Water Well Journal
Issue link: http://read.dmtmag.com/i/451364
"Driver" is used as the generic term for a vertical turbine pump power source as this device can consist of a vertical holloshaft or solid-shaft electric motor or a right angle driven gearhead powered by an internal combustion (gas) or diesel fueled horizontal engine. Motor speeds are demonstrated in poles, such as "2P" for a two pole, or 3600 RPM, motors. See footnotes 5 and 6. Footnotes Footnotes appearing in the headings of the column are listed to assist the de- signer with an understanding and how the terms and conditions associated with each column were derived. The bottom part of Table 1 shows the maximum and minimum flows that were determined and used for each riser or column pipe size diameter and were based on a com- promise between the typical operating costs (friction losses), minimum re- quired uphole velocities, pipe costs, and the well and pump capital costs for new wells. Tables 2 and 3 The information shown in Table 2a reflects typical submersible pump motor data for most of the manufacturers listed. This data was used to develop the selections in Table 1. Table 2b reflects the minimum flow rates associated with the various motor and well casing sizes. The minimum ve- locities shown as recommended velocity in feet per second (FPS) are intended to provide an adequate flow past each motor diameter in order to maintain a motor shell temperature within the allowable range. The flow velocity for the group of 10- to16-inch nominal diameter sub- mersible pump motors of .80 FPS is higher than the minimum of .50 FPS listed by some motor manufacturers. ENGINEERING continues on page 48 WWJ February 2015 47 Twitter @WaterWellJournl Table 2b. Submersible Motor Cooling Data Annulus Area Between Motor and Well Casing/Sleeve (in Square Feet) and Flow (in GPM) Submersible Motor Nominal Diameter (inches) 4" 6" 8" 10" 12" 14" 16" Recommended Velocity (FPS) 25 .50 .50 .80 .80 .80 .80 Well Casing or Sleeve ID/OD Diameter (inches) 4"ID .011 (1.2GPM) 5"ID .06 (6.8GPM) 6"ID .12 .02 (13GPM) (5GPM) 8"ID .27 .17 .02 (31GPM) (38GPM) (5GPM) 10"ID .47 .36 .22 .10 (53GPM) (82GPM) (50GPM) (36GPM) 12"ID .71 .61 .46 .33 .14 (80GPM) (136GPM) (103GPM) (120GPM) (51GPM) 14"OD (13.50"ID) .92 .82 .67 .55 .36 .11 (103GPM) (185GPM) (151GPM) (197GPM) (129GPM) (40GPM) 16"OD (15.25"ID) 1.20 1.08 .94 .81 .62 .38 .15 (134GPM) (243GPM) (212GPM) (292GPM) (223GPM) (137GPM) (54GPM) 18"OD (17.25"ID) 1.54 1.44 1.29 1.16 .98 .73 .50 (172GPM) (325GPM) (290GPM) (418GPM) (353GPM) (263GPM) (180GPM) 20"OD (19.25"ID) 1.94 1.84 1.69 1.56 1.38 1.13 .90 (217GPM) (414GPM) (380GPM) (562GPM) (497GPM) (407GPM) (324GPM) 22"OD (21.25"ID) 2.38 2.28 2.13 2.00 1.82 1.57 1.34 (267GPM) (513GPM) (480GPM) (720GPM) (655GPM) (565GPM) (482GPM) 24"OD (23.25"ID) 2.87 2.77 2.62 2.50 2.31 2.06 1.83 (321GPM) (623GPM) (590GPM) (900GPM) (832GPM) (742GPM) (660GPM) Required water flow past motor (in GPM/square feet) at water temperature < 68°F (20°C) 4" diameter at .25 FPS = 112 GPM/ft 2 . 6" and 8" diameter at .50 FPS = 225 GPM/ft 2 . 10"-16"diameter at .80 FPS = 360 GPM/ft 2 . Example: For 6" submersible motor in 12" well: .64 ft 2 × 225 GPM/ft 2 *#&& +)'! %"! #'" ($" 2 ) past motor.