JP2002192017A - Separator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a separator which separates granular materials from the mixed state of the granular materials and powdery materials and which especially and efficiently separates and removes particulate materials and powdery materials adhering to the granular materials by moisture or static electricity. SOLUTION: The separator has a structure consisting of an outer layer cylinder 1 and an inner layer cylinder 2. An exhausting port 7 to discharge gases and particulate materials 14 is provided in the upper part of the inner layer cylinder, and an output port 9 to take out granular materials 12 to be separated is provided in the lower part. A cylindrical part 3 does not have a hole, but many holes 5 to pass powdery materials 13 are provided only at a conical shape part 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for producing a pellet or an unnecessary powder when a powdery substance remains in a pellet or granular product if the quality is unfavorable in subsequent processing. The present invention relates to an apparatus for efficiently separating substances.

[0002]

2. Description of the Related Art In the processing of pellet products for thermoplastic resins containing additives, etc., a melt extrusion prescription is generally taken, and the molten resin discharged from an extruder is cooled in a water tank, and the pelletizer is used. Cut to the required size to make pellets. At that stage, in addition to the pellets, powdery material called cutting powder is generated and mixed in the pellet product, and the powdery material causes trouble in the later process of molded products Separation and removal of objects are required.

A method using a vibrating sieve is used for the removal, but a part of the powdery substance adheres to the pellets due to moisture or static electricity. At present, the level of separation and removal of the powdery substance is low even after repeated sieving.

In order to improve the effect of separating the powdery material by the vibrating screen, vibration intensity and vibration direction are examined, and vibrations in multiple directions such as vertical and horizontal directions are simultaneously applied, or the screen is driven in a circular direction. Is being developed. However, in these methods, it is relatively easy to separate powdery substances that do not adhere to the pellets, but powdery substances that adhere to the pellet surface due to moisture or static electricity are not separated, and the number of screens is further increased. However, the separation effect does not increase.

In some cases, a washing method using water is employed to enhance the separation of powdery substances. However, this method requires additional treatment such as dehydration and drying to remove the used water, and the pellet production process is complicated. In addition, there is a problem that it involves multiple steps.

As another method, there is a method of separating powdery substances adhered by moisture or static electricity using a cyclone. Compared with the vibrating sieve method, the separation effect of fine powder smaller than powder is obtained, but it is slightly larger than fine powder (size between product size and fine powder size that can be processed by cyclone, medium Separation of powdery substances) and separation of powdery substances adhered by moisture or static electricity.
The level of removal is low. On the contrary, the pellets may be cracked due to the collision of the pellets in the cyclone, and the separation and removal level of the medium-sized powdery material may be lower than that of the processed product of the vibrating screen.

As a method for separating a powdery material using a cyclone, an apparatus having a structure comprising an outer cylinder and an inner cylinder and having holes or sieves in the inner cylinder is disclosed in JP-A-54-86868 and JP-A-54-86868. No. 56-124463, JP-A-64-4
No. 3,361, JP-A-1-274858 and the like.

In the apparatus disclosed in the above publication, the fine powder and the medium-sized powder were certainly better in separation efficiency and performance than the vibrating sieve, but the powder which adhered to the pellet due to moisture or static electricity was used. It was found that the materials could not be separated efficiently. In the apparatuses disclosed in JP-A-54-86868 and JP-A-64-43361, the material fed under pressure rotates around the cylindrical portion of the inner layer cylinder, but has a hole in the cylindrical portion. As a result, since the friction between the inner surface of the cylindrical portion and the material is large, the swirling flow velocity is reduced. Therefore, it is considered that the collision between the materials is reduced, and the effect of separating and removing the powder attached to the pellets is reduced.

In the apparatus described in Japanese Patent Application Laid-Open No. 56-124463, the inflow port is mounted eccentrically with respect to the shaft. Therefore, when the size difference or the weight difference between the pellet and the powder of the material to be treated is large, for example, the pellet size is 3.0 mm in diameter and 3.0 m in length, and the size of the powder is 0.1 mm, When the mixture is 0.1 mm, or when the pellet weight is 3 g and the powdery substance is 0.1 g, the pellets tend to flow in and drop to the center immediately. Therefore, it is considered that powdery substances adhered to the pellets by moisture or static electricity remain attached to the pellet surface, and their classification effect is reduced.

[0010]

The problem to be solved by the present invention is to separate the granular material from the mixed state of the granular material and the powdery material. It is an object of the present invention to provide a separation device for efficiently separating and removing fine particles and powdery substances.

[0011]

As a result of intensive studies to solve the above-mentioned problems, a double cylinder structure comprising an outer cylinder and an inner cylinder, wherein the upper part of the inner cylinder is a cylindrical part and the lower part is In a separation device having a cyclone structure that is a conical portion that is gradually reduced in diameter, the cylindrical portion is not provided with a hole, and the conical portion is formed in consideration of the state of mixing and mixing of powdery materials and the size of granular material. Only by providing a large number of holes with the optimal diameter and setting the opening ratio of the holes within a certain range in order to increase the separation efficiency, powder materials may be mixed or adhered due to moisture or static electricity. The present inventors have found that the granular material is efficiently separated, and have completed the present invention.

That is, the present invention focuses on the fact that the action of rubbing the surface of the granular material is required for separating and removing the powdery material and the cutting powdery material attached to the granular material by moisture or static electricity.
To make full use of the swirling flow due to the cyclone structure, no holes are provided in the cylindrical part, and holes are provided only in the conical part to provide a rubbing effect, so that powdery materials and chips can be separated efficiently. did.

The present invention will be described in detail with reference to the drawings while showing specific examples. FIG. 1 is a schematic device diagram showing an embodiment of the present invention, FIG. 2A is a diagram showing a shape of a pellet as a granular material, FIG. 2B is a diagram showing a powdery material attached to the pellet, and FIG. It is the schematic of the conventional apparatus. 1 and 3, the same reference numerals are used for the devices having the same function.

When holes or screens 5 are provided in the cylindrical portion 3 of the inner layer cylinder 2 as shown in FIG. 3, the inner surface of the inner layer cylinder is not smooth due to the holes or screens (mesh) and is in an uneven state. Particles that have a large friction with the object, which originally enter through the inlet 6, receive a sufficient swirling flow at the upper part of the inner cylinder, and those that should descend along the inner surface decelerate rapidly due to resistance with the inner surface Will be done. As a result, the cyclone effect is reduced, and the granular material falls downward.
Based on this result, as shown in FIG. 1, in the present invention, holes or meshes were not formed in the cylindrical portion.

Even if no hole is provided in the cylindrical portion, if the length L1 of the cylindrical portion is too short, the granular material 11 reaches the conical portion without obtaining a sufficient necessary swirling flow. The effect of rubbing on the inner surface hole of the portion is reduced. That is, since the circumferential speed (rotational flow velocity) of the air flow is rapidly reduced due to the contact resistance at the inner surface hole, the length L2 of the porous surface of the conical portion and the surface area of the hole cannot be used effectively, and Separation efficiency decreases.

On the other hand, if the length L1 of the cylindrical portion 3 is too long,
The speed in the circumferential direction gradually decreases during the revolving passage through the cylindrical portion, and the granular material 11 gathers at the center. For this reason, the amount of granular material contacting the porous surface of the conical portion 4 is reduced, and in many cases, the granular material 13 adhering to the granular material falls into the lower central outlet 9 without being separated.

From the above results, the relationship between the length of the cylindrical portion 3 having no holes and the length of the conical portion 4 having the holes is as follows.
Is sufficiently swirled along the inner surface of the inner cylinder, brought into contact with the porous surface, and rubbed to separate the powder 13 and discharge the powder from the hole into the gap between the outer cylinder 1 and the inner cylinder 2. In
The ratio of the length L1 of the cylindrical portion 3 to the length L2 of the conical portion 4 is
1: 1.5 to 1: 3 is preferred, preferably 1: 1.5 to 1: 1.5.
1: 2 range.

FIG. 2A shows the shape of a pellet as the granular material 12, which is a substantially cylindrical shape having a diameter D and a height L. FIG. 2B shows a powder 13 and a fine powder 14 containing cutting powder adhered to the granules 12. Conical part 4
The diameter d of the holes 5 provided in the hole is 30% to 90% of the diameter D and the height H of the pellets as the granules 12, so that the separation efficiency of the powders 13 can be increased, Preferably, the size is 60% to 80%.

Also, holes 5 for the total surface area of the conical portion 4
The aperture ratio is 15 when considering the durability considering mechanical strength and abrasion and not reducing the turning resistance of the pellet.
-30% is suitable, preferably 18-25%. The aperture ratio of a hole is a percentage obtained by dividing the total area of a large number of holes d provided in a conical portion by the total area of the conical portion.

The upper central exhaust port 7 can be adjusted upward and downward by an adjusting device 10, and the entrance length L3 into the inner cylinder 2 in accordance with the true specific gravity of the material pellets.
Can be adjusted, and when the material is changed, fine adjustment for obtaining suitable conditions can be easily performed, and the time for switching the product number can be reduced.

In the lower portion of the outer layer cylinder 1, a plurality of outlets 8 for taking out the separated medium-sized powdery substances 13 are provided at a plurality of places, in this embodiment three places. Thus, the powder 13 can be prevented from adhering to the porous surface in the conical portion, and the powder can be reliably discharged to the outside without deteriorating the effect of the conical porous surface.
It is also effective in preventing the clogging of the powdery substance at the outlet 8.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The apparatus according to the present invention has a structure comprising an inner cylinder 2 and an outer cylinder 1 as shown in FIG. 1, and an exhaust port 7 for discharging gas and fine particles 14 is provided above the inner cylinder.
In the lower part, an outlet 9 for taking out the granular material 12 to be separated
Was provided. The hole 5 through which the medium-sized powdery substance 13 passes only in the conical portion of the inner layer cylinder composed of the cylindrical portion 3 and the conical portion 4
Are provided, and no holes are formed in the cylindrical portion.

The exhaust port 7 for the fine powder 14 and the discharge port 8 for the medium-sized powder 13 can be used without deteriorating the separation performance even in the open state, but are shown for both scattering and collection of the powder. It is preferable to install a bag filter or the like that does not. Although the present invention is constituted by such a device configuration,
The present invention is not limited to these examples.

The pellets, which are the granular materials 11 to which the powdery materials 13 adhered to the apparatus of the present invention are adhered, move along the inner surface of the inner cylinder 2 according to the principle of cyclone, so that the pellets can appropriately collide with each other. Then, a rubbing action with the hole 5 provided in the conical portion 4 of the inner layer cylinder occurs, and the powdery substance 13 attached by moisture or static electricity is separated from the surface of the pellet. In particular, it is effective in separating chips adhering due to static electricity. The separated powdery substance passes through the hole and is
Discharge more outside.

The height and diameter of the outer layer cylinder and the height and diameter of the inner layer cylinder are determined by the known equations used in the conventional cyclone using the values of the size and throughput of the material pellet to be processed, the pumping power and the true specific gravity. It can be used to calculate suitable conditions and size, and can be used in the same manner as a normal cyclone.

[0026]

The present invention will be described in detail below with reference to examples and comparative examples. (Evaluation of Removal Rate) Samples for evaluating the separation and removal levels of powdery substances will be described. Material pellet 30
After drying 00 g with a hot-air dryer set at 100 ± 5 ° C. for 3 hours, the mixture was left standing for 1 hour in a desiccator, cooled to room temperature, weighed with a balance, and used as the weight of the collected sample before processing.

Next, the measurement sample was placed in a 5000 cc
After transferring to a polyethylene beaker having a capacity and adding a washing solution obtained by mixing 0.001 g of household detergent mama lemon and 2000 cc of tap water for household use, the entire container is slowly tumbled 10 times so as not to give a strong impact. Next, after the liquid component is filtered with a Kanakin No. 3 filter cloth, washing is performed twice with household tap water to remove the detergent. Thereafter, all the material pellets including the powdery substance remaining on the filter cloth are transferred to a beaker, and 2,000 cc of tap water is added.

Next, the granules are filtered through a sieve provided with a screen having openings of 80% of the average size of the pellets. Next, the filtrate was previously filtered with a filter paper of known weight (Toyo Filter Paper No.
Filtration using 2) is performed to obtain a powdery substance that has passed through the sieve as a filtration residue. The filter residue on the filter paper is dried under the above-mentioned drying conditions, then cooled by the same method as described above, and the weight is measured.
The weight of the filtration residue is calculated from the measured value and the weight of the filter paper. The above formulation is referred to as a water washing treatment method. By this method, the weight of the powder attached to the granular material is measured, and the degree of the mixture of the powder and the level of separation and removal of the powder from the particulate are evaluated. Was expressed as a percentage. The removal rate is obtained by calculation of (content of powder before treatment-content of powder after treatment) / content of powder before treatment.

(Preparation of Sample) After melt extrusion, 20 kg of a polypro-based resin colorant (master pellet) cut with a pelletizer was sampled. No treatment was performed in the subsequent step, and an average of 2 to 3% of powdery matter was attached. This is used as a test evaluation sample. 3 kg of each of them was treated by a water washing treatment method to evaluate the degree of mixing of powdery substances.

(Example) A master pellet as a sample was pressure-fed to a separation device of the present invention (pumping force 25 m / sec, 3
(000 mmAq, treatment amount 200 kg / h) A sample treated was collected, and the mixed amount of the powdery substance was evaluated by a water washing treatment method.
Further, the appearance of the treated pellets to be commercialized was visually confirmed, and the degree of adhesion of the powdery substance was evaluated. Table 1 shows the results. Removal rate is (2.2610-0.0008) /2.2610=9
9.96%.

Comparative Example 1 10 kg of the master pellet of the above sample was treated with a vibrating sieve (Tanaka Iron Works PSL type), and 3 kg of the master pellet was evaluated for the mixed amount of powdery substances by a water washing method. In addition, the appearance of the sieved pellets was visually confirmed, and the degree of adhesion of the powder was evaluated. Table 1 shows the results. The content of the powdery material before the treatment was 2.22.
At 12%, the content of the powdery material after the vibrating sieve treatment was 0.1%.
1901%. The removal rate was 91.44%.

(Comparative Example 2) A master pellet as a sample was fed under pressure (a pumping force of 25 m / sec, 3000 mmAq, throughput 200 kg / h), and a cyclone (tube diameter 400 mm, 50 mm).
(0 mm length, cone length 700 mm), and the mixed amount of powdery substances was evaluated by a water washing treatment method. Further, the appearance of the treated pellets to be commercialized was visually confirmed, and the degree of adhesion of the powdery substance was evaluated. Table 1 shows the results. The removal rate was 90.95%.

[0033]

[Table 1]

The apparatus of the present invention is effective for separating powdery substances in the sieving process of granular pellets used for processing coloring agents or additives for thermoplastic resins, and can separate powdery substances. Since the size distribution can be made large, it is easy to increase the efficiency of the sieving process.

In particular, the coloring pellets are required to have a high addition ratio, and the amount of powdered material tends to increase due to the properties of the coloring resin. Separation of powders is becoming more difficult. Even in an environment where a high degree of classification and separation is required, the apparatus of the present invention can be used in the same manner of use as a conventional cyclone without requiring any special apparatus or method of use.

For example, in addition to the sieving process of resin colorant pellets, granular products based on cereals (such as animal feed), chemicals with small particle sizes, and products requiring precision of uniform shape, In particular, it can be used in the separation or classification process of products in which mixing and mixing of powdery substances is regarded as a problem.

[0037]

The present invention has the effect of separating powdery substances in the pellet sieving process, particularly of powdery substances adhering to granular pellets due to moisture or static electricity.

[Brief description of the drawings]

FIG. 1 is an apparatus diagram showing one embodiment of the present invention.

FIG. 2 is a diagram showing a shape of a granular material and a shape of an attached matter.

FIG. 3 is a schematic view showing a conventional apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Outer cylinder 2 Inner cylinder 3 Cylindrical part 4 Conical part 5 Hole 6 Inflow port 7 Exhaust port 8 Discharge port 9 Outlet 10 Adjustment device 11 Granular material 12 Granular material 13 Powder material 14 Fine powder

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) B29B 9/16 B29B 9/16 // B29K 101: 00 B29K 101: 00 F term (reference) 4D021 AA16 CA01 FA25 GA02 GA05 GA06 GA08 GA14 GA20 GB01 HA10 4D053 AA03 AB01 BA01 BB02 BC01 BD04 CB01 CB08 CD08 CD11 CD17 DA01 4F201 AC01 AC04 AG03 AG08 AM27 BA02 BC02 BC12 BC15 BC19 BL47 BL50

Claims (3)

[Claims] 1. A double cylinder structure comprising an outer cylinder and an inner cylinder, wherein a discharge port is provided in the outer cylinder, an upper part of the inner cylinder is a cylindrical part, and a lower part is a conical part whose diameter is sequentially reduced. And
While providing an outlet in the lower part of the conical portion of the inner layer cylinder,
A separation device having a cyclone structure in which an exhaust port is provided above the inner cylinder, wherein only the conical portion of the inner cylinder is formed of a perforated plate. 2. The separation apparatus according to claim 1, wherein the ratio of the length L1 of the cylindrical portion to the length L2 of the conical portion of the inner layer cylinder is 1: 1.5 to 1: 3. . 3. The separation apparatus according to claim 1, wherein a plurality of outlets of the outer cylinder are provided.