Design of an air injection system at the level of the cylinder in a coke drum

Abstract

A system for controlling thermal changes using air injection including a coke drum having a cylindrical outer surface, a material surrounding the cylinder defining an annular space between the material and the cylindrical outer surface, and an air injection system communicated with the annular space for introducing air into the annular space. A method of operating the system is also included.

What is claimed is: 
     
         1 . A system for controlling thermal changes using air injection comprising:
 a coke drum having a cylindrical outer surface,   a material surrounding the drum so as to define an annular space between the material and the cylindrical outer surface, and   an air injection system communicated with the annular space for introducing air into the annular space.   
     
     
         2 . A system as in  claim 1  wherein the material surrounds the drum around the entire cylindrical outer surface. 
     
     
         3 . A system as in  claim 1  wherein the drum comprises a main body defining the outer cylindrical surface and cone shaped bottom connected to the main body. 
     
     
         4 . A system as in  claim 3  wherein a skirt is attached to a top of the cone shaped bottom. 
     
     
         5 . A system as in  claim 1  wherein the air injection system is communicated with the annular space by a toroid tube. 
     
     
         6 . A system as in  claim 5  wherein the toroid shaped tube further comprises an inlet air intake. 
     
     
         7 . A system as in  claim 6  wherein the air injection system injects air into the annular space through the toroid shaped tube. 
     
     
         8 . A system as in  claim 6  wherein air exits the annular space through an outlet at the top of the annular space. 
     
     
         9 . A system as in  claim 1  wherein the material is thermal insulation. 
     
     
         10 . A system as in  claim 1  wherein the material defines an outer layer having a bottom, and wherein the bottom of the outer layer is above the cone shaped bottom. 
     
     
         11 . A system as in  claim 1  wherein the material partially surrounds the drum around cylindrical outer surface. 
     
     
         12 . A method for controlling thermal changes using air injection comprising the steps of,
 monitoring temperature inside a coke drum having a cylindrical outer surface, a material surrounding the cylindrical outer surface so as to define an annular space between the material and the cylinder, and an air injection system communicated with the annular space for introducing air into the annular space, and,   operating the air injection system using air with temperature closer to temperature of items to be placed into the drum than temperature of current contents of the drum, to feed air through the annular space and prevent conditions that lead to bulging of the coke drum.   
     
     
         13 . A method as in  claim 12  wherein the air is injected at a temperature within 1000° C. degrees of the temperature inside of the drum. 
     
     
         14 . A method as in  claim 12  wherein the air is injected at a temperature within 1000° C. degrees of the temperature the top of the drum. 
     
     
         15 . A method as in  claim 12  wherein the air is injected at a temperature within 1000° C. degrees of the temperature at the bottom inside the drum.