JP2012144008A - Dehydration method and apparatus for slurry that is mixture of synthetic resin pellet and hot water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform an efficient dehydration by a slot formed in a screen.SOLUTION: The dehydration method and apparatus comprise a process and a constitution, respectively, to dehydrate a synthetic resin pellet (23a) through a screen (16) in dehydrating a slurry; wherein the slurry is a mixture comprising the synthetic resin pellet and hot water, the pellet (23a) is extruded from an extruder (2) and the screen (16) comprising a punching plate with a number of slots (25) formed in it.

Description

  The present invention relates to a method and apparatus for dewatering a slurry, which is a mixture of synthetic resin pellets and hot water, and more particularly to a novel improvement for efficient dewatering by means of long holes formed in a screen.

In the present invention, as a method for dehydrating a slurry which is a mixture of synthetic resin pellets and hot water, for example, the configurations disclosed in Patent Documents 1 to 4 are proposed.
First, in the case of Patent Document 1, although a dehydrating apparatus that can process a large amount of slurry by combining a cylindrical screen and a spiral plate, the configuration of the apparatus is complicated.
In the case of Patent Document 2, the self-cleaning centrifugal pellet dryer is composed of a cylindrical screen and a pressurized fluid nozzle assembly for cleaning the pellets. However, the apparatus configuration is complicated and large.
Moreover, in the case of patent document 3, although the structure which embossed the screen was used in order to improve the performance of a centrifugal dehydrator, the centrifugal dehydration structure was complicated.
In the case of Patent Document 4, a multi-layered screen is used for the purpose of improving the performance of the centrifugal dehydrator. However, the multi-layered screen has a complicated structure and increases the cost.

As other conventional configurations of the dehydrator disclosed in the above-mentioned Patent Documents 1 to 4, although the patent document is not disclosed, the configuration and screen of the dehydrator shown in FIGS. .
That is, in the configuration of FIG. 7, the synthetic resin raw material 1 supplied into the extruder 2 is melted in the extruder 2 and extruded from the die 3. The extruded molten synthetic resin is cut into a predetermined size in warm water by the underwater cutter 4 and is cooled and solidified in the warm water 9 of the warm water tank 8 to generate synthetic resin pellets 13.
The warm water 9 is stored in the warm water tank 8 and is conveyed by the pump 7.
The slurry 5, which is a mixture of the synthetic resin pellets 13 and the hot water 9, is conveyed to the dehydrator 10 through the pipe 6. Most of the hot water 9 is separated and returned to the hot water tank 8 by the dehydrator 10, but the slurry 5, which is a mixture of a small amount of hot water 9 and the synthetic resin pellets 13, is transported to the centrifugal dryer 11 to be synthesized resin. The water adhering to the pellet 13 is removed. Thereafter, the synthetic resin pellets 13 are sorted by size with the vibrating sieve 12.

Next, the operation of the synthetic resin pellet dehydrator shown in FIGS. 8, 9, 10, 11, and 12 will be described. First, in the configuration of FIG. 8, the box 10 a of the dehydrator 10 includes a slurry supply port 14, a slurry receiver 15, a flat screen 16 installed in an inclined manner in the box 10 a, a slurry discharge port 17, A drain port 18 is installed.
The conveyed hot water 9 and the slurry 5 of the synthetic resin pellets 13 are supplied from the slurry supply port 14, and the slurry 5 is temporarily stored in the slurry receiver 15, and the overflowed slurry 5 flows down on the screen 16 installed in an inclined manner. .

The screen 16 is a metal punching plate in which a round hole 21 is punched. When the slurry 5 flows on the screen 16 installed in an inclined manner, most of the hot water passes through the round hole 21 formed in the screen 16 and is discharged from the drain port 18.
On the other hand, since the diameter of the synthetic resin pellet 23 having the normal diameter is larger than the hole diameter 22 of the round hole 21 processed into the screen 16, the normal diameter synthetic resin pellet 23 flows down on the screen 16 without passing through the screen 16. It is discharged from the slurry discharge port 17 together with the hot water 9.
In addition, since the hole diameter 22 must be smaller than the synthetic resin pellet 23 having the normal diameter as described above, the hole diameter 22 is designed based on the size of the synthetic resin pellet 23 to be manufactured.
As shown in FIG. 9, a cylindrical dehydrator in which an umbrella 20 is installed in the flow path of the slurry 5 to change the flow direction to the surroundings and a cylindrical screen 16 is installed is also conventionally used.

JP 2002-301313 A JP 2006-142814 A Japanese Patent Publication No. 2010-529396 Japanese Patent Publication No. 2008-524553

Since the conventional dehydrator is configured as described above, the following problems exist.
That is, the configurations of the dehydrators disclosed in Patent Documents 1 to 4 described above all have the problems described above, whereas the configurations of the dehydrators illustrated in FIGS. As shown in FIG. 2, a round hole 21 is punched in the screen 16 used in the conventional dehydrator 10. In this case, as shown in FIG. 12, since the diameter of the synthetic resin pellet 23 having the normal diameter is larger than the hole diameter 22 of the round hole 21, the round hole 21 is not clogged. When extrusion is unstable, as shown in FIG. 13, a synthetic resin pellet 23a having a smaller diameter than usual may be generated.
That is, as shown in FIG. 13, this small-diameter synthetic resin pellet 23 a may be clogged in the round hole 21 of the screen 16.
Since the synthetic resin pellet 23a is a sphere (or a cylinder), when the round hole 21 is clogged as shown in FIGS. 14 and 15, the periphery of the inner wall of the round hole 21 is integrated with the screen plate and has elasticity and springiness. Since it was not in a state, it was fixed in a state where force was applied from various places around the inner wall, and did not easily come off the screen 16.
For this reason, there is a problem that the dewatering ability of the dehydrator 10 is lowered and the continuous operation for a long time cannot be performed because the small diameter synthetic resin pellets 23a are clogged in the round holes 21 processed in the screen 16.

  The present invention relates to a dewatering method and a dewatering apparatus thereof in which clogging of a screen does not occur even when a synthetic resin pellet having a smaller diameter than usual is generated by using a metal punching plate with a long hole processed as a screen of a dehydrator. The purpose is to provide.

  The method of dewatering a slurry, which is a mixture of synthetic resin pellets and hot water according to the present invention, comprises a slurry, which is a mixture of synthetic resin pellets extruded from an extruder and hot water in an underwater cutter, with hot water via a screen of the dehydrator. In the method of dewatering a slurry, which is a mixture of synthetic resin pellets and hot water separated into synthetic resin pellets, the screen is a method using a punching plate in which a number of long holes are formed, and the long holes The width along the width direction orthogonal to the length direction is a method that is smaller than the diameter of the synthetic resin pellets, and is a long connecting portion integral with the screen formed between the long holes. The width of the connection portion in the same direction as the width direction of the width is a method that is smaller than the width of the elongated hole, and each elongated hole is in the screen, The longitudinal direction is formed in a horizontal or inclined C shape, and the long holes are arranged in parallel to each other, and is a mixture of the synthetic resin pellets and hot water according to the present invention. The slurry dewatering device is a mixture of synthetic resin pellets extruded from an extruder and warm water in an underwater cutter, and the slurry is separated into warm water and synthetic resin pellets via a dehydrator screen. In the dewatering device for slurry which is a mixture with hot water, the screen is configured to use a punching plate in which a number of long holes are formed, and the width along the width direction perpendicular to the length direction of the long holes is The width of the width of the longitudinal connection portion integral with the screen formed between the long holes is smaller than the diameter of the synthetic resin pellet. The width of the connecting portion in the same direction as the direction is smaller than the width of the elongated hole, and each elongated hole has a C-shaped shape whose length direction is horizontal or inclined in the screen. The long holes are arranged in parallel to each other.

Since the slurry dewatering method and apparatus, which is a mixture of the synthetic resin pellets and hot water according to the present invention, is configured as described above, the following effects can be obtained.
That is, a mixture of synthetic resin pellets and hot water in which slurry, which is a mixture of synthetic resin pellets extruded from an extruder and hot water in an underwater cutter, is separated into hot water and synthetic resin pellets via a dehydrator screen. In the slurry dewatering method and apparatus, the screen uses a punching plate in which a large number of long holes are formed, so that screen clogging does not occur even if synthetic resin pellets having a smaller diameter than usual are generated, and dewatering is performed. Capability has been prevented from decreasing, and continuous operation for a long time has become possible.
Further, since the width along the width direction orthogonal to the length direction of the long hole is smaller than the diameter of the synthetic resin pellet, screen clogging can be prevented even when a synthetic resin having a small diameter is generated.
In addition, the connecting portion width in the same direction as the width direction of the long connecting portion integral with the screen formed between the long holes is smaller than the width of the long holes, The connecting part has sufficient elasticity and springiness to prevent the synthetic resin pellet from fitting into the elongated hole, and even when it is fitted, it will pop out of the elongated hole due to this elasticity and springiness. Can do.
In addition, each of the long holes is formed in a C-shape whose length direction is horizontal or inclined on the screen, and the long holes are arranged in parallel to each other, so Can be efficiently dehydrated.

It is a top view which shows a part of screen in the dehydration apparatus of the slurry which is a mixture of the synthetic resin pellet and warm water by this invention. It is sectional drawing of FIG. It is a top view which shows the state which the synthetic resin pellet engaged with the long hole of FIG. FIG. 4 is a cross-sectional view of FIG. 3. It is a top view which shows the other form of FIG. It is a top view which shows the other form of FIG. It is a block diagram of the granulation apparatus used by this invention and conventionally. It is a cross-sectional block diagram which shows the dehydrator of FIG. It is a cross-sectional block diagram which shows the other form of FIG. It is a top view which shows the conventional screen. It is sectional drawing of FIG. It is sectional drawing which shows the state in which the synthetic resin pellet larger than a hole diameter slides down on the screen of FIG. It is sectional drawing which shows the state which the synthetic resin pellet engaged with the round hole of the screen of FIG. It is a top view which shows the state which the synthetic resin pellet engaged with the round hole of the screen of FIG. It is sectional drawing of FIG.

  An object of the present invention is to provide a method and an apparatus for dehydrating a slurry, which is a mixture of synthetic resin pellets and hot water, which are efficiently dehydrated by long holes formed in a screen.

Hereinafter, preferred embodiments of a method and apparatus for dewatering a slurry, which is a mixture of synthetic resin pellets and hot water, according to the present invention will be described with reference to the drawings.
Note that the same or equivalent parts as in the conventional example will be described using the same reference numerals. Moreover, the granulation apparatus shown in FIG. 7 and the natural flow dehydration type dehydrator which is not the centrifugal dehydration type shown in FIGS. 8 and 9 are also incorporated in the present invention.

The synthetic resin raw material 1 supplied into the extruder 2 in FIG. 7 is melted in the extruder 2 and extruded from the die 3. The extruded molten synthetic resin is cut into a predetermined size in warm water by the underwater cutter 4, cooled and solidified by the warm water 9, and synthetic resin pellets 13 are generated. The synthetic resin pellet 13 has a spherical shape or a cylindrical shape.
The hot water 9 is stored in the hot water tank 8 and is transported by the pump 7.
The slurry 5, which is a mixture of the synthetic resin pellets 13 and the hot water 9, is conveyed to the dehydrator 10 through the pipe 6.
Most of the hot water 9 is separated and returned to the hot water tank 8 by the dehydrator 10, but the slurry 5, which is a mixture of a small amount of hot water 9 and the synthetic resin pellets 13, is carried to the centrifugal dryer 11. In the centrifugal dryer 11, moisture adhering to the synthetic resin pellets 13 is removed, and then the synthetic resin pellets 13 are sorted by size with the vibrating sieve 12.

The box 10a of the dehydrator 10 in FIG. 8 is provided with a slurry supply port 14, a slurry receiver 15, a screen 16, a slurry discharge port 17, and a discharge port 18 installed in an inclined manner in the box 10a. .
The conveyed hot water 9 and the slurry 5 of the synthetic resin pellet 13 are supplied from a slurry supply port 14. The slurry 5 is once stored in the slurry receiver 15, and the overflowed slurry 5 flows down on the screen 16 installed in an inclined manner.
As shown in FIG. 1, the screen 16 is a metal punching plate in which long holes 25 are punched. When the slurry 5 flows on the screen 16 installed in an inclined manner, most of the hot water is transferred to the screen. 16 passes through the long hole 25 processed into 16 and is discharged from the drain port 18. The width 31 along the width direction B orthogonal to the length direction A of the long hole 25 is smaller than the diameter D of the synthetic resin pellet 23a. Between the long holes 25 of the screen 16, an elongated connection portion 30 integrally formed with the screen 16 is formed, and the connection portion width 32 of the connection portion 30 is in the same direction as the width 31. The part width 32 is smaller than the width 31 of the long hole 25.

In the above-described configuration, the diameter D of the normal diameter synthetic resin pellet 23 is larger than the width 31 of the long hole 25 processed into the screen 16, so that the normal diameter synthetic resin pellet 23 does not pass through the screen 16 and passes over the screen 16. It flows down and is discharged from the slurry discharge port 17 together with a small amount of hot water 9.
When a small diameter synthetic resin pellet 23a having a diameter D slightly larger than the width 31 of the long hole 25 flows into the screen 16, the small diameter synthetic resin 23a is clogged in the long hole 25 and is temporarily fixed.
However, in the case of the long hole 25, since the pellet 23a is fixed only by the two connection portions 30, the pellet 23a is easy to move, and the connection portion 30 of the screen 16 is easily elastically deformed by processing the long hole 25. Therefore, when the water flow or the like of the slurry 5 hits, the fixation is easily released, and the small-diameter synthetic resin pellets 23a are dropped from the long holes 25 and discharged together with the slurry 5 from the slurry discharge port 17.
As described above, by using the metal punching plate in which the long hole 25 is processed as the screen 16 of the dehydrator 10, it has been found that the clogging of the screen 16 does not occur even when the small-diameter synthetic resin pellet 23a is generated. .
As a result, the dehydration ability that has been generated due to the clogging of the screen 16 does not decrease, and continuous operation for a long time becomes possible.

Further, the operation will be described.
As shown in FIGS. 14 and 15, in the case of the round hole 21, the small-diameter synthetic resin pellet 23 a is clogged so as to close the entire round hole 21, and is fixed from the entire circumferential direction of the pellet 23 a. Further, since the metal around the plate of the round hole 21 is not easily elastically deformed, once the small diameter synthetic resin pellet 23a is fixed to the round hole 21, it cannot be easily detached.
However, as shown in FIGS. 3 and 4, in the case of the long hole 25 of the present invention, since the pellet 23a is fixed only by the two connection portions 30, the pellet 23a is easy to move. Further, since the connecting portion 30 of the screen 16 is easily elastically deformed by the processing of the long hole 25, the fixing is easily released by the water flow of the slurry 5 and the like, and the small-sized synthetic resin pellets 23a are removed from the long hole 25. Drop off and the downstream process is carried.
As a result of the above action, it was found that when the dehydrator 10 using the screen 16 in which the long holes 25 are processed is used, the small-diameter synthetic resin pellets 23a are not clogged with the screen 16 and can be continuously operated for a long time. did.

In addition, according to the dimensions of the synthetic resin pellets 23a to be produced,
The width 31 of the long hole 25 is: 0.5 mm to 6 mm
The length 33 of the long hole 25 is designed as follows: width of the long hole × 1.2 to 30 times.
In addition, even if the same length direction A is arranged in the horizontal direction as shown in FIG. 5, the long holes 25 are arranged in a C-shape inclined at different angles as shown in FIG. 6. The same effect can be obtained. The long holes 25 are arranged in parallel to each other.
As described above, by using the metal punching plate in which the long hole 25 is processed as the screen 16 of the dehydrator 10, the screen 16 is not clogged even if the small-diameter synthetic resin pellet 23a is generated. It was found that continuous operation for hours was possible.

  The method and apparatus for dehydrating a slurry, which is a mixture of synthetic resin pellets and hot water, according to the present invention can be applied not only to the screen of a naturally-flowing dehydrator but also to a centrifugal dehydrator.

DESCRIPTION OF SYMBOLS 1 Synthetic resin raw material 2 Extruder 3 Dies 4 Submersible cutter 5 Slurry 6 Piping 7 Pump 8 Hot water tank 9 Hot water 10 Dehydrator 10a Box 11 Centrifugal dryer 12 Vibrating sieve 13 Synthetic resin pellet 14 Slurry supply port 15 Slurry receptacle 16 Screen 17 Slurry discharge port 18 Drainage port 20 Umbrella 21 Round hole 22 Hole diameter 23 Synthetic resin pellet (normal diameter)
23a Synthetic resin pellet (small diameter)
25 Long hole A Length direction B Width direction 30 Connection part 31 Width 32 Connection part width 33 Length D Diameter

Claims (8)

The slurry (5), which is a mixture of the synthetic resin pellets (23a) extruded from the extruder (2) and the hot water (9) in the submerged cutter (4), is passed through the screen (16) of the dehydrator (10). In the dehydration method of the slurry, which is a mixture of the synthetic resin pellets and hot water, separated into the hot water (9) and the synthetic resin pellets (23a),
The said screen (16) uses the punching plate in which many long holes (25) were formed, The spin-drying | dehydration method of the slurry which is a mixture of a synthetic resin pellet and warm water characterized by the above-mentioned.   The width (31) along the width direction (B) orthogonal to the length direction (A) of the long hole (25) is smaller than the diameter (D) of the synthetic resin pellet (23a). A method for dehydrating a slurry, which is a mixture of the synthetic resin pellets and hot water according to claim 1.   The connecting portion width (32) in the same direction as the width direction (B) of the width (31) in the elongated connecting portion (30) integrated with the screen (16) formed between the long holes (25). Is smaller than the width (31) of the long hole (25), the method for dehydrating a slurry as a mixture of synthetic resin pellets and hot water according to claim 1 or 2.   The long holes (25) are formed in the screen (16) in the shape of a letter C in which the length direction (A) is horizontal or inclined, and the long holes (25) are arranged in parallel to each other. The method for dehydrating a slurry, which is a mixture of the synthetic resin pellets and hot water according to any one of claims 1 to 3, wherein the slurry is dehydrated. The slurry (5), which is a mixture of the synthetic resin pellets (23a) extruded from the extruder (2) and the hot water (9) in the submerged cutter (4), is passed through the screen (16) of the dehydrator (10). In the slurry dehydrating apparatus, which is a mixture of synthetic resin pellets and hot water separated into hot water (9) and synthetic resin pellets (23a),
The said screen (16) uses the punching plate in which many long holes (25) were formed, The dehydration apparatus of the slurry which is a mixture of a synthetic resin pellet and warm water characterized by the above-mentioned.   The width (31) along the width direction (B) orthogonal to the length direction (A) of the long hole (25) is smaller than the diameter (D) of the synthetic resin pellet (23a). An apparatus for dehydrating a slurry which is a mixture of the synthetic resin pellets and hot water according to claim 5.   The connecting portion width (32) in the same direction as the width direction (B) of the width (31) in the elongated connecting portion (30) integrated with the screen (16) formed between the long holes (25). Is smaller than the width (31) of the long hole (25), the apparatus for dehydrating slurry as a mixture of synthetic resin pellets and hot water according to claim 5 or 6.   The long holes (25) are formed in the screen (16) in the shape of a letter C in which the length direction (A) is horizontal or inclined, and the long holes (25) are arranged in parallel to each other. 8. A slurry dewatering device as a mixture of synthetic resin pellets and hot water according to claim 5, wherein the slurry is a mixture.

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