DE8801215U1 - Water separator - Google Patents

Description

1 February 1988

Wan-Ho Chen
:hanghua hsien, Taiwan

Water separator

The present innovation relates to a water separator, in particular for removing water from wet plastic waste, especially thin plastic waste such as plastic bags, pieces of plastic film, shredded plastic bottles and containers.

Plastic items that end up in the waste are crushed and/or shredded so that the material can be reused as recovered raw material and the fragments are washed with water. Before further processing, this waste must be freed from water. This is a difficult technical task due to the water impermeability and the flat nature of the particles, especially in the case of film particles.

In some cases, water removal and drying is done by heating the waste. This is time-consuming and energy-intensive.

The removal of water is also attempted in machines that spin the water away using centrifugal force. These machines have to be loaded and emptied by hand, which is laborious and not very effective. But even more serious is the disadvantage that the waste fragments, because of their impermeability, do not let the water through when they are

adhere to the outer wall of the water separator drum &igr;. Layers will then build up and the outer layers will prevent the inner layers from being effectively drained. Even if the machine is stopped and the contents are stirred, no significant improvement in water separation will be achieved. These machines therefore still require subsequent heating until the water is completely drained.

Dewatering of plastic waste by means of mechanical pressing is also known. This is done using an endless conveyor belt with a mesh-like structure, along whose path one or more pressing rollers are arranged. The shredded and washed fragments are placed on the conveyor belt and fall under the pressing rollers. However, since the fragments do not absorb the water and can also be quite hard, and since they are rarely evenly distributed across the width of the conveyor belt, the water cannot be effectively pressed out here either. Attempting to achieve better results with higher pressing pressures only has a limited effect, but places considerably more strain on the conveyor belt and the pressing rollers and shortens their service life.

The aim of this innovation is to create a water separator, especially for shredded plastic waste, in which the material to be treated can be effectively dewatered without requiring a great deal of equipment and effort.

Starting with a centrifugal type water separator, this task is solved by the features specified in claim 1. In this innovative design, centrifugal forces act on the waste particles to be dewatered as they pass through the helical flow space for the material to be treated, throwing off the water, and at the same time the particles are repeatedly turned and mixed. The powerful air stream that carries them along also has a blowing and drying effect.

Appropriate further developments of the innovation are specified in the subclaims. The proposed design ensures that the water is completely removed from the balls by means of the metered and thus widely distributed application of the waste particles, the entrainment of the particles by a powerful air stream that suddenly catches them and mixes them up, and the drainage of the spun-off and blown-away water along the entire flow path.

The innovation is explained further below by describing an example of implementation based on the attached drawings. It shows:

Fig. 1 is a perspective view of the water separator;

Fig. 2 the connection between the blower motor and the water separator drum via an injection pipe that provides a first pre-dewatering; Fig. 3 a longitudinal section of the water separator drum, which goes through two starting points offset by 120°;

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Fig. 4 shows the horizontal section through the pipe elbow connecting the outlet collector with the water separator drum;

Fig. 5 a cross-section of the water separator drum; Fig. 6 a division of the drainage channel by means of a dividing plate;

Fig. 7 the section through the feed hopper with the dosing unit and its connection to the blower conveyor.

The water separator consists of a feed hopper 5 into which the wet material to be treated is poured, a blower conveyor 3 connected to this, which generates a powerful air flow which conveys the material to be treated via an inlet blow pipe 23 into a water separator drum 2, after which it is blown out via a pipe bend 24 into an outlet collector 4 and falls out of this in a dewatered state.

The central element of the water separator is the water separator drum 2. This essentially consists of an outer shell, which is formed by three removable or openable shell plates D and an inner shell arranged coaxially in this cylinder 21. Between these, a discharge channel 27 runs in a linear manner and forms a screw channel between its windings.

This screw channel is divided into an inner treatment material flow channel by a sieve wall 25 and a sieve bottom 25' running through it.

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chamber 22 and a separation area 26. The discharge channel 27 has a raised section in the separation area 26 and a lower channel section below the flow area 22 for the material to be treated. \

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This channel section is divided at intervals of 120°' by transverse dividing plates 272 and on the upstream side in front of each dividing plate a drain opening 271 is formed in the inner cylinder (Fig. 6), which leads into the interior of the inner cylinder.

10 Below the inner cylinder 21 is a funnel-

; shaped water hanger 29 with an entry

covering sieve 291. This passes into a discharge pipe 292.

, The blower conveyor 3 is connected via an injection pipe 23 :

connected to the water separation drum 2, whereby: the injection pipe 23 opens into the lower beginning of the treatment material drying chamber 22.

The injection pipe has an S-shaped curved form, as can be seen in Fig. 2. The cross-section is rectangular and on the first upwardly curved section, near the bottom, in continuation of the nozzle of the blower conveyor, a sieve surface 231 is provided, under which a separation zone 232 is formed, at the lowest point of which a drain opening 233 is provided in the area of a recess in the bottom surface. A first pre-dewatering of the material to be treated takes place on this section.

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The outlet nozzle of the water separator drum 2 at its upper end opens via a pipe bend 24 into an outlet collector 4. This is a mesh screen cylinder that is open at its lower end.

As shown in Fig. 4, a sieve partition wall 241 j is arranged in the pipe bend 24 near the inside of the outer wall, which divides off a separation area 242 behind it, which opens into the open air directly next to the outlet collector 4 via a drain opening 243. The pipe bend 24 can be pivoted or repositioned, as indicated by the dot-dash lines.

The feed hopper 5 has the shape of a truncated cone tapering downwards and is connected with its lower mouth end to an air suction nozzle 51 through which the blower conveyor 3 sucks in air in a straight line. In the mouth area of the feed hopper 5 there is a stirrer which doses and evens out the feed of the material to be treated and which consists of a shaft 53 with stirring blades 531 distributed around its circumference. A chute 52 leading to this dosing device is arranged in the hopper.

The operation of the described water separator is such that, when the blower conveyor 3 is running, the wet material to be treated coming from the water wash is poured into the feed hopper 5, from which it is loosened and metered into the air stream that flows through the air suction nozzle 51 under the action of the rotating stirrer 53/531 of the dosing device. The interaction of the stirrer with the chute 52 prevents blockage

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the lower feed hopper mouth and the material to be treated is loosened by the dosing effect and the effect of the air flow and is introduced into it in isolated quantities.

The fragments of the material to be treated are carried along by the air flow and fly through the injection pipe 23 into the water separation drum 2. In the upwardly curved area of the injection pipe 23, a first pre-dewatering takes place in such a way that the water adhering to the particles is thrown downwards through the sieve surface 231 and leaves the separation zone 232 through the drain opening 233.

From the blowing pipe 23, the air flow carrying the material to be treated passes into the screw channel of the water separating drum 2, where the particles in the material to be treated flow chamber 22 fly upwards along a screw line while constantly being swirled around and all the water is shaken off. The water sprays through the support wall 25 and the sieve bottom 25' into the separating drum.

area 26 and falls into the drainage channel 27, where it flows back to the next lower separating plate 272 and through the drainage opening provided here

271 flows into the interior of the inner cylinder 21 and falls into the water suspension 29. The separating plates

272 prevent the separated water from collecting in excessive quantities in the drain channel 27. Due to the excess pressure in the screw channel, the drainage through the drain openings 271 is effectively accompanied by air blowing out.

In this way, in continuous operation

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This involves shaking the particles to be treated dry and aerating them , whereby the water is separated and drained off under the effect of centrifugal forces, while the material to be treated is held in the gridded material flow space 22 and flies through it from bottom to top. Due to the individual release of the particles into the air stream and the turbulence of the same along the entire path, the particles are constantly whirled around, which promotes effective shaking off of the water from all sides and also eliminates the risk of clumping, clogging and sagging. Even if the particles still tend to fold up, the dewatering effect is still far better than with the known methods.

If particularly small particles of the material to be treated pass through the sieve wall 25 into the separation area 26, they will pass together with the separated water through the drain openings 271 into the open air and onto the sieve 291 of the water hanger 29, from where they can be removed by hand.

The performance of the blower conveyor 3 that generates the air-treatment material flow is adapted to the size of the water separator drum 2. A high water separator drum 2 with a correspondingly long treatment material flow space requires a high-performance blower, while for smaller water separator drums, especially those with a low construction height, less powerful blower conveyors are sufficient. It is also possible to switch on several blower conveyors in such a way that the treatment

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good air stream is sent through a blower conveyor halfway up a large water separation in the tronune 1 and is re-pressurized in it. In this way, effective dewatering of plastic waste can be ensured under any initial conditions.

Claims (13)

Protection claims 1. Water separator, especially for shredded plastic waste, in which the waste is freed from adhering water under the effect of centrifugal forces. characterized by a feed hopper (5), | a blower conveyor (3) connected to the latter , a water separating drum (2) connected to the latter with a coaxial inner cylinder (21) running along the entire length of the same, on the outer surface of which a closed, helically wound screw channel is formed, the cross-section of which is divided by a screen wall (25) running parallel to the inner cylinder (21) and correspondingly helically into a flow space (22) for the material to be treated and a separation area (26), wherein the lower end of the flow chamber for the material to be treated (22) is connected to the outlet nozzle of the blower conveyor (3) and an outlet collector (4) is connected to the upper end of the flow chamber for the material to be treated (22). 2. Water separator according to claim 1, characterized in that the outlet collector (4) is connected to the outlet end of the water separator drum (2) via a pipe elbow (24) causing a deflection of 90°. 3. Water separator according to claim 2, characterized in that the pipe elbow (24) is attached to the outlet connection of the water separator drum (2) in a rotatable or repositionable manner. ff ·· »t ff If f» ' · «II t 1 I I f II· 111 JJtI - 11 - 4. Water separator according to one of the preceding claims, characterized by a bottom (27) of the screw channel, which runs below the bottom (25') of the flow space (22) for the material to be treated. 5. Water separator according to claim 4, characterized in that the bottom of the screw channel is designed as a drainage channel (2?), the raised cross-sectional section of which extends into the separation area (26). 6. Water separator according to claims 4 or 5, characterized in that the bottom of the flow chamber for the material to be treated (22) is designed as a sieve bottom (25*). 7. Water separator according to one or more of claims 4 to 6, characterized in that the bottom (27) of the screw channel is divided along its screw line extension by dividing plates (272) into individual sections (C) and that at the lower end of each of these sections a drain opening (271) is worked out, which opens into the interior of the inner cylinder (21). 8. Water separator according to one of claims 2 to 7, characterized in that in the pipe bend (24) on the deflection section near the inner surface of the outer wall a sieve partition wall (241) is arranged which divides a separation area (242), on the downstream edge of which a drainage opening (243) is provided. The » • « ) I Il II I'll · I t · I I « I &igr; &igr; i i I . . Uli - 12 - 9. Water separator according to one of the preceding claims, characterized in that the water separating drum (2) is connected to the blower conveyor (3) via an injection pipe (23) having an upward curvature or inclination and a sieve-dividing wall (231) is arranged near the bottom area thereof, which divides a separation area (232) whose lower end lies in the lee of the flow cross-section and has a drainage opening (233). 10. Water separator according to one or more of the preceding claims, characterized in that the feed hopper (5) has a metering device for the material to be treated at its narrow lower end. 11. Water separator according to claim 10, characterized in that the dosing device is a shaft (53) with stirring blades (531). 12. Water separator according to one of claims 10 or 11, characterized by a chute (52) in the feed hopper (5) leading to the dosing device. 13. Water separator according to one of claims 10 to 12, characterized in that the mouth end of the feed hopper opens into a straight air suction nozzle (51).