JPS624479A - Sorter - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] a. Industrial Application Field The present invention relates to a classifier, and more specifically, it is used to transport and classify various granular raw materials such as synthetic resins and pellets using a carrier gas, or to separate them from the gas. This article relates to a classifier that uses the following methods.

b. Conventional techniques and their problems Conventional conventional methods for classifying various granular raw materials include a sieving method and an air classification method.

The sieving method uses a vibrating sieve, which has a high classification efficiency, but its throughput is relatively low, and there are problems such as the screen becoming clogged.

On the other hand, in the case of the wind classification method, although its classification efficiency is lower than that of the sieving method, its throughput is relatively large.

Therefore, as an improvement plan for these, a wind sieving machine that uses both of the above methods in combination has been proposed.

As shown in Japanese Patent Application Laid-Open No. 57-153775 and Japanese Utility Model Publication No. 54-25097, this wind sieving machine transports raw material granules on a carrier gas onto a flat or cylindrical screen and passes them through. When the raw material is introduced into the screen, fine particles with a predetermined particle size or less pass through the mesh of the screen and are discharged from the fine particle outlet along with the air, while coarse particles that cannot pass through the screen are discharged by their own weight. It falls and is collected from the coarse particle outlet. At this time, since the particle size is approximately the same as that of the screen mesh, and the air flow passes perpendicularly to the screen surface, the particles tend to get stuck in the screen mesh, and the particles that clog the screen are passed through the slits of the air purge pipe. It is scattered and removed by the compressed air that is blown out, so that the throughput of the classifier does not deteriorate.

However, such a wind sieving machine requires a screen cleaning means such as an air purge pipe in order to prevent the screen from clogging, so the structure of the device is complicated.

In addition, as another classifier, the granular raw material is supplied together with a carrier gas to the lower part of a vertical cylindrical container, and the classification gas is supplied from the lower part of the cylindrical container to rise inside the cylindrical container. There is a method in which the fine particles of the granular raw material are taken out from the upper discharge port by the gas, and the coarse particles are dropped by their own weight and collected from the lower discharge port.

However, in such a classifier, the rising speed of the gas rising inside the cylindrical container needs to be set to be quite low, so the cylindrical container is formed to have a large diameter.

Therefore, the classifier itself has become large, and its installation area has also become large.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a classifier that has a simple structure, is easy to downsize, and exhibits excellent classification efficiency.

Means for Solving Problem C9 In the present invention, in order to achieve the above object, an inner cylinder having a screen portion, an outer cylinder surrounding the inner cylinder, and a carrier gas transport the granular raw material to the inner periphery of the inner cylinder. An introduction section to be introduced on the side;
a particulate discharge section that discharges the conveying air and the particulates that have passed through the holes in the inner cylinder; and a coarse particle discharge part that discharges the particulates that have not passed through the holes in the inner cylinder and have fallen to the lower part of the granular raw material. The classifier is composed of the discharge section and the discharge section.

d. Example Hereinafter, an example of the classifier according to the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIGS. 1 and 2, the classifier 1 includes a screen portion 2 formed with a large number of holes 3 except for the upper end portion 2a.
a right cylindrical inner cylinder 2 having a diameter of 1.b, a right cylindrical outer cylinder 4 surrounding the inner cylinder and made of, for example, a steel plate, and the inner cylinder 2 in which the granular raw material is placed on a carrier gas (for example, air). an introduction part 5 for introducing the particles into the core so as to rotate along the inner circumferential surface 2c; a particulate discharge part 6 disposed on the lower side of the outer cylinder 4; and a coarse particle discharge part 6 opened at the bottom of the outer cylinder. The upper opening of the outer cylinder 4 is closed by a lid 8.

The upper end 2a of the inner cylinder 2 has a length that is at least approximately equal to the vertical length of the introduction port 5a of the introduction part 5, so that the gas entering the inner cylinder through the introduction part 5 is It is guided by the upper end portion and smoothly shifts to a swirling motion, so that a swirling flow 9 is formed. There is no particular restriction on the flow rate of the introduction section 5, but it is preferably 5 to 5 Qm/sec, more preferably 10 to 30 m/see, particularly preferably 15 to 25 m/sec.

Further, the screen portion 2b of the inner cylinder 2 can be formed by a perforated plate having a large number of holes 3, but is not limited thereto, and can also be formed by a net.

In that case, a holding member for holding and fixing the cylindrical net at both ends of the classifier may be appropriately added. There is no particular restriction on the flow velocity of the screen portion 2b, but it is 0.1 to 39 m/s.
ec is preferred, more preferably 0.5-20m/5e
cs is particularly preferably 1 to 10 m/sec.

- The size of the pores 3 is appropriately determined depending on the particle size of the target classified fine particles. Usually 0.2-20U, preferably 0.5-10m, more preferably 1-5m
It is fi.

In the classifier 1 configured in this way, the granular raw material is introduced into the inner cylinder 2 in the tangential direction through the introduction part 5 by the carrier gas, and is moved inside while making a swirling motion on the swirling flow 9. It falls downward while moving along the inner peripheral surface 2C of the cylinder 2.

At this time, fine particles and carrier gas having a particle size smaller than the diameter of the hole 3 of the screen portion 2b are guided into the chamber 10 formed between the inner cylinder 2 and the outer cylinder 4 through the hole 3, The particles are sent via the particulate discharge section 6 to a particulate collection device (not shown) such as a cyclone or a back filter.

Further, at this time, coarse particles having a large particle size that cannot pass through the holes 3 fall due to their own weight, and are sent to a storage hopper or the like where the coarse particles are temporarily stored via a coarse particle discharge lower. At this time, by bringing the discharge lower and the storage hopper into close contact with each other, it is possible to prevent a large amount of conveyance air from being discharged from the discharge lower and to effectively discharge the conveyance air through the screen portion to the particulate discharge port 6. Can be done.

In the above classified state, the granular raw material rides on the swirling flow 9 and comes into contact with the screen portion 2b mainly from an oblique direction.
Particles having the same diameter as the pores of the screen are classified without clogging the pores 3.

Note that in the particle collection device, after the particles are collected, the carrier gas is released into the atmosphere.

FIG. 3 shows another embodiment of the classifier according to the present invention, and parts having the same functions as those shown in FIGS. 1 and 2 are given the same reference numerals. In the classifier 1) of this embodiment, the lower end 12a of the inner cylinder 12 is constricted into an inverted conical shape, so that classification can be performed more efficiently.

Note that the action of the classifier 1) is almost the same as that of the classifier 1 described above, so a detailed explanation thereof will be omitted.

FIG. 4 shows still another embodiment of the classifier according to the present invention, and parts having the same functions as those shown in FIG. 2 are given the same reference numerals.

In the classifier 13 in this embodiment, an exhaust pipe 14 is installed so as to open at the center of the lower part of the inner cylinder 12. The particulate-containing gas discharged through the pipe is combined with the particulate-containing gas and sent to a particulate recovery device (not shown) or the like.

In the classifier 13, the valve 15 is completely closed, and the valve 1
When 6 is fully opened, the classifier 1) shown in Figure 2
, and when the valve 15 is fully open and the valve 16 is completely closed, it is a normal solid gas that separates the particles and the carrier gas from the mixed gas of the particles and the carrier gas. It has the same function as a separation cyclone.

Therefore, the classifier 13 can of course be used not only as a classifier, but also as a cyclone when classification is not necessary. Moreover, by appropriately setting the opening degree of the valves 15 and 16, the classification rate can be increased. Adjustments can be made.

Next, we will show an example of how this classifier is generally used in a solid air transportation system. However, this classifier is not limited to this use.

FIG. 5 shows an example in which the classifier 13 is used in a pressure feeding method, and FIG. 6 shows an example in which the classifier 13 is used in a suction method.

5 and 6, 17 is a storage hopper that temporarily stores coarse particles discharged from the coarse particle discharge lower of the classifier 13, 18 is a fine particle recovery device, and 18a is located at the bottom of the fine particle recovery device 18. 19 is a hopper for supplying granular raw materials; 19a is a hopper 19 for supplying granular raw materials;
20 is a blower, 2 is a feeder installed at the bottom of the
1 is a suction blower, and 22 is a filter.

FIG. 7 shows the change in classification rate with respect to the opening degree of valve 15.16 of the classifier 13. The vertical axis shows the classification rate, and the horizontal axis shows the opening degree of valve 15.16 in percentage. There is.

Here, the opening degree of the valve 15 is indicated by A, and the opening degree of the valve 16 is indicated by B.

This graph shows an example of the classification results when classifying small resin particles (fine particles) contained in synthetic resin pellets. In this example, the operation was continued for 12 hours, and the blower pressure during use was There was no change, and the hole 3 of the inner cylinder 12 was not clogged when opened for inspection after use.

The conditions for this test are listed below.

Contains fine particles: 60 mesh pass 200 mesh pass 0.
5wt% Size of inner cylinder 12; diameter 550 m, length 8
00 Size of hole 3 of inner cylinder 12; Diameter 1.5, pitch 3 Size of outer cylinder 4; Diameter 650, length 800
Flow rate of in introduction part 5: Approximately 20 m/sec Flow rate of screen part 2b: Approximately 4 m/sec Conveying pellets; 15 ton/hr Conveying gas; Air conveying gas amount: 47rr? /+atn 60 mesh pass 200 mesh particle classification rate e9 As is clear from the detailed description of the invention, the classifier according to the invention has the following excellent effects.

(1) Since it does not have a device with a complicated configuration such as rotational drive or vertical movement, it has the same classification performance as a conventional wind classifier, but it has a small and simple structure, and the manufacturing cost is also reduced. possible, and there are fewer failures.

(2) Since clogging in the inner cylinder is prevented by the swirling flow, a special mechanism for cleaning the inner surface of the inner cylinder is not required.

(3) Since the classifier can be easily downsized, the area required for installation can be reduced.

(4) Conventional vibrating sieves have a relatively small capacity, and the wind classifier has a large capacity, requiring very large equipment, but the classifier of the present invention has no restrictions on processing capacity and has a large capacity. Even if the capacity is high, the equipment can be small.

(5) Suitable for separating fine fragments of synthetic resin pellet products.

(6) It is suitable for separating a small amount of fine particles with a particle size of 2 or less from a granular material of a certain particle size.

[Brief explanation of drawings]

1 and 2 conceptually show an embodiment of the classifier according to the present invention, FIG. 1 is a sectional view thereof, FIG. 2 is a plan view thereof, and FIG. 3 is a diagram showing an embodiment of the classifier according to the present invention. FIG. 4 is a sectional view conceptually showing another embodiment of the classifier, FIG. 4 is a sectional view conceptually showing still another embodiment of the classifier according to the present invention, and FIGS. FIG. 4 is a block diagram showing an application example of the classifier shown in FIG. 4, and FIG. 7 is a graph showing the characteristics of the classifier shown in FIG. 1, 1). 13... Classifier, 2,12... Inner cylinder, 2b... Screen part, 3... Hole, 4...
...outer cylinder, 5...introduction part, 6...fine particle discharge part, 7...coarse particle discharge port. 1) Figure Figure 3 Figure 2 Figure 4 Hit ○ Suga-×

Claims (2)

[Claims] (1) An inner cylinder having a screen part, an outer cylinder surrounding the inner cylinder, an introduction part that introduces the granular raw material into the inner peripheral side of the inner cylinder by means of a carrier gas, and a screen that connects the carrier gas and the screen of the inner cylinder. A classifier comprising: a fine particle discharging section for discharging passed fine particles; and a coarse particle discharging section for discharging coarse particles of the granular raw material that have failed to pass through the screen and have fallen. (2) The classifier according to claim (1), further comprising an exhaust pipe that opens into the inner cylinder.