CA2111171A1

CA2111171A1 - Automatic color sorting apparatus and method for sorting and recovering cullets

Info

Publication number: CA2111171A1
Application number: CA002111171A
Authority: CA
Inventors: Kazuo Sunohara
Original assignee: KANETSU ENGINEERING CO., LTD.
Current assignee: INNOSIMA KIKAI CO Ltd; KANETSU ENGINEERING Co Ltd
Priority date: 1993-11-10
Filing date: 1993-12-10
Publication date: 1995-05-11
Also published as: DE4344832A1; FR2712210A1; JPH07132269A; GB2283812A; KR950013593A; GB9325040D0

Abstract

ABSTRACT
An automatically operated color sorting apparatus in a cullet recovery system comprises a plurality of pallets (35) for carrying a cullet, a cullet feeding device (27, 31) for feeding one cullet to be sorted to one of the pallets (35), at least one of first conveyer (34) for conveying the pallets (35), at least one of color discriminating device (44) for discriminating the color of the cullet to be sorted, at least one of removing device (47) for removing the cullet from the pallet (35) in accordance with the discriminated result from the color discriminating device (44), and at least one of second conveyer (46) for conveying the cullet removed from the pallet (35).

Description

~1~1171 AUTOMATIC COLOR SORTING APPARATUS AND ME~THOD
FOR SORTING AND RECOVERING CULLETS ~ ;~
BACKGROUND OF THE INVENTION
l. Field of the Invention The present invention relates generally to apparatus and method for automatically sorting glass-fragments by ~ ;-colors. -~ ` ;

2. Description of the Prior Art In order to recycle glass materials such as broken ;~
10 pieces and fragments of vaRious glass-made products, these ~ ;
glass materials to be recycled (referred to "cullet" in the art) should be discriminated and sorted by colors.
Conventionally, such sorting work has been carried out by manual labor. In conventional and many recycle factories, a plurality of workers stand along a conveyor belt ;~
conveying presorted glass-fragments, mixture of various ;;
colors and sizes, and manually pick up specific color and size from the mixture.
However, such conventional hand-operated sorting work has caused following problems.
(l) Working persons are sometimes injured by glass-fragments.
(2j Color-sorting accuracy is poor.

(3) Sorting efficiency is poor.

(4) Working space requires greater.

S~MMARY OF THE INVENTION
.:
:

.~ ' ., 21~117l It is therefore a primay object of ~he present invention to provide an automatically operated color sorting apparatus and method for sorting cullets which can resolve the above described problems.
Another object of the invention is to provide color sorting apparatus and method for sorting cullets which can eliminate smaller cullets prior to color discriminating step.
To accomplish the above objects, an automatically operated color sorting apparatus comprises a plurality of pallets for carrying a cullet, a cullet feeding means for feeding one cullet to be sorted to one of the pallets, at least one of first conveying means for conveying the pallets, at least one of color discriminating means for discriminating the color of the cullet to be sorted, at least one of removing means for removing the cullet from the pallet in accordance with the discriminated result from the color discriminating means, and at least one of second conveying means for conveying the cullet removed from the pallet.
Preferably, the cullet feeding means for feeding one cullet to one of the pallets may include a screenlng means for eliminating smaller cullets prior to the color descriminating operation. The screening means may be preferably composed of a rotary screening drum.
Preferably, the cullet feeding means may includes first and second aligning members arranged in a 2 1 1 1 ~ 7 1 longitudinally stepped form. A first outlet of the first aligning member may be wider than a second outlet of the second aligning member. The first and second aligning `~
members may be adequately provided with a vibrating means, 5 respectively. -~
The first conveying means may be a plurality of conveyer belts arranged parallel in the longitudinal direction and the second conveying means may be a plurality of conveyer belts arranged parallel with each other and at right angle with the first conveying means.
The first conveying means may be driven by an index ;
motor to move the pallets at regular intervals and a predetermined pitch. ~ ;
According to another aspect of the present invention~
an automatically operated color sorting method comprises a cullet feeding step for feeding one cullet to be sorted to one of a plurality of pallets for carrying a cullet, a first conveying step for conveying the pallets, a color discriminating step for discriminating the color of the cullet to be sorted, a removing step for removing the cullet from the pallet in accordance with the discriminated result from the color discriminating step, and a second , conveying step for onveying the cullet removed from the pallet so that the color-sorted cullets can be recovered.

Preferably, the cullet feeding step for feeding one j cullet to one of the pallets may include a screening step ~ ;
for eliminating smaller cullets prior to the color 2~l1171 : ~:

discriminating step.
. .
Preferably, the cullet feeding step may include an aligning step for aligning the cullets in a line one after one by means of a plurality of guide members arranged in a 5 longitudinally stepped form. `~
In the above described automatically operated color sorting apparatus and method, one of cullets having various colors is fed one by one to the pallet. The pallet carrying one cullet is transported by the first conveying 10 means. On the way of this transporting work, the cullet on ~-the pallet is subjected to the discriminating operation by the discriminating means. The cullet is removed from the pallet to one of the second conveying means by the removing : ~:
means in accordance with the result from the discriminating means. According to this discriminating work and the removing work, the cullets are respectively sorted into the predetermined color parts to recover the same color cullets.
Since smaller cullets are eliminated through the screening means prior to the discriminating work, the cullet aligning and discriminating works can be effectively performed. If a rotary screening drum is used for the screening means, the screening work wlll be carried dut at a low noise and a less vibration.
~ 25 The first and second cullet aligning members of the ,~ cullet feeding means are respectively formed in a ~ V-section. The cullets are forcibly aligned along the ~;
"~
' :~- ' ;, ';..' ' : : .
~ 4 _ ~

2 1 1 ~

V-shaped bottom of the first and second cullet aligning members by the vibration of them.
Since the second conveying means are perpendicularly arranged to the first conveying means, working line and space of this apparatus can be extremely shorted and compacted. This arrangement contributes a high yield.
When the first conveying means is driven by an index motor, the pallets transpoted by the first conveying means can be correctly positioned to the color discriminating means even when the conveying means is travelled at a high speed. This improves the color discriminating efficiency of the apparatus.
These and other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING
Fig. l is a plan view showing one embodiment of an automatic color sorting apparatus for sorting cullets according to the present invention;
Fig. 2 is a side elevational view showing the sorting apparatus shown in Fig. l;
Fig. 3 is a front elevational view showing the sorting -;~ apparatus shown in Fig. l;
~ Fig. 4 is a perspective view showing one preferred ;~

2 ~

embodiment of the cullet feeding means associated with the sorting apparatus shown in Fig. l; and Fig. 5 is a partially perspective view showing one ; ;~
preferred embodiment of cullet romoving means associated : ~ ,;,.;
with the sorting apparatus shown in Fig. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Hereinafter, one preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.
Fig. 1 is a plan view showing one preferred embodiment of an automatic color sorting apparatus according to the present invention. Fig. 2 and Fig. 3 show the side and front elevational views of the apparatus.
In the drawings, a numeral 11 denotes the automatic color sorting apparatus which includes a pool box 12 for storing cullets to be sorted at one end (the right side in Fig. 1). Glass products such as bottles collected from waste matters or through social recycle systems are firstly crughed into cullets by a crusher, not shown, associated with this sorting apparatus. The crushed cullets are fed into the pool box by a conveyer belt 13 as shown in Fig. 2.
Since the sorting apparatus is adapted for the cullets of to 90 mm diameter, the crusher is controlled to crush the glass products into the cullets within the range.
The pool box 12 includes a pair of slant plates 14 for dividing the cullets into two ways leading to outlets in : ',-~, ''.'~

- 6 - ~ ~

- ~11117~

the bottom of the pool box 12. Under the outle~s a pair of linear feeders 15 are respectively arranged to feed the cullets to a screening drum 17.
As shown in Fig. 1, since this embodiment employs two sets of the linear feeder 15 arranged in parallel and consituted in the same manner, the same or corresponding parts and elements are represented by the same numerals.
Thus the same explanation will not be repeated.
The pool box 12 further includes a limit sensor 16 as shown in Fig. 1. In this embodiment, the limit sensor 16 is composed of a light transmitting and receiving element and a reflector which are oppositely arranged at both the inner side surfaces of the pool box 12. When the cullets stored in the pool box 12 intercept the light beam, the conveyer belt 13 will slow down its travelling speed to adjust the feeding amount of the cullets into the pool box ;
13.
The linear feeder 15 is composed of a linear plate having a flat top and a vibrating driver for linearly vibrating the linear plate. According to this linear ~ ~:
feeder 15, the cullets gradually dropped onto the linear plate of the linear feeder 15 from the pool box 12 are subjected to the linearly vibrating movement and thus fed ~
forwardly (towards the leftside in Fig. l) at a regular ~ -feeding rate with leveling the cullets. ~ -The screening drum 17, as shown in Fig. 2, includes a drum member 18, a rotary driver l9, a hopper 20 arranged ~ ~ ~ ' '' "'' - 7 - ~
' ` ' ' under the drum member 18, and a smaller cul~et conveyer belt 21 arranged below the hopper 20. The drum member 18 is formed in a cylinderical shape having opened ends and mesh-like many small openings 22 in the cylinderical body.
Further the drum member 18 includes an inner helical plate as like as female screw, not shown, for driving the cullets helically along the inner surface of the drum member 18~
The drum member 18 is rotatably supported by any conventional bearing means so that the drum member 18 is cylindrically rotated by the rotary driver 19 through a drive chain, not shown. The rotation of the drum member 18 is counted by a rotation counter 23 as shown in Fig. 2.
This counted signal from the counter 23 is fed back to the rotary driver 19 to adjust the rotating speed of the drum member 18. Ordinarily, the drum member 18 is forwardly inclined down. This inclined angle is freely adjustable.
The rear opening of the drum member 18 face~ the front end ; of the linear feeder 15 and the front opening of the drum member 18 face~ a distributor 24.
The cullets fed by the linear feeder 15 are dropped into the drum member 18, and several cullets are gradually moved along the helical plate as the drum member 18 is rotated. Smaller cullets having the diameter smaller than the mesh-like small openings 22 formed in the drum member 18 fall through the-small openings 22 during the helical movement. The smaller cullets further fall onto the smaller cullet conveyer belt 21 via the hopper 20, and then transported to another process.
In this embodiment, the smaller cullets are sliminated from the color sorting process in order to increase the working efficiency of this sorting apparatus. In other words, each diameter of the mesh-like small openings 22 of the drum member 18 depends on the working efficiency. The size of the smaller cullet corresponds to the cullets fallen through the mesh-like small openings 22. The smaller cullets, particularly powder-like glass particles mixed in the smaller cullets, are difficult to be aligned and clearly discriminated. In order to treat all sizes of cullets, containing such powder-like glass particles, more complicated and higher accurate system will be required.

.
It is needless to say that such system will increase cost ~
..
16 to recycle glass products. In addition to the problem on cost of constructing such system, the smaller cullets will remarkably reduce the efficiency of aligning and color discriminating works.
If the rotary ~creening drum is replaced by a flat sieve to eliminate the smaller cullets, vibration and noise generated by the screening work will be violently because the flat sieve needs vibrating motion in vertical or horizontal direction. On the other hand, the rotary screening drum does not generate terrible noise and vibration because the drum member 18 is slowly rotated and thus generates only rolling noise of the cullets. Further, the helical plate formed in the drum member 18 can lead the ' _ g _ '-~ , ':
: ., :.. ...

cullets smoothly and control screening ratio of the cullets.
The distributor 24 includes three outlets laterally formed in the bottom and a distributing plate 25 rotatably arranged so as to face one of the t~ree outlets. The distributing plate 25 is driven by a rotary actuator 26 at the rear surface of the bottom of the distributor 24 as shown in Fig. 2. The cullets fed from the screening drum 17 are fed into one of the three outlets by the distributing plate 25. The rotary actuator 26 is energized at a regular interval period to distribute the cullets to the three outlets at substantially a constant amount.
Under each of the outlets, a first aligning member 27 ,~ ,. ..
of a cullet aligning means for aligning the cullets in a line one after is arranged. In this embodiment, three ., : ~.;:..
cullet aligning means are laterally arranged for each the screening drum 17 and have the same structure, so that one of the cullet aligning meanswill be only described in detail.
In the vicinity of the outlet, a cullet sensor 28 is arranged to detect whether the cullet is present on the first aligning member 27 or not, as shown in Fig.l. The "
cullet sensor 28 is also composed of a light transmitting and receiving element and a reflector which are oppositely arranged at both sides of the first aligning member 27.
The cullet sensor 28 feeds back a deected signal to adjust the rotation number of the screening drum 17 and the moving :: - : -~' - 10 - ' ' 211~

amount of the linear feeder 15.
The first aligning member 27 is composed of a guide plate 29 and a vibrating driver as like as the linear feeder 15. In detail, as shown in Fig. 4, the guide plate 29 is substantially formed in a v-shape section (inclined angle about 7 degree). Further a plurality cf gathering ~ ;
plates 30 are fixed on the guide plate 29 for gathering the cullets to the longitudinal center line of the guide plate 29. ~;
The cullets dropped onto the guide plate 29 of the first aligning member 27 are gathered and aligned on the ; ' longitudinal center line by the vibrating motion of the ;
guide plate 29 itself and the gathering plates 30. The aligned cullets are fed one by one to a second aligning 15 member 31 arranged below the first aligning member 27 in a -;
step-like shape. ,-The second aligning member 31 is composed in the same ~ -manner as the first aligning member 27 except for the gathering plates 30 and V-shape angle. That is, the ;~
inclined angle of V-shape section of a guide plate 32 is about 15 degree which configures a deep groove along the longitudinal center line. This deep groove ensures that the cullets are correctly aligned one by one. The second ~;~
aligning member 31 further includes a sensor 33 for detecting whether the cullet is present on the guide plate 32 or not~. This embodiment employs a vibration sensor for -the sensor 33. -~

: :' ' ~"' ~; ,,'`, -:

2 1 ~

The forward end of the second aligning member 31 faces a first conveyer 34 which carries a plurality of pa]lets 35 so that the cullets are succeedingly dropped onto the pallet 35 from the second aligning member 31. Further the forward end of the second aligning member 31 is a sensor 36 for detecting the cullet dropped from the forward end onto the pallet 35, as shown in Fig. 2. This sensor 36 is also composed of a light transmitting and receiving element and ` ;~
a reflector which are oppositely arranged at both sides of -~ ;
10 the guide plate 32 as like as the cullet sensor 28. ~`~
The first conveyer 34 includes a pair of conveyer ; ; ;
chains 39 and a pair of sprocket wheels 37 and 38. The conveyer chains 39 are set around the sprocket wheels 37 and 38 as like as a bridge. Further, as shown in Fig. 5, a 15 plurality of the pallets 35 are continuously laid on the :~ ;
conveyer chains 39 at regular pitches. In this embodiment, the sprocket wheel 37 is mechanically connected to an index motor 41 through a gear unit 40, as shown in Fig. 2.
According to thi~ drive mechanism, the conveyer chains 39 are circularly driven at regular intervals corresponding the pallet pitch by the index motor 41. Although this embodiment uses a singl,e unit of the index motor 41 for driving all of the first conveyers 34, a plurality of drive units may be used for each to independently adjust the conveyers 34.
The pallet 35 is made of a transparent plastic resin and fixed onto the chains 39 so as to keep the surface of : ,:

12 ~
~ -: . :

2~17~ ~
the pallet 35 horizontally during between the sprocket wheels 37 and 38 as shown in Fig~ 5. Under the forward end of the second cullet aligning member 31, the index motor 41 is adjusted to stop the pallet 35 for ensuring the reception of the cullet dropped from the second cullet aligning member 31. On this occasion, the sensor 36 set at the forward end of the second cullet aligning member 31 detects the cullet dropped onto the pallet 35 and outputs a stop signal to the driver for the first and second cullet aligning members 27 and 31. After stopping the succeeding empty pallet 35 is moved again at regular intervals towards the cullet receivig position under the second cullet aligning membr 31. Then the first and second cullet aligning members 27 and 31 are also restarted.
15In this invention, since the cullet should be dropped onto the pallet 35 one by one from the second cullet aligning member 31, the distributing plate 25 is controlled :~ to distribute the cullets to three lines of the first cullet aligning members 27 at a constant rate. The distributing and feeding control is performed in response to the detected signal from the cullet sensor 28 which is set for each the first cullet aligning member 27. When the detected signal represents no or less cullet, the rotary actuator 26 drives the distributing plate 25 to feed one of the first cullet aligning members 27. On the other hand, - when the detected signal represents excess, the linear feeder 15 and the screening drum 17 are slowered to reduce ~ ~ .
':

2 ~

the feeding rate to the first cullet aligning mem~er 27.
Along each first conveyer-34, a pre-check station for detecting opaque substances unfit for this color sorting system, a color discriminating station, and first to fourth cullet removing stations are arranged at regular pitch from the upperstream of the conveyer 34 (from right to left in Fig. 1). The places of these stations respectively correspond to the stop positions of the pallets 35 moved at regular intervals.
Firstly, the pre-check station employs a light sensor 42 which is composed of a light transmitting element and a light receiving element which are oppositely arranged at the upper and lower places with respect to the pallet 35.
This light sensor 42 detects opaque substances such as ceramic, metals and so on through which light can not transmit, and outputs the detected signal to a control station 43 as shown in Fig. 1.
At second stage after the pre-check station, the color discriminating ~tation is provided with a color discriminating camera 44 to discriminate the color of the cullet on te pallet 35. In detail, the camera 44 is firstly exposed to the cullet through an iris diaphragm adjusted at F8 for deep color. Succeedingly, the second exposure at F12 for light color is carried out. If the exposure light is excessive, light blue and light green will not be clearly discriminated. The twice exposing operations at different lense openings ensure a correct '~, '~`,:

~, ~:-;:
~ - 14 - ~
~ '~:',"; ''.'", 2 ~ 7 discrimination between the light blue and light green.
Table l shows the results of the twice exposing -operations and their discriminated colors. -Table l ' '' ~ -Light Color Deep Color Opaque Discriminated Color Brown Blue Green Brown slue Green . ., ON * * * * * OFF Brown ;
10* * * ON * * OFF Brown OFF ON OFF OFF * OFF OFF Blue OFF * OFF OFF ON OFF OFF Blue OFF OFF ON OFF OFF * OFF Green OFF OFF * OFF OFF ON OFF Green 15 * * * ON Opaque In Table l, the mark "*" represents both ON and OFF. ;
: ,... .. ..
The twice exposing operations as described above may be replaced by a single exposing operation. Table 2 shows ~; ;
the results of such a single exposing operation at F8 and their final discriminated colors.

, ;

- 15 - ~

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Table 2 Brown Blue Green Discriminated Color -ON ON ON srown ON ON OFF Brown ON OFF ON Brown -OFF ON OFF Blue OFF OFF ON Green ~ -OFF ON ON Blue-Green OFF OFF OFF Transparent , , ::
The control station 43 selects one of the first to fourth cullet removing stations in response to the ~ ~ ~
discriminated result from the color discriminating camera ~ ~ ;
44. In each of the first to fourth cullet removing stations, a cullet removing device 47 is arranged for each-~
- ~ first conveyer 34. Under the first conveyer 34 and each of ~
the first to fourth cullet removing stations, a hopper 45 ~ ;
, ~ , ,, i8 arranged to receive the cullet from the cullet removing station. Further under the hopper 45 a second cullet ; conveyer 46 is arranged at the right angle with respect to the first conveyer 34 for each color. This embodiment uses ~ ~ "
four lines of the second cullet convey~r 46 for recovering two colors cullets one transparent cullet and one opaque substance. These second cullet conveyers 46 are further connected to any suitable recycle system or recovering deposit, not shown, respectively. The cullet removing l6 ~
L~

211J ~ r7 ~

,. `, device 47 includes a removing brush 48 suspended from a drive unit 48 as shown in Fig. 5. The drive unit 48 drives the removing brush 48 reciprocally in the right angle direction with respect to the travelling direction of the first cullet conveyer 34. This embodiment employs totally 24 sets of the cullet removing device 47 for each first cullet conveyer 34 at each cullet removing station. The removing brush 48 has the same width as the longitudinal length of one pallet 35 to scrape whole surface of the pallet 35 when the drive unir 48 is acutated. The removing brush 48 is ordinarily waited at the side position of the pallet 35 as shown in Fig. 5. The drive unit 49 is for example a reciprocating pneumatic cylinder actuated by pneumatic pressure from a compressor, not shown. The ,,.,.; - ~, ,,~;
cullet is removed from the pallet 35 by the removing brush 48 and dropped to the second cullet conveyer 46 through the hopper 45 arranged under the first conveyer 34.
In this embodiment, the first to fourth cullet removing stations are respectively for transparent cullets, brown cullets, blue-green cullets, and opaque substances.
The control station 43 stores the discriminated data representing, for example brown, from the discriminating camera 44 for a predetermined period, and outputs an acutating signal to the drive unit 49 at the second removing station when the same cullet reaches to and stops . ~ ...... .
, under the second removing station. This brown cullet is - ~-:: .:: .
~ removed by the removing brush 48 and dropped to the second ~' 21~117 i eullet conveyer 46 for brown cullet recovery. It is needless to say that the other removing stations are not actuated while the brown cullet is transported by the first conveyer 34.
This cullet color discriminating and sorting operation is simultaneously and succeedingly carried out along 6 lines of the first conveyers 34.
The index motor 41 for driving the first conveyer 34 includes an index sensor 50, as shown in Fig. 2, for detecting the interval movement of the pallet 35 to fit the pallet movement with the cullet dropping timing from the second cullet aligning member 31, the pre-check timing by the light sensor 42, the color discriminating timing by the camera 44, the removing timing of the removing brush 48 at the first to fourth removing stations. Since the index motor 41 can be accurately rotated at a predetermined angle, the pallet 35 can be quickly moved at regular interval and stopped at required places to accomplish the color discriminating and sorting operation at high speed and accuracy. IE the pallet 35 is not correctly stopped at the curret removing station, the cullet will not be fallen to the hopper 45. Such mis-fallen cullets will cause various troubles or reduce the sorting efficiency.
In the above described automatically operated color soEting apparatus 11, one of cullets is fed one by one to the pallet 35 through the linear feeder 15, the screening drum 17, the distributor 24 and the first and second cullet - 18 ~

2 1 1 1 ~
: : ~
aligning members 27 and 31. The pallet 35 carrying one cullet is transported by the first conveyer 34 at regular intervals. On the way of this transporting work, the cullet on the pallet 35 is subjected to the color discriminating operation by the color discriminating camera 44. The cullet is removed from the pallet 35 to one of the second conveyer 46 by the cullet removing device 47 in accordance with the result from the color discriminating camera 44. According to this discriminating work and the removing work, the cullets are respectively sorted into the predetermined color parts to recover the same color cullets. The yield of the above described embodiment was 99 percent.
As disclosed above, since smaller cullets are eliminated through the screening means prior to the color discriminating work, the cullet aligning and discriminating works can be effectively performed. If a rotary screening drum is used for the screening means, the screening work will be carried out at a low noise and a less vibration.
; 20 Since the cullets are forcibly aligned by two stage configured aligning members, one cullet can be transported . . . .
to the color discriminating device. This will increase the accuracy in color discriminating work.
Since the second conveying means are perpendicularly : - ,,, ~
arranged to the first conveying means, working line and -~
space of this apparatus can be extremely shorted and ; ~--compacted. This arrangement contributes a high yield.

. ~ ,., 21il~.7 1 When the first conveying means is driven by an index motor, the pallets transported by the first conveying means can be correctly positioned to the color discriminating means even when the conveying means is travelled at a high speed. This improves the color discriminating efficiency of the apparatus.
Although the invention has been described in its preferred from with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been changed in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and the scope of the invention as hereinafter claimed.

. .
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Claims

1. An automatically operated color sorting apparatus adapted for recovering cullets comprising;
a plurality of pallets for carrying a cullet;
a cullet feeding means for feeding one cullet to be sorted to one of said pallets;
at least one of first conveying means for conveying said pallets;
at least one of color discriminating means for discriminating the color of the cullet to be sorted;
at least one of removing means for removing the cullet from said pallet in accordance with the discriminated result from said color discriminating means; and at least one of second conveying means for conveying the cullet removed from said pallet.

2. The color sorting apparatus as set forth in claim 1, wherein said cullet feeding means for feeding one cullet to one of said pallets includes a screening means for eliminating smaller cullets prior to said color discriminating means.

3. The color sorting apparatus as set forth in claim 2, wherein said screening means is composed of a rotary screening drum.

4. The color sorting apparatus as set forth in claim 1, wherein said cullet feeding means includes first and second aligning members having V-shape section arranged in a longitudinally stepped form; a first V-shape outlet of said first aligning member being wider than a second V-shape outlet of said second aligning member; and said first and second aligning members being adequately provided with a vibrating means, respectively.

5. The color sorting apparatus as set forth in claim 4, wherein the V-section of said first aligning member has inclined angle of 7 degree, and the V-section of said second aligning member has inclined angle of 15 degree.

6. The color sorting apparatus as set forth in claim 1, wherein said first conveying means includes a plurality of conveyers arranged parallel in the longitudinal direction and said second conveying means includes a plurality of conveyers arranged parallel with each other and at right angle with said first conveying means.

7. The color sorting apparatus as set forth in claim 1, wherein said conveyer of said first conveying means carries said pallets continuously arranged at a predetermined pitch is and is driven by an index motor to move said pallets at regular intervals.

8. An automatically operated color sorting method in a cullets recovery system comprising;
a cullet feeding step for feeding one cullet to be sorted to one of a plurality of pallets for carrying a cullet;
a first conveying step for conveying the pallets;
a color discriminating step for discriminating the color of the cullet to be sorted;

a removing step for removing the cullet from the pallet in accordance with the discriminated result from said color discriminating step; and a second conveying step for conveying the cullet removed from the pallet so that the color-sorted cullets can be recovered.

9. The color sorting method as set forth in claim 8, wherein said cullet feeding step for feeding one cullet to one of the pallets includes a screening step for eliminating smaller cullets prior to said color discriminating step.

10. The color sorting method as set forth in claim 8, wherein said cullet feeding step includes an aligning step for aligning the cullets in a line one after one by means of a plurality of vibrating guide members arranged in a longitudinally stepped form.