In the Turbine Room, where I was most involved, was an Allis Chalmers, 4000 Kilowatt Turbine-Generator that took steam at 650 PSI and exhausted at 150 PSI, and a 3000 Kilowatt General Electric unit that took steam at 150 PSI and exhausted to a surface condenser. The GE was also equipped with an extraction grid that allowed steam to be taken from the fifth stage at 35 PSI.
It surely must have been the intent of the designers to create a completely closed system, as far as heat balance was concerned. The one important thing that they had not considered was that perpetual motion was not yet refined to the point that it could be applied to pulp mill operation.
The idea was to generate steam at 650 pounds pressure, then pass it through the Allis Chalmers Turbine, whose electrical output would be governed by the amount of 150 pound steam that was required for processing and to supply the G-E Turbine with enough steam to satisfy the balance of the electrical requirements. The G-E was to take the 150 pound steam and allow enough of it to be extracted at 35 pounds to operate the Black Liquor Evaporators and satisfy the other needs for low pressure steam, then exhaust the balance of it to the surface condenser.
There were, of course, pressure reducing valves between the 650, the 150 and the 35 pound headers to maintain the correct pressure in the event that the electrical demand was not great enough for the turbines to pass adequate steam to supply the requirements.
Those were the plans, however, we hadn’t operated very long before the owners concluded that the designers must have been dreaming.