Method and apparatus for reusing green sand

Abstract

A method and an apparatus for effectively reusing the green sand that would otherwise overflow the line for molding to be disposed of, even though it is fully usable, are provided. The method for reusing green sand comprising the steps of treating the green sand with ultrasonic waves in water; separating a mixture that is obtained by the step of treating the green sand with ultrasonic waves to form a suspension and to form residual particles of the sand; circulating the suspension to then proceed to the step of treating the green sand with ultrasonic waves so that the suspension is concentrated; storing the concentrated suspension; and feeding the stored suspension to green sand by a predetermined amount when green sand is mulled.

1 . A method for reusing green sand comprising the steps of:
 treating the green sand with ultrasonic waves in water;   separating a mixture that is obtained by the step of treating the green sand with ultrasonic waves to form a suspension and to form residual particles of the sand;   circulating the suspension to then proceed to the step of treating the green sand with ultrasonic waves so that the suspension is concentrated;   storing the concentrated suspension; and   feeding the stored suspension to green sand by a predetermined amount when green sand is mulled.   
     
     
         2 . The method for reusing the green sand of  claim 1 , further comprising:
 a step of removing an Oolitic layer from the residual particles of the sand that have been separated in the step of separating.   
     
     
         3 . An apparatus for reusing green sand comprising:
 an ultrasonic washer for treating green sand with ultrasonic waves in water, the green sand having been used;   a separator for separating a mixture that is obtained by the ultrasonic washer to form a suspension and to form residual particles of the sand;   an apparatus for circulating and making the suspension thicker, which apparatus measures a degree of concentration of the separated suspension, which apparatus returns the suspension to the ultrasonic washer if the degree of concentration that is measured equals, or is below, a predetermined degree of concentration, and which apparatus feeds the suspension to a storage tank for storing the suspension if the degree of concentration that is measured is over the predetermined degree of concentration;   the storage tank that stores the suspension of which the degree of concentration is over the predetermined degree of concentration; and   a volumetric feeder that feeds the stored suspension by a predetermined amount when the green sand is mulled.   
     
     
         4 . The apparatus for reusing the green sand of  claim 3 , further comprising:
 a system for mechanically reclaiming the green sand that removes an Oolitic layer from the residual particles of the sand that have been separated in the separator.