Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65B—MACHINES, APPARATUS OR DEVICES FOR, OR METHODS OF, PACKAGING ARTICLES OR MATERIALS; UNPACKING
  • B65B31/00—Packaging articles or materials under special atmospheric or gaseous conditions; Adding propellants to aerosol containers

Definitions

• the invention relates to a method for packaging aluminothermic mixtures while preventing segregation during storage and transport.
• Aluminothermic mixtures consist chwermetalloxiden of finely divided aluminum and S, where the mixture to dampen the reaction and / or to form an alloy in the reaction, further finely divided metals, metal oxides, or other alloying elements, such as iron filings, copper, copper oxides, chromium, manganese, carbon or the like, can be added.
• the reactants contained in the aluminothermic mixture In order to achieve a uniform reaction and to control it in a controlled manner, it is necessary for the reactants contained in the aluminothermic mixture to be present within a predetermined particle size range and with a desired particle size distribution.
• the "different specific weights of the reactants in the aluminothermic mixture as well as their specific particle shape cause changes in the optimally adjusted mixing ratio of the reactants within one during transport and storage, especially with shaking stress, as they cannot be excluded during loading and transport Packaging unit, for example a cloth bag containing 7 to 15 kg of aluminothermic mixture as the usual packaging form for aluminothermic welding compounds for carrying out aluminothermic rail connection welds.
• This segregation can lead to an uneven course of the aluminothermic reaction.
• the reaction is too violent or uneven due to the segregation, a part of the melt can be thrown out of the crucible, for example, which endangers the operating personnel and can also lead to faulty welds due to the lack of weld metal or the formation of alloys of undesirable composition.
• Demixed aluminothermic mixtures can also react too slowly, which can lead to heat loss and thus also to faulty welds. Since the majority of the aluminothermic mixtures are used for rail connection welding, such sources of error must be excluded for traffic safety reasons alone.
• the invention is based on the object of finding a simple solution to the problem of preventing the segregation of the aluminothermic mixtures which are optimally mixed during production, without the need to add substances to the mixture which remain in the aluminothermic reaction or which interfere in the event of remaining.
• the bulk density of the reaction mixture should not be reduced. All application properties of the aluminothermic mixture should remain unchanged.
• this object can be achieved in a surprisingly simple manner by combining the aluminothermic mixture with a small amount of a C0 2 -binding agent into a packaging unit consisting of flexible, essentially airtight plastic film, which displaces the air in the packaging unit with C0 2 and the packaging unit in a known manner including the lowest possible CO 2 - Volume hermetically sealed.
• the film forming the packaging unit quickly closes tightly around the aluminothermic mixture, which is solidified into a block. Separation is no longer possible.
• the packaging unit is opened by tearing or cutting the film. The aluminothermic mixture is free-flowing immediately after opening the packaging and can be poured into the reaction crucible.
• the CO 2 binding agent can be distributed in the aluminothermic mixture. This is possible above all if the CO 2 -binding agent does not interfere with the aluminothermic reaction and does not contaminate the metal melt obtained. It is therefore particularly preferred to use finely divided soda lime as an effective, inexpensive and metallurgically indifferent CO 2 binder.
• the majority of the alkali carbonate evaporates as an oxide, the alkaline earths are absorbed by the slag.
• the C0 2 -binding agent can be packaged in a cartridge or a bag made of paper or textile material. It is then possible, after opening the packaging of the aluminothermic mixture, to remove the cartridge or the bag containing the agent which has absorbed the carbon dioxide before the reaction.
• the packaging unit for the aluminothermic mixture generally consists of a sack or pouch made of thermoplastic film which can be easily closed by welding. To achieve higher strength, a film can also be used, which is laminated in particular on the outside with paper.
• Polyethylene films with a thickness of approximately 0.1 to 0.3 mm have proven particularly suitable as the film material.
• a bag 20 cm wide and 40 cm long is formed by cross welding from a tube made of polyethylene film. 10 kg of an aluminothermic mixture of iron oxide, aluminum powder, fine steel granules and manganese powder are filled into this bag. A bag made of cotton fabric measuring 5 x 5 cm and containing 5 g of soda lime is also inserted. The air in this packaging unit is now removed by blowing in C0 2 and replaced by CO 2 . The bag is then sealed and the aluminothermic mixture is distributed in the form of a plate. After a few minutes, the film has wrapped itself so tightly around the aluminothermic mixture that a plate-shaped, rigid block has formed. This rigid block is easy to pack and send in boxes.

Landscapes

• Chemical & Material Sciences (AREA)
• Dispersion Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Packages (AREA)
• Bag Frames (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=6128170

Family Applications (1)

Country Status (4)

Citations (2)

Family Cites Families (2)

• 1981
  • 1981-03-25 DE DE3111611A patent/DE3111611C1/de not_active Expired
• 1982
  • 1982-02-02 ZA ZA82672A patent/ZA82672B/xx unknown
  • 1982-03-09 AU AU81211/82A patent/AU8121182A/en not_active Abandoned
  • 1982-03-13 EP EP82102056A patent/EP0061637A1/fr not_active Withdrawn

Patent Citations (2)

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