Furnace for melting vitrifiable material

Abstract

A furnace (1) for melting vitrifiable material has a combined wall structure formed of modules, each module comprising two flat metal panels (3a, 3b) separated by a gap (4) for circulating cooling water.

Description

[0001] The present invention relates to a furnace for melting vitrifiable materials or waste containing vitrifiable materials.

[0002] Furnaces designed to melt vitrifiable materials are known on the market.

[0003] Such furnaces must reach a temperature range of 1200°C to 1600°C in order to properly and completely melt vitrifiable materials, the composition of which may change from time to time.

[0004] For large-scale industrial applications to be realized, furnaces obviously need to have a simple, economical yet robust structure and must withstand the very high temperatures that are reached.

[0005] While the various solutions on the market are practical, they lack versatility and are therefore often not flexible enough to be adapted to specific applications.

[0006] US 2011 / 0236846 discloses a furnace that, due to its construction, may have several drawbacks for industrial-scale use, including the risk of blockage after a period of operation. In fact, due to the intense bubbling of the melt within the furnace, droplets or clumps of melt can rise along with the hot gases. Upon entering the cooler section of the outlet riser, these droplets or clumps rapidly freeze and thus completely block the outlet channel. This creates a pressure pulsation field of hot gases above the melt within the furnace. These pressure pulsations above the melt generate very large melt jet pulsations at the furnace outlet. This, in turn, can lead to a significant decrease in product quality at the fiberization unit outlet. Furthermore, due to the contours of the outlet channel, large clumps of melt may be ejected into the flue. The thermal protection of the chimney is typically weaker than that of the furnace itself. Therefore, there is also a risk of complete sealing or wear of the flue material.

[0007] Therefore, the objective of this invention is to provide a furnace for melting vitrifiable materials that allows for the elimination of the technical disadvantages of the prior art.

[0008] Within the scope of this technical task, the object of the present invention is to provide a furnace for melting vitrifiable materials that is robust, simple and economical in structure, and easy to assemble, disassemble and maintain.

[0009] Another object of the present invention is to provide a furnace for melting vitrifiable materials that can be easily adapted to a particular application.

[0010] The technical task and these and other objectives of the invention are achieved by realizing a furnace for melting vitrifiable materials, characterized in that the furnace has a modular wall structure formed by modules, each module comprising a pair of flat metal panels separated by gaps for circulating cooling water.

[0011] In one embodiment, the gap has a baffle for guiding water.

[0012] In one embodiment, the guide baffle is formed of a flat metal strip fixed orthogonally to the two panels.

[0013] In one embodiment, the panels of each module are connected by bolts passing through the gap.

[0014] In one embodiment, the module has a peripheral connection flange.

[0015] In one embodiment, the wall structure includes: at least one bottom module; a boundary module cooperating with the bottom module to define a melting tank; at least one top module having an outlet for discharging gases generated in the melting tank; and a boundary module defining an upwardly conveying labyrinthine channel for conveying the gases upward from a port of the melting tank to the outlet.

[0016] The furnace is equipped with a burner that can be operated from below if applied via a bottom module, from the side if applied via a boundary module that defines the melting pot, or even from above if applied via a boundary module that defines the labyrinthine passageway.

[0017] In one embodiment, the boundary module for defining the labyrinthine passage includes at least one module that is tilted upwards and overlaps with the port of the melting pot.

[0018] In one embodiment, the tilting module protrudes upward into the wall structure.

[0019] In one embodiment, the side of the tilting module opposite to the melting tank defines an accumulation zone for accumulating material delivered by the gas.

[0020] In one embodiment, the maze-like path has passageways of different areas to accelerate and decelerate the rising airflow.

[0021] In one embodiment, the solidified material deposited in the accumulation zone forms a sliding surface for another material to slide into the molten pool.

[0022] The upwardly inclined module is advantageously arranged as a barrier that facilitates the separation of solidified material particles from the rising airflow by intercepting the rising airflow. These solidified material particles slide along the inclined module to return to the molten pool.

[0023] The present invention also discloses a furnace for melting vitrifiable materials, characterized in that the furnace has a combined wall structure comprising: at least one bottom module; a boundary module for cooperating with the bottom module to define a melting vessel; at least one top module having an exhaust port for discharging gases generated in the melting vessel; and a boundary module for defining an upwardly conveying labyrinthine channel for conveying the gases from the port of the melting vessel upward to the exhaust port. The boundary module defining the labyrinthine channel includes at least one upwardly inclined module overlapping the port of the melting vessel, the inclined module protruding upward into the wall structure. The bottom module is rectangular or square, the dimensions of each peripheral side of the bottom module are in the range of 2m to 4m, the bottom module has parallel rows of longitudinal holes for accommodating burners parallel to two opposite peripheral sides of the bottom module, the spacing of the longitudinal holes is in the range of 0.3m to 0.6m, and the distance between the longitudinal holes and the peripheral sides is in the range of 0.1m to 0.7m.

[0024] This type of furnace design has many advantages.

[0025] The furnace is very easy to assemble, disassemble, clean, and maintain due to its modular structure.

[0026] The shape, size, and proportions of each part can be flexibly adapted to specific applications.

[0027] The module is formed by flat metal panels and straight metal strips, making it very easy to assemble.

[0028] The components of the module (mainly metal panels, metal strips and hardware) can be easily manufactured and / or readily available on the market without complex mechanical processes.

[0029] From a functional perspective, water cooling maintains structural integrity by significantly increasing the average lifespan of the furnace, thanks to the special configuration and arrangement of the water guiding channels, which allows for uniform cooling of the modules.

[0030] Because of the labyrinthine upward conveying channel used to transport the gas upwards, the chimney (i.e., the upper part of the furnace with the gas vent) is completely protected and there is no risk of blockage from material splashes from the melting pot.

[0031] The upward-flowing labyrinthine channels subject the gases generated in the melting tank to turbulent motion, which promotes the precipitation of the material transported by the gas itself. Therefore, this material does not clog the chimney, can be recovered in the accumulation zone, and then reintroduced into the melting tank.

[0032] A specific embodiment of the inclined module with a labyrinthine channel reduces the presence of solidified molten material droplets in the smoke. The labyrinthine path ensures that the smoke contacts the upper inclined module, causing solidified droplets to adhere to the wall of the inclined module and subsequently drip down the wall, thus carrying the material back into the molten pool. Additionally, the vortex or air circulation system increases through narrow sections of the labyrinthine channel, then rapidly decreases in velocity in subsequent, larger passage sections, causing droplets of solidified material to deposit, resulting in material accumulation that can be manually removed or allowed to accumulate in such a way that it forms additional particles sliding towards the interior of the molten pool (made of the accumulated material).

[0033] Furthermore, it must be pointed out that the labyrinthine passages protect the chimney from radiation emitted by the materials present in the melting pot, thus protecting it from overheating, while also reflecting this radiation back into the melting pot.

[0034] Reflected radiation helps melt the material present in the melting pot, thereby improving the thermal efficiency of the furnace.

[0035] It can also recover flue gas to further improve the thermal efficiency of the furnace.

[0036] Other features and advantages of the invention will become more apparent from the description of preferred, but not exclusive, embodiments of a furnace for melting vitrifiable materials according to the invention, which are shown in the accompanying drawings by way of non-limiting example only, wherein:

[0037] Figure 1 A schematic exploded view of a first embodiment of the furnace is shown;

[0038] Figure 2 It shows Figure 1 A top view of the furnace;

[0039] Figure 3 It shows Figure 1 The vertical cross-section of the furnace;

[0040] Figure 4 A schematic exploded view of a second embodiment of the furnace is shown;

[0041] Figure 5 It shows Figure 4 A top view of the furnace;

[0042] Figure 6 It shows Figure 4 The vertical cross-section of the furnace;

[0043] Figure 7 A side elevation view of a possible module of the wall structure is shown, in which the panels are shown in a transparent manner, and bolts are omitted in order to understand the internal guide channels of the module;

[0044] Figure 8 The module is shown along Figure 7 The cross section cut by line GG;

[0045] Figure 9 The module is shown along Figure 7 The cross section intercepted by line DD;

[0046] Figure 10 The module is shown along Figure 7 The cross section intercepted by line AA.

[0047] Equivalent parts in the various embodiments will be indicated by the same reference numerals.

[0048] Referring to the above figures, a furnace for melting vitrifiable materials is shown, generally indicated by reference numeral 1.

[0049] The furnace 1 has a modular wall structure formed by modules 2i, 2ii, 2iii, 2iv, 2v, 2vi, 2viii, 2ix, 2x, 2xi, and 2xii, each module including panels 3a and 3b separated by gaps 4 for circulating cooling water.

[0050] Panels 3a and 3b are preferably flat.

[0051] Panels 3a and 3b are preferably made of metal, especially steel.

[0052] Each module more precisely comprises two parallel panels 3a and 3b separated by a gap 4.

[0053] The gap 4 between the two panels 3a and 3b has baffles 5a and 5b for guiding water.

[0054] Each module has at least one inlet water collector 15 and at least one outlet water collector 16, and is configured to be hydraulically connected in series or in parallel with adjacent modules.

[0055] Baffles 5a and 5b are formed from flat metal strips, particularly steel.

[0056] Baffles 5a and 5b are fixed orthogonally to panels 3a and 3b.

[0057] Panels 3a and 3b are connected by bolts 7 passing through gap 4.

[0058] Bolt 7 resists the expansion of panels 3a and 3b, which withstand the pressure of water circulating in the module, which can reach 10 bar.

[0059] Specifically, baffles 5a and 5b are welded to panels 3a and 3b located on the side of the melting tank, and are simply clamped to panels 3a and 3b located on the opposite side of the melting tank by bolts 7.

[0060] The baffles 5a and 5b include the inner baffle 5a of module 2 and the peripheral baffle 5b around the closed gap 4 of the module.

[0061] The inner baffles 5a are arranged in a parallel baffle array, and these parallel baffles are separated from the surrounding baffles 5b by the passage space 21.

[0062] The inner baffle 5a separates the straight sections 22 of the water channel, which are connected by the 180° curved sections 23 of the water channel, which include the passage space 21 and are defined by the peripheral baffle 5b.

[0063] The water guiding channels in the module are therefore formed by water channels that extend into coils.

[0064] In modules arranged vertically or inclined in the wall structure, the water guiding channel has a straight section 22 with the water channel oriented horizontally.

[0065] In this way, the formation of water stagnation recesses is avoided, which, if present, could alter proper heat exchange and thus risk damaging the wall structure.

[0066] The modules of the wall structure can have different shapes and sizes and have peripheral flanges for interconnection.

[0067] The modules can be bolted or welded together, or bolted and welded together.

[0068] Panels 3a and 3b of the module can have the same shape but different sizes.

[0069] In this case, a peripheral baffle 5b can be applied along the peripheral edge of the smaller panel 3b.

[0070] Some peripheral baffles 5b may have a greater height than gap 4 and may protrude orthogonally from one of panels 3a, 3b.

[0071] The protruding fins 8a of the peripheral baffle 5b can therefore be used as peripheral flanges for connection to adjacent modules.

[0072] Some of the peripheral baffles 5b may extend in a retracted position relative to at least some of the sides of the peripheral edge of the larger panel 3a.

[0073] The wing 8b of the larger panel 3a, located between its peripheral edge and the peripheral baffle 5b, can therefore be used as a peripheral flange for connection to adjacent modules.

[0074] The flanges 8a and 8b of adjacent modules are connected by fixing bolts. The wall structure includes: at least one bottom module 2i, provided with a hole 10 for accommodating a burner (not shown); boundary modules 2ii, 2iii, 2iv, and 2v for cooperating with the bottom module 2i to define the melting tank 11; at least one top module 2xii, provided with an exhaust port 14 for discharging gas generated in the melting tank 11; and boundary modules 2vi, 2vii, 2viii, 2ix, 2x, and 2xi for defining an upwardly conveying labyrinthine channel 17 for conveying the gas upward from the port of the melting tank 11 to the exhaust port 14.

[0075] Although the burner is installed from the bottom of the melting tank in the illustrated case, in other cases, the burner may be installed on the side of the melting tank or from the top of the melting tank.

[0076] The boundary modules used to define the labyrinthine passage 17 include at least one module 2vi that is inclined upward and overlaps with the port of the melting pot 11.

[0077] The tilting module 2vi protrudes upward into the wall structure and protects the discharge port 14 from material splashes from the melting tank 11 by its side 24 adjacent to the melting tank 11, while defining the accumulation zone 18 by its side 25 opposite to the melting tank 11 for accumulating material transported by gas.

[0078] Materials can be emptied by entering the accumulation area 18 through the appropriate door 19.

[0079] Now for reference Figures 1 to 3 The example shown.

[0080] In this case, the boundary module used to define the labyrinthine passage 17 includes at least an upwardly inclined second module 2vii that protrudes into the wall structure and converges toward the first inclined module 2vi to overlap with the port of the melting tank 11.

[0081] More precisely, the first tilting module 2vi partially overlaps with the port of the melting tank 11, and the second tilting module 2vii partially overlaps with the port of the melting tank 11 and extends until the second tilting module also overlaps with the first tilting module 2vi.

[0082] The labyrinthine passageway 17 therefore has at least one passageway section that is completely isolated from the port of the melting tank 11.

[0083] The wall structure of furnace 1 includes: a rectangular bottom module 2i; a first array of four vertical modules 2ii, 2iii, 2iv, and 2v, which are orthogonal to each other to define the melting pot 11; a second array of two vertical modules 2ii and 2v, which are parallel to each other and coplanar with the two modules 2ii and 2v of the first array, which cooperate with the two modules of the first array to define the melting pot 11; two modules 2vi and 2vii, which are inclined upwards and form a third array with the four vertical modules 2viii, 2ix, 2x, and 2xi, which are orthogonal to each other to define the labyrinthine passage 17; and a top module 2xii.

[0084] In this case, the four vertical modules 2ii, 2iii, 2iv, and 2v of the first array are rectangular; the two vertical modules 2ii and 2v of the second array are triangular; the two inclined modules 2vi and 2vii are rectangular; the two parallel vertical modules 2x and 2xi of the third array are rectangular but have different heights; the other two parallel vertical modules 2viii and 2ix of the third array are trapezoidal; and the top module 2xii is rectangular.

[0085] The two sets of coplanar modules are each formed by the rectangular modules of the first array, the triangular modules of the second array, and the trapezoidal modules of the third array.

[0086] Except for the two inclined modules 2Vi and 2vii that are joined to one side of the overlying modules 2xi and 2x along their middle section, all the modules are joined together on the periphery.

[0087] Now for reference Figures 4 to 6 The example shown.

[0088] In this case, the boundary modules used to define the labyrinthine passage 17 include at least a second module 2vii that slopes upward and intersects with the ports of the melting pot 11.

[0089] The first tilting module 2vi completely overlaps with the port of the melting tank 11 and extends toward the second tilting module 2vii.

[0090] The labyrinthine passageway 17 therefore has at least one passageway section that is completely isolated from the port of the melting tank 11.

[0091] The wall structure of the furnace 1 includes: a rectangular bottom module 2i; a first array of four vertical boundary modules 2ii, 2iii, 2iv, 2v, which are orthogonal to each other to define the melting pot 11; two boundary modules 2vi, 2vii, which are inclined upward and a second array of four vertical modules 2viii, 2ix, 2x, 2xi, which are orthogonal to each other to define the labyrinthine passageway 17; and a top module 2xii.

[0092] In this configuration, the two parallel vertical modules 2iii and 2iv of the first array are rectangular, and the other two parallel vertical modules 2ii and 2v of the first array are pentagonal, the two inclined modules 2vi and 2vii are rectangular, the two parallel vertical modules 2x and 2xi of the second array are rectangular, the other two parallel vertical modules 2viii and 2ix of the second array are pentagonal, and the top module 2xii is rectangular.

[0093] The pentagonal modules of the first and second arrays are coplanar and joined along one side of each other.

[0094] The first tilted module 2vi, which completely overlaps with the melting tank 11, joins the common edges of the two pentagonal modules 2ii, 2v and the rectangular module 2iv of the first array along three of its four sides.

[0095] The second tilted module 2vii is joined along one side to the common edge of the rectangular module 2iii of the first array and along its other three sides to the common edges of the two pentagonal modules 2ii, 2v and the rectangular module 2iii of the second array.

[0096] Except for the first inclined module 2vi, which is joined to one side of the overlying module 2xi along its middle section, all the modules are joined together on the periphery.

[0097] The furnace for melting vitrifiable materials according to embodiments of the present invention does not strictly require a water-cooling module.

[0098] Regardless of whether a water-cooling module is provided, according to an embodiment of the invention, the bottom module 2i is rectangular or square, with the dimensions of each peripheral side of the bottom module ranging from 2m to 4m, preferably from 2.5m to 3m. The bottom module has multiple rows of parallel longitudinal holes 10 for accommodating the burner, these holes 10 being parallel to two opposite peripheral sides of the bottom module 2i and spaced between 0.3m and 0.6m, preferably between 0.35m and 0.5m, and the distance between these holes and the peripheral sides of the bottom module 2i ranging from 0.1m to 0.7m.

[0099] The position of the burner at the bottom of the furnace has a very important impact on the speed and quality of the melting process.

[0100] An improperly positioned burner can sometimes significantly worsen the melting process, and in some cases, completely prevent it.

[0101] The batch inlet 12 is located on one side of the melting tank 11, for example, on the module 2iv side.

[0102] In addition, raw materials can be supplied from the top of the melting tank 11, for example from module 2vi.

[0103] The melt outlet 13 is preferably located on the opposite side, on module 2iii. However, if necessary, the melt outlet may be located on the left and right sides, on modules 2ii and 2v.

[0104] In addition, the melt outlet can be located on the bottom module 2i of the furnace.

[0105] Batch feed can be fed below or above the melt level.

[0106] The melting vessel 11 may have multiple doors (not shown in the figure for clarity) for access to the interior to monitor the state inside the furnace and to clean the solidified particles.

[0107] Properly arranging the furnace to remove fumes is crucial.

[0108] Due to the intense bubbling of the melt within melting vessel 11, droplets or large clumps of the melt may rise along with the hot gases. These droplets or clumps cool rapidly as they enter the cooler sections of the labyrinthine passageway 17.

[0109] If the outline of the exit labyrinth channel 17 is incorrect, the cooled droplets or blocks may completely block the exit labyrinth channel 17 during furnace operation.

[0110] Therefore, a pressure pulsation field of hot gas may be generated above the melting pot 11 in the furnace.

[0111] These pressure pulsations above the melting tank 11 can generate very large melt jet pulsations at the furnace outlet.

[0112] Therefore, the pulsation of the furnace's molten output may cause a significant decrease in product quality at the fiberization unit outlet.

[0113] Furthermore, due to the incorrect outline of the exit labyrinthine channel 17, large clumps of melt may be ejected and enter the flow channel.

[0114] The thermal protection of the labyrinthine channel 17 is usually weaker than that of the furnace itself: therefore, there is a high risk of the channel material becoming completely sealed or worn away.

[0115] Advantageously, the furnace top is formed by two inclined modules 2vi and 2vii.

[0116] Both modules 2vi and 2vii are inclined and extend upward from the boundary modules 2ii, 2iii, 2iv, 2v used to define the melting tank 11; the inclined modules may be contained within the vertical peripheral generatrix of the base module, or at least one inclined module may extend beyond the generatrix.

[0117] Modules 2vi and 2vii together form a cone-shaped rectangular maze-like passage 17.

[0118] The angle between module 2vi and the horizontal plane can be in the range of 5 to 20 degrees.

[0119] The angle between module 2vii and the horizontal plane can be in the range of 20 degrees to 60 degrees.

[0120] Typically, in the furnace according to the invention, the minimum cross-sectional area of ​​the labyrinthine passage 17 is 0.5 m². 2 Up to 2.5m 2 Within this range, the flow rate of the molten gas is between 10 m / s and 20 m / s.

[0121] The entire export section 14 can be rectangular or square, and its total circulation area should be 2 to 3 times the minimum circulation area.

[0122] The furnace for melting vitrifiable materials thus conceived is easily subject to a variety of modifications and variations, all of which are within the scope of the inventive concept; furthermore, all details can be replaced by technically equivalent elements.

[0123] In practice, the materials and dimensions used can be any that meet the requirements and existing technology.

Claims

1. A furnace (1) for melting a glassable material, characterized in that, The furnace has a combined wall structure formed by modules, comprising at least one bottom module (2i); a border module (2ii, 2iii, 2iv, 2v) for cooperating with the bottom module (2i) to delimit a melting tank (11); at least one top module (2xii) provided with a discharge (14) for discharging the gas generated in the melting tank (11); and a border module (2vi, 2vii, 2viii, 2ix, 2x, 2xi) for delimiting a labyrinthine channel (17) for upwardly conveying the gas from the ports of the melting tank (11) to the discharge (14), the border module for delimiting the labyrinthine channel (17) comprising a first module upwardly inclined, overlapping the ports of the melting tank (11), which protrudes upwardly into the wall structure; wherein the side of the first module opposite the melting tank delimits an accumulation zone (18) for accumulating the material conveyed by the gas.

2. The furnace (1) according to claim 1, wherein Each module comprises two flat metal panels (3a, 3b) separated by a gap (4) for circulating cooling water.

3. The furnace (1) according to claim 2, wherein The gap (4) has baffles (5a, 5b) for guiding the water.

4. The furnace (1) according to claim 3, wherein The baffles (5a, 5b) are formed by flat metal strips fixed orthogonally to the two panels (3a, 3b).

5. The furnace (1) according to any one of claims 3 and 4, wherein, The baffles (5a, 5b) comprise an inner baffle (5a) of the module, arranged in a parallel baffle array, and a peripheral baffle (5b) of the module, which closes the periphery of the gap (4), the inner baffle (5a) being separated from the peripheral baffle (5b) by passage spaces (21) to define water passages extending as a coil.

6. The furnace (1) according to claim 3 or 4, wherein The panels (3a, 3b) of each module are connected by bolts passing through the gap (4).

7. The furnace (1) according to claim 3 or 4, wherein The modules have peripheral coupling flanges (8a, 8b).

8. The furnace (1) according to claim 1, wherein, The first module has a side (24) adjacent to the melting tank (11) configured to protect the discharge (14) from splashes of material from the melting tank.

9. The furnace (1) according to claim 1, wherein, The accumulation zone (18) is accessible through a door (19) for emptying the accumulated material.

10. The furnace (1) according to claim 1 or 2, wherein The labyrinthine path has passage sections of different areas to accelerate and decelerate the ascending gas flow.

11. The furnace (1) according to claim 1 or 2, wherein The border module for delimiting the labyrinthine channel (17) comprises a second module upwardly inclined, which protrudes into the wall structure and overlaps the ports of the melting tank (11) and converges towards the first module.

12. The furnace (1) according to claim 11, wherein, The first module and the second module each partially overlap the ports of the melting tank (11), and wherein the second module extends to overlap the first module.

13. The furnace (1) according to claim 11, wherein, The roof of the furnace is formed by the first module and the second module.

14. The furnace (1) according to claim 1 or 2, wherein The border module for delimiting the labyrinthine channel (17) comprises a second module upwardly inclined, which overlaps the ports of the melting tank (11).

15. The furnace (1) according to claim 14, wherein The first module completely overlaps the ports of the melting tank (11) and extends towards the second module so that at least one passage section of the labyrinthine channel (17) is completely isolated from the ports of the melting tank.

16. The furnace (1) according to claim 1 or 2, wherein The first module is inclined upward at an angle between 5 and 20 degrees from horizontal.

17. The furnace (1) according to claim 11, wherein The second module is inclined at an angle between 20 and 60 degrees from horizontal.

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