Claims
- 1. A method for removing no-bake rigid coatings from foundry sand and classifying the reclaimed sand according to particle size, which comprises the steps of,
- crushing no-bake foundry sand lumps into grain sized no-bake coated sand grains,
- fluidizing said coated sand grains in a stream to a velocity just sufficient for pneumatic transport,
- pneumatically transporting said coated sand particles to a point where reclaimed and classified sand is to be used, and without accelerating said coated sand particles to higher velocity,
- directing said fluidized sand particles at a target transversely disposed in said stream to cause the rigid no-bake coatings encasing the sand grains to fracture on impact with said target to provide uncoated sand grains and no-bake coating particles, and thereafter separating the re-usable sand grains and the no-bake coatings.
- 2. The method as defined by claim 1, wherein the final step of separating the sand grains of desired particle size from the uncoated sand grains and the no-bake coatings further comprises the steps of,
- forming the uncoated sand grains and the no-bake coating particles into a homogeneous mixture of falling particles, inducing an air flow across the falling sand grains and the no-bake coating particles, said air flow being in the range of perpendicular to the line of flow of sand and coatings to approximately an angle 45.degree. in a quadrant counter to the direction of the flowing sand and coatings at a velocity sufficient to separate the no-bake coatings and fine sand particles from sand grains of desired particle size, and separately discharging the reusable sand grains of desired particle size and the no-bake coatings and the fine sand particles.
- 3. The method as defined by claim 2, wherein the step of separating the sand grains of desired particle size from the uncoated sand grains and the no-bake coating is carried out in a vertical passageway through which the sand and the no-bake coating particle fall and wherein the velocity of the induced separating air flow across the curtain of falling sand and coating particles is regulated by adjusting the cross-sectional area of the passageway at the point at which the air flow is induced.
Parent Case Info
This application is a continuation-in-part of copending application Ser. No. 847,749, filed on Nov. 2, 1977 now abandoned.
US Referenced Citations (5)
Non-Patent Literature Citations (1)
Entry |
Updating No-Bake Molding Systems, Foundry M & T, Feb. 1975, p.66. |
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
847749 |
Nov 1977 |
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