SE452281B - SET AND DEVICE FOR SUBDIVISING PLASTIC OR RUBBER MATERIAL - Google Patents

Abstract

A method of disintegrating plastics and/or rubber material, such as the plastics and/or rubber casings of metal cores, for the purpose of recovering the metal from scrap cables for example. The material to be disintegrated is cooled to a temperature at which it becomes brittle. The embrittled material is then subjected in at least one station to mechanical oscillations which cause the material to disintegrate. The oscillations suitably have a frequency in excess of 30 Hz and an amplitude of about 2-3 mm. The oscillations can be imparted with the aid of a vibratory device with which the embrittled material is brought into contact.

Description

If cooled material enters this device, it will be completely blocked by a tough, adherent mass which is very difficult to absorb................................ There is also a risk of excessive heating of the cooled material for the reason that a significant part of the kinetic energy represented by the hammer is transferred to heat energy in the casing material.Due to the need to use relatively short pipe sections Furthermore, large separation problems are obtained, especially in the case of thin metal conductors, so that the recycled metal or plastic material does not obtain the desired quality (purity), which greatly reduces the value thereof.

According to the second of the above-mentioned British patents No. 1 407 996, a continuous conductor length is produced, which is machined intermittently over successive portions by means of a combined percussion and cutting head. This device has, among other things, the following disadvantages. The processing speed becomes low due to the intermittent working method and the fact that you can only process one line at a time. fr: ru »The method is best suited for coarse cables, while it is hardly applicable to very thin cables or cables containing several separately insulated conductors. Furthermore, the percussion device must be carefully adjusted in relation to the current cable dimension. The cable must also be in relatively large lengths.

The main object of the present invention is to provide a device of the type indicated in the introduction, which with removal of the above-mentioned disadvantages allows a continuous and simple decomposition of plastic and / or rubber material, e.g. for separating plastic and / or rubber casings from metal cores, regardless of the lengths, dimensions and number of cores in each object, and which also allows processing of a plurality of objects simultaneously.

The invention is based on the realization that the known technique of disintegrating the brittle casing material as a result of cooling by means of crushing or cutting blows can be replaced by a technique in which the casing material is subjected to mechanical oscillations which causes the material to disintegrate. The oscillations consist of pressure waves or pulsations with a constant frequency, which waves or pulsations each do not possess sufficient energy for crushing the material, but which when they are brought to propagate through it in the form of a substantially continuous mechanical oscillation results in that this falls apart as a result of the oscillations therein. It is preferred that the frequency of the oscillations exceed 30 periods per second.

The oscillations can be initiated, for example, by means of a vibrating member with which the objects from which the hair is to be removed are brought into contact. Suitably the objects are then allowed to pass between a vibrating plate and a solid surface. This allows, among other things, that when processing cables a large number of cables can be processed simultaneously in the gap between the plate and the substrate. By further utilizing a spring-suspended vibrator plate, the gap will automatically adapt depending on the current cable dimension, whereby the same device can be used for varying dimensions without the need for adjustment. Experiments have shown that mechanical oscillations as above are effectively transmitted between different insulating layers in a cable or bundle of cables, why the method according to the invention entails an efficient separation of insulating material also from multi-conductor cables containing several different, separate insulating sheaths and also allows batch processing of cables. Using the invention, a substantially complete separation between metal and plastic is obtained, which according to the above greatly increases the value of the recycled products.

In a particularly preferred embodiment of a device according to the invention, a vibrator plate is used which is suspended in springs arranged at its opposite end edge portions and the vibrations are applied to the plate closer to the springs attached to one end edge portion than the others, the plate being arranged so that the objects which shall be 452 281 _. 1. 4 is inserted into a gap between said one end edge portion of the plate and a solid support. This means, among other things, that in the case of difficult-to-process casings, energy will be stored in the rear springs, which energy is returned to the front plate edge with a certain gear ratio and gives rise to an increased contact force. Furthermore, it is preferred that at least said front edge portion forms a certain angle relative to the substrate, which means that a successive processing of a cable in a tapered gap is obtained, which is of special value in the case of multi-conductor cables. Other features and characteristics of the invention appear from the claims.

The invention will be described in more detail below with reference to the accompanying drawings. Fig. 1 is an overview view of a plant for dismantling the cable sheaths using the method according to the present invention.

Fig. 2 is a detail view of a vibrating device according to the invention included in the plant according to Fig. 1.

In Fig. 1, 1 generally denotes a part of a guide with a cutting device 2. The guide comprises a number of rollers 3, which cooperate for the direction of the incoming cable 4. Such guides are well known and are not described in detail here. In practice, the guide 1 is rotated 900 towards what is shown, so that the directed and cut cable lengths 5 are oriented across the feed direction in the subsequent cooling duct 6, as indicated in the drawing. The cooling duct 6 consists of an elongate, insulating housing 7 connected to a funnel-shaped feed part 8 for the cut cable lengths 5.

In the feed part 8 a rotatable cell feeder 9 is arranged for batch feeding of cable lengths 5 in the cooling duct. The cell feeder 9 cooperates with a piston means 10 for the continued feeding of the cable lengths through the cooling duct. To facilitate this further transport of the cable lengths, the cooling duct can form an angle with the horizontal plane.

In the cooling duct 6 a number of lines ll, through. man-_ __.... r1 --- .fi n-.t-.xr -... H. un. 452 281 5 which liquid nitrogen is supplied from a container 12. In order to provide an efficient cooling of the cable lengths 5, a number of fans 13 are provided for efficient circulation of the gas in the cooling duct. This 14 is referred to as an exhaust fan for controlled evacuation of the gas. The use of the cell feeder 9 prevents uncontrolled loss of coolant.

The temperature in the cooling channel 6 is sensed by means of one or more temperature sensors 15, wherein 16 denotes a converter which emits an electrical signal corresponding to sensed temperature, which in a unit 17 is compared with a set temperature reference 18. The comparison unit 17 emits a control signal, which controls a control valve 19 in the line from the nitrogen container 12. With this control equipment the temperature in the different sections of the cooling duct can be kept at the desired level.

From the cooling duct 6, the cable lengths 5, the casings of which are now brittle as a result of the cooling, are discharged to a device for disintegrating the brittle casing material.

The disintegration device comprises a vibrator unit 20, in which the rigid cable lengths 5 are fed by means of a piston means 21.

It can be seen from Fig. 2 that the ventilator unit 20 comprises a vibrator plate 22, which is suspended in two front and two rear springs 23 and 23, respectively. 24. These springs are in turn fastened to beams 25, which at their rear ends are pivotable about a fixed axis 26. The front ends of the beams 25 are interconnected by means of a rod 27, which slides in height adjustment of the front ends of the beams i and is lockable L desired position in slot-shaped openings in fixed holders 28.

A vibrator is arranged on the vibrator plate 22, which in this example is shown to comprise two unbalanced flywheels 29, which are driven by an electric motor (not shown). By adjusting the weights and balancing of the flywheels and the rotational speed of the wheels, vibrations with the desired amplitude and frequency can be obtained in a known manner. The vibrator must be located closer to the front springs 23 than the rear 24%. The term 30 refers to a solid base, which 452 281 6 at the rear end of the vibrator merges into a grid formed by longitudinal rails 31. Below the grid 31 a container for receiving disintegrated casing material is arranged, while at the end of the grid a container 33 for collecting the metal cores 34 in the cable lengths is located.

During operation of the disintegration device, a set of directed and cut cable lengths 5 are fed, which are cooled so that their casings are brittle, by means of the piston member 21 in the slit-shaped opening between the vibrator plate 22 and the fixed base 30. The decreasing gap height between the plate and the substrate results in a successive machining of the casing of the fed cables during their passage through the gap. Due to the fact that the casing material is completely rigid, a good propagation of the oscillations generated by the vibrator plate 22 is obtained through the casing material in the entire cables, meaning that both the outer casing and separate casings around individual conductors are effectively decomposed by the oscillations in the material. The device also allows bundled processing of thin conductors, ie. these can be fed in several layers.

Due to the shown spring suspension of the plate 22 and the specified location of the vibrator on the plate, when feeding difficult-to-work or coarse wires or large bundles of wires, the front end of the plate will be lifted during compression of the springs 23 and expansion of the springs. 24. The energy which is then stored in the rear springs 24 is then returned with a gear ratio determined in dependence on the position of the vibrator on the plate 22 in the form of a downwardly acting force on the front end of the plate.

The increased abutment force thus obtained facilitates the disintegration of the casing material of the plate on supplied cable lengths. In tests, the vibrator has with good result been placed on the plate 22 so that the ratio of the distances between the vibrator and the front and rear springs has been 1: 4.

The spring suspension shown by the vibrator plate 22 452 281 7 thus allows the disintegration device to be used for cables of widely varying diameters and entails an increased abutment force against coarse cables or cables with a difficult-to-machine casing. If extremely coarse cables are to be machined, the front end of the plate 22 can be raised by means of the adjusting means 27 and 28.

By rotating the flywheel 29 of the vibrator in the direction shown by the arrow A, an automatic feed of the cables 5 in the gap between the plate 22 and the base 30 is obtained. Furthermore, the vibrating movement of the plate 22 provides a fan action which effectively presses the disintegrated casing material through it. of the rails 31 formed the grid and down into the container 32.

In experiments, very good results have been obtained using an amplitude of 2-3 mm and a frequency of 50 Hz for the vibrations of the plate 22. Despite this relatively low amplitude, a good decomposition effect has also been achieved by relatively coarse cable sheaths, which shows that this is not a question of conventional crushing, but that the relatively high frequency is also of decisive importance. The frequency should not be less than about 30 Hz from a mechanical design point of view, while frequencies over 50 Hz can also be used. In the tests performed, the frequency 50 Hz has been used, as this is easy to achieve in practice when using an electric motor. That, according to the above, there is no question of conventional crushing of the material is also apparent from the low power required. In the experiments referred to above, the vibrator has been operated with a power of only 500 W with good results. However, to increase capacity, a higher power should be used. However, this will in all cases be very low per kg of decomposed material compared with the power required in conventional plants.

The low power also means that there is no risk of overheating of the housing material when the cable lengths pass through the vibrator. The heating 452 281 has in practice been found to be so low that several vibrator devices can be arranged one after the other, should this be desired in any case.

A very significant advantage of the present invention is that a substantially 100% separation of the casing material from the metal cores is obtained, which means that the value of both the recycled metal and the casing material increases. The capacity is also very high, as several cable lengths are machined simultaneously and over their entire length. Furthermore, the device becomes very simple both to handle and to its construction, as, among other things, no adjustments are normally required with varying cable dimensions.

In the embodiment shown, the cut cable lengths 5 are fed in the transverse direction. The lengths are suitably of the order of 1 meter. However, both longer and shorter cables can be machined according to the same principle. It is also possible to feed a plurality of continuous cable lengths axially through a vibrator device according to the invention.

The cable can then possibly run from reel to reel during the passage of a cooling duct and a vibrator device according to the invention. In this case, the metal core is obtained in a continuous length and can possibly be reused without being melted again.

The above-described embodiment of the cooling duct may only be seen as an example, as this can be varied as desired. Furthermore, the nitrogen gas can be exchanged for another gas depending on the desired cooling temperature, which is determined by the casing material. However, this is well known to those skilled in the art and is not described in more detail here. The vibrator unit can also be varied in several respects and, for example, be made movable relative to the fixed surface.

The utilization of vibrations for disintegration of plastic and / or rubber material according to the invention, pre-disintegration of cable sheaths can also be utilized when removing the sheaths from e.g. plastic-coated copper pipes and the like. Other objects can also be broken down, such as car tires and the like. These are then divided into smaller parts, which are cooled down and then passed through a vibrator device according to the invention for disintegrating the brittle rubber material as a result of the cooling down.

The invention can also be varied in other respects, the common feature in all embodiments being the use of mechanical oscillations for disintegration of brittle rubber and / or plastic material by cooling. the oscillations can then be generated by means of a vibrator device or in another way, for example by means of strong air pressure shocks or the like.

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Claims (6)

452 281 _ t 10 PATENT REQUIREMENTS A method of disintegrating plastic and / or rubber materials, such as casings of plastic and / or rubber applied to cores of metal, the material to be disintegrated being cooled to a temperature at which it becomes brittle and then disintegrating, characterized in that the disintegration of the material brittle by cooling is effected by imparting to it at least one station disintegrating mechanical oscillations, by passing it through a slit-shaped passage between two relatively alternating oscillating plates, which abut against the material during its passage of the plates . 2. A method according to claim 1, characterized in that the brittle material is subjected to oscillations with an amplitude of the order of 2 - 3 mm and a frequency exceeding 30 periods per second. Device for disintegrating plastic and / or rubber material, such as casings of plastic and / or rubber applied to cores of metal, comprising means (6) for cooling the material to be disintegrated to a temperature at which it becomes brittle and means (20) for a subsequent disintegration of said material, characterized in that said means (20) for disintegrating the brittle material by cooling are arranged to subject it to disintegrating mechanical oscillations and that they therefore comprise a vibrating plate ( 22) arranged at a small distance from a substrate (30), to form a gap-shaped passage therebetween through which the brittle material is intended to pass under contact with both the vibrating plate (22) and the substrate (30). Device according to claim 3, characterized in that the vibrations of the plate (22) have an amplitude of about 2-3 mm and a frequency exceeding 30 periods per second. Device according to claim 3 or 4, characterized in that the vibrator plate (22) is suspended in springs (23, 24) arranged at its opposite end edge portions, that the vibrations are applied to the plate closer to the springs attached to one end edge portion thereof. (23) than the others, that the brittle material is arranged to be inserted into the slit-shaped passage between said one end edge portion of the vibrator plate (22) and said fixed base (30), and that at least this end edge portion of the vibrator plate forms an angle with the base . Device according to any one of claims 3 - 5, characterized in that the distances between the position on the vibrator plate (22) where the vibrations are applied and the springs (23, 24) at the respective end portions of the plate are approximately 1: 4 .