Scrap melter and impeller therefore

Abstract

A device for submerging scrap metal includes: (a) a drive source, (b) a drive shaft having a first end and a second end, the first end being connected to the drive source, and (d) an impeller connected to the second end of the drive shaft, the impeller preferably having two or more outwardly-extending blades. Preferably, each of the blades has a portion that directs molten metal at least partially downward. The impeller design leads to lower operating speeds, lower vibration, longer component life and less maintenance. Additionally, the impeller preferably has a connective portion. The connective portion is used to connect the impeller to the shaft and preferably comprises a nonthreaded, tapered bore extending through the impeller.

1 . A device for generating a downward and radial stream of molten metal in a scrap melter, the device including:
 (a) a drive source;   (b) a drive shaft having a first end and a second end, the first end connected to the drive source; and   (c) an impeller connected to the second end of the drive shaft, the impeller having two or more outwardly extending blades, at least one blade having a leading face, the leading face including a vertical lip and a portion that directs molten metal at least partially downward, the impeller having a hub wherein each blade extends outwardly from the hub by at least 10″.   
   
   
       2 . The device of  claim 1  wherein the impeller has four blades. 
   
   
       3 . The device of  claim 2  wherein the impeller has an overall length of at least 28″ and an overall width of at least 28″. 
   
   
       4 . The device of  claim 2  wherein each blade has a leading face portion that includes an angled surface and a trailing face that is vertical. 
   
   
       5 . The device of  claim 1  wherein a connective portion is formed in the impeller, the connective portion connecting the impeller to the drive shaft, the connective portion comprising a tapered, non-threaded bore extending through the impeller. 
   
   
       6 . The device of  claim 5  which further includes a nut and wherein the second end of the drive shaft has a threaded section that is positioned beneath the impeller; the nut being threaded onto the threaded section to connect the impeller to the drive shaft. 
   
   
       7 . The device of  claim 1  wherein the portion that directs molten metal at least partially downward is an angled surface. 
   
   
       8 . The device of  claim 7  wherein the angled surface is formed at a 45° angle. 
   
   
       9 . The device of  claim 1  wherein each blade includes a portion that directs molten metal at least partially downward. 
   
   
       10 . The device of  claim 1  wherein the impeller has an overall length of at least 28″. 
   
   
       11 . The device of  claim 1  wherein each blade has a height of between 6″ and 7″. 
   
   
       12 . The device of  claim 1  wherein the hub is a 8″ square in plan view. 
   
   
       13 . The device of  claim 1  wherein the leading face includes a surface that is angled to direct molten metal in a partially upward direction. 
   
   
       14 . The device of  claim 1  wherein the impeller has a top surface and a trailing surface, and a recess formed from the top surface to the trailing surface. 
   
   
       15 . The device of  claim 1  wherein each blade includes a vertical lip. 
   
   
       16 . The device of  claim 1  wherein the impeller has two or more blades, and wherein each blade has a leading face portion that includes an angled surface and a trailing face that is vertical. 
   
   
       17 . A device for generating a downward and radial stream of molten metal in a scrap melter, the device including:
 (d) a drive source;   (e) a drive shaft having a first end and a second end, the first end connected to the drive source; and   (f) an impeller connected to the second end of the drive shaft, the impeller having two or more outwardly extending blades, at least one blade including a vertical face that directs molten metal at least partially outward from the impeller, wherein the blade has a square cross section, and wherein the impeller has a hub and each blade extends outward from the hub by at least 10″.   
   
   
       18 . The device of  claim 17  wherein the impeller has four blades. 
   
   
       19 . The impeller of  claim 17  wherein the impeller is in the shape of a cross. 
   
   
       20 . The device of  claim 17  wherein the vertical face of each blade is at least 6 inches in height. 
   
   
       21 . The device of  claim 17  wherein the vertical face of each blade is more than 4 inches in height. 
   
   
       22 . The device of  claim 17  wherein at least one blade includes a surface that is angled to direct molten metal in a partially upward direction. 
   
   
       23 . The device of  claim 17  wherein each blade has a vertical surface and each blade further includes a surface that is angled to direct molten metal in a partially upward direction. 
   
   
       24 . A device for generating a downward and radial stream of molten metal in a scrap melter, the device comprising:
 a drive source;   a drive shaft having a first end connected to the drive source and a second end; and   an open impeller connected to the second end of the drive shaft for circulating molten metal, the impeller comprising:   a hub;   three or more blades extending outwardly from said hub, there being spaces between the blades,   wherein at least one of said three or more blades includes a leading face with an angled surface for directing molten metal at least partially in a downward direction and a trailing face, and   wherein at least one of said three or more blades includes a leading face with a vertical surface for directing molten metal at least partially in a radially outward direction and a trailing face.   the hub including a non-threaded tapered bore for receiving an end of a drive shaft.   
   
   
       25 . The device of  claim 24  wherein each of the blades includes an angled surface. 
   
   
       26 . The device of  claim 24  wherein each of the blades includes a vertical surface. 
   
   
       27 . The device of  claim 24  wherein the trailing face is vertical. 
   
   
       28 . The device of  claim 24  wherein the impeller has a top surface and a recess formed from the top surface to the trailing surface. 
   
   
       29 . The device of  claim 24  wherein each blade has a height and width, the height being less than four times the width. 
   
   
       30 . A device for melting scrap metal, the device comprising:
 (a) a vessel containing molten metal; and   (b) a scrap melter positioned in the vessel, the scrap melter comprising:
 (i) a drive source; 
 (ii) a drive shaft having an first end and a second end, the first end being connected to the drive source; and 
 (iii) an impeller connected to the second end of the drive shaft, the impeller having two or more outwardly extending blades, at least one blade having a leading face, the leading face including a vertical lip portion and a portion that directs molten metal at least partially downward, the impeller having a hub wherein each blade extends outwardly from the hub by at least 10″. 
   
   
   
       31 . The device of  claim 30  wherein the leading face portion that directs molten metal at least partially downward is an angled surface. 
   
   
       32 . The device of  claim 31  wherein the angled surface is formed at a 45° angle. 
   
   
       33 . The device of  claim 30  wherein the impeller has four blades. 
   
   
       34 . The device of  claim 30  wherein the hub is a 8″ square in plan view. 
   
   
       35 . The device of  claim 30  wherein each blade has a height between 6″ and 7″. 
   
   
       36 . The device of  claim 30  wherein the leading face includes a surface that is angled to direct molten metal in a partially upward direction. 
   
   
       37 . The device of  claim 30  that further includes a circulation pump positioned in the vessel. 
   
   
       38 . The device of  claim 30  wherein the vessel has two compartments.