Oven and method for drying plates of electric accumulators

Abstract

An oven for drying plates of electric accumulators and a method for drying plates of electric accumulators by this oven are described. The oven (100) comprises: a support structure (10) intended to be rested on a floor (P); a drying chamber (20) delimited by the support structure and extending between an inlet door (22) and an outlet door (24); and a conveyor belt (30) slidingly mounted on the support structure (10) and equipped with at least one delivery travel (32), placed across the drying chamber (20) between the inlet door (22) and the outlet door (24). The conveyor belt (10) can be fed, at the delivery travel (32), with a succession of plates (50) for electric accumulators and can be operated to transport the plates for electric accumulators along the drying chamber (20) from the inlet door (22) to the outlet door (24). The oven (100) further comprises infrared heating means (50), which are fixed on the support structure (10) and inside the drying chamber (20) and can be activated to heat by radiation at least one surface of the plates (40) transported by the conveyor belt (30) to at least partially dry the plates for electric accumulators.

Description

[0001] “Oven and method for drying plates of electric accumulators”

[0002] Field of the invention

[0003] The present invention generally concerns the technical field of processes of manufacturing electric accumulators. In particular, the present invention concerns an oven and a method for drying plates of lead or lead-acid electric accumulators.

[0004] Known art

[0005] Lead or lead-acid electric accumulators are the most widely used rechargeable electric accumulators in the world. They consist of positive and negative plates immersed in a solution of sulfuric acid (electrolyte). The active material of the positive plates is constituted by lead dioxide, whereas the active material of the negative plates is constituted by spongy pure lead.

[0006] To produce electric current, a chemical reaction takes place inside the accumulator during the discharge stage, in which the electrolyte combines with the active material of the positive and negative plates, transforming it into lead sulfate. This resulting chemical compound is the lead salt of sulfuric acid and is in the form of white crystals or white powder, which is very poorly soluble in water: it is deposited on the plates during the discharge stage. When the entire electrolyte has chemically reacted with the plates, there is no more possibility of chemical reaction and the accumulator is discharged and must be recharged with energy. During the charging stage, the electric power supplied returns the active material of the positive and negative plates to its original condition. Specifically, lead sulfate is transformed back into metal lead and sulfuric acid in the negative plates and into lead dioxide and sulfuric acid in the positive plates.

[0007] Lines for the industrial production of lead or lead-acid electric accumulators are equipped with a plurality of equipment, which generally involve initially making a grid consisting of lead filaments. Typically, grids are made from a continuous lead alloy strip. The grids are then coated with a lead oxide paste by using a special coating machine. In the case of a continuous strip, the latter is covered on both sides with a layer of paper and then cut into pieces to form individual plates. Next, the individual coated plates are subjected to an oven-drying process and then collected and stacked in bundles. The plate bundles are then stacked on pallets for the curing process, during which an exothermic reaction takes place for reducing the free lead in the active material and achieve proper crystallization and porosity, which have a direct influence on the performance of the accumulator.

[0008] The plates in each bundle are then used, with positive or negative polarity, in assembly plants, where they are organized within box-like body cells and embedded in the electrolyte to carry out the oxidation-reduction reactions necessary to produce electric current.

[0009] The oven-drying step mentioned above is generally carried out to prevent the paste spread on each grid from sticking to other plates, when they are stacked on top of each other, thus keeping them separated.

[0010] To date, this drying step is carried out in special ovens equipped with a drying chamber extending between an inlet door, into which the coated plates to be dried enter, and an outlet door, from which the at least partially dried coated plates exit. In particular, ovens of known type are also equipped with a conveyor belt, which can be moved through the drying chamber and on which the coated plates are intended to be laid, to be moved from the inlet door to the outlet door of the drying chamber itself.

[0011] Furthermore, the ovens of known type for drying plates for electric accumulators are based on energy transfer by convection with hot air. For this purpose, they are equipped with heating means usually constituted by a gas or electric burner, which are arranged inside the drying chamber to directly or indirectly heat the process air circulating in that chamber. Heated process air promotes the evaporation of moisture contained in the paste, at least partially drying the plates to about 2% by weight of the active material.

[0012] The ovens for drying plates for lead or lead-acid electric accumulators of known type are also equipped with one or more fans in order to generate forced air circulation on the heat exchanger of the burner and blow air over the bottom and top parts of the plates via ducts equipped with slotted openings. In particular, plate drying occurs by evaporation of some of the water in the active material, which evaporation is due to the absorption of energy by air blown over the surface. Furthermore, these ovens of known type comprise an outlet shutter of the process air, which is configured to exhaust a fraction of the process air from the drying chamber, in order to allow air exchange with air from outside the drying chamber, for the drying process.

[0013] Ovens of known type, briefly described above, have proven in practice not to be without drawbacks.

[0014] A first drawback is that the gas burner of the heating means feed combustion gases onto the surface of the plates, thus generating chemical reactions that are not required for the production process of electric accumulators. In particular, this gas, containing carbon dioxide and water vapor, reacts with the active material, thus generating compounds such as hydrocerusite, which generates air bubbles during the process of forming the accumulators themselves, possibly causing problems on the surface of the active material.

[0015] Another drawback of the ovens for drying plates for lead or lead-acid electric accumulators of known type is related to the fact that adjusting temperature and relative humidity of the process air contained inside the drying chamber is based on the process temperature and not on the humidity conditions of the air getting on the plates, and this results in differences in operation with daily variations based on external environmental conditions. Indeed, this principle of operation results in an operator using excess temperatures in order to achieve the drying process and prevent the plates from sticking to each other. This results in excessive evaporation of water from the active material, which has a negative impact on the subsequent curing process and thus on the final quality of the accumulator.

[0016] An additional drawback of ovens for drying plates for lead or lead-acid electric accumulators of known type is that much of the energy generated by the gas or electric burner is lost to the environment via the air exhausted to remove the humidity inside the drying chamber. This results in high energy consumption for the drying process, up to more than five times the energy actually required to evaporate the same amount of water from the active material.

[0017] Yet another drawback of the ovens for drying plates for lead or lead-acid electric accumulators of known type comes from excessive heating of the plates, which results in elongation of the lead grid with respect to the wet active material, leading to cracks and gaps between the grid itself and the coated paste.

[0018] Thus, main object of the present invention is to solve or minimize the problems set forth above with reference to the ovens for drying plates for lead or lead-acid electric accumulators of known type, by providing an oven and a method for drying plates for electric accumulators, such that the plates can be dried in a more energyefficient and process-controlled manner.

[0019] A further object of the present invention is to provide an oven and a method for drying plates for electric accumulators, such that the water loss of the active material is minimized, in order to facilitate the curing step of the plates with the creation of smaller crystal size, finer and more diffuse porosity of the material, and lower final residue of free lead.

[0020] Still another object of the present invention is to provide an oven and a method for drying plates for electric accumulators, such that consumption is drastically reduced compared to ovens of known type.

[0021] A further object of the present invention is to provide an oven and a method for drying plates for electric accumulators, such that the humidity conditions of the air inside the drying chamber are automatically adjusted.

[0022] Still another object of the present invention is to provide an oven and a method for drying plates for electric accumulators, such that the surface of the active material is treated with an oxidizing substance to promote the curing process.

[0023] A further object of the present invention is to provide an oven and a method for drying plates for electric accumulators, such that the temperature on the surface of the plates can be adjusted independently depending on the position on the conveyor belt, so as to facilitate process control.

[0024] Still another object of the present invention is to provide an oven and a method for drying plates for electric accumulators, such that the temperature on the surface of the plates can be adjusted so as to prevent excessive heating of the plate grid with respect to the active material and such that, subsequently, they can be detached from each other.

[0025] A further object of the present invention is to provide an oven and a method for drying plates for electric accumulators, so as to reduce the emissions to the outdoor environment of lead particles generated by the residues of active material on the conveyor belt and which is subsequently dried and circulated to the outdoor environment by the air flows used in the process.

[0026] Still another object of the present invention is to provide an oven and a method for drying plates for electric accumulators, such that the thickness of the plates entering the conveyor belt can be adjusted by a specific control device.

[0027] Summary of the invention

[0028] These and additional purposes are achieved by the present invention thanks to an oven for drying plates for electric accumulators according to independent claim 1 and a method for drying plates for electric accumulators according to independent claim 11. Further preferential characteristics and aspects of the invention are set out in the dependent claims.

[0029] The present invention concerns, in a first aspect thereof, an oven for drying plates for electric accumulators, comprising a support structure intended to be resting on a floor; a drying chamber delimited by the support structure and extending between an inlet door and an outlet door; and a conveyor belt, slidingly mounted on the support structure and equipped with at least one delivery travel, placed across the drying chamber between the inlet door and the outlet door. The conveyor belt can be fed, at the delivery travel, with a succession of plates for electric accumulators and can be operated to transport the plates for electric accumulators along the drying chamber from the first inlet door to the outlet door.

[0030] The oven is characterized in that it also comprises infrared heating means, which are fixed on the support structure and inside the drying chamber and can be activated to heat by radiation at least one surface of the plates transported by the conveyor belt to at least partially dry the plates for electric accumulators.

[0031] In an embodiment, the infrared heating means comprises a series of upper infrared heating plates, which are positioned above a delivery travel of the conveyor belt and / or a series of lower infrared heating plates, which are positioned below the delivery travel of the conveyor belt.

[0032] According to an embodiment, the series of upper infrared heating plates and the series of lower infrared heating plates are specular to each other.

[0033] According to an embodiment, the oven comprises an electronic control unit and temperature sensors, each arranged at a respective upper and / or lower infrared heating plate and in electrical communication with the electronic control unit to adjust the operating temperature of the upper infrared heating plates and the operating temperature of the lower infrared heating plates.

[0034] According to an embodiment, each upper infrared heating plate and / or each lower infrared heating plate is combined with a handling device, which is configured to raise or lower the respective plate parallel to the conveyor belt.

[0035] According to an embodiment, the oven further comprises a forced air circulation device, which includes a delivery duct connected to external air and one or more fans configured to feed forced air into the delivery duct, wherein the delivery duct is positioned along the drying chamber and is configured to create an air flow perpendicular to the motion of the conveyor belt.

[0036] In an embodiment, the forced air circulation device further comprises a dehumidifier connected to the delivery duct, wherein the dehumidifier is in electrical communication with the electronic control unit and is configured to control the humidity of the external air which is fed into the drying chamber via the delivery duct.

[0037] In an embodiment, the oven further comprises at least one device for blowingin air, preferably containing from 0.1 to 2 ppm of gaseous ozone, on the plates for electric accumulators, wherein each blowing-in device is supplied by an ozone generator, preferably of the corona discharge type.

[0038] In an embodiment, the upper infrared heating plates and / or the lower infrared heating plates have a coating made of ceramic material.

[0039] In an embodiment, the oven further comprises a device for cleaning the conveyor belt, which is positioned below the drying chamber and comprises two groups of motorized brushes with a rotation opposite the direction of movement of the conveyor belt itself.

[0040] In its second aspect, the present invention concerns a method for drying plates for electric accumulators carried out using an oven as defined above. The method comprises the steps of:

[0041] - placing the plates on a conveyor belt;

[0042] - moving the conveyor belt so as to feed the plates which it supports into a drying chamber of the oven;

[0043] - inside the drying chamber, at least partially drying the plates by infrared heating; and

[0044] - picking up the at least partially dried plates for electric accumulators at the exit of the drying chamber.

[0045] In an embodiment, the method provides, during the drying step, a step of raising and lowering upper infrared heating plates and / or lower infrared heating plates of the oven, parallel to the feed direction of the conveyor belt, in order to increase the drying efficiency of the plates 40 for electric accumulators.

[0046] In an embodiment, the method provides, during the drying step, a step of controlling the temperature on the surface of the upper infrared heating plates and / or the lower infrared heating plates.

[0047] In an embodiment, the method provides, during the drying step, a step of forcedly circulating air on the plates for electric accumulators.

[0048] In an embodiment, the method provides, during the drying step, a step of blowing-in air containing gaseous ozone, preferably from 0.1 to 2 ppm of gaseous ozone, on the surface of the plates for electric accumulators.

[0049] Brief description of the drawings

[0050] This description will be set forth hereinafter with reference to the appended drawings provided for indicative, and therefore non-limiting, purpose only, wherein:

[0051] - figure 1 is a perspective schematic view of an oven for drying plates of electric accumulators according to a preferred embodiment of the present invention;

[0052] - figure 2 is a side schematic view of the oven of figure 1, with parts removed to better depict its internal components; - figure 3 is a schematic view of a detail of figure 2;

[0053] - figure 4 is a schematic view of a detail of figure 3;

[0054] - figure 5 is a perspective schematic view of the oven of figure 3, with additional parts removed; and

[0055] - figure 6 is a plan schematic view of the oven of figure 4.

[0056] Detailed description of embodiments of the invention

[0057] With reference to the figures, depicted therein is an oven for drying plates for electric accumulators, in particular lead or lead-acid electric accumulators, according to a preferred embodiment of the present invention.

[0058] The oven, generally denoted by reference number 100, is adapted for use in a line for producing plates for electric accumulators, preferably downstream of a coating machine adapted for spreading a paste of active material on the plates, and upstream of a packing machine adapted for stacking the coated plates on top of each other. The coating machine and the packing machine are of known type and will not be further described herein.

[0059] The oven 100 comprises a support structure 10, which is adapted to rest on an industrial floor P and is closed at the sides, top and bottom by panels 12 so as to define a drying chamber 20. The oven 100 further comprises a conveyor belt 30, which is slidingly mounted on the support structure 10.

[0060] The drying chamber 20 extends between an inlet door 22 of plates to be dried and an outlet door 24 of dried plates, and the conveyor belt 30 comprises a delivery travel 32 which is placed to cross the drying chamber 20, between the inlet door 22 and the outlet door 24.

[0061] Preferably, the conveyor belt 30 is of the closed loop type, in which case it also comprises a return travel 34 complementary to the delivery travel 32.

[0062] According to the embodiment depicted in the figures, the delivery travel 32 of the conveyor belt 30 is arranged substantially horizontally and even more preferably is parallel to a Y-direction of main or longitudinal extent of the drying chamber 20. Preferably, moreover, and as best seen in figure 3, the return travel 34 of the conveyor belt 30 extends outside the drying chamber 20, for example along a path below the drying chamber 20.

[0063] As best seen in figure 6, the conveyor belt 30 advantageously is constituted by two chains 31 and 33 preferably made of metal material, which are joined by rods 35 better depicted in figure 5, also made of steel or stainless steel. Preferably, the rods 35 are spaced 10 to 35 mm apart from each other and arranged perpendicularly to the dragging direction of the chains 31 and 32, so as to support plates for electric accumulators from the inlet to the outlet of the oven 100.

[0064] The conveyor belt 30 can be fed, at its delivery travel 32, with a succession of plates 40 for electric accumulators (as can be seen in figures 5 and 6) and can be operated to transport these plates 40 for electric accumulators along the drying chamber 20 from the inlet door 22 to the outlet door 24.

[0065] As can be seen in detail in figure 3, the oven 100 further comprises a device 60 for cleaning the conveyor belt 30, in particular its stainless steel rods 35, with each rotation along the closed loop.

[0066] In particular, the cleaning device 60 is positioned below the drying chamber 20, outside of it, so that the conveyor belt 30 enters the device 60 during its return travel 34, in order to reduce dust dispersion on the rods 35 before entering again the drying chamber 20. The cleaning device 60 also allows the amount of lead and lead oxide particles that can be released to the environment both from the tape itself and the plates 40 in all subsequent steps of the production of lead or lead-acid electric accumulators to be reduced.

[0067] Advantageously, the cleaning device 60 of the conveyor belt 30 is constituted by two groups of motorized brushes 61 (only one of which can be seen in figure 3) with a rotation opposite the movement direction of the belt itself. Advantageously, the cleaning device 60 of the conveyor belt 30 is contained in a chamber 62 with a suction system (that cannot be seen in figures) for ejecting the removed lead particles to a filter in the production areas.

[0068] According to the invention, the oven 100 further comprises infrared heating means 50, which are mounted on the support structure 10 and are operable to heat, by radiation, at least one surface of the plates 40 on the conveyor belt 30, which are moving inside the drying chamber 20, for drying at least partially the plates 40 for electric accumulators, for example up to about 2% by weight of the active material.

[0069] In particular, and as shown in detail in figures 2 to 4, the infrared heating means 50 comprise a series of upper infrared heating plates 51 that are positioned above the delivery travel 32 of the conveyor belt 30 and appropriately spaced apart therebetween. Preferably, the upper infrared heating plates 51 are variably spaced 50 mm to 900 mm apart therebetween in the direction of movement of the conveyor belt 30 from the inlet to the outlet of the drying chamber 20.

[0070] In addition to or as an alternative to the upper infrared heating plates 51, a series of lower infrared heating plates 52 can be provided, which are positioned below the delivery travel 32 of the conveyor belt 30 and appropriately spaced apart therebetween. Preferably, the lower infrared heating plates 52 are variably spaced 50 mm to 900 mm apart therebetween along the direction of movement of the conveyor belt from the inlet to the outlet of the drying chamber 20.

[0071] Preferably, each lower infrared heating plate 52 is protected by a metal sheet 58, best seen in figure 4, to prevent residues of active material or paper, present on the plates 40 for electric accumulators on the conveyor belt 30, from falling on the plates 52 themselves, thus reducing their heating effectiveness and creating problems of possible combustion of the residual material. Advantageously, the protection sheets 58 can be removed laterally along the drying chamber 20 for cleaning operations by operators.

[0072] If the lower infrared heating plates 52 are provided in addition to the upper infrared heating plates 51, the upper infrared heating plates 51 and lower infrared heating plates 52 are mirrored to each other.

[0073] Preferably, the upper infrared heating plates 51 and / or the lower infrared heating plates 52 vary in number from two to eight and can be activated independently, as will be described in detail herein below.

[0074] Preferably, the upper 51 and / or lower 52 infrared heating plates are of the electric type, but an alternative, non-electric embodiment, can be provided, such as for example, an indirect burner adapted for using fuels such as gas, diesel or fuel oil, or alcohol, or others.

[0075] Preferably, the upper 51 and / or lower 52 infrared heating plates have a coating made of ceramic material.

[0076] As seen in detail in figure 4, each of the upper infrared heating plates 51 can be raised or lowered parallel to the conveyor belt 30 by means of a handling device constituted by an adjusting screw 53. Similarly, each of the lower infrared heating plates 52 can be raised or lowered parallel to the conveyor belt 30 by means of a handling device constituted by an adjusting screw 54.

[0077] Preferably, the distance between the conveyor belt 30 and the upper 51 and lower 52 infrared heating plates varies between 50 mm and 300 mm. In the embodiment shown, an adjusting screw 53, 54 is provided for each upper heating plate 51 and each lower heating plate 52, respectively, but it is understood that a handling device common to all infrared heating plates or handling devices common to bundles of infrared heating plates can be provided.

[0078] The oven 100 further comprises a control system for the power radiated by the upper 51 and / or lower 52 infrared heating plates, which is configured so as to achieve accurate temperature control over the surface of the heating plates.

[0079] In particular, and as shown in detail in figure 3, this driving system comprises an electronic control unit or CPU 55 and a plurality of temperature sensors 56, 57, which are positioned at a respective heating plate and in electrical communication with the electronic control unit 55. The accurate temperature control of the upper 51 and / or lower 52 infrared heating plates advantageously allows the range of variation between plates to be reduced, with regard to the temperature on the surface and the energy absorbed by the active material and, consequently, the transfer of aqueous mass from the slurry to the air. In other words, the oven according to the present invention advantageously allows the variability in the production process that is however present in known ovens to be reduced, in particular in the starting step or in the step of maintaining the temperature in the drying chamber.

[0080] The oven 100 is also equipped with a forced air circulation device on the surface of the plates 40 for electric accumulators, which is configured to remove the moisture that evaporates from the plates 40 themselves after being irradiated by the infrared heating means 50.

[0081] As shown in detail in figures 1 to 3, the forced air circulation device comprises a delivery duct 70, which is positioned along the drying chamber 20 and connected with outside air, and fans 72, preferably two fans 72, positioned inside the drying chamber 20 at the inlet door 22 and outlet door 24, respectively. The fans 72 feed forced air into the delivery duct 70 to create an air flow perpendicular to the motion of the conveyor belt 30 both above and below. Such forced air flow is applied in the spaces between the subsequent upper 51 and / or lower 52 infrared heating plates, so as not to reduce heat transfer on the surface of the same plates.

[0082] The forced air circulation device further comprises a dehumidifier 76 to which the supply duct 70 is connected and through which ambient air passes before being fed into the delivery duct 70.

[0083] The dehumidifier 76 is in electrical communication with the electronic control unit 55 and is configured to control the ambient air that is fed into the drying chamber 20 by the delivery duct 70, so as to control the absolute humidity during the process and increase the drying capacity.

[0084] The dehumidifier 76 can be constituted by a condenser unit or based on a desiccant wheel system and is controlled by the electronic control unit 55 of the oven 100 depending on the absolute humidity level in the drying chamber 20. In particular, in case the absolute humidity value is higher than a preset value, the dehumidifier 76 is activated by the electronic control unit 55 so as to feed, into the delivery duct 70, dry air to accelerate the drying process.

[0085] The oven 100 is also equipped with an exhaust chimney 79, air inlet channel 77 from the dehumidifier, to remove humid air so as to maintain atmospheric pressure inside the drying chamber 20 and remove, more efficiently, evaporated moisture from the plates 40 for electric accumulators.

[0086] The exhaust chimney 79 for humid air is equipped with a heat recovery unit 78, which preferably is constituted by a plate heat exchanger, for recovering heat from the exhaust air and preheating that fed by the dehumidifier 76. The air exiting the heat recovery unit 78 is exhausted.

[0087] The oven 100 is also equipped with one or more air blowing-in devices 80 containing from 0.1 to 2 ppm of gaseous ozone, directly on the surface of the plates 40 for electric accumulators. Such blowing-in devices 80 are supplied by an ozone generator with corona discharge (not shown in the figures) installed on board the oven 100 and allow surface oxidation of the metallic lead in the active material of each plate 40 for electric accumulators to be achieved and exothermic reaction that will fully take place in the curing step of the plates in specific chambers to be triggered.

[0088] The operation of the oven 100 for drying plates of electric accumulators according to the present invention is evident to the technician in the field from what has been described and in particular is as follows.

[0089] The plates 40 for electric accumulators to be dried are placed on the conveyor belt 30, and then the conveyor belt 30 is moved so as to feed the plates 40 it supports into the drying chamber 20 of the oven 100 through the inlet door 22.

[0090] Inside the drying chamber 20, the plates 40 for electric accumulators are heated by the upper infrared heating plates 51 and / or the lower infrared heating plates 52, so that they are at least partially dried.

[0091] In particular, during the drying step inside the drying chamber 20, one of the following adjustments can be made in order to efficiently control the process parameters:

[0092] - raising and lowering the upper infrared heating plates 51 and / or lower infrared heating plates 52, parallel to the feed direction of the conveyor belt 30, in order to increase the drying efficiency of the plates 40 for electric accumulators;

[0093] - accurately controlling the temperature on the surface of the upper infrared heating plates 51 and / or lower infrared heating plates 52, in order to reduce the range of variation between plates with regard to the temperature on the surface and the energy absorbed by the active material and, consequently, the transfer of aqueous mass from the slurry to the air;

[0094] - maintaining the heat transfer constant on the surface of the plates 40 for electric accumulators, thanks to a forced air flow; and - blowing-in air containing gaseous ozone, preferably 0.1 to 2 ppm of gaseous ozone, directly on the surface of plates 40 for electric accumulators.

[0095] When the drying step inside the drying chamber 20 is finished, the plates 40 for electric accumulators are collected from the outlet of the drying chamber 20 and stacked in bundles.

[0096] The Applicant observed that, using the oven 100 and the drying method according to the present invention, the surface temperature of the plates for accumulators, as they exit the drying chamber of the oven, does not exceed 45°C with a tolerance of 3°C, whereas, in the case of the drying ovens of known type, the plates have temperatures up to 60°C and tolerances up to 15°C degrees.

[0097] Furthermore, the plates for accumulators produced with the oven according to the present invention have better crystallization of the active material in the curing step than the plates produced with known ovens. This results in an advantage both at the level of cell formation of electric accumulators, requiring less energy to complete the process, and in terms of improved capacity measured in Amps available at the same weight with plates produced with known ovens. This increased capacity can be measured in the range of 0.5 to 5% of the nominal capacity of the accumulator.

[0098] Finally, better control of the moisture of the active material in the plates for accumulators is achieved, thus reducing the variability present in known ovens in terms of both moisture and surface temperature of the paste and grid during the production process.

[0099] Various modifications may be made to the embodiment described in detail, all anyhow remaining within the protection scope of the invention, as defined by the following claims.

Claims

CLAIMS1. Oven (100) for drying plates (40) of electric accumulators, comprising:- a support structure (10) intended to be rested on a floor (P);- a drying chamber (20) delimited by the support structure (10) and extending between an inlet door (22) and an outlet door (24); and- a conveyor belt (30), mounted slidingly on the support structure (10) and equipped with at least one delivery travel (32), placed across the drying chamber (20) between the inlet door (22) and the outlet door (24), wherein the conveyor belt (30) can be fed, at the delivery travel (32), with a succession of plates (40) for electric accumulators and can be operated to transport the plates (40) for electric accumulators along the drying chamber (20) from the first inlet door (22) to the outlet door (24); characterized in that it also comprises infrared heating means (50), which are fixed on the support structure (10) and inside the drying chamber (20) and can be activated to heat, by radiation, at least one surface of the plates (40) transported by the conveyor belt (30) to at least partially dry the plates for electric accumulators.

2. Oven (100) according to claim 1, wherein the infrared heating means (50) comprises a series of upper infrared heating plates (51), which are positioned above a delivery travel (32) of the conveyor belt (30) and / or a series of lower infrared heating plates (52), which are positioned below the delivery travel (32) of the conveyor belt (30).

3. Oven (100) according to claim 2, wherein the series of upper infrared heating plates (51) and the series of lower infrared heating plates (52) are mirrored to each other.

4. Oven (100) according to claims 2 or 3, comprising an electronic control unit (55) and temperature sensors (56, 57), each provided at a respective upper (51) and / or lower (52) infrared heating plate and in electrical communication with the electronic control unit (55) to adjust the operating temperature of the upper infrared heating plates (51) and the operating temperature of the lower infrared heating plates (52).

5. Oven (100) according to any one of claims 2 to 4, wherein each upper infrared heating plate (51) and / or each lower infrared heating plate (52) is combinedwith a handling device (53, 54), which is configured to raise or lower the respective heating plate (51, 52) parallel to the conveyor belt (30).

6. Oven (100) according to any one of the preceding claims, further comprising a forced air circulation device, which includes a delivery duct (70) connected to external air and one or more fans (72) configured to feed forced air into the delivery duct (70), wherein the delivery duct (70) is positioned along the drying chamber (20) and is configured to create an air flow perpendicular to the motion of the conveyor belt (30).

7. Oven (100) according to claim 6, wherein the forced air circulation device further comprises a dehumidifier (76) connected to the delivery duct (70), wherein the dehumidifier (76) is in electrical communication with the electronic control unit (55) and is configured to control the humidity of the external air which is fed into the drying chamber (20) through the delivery duct (70).

8. Oven (100) according to any one of the preceding claims, further comprising at least one device (80) for blowing-in air, preferably containing from 0.1 to 2 ppm of gaseous ozone, on the plates (40) for electric accumulators, wherein each blowing-in device (80) is supplied by an ozone generator, preferably of the corona discharge type.

9. Oven (100) according to any one of claims 2 to 8, wherein the upper infrared heating plates (51) and / or the lower infrared heating plates (52) have a coating made of ceramic material and each lower infrared heating plate (52) is protected by a metal sheet (58).

10. Oven (100) according to any one of the preceding claims, further comprising a device (60) for cleaning the conveyor belt (30), which is positioned below the drying chamber (20) and comprises two groups of motorized brushes (61) with a rotation opposite the direction of movement of the conveyor belt (30) itself.

11. Method for drying plates (40) for electric accumulators carried out by using an oven (100) according to any one of the preceding claims, the method comprising the following steps of- placing the plates (40) onto a conveyor belt (30);- moving the conveyor belt (30) so as to feed the plates (40) for electricaccumulators supported by it into a drying chamber (20) of the oven (100);- inside the drying chamber (20), at least partially drying the plates (40) for electric accumulators by using infrared heating; and- picking up the plates (40) for electric accumulators at least partially dried at the exit of the drying chamber (20).

12. Method according to claim 11, wherein, during the drying step, a step is provided of raising and lowering upper infrared heating plates (51) and / or lower infrared heating plates (52) of the oven (100), parallel to the feed direction of the conveyor belt (30), in order to increase the drying efficiency of the plates (40) for electric accumulators.

13. Method according to claim 11 or 12, wherein, during the drying step, a step of controlling the temperature on the surface of the upper infrared heating plates (51) and / or the lower infrared heating plates (52) is provided.

14. Method according to any one of claims 11 to 13, wherein, during the drying step, a step of forced circulation of air on the plates (40) for electric accumulators is provided.

15. Method according to any one of claims 11 to 14, wherein, during the drying step, a step of blowing-in air containing gaseous ozone, preferably from 0.1 to 2 ppm of gaseous ozone, on the surface of the plates (40) for electric accumulators is provided.

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