Page:Popular Science Monthly Volume 88.djvu/893

 Popular Science Monthly

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��result that it cannot drive its generator during higli water periods.

���SECTIONAL ELE.VAT10M

��Vertical section through the turbine and

concentrator, showing different water

levels and other details

The current consumer needs his light and power during rainy seasons and thaw periods. Therefore, the small water power has been considered a hazardous investment without a steam engine or gas engine in reserve.

The river Rouge is a sluggish stream draining a wide flat valley. It flows into the Detroit river, which is often aftected by winds on the Great Lakes. This causes the Rouge to back up and lower the head at the Ford dam at times when other conditions are favorable to good power.

The farms' water power has been modernized. It is now an electric station which provides current for the village pumping station, for Mr. Ford's home, and the various requirements of the farms. The problem of variable heads, and variable flow, in connection

���Sujjer Draft Tube

��Tail Waier

��with constant requirements, was of special importance. Therefore, some new ideas and new apparatus were developed in the solution.

As has been already stated there are times of excess flow, in which the actual head pressure on the turbines is lowered. If a greater number of turbines were installed to use this surplus water the cost, together with the expense of larger foundations and buildings required, would be prohibitive from an investment point of view. This made it necessary to try to increase the head by the use of the surplus water itself, in other

��Head Water Level

���rj Head ' The m^i.^:

���pressure at the lower end of the turbine, and ments the pressure at the intake end

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��The concentrator is in reality a tube within a tube, acting somewhat like a siphon

��words, to set the mischievous water to work. This was done to the extent that the turbines can develop more than their normal power at times when they otherwise would be ren- dered powerless.

This was brought about by an apparatus which leads a portion of the surplus flow to the turbine discharge pipe in such manner that a vacuum is formed for the turbine to discharge into, thereby adding atmospheric pressure, or head, to the water head already acting on the turbine. This produces the full head condi- tions for the turbine. In turn, full power is furnished. This apparatus is called a

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