The White Steam Generator The White Company  manufactured over 10,000 of their impressive steamers from 1901 to 1910, surpassing the entire Stanley production run.  Sensing the change in trend, they shifted to gasoline engines and continued in motor vehicle production until 1980.  A prestige car, a White steamer served Howard Taft as the first official automobile of the President of the United States. (Once-Through Steam Generator) The White steam generator is also of  once-through construction; water entering at the top descends steadily to the bottom, exiting as superheated steam.  The White generator coils are unusual; the flow leaving a coil must pass over a hump before descending to the next coil (see below).  The burners are responsible for the direction of flow in these boilers.  Rollin White’s vaporizing burner (much like the Stanley) heats pressurized liquid fuel into a pressurized gas which exits a nozzle with great velocity and entraps air en route to the burner.  Such burners work best when the flame is free to rise, making the best position for the coils being directly above.  The White gravity traps prevent water from flowing freely downhill through the coil stack and ensures the flow is regulated by the feed water pump and attached control devices. Because the Doble fan-driven burner is insensitive to orientation, it can fire downwards allowing gravity to assist rather than obstruct pump control, making the traps unnecessary. An old rule to maximize heat flow states “cold to cold, hot to hot”; the hottest fluid providing heat should be in contact with the hottest fluid receiving heat and so on down to the coolest of both fluids. Combustion gasses leaving the boiler are the coolest gasses, having given up their heat to generate and superheat steam.  While no longer able to generate steam, the exhaust gas is warmer than the incoming feed water, an ‘economizer’ section transfers some of this heat to the feed and reduces fuel consumption. Energy is saved when the coldest water absorbs heat from the coldest gas, no less a physicist than Albert Einstein remarked on the elegance of this principle.  Doble and White cars must extensively control the burner firing rate and feed water flow because fast-reacting monotube boilers are very sensitive.  A bit too much feed causes the water level to move further towards the tube exit, lengthening the steam generating but shortening the superheater, causing more steam production but with inadequate superheat. Too little feed yields an insufficient quantity of overly superheated steam.