Its not preventing you from doing anything. Just loosen the set screw and pull it out. Its a piece of BX wire covering that they use to push a little combustion air into the auger pipe. It helps keep the fire from migrating down into the auger pipe.
This is where working on a Van Wert becomes a puzzle. The bin pipe is in the coal bin and can't move much, but you need to get the transfer head out far enough from the boiler to change the auger and pipe.
Probably the easiest way to do this if the bin pipe is stuck in the transfer head is;
1) Remove the idler gear by removing the shaft set screw.
2) Remove the bin auger shear pin.
3) Remove the bevel gear from the end of the bin auger.
4) Remove the 3 brass screws holding the bin auger bearing plate in place and pull the bearing plate off.
5) You should now be able to pull the bin auger out of the pipe and transfer head.
6) Cut the Bin pipe off a couple inches from the transfer head.
7) Remove the 2 set screws securing the pipe to the stoker back plate. Now you should be able to pull the transfer head, pot auger and pipe out in one piece. Sometimes the pipe will stick in there so you might have to get creative to get it.
You will need to replace the bin pipe doing it this way. Bin pipe and pot pipe are 2.5" schedule 40. You can use aluminum, steel, stainless or whatever you wallet will handle.
You should also look at the bin auger for and sharp flighting. Look at the end where it goes in the bin and where it dumps coal into the transfer head.
And don't forget to put a load of anti-seize on the pipes where they go into the transfer head. You might be the next guy working on it!
-Don