Molten metal purifying device for casting

A molten metal purifying device for casting comprises a horizontal runner and an inner runner which are formed in a sand mould; a flow choking core matched with the inner runner is placed on the part,around the inner runner, of the sand mould through a step, wherein the longitudinal section of the flow choking core is in an inverted-L shape; the bottom face of the front portion of the flow choking core and the bottom face of the inner runner form an inner runner front area, and the bottom face of the rear portion of the flow choking core and the bottom face of the inner runner form an inner runner rear area; and a ceramic pipe connected with a casting mould cavity is arranged at the bottom of the inner runner rear area. The secondary slag-blocking effect is achieved through the flow choking core cooperating with the inner runner so that the purity of molten metal is improved effectively; and the molten metal purifying device is simple in structure and easy and convenient to operate, the labor productivity is