply valve 32 as a control valve, a controller 34 for controlling the opening degree of the air supply valve 32, and a pressure detection end are inserted into an upper part in the powder fluidizer 11. A pressure sensor 35 is provided. The pressure sensor 35, the controller 34, and the air supply valve 32 constitute a feedback control system that can control the atmospheric pressure in the upper part in the powder fluidizer 11 within an appropriate range.

  The conduit 42 constituting the powder conveying means 41 is rich in flexibility such as a polyurethane tube. The filling nozzle 44 is detachably connected to the distal end portion of the conduit 42. In addition, a gas-powder separation sieve (aeration porous plate) 44a and a plastic ring-shaped soft packing 44b provided so as to surround the outer peripheral surface are provided at the end of the filling nozzle 44 on the conduit 42 side. Install. The outer diameter of the soft packing 44 b is set to a size that can be fitted into the mouth of a powder filling container (hereinafter, powder container) 51. The vent porous plate 44a is similar to the vent porous plate 29 and has a large number of vent holes through which gas passes but does not allow powder to pass, such as a sintered metal plate, a sintered resin plate, or a fine wire mesh. .

Next, an example of an operation method for filling the powder container 51 with powder by the powder filling apparatus having the above-described configuration will be described with reference to FIG.
(A) The filling nozzle 44 is inserted into the powder container 51 as shown in FIG.
(B) The lid 13 of the powder fluidizer 11 is opened and a predetermined amount of powder is charged. Next, the lid 13 is closed to make the powder fluidizer 11 hermetically sealed.
(C) The powder fluidized bed 11a is formed and maintained by the air from the air pump 23.
(D) By supplying pressurized air from the air supply valve 32 into the powder fluidizer 11, the powder in the powder fluidizer 11 (precisely, the powder / air mixture) is derived from the powder. The powder container 51 is filled from the filling nozzle 44 via the pipe 43 and the conduit 42. The powder container 51 is filled with a powder / air mixture, but most of the air passes through the gas-solid separation sieve 44a and is discharged to the outside.
(E) When the powder container 51 is filled with a predetermined amount of powder, the air supply from the air supply valve 32 is stopped, the filling nozzle 44 is inserted into another powder container, and the same powder filling as described above is performed. Repeat the operation.

  In spite of this air supply stop, when the powder in the powder fluidizer 11 is discharged from the filling nozzle 44, the air pump is closed by closing the introduction gas control valve 25 or reducing the opening degree. The air supply from 23 is stopped or the supply amount is reduced.

In the powder filling operation, the air pressure at the upper part in the powder fluidizer 11 is detected by the pressure sensor 35, and this detected air pressure is output to the controller 34. Then, based on the signal from the controller 34, the opening of the air supply valve 32 is appropriately controlled or an appropriate amount so that the detected atmospheric pressure is within a predetermined range (for example, 4.0 to 20.0 kPa). Fully open or close at appropriate times.
When the amount of powder in the powder fluidizing apparatus 11 is reduced to a predetermined amount by repeating the above powder filling operation, a new powder is additionally added thereto, and the powder filling operation is restarted.

  As described above, in the powder filling apparatus and the powder filling method according to the present embodiment, the air pump 23 is used exclusively for forming the powder fluidized bed, and the powder is generated by the pressurized air from the air supply valve 32. The fluidized powder in the fluidizing device 11 is introduced into the conduit 42 and pumped, and pressurized air is appropriately replenished from the air supply valve 32 so that the pumping function is within a predetermined range. Is. Therefore, the fluidized powder in the fluidizing device 11 can be stably filled at a high speed with high density and no dust.

  The downstream end of the conduit 42 is connected to a cyclone dust collector (not shown) to separate the air from the powder / air mixture, and the powder is discharged from the lower end of the inverted cone constituting the dust collector. Can also be configured to recover. Also, instead of the air pump 23 and the pressurized gas supply source (not shown), a cylinder equipped with a pressure reducing valve is prepared, and an inert gas such as nitrogen gas is supplied from the cylinder to the powder flow. You may make it supply to the conversion apparatus 11. FIG.

It is a schematic explanatory drawing which shows the whole structure of the powder filling apparatus which concerns on this invention.

Explanation of symbols

10: Powder filling device 11: Powder fluidizing device 11a: Powder fluidized bed 12: Pressure release valve 13: Lid 21: Gas introduction means 22: Motor 23: Air pump 24: Check valve 25: Introduction gas adjustment Valve 26: Ventilation tube 27: Air header 28: Gas distribution plate 29: Gas-powder separation sieve (venting porous plate)
31: Pressurized gas supply means 32: Air supply valve (automatic control valve)
33: Pressurized air supply piping 34: Controller 35: Pressure sensor 41: Powder conveying means 42: Conduit 43: Powder outlet tube 44: Filling nozzle 44a: Gas-powder separation sieve (ventilated porous plate)
44b: Soft packing 51: Powder container

Claims (3)

Powder is introduced into the powder fluidizer and gas is introduced into the powder fluidizer from the lower part to form and maintain the powder fluidized bed. In this state, pressure is applied from above the powder fluidized bed. A method of filling a powder container with a powder through a conduit by supplying a gas and forming the powder fluidized bed by the pressure of the pressurized gas;
The powder filling rate is characterized in that the powder filling speed in the powder container is maintained within a desired range by controlling the air pressure above the powder fluidized bed in the powder fluidizer within a suitable range. Method.   2. The powder filling method according to claim 1, wherein the pressure above the powder fluidized bed in the powder fluidizer is controlled within a range of 4.0 to 20.0 kPa. A powder fluidizing device, a gas introducing means for introducing a gas for forming a powder fluidized bed from a lower portion of the powder fluidizing device, and a pressurized gas in an upper part of the powder fluidizing device. A powder filling apparatus comprising: a pressurized gas supply means for supplying; and a powder conveying conduit having one end opened in the powder fluidizing apparatus and the other end provided with a powder filling nozzle. Because
The pressurized gas supply means includes
One end opened to an upper part in the powder fluidizer, the other end connected to a pressurized gas supply source, and a pressurized gas supply pipe provided with an automatic control valve;
Control means for controlling the opening of the automatic control valve;
A pressure detection end, and a pressure sensor inserted in an upper part of the powder fluidizer;
The pressure sensor, the control means, and the automatic control valve constitute a feedback control system that can control the atmospheric pressure of the upper part in the powder fluidizer within the appropriate range.
A powder filling apparatus characterized by that.

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