Valve Plunger with Conical Tip for KO Drain
Publication Date: 2017-May-12
The IP.com Prior Art Database
Valve with Extended Plunger to Prevent Ice Blockage
In situations in which a valve is employed to drain water and purge gases, such as in the anode loop of a fuel cell system, the valve plunger can be submerged under water during periods of system inoperation. When exposed to cold environments, this water can freeze, resulting in one or both of the following problems: 1) The plunger could be stuck in ice and prevented from opening during subsequent operating states, and 2) the valve may be able to open but the ice above the valve blocks the flow of fluids through the valve. See Figure 1.
In the case of the anode loop of a fuel cell system, such ice blockage could lead to cell voltage reversals, system shutdown, or cell damage due to the inability to purge waste gases from the anode. These effects can begin to take place within seconds of system startup in cold ambients.
A solution is to extend the plunger geometry such that it will penetrate the surface of water that may reside on top of it during states of inoperation. When the valve is subsequently operated, the extended plunger will be removed from the ice, leaving an open passage through the ice for fluids to leave the system immediately. See Figure 2.
One measure to ensure that the plunger can be withdrawn from any ice is to add a heating element tothe plunger. Rather than melting all of the ice above the plunger, however, the heater must only melt the boundary layer of ice that contacts the extended plunger...