FR2474893A1 - METHOD AND INSTALLATION FOR FRAGMENTING PLASTIC MATERIALS AND / OR RUBBER - Google Patents

Abstract

FOLLOWING THIS PROCESS WE FRAGILIZE THE MATERIAL TO FRAGMENT BY COOLING, IN A TUNNEL 6, USING LIQUID NITROGEN, BEFORE FRAGMENTING IT. THE MATERIAL IS PASSED THROUGH, FOR EXAMPLE, ELECTRIC CABLE SECTION 5 BETWEEN A SUPPORT SURFACE AND A PLATE 22 SUSPENDED BY SPRINGS 23 AND 24 AND WHICH IS MIXED BY A VIBRATER 29, FOR EXAMPLE, BY A BALANCER. THE OSCILLATIONS ARE PREFERABLY OF A FREQUENCY HIGHER THAN 30 PERIODS AND AN AMPLITUDE OF APPROXIMATELY 2 TO 3MM. THESE OSCILLATIONS SPREAD THROUGHOUT THE MASS OF THE CABLE INSULATION AND ENTIRELY FRAGMENT THIS INSULATION. THE INSULATION FRAGMENTS FALL INTO A BOX 32 WHILE THE STRIPED CABLES FALL IN A BOX 33. THE PIECES OF TWO MATERIALS ARE NOT TO BE SEPARATED.

Description

The present invention relates to a method for fragmenting

  plastics and / or rubber by

  example plastic or rubber sheaths

  turning a metallic core, a process in which the plastic or rubber is cooled to a temperature at which it becomes brittle, and then it is fragmented. The invention

  also relates to an installation for implementing

vre of this process.

  We have been looking for a long time for a process that allows-

  to separate from their core the plastic or rubber sheaths coating a metallic core such as the copper or aluminum core of insulated targets, copper tubes and the like and by means of which, not only can one completely separate the material of the sheath of his soul

  metallic, but we can also separate the various

  titrants in a correct and convenient way, so that the metal

  as well as the material of the sheath can be reused.

  The process most commonly used until pre-

  sent consisted of burning the material of the sheath. Unhappy-

  This process leads to the production of polluting substances.

  tos of 1 atmosphere which are harmful to the environment and it is currently prohibited. Furthermore, if this method is used, the materials of the sheaths or coatings cannot be reused. In another method, the electric cables are subjected to a fragmentation operation, that is to say that they are cut or chopped into pieces small enough so that most of the insulating material is

  detaches conductors. However, this process is relative-

  time consuming and costly and furthermore poses problems of

  separation difficult to resolve.

  In patents G-B Nos. 1,303,167 and 1,407,996, methods are described in which the cladding material is cooled to a temperature at which it becomes brittle after Ban has mechanically treated it. A serious drawback of the installation used in the process of the first patent.

  1 303 167 resides in its relatively com-

  which includes both a hammer mill and a downstream separator drum. If, for example, material which has not been sufficiently cooled is allowed to enter the machine at any time, the machine becomes engorged and is blocked by an adherent, tenacious and difficult mass.

  to eliminate. There is also a risk of overheating-

  matter, which results from the fact that a fraction

  carrying kinetic energy developed by hammers

  turns into thermal energy in the sheathing material.

  Furthermore, the need to use pieces of conduc-

  relatively small soul or soul poses difficult problems

  separation, especially in the case of metal conductors

  fine liquids and the result is that the plastics or rubber recovered do not have the desired quality (purity), and

  that the value of the material is considerably reduced.

  In the process described in the second of the aforementioned patents, No. 1 407 996, a continuous length of conductor and the different segments of

  this length are treated successively by a combi-

  born of percussion and cutting. This machine is affected

  of the following disadvantages. Because the operating mode-

  Because it is intermittent and that you can only work on one length segment at a time, the speed and the work capacity are reduced. The process is mainly applicable to large cables and it cannot be effectively applied to

  cables of very small diameter or cables with more

  separate conductors and individually insulated. By

  elsewhere, the impact crusher device must imperatively-

  must be set exactly for the cable dimensions to

  process and this cable should be relatively large in length.

  The main object of the invention is to create a pro-

  transferred and an installation of the aforementioned kind which do not have the drawbacks described above and by means of which it is possible to fragment continuously and without difficulty

  plastics or rubber, for example,

  adorn the plastic or rubber sheaths of the metallic core, whatever the length, dimension and number of elements of the core of the part to be treated, and at

  by means of which several parts can be treated simultaneously

  these. The invention is based on the principle consisting in replacing the known technique in which the sheathing material is weakened and this material is then fragmented using hammers or cutting tools, by a technique

  in which the fragile material is subjected to oscillations

  mechanical conditions which compel it to fragment. These oscil-

  lations include pressure waves or pressure pulses of constant frequency which, individually, have

  insufficient energy to break down the material but which, when

  that they are compelled to propagate in matter in the form

  of a continuous mechanical oscillation, ensure the fragmenta-

  tion of matter by the effect of vibrations generated therein

  drées. The frequency of the oscillations is preferably higher than

less than 30 periods per second.

  For example, oscillations can be generated

  dredged by a vibrating means with which the product which it

  git to eliminate the cladding is brought into contact. In a preferred embodiment, the products are passed between a

  vibrating plate and a fixed support surface. This allows, in-

  other, in the case of cables, to treat simultaneously

  a large number of cables in the space between the plate

  that vibrating and the support surface. When the vibrating plate

  is mounted on a spring suspension, the width of the slot automatically adjusts to the dimensions of the parts to be

  treat, especially with cables, which allows the use of the ma-

  china for parts of different dimensions without having &

  modify its setting. Tests have shown that the oscillations

  The aforementioned tions can be effectively transmitted from one to the other of the different layers of insulation of a cable or bundle of cables and the process according to the invention is therefore also capable of effectively separating the insulation from multiconductor cables which include several separate insulating sheaths and is even applicable to the treatment of cables in batches. The application of the invention ensures practically total separation of the metal and the insulating material, which gives the recovered material a value greater than that which

  is recovered by the methods of the prior art.

  In a particular embodiment of a

  installation according to the invention, a vibrating plate is used

  te which is suspended by springs provided in parts

  opposite extremes of the plate and vibrations are transmitted

  its to the plate at a point which is closer to the springs of a first of the end parts than to the other springs, the plate being arranged so that the parts to be treated are introduced into a space comprised between the first end part of the plate and a fixed support surface. Between

  others, this has the effect that, in the case of different cladding

  working eyelashes, energy will be stored in the rear springs and will be transmitted, with a certain transmission ratio, to the front edge of the plate to generate a

  greater support force. In a pre-

  fairy, the plate forms an angle with the support surface at least in its extreme front part which has the effect that the cable or other part will be treated gradually in

  a slit that gradually narrows, which is parti-

  particularly advantageous in the case of multi-core cables.

  Other features of the invention appear

  tront during the description which follows. At drawings

  attached - Fig. 1 is an overview of an installation

  intended to fragment the insulating sheath of cables by application

  cation of the process according to the invention;

  - Fig. 2 is a detailed view of a machine vi-

  brante according to the invention used in the installation

shown in Fig. 1.

  In Fig. 1, the reference 1 designates in its

  seems to be part of a dresser comprising a means of

  pe 2. This straightener comprises rollers 3 which cooperate to straighten a cable 4 which is introduced therein. This trainer is known and will therefore not be described in detail below.

  As shown in FIG. 1, the cable lengths

  ble 5 previously erected and cut are introduced into a cooling tunnel 6 and, in practice, the position of the straightener is perpendicular to that shown in the drawing, so that the lengths of cables are oriented transversely to the cooling tunnel 6. This tunnel comprises a thermally insulated envelope 7 of elongated shape which is connected to an inlet part 8 in the form of a funnel to receive the lengths S of the cut target. A feeder 9 of the rotary vane type is arranged to rotate in

  the input part 8 so as to introduce lots of long

  target fighters 5 in the cooling tunnel. The food

  guard 5 cooperates with a piston 10 to introduce continuously

  the cable lengths 5 in the cooling tunnel.

  To facilitate this introduction of the cable lengths 5,

  the cooling tunnel can be tilted downwards.

  Tubes 11 which open into the return tunnel

  cooling 6 convey liquid nitrogen supplied by a

  tank 12. To effectively cool cable lengths

  ble 5, the tunnel 6 has fans 13 which make it

  circulate nitrogen. This tunnel is also equipped with a ventila-

  suction valve 14 used to evacuate the gas at a regulated flow rate.

  The use of the rotary vane feeder 9 avoids

  that the refrigerant gas escapes uncontrollably.

  The temperature prevailing in the cooling tunnel

  6 is captured by one or more temperature sensors.

  ture 15, arranged to cooperate with a converter 16 which produces an electrical signal corresponding to the temperature sensed by the sensor or sensors 15. This signal is compared in a comparator 17 to a determined reference temperature, 18. The comparator 17 is constructed to generate a signal

  control which controls a valve 19 interposed in the con-

  pick connected to the nitrogen tank 12. Thanks to this apparatus

  control age, it is possible to maintain the different

  parts of the cooling tunnel 6 at temperature

sirée.

  Cable lengths 5, the sheath of which is now

  weakened by cooling, are transmitted from

  tunnel 6 to a machine in which the embrittled material-

  is fragmented. The fragmentation system comprises a vibrator group 20 in which the rigid cable lengths 5 are

introduced by a piston 21.

  Referring to Fig. 2, we can see that the group

  eg vibrator 20 comprises a vibrating plate 22 which is above

  hung by two front springs 23 and two rear springs 24.

  These springs are in turn carried by beams 25, the rear ends of which can be pivoted about a fixed axis 26. The front ends of the beams 25 are joined to one another by a bar 27. In the form of achievement

  shown, to adjust the height of the ends

  tees before beams 25, these ends are arranged to slide in slots made in fixed supports 28 and to be able to be locked in the desired position inside

of these slots.

  On the plate 22 is mounted a vibrator which comprises,

  in the embodiment shown, two flywheels

  heavy 29 driven by a motor not shown. We can get

  provide vibrations of the desired amplitude and frequency

  by appropriate adjustment of weight, balance and speed

  peripheral rotation speed of the flywheels 29, in a con-

  naked in itself. The vibrator should be placed closer to the

  front lots 23 as rear springs 24. The reference 30 designates a fixed support surface which ends, at the rear end of the vibrator, by a

  grid comprising bars 31 of elongated shape. At the-

  under the grid 31 is placed a container 32 intended for

  cevoir the fragmented material of the sheaths while a reci-

  pient 33 is placed at the end of the grid to collect

  the metallic core 34 of the cable lengths.

  In operation, the piston 21 introduces a charge of cable lengths 5, previously erected and cut which have been weakened in the cooling tunnel 6, in

  the slot formed between the vibrating plate 22 and the surface-support

  fixed port 30. The progressive reduction in the height of the slot formed between the plate and the support surface results in a progressive work of the sheath of the cables introduced.

  in the machine as they pass through this slot. E-

  as the material of the sheaths is entirely rigid,

  the vibrations produced by the vibrating plate 22 propagates

  suit suitably in all the thickness of the sheaths of all

  cables, which causes the oscillations to generate

  in the material both fragment the outer sheaths

  than the separate sheaths that surround the individual conductors. The machine can also efficiently process thin conductors assembled in bundles, i.e. the conductors can be introduced into the machine

in multiple layers.

  Because of the way in which the plate 22 is suspended and the way in which the vibrator is mounted on this plate, when cables are difficult to treat or very large in diameter are introduced into the machine, or even large bundles of conductors, the front end of the plate lifts up,

  compressing the springs 23 and lengthening the springs 24.

  The energy thus stored in the rear springs 24 is then retransmitted to the front end of the plate in the form of a force oriented downwards with a transmission ratio which is determined by the position of the vibrator on the plate 22. The increase in contact force which

  is obtained this way facilitates the fragmentation of the gai-

  do cable lengths routed to the machine. Good results have been obtained in tests in which the vibrator was placed on the plate 22 so as to give the ratio

  distances which respectively separate the vibrator from the

  front and back spells worth 1: 4.

  The spring suspension of the vibrating plate 22

  which is described and represented therefore makes it possible to use effectively

  cement the fragmentation machine with cables whose diameters vary within wide limits. This suspension mode

  also has the effect of increasing the contact force exerted by

  created on large diameter targets or on cable sheaths

  difficult to work. When the cables to be treated pre-

  feel an excessively large diameter, the ex-

  front end of the plate 22 using the adjusting means

27 and 28.

  The flywheels 29 of the vibrator are arranged to turn

  in the direction of arrow A so as to contribute to

  automatically re-advance the cables 5 into the slot between the plate 22 and the support surface 30. The movement of

  vibration of the plate 22 also creates a ventilation effect

  reader which drives the fragmented material from the sheaths through the grid formed by the bars 31 to make it fall into

the container 32.

  Very good results have been obtained during testing

  when the vibrations created by the plate 32 had an am-

  2 to 3 mm fullness and a frequency of 50 Hz. Despite this-

  relatively small amplitude, a good fragmentation effect was obtained, even in the case of cables having a thickness

  relatively large sheath, which shows that the ma-

  china does not work by crushing like conventional machines-

  but the relatively high frequency is also of decisive importance. The frequency should not be less than about 30 periods per second, among others

  for mechanical reasons, and we can also

  use frequencies above 50 Hz.

  know who were mentioned above, the frequency used was

  of 50 Hz because this frequency can be easily obtained

  naked in practice by means of an electric motor. The fact that the machine does not drag like a conventional crusher

  also results in low power consumption.

  In the above tests, the vibrator was driven with a power consumption of only 500 W and gave

  good results. However, to increase the ability to pro-

  machine, you can apply more power

  input, for example from 1 to 1.50 kW. However, in

  i: ou5 the cases, the power consumed per kilogram of material

  fragmented re will be very small compared to the power

  consumed by conventional machines designed for the same purpose

  plication. This low power consumption means that

  the material of the sheaths is not likely to be excessively hot

  fairy during the passage of the lengths of cables in the machine

  born. In practice, it has been found that the heating of the material

  re sheaths were low enough that we could

  place several vibrating machines one after the other

  be if necessary.

  An important advantage provided by the invention consists

  in that the sheath material is detached from the metal core-

  lique in a proportion reaching almost 100%. This means

  fie that the metal and the material of the sheaths which are recovered in the machine have a great commercial value. Given

  that it is possible to work simultaneously several

  cable runners over their entire extent, the working capacity of the machine is very high. Furthermore, the machine is very easy to use and simple in construction. Normal-

  You don't have to make any adjustments to process cables.

wheat of variable size.

  In the embodiment shown, the long

  5 cable cutters are introduced into the machine

  in a transverse orientation. These lengths are before-

  in the order of 1 m. However, it is possible to

  process shorter or longer lengths as well.

  It is also possible to advance several lengths

  of continuous cable in the axial direction in a machine vis-

  brante according to the invention. The cable can be arranged to unwind from one reel and wind on another after being

  passed through the cooling tunnel and into the machine

  brante according to the invention. In this way, the metallic core of the cable can be recovered in length in one piece and

  can possibly be reused without having to be previously

badly recast.

  The embodiment of the cooling tunnel which has been described above should only be considered as

  a nonlimiting example and we can bring it all modifi-

  cations wanted. In addition, nitrogen gas can be replaced

  created by another gas, depending on the cooling temperature

  desired, which is itself determined by the nature of the ma-

  third of the sheaths. This is well known to those skilled in the art and there is no need to dwell on this subject. It is

  also possible to modify the vibrating device and, for example

  ple to mount it so that it can move relative

port on the fixed support surface.

  The process according to the invention which uses vi-

  brations to fragment plastics or rubber-

  it chouc, can also be applied to separate the sheaths from other elements such as, for example, copper tubes

  coated with plastic or other equivalent elements.

  The process and installation according to the invention are also

  Are able to crush other objects such as pneumatic

  vehicle ticks or equivalent objects. We divide everything

  first these objects in small pieces that we weaken in-

  and then passed through the following vibrating machine

  vant the invention, this operation having the effect of frag-

lie the weakened rubber.

  It goes without saying that modifications to other aspects of the invention can also be made provided that the characteristic common to all forms of

  realization which consists in using mechanical oscillations

  to fragment rubber and / or plastic materials

  which have been weakened by cooling. Oscillated them

  tions can be produced by means of a device or in another way, for example by shocks generated by

  pneumatic or by equivalent means.

Claims (8)

R E V E N D I C A T I 0 N S   1 - Process for fragmenting plastics   and / or rubber, for example plastic sheaths   that and / or the rubber coating a metallic core, in the-   which the material to be fragmented is cooled to a temperature at which it becomes brittle and which is then fragmented, characterized in that the brittle material is subjected, in   at least one station, with mechanical oscillations which   fragmentation of matter.   2 - Method according to claim 1, characterized in that the fragile material is subjected to oscillations   with a frequency of around 30 periods per second.   3 - Method according to one of claims 1 and 2,   characterized in that the oscillations are generated using a vibrating device with which the embrittled material is put in contact.   4 - Method according to claim 3, characterized   in that the fragile material is passed between a plate   vibrating and a fixed support surface.   - Installation for fragmenting plastics and / or rubber, for example plastic and / or rubber sheaths coating a metallic core, which   includes means (6) for cooling the material to be broken   lie at a temperature at which this material becomes cold   gile and means (20) for then fragmenting the material   re weakened, characterized in that the means of fragmen-   tation (20) are arranged to subject the embrittled material to mechanical oscillations which cause fragmentation of this material.   6 - Installation according to claim 5. character-   laughed at in that the frequency of the oscillations is higher at 30 periods per second.   7 - Installation according to one of claims   and 6, characterized in that the amplitude of the oscillations is approximately 2 to 3 mm.   8 - Installation according to one of claims 5   a 7, characterized in that the means (20) for subjecting   be the material weakened by mechanical oscillations   take a vibrating plate (22) arranged at a small distance   above a fixed support surface (30) to form relative   port on this surface a passage or a slit through which the fragile material is passed by putting it at the same   time in contact with the vibrating plate and the support surface.   9 - Installation according to claim 8, charac-   characterized in that the vibrating plate (22) is suspended from springs (23, 24) arranged in opposite end parts of the plate, in that the oscillations are applied to the   plate at a point closer to the springs (23) of the first   re extreme part than other springs; in that the ma-   weakened face is arranged so as to penetrate the passage between the first end part of the vibrating plate (22) and the fixed support surface (30); and in that at least the first end part of the vibrating plate forms an angle with the support surface.   - Installation according to claim 9, charac-   checked in that the distances between the springs (23 and 24) provided at the respective end portions of the plate and the   point of the vibrating plate (22) where the vibrations are applied   that this plate, are with each other in a ratio of envi- ron 1: 4.