How will the reactor remain in an oxygen free state during normal productionoperation?

How will the reactor remain in an oxygen free state during normal production operation?

How is oxygen prevented from entering the duct work?

At the begining,inside the reactor,there is little oxygen,but after heating,the oxygen will becoming less and less,until no left.

Besides,the reactor is totally sealed,when heating,the oil gas could only comes out from the oil pipe,so it is oxygen free.

Also,there is vacuum device,it ensuresthe oil gas always coming out,and won't comes back.