Bed No. 4 is now standing full and No. 1 is filling. When compression dome chamber No. 4 was filled, water started flowing through timing siphon valve No. 4 into timing chamber No. 4 at a rate determined by the amount of the opening of the timing valve. As this chamber fills compression is transmitted to blow-off trap 4b and when sufficiently great this trap is blown and timed siphon No. 4 is put into operation. Bed No. 4 is emptied by it, and compression dome chamber No. 4 is emptied through the withdraw siphon at the same time. This completes a cycle for the filling and emptying of one bed and the method of passing the dose on to another bed has been explained. The principle can be extended to the operation of any number of beds.

Fig. 186.—Plural Timed and Alternating Siphons for Contact Bed Control.
Courtesy, Pacific Flush Tank Co.

INDEX


[1]. Frontinus and the Water Supply of Rome, p. 81, by Clemens Herschel.

[2]. Estimated by G. W. Fuller, Trans. Am. Society of Civil Engineers, Vol. 44, 1905, p. 148. The total population connected with sewerage systems was assumed to be the total population in the United States in cities over 4000 in population.

[3]. Estimated by Metcalf and Eddy, American Sewerage Practice, Vol. III, p. 240.

[4]. Computed from report of the United States Census, 1920, on the same basis as Fuller’s estimate for 1905.