JP3154960B2 - Powder compression machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a feeder for supplying powder and a method for compressing the supplied powder to increase the bulk specific gravity.
The present invention relates to a powder compressor comprising an axial roll compressor.

[0002]

2. Description of the Related Art When kneading powder such as talc or calcium carbonate with a liquid resin or the like, if the powder is bulky, the air in the powder is large and the kneading ability is reduced. To prevent this, the powder is compressed using a powder compressor to increase the bulk specific gravity of the powder, thereby facilitating the kneading of the powder with the liquid resin or the like. That is, when the powders are compressed, the powders agglomerate,
Air in the powder is reduced, and kneading becomes easier.

[0003] However, if the bulk specific gravity of the powder is too high, the powder is dispersed in the resin in a kneading process without being loosened up in a coagulated state. With this, sufficient kneading cannot be performed. For this reason, it is necessary to keep the bulk specific gravity of the powder within a predetermined range.

[0004] In order to maintain the bulk specific gravity (weight) of the powder within a predetermined range, as a method of measuring the weight of the powder, a powder compressed by a powder compressor is automatically slid every predetermined time. It is known to sample and weigh the sample (see JP-A-59-42200).

[0005]

However, in the above method, since the bulk specific gravity is not continuously measured, the bulk specific gravity cannot be adjusted immediately in response to a change in the bulk specific gravity. For this reason, it is difficult to obtain a powder having a predetermined bulk specific gravity. Also,
This device requires an automatic sampling device and an automatic weighing machine, and further requires a transfer means for returning the sampled powder to the original system, which complicates the entire device.

It is an object of the present invention to provide a powder compressor equipped with a bulk specific gravity measuring device capable of continuously measuring the bulk specific gravity and having a simple structure.

[0007]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a powder compressor in which powder is fed between a pair of rolls of a twin-screw roll compressor by a screw feeder and the powder is compressed. In, provided a chute for sending the powder compressed by the pair of rolls to the next step,
The chute has a portion whose path is oriented in the vertical direction. The inner volume of the chute, which receives a part of the compressed powder that falls, is set in the portion oriented in the vertical direction inside the chute.
A fixed sampling unit and a scale that weighs this sampling unit
The bulk specific gravity measuring device having a quantity unit provided, so that a predetermined bulk density, the powder supply amount to the upper Symbol biaxial roll compressor, the rotational speed of the pair of rolls, or, in the pair of rolls It is characterized in that at least one of the pressures between the rolls is controlled.

[0008] The above-mentioned bulk specific gravity measuring device is constituted by a cylinder having an open upper surface, a sampling section comprising an extrusion screw provided on a lower surface of the cylinder, and a weighing section for weighing the sampling section. By opening the tip of the screw of the sampling section, receiving a part of the compressed powder falling in the chute in the cylinder of the sampling section, and continuously extruding the cylinder with the extrusion screw,
It is characterized by continuously measuring the bulk specific gravity.

Since the bulk specific gravity measuring device capable of continuously measuring is provided in the chute, it is possible to continuously measure the bulk specific gravity of the falling powder, and to maintain the predetermined bulk specific gravity. Can be controlled.

Also, since the bulk specific gravity measuring device is provided in the chute, it is easy to return the sampled powder into the chute, and the structure of the bulk specific gravity measuring device can be simplified.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. The powder compressor according to the present invention includes:
As shown in FIG. 1, the screw feeder 1 feeds powder between a pair of rolls 21 and 22 of a twin-screw roll compressor 2 and compresses the powder.

The screw feeder 1 has a screw 13 suspended from a hopper 11.
It is rotated by a motor 12. An opening 14 is provided at the upper end of the hopper 11, from which powder to be compressed (hereinafter, referred to as "raw material powder") is supplied.

The twin-screw roll compressor 2 includes a pair of rolls 2.
1, 22 are arranged such that their peripheral surfaces can contact each other. A motor 23 is connected to the roll 21, and the roll 21 serves as a driving roll. Roll 2
2 is connected to a hydraulic cylinder 24 and can press the roll 22 against the roll 21. The roll 22 is rotated by a gear attached to the roll 21. Roll 21
And the roll 22 are disposed so as to be located at the top of the screw 13 above, and the raw material powder conveyed by the screw 13 is supplied between the roll 21 and the roll 22.

The powder compressed by the rolls 21 and 22 (hereinafter referred to as "compressed powder") falls below the twin-screw roll compressor 2, and is sent to the next step. A chute 25 is provided. This shoot 25
Has a part whose path is oriented in the vertical direction, and the bulk specific gravity measuring device 3 is provided in this part.

The bulk specific gravity measuring device 3 comprises a sampling unit 31 and a weighing unit 32, as shown in FIG. The weighing section 32 includes weighing means 35 such as an upper balance for weighing the sampling section 31. The sampling unit 31 includes a cylinder 33 having an open top surface,
It comprises an extruding screw 34 provided on a lower surface of the weighing unit 32, a mounting table 36 mounted on the weighing unit 32, and a motor 39 for rotating the extruding screw 34. The tip of the screw 34 is opened to form an open end 42. In addition, a column 37 is suspended from a mounting base 36 placed on the weighing unit 32. The cylinder 33 is fixed to a column 37 by an arm 38 penetrating the chute 25. A motor 39 is mounted on the mounting base 36.
Is mounted, and is connected to the extrusion screw 34 by the rotating shaft 40. Therefore, the entire sampling unit 31 is placed on the weighing unit 32, and the entire sampling unit 31 is weighed. The rotation of the rotating shaft 40 is held by bearings 41 provided on both sides of the support 35. The arm 38
And the rotating shaft 40 are connected to the protection tube 2 provided on the chute 25.
6 and 27 are protected. In addition, protection tubes 26 and 27
Also has a function of preventing the compressed powder from leaking from inside the chute 25.

Next, the operation of this embodiment will be described.
The raw material powder is supplied from the opening 14 of the hopper 11 and sent to the twin-screw roll compressor 2 by the screw 13. The fed raw material powder is roll 21 of the twin-screw roll compressor 2,
22. The compressed powder that has been aggregated by the compression falls into the chute 25. This shoot 2
The bulk specific gravity measuring device 3 is provided at a portion where the path 5 is oriented in the vertical direction. Therefore, a part of the compressed powder that falls falls into the cylinder 33 of the bulk specific gravity measuring device 3. If the compressed powder falls when the cylinder 33 is full, more compressed powder spills out of the cylinder 33 and falls below the chute 25.

If the weight of the sampling unit 31 when the compressed powder is not filled is previously measured by the weighing means 35, the weight of the filled powder is determined by measuring the weight of the sampling unit 31 at that time. Can be calculated. Since the internal volumes of the cylinder 33 and the extrusion screw 34 are determined, the bulk specific gravity of the filled powder can also be calculated.

At this time, when the extruding screw 34 is rotated, the compressed powder at the lower part of the cylinder 33 is pushed out of the sampling section 31 from the opening 42 by the extruding screw 34. When the compressed powder is extruded, the amount of the compressed powder in the cylinder 33 decreases, and new compressed powder falling from above the cylinder 33 is received. Therefore, by rotating the extrusion screw 34, the compressed powder in the cylinder 33 is sequentially replaced. Thus, if the weight of the sampling unit 31 is continuously measured, the average bulk specific gravity of the compressed powder in the cylinder 33 can be continuously measured. Therefore, when the bulk specific gravity of the falling compressed powder changes, the state of the change can be immediately grasped.

When a change in the average bulk specific gravity of the compressed powder occurs,
Each device is controlled to maintain a predetermined value of bulk specific gravity. In FIG. 1, the data of the bulk specific gravity measuring device 3 is sent to the controller 43, and the motor 23 is controlled to control the number of rotations of the roll 21, that is, the number of rotations 21 and 22 of the pair of rolls. The bulk specific gravity of the obtained compressed powder is kept at a predetermined value. The control target is not limited to the rotation speeds of the pair of rolls 21 and 22, and the amount of powder supplied to the screw feeder 1,
The amount of powder supplied to the twin-screw roll compressor 2, that is, the rotation speed of the screw 13, the pressure between the pair of rolls 21 and 22, ie, the pressure of the hydraulic cylinder 24 may be used. At least one of these may be controlled,
A plurality of controls may be performed.

The screw feeder 1 shown in FIG. 1 is of a vertical type, but may be of a horizontal type as shown in FIG. In this case, a screw feeder 51 is formed by covering the horizontal screw 53 with a casing 54. The hopper 52 is provided vertically at one end of the screw feeder 51. A twin-screw roll compressor 55 is attached to the other end of the screw feeder 51, and is arranged between the two rolls 21 and 22 so as to feed the raw material powder from the screw 53.
Then, the compressed powder compressed by the twin-screw roll compressor 55 is sent to the next step through a chute 56 having a portion whose path is oriented in the vertical direction. The above-mentioned bulk specific gravity measuring device 3 is provided in a portion of the chute 56 whose path is oriented in the vertical direction, and is controlled through a controller 57 so that the bulk specific gravity of the compressed powder is maintained at a predetermined value. Is done. That is, the powder compressor shown in FIG.
Is made horizontal, and the equipment and the arrangement method thereof are changed in accordance with the horizontal type. The operation and effect of each part are exactly the same as those of the powder compressor shown in FIG.

[0021]

According to the present invention, the bulk specific gravity of the compressed powder is continuously measured, and based on the measured value, the number of rotations of the roll,
The amount of powder supplied to the screw feeder, the number of rotations of the screw,
Since the pressing force between the pair of rolls is controlled, the change in the bulk specific gravity of the compressed powder can be quickly grasped, and the bulk specific gravity can be maintained at a predetermined value.

[Brief description of the drawings]

FIG. 1 is a schematic front view showing an example of a powder compressor according to the present invention.

FIG. 2 is an enlarged view of a part of a bulk specific gravity measuring device of FIG. 1;

FIG. 3 is a schematic front view showing an example of another powder compressor according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Screw feeder 2 Biaxial roll compressor 3 Bulk specific gravity measuring device 11 Hopper 12 Motor 13 Screw 21 Roll 22 Roll 23 Motor 24 Hydraulic cylinder 25 Chute 26 Protective tube 27 Protective tube 31 Sampling part 32 Weighing part 33 Tube 34 Screw 35 Weighing means 36 Mounting stand 37 Support 38 Arm 39 Motor 40 Rotating shaft 41 Bearing 42 Opening 43 Controller 51 Screw feeder 52 Hopper 53 Screw 54 Casing 55 Biaxial roll compressor 56 Chute 57 Controller

Claims (2)

(57) [Claims] 1. A powder feeder for feeding powder between a pair of rolls of a twin-screw roll compressor by a screw feeder and compressing the powder, wherein the powder compressed by the pair of rolls is transferred to the next step. A chute for feeding is provided, and this chute has a portion whose path is oriented in the vertical direction, and falls into a portion oriented vertically in the chute.
A constant volume sampler that receives a part of the compressed powder
The <br/> bulk specific gravity measuring device provided with a weighing unit for weighing the sampled portion and the ring portion, such that the predetermined bulk density, the powder supply amount to the upper Symbol biaxial roll compactor, the pair A powder compressor, wherein at least one of the number of rotations of the roll and the pressure between the pair of rolls is controlled. 2. The above-mentioned bulk specific gravity measuring device comprises a cylinder having an open upper surface, a sampling unit comprising an extrusion screw provided on a lower surface of the cylinder, and a weighing unit for weighing the sampling unit. The tip of the screw of the section is open, a part of the compressed powder falling in the chute is received by the cylinder of the sampling section, and is continuously extruded from the cylinder by the extrusion screw, thereby continuously. The powder compressor according to claim 1, wherein the bulk specific gravity is measured.