DE2745373A1 - Refractory structure for furnace components - partic. for air-cooled burner support beams and injection heads in limestone furnaces - Google Patents

Abstract

A refractory structure, for building internal components of vertical furnaces, incorporates a core of sheet metal, with longitudinal and transverse partitions fixed on it, perpendicular to its surface. The partitions form four-sided cells closed on one side by the core and open on the other side. The cells are filled with refractory material. The structures are partic. for use in limestone furnaces, for mixing supporting beams for burners cooled by air protecting supports for a side burner, and burner injection heads. The use of this structure for constructing injection heads avoids the blockages of the burners without the bad effects on fuel distribution experienced in existing furnaces.

Description

Fire-resistant structure for the internal organs

vertical kilns, particularly lime kilns The invention relates relying on a refractory structure for the construction of the internal organs of vertical furnaces, especially lime kilns, these internal organs normally in the granules with which the ovens of this type are filled.

In particular, the invention has the application of such a structure for the construction of a support beam for a central burner or a rod burner for lime kilns or a protective support for a side burner to the goal. The invention also includes the use of such a refractory structure Injection heads for central burners or rod burners aimed at those in lime kilns be used.

The following is known of the vertical ovens in question: the Injection of the gaseous fuel in the midst of the bulk of those in the furnace Granulate is effected by means of a central burner or rod burner, which is inserted into the granulate are immersed.

The central burner located in the middle of the furnace cross-section injects the gaseous fuel either alone or in mixed form, be it with recirculated exhaust gases with or without air, ei it with; Air alone.

A major advantage of the central burner is in one size and iIi to see a relatively low weight, whereby the fuel in the Middle can be injected into the material to be treated. It does not disturb the circulation of the material and can easily be modified. The main disadvantage of this Burner is seen in that the injection of the fuel in a very limited liiche takes place.

The rod burner is formed by a self-supporting element, since exceeds the horizontal cross-section of the furnace and has a number of injectors for comprises the gaseous fuel which, as mentioned above, either alone or can be fed in in mixed form. Its advantage is that it allows an injection distributed over a longitudinal area, whereby one over the Cross-section of the furnace gives better fuel distribution.

The main disadvantage of these burners is that they are inevitable are located in the relatively hot zones of the furnace, which is reflected in the construction work and is reflected in manufacturing costs.

Due to the arrangement of the vertical furnace, the position can be <1es central burner for using a l'raghalken. force animal in a relative is located in the hot zone of the furnace.

The supporting beams and rod burners made of metal, which are in the hein zones of the vertical ovens are generally cooled with water.

However, water cooling has the following disadvantages: 1. Significant Water circulation (at 1-2 m- / t lime), which makes the installation of a closed one Circuit becomes relatively expensive, 2. complicated installation in the case of a safety circuit, 3. Considerable heat losses through the cooling water (5-10% or 60-100 Kcal / kg lime), 4. Risk of accident due to a water pipe burst, which has serious consequences for the stove may have.

In order to avoid water cooling, attempts have already been made to use the metal beam to protect with a fireproof cladding. Due to the very high demands to which the beam is subject, however, took advantage of the refractory cladding nb, so there '? one has refrained from this solution again.

Just like the supporting beams in the vertical furnace, the injection heads must be the burners that work immersed in the granules filled in the furnace, the withstand very high thermal loads, with the injection heads above it also against the risk of clogging by the grains of the material to be treated (Lime, dolomite, etc ...) must be protected.

In order to avoid the @@@ fencing, they are often directed from top to bottom Outlet nozzle used. This solution has two major disadvantages: The Outflow of the fuel from these nozzles is generally through the granules, that is near the outlet openings of the nozzles suddenly becomes strong braked. The distribution of the fuel is influenced by it and is flour or less uncertain.

The injection heads must be solid workpieces, possibly by casting be trained.

These various disadvantages become with the invention thanks to the use a fireproof, load-bearing and cell-like structure for the construction of the supporting beams and the injection heads avoided. The structure in question has a core made of sheet metal, furthermore longitudinal and transverse partition walls, clie # vertically are attached to the surface of the core, the drift walls having a plurality of four-sided cells determine whose one end is closed by the nucleus and whose the opposite end is open, and finally a refractory finish Material that is filled in each cell.

If you have a structure for building the walls of a central girder used in accordance with the invention, one is no longer dependent on water cooling, and natural or forced air cooling is sufficient, whereby the previously mentioned disadvantages are eliminated.

In a similar way, a burner injection head can be realized, in which the fuel injector is surrounded by a hat that opposes the injector protects the granules filled in the oven and between its inner surface and the Injector an annular gap to the outlet of the fuel is provided, and in which the hat by a fireproof, load-bearing and cell-like Structure is formed according to the invention, its fire-resistant equipment to the outside is swept.

In this way, MRII creates a ring-shaped dome around the injector Granules free-i kept area and protects the outlet openings for the gaseous Fuel against clogging by the grains of the granules.

A refractory structure according to the invention, which has a core made of sheet metal has, on the longitudinal and transverse, fillable with refractory material Cell-forming partitions are attached, is just as guit: for building on the side Burners suitable for processing the gaseous fuel in the peripheral area of the inject granules (lime, dolomite, clay and the like) into a vertical furnace.

The known side burners have had numerous difficulties to fight because they are due to very high mechanical and thermal loads exposed to the fact: in (-l, since "the for better, by the action of the Wall-influenced temperature distribution must penetrate into the granulate.

In the implementation of this burner type, according to the state of the Technique following solutions with regard to mechanical and thermal protection of the burner: 1. Protective coating made of a refractory ceramic Material; 2. water cooling; 3. Metal protection created by air injected into the furnace is cooled.

All of these attempted solutions have their disadvantages, namely: In the first solution there is a risk that the refractory ceramic material breaks.

The second solution has the same disadvantages as her described in connection with the water-cooled girder of a central burner have been.

The third solution has the disadvantage that the cooling air enters the furnace arrives so that a high temperature area at the tip of the torch and part the metal protection is created, which is therefore particularly thermally stressed.

In addition, the outflow of cooling air from the metal protection The thermal efficiency of the furnace is reduced because it takes the place of general Combustion air occurs, which is previously preheated in connection with the lime before it is burned off has been.

The third line leads in despite the aforementioned air cooling quite high metal temperatures of the injectors.

These disadvantages become with the invention thanks to a refractory cell-like A structure of the kind described above avoided that on a lateral Burner of a vertical furnace is applied. The core of this structure is as Ilohlprofil designed to accommodate the side burner in its interior, the outlet of the burner opening in the vicinity of one end of the core, and penetrates only one of the refractory winds of the furnace and protrudes with one End in the interior of the furnace. The cells provided with refractory material this structure extend at least over the part of the core that goes into the interior of the oven protrudes and is usually immersed in the granules filled in the oven.

The invention also relates to a side burner for a vertical furnace, particularly an air-cooled side burner that has such a having refractory cell-like structure.

The invention winds now to execution> sbeispielen and based on explained in more detail in the accompanying drawings. The drawing shows: Fig. 1 schematically a section through a vertical lime kiln with one on a support beam arranged central burner is equipped, Fig. 2 is a perspective view of a part of a cell-like structure according to the invention, which is used to form a wall of a Burner support beam is used, Fig. 3 shows a section along the plane III-III 2, 4 show a section analogous to FIG. 3, another embodiment of the invention, a 5a, 5b, a cross section, a longitudinal section and a 5c plan view on a support beam for a central burner or a rod burner, figures analogous views of a support beam equipped with Ea, 6b, a central burner whose injector is protected according to the invention by a cell-like structure, 7 shows a section through a burner according to the invention, which is mounted on a conventional Support beam can be arranged, Fig. 8 shows a longitudinal section through a lateral Burner with a refractory cell-like structure and FIG. 9 shows a cross section through the same burner.

In Fig. 1, a vertical furnace 1, a lime kiln, is shown, it with a central burner 3 carried by a transverse support beam 5 is equipped.

The exhaust gases with or without air or with riur Gaseous fuel mixed with air for the burner is fed through a pipe 7, (lies inside the hollow support beam, led out to the burner 3.

The support beam is a self-supporting element that extends over the horizontal cross-section of the furnace extends and, for example, a length of about 4 m.

The supporting beam, like the burner, is in the hot hollow of the furnace and is subject to considerable mechanical stresses due to the fact subject to being immersed in the goods filled in the oven.

The requirement for the mechanical and chemical strength of the Support beam poses difficult problems, thanks to the invention without the aid a water cooling can be solved. In the furnace 1 equipped according to the invention the cooling of the hollow girder is simply natural or forced Air circulation ensured.

In the latter case, the air is blown by a fan 9 through a duct 8 introduced.

According to the invention, the support beam is made with the help of elements with cellular Structure built up, which are shown in Figures 2, 3 and 4 and the walls of the form hollow support beam.

Each element with a cell-like structure has a core 11, E.g. a (metal) sheet with a thickness of 15 or 20 mm on the lengthwise Partitions 13 and transverse partitions 15 are attached.

In this way a load-bearing structure is divided by partition walls :; Structure formed on one side by the core 1 '. closed and open cells 17 with a refractory material on the opposite side 19, in particular refractory concrete, are filled.

The separating winch 1), 15 can be made of sheet metal strips with a thickness of for example 10 rmn, which are welded on the core. As partitions but also profiled sheets, e.g. with T or I profile, or rails 21, such as it is suitable in Fig. 4 can be used.

In practice, each element can have a length of about 5 m and one Have a width of about 40 - 60 cm.

The cell-like structure ensures the mechanical strength of the refractory Equipment 19, whereas this is the responsibility of the thermal protection of the supporting beam. The cell-like structure serves to ensure the thermal protection Fireproof equipment 19 to protect and fix, and on the other hand, the To increase rigidity of the supporting beam or the walls of the supporting beam, which leads to a contributes to better retention of the refractory equipment.

Based on elements with a cell-like, stable structure According to the invention, support beams for central burners or rod burners with several Injection heads of the type shown in Figures 5a, 5b and 5c, be realized.

To form a hollow beam, at least three are strip-shaped Elements with a cellular structure, but preferably 5 elements 231 232, 233, 234 and 235 (Fig.5a) are used to construct a beam with a pointed roof-shaped top to obtain, so that the furnace material coming down from above has less resistance will.

It should be hitewieseri, <leave the furnishing with fire-proof Material is turned outward relative to the beam in order to protect the core 11.

One or more injection heads 15 can be arranged on the beam : one. They will run over one inside the beam (he line 7 with supplied with gaseous fuel.

There can also be several, preferably concentric to one another Lines may be provided which contain the different constituents of a fuel mixture (Air, recirculated exhaust gases, etc.).

The cooling air circulates inside the hollow beam, e.g.

in the direction of arrows 27 (Figure 5b). It can be a natural one or a forced circulation (Figure 1) act. This is how you switch all of the disadvantages of the well-known water cooling and ensures overall for excellent mechanical and thermal strength of the beam. Be it Particularly noted here that the refractory material in perfect Way is retained in the cells, even if there are cracks in the refractory Form material that remains limited to the respective cell and also for one provide thermal protection.

The cell-like structure according to the invention can also be used in the construction of injection heads of burners for vertical furnace are applied, preferably being these injection heads in combination with supporting beams or rod burners, as you have just seen can be used.

Such a combination is shown in Figures 6a, 6b and 6c, the injection head being shown in more detail in FIG.

A vent 28 of the injection head 25, in the one with the line 7th connected line 7 'opens for the delivery of the fuel, is on a conical Injector 29 arranged with outlet openings 41 for the gaseous fuel or the fuel mixture is provided.

The conical injector 29 is against the granules filled into the oven protected by a hat 33 or some other mushroom-like attachment that is around the conical injector leaves an annular area 35 free into which the Granules cannot penetrate.

The hat 33 is on the conical injector 29 at a distance from this held by means of ribs 37.

The hat 33 is made of the cell-like filled with the refractory material 19 Structure constructed as it has been described in connection with Figure 2, wherein the core 11 'of the cell-like structure now passes through instead of a flat sheet a sheet metal shaped into a cone is formed.

As with the beam, the cell-like structure protects the one or the other Injectors both mechanical and thermal.

Such an injection head has the disadvantages described above the known injection heads avoided. Thanks to the ring-shaped one kept free from the granulate A braking of the fuel flow is avoided in the area 35 around the injection head, which can now emerge unhindered, as indicated by the arrows 39 in FIG is.

In the known arrangements where the outflow channels run downwards, a deceleration and an uneven distribution of the gas flows is caused.

the outlet openings are in the injection head according to the invention @ 1 for the gaseous fuel a clogging by the Grains of the granulate are protected, and the distribution of the fuel is improved and stahili i ert.

This injection head also allows the introduction of two or more Garden (fuel, air, recirculated exhaust gases, etc.) without premixing because the Mixing takes place at the exit of the annular space 35 and in the granulate instead of the one with which the oven is filled.

This possibility of separate injection of fuel, air, the recycled gases etc. increases the safety of the system because mixtures that are already flammable or explosive on their own, are not conveyed have to.

Such an injection head can be based on common workpieces how sheets, pipes, etc. can be built without the use of massive Spezialwerkstficke.

Preferably, the cell-like hat 33 of the injection head is given forming a conical shape. You might as well have the shape of a pyramid or a support roof, but can then under the action of in the Asymmetrical forces act on the cell-like structure in the granulate located in the oven.

Of course, one or more injection heads can also be used described type on a beam with a cell-like structure such as it is shown in Figures 5 and 6, can be arranged.

In the statements made above with regard to the burner support beams above all we are talking about beams in which the refractory structure itself forms the load-bearing element of the beam.

But the cell-like structure can just as well be just a hollow one Form a shell that surrounds and protects an inner, load-bearing beam.

Starting from strip-shaped, flat cell-like structures The construction of i3alks with an triangular cross-section is described. Jec3och can Refractory cell-like structure according to the invention also for building more load-bearing Beams or refractory lijillen are used for load-bearing beams that are in Cross-section are round or elliptical.

If the cells are in place with a first in plastic In the form of a silicon-aluminum-containing, refractory material that is poured out, it is advantageous to hold the refractory material in the cells by means of claws to improve (as shown in the upper cell of Figure 3) that at be welded to the core 11 of the structure.

Han can just as easily provide ramps (as they do in the lower cells of Figure 3), which are welded to the dividing walls of the cells or penetrate these partitions. These ramps can be replaced by bars if necessary that run across the entire refractory block and into the partitions 13 provided holes are held.

According to a modification, the refractory material, e.g.

Concrete that is poured into the cells on the spot, through prefabricated Refractory blocks are replaced, which are introduced into the cells and there for example held in place by a rod having a hole provided in the blocks penetrates and held in holes provided in the partition walls, as mentioned above is.

It can also be advantageous to provide partition walls 13, the height of which a little less, for example 10 to 20 mm, than the thickness of the equipment with refractory material 19 is. That way you can get the ends of the partitions better protect, and the fire-resistant wall can move more freely at high temperatures stretch in the transverse direction.

It will now be used in conjunction with FIGS. 8 and 9 of a refractory cell-like structure according to the invention for a lateral structure Brenner described.

In Figure 8, an area on the outer circumference of a vertical furnace is shown, the refractory wall 41 of a passage 43 for receiving a lateral Burner 45 is penetrated. The burner 45 is through an ear 47 made of refractory Steel is formed through which the fuel is injected and that with its end 49 opens into the interior of the furnace.

The tube 47 is supported and protected by a cell-like structure 51, a core made of refractory steel 53 with a hollow profile, for example in The shape of an inverted IJ. On at least part of the core 53, the protrudes into the interior of the furnace, are longitudinal partition walls 13 (Figure 9) and transverse partitions 15 attached to the filled with refractory material 19 Cells form.

Preferably there is; Hollow profile of the core 53 closed, for example through a sheet 55 made of refractory steel, which is also made with refractory material bears filled cells. The same is preferably the one located in the interior of the furnace End of the hollow core with closed profile 53, 55 closed by an end wall 57, which is also provided with cells filled with refractory material, the End wall 57 and its refractory equipment only have a passage for the end 49 of the fuel injection tube 47.

The eggs 53, 55 are in the passage 43 of the refractory wall 41 de :; Oven lurch holder 58 supported, which engage in a flaltering 4t) of the oven.

The core 55, 55 and its end wall 57 are like a glove finger placed around the burner, due to a circulation of a coolant, in particular a forced air circulation, can be cooled, whereby the air over a Feed and discharge line 61 or b1 'is fed and discharged.

To increase the stability of the burner inside the refractory envelope increase, an I-profile 63 can be provided, which is entirely made of ordinary steel can exist because it is in the flow path of the cooling air.

This profile also ensures a division inside the refractory Sheath and defines channels 65, 65 'through which cooling air circulates without it being in enters the furnace.

So far it was mainly from the application of the cell-like according to the invention Structure on Kalkbrennöfen 'the speech, however, the invention can just as well also on the equipment of all vertical furnaces of a similar type, such as dolomite kilns, are used, Magnesia kilns, fireclay kilns, and even garbage incinerators.

L e r s e i t e

Claims (21)

Refractory vessels for the internal organs of vertical furnaces, in particular Calibration kilns Patent claims 1. Refractory structure for the structure of the internal organs vertical kilns, especially lime kilns, installed in the in the. Stoves filled Granules are immersed, especially for the construction of air-cooled torch support beams, Protective supports for side burners and injection heads of burners, marked by a core (11; 53-55) made of sheet metal, longitudinal and transverse partition walls (13, 15,) which are fixed perpendicular to the surface of the core, with the partitions a multitude of versatile cells (17) determine one end of which is through the core closed and the opposite end of which is open, and by equipment (19) with refractory material poured into each cell. 2. Burner support beam for a vertical furnace, characterized by at least one iliille made of a refractory cell-like structure according to claim 1 that forms a hollow beam: and in which the fireproof fittings to the outside is swept. Firing support beam according to Claim 2, characterized in that the casing is self-supporting with the cell-like structure. 4. Burner support beam for a vertical furnace, characterized in that that the burner support beam consists of at least three cell-like structures according to claim 1 is composed, each of which is strip-shaped and has a hollow beam form, with the refractory equipment facing outwards. 5. burner support beam according to one of claims 2, 3 or 4, characterized characterized in that the longitudinal and transverse partition walls (13, 15) by flat Sheet metal strips are formed which are welded onto the core (11) of the structure. 6. Burner support beam according to one of claims 2, 3 or 4, characterized characterized in that the ling and transverse partitions are made of metal profiles (21) are formed, which are welded onto the core (11) the structure. 7. Burner support beam according to one of claims 2-6, characterized in that that the refractory material filled into the cells (17) is refractory concrete. 8. Burner support beam according to one of claims 2-6, characterized in that then the refractory material in the form of prefabricated blocks into the cells (17) is introduced and hooked to the structure. 9. Burner support beam according to one of claims 2-8, characterized by five strip-shaped elements (231-23) each made of a refractory structure to form a hollow beam with a pointed roof-shaped top. 10. Burner support beam according to one of claims 2-9, characterized by natural air circulation inside the hollow beam to cool it. 11. Burner support beam according to one of claims 9, characterized by a forced air circulation inside the hollow beam to cool it. 12. Injection head of a burner for vertical furnaces, characterized in that that the fuel injector (29) is surrounded by a hat (33) which the injector against the granulate placed in the oven protects and between its inner surface and an annular gap (35) is provided for the fuel to exit the injector is, and that the hat by a cell-like refractory structure according to claim 1 is formed, the refractory equipment (19) nacfi is swept outside. 13. Injection head according to claim 12, characterized by several Lines (7) for the supply of gases, their mixing without mixing in the annular Gap (35) and takes place in the granules filled into the oven. 14. Injection head according to claim 12 or 13, characterized in that that the hat (33) is conical and the core (11 ') of the cell-like structure forming the hat Structure is formed by a sheet rolled into a cone. 15. Refractory cell-like structure according to claim 1, characterized in that that the core (53) of the structure as a hollow profile to accommodate a lateral burner (45) is formed with its fuel injector outlet in the vicinity of one end of the core is arranged so that the core t3) only one of the refractory walls 61) of Oven (1) penetrates and protrudes with the mentioned end into the interior of the oven, and that the cells of the structure (51) provided with the refractory material are at least extend over the part of the core that protrudes into the interior of the furnace and normally immerse in the granulate filled in the oven. 16. delivery festival; Structure according to claim 15, characterized in that that the hollow core (54) is closed in profile, that that in the interior of the furnace located end of the core is closed by an end wall (57) which is only the outlet of the fuel injector (45) and that the end wall (57) like the core (53-55) itself is provided with cells filled with a refractory material. 17. Protective support for a side burner of a vertical furnace, characterized by a shell made of a refractory cell-like structure according to one of claims 15 or 16. 18. Protective carrier according to claim 17, characterized in that the hollow core (53-55) with a closed profile on its protruding into the outer space of the furnace (1) End with a supply line (G1) and a discharge line (61 ') for an inside the core is provided with circulating cooling medium. 19. Protective carrier according to claim 18, characterized in that the The cooling medium is air. 20. Schutztriiger according to one of claims 18 or 19, characterized in that that the hollow core (53-55) through a longitudinal partition (63) into two parallel channels for the circulation of the cooling medium is divided. 21. Protective carrier according to claim 20, characterized in that the Longitudinal partition (63) is a workpiece, in particular an I-profile, which is between the lower side of the injector tube (47) and the upper inside of the hollow core is used.