Document Ne1pz9EYOpV4Kj9QDZB8L3vDp

CHEMICAL FEED Tan|| CHARGING INSTRUCTION SINGLE CHEMICAl-DlSSOLVINO TANK serves a botlery of separate storage tanks. Fig. I and 2. It gives o relatively smoil design, lets you use stainless metals e Wlel out A* laqvIrU cS,*)-., bcS#t patMad * Om aacioory r**t vat*M Op** drain valv* an katiaat | 3 (Swed. ftaiti lent by epail*. (aid vat** t* that tank, in ucsnd pailHan (han^l* vnl1r!!!v*jS e Attar, flutblae. ties* Maaltdd *t diractiae valv* la tint patlllaa f__ aantel). fill funatl t* i-h, d^ik'.i; "tiiH-rlne'* ***. TTita tin* i^, ^ Opaa tia StuaMiig-vatn tla? vpai'j velar ratal** la tgaaal pradaefli dli,^ cbwnlcal late hmaal la i*ch * *, It all ia lint bl*ra vttr rttcfca |j Hew pip* Claw dltiatviag-votaf it*p vaht, a,, mealftld retva I* taS t* b* iu^i|j vaUltas ta drain lata lank. Wit* h"_ atapty. Itmb bp bilaflp apaalag 'fit*;* ttap vi*a t* ciaon (m*I at Caaplata tilling lb* tank hp piatb^vS, ractlap valv* I* taeand pmli)** (kaadb^ti cel). Wban tank it tall, elm* Opan manifold diola valv* * N t Hath Kn, tht* ci*t*. bmtar* f^tettaj j| t* tint patitlan (bondt* bmiuatal) 'V<*4> Rant vanI valval vbaa aacaitarp (an laad, wUlta tenfct) ta drsv ban b Whr* nat la uu, otl chemical cbarthgli staff b* ( rti ctmad patitlan li' dJrSSam PW" ond layout of a working discharge diuotver in the photo on (ocing poge fils smoothly I i) design lf^ieo,#l how the 'ow-heod bottom- into the simplified Mow procedure pictured below In Fig. 2 .4 V 'Stoinltu-stiit ~'X ' JtttbjwhQ'.fuMit - * ` '*frt IvAnrt ff ,, to tiH rortU mitfi CTroWwfr 9*ft* I-tatrnotfc orrongement of dissolver and itorage-tonk 'poriTtoys^rtw role of manifold In simplifying design layout Standard ottr *Thrtt**oy pt*v supply Various parts moking up bottom-feed discharge dissolver hove stondord dimensions, use stainless steel where needed Troublefree Chemical Feed SystCHflilts From an Integrated Design Seemingly simple job of dis solving and feeding chemicals into a boiler-water cycle raises problems all its own. Here's a sure method that's proved fully reliable over a 5-year period in a large-scale central station plant out in California By R C ALEXANDER Mtehcnlcal tnglnoot Deportment of Wot*r A Povar Los iagain, Colli. So MANY POWER PLANTS OCrOIS the water. The newly developed c*1 country use roughly the same chemicals tulfites have greatly accelerat'd; for water treatment that you'd expeet (ion rates so time and neratioo some general agreement on what's good are of even greater consequence! equipment for feeding these chemicals Sticky Pastes. Certain other f into the boiler cycle. But actually you'll ' cals, like finely powdered snfy find anything but agreement. In many disodium phosphate, form sticky,' instances this seemingly simple process lo-dissotve pastes that require vij proves a source of operating troubles. mechanical agitation. * The more Important phases of the Undesirable Insolubles. IndusU^ chemical.feeding problem fall into three' commercial-grade chemicals ordiaj divisions: (1) pickup of unwanted out* contain a small percentige of ii side air (2) handling of sticky. Inter hies that should be screened out lJ mediary pastes (3) removal of undesir teet chemical feed pumps, check.' able insolubles in commercial grades of lines, control valves. ' chemicals as supplied. Each and every one of these Outside Air. In dissolving a solid soli ties can be solved by proper like sodium sulfite it Is essential to com What's more, the overridingr hheat plete the solution os quickly as possible of eorrosion to chemical feeder P^1 with.as little air pickup os possible. The also be reduced or controlled enlhf longer the time, the1 more outside air the design stage. It's olwaye reaction takes place. Then the chemical ' estlng point for the average has leu working eopacity to deliver realise sodium sulfite, eonupoWyj where you Want it most--in the feed- to prevent oxidation corrosion ' ENGINEERING 'AND MANAGEMENT SECTION *lSSi9Wi,.!,Tcre coi roilon of the steel \?WgiJahkx ^JdeiUpproacb to meeting all these design lor separate etoriJ^fiWjbkfqr the different chemicals Ej&WifPtvTh*" pul in a piping mnnt- ,0 8 'ingle dissolver. This dissolver design r[^l*$!7f|uilaUt and hence use stain- corroalve arena, interconnecting system, adequate flushing faalone Insures freedom from , J^aUminatlon of later solutions by ^V^of^revlously mixed chemicals. l^e order of 60 mesh or bailed on the dissolver prevcnl undesirable In-, Aotild be removable and the P8ralf o be can M ne*cie^: Eaperlence iy2v?~pjt,*'*tcei screening, silver- p^nce* #Ivm best results. VWr * dissolver is to sup- ply a solution carrying the correct weight of chemicals, completely mixed throughout, with no stratification and us free of contaminants as possible. Working - System. Illustrations on these pages show a chemical storage and dissolving system in service at the Har bor Steam Plant, Unit No. 2, that has hung up a- completely 'satisfactory 5-yr record. It involves chemical mixing and feedings, and handles sodium hydrox ide, sodium sulfito, dUodium phosphate, strong solutions for boiler and feed water treatment and mixed chemicals for evaporator liquor treatment. Fig. 2 .hows the essentials of the system, its speeiot dissolving funnel and the various storage-lack manifold piping. .The funnel, Fig. 2, 3, is built above an annular chamber, which houses four tangent noulea, right, Fig. 3. Water enters this chamber from the nozzles and gives e vigorous swirling motion to the liquid as the funnet -fills. When this swirling liquid reaches a suitable height in the funnel, the dry chemical Is added at a high rate. There Is little tendency (or the chemical to agglomerate into a paste since the -hydroulie shear forces break up the chemical. In fact, we've run tests where we've fed as high os S lb of fine powdered anhydrous sodium sulfite, in tpass, and found U completely `dissolved by the'timethe funnel was full. Once the dissolving Is complete we open the proper tank valve and let the solution drain by gravity from the dis solver into that lank. Then we bring water through the. funnel rinse-ring i<> thoroughly clean all parts of any adher ent solution. This rino water flows out through the grovity feed line Into the storage tank so. the. pmnifold Is also thoroughly flushed. In addition a drain, Biting to the sower, ties in at (he end of the manifold so the flushing can be cor ded out for the full manifold length when so desired.. ENGINEERING AND MANAGEMENT SECTION