The invention treated in the present patent's claim refer to an oven and a wood coal process which uses apparatus that generates electromagnetic waves, microwaves, as source of thermic energy to do wood's tiring and carbonization tiring, following by cooling, getting, at the end, vegetable coal.

Normally, the conventional coal processes use ovens constructed in masonry, with massive bricks, or metallic materials with varied shapes and sizes. These processes are developed in productive cycles of 10 (ten) to 15 (fifteen) days, varying according to the coal volume to be produced and the oven's size. The coal's productive process is composed basically by 3 (three) distinct phases. The first consist in the wood tire; the second, in the carbonization ; and the last, in the coal's cooling.

The conventional processes of making coal occur by the energy supplying inside the oven, raising its internal temperature and unleashing a process of water release and volatilization of the holocelulose and lignin molecules. To the temperature around 270°C, this process physique- chemical is endothermic, demands energy supply and, in higher temperatures, exothermic, where the energy is generated by carbonization reactions, becoming a self-supportive process.

The physique-chemical transformations resultant of the making coal process originate five kinds of products: a) gases incondensable composed by: carbon, methane and hydrogen monoxide and dioxide; b) pyroxyle acid which is condensable and contains more than 80 % of water, and the rest can be identified as acetic formic and prop ionic acid, methanol, formaldeid, acetone and soluble tar or B tar (solved in acetic acid); c) insoluble tar or A tar, also condensable and which is a complex mixture of

substances; d) firebrand-semi-carbonized wood with high text of volatile materials and; e) vegetable coal.

The making coal in conventional processes, as what occur in masonry ovens, claim that part of the wood, approximately 13 % of the mass put in the oven, be burned to supplying the energy process. The ignition is made with the help of burning coals and firebrands put through the air entrance control. The hot gases generated by combustion go up by difference of density, generating flux which crosses the rest of the wood and transfers heat to the bedstead. After the tiring phase, the wood degrades itself thermically originating the coal. The carbonization cycle, in these ovens, last around 3 (three) to 5 (five) days, varying according to the humidity and size of the wood blocks, the weather, the ovens'maintenance and internal temperature.

The cooling phase will occur after the carbonization cycle and can be accomplished in a natural or forced way. For the natural cooling, all the holes must be hinder with clay, waiting for the oven active the right temperature for the discharge, which is between 60 and 80°C. This kind of cooling can last between 7 (seven) and 10 (ten) days, depending on the ovens dimensions. Meanwhile, for the forced cooling, the waiting time is from 5 (five) to 7 (seven) days, and is accomplished by injection of 10 (ten) thousand liters of pulverized water in the oven. This water volume is injected by four stages and represents a waste of, approximately, 200 (two hundred) liters of water per cubic miter of produced coal.

The making coal conventional process is morose and little productive, since the complete cycle, from the wood tiring to the coal cooling, last around 10 (ten) to 15 (fifteen) days, generating prejudices for the environment, like the excessive waste of water in the forced cooling

process and the difficulty to control the toxic residues emission at the atmosphere.

Some experiments of substitution of the making coal conventional process by other more economic, less polluter and quicker were developed from scientific studies which pointed to malefic effects of the making coal conventional processes to the environment. Examples of this trial are some patent's claims pertinent to this subject, deposited at the Brazilian Industrial Property National Institute: PI 9100071 from January, the forth, 1991, PI 9905567 from December, the first, 1999 and PI 0005493 from November, 21, 2000.

The present patent's claim proposes the construction of a making coal's oven which substitutes the conventional thermic springs used for other originated from microwaves, where the heat is generated by the waves action in the particles component of the wood, provoking intense molecular vibration. From the tiring and carbonization process in the oven to making coal by microwaves, follow the cleaning and gases treatment for posterior utilization at the cooling phase of the product obtained with the wood tiring and carbonization, which is, vegetable coal.

The microwaves are a kind of radiant energy and, like the radio waves, the visible light, the infrared and the electricity, are a part of the electromagnetic specter, what means, they are a form of"plectromagnetic radiation". They are classified as"unionizing radiations", since, differently of the X-rays and the Alfa, Beta and Gamma rays, their effects are rigorously thermic and, therefore, don't moillfy the molecular structure of the item which is being irradiated.

The present invention makes possible a making coal process less polluter, quick and economic. The process achieves the wood's tiring and carbonization in the two initial phases and at the end, accelerates the cooling of the coal produced using part of the gases produced at the anterior phases.

From a microwaves metallic oven (Fig. 01) constructed with thermic isolation and hermetically closed (1) when functioning, begin the making coal process by microwaves. This oven is feed by microwaves from termionic valve (3), magnetrons, installed at its exterior. The wood to be carbonized (4) is packed in a gyratory dielectric compartment, a species of "dielectric cage" (2) which turns slowly around its own axle to allow that all the packed wood gets the same quantity of energy from the electromagnetic waves field, since the microwaves springs are fixed. The gyratory dielectric compartment, "dielectric cage" (2), is a n arming constructed in material that presents the characteristic of being insensitive to the microwaves effects and doesn't conduct electric chain (dielectric).

The oven is hermetically closed (1) to avoid the microwaves leakage and the air entrance (oxygen) during the wood's process, to avoid the combustion. The making coal microwaves ovens can be constructed in various forms and sizes, adjusting to the wanted process's needs.

The wood to be processed in the microwaves making coal oven is introduced into it by a door which opens for wood's loading and coal discharge. As much the loading as the discharge can be made automatically. After the"dielectric cage" (2) loading, the oven's door is closed, the oxygen is taken off by suction bombs and begins the making coal process with the magnetrons energization.

The microwaves making coal process (Fig. 2), like the conventional processes, generally accomplished in masonry ovens, completes in three phases. In the first phase, the wood's tiring is made, follow the second phase with the carbonization and, at the end, the last phase, moment when occur the produced coal's accelerated cooling, using the cleaned, treated and cooled gases, produced in the anterior phases. All the process is monitored and executed by a temperature controlling apparatus (12) which maintain under control the temperature and pressure during the two first phases processing.

The gases produced during the two initial phases are conducted to cleaning and treatment system which begins in a gases cleaning chamber (5) where all the water soluble substances are taken off for loading in a tank (6). A reservoir (7) constantly stored with water as soon as it is saturated. The gases, after the cleaning (5), go to the cooling system where the heat exchanging (8) and a cooling condenser of the exchanging cooling liquid (9), store and cool the gases. The gas exceed is filtered, according to the valid legislation's exigencies, and liberated to the atmosphere by a chimney (10).

The carbonization phase is finished because of the results proceeding from a gases analyzer apparatus (14) located at the cleaning system exit (5).

The last phase, coal cooling, can be started.

The coal cooling at the microwaves making coal oven, last phase of the process implemented by the invention, is done through the opening of the gas injection valve (13) stored at the cooling system (8 and 9). The cooled gases application reduces the time duration in this phase of the process, besides it's perfectly safe, there's no risk of explosion or fire.

Compared to the forced cooling system of the conventional ovens, the cooling system developed in the present invention, besides it reduces

expressively the coal cooling time, still adds the benefits of saving large volumes of water e doesn't produce coal gases, rich in methane (gasogeny), detected at the forced cooling in the conventional processes.

The new making coal process, implemented from a microwaves making coal oven, completes in a time 1000 (one thousand) times less than the time expended in the conventional processes, this means reduction at the coal production of 10 (ten) to 15 (fifteen) days to approximately 10 (ten) to 15 (fifteen) minutes, depending on the volume and the quality of the wood to be processed, besides the potency of the energy applied to the oven, conform the tests realized in laboratory showed.

The thermic energy springs'substitution in making coal processes by microwaves generates advantages as: a) reduction of the coal productive cycle time; b) continuo control of the making coal temperature; c) attendance and continuo control of the gases liberated to the atmosphere; d) reduction of the cooling time; e) utilization of the residues originated from the carbonization process; f) continuo coal production; g) increase of the security in the execution of the process to the operator ; h) improvement and control of the produced coal quality ; i) absence of expenses with water for cooling; j) automatic load and discharge of material; 1) social benefits adds: bigger possibility of controlling the utilization of infantile manual work on a job, seeing that it is a process which needs bigger undertaking organization to be implemented and improvement of operator's work conditions.

Beyond the advantages put in relief above, the coal production process by microwaves defers from the conventional processes by the fire absence. At the conventional processes, we burn part of the oven's wood to generate the necessary energy to the making coal, fact that produce also pollution when occurs the gases emission directly in the atmosphere, at the

making coal process by microwaves there's no burning of the woods in the oven, excluding the emission of the gases deriving from the fire applied to the wood.

The present invention can accelerate the carbonization process through the irradiation of electromagnetic waves, warming the wood directly by the molecules vibration, fact that provokes the quick water expulsion. The first result is the drying and then the carbonization without combustion, because inside the oven there's no oxygen. This carbonization process also produce the same gases generated in the conventional processes, fact that needs the development of the gases control and treatment system, making possible still the production of sub products as A pitch and cooled gases which are used in the produced coal cooling (figure 2). Accelerated too is the coal cooling process by the using of the produced gases in the two first phases, being these injected inside the oven after cooled.

Then, the significant time reduction in the making coal process provided by the present invention, makes the conventional making coal process very inefficacious, beyond generates residues to the environment in scale infinitely minor, without compromising the final product quality, before that, improving it.

The implemented velocity in the coal production allows still the development of a temperature continuo control system. The control makes possible produce coal with diverse texts of carbon, conform shows the follow table, developed for Eucalyptus carbonization : Table 1-Text of fixture Carbon at Eucalyptus Temperature (°C) 300 400 500 500 Carbon Text (%) 57 68 77 82

The carbon text found in the coal varies in function of diverse factors, but it is possible to make inference by the measure and control of the making coal temperature. Then, in the present invention, the temperature control is done through a controlling apparatus (12) which measures, helped by a sensor (11) and by the verification of the putting in (turn on/turn of) of the magnetron valves (3), the oven's temperature during the process. The control apparatus (12) allow the temperature continuo control during the carbonization process, which is impossible for a conventional system because of the elevated propagation time and temperature response. With this, we can adjust the desired temperature for the carbonization and produce the coal with the carbon text that is desirable, just increasing or reducing the incidence potency of the microwaves in the processed wood.

Then, making easy the present invention's patent claim understanding, we present a brief description of the illustrative draws of the oven (Figure 1) and the process (Figure 2) of making coal by microwaves : Figure 1-Making coal oven by microwaves: (1) Metallic oven hermetically closed for coal production in environment with absence of 02 ; (2) Gyratory dielectric package; (3) Termionic valves whole-Magnetrons; (4) Wood to be carbonized ; (13) Valve for cooled gas'injection; (15) Exit of the drying and making coal gases.

Figure 2-Making coal process by Microwaves : (1) Metallic oven hermetically closed for coal production in environment with absence of 02 (2) Gyratory dielectric box, "dielectric cage", for wood packed; (3) Termionic valves whole-Magnetrons; (4) Wood to be carbonized ; (5) Gases cleaning chamber; (6) Tank for packing of chemic products taken from the gases ; (7) Tank for packing water for gases cleaning; (8) Heat exchanging for cooling the gases to be throw at the atmosphere; (9) Condenser for cooling the cool liquid of the heat exchanging ;' (10) (1) Chimney for gases elimination ; (11) Sensor of oven's temperature; (12) Temperature controlling apparatus ; (13) Valve for cooled gas injection ; (14) Apparatus for gases quality analysis ; (15) Whole for exiting of gases for treatment and cleaning.