Abstract
Those familiar with hydroelectric power-house operation where curved draft tubes are employed cannot have failed to notice the boiling and disturbance of the water at the outlet from the curved tubes, which disturbance is clearly an evidence of inefficiency and loss of energy. The device described in this paper — the hydraucone regainer — provides a means for efficiently recovering the energy discharged from the runner for useful effect on the water wheel within the limited space available in the power-house foundations.
This new method of regaining pressure from velocity of fluids in motion consists in causing the stream flow to impinge upon some definite shape, either flat, conical or concave, thus changing its direction, and then placing an envelope around this shape so formed upon the particular base used, which envelope conforms to the shape of the fluid at entrance and gradually recedes from what would be the normal or free shape of the non-enclosed fluid impinging upon the particular base used; the effect of this gradually diverging envelope being to change the velocity head of fluids flowing at high velocity into its entrance into pressure and low velocity at its exit.
The field of application of the hydraucone regainer, according to the author, will be greater on low-head plants, although it is now being installed in connection with two 40,000-hp. units which are to operate under a head of 421 ft. Hydraucone regainers are now in operation or in course of construction in a number of plants to operate under heads varying from 8 ft. to 421 ft. and with waterwheels developing from 150 to 40,000 hp.
The paper gives very complete particulars of the long series of experiments resulting in the development of the hydraucone regainer, as well as data of a series of tests made at the Holyoke Testing Flume showing the increase in power-plant efficiency obtained by its use.
