JPH02307522A - Particulate material mixing apparatus - Google Patents

Abstract

PURPOSE:To enhance blend capacity by arranging a confluent pipe on the way of transport piping and inserting an additive charging pipe in the upper part of the confluent pipe. CONSTITUTION:Chips C flow down through a transport pipe 9 from a supply tank 1 so as to fill the transport pipe 9 and enters a confluent pipe 6 to be controlled to a level position L embedding the lower opening 8 of a charging pipe 7. The additive B discharged from a quantitative feeder 2 falls naturally through the charging pipe 7 and enters the confluent pipe 6 to meet with the chips C and these chips C are supplied to an extruder 3 from the lower end opening 8 through a transport pipe 5 while mixed with the additive B. The confluent pipe 6 has a diameter larger than that of the transport pipe 9 and the lower end opening 8 of the charging pipe 7 is arranged at an embedded position so as to become lower than the chip level surface L becoming the vicinity of the connection part of the transport pipe 9 to be capable of contributing to the enhancement of a kneading degree without receiving effect due to an angle of repose.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is directed to the use of powder or granular materials, particularly thermoplastic polymer granules such as polyamide, polyester, or polypropylene, in synthetic fiber manufacturing equipment, synthetic resin molding equipment, etc. It relates to a device for introducing and mixing additives such as matting agents, dyes, pigments, different types of pellets or chips in a conveying pipe.

(Prior Art) In recent years, various additives are added and mixed to chips in synthetic fiber manufacturing equipment, synthetic resin molding equipment, etc., and the chips are supplied to extruders, molding machines, etc. At this time, if the additives are insufficiently mixed, component unevenness will occur in the product after melt extrusion using an extruder, etc., so in addition to improving the accuracy of the additive supply device, it is necessary to use a biaxial extruder, a longer axis, and a molten polymer. A static in-tube mixer is installed in the system to improve kneading performance during melting.

On the other hand, the blending method at the chip stage is also very effective, and there are two ways to use it: a batch method and a continuous method.

Batch method uses Nauta mixer, double cone blender,
There are various models such as Henschel mixer, but
Since these devices are batch-type, they have good blending performance, but require a large space. In addition, they are extremely expensive and have complicated mechanisms, and require a lot of effort to maintain.

On the other hand, the continuous method requires a small space and is inexpensive and simple in terms of equipment, but the blending performance is generally poor.

As a means of improving this blending performance, it is conceivable to arrange a static type in-pipe mixer in the middle of the chip transport piping.

However, in order to improve the blending performance with this mixer alone, the number of elements in the mixer must be increased, which results in a long mixer, and the shape of the elements arranged in the tube is complex, resulting in a narrow space for the chips to pass through. There is a problem that clogging of the chip occurs within the flow path. In particular, those containing deformed or abnormal chips that occur during the granulation process and drying process after the polymerization process are likely to become clogged, and there is also the problem that an unnecessarily large mixer must be used.

(Purpose of the Invention) The present invention has been made in order to solve such conventional problems, and has been made in terms of space, energy saving, equipment cost, etc. when mixing additives in the transportation pipe of powder and granular materials. The purpose is to provide an efficient blending device.

(Structure of the Invention) That is, the present invention provides an apparatus for adding and mixing other powder or granular additives into a pipe that is filled with powder and transports the same in a fixed amount, and in which a part of the pipe is filled with powder and granules and is mixed with the other powder or granular additive in a substantially vertical direction. A confluence pipe is provided, and the transport pipes are connected so that the side part of the confluence pipe is the inlet of the powder and the lower end is the outlet, and the lower end opening is below the level of the powder and granule at the top of the confluence pipe. A powder and granule mixing device, characterized in that an additive input tube is inserted so as to be buried therein, and a stirrer is provided in the input tube such that the upper part of the stirring blade is positioned on the surface of the powder and granule. be.

Hereinafter, the present invention will be specifically demonstrated by examples.

(Example) Figure 1 is a schematic layout diagram showing an example of the present invention, and Figure 2 is an enlarged sectional view of section A in Figure 1. It was applied.

In the figure, 1 is a supply tank for synthetic polymer chips, 2 is a fixed quantity feeder for additives placed on the side thereof, and 3 is a melt extruder for chips placed below the fixed quantity feeder 2.

A transport pipe 5 for supplying chips is connected almost vertically to the supply port 4 of the extruder 3, and is connected to a merging pipe 6 disposed in the middle. A chemical injection pipe 7 is inserted, and a transport pipe 9 from the chip supply tank 1 is connected to the side.

As shown in FIG. 2, the merging pipe 6 has a larger diameter than the transport pipe 9, and the lower end opening 8 of the input pipe 7, which is inserted concentrically and perpendicularly to the upper end, faces the chip level near the connecting part of the transport pipe 9. It is placed in a position where it is buried lower.

Further, a stirrer 10 provided with stirring blades 11 is installed in the input pipe 7 so as to operate near the chip level surface. 12 is the motor of the stirrer.

In such a device, the chips C flow down from the supply tank 1 into the transport pipe 9 in a full state and enter the confluence pipe 6, where they are brought to a level position so as to bury the lower end opening -8 of the input pipe 7. regulated and maintained at approximately that level L. On the other hand, additive B, which is continuously and quantitatively discharged from the metering feeder 2, naturally falls down the input pipe 7 and enters the confluence pipe 6, where it enters the chip C.
and is mixed and supplied to the extruder 3 from the lower end opening 8 via the transport pipe 5.

In this case, in the case where two pipes are connected in a branched manner as shown in FIG. Nearby, the level surface L° of the chip C forms a slope with an angle approximately equal to its angle of repose, so the fallen additive B rolls down the slope and concentrates at the lowest part of the slope.

For this reason, the additive B flows in a solid state at one corner of the tube wall, and is not smoothly dispersed into the chip C, making it impossible to perform good mixing.

In contrast, in the present invention, the lower end opening 8 of the input tube 7 protrudes into the tip C of the merging tube 6 so as to be buried within the tip C, so that it is not affected by the angle of repose as described above. Additive B is dispersed over a considerable range and is no longer concentrated in one place.

However, the upper layer flows down while gathering at the center, and as it gets to the lower layer, it tends to flow like a piston flow. Almost uniform dispersion takes place, and the mixture flows down.

Here, the diameter of the input pipe 7 may be smaller than that of the transport pipe 5, but it is usually preferable to make it larger, and the flow of the chips C in the annular part surrounded by the input pipe 7 and the merging pipe 6 is greatly hindered. It is better to bring the diameter closer to the diameter of the confluence pipe 6 within a range where the diameter is not increased.

In addition, if the stirring blade 11 is a plate type, it is best to arrange it so that the lower end of the blade is approximately 5 to 50 mm below the chip level in the input pipe 7; even if it is deeper than this, the load on the motor will be reduced. Although it increases, the improvement in mixing degree is small.

It is preferable that the upper end of the stirring blade 11 protrude somewhat above the chip level. If the upper end is buried in the chip, foreign matter such as whisker-like chip debris may get wrapped around it, resulting in a decrease in the mixing degree. This can easily cause trouble.

The chips C that have exited the confluence tube 6 are supplied to the extruder 3 from the transport pipe 5 to become a melt and are transferred to the next spinning device, but the transport pipe 5 may be further provided with a static type in-tube mixer.

In this case, the static in-tube mixer does not necessarily need to be large and long as in the past, but even a simple and short type can be combined with the device of the present invention to further improve the mixing effect.

Next, using the equipment shown in Figures 1 and 2,
Add 3 colored chips of the same shape to a 2.5L (including a very small amount of deformed material) nylon chip 1-1 kg/sin.
It was added at a feed rate of 0 g/sin, and the mixing situation at the end of the transport pipe 5 was examined.

In order to compare the effects, an example in which a static type in-tube mixer was added to the one shown in Figure 3 is also shown.

The evaluation was carried out by attaching a square partition frame to the outlet of the transport pipe, measuring the number of two types of chips present in the square, and calculating the degree of mixing using the following formula. The results are shown in Table 1.
- σ2-σ2 M = - σ2-σ2 0 Y Here, M: Mixing degree (M=0 before mixing, complete mixing M-1) σ. 2
= Variance before mixing σa2: Variance in completely mixed state c'(1-21')/n
σ2: Dispersion c, : Contamination ratio of colored chips in material i ξ : Contamination ratio of colored chips in i in all materials n : Number of materials (number of squares) (Hereafter, blank space) Table 1: kenics: Number of chambers in the pipe 21 -m1xe
r: Number of chambers in the pipe 4 As is clear from Table 1, in the conventional device shown in Fig. 3, (
No. 1 to 4), it was difficult to obtain a product that is compact, free from blockage, and has a high degree of mixing, but with the device according to the present invention as shown in Figure 1 (No. 5 to 7), it is extremely compact. It can be seen that chips with good mixing properties without clogging can be stably obtained.

The motor load at this time is about 20 W, which is energy saving, and the initial cost is low.

Also, in No. 5, the space that required 1.2 m in No. 3.4 was shortened to 0.4 m.

In addition, as shown in No. 6.7, it is shown that the mixing effect can be further improved by combining a static type in-tube mixer on the downstream side.

(Effects of the Invention) As described above, according to the present invention, it is possible to efficiently mix powder and granules in the course of the chip supply piping in terms of space, energy saving, cost, etc., and also in the subsequent process. It greatly contributes to improving the degree of kneading, and its effects are extremely large.

[Brief explanation of drawings]

FIG. 1 is a schematic layout diagram showing an embodiment of the present invention, FIG. 2 is an enlarged sectional view of section A in FIG. 1, and FIG. 3 is an explanatory diagram of main parts showing a conventional example.

Claims (1)

[Claims] In a device that mixes other powder or granular additives into a pipe that is filled with powder and is transported in a fixed amount, a confluence pipe is arranged in a substantially vertical direction in the middle of the transport pipe, and the confluence pipe is The transport pipes are connected so that the side part is the inlet of the powder and the lower end is the outlet, and the additive input pipe is installed at the top of the confluence pipe so that the lower end opening is buried below the level of the powder. 1. A powder and granule mixing device, characterized in that a stirrer is installed in the input pipe and is arranged such that the upper part of a stirring blade is positioned on the surface of the powder and granule.