FR2611247A1 - DETECTION RESISTANT SUPPORT MEMBER FOR ECLATEMENT SAFETY DEVICE AND METHOD FOR MANUFACTURING SAME - Google Patents

Abstract

THE INVENTION RELATES TO A DEPRESSION RESISTANT SUPPORT ORGAN. IT RELATES TO A SUPPORT ORGAN 18 INTENDED TO PREVENT THE SAGNING OF A DISK 22 FROM BURST WHEN A DEPRESSION REACHES IN A CONTAINER CONNECTED TO A PIPING 14. ACCORDING TO THE INVENTION, THE SUPPORT ORGAN 18 TO THE SHAPES A DOME AND IS CUT BY SLOTS 44, 66 OF WHICH TWO ENDS 45, 68 FORM A HINGE. ACCORDING TO THE INVENTION, THE SLOTS ARE CUT IN A SENSITIVELY PERPENDICULAR DIRECTION TO THE SUPPORT ORGAN SO THAT, WHEN A DEPRESSION IS APPLIED, THE EDGES OF THE SLOTS COME TO APPLY TO ONE AGAINST THE OTHER AND PROVIDE MECHANICAL SUPPORT. APPLICATION TO THE PROTECTION OF ENCLOSURES AGAINST OVERPRESSIONS, ESPECIALLY IN THE CHEMICAL INDUSTRY.

Description

QRGANE OF SUPPORT RESISTANT TO A DEPRESSION FOR ORGAN

  SAFETY DEVICE AND METHOD OF MANUFACTURING THE SAME.

  The present invention relates to a support organ

  vacuum-resistant safety port for a pressure relief member, the latter being

  intended to burst by bursting when a difference

  predetermined pressure is applied in one direction, so that it protects a pressure vessel, and it also relates to a method of manufacturing such

  support members resistant to depression.

  A known type of safety pressure relief assembly includes a supported burst disk

  between two complementary bodies or flanges of

  port which are themselves connected to a container or

  a circuit containing a fluid under pressure.

  These devices are often used at

  high temperature and under conditions of corrosion and

  alternation of pressure and depression

  if we. When these discs are exposed to alternating internal and external pressures, the central part

  of the disc fluctuates under the action of the differences

  and thus creates stresses that may ultimately cause bursting or rupture of the disk for a different pressure difference from that for which the disk was provided. As used herein, the term "pressure" refers to a state in which the pressure in the container is greater than the pressure on the other side of the safety pressure relief assembly, while the term "vacuum" refers to state in which the pressure in the container is lower than the pressure on the other side of the discharge assembly

pressure.

  A vacuum-resistant support member is placed inside the bursting disc and is clamped between complementary flanges or flanges so that the bursting disc is stabilized against pressure fluctuations, under the action of differences in pressure. alternating internal and external pressures. In some constructions, a sealing member is

  placed between the support member resistant to depression

  sion and the bursting disc. US patents

  United States of America Nos. 2,523,068 and 2,953,279 represent

  examples of such support members.

  In many applications, the vacuum-resistant support member must be sufficiently thick to support the bursting disc or

  ensures tightness in the presence of a large depression.

  At the same time, the support member resisting

  pressure must also be able to open fully, in pre-

  pressure for which the bursting disk

  must open nominally. When the burst disk is intended to open for pressure

  relatively low internal strength, the support member resists

  so much to the depression must be so thick that the break

  of the disc or the total opening of the whole to the

  predetermined resolution is not possible so that the

  circulation is prevented or reduced.

  The known support members resistant to

  for example, several petals

  mite by radial cuts formed in the support member resistant to depression. Legs are welded to the support member near the cutouts so that the support member retains its integrity in the presence of a depression, while a sufficient predetermined pressure causes a spacing of the petals during

  the bursting of the disc. So far, we have had to

  depression-resistant support members with varying thicknesses depending on the value of the

  depression that must support the support member.

  In addition, the legs that are spot welded

  on the known support organs constitute irreversible

  surface irregularities on which can accumulate

  the treated materials in the container. When the

  implemented is corrosive, in particular in

  presence of high temperatures, the effective duration of

  use of the support member is reduced.

  It is important that, when the internal pressure of the container reaches the predetermined pressure for which the bursting disk opens, the vacuum-resistant support member opens completely and completely while retaining its parts so that

  fragments of the support organ are not trans-

  placed downstream of the safety pressure relief device. According to the present invention, a depression-resistant support for use with an organ

  bursting pressure relief

  carries a disc having a convex side and a convex side

  cellar, the convex side being intended to be placed against

  one side of the bursting member so that it

  carries the latter when the pressure of the concave side of the disc is less than the pressure on the other side of the burst member, at least one slot being formed in the disc, this slot at least being delimited by two opposite edges substantially parallel which are pushed against each other by the bursting member

  when the pressure on the concave side of the disc is

  than the pressure on the other side of the

  the edges of the disc constituting the only

  support of the parties against each other when

that they are thus repulsed.

  A support member resistant to depression according to the invention can be made in a simple and easy way, can open completely and positively to

  low pressure of a bursting disc while

  carrying the bursting disk in the presence of a

  the support member can be used with bursting discs having a wide range of

  nominal values of depression and burst pressure

  and able to open positively and completely without fragmentation when the internal pressure of the container exceeds the nominal opening pressure

of the bursting disc.

  In another aspect of the invention, a method of manufacturing a vacuum-resistant support member for use in a burst-type safety pressure relief device comprises the steps of: a disc having a convex upper side and a lower side

  concave, and the formation of at least one slot in the

  that, the slot separating it in an upper part and a lower part generally, the slot being sufficiently narrow, given the thickness

  the disc, so that it closes and prevents sagging.

  from the top to the bottom, in the lower part, under the action of a downward

  applied to the upper part.

  Other features and advantages of the

  will be better understood when reading the description of

  FIG. 1 is a perspective view with torn parts of a safety pressure relief device comprising a resistive support member embodiment. depression according to the invention, also having parts torn off;

  Figure 2 is an exploded perspective of the

  safety pressure relief device of Figure 1; Fig. 3 is an enlarged partial sectional view of a portion of the safety pressure relief device of Fig. 1; Fig. 4 is a plan view of the vacuum-resistant support member in the safety pressure relief device of Fig. 1;

  Figure 5 is a section along the line 5-

  of Figure 4; Figure 6 is an enlargement of a portion of Figure 5;

  FIG. 7 is a section of the device for

  safety pressure load of Figure 1; Figure 8 is a view similar to Figure 7, after bursting the safety pressure relief device; FIG. 9 is a section of a second mode of

  realization of support member resistant to a depression-

  sion, made according to the invention; and Figure 10 is an enlargement of a part

of Figure 9.

  The structure 10 shown in FIG.

  takes a basic flange 12, screwed on a pipe which acts as a pressure relief outlet of a pressure vessel which must be protected. A

  device 16 for discharging safety pressure

  carries a support member 18 resistant to depression

  a sealing member 20 and a disc 22

  mounted together between the base flange 12 and

  a flange 24 for holding. The holding flange is

  provided with a thread 26 or other suitable pipe connection device (no

  shown) allowing the evacuation of the fluids to be dis-

  tance of the container area, if any. The breaks

  12, 24 are fixed by bolts 28, the device 16 forming a seal between the flanges 12, 24 so that it ensures the tight connection with the container

under pressure.

  The burst disk 22 has a convex upper side 30 (FIG. 2) and a concave lower side (not visible in FIG. 2), and a fixing flange 32

  (Figure 7). Several slots 34 are formed radially

  outward from a solid central part,

  and a hole 38 is drilled or perforated at the upper end.

  of each of the slots so that the stresses do not focus on the upper ends of the

slots.

  The burst disk 22 is made to burst when the pressure in the tubular member 14 exceeds the pressure on the other side of the pressure relief device by a predetermined amount which, for a given diameter of the discharge device

  safety pressure, can be selected by changing the

  the thickness of the metal, the tensile strength of the metal in question, and the variation in the length of the slots 34. For example, the larger the slots

  are long and their proximity in the central part

  36 burst disk 22's scale is large plus the area between the slots so that they resist

  at the internal pressure of the container, is small.

  The sealing member 20 is made in a manner

  that it corresponds to the configuration of the disc 22 of

  or it must have sufficient flexibility for it to take such a form when it is mounted as a whole. Since the role of the sealing member is simply to prevent leaks in the device 16 and to prevent the corrosion of the bursting disc 22, it can be made of a very wide variety of materials.

  material being chosen individually for each

  in order to protect against corrosion

  bursting disc 22 is ensured. In addition, the

  20 and the bursting disc 22 can

  can be combined as a single disk of

  which also ensures watertightness by preventing leaks. As shown in more detail in FIGS. 4 to 6, the vacuum-resistant support member 18 has a circular disk 39 having an upper side 40 of generally convex shape and a lower side 42 of generally concave shape, these sides being each partially spherical shape. A substantially horizontal slot 44 (as shown in Figure 5) is formed through the support member 18 resistant to depression and defines an arc centered on the central axis 46 of the disc 39. A first end

  of the slot 44 leads to a hole 45 so that the

  stresses do not focus on this location. The window

  44 separates the disc 39 into an upper part 48

and a lower portion 50.

  An anchor flange 52 is formed around the radially outer circumference of the disc 39 and has a flat outer annular portion 54 which is clamped between

  the flanges 12, 24 when the support member 18, the or-

  20 and the bursting disk 22 are housed in each other as shown in FIGS.

Figures 1 and 7.

  The slot 44 is delimited by upper edges

  and lower 56 and 58 of the disc, these edges being sensi-

  parallel to each other and, as shown, each forming an angle of substantially 60 with the axis 46. A second axis 60 is shown in Figure 6, this axis being perpendicular to the axis 46 and being parallel

  at the annular portion 54. A third axis 62 is parallel to

  laces at the edges 56, 58 of the disc. Thus, in the particular embodiment of the invention, the angle 64 formed by the axes 60 and 62 is practically equal to 300. It has been found that the safety pressure relief device according to the invention can operate from a particularly satisfactory manner when the terminals 56, 58 of the disc are oriented so that the angle

64 is between 0 and 45.

  A second slot 66 is formed through the disc

  39 and it is symmetrical with the slot 44 and has a hole 68 at one end so that the constraints can not concentrate. The slot 66 has upper and lower edges 56, 58 which are parallel to each other and form an angle of about 60 to the axis 46, although this does not appear in the drawings. Each of the slots 44, 66 has a first end terminating in holes 45, 68 and another

  end 70, 72 respectively. The part of the disc

  taken between the holes 45 and 68 is called in the pre-

  memory "hinge portion 69" of the support member, and the portion of the disc between the ends 72 is referred to herein as "part 73

  of the support member, this last

  now maintaining the upper part 48 in the

  the lower part 50 when the organ 18 of

  support, the sealing member 20 and the disc 22

  are nested within each other and form

  an assembly as shown in Figures 1 and 7.

  In operation, the vacuum-resistant support member 18, the sealing member 20 and the burst disk 22 are mounted between the flanges 12, 24, the pressure in the container to be protected being applied on the concave side. of the sealing member 20 through the slots 44, 46 and the formed holes 45, 68

  in the support member 18. When it is convenient

  mounted, the sealing member 20 is disposed in the concave side of the burst disk 22 so that the pressure transmitted to the sealing member 20 is applied by it to the concave side of the disk 22

burst.

  When the pressure in the tubular member 14

  falls below the pressure on the convex side of the

  that bursting, the support member 18 prevents a

  significant bending of the disc burst 22 and the or-

  20, when pressure fluctuations occur.

  When the internal pressure of the tubular member 14 is lower, a downward force is applied by the sealing member 20 to the support member 18

  resistant to depression, so that the upper body

  56 of the slot 44 is pushed against the lower edge

  58 and similarly the upper and lower edges of the slot 66 are pushed against each other if

  although the support member takes the configuration

  shown in FIG. 3. Given the dome shape of the support member 18 and the contact of the edges of the

  the slot flat against each other, the body 18 of sup-

  port can keep the configuration shown on the

  Figure 3, even in the presence of very large depressions.

  This behavior is observed even when the support member is formed of a thinner material than that used for the prior art vacuum-resistant support members. A pressure inside the tubular member 14 which is greater than the pressure on the other side of the

  security device 16 acts on the body 20 of

  and the lower side of the burst disk 22.

  When this pressure reaches the value at which the disc 22 is to burst, the metal between the holes (such as the hole 38 of the upper part of the disc 22) separates, except between a set of holes as shown in FIG. although the disc may open as shown. When the burst disk 22 opens,

  the pressure causes a tear in the body 20 of

  and the opening of the support organ 18

  calf of the hinge or hinge, the material between the ends 70, 72 of the slots breaking and allowing the support member to open by folding

as shown in Figure 8.

  The support member 18 resistant to depression

  can be achieved in such a way that it

  chosen value without collapsing. The mechanical strength of the support member, when exposed to a vacuum, is determined by the radial distance

  between the axis 46 and the slots 44, 66, by the

  64, the thickness of the disk and the width of the slots, that is to say the distance between the edges 56, 58. The amplitude of the depression that can

  supporting the support member is a function of the thickness

  The width of the slits varies with the thickness of the disc from which the disc is formed, ie the distance between the holes, 68. It should be noted that the width of the slits varies with the thickness of the disc from which the disc is formed. support member and the distance between the ends 70, 72 varies with the diameter of the disc of the support member which itself depends on the diameter of the bursting disc with which the support member is used. Thus, the structure of the support member according to the invention can absorb significant depressions

  thanks to the particular operation of closing the window

  te, the lower part 50 of the disk supporting the

  upper portion 48 as shown in Figure 3.

  Since the structure of the support member can be

  Made of a material thinner than that of the known members of support resistant to depression, this member can open positively and completely for low pressures. Thus, unlike the known vacuum-resistant support members, for a given size of the bursting disk, the support member according to the invention can be used over a wide range of pressures and nominal depressions, for a disk

bursting partner.

  Figures 9 and 10 show a second mode

  embodiment 75 of support member resistant to the de-

  pressure, constructed according to the invention and comprising a pair of symmetrical slots, one of which is the slot 76,

  the slots being formed in a portion having the

  figuration of a dome and forming part of the organ of

  support which is similar to the support member 18. The or-

  bracket 74 has a radial radial flange sensi-

  plan 78 which is used for mounting the

  bracket in a different type of mounting flange.

  12, 24 of FIG. 1. Moreover, the support member 74 has an operation similar to that of FIG. 1 (with a bursting disc and an associated sealing member, each having a flat flange similar to flange 78). Other devices of

  mounting a support member resistant to depression

  according to the invention can be used.

  Referring now to FIG.

  feels a laser 80. When making the organ

  18, the laser 80 is used for

  slits 44, 66 with an aligned laser beam

  on the axis 62 so that the edges 56, 58 of the slots

  an angle which depends on the orientation of the laser 80. The latter allows a precise adjustment for the selection of both the angle of the edges 56, 58 and the width of the slot 44, so that it allows a production

  the support body so that it can

  to wear a determined depression. A depression-resistant support member thus formed comprises a

  number of elements below that of the

  Prior art carriers usually have point-welded tabs near the cutouts that are formed in the disc 39 so that a predetermined value depression can be supported. As shown, the axis 62 passes through the center of curvature of the partially spherical dome-shaped portion of the support member so that the slot edges are perpendicular to the adjacent surface of the dome and thereby reduce any tendency of the edges to slide

  on each other when a depression is applied.

  Of course, various modifications can be made by those skilled in the art to the support members and to the manufacturing processes which have just been described solely as non-limiting examples.

  without departing from the scope of the invention.

Claims (17)

  1. Support member (18) resistant to depression   intended for use with a splitting device (22)   providing a safety pressure relief, the support member comprising a disk (39) having a   convex side (40) and a concave side (42), the convex side   vexe (40) being intended to be placed against a first side of the burst member (22) so that it supports   the bursting member when the pressure on the con-   cellar (42) of the disc (39) is less than the pressure   on the other side of the burst member (22),   in that at least one slit (44, 66) is formed   in the disk (39) and is delimited by two edges es-   paces, substantially parallel and opposite (56, 58) of the disk, separating the disk into portions (48, 50), the edges being pushed against one another by the burst member (22) when the pressure of the disk concave side (42) of the disc is less than the pressure on the other side of the burst member (22), and that the   edges of the disc constitute the only device   wearing said parts (48, 50) against each other during that they are thus repulsed.   2. Support member according to claim 1, characterized in that the distance between the edges (56, 58) of the disc is less than the thickness of the disc.   3. Supporting body according to one of the claims   1 and 2, characterized in that the support member (18) has a first and a second slot (44, 66), the slots have a first pair of opposite ends (45, 68) defining a hinge portion. (69) of the support member, between its ends, and a second pair of opposite ends (70, 72) delimiting between them   a portion (73) for positioning the support member.   4. support member according to claim.3, characterized in that the portion (73) for positioning the support member is significantly shorter than the   hinge portion (69) of the support member.   5. Supporting body according to any one of   preceding claims, characterized in that the   slot at least (44, 66) is arranged in an arc.   6. Support member according to the claims   3 and 5 taken together, characterized in that the first   first and second slot delimit an arc together circle greater than 270.   7. Supporting body according to one of the   5 and 6, characterized in that the convex side (40), the concave side (42) and the arc or arcs are centered on a common axis (46).   8. Support member according to claim 7,   characterized in that the disk edges (56, 58) form   an angle (64) between 45 and 90 with the axis.   9. Support member according to claim 8, characterized in that said angle is substantially equal to 60.   10. Supporting body according to one of the claims   8 and 9, characterized in that the concave sides   and convex disc have a partially spherical shape   and the edges (56, 58) of the disk are formed on   surfaces passing through the center of curvature of spheres   res, so that the edges of the disk are perpendicular   adjacent portions of the concave sides and   upset. 11. Supporting body according to any one of   preceding claims, characterized in that said   at least one slot is substantially horizontal, so that it forms upper and lower portions (48, ) of the disc.   A method of manufacturing a vacuum-resistant support member for use in a burst-type safety pressure relief device, the method characterized by comprising forming a disk having a side   upper convex and one concave lower side, the   at least one slot passing through the disk and dividing   this one into a higher part and a part   lower in general, the slot being sufficiently   narrow in relation to the thickness of the disc so that it can close and prevent downward sloping of the upper part in the lower part   when pressure is applied downwards to the superior.   13. The method of claim 12, characterized   rised in that the formation of a slit is performed by cutting with a laser beam.   14. Method according to one of claims 12   and 13, characterized in that the slot is cut with   a width less than the thickness of the disc.   15. A method according to any of the claims   12, 13 and 14, characterized in that the slot   is cut into a curve arc.   16. A method according to any of the claims   12 to 15, characterized in that the slot is cut with two substantially parallel edges and   opposite of disk on both sides of the slot.   17. The method of claim 16, characterized   at least the slot is cut to form edges having an inclination   between 45 and 90 in relation to the longitudinal axis of the than.