JP2008080679A - Cleaning apparatus for waste plastics - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively separate and remove the foreign matter adhered to the surfaces of waste plastics P by suppressing the tailing rotation of the waste plastics P. <P>SOLUTION: This washing apparatus of the waste plastics is an apparatus for separating the adhered foreign matter of the waste plastics charged in a cylindrical screen 25 by rotating stirring blades 24. Since the screen has a regular polygonal cross-sectional shape, the gaps between the inner peripheral surface of the screen and the leading ends of the stirring blades are changed large and small toward the rotary direction of the stirring blades. The friction resistance with the inner surface of the screen of the waste plastics when the stirring blades are once rotated in the screen is changed by this change to suppress the tailing rotation of the stirring blades and the waste plastics. Further, the gaps are changed from large to small or from small to large during one rotation of the stirring blades and the waste plastics are strongly pressed to the inner peripheral surface of the screen at a part where the gaps are changed to small and the pressing force of the waste plastics becomes weak at a part where the gaps are changed to large. Since action like rub-washing with a washing plate is repeated, the waste plastics are sufficiently rubbed with each other and the adhered foreign matter is effectively separated. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a waste plastic cleaning apparatus for removing foreign substances adhering to the surface of waste plastic and recycling the waste plastic to high quality recycled plastic.

  Various foreign substances are usually attached to the surface of waste plastic (hereinafter referred to as “waste plastic”). For example, in agriculture, plastic sheets used for tunnel cultivation have soil and sand and various fertilizer residues. Residues of food and various seasonings are attached to plastics used in the food industry. If the waste plastic is recycled with foreign matters such as residues attached, it is difficult to obtain a high-quality recycled plastic.

For this reason, various types of waste plastic cleaning devices for removing foreign substances have been proposed in the past. As an example of such a device, a spindle equipped with a stirring blade is fastened in a cylindrical screen disposed in a casing. Rotate, stir the waste plastic thrown into the screen with a stirring blade, rub the waste plastics together to blow off the adhering foreign matter out of the screen with centrifugal force, and treat the treated waste plastic as plastic material There is what to collect (patent document 1).
JP, 2002-316101, A Refer to Drawing 1

  In this waste plastic cleaning device, the waste plastic spreads outward in the screen by the rotation and stirring of the stirring blade, and moves in the circumferential direction along the inner peripheral surface of the screen. At that time, since the screen has a cylindrical shape, the waste plastic is brought along with the stirring blade along its inner peripheral surface. When the waste plastic is provided, the waste plastics are not sufficiently rubbed together, and foreign matter such as earth and sand and residues adhering to the surface of the waste plastic is not sufficiently removed.

  This invention makes it a subject to suppress the rotation of a stirring blade and waste plastic.

  In order to solve the above-described problems, the present invention is configured such that the gap between the inner peripheral surface of the screen and the tip of the stirring blade changes in the direction of rotation of the stirring blade.

  In this way, the clearance between the inner peripheral surface of the screen and the tip of the stirring blade changes in size, and the frictional resistance with the screen inner peripheral surface of the waste plastic changes when the stirring blade makes a round in the screen. Therefore, the rotation of the stirring blade and the waste plastic is suppressed as much as possible.

  In addition, there is a portion where the gap changes at least from large to small and from small to large while the stirring blade goes around the screen. In the portion where the gap changes small, the waste blade Is strongly pressed against the inner peripheral surface of the screen, while the waste plastic is weakly pressed by the stirring blade in a portion where the gap changes greatly.

  This action is similar to washing with a washing board. By repeating this action, the waste plastics are sufficiently rubbed together, and the foreign matter adhering to the surface of the waste plastics is effectively separated.

  As a configuration of the present invention, a stirring blade is provided in a cylindrical screen so as to be rotatable around the cylindrical axis of the screen, and the stirring blade is rotated to adhere to the waste plastic put into the screen. In the waste plastic cleaning apparatus for separating foreign matter and discharging it to the outside of the screen, the screen has an inner space where the clearance between the inner peripheral surface and the tip of the stirring blade changes in the direction of rotation of the stirring blade. What has a surrounding surface is employable.

  In order to change the gap between the inner surface of the screen and the tip of the stirring blade to a larger or smaller size, for example, rods extending over the entire length in the cylinder axis direction are arranged on the inner surface of the screen, for example, at a necessary interval in the circumferential direction, or appropriately on the entire inner surface Protrusions can be provided at intervals, and the screen can have a polygonal cross section.

  In the case of a rod or protrusion, if the tip of the bar or projection faces the rod or protrusion as the stirring blade rotates, the gap between the two becomes narrow, and the size of the gap changes before and after the opposed position. In the case of a polygonal section screen, as the stirring blade rotates, the gap between the tip of the stirring blade and the inner surface of the screen changes over the entire length of each side of the section polygon of the section polygonal screen, The gap is the maximum at each corner. For this reason, the size of the gaps changes by the number of polygons (for example, 15 times for a fifteen-sided shape) while the stirring blade makes a round. At this time, if the screen has a regular polygonal cross section, the size of the gap changes uniformly over the entire periphery of the screen, and the scouring is made uniform.

  The screen may be in any form as long as it has a discharge hole of a size capable of discharging the waste plastic adhering foreign matter, and the discharge hole is appropriately positioned in consideration of the strength of the screen, for example, It may be provided over the entire area of the screen.

  When the screen has a polygonal cross section, each side of the screen usually changes from a large to a small gap and further changes from a small to a large portion, and the waste plastic is strongly and weakly pressed by a stirring blade. In addition, since the foreign matter adhered when moving from weak to strong is separated, there are many separated foreign matters at the side, and if there is a discharge hole at the side, the separated foreign matter is removed from the discharge hole. It is discharged smoothly.

  As described above, the present invention suppresses the rotation of the stirring blade and the waste plastic as much as possible, and separates the foreign matter adhering to the waste plastic by an action similar to the washing with the washing plate. Foreign matter can be effectively removed.

  1 to 4 show an embodiment of the present invention. A waste plastic cleaning apparatus 10 according to this embodiment includes a laterally rectangular tube-like casing 11 supported by its left and right frames 12, and opposite side plates 13 of the casing 11 facing each other. Is provided with a bearing stand 14.

  An inlet 16 for introducing the waste plastic P is formed in the upper part of one side plate 13 of the casing 11, and an outlet for discharging the processed waste plastic P in the lower part of the bearing base 14 of the other side plate 13. 17 and a foreign matter discharge port 18 for discharging the foreign matter separated and removed from the waste plastic.

  A main shaft 19 is rotatably supported between the left and right bearing bases 14 via a bearing 15, and the main shaft 19 is fixed to the frame 12 by a belt 22 being stretched over a pulley 21 attached to one end thereof. The power of the rotational drive motor 23 is transmitted.

  As shown in FIG. 3, a cylindrical screen 25 is provided in the casing 11, and the main shaft 19 passes through the cylindrical axis of the screen 25. A plurality of feed blade-like stirring blades 24, 24 extending outward in the radial direction are integrally provided on the main shaft 19 with a predetermined interval. By the rotation of the stirring blades 24, 24, the waste plastic P in the screen 25 is provided. Is sent toward the outlet 17.

  The stirring blade 24 may be provided in a continuous spiral shape or intermittently along a spiral track on the main shaft 19. Thus, if the stirring blade 24 is formed in a spiral shape, the rotation causes the waste plastic P introduced into the screen 25 to be smoothly conveyed from the upstream side (input port 16) to the downstream side (discharge port 17). be able to.

  As shown in FIG. 3, the screen 25 in the casing 11 is arranged in a horizontal shape in which the cylinder axis direction is a horizontal direction, and the cross-sectional shape is a regular pentagon. The ridge line part (butting part) of each side part 26 becomes the corner part 27.

  When the stirring blade 24 rotates, the screen 25 has a regular pentagonal cross section as shown in FIG. 4, so that when the tip of the stirring blade 24 faces the center of the side portion 26 (when positioned, The gap b between the tip of the screen 25 and the inner surface of the screen 25 is minimized, and the gap a between the agitating blade 24 and the agitating blade 24 is maximized when facing the corner portion 27 (state of the dashed line in the figure). For this reason, while the stirring blade 24 goes around the screen 25, the gap gradually changes from large to small and from small to large, and the change is repeated (a → b → a → b ·・).

  Thus, when the stirring blade 24 rotates, the waste plastic P is strongly pressed by the stirring blade 24 against the inner peripheral surface of the screen where the clearance from the tip of the stirring blade 24 is gradually reduced. On the inner peripheral surface where the gap is gradually increased, the pressing force by the stirring blade 24 is weakened. This action is similar to washing with a washing board. By repeating this action, the waste plastics P, P are sufficiently rubbed together, and the foreign matter adhering to the surface of the waste plastic P is effectively removed. To be separated.

  A large number of discharge holes 29 are formed in each side portion 26 of the screen 25, and the foreign substance c peeled off from the waste plastic P is discharged to the outside from the discharge holes 29. At this time, each side portion 26 of the regular pentagonal screen 25 is a portion where the gap is changed from large to small and further from small to large, and the waste plastic P is pressed by the stirring blade 24. Since the foreign material c is separated when the power is weak to strong, and further transitions from the strong to the weak, there is a large amount of the separated foreign material c in the side portion 26, and the side portion 26 has the discharge hole 29. The peeled foreign matter c is smoothly discharged from the discharge hole 29.

  As shown in FIG. 2, a screw 28 extending toward the foreign matter discharge port 18 is provided at the bottom of the casing 11, and the foreign matter c discharged from the discharge hole 29 of the screen 25 is collected by the screw 28. Then, it is sent to the foreign matter discharge port 18 and discharged from the discharge port 18.

  The number of sides of the polygonal section of the screen 25 (the number of side portions 26) is not limited to fifteen sides as long as the above-described stagnation action is effectively performed. For example, the number of sides is It can be set to six sides or more and thirty sides or less (hexagonal to trigonal).

  In this waste plastic cleaning device, when waste plastic P is introduced into the screen 25 from the inlet 16 of the casing 11, the waste plastic P spreads outward in the screen 25 by the centrifugal force of the stirring blade 24, and is stirred. The stagnation action by the blade 24 is repeated, and the waste plastics P, P are sufficiently rubbed together.

  By this rubbing, the adhering foreign matter c such as earth and sand, food residue and seasoning residue adhering to the waste plastic P is effectively separated, and the separated foreign matter c is discharged into the discharge hole by the centrifugal force of the stirring blade 24. 29 is blown off to the outside of the screen 25, and is discharged from the foreign matter discharge port 18 by the screw 28. On the other hand, the waste plastic P from which the adhered foreign matter c has been peeled is discharged from the discharge port 17 of the casing 11 and transferred to a recycling process as a plastic material.

  Next, another example of this embodiment is shown in FIG. In this embodiment, as shown in the figure, the discharge holes 29 of the side portions 26 of the screen 25 are formed so that the inner walls of the discharge holes 29 extend from the inside toward the outside. Unlike the case (see FIG. 5A), other configurations are the same as those of the above-described embodiment.

  When the inner wall of the discharge hole 29 is formed so as to spread from the inside to the outside, the foreign matter c separated from the waste plastic P is likely to move to the outside along the inner wall of the discharge hole 29. It becomes easy to be done.

(A) Appearance front view of one embodiment of waste plastic cleaning apparatus according to this invention, (b) Appearance side view of the above Sectional drawing in the AA line of FIG.1 (b) Sectional drawing in the BB line of Fig.1 (a) The expanded sectional view which shows the positional relationship with the stirring blade of the screen of the embodiment (A) Partially enlarged sectional view showing the same screen, (b) Partially enlarged sectional view showing another embodiment of the same screen.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Waste plastic washing apparatus 11 Casing 12 Frame 13 Side plate 14 Bearing stand 15 Bearing 16 Insertion port 17 Discharge port 18 Foreign material discharge port 19 Main shaft 21 Pulley 22 Belt 23 Rotation drive motor 24 Stirring blade 25 Screen 26 Screen side 27 Corner 28 Screw 29 Discharge hole P Waste plastic (waste plastic)
c Adhering foreign matter

Claims (3)

In the cylindrical screen (25), a stirring blade (24) is provided so as to be rotatable around the cylindrical axis of the screen (25), and the stirring blade (24) is rotated so that the screen (25) is rotated. In the waste plastic cleaning apparatus for separating the foreign matter c adhering to the thrown-out plastic and discharging it out of the screen (25),
The screen (25) is characterized in that a gap (a, b) between the inner peripheral surface of the screen (25) and the tip of the stirring blade (24) varies in the direction of rotation of the stirring blade (24). Waste plastic cleaning equipment.   The screen (25) is formed in a polygonal cross section, and the clearance (a, b) between the inner peripheral surface of the screen (25) and the tip of the stirring blade (24) is the rotation of the stirring blade (24). 2. The waste plastic cleaning apparatus according to claim 1, wherein the plastic cleaning apparatus changes in size in the direction of the direction.   The discharge hole (29) of the foreign substance c adhering to the waste plastic of the cross-sectional polygonal screen (25) is provided in each side part (26) of the cross-sectional polygon. Waste plastic cleaning equipment.

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