Soundproof fume discharge conduit

Abstract

A soundproof fume discharge conduit adapted to be arranged between a ventilation system and an outlet chimney, the conduit defining a fume path therein, wherein at least one side surface of the conduit is provided with at least two protrusions, each protrusion internally defining a respective step-shaped recess, whereby the path is provided with at least two step-shaped recesses adapted to reflect sound waves propagating along the path, and wherein the step shape of each recess is defined by two first walls, which are incident at a first end thereof, and at least one wall of the two first walls is coated with a first sound absorbing material.

Claims

1. A steel plant comprising a fume outlet chimney, said outlet chimney being connected to at least one soundproof fume discharge conduit, said conduit being arranged between a ventilation system and said outlet chimney and defining a fume path therein, wherein at least one side surface of the conduit is provided with at least two protrusions, each protrusion internally defining a respective step-shaped recess, whereby the path is provided with at least two step-shaped recesses adapted to reflect sound waves propagating along the path, wherein the step shape of each recess is defined by two first walls, which are incident at a first end thereof, and at least one wall of the two first walls is coated with a first sound absorbing material.

2. The plant according to claim 1, wherein said at least two protrusions are externally step-shaped.

3. The plant according to claim 1, wherein there are provided a first stretch of the conduit, defining a first longitudinal axis X and adapted to be connected to the ventilation system, and a second stretch of the conduit defining a second longitudinal axis Y inclined with respect to the first longitudinal axis X and adapted to be connected to the outlet chimney; and wherein said at least one side surface of the conduit is an upper surface of the second stretch.

4. The plant according to claim 3, wherein said at least two protrusions are also provided on a lower surface and/or on side surfaces of the second stretch.

5. The plant according to claim 1, wherein a panel is included, provided with a plurality of holes and resting on second ends of the two first walls, opposed to the first ends, thus delimiting a volume of the step-shaped recess together with two second side walls which are parallel to each other and transversal to said two first walls.

6. The plant according to claim 5, wherein a single panel is provided resting on the second ends of the two first walls of each step-shaped recess.

7. The plant according to claim 5, wherein said panel is made of metal sheet coated with a second sound absorbing material.

8. The plant according to claim 5, wherein said panel has a percentage ratio of area of the plurality of holes to area of a solid part of the panel which is less than 50%.

9. The plant according to claim 7, wherein said second sound absorbing material is selected from the following: expanded clay; steel wool; mineral wool.

10. The plant it-according to claim 3, wherein the second stretch of the conduit has a circular or polygonal cross-section; and wherein both the first walls of at least one step-shaped recess have a first side with a shorter length than half of an average diameter of the second stretch in the case of a circular section or than half of a width of the second stretch in the case of a polygonal section.

11. The plant according to claim 10, wherein the second stretch of the conduit has a quadrangular section; and wherein both the first walls of at least one step-shaped recess have said first side with a shorter length than half of the width of the second stretch and a second side with a length which is equal to the width of the second stretch.

12. The plant according to claim 1, wherein said first sound absorbing material is selected from the following: expanded clay; steel wool; mineral wool.

13. A fume outlet chimney of a steel plant, said chimney being connected to at least one fume discharge conduit arranged between a ventilation system and said outlet chimney and defining a fume path therein, wherein at least one side surface of the conduit is provided with at least two protrusions, each protrusions internally defining a responsive step-shaped recess, whereby the path is provided with at least two-step recesses adapted to reflect sound waves propagating along the path, wherein the step shape of each recess is defined by two first walls, which are incident at a first end thereof, and at one wall of the two first walls is coated with a first sound absorbing material.

14. The plant according to claim 4, wherein the second stretch of the conduit has a polygonal section.

15. The plant according to claim 8, wherein said percentage ratio is from 25 to 35%.

16. The plant according to claim 9, wherein said second sound absorbing material is the same as the first sound absorbing material.

17. The plant according to claim 9, wherein said expanded clay is in form of granules.

18. The plant according to claim 12, wherein said expanded clay is in form of granules.

19. The fume outlet chimney according to claim 13, said chimney being connected at the bottom thereof to said at least one fume discharge conduit.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) The description of the invention relates to the accompanying drawings, which are provided by way of non-limiting example, in which:

(2) FIG. 1 shows a diagrammatic side view of a first embodiment of the conduit according to the invention;

(3) FIG. 2 shows a top view of the conduit in FIG. 1;

(4) FIG. 3 shows a perspective view of part of a second embodiment of the conduit of the invention, connected to a chimney;

(5) FIG. 4 shows a perspective view of the conduit shown in FIG. 3;

(6) FIG. 5 diagrammatically shows a section of the conduit in FIG. 3;

(7) FIG. 6 diagrammatically shows a section of a variant of a conduit according to the invention;

(8) FIG. 7 shows a top plan view of part of a component of the conduit shown in FIG. 6;

(9) FIG. 8 diagrammatically shows a section of another variant of a conduit according to the invention;

(10) FIG. 9 diagrammatically shows a section of another variant of a conduit according to the invention;

(11) FIG. 10 shows the view in FIG. 5, with a diagrammatic depiction of the reflection of the sound waves along the conduit of the invention.

(12) The same reference numerals in the drawings identify the same elements or components, or similar elements or components.

DESCRIPTION OF EMBODIMENTS OF THE INVENTION

(13) With reference to the drawings, some examples are described of a fume discharge conduit 1 according to the invention.

(14) The fume discharge conduit 1 is soundproof and is adapted to be arranged between a ventilation system (not shown) and a chimney 20 (partially shown in FIG. 3).

(15) The conduit 1 is particularly adapted to be connected to the ventilation system and to the chimney 20. One or more conduits 1, for example one, two, three or four conduits 1, can be connected to the chimney 20. The conduit 1 comprises an inlet section 61, through which the fumes are emitted into conduit 1, and an outlet section 71, from which the fumes leave the conduit 1 to be introduced into the chimney 20.

(16) In particular, the conduit 1 is a suction branch of the chimney 20.

(17) In all the embodiments of the invention, the conduit 1 defines a fume path therein, and at least one side surface of conduit 1 is provided with at least two protrusions 2. Each protrusion 2 internally defines a respective step-shaped recess 3, whereby the path is provided with at least two step-shaped recesses 3. The step-shaped recesses 3 are advantageously adapted to reflect sound waves, in particular generated by the ventilation system, which propagate along the fume path defined by the conduit 1.

(18) FIG. 10 diagrammatically shows the upward sound waves and the sound waves which are advantageously absorbed and/or reflected by the steps 3, in particular by the walls 4 and/or by the walls 5.

(19) The step shape of each recess 3 indeed is defined by two walls 4, 5 (also called first walls) which are incident at a first end thereof 41, 51 (FIG. 1). For each recess 3, also called step 3, at least one wall of the two walls 4, 5 is coated with a sound absorbing material. In other words, the wall 4 and/or the wall 5 are coated with sound absorbing material. In particular, the surface, inside the conduit 1, of the wall 4 and/or of the wall 5 is coated with sound absorbing material.

(20) The sound absorbing material preferably comprises or consists of expanded clay, in particular expanded clay granules, or steel wool or mineral wool or polyester fluff.

(21) For each recess 3, the end 41 of the wall 4 is preferably joined, in particular directly joined, to the end 51 of wall 5.

(22) More generally, the recesses 3 preferably are consecutive to one another, preferably adjacent to one another.

(23) According to the number of protrusions 2, at least one wall 5 of one protrusion 2 is preferably joined to a respective wall 4 of the consecutive protrusion 2.

(24) In particular, for each recess 3, the wall 4 and the wall 5 are mutually inclined. The wall 4, with wall 5, forms an angle, for example but not exclusively equal to about 90°. Preferably, but not exclusively, the walls 4 are parallel to one another and/or the walls 5 are parallel to one another.

(25) Preferably, said at least two protrusions 2 are externally step-shaped.

(26) With particular reference to FIG. 1, the conduit 1 comprises two mutually inclined stretches 6, 7. In particular, the two stretches 6, 7 are joined to each other by a connecting stretch 72 which is preferably curved. The connecting stretch 72 preferably is a portion of the stretch 7.

(27) The stretch 6 of the conduit 1 is adapted to be connected to the ventilation system. The inlet section 61 of the conduit 1 is preferably delimited by the stretch 6.

(28) The stretch 6 defines a longitudinal axis X. The longitudinal axis X preferably crosses the inlet section 61.

(29) The stretch 7 of the conduit 1 is adapted to be connected to the outlet chimney 20. In particular, the outlet section 71 of the conduit 1 is preferably delimited by the stretch 7.

(30) The stretch 7 defines a longitudinal axis Y, which is inclined with respect to the longitudinal axis X of the stretch 6. The longitudinal axis Y preferably crosses the outlet section 71.

(31) At least the upper surface 79 of the stretch 7 is provided with at least two protrusions 2, for example three protrusions 2, as shown in FIG. 1, or four protrusions 2, as shown in FIGS. 3, 4, 5, 6, 8, 9, 10, in which the fourth protrusion preferably is at the upper surface of the connecting stretch 72.

(32) The upper surface 79 of the stretch 7 is, in particular, the surface which is distal from the chimney 20 when the conduit 1 is connected to the chimney 20. Preferably, at least part of the upper surface 79 is substantially opposed to the outlet section 71.

(33) The protrusions 2 are preferably arranged in sequence, for example in sequence substantially along the axis Y.

(34) The stretch 7 preferably has a circular or polygonal cross-section. The cross-section of the stretch 7 can, for example, be substantially quadrangular, in particular in the variants shown in FIGS. 8 and 9.

(35) FIG. 8 shows a variant in which also the lower surface 78 of the stretch 7 is provided with protrusions 2, for example two protrusions 2.

(36) The lower surface 78 preferably is close to, for example adjacent to, the outlet section of the conduit 1.

(37) In the variant shown in FIG. 8, each protrusion 2 internally defines a respective step-shaped recess 3, substantially as described above. The protrusions 2 protrude outward so as not to substantially alter the flow rate of the fumes.

(38) In the variant shown in FIG. 9, in addition to the upper surface 79, also the side surface 76 and the side surface 77 of the conduit 1 are each provided with at least two protrusions 2. Each protrusion 2 of the side surfaces 76, 77 internally defines a respective step-shaped recess 3, substantially as described above.

(39) For example, four protrusions 2 are provided for each side surface 76, 77. The side surface 76 and the side surface 77 preferably are opposite to each other.

(40) In all the embodiments, a panel 8 (FIGS. 6 and 7) to improve the soundproofing is preferably included, the panel being provided with a plurality of holes 9, in particular through holes, and resting on second ends 42, 52 of the two first walls 4, 5, opposed to the first ends 41, 51, thus delimiting the volume of the step-shaped recess 3 together with two second side walls 10 which are parallel to each other and transversal, e.g. orthogonal, to the walls 4, 5. FIG. 6 shows only one of the two walls 10 for each step-shaped recess 3.

(41) In the variant shown in FIGS. 6 and 7, the panel 8 particularly rests on the ends 42, 52 of the steps 3 of the upper surface 79 of conduit 1.

(42) The panel 8 is preferably made of metal, in particular metal sheet. The metal sheet is preferably coated with a sound absorbing material. The sound absorbing material preferably comprises or consists of expanded clay, in particular expanded clay granules, or steel wool or mineral wool or polyester fluff. The sound absorbing material can be the same sound absorbing material with which the walls 4 and/or 5 are coated or a different sound absorbing material.

(43) To obtain better soundproofing performance, the panel 8 preferably has a percentage ratio of the area of the plurality of holes 9 (intended as the sum of the areas of holes) to the area of the solid part 11 of the panel 8 which is less than 50%, preferably from 25 to 35%.

(44) A single panel 8 is preferably provided resting on the second ends 42, 52 of the two walls 4, 5 of each step-shaped recess 3.

(45) As already mentioned, the stretch 7 of the conduit 1 preferably has a circular or polygonal cross-section, for example a quadrangular cross-section. In order to improve the soundproofing without affecting the flow rate of the fumes, both walls 4, 5 of at least one step-shaped recess 3 (for example, of all the step-shaped recesses 3) preferably have a respective first side 12′, 12″ (FIG. 3) with a length less than the average diameter, preferably less than half the average diameter, of the stretch 7 (when the latter has a circular cross-section), or less than the width, preferably less than half the width, of the stretch 7 (when the latter has polygonal cross-section).

(46) When the stretch 7 of the conduit 1 has a quadrangular cross-section, both walls 4, 5 of at least one step-shaped recess 3 preferably have said first side 12′, 12″ with a shorter length than the width of the stretch 7, preferably less than half the width of the stretch 7, and preferably a second side with a length substantially equal to the width of the second stretch 7. The side 12′ of the wall 4 preferably defines the depth of the step 3, and the side 12″ of the wall 5 preferably defines the height of the step 3, or of the protrusion 2.

(47) The invention also relates to a fume outlet chimney 20 of a steel plant, the chimney 20 being connected, in particular at the bottom or at the side, to at least one fume discharge conduit 1, for example one, two, three, four or more conduits 1.