EA046278B1 - FURNACE FOR MELTING GLASS MATERIAL - Google Patents

Description

The present invention relates to a furnace for melting vitrified material or waste containing it.

There are furnaces on the market designed for melting vitrified material.

Temperatures in such furnaces must reach between 1200 and 1600°C to properly and completely melt the vitrified material, the composition of which may change from time to time.

To find industrial use on a large scale, furnaces obviously need to be of a simple and economical yet robust design that can withstand the very high temperatures reached.

The various solutions on the market, although functional, have poor versatility, so they often cannot be flexibly adapted to specific applications.

US 2011/0236846 discloses a furnace which, due to its configuration, may have some disadvantages when used on an industrial scale, including the risk of blocking after a certain period of activity. Indeed, due to the intense formation of bubbles in the melt inside the furnace, drops or large blocks of melt can be trapped along with the hot gases. Upon entering the colder part of the exit ascending channel, these droplets or blocks quickly freeze and therefore completely block the exit channel. Thus, a field of pulsating pressure of hot gases is created in the furnace above the melt. These pressure pulsations above the melt create very large pulsations of the melt jet at the outlet of the furnace. This, in turn, can lead to a significant deterioration in the quality of the product leaving the fiber production unit. In addition, thanks to the exhaust channel profile, large pieces of melt can be shot a long distance into the chimney. The chimney usually has weaker thermal protection than the stove itself. Consequently, there may also be a risk of complete blocking or wear of the chimney material.

Thus, the technical problem solved by the present invention is to provide a furnace for melting vitrified material, which overcomes the technical disadvantages of the prior art.

Based on the above technical problem, the object of the invention is to provide a furnace for melting vitrified material, which is structurally sound, simple and economical, easy to assemble, disassemble and maintain.

Another object of the invention is to provide a furnace for melting vitrified material, which can be easily adapted to specific applications.

This technical problem, as well as these and other problems according to the present invention, are solved by providing a furnace for melting vitrified material, characterized in that it has a composite wall structure formed by modules, each of which contains a pair of flat metal panels separated by a gap for the circulation of cooling water .

In one embodiment, said gap has partitions to form channels for water.

In one embodiment, said channel-forming partitions are formed by flat metal strips fixed orthogonally to said two panels.

In one embodiment, said panels of each module are connected by bolts that cross said gap.

In one embodiment, said modules have perimeter connection flanges.

In one embodiment of the invention, said wall structure comprises at least one lower module, limiting modules for confining a melting tank together with said lower module, at least one upper module having an outlet for discharging gases generated in the melting tank, and limiting modules for limiting an ascending transport labyrinth channel for transporting said gases upward from the opening of said melting tank to said outlet opening.

The furnace contains burners that can operate from below if they are installed through a bottom module, from the side if they are installed through limiting modules to limit the melting tank, or even from above if they are installed through limiting modules to limit the labyrinth channel.

In one embodiment of the invention, said limiting modules for limiting said labyrinth channel comprise at least one module inclined in an upward direction, blocking the opening of the melting tank.

In one embodiment, said inclined module projects upwardly within said wall structure.

In one embodiment of the invention, the side of said inclined module opposite said melting tank defines a storage zone for accumulating material transported by said gases.

In one embodiment, said labyrinthine channel has passage sections with different

- 1 046278 area for accelerating and decelerating the upward flow of gas.

In one embodiment of the invention, the solidified material that is deposited in said collection zone forms a sliding surface for other material sliding toward the melting bath.

Preferably, said inclined module is made in the form of a barrier, which, by blocking the upward gas flow, facilitates the separation of particles of solidified material from the upward gas flow, which slide along said inclined module (2vi) to return to the melting bath.

The present invention also relates to a furnace for melting vitrified material, characterized in that it has a composite wall structure containing at least one lower module, limiting modules for limiting the melting tank together with said lower module, at least one upper module having an outlet an opening for discharging gases generated in the melting tank, and limiting modules for limiting an ascending transport labyrinth channel for transporting said gases upward from the opening of said melting tank to said outlet opening, said limiting modules for limiting said labyrinth channel contain at least one module inclined in an upward direction, blocking the opening of the melting tank, said inclined module projects in an upward direction within said wall structure, said lower module having a rectangular or square shape, having a perimeter size of each side ranging from 2 to 4 m, having parallel rows of longitudinal openings for burner placement parallel to two opposite sides of the perimeter of said lower module, said longitudinal holes having a pitch in the range of 0.3 to 0.6 m and a distance from said sides of the perimeter in the range of 0.1 to 0.7 m.

A stove designed in this way has many advantages.

The oven, thanks to its integral modular design, is extremely easy to assemble, disassemble, clean and maintain.

The shape, dimensions and relationships between the various parts can be flexibly adapted to specific applications.

The module, formed by flat metal panels and straight metal strips, is very easy to assemble.

The module components, essentially metal panels, metal strips and fasteners, are easily manufactured without complex mechanical processes and/or are readily available on the market.

From a functional standpoint, water cooling maintains structural integrity by significantly extending the average life of the furnace and by specially configuring and positioning the water channel to allow the module to be cooled evenly.

Chimney, i.e. The upper part of the furnace with gas exhaust hole is completely protected and free from the risk of splashing material coming from the melting tank thanks to the ascending transport labyrinth channel for transporting said gases upwards.

The upward labyrinthine channel exposes the gases generated in the melting tank to turbulent movement, which promotes the deposition of material carried by the gases themselves. This material therefore does not clog the chimney and can be recovered in the collection zone and then reintroduced into the melting tank.

A particular embodiment with inclined labyrinth channel modules reduces the presence of droplets of solidified molten material in the exhaust gases. Thanks to the labyrinth channel, the exhaust gases, in contact with the upper inclined modules, cause the solidified drops to attach to the walls of the inclined modules and subsequently flow along the walls, leading to the return of the material back to the melting bath. In addition, vortices or air circulation systems passing through a narrow section of the labyrinth channel increase and then sharply decrease the speed in the subsequent passage section with a larger area and therefore cause droplets of solidified material to settle, resulting in an accumulation of material that can be removed manually or can be accumulated in such a way as to create an internal sliding surface (from the accumulated material) for additional particles towards the melting bath.

In addition, it should be noted that the labyrinth channel, on the one hand, protects the chimney from the radiation emitted by the material present in the melting tank, protecting it from excessive heating, on the other hand, it reflects these radiations into the interior of the melting tank.

The reflected radiation helps to melt the material present in the melting tank, thereby increasing the thermal efficiency of the furnace.

Flue gas can also be recovered to further improve the thermal efficiency of the furnace.

Additional features and advantages of the invention will become more apparent from the description of a preferred, but not exclusive, embodiment of a furnace for melting vitrified material in accordance with the invention, illustrated by way of non-limiting example only in the accompanying drawings, in which:

in fig. 1 shows a schematic exploded view of the first embodiment

- 2 046278 oven installation;

in fig. 2 shows a top view of the furnace of FIG. 1;

in fig. 3 shows a vertical section of the furnace according to FIG. 1;

in fig. 4 is a schematic exploded view of a second embodiment of the furnace;

in fig. 5 shows a top view of the furnace of FIG. 4;

in fig. 6 shows a vertical section of the furnace according to FIG. 4;

in fig. 7 is a side view of an embodiment of a wall structure module in which the panel is shown in a transparent form, without bolts, to demonstrate the internal channels of the module;

in fig. 8 shows a section of the module taken along line G-G from FIG. 7;

in fig. 9 shows a section of the module taken along line D-D from FIG. 7;

in fig. 10 shows a section of the module taken along line AA from FIG. 7.

Equivalent parts in different embodiments of the invention are designated by the same reference number.

With reference to the above figures, a furnace for melting a vitrified material is shown, generally designated by reference number 1.

The furnace 1 has a prefabricated wall structure formed by modules 2i, 2ii, 2iii, 2iv, 2v, 2vi, 2vii, 2viii, 2ix, 2x, 2xi, 2xii, each of which contains panels 3a, 3b separated by a gap 4 for the circulation of cooling water.

The panels 3a, 3b are preferably flat.

The panels 3a, 3b are also preferably metal, in particular steel.

More precisely, each module contains two parallel panels 3a, 3b, separated by a gap 4.

The gap 4 between the two panels 3a, 3b has partitions 5a, 5b for directing water.

Each module has at least one water inlet manifold 15 and at least one water outlet manifold 16 and is designed to be hydraulically connected in series or in parallel with adjacent modules.

The partitions 5a, 5b are formed by flat metal strips, in particular steel.

The partitions 5a, 5b are fixed orthogonal to the panels 3a, 3b.

Panels 3a, 3b are connected by bolts 7, which pass through the gap 4.

The bolts 7 provide resistance to swelling of the panels 3a, 3b, subjected to the pressure of water circulating in the module, which can reach 10 bar.

In particular, the partitions 5a, 5b are welded to the panels 3a, 3b located on the side of the melting tank, and are simply pressed with bolts 7 to the panels 3a, 3b located on the side opposite the melting tank.

The partitions 5a, 5b contain internal partitions 5a of the module 2 and perimeter partitions 5b of the module, which close the gap 4 around the perimeter.

The internal partitions 5a are arranged in the form of a lattice of parallel partitions, separated from the perimeter partitions 5b by a passage gap 21.

Internal partitions 5a separate straight water channel sections 22, connected by 180° curved water channel sections 23, which include a passage space 21 and are limited by perimeter partitions 5b.

Thus, the water drainage in the module is formed by a water channel, which runs in the form of a coil.

In wall structure modules located vertically or obliquely, water drainage has straight sections of 22 water channels oriented horizontally.

This prevents the formation of pockets of stagnant water, which, if present, could alter the correct heat exchange with the consequent risk of damage to the wall structure.

Wall structure modules can have different shapes and sizes and have perimeter flanges for interconnection.

The modules can be bolted or welded together, or bolted and welded.

The panels 3a, 3b of the module may have the same shape, but different sizes.

In this case, perimeter partitions 5b can be placed around the perimeter of the edge of the smaller panel 3b.

Some of the perimeter partitions 5b may have a greater height than the gap 4 and may protrude orthogonally from one of the panels 3a, 3b.

Thus, the projecting flap 8a of the perimeter partitions 5b can function as a perimeter flange for connection with an adjacent module.

Some of the perimeter partitions 5b may extend in a retracted position relative to at least some sides of the perimeter edge of the larger panel 3a.

Thus, the flap 8b of the larger panel 3a, located between its perimeter edge and the perimeter partition 5b, can function as a perimeter flange for the

- 3 046278 connection with an adjacent module.

The flanges 8a, 8b of adjacent modules are connected using fastening bolts. The wall structure contains at least one lower module 2i, equipped with holes 10 for accommodating burners (not shown), limiting modules 2ii, 2iii, 2iv, 2v for limiting the melting tank 11 together with the lower module 2i, at least one upper module 2xii, provided with an outlet 14 for removing gases generated in the melting tank 11, and limiting modules 2vi, 2vii, 2viii, 2ix, 2x, 2xi for limiting the ascending transport labyrinth channel 17 for transporting said gases upward from the opening of the melting tank 11 to the outlet 14.

Although in the case shown the burners are mounted on the bottom of the melting tank, in other solutions the burners may be mounted on one side of the melting tank or on top of the melting tank.

The limiting modules for limiting the labyrinth channel 17 contain at least one module 2vi extending with an inclination in the upward direction, blocking the opening of the melting tank 11.

The inclined module 2vi projects upward within the wall structure and its side 24 adjacent to the melting tank 11 protects the outlet 14 from splashes of material coming from the melting tank 11, and with its side 25 opposite the melting tank 11 it limits the storage area 18 for accumulation material transported by gases.

Access to the collection zone 18 may be provided through a suitable material removal door 19.

The embodiment of the invention shown in FIG. 1-3.

In this case, the limiting modules for limiting the labyrinth channel 17 comprise at least a second module 2vii inclined in an upward direction, which protrudes inside the wall structure and covers the opening of the melting tank 11, approaching the first inclined module 2vi.

More precisely, the first inclined module 2vi partially covers the opening of the melting tank 11, the second inclined module 2vii partially covers the opening of the melting tank 11 and continues until it also covers the first inclined module 2vi.

Thus, the labyrinth channel 17 has at least one passage section, completely shielded from the opening of the melting tank 11.

The wall structure of the furnace 1 contains a rectangular bottom module 2i, a first group of four vertical modules 2ii, 2iii, 2iv, 2v, orthogonal to each other to limit the melting tank 11, a second group of two vertical modules 2ii, 2v, parallel to each other and coplanar to the two modules 2ii, 2v of the first array with which they interact to delimit the melting tank 11, two modules 2vi, 2vii, inclined upward, delimiting the labyrinth channel 17 with a third group of four vertical modules 2viii, 2ix, 2x, 2xi, orthogonal to each other, and upper module 2xii.

In this case, four vertical modules 2ii, 2iii, 2iv, 2v of the first group are rectangular, two vertical modules 2ii, 2v of the second group are triangular, two inclined modules 2vi, 2vii are rectangular, two parallel vertical modules 2x, 2xi of the third group are rectangular, but with different heights, and the other two parallel vertical modules 2vii, 2ix of the third group are trapezoidal, and the upper module 2xii is rectangular.

Each of the two sets of coplanar modules is formed by a rectangular module of the first group, a triangular module of the second group and a trapezoidal module of the third group.

The modules are connected together along the perimeter, with the exception of two inclined modules 2vi, 2vii, which are connected along their intermediate section on one side of the overlapping module 2xi, 2x.

The embodiment of the invention shown in FIG. 4-6.

In this case, the limiting modules for limiting the labyrinth channel 17 contain at least a second module 2vii, inclined in the upward direction, which is staggered relative to the opening of the melting tank 11.

The first inclined module 2vi completely covers the opening of the melting tank 11 and extends in the direction of the second inclined module 2vii.

Thus, the labyrinth channel 17 has at least one passage section, completely shielded from the opening of the melting tank 11.

The wall structure of the furnace 1 contains a rectangular lower module 2i, a first group of four vertical limiting modules 2ii, 2iii, 2iv, 2v, orthogonal to each other, to limit the melting tank 11, two limiting modules 2vi, 2vii, inclined upward to limit the labyrinth channel 17 with a second group of four vertical modules 2viii, 2ix, 2x, 2xi, orthogonal to each other, and an upper module 2xii.

In this case, two parallel vertical modules 2iii, 2iv of the first group are rectangular, and two other parallel vertical modules 2ii, 2v of the first group are pentagonal, two inclined modules 2vi, 2vii are rectangular, two parallel vertical modules 2x,

- 4 046278

The 2xi of the second group are rectangular, the other two parallel vertical modules 2viii, 2ix of the second group are pentagonal and the top module 2xii is rectangular.

The pentagonal modules of the first and second groups are made coplanar in pairs and connected along one side.

The first inclined module 2vi, which completely covers the melting tank 11, is connected on three of its four sides to the corresponding sides of two pentagonal modules 2ii, 2v and a rectangular module 2iv of the first group.

The second inclined module 2vii is connected along one of its sides to the corresponding side of the rectangular module 2iii of the first group and along its other three sides to the corresponding sides of two pentagonal modules 2ii, 2v and rectangular module 2iii of the second group.

The modules are connected together along their entire perimeter, with the exception of the first inclined module 2vi, which is connected along its intermediate portion to one side of the overlying module 2xi.

In a furnace for melting vitrified material in accordance with an embodiment of the invention, there is no strict need for water-cooled modules.

Regardless of whether water-cooled modules are provided, according to an embodiment of the invention, the lower module 2i has a rectangular or square shape, has a perimeter size of each side in the range of 2 to 4 m, preferably 2.5 to 3 m, has parallel rows of longitudinal holes 10 for accommodating burners, these holes 10 are parallel to two opposite sides of the perimeter of the lower module 2i and have a pitch in the range of 0.3 to 0.6 m, preferably in the range of 0.35 to 0.5 m, and a distance from the sides of the perimeter lower module 2i in the range from 0.1 to 0.7 m.

The position of the burners on the bottom of the furnace has a very important influence on the speed and quality of the melting process.

Incorrect burner placement can sometimes lead to a significant deterioration in the melting process, and in some cases, block it completely.

The inlet 12 for the charge is made on one side of the melting tank 11, for example on the side of the module 2iv.

In addition, the raw material can be supplied from the top of the melting tank 11, for example through the module 2vi.

The melt outlet 13 is preferably located on the opposite side of the module 2iii. However, if necessary, the melt outlet can be located on the left and right sides of modules 2ii and 2v.

In addition, the melt outlet may be located on the lower furnace module 2i.

The charge can be fed below the melting level or from above.

The melting tank 11 may have multiple doors for access to the interior, not shown for clarity in the figures, for monitoring the condition of the interior of the furnace and for cleaning out solidified particles.

It is very important to properly organize the removal of gases from the furnace.

Due to the intense bubbling of the melt inside the melting tank 11, droplets or large blocks of melt may become entrained in the hot gases. Upon entering the colder part of the labyrinth channel 17, these drops or blocks quickly cool down.

If the profile of the exit labyrinth channel 17 is incorrect, cooled drops or blocks may completely block the exit labyrinth channel 17 during furnace operation.

Thus, a pressure pulsation field of hot gases can be created in the furnace above the melting tank 11.

These pressure pulsations above the melting tank 11 can create very large pulsations of the molten jet at the outlet of the furnace.

Consequently, pulsation of the molten furnace output can result in significant deterioration in the quality of the output product exiting the fiber unit.

In addition, due to the irregular profile of the exit labyrinth channel 17, large pieces of melt can be shot over a long distance into the chimney.

The labyrinth channel 17 usually has weaker thermal protection than the stove itself: thus, there is a high risk of complete blocking or wear of the chimney material.

Preferably, the furnace roof is formed by two inclined modules 2vi and 2vii.

Both modules 2vi and 2vii are inclined and extend in an upward direction from the limiting modules 2ii, 2iii, 2iv, 2v for limiting the melting tank 11; the inclined modules may be contained within the vertical perimeter members of the base module, or at least one may extend outside them.

Both modules 2vi and 2vii form a tapering rectangular labyrinth channel 17.

The angle of the 2vi module with the horizontal surface can be in the range from 5 to 20°.

The angle of the 2vii module with the horizontal surface can be in the range from 20 to 60°.

Typically, in a furnace in accordance with the present invention, the minimum cross-sectional area of the labyrinth channel 17 is in the range from 0.5 to 2.5 m ² , which ensures the melting fluid flow rate

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Claims (17)

gases from 10 to 20 m/s. The overall outlet section 14 may be rectangular or square, and its total flow area should be 2-3 times the minimum flow area. The vitrified material melting furnace thus constructed is susceptible to numerous modifications and variations, all of which fall within the scope of the present invention; all parts can, in addition, be replaced by technically equivalent elements. In practice, the materials used, as well as the dimensions, can be any in accordance with the requirements and the state of the art. CLAIM 1. A furnace (1) for melting vitrified material, characterized in that it has a composite wall structure formed by modules, said wall structure contains at least one lower module (2i), limiting modules (2ii, 2iii, 2iv, 2v) for limits of the melting tank (11) together with the specified lower module (2i), at least one upper module (2xii) having an outlet (14) for removing gases formed in the melting tank (11), and limiting modules (2vi, 2vii , 2viii, 2ix, 2x, 2xi) for limiting the ascending transport labyrinth channel (17) for transporting said gases upward from the opening of the specified melting tank (11) to the specified outlet opening (14), and the specified limiting modules for limiting the specified labyrinth channel (17 ) comprise a first module (2vi) inclined in an upward direction, covering the opening of the melting tank (11), said first module (2vi) protruding in an upward direction within the wall structure. 2. The furnace according to claim 1, in which each module contains two flat metal panels (3a, 3b) separated by a gap (4) for circulation of cooling water. 3. Oven (1) according to claim 2, in which said gap (4) has partitions (5a, 5b) to form channels for water. 4. Oven (1) according to claim 3, in which said channel-forming partitions (5a, 5b) are formed by flat metal strips fixed orthogonally to said two panels (3a, 3b). 5. Oven (1) according to any one of claims 3 or 4, in which said partitions (5a, 5b) contain internal partitions (5a) of the module and perimeter partitions (5b) of the module, which close the perimeter of the specified gap (4), and said internal partitions (5a) are arranged as a group of parallel partitions separated by a passage space (21) from said perimeter partitions (5b) so as to define a water channel which extends in a serpentine manner. 6. Oven (1) according to any one of claims 2 to 5, in which the panels (3a, 3b) of each module are connected by bolts that cross the specified gap (4). 7. Oven (1) according to claim 3 or 4, in which said modules have perimeter connecting flanges (8a, 8b). 8. Oven (1) according to claim 7, wherein said modules have bolts for fastening to each other on said perimeter flanges (8a, 8b). 9. Furnace (1) according to any one of the preceding paragraphs, in which the side (25) of said first module (2vi) opposite said melting tank defines a storage zone (18) for accumulating material transported by said gases. 10. The furnace according to claim 9, wherein the first module (2vi) has a side (24) adjacent to the melting tank (11) configured to protect the outlet (14) from splashes of material coming from the melting tank (11). 11. Oven according to claim 9 or 10, in which access to the accumulation zone (18) is provided through a door (19) to remove accumulated material. 12. Furnace (1) according to any one of the preceding paragraphs, in which the specified labyrinth channel has passage sections with different areas for accelerating and decelerating the upward gas flow. 13. Furnace (1) according to any one of the preceding paragraphs, in which said limiting modules for limiting said labyrinth channel (17) comprise a second module (2vii) inclined in an upward direction, which protrudes inside the wall structure and covers the opening of the melting tank (11) , approaching the first module (2vi). 14. The furnace (1) according to claim 13, wherein each of the first module (2vi) and the second module (2vii) partially covers the opening of the melting tank 11, and the second module (2vii) extends so as to cover the first module (2vi) . 15. The furnace according to claim 13 or 14, in which the furnace roof is formed by a first module (2vi) and a second module (2vii). 16. The furnace according to any one of claims 1 to 12, in which said limiting modules for limiting said labyrinth channel (17) comprise a second module (2vii) inclined in the upward direction, which is staggered relative to the opening of the melting tank (11). 17. The furnace according to claim 16, in which the first module (2vi) completely covers the opening of the melting tank -