Method and apparatus for tapping a blast furnace

Abstract

A drill bit shaft member for tapping a hole in a blast furnace is disclosed. The drill bit shaft member comprises an elongate rod, a first fluid pressure inlet, a second fluid pressure inlet, a chamber in fluid communication with the first fluid pressure inlet and the second fluid pressure inlet, and an outlet in fluid communication with the chamber. A liquid and a gas are combined in the drill bit shaft member to form a mist to provide cooling for the drill bit shaft member. By cooling the drill bit shaft member, certain components that would normally be destroyed may be re-used.

We claim:  
     
         1 . A drill bit shaft member for interconnection to a drilling apparatus, the drill bit shaft member comprising: 
 a first shaft member comprising a first elongate rod having a distal end and a proximal end, the proximal end having a first fluid pressure inlet, a second fluid pressure inlet, a chamber in fluid communication with the first fluid pressure inlet and the second fluid pressure inlet, and an outlet in fluid communication with the chamber.    
     
     
         2 . The drill bit shaft member of  claim 1  further comprising: 
 a second shaft member joined to the distal end of the first shaft member, the second shaft member comprising a second elongate rod having a fluid entrance and a fluid exit, the fluid entrance in fluid communication with the outlet of the first shaft member and the fluid exit.  
 
     
     
         3 . The drill bit shaft member of  claim 2  further comprising: 
 a tubular sleeve axially disposed around the second elongate rod to form an open volume between the second elongate rod and the tubular sleeve, a first end of the tubular sleeve adjacent to a first end of the second elongate rod and joined to the second elongate rod to form a seal with the second elongate rod.  
 
     
     
         4 . The drill bit shaft member of  claim 3  wherein the second elongate rod has a first port in fluid communication with the fluid entrance of the second elongate rod and the open volume.  
     
     
         5 . The drill bit shaft member of  claim 4  wherein the second elongate rod has a second port in fluid communication with the open volume and the fluid exit of the second elongate rod.  
     
     
         6 . The drill bit shaft member of  claim 5  further comprising: 
 a drill bit joined to a second end of the second elongate rod, the drill bit adapted for receiving a fluid pressure from the second shaft member and delivering the fluid pressure to a drill site.  
 
     
     
         7 . The drill bit shaft member of  claim 6 , wherein a second end of the tubular sleeve opposite the first end of the tubular sleeve is adjacent to the drill bit.  
     
     
         8 . The drill bit shaft member of  claim 7  wherein the second end of the tubular sleeve abuts the drill bit.  
     
     
         9 . The drill bit shaft member of  claim 8  further comprising: 
 an exit port in the tubular sleeve in fluid communication with the open volume.  
 
     
     
         10 . The drill bit shaft member of  claim 1  wherein the first fluid pressure inlet is axially disposed within the second fluid pressure inlet.  
     
     
         11 . The drill bit shaft member of  claim 1  wherein the first fluid pressure inlet delivers a liquid and the second fluid pressure inlet delivers a gas.  
     
     
         12 . A drill bit shaft member for interconnection to a drilling apparatus, the drill bit shaft member comprising: 
 an elongate rod comprising a first fluid inlet, a second fluid inlet, a chamber in fluid communication with the first fluid inlet and the second fluid inlet, a tubular sleeve axially disposed around the elongate rod to form an open volume between the elongate rod and the tubular sleeve, a first end of the tubular sleeve adjacent to a first end of the elongate rod and joined to the elongate rod to form a seal, and a fluid exit in fluid communication with the chamber.    
     
     
         13 . The drill bit shaft member of  claim 12  wherein the elongate rod has a first port in fluid communication with the chamber and the open volume.  
     
     
         14 . The drill bit shaft member of  claim 13  wherein the elongate rod has a second port in fluid communication with the-open volume and the fluid exit.  
     
     
         15 . The drill bit shaft member of  claim 14  further comprising: 
 an exit port in the tubular sleeve in fluid communication with the open volume.  
 
     
     
         16 . The drill bit shaft member of  claim 12  wherein the first fluid pressure inlet is axially disposed within the second fluid pressure inlet.  
     
     
         17 . The drill bit shaft member of  claim 12  wherein the first fluid pressure inlet delivers a liquid and the second fluid pressure inlet delivers a gas.  
     
     
         18 . A low-cost method for drilling a tap hole in a blast furnace, the low-cost method comprising the steps of: 
 providing a first fluid pressure source;    providing a second fluid pressure source;    providing a drill shaft member comprising a first fluid pressure inlet, a second fluid pressure inlet, a chamber, and a fluid exit;    providing a drill bit interconnected to the drill shaft member;    introducing a first fluid pressure from the first fluid pressure source through the first fluid pressure inlet to the chamber;    introducing a second fluid pressure from the second fluid pressure source through the second fluid pressure inlet to the chamber;    mixing the first fluid pressure and the second fluid pressure within the chamber to form a mixture of the first fluid pressure and the second fluid pressure;    expelling the mixture of the first fluid pressure and the second fluid pressure through the fluid exit; and,    providing a drilling force to the drill bit.    
     
     
         19 . The low-cost method of  claim 18  wherein the first fluid pressure inlet is axially disposed within the second fluid pressure inlet.  
     
     
         20 . The low-cost method of  claim 18  wherein the first fluid pressure is a liquid and the second fluid pressure is a gas.