MXPA99005083A - Method and apparatus for continuous devulcanization of rubber - Google Patents

Abstract

An apparatus for devulcanizing vulcanized rubber or cross linked polymeric material has an ultrasonic exposure portion including a body forming an exposure channel through which particles of the material flow and an ultrasonic generator including a horn extending generally traverse to the direction of the material flow. The apparatus also has a preconditioning portion for feeding the particles to the ultrasonic exposure channel. The method for devulcanizing vulcanized rubber or cross linked polymeric material comprises the steps of preconditioning and feeding particles of the material, including heating the particles;feeding the particles through a pressurized exposure channel;and exposing the particles to ultrasonic energy within the exposure channel with an ultrasonic wave propagated in a direction traverse to the direction of the channel to effect devulcanization by breaking chemical bonds in the material.

Description

n.

METHOD AND APPARATUS FOR THE ROLLING CONTINUOUS RUBBER ADJUSTMENT FIELD OF THE INVENTION This invention relates to the recycling of rubber and other interlaced polymeric materials and, in particular, to a continuous process for the devulcanization of said materials so that they can be reused. DESCRIPTION OF THE PREVIOUS TECHNIQUE The elimination of tires has become a major environmental concern. Garbage dumps and landfills filled with discarded tires are common. Until recently, there has not been a satisfactory technique for the disposal or reuse of tires and other products made of natural or synthetic rubber reinforced with other materials. Although some tires have been used for retaining walls or traffic separators or have been used in other ways, the demand for such uses is very limited, and they do not provide adequate means for the absorption of all waste tires. Several treatments have been explored for the recovery of tire rubber in a reusable form, but these attempts have generally not been very successful. However, a process that has invoked interest consists of ultrasonic devulcanization in which the vulcanized rubber of tires and other products, such as hoses and belts, is milled to form particles and exposed to ultrasonic energy in a controlled process. When properly exposed to ultrasonic energy, the carbon-sulfur and sulfur-sulfur bonds in the vulcanized rubber are broken, creating a material that is substantially devulcanized and can therefore be reused in the manufacture of rubber products. In U.S. Patents Nos. 5,258,413 and 5,284,625 issued to Isayev et al., Apparatuses and methods for the devulcanization of rubber using ultrasonic energy are described. Although these devices and methods are generally effective, they do not provide a method for the continuous processing of large quantities of material in a cost-effective manner. One of the problems encountered in the design of a continuous ultrasonic devulcanization process is to provide a continuous exposure of the material to the ultrasonic energy in an efficient manner that allows for the proper devulcanization of the material. In the aforementioned US Patents Nos. 5,258,413 and 5,284,625, this was achieved by placing an ultrasonic funnel or horn in a coaxial direction within the material flow at the exit of the extruder. This required that the flow of the material pass in front of the ultrasonic horn because the horn, in essence, blocked the exit through which the material flowed. Although in general this design was effective for the devulcanization of rubber, it limited the amount of material that could be processed because the position of the horn severely restricted the flow of the material when being evacuated by the exit of the extruder. SUMMARY OF THE INVENTION The present invention overcomes the problems of the method and apparatus in the prior art, and provides other advantages not previously understood. In accordance with the present invention, a continuous ultrasonic devulcanization process is provided in which the ultrasonic horn is positioned in a transverse or radial direction with respect to the axial direction of the flow. In this way, the horn does not impede or restrict the flow of the material, and the material can be continuously processed in an efficient and cost-effective operation. Following the design of the present invention, the material is preferably guided through a plurality of helical channels formed by helical grooves inside an exposure body having a cylindrical core that rotates inside the body. The channels define a circulation path for the material, where it is continuously exposed to the ultrasonic energy provided by a generator that includes a horn inserted into the channel. The ultrasonic energy, then, it is transmitted to the interior of the material in a direction generally transverse to the flow direction, so that the material can be processed efficiently. The present invention also includes a preconditioning portion upstream of the ultrasonic treatment portion and a postconditioning portion downstream of the treatment portion. The preconditioning portion, which preferably includes a feeder thread inside a locked and cooled cylinder, allows the treated material to cool without exposing the material to the air or allowing the escape of gases or byproducts. The method and apparatus of the present invention provides an elongated axial design in which the material continues to flow along the axis during and after the ultrasonic treatment. This axial design allows the method and apparatus to be combined with other processes so that the treated material can be processed later, after its exit from the apparatus. For example, an extrusion process or other axial feeding process can be carried out with the material at the exit point of the apparatus of this invention. The method and apparatus of this invention, therefore, allows post processing to the ultrasonic treatment of the material. These and other advantages are provided by the present invention of an apparatus for the devulcanization of vulcanized rubber or degraded polymeric materials, which comprises an ultrasonic exposure portion including a body that forms an exposure channel through which the particles of the material flow, and an ultrasonic generator including a horn that extends generally in transverse to the direction of the channel; and also comprising a preconditioning portion for feeding the particles into the ultrasonic exposure channel. The present invention also contemplates a method for devulcanizing vulcanized rubber or degraded polymeric material, comprising the steps of preconditioning and feeding the particles of the material, including heating the particles; Feed the particles through a pressured exposure channel; and exposing the particles to ultrasonic energy within the exposure channel with an ultrasonic wave propagated in a direction transverse to the direction of the channel to effect devulcanization by breaking the chemical bonds in the material. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a sectional side view of the apparatus of the present invention for executing the method of the present invention. Fig. 2 is a sectional side view of the preconditioning portion and the ultrasonic exposure portion of the apparatus of Fig. 1 on a larger scale. Fig. 3 is a side sectional view of the postconditioning portion and the ultrasonic exposure portion of the apparatus of Fig. 1 on a larger scale. Fig. 4 is a sectional end view of the postconditioning portion taken along line 4-4 of Fig. 3. Fig. 5 is a sectional end view of the ultrasonic exposure portion taken along the length of the line 5-5 of Fig. 3 Fig. 6 is a sectional side view of the ultrasonic exposure portion taken along line 6-6 of Fig. 5. Fig. 7 is a terminal view in elevation of the ultrasonic exposure portion of Fig. 5, disassembled. Fig. 8 is a plan view of the interior of the body of the ultrasonic exposure portion taken along line 8-8 of Fig. 7.

Fig. 9 is a side elevational view, partly in section, of Fig. 7. Fig. 10 is a sectional side view, similar to Fig. 9, of an alternating horn. DETAILED DESCRIPTION OF THE PREFERRED MODE With reference more particularly to the drawings and initially to FIG. 1, the apparatus of the present invention is shown comprising a devulcanizer extruder assembly 10 having three portions: a preconditioning portion 11, an exposure portion ultrasonic 12, and a postconditioning portion 13. The preconditioning portion 11 comprises a main body 17 at one end of which an elongate cylinder 18 is attached 18. The main body 17 has a central hole in the interior lined with a cylindrical liner 19, forming a feeder chamber 20 inside the liner. A radially extending opening 21 is formed in the upper portion of the main body 17, through which material can be fed into the chamber 20. A hopper 22 is positioned above the opening for controlled delivery of the material to be treated . The cylinder 18 also has a central hole forming a feeder chamber 26. The cylinder 18 is attached to the downstream end of the main body 17 using suitable means (not shown) with the cylinder and the liner 19 in concentric relation to each other, for that the chambers 20 and 26 form a continuous feeding chamber in which a feed thread 27 is located. The feed thread 27 is connected at one end by means of a coupling 28 to a motor shaft 29. The motor shaft 29 is connected , in turn, to the input shaft 30 by means of a gear train (not shown) contained within the enclosed space 32 mounted on a base 32. The input shaft 30 is connected by means of a coupling 33 to the shaft 34 of a suitable electric motor 35. Most of the elements of the preconditioning portion 11 of the apparatus of this invention can be suitably adapted from other elements known and used in the food industry. Entering and extruding material, so it is not necessary to mention them in greater detail here. Feeding thread 27 is typical of threads used in the feeding of material in extrusion processes, and is typically tapered in the upstream direction, so that its root diameter is extended as the downstream material flows, thereby increasing the pressure of the material to be driven through the cylinder 18. The feeder thread 27 includes a typical spiral step 29 (Fig. 2) along its length to assist in the movement of the material. A simple step 39 is shown along most of the length of the feeder thread 27, although more than one step can be used. At the downstream end of the feeder thread 27, a double step 40 is provided to evenly distribute the pressure on the material fed to the exposure portion 12. A plurality of heaters (not shown) are mounted around the cylinder 18 throughout its entire length. length to conduct heat through the cylinder to the material being fed thereto, heating the material to an elevated temperature, preferably to about 300 ° F (166.67 ° C), before reaching the ultrasonic exposure portion 12, so that the Ultrasonic devulcanization process can be effective. Suitable temperature sensors, such as thermocouples 44, are also provided inside the cylinder to measure the heat provided by the heaters, to control the temperature. In addition, suitable pressure transducers (not shown) can be located inside the feeder chambers 20 and 26, preferably at the downstream end, to measure the pressure of the material in the chamber and maintain an appropriate pressure before introducing the material into the chamber. the ultrasonic exposure portion 12, so that the ultrasonic devulcanization process can be carried out effectively. The length of the cylinder 18 is supported by means of an appropriate support 45. The ultrasonic exposure portion 12 comprises a molding or body 49 attached to the outlet end of the cylinder 18 by screws 50 (Fig. 6). The body 49 comprises, preferably, a hollow molded part having a central cylindrical opening which is generally coaxial with the feeder chamber 26 of the cylinder 18. The central opening in the body 49 is provided with a plurality of steps 51 and channels 52 (Figures 7 and 8) which extend spirally on the inner surface of the cylindrical opening. A central mandrel 53 (Fig. 6) rotates inside the central opening. Unlike the stepped feeder thread 27, the mandrel 53 has a smooth outer surface. The steps 51 and the helical channels 52 on the inner surface of the central opening of the body 49, together with the outer surface of the mandrel 53, provide the flow path for the material along the ultrasonic exposure portion 12. The mandrel 53 is attached to the feed thread 27 by means of a threaded joint (not shown), so that the mandrel rotates in conjunction with the feeder thread. As the mandrel 53 is turned inside the central opening of the body 49, the rotation of the mandrel 53 together with the stationary steps 51 causes the material to circulate through the spiral channels 52. This flow is supplemented by the pressure of the material introduced into the body 49 by the action of the feeder thread 27. Subject to the body 49 and extending therefrom in a transverse or radial direction relative to the axis of the flow there is one or more assemblies of ultrasonic generation 58 (Fig. 5). Each ultrasonic generation assembly 58 comprises a transducer 59 connected to a waveguide or horn 60. The transducer 59 preferably includes a piezoelectric or magnetostrictive element vibrating in the ultrasonic frequency range, 'preferably at plus or minus 18 to 22 kHz . The front end 61 of each of the horns 60 extends into a corresponding hole 62 that extends through the body 49 in a radial direction relative to the general axis of flow. There is preferably a very close tolerance between the hole 62 and the horn 60 to effectively occlude the hole. Each assembly 58 is joined by the connection of a mounting flange 63 to the body 49 using a vibration isolator ring 64 and a jaw collar 65 which is fastened to the body 69 by means of screws 66 (Figs 5 and 7). A pin 67 extends through an opening in the flange 63 and enters a corresponding hole in the body 49 towards the position of the horn with respect to the body. A packing or spacer 68 is positioned between the vibration isolating ring 64 and the body surface. The horn 60 is constructed in one piece to properly oscillate and is made of a suitably acoustic material, such as aluminum, magnesium or titanium alloys, having properties for transmitting ultrasonic energy to the material to be treated. The length of the horn 60 depends, of course, on the desired ultrasonic frequency being produced and the material of the construction. The flange on the horn 60 extends radially outwardly from the outer circumference of the horn at one of the nodal points of the vibrating horn to allow the horn to be fixedly mounted and at the same time allow the horn to vibrate at the desired ultrasonic frequency in accordance with the ultrasonic techniques already known. As particularly shown in Fig. 7, the front end 61 of the horn 60 is bent to conform to the inner surface of the channel 52 and the mandrel 53. Due to the temperature of the material before it reaches the exposure portion 12, and the heat generated during the ultrasonic devulcanization process, the horn 60 is internally cooled. For example, as shown in Fig. 9, the horn 60 may be provided with an internal cooling passage 70 that allows circulation of a cooling liquid, such as water, through the horn. The passage 70 is connected to an opening 71 along one side of the horn 60, and suitable supply and discharge hoses (not shown) can be connected to the opening 71. Alternatively, according to Fig. 10, a horn 60a it can be provided with cooling passages 70a, each of which is formed by drilling a conduit at an angle with respect to the axis of the horn. The access to the two passages 70a is provided by the openings 71a, where the passages can be connected to suitable supply and discharge hoses. The cooling of the horn 60 using the passages 70 or 70a not only prevents overheating of the horn, but also provides means for controlling the tolerance between the horn and the hole 62 by means of which the horn is mounted on the body 49. Since the horn 60 is subject to thermal expansion, the effective outside diameter of the horn can be controlled with a narrow tolerance by adjusting the cooling level. In this manner, the tolerance between the horn 60 and the hole 62 can be controlled to very fair tolerances. The number of ultrasonic generation assemblies 58 corresponds to the number of exposure channels 52 provided in the body, so that the material in each channel is exposed to the ultrasonic energy as it passes through the channel. As shown in the preferred embodiment, there are two ultrasonic generation assemblies 58 and two spiral channels 52 formed by the grooves on the inner surface of the central opening of the body 49. Other numbers of ultrasonic generation assemblies and channels are possible.; for example, four ultrasonic generation assemblies spaced at 90 ° around the circumference of the body 49, with four corresponding channels, could be provided. The configuration of the channels and the curved end of the horn associated with the channel is important to effect the devulcanization operation. Preferably, the end 61 of the horn, as shown in Fig. 9, is larger than the amplitude of the groove forming the channel 52 (Fig. 8), so that all the material passing through the channel is exposed to Ultrasonic energy for a certain period of time. In addition, the assembled clearance 73 (Fig. 5) between the face of the horn 61 and the mandrel 53 for each of the assemblies 58 must be minimized so that a relatively thin layer of material is exposed to the ultrasonic energy. Clearance 73 can be adjusted and determined and established using spacers 68 of a variety of thicknesses. For a horn of an aluminum alloy adapted to transmit ultrasonic energy at a frequency of 20 kHz, the horn has a length of 5 inches (12.7 cm) and a diameter of 2.25 inches (5.715 cm), and the grooves that form the 52 channels should not go over 2 inches (5.072 cm) wide per inch (.635 cm) deep. The clearance 73 between the face of the horn 61 and the mandrel 53 can be adjusted by moving the horn radially inwardly or outwardly of the hole 62 in which the horn is mounted in the body 49. To increase the clearance 73, a additional wedge or spacer 68, or a spacing having a different thickness, may be mounted in front of the vibration isolating ring 64 around the flange 63 where the horn 60 is mounted on the body 49. To decrease the clearance 73, the die or spacer 68 can be reduced or eliminated. The presence of the mandrel 53 is important in the process of the present invention because it provides a reflective backing for the ultrasonic waves generated by the horn 60. As the ultrasonic energy is produced by the horn 60, it is transmitted to the material occupying the free space 73 and then it is struck against the outside of the mandrel 53. The mandrel 53 thus provides a bottom that absorbs the energy or reflects the energy back to the material, and in other ways prevents the material from falling apart, nothing else, from the speaker in response to ultrasonic waves. The action between the horn 60 and the mandrel 53 is somewhat similar to a hammer and anvil, the horn being the hammer and the mandrel the anvil. Together, these elements increase the effectiveness of the ultrasonic treatment of the material. Since the horn 60 is cylindrical, the end 61 of the horn adjacent to the channel 52 is circular in cross section. This means that, as shown in Fig. 8, the material traveling through the center of the channel 52 is exposed to the ultrasonic energy for longer than the material traveling along the edges. The front end 61 of the horn is also preferably provided with a round edge on the upstream side to minimize interruptions in material flow while finding the horn, thus lowering the pressure and pre-treating the material. The exposure channels 52 are preferably helical, although straight channels can also be used. The helical channels 52, however, result in a downstream flow component imposed on the material by the rotation of the mandrel 53 to help transport the material through the channel. In addition, the helical design of each channel 52 - creates a shearing stress that causes the hodgepodge or jumble of the material particles as the material flows through the channel.

This hodgepodge of the material traveling through the channel makes the mixture of the material more homogeneous and helps in the exposure of more particles of the material to the ultrasonic energy in the free space 73. It also prevents some of the particles of the material from overheating because of a prolonged exposure to ultrasonic energy. After the exit of the material from the ultrasonic exposure portion 12, it is introduced into the postconditioning portion 13, where it is cooled without being exposed to air. Although the material is at approximately 300 ° F (166.67 ° C) when the ultrasonic exposure portion 12 enters, the ultrasonic energy transmitted to the material, together with the chemical reactions resulting from the breakdown of carbon-sulfur and sulfur-sulfur bonds, significantly increases the temperature of the material, so that the material can reach, for example, about 500 ° F (260 ° C) when leaving the exposure portion 12. If the material is simply collected, when it leaves the exposure portion 12, the elevated Temperature of the material together with exposure of the material to the air could result in significant oxidation or degradation of the material, creating undesirable byproducts. In addition, hot material could cause the release of harmful gases. Accordingly, instead of simply collecting the material after it leaves the exposure portion 12, the present invention provides the postconditioning portion 13, where the material is cooled in an enclosed conduit that prevents exposure to air. In addition, the material is fully combined to provide a homogeneous mixture of the material. As shown in Fig. 3, the postconditioning portion 13, which is connected to the downstream end of the exposure portion 12, comprises a cylindrical assembly 75 attached to the body 49 of the exposure portion. Inside the cylinder 75 there is a feeder thread extension 76 which is connected to the mandrel 53 so that they rotate together. Preferably, the mandrel 53 is formed integrally at the upstream end of the feeder thread extension 76. Because the mandrel 53 is connected to the lament thread 27, the feed thread 27, the mandrel 53 and the extension of the The feeder thread 76 is all interconnected, and rotates together driven by the drive motor 35 through its connection to the feeder thread 27. The cylindrical assembly 75 is formed of an inner sleeve 77 and an outer liner 78 with a plurality of cooling ducts. 79 to cool the cylindrical assembly 75 and thereby cool the material as it circulates through the postconditioning portion 13. Hose connections 80 are provided in the liner 78 by means of which the cylindrical assembly can be connected to a coolant supply. The cylindrical assembly can be provided with suitable temperature and pressure transducers (not shown) for recording and controlling the temperature and pressure of the material after its exit from the exposure portion 12. The cylindrical assembly 57 is supported by a support member 81. As shown in Fig. 4, the configuration of the extension of the feeder thread 76 is different than that of the feeder thread 27. The upstream end of the feeder thread extension 76 comprises round helical lobes 85 instead of steps. The lobes 85 help combine the devulcanized material as it flows through the postconditioning portion 13 so that the material can be cooled better by the inner sleeve 77 of the cylindrical assembly and to obtain a more homogenous mixture of treated material. The downstream end of the feeder thread extension 76 has steps 86 (Fig. 3) which help to transport the treated material out of the cylindrical assembly 75. The feeder thread extension 76 also has an inner conduit 87 (Fig. 4) for the circulation of a coolant liquid. A sealing device, such as an O-ring 88 (Fig. 6) seals the inner fluid conduit 87 of the feeder thread extension 86, the mandrel 53 and the feeder thread 27. The treated material is discharged from the outlet end of the postconditioning portion. 13. A suitable collection container can be placed at the exit to collect the material when it is unloaded. The steps of the extension of the feeder thread 86 have the ability to pressurize the treated material, thus allowing the flow of the material through a matrix (not shown) that can be mounted at the end of the outlet. The matrix would make the material treated in a discrete geometry useful for packaging or further processing. In operation, a measured supply of untreated material is fed by means of the hopper 22. If desired, a supply system, such as a conveyor belt, can be connected to the hopper 22 to provide a measured and continuous supply of material not treated. The material is preferably ground and untreated vulcanized rubber particles that have been classified by particle size and distribution. Such material can be recovered from used tires, but must also be substantially free of fabrics and metals. The material is led from the hopper 22 to the feed chamber 20 of the main body 17, where it is driven by the action of the feed thread in rotation to the preconditioning portion 11 of the apparatus. The feeder thread 27 rotates by means of its connection to the drive motor 35 by means of the gear train located inside the enclosed space 31. Preferably, the feeder thread rotates at a speed of plus or minus 40 r.p.m. As the material flows downstream, it is heated by means of the heaters around the cylinder 18 and the pressure of the material increases as the diameter of the body of the feeder thread 27 increases. When the material reaches the outlet end of the preconditioning portion 11. , the material is heated to a temperature, preferably 300 ° F (166.67 ° C) and is at a pressure of 1,000 psi (6,894.76 kilopascals). The material is supplied from the feeder chamber 26 of the preconditioning portion 11 to one of the exposure channels 52 formed on the inner surface of the central opening in the exposure portion of the body 49. Because the channels 52 are helical, the material continues to be mixed or stirred as it flows through the channel. At the location of the horn 60, the material is exposed to ultrasonic energy, preferably in the range of 18-22 kHz. Ultrasonic energy is provided by the transducer 59 of one of the ultrasonic generation assemblies 58 that vibrates the horn 60. The ultrasonic energy acts to break the chemical bonds, specifically the carbon-sulfur and sulfur-sulfur bonds, in the material of rubber, effectively devulting it. After devulcanization, the material continues to flow through the channel 52 and to the postconditioning portion 13, where it is mixed and cooled by the action of the extension of the feeder thread 76 and the cooled cylindrical t-assembly 75. At the discharge end of the cylindrical assembly, the devulcanized material leaves the apparatus. While the ultrasonic generation assemblies 58 preferably extend radially relative to the flow axis, as shown by the preferred embodiment, they need not be precisely in the radius. There could be a small angle between the radius of the exposure portion of the body 49 and the axis of the horn 60 of the assembly 58. It is important only that the ultrasonic generation assemblies are generally transverse to the material flow direction so that the Horn does not impede the flow of the material. Other variations and modifications of the specific embodiments shown and described herein will become apparent to those skilled in the art., all within the intentional spirit and scope of the invention While the invention has been shown and described with respect to particular embodiments thereof, these are to illustrate and not to limit. Accordingly, the patent should not be limited in scope or effect to the specific embodiments shown and described herein, or in any other manner that is inconsistent with the degree to which the progress of the art has been advanced by the invention.

Claims (12)

1. CLAIMS 1. An apparatus for devulcanizing vulcanized rubber or degraded polymeric material, characterized in that it comprises: an ultrasonic exposure portion including a body forming a plurality of exposure channels through which particles of the material flow, and a plurality of generators ultrasonics each being associated with one of the channels and each including a horn that extends generally transverse to the direction of the channel; a preconditioning portion for feeding the particles in the ultrasonic exposure channel, and a plurality of ultrasonic generators, each being associated with one of the channels.
2. 2. A device for de-vulcanizing vulcanized rubber or degraded polymeric material according to claim 1, characterized in that the channels extend in helical configuration through the body.
3. 3. An apparatus for devulcanizing vulcanized rubber or degraded polymeric material according to claim 1, characterized in that it also comprises a postconditioning portion connected to the ultrasonic exposure portion for receiving the material of the ultrasonic exposure portion.
4. 4. An apparatus for devulcanizing vulcanized rubber or degraded polymeric material characterized in that it comprises: an ultrasonic exposure portion including: a body having an opening through it, a plurality of grooves being formed in the interior part of the opening; a cylindrical mandrel adapted to rotate within the aperture, the outer portion of the mandrel and grooves forming a plurality of helically extending exposure channels through which the material flows, and a plurality of ultrasonic generators, each being associated with one of the channels; and a plurality of ultrasonic generators, each being associated with one of the channels and each including a horn that extends generally transverse to the direction of the associated channel; a preconditioning portion connected to the ultrasonic exposure portion for feeding the particles to the ultrasonic exposure portion.
5. 5. An apparatus for devulcanizing vulcanized rubber or degraded polymeric material according to claim 4, characterized in that the preconditioning portion includes a cylinder with a feed thread that rotates inside the cylinder to feed the particles to the ultrasonic exposure portion.
6. 6. An apparatus for devulcanizing vulcanized rubber or degraded polymeric material according to claim 5, characterized in that the mandrel is connected to the feed thread so that they rotate in conjunction.
7. 7. An apparatus for devulcanizing vulcanized rubber or degraded polymeric material according to claim 4, characterized in that it also comprises a postconditioning potion connected to the ultrasonic exposure portion for receiving the material of the ultrasonic exposure portion.
8. 8. An apparatus for devulcanizing vulcanized rubber or degraded polymeric material according to claim 7, characterized in that the postconditioning portion includes a cylinder and a feeder thread extension adapted to rotate inside the cylinder for transporting the material of the ultrasonic exposure portion. .
9. 9. An apparatus for de-vulcanizing vulcanized rubber or degraded polymeric material according to claim 8, characterized in that the mandrel is connected to the feeder thread to allow them to rotate in conjunction.
10. 10. An apparatus for devulcanizing vulcanized rubber or degraded polymeric material, characterized in that it comprises: an ultrasonic exposure portion including a body having an opening through it, a plurality of grooves being formed in the interior part of the opening; a cylindrical mandrel adapted for rotation within the opening, the outer part of the mandrel and the grooves forming a plurality of helically extending exposure channels through which the material flows; and a plurality of ultrasonic generators, each being associated with one of the channels and each including a horn that extends generally transverse to the direction of the associated channel; a preconditioning portion connected to the ultrasonic exposure portion, the preconditioning portion including a first cylinder having heaters to heat the particles as it passes the first cylinder; and a feeder thread adapted to rotate inside the cylinder to feed the particles in the ultrasonic exposure portion, the feeder thread being connected to the mandrel to allow its rotation in conjunction; and a postconditioning portion connected to the ultrasonic exposure portion for receiving material from the ultrasonic exposure portion, the postconditioning portion including a second cylinder having cooling channels for the circulation of a cooling fluid to cool the material while passing through the second cylinder , and a feeder thread extension adapted to rotate inside the cylinder to convey the material of the ultrasonic exposure portion, the feeder thread extension being connected to allow its rotation in conjunction.
11. 11. A method for the devulcanization of rubber or degraded polymer material, characterized in that it comprises the steps of: preconditioning and feeding the particles of the material, including the heating of the particles; feeding the particles through a plurality of pressurized exposure channels, and exposing the particles to the ultrasonic energy within the exposure channels by means of an ultrasonic wave propagated by one of a plurality of ultrasonic generators, each being associated with one of the channels in a direction transverse to the direction of the channel to effect the devulcanization by means of the breaking of the chemical bonds in the material.
12. 12. - A method for the devulcanization of rubber or degraded polymeric material according to claim 11, characterized in that the particles are fed through a plurality of helical extension exposure channels. EXTRACT OF THE INVENTION An apparatus for the devulcanization of vulcanized rubber or degraded polymeric material has an ultrasonic exposure portion including a body that forms an exposure channel through which particles of the material flow and an ultrasonic generator including an ultrasonic horn that it extends generally transverse to the direction of material flow. The apparatus also has a preconditioning portion for feeding the particles into the ultrasonic exposure channel. The method for the devulcanization of vulcanized rubber or degraded polymeric material comprises the steps of preconditioning and feeding the particles of the material, including the heating of the particles; the feeding of the particles through a pressured exposure channel; and exposing the particles to ultrasonic energy within the exposure channel using an ultrasonic wave propagated in a direction transverse to the direction of the channel to effect devulcanization by breaking the chemical bonds in the material.