Patent Application
20090178914
The present invention relates to a method for activating chemical and/or physical processes hereafter called “chemical-physical processes”, where as energy source ultrasonic waves and microwaves are used at the same time.
Furthermore, the invention relates to an apparatus that carries out this method.
As well known, many chemical and/or physical processes are activated, or in any case enhanced, by high temperature and/or pressure. Therefore, in many cases a mass in a reactor is subject to a energy source that can create these conditions. For increasing temperature, traditionally, a heating apparatus is provided transferring heat to the mass in the reactor by conductivity or convection. For example, devices exist that use ultrasonic waves usually at a frequency set between 20 and 500 kHz to assist the conveying energy processes also through cavitation phenomena. Such apparatus normally provide an electric generator that delivers periodic waves to a transducer comprising a piezoelectric element connected to a vibrating element arranged in a chamber where the reacting mass is present.
More recently a wide diffusion of microwave apparatus has occurred for uses in laboratories and in the industry. In this type of apparatus, a quick variation of an electromagnetic field that penetrates the mass causes its direct heating with a maximum efficiency with respect to the traditional heating methods.
The microwave apparatus provide typically the use of a container, or reactor, of plastic material, or of glass, and in any case of not metallic material, which is arranged to form a closed metal cavity, such as a oven, a resonating cavity or a wave guide for being irradiated by radio waves at high frequency, usually comprised between 109 and 1012 Hz. More in detail, microwaves propagate in the closed metal cavity by reflection on the inner walls. The microwaves are generated by a Magnetron that causes a electronic beam to oscillate at a very high frequency, thus creating the microwaves, or more recently by solid state oscillating devices. These apparatus have relevant advantages with respect to the traditional heat sources. In fact, they are capable of providing an exceptionally quick heating of the mass in the reactor, quickly reaching higher temperatures than in the apparatus conventionally used.
However, the heating technology with use of microwave ovens or metal wave guides has some drawbacks.
Firstly, the reactors used for this type of technology have to be made of a material that is in general transparent to microwaves. The reactors, are usually closed in microwave ovens or in wave guides, i.e. in metal containers, causing problems to the operator because they block a direct visual, manual and instrumental access. Furthermore, it is not possible to use microwaves in case of reactions that take place at high pressures, since metal reactors with high thicknesses required for these reactions cannot be run across by microwaves.
In the last years, furthermore, studies have been carried out for evaluating the possibility of a combined use of microwaves and ultrasonic pulses. However, such studies have shown that relevant problems exist to use at the same time such technologies. In particular, the introduction of ultrasonic transducers consisting of metal sticks in reactors, or wave guides, irradiated with microwaves, generates electromagnetic interference phenomena. On the other hand the use of ultrasonic pulses in the shape of quartz sticks, i.e. transparent to microwaves, in the microwave resonating cavities reduces the efficiency of the process and does not eliminate the above described drawbacks.
It is therefore a first feature of the invention to provide a method for activation of chemical-physical processes by a simultaneous use of microwaves and ultrasonic pulses to increase the efficiency of the processes same.
It is another feature of the invention to provide such a method that is extremely easy, i.e. that can be used in many application fields.
It is also a feature of the invention to provide such a method that is adapted to overcome the difficulties of the prior art.
It is a further feature of the invention to activate chemical-physical processes by a simultaneous use of microwaves and ultrasonic pulses for applying the microwave technology also in the field of reactions that take place in conditions of high pressure.
It is also a feature of the invention to provide such an apparatus that is cheap with respect to apparatus of prior art.
Hereinafter with the term “reaction” a desired type of phenomenon is to be understood that is not exclusively of chemical type, but also of physical type or a combination thereof, and with the expression “reacting mass” a desired type of material subject to this process is to be understood.
These and other features are accomplished with one exemplary method for activation of chemical-physical processes by a simultaneous use of microwaves and ultrasonic pulses comprising the steps of:
whose main feature is that said activation is made by propagating directly in the reacting mass electromagnetic energy and ultrasonic energy, whereby a high efficiency is obtained of the processes same.
In particular, the reacting mass is activated by a simultaneous action, either in phase or out of phase, of a microwave electromagnetic field and of a pressure field operating at ultrasonic frequencies.
Advantageously, before starting the activation step, the reacting mass is previously put in a process chamber.
According to another aspect of the invention, an apparatus for activation of chemical-physical processes by a simultaneous use of microwaves and ultrasonic pulses comprises:
whose main feature is that the means for transmitting the microwaves and the means for transmitting ultrasonic pulses are arranged at direct contact of the reacting mass.
In particular, the apparatus can comprise, furthermore, a process chamber in which the reacting mass is arranged. More in detail, the process chamber can be a reactor for chemical and/or physical applications of the type commonly used in industrial fields or in laboratories. The possibility of putting the means for transmitting the microwaves in the reacting mass and then in the container allows in particular, to make the latter of a metal material. This allows, in particular, to use microwaves also in processes that occur at high pressures and then to increase remarkably the variety of possible applications.
Preferably, the means for transmitting the microwaves comprise at least one microwave antenna, for example of co-axial, type, or in wave guide, arranged at an end of a connector for being operatively connected to the microwave source, and at the other end of a microwave emitter adapted to irradiate onto the reacting mass.
In particular, the end of the antenna at which the transmission of microwaves is carried out can be of the type with dipole, or monopolar type, and have one form selected from the group comprised of:
Preferably, the ultrasonic transmission means comprises at least one ultrasonic wave emitter having elongated shape. This way, it is possible to position the means for transmitting the microwaves and the ultrasonic transmission means very close to each other optimizing the desired synergistic effect.
Advantageously, in operative conditions the means for transmitting the microwaves and the means for transmitting ultrasonic pulses are arranged substantially at right angles.
In particular, the apparatus can comprise, furthermore, means for measuring at least one parameter of process, for example pressure or temperature.
Furthermore, the apparatus can provide also means for mixing the reacting mass, for example a mixer of the type with magnetic bar.
Advantageously, the reaction container can provide a coating layer of a heat-insulating material.
Advantageously, the antenna is coated with a closed sheath of inert material, for example PTFE, glass, ceramic etc., adapted to avoid a direct contact with the reagents.
In particular, means can be provided for modulating the frequency of microwaves and means for modulating ultrasonic frequency to adjust the power transmitted to the reacting mass responsive to the type of process.
The apparatus for activation of chemical and/or physical processes, as above described, increases considerably the control, the speed, the selectivity and the tightness of the processes for which it is employed.
In case of use of high energy power to avoid residual emissions out of the reaction container, a shielding layer opaque to microwaves can be provided, for example, a film, a varnish, or a metal net.
According to a further aspect of the invention the method for activation of chemical-physical processes by a simultaneous use of microwaves and ultrasonic pulses above described can be advantageously used for one of the following applications:
The invention will be now shown with the following description of an exemplary embodiment thereof, exemplifying but not limitative, with reference to the attached drawings wherein:
In
The arranging the microwave antenna 3 and of the ultrasonic transducer 2 in the reacting mass 15 allows to optimize the efficiency of the process through a synergistic effect of the electromagnetic field and of the ultrasonic field.
The process chamber can be a common container for laboratories, for example a sphere with 3 apertures 10a, 10b and 10c (
In case it is necessary to use high power reaction container 10 can be coated with a shielding layer next to the external walls and opaque to microwaves. This prevents propagation of microwaves out of the container avoiding losses and allowing the operators to operate in conditions of extreme safety. The shielding layer can be made for example, by a film, a varnish, or a metal net that reflect microwaves back to the reacting mass 15. For mixing effectively the reacting mass 15, in the reaction container 10 a magnetic bar 16 (
The method, according to the invention, has furthermore, a high versatility and provides very different applications. In particular, the methodology proposed is applicable even with reacting mass 15 not necessarily contained in a container of process 10. For example, as shown in
The foregoing description of a specific embodiment will so fully reveal the invention according to the conceptual point of view, so that others, by applying current knowledge, will be able to modify and/or adapt for various applications such an embodiment without further research and without parting from the invention, and it is therefore to be understood that such adaptations and modifications will have to be considered as equivalent to the specific embodiment. The means and the materials to realise the different functions described herein could have a different nature without, for this reason, departing from the field of the invention. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.
| Number | Date | Country | Kind |
|---|---|---|---|
| PI2006A000018 | Feb 2006 | IT | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/IB2007/000334 | 2/13/2007 | WO | 00 | 11/21/2008 |
