JP2001105432A - Stain removing method for waste plastic - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stain removing method for a waste plastic capable of preliminarily removing stains such as mud or the like bonded to the surface of the waste plastic material by a dry system to prevent the damage of a crusher and capable of reducing the load of water used in wet classification. SOLUTION: A waste plastic material to which a stain is bonded is applied to a crusher not only to be crushed but also to be washed by a dry system to remove the stain. Subsequently, the crushed waste plastic material is sent to a cyclone along with the separated stain to remove the stain. The crushed waste plastic material is returned to the crusher and, on and after, the crushing of the waste plastic material by the crusher, the dry washing thereof and the removal of the stain by the cyclone are repeated. A part of the circulated waste plastic material between the crusher and the cyclone is taken out of a circulating route to be supplied to a sieve to further remove the stain from the crushed waste plastic material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION When crushing or pulverizing waste plastics for recycling, recycling or recycling of waste plastics, dirt such as mud adhering to the surface of the waste plastics causes wear of the crusher. And hinder the improvement of the quality of waste plastic. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for effectively removing dirt from waste plastic, preventing wear of a crusher and improving the quality of waste plastic.

[0002]

2. Description of the Related Art In a waste plastic oiling facility, waste plastics are often classified into oily materials and unsuitable materials. In this case, there is an example in which the waste plastic that has been roughly crushed is further finely crushed, and the finely pulverized material is washed by a wet method, and then classified into oily substances and unsuitable substances according to a difference in specific gravity.

[0003] In such a case, if mud or the like adheres to the surface of the waste plastic, it damages the blade of the fine crusher and pollutes the water for wet classification, and further imposes a burden on wastewater treatment. Will hang.

[0004] In addition, the mud often enters bearings of rotary machines such as crushers and causes troubles. In addition, if mud is mixed with water in the wet classification, the density of the water increases, which lowers the classification efficiency and causes an increase in SS in the wastewater treatment.

[0005]

SUMMARY OF THE INVENTION In view of the above, the present invention removes dirt such as mud adhering to the surface of waste plastics in advance by a dry method to prevent damage to the crusher and to remove water used for wet classification. It is an object of the present invention to provide a method for removing dirt from waste plastics, which can reduce the burden on the user.

[0006]

SUMMARY OF THE INVENTION According to the present invention, waste plastic on which dirt is adhered is crushed by a crusher and dry-cleaned to remove dirt, and then the waste plastic crushed product is sent to a cyclone together with the fallen dirt. Remove the dirt from the crushed material with a cyclone, return the waste plastic crushed material from the cyclone to the crusher, and then repeat the crushing of the waste plastic by the crusher, dry cleaning and removal of the dirt by the cyclone. A part of the waste plastic circulating material is removed from the circulation path and passed through a sieving machine to further remove dirt from the waste plastic crushed material.

[0007] The crusher is preferably rotated at 1800 to 4000 rpm. The crusher may be a so-called pin-type crusher in which pins are vertically set on an internal rotating disk, or a disk-type crusher used for crushing pulp chips.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described based on the illustrated embodiment.

In FIG. 1 to FIG. 4, waste plastic collected separately is firstly subjected to coarse pulverization and coarsely pulverized, and then subjected to magnetic separation to remove metals. Thereafter, the coarsely crushed material is introduced into the crusher (1) from its input hopper (6), further crushed and dry-washed.
The crusher (1) has a fixed disk inside, as shown in Fig. 2.
(2) A fixed blade (3) in which a plurality of tooth-shaped protrusions are circumferentially arranged at predetermined intervals on the inner surface, and small rod-shaped pins are arranged on the inner surface at predetermined intervals in the circumferential direction. The fixed blade (3) is disposed outside the rotary blade (5) and concentrically therewith. As shown in FIG. 3, the pin of the rotary blade (5)
Pyramidal (FIG. 3a), prismatic (FIG. 3b), conical (FIG. 3)
c) and the like. The rotary blade (5) is rotated at a variable speed by a motor (10) with an inverter. Screen diameter:
A crusher having a diameter of 10 mm, a rotation speed of 1800 to 4000 rpm, a single pass, and a supply amount of 100 g / min is preferable.

[0010] The coarsely crushed waste plastic put into the crusher (1) is rotated between the fixed blade (3) and the rotary blade (5) by a rotary blade.
As a result of being hit by (5) and being subjected to shearing and crushing, dirt such as mud attached to the waste plastic surface is scraped off the surface. Next, the waste plastic crushed and dry-cleaned material coming out of the crusher (1) is dumped together with the scraped-off dirt.
After passing through (7), it is sent to the cyclone (8) where fine dirt is separated from the crushed material and discharged from the upper part of the cyclone. Waste plastic is crushed from the lower part of the cyclone (1)
With the suction force of the rotary blade (5), it is sucked into the center of the crusher (1), and is again applied to the crusher (1) to remove dirt. Thus, the waste plastic can be circulated between the crusher (1) and the cyclone (8) for an arbitrary time.

After the circulation for a predetermined time, the damper (7) is switched, and a part of the waste plastic circulating material is taken out from the outlet (9) and sent to a sieving machine (not shown), where the waste plastic crushed material is removed. Is further cleaned. The thus-removed waste plastic is then subjected to a fine crusher for converting the waste plastic into fuel or oil.

[0012] As a waste plastic, a polyvinyl chloride film for agriculture dried, and then chopped into a business card size was applied to the method of the present invention. FIG. 5 shows the relationship between the residence time in the crusher and the mud adhesion rate. The adhesion rate of the mud was determined from the difference in weight between before and after the water washing, after drying and washing the sample at 105 ° C. As is clear from the figure, the mud adhesion rate before the introduction was about 10%, but the mud was removed to a level of less than 2% by the above method, and the dry cleaning was performed effectively. I understand.

[0013]

According to the present invention, it is possible to reduce the burden on water used for a crusher and wet classification, and to improve the quality of waste plastics for use as fuel or oil. In addition, it is possible to prevent the blade of the fine crusher for converting waste plastic into fuel or oil to be damaged by dirt.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a connection configuration of a crusher, a damper, and a cyclone.

FIG. 2 is an exploded perspective view showing an internal configuration of the crusher.

FIGS. 3 (a), 3 (b) and 3 (c) are perspective views showing modified examples of a pin of a crusher.

FIG. 4 is a flow sheet illustrating the method of the present invention.

FIG. 3 is a graph showing a cleaning effect.

[Explanation of symbols]

 1: Crusher 3: Fixed blade 5: Rotary blade 7: Damper 8: Cyclone

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4D063 FF14 FF21 GA10 GC05 GC12 GC19 GC21 GC36 GD24 4F301 AA11 AA21 AD03 BA01 BA03 BD05 BF03

Claims (2)

[Claims] Claims: 1. A waste plastic to which dirt has adhered is crushed by a crusher and dry-cleaned to remove dirt.
Next, the waste plastic crushed material is sent to the cyclone together with the fallen dirt, the dirt is removed from the crushed material by the cyclone, the waste plastic crushed material is returned from the cyclone to the crusher, and thereafter the crushing of the waste plastic by the crusher and dry cleaning. And repeating the removal of dirt by a cyclone, removing a part of the waste plastic circulating material between the crusher and the cyclone from the circulation path, passing it through a sieving machine, and further removing the dirt from the waste plastic crushed material. How to remove plastic stains. 2. The method for removing dirt from waste plastic according to claim 1, wherein the crusher is rotated at 1800 to 4000 rpm.