CA2310169A1 - Compost particle separation unit - Google Patents
Compost particle separation unit Download PDFInfo
- Publication number
- CA2310169A1 CA2310169A1 CA 2310169 CA2310169A CA2310169A1 CA 2310169 A1 CA2310169 A1 CA 2310169A1 CA 2310169 CA2310169 CA 2310169 CA 2310169 A CA2310169 A CA 2310169A CA 2310169 A1 CA2310169 A1 CA 2310169A1
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- Canada
- Prior art keywords
- compost
- vessel
- plastic
- mixture
- pipe
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B07—SEPARATING SOLIDS FROM SOLIDS; SORTING
- B07B—SEPARATING SOLIDS FROM SOLIDS BY SIEVING, SCREENING, SIFTING OR BY USING GAS CURRENTS; SEPARATING BY OTHER DRY METHODS APPLICABLE TO BULK MATERIAL, e.g. LOOSE ARTICLES FIT TO BE HANDLED LIKE BULK MATERIAL
- B07B7/00—Selective separation of solid materials carried by, or dispersed in, gas currents
- B07B7/08—Selective separation of solid materials carried by, or dispersed in, gas currents using centrifugal force
- B07B7/086—Selective separation of solid materials carried by, or dispersed in, gas currents using centrifugal force generated by the winding course of the gas stream
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B07—SEPARATING SOLIDS FROM SOLIDS; SORTING
- B07B—SEPARATING SOLIDS FROM SOLIDS BY SIEVING, SCREENING, SIFTING OR BY USING GAS CURRENTS; SEPARATING BY OTHER DRY METHODS APPLICABLE TO BULK MATERIAL, e.g. LOOSE ARTICLES FIT TO BE HANDLED LIKE BULK MATERIAL
- B07B1/00—Sieving, screening, sifting, or sorting solid materials using networks, gratings, grids, or the like
- B07B1/04—Stationary flat screens
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B07—SEPARATING SOLIDS FROM SOLIDS; SORTING
- B07B—SEPARATING SOLIDS FROM SOLIDS BY SIEVING, SCREENING, SIFTING OR BY USING GAS CURRENTS; SEPARATING BY OTHER DRY METHODS APPLICABLE TO BULK MATERIAL, e.g. LOOSE ARTICLES FIT TO BE HANDLED LIKE BULK MATERIAL
- B07B4/00—Separating solids from solids by subjecting their mixture to gas currents
- B07B4/02—Separating solids from solids by subjecting their mixture to gas currents while the mixtures fall
- B07B4/025—Separating solids from solids by subjecting their mixture to gas currents while the mixtures fall the material being slingered or fled out horizontally before falling, e.g. by dispersing elements
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B07—SEPARATING SOLIDS FROM SOLIDS; SORTING
- B07B—SEPARATING SOLIDS FROM SOLIDS BY SIEVING, SCREENING, SIFTING OR BY USING GAS CURRENTS; SEPARATING BY OTHER DRY METHODS APPLICABLE TO BULK MATERIAL, e.g. LOOSE ARTICLES FIT TO BE HANDLED LIKE BULK MATERIAL
- B07B7/00—Selective separation of solid materials carried by, or dispersed in, gas currents
- B07B7/08—Selective separation of solid materials carried by, or dispersed in, gas currents using centrifugal force
- B07B7/083—Selective separation of solid materials carried by, or dispersed in, gas currents using centrifugal force generated by rotating vanes, discs, drums, or brushes
Abstract
An apparatus and method for separating plastic material from a shredded compost-plastic mixture. The compost plastic separation unit is comprised of various stages including first and second stage separation units. After initial separation of larger organic material from the shredded compost-plastic mixture, the mixture is sequentially delivered to a first stage separation unit where a coarser compost component is separated from the mixture. The lighter fine compost and plastic components are drawn into a pipe by suction and subsequently transported to the second stage separation unit by an air stream.
The heavier coarse compost component which is not drawn into the pipe exits at the base of the first stage separation unit under the force of gravity. At the second stage separation unit, plastic material is further separated from the fine compost.
The heavier coarse compost component which is not drawn into the pipe exits at the base of the first stage separation unit under the force of gravity. At the second stage separation unit, plastic material is further separated from the fine compost.
Description
TITLE: ~ COMPOST PARTICLE SEPARATION UNIT
INVENTORS: Gary Nethercott & Les Zinn BACKGROUND OF THE INVENTION
The present invention relates to an apparatus and method for separating plastic material from an organic compost plastic mixture.
Most residential organic yard waste is collected in large plastic bags.
Typical organic yard waste includes tree branches, leaves, grass clippings and the like. The plastic bags of organic waste are subsequently placed at the curb to be collected by municipal waste collection services for disposal. Instead of being taken to overcrowded landfills, such organic yard waste is capable of being used as compost which is also better for the environment.
Furthermore, compost which is free of non-biodegradable matter or impurities such as plastic, is commercially valuable. Current commercial composting operations arising from plastic bag collection of organic yard waste, result in impure compost since the plastic bags are shredded along with the organic material contained within. The presence of plastic material in the compost significantly diminishes its value.
INVENTORS: Gary Nethercott & Les Zinn BACKGROUND OF THE INVENTION
The present invention relates to an apparatus and method for separating plastic material from an organic compost plastic mixture.
Most residential organic yard waste is collected in large plastic bags.
Typical organic yard waste includes tree branches, leaves, grass clippings and the like. The plastic bags of organic waste are subsequently placed at the curb to be collected by municipal waste collection services for disposal. Instead of being taken to overcrowded landfills, such organic yard waste is capable of being used as compost which is also better for the environment.
Furthermore, compost which is free of non-biodegradable matter or impurities such as plastic, is commercially valuable. Current commercial composting operations arising from plastic bag collection of organic yard waste, result in impure compost since the plastic bags are shredded along with the organic material contained within. The presence of plastic material in the compost significantly diminishes its value.
Despite the availability of bio-degradable plastic and paper bags for organic yard waste, such bags have not gained widespread acceptance among consumers because of their higher cost and unreliability. The shelf life for such bags is short and they tend to rip easily or fall apart when exposed to the elements. Existing methods available to separate the plastic component from the shredded compost-plastic mixture include removing the plastic by hand, the use of gravel style vibrating screens and the use of revolving topsoil screens. These methods are relatively costly or labour intensive and, moreover, are not totally effective in producing a plastic free compost product.
The present invention, which we have named a Compost Particle Separation Unit (hereinafter CPSU), is intended to overcome the disadvantages of the prior art described above. The object of the present invention is to provide an efficient and effective means of obtaining high quality compost product, free of plastic contamination. This object is achieved by using the CPSU to separate the plastic particulate from the commercially valuable organic compost.
According to the invention, the shredded compost-plastic mixture is deposited into the CPSU in batches. The CPSU is then used to separate the mixture into a number of commercially useful products such as, oversize bulking agents, standard bulking agents, coarse compost, fine compost, and plastic.
The present invention, which we have named a Compost Particle Separation Unit (hereinafter CPSU), is intended to overcome the disadvantages of the prior art described above. The object of the present invention is to provide an efficient and effective means of obtaining high quality compost product, free of plastic contamination. This object is achieved by using the CPSU to separate the plastic particulate from the commercially valuable organic compost.
According to the invention, the shredded compost-plastic mixture is deposited into the CPSU in batches. The CPSU is then used to separate the mixture into a number of commercially useful products such as, oversize bulking agents, standard bulking agents, coarse compost, fine compost, and plastic.
Oversized bulking agents include, for example, tree limbs. Standard bulking agents include, for example, wood chips. It is the fine compost product, however, which is particularly valuable.
SUMMARY OF THE INVENTION
The object of the present invention is to provide an improved apparatus for separating plastic material from a shredded compost plastic mixture and method of using the apparatus to achieve plastic separation. We have named this apparatus a Compost Plastic Separation Unit (CPSU).
The CPSU according to this invention has several stages including a first stage separation unit and a second stage separation unit. Prior to using the CPSU, organic yard waste is collected in plastic bags. The plastic bags and organic waste contained within are then shredded by conventional means resulting in a shredded compost plastic mixture. Initial separation of larger objects from the mixture is achieved by means of a grate positioned over a hopper into which the mixture is delivered. Next, a continuous stream of shredded compost plastic mixture is sequentially delivered to the first stage separation unit from the hopper by a system of conventional conveyors. The first stage separation unit operates to separate the coarser compost component from the compost plastic mixture.
SUMMARY OF THE INVENTION
The object of the present invention is to provide an improved apparatus for separating plastic material from a shredded compost plastic mixture and method of using the apparatus to achieve plastic separation. We have named this apparatus a Compost Plastic Separation Unit (CPSU).
The CPSU according to this invention has several stages including a first stage separation unit and a second stage separation unit. Prior to using the CPSU, organic yard waste is collected in plastic bags. The plastic bags and organic waste contained within are then shredded by conventional means resulting in a shredded compost plastic mixture. Initial separation of larger objects from the mixture is achieved by means of a grate positioned over a hopper into which the mixture is delivered. Next, a continuous stream of shredded compost plastic mixture is sequentially delivered to the first stage separation unit from the hopper by a system of conventional conveyors. The first stage separation unit operates to separate the coarser compost component from the compost plastic mixture.
The first stage separation unit is generally comprised of a vertically aligned elongated walled vessel having a substantially circular cross-section. The vessel has an intake opening portion and intake opening at the top, an exhaust opening portion and exhaust opening at the bottom, and a body portion between the intake opening portion and exhaust opening portion.
Housed within the vessel is a rotatable platform, a pipe having a substantially circular opening at the top thereof, air jet nozzle means circumferentially arranged in the body portion, and suitably adapted support members.
The rotatable platform is horizontally aligned and substantially circular. The diameter of the platform is less than the diameter of the vessel, thereby forming an annular opening. As well, the top surface of the platform is sloped downwardly from its center and attached to the top surface of the platform is a plurality of fins at regular angular intervals.
During operation of the CPSU, a continuous stream of compost plastic mixture is deposited onto the top surface of the rotating platform. In response to the rotation of the platform, the compost plastic mixture is peripherally and uniformly ejected against the inner surface of the vessel wall. The compost plastic mixture then falls along the vessel wall under the force of gravity, through the annular opening, into the body portion of the vessel.
The circular opening of the pipe is located underneath the rotatable platform 5 and has its axis in alignment with the longitudinal axis of the vessel and rotatable platform. Attached to the base of the pipe is an interconnecting duct system leading to the second stage separation unit. A material handling fan, located within the duct system generates a suction effect or area of lower pressure surrounding the opening of the pipe by drawing a continuous volume of air into the vessel and subsequently into the pipe through its opening. The lighter fine compost and plastic components of the compost plastic mixture are thereby caused to move towards the lower pressure area and form part of an air stream flowing into the pipe. The air stream, which is drawn into the opening of the pipe by the material handling fan, thus captures the lighter fine compost and plastic components of the compost plastic mixture and carries them into tt~e pipe.
The air jets are supplied with a source of pressurized air and the nozzles of the air jets are angled diagonally upwards towards the longitudinal axis of the vessel. The air jets perform a number of functions including helping to direct the falling compost plastic mixture, specifically the lighter fine compost and plastic towards the opening of the pipe. As well, the air jets aid in separating the compost plastic mixture by drying the mixture and also by air agitation and turbulence.
The coarse compost component, which is too heavy to be captured by the air stream and drawn into the pipe, continues travelling downwardly through the vessel under the force of gravity. It exits the vessel through the exhaust opening onto a conveyor leading away from the CPSU.
The fine compost and plastic material suspended in the air stream and drawn into the pipe is transported by means of the interconnecting duct system to the second stage separation unit for further separation. The fine compost and plastic is exhausted into the second stage separation unit, which is comprised of an air chamber. Within the air chamber, a cyclone separates the fine compost from the plastic. The fine compost and plastic slide down the tapered walls of the air chamber and exit through an exhaust opening at the base thereof onto a downwardly inclined vibrating screen.
Final separation of the compost from the plastic is achieved by sifting the fine compost through the perforations of the vibrating screen. The separated fine compost and plastic components are collected on conventional conveyors and carried away from the CPSU.
Housed within the vessel is a rotatable platform, a pipe having a substantially circular opening at the top thereof, air jet nozzle means circumferentially arranged in the body portion, and suitably adapted support members.
The rotatable platform is horizontally aligned and substantially circular. The diameter of the platform is less than the diameter of the vessel, thereby forming an annular opening. As well, the top surface of the platform is sloped downwardly from its center and attached to the top surface of the platform is a plurality of fins at regular angular intervals.
During operation of the CPSU, a continuous stream of compost plastic mixture is deposited onto the top surface of the rotating platform. In response to the rotation of the platform, the compost plastic mixture is peripherally and uniformly ejected against the inner surface of the vessel wall. The compost plastic mixture then falls along the vessel wall under the force of gravity, through the annular opening, into the body portion of the vessel.
The circular opening of the pipe is located underneath the rotatable platform 5 and has its axis in alignment with the longitudinal axis of the vessel and rotatable platform. Attached to the base of the pipe is an interconnecting duct system leading to the second stage separation unit. A material handling fan, located within the duct system generates a suction effect or area of lower pressure surrounding the opening of the pipe by drawing a continuous volume of air into the vessel and subsequently into the pipe through its opening. The lighter fine compost and plastic components of the compost plastic mixture are thereby caused to move towards the lower pressure area and form part of an air stream flowing into the pipe. The air stream, which is drawn into the opening of the pipe by the material handling fan, thus captures the lighter fine compost and plastic components of the compost plastic mixture and carries them into tt~e pipe.
The air jets are supplied with a source of pressurized air and the nozzles of the air jets are angled diagonally upwards towards the longitudinal axis of the vessel. The air jets perform a number of functions including helping to direct the falling compost plastic mixture, specifically the lighter fine compost and plastic towards the opening of the pipe. As well, the air jets aid in separating the compost plastic mixture by drying the mixture and also by air agitation and turbulence.
The coarse compost component, which is too heavy to be captured by the air stream and drawn into the pipe, continues travelling downwardly through the vessel under the force of gravity. It exits the vessel through the exhaust opening onto a conveyor leading away from the CPSU.
The fine compost and plastic material suspended in the air stream and drawn into the pipe is transported by means of the interconnecting duct system to the second stage separation unit for further separation. The fine compost and plastic is exhausted into the second stage separation unit, which is comprised of an air chamber. Within the air chamber, a cyclone separates the fine compost from the plastic. The fine compost and plastic slide down the tapered walls of the air chamber and exit through an exhaust opening at the base thereof onto a downwardly inclined vibrating screen.
Final separation of the compost from the plastic is achieved by sifting the fine compost through the perforations of the vibrating screen. The separated fine compost and plastic components are collected on conventional conveyors and carried away from the CPSU.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings, which form part of the specification and are to be read in conjunction therewith and in which like reference numerals are used to indicate like parts in the various views.
Figure 1 is a schematic sectional view of the Compost Particle Separation Unit.
Figure 2 is a schematic sectional view of the first stage separation unit.
PREFERRED EMBODIMENT
Turning now to the drawings in greater detail and initially to Figure 1, the Compost Particle Separation Unit (CPSU) has several stages. It is generally comprised of a grate 1, a hopper 2, a first stage separation unit 3, a second stage separation unit 4, a material handling fan 5, a duct system 6, and a number of conventional conveyors, for example at 10 and 11. The conveyors carry the compost-plastic mixture between initial stages of the separation process and separated materials away from the CPSU.
Prior to being processed by the CPSU, the plastic bag and organic material contained within is shredded by conventional means resulting in a shredded compost plastic mixture. The shredded organic waste consisting of tree limbs, leaves, grass and the like, as well as any plastic material, is sequentially deposited into the hopper 2 by a loader. A grate 1 comprised of regularly spaced parallel bars positioned over the intake opening of the hopper permits only material of a predetermined size to pass through. More specifically, it functions to separate larger objects, for example tree limbs, from the smaller shredded compost and plastic material. The removal of objects larger than approximately four inches in diameter is necessary at this time, as such objects may plug the first stage separation unit 3. The larger objects, which are denied entry into the hopper 2 remain on the top surface of the grate 1 and must be manually removed and collected.
The smaller sized material, which is a compost-plastic mixture, passes through the bars of the grate 1 and enters the hopper 2. The hopper is preferably capable of holding six yards of material. Material in the hopper is funneled onto a first conveyor 10, which is located below the exhaust opening at the base of the hopper. The conveyor is approximately three feet in width and operates substantially parallel to the ground. It is hydraulically driven and the speed of the belt is variable. The stream of compost-plastic mixture carried by conveyor is approximately three feet deep and three feet in width.
During typical operations, the speed of the conveyor can be adjusted to accommodate between 60 and 100 yards of compost-plastic mixture per hour.
The first conveyor 10 carries the compost-plastic mixture to a second conveyor 11, which is inclined upwardly with reference to the first conveyor.
The second conveyor is only two feet in width and is, therefore, narrower than the first conveyor. The stream of compost-plastic mixture carried by the first conveyor is funneled onto the second conveyor by two angled plates 13. The second conveyor carries the compost-plastic mixture upwardly to the first stage separation unit 3. The first stage separation unit is described in greater detail later.in the specification.
Preferably, the second conveyor 11 operates at a speed approximately six times greater than the first conveyor 10. The increased speed of the second conveyor acts to thin out the stream of compost plastic mixture being transported to the first stage separation unit 3. In the example given, the compost-plastic mixture carried on the second conveyor is approximately 1.2 feet deep and one foot in width. The purpose of thinning out the compost-plastic mixture is to deliver a more even and controlled flow of the mixture into the first stage separation unit.
The first stage separation unit 3 acts to separate the coarser compost component from the compost-plastic mixture. The first stage separation unit, shown enlarged in Figure 2, is comprised generally of a vertically aligned elongated walled vessel 20. The vessel has an intake opening portion 21 at 5 the top, an exhaust opening portion 22 at the bottom, and a body portion 23 therebetween. An intake opening 25, forming part of the intake opening portion is located at the top of the vessel, and exhaust opening 26, forming part of the exhaust opening portion is located at its base. The first stage separation unit is further comprised of a substantially circular rotatable 10 platform 30, a centrally located circular pipe 31, a plurality of high-pressure air jets, for example at 35A, 35B and 35C, and suitably adapted support members, for example at 34A and 34B. Each of these constituent parts is housed within the vessel and is hereinafter described in greater detail.
Referring tQ Figure 2, the rotatable platform 30 is horizontally aligned and is rotatable about its center axis. Furthermore, the center axis of the platform and the center axis of the circular pipe 31 are in alignment with the central axis of the vessel 20. The circular pipe, which is located within the body portion 23 of the vessel, has an intake opening 31A at the top thereof. The intake opening of the circular pipe is located underneath the rotatable platform. The diameter of the circular pipe 31 is less than the diameter of the rotatable platform 30.
' 11 The operation of the first stage separation unit relies on a material handling fan 5 (shown in Figure 1). The material handling fan moves a volume of air through the first stage separation unit at all material times and creates a suction effect or area of lower pressure surrounding the intake opening of the circular pipe 31A. The lighter fine compost and plastic components are drawn into the circular pipe 31 and subsequently transported to the second stage separation unit 4 (shown in Figure 1) for further separation. The heavier coarse compost falls downwardly and exits the first stage separation unit through the exhaust opening 26 at the base of the vessel. The operation of the first stage separation unit is hereinafter described in greater detail.
Referring still to Figure 2, a stream of compost-plastic mixture is delivered to the first stage separation unit through the intake opening 25 at the top of the vessel. Located within the intake opening portion 21 is the rotatable platform 30, which is approximately 5 feet in diameter. After entering the vessel, the incoming stream of compost-plastic material falls under the force of gravity onto the top surface of the platform. The stream of compost plastic material is naturally.divided in half with reference to the platform since each half of the stream falls onto the corresponding half of the platform. The splitting of the compost-plastic mixture into two streams in the manner described, achieves a more uniform distribution of the mixture on the top surface of the rotatable platform.
The center of the rotatable platform 30 is preferably raised with reference to the outside of the platform, thereby forming a downward slope from the center. The rotatable platform has suitable means to adjust and control the speed of rotation. Furthermore, the top surface of the platform has a plurality of fins, for example at 40, disposed at regular angular intervals. The fins extend vertically at substantially 90 degrees with reference to the top surface of the platform. As such, the top surface of the rotatable platform is not only sloped downwardly but also compartmentalized.
After the compost-plastic mixture is deposited onto the rotatable platform 30, the material is distributed outwardly by means of a centrifugal force and is peripherally ejected against the inner wall surface of the vessel 20. The fins 40, described above, aid in the peripheral ejection of the compost-plastic mixture. The compost-plastic mixture is, therefore, uniformly distributed 360 degrees against the inner wall of the vessel by the rotatable platform. It also has the effect breaking apart some of the larger pieces of compost, which in turn helps to loosen the plastic from the organic material.
As described, the center axis about which the platform 30 rotates is vertically aligned with the central axis of the vessel 20 and the diameter of the vessel is greater than the diameter of the rotatable platform. The difference in diameter between the rotatable platform 30 and the vessel wall creates an annular opening 41 allowing the compost-plastic mixture to enter the body portion 23 of the vessel. The peripheral ejection of the compost-plastic mixture against the vessel wall, therefore, has the further effect of uniformly delivering a volume of material to the body portion of the vessel through the annular opening.
Within the body portion 23 of the vessel, the compost-plastic mixture falls along the inner surface of the vessel wall under the force of gravity. A
plurality of high-pressure air jet nozzle means, shown for example at 35A, 35B and 35C, are circumferentially arranged within the body portion of the vessel. The air jet nozzle means are supplied with a source of pressurized air and direct air diagonally upwards, towards the central axis of the vessel and intake opening of the circular pipe 31A. The function of the air jets is to further separate the plastic from the organic material by air agitation and turbulence. The jets also have a drying effect, which further facilitates the separation of the plastic component from the organic material since moisture and electrostatic attraction tends to adhere the smaller fine compost particles to the plastic material. Additional air jets may be used on the supporting members of the first stage separation unit, for example at 34A and 34B, such that plastic~will not wrap or collect on support bars.
The circular pipe 31, which is vertically aligned along the central axis of the vessel 20 has a diameter less than the diameter of the rotatable platform 30.
The material handling fan 5 operates to draw air into the circular pipe by creating a suction effect or area of low pressure surrounding the intake opening of the circular pipe 31A. The lighter fine compost and plastic material moves naturally towards the lower pressure area. The air stream drawn into the circular pipe captures and carries the fine compost and plastic material through the circular pipe and subsequently to the second stage separation unit 4 by means of a suitable interconnecting duct system 6, as shown in Figure 1. The air stream which travels through the duct system carries fine compost and plastic to the second stage separation unit, where further separation of the compost-plastic mixture occurs. The material handling fan 5, which operates at 15,000 CFM is located outside of the first stage separation unit 3 within the duct system 6. The duct system consists of conventional ducting and is comprised, for example, of circular or rectangular type ducts, or a combination thereof.
An additional purpose of directing the air jets 35 slightly towards center is to direct the compost-plastic mixture, specifically the lighter plastic and fine compost components towards a deflector plate (not shown in Figures) located inside the body portion 23 of the vessel. Specifically, the deflector plate is located below the rotatable platform and above the intake opening of the circular pipe 31A. This deflector assists in the separation of the fine compost 5 and plastic by directing the compost-plastic mixture towards the intake opening of the circular pipe 31A and previously described area of low pressure created by the material handling fan 5.
Referring to Figure 2, the coarse compost component, which is to heavy to be 10 drawn into the circular pipe 31 exits the vessel 20 by means of the exhaust opening 26. The vessel, specifically the exhaust opening portion 22, is inwardly tapered towards the central axis. Coarse compost exiting at the base of first stage separation unit is for convenience deposited on a conveyor (not shown in Figures) to be carried away from the CPSU. The coarse 15 compost component is largely free from plastic contaminants since most of the plastic material was removed and carried away in the manner described.
Referring once again to Figure 1, the material handling fan 5 is located within the interconnecting duct system 6. The air stream generated by the material handling fan carries fine compost and plastic within the duct system from the first stage separation unit 3 to the second stage separation unit 4. In the section of the duct system between the first stage separation unit and the material handling fan 5, the fine compost and plastic mixture is drawn towards the material handling fan in response thereto. The fine compost plastic mixture subsequently passes through the material handling fan and is blown upwards into the second stage separation unit.
Referring to Figure 1, the second stage separation unit 4 acts to separate the plastic component from the fine compost component. Within the second stage separation unit a vortex air chamber 50 helps to further separate the organic compost material from the plastic. The air is exhausted out of the top of the second stage separation unit while the fine compost and plastic collect around the outside of the cyclone and slide down the inner surface of the chamber wall under the force of gravity. The strong action of the cyclone and the force exerted of the compost-plastic mixture when it comes in contact with the chamber wall act to separate the fine compost from the plastic. The fine compost material and plastic material drop out the bottom of the second stage separation unit and exits the chamber through a sized discharge elbow (not shown in Figures).
After exiting the discharge elbow, the fine compost and plastic is deposited onto a downwardly inclined 118" vibrating screen (not shown in Figures). At this stage, most of the plastic is in a loose fluffy state and is on top of the fine compost. The fine compost is sifted through the perforations of the screen onto a conveyor positioned below. It is then carried away from the CPSU
where it can be collected in a pile or appropriate container. The fine compost is close to 100% free of plastic material. The plastic material continues downwardly along the inclined screen aided by the vibrating action where it is ultimately deposited in a collection box to be appropriately disposed of.
From the foregoing, it will be seen that this invention is one well adapted to attain all the ends and objects hereinabove set forth together with other advantages which are obvious and which are inherent to the structure.
It will be understood that certain features and sub-combinations are of utility and may be employed without reference to other features and sub-combinations. This is contemplated by and is within the scope of the claims.
Since many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.
In the accompanying drawings, which form part of the specification and are to be read in conjunction therewith and in which like reference numerals are used to indicate like parts in the various views.
Figure 1 is a schematic sectional view of the Compost Particle Separation Unit.
Figure 2 is a schematic sectional view of the first stage separation unit.
PREFERRED EMBODIMENT
Turning now to the drawings in greater detail and initially to Figure 1, the Compost Particle Separation Unit (CPSU) has several stages. It is generally comprised of a grate 1, a hopper 2, a first stage separation unit 3, a second stage separation unit 4, a material handling fan 5, a duct system 6, and a number of conventional conveyors, for example at 10 and 11. The conveyors carry the compost-plastic mixture between initial stages of the separation process and separated materials away from the CPSU.
Prior to being processed by the CPSU, the plastic bag and organic material contained within is shredded by conventional means resulting in a shredded compost plastic mixture. The shredded organic waste consisting of tree limbs, leaves, grass and the like, as well as any plastic material, is sequentially deposited into the hopper 2 by a loader. A grate 1 comprised of regularly spaced parallel bars positioned over the intake opening of the hopper permits only material of a predetermined size to pass through. More specifically, it functions to separate larger objects, for example tree limbs, from the smaller shredded compost and plastic material. The removal of objects larger than approximately four inches in diameter is necessary at this time, as such objects may plug the first stage separation unit 3. The larger objects, which are denied entry into the hopper 2 remain on the top surface of the grate 1 and must be manually removed and collected.
The smaller sized material, which is a compost-plastic mixture, passes through the bars of the grate 1 and enters the hopper 2. The hopper is preferably capable of holding six yards of material. Material in the hopper is funneled onto a first conveyor 10, which is located below the exhaust opening at the base of the hopper. The conveyor is approximately three feet in width and operates substantially parallel to the ground. It is hydraulically driven and the speed of the belt is variable. The stream of compost-plastic mixture carried by conveyor is approximately three feet deep and three feet in width.
During typical operations, the speed of the conveyor can be adjusted to accommodate between 60 and 100 yards of compost-plastic mixture per hour.
The first conveyor 10 carries the compost-plastic mixture to a second conveyor 11, which is inclined upwardly with reference to the first conveyor.
The second conveyor is only two feet in width and is, therefore, narrower than the first conveyor. The stream of compost-plastic mixture carried by the first conveyor is funneled onto the second conveyor by two angled plates 13. The second conveyor carries the compost-plastic mixture upwardly to the first stage separation unit 3. The first stage separation unit is described in greater detail later.in the specification.
Preferably, the second conveyor 11 operates at a speed approximately six times greater than the first conveyor 10. The increased speed of the second conveyor acts to thin out the stream of compost plastic mixture being transported to the first stage separation unit 3. In the example given, the compost-plastic mixture carried on the second conveyor is approximately 1.2 feet deep and one foot in width. The purpose of thinning out the compost-plastic mixture is to deliver a more even and controlled flow of the mixture into the first stage separation unit.
The first stage separation unit 3 acts to separate the coarser compost component from the compost-plastic mixture. The first stage separation unit, shown enlarged in Figure 2, is comprised generally of a vertically aligned elongated walled vessel 20. The vessel has an intake opening portion 21 at 5 the top, an exhaust opening portion 22 at the bottom, and a body portion 23 therebetween. An intake opening 25, forming part of the intake opening portion is located at the top of the vessel, and exhaust opening 26, forming part of the exhaust opening portion is located at its base. The first stage separation unit is further comprised of a substantially circular rotatable 10 platform 30, a centrally located circular pipe 31, a plurality of high-pressure air jets, for example at 35A, 35B and 35C, and suitably adapted support members, for example at 34A and 34B. Each of these constituent parts is housed within the vessel and is hereinafter described in greater detail.
Referring tQ Figure 2, the rotatable platform 30 is horizontally aligned and is rotatable about its center axis. Furthermore, the center axis of the platform and the center axis of the circular pipe 31 are in alignment with the central axis of the vessel 20. The circular pipe, which is located within the body portion 23 of the vessel, has an intake opening 31A at the top thereof. The intake opening of the circular pipe is located underneath the rotatable platform. The diameter of the circular pipe 31 is less than the diameter of the rotatable platform 30.
' 11 The operation of the first stage separation unit relies on a material handling fan 5 (shown in Figure 1). The material handling fan moves a volume of air through the first stage separation unit at all material times and creates a suction effect or area of lower pressure surrounding the intake opening of the circular pipe 31A. The lighter fine compost and plastic components are drawn into the circular pipe 31 and subsequently transported to the second stage separation unit 4 (shown in Figure 1) for further separation. The heavier coarse compost falls downwardly and exits the first stage separation unit through the exhaust opening 26 at the base of the vessel. The operation of the first stage separation unit is hereinafter described in greater detail.
Referring still to Figure 2, a stream of compost-plastic mixture is delivered to the first stage separation unit through the intake opening 25 at the top of the vessel. Located within the intake opening portion 21 is the rotatable platform 30, which is approximately 5 feet in diameter. After entering the vessel, the incoming stream of compost-plastic material falls under the force of gravity onto the top surface of the platform. The stream of compost plastic material is naturally.divided in half with reference to the platform since each half of the stream falls onto the corresponding half of the platform. The splitting of the compost-plastic mixture into two streams in the manner described, achieves a more uniform distribution of the mixture on the top surface of the rotatable platform.
The center of the rotatable platform 30 is preferably raised with reference to the outside of the platform, thereby forming a downward slope from the center. The rotatable platform has suitable means to adjust and control the speed of rotation. Furthermore, the top surface of the platform has a plurality of fins, for example at 40, disposed at regular angular intervals. The fins extend vertically at substantially 90 degrees with reference to the top surface of the platform. As such, the top surface of the rotatable platform is not only sloped downwardly but also compartmentalized.
After the compost-plastic mixture is deposited onto the rotatable platform 30, the material is distributed outwardly by means of a centrifugal force and is peripherally ejected against the inner wall surface of the vessel 20. The fins 40, described above, aid in the peripheral ejection of the compost-plastic mixture. The compost-plastic mixture is, therefore, uniformly distributed 360 degrees against the inner wall of the vessel by the rotatable platform. It also has the effect breaking apart some of the larger pieces of compost, which in turn helps to loosen the plastic from the organic material.
As described, the center axis about which the platform 30 rotates is vertically aligned with the central axis of the vessel 20 and the diameter of the vessel is greater than the diameter of the rotatable platform. The difference in diameter between the rotatable platform 30 and the vessel wall creates an annular opening 41 allowing the compost-plastic mixture to enter the body portion 23 of the vessel. The peripheral ejection of the compost-plastic mixture against the vessel wall, therefore, has the further effect of uniformly delivering a volume of material to the body portion of the vessel through the annular opening.
Within the body portion 23 of the vessel, the compost-plastic mixture falls along the inner surface of the vessel wall under the force of gravity. A
plurality of high-pressure air jet nozzle means, shown for example at 35A, 35B and 35C, are circumferentially arranged within the body portion of the vessel. The air jet nozzle means are supplied with a source of pressurized air and direct air diagonally upwards, towards the central axis of the vessel and intake opening of the circular pipe 31A. The function of the air jets is to further separate the plastic from the organic material by air agitation and turbulence. The jets also have a drying effect, which further facilitates the separation of the plastic component from the organic material since moisture and electrostatic attraction tends to adhere the smaller fine compost particles to the plastic material. Additional air jets may be used on the supporting members of the first stage separation unit, for example at 34A and 34B, such that plastic~will not wrap or collect on support bars.
The circular pipe 31, which is vertically aligned along the central axis of the vessel 20 has a diameter less than the diameter of the rotatable platform 30.
The material handling fan 5 operates to draw air into the circular pipe by creating a suction effect or area of low pressure surrounding the intake opening of the circular pipe 31A. The lighter fine compost and plastic material moves naturally towards the lower pressure area. The air stream drawn into the circular pipe captures and carries the fine compost and plastic material through the circular pipe and subsequently to the second stage separation unit 4 by means of a suitable interconnecting duct system 6, as shown in Figure 1. The air stream which travels through the duct system carries fine compost and plastic to the second stage separation unit, where further separation of the compost-plastic mixture occurs. The material handling fan 5, which operates at 15,000 CFM is located outside of the first stage separation unit 3 within the duct system 6. The duct system consists of conventional ducting and is comprised, for example, of circular or rectangular type ducts, or a combination thereof.
An additional purpose of directing the air jets 35 slightly towards center is to direct the compost-plastic mixture, specifically the lighter plastic and fine compost components towards a deflector plate (not shown in Figures) located inside the body portion 23 of the vessel. Specifically, the deflector plate is located below the rotatable platform and above the intake opening of the circular pipe 31A. This deflector assists in the separation of the fine compost 5 and plastic by directing the compost-plastic mixture towards the intake opening of the circular pipe 31A and previously described area of low pressure created by the material handling fan 5.
Referring to Figure 2, the coarse compost component, which is to heavy to be 10 drawn into the circular pipe 31 exits the vessel 20 by means of the exhaust opening 26. The vessel, specifically the exhaust opening portion 22, is inwardly tapered towards the central axis. Coarse compost exiting at the base of first stage separation unit is for convenience deposited on a conveyor (not shown in Figures) to be carried away from the CPSU. The coarse 15 compost component is largely free from plastic contaminants since most of the plastic material was removed and carried away in the manner described.
Referring once again to Figure 1, the material handling fan 5 is located within the interconnecting duct system 6. The air stream generated by the material handling fan carries fine compost and plastic within the duct system from the first stage separation unit 3 to the second stage separation unit 4. In the section of the duct system between the first stage separation unit and the material handling fan 5, the fine compost and plastic mixture is drawn towards the material handling fan in response thereto. The fine compost plastic mixture subsequently passes through the material handling fan and is blown upwards into the second stage separation unit.
Referring to Figure 1, the second stage separation unit 4 acts to separate the plastic component from the fine compost component. Within the second stage separation unit a vortex air chamber 50 helps to further separate the organic compost material from the plastic. The air is exhausted out of the top of the second stage separation unit while the fine compost and plastic collect around the outside of the cyclone and slide down the inner surface of the chamber wall under the force of gravity. The strong action of the cyclone and the force exerted of the compost-plastic mixture when it comes in contact with the chamber wall act to separate the fine compost from the plastic. The fine compost material and plastic material drop out the bottom of the second stage separation unit and exits the chamber through a sized discharge elbow (not shown in Figures).
After exiting the discharge elbow, the fine compost and plastic is deposited onto a downwardly inclined 118" vibrating screen (not shown in Figures). At this stage, most of the plastic is in a loose fluffy state and is on top of the fine compost. The fine compost is sifted through the perforations of the screen onto a conveyor positioned below. It is then carried away from the CPSU
where it can be collected in a pile or appropriate container. The fine compost is close to 100% free of plastic material. The plastic material continues downwardly along the inclined screen aided by the vibrating action where it is ultimately deposited in a collection box to be appropriately disposed of.
From the foregoing, it will be seen that this invention is one well adapted to attain all the ends and objects hereinabove set forth together with other advantages which are obvious and which are inherent to the structure.
It will be understood that certain features and sub-combinations are of utility and may be employed without reference to other features and sub-combinations. This is contemplated by and is within the scope of the claims.
Since many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.
Claims (10)
1) An apparatus for separating plastic material from a shredded plastic compost mixture comprising:
a vertically aligned elongated walled vessel having a substantially circular cross-section having a first diameter and a longitudinal axis therethrough; said vessel having an intake opening and intake opening portion at the top, an exhaust opening and exhaust opening portion at the bottom, and a body portion between said intake opening portion and said exhaust opening portion;
a horizontally aligned substantially circular rotatable platform located within said intake opening portion having a top surface and second diameter and having its longitudinal axis in alignment with said longitudinal axis of said vessel, said second diameter being less than said first diameter;
means to rotate said platform;
a pipe having a third diameter and a substantially circular opening, said opening of said pipe being located within said body portion of said vessel and underneath said rotatable platform, said opening of said pipe further having its longitudinal axis in alignment with said longitudinal axis of said vessel, said third diameter being less than said second diameter;
first support means for the attachment of said platform to the interior surface of said walled vessel;
second support means for the attachment of said circular pipe to the interior surface of said walled vessel;
air jet nozzle means circumferentially located on the interior of said body portion of said vessel adjacent to and below said opening of said pipe; and means to draw a continuous volume of air into said vessel through said intake opening and into said opening of said pipe.
a vertically aligned elongated walled vessel having a substantially circular cross-section having a first diameter and a longitudinal axis therethrough; said vessel having an intake opening and intake opening portion at the top, an exhaust opening and exhaust opening portion at the bottom, and a body portion between said intake opening portion and said exhaust opening portion;
a horizontally aligned substantially circular rotatable platform located within said intake opening portion having a top surface and second diameter and having its longitudinal axis in alignment with said longitudinal axis of said vessel, said second diameter being less than said first diameter;
means to rotate said platform;
a pipe having a third diameter and a substantially circular opening, said opening of said pipe being located within said body portion of said vessel and underneath said rotatable platform, said opening of said pipe further having its longitudinal axis in alignment with said longitudinal axis of said vessel, said third diameter being less than said second diameter;
first support means for the attachment of said platform to the interior surface of said walled vessel;
second support means for the attachment of said circular pipe to the interior surface of said walled vessel;
air jet nozzle means circumferentially located on the interior of said body portion of said vessel adjacent to and below said opening of said pipe; and means to draw a continuous volume of air into said vessel through said intake opening and into said opening of said pipe.
2) The invention as claimed in Claim 1, wherein said exhaust opening portion is tapered inwardly towards said longitudinal axis of said vessel.
3) The invention as claimed in Claim 2, wherein the top surface of said platform is uniformly and downwardly sloped from the center thereof.
4) The invention as claimed in Claim 3, wherein the top surface of said platform has attached thereto a plurality of fins disposed at regular angular intervals.
5) The invention as claimed in Claim 4, wherein said pipe exits said vessel through said exhaust opening at the base thereof.
6) The invention as claimed in Claim 4, wherein said pipe exits said vessel through an opening in the vessel wall.
7) The invention as claimed in Claim 5 or 6, wherein said air jet nozzle means comprises a plurality of nozzles pointing inwardly and upwardly towards said longitudinal axis of said vessel.
8) The invention as claimed in Claim 7, wherein said means to draw a volume of air into said vessel and into said opening of said pipe comprises a material handling fan.
9) A method for separating the plastic component from a shredded plastic compost mixture comprising:
passing said mixture through a grate to achieve initial separation of larger objects of a predetermined size from the mixture, delivering a continuous quantity of said mixture to the apparatus defined in Claim 1 and depositing said mixture onto a rotatable platform operating to peripherally eject the mixture against the inner wall of said vessel, separating a coarse compost component from said mixture by means of capturing and drawing the lighter fine compost and plastic material into said pipe through said opening of said circular pipe by means of an air stream, the heavier coarse compost component continuing downwardly under the force of gravity and exiting at said exhaust opening of said vessel;
transporting said lighter fine compost and plastic material to an air chamber by means of said air stream contained within an interconnected duct system;
exhausting said fine compost and plastic material into said air chamber where the fine compost and plastic material is further separated by means of air agitation and turbulence, said fine compost and plastic material exiting through an opening at the base of said chamber and deposited onto a downwardly inclined vibrating screen;
achieving final separation of said fine compost and plastic material by means of sifting said fine compost through said vibrating screen;
transporting the separated fine compost and plastic components away from the apparatus by means of conventional conveyors.
passing said mixture through a grate to achieve initial separation of larger objects of a predetermined size from the mixture, delivering a continuous quantity of said mixture to the apparatus defined in Claim 1 and depositing said mixture onto a rotatable platform operating to peripherally eject the mixture against the inner wall of said vessel, separating a coarse compost component from said mixture by means of capturing and drawing the lighter fine compost and plastic material into said pipe through said opening of said circular pipe by means of an air stream, the heavier coarse compost component continuing downwardly under the force of gravity and exiting at said exhaust opening of said vessel;
transporting said lighter fine compost and plastic material to an air chamber by means of said air stream contained within an interconnected duct system;
exhausting said fine compost and plastic material into said air chamber where the fine compost and plastic material is further separated by means of air agitation and turbulence, said fine compost and plastic material exiting through an opening at the base of said chamber and deposited onto a downwardly inclined vibrating screen;
achieving final separation of said fine compost and plastic material by means of sifting said fine compost through said vibrating screen;
transporting the separated fine compost and plastic components away from the apparatus by means of conventional conveyors.
10) The method as claimed in Claim 9, wherein said delivery means comprises at least one conventional conveyor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2310169 CA2310169A1 (en) | 2000-05-30 | 2000-05-30 | Compost particle separation unit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2310169 CA2310169A1 (en) | 2000-05-30 | 2000-05-30 | Compost particle separation unit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2310169A1 true CA2310169A1 (en) | 2001-11-30 |
Family
ID=4166312
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2310169 Abandoned CA2310169A1 (en) | 2000-05-30 | 2000-05-30 | Compost particle separation unit |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2310169A1 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107931082A (en) * | 2017-12-26 | 2018-04-20 | 安徽鼎梁生物能源科技开发有限公司 | A kind of stalk powder-cutting machine product body-packing |
| CN113042351A (en) * | 2021-04-26 | 2021-06-29 | 中国科学院烟台海岸带研究所 | Little plastic separator in soil |
| CN114682487A (en) * | 2022-04-09 | 2022-07-01 | 合肥市新庆申新型建材有限公司 | Novel building materials are made with defeated material equipment |
-
2000
- 2000-05-30 CA CA 2310169 patent/CA2310169A1/en not_active Abandoned
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107931082A (en) * | 2017-12-26 | 2018-04-20 | 安徽鼎梁生物能源科技开发有限公司 | A kind of stalk powder-cutting machine product body-packing |
| CN107931082B (en) * | 2017-12-26 | 2024-03-26 | 安徽鼎梁生物能源科技开发有限公司 | Straw powder cutting machine result partial shipment mechanism |
| CN113042351A (en) * | 2021-04-26 | 2021-06-29 | 中国科学院烟台海岸带研究所 | Little plastic separator in soil |
| CN114682487A (en) * | 2022-04-09 | 2022-07-01 | 合肥市新庆申新型建材有限公司 | Novel building materials are made with defeated material equipment |
| CN114682487B (en) * | 2022-04-09 | 2023-01-24 | 合肥市新庆申新型建材有限公司 | Novel building materials are made with defeated material equipment |
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