JPH0344484Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a mixing hopper used for manufacturing a strip such as a plastic film or sheet from a mixture of the pulverized product of the strip and a granular raw material.

PRIOR TECHNOLOGY In order to manufacture belt-shaped products such as plastic films and sheets, a method is generally adopted in which raw materials are put into a hopper, stirred and mixed, and then sent to an extruder and extruded from a T-die or the like. Conventionally, a method has been adopted for raw materials to be introduced into the container, in which a crushed product obtained by recycling the non-products (so-called loss products) of the band-shaped material is added to new granular raw materials, and these are mixed in a mixing hopper. The above-mentioned non-products include so-called ears made by cutting the sides of a film or sheet to an appropriate width, products that are outside the standard width, defective products such as products with irregular thickness, cut scraps, and unsteady conditions at the start of operation. Rising products, etc. that occur in As mentioned above, the pulverized material obtained by pulverizing these materials is mixed with new granular raw materials to save granular raw materials and to effectively recycle non-products. In this case, it is necessary to sufficiently mix the two, and a mixing hopper is used.

FIG. 5 shows a conventional mixing hopper commonly used.

In the figure, the hopper main body 1 is formed from a conical portion 1a that expands upward and a cylindrical portion 1b that is connected to this expanded end. A granular raw material 2 and a pulverized material 3 are fed into the hopper main body 1 by suction or pressure feeding. The figure shows the case of pressure feeding, and the upper side of the hopper main body 1 has charging cylinders 6 and 7 having cyclones 4 and 5.
are concatenated. The granular raw material 2 is made of molten plastic cut in water or in the air, for example 3
A rod with a diameter of mm and a length of 3 mm, a 3 mm ball, 2 mm or 3
The crushed material 3 is formed from something like a square plate of mm square, and the crushed material 3 is a material obtained by pulverizing the above-mentioned strip, and the long side is 6 mm to 8 mm.
It is formed from a flat plate. Note that the bulk density of the pulverized material 3 is smaller than that of the granular raw material 2. The granular raw material 2 and the crushed material 3 are introduced into the cyclones 4 and 5 from the inlets as shown by arrows A and B. Furthermore, rotary valves 8 and 9 are interposed near the input cylinders 6 and 7 in the cyclones 4 and 5 for supplying a fixed amount of the granular raw material 2 or the pulverized material 3 into the hopper body 1.

A motor 10 and a reducer 11 are arranged in the upper part of the hopper main body 1, and the reducer 11 has an agitator 12.
A rotating shaft 12a of the hopper body 1 is connected to the hopper body 1, and is arranged to hang down from the center of the hopper body 1. A spiral blade 12c supported by an arm 12b is wound around the rotating shaft 12a at an appropriate twist angle. Note that the rotating shaft 12a rotates as shown by arrow c.

A level meter 13 is provided in the cylindrical portion 1a of the hopper body 1.
14 and 15 are provided, and a level meter 16 is also suspended at approximately the same position as the level meter 13 near the rotating shaft 12a. These level meters 13, 14, 15, 16 are connected to drive motors 17, 18 via control means (not shown). The drive motors 17 and 18 are used to adjust the opening degrees of the rotary valves 8 and 9. Also level meters 13, 16
indicates the upper limit of the granular raw material 2 and pulverized material 3 fed into the hopper main body 1, and the supply is stopped at this position. Further, the level meter 14 is used to display the lower limit, and is used to start supplying raw materials when the stored amount reaches this position. Further, the level meter 15 is for abnormality, and is used to issue an alarm when the storage amount falls below this level to notify of an abnormality. In addition, level gauges 13, 14, 15, and 16 are paddle type.
Various types such as electrostatic type, vibration type, and rotary type are used.

The hopper main body 1 having the above structure is connected to an extruder 19.

The granular raw material 2 and the crushed material 3 fed from the cyclones 4, 5 through the rotary valves 8, 9 into the hopper main body 1 from the feeding tubes 6, 7 are appropriately stirred and mixed by the spiral blades 12c of the agitator 12, and gradually enter the conical portion. It advances to the lower part of 1a, enters the extruder 19, and is sent out, for example, to the T-die side by the screw 20.

Problems to be Solved by the Invention The granular raw material 2 and the pulverized material 3 are stirred and mixed as described above using a mixing hopper as shown in FIG.
It had the following shortcomings.

1 To grasp the supply amount and storage amount with high precision using level meters 13, 14, 15, and 16, 1 each is required.
It is not enough to have one, and it is necessary to provide at least two of them at the same level, which makes them expensive. Furthermore, the level gauges 13, 14, 15, and 16 are all prone to failure and require time and effort to replace, causing a decrease in the operating rate of the hopper.

2 Drive motors 17 and 18 control rotary valves 8 and 9 by signals from level meters 13, 14, 15, 16, etc., but between the rotary blades and fixed blades of rotary valves 8 and 9, granular raw material 2 and crushed material 3 Problems such as jamming and malfunctions frequently occur, which reduces the operating rate of the hopper in the same way as described above.

3 In addition, if the rotary valves 8 and 9 are temporarily removed to solve the above-mentioned problem, not only will it become impossible to control the supply amount, but also the air for pressure feeding the material will directly enter the hopper body 1, causing the crushed material 3 inside the hopper body 1 to This may cause problems such as particles flying up and flying out from the cyclones 4 and 5 and being scattered around, or problems such as powder leaking from the seal portion of the screw 20 of the extruder 19.

4 Furthermore, even if the mounting positions of the level gauges 13, 14, 15, and 16 are selected well, the level inside the hopper body 1 is not constant, so the accurate raw material level cannot be ascertained, and the raw material is not supplied to the extruder 19 side. As a result, the thickness of the product becomes uneven, resulting in defects that reduce product quality.

This invention solves each of the above-mentioned problems. It eliminates the need for a level meter or rotary valve, simplifies the structure, significantly reduces costs, improves the hopper operation rate, and maintains the level of the deposited material at a constant level at all times. To provide a mixing hopper which enables smooth stirring and mixing of raw materials, improves product quality and yield through stable operation, and prevents powder leakage.

Means for Solving the Problems For this purpose, the present invention provides a partition member of an appropriate height across the hopper body above the spiral blade of the agitator that stirs and mixes the raw materials, etc. in the hopper body. The input end of one of the input tubes for inputting granular raw materials and crushed materials connected to the partition member is arranged above the upper end of the partition member, and the horizontal angle of the inclined line connecting the two is set so that the input tube is connected to the input tube for inputting granular materials and crushed materials. The input end of the other input tube is arranged above the lower end of the partition member, and the horizontal angle of the inclined line connecting the two is set to be at least smaller than the angle of repose of the raw material input from the input tube. The means for this purpose is a mixing hopper which is formed to be at least smaller than the angle of repose, and the helix angle of the spiral blade is formed in a direction in which the outer spiral blade advances upward as the agitator rotates.

Effect: The granular raw material and the crushed material are allowed to fall freely from the input cylinder above the mixing hopper, and are piled up in a state below the angle of repose limited by the partition member.In this state, the agitator is rotated, and, for example, the granular material is collected by the partition member. The pulverized material is covered over the pulverized material side, stirred and mixed, and the mixture is sent to the extruder side.

Embodiments Hereinafter, embodiments of the present invention will be described based on the drawings.

Components in FIGS. 1 to 4 with the same reference numerals as in FIG. 5 indicate the same components or components having the same function.

A charging cylinder 21 for inserting the granular raw material 2 into the hopper main body 1 and a charging cylinder 22 for charging the crushed material 3 are inserted above the hopper main body 1, respectively. Intermediate hoppers 23 and 2 are provided in the charging cylinders 21 and 22.
Cyclones 4 and 5 are connected via 4. From cyclones 4 and 5 to intermediate hoppers 23 and 24
The granular raw material 2 and the pulverized material 3 are fed under pressure, but the introduction from the intermediate hoppers 23 and 24 into the charging cylinders 21 and 22 is performed by free fall.

As shown in FIG. 2, the cylindrical portion 1 of the hopper body 1
A partition member 25 is installed across b,
It is fixed with a nut 26 or the like. The partition member 25 is formed, for example, from a square rod with a rectangular cross section, and has a height l along the axial direction of the rotating shaft 12a (FIG. 1).
is formed to an appropriate height. This dimension l is appropriately selected in consideration of the angle of repose of the granular raw material 2, the crushed material 3, the capacity of the extruder 19, etc. The partition member 25 is disposed above the spiral blade 12c as shown in FIG. 1, and the relationship between the partition member 25 and the charging tubes 21 and 22 is set as follows.

That is, the input end (insertion end) D of the input cylinder 21 is arranged above the upper end E of the partition member 25, and the horizontal angle α of the inclined line (indicated by a two-dot chain line) connecting therebetween is the same as the granular raw material 2. The angle of repose is at least smaller than the angle of repose of In addition, the input cylinder 22 input end (insertion end)
F is arranged above the lower end G of the partition member 25, and the horizontal angle β of the inclined line (indicated by a two-dot chain line) connecting therebetween is formed to be at least smaller than the angle of repose of the crushed material 3. Here, the angle of repose refers to the angle that the generating line of this cone makes with the horizontal plane when powder is gently dropped onto a flat surface from a funnel etc. It is the angle that the generatrix of this cone makes with the horizontal plane (Chemical Engineering Handbook), and the coefficient of friction of the powder etc. It is determined by the properties of Therefore, if the granular raw material 2 and the powder frame 3 are allowed to fall freely, they will be piled up in the hopper body 1 at their respective angles of repose. In FIG. 1, level types 27 and 28 are provided in the intermediate hoppers 23 and 24 to control the supply amount of the granular raw material 2 and the crushed material 3 that are fed under pressure from the cyclones 4 and 5, but in this embodiment, this is not always the case. It's not necessary.

Next, the operation of this embodiment will be explained in more detail.

For convenience of explanation, the horizontal angles α and β will be explained as being equal to the angles of repose of the granular raw material 2 and the pulverized material 3, respectively.

As described above, when the granular raw material 2 and the crushed material 3 are allowed to fall freely from the input cylinders 21 and 22, they are obstructed by the partition member 25, and the granular raw material 2 is piled up on the right side of the partition member 25 as shown in FIG. However, the crushed material 3 is piled up on the left. In this case, since the horizontal angles α and β are equal to the angle of repose, the granular raw material 2 is placed at the input end d of the input cylinder 21.
and the upper end E of the partition member 25, and the crushed material 3 rises and is deposited between the input end F of the input tube 22 and the lower end G of the partition member 25.
This rising state is always maintained in the same state unless the spiral blade 12c is rotated. Of course, the granular raw material 2 and the powder frame 3 are mixed in through the gaps between the spiral blades 12c, but the overall state is stably maintained as described above.

Next, as shown in FIG. 4, when the agitator 12 is rotated, the spiral blades 12c move upward as described above, so that the granular raw material 2 that has climbed upwards is transferred to the upper end E of the partition member 25. Move over the pulverized material 3 so as to cover it. Therefore, the accumulated amount of the granular raw material 2 is reduced by the amount of movement, so that the same amount of the granular raw material 2 is freely fallen and supplied from the input cylinder 21.
The granular raw material 2 moved to the pulverized material 3 side is moved to the spiral blade 12
While being stirred and mixed by c, the mixture advances below the conical portion 1a of the hopper main body 1 and is delivered to the extruder 19 side.
Therefore, the amount of crushed material 3 also decreases, and the amount of the input cylinder 22 decreases by that amount.
The pulverized material 3 is supplied from.

The above operations are repeated and the mixture is transferred to the extruder 19.
However, since the amount of the granular raw material 2 and the crushed material 3 deposited in the hopper body 1 is always kept constant, there is no need for a level meter as in the prior art. Furthermore, as mentioned above, since the reduced amount is supplied in a free fall manner, there is no need for a rotary valve or a drive motor for the rotary valve. This simplifies the device and allows it to be formed at low cost, and since there is no level meter or the like which often breaks down, there is no need to stop the device, and the operating rate of the hopper can be greatly improved. Further, as described above, since the raw materials can be stirred and mixed at the same deposition level at all times, stable mixing is performed, product quality is stabilized, and yield is improved. Further, unlike the prior art, the raw material is not directly forced into the hopper body 1, but is supplied by free fall, so that problems such as rising of the raw material and powder leakage from the extruder etc. do not occur.

In this embodiment, a rectangular section is used as the partition member 25, but the present invention is not limited to this, and the installation position, number, etc. of the partition member 25 are not limited to those shown in the drawings. Further, in this embodiment, the side into which the granular raw material 2 is introduced is arranged above the partition member 25, but the arrangement may be reversed so that the pulverized material 3 side is on the upper side.
Although not shown, in order to prevent the mixture from adhering to the inner wall of the hopper body 1, a scraper may be attached to the rotating shaft 12a of the agitator 12, for example, to remove the adhering material. Further, the spiral blade 12c is not limited to that shown in the drawings, but may be wound in multiple layers.

Effects of the invention As is clear from the above explanation, the invention eliminates the need for level meters, rotary valves, etc., simplifies the structure, significantly reduces equipment costs, prevents equipment failure, and improves hopper operation. In addition to improving
It is possible to maintain a constant level of deposited raw materials at all times, smoothly stir and mix raw materials, ensure stable product quality, improve yield, and prevent powder leakage from various parts. .

[Brief explanation of the drawing]

Fig. 1 is an axial sectional view of an embodiment of the present invention, Fig. 2 is a sectional view taken along the line - - of Fig. 1, Figs. The figure is an axial sectional view showing the structure of a conventional mixing hopper. 1... hopper body, 1a... conical part, 1b...
Cylindrical part, 2... Granular raw material, 3... Pulverized material, 4, 5
...Cyclone, 8, 9...Rotary valve, 1
0...Motor, 11...Reducer, 12...Agitator, 12a...Rotating shaft, 12b...Arm, 1
2c...Spiral blade, 13, 14, 15, 16, 2
7, 28... Level meter, 17, 18... Drive motor, 19... Extruder, 20... Screw, 21,
22...Insertion tube, 23,24...Intermediate hopper, 2
5...Partition member, 26...Natsuto.

Claims (1)

[Scope of utility model registration request] Granular raw materials and pulverized strips such as plastic films and sheets are charged into the hopper body from separate input cylinders, stirred and mixed by an agitator with a spiral blade on the rotating shaft, and the mixture is sent to an extruder. In the mixing hopper for forming the strip, a partition member of an appropriate height is installed above the spiral blade of the agitator in the hopper main body, and the feeding end of any one of the feeding tubes is connected to the upper end of the partitioning member. The horizontal angle of the inclined line connecting the two is formed to be at least smaller than the angle of repose of the raw material to be charged into the input tube, and the input end of the other input tube is set higher than the lower end of the partition member. The horizontal angle of the inclined line connecting the two is formed to be at least smaller than the angle of repose of the raw material charged into the input cylinder, and the helical angle of the helical blade of the agitator is adjusted as the agitator rotates. A mixing hopper characterized in that the spiral blades are formed in an upward direction.