Document LJMB3zaNj3EwbB3Mw644jbBr3

TECHNICAL BRIEFS ' 9 Oijuts lor yon on: WATER TREATMENT latest engineering developments hr busy power men INSULATION ELECTRICAL EQUIPMENT fjnf" For this addition to their New York City power plant at East River and 14th Street... Potential metal pickup in the prebolter cycle by various O Special apporotus for running metal, pickup tests, le(t;-i suspected moteiiat* was the basis for above test curves required removing condensote from steam boforo it cooled j SpieledSSS..I, Vim of rKon'If com.ooo-o o Coa.olldiited NEdimd'l- powe- plont... ".other S3i.' Oo 01 it* HlW'MilMili InsuIncJtm on boil- 8fKfid:lloR- l ** Prt,T ||limitedby the Aibeuo* CoMf'ue- BuaftOuopsnr. I- *** ,"wnd* HIiai'J-M:Insulation Contractor. Water Treatment Gets Heavy Attention Prevention of Metal Losses In Iho Wet with the steam before cooling to insure (team Areas of Steam Turbines. By F L duplication of condilfona within the tur. Archibald and John IF Purnell Jr, Bos bine. The moisture was starting to form ton Edison Co; Frederick C Straub, in the rogion below the 18th stage which University of Illinois. was about 15 psia under full load oo This paper deals with the potential the turbine and down to 4 or 5 psia metal pickup in the various portions of, under low. loads. The apparatus used the preboiler cycle from the initial point for sampling is shown in Fig. 2, above. of moisture condensation in the turbine, This allows for a continuous sample through the condensers, heaters, pumps of the water separated from the steam and economizers. It shows the effect of to be cooled and then tested for the various materials such os sulfur specific conductance and pH before ex* dioxide, hydrogen sulfide,' carbon diox* posure to air. Samples could then be ide, oxygen, smmonia and organic collected and analyzed for Iron, am* amines on the metal pickup in the cycle. monia and reducing -power. Tho sam* Stress is laid on tho temperature and equipment was constructed of 18*8 vapor pressure relationship of these mo* stainless steel in order to reduce iron terlals at the points of condensation in contamination. the turbine and condenser. This has The results of the tests, Fig. 1, above, resulted in the modification of the chenv run. with the regular water treatment leal treatment to prevent metal pickup ' in use, showed that when die pH in the cycle. Some early experience in of the steam leaving the bolter was Hydrotine is alio presented. around 9.0, the sample of water removed Early in 1952 a program of investi- from the 18th stage of the turbine had gation was started at Mystic Station to a pH between 6 and 7 and the conden study the effect of the various chemicals sate at the condensate pumps had a pH used in the water treatment on the Iron around 9.0, The ammonia content was pickup in .the areas of metal loss. In about the same at the three sampling order to determine the composition of points. Tests run to determine the re the moisture os it forms in the turbine ducing power of the steam showed al It was necessary to remove the steam most a tenfold increase in the 18th stage water mixture from the machine and samplo-with a marked increase in Iron separate the water from the steam for pickup. The reducing power was further testing. It is important that the thought to he the result of liberation of condensate be removed from contact sulfur dioxide from the sulfite in the boiler water, since it varied in propor^ lion to the sulfite'content of the boiler.' water. No hydrogen sulfide could detected at any time. . These results indicated that the sulfur.* dioxide was concentrating in the Liquid/** phase to form eulfurous acid. The an-1 monia was partially neutralizing the. scid but was not present in sufRcieot amounts to increase the pH to the de^ sired range. This decrease in pi! in the; liquid phase in contact with the roctar in the turbine would tend to allow the,** iron to go Into solution as the eolublt* ferrous hydroxide. When the tempers-^ lure decreases and the liquid tends lo* be subcooled below its steam saturates:*, 'temperature the ammonia dissolves toy the liquid raising the pH. Thus at Uw* condensate pump the pH approaches'^ basic. .*} This increase in pH decreases the-1 solubility of the ferrous hydroxide and'T causes the precipitation of .the iron osj the lower pressures blades and dia-;.t phragms and on the condenser tubes-^ Often'it does not show as soluble iron ri in the condensate-samples taken at ihe'j condensote pumps since it has olreadfs- been precipitated out of solution. Several of the chemicals being fed to,- the cycle were then varied in order W? study their effect. Fig.' 1 shows in graph \ form a summary of the results. (Continued on page 152) 110 READER SERVICE SECTION POW&5 ^. CON EDISON SPECIFIES J-M 85% MAGNESIA MPE INSULATION FOR MAXIMUM FUEL SAVINGS [UkraU. materials thei went into the new mcraf.r)plant addition of New York's lead* nag)gti-and electric supplier...the pipe MMuUVioQ had to be the but. That's why fCoMOlidated Bdison Co. specified J-M 8598 [Magnesia... industry's No. I insulation for [many decides and still (he leader i n its class. HpJ:Mj8S9& Magnesia is the leading insulajuopjoa the market for temperatures up to jeOOF.'lt U bonded with asbestos fibers. This Lfyggni'insularion W`N not distort regard* 'tew of the length of time it stays in service. fJ-Mi8596 Magnesia fits snug and stays put. [Heat savings, therefore, remain constant for i&C'Uje of the equipment on which this in* imUtion it applied. Q^Fot temperatures over 600F, J-M 8598 t'Mjgncsia is used in combination with jjxSuperex*, a j-M insulation for service to This double-layer construction, U Superex Combination, eliminates ^ *J9_ugb joiots and protects the jacket .gainst scorching. It also utilizes the higher Stes-. heat resistance of Superex next to the hot surface, and the greater insulating value of J*M 8598 Magnesia for the outer layer. Experience has proved that atl insula tions must be properly Installed to pay maximum dividends. *I7iat'i why JohnsManville offers industry the services of ex perienced Insulation engineers aod installa tion contractors who have made a career of solving complex insulation problems. From coast to coast, these engineers and the con tractor's highly skilled mechanics stand ready to combine their talents and give you an insulation job that will more than pay off your initial investment with maximum fuel savings through the years. When you face your next insulating problem ... remember that Johns-Manville is "Insulation Headquarters." Coosult your near-by J-M Insulation Contractor ... or .write direct to Johns-Manville, Box 60, New York 16, New York. In Canada, write 199 Bay Street, Toronto 1, Ontario. MlItod Applicators oo the team of a J-M losulation Contractor applying J-M 8596 Magnesia to pipelines. Located throughout the nation, these contractors have had yean of experience handling all types of installations. They know J-M 8596 Magneiia and other J-M Insulations ar qusttij product!, aod take pride la applying them property. Result \ ao Inso lation fob that pays dividends through the years in maximum fact ravings. HJIohns-Manville first in INSULATION NOIHIIBIMO - APPIKAVIOM AUOUST 1953 -151