Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D88/00—Large containers
  • B65D88/02—Large containers rigid
  • B65D88/06—Large containers rigid cylindrical
  • B65D88/08—Large containers rigid cylindrical with a vertical axis
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D88/00—Large containers
  • B65D88/74—Large containers having means for heating, cooling, aerating or other conditioning of contents
  • B65D88/744—Large containers having means for heating, cooling, aerating or other conditioning of contents heating or cooling through the walls or internal parts of the container, e.g. circulation of fluid inside the walls

Definitions

• the invention relates to a silo for the storage of products containing organic materials, products for which appear self-heating phenomena, the silo being of the kind of those comprising a cylindrical outer envelope or prismatic vertical axis, having an upper part and a lower part, this envelope being made of a heat conductive material, in particular metal, and comprising at least one inlet and one outlet for the products, a roof closing the silo at the top, and a device for evacuation closing the silo at the bottom, the silo having at least one inner chimney in a heat conductive material, in particular metal, communicating with the atmosphere at the top and bottom, the internal volume of the chimney being free to allow the circulation of air and the evacuation of heat.
• a silo of this type is shown in documents BE 521 214 A or FR 1 444 136 A.
• the invention relates more particularly, but not exclusively, to such a silo for storing dried sludge from wastewater treatment plants or the like.
• the storage capacity of current silos is limited by the phenomenon of self-heating of the stored product.
• the cross section of the silos in particular the outer diameter (apart from the wall thickness) in the case of a circular section, is limited because of the phenomenon of self-heating of the stored product.
• Rc a critical radius which corresponds to a maximum permissible radial product thickness so that the heat generated by self-heating is sufficiently evacuated to the atmosphere through the product mass and the outer envelope. in order to avoid a start of pyrolysis when the temperature rises.
• the object of the invention is, above all, to make it possible to increase the storage capacity of a silo of the kind defined above, without however reducing the safety with respect to the phenomenon of self-heating of the stored products.
• a silo for the storage of dried bulk products, containing organic materials, in particular for the storage of dried sludge from wastewater treatment plants, products for which there appear phenomena of self-heating is characterized in that the outer diameter of the chimney "d" is greater than (D-4R C ) D being the outer diameter of the casing and R c the radius critical products to store in the silo.
• a silo for the storage of dried bulk products, containing organic materials, in particular for the storage of dried sludge from wastewater treatment plants, products for which phenomena appear is characterized in that the chimney is in an eccentric position with respect to the casing, the eccentricity of the chimney being equal to half of its outer diameter, the critical radius Rc being equal to or greater than D / 4 (Rc> D / 4), where D is the outside diameter of the envelope.
• the casing internally comprises in the lower part a support means for the inner chimney adapted to ensure communication of this inner chimney with the atmosphere, preventing any product entry into said inner chimney.
• the support means of the inner chimney may be provided to allow the evacuation of rainwater and the circulation of the air.
• the support means may comprise tubes welded to the chimney and opening into this chimney, each tube passing through the wall of the envelope to which it is welded and opening outwards.
• the support means may comprise three tubes forming a tripod.
• the diameter of the envelope is at least equal to three meters, the inner chimney having a diameter at least equal to one meter.
• the inner chimney can be coaxial with the outer shell.
• the silo may comprise several internal chimneys of parallel axes.
• Fig. 1 is a schematic perspective view with torn parts of a silo according to the invention.
• Fig. 2 shows, similarly to Fig.1, an alternative embodiment.
• a silo S for the storage of bulk products P, containing organic materials.
• the products P consist of dried sludge from wastewater treatment plants.
• Such products give rise to self-heating phenomena and may give rise to pyrolysis starts when the temperature rises, if the heat produced is not sufficiently discharged to the atmosphere.
• the silo S comprises an outer casing 1, generally made of sheet steel.
• the casing 1 may have a cylindrical shape, circular in section, with a vertical axis, having an upper part 1a and a lower part 1b.
• Support means for this envelope 1 in the vertical position are provided but not shown in the drawings.
• Other forms of envelopes 1 would be possible, for example prismatic envelopes.
• the axis of the envelope could be inclined with respect to the vertical angle that does not affect the descent by gravity of the bulk product.
• the silo is closed at the top by a roof 2, in particular formed by a sheet disk, closing the upper part of the cylinder.
• An entry E for the bulk products is provided in the upper part, for example in the cylindrical wall of the casing 1.
• An output A for the products is provided in the lower part.
• the silo S comprises in the lower part a product dispensing device G formed by a cone of concentration 3 whose small base is directed downwards. This small base is opened and forms the exit A.
• the cone 3 makes it possible to regroup the product in bulk at the exit.
• the cone 3 is advantageously equipped with a vibrating bottom 4 to facilitate the flow of bulk products.
• the silo S comprises at least one inner chimney 5 made of a heat-conducting material, in particular a metal chimney, communicating with the atmosphere at the top 5a and at the bottom 5b.
• the chimney 5 is generally made of sheet steel.
• the chimney 5 is cylindrical with a circular section, coaxial with the silo S.
• the chimney 5 could have a different shape, in particular a prismatic shape with a polygonal cross-section.
• the chimney 5 passes through a hole provided in the roof 2.
• the seal between the contour of the chimney 5 and the perimeter of the hole provided in the roof 2 can be provided by a weld bead which establishes a mechanical connection between the two elements.
• the upper end 5a of the chimney is completely open to the atmosphere, or may be covered with a grating or a protective grid leaving the passage free to air.
• the lower part 5b of the chimney communicates with the atmosphere by tubes 6 welded to the lower part of the chimney and opening into this chimney 5.
• the tubes 6 are inclined downwards from the chimney, in planes passing through the axis of the chimney, and pass through the wall of the cone 3 to open to the outside.
• Each tube 6 is fixed, in particular by welding, to the wall of the cone 3 at the orifice through which it passes through this wall, the assembly of the tubes 6 constituting a support means B of the chimney 5.
• three tubes 6 are provided, angularly spaced 120 °, to form a support tripod of the chimney 5. Any other means for supporting the chimney 5 in the silo S may be considered.
• the central chimney 5 is thus open at the low point via the tubes 6.
• the opening of the tubes 6 allows natural draft and evacuation of rainwater.
• the cumulative surface of the section of the tubes 6 is dimensioned so as not to slow down the natural draft of the chimney 5.
• the lower axial end of the chimney 5 is closed, for example by a disc. Where appropriate, to enhance the flow of natural ventilation, there may be a fan 7 in the chimney 5, preferably in the upper part.
• H the height of the cylindrical part of the silo
• D the outer diameter of the casing 1 and d the outside diameter of the chimney 5.
• the ratio d / D is preferably equal to or greater than 0.12 (d / D> 0.12).
• the diameter d can be of the order of 1 meter, while the diameter D can be between 3 and 8 meters.
• Rc critical radius
• the maximum distance between a point of the stored product and a wall (wall the envelope or wall of the chimney) in contact with the atmosphere is equal to (Dd) / 4.
• the products to be stored safely may have a critical radius Rc> (Dd) / 4, much lower than that of a conventional silo with the same outside diameter.
• the outside diameter of the chimney “d" is calculated in such a way that the safety stress defined by the radius Rc is respected: D ⁇ 4 R c + d, ie d> D - 4 R c .
• the chimney 5 thus created can be equipped with an access means, such as a crinoline ladder, or a spiral staircase, which allow the installation of instrumentation or equipment in the chimney.
• an access means such as a crinoline ladder, or a spiral staircase, which allow the installation of instrumentation or equipment in the chimney.
• the concentric arrangement of the chimney according to FIG. 1 is optimal from the point of view of mechanical strength, thanks to the concentricity of the forces on the central chimney 5, and from the point of view of self-heating.
• the chimney 5 'in an eccentric position relative to the casing 1.
• the upper and lower parts of this chimney are designated by 5'a and 5' b.
• the eccentricity of the chimney 5 ' is equal to half of its outer diameter, that is to say d / 2.
• D / 4 the maximum distance between a point of the stored product and a wall (wall of the envelope or wall of the chimney) in contact with the atmosphere.
• D / 4 the maximum distance between a point of the stored product and a wall (wall of the envelope or wall of the chimney) in contact with the atmosphere.
• the wall of the chimney 5 ' contains the geometric axis of the envelope 1.
• the critical radius Rc is then equal to or greater than D / 4 (Rc> D / 4).
• the eccentricity may take different values but the coaxial solution remains preferred. It is also possible to provide several chimneys inside the casing 1, with parallel axes distributed to ensure good heat dissipation. For example, the axes of the chimneys could be evenly spaced on a circumference concentric with the casing 1.
• the invention makes it possible to increase the outside diameter of the silo, while remaining consistent with the critical radius of self-heating.
• the heat provided by the self-heating can be dissipated both by the outer casing 1 and the inner chimney 5, 5 '.
• a silo according to the invention will have a volume of 377 m 3 , against only 70.7 m 3 for a conventional silo without coaxial chimney.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Treatment Of Sludge (AREA)
• Storage Of Harvested Produce (AREA)
• Drying Of Solid Materials (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=38157860

Family Applications (1)

Country Status (8)

Cited By (1)

Families Citing this family (2)

Family Cites Families (23)

• 2006
  • 2006-12-18 FR FR0611015A patent/FR2909984B1/fr not_active Expired - Fee Related
• 2007
  • 2007-12-14 BR BRPI0721353-0A patent/BRPI0721353A2/pt not_active IP Right Cessation
  • 2007-12-14 RU RU2009127804/12A patent/RU2009127804A/ru not_active Application Discontinuation
  • 2007-12-14 EP EP07871866A patent/EP2094588A2/de not_active Withdrawn
  • 2007-12-14 CN CNA2007800467233A patent/CN101563277A/zh active Pending
  • 2007-12-14 CA CA002672774A patent/CA2672774A1/fr not_active Abandoned
  • 2007-12-14 US US12/519,381 patent/US20100126694A1/en not_active Abandoned
  • 2007-12-14 WO PCT/FR2007/002075 patent/WO2008087301A2/fr not_active Ceased

Non-Patent Citations (1)

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