Document bBbLzxKEk3R5DD4XyyxEVGeV3

CHAN IINBI, modem look of lodoy'i power itotloni, oven . reflect sound engineering. 6ut here's a plea for the some the smaller ones like this 7500-kw Rocky Ford. Colo, plont, attention to detail for tha nation's coollng-woter service Bearings, Glands Need Clean Water Too Station cooling-water services clog up from iron and solids By PAUL SNYDER, Ore/ Inglneet, Rocky ford Mont, Soulkern Colored* Power Co AS MORE POWER PI.APTS go up III semlarid regions, a rather specialized water-conditioning problem for station water service is bound to crop up un less steps are taken at the design stage. At least that was our experience in the Rocky Ford, Colo, plant of the Southern Colorado Power Co after Its 1951 start. Here, we'd put in a 100,000-lb-per-hr 600-psig 825-F-total temperoture steam generator to supply a. 7500-kw steamturbine-driven generslor. Makeup water for cooling'tower, boiler and all station service-cooling needs come from two 900-ft-deep wells. These wells flow freely at about 10 gpm. So we set the pumps at 250 It, and the two wells delJver'150 gpm. This woll water shows a total hard ness of 52 ppm ns CaCO* o calcium hardness of 18 ppm, s magnesium hard ness of 54 ppm, a zero phenolphtholein alkalinity and 208-ppm methyl-orange alkalinity, all expressed as CaCOt. Chlorides, ss NaCl,' run 36' ppm; sulfntes, as Nn,SO,, 667 ppm; silica, as SiOh'll ppm; phosphates show 0 ppm as' POi-' Total iron analyzes: 6.9 ppm, sa fe; carbon dioxide. 34.6' ppm; am monia, as NH* 2.0 ppm; sulfide, as H,S, 1.1 ppm; pH measures 7.0. We started the plont off with a 4-in. standby connection to the city-water supply, which carries a total hardness of 250 ppm, as CaCOt, in summer, and 600 ppm in winier. When well water is released to at mospheric pressure much of the carbon dioxide and hydrogen sulfide escape, so dissolved iron drops out of solution. .This chain of reactions lakes place es pecially where flow is not turbulent.' ' Our external water-conditioning sys tem, employing one of the new synthetic zeolites, does an excellent job'of remov ing total-hardness; iron and ammonia. One thing we did find, though: To getrid of ammonia, we had to recharge the zeolite about three times as often'as we' would'have for hardness salts alone. Dot our station cooling-water supply was a different story. Flow rates to our water-cooled bear ings, air-compressor jackets'and holler- 6 ENGINEERING AND MANAGEMENT SECTION POWER 7 MUD, WON ond Ingok/ble rcole in row water, normoiJy lopped. ice problem In the supply system, especially in semlarid re /lor ptnorol *t'atkxi-*ervlce cooling needs, con become o serv gions where the cooling duty runs much heavier ond longer feed pump's gland-jackets ran very low ditions, we cleaned them one at a time >nd quiet. As a direct result, iron, drop with Inhibited muriatic acid. ping out of solution from the wall water, Then'we put .in special copper-core .as it neared, atmospheric, pressure in- fan-cooled radiators, lop right photo, tbe connecting pipings or the water-' 8 it above each air compressor and In copied parts, filled them up from one- duced-draft fan's,bearing near the out half to iwo^lhirds of their volume within side woll. This way, each fan has an a single year,.photos.above. . outside-air intake. Once In place, we W knew the answer, ond so starjed tied these radiators into the equipment's the engineering snd investigation of an cooling-water . conaectlans by lV4*ln. aerator, followed by thecold-Uma soften- pipe and hose .fittings. Piping was laid ng process for complete station satis ' out to give maximum circulation by faction. But, in the meantime, we had thermal-siphon stone. Tho former cool- major problem on our hands. ing-waier supply was cut off snd con . To get the induced-draft fan's bearing- densate was put in the loop with 500 cc water-jackets, the air compressor's of potassium-dlchromate rust inhibitor water-jackets and the boiler-feed pump's added. Mokeup is nil. . . gland-jackets baek to their stort-up eon- Mercoid oquauali in the topi tank of each radiator switch the fans on and off as circulating-water temperature requires. The boiler-feed pump's pocking glanda now draw their cooling-water supply through one-inch copper piping that tape into the condenser-hotwell pump header. Discharge goes into the condensate stream just aheod of the low-pressure extraction heoler. An auto matic throttling valve on the hotwell level gives enough pressure differential (or circulation through the glands. With these changes we dropped our station water-cooling needs from 26 gpm to I* gpm. This last 1V$ gpm comes from cHy water, which also supplies the zeolite-softened evaporator makeup. WW.1933 ENGINEERING AND MANAGEMENT SECTION IT