JPH08231051A - Operation method for powder filling device equipped with deaeration mechanism - Google Patents

Abstract

PURPOSE: To fill powder having large bulk density in a packaging material at a high speed and by assured filling quantity, by starting deaeration at the same time when the filling operation of a powder filling device is started, and by stopping the deaeration within the time of the specific range in the whole filling time after started. CONSTITUTION: Deaeration is started at the same time when filling operation for filling powder 11 in the packaging material of a bag 34, that is, when the rotation of a screw 16a is started, and the deaeration is stopped within 30 to 70% of the whole filling time, so that the powder 11 is filled in the packaging material just under a powder discharging opening 14a as powder which is compacted to have desired specific gravity while necessary deaeration is executed at an initial stage, and the screw 16a is stopped so as to finish filling after the deaeration is stopped and the compacted powder 11 having desired specific gravity is filled for predetermined time in the latter half. Therefore, the powder 11 to be filled in the bag 34 is compacted to have sufficient specific gravity for filling predetermined quantity by initial deaeration, and besides the powder 11 having assured filling quantity is filled in the bag 34 without any uneven filling by the deaeration so that a shortage of filling quantity and a failure of packaging may not occur.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for operating a powder filling apparatus having a degassing mechanism, and more specifically, by degassing the powder, the bulk specific gravity (bulk density) of the powder is increased. The present invention relates to an operation method of a powder filling device that fills and packs a powder having a large bulk specific gravity into a pouch or the like by an accurate filling amount.

[0002]

2. Description of the Related Art Conventionally, a vertical screw auger type powder filling device has been often used for packing powder into a bag. The use of this device is advantageous in that even powder having a low bulk density can be easily consolidated when filling, and can be easily packed in a packaging material having a predetermined size. However, since the powder is usually subjected to various treatments such as pulverization, classification, pneumatic transportation, and mixing, it contains air, and its amount is not limited to the state of the powder but also the type of the powder and the type of the powder. It also depends on the place of origin of the raw material. That is, the bulk specific gravity of the powder is considerably smaller than its true density, and varies greatly depending on the state of the powder, the type, the place of origin of the raw material, etc.
It varies from 5 to 0.65.

On the other hand, when packaging a powder product, a packaging material for packaging the powder, for example, a bag (inner-side resin-coated paper bag) is filled with a certain weight (actually a certain weight or more) of the powder. There is a need. However, even with the same powder,
If the bulk density varies depending on the condition and the place of origin,
The volume (size) of the packaging material must be determined in consideration of the case where the bulk specific gravity is the smallest, and therefore the size becomes large, not only the cost of the packaging material but also the transportation and storage of the packaging powder product. This leads to higher costs. Therefore, in the case of a packaging material for filling a certain weight of powder, for example, a small bag packaging of wheat flour or the like, the size of a bag of 250 g packing, 500 g packing, 1 kg packing, etc. should be as small as possible due to the above-mentioned economic reasons. It is preferably small and minimized as much as possible.

By the way, when the powder to be packaged is to be used for food and drink, etc., in order to crush the lumps such as lumps existing in the powder, and in the unlikely event that foreign matter is accidentally mixed in, The powder is sieved just before packaging the powder so that it can also be removed. Powders sieved in this way, such as wheat, rice, buckwheat, corn and other grain powders, dry milk, powders such as mixed powders for cakes and cookies, contain a considerable amount of air. Becomes
Its bulk specific gravity is small, that is, the volume per given weight is considerably large. Therefore, in order to pack a predetermined amount (weight) of powder without changing the size of the bag, the apparent specific gravity of the powder is increased and the powder is compressed. This method is particularly effective when the difference between the volume of a given weight of powder to be packed and the size of the bag is small. As one method of powder compression, in addition to tapping the bag after filling, interstitial air is deaerated from the powder before filling the bag. As one of the degassing methods,
A mesh is provided on the casing of the screw or auger to suck and deaerate.

FIG. 5 shows a conventional powder filling device for degassing during powder packaging in this way. This powder filling device is a device for packing powder products such as wheat flour in a bag. As shown in the figure, a conventional vertical powder filling device 50
Is a hopper 52 having a powder input port 54 in the upper part, a powder discharge port 56 in the lower part, and an upper part connected to the lower end of the hopper 52, a casing 55, and a hanger suspended from the outer upper part of the hopper 52. A screw (screw auger, screw conveyor) 58 inserted into the hopper 52 and extending to the vicinity of the powder discharge port 56 of the casing 55,
A filter 60 which is mounted on the casing 55 and is made of metal wire or punching metal for degassing the powder conveyed by the screw 58, a powder degassing device 62 for depressurizing and sucking the powder through the filter 60, and a powder A constant flow rate control device 64 for controlling the intake amount of the body deaerator 62 to a predetermined amount is provided.

In this vertical powder filling device 50, a bag of a predetermined shape for packing the powder is placed below the powder discharge port 56, and then the screw 58 is moved at a predetermined speed for a predetermined time. While rotating and conveying the powder contained in the hopper 52 to the powder discharge port 56 side through the casing 55, the casing is controlled by the powder deaerator 62 whose intake amount is controlled by the constant flow rate controller 64. This air is removed from the powder containing a large amount of air through the filter 60 attached to 55, and a predetermined amount of powder is discharged from the powder discharge port 56. Note that the hopper 52 is controlled so that a predetermined amount of powder is always stored therein, and when the storage amount is reduced by discharging the powder, the powder is sieved.
That is, the powder having a small bulk specific gravity is immediately charged into the hopper 52 from the powder charging port 54 to be replenished, and the powder discharging port 56 continuously repeats bag packing of the powder.

Here, the suction for deaeration has been conventionally performed at least while the screw auger is rotating, that is, while the packaging material such as a bag is filled with the powder. Alternatively, in some cases, the screw auger is continuously rotated without stopping during rotation of the screw auger or during rotation stop, that is, during movement of the bag before and after filling.

However, in the method of filling the bag while deaerating the powder, the flow of the powder is degassed when the powder conveyed by the screw conveyor falls from the powder discharge port. There is a problem in that the flow is irregular due to the action, the powder flow becomes irregular, and the filling amount often varies. In particular, in a vertical screw auger type powder filling device of a type in which the filling amount is controlled by the rotation speed and rotation time of the screw auger as shown in FIG. 5, the filling amount depends on the outflow state of the powder from the screw auger. Since it is affected, there is a problem that the degassing tends to cause variations in the filling amount.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the various problems based on the above-mentioned prior art, and to eliminate the problems in a screw auger type powder filling device equipped with a deaeration mechanism near the powder discharge part. Even if the powder is degassed by the air mechanism, there is no variation in the filling amount of the packaging material such as a bag, and it is possible to fill the packaging material with a high bulk density at a high speed and an accurate filling amount. It is another object of the present invention to provide a method of operating a powder filling device for carrying out the body filling method.

[0010]

In order to achieve the above object, the present inventor has made a bag of deaerated powder in a screw auger type powder filling device equipped with a deaeration mechanism in the vicinity of the powder discharge portion. When filling the packaging material such as, the method of operating the powder filling device so that the bulk density of the powder is sufficiently increased and the bulk density of the powder is sufficiently increased and the filling amount does not fluctuate. That is, the present invention has been achieved by obtaining the above knowledge.

The deaeration action in the above-described powder filling device is performed near the powder discharge portion, so that it is performed by, for example, sucking from the filter attached to the outer cylinder portion near the discharge port of the screw casing. Therefore, it is considered that the state of the inside of the powder is different from the state of the outside, and even if the screw is rotated, the powder becomes partially uneven. Therefore, in order to eliminate the unevenness of the powder flow, the time and space for that amount are required. Therefore, it is possible to stop the degassing time earlier, but if the degassing is stopped early, the degassing time may be insufficient and the apparent specific gravity (bulk density) of the powder may not be increased. According to the results of various studies by the inventors, it was found that a large increase in apparent specific gravity is mainly performed in the initial stage of degassing.

That is, according to the present invention, a screw auger type powder filling for filling a predetermined amount into a packaging material after degassing powder containing gas by a degassing mechanism provided in the vicinity of a powder discharge port for discharging powder A method for operating the apparatus, wherein degassing is started at the same time when the filling operation of the powder filling apparatus is started, and the degassing is stopped 30 to 70% of the total filling time after the start. The present invention provides a method for operating a powder filling device equipped with a pneumatic mechanism. Here, the degassing time from the start of degassing to the stop is 40 to 60% of the total filling time after the start of degassing.
Is preferred.

Further, the powder filling device includes a hopper having a powder charging port provided at an upper end of one end of the casing,
A casing having a powder discharge port below, in which a deaeration mechanism is incorporated so as to configure at least a part of the inner peripheral surface of the cylinder, and a screw incorporated in the casing,
It is preferable that the powder filling device is a vertical mold having a suction device that sucks and decompresses the deaeration mechanism. Further, the filter forming the degassing mechanism on the inner peripheral surface may be a porous sintered cylinder.

Further, the degassing mechanism uses at least one ring-shaped filter element having at least one surface roughened so that at least one of the contact surfaces becomes the roughened surface. A cylindrical laminated filter unit formed by laminating the filter elements is preferable. The filter is not particularly limited to this. here,
Although it is described as a vertical type powder filling device,
The powder filling device is not limited and may be a horizontal type.

[0015]

The operation method of the powder filling apparatus according to the present invention is a filling method for filling a packing material such as a bag with powder in a screw auger type powder filling apparatus equipped with a deaeration mechanism near the powder discharge port. Since the degassing is started at the same time as the operation, that is, the rotation of the screw auger is started, and the degassing is stopped at the time of 30 to 70%, preferably 40 to 60% of the total filling time, the powder containing gas such as air should be removed. In the initial stage, necessary deaeration was performed, and then the powder was packed into the packaging material placed directly below the powder discharge port as powder that had been consolidated to the required apparent specific gravity, and in the latter half, deaeration was stopped. After the compacted powder having a required apparent specific gravity is continuously filled for a predetermined time, the rotation of the screw is stopped and the filling is completed. Therefore, according to this operation method, the powder filled in the bag is compacted to an apparent specific gravity sufficient to fill the predetermined amount (weight) by the initial degassing, and the filling unevenness caused by the degassing is caused. Since the bag is filled with an accurate filling amount of the powder, the filling amount is not insufficient and the packaging is not defective.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for operating a powder filling apparatus having a deaeration mechanism according to the present invention will be described below in detail with reference to the preferred embodiments shown in the accompanying drawings.

FIG. 1 is a schematic block diagram of an embodiment of a powder filling apparatus having a degassing mechanism for carrying out the powder filling method according to the operating method of the present invention. As shown in the figure, the powder filling apparatus 10 has a popper 12 having a powder input port 12a in the upper part, a powder discharge port 14a in the lower part, and an upper part connected to the lower end of the popper 12. 14, a screw conveyor 16 suspended from the outer upper portion of the popper 12, inserted into the popper 12, and extending to the powder discharge port 14a of the casing 14, and the screw conveyor 1
6, a motor 18 for rotationally driving the motor 6, a transmission unit 20 for transmitting the rotation of the motor 18 to the screw conveyor 16, a level sensor 22 attached to the powder feeding port 12a of the popper 12, a casing 14, and a screw conveyor 16. The powder degassing device 26 has a filter 24 that allows only gas to pass from the powder carried by the powder degassing device 26, and degasses the powder through the filter 24. Constant flow rate control device 28 for quantitative control
And a vacuum pump 30 for sucking and depressurizing the powder deaeration device 26 with a predetermined intake amount via a constant flow control device 28, and provided between the powder deaeration device 26 and the constant flow control device 28. A sensor 3 for checking that an automatic valve 32 for controlling the deaeration time by the deaeration device 26 and a packaging container (hereinafter, simply referred to as a bag) 34 such as a bag are in a fixed position immediately below the powder discharge port 14a.
6 and a control device 38 that receives signals from the level sensor 22, the position sensor 36, and the like, and controls the rotation of the motor 18 and the opening / closing of the electromagnetic valve 32.

Here, the popper 12 stores the powder 11, and the degassed powder 11 is discharged from the powder discharge port 14a of the casing 14, and the powder 11 in the popper 12 is discharged.
At the same time, the powder 11 having a small bulk density, which has been sieved, is immediately replenished from the powder charging port 12a by a conveyor or the like not shown, and the powder 11 in the popper 12 is replenished.
Is controlled by the level sensor 22 so that the powder surface is always constant, and the powder pressure applied to the screw conveyor 16 is always constant.

In the powder filling apparatus 10 of the illustrated example, 1
Since the amount (weight) of powder to be filled in each bag 34 is set by the total number of rotations of the screw conveyor 16, that is, the rotation speed (number of rotations per unit time) and the driving time, the powder in the popper 12 is set. The state, the storage amount, the powder pressure applied to the screw conveyor 16 and the like are made constant. The rotation speed and drive time of the screw conveyor 16 are
It is configured to be accurately controlled to a value set according to the filling amount per time. The screw conveyor 16 conveys the powder 11 from the popper 12 through the casing 14 and after deaerating by the powder deaerator 26, the powder discharge port 14
It has a screw blade 16a for conveying the powder 11 and is rotated by a screw rotating shaft 16b. The screw rotating shaft 16b may have a stirring blade for crushing and stirring the powder above the screw blade 16a in order to make the powder density uniform.

The rotation of the motor 18 is controlled by the screw conveyor 1
6 is a gear (chain sprocket) 20 attached to the upper end of the screw shaft 16b.
a, a gear (chain sprocket) 20b attached to the rotary shaft of the motor 18, and these gears 20a and 2a.
0b and a toothed belt 20c that is stretched between them.
As described above, the filling amount per time is controlled by the total number of rotations of the screw conveyor 16, so that the motor 1
8 and the transmission means 20 must accurately start and stop driving of the screw conveyor 16. Therefore, the transmission means 20 can accurately transmit the rotation of the motor 18, and it is preferable to use a motor with a brake as the motor 18, but the present invention is not limited to this, and the motor with a brake can be used for the screw shaft. It may be directly connected to 16b, or a motor without a brake may be used.
A clutch or the like may be incorporated in the 0, or a rack and pinion may be used as the transmission means 20.

The casing 14 has a right cylindrical shape and is provided at the lower part of the popper 12 and has a powder discharge port 14a at the lower part thereof. The right cylindrical part slightly upstream of the powder discharge port 14a has an inner periphery. A powder deaerator 2 having a filter 24 that forms a surface and a suction device that sucks a gas such as air in the powder through the filter 24 is provided on the outer periphery of the filter 24.
6 is attached. Here, the filter 24 may be of any type as long as it can filter only the air in the powder, for example, a wire mesh, a punching metal (punching plate),
It is possible to use a porous screen, a sintered body of porous ceramics or metal, or a contact rough surface type laminated filter unit shown below. Also, filter 2
4 may be formed on the entire inner peripheral surface of the casing 14 or may be formed on a part thereof.

FIG. 2 is a sectional view showing the structure of an embodiment of the casing 14 incorporating the contact rough surface type laminated filter unit 40 used as the filter 24 in the present invention. In the figure, a casing 14 has an upper casing 41 having a connection port 41a for connecting to the popper 12 (see FIG. 1) in the upper part, and a right cylindrical portion 4 having a powder discharge port 14a in the lower part.
2, a filter casing 43 in which the laminated filter unit 40 is incorporated as the filter 24, and a suction degassing port 44a for sucking and degassing through the laminated filter unit 40, and the filter casing 43. 43 and a filter retainer 44 that supports the laminated filter unit 40. Here, each of the upper casing 41, the filter casing 43, the laminated filter unit 40, and the filter retainer 44 has an inner peripheral surface having the same diameter, and the screw conveyor 16 (see FIG. 1) can be housed therein.

The laminated filter unit 40, the filter casing 43 and the filter retainer 44 constitute the powder deaerator 26. The laminated filter unit 40 shown in FIG. 2 is formed by laminating the ring-shaped filter elements 45 shown in FIG. 3, and 11 laminated layers in the illustrated example. The filter element 45 has innumerable irregularities 47 formed on the laminated contact surfaces 46, that is, on the upper and lower surfaces of the filter element 45 in the figure, and has a roughened surface (rough surface) having a predetermined surface roughness. ) Is formed and laminated to form a predetermined gap, which functions as a filter. The contact surface 46 of the filter element 45 may be roughened on both the upper and lower surfaces, or on either surface, and can be formed by, for example, shot blasting or embossing. Filter element 45
Can be made of a material having a desired mechanical strength such as metal or ceramics.

The filter element 45 is provided with a collar 48 on the outer periphery of the roughened contact surface 46, and vent holes 49 are formed at several points of the collar 48, four points in the illustrated example.
In the lamination of the filter element 45, the ventilation hole 49
When the filter casing 43 and the filter retainer 44 are assembled, the corresponding ventilation holes 49 of the laminated filter unit 40 are configured to communicate with the suction / deaeration port 44a. Such a laminated filter unit 40 has a required mechanical strength, is less likely to be damaged even if it accidentally comes into contact with the blades 16a of the screen conveyor 16, and has a plurality of filter elements 45.
Since it can be disassembled individually, it has a feature that cleaning is extremely easy.

By the way, the right cylindrical portion 42 of the casing 14
Is preferably provided because it has a function of rectifying the flow of the powder discharged from the powder discharge port 14a, but it is not necessarily provided. Further, in order to prevent the powder from falling from the powder discharge port 14a after the screw conveyor 16 is stopped,
Although not shown, a shutter that operates simultaneously with the stop of the screw conveyor 16 may be provided.

The powder deaerator 26 is connected to the vacuum pump 30 via the automatic valve 32 and the constant flow controller 32 via the pipe 31, constitutes an intake system, and is operated during operation of the powder filling apparatus 10. The vacuum pump 30 is continuously operated, and the most characteristic deaeration time control of the present invention is performed by the automatic valve 32. The intake system used in the present invention is not particularly limited and is not limited to the illustrated example. The type of the automatic valve 32 is not particularly limited, and for example, an electromagnetic valve or the like can be used. Further, there is no particular limitation on how to combine the pipes 31, and the vacuum pump 30 serving as an intake source is not particularly limited, and any intake source may be used as long as it can inhale, for example, a fan, a blower, a compressor, a suction pump, or the like. May be used.

Further, the constant flow rate control device 28 provided in the intake system of the illustrated example is for making the degassing amount constant regardless of the internal state of the powder, and for improving the degassing efficiency. Is preferably provided in the intake system. In addition, the constant flow rate control device 28 has the effect of reducing the variation in the filling amount, and is therefore preferably used. The constant flow rate control device 28 is a device that obtains a constant flow rate by opening and closing a valve by utilizing a differential pressure due to Venturi, and a commercially available device can be used.

The control device 38 receives the signal from the level sensor 22 to control the replenishment of the powder 11 into the popper 12, and receives the signal from the position sensor 36 to detect the powder discharge port 14a of the casing 14. It is confirmed that the bag that has been filled is moved from immediately below and that a new unfilled bag is in a predetermined position immediately below the powder discharge port 14a, and the start and end of driving of the motor 18, that is, the filling time and the most of the present invention. This is for carrying out the operating method of the present invention by controlling the opening and closing of the automatic valve 32 that sets the characteristic deaeration time.

The powder filling apparatus for carrying out the operating method of the present invention is basically constructed as described above, and its operation and the operating method of the present invention will be described below. The controller 38 is set in advance with a filling time according to the size of the bag 34 and a predetermined deaeration time of 30 to 70% of the filling time. The vacuum pump 30 is steadily operated in advance so as to have a predetermined depressurized pressure, the automatic valve 32 is closed by the control device 38, the motor 18 is stopped, the shutter of the powder discharge port (not shown) is closed, and the level sensor 22 outputs. Upon receiving the signal, it has been confirmed that the level of the powder surface of the powder 11 in the popper 12 is at a predetermined level.

Here, the unfilled bag 34 is the powder outlet 14
When it comes to a fixed position directly under a, the position sensor 36 detects the bag 34 and transmits a signal to that effect to the control device 10. The control device 38 receives the signal from the position sensor 36 and receives the signal from the motor 18
Then, the automatic valve 32 is opened and the shutter of the powder discharge port (not shown) is opened. With the start of rotation of the motor 18, the screw conveyor 16 starts rotating via the transmission means 20, and the powder 11 is discharged from the powder discharge port 14a.
It is discharged from the bag and filled in the bag 34 immediately below. On the other hand, since the automatic valve 32 is also opened at the same time, the powder 11 is degassed by the powder degassing device 26 via the filter 24 provided in the straight cylindrical portion of the casing 14. Therefore, the powder 11 is filled in the bag 34 while being deaerated to the required degree.

During this time, the control device 38 rotates the motor 18 at a predetermined rotation speed and counts the time from the start of rotation or the cumulative number of rotations of the screw conveyor 16. Time from the start of this rotation (or cumulative number of rotations)
Becomes the preset deaeration time (or the converted number of revolutions), the control device 38 controls the automatic valve 32 to close. Although the degassing is stopped in this way, the screw conveyor 16 continues to rotate after the degassing is stopped, the powder is continuously discharged from the powder discharge port 14a, and the bag 34 is continuously filled with the powder. In this way, when the time from the start of rotation of the screw conveyor 16 or the accumulated number of revolutions reaches the preset filling time (or accumulated number of revolutions), the control device 38 stops the rotation drive of the motor 18, and the screw conveyer 16 To stop the rotation of. At this time, a shutter (not shown) of the powder discharge port 14a is closed at the same time. Motor 1
When a brake motor is used as 8 and a shutter is used, there is little variation due to information, and more accurate filling is possible.

In this way, the bag 34 filled with an accurate predetermined amount of powder having a sufficiently increased bulk density has the powder outlet 14
The bag is moved from immediately below a and conveyed to a sealing device (not shown), the mouth of the bag is sealed, and the packaging is completed. When the filled bag 34 moves from immediately below the powder discharge port 14a, the position sensor 36 detects this and transmits it to the control device 38.
After this, the control device 38 prepares or waits for the next filling until the next unfilled bag 34 comes directly below the powder discharge port 14a, and outputs a signal indicating that the bag 34 has come to the predetermined position. After receiving from the sensor 36, the above-mentioned filling operation is repeated again.

Thus, a predetermined weight, for example, 250 g, 5
High-speed filling of powder of 00g and 1000g into a bag of a predetermined size, for example, 60 bags / min, 120 at higher speed
It can be done continuously in bags / minute. Needless to say, the operating method of the present invention can be applied to filling at low speed, for example, when the filling time is 2 to 10 seconds / bag. Needless to say, the bag filled with the powder may be passed through a filling auxiliary device such as tapping as a post-process.

The most characteristic feature of the operating method of the present invention is that, in the powder filling apparatus having the degassing mechanism having the above-described structure, degassing is started at the same time when the powder is packed into the bag. However, it is to stop degassing within 30 to 70%, preferably 40 to 60% of the time required to start degassing for the filling time required to fill the predetermined amount. Here, in the present invention, the effect of increasing the apparent specific gravity (bulk specific gravity) due to degassing is that the degassing is not performed during the entire filling period and is stopped midway.
It started immediately after degassing and after some progress,
This is because the effect of increasing the bulk specific gravity is small even if the gas is saturated and degassing is continued to the end, and conversely, the variation in the filling amount due to degassing gradually increases.

In the present invention, the degassing time is 3 times the filling time.
When it is less than 0%, the deaeration time is insufficient, the deaeration of the powder is insufficient, the bulk density is low, and a bag of a predetermined size cannot be filled with a predetermined amount of powder or can be filled. However, there is a fear that the mouth of the bag will not be sealed well. On the other hand, when the deaeration time exceeds 70% of the filling time, the bulk density of the powder becomes sufficiently large, and the powder of a predetermined size can be filled well, but the filling amount varies.

The present inventors have found that the powder filling device 1 shown in FIG.
Using No. 0, the filling operation of filling 1 kg of wheat flour into the dedicated packaging container 34 was performed while changing the deaeration time. The filling time of the flour into one bag 34 during the filling operation is the time from the start of rotation of the motor 18 to the stop, and the change of the deaeration time changes the closing time of the automatic valve 32 and the opening time of the automatic valve 32. Was changed. The filling operation was continuously performed 100 bags for one type of deaeration time, and the weight of the flour filled in each of these 100 bags was measured, and the variation was measured as a standard deviation. Also, a packaging container 3 filled with flour
4 is constrained so that it closely fits a prismatic container having the same bottom, the height from the bottom is measured, and the volume is measured, and 100 is calculated from the total volume and total weight of 100 bags.
The average bulk density of the bag was measured. At this time, a larger packaging container was used, and filling was performed in the same manner even when degassing was not performed, and the variation in the filling amount and the bulk density were measured. FIG. 4 shows the results.

Incidentally, the structure of the main part of the powder filling device 10,
The dimensions and operating conditions are as follows. Length of screw conveyor 215mm Screw diameter 58mm Screw pitch 45mm Filter type Sintered wire mesh filter size 94mm Screw rotation speed 300rpm Depressurization 600mmHg Total filling time 0.7s Filling speed 43 pieces / min

As is apparent from FIG. 4, the effect of bulk specific gravity due to degassing begins immediately after the start of degassing and reaches a saturated state after progressing to some extent. On the other hand, looking at the influence of degassing on the filling by the screw conveyor, that is, the variation (standard deviation) of the filling amount due to the difference in the timing of stopping the intake for degassing before reaching the predetermined filling amount, It can be seen that when the time of stopping the intake of is longer than about half of the total filling time, the variation gradually increases, and when suction is continued until the total filling time required for filling, it considerably varies. Therefore, the degassing time should be 30 times the total filling time.
It can be seen that when the content is ˜70%, preferably 40 to 60%, the required increase in bulk specific gravity and the low variation in the filling amount can be obtained. Therefore, the degassing time is 3 times the total filling time.
It can be freely selected from 0 to 70% as required.

[0039]

As described above in detail, according to the present invention, the required deaeration can be sufficiently performed from the powder containing a gas such as air, and the bulk density is sufficiently increased to the required degree. The powder can be continuously filled at an accurate filling amount at high speed, and the variation in the filling amount can be suppressed.

[Brief description of drawings]

FIG. 1 is a schematic view of an example of a powder filling device that carries out an operating method of the present invention.

FIG. 2 is a cross-sectional view of an embodiment of a powder filling device casing used in the present invention and a powder degassing device incorporated therein.

FIG. 3 is a perspective view of an embodiment of a ring-shaped filter element of the powder degassing apparatus used in the present invention shown in FIG.

FIG. 4 shows the relationship between the variation (standard deviation) of the filling amount and the average bulk density of the filling powder with respect to the degassing time during the entire filling time when continuous filling is performed using the powder filling apparatus shown in FIG. It is a graph which shows.

FIG. 5 is a schematic view of an example of a conventional powder filling device.

[Explanation of symbols]

 10,50 Powder filling device 11 Powder 12,52 Popper 12a, 54 Powder input port 14,55 Casing 14a, 56 Powder discharge port 16,58 Screw conveyor 16a, 59 Screw blade 16b Screw rotating shaft 18 Motor 20 Transmission Means 22 Level sensor 24, 60 Filter 26, 62 Powder deaerator 28, 64 Constant flow controller 30 Vacuum pump 31 Piping 32 Automatic valve 34 Packaging container (bag) 36 Position sensor 38 Controller 40 Multilayer filter unit 41 Upper casing 42 Straight cylindrical part 43 Filter casing 44 Filter retainer 44a Suction degassing port 45 Filter element 46 Contact surface 47 Uneven surface 48 Collar 49 Vent hole

Claims (5)

[Claims] 1. A method of operating a screw auger type powder filling device for degassing powder containing gas by a degassing mechanism provided in the vicinity of a powder discharge port for discharging powder, and then filling a predetermined amount in a packaging material. The degassing mechanism is characterized in that degassing is started at the same time as the start of the filling operation of the powder filling device and is stopped 30 to 70% of the total filling time after the start. How to operate the powder filling device. 2. The degassing time from the start of degassing to the stop,
It is 40 to 60% of the total filling time after the start.
The method for operating the powder filling device according to 1. 3. The powder filling device has a hopper having a powder charging port provided at an upper end of one end of a casing and a powder discharging port below, and at least a part of an inner peripheral surface of the cylinder is configured. A casing with a built-in deaeration mechanism so that
The method for operating a powder filling apparatus according to claim 1 or 2, which is a vertical type powder filling apparatus having a screw incorporated in the casing and a suction device that sucks and decompresses the deaeration mechanism. 4. The method for operating a powder filling apparatus according to claim 1, wherein the degassing mechanism is a porous sintered cylinder. 5. The degassing mechanism comprises at least one ring-shaped filter element having at least one surface roughened.
The powder according to any one of claims 1 to 3, which is a cylindrical laminated filter unit in which the filter elements are laminated so that at least one of the contact surfaces is a roughened surface. How to operate the filling device.