Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22C—FOUNDRY MOULDING
  • B22C5/00—Machines or devices specially designed for dressing or handling the mould material so far as specially adapted for that purpose
  • B22C5/04—Machines or devices specially designed for dressing or handling the mould material so far as specially adapted for that purpose by grinding, blending, mixing, kneading, or stirring
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22C—FOUNDRY MOULDING
  • B22C5/00—Machines or devices specially designed for dressing or handling the mould material so far as specially adapted for that purpose
  • B22C5/10—Machines or devices specially designed for dressing or handling the mould material so far as specially adapted for that purpose by dust separating
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S241/00—Solid material comminution or disintegration
  • Y10S241/10—Foundry sand treatment

Definitions

• the invention relates to a method for regenerating pebbles from coated grains with an irregular surface, in particular with a jacket of the like or the like. occupied foundry sands, in which the casing is broken down by friction.
• foundry sands can be found, for example, in the foundry encyclopedia, Berlin 198011, pages 675 to 681. Above all, the regeneration of old sands is essential so that they can be largely reused after a casting process - to save new sand and to reduce the amount of landfill. It is among other things required, the individual grains of sand or the like from the surrounding binder or the like. To clear up impurities, mainly using friction or impact forces; the surface of the grain is cleaned by impacting on a surface or by means of sand grain. The binder casings adhering to the grain surface are removed - depending on the equipment of the process mainly by impact or friction.
• DE-PS 24 08 981 proposes to accelerate foundry sand by rotation and to drive it at high speed against a bulk material bed serving as an impact cushion; the grains are disrupted or cleaned under the action of centrifugal forces by friction in the bulk bed.
• DE-OS 22 02 311 discloses sand cleaning with a centrifugal wheel and inclined baffle plates.
• DE-OS 24 48 333 the sand is hurled against a baffle by means of a pneumatic device which, for example, spans a vertical, inclined or horizontal sand pipe at a distance.
• DE-PS 25 19 135 also discusses a cleaning system for impact cleaning of granular material by means of a nozzle connected to a gas flow source opposite an impact surface.
• DE-PS 22 33 111 describes a pneumatic regeneration process in which foundry sand or the like - optionally with admixture of new sand - of prestressed air against an impact bell or the like. is thrown up. Upon impact, the individual quartz grains enveloping binder layers burst, and the quartz grain can then assume a binder coating again. With this treatment, quartz grains can be damaged and then accumulate as dust.
• the inventor has set itself the goal of offering a method with an increased regeneration effect in which binder residues located in concave areas of the sand grains are removed as far as possible, or at least reduced.
• the inventor takes advantage of the idea that the dust accumulating in the processing zone is not - as is done in the prior art - extracted and removed from the system, but at least partially used for the digestion of the sand to be cleaned; the sand is treated according to the invention with a granular abrasive, the grain size of which is considerably smaller than the grain size of the sand to be cleaned.
• the quartz portion of the dust produced by the sand treatment should preferably be separated off, recycled and used for this purpose.
• the scouring agent can also be a fine-grained material made of quartz, iron or the like. be.
• a grain size of the so-called abrasive of a maximum of 0.125 mm should be specified for a "Frechen" type quartz sand with the designation F 32 with an average grain size of 0.23 mm, for an F 34 (0.20 mm) from 0.09.
• F 32 with an average grain size of 0.23 mm
• F 34 (0.20 mm) from 0.09.
• the upper grain size limit of the so-called scouring agent preferably corresponds to approximately 50% of the average grain size of the sand to be regenerated.
• the abrasive effect on the surface of the grain of sand is achieved in that the abrasive to the sand receives a speed which differs in amount and / or direction and thus hits the surface of the grain of sand; it then penetrates into the concave areas of the grain of sand.
• the treatment can take place, for example, in a rotating field, in a fluidized bed, in channels in cocurrent or countercurrent, the material flows may also cross.
• the sand can also be heated or cooled for embrittlement and / or drying of the adhesive binder casings.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Mold Materials And Core Materials (AREA)
• Processing Of Solid Wastes (AREA)
• Molds, Cores, And Manufacturing Methods Thereof (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=6428280

Family Applications (1)

Country Status (7)

Families Citing this family (4)

Citations (4)

Family Cites Families (13)

• 1991
  • 1991-03-27 DE DE4109993A patent/DE4109993A1/de active Granted
• 1992
  • 1992-02-19 EP EP92102725A patent/EP0505722A1/de not_active Withdrawn
  • 1992-02-21 US US07/838,831 patent/US5259434A/en not_active Expired - Fee Related
  • 1992-03-17 JP JP4060398A patent/JPH0576986A/ja active Pending
  • 1992-03-26 HU HU9200930A patent/HUT65812A/hu unknown
  • 1992-03-26 CS CS92917A patent/CS91792A3/cs unknown
  • 1992-03-27 CN CN92102211A patent/CN1065225A/zh active Pending

Patent Citations (4)

Non-Patent Citations (1)

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