RU2403518C2 - Beams for furnaces that process large-sized materials (versions) and furnaces (versions) - Google Patents

Abstract

FIELD: heating.

SUBSTANCE: invention relates to support/protective elements (26), which may be used in furnaces (1) for baking and agglomeration of large-sized materials, for instance limestone, dolomite, etc. In particular, the present invention relates to beam of furnace for baking of large-sized materials arranged at the level of zones (2, 3, 4, 5, 6) of processing in furnace, comprising central part, having cavities to provide for circulation of hot air and/or effluent gases to create an according system of circulation, and oil cooling circuit. Versions of beam and furnace comprising such beams are also characterised.

EFFECT: reduced wear, increased time of furnace maintenance-free operation.

37 cl, 15 dwg

Description

The present invention relates to elements for supporting / protecting bridges of combustion chambers in furnaces for processing lumpy materials. The term material in pieces means any large-sized material of different sizes made of stone with a high content of calcium carbonate, double carbonate of magnesium and calcium or dolomite. In particular, the present invention relates to supporting / protective devices that can be used in calcining (calcining) furnaces of bulky materials such as limestone, dolomite or the like.

It is known that the processing of lumpy materials for the production of, for example, quicklime or, in general, for the dissociation of volatile components present in a solid, is carried out in kilns in which the material is subjected to heat treatment.

In particular, lumpy materials such as limestone, dolomite, etc. can be loaded through the furnace top, for example, an annular shaft type, which is a substantially vertical axis. The materials are passed sequentially from the top to the hearth through the heating zone, the firing zone with two or three combustion chambers, preferably in countercurrent, where in the lower part of this zone there are first-level combustion chambers equipped with burners at the annular wall of the furnace, the second firing zone in counterflow, where in the lower part of the second zone there are provided second-level combustion chambers equipped with burners at the annular wall of the furnace, the final third combustion zone, the averaging zone in the direct-flow, in which it is recycled The gas moves down due to the action of nozzles in the same direction of movement of materials passing down from the calcination zone, the cooling zone in countercurrent and the discharge zone of the calcined material.

Therefore, the firing zone runs longitudinally along the vertical axis of the furnace and contains several combustion chambers installed radially sequentially and at many levels. In particular, the combustion chambers are formed by an annular part external to the shaft and part internal to the shaft, having a substantially pyramidal shape with an upper part usually made of refractory bricks, and a supporting part formed by a bridge structure that defines the firing zone. When the kiln is loaded with calcining material and almost the entire shaft is filled with material, the pieces are located around the bridges between the top and bottom, and, as the calcination proceeds, they continuously move down to the calcining zones of the following levels. The bridges of the combustion chambers are designed to carry a load, usually very large, created by the material to be processed in addition to the own load of the upper part.

In addition, bridges are usually made with three overlapping arches of refractory material, one of which limits the arch of the combustion chamber and therefore is in direct contact with flue gases.

Consequently, the arch that forms the arch of the bridge is constantly exposed to very high temperatures. After a certain period of time, which can be of variable duration and even only a few months, the mentioned arch needs to be replaced due to heavy wear. In fact, such wear of the arches should lead to the fall of the entire bridge due to the lack of support for the bridge itself. Obviously, the fall of bridges with damage to the furnace results in the complete cessation of the operation of the furnace itself.

The technical problem that is the basis for the present invention is precisely the need to provide a system to address such a serious drawback.

This problem is solved by using elements for supporting / protecting the bridges of the combustion chambers in furnaces for processing materials such as limestone or dolomite, which should be especially resistant to wear caused by exposure to high temperatures.

In connection with the foregoing, the first objective of the present invention is to provide a device suitable for support / protection, according to the attached claims.

A second object of the present invention is to provide a furnace for processing limestone, dolomite and the like, comprising a supporting / protective device.

Additional features and advantages of the present invention are apparent from the following description relating to an embodiment given as a representative example without any restrictions, with reference to the accompanying drawings:

- figure 1 is a side section of a furnace for processing lumpy materials containing supporting / protective elements in accordance with the present invention;

- figure 2 is a partial section along the line II-II of the furnace shown in figure 1;

- figure 3 is a section along the line III-III in figure 2;

- figure 4 is a section along the line IV-IV in figure 2;

- FIG. 5A is a cross-sectional perspective view of an external element of a support / protective device in accordance with the present invention;

- figv is a cross-sectional view in perspective view of the extension element of the part of the device shown in figa;

- figs - cross section in perspective of the device depicted in figv;

- fig.5D is a longitudinal section of the device depicted in figv, supplemented by the circulation of the coolant;

- figa is a cross-section of a support / protective device in accordance with the first embodiment of the present invention;

- figv is a longitudinal side section of the device depicted in figa;

- figa is a cross section of a support / protective device in accordance with the second embodiment of the present invention;

- figv is a longitudinal section of the device depicted in figa;

- figs - section on the bottom view in horizontal projection of the device depicted in figv;

- Fig.8 diagram of the cooling circuit of the support / protective device in accordance with the present invention;

- Fig.9 is a cross section of a device in accordance with a third embodiment of the present invention.

Figure 1 shows a General example of a kiln for firing large-sized material such as limestone or dolomite. The preferred embodiment is an annular shaft type furnace, but there may also be a circular, square or rectangular shaft furnace, or a twin shaft furnace, or a regenerative furnace.

The furnace 1, widely known in the art, runs along the vertical axis XX and contains, from the top to the hearth, a heating zone 2, where the material to be fired is fed into the furnace through conventional devices (not shown), the firing zone in countercurrent, in which the combustion chambers of two levels, the upper 3 and lower 4, with burners are located near the annular wall of the furnace, an averaging zone 5 in the direct flow, in which the recirculated gas moves down due to the action of nozzles (not shown) in the same direction of movement of materials passing down from the zone life safety fundamentals yoke, cooling zone 6 in countercurrent and zone 7 of unloading of calcined materials. A furnace of this type is described, for example, in German patent DE 3140582, incorporated herein by reference.

The shaft element, indicated by 8, is inserted into the furnace in the manner described, for example, in German patent DE 3140582. An annular shaft 12, in which the material to be fired continuously moves through the furnace from the top to the hearth, is made between the outer wall 9 of the shaft element 8 and the inner surface 10 of the outer wall 11 of the furnace. Then, the shaft element 8 is closed at the lower end by the wall 13 and at the upper end by a cover 14 having, for example, a conical shape. In addition, the shaft element 8 is divided along the transverse wall 15 into an upper inner section 16 in the form of a cylinder and a lower section 17 in the form of a cylinder. In particular, the upper section 16 separates the aforementioned firing zones, and the lower section 17 communicates with the annular shaft 12 through the cooling air openings 18 (only one given opening is shown in FIG. 1).

In addition, each of the firing zones, the first 3 and second 4, refers, respectively, to the first 19 and second 20 of the combustion chamber. In particular, these combustion chambers are located at the base of each of the firing zones, in such a way that the flue gases that are generated in the combustion chamber pass sideways and upward in the firing zones in the usual manner.

As shown more clearly in FIGS. 2-5, the combustion chambers, the first 19 and the second 20, are bounded and divided into respective firing zones by means of a pyramidal structure 22.

In particular, the pyramidal structure 22 comprises an upper portion 23 and a vaulted portion 24 (FIG. 5).

In accordance with the present invention, it is particularly advantageous that the vaulted portion 24 comprises a series of arches 25 which, instead of being supported laterally by the supports of the internal wall of the furnace in accordance with a well-known method, are supported by supporting / protective devices 26.

Each of the combustion chambers, the first 19 and second 20, is usually equipped with burners (not shown in FIGS. 1-5) of a traditional type, preferably operating on gaseous fuels, liquid fuels and / or dusty solid fuels mounted on the outer surface of the furnace 1 at the inlets of the 27 combustion chambers or on their sides.

The support / protection devices 26 are preferably beams that extend along the length along one axis YY, as shown more clearly in FIG. 5 B. The beams 26 are mounted radially, two on each bridge, with axes YY essentially perpendicular to the X axis X of the furnace itself, as shown in FIG. In addition, the beams are inserted into the combustion chambers in such a way as to rest with the distal end 28 on a niche 29 made in the inner refractory wall of the furnace 1, and the proximal end 30 on the platform 31, made horizontally in the outer wall of the furnace, near the inlet 27 of the combustion chamber ( figure 3).

As shown in FIG. 5A, the beams 26 have a transverse T-section with the upper part 32 and the housing 33. Both the upper part and the housing have casings 34 to allow the passage of coolant. The coolant can pass in the casing along any type of path, preferred or selected according to specific needs, for example, along the path shown by arrows in FIGS. 5C and 5D.

The central part of the housing 33 of the beams 26 can advantageously accommodate burners, preferably fuel lines 35 of the burners, as is clearly shown in FIG. 5B, in special cavities 36 having the function of accommodating a variable number of burners. The cavities 36 may be larger than one, and, as is more clearly shown in FIG. 5A, each of the cavities is divided by a longitudinal vertical partition 37. The fuel lines of the burners 35 contain tubes 38 of the burners that run parallel to the beams 26, preferably one above the other. The pipes 38 may preferably be enclosed in cavities 39 having the purpose of providing combustion air for each individual burner fuel line or a set of burner fuel lines to achieve improved air distribution control in addition to being able to continuously measure and control the flow. In particular, combustion air is injected into the beams through openings (not shown) located preferably on the lower side to the furnace 1 and follows a path similar to that described below with reference to FIGS. 7A and 7B. Alternatively, openings can be used for flue gas recirculation.

The fuel lines 35 of the burner or cavity 39 are supported both on the partition 37 through the spacers and on the lower part of this cavity 39 through a series of wheels 60 (shown in FIG. 5B), which provide the advantage of inserting and removing the set of fuel lines 35 and cavities 39. In addition, the pipes inside the cavities may include spacers 41 to prevent contact between the pipes and the walls of the cavities.

As shown in FIG. 5B, each burner fuel line 35 has one open end 42, such ends being located where there are corresponding openings 43 in the outer wall of the beams 26, and these openings 43 are located in different places along the beam so that the fuel can exit the beam itself at several points and permeate the furnace at predetermined points. Thus, it is possible to evenly distribute the air-fuel mixture along the beam.

The beams 26 are preferably made of heat-resistant steel or steel that is able to withstand the operating temperature of the furnace 1. In fact, in this case, the steel can withstand temperatures of 200 ° C-300 ° C, since the cooling system described below allows the temperature of the beams to be kept constant. In any case, such steels are widely known in the art as, for example, high-quality unalloyed steel, special unalloyed steel and special alloyed steel. The steels of all the above categories are suitable for maintaining temperatures and significant loads, so that they show a mechanical strength suitable for use as beams in a furnace of the type described above.

In particular, the above requirements can be satisfied, for example, by such steels that are indicated by the code P275N (No. 1.0486), P275NH (No. 1.0487), P275NL1 (No. 1.0488) and P275NL2 (No. 1.1104).

In accordance with the above description, the beams 26 are preferably cooled by a coolant passing through the circulation system. In a preferred embodiment, a diathermic liquid, for example, water, mineral, vegetable or synthetic (MONSANTO) oils, biphenyl and a derivative, tetraaryl silicate, a mixture of molten salts, liquid products such as glycerin, silicone, a naphthalene derivative, most preferably a diathermic mineral oil. Of all the oils, diathermic mineral oils used for cooling steam boilers, heat exchangers and the like are particularly preferred. Examples of these oils are oils marketed under the trademarks ESSOTHERM 300 (ESSO), TEXATHER 46 (TEXASO) and SHELL THERMIA OIL B.

Coolant is circulated under pressure in the casings 34 of the beams 26 to prevent the temperature of the beam from rising above 300 ° C. Thus, the liquid is designed to remove heat produced by combustion, and, therefore, maintains the optimal, from the point of view of safety, operating mode of the beams.

An example of fluid circulation in the casings 34 of the beams 26 is shown by arrows in FIGS. 5C and 5D.

In particular, an example of a circuit for supplying oil to the beams and oil recirculation is shown in Fig. 8. The circuit is made with a first heat exchanger 44 ', for example, of a tubular type, with a ribbed surface or an equipped blower 45', with heat recovery (as shown by the inlet / outlet arrows for the heat exchanger 44 ') and with a second heat exchanger 44, for example, a heat exchanger with a ribbed surface with 45 blowers for exhaust air (or disposal). Both heat exchangers allow you to remove the heat removed from the beam, in the traditional way.

Then the oil passes a filter, which is not shown, but is a filter of the usual type, and which ensures the absence of impurities in the oil.

Behind the filter along the way, a small decanter can be provided, not shown, to exclude the possible last residue present in the oil, and create a non-turbulent zone to facilitate the operation of the oil circulation pumps.

Behind the decanter along the way, a pump group 46 is provided, made of two centrifugal pumps, each of which is equipped with an electric motor, and an additional pump with a diesel engine (all three pumps are installed parallel to the inlet to ensure the same pressure and flow to the exhaust manifold). Typically, the system works with only one of the two electric pumps (the other pump is a backup pump and turns on in the event of a decrease in pressure or oil flow). The diesel pump is turned on in the event of a temporary interruption in the power supply with the consequent shutdown of electric pumps: thus, the service life of the beams is maintained by supporting the circulation of oil in the beams to ensure their cooling and, therefore, safety.

On the discharge side of one of the pumps, the pipe 48 feeds the intake manifold 49, from which the primary circuit pipe 50 starts up to one of the beams 26 in each pair. The fluid is circulated through a secondary circuit pipe 51 to a beam located at a different level. After the third conduit 52 allows the fluid to be returned to the second pump of the first pair at the outlet of the second beam, the fluid is drawn by the fourth conduit 53 to the second beam of a different level. And finally, the fifth conduit 54 provides a fluid supply to the exhaust manifold 55 and, through the return conduit 56, to the heat exchanger 44 '.

It should be emphasized that this particular circuit allows you to maintain, preferably, a reduced flow rate of the coolant and, in particular, diathermic oil, with the resulting savings in the total volume of the circulating fluid and the efficiency of the system as a whole.

An expansion tank 47 for oil is installed on the furnace top to maintain a constant pressure on the pump group and also compensate for small volumetric expansion of the oil, which is caused by the temperature difference from the ambient temperature to the operating temperature of about 200 ° C.

And finally, the storage tank 48 ', set at zero level, provides a long supply of oil for the circuit and also allows, in case of stopping the furnace for maintenance (for example, to replace beams, etc.), to have an oil storage tank, contained in the circuit.

It must be borne in mind that, if necessary and based on preferences, modifications can be made to the cooling circuit. For example, branch pipelines may include a first pipeline that runs up to one beam from a pair of the same level, a second pipe that delivers fluid to another beam from the same pair of one level, a third pipeline that supplies fluid to the first beam from a pair of another level, and a fifth conduit that supplies fluid to the exhaust manifold.

You can also exclude the first heat exchanger 44 'if it is not designed or is not necessary for the recovery of heat, which can be returned to the furnace in accordance with traditional systems.

In any case, further modifications to the oil circuit are apparent to those skilled in the art.

A complete system typically operates automatically under the control of a traditional programmable logic controller (PLC).

On figa and figv shows other configurations for the implementation of the beam 26.

In particular, the beams 126 from a structural point of view correspond essentially to half of the beams 26 or one of two sections separated by a longitudinal vertical partition 37, therefore, there is no detailed description of these beams, and the positions identical to those indicated in figures 5A-5D represent identical parts or sections .

The advantage of using beams 126 is that with this particular design, flue gases can only be generated from one side of the beam, and in particular from the side outward from the combustion chamber. Therefore, for specific applications, when the location of the fuel lines of the burners on only one side of the beam is sufficient, this solution allows to simplify the implementation of the installation as a whole and reduce the size of the beams with an increase in surface finish and lower costs.

In addition, a beam similar to the type of the above-described beam can also be used in a furnace having a round, square or rectangular, rather than an annular cross-section, where submerged beams that cross the furnace section and which are located near the furnace walls can be used without the use of burner fuel lines near the wall and provide only those burners that are facing the center of the furnace. The need for external and / or peripheral burners that penetrate inside the limestone layer is also eliminated.

According to a further embodiment of the invention, the beam 226 is similar to the beam 26 in FIG. 5C, but without the upper portion 32, the baffle 37 and the burners 3, as shown in FIGS. 7A and 7B.

In particular, the beam 226 comprises a section that is almost rectangular in shape, with a cooling jacket system 234 substantially identical to the system described above. In addition, in the central part there is a cavity 261 for circulating hot air and / or exhaust gases to create an appropriate circulation system. In fact, in the beam 226, holes 262 can be made on the side facing the bottom of the furnace, through which the hot air, which passes through the cavity 261 upwards, is pumped into the beam through the cavity 261 in the traditional way to approach the burners and to ensure optimal combustion.

Alternatively, the flue gas can also be sucked in from the inside into the beam and follow the same path of the circuit described above, but with the flow into the traditional disposal system.

In addition, the beam 226 can be performed without holes 262 to perform the function of simply supporting / protective device of the set of combustion chambers cooled by the cooling system.

The beam 226 can perform the additional function of an exhaust beam, also cooled previously described, and which can also be installed on the border of the afterburning zone in shaft-type furnaces, in which the beams extend across their entire section and are immersed in the material to be processed.

The beams according to the object of the present invention can preferably be lined with heat insulating and refractory materials, for example, brick and / or refractory concrete, to prevent contact between the limestone in the firing zone and the surface of the beam, which is relatively cold. In fact, such a contact during operation of the furnace could bring limestone into contact with the beams in violation of the principle of cooling, as well as in any case other operating conditions compared to that in which the limestone is not in contact with the beams.

Beams can be installed in different quantities and in accordance with two distribution methods: along the same vertical axis at each level of the combustion chambers or with an offset relative to the vertical axis for any two levels. In fact, the solution with the beams installed on the same vertical axis allows not very hot flue gases generated during combustion at the lower firing level to be contacted in countercurrent with quicklime, already completely annealed at the upper firing level, and, thus, creates the possibility of compaction of the crystalline structure, which leads to a decrease in the specific surface and, thus, to a decrease in the chemical activity of lime.

It should also be borne in mind that fuel consumption, regardless of whether the fuel is gaseous, liquid or solid, dusty, is advisable to adjust and measure automatically for each set of burner fuel lines and automatically or manually for each individual burner fuel line. In the case of gaseous fuels, a system with control valves, which are controlled by PLC controllers, as described earlier, is used. In particular, the PLC system controls the flow of gaseous fuel by opening and closing the valves in accordance with the settings. This system operates with sensors that transmit a signal to a control system that will constantly compare the received signal with the settings and will control the generation of a control signal that will drive a suitable device to open or close the valves. In the case of liquid fuels, metering pumps are required, and in the case of pulverized solid fuels, a dynamic metering system and a static system for redistribution are required; both systems are standard in type, for example, rotary dampers, screw conveyors or separation devices, operating with PLC control. Combustion air flow is also regulated by control valves and is measured with suitable instrumentation. These systems, which are regulated by the PLC system, provide the ability to control the amount of fuel and air for each burner in order to achieve a different distribution of both calories and excess air in the furnace. This is a condition, together with different levels of excess negative and / or positive pressures that can be obtained in the furnace, for the production of highly active materials, up to agglomerated material and materials with all intermediate characteristics.

As described above, in a preferred embodiment, the beams in accordance with the present invention can be cooled with liquids of various types, depending on preference and specific needs.

In fact, any type of liquid, preferably demineralized water, and, more preferably, diathermic oil (mineral type) similar to the above oil, can be used in the above ring shaft furnace. For shaft furnaces with submerged beams, the use of mineral diathermic oil is, of course, the optimal solution.

In fact, the water cooling system involves the use of pipes and valves with much larger nominal bores compared to the corresponding parameters of the oil system and the need to use demineralized water to avoid the formation of inconvenient calcium carbonate deposits. The foregoing implies that equipment with larger dimensions and higher operating costs is required.

On the other hand, the smaller dimensions in the case of diathermic oil make it possible to simplify the installation with pipelines and valves of a smaller size due to compact elements and equipment. In addition, operating costs for the entire installation are drastically reduced due to the fact that diathermic oil can be replaced after many years of operation.

In addition to the foregoing, the use of diathermic oil allows the reuse of heat through heat exchangers to heat combustion air with a corresponding increase in furnace efficiency.

In any case, the unexpected advantage that is obtained when choosing beams with diathermic oil is that it is possible to provide a significant reduction in the oil casing of the beams. As a result, processing of lumpy material is technologically much more efficient, since reducing the size of the beam inside any type of furnace for roasting lumpy materials increases the working surface and capacity of the furnace or, in any case, suggests favorable conditions for the material to pass down inside the furnace. In particular, it turned out that the flow rate of the coolant and the cross section of the casings for the coolant can be reduced by 30% compared to traditional fluids.

Of course, it is obvious to a person skilled in the art the possibility of creating support / protective devices in accordance with the present invention with additional modifications and additional options to meet special specific needs, but in all cases within the scope of protection of the present invention defined by the attached claims.

For example, the shape, dimensions and thickness of the beams can be modified depending on the specific design conditions, but, in any case, with the possibility of functioning in accordance with the above description. In particular, the size and thickness can be increased in the case when the arches of bridges that support the upper part of the combustion chambers are completely excluded or their number will be variable depending on specific needs and / or conditions.

The number, location and type of burners inside the beams, in particular burner fuel lines, can be changed depending on some specific needs. For example, it is possible to provide fuel lines for burners in which an outlet for combustible fuel is located on the beam body at a level parallel to the upper part of the beam. In this case, you can also use pulverized fuel in accordance with traditional methods. In addition, in accordance with the above description, the beams that are the object of the present invention can be converted by a technician for furnaces of various types, for example, shaft furnaces of circular, ring, square or rectangular type, and of the type in which the beams are immersed in the layer to be processed material without performing a supporting function.

In addition, the beams can be located inside the furnace in accordance with the above schemes or otherwise. For example, the beams can be located on one or two levels corresponding to one or two combustion chambers, depending on the type of furnace and / or the type of processing to be performed. Of course, in this case, it is possible to make changes in the size and shape of the beams, as indicated above.

In accordance with a further embodiment of the invention shown in FIG. 9, the beam 326 is substantially identical in shape and cross section to the beam 226 in FIG. 7A and comprises a cavity 361 in which a set of fuel lines 335 of the burners are located. In a preferred embodiment, the fuel lines 335 of the burners are surrounded by chambers 339 identical to those shown in FIG. 5A. In particular, the open ends 342 of the fuel lines 335 of the burners are located respectively to the openings 343 made in the outer walls of the beams corresponding to the side facing the hearth of the furnace. This particular arrangement applies to the use of pulverized fuel. In addition, a set of fuel lines 335 of the burner is located in the cavities 361 and slides in them thanks to the wheels 360, identical to the wheels shown in figv.

Attention should be paid to such an advantage as the implementation of the beam 326 in a dual configuration, which means that it is possible to place 2 sets of fuel lines 335 of the burner in the cavity 361, divided by a partition identical to the partition shown in figa.

The advantage of this additional option is that the combustion performance can be doubled, especially when pulverized fuel is used.

From the above description it is obvious that the shape of the beam, the fact of the presence or absence of burners and their location inside the beams can be changed depending on specific needs, which can be easily performed by a person skilled in the art.

For example, the wheels 60, 360 can move on the insertion diagram inside the cavity 39, 339 of the beams 26, 326, which ends in a downward slope to indicate that the burner fuel lines are in the proper working position and also to prevent them from getting out of this proper position. Alternatively, the wheels can move along an appropriate guide raised above the bottom of the cavity in which the fuel lines of the burners are located.

Claims (37)

1. Beam (26; 126; 226; 326) of the furnace (1) for firing large-sized materials located at the level of zones (2, 3, 4, 5, 6) of processing in the furnace, characterized in that it contains a central part having cavity (261) to circulate hot air and / or exhaust gases to create an appropriate circulation system, and an oil cooling circuit. 2. The beam (26; 126; 226; 326) according to claim 1, in which the oil cooling circuit comprises housings (34) located along the peripheral zone of the beam, which allow the passage of cooling oil to remove heat from the entire surface of the beam and to maintain constant optimum working temperature of the beam. 3. The beam (26; 126; 226; 326) according to claim 1 or 2, which is selected from a support / protective beam, an exhaust beam, an exhaust gas beam, a combustion air exhaust beam, and a beam resulting from any combination of the above beams . 4. The beam (26; 126; 226; 326) according to claim 1 or 2, which extends along the length (YY) and contains at least one cavity (36; 261; 361) suitable for ensuring the passage of combustion air and / or off-gas and / or burner placement (35; 335). 5. The beam (26) according to claim 4, containing two cavities (36), separated by a vertical longitudinal partition (37), and at least one burner (35) is placed in both cavities. 6. The beam (26) according to claim 4, in which at least one burner (35) individually or in a group is surrounded by a chamber (39), which allows the passage of combustion air. 7. The beam (26) according to claim 6, in which the chamber (39) is connected to the partition (37) by means of spacers (40). 8. The beam (26) according to claim 6 or 7, containing spacers (41) between the burners (35) and the walls of the chambers (39). 9. The beam (26; 326) according to claim 5, containing wheels (60; 360), which provide insertion into the beam of the burners and removal of the burners from the beam (35; 335). 10. The beam (26; 126; 226; 326) according to claim 4, in which the burners (35; 335) are in the form of fuel tubes that are located along the longitudinal axis (Y-Y) of the beam and end at different distances along this axis. 11. The beam (26; 326) according to claim 10, in which the fuel tubes (35; 335) contain pipelines (38) with open ends (42; 342) corresponding to holes (43; 343) made in the walls of the beams in different places along their longitudinal axis. 12. The beam (26) according to claim 4, which has an essentially cross section of a T-shape with the upper part (32) and the housing (33). 13. The beam (26) according to item 12, in which the upper part (32) of the beam accommodates the casings (34) connected to the casings (34) enclosed in the housing. 14. The beam (26) according to item 13, in which the body (33) of the beam contains at least one cavity (36) surrounded by casings (34). 15. The beam (26; 126; 226) according to claim 4, containing intersecting openings (62; 262), suitable for ensuring the passage of combustion air or exhaust gases from the outside into the beam. 16. The beam (126) according to claim 4, which has an essentially cross section in the form of half T and contains a cavity (36) suitable for receiving burners (35), the ends of which (42) are open only on one side in the form half T. 17. The beam (226) according to claim 4, which has an essentially rectangular cross-section with a cavity (261) for the passage of combustion air or exhaust gases, limited by the casings (34) for the passage of cooling oil. 18. The beam (26; 126; 226) according to claim 1, which is made of high quality unalloyed steel, special unalloyed steel and special alloyed steel. 19. The beam (26; 126; 226) according to claim 18, for which the aforementioned steel is selected from steels P275N, P275NH, P275NL1 and P275NL2. 20. The beam (26; 126; 226) according to claim 1, wherein the cooling oil is a diathermic oil used to cool steam boilers, heat exchangers, and the like. 21. The beam (26; 126; 226) according to claim 20, in which the aforementioned oil is selected from vegetable oils, mineral oils and synthetic oils. 22. The beam (26; 126; 226) according to claim 21, wherein the oil is a diathermic oil selected from the oils marketed under the trademarks ESSOTHERM 300, TEXATHER 46 and SHELL THERMIA OIL B. 23. The beam (26; 126; 226) according to claim 1, comprising an outer lining formed by a heat insulating material, preferably of a refractory type. 24. The beam (26; 126; 226) according to claim 1, further comprising a fuel consumption control system with control valves and metering pumps. 25. The beam (26; 126; 226) according to claim 1, further comprising a fuel consumption control system with a metering dynamic system and a distribution static system. 26. A beam (26; 126; 226) according to claim 24 or 25, further comprising combustion air flow control valves controlled by a suitable device. 27. A beam (26; 126; 226) according to claim 26, which comprises a device for measuring combustion air. 28. An oven (1) for firing large-sized materials, containing at least one firing zone (3, 4), with which at least one combustion chamber (19, 20) is connected, equipped with a vaulted structure (24), characterized in that the support / protection for the vaulted part is a beam according to any one of claims 1 to 27. 29. The furnace according to claim 28, which is a shaft furnace of a circular, circular, square or rectangular section, a twin shaft furnace or a regenerative furnace. 30. The furnace according to claim 28, in which the beams (26; 126; 226; 326) are arranged radially, in pairs, two at one or more levels along the longitudinal vertical axis (XX) of the furnace so that their longitudinal axis (YY ) is essentially perpendicular to the axis (XX) of the furnace. 31. The furnace according to claim 28, in which the beams are arranged one at a time or radially in pairs of two at one or more levels along the longitudinal vertical axis of the furnace with an offset relative to the vertical axis. 32. The kiln for firing large-sized material, in particular limestone or dolomite, shaft type, annular, square or rectangular section, the furnace is located along the longitudinal vertical axis, contains from the top to the bottom of the heating zone, at least one firing zone, cooling zone and unloading zone, characterized in that these zones contain at least one beam (26; 126; 226; 326) according to any one of claims 1 to 27, which completely crosses the section of the furnace and therefore must be immersed in processing material. 33. The furnace according to claim 32, in which the beams (26; 126; 226; 326) are arranged radially, in pairs, two at one or more levels along the longitudinal vertical axis (XX) of the furnace so that their longitudinal axis (YY ) is essentially perpendicular to the axis (XX) of the furnace. 34. The furnace according to claim 32, in which the beams are located one at a time or radially in pairs, two at one or more levels along the longitudinal vertical axis of the furnace with an offset relative to the vertical axis. 35. A kiln (1) for firing large-sized material, in particular limestone or dolomite, an annular section, shaft type, which runs along the longitudinal vertical axis (XX), containing from the top to the bottom a heating zone (2), the upper level ( 3) firing, below which the first combustion chamber (19) is located, the lower level (4) of firing, below which the second combustion chamber (20) is located, the cooling zone (6) and the discharge zone (7), characterized in that the first (19) ) and the second (20) combustion chambers are equipped with vaulted parts (24) supported by supports and protected by a beam (26; 126; 226; 326) made of refractory steel and cooled by oil. 36. Beam (26; 126; 226; 326) of the furnace (1) for firing large-sized materials located at the level of zones (2, 3, 4, 5, 6) of processing in the furnace, characterized in that it contains a central part having cavity (261) for circulating hot air and / or exhaust gases to create an appropriate circulation system, and a cooling circuit with a diathermic liquid selected from water, preferably distilled, biphenyl and a derivative, tetraaryl silicate, a mixture of molten salts, various liquids such as glycerol, silicones derivatives of mothballs a. 37. Furnace (1) for roasting large-sized material, in particular limestone or dolomite, an annular section, shaft type, which runs along the longitudinal vertical axis (XX), containing from the top to the bottom a heating zone (2), the upper level ( 3) firing, below which the first combustion chamber (19) is located, the lower level (4) of firing, below which the second combustion chamber (20) is located, the cooling zone (6) and the discharge zone (7), characterized in that the first (19) ) and the second (20) combustion chambers are equipped with vaulted parts (24) supported by supports and protected by a beam (26; 126; 226; 326) made of refractory steel and cooled by means of a diathermic liquid selected from water, preferably distilled, biphenyl and derivatives tetraarilsilikata, the mixture of molten salts, various glycerol type fluids, silicones, derivatives of naphthalene.

Images