Method and device by which moulding compound to be processed is kept moist during the production of moulds or cores

Abstract

In order to produce molds or cores for foundry purposes from a mixture (M) of molding compound or sand and at least one binder, the mixture is mixed (M) by a mixing device ( 20 ) and is fed with the aid of a feeding system ( 30 ) to at least one sand storage unit ( 40 ) of a core or mold production device ( 50 ), wherein the mixture-free region ( 21 ) of the mixing device ( 20 ), at least at times, and/or the feeding system ( 30 ) located between the mixing device ( 20 ) and the core or mould production device ( 50 ), and/or the sand storage unit ( 40 ) downstream of the feeding system ( 30 ) and upstream of the core or mould production device ( 50 ), is moistened or kept moist by means of a liquid ( 71 ). The liquid ( 71 ) used for moistening is atomised by at least one ultrasonic atomiser ( 60 ) to form a suspended aerosol and is fed to the mixing device ( 20 ) and/or the feeding system ( 30 ) and/or the sand storage unit ( 40 ) via pipes ( 81, 82, 83 ).

1 . A method for producing molds or cores, comprising mixing molding compound or sand and at least one binder which is predominantly at least one of inorganic, water-soluble or hygroscopic using a mixing apparatus ( 20 ) to form a mixture (M), and feeding the mixture (M) to at least one sand storage unit ( 40 ) of a core or mold production apparatus ( 50 ) using a feed device ( 30 ), and at least one of moistening or keeping moist at least one of a mixture-free region ( 21 ) of the mixing apparatus ( 20 ), a mixture-free region ( 31 ) of the feed device ( 30 ) located between the mixing apparatus ( 20 ) and a core or mold production apparatus ( 50 ), or a mixture-free region ( 41 ) of the sand storage unit ( 40 ) downstream of the feed device ( 30 ) and upstream of the core or mold production apparatus ( 50 ). 
     
     
         2 . The method as claimed in  claim 1 , wherein the mixture-free region ( 21 ) of the mixing apparatus ( 20 ) is moistened or kept moist at least at times at least during the mixing operation. 
     
     
         3 . The method as claimed in  claim 1 , wherein evaporation or escape of moisture from the mixture (M) is prevented by keeping atmospheric humidity above the mixture (M) high at approximately 70% to 100%. 
     
     
         4 . The method as claimed in  claim 1 , wherein a liquid ( 71 ) which serves for moistening or water which serves for moistening is atomized by ultrasound to form a suspendable aerosol and fed to at least one of the mixing apparatus ( 20 ), the feed device ( 30 ), or the sand storage unit ( 40 ). 
     
     
         5 . The method as claimed in  claim 4 , wherein the aerosol formed from the liquid ( 71 ) or the water and a magnitude of a volumetric flow provided with the aerosol are set by changing pulse packets emitted by at least one ultrasound generator or by changing a voltage of the at least one ultrasound generator. 
     
     
         6 . The method as claimed in  claim 5 , wherein the suspendable aerosol is formed and conducted via one or more lines ( 81 ,  82 ,  83 ) to at least one of the mixing apparatus ( 20 ), the feed device ( 30 ), or the sand storage unit ( 40 ). 
     
     
         7 . An apparatus for producing molds or cores, comprising a mixing apparatus ( 20 ) for mixing molding compound or sand and a binder which is predominantly at least one of inorganic, water-soluble or hygroscopic to form a mixture (M), a feed device ( 30 ) for conveying the mixture (M) to a sand storage unit ( 40 ) of a core or mold production apparatus ( 50 ), at least one of the mixing apparatus ( 20 ), the feed device ( 30 ), or the sand storage unit ( 40 ) are provided with a moistening device ( 2 ), which acts upon an interior thereof or opens out into the interior thereof. 
     
     
         8 . The apparatus as claimed in  claim 7 , wherein the moistening device ( 2 ) has at least one ultrasound generator in the form of an ultrasound atomizer ( 60 ) for water or for a liquid ( 71 ) containing water. 
     
     
         9 . The apparatus as claimed in  claim 8 , wherein the ultrasound atomizer ( 60 ) and a liquid reservoir ( 70 ) belonging thereto are arranged spatially separate from at least one of the mixing apparatus ( 20 ), the feed device ( 30 ), or the sand storage unit ( 40 ) and are connected to region(s) to be moistened via at least one tubular or hose line ( 81 ,  82 ,  83 ). 
     
     
         10 . The apparatus as claimed in  claim 9 , wherein the mixing apparatus ( 20 ), the feed device ( 30 ) and the sand storage unit ( 40 ) are each connected to the liquid reservoir ( 70 ) via a tubular or hose line ( 81 ,  82 ,  83 ). 
     
     
         11 . The apparatus as claimed in  claim 10 , wherein the a number of the ultrasound atomizers ( 60 ) at least corresponds to a number of tubular or hose lines ( 81 ,  82 ,  83 ), and at least one of the ultrasound atomizers ( 60 ) is provided for each of the tubular or hose lines ( 81 ,  82 ,  83 ). 
     
     
         12 . The apparatus as claimed in  claim 11 , wherein a fan ( 9 ) or a pressurized gas connection ( 10 ) is arranged above a liquid surface in the liquid reservoir ( 70 ) in order to transport the moisture or the aerosol from the ultrasound atomizer(s) ( 60 ) to at least one of the mixing apparatus ( 20 ), the feed device ( 30 ), or the sand storage unit ( 40 ). 
     
     
         13 . The apparatus as claimed in  claim 7 , wherein the feed device ( 30 ) comprises at least one movable transport bucket.