Foundry Sand, U.S.
Fewer rejected castings and less wasted raw materials using Solex heat exchange technology
In the no-bake foundry process, sand is blended with a small amount of expensive ingredients including a chemical binder and catalyst in a high speed mixer. The ingredients begin a chemical reaction process of hardening when discharged from the mixer to the mold or core box. An important step in this process is to maintain consistent temperature of the sand before it is blended with the ingredients. If the sand is too hot or too cold the amount of ingredients added has to be adjusted, which can create inconsistencies in the castings quality as well as wasting expensive raw materials.
A foundry sand customer in the U.S. understood the importance of this chemical reaction and, when expanding their production capacity, wanted to maintain each sand grain to within 2⁰F of 75⁰F. The sand temperature entering the process could be as low as 60⁰F or as high as 120⁰F. Another challenge was fitting the equipment into a space of less than eleven feet tall by three feet square while achieving a production rate of 8,000 pounds per hour. Fluidized bed technology was not preferred as it would have required much more overall space, extensive air handling equipment and ducting as well as requiring more utility consumption and maintenance.
Description of equipment (solution)
Solex Thermal Science was awarded the project based on a modeled design using a standard plate bank style exchanger. To further guarantee the system performance, Solex also provided the closed loop heating/cooling water temperature control module or TCM. In the cold months when the sand is below 75⁰F, the TCM is reheating water in the closed loop and cooling the water when the sand is above 75⁰F.
Solex heat exchange technology advantages (benefit)
In a sand casting foundry it is critical to maintain the consistency of AFS-GFN (American Foundry Association Grain Fineness Number). Great care goes into designing equipment to prevent and eliminate sand segregation. Sand is an abrasive product so there is always concern on its abrasiveness to process equipment. Solex technology offers this advantage since there is neither abrasion nor segregation occurring within the equipment.
The system maintains the highest obtainable efficiency using water indirectly as the heat transfer medium. Fluidized beds require blowers, ducting, and cleaning equipment.
Solex heat exchange technology comes in a compact design with a small footprint and easy access to heat exchange plates, with no moving parts or pinch points for safety.
Return on investment
As a result of using Solex technology there are fewer castings rejected and there is less waste of expensive raw materials.
Solex background
Solex Thermal Science Inc. is a global leader in thermal engineering and bulk materials handling. Our company has installed more than 800 projects in more than 50 countries on a variety of applications including fertilizer, oilseeds, plastics, chemicals, industrial minerals, biosolids and food products.