Park, Chan-jin (Daegong Apt, 1284 Sanggye-don, Nowon-gu Seoul_139-200, 101-1202, KR)
Lee, Ho-geun (Cheongdam-maul, 210-2 Deokjeong-don, Yangju-si Gyonggi-do_482-060, 408-1301, KR)
Park, Chan-jin (Daegong Apt, 1284 Sanggye-don, Nowon-gu Seoul_139-200, 101-1202, KR)
| 1. | A method of separating waste asphalt concrete from construction waste, which comprises feeding collected construction waste, crushing the fed construction waste and removing a metal material, transferring and sorting the crushed construction waste, washing the sorted construction waste and removing floating materials, and recirculating the waste to improve a shape of waste particles, the method comprising : a first step of sorting the construction waste, transferred after having undergone washing to remove impurities from a surface thereof, according to a particle size using a sorting screen; a second step of guiding the construction waste having a predetermined particle size into a reversed funnelshaped base ; a third step of distributing the construction waste positioned in the base into a plurality of transfer passages and subsequently transferring the distributed waste ; a fourth step of sensing the washed waste asphalt concrete, transferred from the third step, from a short distance depending on a unique color or a chemical reaction thereof to detect only the waste asphalt concrete of the construction waste ; a fifth step of selectively opening a plurality of air spray nozzles positioned at an upper portion of the transfer passage to spray air in response to an electrical signal applied as a result of the performance of the fourth step, which are connected to position detection means so that selection among the air spray nozzles and orientation of the air spray nozzles toward the waste asphalt concrete positioned adjacent to a discharge port are controlled; a sixth step of forcibly returning the waste asphalt concrete along with general construction waste to the fourth step to be reseparated if the general construction waste remains in the waste asphalt concrete discharged from the transfer passage by the air spray nozzle ; and a seventh step of collecting only the discharged waste asphalt concrete and transferring the collected waste asphalt concrete to a storage location. |
| 2. | An apparatus for separating waste asphalt concrete from construction waste, which includes a hopper, a first crusher including a jaw crusher, a magnetic separator, a first sorter including a flat screen or a cylindrical trommel, a washing bath, a recirculation passage, a second crusher, a second sorter, and a recirculation passage, the apparatus comprising: a reversed funnelshaped base including a rotating part, which is rotated normally and reversely by a power supply source, so that the construction waste guided through the second sorter is uniformly distributed and transferred; a plurality of transfer passages driven by a conveyor manner or a gravitypowered sliding manner to unidirectionally convey the construction waste fed from the base; an electronic sensor positioned at an upper portion of each transfer passage to sense the waste asphalt concrete from a short distance depending on a unique asphalt color or a chemical reaction thereof; a plurality of air spray nozzles positioned at an upper portion of the transfer passage to instantaneously spray high pressure air toward the adjacent waste asphalt concrete mass in response to the applied electrical signal of the sensor, so that only the waste asphalt concrete is discharged from the transfer passage; a monitor to display the selective separation of the waste asphalt concrete ; and a discharge passage to separately collect and store and then recycle the separated and discharged waste asphalt concrete and waste concrete. |
| 3. | The apparatus according to claim 2, wherein the sensor comprises at least one means selected from among infrared rays, light and a photosensor. |
| 4. | The apparatus according to claim 2, wherein the sensor is replaced with a touch sensor to sense physical properties of the surface of the asphalt concrete. |
| 5. | The apparatus according to claim 2, wherein the air spray nozzle is replaced with a piston type air cylinder. |
| 6. | The apparatus according to claim 2, wherein both side walls of the transfer passage having a width suitable for individually transferring the distributed waste are partially opened, and the air spray nozzle is mounted to the open portion to discharge the sensed waste asphalt concrete. |
| 7. | The apparatus according to claim 2, further comprising a wide transfer conveyor provided at a lower end of the transfer passage to continuously accept the waste asphalt concrete mass dropping from each transfer passage and load the accepted waste asphalt concrete thereon. |
| 8. | The apparatus according to claim 2, wherein the transfer passage is further provided with a discharge chute to receive the waste asphalt concrete mass at left/right sides thereof. |
| 9. | The apparatus according to claim 2, further comprising chemical applying means for producing a color of the waste asphalt concrete distinguished from that of the waste concrete through a reaction with the asphalt to obtain a distinctive color of the waste asphalt concrete. |
| 10. | The apparatus according to claim 2, wherein the air spray nozzle is provided with electronic solenoid type open/close means. |
| 11. | A method of separating and recycling waste asphalt concrete from construction waste, comprising: a first step of feeding separated, sorted and collected waste asphalt concrete ; a second step of crushing and sorting the fed waste asphalt concrete according to a predetermined particle size ; a third step of feeding the sorted waste asphalt concrete into a melting furnace; a fourth step of adding an emulsion containing a surfactant to a melt of waste asphalt concrete heated to a high temperature and then discharged ; a fifth step of forcibly transferring the discharged melt onto a slide screen in a vacuum chamber by air; a sixth step of scraping the transferred melt on the slide screen using a scraper for primary separation of asphalt colloid from large aggregate through the slide screen, provided that high pressure air bursting and adsorption simultaneously occur at upper/lower portions of the slide screen to feed the asphalt into a collecting tank disposed at a'lower end of the screen and to drop the large aggregate into a lower end of the screen ; a seventh step of retransferring the dropped aggregate through the heated transfer conveyor, provided that a melting agent is sprayed for chemical pyrolysis between the asphalt adhering to the large aggregate and the large aggregate ; an eighth step of feeding the transferred aggregate into a centrifuge for secondary separation of the asphalt from the large aggregate; a ninth step of transferring the separated asphalt into an asphalt collecting tank, and feeding the transferred aggregate into a cooling chamber ; a tenth step of stepwisely washing the cooled aggregate to restore the surface of the aggregate ; an eleventh step of discharging and transferring the washed and transferred aggregate using screw type transfer means, provided that an aqueous alkali solution is applied on the aggregate to be transferred so as to coat the surface of the aggregate ; and a twelfth step of transferring the collected asphalt to a filter press to be separated from small aggregate. |
| 12. | The method according to claim 11, wherein the melting agent used in the seventh step is ethylene chloride. |
| 13. | A method of separating and recycling waste asphalt concrete of construction waste, in which the waste asphalt concrete is stepwisely separated from the construction waste and recycled, provided that an interlocking system is applied to each step so that proceeding to a subsequent step is interrupted if any one intermediate step encounters a problem. |
Generally, ascon, that is, an asphalt concrete mixture, which is recently receiving attention in industrial societies due to its various end uses and functions, has been widely applied in a variety of fields depending on its inherent properties and usability.
For example, asphalt concrete for use in paving roads may be variously applied to build a bicycle path, a plaza, <BR> etc. , as well as footpaths and driveways due to its<BR> inherent properties as well as added properties (e. g. , non- slip surfaces, water permeability, colored concrete, etc.),
therefore conferring comfort, safety and visual satisfaction for a user.
However, since asphalt concrete is composed mainly of asphalt which has chemical by-products that are harmful to human beings, it has specific properties and should be cautiously handled, unlike general construction waste formed of inorganic material that is harmless to human beings.
That is, when the waste asphalt concrete is allowed to stand, severe contamination of soil, water and air may result. Thus, the disposal problems of waste asphalt concrete, breaking the natural ecosystem and impeding the growth of animals and plants, must urgently be solved to protect the environment in industrial societies.
To solve the above problems, the preparation and construction of asphalt concrete and as well a subsequent additional treatment process after construction therewith are required. Although desired usability of asphalt concrete is manifested, the required procedures must be additionally carried out, and the necessary process and apparatus must be further added, and the cost may increase, thus negating economic benefits.
Hence, in the case where re-pavement work is performed after the removal of asphalt due to the construction of additional facilities or repair work, as well as the construction of new paved roads, the above-mentioned
problems have further burdened construction companies.
Most of all, since conventional methods of recycling waste asphalt concrete are somewhat limited, more effective methods of separating and recycling waste asphalt concrete in the re-treatment of construction waste are thus required.
Nevertheless, appropriate methods for the disposal of waste asphalt concrete have not yet been developed. At present, almost all removed waste asphalt concrete has been permanently buried underground.
Waste concrete, which constitutes the majority of construction waste along with waste asphalt concrete, is recycled at a level of 60% or more into a novel construction material, attributable to the development of re-treatment techniques. The amount of waste concrete that is recycled is expected to gradually increase.
In these days, methods of re-treating waste concrete using a crusher and a sorting screen, most of which are pending or used as novel construction techniques protecting the environment, have been rapidly developed.
However, methods of recycling waste asphalt concrete have not been greatly developed until now, unlike those of waste concrete of construction waste. Almost all of the patented techniques inside or outside the country are restricted only to the improvement of usage methods.
The techniques related to recycling waste asphalt
concrete do not pertain to the separation of chemical asphalt of the asphalt concrete from large aggregate and the recycling thereof. Only, methods including again melting the waste asphalt concrete itself, and re-adding asphalt and aggregate to the melted waste asphalt concrete to prepare an asphalt mixture, which is then recycled unchanged to make pavement, have been disclosed.
In this regard, Korean Patent Application No. 2001- 53048, which was previously filed and laid-open, discloses a"batch type cold mix recycling asphalt concrete manufacture apparatus and method". In addition, Korean Patent Application No. 2001-56368, which was previously filed and laid-open, discloses a"method for manufacture of ascon using industrial waste matter, sand and pebbles". In addition, Korean Utility Model No. 235445, which was filed and registered, discloses"apparatus for manufacturing a recycled mixture using waste asphalt pavement".
As such, attempts to automatically selectively separate waste asphalt concrete from mixed construction waste have not been made. Therefore, the waste asphalt concrete has been manually treated by workers using the naked eye, and thus, it is impossible to efficiently re- treat the waste asphalt concrete.
Actually, the above problem occurs because waste asphalt concrete can only be handled along with waste concrete.
Even if asphalt concrete is separated from the general waste concrete, recycling it is difficult due to the properties of the adherent chemical by-products of asphalt compared to waste concrete. Still, the slow development of techniques for recycling waste asphalt concrete remains a problem to be solved in view of industrial and environmental policies.
Accordingly, if methods of selectively separating and recycling the waste asphalt concrete are realized to recycle the asphalt and the aggregate as useful construction materials, they will be rapidly applied for efficient use of resources, land conservation and to secure a pleasant lifestyle.
In particular, legislation revising the laws related to the disposal of waste asphalt concrete is a sufficient motive for government and waste disposal companies to develop recognition and disposal techniques.
Background Art Accordingly, the present invention has been made keeping in mind the above problems occurring in the related art, and an object of the present invention is to provide the selective separation of waste asphalt concrete from general construction waste according to a predetermined particle size for loading thereof.
Another object of the present invention is to make possible the collection of only waste concrete having high purity by separating waste asphalt concrete.
A further object of the present invention is to provide a method of recycling the separated and collected waste asphalt concrete, in which the separation of the asphalt as a chemical by-product from the aggregate is realized to independently reuse the asphalt material and the aggregate so that the aggregate for asphalt concrete may be usefully applied to general ready mixed concrete.
Still a further object of the present invention is to provide an apparatus required to perform the above method.
The above objects are accomplished by a method of detecting the waste asphalt concrete based on the properties of only the waste asphalt. concrete distinguishing it from general construction waste, using means for discharging the detected waste asphalt concrete.
Best Mode for Carrying Out the Invention Hereinafter, a detailed description will be given of a method and apparatus for separating and recycling waste asphalt concrete from construction waste of the present invention, with reference to the appended drawings.
FIG. 1 is a flowchart showing the selective separation of waste asphalt concrete, and FIG. 2 is a view
showing the treatment apparatus for selective separation, according to the present invention.
First, various collected construction waste is fed into a hopper 10 having a predetermined capacity. In this way, the fed construction waste is crushed into a predetermined size by use of a jaw crusher serving as a first crusher 11. Subsequently, the crushed waste is loaded on the transfer conveyor to be transferred to the following process. During the transfer, metal materials such as reinforcing bars or nails may be removed from the crushed waste using a magnetic separator 12.
As such, the magnetic separator 12 may be appropriately disposed in one or a plural number at each of the transfer passages, the number of which depends on work procedures.
The crushed and transferred construction waste is fed into a first sorter 13, such as a flat vibrating screen or a cylindrical trommel, to be separated from crushed waste having a predetermined particle size or less with soil and sand. In particular, to efficiently perform the sorting process while removing waste vinyl or fabric pieces, an air blowing system may be operated using a plurality of air blowers 13a.
The sorted waste is fed into a washing bath 14 provided at a transfer path. While the waste passes through the washing bath 14, floating materials, such as waste
wood, are removed from the waste, and simultaneously the surface of the waste is washed to remove impurities. To this end, a high pressure water spray nozzle and an aerated water bath are continuously operated to uniformly wash the precipitated waste for a sufficient time period.
As such, the washed waste contaminated by asphalt is collectively fed into an additional water precipitation bath, and then undergoes chemical treatment to remove solidified oil and dirt.
After the completion of the washing process, the washed waste is transferred to a second crusher 15 such as a jaw crusher to be crushed into a size suitable for the separation of waste asphalt concrete, and then fed into a second sorter 16 to finally separate waste having a size of about 50 mm. As such, a forcible re-circulating step may be provided to improve a shape of crushed waste particles, if required.
In addition, the washing bath 14 may be provided at the position following the second crusher 15 as in FIG. 2b, or may be provided in a plural number after the second crusher 15, to realize a complete washing or disposition arrangement of the present invention.
After performing the above-mentioned processes partially corresponding to conventional construction waste disposal processes, construction waste having a predetermined particle size thanks to the second sorter 16
is subsequently guided into a reversed funnel-shaped vibrating base 20. As such, the waste is separated and arranged while being sequentially distributed to left and right sides using a rotating part 21 which is rotated normally and reversely by a power supply source and a decelerator in a controller shown in FIG. 5, so that they are transferred in a uniformly distributed state without gathering together at any one portion.
The construction waste distributed and guided to slide down from the base 20 is sequentially fed into each transfer passage 22 to unidirectionally proceed, as shown in partially enlarged views of FIGS. 3a and 3b. As such, each transfer passage 22 may use a conveyor system or maintain a slope at a predetermined angle for gravity- powered sliding, if necessary.
At an upper portion of the transfer passage 22, an electronic sensor 23 is provided to sense the waste asphalt concrete from a short distance by detecting the unique asphalt color or a chemical reaction of the waste asphalt concrete. Also, a height difference with the transferred waste of up to 60 mm is maintained, to assure the accuracy of sensing.
In response to an electrical signal applied at the same time as the sensing by the sensor 23, a plurality of high pressure air spray nozzles 24 positioned at both sides or either side of the transfer passage 22 instantaneously
sprays high pressure air toward the adjacent waste asphalt concrete mass, so that only the waste asphalt concrete mass is discharged from the transfer passage 22. The simultaneous operation of sensing the adjacent waste asphalt concrete and spraying the air in response to the signal from the sensor 23 may be controlled by an additional controller depending on control measurement and number control. In the present invention, an automatic control system is applied.
In FIGS. 3a and 3b, the transfer passage is partially enlarged in a planar state. In addition, FIGS. 4a and 4b illustrate three-dimensional perspective views of FIGS. 3a and 3b. As in FIG. 3a, the width of one transfer passage 22 is set to be slightly larger than the individual particles of the crushed waste, after which both side walls thereof are partially opened to a predetermined length a. The air spray nozzles 24 are provided at the open portion, and the sensed waste asphalt concrete mass is discharged from the portions lacking passage 22 side walls.
In this case, a wide transfer conveyor 30 is disposed at the lower end of each transfer passage 22 so as to continuously accept the waste asphalt concrete mass dropping downwards and then load it thereon.
In addition, as seen in FIG. 3b, a separate discharge chute 25 is provided at lower left/right portions of the transfer passage 22 having a slightly wide width and a
planar configuration without side walls. Thereby, the waste asphalt concrete mass dropped by the air spray nozzle 24 positioned on left/right sides of the transfer passage 22 may be dropped into the discharge chute 25 to be loaded thereon for transfer.
As such, a single sensor 23 may be provided, or a plurality of sensors 23 including first and second sensors may be provided. The second sensor 23a of the plurality of sensors is positioned at the terminal end of the transfer passage 22 to confirm whether waste asphalt concrete remains in the finally separated waste concrete. If waste asphalt concrete remains, the second sensor 23a causes forcible re-circulation of the remaining waste asphalt concrete.
The sensor 23 includes at least one means selected from among infrared rays, light, a photosensor, and combinations thereof. In addition, the sensor 23 may be replaced with a touch sensor to sense the physical properties of the surface of the asphalt concrete.
Further, a process of applying a chemical material may be additionally performed to produce a color distinguishing asphalt from waste concrete through a reaction with asphalt to obtain a distinctive color of the waste asphalt concrete.
The air spray nozzle 24 is provided with electronic solenoid type open/close means, and may be replaced with a
piston type air cylinder.
All the processes of the present invention are displayed through a monitor 40 to be easily read by a worker, and thus may be externally controlled.
The waste asphalt concrete and waste concrete thus separated and discharged are separately collected and stored, and then recycled.
The above-described processes are regarded as a primary pre-treatment for separating only the waste asphalt concrete from general construction waste.
Subsequent to the above pre-treatment, a secondary post-treatment for re-treating the waste asphalt concrete is described below. First, the waste asphalt concrete, which has been separated and collected, is fed into a hopper and crushed and sorted according to a predetermined particle size. Subsequently, the sorted waste asphalt concrete is fed into a hot melting furnace.
The melted waste asphalt concrete, which has been heated to a high temperature in the melting furnace and then discharged from the furnace, is uniformly added with an emulsion containing a surfactant, and then forcibly transferred onto a flat slide screen in a vacuum chamber by air.
For primary separation of colloidal asphalt from large aggregate through a slide screen, the above melt on the screen is scraped and slid using a scraper. High
pressure air bursting and vacuum adsorption at upper/lower portions of the slide screen simultaneously occur. Thereby, the colloidal asphalt is dropped into a collecting tank positioned at a lower end of the screen, while the large aggregate drops onto the lower end of the screen due to its own weight, thus achieving the primary separation of the asphalt from the large aggregate.
The dropped aggregate is re-transferred through a heated transfer conveyor. As such, a melting agent such as ethylene chloride is sprayed for chemical pyrolysis between the asphalt adhering to the aggregate and the aggregate.
Then, the transferred aggregate is fed into a centrifuge for the secondary separation of asphalt from the large aggregate.
The asphalt separated using the centrifuge is transferred into the asphalt collecting tank, and the large aggregate is separately fed into a cooling chamber to cool it. The cooled aggregate is stepwisely washed to restore its surface.
After the aggregate is washed, it is discharged and transferred using screw type transfer means. An aqueous alkali solution is applied on the transferred aggregate using an additional spray nozzle, and thus pores of the surface of the aggregate are coated with colloidal silicic acid and thus filled therewith.
The collected asphalt is transferred to a filter
press, and then undergoes a final process of separating it from small aggregate (sand).
In the overall process of the present invention, an interlocking system is applied to the processes. Thus, if any one intermediate process or apparatus encounters a problem, a subsequent process is instantly stopped. This system may be applied to primary pre-treatment and secondary post-treatment.
Brief Description of the Drawings The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG. 1 is a flowchart showing the overall process for the selective separation of waste asphalt concrete, according to the present invention; FIGS. 2a and 2b are views showing the disposition of the treatment apparatus operated according to the process sequence of FIG. 1 ; FIGS. 3a and 3b are partially enlarged views showing the main portion of FIGS. 2a and 2b; FIGS. 4a and 4b are three-dimensional perspective views showing the parts in FIGS. 3a and 3b ; and FIG. 5 is a perspective view showing the controller
for use in the separation and arrangement of the crushed construction waste, according to the present invention.
Industrial Applicability As described hereinbefore, the present invention provides a method and apparatus for separating and recycling waste asphalt concrete from construction waste.
By using the apparatus for separating the waste asphalt concrete of the present invention, the waste asphalt concrete mass, which is discharged as a chemical by-product along with various types of construction waste, can be selectively separated from the waste concrete mass and then discharged. Hence, the waste asphalt concrete may be usefully recycled, thereby realizing environmental conservation.
That is, since the separated and discharged waste asphalt concrete is waste mass comprising asphalt, large aggregate, fine aggregate, and a pavement filler heated or mixed at room temperature, it has caused severe problems with regard to the intermediate disposal of construction waste. However, in the present invention, a method of selectively separating the waste asphalt concrete from general construction waste and then recycling the separated waste asphalt concrete is provided, and thus, is expected to be very useful in industrial processes.
Although the preferred embodiments concerning the method and apparatus of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.
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