DE29924923U1 - Apparatus for separating mixed plastics comprises stirring tank for plastics and separating agent and separator containing upper and lower inner container cones with tips facing and upper and lower discharge cones whose bases enclose them - Google Patents

Abstract

Apparatus for separating plastics mixtures comprises a stirring tank (2) for plastics and separating agent. A pump feeds the mixture to a separator containing upper and lower inner container cones (11, 12) with tips facing and upper (13) and lower (15) discharge cones whose bases enclose them. An inlet (18) feeds separating medium into the upper discharge cone and through outlets at its base (14). A pump (20) feeds the heavy fraction from the lower container cone to a dewatering unit (24), while the light fraction flows from the tip of an upper outer cone (8) into a second unit (24).

Description

The The present invention relates to a device for the separation of Plastic mixtures.

Numerous attempts have been made in the art to separate plastics from mixtures for the purpose of recycling. The DE 28 27 335 A1 describes a funnel-shaped separator with central stirrer and separation of up to 200 ° C heated plastic particles. The agitator causes a turbulent flow against Absetzbleche in the middle part of the funnel. The heating of the separation medium leads to a change in specific gravity. This proposal can only lead to an imperfect degree of separation of multilayer plastic articles.

The DD 256049 A3 describes a process for the treatment of "plastic waste". Also, this prior art uses a funnel-shaped separator with baffles in the upper part of the task of the material to be separated. The short separation path with turbulent vortices only allows incomplete separation of a light fraction from a heavy fraction. The separate, low-purity product can only be used for low-quality products. A recyclate made of pure plastic with defined physical and technical data for a dosing can not be made.

The FR 2573340 describes a process for the preparation of plastic material after separation of paper with an intensive stirrer. It aims to plastic particles in a cylindrical tube with a narrowing below an inlet tube by creating a zone of reduced flow velocity in a light, floating and in a heavy; sinking fraction are separated. In another constructive training, a separation should take place in funnels stacked on one another with the broad tops. This is to be effected in that the separation space has parallel, vertical partitions, which also represent tubular separation surfaces. On the circular dividing line of the two funnels should form a small volume of a calming zone. However, this zone is flowed through in a horizontal direction by the incoming and outgoing separation medium.

These Device only allows the separation of plastics due to their chemical composition greater differences of their specific Have weight. However, there is only an insufficient degree of separation and achieved no single-grade product. The throughput capacity is also in this device low, since the formation of a turbulent flow the parallel sheets must be reduced.

The EP 0557816 A2 describes a process with plant for the separation of plastics.

there stand two cones with the tips to form a defined Room opposite, um a decrease in flow rate to achieve. The separation into fractions is said to be in two interconnected, subsequent cylindrical spaces respectively. about adjoining it conical spaces should these fractions emerge. The advantages of this procedure be through the constructive training that constipation in leads the cone parts, limited. Thus, the field of application is only for granule-like plastics and also here with low density difference to the separation medium with the risk of clogging, possible. Allow mixed plastics with a high proportion of plastic films under production conditions only with high system failure to process.

This Disadvantage is eliminated by the invention.

The DE 197 50 983 A1 describes a method similar to the EP 0557816 A2 , Only the construction of the cones facing each other with the tips is supplemented with parallel baffles and at the discharge with calming plates. The disadvantages of EP 0557816 A2 will not be eliminated. On the contrary, the risk of clogging of the space by hanging pieces of film increases due to the decrease in the flow velocity in the space that form in the short facing cone with the baffles. There are in practice required twelve to fifteen calming plates. Further, by slipping parts along the baffles by the frictional force that arises, it is likely to get stuck in large measure. This danger is particularly in the up or Abschweben the parts in the conical upper and lower discharge segments of the separation vessel, since here a supporting flow velocity of the separation medium is very small and increases too slowly linear. The described solution of the lower Austrages with a height-adjustable hose, which must be raised to the level of the upper Austrages, will lead to constipation in material with much higher density than the separation medium.

Of the Use of a propeller rotor with adjustable wings as Einrührer in the stirred tank leads to material and material mixtures with low bulk density (eg film) for Failure of the stirring vortex and thus the formation of a homogeneous mixture with the separation medium disturbed. When separating mixed plastic is also the proportion of cork and EPS (or other foams) very high. A stir this Materials is only conditionally possible and undesirable in obtaining PE as a separate material Foreign material.

Also These disadvantages are eliminated by the invention.

The inventive solution called in the skin claim.

The The invention relates to a separation plant in predictable geometric Execution, which in their performance and effectiveness of the separation effect the user-related Requirements by explanation all dependent Influencing factors a defined separation exclusively after the density of the materials in relation to the density of the material used Separation medium allows. Another special meaning is in the successful and trouble-free Discharge of the separated materials within a separation vessel, without Use of other mechanical devices and aids.

The Invention allows to solve the economically significant problem that blends from household or industry incurred plastic waste after crushing and if necessary after a pre-wash, too compatible Mixtures or to single-grade plastics, which are in approximately the same density define, separate. This method works with high economy, low use of resources and labor to get out of plastic waste to allow recycling.

Further Details, advantages and features will be apparent from the following Description of the drawing and the dependent claims.

It demonstrate:

1 a schematic embodiment of the inventive arrangement and

2 describes the same functional relationship of the arrangement as in 1 ,

The comminuted, possibly prewashed plastic mixture is passed through a cyclone or inlet channel 1 with the addition of a separation medium 27 in a stirred tank 2 flushed. The stirred tank 2 was previously using his level gauge 4 with the separation medium 27 via a supply line with a control valve 23 filled. The filling height is at approximately the same height as the height of the upper discharge opening 18a a separation tank 6 set. The separation tank 6 is completely flooded with separation medium and this is done via a Trennmediumzufluß 17 with another control valve 23a ,

The Einrührer with Einrührt dishes 3 produces a homogeneous mixture. This mixture is via a flow pump 5 from the storage container 2 withdrawn and passes through an inflow pipe 16 in a separating device 10 , The flow rate of the flow pump 5 is infinitely adjustable.

The separating device 10 consists of two circular cones facing each other 11 . 12 where one of the cones 11 due to the inflow pipe ending in it 16 represents a circular truncated cone.

The inflowing mixture is in a horizontal, evenly from the center of the separating device 10 diverted circulating flow. Due to the fact that the flow cross-section increases quadratically in the ratio of the circle radius of the cones, the flow velocity decreases inversely proportionally. Thus, in the same proportion, the resultant force acting on the particles changes both in their acting direction and in their size.

The particles separate increasingly fast, the farther a separation space 28 , formed by the opposing cone, flows away from the center. This separation takes place exclusively on the basis of the acting up or down force, caused by the density difference of the particles with respect to the separation medium used. Floating particles, as particles with the same density as the separation medium, separate purely randomly.

When leaving the separation chamber, the separation must be completed, since here the flow of the separation medium in a lower flow, generated by the delivery volume of a lower discharge pump 20 and a resulting upper flow, divides.

With passing through the lower and upper circular ring sections, formed by the radius of the circular cone and the radius of the separator 10 enclosing cylindrical outer segment 7 the separation vessel is increased by an increasingly narrowing cross-section, the flow velocity of the separation medium and accelerated to the same extent the separated ten fractions in their up or down movement. According to the invention this is effected by an upper outer segment 8th and an upper inner discharge cone 13 the separation vessel and a lower outer segment 9 and a lower inner Austragkegel 15 of the separation tank. For additional promotion of this flow rate can regardless of the flow rate of the flow pump 5 Separating medium in a drive and driven space 29 . 30 enter. This is done via a Trennmediumzufluß in the upper inner cone of a separation vessel 17 and / or in a lower inner cone of the separation vessel 31 , regulated in quantity by the control valve 23 , The here pumped separation medium occurs in the lower quarter via outlet openings 14 out. The fractions becoming increasingly concentrated and faster down and up are considered to be heavy fractions via the lower discharge pump 20 discharged with the separation medium and a dewatering unit 24 directly fed and as a light fraction through the separation medium via the upper outlet opening 18 lifted and runs over an outlet trough 19 also on a dewatering unit 24 ,

The separated from the fractions separation medium is placed in a circulation container 25 passed and fed via the circulation pump in turn the process. Only the entrained by the heavy and light fraction amount of separation medium will supplement the circulatory system, the thus obtained heavy and light fraction can further drying or further separation according to the same structure described under appli cation of a separation medium of different density and / or further processing than Recyclable material.

The 2 describes the same functional context as above 1 described, with the modification that is dispensed with the flow pump and the Einrührbehälter 2 over the inflow pipe 16 directly with the separator 10 in the separation tank 6 connected is.

It will be in place of an open upper outlet 14 on an upper opening directly an upper discharge pump 21 attached, the flow rate is infinitely variable. By working together the lower and upper discharge pump 20 . 21 becomes a negative pressure in the separation tank 6 produced and this suction pulls the homogeneous mixture from the stirred tank 2 over the inflow pipe 16 into the separating device 10 ,

Separable Mixtures of plastics are assigned to the following consumables:

By Combination of the described system in series and use of separation media different specific density is the almost varietal Separation of the individual plastics from the input mixture possible.

1

cyclone or inlet channel with flushing

2

mixing tank

3

Stirrer with Einrührteller

4

level meter

5

Flow pump

6

separation vessel

7

Cylindrical outer segment of the separation tank

8th

Upper outer cone of the separation tank

9

Lower outer cone of the separation tank

10

cleaver

11

lower Cone of the separating device

12

Oberer Cone of the separating device

13

Oberer inner discharge cone of the separation tank

14

outlet openings

15

lower inner discharge cone of the separation tank

16

supply pipe into the separating device

17

Trennmediumzufluß in the upper inner cone of the separation tank

18

Upper outlet opening

19

discharge chute

20

Lower discharge pump

21

Upper discharge pump

22

Gate valves

23

Control valve

24

dehydration unit

25

Circulation container

26

Circulation pump

27

Trennmediumzufluß

28

separating space

29

buoyancy space

30

output space and

31

Trennmediumzufluß in the lower inner cone of the separation tank

Claims (12)

Device for separating plastic mixtures of different density in fractions, with a stirred container kept at a constant filling level of a separating medium ( 2 ) for introducing a, optionally prewashed and comminuted plastic mixture to be separated with the addition of separation medium containing a stirrer with stirring plate ( 3 ), with which the flushed plastic mixture can be stirred into a homogeneous mixture, and a flow pump ( 5 ) with adjustable flow rate, from the conical lower part of the Einrührbehälters ( 2 ) withdrawing the homogeneous mixture has, a completely flooded with the mixture separation vessel ( 6 ), which is a central separation device ( 10 ), comprising a lower inner container cone ( 11 ) and an upper inner container cone ( 12 ), which face each other with their pointed sides, and a cylindrical segment containing the separating device ( 10 ), characterized by a lower inner Austragkegel ( 15 ) and an upper inner Austragkegel ( 13 ), which are averted with their pointed sides of each other and each to the inner container cone ( 11 . 12 ) at their base surface, an opening ( 18 ) of the upper inner Austragkegels ( 13 ) for the inflow of separation medium, a valve ( 23 ) for regulating the inflow through the opening ( 18 ), Outlet openings ( 14 ) in the lower quarter of the upper inner Austragkegels ( 13 ) via which the separating medium can emerge, a pump controllable with respect to its delivery ( 20 ) for withdrawing the separated heavy fraction from the lower inner container cone ( 11 ) and to forward this heavy fraction to a dewatering aggregate ( 24 ), an upper outlet opening ( 18a ) in the upper outer cone ( 8th ), through which the separated light fraction via an outlet trough ( 19 ) in a dewatering unit ( 24 ) and recirculation means to pass through the dewatering units ( 24 ) resulting separation medium a circulation container ( 25 ) or depending on a level gauge ( 4 ) in the stirred tank ( 2 ) directly to the stirred tank ( 2 ). Apparatus according to claim 1, characterized in that the separating device ( 10 ) from two cones ( 11 . 12 ), which face the tips and the tip of the lower cone ( 11 ), by the vertically ending from below inflow pipe ( 16 ) is interrupted by the flow pump ( 5 ) from the stirred tank ( 2 ) comes. Device according to claim 1, characterized in that and the two cones ( 11 . 12 ) have the same geometric dimensions and the cone angle and bevel radius is formed so that the flow of the mixture of plastic and separation medium square, measured from the center of the opposing cone in a horizontal direction, decreases and the buoyancy or output force of the plastic mixture, which is made the density difference to the separation medium sets, greater than that through the two cones ( 11 . 12 ) is horizontally deflected flow force and thus sets a clear density difference separation of the plastic mixture in the separation medium, which is determined by resulting resulting force vector in the direction and size, which acts on the respective particles. Apparatus according to claim 1, characterized in that the cone angle of the two opposing cone ( 11 . 12 ) of the separating device ( 10 ) is formed so that at the conical surfaces ( 11 . 12 ) along sliding material is not hindered by the self-adjusting frictional force on the locomotion and is expediently less than 120 °, but is still so great that a successful separation according to the density difference in the volume of the separating device ( 28 ), which is formed by the center of the two opposing cones ( 11 . 12 ) in a horizontal direction to the exit, assumed by the imaginary cylindrical surface formed by the radius of the cone and the distance between the two radii. Apparatus according to claim 3, characterized in that the exit surface formed by the imaginary cylindrical surface of the opposing cone ( 11 . 12 ) of the separating device ( 10 ), formed by the bevel radius and the distance between the two radii, as arithmetic product of the circumference of a cone and the vertical distance to the opposite cone and the resulting calculable exit velocity of the separation medium, formed as a mathematical quotient of flow from the Einrührbehälter ( 2 ) into the separation tank ( 6 ) and this area, less than 10 mm / s and the pump capacity of the controllable flow pump ( 5 ) between stirred tank ( 2 ) and separating containers ( 6 ) is still so big that there is no supersaturation. Device according to claim 3 and 4, characterized in that the outer cylindrical container segment enclosing the separating device ( 7 ) a height corresponding to the height of the two opposing cones ( 11 . 12 ) of the separating device ( 10 ) and is formed by a radius approximately equal to the root of the sum of the product of twice the height of the distance between both opposing cones of the separating device with the radius of the cones and the square of the radius of the cones. Apparatus according to claim 1 to 5, characterized in that the cylindrical middle Trennbehältersegment ( 7 ) subsequent upper conical containers ( 8th ) with its volume formed by an inner conical body ( 13 ), which in turn is directly on the upper cone ( 12 ) of the separating device ( 10 ) and the upwardly decreasing area cross-section allows a uniform increase in the flow velocity of the separation medium and thus also the separated light fraction and the height of both conical bodies ( 8th . 13 ) is about the same size and this height is so great that the resulting cone angle of the outer container cone ( 8th ) is chosen as large as practically possible, but not greater than 60 °. Device according to claim 7, characterized in that in the inner upper conical body ( 13 ) is pumped from above separation medium whose amount is adjustable ( 17 . 23 ) and this separation medium in the lower quarter through outlet openings ( 14 ) from the conical body ( 13 ) and the exit flow velocity of the separation medium from these openings, formed from the calculated quotient of the amount of separation medium pumped in and the sum of all the individual exit surfaces, is significantly smaller than the flow rate of the upwardly flowing separation medium mixed with the separated light fraction. Apparatus according to claim 1 to 6, characterized in that the cylindrical middle separation container segment ( 7 ) subsequent lower conical containers ( 9 ) is limited by its formed volume, by an inner conical body ( 15 ), which in turn directly on the lower cone ( 11 ) of the separating device ( 10 ) and the downwardly decreasing area cross-section generates a uniform increase in the flow velocity of the separation medium and thus also the separated heavy fraction and the height of both conical bodies ( 9 . 15 ) is about the same size and this height is so large., That the resulting cone angle of the outer container cone ( 9 ) is as large as practically possible, but not greater than 60 ° and the flow rate from the variable capacity of the lower discharge pump ( 20 ), which at the end of the lower conical body ( 9 ) and the lower heavy fraction with separation medium a dewatering unit ( 24 ) feeds. Apparatus according to claims 1 to 9, characterized in that all the inner surfaces which pass through the inner surfaces of the central cylindrical separating vessel segment ( 7 ) and the conical separating container segments adjoining above and below ( 8th . 9 ) and the outer surfaces of the opposing cones ( 11 . 12 ) with the upper and lower conical bodies ( 13 . 15 ) is formed, has no sharp edges or projections and all joints are rounded and smoothed and the upper outlet opening ( 18 ) is circularly beaded and polished with its circular outlet edge. Apparatus according to claim 1 to 10, characterized in that in another embodiment, the flow pump ( 5 ) containing the stirred homogeneous mixture from the stirred tank ( 2 ) into the separation tank ( 6 ), by a direct pipe connection ( 16 ) is replaced and on the upper outlet opening ( 18 ) of the separation tank ( 6 ) an upper discharge pump ( 21 ) is connected with adjustable capacity, which in conjunction with the controllable lower discharge pump ( 20 ) over the self-adjusting negative pressure in the separation tank ( 6 ) the stirred homogeneous mixture from the stirred tank ( 2 ) sucks. Apparatus according to claim 1 to 11, characterized in that via the drainage units ( 24 ) resulting separation medium in a circulation container ( 25 ) is brought together and from this directly into the stirred tank ( 2 ) via the supply line ( 27 - 23 ), regulated by the level gauge ( 4 ) of the stirred tank ( 2 ) and only the amount of separation medium in the circulation container ( 25 ), which is dragged out of the system by the dewatered light and heavy fraction, and the amount supplied is controlled by the level gauge ( 4 ) in the circulation container ( 25 ) the circulation container ( 25 ) is supplied.