If one is purging a system with pure Argon gas, then it should be feasible to expunge all the water vapor from the system by replacing all the gas with Argon. So, yes, it seems this should be possible, but it would take continuous purging with Argon gas, to ensure no water vapor leaks back in. 

I assume you're talking about cleaning an apparatus, not a reaction mixture. Merely flowing Argon could take awhile to get rid of all the water. Again, depends on your application and what concentration you deem acceptable. If you can pull a vacuum on the system, save some time in getting rid of water by baking the system under vacuum. The hotter, the better--but obviously within the limits on your components (gaskets, attached electronics, etc.)

Dear Justin Wiens

Here we are talking about a reaction in which plenty of hydrogen and oxygen are produced. Now, we want to create an extra heat energy by burning the as-produced hydrogen which is only possible if we could prevent the formation of water vapors. If we use vacuum, it will suck up both the oxygen and hydrogen which is not our goal. Our goal is to prevent the formation of water vapors to utilize the as-produced hydrogen and oxygen as a heat source. 

Mr. Ahmad,

I was only talking about baking and pumping before the experiments to get rid of residual water. Since you are talking about creating its precursors throughout the experiment, the situation is more difficult. I don't know what quantities of gases you're dealing with. In principle you could freeze out any water that is formed with a cryogenically cooled region on your apparatus. The more cold surface area, the better! Depending on the concentrations of gases, amount of reaction time between your cooled region and your detector or sampler, etc., this may be enough to solve the problem.