Gas-transfer foot

Abstract

The present invention includes a molten metal pump and associated components that enable gas to be released into a stream of molten metal. The gas may be released into the molten metal stream (preferably into the bottom of the stream) flowing through a passage. Such a stream may be within the pump discharge and/or within a metal-transfer conduit extending from the pump discharge. The gas is released by using a gas-transfer foot that is positioned next to and is preferably attachable to the pump base or to the metal-transfer conduit. Preferably, the conduit (and/or discharge) in which the gas is released comprises two sections: a first section having a first cross-sectional area and a second section downstream of the first section and having a second cross-sectional area, wherein the second cross sectional area is larger than the first cross-sectional area. Preferably, the gas is released into or near the second section so that the gas is released into an area of relatively lower pressure.

1 . A molten metal pump including: 
 (a) a motor;    (b) a rotor;    (c) a shaft connecting the motor to the rotor;    (d) a base comprising: 
 a pump chamber;  
 a discharge in communication with the pump chamber, the discharge having a bottom surface and a first section having a first cross-sectional area and a second section having a second cross-sectional area, the second section being downstream of the first section and the second cross-sectional area being greater than the first cross-sectional area; and  
 an opening on the bottom surface in communication with one or more of the group consisting of the first section and the section; and  
   (e) a gas-transfer foot, the gas-transfer foot comprising: 
 a gas-inlet port through which gas enters the foot; and  
 a gas-outlet port in communication with the opening so that gas can be transferred from the gas-outlet port through the opening and into the discharge.  
   
   
   
       2 . The pump of  claim 1  wherein the gas-transfer foot is connected to the base.  
   
   
       3 . The pump of  claim 1  wherein a notch is constructed in the base, the notch configured to receive at least part of the gas-transfer foot such when the gas-transfer foot is received in the notch the gas-outlet port is in communication with the opening.  
   
   
       4 . The pump of  claim 1  that further includes a metal-transfer conduit extending from the discharge.  
   
   
       5 . The pump of  claim 1  wherein the opening is in the first section.  
   
   
       6 . The pump of  claim 1  wherein opening is in the second section.  
   
   
       7 . The pump of  claim 1  wherein opening is in both the first section and the second section.  
   
   
       8 . The pump of  claim 1  that further includes a gas-transfer conduit having a first end connectable to a gas source and a second end connectable to the gas-inlet port of the gas-release foot.  
   
   
       9 . The pump of  claim 1  wherein the pump base and the gas-transfer foot are comprised of graphite.  
   
   
       10 . The pump of  claim 1  wherein the notch has a first end at a side of the base and a second end opposite the first end, the first end having a width greater than the width of the second end.  
   
   
       11 . The pump of  claim 10  wherein the gas release opening is formed at the second end.  
   
   
       12 . The pump of  claim 1  that further includes a metal-transfer conduit in communication with the discharge such that at least some of the molten metal moving through the discharge enters and passes through the metal-transfer conduit.  
   
   
       13 . The pump of  claim 12  that further includes a structure for releasing gas into the discharge.  
   
   
       14 . The pump of  claim 1  wherein the discharge has sections in addition to the first section and second section.  
   
   
       15 . A molten metal pump including: 
 (a) a motor;    (b) a rotor;    (c) a shaft connecting the motor to the rotor;    (d) a base comprising: 
 a pump chamber; and  
 a discharge in communication with the pump chamber;  
   (e) a metal-transfer conduit extending from the discharge, the metal-transfer conduit in communication with the discharge such that at least some of the molten metal moving through the discharge also moves through the metal-transfer conduit; 
 the metal-transfer conduit having an internal channel including a first section having a first cross-sectional area and a second section having a second cross-sectional area, the second section being downstream of the first section and the second cross-sectional area being greater than the first cross-sectional area; and  
 a gas-release opening on the bottom surface of the channel in communication with one or more of the group consisting of the first section and the second section; and  
   (f) a gas-transfer foot comprising: 
 a gas inlet port through which gas passes into the gas-transfer foot; and  
 a gas outlet port in communication with the gas-release opening so that gas can be transferred from the gas outlet port through the gas-release opening into the conduit path.  
   
   
   
       16 . The pump of  claim 15 , wherein a notch is formed in the metal-transfer conduit such that when the gas-transfer foot is inserted into the notch it is in communication with the gas-release opening.  
   
   
       17 . The pump of  claim 15  wherein the gas-release opening is in communication with the first section.  
   
   
       18 . The pump of  claim 15  wherein the gas-release opening is in communication with the second section.  
   
   
       19 . The pump of  claim 15  wherein the internal channel has sections in addition to the first section and second section.  
   
   
       20 . A gas-transfer assembly for a molten metal pump, the gas-transfer assembly comprising: 
 (a) a gas-transfer conduit having a gas-release end and an opposite end connectable to a gas source; and    (b) a gas-transfer foot, the gas-transfer foot comprising: 
 a gas-inlet port in communication with the gas-release end of the gas-transfer tube; and  
 a gas-outlet port downstream from the gas inlet port, wherein the gas-transfer foot is attachable to a component of the molten metal pump such that the gas outlet port can transfer gas into the bottom of a flow of molten metal.  
   
   
   
       21 . A gas-transfer foot for a molten metal pump, the gas-transfer foot comprising: 
 (a) a gas inlet port through which gas passes into the foot;    (b) a gas outlet port downstream from the gas inlet port, wherein the gas-transfer foot is attachable to a component of the molten metal pump such that the gas outlet port can transfer gas into the bottom of a flow of molten metal.    
   
   
       22 . A base for a molten metal pump, the base comprising: 
 (a) a pump chamber;    (b) a discharge in fluid communication with the pump chamber for discharging a molten metal stream, the discharge having a bottom surface;    (c) a gas-release opening on the bottom surface of the discharge; and    (d) a notch constructed in the base such that an inserted gas-transfer foot is in communication with the gas-release opening so that gas may be released into the discharge.    
   
   
       23 . The base of  claim 22  wherein the discharge includes a first section having a first cross-sectional area and a second section having a second cross-sectional area, the second section being downstream of the first section and the second cross-sectional area being greater than the first cross-sectional area.  
   
   
       24 . The base of  claim 23  wherein the gas-release opening is in communication with the first section.  
   
   
       25 . The base of  claim 23  wherein the gas-release opening is in communication with the second section.  
   
   
       26 . The base of  claim 23  wherein the discharge has sections in addition to the first section and second section.  
   
   
       27 . A metal-transfer conduit for a molten metal pump, the metal-transfer conduit comprising: 
 (a) an internal channel extending therethrough, the channel having a bottom surface;    (b) a gas-release opening in the bottom surface of the channel; and    (c) a notch formed in the metal-transfer conduit, the notch configured to receive a gas-transfer foot having a gas-outlet port such that when the gas-transfer foot is received in the notch, the gas-outlet port is in communication with the gas-release opening so that gas may be released into the channel.    
   
   
       28 . The metal-transfer conduit of  claim 27  wherein the conduit path includes a first section having a first cross-sectional area and a second section having a second cross-sectional area, the second section being downstream of the first section and the second cross-sectional area being greater than the first cross-sectional area.  
   
   
       29 . The metal-transfer conduit of  claim 28  wherein the gas-release opening is in communication with the first section.  
   
   
       30 . The metal-transfer conduit of  claim 28  wherein the gas-release opening is in communication with the second section.  
   
   
       31 . The metal-transfer conduit of  claim 28  wherein the conduit path has sections in addition to the first section and second section.