Laserfiche WebLink
_ ~ ~' <br />,:. <br />,_ , , . ,.. <br />MAR 181996 <br />Ri~]rard Fox DMG <br />Fox Stlgnoecing <br />1110 Oak Circle S. <br />Broomfield, CO 80020-1065 <br />Match 17,1996 <br />Mr. AAen C. Saeawn <br />DMsion of Mlnerale and Geolo6y <br />Department of Nanaal Rewmt,es <br />1313 Sherman St., Room 215 <br />Denver, CO 80203 <br />Re: Water Spray Evaporation Calerilatiaru and Deaigri, Gold Hill Mill <br />File No. M 94-117 <br />Dear Mr. Sorenson: <br />In the time I have been able to spend reviewing available IltaaRuro and talking with evaporation <br />systems operators, I have not came up with s greet deal of tocnieal err operating data on splay <br />ponds. I did obtain a Technical Manuel (No. 401). titled "Spray Pads for Cooling end <br />Evaporation", published by Spraying Systems Co. of Wheaton,. Illinois. <br />Basic thermodyrusniea require 120 gallons of water losing 1'F to evspoaate 0.112 gallons of <br />water. The tanperaGse loss available is the difference betweta the water temperautre sod the war <br />bulb temperature. This moans that during each spraying cycle, evaporating approximrmely 1% of <br />the water will cool the wow 10°F. Continued rsepraying of the water brings the tempereM1ure <br />down to wet bulb temperattQe. The low wstar temperature coming from the Haul A edit will <br />normally give ua less than 1% evaporation 1oas. <br />The other loss that is available in spray ponds is wind drift lou. I could find only one example <br />calculation for overall pond spray losses that gave a manber for wind drift lose. The axemplc <br />gave a 2% spray lose fora 5 mph wind speed If we would ••~+~" that this lose is liners, there <br />would be s 1•~6 inetearental loss per 2.5 mph wind speed irrcrea9e. <br />If a maximrmr 1°/. evaporation loss is avumed end a 3.28% wind drill lass (baud on 8.2 mph <br />avereQe wind speed from rho Gold Hill Water Balance table). a m®dmum average of 4.28% <br />evaporation loss per rycle can be assumed for spray loss calculations. <br />To evaporate end lose thmugh spray lose en average of 20,000 gallons per pump cycle from the <br />Hegel A would mquiro pumping 230 gpm per rycle through spray novlea for about 31 hours. <br />Total pumped volume would be epproxim~oly 467,000 gallons. At a 0% evaporation loss and <br />•..i ...:_a .is ~„__ ~ Y _~ nen ~ _.M.i~ b2 r2Qlllr2~ far fi6.5 h61u--a a'fiu n iuiiti yuu~you <br />~>o wuiu uuu Ewa, wig u i~~ ll MVW <br />volrane would bespprnximately 100,000 aslloN. <br />The system dealgn wlll Include a low head, hlgJr volume pump [o reryele water fn the pond. 17x <br />water will be pumped throtrgtt a 3-in. diameter disMbution pipe with reducing toes plece+i nn <br />aliproximately 20-ft, caters. The piping will be reduced to 3/flirt et each tee and n X manifold <br />