The Sullivan Air Lift Pumping System

u 8 □ £ Back- Blowing and Cleaning a Well with Air 0U5H FOR qotjQE w nr z <r j L the percentage of submerg- cnce, as both factors change the amount of air. If the i j oAsiwq. Ui 0. £ « pipe is too large, then there is slippage of the air past the water, unless more air is used to keep up the velocity; or if too small a pipe is used, undue friction will increase valve the power needed. Each separate well or group of wells is an engi- neering problem that should be carefully studied, and the most complete data obtain- able should be furnished, so that a system can be designed to cover all points. The standard practice of well drillers is to equip gravel and sand wells with a strainer, designed to shut out the sand from the working barrel of a deep well pump. In time, these strainers become clogged with sand and the flow into the well is thus reduced. By a system of back-blowing, Arrangement of piping a well for back-blowing the output from such weßs can be permanently increased. The correct strainer for wells of this dass, pumped by the air lift, is a perforated screen with openings of a suitable size to admit the fine material into the well, from which it can be pumped, and to hold back the coarser particles, so as to form a natural gravel filter bed outside of the artificial one. The force available for getting water into a well is the head, due to the difference between the static level in the water strata outside the well and the pumping level in the well, minus friction due to the strata and screen. Therefore, the more this friction can be reduced, the greater will be the flow, providing of course, that an abundance of water is available. “Back-blowing” can be applied to all wells. The top of the well casing should be sealed; next, by closing the discharge pipe while 16