Document qaManOa8kqBKYOaY6vJ5rpLXM

? POWER ENGINEERS' NOTEBOOK PIAHMESTCD (OCAS TO SOLVE PROBLEMS. OF DESIGN, OPERATION AND MAINTENANCE HYDRAULICALLY DRIVEN BOOSTER PUMP ALLOWS ELEVATED PLANT LOCATION High oemano for cooling water pri marily dictates the placing of steamelectric plants within the area of a system. Because of the steady flow and relatively high-energy consumption lor pumping required, special effort is usually directed toward maintaining a low pumping head through which the Cooling water is lifted. This further limits locating the plant, along river banks, to sites of low elevation. Studies of some sites have shown that placing plants at higher elevations than normal river level would lower substructure costs. This, together with the reduction in construction and oper ating hoisrds from flood waters, would justify the extro cooling-water pumping costs. Added to this advantage it proves economical to salvage part of the pump ing energy by applying a booster pump driven by a water turbine that uses the energy in the cooling water discharged from the main condenser, as shown in the diagram. This system was jointly developed by the engineering departments of EIoc- trie Advisers, Inc end Worthington Pump ft Machinery Corp. One installa tion in the R E Burger plant of the Ohb J Public Service Co pumps 55,000 gpa,'J The main electrically driven circulating pump, of 600-hp rating, can deliver' 60% of maximum flow when working' olonc against about 60-(t static head ] plus friction losses. Full flow develops when the water turbine drives the. booster pump. Combined efficiencies of the hydraulic units are such that the turbine-pomp ' unit salvages 70 to 80% of the power needed to develop the extra head Water flow reaches design flow for low-'.l est river stege end increases to 5% more at higher river stages. Power in- '.I pul to the motor-driven pump remains procticolly constant under the river coodillons experienced. Pump and turbine'' characteristics are selected so that ths> control-tank water level remains stable. 1 Pump-system factors are self-corapeo-f sating and control proves no problem., At normal river stages the water turbo- '] booster recovers about 425 hp net USING AVAILABLE VOLTAGES INCREASES SPEED RANGE In TltC STA HOARD HOOKUP of e 240-v de motor driving a fan, the available speed range was 1700 to 8S0 rpm, or 2:1. The fen supplies cooling air to a dry-type radiator and this speed range proved ample in warm weather. For winter conditions os well as light-load periods less air is needed than that provided by the lowest speed. To reduce the re sulting excess auxiliary demand, motor connections were rearranged as shown in the diagram with the aid of a 2-pole doublo-throw switch. Thus either 240 or 120 v could be thrown across the motor armature circuit with the Geld always fed at 240 v. ).o/np,e-po* bb-ttvow twitch r ------ tOO'omp 6~POt* mfusetsafety twitch * \1 Storting rheostat --t40V Hotting coil, aiwojfton HQV This gives the motor an additional total range of approximately 3.2S to I- speed range from B50 to S20 rpm or a (Continutd on page 112) 110 (44) POWER January I94l Location: NATIONAL LOCK CO., Rockford, Illinois. Contractor: THE AUSTIN CO., Chicago, Illinois.. Springfield service Includes design, fabrication, sod erection ofunits complete with bring, draft, usd control equipment--ell taken under "Single Responsibility" contract.WE will be glad to submit s proposal covering your requirements. Write to our main office in Springfield, or see yous neatest Springfield representative. SPRINGFIELD BOILER CO., 199 J 8. Capitol Ave.. Springfield, Illinois. lEI.Tfc ANY PRESSURE