Systems for modifying pressure differential in a chemical vapor process

Abstract

A process for densifying an annular porous structure comprising flowing a reactant gas into an inner diameter (ID) volume and through an ID surface of the annular porous structure, flowing the reactant gas through an outer diameter (OD) surface of the annular porous structure and into an OD volume, flowing the reactant gas from the OD volume through the OD surface of the annular porous structure, and flowing the reactant gas through an ID surface of the annular porous structure and into the ID volume.

1 . An apparatus for densifying an annular porous structure comprising:
 a graphite susceptor supporting the annular porous structure, wherein the annular porous structure defines an inner diameter (ID) volume and an outer diameter volume (OD), wherein the graphite susceptor comprises a lid;   a first plug disposed in a first opening of the lid, the first opening in fluid communication with the ID volume;   a second plug disposed in a second opening of the lid, the second opening in fluid communication with the OD volume;   a third plug disposed in a third opening of the lid, the third opening in fluid communication with the OD volume; and   a control arm configured to remove at least one of the first plug, the second plug, or the third plug.   
     
     
         2 . The apparatus of  claim 1 , wherein the graphite susceptor is disposed in a furnace. 
     
     
         3 . The apparatus of  claim 2 , wherein the furnace is at least one of gas heated or induction heated. 
     
     
         4 . The apparatus of  claim 2 , wherein the control arm is configured to insert the first plug into the first opening, the second plug into the second opening, and the third plug into the third opening. 
     
     
         5 . The apparatus of  claim 1 , wherein the control arm is controlled by a mechanical controller. 
     
     
         6 . The apparatus of  claim 2 , further comprising a reactant gas source is in fluid communication with the furnace and configured to provide a reactant gas, wherein the reactant gas comprises at least one of methane, ethane, propane, cyclopentane, hydrogen, nitrogen, helium, argon, or an alkane. 
     
     
         7 . The apparatus of  claim 1 , wherein the annular porous structure comprises a carbon fiber.