Steam Challenge: Special Supplement To Energy Matters
STEAMCHALLENGEA Special Supplement to Energy MattersHelping Industry To Be Steam SmartSteam ChallengeCommittee MembersAmerican Boiler ManufacturersAssociationArmstrong InternationalBASF CorporationBethlehem Steel CorporationConsortium for Energy EfficiencyCoorsCouncil of Industrial Boiler OwnersDuke SolutionsDuPontEnergy Center of WisconsinEngineered SolutionsElectric Power Research InstituteGas Research InstituteGeorgia-PacificGestraHoneywell, Inc.Institute of Textile TechnologyInternational District Energy AssociationIowa Energy CenterKnauf Fiber GlassNALCO ChemicalNational Board of Boiler and PressureVessel InspectorsNational Insulation AssociationNorth American InsulationManufacturers AssociationNew York State Energy Research andDevelopment AuthorityPlant Support and EvaluationsRock Wool ManufacturingRohm-HaasSpirax Sarco, Inc.SwagelokTrigen EnergyUtah Steam Technology CoalitionYarway CorporationSteam Challenge is a voluntary, technical assistance program to help U.S.industry become more competitive through increased steam systemefficiency. Its goal is to promote a systems approach in designing, purchasing,installing, and managing boilers, steam distribution systems, and steamapplications. For any end-user of steam, Steam Challenge provides credibleresources to help improve steam systems, enhancing process operation andreducing fuel costs.Steam Challenge is co-managed by the U.S. Department of Energy (DOE)and the Alliance to Save Energy, a national non-profit working on energy issues.The program is directed by a group of industrial end users, equipment suppliers,and organizations involved in the steam marketplace, acting together topromote the comprehensive upgrade of industrial steam systems. These arelisted at left.Optimization of industrial steam systems represents one of the largest nonprocess, industrial energy opportunities, with improvements of 30% readilyachievable in typical plants through the introduction of a best practiceapproach. Steam accounts for 25 billion per year of U.S. manufacturing energycosts and 201 million metric tons of carbon equivalent (MMTCE), representing13% of total U.S. emissions and 40% of U.S. industrial emissions.Lack of unbiased information has been a primary barrier to realizing substantial improvements in efficiency, reliability, productivity, and safety. Often, plantoperators may not have the resources to devote to better system management.Steam Challenge Provides:Technical resources and assistance Lists of commercial training opportunities Case studies Lists of equipment providers Information to make the case on improving steam system management How Companies Can Become Involved: Implement steam system projects Participate in or sponsor workshops to raise awareness of efficiencyopportunities Submit data for a case study Use Steam Challenge documents and literature for their own clients andworkshopsContact the Steam Challenge by phone at (800) 862-2086, or e-mail atsteamline@energy.wsu.edu. Visit the Web site at www.oit.doe.gov/steam.Steam Challenge1
Steam System OptimizationBy Bob Aegerter, Equistar Chemicals, L.P.required to maintain the pressure controller’s set point. A better solution than utilizing excess steam, which costs less andusually yields better savings, is to eliminateor reduce steam entering the steam header.A steam balance is an excellent tool toidentify the steam sources. To eliminateexcess steam, a plant can:This article is condensed from a technicalpaper presented at the 1998 IndustrialEnergy Technology Conference Steam Session. For the full paper, call (800) 862-2086.Using today’s energy costs, the incremental cost of generating 1,000 lb./hr.of steam is typically 25,000– 35,000/year.This article explores numerous opportunities that may exist in your plant to saveseveral thousand pounds per hour of steamfor little or no cost. After several of theseprojects are implemented, the total savingscan be significant.Shut down turbines. The easiest solution toeliminate excess steam is shutting downsteam turbines that exhaust into the headerand start up the motor-driven spare equipment. Often, this is enough to eliminate theventing. Shutting down steam turbines maynot be the most cost-effective solutionbecause an electric motor is now beingDevelop a Steam BalanceTo be able to optimize the steam system,you must understand the system. Developing an accurate steam balance of actualoperating conditions is an excellent tool forunderstanding your steam system. Specialattention should be made to accurately measure steam flows through steam let downstations and atmospheric vents for bothsummer and winter operating conditions.Check leaking valves. To eliminate theexcess steam condition, all sources ofsteam that contribute to the excess steamcondition must be identified. The surplussteam may be from a higher-pressure steamheader. One of the best places to look issteam let down control valves. If a let downcontrol valve is open from a higher-pressure header and steam is being vented at aSteam traps that discharge into a steamheader should be checked for proper operation. Badly leaking steam traps can overpressure a steam header.Examine turbines. If let down valves arenot contributing to the excess steam problem, steam turbines exhausting into thatheader should be examined. Hand valvepositions on steam turbines should be initially examined. Typically, hand valves areopened up when the turbine is new andleft open. Operating a steam turbine withhand valves open when additional horsepower is not needed causes the turbine touse higher steam flows than required.Open valves should be closed while(continued on page 3)Don Meadows, TAPPI JournalBalance Steam Excess or DeficitTypically, a plant will either vent excesslow-pressure steam or let down steam tomeet low- pressure steam demand. If yourplant is large and has several operating areaswith independent steam systems, someareas may have an excess of low-pressuresteam and other areas may have a deficit.To optimize a steam system, the plant mustbe integrated as much as possible so thatone operating area’s excess steam can eliminate the deficit of steam in another area.Reducing steam costs should be a continuous process of eliminating sources of excesslow-pressure steam until a steam deficitexists and then implementing heat recoveryprojects to create a condition of excesslow-pressure steam. Use the steam balanceas the blueprint to coordinate projects, solarge amounts of steam are never vented.operated. If excess steam can be eliminatedwithout shutting down steam turbines,other solutions should be pursued. If theplant’s electrical rate schedule includesheavy penalties to creating new peakdemands, consider setting new electricalpeak demands when turbines are shutdown and motors started up.lower pressure level, steam is at excess atthe higher steam pressure level. Sources ofsteam supplying the higher-pressure headermust be investigated. If the steam let downcontrol valves are closed and steam isbeing vented, the let down valves may beleaking, contributing to the excess steam.The easiest way to determine a valveleak is to isolate the control valve and thenobserve the steam vent to see if the ventflow decreases. Replacing a leaking valvewith an ANSI class V control valve can bejustified over repairing a standard shut-offvalve. Class V control valves seat muchtighter and will have a positive seat muchlonger than standard control valves.Eliminate Excess SteamSteam is vented from a pressure controlvalve when the amount of steam enteringthe header exceeds the amount of steamMany low-cost opportunities exist in your plant for steam system savings.2Steam Challenge
continued from page 2checking the turbine ’s speed. If the turbinemaintains operating speed after handvalves are closed, the valves should remainclosed. Hand valves should be operated ineither fully open or fully closed positions.They are not meant for throttling steam.Upgrade turbines. If hand valves areclosed, check the nozzle block pressure. Ifthere is a pressure drop across the governor valve of more than 10% of the steaminlet pressure, the turbine is over designedand could be rerated to operate more efficientl y. Usually, this requires installing anew nozzle block. Rerating a steam turbine is relatively inexpensive and can bejustified if the turbine is causing 1,000lb./h r. of steam to vent to the atmosphere.Work with the steam turbine ’s manufacturer to obtain a proper rerate.Although more expensive than reratingan existing turbine, it may be necessary toreplace a steam turbine with a more eff - icient turbine or an electric motor driver toobtain the required steam flow reduction.When replacing a steam turbine, efficiencyshould be the prime concern. ypicallTy,single-stage steam turbines operate mostefficiently in the 5,000-6,000 rpm range.Most rotating equipment operates at either1,800 rpm or 3,600 rpm.T o get the desiredadditional turbine efficienc ,yit may be ne cessar y to speed the turbine up with a gearbox. The additional cost of pu rchasing andinstalling the gearbox can be justified bythe reduced steam flow through the turbine.Another option to replacing a steam turbine that drives a fan or horizontally splitcase pump is extending the shaft on bothends of the driven equipment and having amotor driver and a steam turbine installedon opposite ends of the driven equipment.Either the motor or the turbine can easilybe selected as the main driver by increasing or decreasing the speed of the steamturbine above or below the synchronousspeed of the moto r.Vary header pressures. Varying steamheader pressures can affect the steam ratethrough turbines. To lower turbine steamrates, either the inlet steam pressure canbe increased or the exhaust pressuredecreased. Lowering exhaust pressure willhave more impact on turbine steam ratesthan raising the inlet pressure. The sametechnique can be used to obtain morehorsepower from a steam turbine that has afully open governor valve. Varying steamheader pressures can also help transportsteam between battery limits, which canhelp eliminate excess steam conditions.Optimize deaerator operation. If it is notpossible to eliminate excess low-pressuresteam, then effectively utilizing the steamis the next best alternative . Your boilerarea ’s deaerator offers a low-cost opportunity to recover excess low-pressure steam.If your deaerator is rated for a much higherpressure than it is operating, the deaeratorpressure can be increased to absorb moresteam. The resulting hotter boiler feedwater reduces the amount of fuel requiredin the boilers and increases the amount ofsteam generated in waste heat boilers.Eliminate Steam DeficitsIf steam is constantly being let down tomeet the demands of the low-pressuresteam heade r, then steam header demandsshould be reduced. Condensate and steamleaks should be repaired soon after theyare detected because they can grow significantly la rger in a very short time. If the leakcannot be isolated, several companies specialize in stopping steam leaks . Also, toreduce steam deficits:Test traps. The plant ’s steam trap testingand repair program should be reviewed todetermine its effectiveness . Ask: How frequently are steam traps tested?What is the method of testing?What is the steam trap failure rate?What method is used to repair orreplace the steam traps?How long does it take after the faultytrap has been detected before it isreplaced?Standardizing on a specific trap thatfunctions well in your plant, maintaining agood steam trap testing program, andrepairing faulty steam traps soon after theyare identified will minimize your steamtrap ene rgy costs.Use correct amount of steam. Using thecorrect amount of steam for the requiredduty of equipment can significantly reducesteam use. Using the plant steam balanceand plant design information, compareactual versus plant design steam use for allmajor steam users. La rge discrepancies insteam use that cannot be accounted for bychanges in plant operation suggest savingsopportunities.Most plants can control steam flow witha flare steam control monito r. This monitoruses an infrared detector to determine theamount of smoking at the flare tip andadjusts the steam flow to the flare to elim inate the smoking. Flare steam control mo nitors can usually be economically justified.Insulate. Proper insulation of piping andequipment should never be overlooked toreduce the steam demand. Often flanges,control valves, steam turbines, man ways,sections of piping, heads on vessels, etc.are uninsulated. If steam is in demand atthe steam pressure level of the uninsulatedpiping and equipment, the piping andequipment should be insulated. Conduct asurvey of the condensate and steam system.Also conduct a study of all insulated hightemperature piping that has been in servicefor numerous years. It may be economicallyjustifiable to repair damaged insulation orto add an additional layer of insulation.Recover Waste HeatIf all of your steam users are efficientlyusing steam, then waste heat recoveryopportunities need to be explored. Compare the duties and temperature profiles onservices cooled by air or water to servicesheated by steam. If the profiles comparefavorabl y, consider projects to recoverwaste heat ene rgy.One excellent heat sink for waste heatrecovery is deaerator make-up wate r.When the deaerator make-up water is preheated, the deaerato r’s steam demand willbe reduced.If, after reducing the demand on allsteam users and implementing al economlically attractive waste heat recovery projects,steam is still being let down to meet thedemands of a low-pressure steam heade r,consider installing steam turbine drivers to(continued on page 4)Steam Challeng e 3
Steam System Optimizationcontinued from page 5Boiler Efficiency vs. Steam Quality: The Challenge of CreatingQuality Steam Using Existing Boiler Efficienciesreplace electric motor drivers. Again,steam turbine efficiency needs to be aprime concern.By Glenn Hahn, Technology Manager,Spirax Sarco, Inc., Allentown, PAAdd FlexibilitySteam systems are dynamic. Changes inthe process can change the amount ofsteam that is venting to the atmosphereand being let down between pressure levels. Consider the following to add flexibility to your steam system: Identify steam turbines and motordrivers that can be started up or shutdown to minimize steam vents and letdown flows.Adjust steam header pressures to allowsteam to be transported to other locations or to reduce the steam flowthrough turbines.Vary deaerator pressure slowly to eliminate steam venting but avoid excessivesteam being let down.Optimize Steam BoilersRepairing steam leaks and insulatingequipment is also important at your steamboilers. Since boiler steam pressure andtemperature levels are the highest in theplant, these measures will pay out quickly.Also, repair air leaks around boilers. Onnegative draft boilers, air leaks waste fueland cause refractory damage and erroneous excess oxygen readings. On positivedraft boilers, air leaks waste fuel and cancause personal injury. Some fan and boilercapacity is also lost with air leaks.Repair of damaged refractory can saveenergy because hot spots on the outer shellof the boiler result in heat loss to theatmosphere and reduced boiler efficiency.Refractory damage can also lead tomechanical damage to the boiler and possible personal injury.Boilers need to be excess oxygen controlled. Oxygen analyzers should be calibrated and the fuel/air ratio controller tuned.Control boiler excess oxygen levels at theboiler manufacturer’s recommendations.Contact Bob Aegerter at (815) 942-7390;e-mail to Robert.Aegerter@Equistarchem.com.4Steam ChallengeThis article is condensed from a technicalpaper/video presentation at the 1998Industrial Energy Technology ConferenceSteam Session. For the full paper, call(800) 862-2086.Aboiler works under pressure, and it isnot possible to see what is happeninginside of it. The terms “wet steam” and“carry over” are every day idioms in thesteam industry, yet very few people haveever seen these phenomena, and the actualwater movement inside a boiler hasremained highly speculative. This articleillustrates the effects of steam quality vs.boiling efficiency during different boilerand steam system demands. The four different operating situations described belowcan affect steam quality.Case 1: On/Off Boiler FeedSimply stated, boilers operate using ahot heat transfer surface covered withwater. Steam bubbles produced at thetransfer surface rise through the water andenter the steam system. Higher pressure atthe heat transfer surface than at the water’ssurface causes steam bubbles to either a)leave the boiler slightly superheated, or b)cool to the saturation temperature of thewater as they rise through the water. Undernormal conditions, the steam bubbles tendto cool to saturation temperature as theyrise through the water.Feed water enters the boiler betweenthe heat transfer surface and the surfaceof the boiling water. Although preheated,the feed water is still colder than the waterin the boiler, creating a cold layer withinthe boiler water. Steam bubbles risethrough this cold layer; they cool and someof the steam condenses. This causes twoserious problems.First, steam bubbles leave the water’ssurface and enter the steam system containing water mist. If a large amount offeed water enters the boiler, the steamspace above the water level becomesfoggy. This fog and the low-quality steamSteam quality is affected by water movementduring different boiler operating situations.that results continue until the water in theboiler becomes reasonably isothermal.Second, this large amount of cooler waterslows the rate of steam production until thewater reaches saturation temperature.These problems are preventable byusing continuous boiler feed rather thanon/off boiler feed. A modulating feed addswater at a very low rate, which keeps theboiler water relatively isothermal and prevents clouding.Case 2: Reduced Operating Pressure“Operate the boiler at its maximumdesign pressure,” say the boiler designers.Too often, this rule is not followed whenenergy cost reductions are needed. Duringlow steam demand, or when all the usepoints require pressure reduction stations,boilers are often operated at substantiallyless than design pressure. While, in someboilers, operation at lower pressure canslightly increase energy efficiency, it alsoreduces steam quality.Lower Pressure Increases EntrainmentWater entrainment occurs as steam bubbles break through the final water layer into(continued on page 5)
continued from page 4the steam space. The bubble’s initial burstproduces a rush of high-velocity steam thatcarries a small amount of water into thesteam space. Additionally, the loss of thesteam bubble from the water surface createsa crater and splashing, and water dropletsare easily entrained in the rising steam.Low-pressure operation requires a largervolume of steam to carry heat energy. Thisproduces more and larger steam bubbles,which creates greater turbulence on thewater surface. Higher vapor velocity fromlow-pressure operation combined with theturbulence tends to carry water dropletsinto the steam system.The solution is to operate the boiler atits maximum design pressure and use pressure-reducing valves where required.Case 3: Rapidly Fluctuating DemandIn most industrial steam systems, steamdemand fluctuates widely and can seriously affect steam quality. A rapid, shortterm steam demand increase of only 15%can cause high entrainment of water in theboiler. Such demand increases occur quitefrequently in industrial plants when steamvalves are opened all at once.When a steam valve opens, two problems occur in the boiler. First, steam pressure drops rapidly and causes entrainment.Second, the interface between water andsteam rises. A phenomenon known as“swell” results as the water level rises andis sucked into the steam line. This boilerwater loss can shut down the boiler; in themeantime, the steam lines fill with water.Compact Boilers Can Magnify the ProblemModern boilers are highly efficient andvery compact. While this design hasadvantages, these boilers have little steamspace to dampen changes in steamdemand. If steam use increases onlyslightly, the pressure in the boiler can dropsignificantly, increasing entrainment.High Entrainment Fools Low WaterLevel AlarmSometimes, steam demand increases areso disruptive that the boiler life and steamquality suffers. The external indicatormight show a satisfactory water level; yetthe actual level of the water/steam mixturein the boiler may be filling the steamspace, and water may be pouring into thesteam lines. Tubes can overheat and canbe damaged by the time the externaldetector identifies a low water level andshuts down the boiler. The plant will bewithout steam until the boiler is restarted.The key to reducing this cause of poorsteam quality is to prevent rapid increasesin steam demand. Modern computerizedcontrol systems using a PLC or DCS canaccommodate this solution.Case 4: High TDSHigh or fluctuating total dissolved solids(TDS) in boiler water increases tube corrosion and/or fouling. The table below showsexamples of additional operating costs thatcan result from poor quality feed water. TDSresults in low heat transfer, reduced boilercapacity and efficiency, and shortenedtube life. It can also affect steam quality.Increased TDS in the boiler waterincreases foam production on the water’ssurface. This foam is produced by, and iseasily entrained by, the steam rising out ofthe water. It can be drawn into the steamsystem, depleting the boiler of waterbefore the level detector can identify theproblem while filling the steam lines withcorrosive water.The solution is to keep TDS at least aslow as that recommended by the boilermanufacturer. There is no definitive evidence indicating a steam quality differencebetween on/off or modulating blowdownto control TDS. However, given the adverseeffect of rapid and intermittent inflows ofmake-up water, modulated blowdown ispreferred.ConclusionSteam quality—a measurement of theamount of water entrained in the steam—depends not on the efficiency of the boilerbut on the ability of the steam to separatefrom boiling water, without carrying liquidwater particles over the range of boileroperations. To prevent poor quality steam:A. Control steam usage to ensure thatsteam demand does not exceed boilercapacity.B. Control steam usage change to ensurerapid changes in steam demand will notreduce steam quality.C. To affect A and B above, use modulating instead of on/off valves at steam usepoints.D. Add boiler feed water with modulating,not on/off, controls.E. Use TDS controls rather than timebased blowdown.F. Operate the boiler near its maximumdesign pressure.When these recommendations are notfollowed, reductions in steam quality canbe dramatic. Low steam quality can damage steam distribution equipment, controlvalves, and heat exchangers by water hammer, erosion, and corrosion. This results inshortened equipment service life, steamloss, low operating efficiency, and evensafety problems.Contact Glenn Hahn at (800) 624-1817x2099 with questions or for informationabout the video that accompanies thispaper.ADDITIONAL OPERATING COSTS FROM POOR-QUALITY FEED WATERSteam flow 100,000 lb/hr and feed water temperature 230 F in all cases.Steam Temperature: Saturated/Steam Pressure: 300 psigBlowdown, %210Steam Temperature: 850 F/Steam Pressure: 850 psig210Boiler duty, MM Btu/hr100.8102.4123.1125.7Heat input, MM Btu/hr121.5123.4148.4151.5Flash steam recovery, %20Additional cost per year–33 36,840– 49,850Same efficiency of 83% HHV assummed in all cases.Source: V. Ganapathy, “Examining the Costs of Boiler Operation,” Chemical Online.Steam Challenge5
Steam System Improvement: A Case StudyBy Ven V. Venkatesan, Director of Engineering Services and Novi Leigh, SteamSystems Engineer, Armstrong Service, Inc.,Orlando, FloridaThis article summarizes a case study presented at the 1998 Industrial Energy Technology Conference Steam Session. For thefull paper, call (800) 860-2086.Steam plays a pivotal role in industrialplants because of its availability andadvantageous properties for use in heatingprocesses and power cycles. Therefore, itis widely used as a heating medium. Steamsystems consist of components such as thesteam generator (boiler), steam distributionlines, process heating equipment, steamturbines, pressure reducing valves, condensate return lines, and steam traps.A thorough review of a major petroleumrefinery system confirmed energy savingspotential in its boiler, steam distribution,and condensate systems. This article highlights eight energy-saving opportunitiesidentified at the site, and the measurestaken to realize these savings.Replace All Defective Steam TrapsSteam traps remove condensate fromthe steam distribution system. They alsoremove air and other non-condensablegases that cause corrosion and impedeheat transfer. Misapplication, improper sizing, and piping conditions are the commoncauses of failed steam traps.Selection of steam traps depends on theconditions of the system handled, such ascondensate load, back pressure, air and noncondensable gas content, and process application like constant pressure or modulating.The wrong steam trap in an applicationcan be as disastrous as a failed steam trapin an open or closed position; both errorslead to energy waste. Undersized steamtraps will not remove condensate, whichcauses flooding of the equipment and canproduce damaging water hammer. Oversized traps may result in wasted live steam.Steam trap applications can be dividedinto three categories: 1) line drip service,2) tracer service, and 3) process service.There are over 3,000 steam traps at the site.Most of them are for drip and tracer application, with a small portion for coils and heatexchangers. At this site, 60% of the steam6Steam Challengetraps are in service, and 23%of those were found defectivein blow-through, coldplugged, or leakage. A diligent maintenance process isrequired to capture and sustain savings from steam traps.Optimize Combustionin BoilersOptimum boiler combustionoccurs when excess air issupplied at the correctamount so that fuel is completely burned and flue gasheat loss is minimized. Optimum excess air depends onReview of a refinery’s boiler, steam distribution, and condenthe type of fuel and burnersate systems revealed potential energy savings of 1 million .design. In this plant, combusconservation opportunities. Benefits includetion air is supplied either from a forcedreductions in make-up water and waterdraft (FD) fan or by the hot exhaust gasestreatment costs, boiler blowdown resultingfrom a gas turbine. Analysis of operatingin direct fuel savings, steam requirementdata shows the boilers operate at 30% tofor boiler feed water deaeration, raw water35% excess air levels. In general, gas burncosts, and sewage discharge costs.ers are designed for excess air levelsThe overall condensate recovery at thebetween 5% and 10%.site is between 55% and 60% of steamAn eight-step action plan was recomgeneration. High back pressure in themended to optimize excess air levels at thereturn line causes condensate from steamboilers:traps to drain into the atmosphere at some1. Stabilize boiler at its normal operatinglocations. A major reason for this is steamload.passing through failed traps. Insufficient2. Verify present combustion conditionssizing and orientation of condensate returnwith a portable flue gas analyzer.lines also contribute to back pressure.3. If combustibles and CO are not present,Back pressure in the return headerreduce FD air in smaller steps.shouldbe corrected to enhance conden4. Verify combustion conditions again aftersate recovery. Enhancing condensate10 minutes of stable boiler condition.recovery involves additional time and5. If combustibles are not present, repeateffort. Nonetheless, this could potentiallysteps 3 and 4 until oxygen level in theimprove condensate recovery to over 80%.stack gas reaches around 2% to 3%.6. Reset the oxygen trimming system inthe fuel-air ratio controller of the boilerin conjunction with the combustibles/CO analyzer.7. Repeat steps for other boilers.8. Nominate utility operating personnel toEfficient Boiler Operation seminars.A decision was also made to install anew combustibles analyzer and hook upoxygen trimming with the existing fuel-airratio controller.Eliminate Back Pressure in CondensateLine to Enhance Condensate RecoveryCollection and return of clean condensate streams and utilization of availableheat are practical and economical energyInstall Low-pressure EconomizerThe largest energy loss in every combustion process is flue gas heat. Reducing fluegas temperature improves boiler efficiency.As a rule, every 40 F reduction in stack temperature increases boiler efficiency by 1%.Installing waste heat recovery equipmentin a natural gas-fired boiler can improve itsefficiency when the stack temperatureexceeds 250 F. The limiting factor to fluegas heat recovery is corrosion if oxides ofsulfur condense as flue gas cools. Thisoccurs only when the fuel contains sulfur.(continued on page 7)
continued from page 6An economizer can recover the heatfrom flue gas to preheat the boiler feedwater. Generally, every 11 F temperaturerise in the feed water increases boiler efficiency by 1%.The utility boilers at the site are designedwith economizers. Boilers are gas-firedwith little or no sulfur content in the fuel.Combustion air is supplied from gas turbine exhausts, and flue gas exits the boilersat approximately 310 F-320 F. Flue gascannot be cooled below 310 F becauseboiler feed water temperature at the deaerators is maintained between 275 F-285 F.This restricts heat recovery despite firingwith low-sulfur fuel.Installing a low-pressure economizer inthe boiler flue gas duct would connect theexisting economizer and chimney. The fluegas temperature would be 230 F. Thismethod of he
Steam traps that discharge into a steam header should be checked for proper oper-ation. Badly leaking steam traps can over pressure a steam header. Examine turbines. If let down valves are not contributing to the excess steam prob-lem, steam turbines exhausting into that header should be examined. Hand valv
17 Table 3. Compressed Water and Superheated Steam (continued) 0.01 MPa (ts 45.806 C) 0.02 MPa (t s 60.058 C) 0.03 MPa (t s 69.095 C) v ρh s t, C v h s t, C v ρ h s 26 446. 0.037 814 3076.7 9.2827 300 13 220. 0.075 645 3076.5 8.9625 300 8811.0 0.113 49 File Size: 630KBPage Count: 60Explore furtherCalculator: Superheated Steam Table TLV - A Steam .www.tlv.comSuperheated Steam Tables - Gilson Enggilsoneng.comCalculator: Superheated Steam Table TLV - A Steam .www.tlv.comCalculator: Superheated Steam Table TLV - A Steam .www.tlv.comSteam Table Calculator Superheated Steam Region Spirax .www.spiraxsarco.comRecommended to you b
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2. Use the steam control to select the amount of steam you want ( m low, l medium, h high). 3.2. Squeeze the steam button to produce steam, release it to stop. NOTE: When you first start your steam station and pull the trigger for steam ironing, there will be a delay as your steam station pumps water from the reservoir to prime the system.
Superheated steam. Properties of steam Steam tables To determine various steam properties . Guide C, Section 4, or IOP Guide Total enthalpy, h g h f (sensible) h fg (latent) Extract from superheated steam tables Extract from the saturated steam tables Do you know how to use these steam tables? (Source: www.spiraxsarco.com .
Steam Source All sterilizers are supplied ready to accept a site steam supply of 50 to 80 psi. The sterilizer steam connection is valved and trapped to accept a ½ NPT steam supply. If site steam is not available, please see the steam generator option below. Steam pipe work is constructe
steam nozzle on the hand-held steam cleaner or hose. Firmly press the hose or variable nozzle onto the steam nozzle (7) of the hand-held steam cleaner or hose such that it is fully seated, and release the clips. WARNING: CInspect the seal on the steam nozzle of the hose and handheald steam cleaner before each use (Figure C). If the seal is .
cooled steam 1 Transmitter 3 Steam conditioner 2 Controller 4 Control valve for cooling water Fig. 2: Steam pressure/temperature control with steam conditioner Steam converters reduce the pressure and the temperature to the set points adjusted at the pressure controller and the tem-perature controller (Fig. 2). They consist of a Type 3286 Steam
in love with us, knows us, and our needs more intimately than we do. PURPOSE OF THE GIFT: The optimum use of any gift is possible, when we know the mind of the gift giver. If I distance myself or dislike the one who has given me a gift I may not like the gift, or I may not use the gift at all or even I may go to the extent of misusing it. So, knowing God’s purpose to give, the gift of my .
