Coking drum related method and apparatus

Abstract

A safety system for a coking facility where there is a coke drum and a drill assembly. When the coke accumulates in the drum, a drill head of the drill assembly is lowered into the coke drum to emit high pressure water jets to remove the coke from the coke drum. There is a enclosing structure with an access door which is fixedly mounted at a location above an upper opening of the coke drum, so that when the drill head is moved out of the coke drum and there is an accidental jet water discharge, it will be redirected at a location within the enclosing structure. Interlock systems are provided.

1 . A safety system for use in a coking facility where there is a coke drum having an upper end opening defined by a surrounding opening structure of the coke drum, and a drill assembly comprising a drill stem, a drill head at a lower end portion of the drill stem, and a liquid discharge system to provide high pressure liquid for a liquid discharge section of the liquid discharge system at said drill head, said drill assembly being arranged to raise and lower said drill head between a lower operating location where the liquid discharge section is positioned to emit a liquid jet discharge in said coke drum for removal of coke material in the drum, and having an upper retracted position at a retracted location where said drill head is located above said drum, said system comprising: 
 a) an enclosing structure which is located above the upper end opening of the coke drum so as to enclose the retracted location in a manner that if the drill head is in the retracted location and emits a jet discharge therefrom, said enclosing structure causes the jet discharge to be redirected in the enclosing structure;    b) an access system which comprises an opening structure in said enclosing structure to provide access to said drill head in its retracted position, and a door which is movable between a closed position and an open position, with the door in its closed position blocking the jet discharge from passing out through the access opening, and with the door in its open position permitting access to the drill head inside said enclosing structure.    
   
   
       2 . The system as recited in  claim 1 , wherein there is a guide section located relative to the enclosing structure so as to be above the drill head with the drill head in its retracted position, said guide section having a through opening to accommodate the drill stem and is arranged to center the drill stem so that the drill head properly travels into and from the drum.  
   
   
       3 . The system as recited in  claim 2 , wherein said guide section further comprises a brass bushing which engages said drill stem to prevent unwanted sparking.  
   
   
       4 . The system as recited in  claim 2 , wherein said guide section is arranged to limit upward travel of the drill head outside of a region within the enclosing structure.  
   
   
       5 . The system as recited in  claim 1 , wherein there is a door interlock system which is responsive to the door being in its open or closed position, and also an operative connection to the liquid discharge system to be able to prevent flow of high pressure liquid from the liquid discharge section at the drill head in a manner that when the door is in the open position, jet liquid discharge from the discharge section at the drill head is prevented.  
   
   
       6 . The system as recited in  claim 5 , wherein there is a door interlock control valve in the liquid discharge system, and said door interlock system operates to close said door interlock control valve when the door is in the open position.  
   
   
       7 . The system as recited in  claim 6 , wherein there is a drill head position interlock system which is responsive to location of the drill head and has an operative connection to the liquid discharge section, said drill head position interlock system being arranged so that when the drill head is moved out of its operating position within the drum, the liquid discharge system is prevented from discharging liquid through the discharge section at the drill head.  
   
   
       8 . The system as recited in  claim 7 , wherein the head position interlock system has a head position interlock control valve to prevent flow from the liquid discharge section as a jet discharge at the drill head, and the door interlock control valve and the drill head position interlock control valve are in series so that when either of the interlock systems is operative to close its control valve, flow of the jet discharge to the discharge section at the drill head is prevented.  
   
   
       9 . The system as recited in  claim 5 , wherein there is a drill head position interlock system which is responsive to location of the drill head, and has an operative connection to the liquid discharge section, said drill head position interlock system being arranged so that when the drill head is moved out of its operating position within the drum, the liquid discharge section is prevented from discharging liquid through the discharge section at the drill head.  
   
   
       10 . The system as recited in  claim 1 , wherein there is a venting system to cause cooling air to enter a region defined by the enclosing structure, and to flow through the region defined by the venting structure to have a cooling effect within the enclosing structure.  
   
   
       11 . The system as recited in  claim 10 , wherein venting system comprises an inlet air section to enable air to enter into a lower portion of the region defined by the enclosing structure, and an air outlet section to enable flow in the region defined by the enclosing structure to flow outwardly from the enclosing structure.  
   
   
       12 . The system as recited in  claim 11 , wherein said air outlet section comprises structure at an upper end location of said enclosing structure, and there is a venting structure at said upper end location.  
   
   
       13 . The system as recited in  claim 12 , wherein there is a guide section located relative to the enclosing structure so as to be above the drill head with the drill head in its retracted position, said guide section having a through opening to accommodate the drill stem and to center the drill stem so that the drill head properly travels into and from the drum.  
   
   
       14 . The system as recited in  claim 1 , wherein said door is hinge-mounted to the enclosing structure.  
   
   
       15 . The system as recited in  claim 1 , wherein said door is slide-mounted to said enclosing structure.  
   
   
       16 . A method for providing increased safety and reducing personnel exposure in a coking facility where there is a coke drum having an upper end opening defined by a surrounding opening structure of the coke drum, and a drill assembly comprising a drill stem, a drill head at a lower end portion of the drill stem, and a liquid discharge system to provide high pressure liquid for a liquid discharge section of the liquid discharge system at said drill head, said drill assembly being arranged to raise and lower said drill head between a lower operating location where the liquid discharge section is positioned to emit a liquid jet discharge in said coke drum for removal of coke material in the drum, and having an upper retracted position at a retracted location where said drill head is located above said drum, said method comprising: 
 a) positioning an enclosing structure above the upper end opening of the coke drum so as to enclose the retracted location in a manner that if the drill head is in the retracted location and emits a jet discharge therefrom, the enclosing structure functions to redirect the jet discharge;    b) providing access through said enclosing structure to said operating head in its retracted position by providing an access opening in the enclosing structure and also providing a door which is movable between a closed position and an open position, with the door in its closed position blocking the jet discharge from passing out through the access opening, and with the door in its open position permitting access to the drill head inside said enclosing structure.    
   
   
       17 . The method as recited in  claim 16 , wherein said drill head is centered by positioning a guide section so that with the drill head in its retracted position, the guide section is above the drill head, and engaging the drill stem with the guide section to center the drill stem so that the drill head properly travels into and from the drum.  
   
   
       18 . The method as recited in  claim 16 , comprising arranging a door interlock system to be responsive to the door being in its open or closed position, and operatively connected to the liquid discharge system, and operating said door interlock system to prevent flow of high pressure liquid from the liquid discharge section when the door is in the open position.  
   
   
       19 . The method as recited in  claim 18 , comprising arranging a drill head position interlock system to be responsive to location of the drill head, and through an operative connection to the liquid discharge section so that when the drill head is moved out of its operating position within the drum, the liquid discharge section is prevented from discharging liquid through the discharge section at the drill head.  
   
   
       20 . The method as recited in  claim 1 , further comprising directing cooling air into a region defined by the enclosing structure to flow through the region to have a cooling effect within the enclosing structure.