A PLANT FOR THE HEATH TREATMENT OF MANUFACTURES ARTICLES

Abstract

 A plant (1) for the heat treatment of manufactured articles, comprising a longitudinal casing (2), a convection tunnel oven (3) positioned longitudinally in the casing (2), a plurality of stackable trays (4) wherein the manufactured articles may be housed, comprising a conveyor (50) configured to transport a single row of stacks of stackable trays (4) through the oven (3) and a forced hot air circulation circuit through the oven (3); wherein the casing (2) has a first longitudinal sidewall (2a) and a second longitudinal sidewall (2b); wherein the oven (3) has an inlet end and an outlet end of the stack of stackable trays (4), a first longitudinal sidewall (3a) provided with hot air inlet openings and a second longitudinal sidewall (3b) provided with hot air outlet openings; wherein the homologous sides of the casing and the oven face each other wherein the first longitudinal sidewall (2a) and the second longitudinal sidewall (2b) of the casing (2) have a lower portion respectively (2a', 2b') facing the first homologous longitudinal sidewall (3a) and the second homologous longitudinal sidewall (3b) of the oven (3), and an upper portion (2a", 2b") respectively extending vertically to a higher elevation of the first and second homologous longitudinal sidewall (3a, 3b) of the oven (3) wherein the forced hot air circulation circuit comprises a horizontal flame burner (20) for heating the air, a fan (5) positioned in the upper part of the casing (2) above the burner (20), a descending ducting (6) of the hot air from the outlet of the fan (5) to the first longitudinal sidewall (3a) of the oven (3) and an ascending duct (7) of the hot air from the second longitudinal sidewall (3b) of the oven (3) to the inlet of the fan (5); wherein the ascending duct (7) comprises a heating chamber (8) overlying the oven (3); wherein the burner (20) is positioned within the heating chamber (8); wherein the heating chamber (8) is bordered by the upper portion (2b") of the second longitudinal sidewall (2b) of the casing (2); and wherein the horizontal flame burner (20) protrudes from the upper portion (2b") of the second longitudinal sidewall (2b) of the casing (2).

Description

[0001] The present invention relates to a plant for the heat treatment of manufactured articles.

[0002] Plants for the heat treatment of manufactured articles, typically small semi-finished products from previous mechanical processing stations downstream of which heat treatments are required to complete and consolidate specific properties and characteristics required by the finished product, have long been on the market.

[0003] It is well known that plants for the thermal treatment of manufactured articles can be bulky and occupy large spaces within the production areas of industrial areas.

[0004] It is also well known that plants for the heat treatment of manufactured articles must be able to guarantee a controlled and homogeneous distribution of temperatures over all the manufactured articles being treated.

[0005] EP 3303961B1 teaches a system for the hot air heat treatment of friction elements, in particular brake elements such as brake pads.

[0006] Such systems can be inefficient, as the forced circulation of heated air does not always guarantee an even distribution of temperature in the heating fluid and thus of the heat transferred to the manufactured articles in the process, or inefficient because the force air circuit is particularly tortuous and requires significant energy expenditure to be sustained.

[0007] There is therefore a need to improve the structure of a plant for the heat treatment of artefacts of known type.

[0008] The technical task proposed by the present invention is, therefore, to realise a plant for the heat treatment of manufactured articles that can eliminate the complained of technical drawbacks of the known technique.

[0009] In the context of this technical task, one aim of the invention is to realise a system for the hot-air heat treatment of manufactured articles that is compact, ensures proper homogenisation of the heating fluid and consistent heat transfer to the manufactured articles being processed.

[0010] A further purpose of the present invention is to realise a plant for the hot-air heat treatment of manufactured articles that is compact, simple and energy-efficient.

[0011] The technical task, as well as these and other purposes, according to the present invention are achieved by making a facility for heat treating manufactured articles , comprising a longitudinal casing, a convection tunnel oven positioned longitudinally in the casing, a plurality of stackable trays wherein the manufactured articles may be housed, comprising a conveyor configured to transport a single row of tray stacks through the oven and a forced hot air circulation circuit through the oven; wherein the casing has a first and a second longitudinal sidewall; wherein the oven has a tray stack inlet end, a tray stack outlet end, a first longitudinal sidewall provided with hot air outlet openings and a second longitudinal sidewall provided with hot air inlet openings; wherein the homologous sides of the casing and the oven face each other; wherein each sidewall of the casing has a lower portion facing the homologous sidewall of the oven and an upper portion extending vertically to an upper portion of the homologous sidewall of the oven; wherein the forced hot air circulation circuit comprises a horizontal flame burner for heating the air, a fan positioned above the oven, a descending hot air ducting from the outlet of the fan to the first sidewall of the oven and an ascending hot air ducting from the second sidewall of the oven to the inlet of the fan; wherein the ascending ducting comprises a heating chamber above the oven; wherein the burner is positioned within the heating chamber; wherein the heating chamber is bounded by the second sidewall of the casing ; and wherein the horizontal flame burner protrudes from the upper portion of the second sidewall of the casing.

[0012] In one embodiment, the ascending channelling includes a gap between the lower portion of the second sidewall of the casing and the homologous sidewall of the oven.

[0013] In one embodiment, the descending ductwork comprises a wall of the heating chamber that extends upwards from the first sidewall of the oven and delimits a cavity with the first sidewall of the casing.

[0014] In one embodiment, the ascending ducting provides baffles to the fan intake, between which the burner is positioned.

[0015] In one embodiment, the artefacts are brake pads.

[0016] In a embodiment, artefacts are friction materials.

[0017] Other features of the present invention are also defined in subsequent claims.

[0018] Further features and advantages of the invention will become more apparent from the description of a preferred but non-exclusive embodiment of a plant for the heat treatment of manufactured articles according to the invention, illustrated by way of illustration and not limitation in the accompanying drawings, in which

• Figure 1 shows an axonometric overview of the plant;
• Figure 2 shows a vertical longitudinal section of the plant;
• Figure 3 shows a vertical cross-section of the plant;
• Figure 4 shows a horizontal section of the plant;

[0019] The following detailed description refers to the attached drawings, which form part of it.

[0020] In drawings, similar reference numbers typically identify similar components, unless the context indicates otherwise.

[0021] The illustrative embodiments described in the detailed description and drawings are not intended in a limiting sense.

[0022] Other embodiments may be used, and other modifications may be made without departing from the spirit or scope of the subject matter depicted here.

[0023] The aspects of this description, as generally described in this context and illustrated in the figures, can be arranged, substituted, combined, and designed in a wide variety of different configurations, all of which are explicitly contemplated and are part of this description.

[0024] With reference to the above-mentioned figures, a plant for the heat treatment of artefacts is shown according to the overall finding indicated with reference number 1.

[0025] Plant 1 for the heat treatment of artefacts comprises a longitudinal enclosure 2, a convection tunnel oven 3 positioned inferiorly and longitudinally in the enclosure 2, and a plurality of stackable trays 4 where the artefacts can be stored.

[0026] Typically, items subjected to heat treatment include friction materials, typically including brake pads.

[0027] Plant 1 comprises a conveyor 50 configured to transport a single row of stackable tray stacks 4 through the oven 3, which has an inlet end of the tray stacks and an outlet end of the stackable tray stacks 4 and where a forced hot air circulation circuit provides heat treatment of the products.

[0028] Enclosure 2 has a first longitudinal sidewall 2a and a second longitudinal sidewall 2b.

[0029] Oven 3 has a first longitudinal sidewall 3a and a second longitudinal sidewall 3b where the homologous sidewalls of enclosure 2 and oven 3 face each other.

[0030] Typically, each longitudinal sidewall of the casing 2a, 2b has a lower portion 2a', 2b' directly facing the homologous sidewall 3a, 3b of the oven 3 and an upper portion 2a", 2b" extending vertically to a higher elevation of the homologous sidewall 3a, 3b.

[0031] In the path of the forced hot air circulation circuit in the oven 3, the first longitudinal sidewall 3a is equipped with hot air inlet openings and the second longitudinal sidewall 3b is equipped with hot air outlet openings.

[0032] Typically, the forced hot air circulation circuit comprises a horizontal flame burner 20 for heating the air and a fan 5 positioned in the upper part of the casing 2 above the burner 20: at the first sidewall 3a of the oven 3 there is a downward ducting 6 of the hot air from the supply of the fan 5, while at the second sidewall 3b of the oven 3 there is an upward ducting 7 of the hot air to the intake of the fan 5.

[0033] The ascending duct 7 comprises a cavity 9 bounded by the lower portion 2b' of the second sidewall 2b of the casing 2 and the homologous sidewall 3b of the oven 3.

[0034] Advantageously, the ascending ducting 7 includes a heating chamber 8 within which the burner 20 is positioned.

[0035] The heating chamber 8 is bounded by the upper portion 2b" of the second sidewall 2b of envelope 2.

[0036] The horizontal flame burner 20 protrudes from this upper portion 2b" of the second sidewall 2b of the enclosure 2.

[0037] The descending ducting 6 comprises a wall 10 of the heating chamber 8 extending upwards from the first sidewall 3a of the oven 3 and bordering a cavity 11 with the first sidewall 2a of the casing 2.

[0038] The fan 5 is a centrifugal fan with vertical axial suction and horizontal discharge arranged in the upper part of the casing 2, above the heating chamber 8, and in a central position with respect to the longitudinal development of the oven 3 and in an off-centre position towards the second sidewall 3b of the oven 3 with respect to the transverse development of the oven 3. Advantageously, the ascending ducting 7 includes baffles 12 that direct the flow of hot air to the fan intake 5.

[0039] Advantageously, according to the present invention, there are at least two baffles 12 between which the burner 20 is positioned.

[0040] Advantageously, the baffles 12 surmount the gap 9 between the lower portion 2b' of the second sidewall 2b of the casing 2 and the homologous sidewall 3b of the oven 3.

[0041] The baffles 12 are confined in a region of the heating chamber 8 adjacent to the second sidewall 2b of the casing 2, are tapered from top to bottom, and converge at an opposite angle towards the fan intake 5.

[0042] Advantageously, the baffles 12 are configured and arranged to perform at least a tripartition of the flow of hot air conveyed to the intake of fan 5 into a first part of flow taken from the zone of the inlet end of the oven 3, a second part of flow taken from the zone of the outlet end of the oven 3 and a third part of flow taken from the central zone of the oven 3.

[0043] This prevents the flow sucked in by the fan from coming to a greater extent from the central zone of oven 3 and to a much lesser extent from the end zones of oven 3, and thus ensures uniform heat treatment of all products passing through oven 3 by means of the step drive of conveyor 50. Advantageously, in order to promote the correct recirculation of hot air without excessive pressure drops, the hot air inlet openings provided in the first longitudinal sidewall 3a are horizontally aligned with the gaps between the trays of stacked artefacts and are equipped with horizontal diffusers, e.g. horizontal vents extending along the direction of advancement of the trays, which horizontally direct the flow of hot air.

[0044] The operation of a plant for the heat treatment of manufactured articles according to the invention is apparent from what has been described and illustrated and, in particular, is substantially as follows.

[0045] The fan 5 positioned in the upper part of the casing 2 draws in air from the heating chamber 8 at the bottom; the supply air of the fan 5 is suitably conveyed into the downward ducting 6 in the cavity 11 defined by the wall 10 and the first sidewall 2a of the casing 2 in continuity with a lower section defined by the first longitudinal sidewall 3a of the oven 3 and the first sidewall 2a of the casing 2.

[0046] Advantageously, the first longitudinal sidewall 3a is provided with appropriate hot air inlets in the oven 3 to the plurality of stacking tray stacks 4 where the manufactured articles are housed in the process.

[0047] The hot air passes through the trays and laps at the artefacts, transferring the expected amount of heat, and reaches the second longitudinal sidewall 3b, which is equipped with openings for the hot air to exit the oven 3 towards the ascending duct 7.

[0048] The ascending duct 7 comprises a cavity 9 between the second longitudinal sidewall 3b and the lower portion 2b' of the second sidewall 2b of the casing 2.

[0049] The ascending ducting 7 continues above and includes a heating chamber 8 inside which the flame burner 20 is positioned.

[0050] Advantageously and suitably, according to the present invention, at least two baffles 12 are provided in the ascending ducting 7 and inside the heating chamber 8 which convey the air heated by the flame burner 20 to the fan intake 5 located above the heating chamber 8.

[0051] Advantageously, the baffles 12 contribute to the acceleration of the heated air towards the fan 5 inlet and to the homogenisation of the temperature of the heated fluid mass upstream of the fan 5 outlet towards the downward ducting 6.

[0052] Advantageously, the forced-air circuit, being configured and arranged in such a way that it cannot have a frontal interaction with the flame delivered by the burner 20, prevents the flame from tearing and the efficiency and effectiveness of the burner 20 from being affected.

[0053] The forced air circuit, in the ascending section, is also extremely linear and free of loops or tortuosity which could, if present, lengthen the air path between the oven exit and the fan intake as well as increase pressure drops with negative effects on energy consumption.

[0054] In practice, it was found that a system for the heat treatment of manufactured articles according to the invention is particularly advantageous to ensure, with the forced circulation of the heated air thus conceived, an even distribution of the temperature in the heating fluid and thus of the heat transferred to the manufactured articles in the process.

[0055] A plant for the heat treatment of manufactured articles thus conceived is susceptible to numerous modifications and variations, all of which fall within the scope of the inventive concept as defined by the claims; moreover, all details are replaceable by technically equivalent elements. In practice, the materials used, as well as the dimensions, can be any according to requirements and the state of the art.

Claims

1. A plant (1) for the heat treatment of manufactured articles, comprising a longitudinal casing (2), a convection tunnel oven (3) positioned longitudinally in said casing (2), a plurality of stackable trays (4) wherein said manufactured articles may be housed, a conveyor (50) configured for transporting a single row of stacks of said stackable trays (4) through said oven (3) and a forced hot air circulation circuit through said oven (3); wherein said casing (2) has a first longitudinal sidewall (2a) and a second longitudinal sidewall (2b); wherein said oven (3) has an inlet end and an outlet end of said stacks of said stackable trays (4), a first longitudinal sidewall (3a) provided with hot air inlet openings and a second longitudinal sidewall (3b) provided with hot air outlet openings; wherein said homologous sides of said casing and said oven face each other; wherein said first longitudinal sidewall (2a) and said second longitudinal sidewall (2b) of said casing (2) present a lower portion (2a', 2b') respectively facing said first homologous longitudinal sidewall (3a) and said second homologous longitudinal sidewall (3b) of said oven (3), and an upper portion (2a", 2b") respectively extending vertically to an upper height of said first and said second homologous longitudinal sidewall (3a, 3b) of said oven (3); wherein said forced hot air circulation circuit comprises a horizontal flame burner (20) for heating air, a fan (5) positioned in the upper part of said casing (2) above said burner (20) a descending duct (6) of hot air from the outlet of said fan (5) to said first longitudinal sidewall (3a) of said oven (3), and an ascending duct (7) of hot air from said second longitudinal sidewall (3b) of said oven (3) to the inlet of said fan (5); wherein said ascending duct (7) comprises a heating chamber (8) above said oven (3); wherein said burner (20) is positioned within said heating chamber (8); wherein said heating chamber (8) is bounded by said upper portion (2b") of said second longitudinal sidewall (2b) of said casing (2) and wherein said horizontal flame burner (20) protrudes from said upper portion (2b") of said second longitudinal sidewall (2b) of said casing (2), characterised in that said ascending duct (7) provides baffles (12) conveying the flow of hot air towards the intake of said fan (5), said burner being positioned between two of said baffles.

2. A plant (1) for the heat treatment of manufactured articles according to claim 1, characterised in that said baffles (12) are configured and arranged to perform at least a tripartition of the flow of hot air conveyed towards the intake of said fan (5) into a first part of flow taken from the zone of said inlet end of the oven (3), a second part of flow taken from the zone of said outlet end of the oven (3) and a third part of flow taken from the central zone of the oven (3).

3. A plant (1) for the heat treatment of manufactured articles according to any preceding claim, characterised by the fact that said ascending duct (7) comprises a cavity (9) between said lower portion (2b') of said second sidewall (2b) of said casing (2) and said homologous longitudinal sidewall (3b) of said oven (3).

4. A plant (1) for the heat treatment of manufactured articles according to the preceding claim, characterised by the fact that said baffles (12) surmount said cavity (9) between said lower portion (2b') of said second longitudinal sidewall (2b) of said casing (2) and said homologous longitudinal sidewall (3b) of said oven (3).

5. A plant (1) for the heat treatment of manufactured articles according to any preceding claim, characterised by the fact that said baffles (12) are confined in a region of said heating chamber (8) adjacent to said second longitudinal sidewall (2b) of said casing (2).

6. A plant (1) for the heat treatment of manufactured articles according to any preceding claim, characterised by the fact that said baffles (12) are tapered from top to bottom.

7. A plant (1) for the heat treatment of manufactured articles according to any of the preceding claims , characterised by the fact that said baffles (12) converge with opposite inclination towards the intake of said fan (5).

8. A plant (1) for the heat treatment of manufactured articles according to any preceding claim, characterised in that said descending duct (6) comprises a wall (10) of said heating chamber (8) extending upwards from said first longitudinal sidewall (3a) of said oven (3) and delimiting a cavity (11) with said first longitudinal sidewall (2a) of said casing (2).

9. A plant (1) for the heat treatment of manufactured articles according to any of the preceding claims, characterised in that said fan (5) is a centrifugal fan with vertical axial suction and horizontal discharge arranged in the upper part of said casing (2) above said heating chamber (8) in a central position with respect to the longitudinal development of said oven (3) and in an off-centre position towards said second longitudinal sidewall (3b) of said oven (3) with respect to the transverse development of said oven (3).

10. A plant (1) for the heat treatment of manufactured articles according to any preceding claim, characterised by the fact that said articles are brake pads.

Drawing