JPH09173982A - Separating device for granular material and its separation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To separate the structural elements of a granular material from each other corresponding to a different attribute by dispersing a mixed granular material charged on a perforated member in an air flow moving upward in a duct, feeding a certain particle upward from the duct and discharging another particle through the perforated member from the bottom of the duct. SOLUTION: The mixed material 44 is charged from a hopper 58 on a porous screen formed from a grating 36 arranged along an inclined chute 60 in a separating section 24. The grating 36 has many narrow rod members arranged to be extended across the duct 22 between a material inlet 40 and a scrap outlet 42 in an adjacent material. The grating 36 is supported in cantilever by a mounting part 46 supporting the grating 36 elastically on a spring and a ferromagnetic member 50 is mounted to the grating 36, which is vibrated by a solenoid 52. Then, a certain material 44 is fluidized with air moving upward and is discharged from the separating section 24 through the duct 36 Another particle material 44 is discharged from the separating section 24 through the bottom 34 of the duct to be collected on a conveyer.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates generally to apparatus and methods for separating debris of particulate material. More particularly, the present invention relates to apparatus and methods for using air to separate components of particulate material based on different attributes.

[0002]

BACKGROUND OF THE INVENTION Separation of particulate material into various debris based on density is practiced in many industrial processes. In the mining industry, heavy minerals are aggregated and extracted from ores. In agriculture, airflow is used to lift lighter rice husks and leaves from grains and stalks to separate the grain and rice husks and the leaves and stems.

In the wood pulp industry, a device known as an air density separator has been used to separate light colored wood chips from chips containing higher density knots.

The air density separator has 4,000 to 5,000.
A vertical separation chamber is used that attracts the air stream at velocities in the range of 0 feet / minute. The wood chips to be separated are metered into the separation chamber by means of an auger (rotary punch), where they are evenly dispersed by a high-speed air stream. The higher density nodes fall through the upward flow of air and are eliminated. The lighter chips are drawn from the separation chamber by the air stream and separated from the air by the cyclone.

The recent interest in waste recycling and the development of waste recycling after use has created new and unique problems in the separation of materials. Collection and segregation of voluntary and sometimes compulsory recycling of a series of post-use packaging materials made up of large amounts of material and therefore regarded as economical recycling candidates is underway. These materials are ubiquitous aluminum cans, glass bottles, plastic milk containers and 1, 2 and 3 liter plastic bottles.

[0006]

Although recycling of milk bottles and plastic bottles is considered an economical recovery candidate, the value of the recycled product depends largely on its purity.

The recovery of high value materials from post-use waste plays a crucial role in reducing landfill disposal of post-use waste. High value products such as aluminum cans, newsprint and plastic cans can reduce the cost of government subsidies and help finance the recovery of other materials from waste streams.

In addition, by producing and selling the most expensive components of municipal waste, the market and social climate of key recycled products for economically recovering a larger portion of the user's waste is increased. Be created.

One major problem in recycling used plastic bottles is from the plastic bottle to the label,
Especially to remove the paper.

What is needed is an apparatus and method for removing paper and thin plastic from a used plastic bottle.

[0011]

The air density separation device of the present invention employs a vertical air separation chamber. The vertical air separation chamber is connected to a cyclone, and the cyclone is connected to a fan. The fan pulls air from the cyclone, which then pulls it up through a bottom-opened separation chamber.

In conventional air density separators used to separate wood and wood chips, the air is 4,000-5.
It is rapidly pulled through the separation chamber at a rate of 000 feet / minute. Wood chips are airlock (air stop passage)
Alternatively, it is metered into the separation chamber through a supply auger. The auger throws the chips into a high velocity air stream, where the high velocity air disperses the chips transversely to the separation chamber, thus an upflow of air separates the chips based on their density and cross-sectional area.

In the low speed air density separator of the present invention, the separation chamber is somewhat lengthened and air is pulled through the chamber at about 700 to 800 feet / minute. Due to the relatively low velocity of the air stream, the air stream itself is insufficient to evenly disperse the crushed plastic bottle and the paper label attached to it in the air stream.

In order to achieve a uniform distribution of the crushed bottles and labels in the air stream, a grid of closely spaced thin rod members extends into the separation chamber. The rod member is supported in a cantilever manner inside the separation chamber and is vibrated by a vibrating device.

The crushed material is fed onto the lattice base of the bar member by a normal chute without an air lock. The rapidly moving air between the rod members lifts and separates the various components of the crushed bottle. The denser plastic bottle wall material falls through the bar and is collected as heavy, recyclable bottle fragments.

Light weight paper is pulled through a separation chamber into a cyclone. The cyclone removes lightweight paper from the air stream, and air is drawn from the cyclone by a fan.

In an experiment with a bulk density material of 18.5 lbs / ft3, the air density separator of the present invention showed that the paper density was less than 95% of the paper with only 1% loss of paper plastic per crushed plastic bottle input. It is estimated to remove ~ 98%.

One feature of the present invention is the separation of shredded paper from shredded plastic.

Another feature of the invention is the purification of recycled plastic from post-use waste.

A further feature of the invention is to provide an air density separator for separating sand, soil and wood chips from wood chips.

A further feature of the present invention is to provide a method of purifying used plastic waste for recycling.

A further feature of the invention is to provide an apparatus for introducing and dispersing particulate material in a stream of air.

Further objects, features and advantages of the invention will be apparent from the following detailed description and the accompanying drawings.

[0024]

1 and 2, like numbers refer to like parts and will be described in more detail with reference to these figures. A low speed air density separator 20 is shown in FIG.

The air density separator 20 comprises a vertical air separation chamber 2
4 having vertically arranged conduits 22. The mixed granular material 44 is introduced into the separation chamber 24 from the material hopper 58. The air separation chamber 24 is connected to the cyclone 2 by a duct 26.
8 is connected.

The cyclone is connected to the fan 30. The fan draws air from the cyclone 28, which draws air through the duct 26, thus the air flow is indicated at the bottom 3 of the conduit 22 as indicated by arrow 32.
Come in 4.

The mixed material 44 is distributed from the hopper 58 along the slanted chute 60 in the separation chamber 24 to the grid 36.
It is put on a porous screen formed by. The grid 36 has a number of closely spaced thin rod members 38 extending across the conduit 22 between a material inlet 40 and a waste outlet 42.

The lattice 36 is cantilevered from a mounting portion 46 that elastically supports the lattice 36 on a spring 48. A ferromagnetic member 50 is attached to the grid 36 and is excited by a solenoid 52 to cause the grid 36 to vibrate at about 60 hertz.

Some materials flow with air moving upwards,
Exit the separation chamber through duct 26. The remaining particulate material, which does not flow with the air and passes through the grid 36, exits the separation chamber 24 from the bottom 34 of the conduit 22 and is collected on a conveyor 35.

In conventional air density separators, air is pulled through the separation chamber at a rate of 4,000 to 5,000 feet / minute, while separated particulate material, such as wood chips, is separated from the separation chamber. It is fed into the air chamber either by a chute with air locks or augers that distribute the material laterally.

In the conventional air density separator, the granular material separated by the air flow is dispersed by the high-speed air flow rising in the separation chamber. The sufficiently dense material falls through the separation chamber and the lighter material is entrained in the air and drawn into the cyclone where it is separated.

Air density separators have a ballistic coefficient of aerodynamics.
Separate the particles by what is known as. The drag coefficient is a function of the coefficient due to the density of the object, the area and shape of the object exposed to the air flow.

Therefore, the drag coefficient of an object increases with its density, decreases with increasing area, and decreases with increasing thickness of the object facing the air stream. The drag coefficient regulates the maximum velocity at which an object falls through a stationary column of air.

Since the resistance of an object passing through air increases with speed, an object accelerated by the gravity of the earth finally reaches a speed at which the acceleration force of gravity and the drag force of air passing through the object are in equilibrium. .

The above principles are utilized to separate a granular material into two or more components by the drag coefficient of the particles. The particulate material is separated into two parts by introducing the particles into an upward flow of air that is greater than the terminal velocity of one particle and less than the terminal velocity of another particle.

Thus, in order to separate the wood chips from the knots, the terminal speed of the wood chips exceeding 4,000-
Air velocities in the range of 5,000 ft / min have been selected,
This raises the wood chips to the top of the air chamber and through the duct into the cyclone. On the other hand, 4,000
Knots with terminal velocities greater than ~ 5,000 ft / min fall through the air and exit the bottom of the separation chamber.

A typical problem with low speed air density separator 20 is to separate shredded paper from shredded plastic. The recycling of used plastic bottles results in plastic milk containers and raw materials formed by crushing plastic bottles.

Raw materials include both plastics obtained from bottles and papers obtained from labels on the bottles. Separation of paper from plastic is necessary to make the raw material a product of economic value.

Since the plastic debris 54 as seen in FIG. 2 is a thicker material than paper or light weight plastic labels, they have a higher coefficient of resistance and can theoretically be separated by an air density separator. is there. However, both plastics and papers have a relatively low coefficient of resistance, so the air velocities in the air density separator should be in the range of 500 to 1,000 feet / minute, preferably 700 to 800 feet / minute.

The problems associated with these low speeds can be easily illustrated by grasping a handful of paper pieces, such as the punched pieces of a paper punch, and dropping them into the air. Some of the paper pieces disperse, reach terminal velocity rapidly and slowly settle on the bed. However, the others fall into a lump as a group that reaches the floor first.

Thus, for lightweight materials, these materials must be properly dispersed in the column of air rising through the vertical separation chamber 24 in order to reliably separate them based on the coefficient of resistance. I know I have to do it.

In the air density separator 20, proper dispersion is achieved by a grid 36 formed by closely spaced thin rod members 38. About 14 inches x 26
In a room with inch dimensions, the average size is 1 /
For handling 4 to 1/2 inch of crushed material 44, bar member 38 is 1.5 inches high and 0.06 to 0.12 inches wide (1.5 to 3 millimeters). A suitable interval is 1/8 to 1/4 inch.

The rod member 38 is surrounded by the frame 64 and is formed in the lattice 36. Lattice 3 formed by rod members 38
The lower surface of 6 is provided with one or more transverse reinforcement members (not shown).

The low speed air density separator 20 shown in FIG. 1 is provided with a fan 30 having a capacity of 5 horsepower. Table 1
Indicates the performance parameters of a 5 hp fan.

The suction pressure head is measured on the fan 30. This measurement was made for the evaluation of the velocity and cubic feet / minute flow rate through the separation chamber 24. Experiments were conducted on crushed plastics, including paper, to determine the optimum fan operating level for clean separation of paper and plastics.

[0046]

[Table 1]

Internal dimensions are 13.75 inches x 25.75
For a particular system with an inch air separation chamber 24, a 4 inch hydrostatic head in the fan was found to provide good paper to plastic separation.

As shown in FIG. 2, the crushed plastic and paper are fed from the chute 60 onto the platform 62 of the grid 36. The chute 60 extends partially over the grid 36 in the separation chamber. A cover 63 may be provided to prevent the material from staying in the outdoor portion of the lattice.

The vibrating grid 36 disperses the particulate material laterally of the platform. The airflow rising through the rod members 38 of the platform lifts the lightweight paper 56 and entrains it in the airflow.
The heavier plastic 54 slides past the bar,
It falls outside the open end of conduit 22.

[0050]

[Table 2]

Table 2 shows the values of 20 in the air density separator 20.
It summarizes the results of three experiments performed on a pound sample. When a mixture of crushed plastic and paper with a bulk density of 18.5 lbs / ft3 was loaded into the separation chamber at a rate of 1,500 lbs / hr, 5.8% of the material was recovered by paper in a cyclone. And 94.2
% Was recovered as a plastic component from the bottom of the separation chamber.

Similarly, 2,000 pounds / hour and 2.5
Experiments were conducted with a dosage of 00 pounds / hour. A slightly lower amount of paper was recovered at a higher rate. Separation of paper from plastic seems to be slightly less effective at higher rates. Visual inspection of the separated plastic and paper shows that approximately 95-98% of the paper was removed from the plastic and only less than 1% of the plastic was lost with the removed paper.

The inlet 40 of the air density separator 20 does not require an air lock because it has a relatively low air velocity. The relatively small effect that the openings in the wall 70 of the conduit 22 have on the flow allows the tray 72 of sufficiently large size to extend from the platform 62 of the grid 36 through the wall 74 facing the inlet wall 70. .

The debris contained in the particulate material 44 traverses over the slanted grid 36, exits the conduit 22 on the chute 72, and is routed there from the waste container 78 shown in FIG. .

Cyclone 28 utilizes centrifugal forces to separate most of the particulate material from the air stream. The cyclone has an air lock 80 from which the paper can be taken out of the cyclone. The air drawn from the cyclone passes through a fan and then into a baghouse (not shown), where residual debris is removed before being discharged into the atmosphere.

The low speed air density separator 20 may employ a porous member other than the lattice of thin rod members. For example, the porous member may be a vibrating screen or a vibrating plate with perforated holes. Further, the porous member may be made of screens of bar members that are combined to vibrate alternately 180 degrees out of phase with respect to adjacent bar members.

A separation chamber 24 having a height of about 10 feet
Although shown, the separation chamber can be shorter or longer.

The low speed air density separator can also be used to separate crushed products other than used plastic containers. For example, the density separator 20 also has the effect of separating soil and sand from wood chips.

When the term vibration is used, this is not limited to the vibrational action in the vertical plane caused by the solenoids of the arrangement shown in FIGS. 1 and 2, but any such as used in bar member screens. Includes in-plane vibrations and vibrations.

Although a coil spring is shown resiliently supporting the porous member 36 of the grid for vibration, other supports, such as leaf springs, are also possible.

The point that the solenoid excited by a linear frequency of 60 hertz causes the porous member to vibrate at 60 hertz is that the lattice 36 can be vibrated at another frequency, and as a mechanism for causing vibration, Other mechanisms may also be employed including an exciter using an eccentric weight, a cam follower with a crankshaft, a piezoelectric actuator and a high amplitude low frequency air pressure wave excitation system including sound waves.

The invention is not limited to the specific arrangements and arrangements of the parts shown and described herein, but also includes modifications within the scope of the claims.

[0063]

As described above, according to the present invention, in addition to separating paper used as a bottle label or the like from crushed granular material, separation of recycled plastic, sand, soil and It is possible to effectively carry out appropriate separation according to the property of the granular material to be treated, such as separation of wood chips.

[Brief description of the drawings]

1 is a schematic side view of a low speed air density separator of the present invention.

2 is a partially cutaway perspective view of the separation chamber and material input mechanism of the low speed air density separator of FIG. 1. FIG.

[Explanation of symbols]

 20 Air Density Separator 22 Conduit 24 Vertical Air Separation Chamber 26 Duct 28 Cyclone 30 Fan 32 Arrows 34 Bottom 35 Conveyor 36 Lattice 38 Bar Material 40 Material Inlet 42 Waste Outlet 44 Mixed Granular Material 46 Attachment 48 Spring 50 Ferromagnetic Member 52 Solenoid 54 Plastic shards 56 Paper 58 Material hopper 60 Chute 62 units 63 Cover 64 Frame 70 Wall 72 Tray 74 Wall 78 Waste container 80 Airlock

Claims (18)

[Claims] 1. A conduit that extends substantially vertically with a wall having a top and a bottom that opens downwards and that defines an upward air flow path; and for pulling air through said conduit. A duct connected to the top of the conduit; a fan connected to the duct to draw air through the conduit; a porous member extending into an air flow path within the conduit; a means for vibrating the porous member; Wherein the mixed particulate material loaded onto the porous member is dispersed in an upwardly moving air stream within the conduit, some particles flow with air and are sent upward from the conduit, and other particles are An apparatus for separating granular material, characterized in that it passes through a porous member and exits the bottom of the conduit. 2. The apparatus for separating granular material according to claim 1, wherein the porous member comprises a plurality of thin rod members arranged in parallel at intervals. 3. The bar member forming the lattice has a width of 0.0
The granular material separating apparatus according to claim 2, wherein the granular material has a size of 6 to 0.12 inch and is arranged at intervals of 1/8 to 1/4 inch. 4. The apparatus for separating granular material according to claim 1, wherein the porous member is elastically provided outside the conduit and is inclined downward in the conduit. 5. The method of claim 1 further comprising a dosing chute extending into the conduit and located at the top of the porous member for supplying the mixed particulate material to the porous member. Granular material separation device. 6. The granular material separating apparatus according to claim 1, further comprising a cyclone connected between the duct and the fan. 7. The wall of the conduit forms a cross-section, and the fan has 500-1,0 air per minute during maximum capacity operation.
The granular material separation apparatus of claim 1, having a pulling capacity of 00 cubic feet / square foot cross-sectional area. 8. The granular material separating apparatus according to claim 1, wherein the means for vibrating the porous member is a solenoid that magnetically engages with the porous member to vibrate the porous member. 9. The conduit has a material inlet and a material outlet below and facing the inlet, and the porous member extends between the inlet and the outlet and downwardly from the inlet toward the outlet. Granular material on the porous member, which is inclined so that it does not fall through the porous member and does not flow with air rising through the conduit, travels along the porous member and exits the conduit. The granular material separating apparatus according to claim 1, wherein the separating apparatus is formed as follows. 10. The conduit of claim 1 wherein the conduit has a rectangular cross section and the porous member has a surface area substantially equal to or greater than the cross section of the conduit. Separation device for crushed granular material. 11. A flow of particulate material having at least two components having different terminal velocities is fed to an oscillating porous member provided in a conduit; and a flow of air through said conduit from 500 to 1 5,000 ft / min .; at least a portion of the air passes through the porous member such that air passing through the porous member disperses the particulate material. A method for separating a granular material, characterized in that the granular material is separated based on a terminal velocity in a flow. 12. The separated granular material comprises a post-use plastic product that has been crushed to form the granular material and the first component comprises a plastic piece.
12. The method of separating particulate material of claim 11, wherein the second component comprises a thinner material having a lower terminal velocity. 13. A substantially vertically extending conduit having a bottom open to the atmosphere and a top connected to the duct,
A flow of air is drawn from the bottom to the top of the conduit; comprising a grid of parallel narrowly spaced thin bar members such that the bar members slope downwardly within the conduit. And a means for oscillating the grid externally of the conduit; a mixed particulate material having at least two components with different terminal velocities in the grid. A mixing chute connected to the duct at the top of the conduit; and a charging chute extending to the top of the grid in the feeding conduit, wherein the component of the mixed particulate material having a lower terminal velocity is received in the cyclone A fan that flows with the entrained air and is separated from the air in the cyclone; and a fan connected to the cyclone that draws a flow of air through the conduit and the cyclone. At least Il terminal velocity, characterized in that it comprises an isolation device for particulate material having two components. 14. The rod member forming the lattice has a width of 0.
The granular material separating apparatus according to claim 13, wherein the separating apparatus has a size of 06 to 0.12 inch and is arranged at intervals of 1/8 to 1/4 inch. 15. The apparatus for separating granular material according to claim 13, wherein the lattice is elastically provided outside the conduit and is inclined downward in the conduit. 16. The wall of the conduit forms a selected cross section, and the fan operates at 5 air per minute during maximum capacity operation.
14. An apparatus for separating particulate material as claimed in claim 13 having a pulling capacity of from 0 to 1,000 cubic feet / square foot of conduit cross-sectional area. 17. The apparatus for separating granular material according to claim 13, wherein the means for vibrating the grid is a solenoid that magnetically engages with the grid to vibrate the grid. 18. The conduit has a material inlet and a material outlet below and facing the inlet, and the grid extends between the inlet and the outlet and slopes downwardly from the inlet toward the outlet. Such that material on the grid that does not fall through the grid and that does not flow with air rising through the conduit travels along the grid and exits the conduit. 14. The granular material separating apparatus according to claim 13, wherein: