 FLUIDCORE furnaces for core debonding |
The fluidcore fluidised bed consists of a retort filled with foundry sand identical to that used in sand cores. Fluidisation occurs when a mixture of air and gas is passed through a distributor at the base of the retort, which causes the particles of sand to separate and fluidise. The mixture of gas and air is ignited by a pilot burner and the bed heats by internal combustion.
The fluidised bed then behaves like a liquid but remains dry. It is best visualised as being similar to boiling water or quicksand.
Due to the high heat transfer rates, and pressure within the fluidised bed, the hot gases penetrate the internal passageways of castings. This results in high quality cleaning.
The fluidised bed debonds cores by pyrolising the organic binders in the sand core. When the castings are heated to 450 - 500oC these binders decompose into light hydrocarbon gases. These off gases are mixed with additional air and ignited immediately above the surface of the fluidised bed to a temperature of 800oC, before being discharged via a grit collection box to the atmosphere.
As the binder decomposes, the sand of the sand core is fluidised and flows out of the casting and into the fluidised bed increasing the quantity of hte sand within the bed. The recovered sand is discharged through an overflow port and may be reused. The casting can then be heat treated all in one process.
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Rapid heating - high heat transfer rate
Temperature uniformity
Controlled cooling rates from air to oil in a single fluidised bed quench.
Core debonding and solution treatment all in one process.
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© 2002 Quality Heat Technologies Pty. Ltd. |
