Document EdO6O5er1a6KEVv72Q43okN3g

HERE'S WHAT IS AVAILABLE: FIT YOUR REQUIREMENTS tiro--v * TYPES--Square w ma4 lap llufti. b1ii4 r tud*. 9tM Daaqt nigutw or mil collar. 0 DERATION--Band wheel paekt ifaeave, UmI pocket ibim. bell or teeWriaed. PQaiTlOK--Vertical at lacUnea Mi. SODY MATSBIALS--Carbon i*L *talnt*u. mbbir-Dsid. ltATVllE8-Gali peeltUa Indicator* el lop. befieie or n ebels. lotwool pressure voire* available up 19 IM. ftMipkiite ptnim pr tq. la. Special dnlpu ondt b Hi year Midi. srocxWrit* far bulletin*. Addrau wcixEijunc compajtt Clitilnd 11,. Obla 156 f446bb Silica Removal (Continued jrom page 77) amount was relatively email. For thb reason, stoppage of chemical feed to the old softener* caused'Immediate In. crease in hordness which rapidly ep> . proached that of the raw water. EFFLUENT TURBIDITY ' Turbidity of the effluent from the new softener is unusually low. The average for the three months of opera* lion was 9 ppm. Thorough seeding of the water and filtering of the smaller particles by the larger partictes of the sludge bed probably caused the lew* turbidity. Visual estimates made dur ing the operation of the conventional softeners Indicate that turbidities (rots, these units were several times as high' as from the sludge-blanket softener. , Sometimes the turbidity from a eoa-. ventionahtype softener is less than 10-' ppm, but generally it is substantially * higher; at this plant it was regularly' higher than from most hot lime-soda1 softeners. With hot lime-soda treat-;ment the pH of the water must be1* higher than 10.0 for eQeetive soften-^ ingj therefore, turbidity cannot be* controlled by varying the pH as b^1' done in the Cold process where clariScation is the essential problem. At thir' plant the pH was substantially the^i' tame with both the old and the new, softeners, so (hat the better clarifies-' tlon In the new unit could be eecounted for only by the filtering action of tbs;./ concentrated sludge bed and by dik' ferences in size of pariieles formed to'n the two types. Lower hardness and lower turbidity,' Of the effluent from the sludge-blaaknj design softener reduces the phosphite . requirements, since all of the ealciusv in the form of hardness and at least il pari of the ealeium in the form Ls suspended particles of calcium bonate must be reacted with by pbes* phate in the second stage. J EFFECT OF FLOW CHANGES j The sludge bed was found to be equally effective for silica and turbidity.' removal at all rates of flow varymt' from 10 percent to 60 percent of *}? pacity. In normal plant operation coat., siderable variations in rates of c0f|l dentate return and steam demi4j caused Urge changes in the amount B|ii makeup required. These variations ^|i[ not unduly effect turbidity or sitftjT removal at eny'time. jj When the new softener was operated, the aludge level was kef*j .POWER July Since 1905 triple Adliit in-Ratwrn VoKi onO Automatic tnglne tap Value Known for Quality' and Dependability GOLDEN-ANDERSON POSITIVE CONTROL VALVES Nyevawlk Ooubic Cuthloned Chock Vetvo Stop Chock Single Ailing Attitude Volvo for every service Water houert toller Valve GOLDEN- ANDERSON wi,. Mr 1741 l/afre Throttle end Automatic toglne Step Valve*. emergency Trip Valve* . 6 Steam and Water Prenvro Redwing Valve* I Pretiure Reducing and Sustaining Valve* 6 Pressure Reducing and Belief Valves Pressure Reducing and Chotk Valve* Water Pressure ReUet Votve* Altitude Central Valve* Float Operated Central Valve* B Water Service Velvet Cake Quenching Valves Counterbalanced Rotlreed Standpipe Vehre* More than 1500 types and sites ol flow control valves for the moat difficult Power Plant and Indus trial applications are manufactured by GoldenAnderson. Write today for complete catalogs. SPECIALTY CO. Keenan Bldg. Pittsburgh 22, Pa. 167