JPH04201413A - Classification cooling machine for synthetic resin molded particles - Google Patents

Abstract

PURPOSE:To obtain a classifying and cooling machine, which is excellent in cleanability and cools and classifies various granules with no lowering of their qualities by a method wherein a holding tank equipped with a bottom plate, which has a plurality of vent holes with the diameter smaller than that of synthetic resin granule, and a partition plate is vibrated so as to successively classify granules run over the partition plate. CONSTITUTION:A holding tank 31 has a U-shaped bottom plate 33, onto which a plurality of vent holes 32 with the diameter smaller than that of pellet particle cooled primarily with a cyclone, and a blow port 34, through which cooling air is blown in, on the side wall below the bottom plate 33. Further, at one side of the tank, a partition plate 35 leaning to the direction so as to open its upper end wider than its lower end. Furthermore, the holding tank 31 is supported through springs 37 on a trestle so as to be vertically vibrant with vibrators 39. A classifying plate 40 is equipped with classifying holes 41 and 42, which have two kinds of hole diameter successively formed on the side at the upper end of the partition plate 35, so as to classify pellets run over the upper end of the partition plate 35. In addition, at the upper and lower parts of the partition plate 35, notched windows are formed so as to be openable and closable by shutters 48 and 49 and, in addition, said partition plate is preferably constituted detachably.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention is a method for producing molded synthetic resin particles (pellets) such as vinyl chloride resin extruded by an extruder and classifying them into particle sizes while cooling them. This relates to a classification cooler. [Prior Art] Molded granules of synthetic resin such as vinyl chloride resin used as coating material for electric wires are formed using an extruder, but immediately after extrusion, the granules are heated at a high temperature of 150°C to 200°C. Therefore, after cooling to about room temperature, it is classified according to particle size. Conventionally, as a method for cooling such high-temperature molded grains,
Air-cooled type and water-cooled type are known. FIG. 5 is a block diagram showing the configuration of an air-cooled classification cooler, in which high-temperature synthetic resin molded particles extruded from an extruder 1 are cut into predetermined sizes by a hot-cut device 2 to form hot-cut pellets. becomes. The hot-cut pellets are forced into a primary cooling cyclone 4 by high-pressure air from a pressure blower 3, where they are primarily cooled by cooling air from an auxiliary cooling blower 5. The primarily cooled pellets are led to the flow chamber 6, where they are retained, and then sent to the air cooling base 7 where they are air cooled. At this time, the airflow at the inlet of the air cooling base 7 is sucked by the exhaust blower 9 via the dust collector 8, thereby removing dust and the like adhering to the pellets. The pellets cooled by the air-cooling base 7 fall onto a vibrating sieve 10 disposed below the air-cooling base 7, where they are vibrated by being vertically vibrated by a vibrator 11. Then, the larger the particle size, the lower the height at which it jumps, so it falls from the classification hole 12 with the smallest height barrier, and the medium particle size falls through the classification hole 13 with the next lowest height barrier. The particles with the smallest size fall from the classification hole 14 where the barrier is the highest. This classifies the particles into large, medium, and small particle sizes. FIG. 6 is a block diagram showing the configuration of a water-cooled classification cooler, in which high-temperature synthetic resin molded particles extruded from an extruder 1 are cut into a predetermined size by a hot-cut device 2 into hot-cut pellets. becomes. The hot-cut pellets are cooled by being sprayed with cooling water supplied from the self-priming pump 16, and then sent to the transport pipe 17. At this time, the warmed cooling water falls from the sluice 18 provided in the middle of the transport pipe 17, and flows into the hot water tank 19 with a filter.
It is collected after being filtered by a filter 20. Cold water is constantly supplied to this hot water tank 19 with a filter through a valve 21, and a drain pipe 22 is attached to the upper side wall of the tank. As a result, even if the warmed cooling water is recovered from the sluice 18, the hot cut device 2 can always be supplied with cooling water below a certain temperature through the self-priming pump 16. The pellets that have passed through the sluice 18 are introduced into a centrifugal dryer 23, where they are dehydrated and dried by centrifugal separation. After that, it is introduced into a vibrating sieve machine, where it is vibrated in the same way as in the case of an air-cooled type, and is classified into large, medium, and small particle sizes, and collected from the classification holes 25, 26, and 27. Ru. [Problems to be Solved by the Invention] However, in the above air-cooled classification cooler,
Since there are many pneumatic feeding stages from the outlet of the hot cut device 2 to the vibrating sieve machine 10, the pellets are When changing colors or types, it is necessary to clean over a wide area, and there is also the problem that the quality becomes unstable due to the residue of the previous product. Also, setup time becomes longer,
The problem is that it is inefficient. On the other hand, in a water-cooled classification cooler, it is necessary to constantly supply cooling water at a constant temperature or lower, so securing and treating water becomes a major problem, leading to an increase in cost. Furthermore, since the pellets come into direct contact with the cooling water, there is a risk that the quality will deteriorate due to moisture absorption. The present invention was developed in view of the above circumstances, and has excellent cleaning properties and can efficiently produce molded synthetic resin particles of various types and colors.
It is an object of the present invention to provide a classification cooler for synthetic resin molded particles that can be cooled and classified at low cost without deteriorating quality. Means for Solving the Problems In order to achieve the above object, the classification cooler for synthetic resin molded particles of the present invention has a bottom plate in which a plurality of ventilation holes are formed with a diameter smaller than the diameter of the molded synthetic resin particles. a retention tank in which molded synthetic resin particles are retained on the bottom plate; cooling air is blown from below the bottom plate through the ventilation hole; and the molded synthetic resin particles retained in the retention tank; an excitation means for vibrating the retention tank; a partition plate provided on one side of the retention tank with an inclination in a direction in which the upper end opens more than the lower end; and an upper end of the partition plate. A classifying means is provided for classifying the molded synthetic resin particles that have passed over the upper end of the partition plate into a plurality of particle sizes using a plurality of classification holes sequentially formed on the sides of the partition plate. Preferably, the partition plate is configured to have a variable height from the bottom plate surface to the upper end. Further, it is preferable that the partition plate is configured to be removable from the retention tank. Furthermore, it is preferable that the retention tank is provided with stirring means for stirring the molded synthetic resin particles. [Function] According to the above structure, the molded synthetic resin particles are introduced into the retention tank, where they are cooled by the cooling air blown from below the bottom plate while being vibrated. The cooled molded grains move toward the partition plate while vibrating. Most of the molded grains, except for particularly oversized molded grains, climb over the upper end of the partition plate and reach the position of the classification means. Then, the particles are classified according to particle size using a plurality of types of classification holes. [Example] Hereinafter, the classification cooler for synthetic resin molded particles of the present invention will be explained based on Examples. FIG. 1 is a block diagram showing an embodiment of the classification cooler of the present invention, in which high-temperature synthetic resin molded particles extruded from an extruder 1 are cut into predetermined sizes by a hot-cut device 2, and hot-cut. Becomes a beret. The hot-cut pellets are fed by high-pressure air from a pressure blower 3 to a primary cooling cyclone 4, where they are further cooled. The primarily cooled pellets are transported to the classification cooler 30 of this embodiment.
guided by. FIG. 2 is a front view and side view showing the detailed configuration of the classification cooler 30 of this embodiment, and FIG. 3 is an exploded perspective view of the retention tank. In these figures, 31 has a 0-shaped bottom plate 33 in which a plurality of ventilation holes 32 having a diameter smaller than the grain size of the pellets that have been primarily cooled by the cyclone 4 is formed, and the pellets are fixed on this bottom plate 33. A cooling air blowing port 34 for blowing cooling air is provided on the lower left side wall of the bottom plate 33. Further, a partition plate 35 is provided on the right-side portion, and the partition plate 35 is inclined in a direction in which the upper end opens more than the lower end, that is, to the right in FIG. 2(a). This retention tank 31 is supported on a pedestal 36 via four springs 37 so as to be able to vibrate up and down. 38 is a blower that blows cooling air from the cooling air blowing port 34 to cool the pellets held in the retention tank 31 from below the bottom plate 33; 39 is a vibrator that vibrates the retention tank 31 in the vertical direction; Two types of hole diameters φa and φb (φa
This is a classification plate that classifies the pellets that have passed over the upper end of the partition plate 35 into two particle sizes using the classification holes 41 and 42 of φb). A fine grain outlet 43 is provided to collect pellets of a fine grain size that fall through the hole 42, and a suitable grain outlet 44 is provided below the classification hole 42 to collect pellets of a suitable grain size that fall through the hole 42. is provided. A coarse particle outlet 45 is provided in front of the classification hole 42 to collect pellets having a coarse particle size that cannot pass through both of the classification holes 41 and 42. The partition plate 35 arranged on the right side of the retention tank 31 is
Concave cutout windows 46 and 47 are formed in the upper and lower parts,
These windows 46 and 47 can be opened and closed by upper opening and closing plates 48 and 49, respectively, and can be detachably fixed in a fixing groove 52 formed inside the bottom plate 33. 50 is a pellet inlet plate placed on the upper part of the retention tank 31, the pellet inlet 51 formed in the center is connected to the outlet of the cyclone 4, and the primarily cooled pellets are retained from this pellet inlet 51. It is guided into the tank 31. In the classification cooler configured in this way, the extruder 1
When the pellets extruded from the pellets are cooled and classified, the blower 38 is operated to blow cooling air from the cooling air inlet 34 below the O-shaped bottom plate 33. Further, the vibrator 39 is activated to vibrate the retention tank 31 in the vertical direction. In this state, the pellet is extruded from the extruder 1. Then, the pellet is cut into a predetermined size by a hot cut device 2, and then introduced into a cyclone 4 by high pressure air from a pressure blower 3, where it is further cooled. The primarily cooled pellets fall from the pellet inlet 51 onto the bottom plate 33 of the retention tank 31, which has a U-shaped side cross section. Among the fallen pellets, fine pellets smaller in diameter than the ventilation hole 32 of the bottom plate 33 fall below the bottom plate 33 and are collected into the fine particle outlet 53. However, many pellets remain on the bottom plate 33 while vibrating in the vertical direction. In this retained state, the cooling air is blown out from below the bottom plate 33 through the ventilation holes 32 to cool it down. When the amount of accumulated pellets increases and the accumulated height reaches near the upper end of the partition plate 35, the upper layer of the cooled pellets vibrates in the direction of the partition plate 35 due to vibration by the vibrator 39. Moving. and,
Except for particularly large pellets, the upper pellets climb over the upper end of the partition plate 35 and fall to the position of the classification plate 40. Here, the particles are first classified by the smaller diameter classification hole 41, and then classified by the larger diameter classification hole 42 located in front of the smaller diameter classification hole 41. As a result, pellets smaller than the diameter φa of the classification hole 41 fall from the classification hole 41 and are collected from the fine particle outlet 43. Further, pellets that are larger than φa and smaller than the diameter φb of the classification hole 42 fall from the classification hole 42 and are collected from the suitable grain outlet 44. Furthermore, coarse pellets larger than φb are used at the coarse grain outlet 45.
recovered from. Note that if the layer thickness of the pellets retained in the retention tank 31 becomes too large, the cooling air may not reach the upper layers, resulting in uneven cooling.In this case, remove the upper opening/closing plate 35, Cooling may be performed while the height to the upper end of the partition plate 35 is lowered and the retention height is lowered. In addition, if pellets of other types or colors remain on the bottom plate 33 or the classification plate 40 at the beginning or end of cooling, remove the lower opening/closing plate 49 or the entire partition plate 35 from the bottom plate 33, and High pressure air is blown out from 38. As a result, pellets of other types or colors remaining on the bottom plate 33 or the classification plate 40 are blown away by the high-pressure air and cleaned to a clean state. Therefore, it becomes extremely easy to clean. As described above, in this embodiment, since the pellets are cooled and classified using only the retention tank 31 in an air-cooled manner, the quality does not deteriorate due to moisture absorption, and it is possible to perform the cooling and classification at low cost. Further, since the structure is simple, with a bottom plate 33 having ventilation holes 32 disposed within the retention layer 31, cleaning is easy and setup is simple. Therefore, pellets of various types and colors can be efficiently and inexpensively cooled and classified. Furthermore, by changing the retention height of the retention tank 31 as necessary, the degree of cooling can be changed. 4(a) and 4(b) are a front view and a side view of a retention tank showing another embodiment of the present invention, in which a stirrer 54 for stirring the inside of the retention tank 1 is provided. The agitator 54 includes a plurality of agitating blades 55 protruding from the upper end of the retention tank 31 toward the inside of the U-shaped bottom plate 33, and a rotating mechanism that coaxially connects the rotation centers of the agitating blades 55. A frame-side rotation shaft 58 coupled to one end of this rotation shaft 56 via a vertical vibration absorption mechanism 57, and this rotation shaft 58 at an angle of about 45 degrees when looking at the side of the arm 59. The hydraulic cylinder 60 rotates at a rotation angle of . Note that the same or equivalent parts as in the embodiments of FIGS. 1 to 3 are represented by the same reference numerals. In this embodiment, when the hydraulic cylinder 60 is reciprocated, the rotation shafts 58 and 56 rotate within a rotation angle range of approximately 45 degrees when viewed from the side, so that the stirring blades 55 rotate within a rotation angle range of approximately 45 degrees. It moves back and forth. As a result, the pellets retained in the retention tank 31 are stirred and cooled evenly and quickly. As a result, even if the pellets are highly adhesive, the pellets will not stick to each other and form clumps, preventing accidents such as the outlet of the classification plate being clogged by pellet clumps, and ensuring continuous This allows for stable operation. Although the classification is performed using a classification hole, it can also be performed using a slit or the like having a size corresponding to the particle size to be classified. Effects of the Invention As is clear from the above description, the classification cooler for synthetic resin molded particles of the present invention has a bottom plate in which a plurality of ventilation holes are formed with a diameter smaller than the diameter of the molded synthetic resin particles. and a retention tank in which molded synthetic resin particles are retained on the bottom plate, and cooling air is blown from below the bottom plate through the ventilation hole,
a blower for cooling molded synthetic resin particles retained in the retention tank; a vibrator for vibrating the retention tank; and a side portion of the retention tank that is inclined in a direction in which the upper end opens more than the lower end. The molded synthetic resin particles that have passed over the upper end of the partition plate are classified into multiple particle sizes using a partition plate provided as a partition plate and multiple types of classification holes sequentially formed on the sides of the upper end of the partition plate. Since the present invention is equipped with a classifying means, it has excellent cleaning properties, and can efficiently and inexpensively cool and classify molded synthetic resin particles of various types and colors without deteriorating quality. If the height from the bottom plate surface to the upper end of the partition plate is variable, the retention height of the retention tank can be changed as necessary to change the degree of cooling. - In addition, if the partition plate is configured to be removable from the retention tank, cleaning can be completed extremely easily by blowing off the molded grains remaining on the bottom plate etc. with cooling air, and the molded grains of the next type or color can be removed. It is possible to move on to cooling and classification work. Furthermore, if the retention tank is equipped with a stirring means for stirring the formed particles, the cooling efficiency will be improved, a uniform cooling effect will be obtained, the classification processing speed will be accelerated, and the formed particles with high adhesion will be Even if it is a granule, the molded grains will not stick to each other and become lumps, prevent accidents such as the exit of the classification plate being clogged by the molded grain agglomerates, and ensure continuous and stable operation. Effects such as being able to do this can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention, and FIG.
The figures are a front view and a side view showing the detailed configuration of the classification cooler of the embodiment shown in Fig. 1, Fig. 3 is an exploded perspective view of the retention tank, and Fig. 4 is a front view showing another embodiment of the present invention. A side view, FIG. 5 is a block diagram showing a conventional configuration of an air-cooled classification cooler, and Section 6 is a block diagram showing a conventional configuration of a water-cooled classification cooler.

Claims (4)

[Claims] (1) A retention tank having a bottom plate in which a plurality of vent holes having a diameter smaller than the diameter of the molded particles of the synthetic resin are formed, and on which the molded particles of the synthetic resin are retained; a blower that blows cooling air from below to cool the molded synthetic resin particles held in the retention tank; a vibrator that vibrates the retention tank; and a lower end on one side of the retention tank. A partition plate is provided with the upper end slanted in the direction in which the upper end opens from the upper end of the partition plate, and multiple types of classification holes are sequentially formed on the sides of the upper end of this partition plate, so that the synthetic resin can pass over the upper end of the partition plate. A classification cooling machine for synthetic resin molded grains, comprising: a classification means for classifying molded grains into a plurality of particle sizes; (2) A classifying and cooling machine for synthetic resin molded grains, wherein the partition plate is configured such that the height from the bottom plate surface to the upper end can be varied. (3) A classification cooler for synthetic resin molded particles, characterized in that the partition plate is configured to be removable from the retention tank. (4) A classification cooler for synthetic resin molded particles, characterized in that the retention tank is provided with stirring means for stirring the synthetic resin molded particles.