Technical Field The invention concerns thermal decomposition of rubber and/or plastic and solves ecological processing of waste containing rubber and/or plastic and their transformation to again usable raw materials.

Description of Prior Art

It is known that it is possible to extract from wastes containing rubber and/or plastic by heat effect substances, that can be reused. This is carried out in the environment separated from surrounding atmosphere by reason of ecological load reduction.

From document CZ PV 2002 - 3467 and from CZ 12817 U it is known the device for processing of matters on rubber basis. This processing is carried out in the rotary reactor having shape of horizontally oriented cylinder, in rotation axis of which a tube for drawing off reaction products is located. The tube passes through the whole cylinder and is provided with holes in the cylinder interior. In the course of thermal decomposition of the charge, the cylinder rotating on its own axis, in the process the wall forming a casing of cylinder is heated from the outside. Decomposition products are drawn off into the combustion chamber. Disadvantage of this device is that the decomposition temperature can easily exceed 600 ⁰ C, namely not only locally, but also in the whole volume. Therefore, there arise products, which cannot be liquefied under standard conditions, and so the pyrolysis product suits only for combustion. Another device, in which not liquefiable gases arise under standard condition, is known from document CZ 17103 U. The device for ecological rubber waste disposal is concerned in this document. Device is formed with a chamber, around which rooms for heat sources are made. The chamber is provided with outflows of liquid and gas outlets, which run into condensing plants regulating ratio of liquid and gas substances. It results from the description that common thermal decomposition retort is concerned. At this retort neither circulation of gases forming internal atmosphere, nor mixing of charge occurs. Its disadvantage is therefore unequal heating of the charge, at which there can easily occur local overheating and formation of products, which cannot be in liquid state under standard conditions. Such device must be followed by technology for processing of arisen gases and that is why cannot be mobile. From documents CZ PV 2001-3791, CZ 18799 U and CA 2584557 there are known technologies, where liquefiable components of products arisen by thermal decomposition of rubber or plastic are burnt. From document CZ PV 2001-3791 the device for catalytic transformation of polyolefinic wastes to hydrocarbon products is known. The reaction zone equipped with a stirrer is partially surrounded with a combustion chamber and combustion gases leave the combustion chamber through heating tubes, which pass through the reaction zone. Reaction products are drawn off outside the reaction zone, where they are cooled, whereas the condensed liquid is drawn off into an expansion tank heated to 40 ⁰ C, and residual gases are delivered into the combustion chamber. Disadvantage of this technique is that processed material must be crushed in advance, as unequal heating of greater pieces results to unwanted prolongation of processing time. The next disadvantage is unequal heating. In document CZ 18799 U the device for continual ecological rubber waste disposal is described. This device contains a swinging heated chamber provided with a hole for charge insertion and with a hole for removal of indecomposable residue. Due to swinging motion of the chamber, the charge stepwise moves from chamber inlet side to chamber outlet side, whereas it undergoes to thermal decomposition. Released pyrolytic gases are drawn off outside the chamber, where they are separated to gas fraction, liquid fraction and solid impurities after cooling-down. The gas fraction is burnt in the course of chamber heating. Disadvantage of this device is that the processed rubber waste must be crushed in advance. This increases costs in particular when used tires are processed. In the document CA 2584557 a device for thermal decomposition of rubber waste containing an exchangeable reaction chamber provided with heating elements and an off-take tube is described, with which arisen pyrolytic gases are drawn off into a condenser. In the condenser cooling down of pyrolytic gases and liquefaction of liquefiable fraction occur. The gas fraction is drawn off into the combustion equipment, while the liquid fraction is conducted into the reservoir. Part of the liquid fraction from the reservoir is injected at high speed into flow of pyrolytic gases yet before the inlet into the condenser. Disadvantage of this device is that the reaction chamber is equipped with no device assuring equal temperature of the charge so that there also arises gas fraction formed with substances, which are not in liquid or solid state under standard conditions. These matters are drawn off for combustion; therefore this device cannot be mobile. From documents EP 1 785 248 and CZ 17601 U there are known technologies, at which the not liquefiable phase of pyrolytic gases is in the first cooling phase led back to the reaction zone. In the case of EP 1 785 248 processing of used tires is concerned. The charge formed with crushed tires is subjected to temperature 550-800 °C, namely in reduction gas atmosphere, whereat the liquefiable fraction is separated from released gases. A part of the gas fraction is burnt and the rest is after preheating inducted back into reactor. Here it acts as a heat source for further thermal decomposition. Disadvantage of this technology is that there occurs not only releasing of substances, which are not liquid under standard conditions, but also gas arises, whereas a part of gas, which was cooled down in the course of condensation of liquefiable fraction, must be reheated before entering the reaction zone. In the document CZ 17601 U is described the device for separation of pyrolytic oil for processing of waste rubber. This device comprises the reaction chamber, in which the charge is inserting. Inside the reaction chamber there are elements for heating. Furthermore, the reaction chamber is provided with outlet for off-take of pyrolytic gases outside the reaction chamber, where the pyrolytic gases are cooled down, whereas condensation of liquid fraction occurs. The non-condensed gas fraction is forced back into the reaction chamber, while the liquid fraction is collected in the receiving tank. Disadvantage of this device is that the not liquefied gases forced into the pyrolytic chamber are cool. They uselessly cool down both, the chamber and the charge. Heat delivered for pyrolysis ensuring is then uselessly extracted by condensation of liquefiable substances.

There are known technologies assuring that the determined temperature will be not locally exceeded. At these technologies it is possible to assure that no substances, which could not be transferred into liquid and solid state under standard conditions arise. For example, from EP 1 664 240 there are known the method and the device for continual conversion of organic waste, in particular of contaminated waste of plastic and used tires, at which the charge is continuously led into molten mass of inorganic substances, e.g. into the molten mix of tin, lead and bismuth or into the mix of inorganic salts or metal hydroxides comprising metals of the I-st and the II-nd group of the periodic classification of elements, whereas gas products are collected above the bath. Disadvantage of this technology is that inorganic salts forming the molten bath represents, after depletion of the bath, a waste, which is technologically difficult to treat. If the hot bath is made of melt metals, this bath is very expensive in case that the device should have higher capacity. Furthermore, operation of such bath, if it contains lead, endangers health of operating staff. The device is thanks to mechanical forcing of the charge under hot bath surface very complicated, and therefore it is also maintenance-intensive.

Disclosure of Invention The method and device for thermal decomposition of rubber and/or plastic according to the invention solve the stated disadvantages.

The base of method is that the charge containing rubber and/or plastic is inserted into the reaction zone, which is a part of the working area, the working area is separated from ambient atmosphere and the charge is subjected to temperature in the range of 100 up to 600 ⁰ C. Through temperature effect there occurs releasing of pyrolytic gases, which are drawn off from the working area. However, at least a part of gases located in the working area circulates, whereas it is repeatedly directed to the vicinity of heat source, where it is heated to temperature at most 600 ⁰ C, and flow of these gases is led in direction to the charge or under its surface and gases drawn off from the reaction zone are subsequently cooled down up to at least partial liquefaction. After finishing of thermal decomposition of the charge, the reaction zone is advantageously cooled down, at best with air from ambient atmosphere, which is delivered into the area between the reaction zone and thermal-insulating layer, with which the reaction zone is at least partially surrounded. The reaction zone can be also cooled down with gas delivered into the reaction zone. In the finishing phase of thermal decomposition of the charge it is advantageous into the reaction zone to induct a part of pyrolytic gases, which is not liquefied through cooling down. The base of the device is that it consists of the working chamber, the walls of which are at least partially provided with thermal-insulating material. The working chamber is provided with at least one outlet of pyrolytic gases and at least one lockable hole. In the working chamber there is located the reaction zone for placing of the charge containing rubber and/or plastic and heating elements, which at least partially surround the reaction zone. Inside the working chamber there is located the fan for assuring of circulation of at least a part of gases located in the working chamber, and at least one slat for flow directing of gases. At least one outlet of the working chamber is connected with the inlet of at least one first cooler, which is provided with the outlet of the first cooler for first liquid fraction and with the gas fraction outlet, whereas the gas fraction outlet is connected with the inlet of at least one second cooler, which is provided with the first outlet of the second cooler for second liquid fraction and at least one second outlet of the second cooler for not liquefied residue. Alternatively there can be further located inside the working chamber the cooling zone, provided with cooling medium inlet and the cooling medium outlet. The second cooling zone is alternatively located from inner side of the cover for closing of the lockable hole. For processing of piece or meltable waste, at least one tank for placing of the charge in the reaction zone is alternatively a part of the device. Alternatively the slats can at least partially surround the reaction zone. From inner side of the cover for closing the lockable hole the second cooling zone can be alternatively located. Alternatively is working chamber is further provided with inlet of gas, which is connected with the second outlet of the second cooler for not liquefied residue, whereas with advantage there are located the auxiliary cooler and/or the desludger between the second outlet of the second cooler for not liquefied residue and the inlet of gas into the working chamber. According to the next alternative, the second outlet of the second cooler for not liquefied residue can be connected with the inlet of the suction pump, the outlet of which is connected with the cogeneration unit and/or with the tank of not liquefied residue, whereas with advantage there are located the auxiliary cooler and or desludger between the second outlet of the second cooler for not liquefied residue and the inlet of the suction pump. According to further alternatives the first outlet of the second cooler for the second part of liquid fraction can be inducted under the level of the second liquid fraction, which is located in the sedimentation tank, which is advantageously connected through the overflow with the reservoir of the second part of the liquid fraction, and the outlet of the first cooler for the first part of liquid fraction can be inducted under the level of the first liquid fraction part, which is located in the settler. Alternatively, it is also advantageous, if the inlet of the cooling zone is connected to the outlet of cooling unit, namely advantageously through the first fan.

Advantage of thermal decomposition of rubber and/or plastic according to this invention is that the charge is equally heated so that there occurs no local overheating, which could result in releasing of such substances, which could not be subsequently liquefied and would have to be ecologically disposed, for example with combustion. Advantage of reaction zone cooling is quick termination of thermal decomposition, which enables opening of device interior without releasing of undesirable substances into atmosphere. If the reaction zone is cooled by air, which cannot mix with gases located in the reaction zone, no its contamination occurs and it can be released back into ambient atmosphere. Thanks decreasing of cooling time, increasing of the capacity of the device occurs. Advantage of inducting of not yet liquefied gases, which are mixed with air closed in the device after insertion of the charge to the pyrolytic gases, drawn off from the reaction zone, is its cooling down yet before their cooling down in the cooler. As not yet liquefied components of pyrolytic gases in the device circulate, they can pass through the cooler several times. That is why capacity and price of the cooler are lower, than it could be in the case, that all liquefacient substances from pyrolytic gases should be liquefied by one pass through the cooler. It is also advantageous if the not liquefied fraction is inducted into the reaction zone in the course of its cooling down, because circulation of these gases through the cooler and so indirectly cooling down of the reaction zone by the cooler is enabled. Description of the Drawings

Figures 1, 2, 5, and 6 in enclosed drawings refer to exemplary embodiment according to the example 1, whereas Figure 5 shows a diagram of the whole device in phase of thermal decomposition of the charge, and Figure 6 shows a diagram of the whole device in cooling phase. Figures 1 and 2 represent in more detail this part of embodiment according to the example 1, in which thermal decomposition of the charge is carried out, whereas Figure 1 shows the section B - B from Figure 2, but with the inserted charge, and Figure 2 shows the section A - A from Figure 1, but without the charge. Figures 3 and 4 are equivalents of Figures 1 and 2 according to the example 2, whereas Figure 3 shows the section D - D from Figure 4, but with the inserted charge, and Figure 4 shows the section C - C from Figure 3, but without the charge. Examples of an Embodiment Example 1 The device according to the example 1 is intended for thermal decomposition of rubber from used tires, which are processed without any previous treatment and which form the charge 9. The device consists of the working chamber I ₃ the walls 2 of which are provided with the thermal-insulating material 21. The working chamber I is provided with the first outlet JJ _. of pyrolytic gasses, the second outlet 15 of pyrolytic gases and with the lockable hole J2, which serves for filling the working chamber I with the charge 9 and for removal of not gasifiable residues. The lockable hole 12 is closed in the course of thermal decomposition of the charge 9 with the cover 121. In the working chamber I there are located the reaction zone 3 for placing the charge 9, heating elements 4, at least partially surrounding the reaction zone 3, the fan 5_ for assuring of circulation of gases, which have not been drawn off through the outlets H, 15 of pyrolytic gases until now and which are located in the working chamber 1, and the slats 6 for flow directing of circulating gases, which also surround the reaction zone 3. The slats 6 are horizontally oriented and are fitted on the supporting structure 61. The fan 5 is located above the reaction zone 3, is rotating on vertically oriented axis and is connected with the motor 5JL of fan located outside the working chamber 1. Inside of the working chamber 1 there is also located the cooling zone 7, provided with the cooling medium inlet H and the cooling medium outlet 14. This cooling zone 7 is delimited with the partition wall JO located in the working chamber 1 and the walls 2 of the working chamber 1. Furthermore, in the reaction zone 3 there are located supports 9J. for placing of tires, forming the charge 9. The working chamber 1 is also provided with the inlet J6 of gas, through which cold gas is delivered in cooling phase, advantageously not yet liquefied residue of pyrolytic gases. The outlets H, 15 of pyrolytic gases from the working chamber 1 are connected with the inlet 73 of the first cooler 79, which is provided with the outlet 72 of the first cooler 79 for first part of liquid fraction and the gas fraction outlet 77. The gas fraction outlet 77 is connected with the inlet 24 of the second cooler 29. The second cooler 29 is provided with the first outlet 23 of the second cooler 29 for second part of liquid fraction and the second outlet 22 of second cooler 29 for not liquefied residue. The second outlet 22 of second cooler 29 for not liquefied residue is connected through the auxiliary cooler 42, through the first valve 421 and through the second fan 161 with the inlet 16 of gas into the working chamber I. The outlet of the auxiliary cooler 42 is also connected with the inlet 311 of the suction pump H, namely through the second valve 422. The outlet 312 of the suction pump 31 is connected with the cogeneration unit 4L Instead of the cogeneration unit 41 there can be alternatively also to the outlet 312 of the suction pump 3_1 connected the reservoir for gas storage or the distribution pipeline to other gas appliances, in this case to appliances of not liquefied residue of pyrolytic gases. The first outlet 23 of the second cooler 29 for second part of liquid fraction is inducted under level of the second part of liquid fraction, which is located in the sedimentation tank 52. The sedimentation tank 52 is connected via the overflow 5_3 with the reservoir 62 of the second part of liquid fraction. The outlet 72 of the first cooler 79 for the first part liquid fraction is inducted under level of the first liquid fraction, which is located in the settler 82. For the purpose of assuring of sufficient level in the first part of the settler 82, the settler 82 is divided with the partition wall 83 of the settler 82 into two parts. The second part of the settler 82 is provided with the outlet hole 84- For the purpose of maintenance of the first part of liquid fraction in sufficient liquid state, the settler 82 is in contact with the heating element 8L The inlet H of the cooling zone 7 is connected through the third fan 132 to the outlet of the cooling unit 100. In the pipeline interconnecting the outlets H, 15 _. of pyrolytic gases with the inlet 73 of the first cooler 79 the first sensor 191 for monitoring of temperature and composition of pyrolytic gases is located. In the pipeline between the second outlet 22 of the second cooler 29 for not liquefied residue and the inlet of the auxiliary cooler 42 the third sensor 193 for monitoring of temperature and chemical composition of gases is located, and in the reaction zone 3 of the working chamber I the second sensor 192 for temperature monitoring is located. All sensors 191. 192. 193. same as the fans 132, 161 and the valves 421, 422 are connected to a not shown control unit.

Method in accordance with the invention is carried out according to this example as follows. Used tires forming the charge 9 are put on the supports £1 for pacing tires, which are located in the reaction zone 3, which is a part of the working are. Afterwards, the working chamber 1 is closed with the cover 121, wherewith the working area is separated from ambient atmosphere. The working room, inclusive of the reaction zone, is stepwise heated with the heating elements 4. Starting with temperature 100 °C, rubber contained in tires begins to decompose. With the help of the fan 5, flow of a part of released gases is inducted by means of the slats 6 to the vicinity of heating elements, where heating of these gases to maximum temperature 600 ⁰ C occurs. Flow of heated gases is directed through the slats 6 towards tires. Gases drawn off from the reaction zone are subsequently cooled down in two phases, namely in the first phase to temperature in the range of 80 up to 100 ⁰ C, namely at formation of the first part of liquid fraction and in the second phase to temperature about 20 ⁰ C at formation of the second part of liquid fraction. Not liquefied residue is sucked off, in the course of pyrolysis, from the second outlet 22 of second cooler 29 for not liquefied residue by means of the suction pump 31. Capacity of the suction pump H is controlled on the basis of pressures, picked up with the first sensor 191 and the third sensor 193. whereas slight overpressure against ambient pressure is maintained in the working chamber. Power input of the heating elements 4 is controlled on the basis of temperature picked up with the second sensor 192 for temperature monitoring. Procedure of pyrolysis is monitored on the basis of chemical composition of pyrolytic gases with the first sensor 191 for monitoring of temperature and composition of pyrolytic gases. The first part of liquid fraction obtained in the first cooler 79 is collected in the settler 82, which is maintained at the temperature above 80 ⁰ C to prevent unwanted solidification of the first part of liquid fraction. The second part of liquid fraction, obtained in the second cooler 29 _^ is collected in the sedimentation tank 52 and at its topping it overflows into the reservoir 62. Not liquefied residue is sucked off from the second outlet 22 of second cooler 29 for not liquefied residue by means of the suction pump 31 and is inducted into the cogeneration unit 4J _. for further processing. For process finishing the heating elements 4 are turned off, and the interior of the working chamber 1, inclusive of the reaction zone 1 containing not gasified tire residues, is cooled down through air delivery from ambient atmosphere into the cooling zone 7, which is located between the reaction zone 2 and the thermal-insulating layer 2J_. Cooling air is not mixed with gases located inside of the working chamber 1. Interior of the working chamber 1 is further cooled down through not liquefied gases delivered with the second fan 161 from the second outlet 22 of second cooler 29 for not gasified residue through the auxiliary cooler 42 with desludger into the gas inlet 16 to the working chamber 1. So extraction of further heat from the reaction zone occurs. After sufficient cooling down of interior and complete condensation of substances, which are released from the charge, the chamber I is opened and not gasifiable residues are removed. The device is herewith ready for further usage.

Example 2

The device according to the example 2 is intended for thermal decomposition of piece rubber and piece plastic. Plastics, which melt by heat effect can be used. This device differs from the device described in the example 1 in that there are not, located in interior of the working chamber I _x any supports 91 for pacing tires, on which the used tires could be placed, but the tanks 8 with piece charge 9 are located in the reaction zone 3. The tanks 8 have a form of from above opened bathes, which are located above each other so that hot gases could be delivered to the vicinity of the charge 9, which is located in them. The device according to the example 2 further differs from the device described in the example 1 in that the cover 121 is thermal- insulating and contains between its walls the cooling zone H of cover 121. which is located at inner wall of the cover Y2Λ. The cover ΩΛ is provided with the cooling medium inlet 1.31 to the cover 121 and the cooling medium outlet 141 from cover 121, which runs into the cooling zone Zl of over 121. On the device according to the example 1 there is applied the same method, which was described in the example 1, but the difference is that the charge of plastic materials further contains matters facilitating depolymerization of plastic materials. Industrial Applicability

The invention can be utilized for thermal decomposition both, solid and meltable matters, namely also in case that such thermal decomposition is to be enabled or be conditioned with presence of catalytic agents or if it is to be induced through chemical reactions with other substances added to the charge.