Presentation on theme: "en l ’an ans d ’expérience sur la vapeur"— Presentation transcript:
1en l ’an 2000 100 ans d ’expérience sur la vapeur Armstrong International100 years of experience inSteam applicationsen l ’an ans d ’expérience sur la vapeur
2The purpose of a condensate steam trap. To obtain a maximum efficiency and productivity from an installations, a steam trap should not only provide the separation of water and steam. A number of criteria, grouped in four categories must be satisfied.Operation and outputEnergy conservationMaintenance and life spanInstallation/investment
3Operating criteria Instant condensate evacuation Adapt to flow variationsAdapt to upstream pressure variationsFunctioning in presence of back pressureVenting of non-condensables on start-upVenting of non-condensables at steam temperatureInsensitive to climatic changesPressure/flow operating rangeFollow the saturation curve.Check valve fonction
4Energy conservation criteria Tight shut off valve and seat arrangementNo leaks at body jointsTight shut-off at closure or no delay at closureEfficient at low flowPossibility of trap insulationSub-cooling energy conservation
5Maintenance and life span criteria Ability to handle dirtResistance to wearInternal and external corrosion resistanceResistance to superheatWater hammer resistanceResistance to damage from freezingEasy maintenanceEasy and fast trap testing diagnostic
6Assembly and investment Criteria Capacity / size ratioPriceEase of installationApplication versatilitySpare parts prices
7Steam straps various technology Type Method of operation FamilyMechanical Density differencial I.B.F.&.TTemperature Temperature differencial B.MCapsuleThermodynamics Speed differencial T.DVenturi Pressure loss Orifice
8Inverted bucket steam trap. Principal of operation (I.B.) InletsortieValve and seatLeverInlet TubeBucketentréeStart up modeOutlet
9Steam+AirCondensatePresence of steam = Steam trap closing
13IB Steam trap Avantages No loss of live steam : the steam trap water seal prevent the loss of steam.Continuous condensate dischargeLong life expectancyWater hammer resistanceRemove air and CO2 at saturated steam temperature
14IB Steam trap Advantages Adapt to upstream pressure variationsInstant response to condensate load variationsNot affected by dirt because of its discharge orifice at the top of the trap and the syphon effect when the orifice is completely openFail open steam trap
15Important details of conception The mechanism is free-floatingValve continues to seat itself deeper withwear, preserving a tight seal.
16IB Steam trap inconveniencies For all the models , except the models with connector, the IB should be installed only on horizontal or vertical lines.Some model have a tendency to pass live steam on superheated steam application, if proper piping installation is not done .
17Operation principals of Float & Thermostatic steam trap Thermostatic air ventlevierFloatWater seal valveStart up mode
18Presence of steam - Thermostatic air vent closing
19F & T steam trap advantages Can vent a large quantity of non-condensables because the air vent mechanism is distinct from the steam trap condensate mechanism.Continuous condensate discharge without retaining water upstream of the steam trapThe discharge orifice is surrounded by a water seal, preventing live steam loss.Capable of handling large capacity of condensate
20F & T steam trap inconveniences Because the orifice is at the bottom of the trap and the continuous discharge principle this steam trap is sensitive to dirt.When steam is shut off, water stays in the steam trap body becoming sensitive to frost damage.Water hammer can damage the float by implosion and destroy the thermostatic element.Can’t be used in superheated steam because of thermostatic element limitations.Fail close position.
21Operation principals of thermodynamics steam traps Pressure chamberDiscSeatDischargeorifice
22CondensateFlash SteamSteamInletOutletAt start-up, the condensate removes the disc from the seat
23The steam penetrates inside the steam trap Flash SteamCondensateThe steam penetrates inside the steam trap
24The steam occupies the chamber capacity – Steam trap closing
29Features of a thermodynamic steam trap Small, light weight, easy to install.One size orifice for all pressure ranges,Stock reduction.Large capacity in proportion to it’s size.It’s one mobile part make it resistant to ‘’water hammer’’.Competitive pricing
30Inconveniences of the thermodynamic steam trap The disc opening cycle depends on the pressure over the disc. The climatic conditions therefore influence the operation of each cycle, by cooling the body of the trap, where a rapid condensation of the steam and a pressure drop occur over the disc.Operation cycle, fast at low loads, cause a premature wear and tear.The operation cycle speeds up when seat wear appears, this accelerates the wearing process and reduces the service life of the steam trap.
31Inconveniences of the thermodynamic steam trap Does not close if back pressure reaches 50 % of upstream pressure.A steam trap leak could drive other steam traps that are connected to the same line system to leak.Does not close if a pressure drops under 5 psi.The requirements specified for the surface conditions, makes it very sensitive to dirt.No instant reaction to condensate loads variations. Retains the condensate between cycles.
322 main reasons why the TD steam trap wear and tear rapidly Snap closure of the discagainst the seat at each cycle.High velocity outlet = prematureerosion of disc and lost, of seattightness.
33Operation principals of thermostatic bellow steam strap AlcoholValveSeat
34Operation principal of thermostatic bellow steam strap CondensatecoolingSteam
35Operation principal of thermostatic wafer steam trap Distilled water+ alcoholDiaphragm
38Advantages of Wafer Steam trap and Bellow Steam strap In general sizes are small and lightReduces the amount of flash steamAllows sensible heat recuperationWill adapt to pressure and discharge variationsAt start-up, it will remove the non-condensables
39Inconveniences of bellow steam trap Sensitive to dirtUpstream condensate retention (sub cooling) causes a reduction in Ph which develops corrosion and premature wearSensitive to water hammerNot adapted for superheated steamCan fail close
46Opening curve of a Bimetallic Steam Trap Saturated curvedsteamtemperatureDelta TClose steam trapwaterOpen steam trappressure
47Bimetallic Steam Trap Advantages Ability to handle start-up air loadsRecuperation of sensible heatReduces the amount of flash steamResistance to water hammer
48Bimetallic Steam Trap inconveniences Sensitive to dirtSensitive to back pressureSensible to upstream pressure variationImproper continuous air ventingNot adapted for process applicationsValid capacity curves for a given temperature
49Selection methodology for condensate steam trap Steam Main Boiler Header Unit Heather Exchanger Tracing Drum dryerQ=L.M.Cs.t Q=V..Cs.t Q=<1 kg/h.mr.temps rQ= Cap. Boiler Q=V..Cs.t Q=L.Ø..35 kg/h.m² 0, rQx1, QX QX QX Aucun Q x3 à QX QX3ApplicationCalculation of flow in kg/hSafety margin