JPH0775744A - Gravity sorter for refuse plastic fluff of general waste - Google Patents

Abstract

PURPOSE:To unravel both of light gravity and heavy gravity fluff and to enhance efficiency of separating both fluff by applying mechanical impact from outside to the refuse plastic fluff in a gravity sorting tank where light duty fluff groups and heavy duty fluff groups are mingled with each other by means of comb-shaped raking vanes without disturbing the flow of the water and fluff in the tank. CONSTITUTION:This gravity sorter 10 for the refuse plastic fluff which sorts the refuse plastic fluff to the light gravity fluff groups floating on water and the heavy gravity fluff groups sinking in the water is provided with a device 60 for wetting the refuse plastic fluff 20 formed by crushing the refuse plastic and the gravity sorting tank 40 filled with the water. The sorter is also provided with the comb-shaped raking vanes 50, 51, of which the revolving shaft is installed upper than the water surface of the gravity sorting tank 40. The mechanical impact is applied from outside to the refuse plastic fluff in the gravity sorting tank where the light gravity fluff groups and the heavy gravity fluff groups are mingled with each other without disturbing the flow of the water and the fluff in the tank by these raking vanes, by which the efficiency of separating both of the light gravity and heavy gravity fluff is enhanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pretreatment facility for an oil liquefaction facility for the recycling treatment of general waste waste plastic (garbage plastic).

[0002]

2. Description of the Related Art The use of plastics has been increasing year by year, and the production volume in 1991 reached 13.5 million tons. There are some plastics that become waste immediately after a certain time lag from those that become waste, but in 1991, industrial waste plastics were 260
10,000 tons, 3.4 million tons of general waste plastic. On the other hand, the amount recycled is only 700,000 tons for both simple recycling and compound recycling, and most of them are incinerated and landfilled.

In order to recycle waste plastics, it is necessary to advance the sorting technology, and if sorting by type of plastic is possible, the amount of recycling increases. In this sense, industrial waste plastics are known to some extent and can be recycled relatively easily. There are various ways to recycle waste plastics, one of which is the heat utilization method. Most of the heat utilization methods are so-called thermal recycling methods in which incineration is performed and the thermal energy generated at that time is utilized.
However, in recent years, a material recycling system has been constructed in which waste plastic is turned into fuel, and the form of the fuel is prepared and recycled.

One of the uses of waste plastics as fuel is the use of solid fuels. This is a system in which waste plastics with low chlorine compounds are sorted and collected, converted into fuel by a molding machine, and supplied as fuel for industrial boilers, and operations have started at several locations. Another method of converting to fuel is oil conversion, which has started operation at several locations. An example of the oilification method is as follows: When waste plastic is melted at a high temperature and further heated and vaporized, and this vapor causes catalytic cracking reaction with the zeolite catalyst, the plastic is converted into high-quality, relatively light petroleum. it can. Plastics that can be converted to petroleum are polyolefin plastics such as polyethylene, polypropylene and polystyrene, and waste plastics composed of these can be easily collected if they are industrial wastes.

However, general waste plastics, especially "garbage plastics" discharged from general households, are chlorine compounds such as vinyl chloride, many thermosetting resins, laminated products with metals, and other miscellaneous substances. Since it cannot be used as it is as an oilification raw material, it is necessary to wash and select the raw material plastic as a pretreatment for oilification. 2-3
The method of selecting one kind of plastic from the kinds of mixed plastics includes the dry type wind power selection method, the fluidized bed selection method,
There are a wet gravity selection method and a cyclone method. The wet gravity sorting method utilizes the water-floating property of polyolefins such as polyethylene, polypropylene and expanded polystyrene.

[0006] The wet gravity sorting method has been used in the past for washing and sorting crushed vinyl products for agriculture, and for washing and sorting crushed PET bottle products. Not used. However, gravity sorting is effective in sorting out a wide variety of waste plastics such as garbage plastics both physically and chemically.

The properties of the raw material handled in the conventional gravity sorting are simpler than those of waste plastics, and the difference in specific gravity between the objects to be sorted is large. Therefore, the gravity sorting tank itself is not so devised. There wasn't. For example, plastic cannot be subjected to the original specific gravity selection unless the surface is completely wet, but with a simple system in which the number of types of raw materials for selection is small, it was possible to wet the plastic without necessarily devising it. In addition, when it comes to a system where thin films exist, heavy fluff will enter into the light fluff group (scraps of dust plastic floating on water) in water, or the heavy fluff group (scraps of dust plastic sinking on water). However, no measures were taken to loosen them and reduce contamination to both the heavy fluff group and the light fluff group.

[0008]

The waste plastics (garbage plastics) of general waste type are various and various such as plastic bags for shopping, food packaging materials, foam trays, polystyrene trays, wrap films, cosmetic bottles, detergent bottles, etc. It is characterized by the fact that each material is different in thickness, and that paper, aluminum foil, and laminated products are mixed.

These waste plastics are crushed by a crusher.
It is crushed to a size of about 10 mm, washed, and then fed to a gravity sorting tank for selection of oil-incompatible products for selection. The component of the fluff entering the gravity sorting tank is polyethylene (specific gravity 0.91).
~ 0.96), polypropylene (0.90 to 0.91), expanded polystyrene (0.5 or less), vinyl chloride (1.1 to 1.1).
6), polyvinylidene chloride (1.65 to 1.72), polystyrene (1.04 to 1.09), etc. and thermosetting resin such as phenol resin (1.2 to 1.3) and urea resin (1). .47 to 1.5
2), acrylic resin (1.3 to 1.4) and the like. Among them, polyethylene, polypropylene and expanded polystyrene are basically floated on water, and other resins are submerged in water.

However, in reality, the fluffs are overlapped with each other and it is difficult for the fluffs to float and sink as a single piece, and the fluffs to float or to float unless a mechanical impact is given to the fluffs. Is extremely decreased, and on the contrary, sedimentation or fluff floating in water is increased.
In other words, the fluff exits the washing tank together with water and is guided to the gravity sorting tank, where gravity sorting is performed to separate it into the light fluff group and the heavy fluff group due to the difference in specific gravity. At this time, if the fluff is pushed downstream by the water flow while being supplied to the gravity sorting tank, the heavy fluff group overlapping the light fluff group and the light fluff group overlapping the heavy fluff group will float or settle as they are. Therefore, the recovery rate of the light fluff group is lowered, and the oilification efficiency of the light fluff group is lowered.

An object of the present invention is to solve the above problems.
Without disturbing the flow of water and fluff, mechanical impact is given to the light fluff group and the heavy fluff group that are about to rise from the upper part of the aquarium, and both light and heavy fluff are loosened. An object of the present invention is to provide a gravity sorting device that enhances separation efficiency.

[0012]

In order to achieve the above object, the present invention comprises a device for wetting a waste plastic fluff obtained by crushing waste plastic, and a gravity sorting tank filled with water. In a gravity sorting device for a dust plastic fluff that sorts into a group of light fluff floating on water and a group of heavy fluff sinking in water, a rotary shaft further comprises a comb-shaped blade installed above the surface of the water in the gravity sorting tank. Provided is a gravity sorting device for garbage plastic fluff, which is characterized by being provided.

[0013]

Embodiments of the present invention will now be described, by way of example only, with reference to the drawings. FIG. 1 shows a gravity sorting device 10. Gravity sorter 10 is a waste plastic fluff 20.
Screw feeder 3 for feeding, which is a device for wetting
0, a gravity sorting tank 40 filled with water, two pairs of first comb-shaped blades 50 and a pair of first comb-shaped blades 51.

The supply screw feeder 30 has a rotating shaft 31 rotated by a driving device such as a motor (not shown) installed on the upper portion, a spiral screw blade 32 attached to the rotating shaft, and a waste plastic. Vertical outer casing 3 having an opening 33 for introducing a fluff
4 and. The supply screw feeder 30 is provided in the vertical cleaning tank 60, and the waste plastic fluff 2
0 is pushed into the cleaning tank 60 by the rotation of the screw blade 32. The cleaning tank 60 is designed so that the circulating water 70 causes water to overflow. Cleaning tank 6
0 is provided with an agitator 80 for agitating the waste plastic fluff 20 in water.
Has a rotary shaft 81 that is rotated by a drive device such as a motor (not shown) installed on the upper part, and a blade 82 attached to the lower part of the rotary shaft. In addition, a tank valve 9 for discharging dust generated during cleaning is provided under the cleaning tank 60.
0 is provided. Further, the cleaning tank 60 is provided with a gutter 100 for sending the waste plastic fluff 20 overflowing with water to the gravity sorting tank 40. Therefore, the installation level of the cleaning tank 60 is preferably higher than that of the gravity sorting tank 40.

The gravity sorting tank 40 is a horizontal square tank filled with water, and has two pairs of first comb-shaped blades 50 and a pair of second comb-shaped scraping blades having a rotating shaft above the water surface in the upper part. Feather 51
The overflow weir 110 is provided at the bottom of the gravity sorting tank 40 with a scraping scraping screw 120 and a submersible pump 130 for pumping the sediment. The submersible pump 130 is connected to a trommel 150, which is a thin-walled cylindrical container having a porous surface, through a pipe 140. Below the trommel 150, a chute 170 and a conveyor 180 for collecting the heavy fluff group 20H, a pan 190 for collecting water, and a pipe 200 connected to the pan 190 and returned to the inlet of the gravity sorting tank 40. And are provided.

2 and 3 are perspective views of the first comb-shaped blade 50 and the second comb-shaped blade 51, respectively. The comb shape of the comb-shaped blade is a round bar 52 having a diameter of 3 to 10 mm, which is mounted on the rotary shaft 53 at a pitch of 20 to 50 mm.
The length of the comb is within 500 mm of the water depth, and the number of combs is the rotating shaft 53.
It is preferable to install it every 45 ° or 90 °. The number of the first comb-shaped blades 50 can be arbitrarily increased according to the length of the gravity sorting tank 40 in the longitudinal direction. . The second comb-shaped blade 51 is for the rearmost part of the gravity sorting tank 40, and as shown in FIG. 3, a rotary shaft 53 is provided to help the light fluff group 20L to overflow the overflow weir 120 together with water. A flat plate 54 is provided for each comb at the opposite end.

The present invention is configured as described above,
The operation will be described below. The waste plastic fluff 20 is conveyed to the cleaning tank 60 via the conveyor 210, passes through the opening 33, and the screw feeder 30 for supply.
Supplied within. Next, garbage plastic fluff 20
Is pushed into water by the spiral screw blades 32 of the supply screw feeder 30 to wet the entire waste plastic fluff 20, and is mixed with water by the circulating water 70 and the agitator 80 for washing. The tank valve 90 is normally in a closed state, but it is opened when deposits such as sand and wire are received in the dust receiver 220 during cleaning. The residence time of water and fluff for cleaning in the cleaning tank 60 is 2
For 3 minutes, the ratio of water and fluff continuously supplied is 30 to 100 weight of water to 1 weight of fluff.

The waste plastic fluff 20 is mixed with water to remove food waste and the like, and then overflows with water to enter the gravity sorting tank 40 through the gutter 100. Cleaning tank 6
The dust plastic fluff 20 that has fallen from 0 to the gravity sorting tank 40 is sufficiently wet and thus is separated into a light fluff floating in the gravity sorting tank 40 and a heavy fluff that sinks. However, at the time of dropping, these are mixed with each other, and the comb portions of the first and second comb-shaped blades 50, 51 give mechanical impact to the dust plastic fluff 20 to loosen the fluff that is floating or sinking. Done and facilitates separation. Each of the comb-shaped blades 50 and 51 is rotated in the same direction as shown in FIG. 1 by a chain using a motor or the like (not shown) as a driving device, and the separated fluffs are shown in FIG.
Shed in the direction of the arrow.

The floated light fluff group is dam 11 together with water.
Overflow 0 and dehydrator for the next process (not shown)
Enters and is separated from water and collected as a light fluff group 20L. On the other hand, the heavy fluff group 20H that settled in water
The screw 120 at the bottom is raked to one end in the longitudinal direction of the gravity sorting tank 40, and the submersible pump 130 together with water.
Trommel 15 pumped by piping 140
Enter 0. Further, the heavy fluff group 20H is separated from water and is collected as the heavy fluff group 20H via the chute 170 and the conveyor 180. The water separated by the trommel 150 passes through the pan 190 and the pipe 200, and the gravity sorting tank 4
Returned to the 0 entrance.

The fluff of domestic waste garbage plastic, which is a general waste, was sorted in the following gravity sorting tank with a washing tank. 1. Raw material name Garbage plastic fluff Dimensions 10mm or less Processing amount 60kg / h 2. Cleaning tank type Vertical cylinder type 900φ, 1260mmH Stirrer 0.75kW 3. Gravity sorting tank type Horizontal square type Dimensions 1000mm width, 1500mm height, 4000mm Long comb type blade: Number of blades 3 steps Comb diameter 6 mm Comb length 500 mm Number of combs (per step) 4 (90 ° interval) Comb pitch 30 mm Rotation speed 8 rpm 4. Sorting result Light fluff group recovery amount Fifty
kg / h Heavy fluff group in the light fluff group 0 kg / h Light fluff group in the heavy fluff group 1.5 kg / h Although the embodiment of the present invention has been illustrated and described in detail, the scope of the present invention It will be apparent that various changes can be made to the disclosed embodiments without departing from the spirit. For example, a feeding screw feeder 30 which is a device for wetting the waste plastic fluff 20 with water may be provided in the gravity sorting tank 40.

[0021]

According to the gravity sorting apparatus of the present invention, the flow of water and fluff in the waste plastic fluff in the gravity sorting tank in which the light fluff group and the heavy fluff group are mixed by the comb-shaped blades. It is possible to increase the oil conversion efficiency of the light fluff group by increasing the recovery efficiency of the light fluff group by separating the light fluff group and the heavy fluff group by applying a mechanical shock from the outside without disturbing.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of a gravity sorting device according to the present invention.

FIG. 2 is a perspective view of a first comb-shaped blade according to the present invention.

FIG. 3 is a perspective view of a second comb-shaped blade according to the present invention.

[Explanation of symbols]

 10 Gravity Sorting Device 20 Garbage Plastic Fluff 30 Feeding Screw Feeder 40 Gravity Sorting Tank 50 First Comb-Shaping Blade 51 Second Comb-Shaping Blade 52 Round Bar 53 Rotating Shaft 60 Cleaning Tank

Claims (3)

[Claims] 1. A light fluff group that floats on the water and a heavy fluff that sinks into the water, comprising a device for wetting the waste plastic fluff obtained by crushing the waste plastic and a gravity sorting tank filled with water. In a gravity sorting device for dust plastic fluff for sorting into groups, a gravity sorting device for dust plastic fluff, further comprising a comb-shaped blade whose rotation axis is installed above the surface of the water in the gravity sorting tank. apparatus. 2. The comb-shaped scraping blade includes one rotation shaft and a plurality of combs that are separated from each other by a constant angle around the rotation shaft, and the comb is constant in the longitudinal direction of the rotation shaft. The gravity sorting device according to claim 1, wherein the gravity sorting device is composed of a plurality of round bars that are connected to the rotating shaft substantially in parallel with each other at intervals. 3. The gravity sorting apparatus according to claim 1, further comprising a washing tank for washing the garbage plastic fluff before the garbage plastic fluff is sorted by the gravity sorting tank. Gravity sorter.