Patent Application
20080035079
These and other advantages and characteristics of the invention will be best understood by anyone skilled in the art from a reading of the following description in conjunction with the attached drawings given as a practical exemplification of the invention, but not to be considered in a limitative sense, wherein:
Reduced to its essential structure and with reference to
Advantageously, the upper base (10) of the depolymerising device (1) is mounted on vertical guides (13) and is connected to an electric motor (14) by means of a pinion and toothed rack (15, 16), to allow the rising and the lowering of the same base, i.e. to allow the introduction of the materials to be treated in the depolymerising device (1) and, successively, the tight closing of the base, which is ensured by a circular seal placed under the aforesaid base (10) and coincides with the upper circular edge of the depolymerising device (1).
In proximity of its lower base (11), the depolymerising device (1) has an opening provided with a valve (17) which constitutes a passage for a burner (18) disposed on a carriage whose function, as best described thereafter, is to start the combustion of the rubber products introduced into depolymerising device.
In said interstice (100) it is also conveyed water, when necessary.
Advantageously, there are three thermal control sensors (81, 91, 31). The first of them (81) is placed in the interstice (100) of the depolymerising device (1) for sensing the air temperature in a lower position in respect to the aforementioned grid (19). The second sensor (91) is placed on the lower or inner surface of the upper base (10) of the depolymerising device (1) and it senses the temperature of the products heap during the depolymerisation. The third sensor (31) is placed in the pipe (3) which connects the depolymerising device (1) to the phases separator (2) to sense the temperature of the fluid which transits in the latter.
The phases separator (2) is made, as previously described, by a substantially cylindrical body with an upper base (20) and a lower base (21), delimiting, in such a way, a corresponding chamber (25). On a side of the chamber (25) a septum or wall (26) is placed, so as to delimit a second chamber (27) which is closed on the upper side and open in the lower side. Said second chamber (27) houses a vertical pipe (28) having an end in correspondence of the aforesaid opening (24) of the lower base (21) of the body (2): the other end of the pipe (28) being at a predetermined distance from the lower opening of the wall (26). In such a way, the pipe (28) is connected with the unit (4) by the pipe (6). Under said opening (23) provided by the separator (2), a container (29) is placed, in which the liquid exiting from the separator is conveyed by a correspondent pipe (290). Said container (29) has a lower opening (293) connected with a pump (291) which reintroduces in the chamber (25) the liquid which is discharged from the same, by means of one or more injectors or atomizers (292) disposed at a predetermined distance from the upper base (20) of the body (2). The connection between said opening (293) of the container (29) and said pump (291) is made by means of a pipe (295) and the connection between the pump (291) and the injectors (292) is made by means of a further pipe (296) whose final portion is inside the chamber (25) and passes through the upper base (20) of the body (2). Moreover, said container (29) exhibits an upper opening (294) for draining the liquid which is not re-circulated by the pump (291) and which, in practice, constitutes the liquid phase hydrocarbons production of the moment. The length of said pipe (290) is related to the prevalence of the unit (4) and is determined in such a manner that the latter does not allow aspiration of air through the upper opening (294) of the container (29). For example, if the prevalence of the unit (4) is 150 mm water column, the distance between the lower end of the pipe (290) and the opening for draining (294) of the container (29) must be higher than 150 mm.
Said unit (4) provides either for the aspiration of the products in the mostly gaseous phase from the pipe (28) inside the body (2) and for their compression before the introduction into the burner (5). Both the unit (4) and the burner (5) are of the known type and, consequently, they are not further described.
The operation of the plant described above is as follows.
Once introduced the tires and other rubber products to be treated and calcium oxide in the depolymerising device (1), and after having closed the upper base (10) of the latter, the burner (18) is disposed inside the depolymerising device by means of the respective carriage (180). Then the burner (18) is activated for a predetermined time (for example, a programmable time between 5 and 10 minutes) so as to start the combustion of tires. Then, the burner (18) is de-activated and disposed out of the depolymerising device (1) and the combustion continues in an autonomous way, thanks to the air passing through the valve (Y) provided under the interstice (100), through the interstice (100) and the openings (X) placed on the base horizontal grid (19). During these operations, the valve (Y) is always open. The thermal process which is carried out inside the depolymerising device (1), wherein the working temperature is about between 100° C. and 135° C. and the pressure is up to 10 mBar lower than the atmospheric pressure, consists of a depolymerisation of the rubber of the products introduced into depolymerising device, with formation of a bi-phases mixture comprising combustible micro-particles deriving from the depolymerisation. The fluid which, thanks to the depression ensured by the unit (4) disposed downstream, arrives at the phases separator (2) is subject, within the latter, to a physical separation of at least a part of the liquid phase from the gas phase. In detail, when the fluid enters the separator (2) through the opening (22), it is subject to cooling, a condensation phenomenon takes place, and the thus formed liquid directs towards the bottom (21) of the body (2) and, from there, through the pipe (290), it arrives at the container (29); meanwhile, the mostly gaseous phase is aspired through the pipe (28) and the pipe (6) to be compressed and sent to the burner (5). The liquid aspired by the pump (291) and pulverized by the injectors (292) in the chamber (25) involves the aforementioned condensation, since the particles of the liquid phase tend to aggregate around the particles exiting from the injectors. The liquid drawn from the container (29) is a combustible substance, storable in tanks, cans and any other suited container in which it can be decanted, and has the physicochemical characteristics shown in the table 1 which follows, as resulting from analyses carried out on a sample taken at the end of a cycle.
The gases exiting the burner (5) exhibit the characteristics indicated in the table 2 which follows, resulting from analyses especially carried out (Methods of test: according to DM 25 Aug. 2000-Unichim No. 494-UNI 10493-Handbooks Unichim No. 122, 158).
Tests carried out with an experimental plant made it possible to check a production of combustible liquid ranging between 35 and 40% of the weight of tires (about 350-400 kg of liquid each 1000 kg of tires introduced and treated into the depolymerising device 1). The combustible liquid thus product can be advantageously used also to feed an ordinary diesel engine, even mixed with diesel oil.
The calcium oxide (introduced into the depolymerising device 1 in a quantity ranging between 1% and 3% in weight of the products to be treated) with the steam which develops from depolymerisation and with the steam introduced as described below, determines the formation of calcium hydroxide which, while binding to chlorine and sulphur released by the waste material during depolymerisation, comprises inert salts which deposit with the metal residues on the bottom of the depolymerising device. Thus, introduction of acid substances into the environment is avoided. The residues are basically made up by the metallic materials which constitute the armours or metal structures of the products to be depolymerised, having a melting point higher than the working temperature of the depolymerising device (1). These residues, which contain carbon, steel or other metals, can be directly destined to foundries or, alternatively, can be selected for separating the various metal components from the non-metal ones, in which carbon is prevailing, and separately used.
When the temperature sensed by the sensor (81) exceeds 50° C., water is introduced into said interstice (100) through a corresponding valve, not visible into the annexed drawings. The quantity of water introduced into the interstice (100) raises when the temperature sensed by the sensor (81) increases.
When the temperatures sensed by the sensors (91) and (31) are higher than 135° C. and, respectively, than 200° C., there is a lower gas demand from the burner (5) or, in reference to the plant schematically represented in
With reference to the diagram of
With reference to the diagram of
In both cases, as illustrated in detail in
The starting and the coordination of the components of the described installation are automatically controllable with programmable electronic means. Such programmable means are of known type by the technicians of industrial automation and, therefore, are not described more in detail.
With reference to the diagram of
Analyses expressly carried out on gas at the outlet of the filter (90) made it possible to check the characteristics described in the table 3 which follows.
The filtered gas introduced with the air into the diesel engine contributes, relating to the working conditions of the latter, for 5-20% of the energy necessary to the operation of the engine, the remaining part of energy being provided by the decanted liquid produced by the same plant and mixed with diesel oil. Experimental tests were carried out by means of a Ford 80 HP aspired diesel engine coupled to a 30 KVA three-phase asynchronous electric motor connected to a balanced resistive load.
Table 4 shows the results of four tests. In each test it was measured the power provided by the engine supplied with the air and decanted oil mixed with ⅕ in volume of diesel oil. Successively, without varying the flow rate of the mix liquid/diesel oil, the filtered gas was sent to the aspiration of the air of the engine, by measuring the flow rate of gas, and thus the thermal power relating to the gas, and the new values of electric output. In each test thus carried out the positive contribution of gas to the output of the thermodynamic transformation is resulted equal to almost the 20%.
In table 4 the symbols used in the first column have the following meanings:
The lower heating power of gas obtained by depolymerisation of tires only we has been considered equal to 695 Kcal/Nm3, equivalent to 808 Wh/Nm3.
The process for the production of combustible substances in accordance with the present invention comprises, as previously described, a phase of depolymerisation of rubber products like worn tires and the like, with production of a two-phases fluid mixture, and involves separating and collecting at least a part of the liquid phase of said mixture. Both the depolymerisation and the separation of the phases are realizable under depressurized conditions. The mostly gaseous phase is usable to supply a burner, to be introduced, with the combustive air, in a diesel engine or in any other manner. In practice, the execution details may vary as regards the shape, the size, the arrangement of the elements, the kind of material used, but they are within the limits of the solution adopted and within the limits of the protection offered by the present patent.
| Number | Date | Country | Kind |
|---|---|---|---|
| FI2004A000127 | Jun 2004 | IT | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/IT05/00309 | 5/31/2005 | WO | 00 | 11/22/2006 |
