JP3684114B2 - Volume reduction granulation method and apparatus for waste plastic containing combustible waste - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a screw-type volume reduction granulation method and apparatus for volume reduction and granulation of waste plastic containing combustible waste.
[0002]
[Prior art]
There are roughly two types of used waste plastic: industrial and general. Their shapes vary and are often difficult to handle. When waste plastic is burned, harmful gases are generated, which adversely affects the human body and damages the combustion furnace. Also, the combustion gas pollutes the atmosphere and causes environmental problems. For this reason, landfill processing is performed. For example, general waste plastic is bulky, and if it is landfilled as it is, problems such as space and land stability may occur. For this reason, compression and heat melting are performed using a twin screw type extruder or the like, and the volume is reduced to reduce the bulk and the land is filled. For example, JP-A-7-256645 and JP-A-10-315237 disclose the following twin-screw extruder type volume reduction solidification device. That is, the waste is crushed to, for example, a 50 mm square and then supplied to the inlet of the twin screw extruder. Waste is crushed, kneaded, pressurized and compressed by the rotation of two special screws, and then proceeds to the downstream side. It is discharged from a flat die provided at the tip of the screw and cut to an appropriate length. Pelletized. Normally, the supplied waste has a lot of moisture, which prevents the plastic in the waste from melting, but the plastic is melted by external heating from the extruder cylinder and shear heat generated by the screw. The melted plastic content is kneaded into the other components and serves as a binder to attach the other components, and the waste is given fluidity to be extruded from the die nozzle into pellets (grains).
[0003]
[Problems to be solved by the invention]
As described above, in an apparatus for producing pellets by extruding compressed plastic, heat-melted waste plastic from a die nozzle, from the viewpoint of preventing generation of hydrogen chloride due to thermal decomposition of chlorinated polymer in waste plastic and saving energy, The degree of melting is kept low, and there are many unmelted resins. In addition, because waste plastic contains paper, wood, metal pieces, etc., the fluidity between the screw and the die decreases and does not flow, or the resistance of the inner wall of the die nozzle increases and the fluid does not flow. The so-called die nozzle clogging often occurs. When clogging occurs, there is a problem that the operation must be interrupted and work to clear clogging of the die nozzle must be performed. Waste plastics that often cause clogging include polypropylene resin, polyester resin thick packaging tape, polyester resin, and high melting point resin molded products such as nylon.
[0004]
Furthermore, there is a problem that the melting of the waste plastic fluctuates due to fluctuations in the composition and water content of the raw material waste plastic. Insufficient melting due to a low melting point resin shortage or a high moisture content impairs the degree of molding of the pellets (solid fuel) after volume reduction, tends to lose its shape, and has a low bulk density. This increases the landfill space when landfilling. In addition, when using fuel, handling becomes difficult, dust and the like are easily generated, and a sanitary problem occurs. Moreover, if the melting degree of waste plastics is too high, the polyvinyl chloride in the waste plastics will be partially thermally decomposed to generate hydrogen chloride, which may damage the machinery and the health of operators. .
[0005]
The present invention has been made to solve the above-described conventional problems, and can prevent clogging of a die nozzle and adjust the degree of melting and volume reduction of waste plastic. It is an object of the present invention to provide a volume reduction granulation method and apparatus for waste plastic containing combustible waste.
[0007]
[Means for Solving the Problems]
The volume reduction granulator for waste plastic containing combustible waste according to the present invention has a back pressure adjusted downstream of the kneading part of the screw consisting of a supply part, a kneading part and an extrusion part to adjust the degree of melting and volume reduction of the waste plastic. Cutter that installs waste plastic passage flow path adjustment device that adjusts the degree of conversion, makes the screw extrusion part a multiple flight, forms a discharge port by the screw groove of the extrusion part and the inner wall of the cylinder, and cuts molten waste plastic at the discharge port Is provided .
[0009]
According to the present invention, waste plastic can be crushed, kneaded, compressed, heated and partially melted to increase the bulk density of the waste plastic to obtain a solidified product such as pellets.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described based on examples with reference to the drawings.
[0011]
FIG. 1 is a schematic configuration diagram of a waste plastic volume-reduction granulating apparatus containing combustible waste according to the present invention.
[0012]
The waste plastic volume reducing granulation apparatus containing combustible waste of the present invention includes a cylinder 3 provided with a waste plastic raw material supply inlet 1 at one end and a waste plastic discharge port 2 reduced at the other end, The screw 7 is mounted in the cylinder 3 and has a supply part 4, a kneading part 5 and an extrusion part 6, and a fixed blade 8 as a cutter disposed in the discharge port 2 of the cylinder 3. The screw 7 is driven by a motor 10 via a speed reducer 9. In addition, the volume reduction granulation apparatus of the waste plastic of a present Example is a different direction rotation biaxial screw type extruder, the supply part 4 and the kneading part 5 of the screw 7 are large-diameter meshing type, and the extrusion part 6 is a small diameter. In non-meshing form.
[0013]
The extrusion part 6 of the screw 7 is composed of a multi-strip flight, and is usually 2 to 64, although it varies depending on the screw diameter and processing capacity. The tip of the screw 7 is a plane that is perpendicular to the axis.
[0014]
A back pressure adjusting gate 11 having an orifice for adjusting the degree of melting and volume reduction of the waste plastic by adjusting the pressure of the kneading section 5 on the upstream side is provided on the tip side of the cylinder 3. The cylinder 3 is heated by electricity, steam or heat transfer oil. Instead of the orifice of the back pressure adjusting gate 11, a taper portion is provided between the kneading portion 5 and the extrusion portion 6 of the screw 7, and the cylinder 3 is also provided with a taper portion at the same position. It is good also as a structure which forms and moves the screw 7 or the cylinder 3 back and forth, and changes the clearance gap of a slot part.
[0015]
When the fixed blade 8 comes into contact with the tip surface of the cylinder 3 and cuts the molten waste plastic, there is a problem that the cylinder end surface and the screw end surface are not positioned due to the effect of the cylinder heating. A gap adjusting ring 12 is provided for adjusting.
[0016]
As shown in FIG. 1A, the fixed blade 8 is pressed by a spring toward the end faces of the screw 7 and the cylinder 3, and as shown in FIG. 1B, the fixed blade 8 is in a direction opposite to the rotational direction of the screw 7. It is pressed against the spring. The cutter may be a rotary blade.
[0017]
Next, the operation will be described.
[0018]
Waste plastic as a raw material is supplied from the raw material supply port 1 and is sent forward by the supply unit 4 and kneading unit 5 of the screw 7, while heating from the cylinder 3 and shearing heat generated between the screw 7 and the cylinder 3. , Compression by the screw 7 and resistance of the back pressure adjusting gate 11 provided in front of the kneading part 5 are filled, the kneading part 5 is filled, and the kneading part 5 is subjected to kneading and dispersing action to generate heat and melt and reduce. Tolerated. The molten waste plastic passes through the back pressure adjusting gate 11 and is transported downstream by the multi-strip flight of the extrusion portion 6 of the screw 7, and the discharge port 2 constituted by the screw groove 7 a at the screw tip and the inner wall of the cylinder 3. Is discharged without any clogging.
[0019]
The discharged molten waste plastic is cut into an appropriate length by the rotation of the screw 7 and the fixed blade 8 provided at the discharge port 2. As a result, pellets having a high bulk density, a high volume reduction, and undecomposed polyvinyl chloride, such as solid fuel, can be produced.
[0020]
【The invention's effect】
Since the present invention is configured as described above, the following effects can be obtained.
(A) Waste plastics may vary or change due to locality and seasonality of the raw material composition and daily fluctuations in water content, but the back pressure adjustment gate allows the degree of melting and volume reduction of waste plastics to be freely controlled. Can be adjusted. In addition, waste plastics of any composition can produce pellets (such as solid fuel) with a large volume reduction without causing thermal decomposition of the vinyl chloride resin.
(B) The molten waste plastic is discharged from the screw groove to the outside, and since there is no conventional so-called die, it can be discharged without clogging even when a high-melting point resin or foreign matter comes.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a schematic configuration diagram of a waste plastic volume reducing granulation apparatus according to the present invention, in which (a) is a cross-sectional plan view and (b) is a view as seen from an arrow A in (a).
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Raw material supply port 2 Discharge port 3 Cylinder 4 Supply part 5 Kneading part 6 Extrusion part 7 Screw 7a Screw groove 8 Fixed blade (cutter)
9 Reducer 10 Motor 11 Back pressure adjustment gate (Waste plastic passage flow adjustment device)
12 Gap adjustment ring

Claims (2)

In a screw-type volume reduction granulator for reducing and granulating waste plastic containing combustible waste, a kneading part (5) of a screw (7) comprising a supply part (4), a kneading part (5) and an extrusion part (6) ), A waste plastic passage channel adjusting device (11) for adjusting the degree of melting and volume reduction of the waste plastic by adjusting the back pressure is installed, and the pushing portion (6) of the screw (7) Is a multi-flight, a discharge port (2) is formed by the screw groove (7a) of the extrusion portion (6) and the inner wall of the cylinder (3), and a cutter (8) that cuts molten waste plastic into the discharge port (2). ), A volume reduction granulator for waste plastics containing combustible waste. The front end surface of the cylinder (3), the cylinder end face and the gap adjustment ring for adjusting the screw end face (12), characterized in that the provided claims 1 volume reduction granulated waste plastic containing the combustible waste according apparatus.

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