Machine for dusting a profiled roof tile comprising raised patterns with particulate matter

Abstract

A machine for dusting a shape with particulate matter, the shape being a profiled roof tile including raised patterns extending in the lengthwise direction thereof, and including raised portions laterally separated from hollow portions by sloped portions, the tile having a predetermined width, and being preferably corrugated, the machine including a dusting element forming a homogeneous linear curtain of particulate matter falling across the width of the tile, the tile travelling longitudinally under the linear curtain. Deflectors of the curtain are arranged above the tile to intercept the particulate matter above the areas at the bottom of the sloped portions and redistribute the intercepted particulate matter towards an intermediate level of each corresponding sloped portion in order for the amount of particulate matter on the surface of the plate ultimately to be substantially homogeneous after a portion of intercepted particulate matter has slid towards the bottom of the sloped portion.

Claims

1. A system for dusting a shape with a particulate matter, said shape being a profiled roofing sheet having raised patterns extended in the direction of the length thereof, said raised patterns having elevated parts laterally separated from trough parts by sloping parts which are inclined, said profiled roofing sheet having a determined width, said system including a machine; the machine comprising: a hopper adapted for distribution of the particulate matter and creating an homogeneous curtain of the particulate matter falling transversally, across the width of the profiled roofing sheet, said curtain of the particulate matter is linear; the profiled roofing sheet having a relative translational displacement with respect to the curtain of the particulate matter; deflectors of the curtain of particulate matter are arranged under the hopper and directly above bottom areas of the sloping parts of the profiled roofing sheet, so as to transversally divert a direction of a vertical flow of parts of the curtain of the particulate matter directly above the bottom areas of the sloping parts to redistribute diverted portions of particulate matter towards an intermediate level of each corresponding sloping part so as to homogenize the quantity of the particulate matter at a surface of said profiled roofing sheet after sliding, towards the bottom of the sloping part, of the diverted portions of the particulate matter; and each deflector includes at least one upper surface face of interception and deflection of the particulate matter of the curtain, each upper face having an inclination of uniform direction, opposite to the direction of inclination of a sloping part above which the deflector is located.

2. The system according to claim 1, wherein the flow of the curtain of the particulate matter is not modified above the elevated parts of the profiled roofing sheet.

3. The system according to claim 1, wherein the shape is a corrugated cover sheet with regular corrugations and each deflector includes two upper faces and is of upwardly convex transverse shape, each deflector being arranged above the trough parts of the corrugations, each of said upwardly convex shapes having a crest line and being symmetrical with respect to the crest line that is elongated in a direction of a corrugated cover sheet length, perpendicularly to the curtain of particulate matter.

4. The system according to claim 3, wherein each deflector of convex shape includes two upper faces of interception of the particulate matter, lateral to the crest line, said upper faces are among: planar faces, or downwardly curved faces, each of the two upper faces of the deflector being then partially upwardly concave, or upwardly curved faces, each of the two upper faces of the deflector being then partially upwardly convex.

5. The system according to claim 1, wherein the shape is a corrugated cover sheet with alternated corrugations, two adjacent corrugations forming two elevated parts being separated by a planar area forming the trough part and each deflector includes an upper face having an inclination of uniform direction, opposite to the direction of inclination of the sloping part above which the deflector is located.

6. The system according to claim 5, wherein the upper face of each deflector is chosen among: a planar face, or a downwardly curved face, said upper face of the deflector being then partially upwardly concave, or an upwardly curved face, said upper face of the deflector being then partially upwardly convex.

7. The system according to claim 1, wherein the deflectors are adjustable in height with respect to the profiled roofing sheet.

8. The system according to claim 1, wherein the hopper for the distribution of the particulate matter is arranged above the profiled roofing sheet, the distribution hopper spreading uniformly said particulate matter across the width thereof and including a linear downward end oriented according to the width of the profiled roofing sheet and from which downward end said particulate matter falls freely towards the profiled roofing sheet hence creating the homogeneous curtain of the particulate matter.

9. The system according to claim 1, wherein the hopper creating the homogeneous curtain of the particular matter falling on the profiled roofing sheet is fixed, and the profiled roofing sheet is displaced evenly.

10. The system according to claim 1, wherein the profiled roofing sheet and the hopper creating the homogeneous curtain of the particular matter falling on the profiled roofing sheet are evenly mobile but in opposite directions.

Description

BRIEF DESCRIPTION OF THE DRAWING FIGURES

(1) The present invention will now be exemplified, without being limited thereby, by the following description of embodiments and implementations in relation with:

(2) FIG. 1, which shows three juxtaposed graphs with, from the top to the bottom, the thickness e of matter supposed to be deposited at the surface of the sheet, the corrugated profile of the sheet, the thickness obtained at the surface of the sheet (by simplified calculation taking into account only the sheet profile),

(3) FIG. 2, which shows four juxtaposed graphs with, from the top to the bottom, the thickness e of matter supposed to be deposited at the surface of the sheet, the corrugated profile of the sheet, the thickness obtained at the surface of the sheet (by simplified calculation taking into account only the sheet profile), the thickness obtained at the surface of the sheet (by simplified calculation taking into account both the sheet profile and the gravity making so that the particulate matter slides/rolls along the sloping part),

(4) FIG. 3, which shows a magnification of a part of the sheet, viewed in profile, in the axis of the length thereof, and showing the effect of inhomogeneity on the distribution of the particulate matter both of the sheet profile and of the gravity making so that the particulate matter slides/rolls along the sloping part,

(5) FIG. 4, which shows the principle of the deflection of the particulate matter to obtain an homogeneous distribution of the particulate matter at the surface of the sheet,

(6) FIG. 5, which shows two applications of the invention to two types of cover sheets, the first with a sheet having regular corrugations and the second with corrugations alternating with flats,

(7) FIG. 6, which shows several examples of deflectors with, on the top line, deflectors adapted for a sheet having regular corrugations and, on the two bottom lines, deflectors adapted for a sheet having corrugations alternating with flats,

(8) FIG. 7, which shows dimensional variables having an influence on the result of the invention, and

(9) FIG. 8, which shows a schematic view of the machine of the invention.

(10) The invention hence permits to make uniform the distribution of particulate matter, for example a fire-protection particulate coating, on the surface of a corrugated cover sheet 1, 1, in particular a sheet of cellulose impregnated with bitumen, during an operation of dusting of the sheet with a linear particulate curtain 3 making it possible to linearly deposit the particulate matter on the sheet. During this operation, the sheet moves perpendicularly to the particulate curtain 3, this latter being preferably extended across the width of the sheet and the sheet moving according to its length under the curtain of particulate matter.

(11) The sheet has raised patterns extended in the direction of the length thereof, said raised patterns having elevated parts separated laterally from trough parts by sloping parts inclined from the top to the bottom and laterally. Each elevated part hence forms a convex shape towards the top and the two lateral inclined sloping parts on each side of the elevated part are downwardly divergent.

(12) To make the distribution of the particulate matter 2 on the sheet 1, 1 uniform, a deflector 4, 4 is installed above and opposite (in other word right above) the lower area or bottom part of each sheet sloping part. An example of implementation is illustrated by FIG. 4 for a regular-corrugation sheet 1 for which each deflector includes two upper faces of interception/deflection 5a-5b of inclinations opposite to those of the bottom of the respective sloping part opposite/above which they are arranged. By way of example, in FIG. 6 is shown the inclination 7 of the upper face 5b of the deflector 4 and the inclination 8 of the sloping part above which it is located, these inclinations 7 and 8 are opposite to each other.

DETAILED DESCRIPTION OF THE INVENTION

(13) We specify herein the double function interception/deflection because it is understood that the deflection occurs only because there is also interception of the flow of particulate matter of the curtain 3.

(14) It will be seen that, for a sheet with corrugations alternated with a flats 1, each deflector includes only an upper face of interception/deflection 5a or 5b.

(15) The equalization of the distribution of the particulate matter 2 on the sheet 1 can be optimized by acting on several parameters. Among these parameters, it can be mentioned: the number of deflectors 4, 4, to be chosen as a function of the profile of the corrugated sheet, the geometrical shape and the size of the deflector, in particular its upper face of interception/deflection 5a-5b, 5a or 5b, the positioning in space of each deflector according to the profile of the corrugated sheet, the matter or the state of surface of the deflectors 4, 4.

(16) The number of deflectors is linked to the geometrical profile of the corrugated sheet and, more specially, to the number of corrugations, and hence of sloping parts, given that there must be an upper face of interception/deflection opposite/above each bottom area of the sloping part if it is wanted to finally obtain a uniform distribution over the whole width of the sheet surface. This parameter is hence relatively constrained.

(17) Hence, in FIG. 5, we have, at the top, for the regular-corrugation sheet 1, a deflector 4 with two upper faces of deflection 5a-5b each opposite/above each trough part of the plate. Still in FIG. 5, we have, at the bottom, for the alternated-corrugation sheet 1 (elevated parts between flats), a deflector 4 with one upper face of interception/deflection 5a or 5 each opposite/above each bottom area of the sloping part.

(18) It is understood that the shape of the upper face(s) of interception/deflection 5a-5b, 5a or 5b may be optimized as a function of the needs, in particular taking into account an effect of this shape to send more or less laterally far from the deflector the particulate matter that has been intercepted.

(19) By way of example, several general types of deflector shapes have been shown in FIG. 6. On the top line, the deflectors 4 are adapted to a sheet 1 with regular corrugations, and, from the left to the right, we have upper faces of interception/deflection 5a-5b: planar; upwardly curved faces, that is to say that each upper face of interception/deflection is partially upwardly convex; and downwardly curved faces, that is to say that each upper face of interception/deflection is partially upwardly concave.

(20) On the two bottom lines of FIG. 6, the deflectors 4 are adapted to a sheet 1 with corrugations alternating with flats, and, from the left to the right, we have an upper face of interception/deflection 5a or 5b: planar; an upwardly curved face, that is to say an upper face of interception/deflection partially upwardly convex; and a downwardly curved faces, that is to say an upper face of interception/deflection partially upwardly concave.

(21) In FIG. 6, the dimension Ld (projected width of the deflector) can be adjusted as a function of the shape of the corrugation, in particular the corrugation Height H and the corrugation Pitch P, such dimensional variables being represented in FIG. 7.

(22) In the case of a regular-corrugation sheet, in the horizontal axis, the axis of symmetry of the deflector must be merged with the axis of symmetry of the repeated geometrical pattern of the sheet profile considered as located in the bottom part of the patterns. In the vertical axis, the positioning of the deflector in height h is adjusted experimentally, with the corrugation height H of the sheet profile.

(23) The length of each deflector must be sufficient to intercept efficiently and to redistribute the particulate matter of the curtain of particulate matter.

(24) The state of surface of the deflector must be chosen as a function of the particulate to be deposited so as to avoid the problems of electrostatic charges, the problems linked to the frictions (coefficient of friction), the problems of wearing. This list is not exhaustive.

(25) In the case of a coating of flakes of graphite, a deflector made of aluminum seems particularly adapted.

(26) Taking into account the four variables of adjustment described hereinabove, it has been shown, in a machine implementing deflectors according to the invention, that the homogeneity of the distribution of the solid particles applied by gravity on the surface of a corrugated sheet was greatly improved. In the machine in question, it has been implemented brushed-aluminum deflectors of geometrical shape of the angle type of 25 mm, positioned in the axis of symmetry of the corrugations at a height h=1.5*H.

(27) It is to be noted that, except advanced optimization, for example with partial interception of the particulate matter, it is in practice impossible to totally compensate for the Geometry effect. However, in the common practice of a total-interception deflector, the profile corrected using a chosen deflector, adapted and regulated, makes it possible to get strongly closer to the ideal profile (iso-thickness).

(28) Thanks to the invention, the coating of flake of graphite at the surface of the corrugated sheets to improve the fire resistance has permitted to pass with success all the tests of resistance to an external fire contrary to the corrugated sheets for which the coating had been made without implementation of the deflectors of the invention.

(29) In FIG. 8, the machine of the invention is schematized in longitudinal view and a corrugated sheet 1 moves in translation under a fixed hopper 6 that produces a curtain of particular matter 3. Deflectors 4 intercept and redistribute the particular matter of the curtain of particulate matter opposite/above trough parts of the corrugated sheet to send back the particulate matter intercepted higher along sloping parts of the corrugated sheet 1.