Document g2qd4r2zR583yzgKY2xExaR0J

6c/frr- 5 Flywheel on thoft. The shoft Is blocked In pJoce in the ossombly pit. It Is reedy for Its flywheel which the dtogram. shows being forced Into Its ploce by hydraulic locks SSteanvheotlno box Is shown et tower left A flywheel Is blocked on edge In o steon box for hooting. Everything Is In reodiney to press In its shaft at tho right tin* end causes it to grip the shaft so the sections will be solidly together. Never put two or more heated sections on a shaft at the same time. The outside faces of the sections hubs will grip the shaft and draw apart as they cool. The kerywoys also expend so dummy keys mutt be driven into the pole key slots to hold them In alignment as aectlons cool. Three or four such keys* distributed around the circumference* are sufficient. Herixontel-Sfiaft Rotors. When assem* bling o horizontal-shaft rotor, assemble tho pressing rig end hold the section against the shaft shoulder or stop blocks until it has gripped the shaft A flywheel or single-section rotor cao he blocked on edge. Put the keyway on top* and heat either by electric heaters or steam. When heating Is completed lift off the heater box and bring the shaft to the hot piece. Fig. 6 shows- a flywheel in o steam box with the strong back, holts, jacks and blocking ready (or instant use if neces* eery. Severe! of tbeso esseinblies have been completed by putting the shaft in with a chain block or using o limber as a battering ram. If o hub seizes before it is home it will be difficult if not Im possible to gef it either on or off. On the other hand when everything goes well,' assembly is made quickly. A hot section has been lifted from the oven, placed on tho shaft and tho next cold section put in.-in less than IS min. .Removing Rover From Shaft. It is some- times necessary to remove o rotor from its shoft. It is foolhardy to attempt this wilhoni heating the rotor, cooling the abaft, or both. It may require three or more times more pull to start the rotor off than it took to put on the shaft. If the rotor was healed before putting on the shaft, the problem, is more difficuh than when a cold-press installa tion job was done. Build a strong back of plates, de scribed on p 69, Juno Powek, to 6t against the hub of a forged coupling if the shaft hss one or against the oil shedder of the bearing journal. Cut wood blocking and arrange to place the largest capacity jacks avail able between the strong hack and the hub. Four 150-ton Independent pump jacks with a common pump la not too large. If the rotor has a cast rim and pokea, heat the rim by induction. If the rotor la laminated or has s wind ing, place electric healers as near the circumference os possible. Raise tem perature to around 160 F and et tbe same time, keep the shaft cooled with ice and salt, or dry ice if obtainable. Put full pull on tho jacks and if rotor doesn't start, hold the pressure and bump end of shaft with a heavy timber or steel billet. A heavy blow often starts an obstinate rotor. Do not apply direct heat to the bub of a largo rotor. Tbe colder rim and spokes prevent expansion away from the shaft to the hub may grip the shaft harder ihta be fore heating. . Romovtog d Domogri Shoft. Fig. 8 shows a rotor, ol (our cast-steel w> lions, whose rim was heated to shoot 2S5 F by induction in about 2 br while (he hub's temperature Increased ta about 75 F with scarcely any Increase in shaft teaperelu/e. After bestial, four 150-ton jacks were used eo tho strong backs to remove the esst-steel rotor from Its shaft, badly damaged by an accident io handling. The rotor started at 450-ton pleasure and Isms off easily. Against orders, not to try replscia* the four sections on a new ehsft j one time, the same winding wss osed to expand the rotor bore when in' stalling the new shaft. Use end sefr tions bit first on the shaft. After that all lengthwise contraction of the *~ occurred between the end sections- As^ a result there was a space between sections around the through-bolt boss when the rotor cooled. Specie! bssw* fitted blocks had to be put between, sections to prevent springing the sW when the through bolts were tight*8**- 78 (684) POWER * Novsiab** ,WI 4 During earlier yean S. Johns River water was cleaner ceusing less eondonser 4 Variation in wet and dry bulb raiding I .. a i i .-L .L. _> .. .(lui --. I--- ------ ----. I.l.l.^ikla . a --------------- mAUhlM IIWlMfll in 00^100 How Talleyrand's Condenser Operating Experience Varied Over the Years Growing population qjid chonging river, conditions continuously - posed new problems in keeping turfoee condensers clean. Increating fuel costs made It imperative to find optimum means of reducing fouling with minimum hatard to station personnel By T W BOSTWICK. J A CASSID6V and J P HANCOCK* CItf of Jacksonville, Merida j* the west bank of the St. Johns Rivet j0 Jacksonville, woa one ol the first *r8 steam-power plants built ir From 6000 kw in 1913 th< f l/cS 6rwn to o total capacity o. * , kw In five units today. An inter 8 phase of this growth Is the devel * Operating and rnaintenanci |- A|n[. t0 conlrol lurfaco-condense Table 1 lists princlpo 4 f^6 main condensere. No. 1 . * kove more surface per k **** than 6 and 7. This graph! colly illustrates the condenser manufac turer's contribution to the advancement of power plant design. Steam lanes give more effective surfoee use end, combined with more complete air re moval, represent a relative saving in equipment coat. Clrculotlng Water. Average temperoture of the St. Johns water has been 73 F for 20 years, with maximum and minimum yearly averages of 74 and 71 F. In contrast, the chemical and bac * Abarta r sap* w*C Mm riMWi taUea A0J1E I April ISIS PHIIU W Ftortd* EBctMWtag Bactftp teriological content has varied mark edly. Once the plant site f* chosen, little can be done to-change cooling* water type and character. The operat ing and development engineer must de vise maintenance methods to cope with the ever-changing problem. In the early 1930* the St. Jobne RWer was relatively unpolluted. Jacksonville s population waa then about 130,000; today it is above 235,000. The low chlorine demand ol 3 ppm, bottom ol table II, indicotes tho low pollution from raw sewage and industrial wastes. Water salinity as tested over a 20-year period shows a variation from 180 to 17,000 ppm sodium chloride. No trend has been found In this factor. Stream pollution from all sources has been an ever-increasing problem. Trode waste from nearby industrial plants has multiplied the chlorine demand three to four times. Microscopic plant and animal life has changed in type and variety to survive and flourish under the latest conditions. Early difficulties were encountered with mussels, barnacles and heavy moss deposits in intake tunnels. Today slime-producing organ- Novpmbar |7S8 (605) 79