AERATING DEVICE FOR SALT WELL WATER 



165 



NUMBER OF TRAYS 



O 



q: 



!4i 20 



FREE FALL / 

 / 



V/ 



I ^ Ill L 



J L 



J L 



I 2 3 4 5 6 7 8 9 10 12 15 18 



24 34 36 



SPACE BETWEEN TRAYS IN INCHES 



48 



60 



Figure 5. — Relation between percentage oxygen saturation, tray number, and tray spacing. Broken 

 line represents time/distance relation for a body in free fall. 



trays. Also not evident is the oxygen con- 

 tent of the incoming water; this ranged 

 from 0.15 to 0,69 ml./L, but was most 

 often 0.17 to 0.20 ml./L. The highest 

 saturation achieved with the model aerator 

 was 93 percent; the highest obtained by 

 prolonged bubbling of air through the 

 water was 96 percent. 



Two aspects of figure 5 merit brief 

 discussion. The first is the shape of the 

 saturation curves: as is apparent, these 

 have the general conformation of the curve 



describing the distance traveled by a freely 

 falling body. Saturation is a function of 

 the amount of exposure to air, and this 

 varies with drop size, velocity, and height 

 of fall. The left portion of each satura- 

 tion curve is flatter than the corresponding 

 part of the free-fall curve, undoubtedly 

 representing additional exposure to air be- 

 cause of splashing, flow over the tray sur- 

 faces, or a velocity decrease caused by air 

 resistance. Also contributing to the shape 

 of tlie curves are such factors as water 



10 12 14 



TRAY SPACING IN INCHES 



20 



22 



24 



Figure 6. — Height of aerator needed to produce a given i^ercentage of oxygen saturation. 



