FR2943043A1 - Protection panel for sealing of opening of e.g. silo utilized for storing powder products, has spacer whose height corresponds to joint compression area such that gap defines adjusting degree of integration of panel in panel position - Google Patents

Abstract

The panel (1) has a square metal sheet (10) with an embrittlement zone situated inside fixation zones i.e. sides, where the panel is of square, rectangle/circular shape. Each zone is defined by orifices i.e. bores, where each orifice is housed in a rigid spacer e.g. cylindrical flangless ring (4). Spacer height (h) larger than that of the orifice corresponds to an compression area of a sealing joint (3) such that an existing gap (j) defines an adjusting degree of integration of the panel with a chamber (20) in associated position of the panel against a chamber opening and before integration. Independent claims are also included for the following: (1) a chamber comprising an opening (2) a method for fixing a protection panel against a support surface of an opening of a chamber.

Description

PROTECTIVE PANEL FOR AN ENCLOSURE CONTAINING PRESSURIZED GASES AND ENCLOSURE EQUIPPED WITH SUCH A PANEL

The invention relates to a protection panel limiting the risk of explosion in a product storage chamber, in particular powder, the panel having a weakened zone susceptible to tear in case of abnormal pressure in the enclosure.

This type of panel protects facilities for storing or transporting, products giving off explosive dust, such as flour, cereals, sugar, starch, wood, etc. The installations or enclosures accommodating these powdery products, such as silos Hoppers, filters, mixers, pipes, are thus surrounded by one or more protective panels that can have various shapes, square, rectangular, round.

The products stored in the closed chamber may under certain conditions cause a consequent explosion including an increase in pressure and temperature inside the enclosure. In order to avoid any risk of explosion, or at least to limit the effects in the event of an explosion which could otherwise lead to serious consequences, the protective panel is able to tear in its weakening zone in the event of abnormal excess pressure in the pregnant, the pressurized gas escaping through the tear hole. A protective panel usually comprises a metal sheet comprising an embrittlement zone near the peripheral edge of the sheet, this area consisting of a groove or a multitude of narrow slots aligned and separated by a few millimeters by the constituent material of the sheet. . In case of overpressure, this area gives way, lifting the central part of the sheet to create an exhaust hole.

This panel is intended to close the opening of an enclosure by being fixed on its entire periphery. For this purpose, the sheet of metal is provided with a multiplicity of orifices distributed over its entire perimeter and intended to be placed opposite corresponding orifices arranged on the periphery of the opening of the enclosure, the sheet of metal being secured to the enclosure by bolt-type fastening means which cooperate with the mutual ports of the panel and the enclosure. The attachment is located near the edge of the panel defining a peripheral frame, and within and near which is the weakened zone.

A seal is made between the panel and the enclosure by means of a seal 15 forming a peripheral frame, of compressible material and preferably food grade, for example expanded polyethylene. The gasket is disposed at the peripheral mounting frame of the panel and comprises a series of holes distributed so as to be located opposite the orifices of the panel and the enclosure. Such a panel is for example described in the patent FR2870833-B1. The panel of this document has the further advantage of having a small thickness and thus be limited in weight of metal. It consists of a thin metal sheet such as 0.8 mm and comprising a peripheral flange folded at 180 ° below it and extending substantially beyond the embrittlement zone. This edge contributes to the rigidity of the sheet.

The rim houses a seal which thus makes it possible to seal the panel at the weakening zone. The seal of course includes holes opposite the fixing holes of the panel.

Finally, the seal between this panel and the enclosure is provided in a conventional manner with a second peripheral seal pressed between the outer face of the flange and the enclosure. The tightening of the fastening means ensures the compression of the second seal which thus fully fulfills its function. However, the clamping also causes compression of the seal housed in the edge of the sheet and facing the embrittlement zone. Clamping rules are recommended so that the seal crushes in a balanced way, without excess. Indeed, too much crushing may cause tearing of the embrittlement zone located in the immediate vicinity of the fastening zone, and consequently damage the panel which becomes unusable.

For this purpose, each of the fixing bolts is tightened by means of a torque wrench which makes it possible to adjust the tightening torque to a well-defined value.

However, this clamping requires always having such a key available, and proves tedious, because the control must be repeated for each bolt.

The object of the invention is therefore to provide an alternative solution to the usual control means for clamping fastening means forming a protection panel against an enclosure opening 30 storing products of an explosive nature.

Thus, the invention relates to a protective panel intended to close off an enclosure opening that can contain dangerously high pressure gases, comprising at least one weakening zone located near and inside a fixing zone. of said panel, this fixing zone being delimited by a multitude of orifices, in particular bores, intended to receive fixing means, the panel being characterized in that in each fixing orifice is housed a rigid element forming a spacer, such as a ring, and whose io height greater than the height of the orifice corresponds to a magnitude such that in the associated position of the panel against the opening of the enclosure and before securing, a game exists defining the degree of securing adjustment of the panel to the enclosure.

The height is understood in the remainder of the description as a dimension extending perpendicularly to the large dimensions of the panel and parallel to its thickness.

Thus, the spacer associated with each orifice makes it possible to use the fastening means, of the bolt type, without having specific equipment for precise control of the fastening of the panel. There is no concern about the degree of clamping required when attaching the panel.

The spacer or ring acts as a means of controlling the degree of crushing of the seal intended to be positioned between the panel and the bearing structure and fixing the enclosure.

Its height is defined according to the characteristics of the thickness of the panel in the area of attachment and the thickness of the joint, so that the difference between the sum of said thicknesses of the joint and the panel and its height correspond to the remaining play. . This amount of clearance is equivalent to the degree of compression that it is necessary to transmit to the seal, and in the case of fixing means constituted by bolts, the tightening torque imposed on said bolts. In particular, a torque wrench is no longer necessary.

According to one characteristic, the spacer comprises an elongate body, and preferably comprising a flange abutting against a face of the panel intended to be oriented on the outside of the enclosure.

The spacer may form a single piece or consist of a stack of a plurality of pieces to obtain the desired height.

Depending on the configuration of the spacer, such as a ring with or without flange, once the panel in mounting position against the enclosure, the clearance is obtained towards the inner side of the enclosure or respectively towards the outer side .

In the embodiment without collar, according to a simple elongated body of the spacer, and when the spacer is intended to be associated with the panel before mounting the panel against the enclosure, a seal is provided on the face intended for be facing the inside of the enclosure to retain the spacer in the orifice, this seal being adapted to be torn by force during the crossing of the fastening means.

The spacer is advantageously made of stainless steel.

According to one characteristic, the panel comprises a metal sheet, the zone or zones of weakness being constituted by grooves and / or discontinuous slots connected by frangible parts.

The panel may have a square, rectangular or circular shape.

According to an advantageous embodiment of the panel, the latter consists of a metal sheet having a peripheral flange folded at 180 ° below it and extending substantially beyond the embrittlement zone, an element of sealing being housed inside this flange, the orifices of the panel passing through the sheet, the flange and the sealing element.

The invention also relates to a chamber provided with an opening 15 having a peripheral bearing and fixing surface against which is fixed the panel of the invention, a seal being arranged between the bearing surface and fixing the enclosure and the panel, and securing the panel being achieved through fastening means passing through the seal and the spacers housed in the orifices 20 of the panel, the opposite free ends of each of the spacers being in stop, respectively, against the bearing surface and fixing the enclosure and the fixing means.

According to one feature, before securing the panel to the bearing and fixing surface, the clearance defining the degree of securing adjustment is established on the side of said support and fixing surface when the spacer such as a ring comprises a flange abutting against the surface of the panel facing the outside of the enclosure. Conversely, before the panel is secured to the support and fixing surface, the clearance is established on the side of the panel when the spacer is flangeless and abuts against the bearing and fixing surface of the panel. 'pregnant. The enclosure is a product storage chamber, particularly pulverulent, type silo, hopper, mixer, piping, filter.

By storage enclosure is meant in the remainder of the description, any closed enclosure in which said products are allowed to stay or to circulate there at least momentarily.

Finally, the invention relates to a method of fixing a protection panel as described above, against a bearing surface of an enclosure opening that can contain dangerously high pressure gases. The method consists in: i) positioning the panel against the support surface of the enclosure, ii) inserting if it is not already done before the positioning of the panel, a spacer in each hole of the panel, one ends of the spacer abutting against the outer surface of the panel, or against the bearing surface of the enclosure, iii) introducing into each spacer the fastening means, and iv) actuating the fastening means until that the other end 25 of the spacer is in abutment against the bearing surface of the enclosure, or else abuts against the fastening means.

The present invention is now described with the aid of examples which are only illustrative and in no way limitative of the scope of the invention, and from the attached illustrations, in which: FIG. 1 represents a perspective and top view of a protective panel according to the invention; Figure 2 is a sectional view of the panel in position mounted against the opening of a storage chamber; Figure 3 is a perspective view of an exemplary embodiment of a ring according to the invention whose role is to adjust the degree of securing of the panel to the enclosure; Figure 4 is a partial sectional view of the assembly of the panel against the enclosure before complete securing; Figure 5 shows the view of Figure 4 after complete joining; FIG. 6 illustrates, according to an alternative embodiment of the means for adjusting the degree of attachment of the panel to the enclosure, a partial sectional view of the mounting of the panel against the enclosure before complete securing; Figure 7 shows the view of Figure 6 after complete securing; Figure 8 illustrates a partial sectional view of the assembly of the panel against the enclosure before complete connection according to an alternative embodiment of the panel.

The protection panel 1 illustrated in FIG. 1 is intended, as can be seen in FIG. 2, to seal an opening 2 of an enclosure 20 storing powdery products.

The peripheral seal between the panel and the enclosure is provided by a seal 3 (Figure 2) of compressible material and preferably food grade, for example expanded polyethylene.

The panel 1 is placed, via the seal 3, against a bearing surface 21 of the enclosure delimiting the opening 2. The fastening of the panel to the bearing surface 21 is obtained by means of fixing means 5, such as that screws 50 and nuts 51.

The protective panel as shown in Figure 1 comprises a metal sheet 10 of shape for example square, four sides 11, 12 13 and 14, and central portion 10a.

For fastening the panel, the latter comprises over its entire periphery and near its edges, a multitude of orifices, and more particularly bores, 15.

The metal foil has an embrittlement zone referenced 16 in the figure, which zone is able to tear in case of abnormal overpressure, once installed in real conditions of use. This zone here has a U-shaped pattern whose three "branches" 16a, 16b and 16c extend parallel and close to the sides 11, 12 and 13 respectively of the sheet. More precisely, this zone is located not far from the bores 15 on the inside of the sheet.

The side 10 of the sheet 1 is thus devoid of such a zone.

If the panel were circular in shape, the zone of weakening would have 3o rather a C shape. When the zone of weakness gives way under certain conditions, the central part of the sheet will rise while remaining integral with its peripheral part. by the region parallel to the side 10. 5 or weakening zones consist for example of a groove made in the sheet, by removal of material on its surface. Or preferably, it consists of a series of narrow slots, arranged in the extension of one another and separated at most by a few millimeters by the material which constitutes the sheet 1. The slots are for example obtained by cutting laser. Separation areas can be described as frangible zones, which means that they have the ability to surrender under certain conditions.

The exemplary panel illustrated in FIGS. 1 to 7 is in particular that described in French patent FR2870833-B1. It has the advantage of being made of a simple thin metal sheet, for example 0.8 mm, having a flange 18 folded at 180 ° below the metal sheet 10 and extending somewhat beyond of the embrittlement zone 20 formed by slots 17.

The inside of the flange houses a seal member 19 of the usual seal type and forming a frame on the entire periphery of the sheet. The orifice 15 is in this panel configuration made according to the thicknesses of the metal sheet 10, the seal 19 and the flanged edge 18.

According to the invention, the panel comprises, for fixing it, spacers 4 intended to ensure the compression adjustment of the sealing gasket 3. An exemplary spacer embodiment is in the form of a ring and is illustrated in FIG. Figure 3.

Each ring 4 comprises a cylindrical body 40 intended to be housed in a bore 15.

Preferably, to facilitate its implementation in the bore and especially in case of disassembly, the ring comprises a flange 41 intended to bear against the outer face 10b of the panel, as shown in Figures 2 and 8.

In order to play its role of adjustment as to the joining of the panel to the enclosure, the ring 4 has defined dimensions.

Thus, as illustrated in FIG. 4, the elongated body 40 of the ring, generally of cylindrical shape and optionally comprising the flange 41, has a size h greater than the height of the bore 15 or the thickness of the panel 1 in its attachment zone, and such that in mounted position of the panel against the opening and before securing, a clearance j (Figure 4) exists between the free end 42 opposite the flange 41 and the bearing surface 21 of the enclosure. The clearance j has a dimension corresponding to the ideal compression size of the seal 3 so that the crushing does not cause the deterioration of the weakening zones.

The fastening means 5 are screws 50 and nuts 51. Each screw 50 passes through the hollow body of a ring 4, its head 52 abutting against the flange 41 of the ring.

The tightening of the nut 51 causes the compression of the seal 3 and the reduction of the clearance j. The tightening becomes sufficient when the clearance j is zero and the end 42 of the ring abuts against the bearing surface 21. This game j, which induces the size of the height h, is dimensioned to correspond to the torque of tightening necessary for proper crushing of the joint.

Thus, depending on the thickness of the panel near the embrittlement zone and the tightening torque to be provided, the height of the spacer will be adapted. For example, for a panel 1 whose bore 15 has a size according to the extension of the panel thickness (leaf and flange) of 6.6 mm, the height h of the ring is 10.4 mm to provide a clearance of 2.5 mm corresponding to a tightening torque of 5 Nm

FIGS. 6 and 7 illustrate the mounting of a front protection panel 15 and respectively after complete securing according to an alternative embodiment of the adjustment ring 4.

This ring 4 has a simple cylindrical shape without flange. Slip into the bore 15, it comes as shown in Figure 6 abutting against the bearing surface 21 of the enclosure, its height h being such that the game j remaining before crushing the seal 3 is disposed of side of the head 52 of the screw.

After tightening (FIG. 7), the clearance j becomes zero and the compression of the seal is stopped by the abutment of the screw head 52 against the free end 43 of the ring.

Figures 1 to 7 illustrate the example of panel described in FR2870833-B1. However, the invention applies to any protective panel which may have a single flangeless thickness as illustrated in the cross-sectional view of FIG. 8. A spacer is inserted into the fastening aperture 15 according to the thickness the panel; it is retained by its shoulder or flange 41 at its upper free end against the outer face 10b of the panel. This spacer will come after clamping, abutting by its opposite free end 42, against the bearing surface 21 of the enclosure adequately compressing the seal 3.

The method of attaching a protective panel to close an opening of an enclosure storing powdery products is now described.

The panel is disposed on the bearing surface 21 of the opening to be closed. The orifices 15 of the panel may comprise beforehand the spacers 4 retained by protective films. In the opposite case, a spacer 4 is inserted into each orifice 15 of the panel.

The fastening means 5 are then introduced into the spacers. Finally, it is sufficient to actuate the fixing means, for example by tightening screws and nuts, until the spacer comes into abutment, against the support surface 21 of the enclosure if said spacer is provided with an outer flange, or against the upper end of the fastening means when the spacer has no shoulder.

The invention makes it possible, by inserting spacers of suitable height in each of the bores of the panel, to provide a simple means of controlling the useful compression of the joint without having to use a specific tool, such as a key. torque. The invention also gains in control time of a suitable tightening. It also avoids any risk of human error in the control of the clamping force.

Claims (12)

REVENDICATIONS1. Protective panel (1) for closing off an enclosure opening which can contain dangerously high pressure gases, comprising at least one embrittlement zone (16) located near and within a zone (11, 12, 13, 14) for fixing said panel, said fixing zone being delimited by a multitude of orifices (15) intended to receive fastening means (5), characterized in that in each fixing orifice is accommodated a spacer (4). ) of rigid material whose height greater than the height of the orifice (15) corresponds to a magnitude such that in the associated position of the panel against the opening of the enclosure and before securing, a set (j) exists defining the degree of securing adjustment of the panel to the enclosure. 2. Panel according to claim 1, characterized in that the spacer (4) comprises an elongate body (40), preferably comprising a flange (41) bearing against a face (10b) of the panel intended to be oriented from outside the enclosure. 3. Panel according to claim 1 or 2, characterized in that the spacer (4) is made of stainless steel. 4. Panel according to any one of the preceding claims, characterized in that the spacer consists of a single piece or a stack of a plurality of parts. 5. Panel according to any one of the preceding claims, characterized in that it comprises a metal foil (10), the embrittlement zone or zones (16, 17) being constituted by latrines and / or discontinuous slits connected by frangible parts. 6. Panel according to any one of the preceding claims, characterized in that it has a square, rectangular or circular shape. 7. Panel according to any one of the preceding claims, characterized in that it comprises a metal sheet (10) having a peripheral flange (18) folded at 180 ° below it and extending substantially beyond the zone of weakness, a sealing member (19) being housed inside this flange, the holes (15) of the panel passing through the sheet, the flange and the sealing member. 8. Enclosure (20) provided with an opening (2) having a peripheral bearing and fixing surface (21) against which is secured the panel (1) according to any one of the preceding claims, a seal (3) being arranged between the bearing surface and fixing (21) of the enclosure and the panel (1), characterized in that the fastening of the panel is achieved by means of fixing means (5) passing through the joint the spacers (4) housed in the orifices (15) of the panel, and in that the opposite free ends (41, 42) of each of the spacers abut, respectively, against the bearing surface and fixing (21) of the enclosure and the fixing means (5). 9. Enclosure according to claim 8, characterized in that before securing the panel to the bearing surface and fixing (21), the game (j) is established on the side of said bearing surface and fixing (21) when the spacer, such as a ring, comprises a plunger (41) abutting against the surface (10b) of the panel facing the outside of the enclosure. 10. Enclosure according to claim 8, characterized in that before securing the panel to the bearing surface and fixing (21), the game (j) is established on the side of the panel (1) when the spacer is without collar and abuts against the support and fixing surface (21) of the enclosure. 11. Enclosure according to any one of claims 8 to 10, for the storage of products, including pulverulent, type silo, hopper, mixer, piping, filter. 12. A method of fixing a protective panel (1) according to any one of claims 1 to 7, against a bearing surface (21) of an opening (2) enclosure that can contain pressure gases. dangerously high, the method consisting in: i) positioning the panel (1) against the bearing surface (21), ii) inserting if it is not already done before the positioning of the panel, a spacer (4) in each orifice (15) of the panel, one of the ends of the spacer (41, 42) abutting against the outer surface of the panel, or against the bearing surface of the enclosure, iii) introducing into each spacer (4) the fastening means (5), and iv) operating the fastening means (5) until the spacer is in abutment against the bearing surface (21) or abutting respectively against the means of fixation (5).