Pneumatic conveyors and silos for powdered materials

Sand is normally delivered in bulk and discharged directly to a silo via a pneumatic conveyor, conveyor belt or grab. Specialist sands may arrive in bags or by tanker. Used sands are stored in silos for regeneration and in silos or heaps for transport for external re-use or disposal. 

Liquid binders and oil products are delivered in drums, by bulk container or by road tanker. They are stored in their delivery containers or, in the case of rail tankers, discharged direct into a dedicated storage. The containers are connected by pipe directly to the sand/resin/catalyst-mixing unit. Some catalysts and co-reactants are used in a gaseous form, but these are also delivered as liquids and handled in a similar fashion before being vaporised and mixed with a carrier gas. Evaporation is enclosed and may be carried out by a variety of methods. 

Refractories, release agents and other minor deliveries are stored indoors. 

Coarse solid residues, such as used refractories and slags, are stored on separate heaps, in a subdivided storage area or in boxes. They are moved and handled using small lift trucks. Fine solid residues are collected at the filter unit into big bags or containers, which may be stored intermediately before transport for disposal. In order to avoid soil contamination from the various classes of materials, specific measures are taken. Potential impacts are listed in Table 2.5. 

Additional alloying elements can be added to the charge as ferro-alloys such as FeSi, FeMn, FeCr, or pure such as Cu, C, Ni. However most alloys are added to the molten metal to prevent metallic losses due to oxidation. Alloying elements are usually present in the foundry in small quantities and are always stored inside the building, preferably close to the melting installation. [32, CAEF, 1997]. 

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Figure 2.8 Pneumatic conveyors and silos for powdered materials [237, HUT, 2003]...

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