Proposed Vibration Monitoring And Analysis Engineering Essay

shudder is a broad commensurate country that has go along to pull research over the old ages because of its import in near every aspect of daily life. From aircraft patterning to constructing intent in temblor bookn over split of the universe from incontrovertible condition supervise in interact indetritusrial kit and caboodles to wheel reconciliation and every last(predicate)iance at the local car garage, an action of the cognition of thump rules sess be look ond.The frisson of an commissionive give the gate scarce be referred to as the oscillating motion of that object ab turn verboten a average equilibrium place. The communicate is brought approximately by the application of nearly force or passion. Common metaphors of this phenomenon include the gesture of plucked guitar strings, the gesture of tuning forks, and the shaking felt at the broadcast floor when a train base on ballss, the agitating observed on the r disclosee when a heavy truck base on ballss or the rattle of the r oute workers impact diaphysis. rough dumbfound except is non every bit pronounced as the illustrations given. For case houses and Bridgess vibrate every bit intimately. Normally, these charges passel non be detected by simply looking. When the rousement is big mound, the vibrational gesture clear be seen and this would likely practise in the prostration of the whirl.From the foregoing, it send word be seen that some ticktock is profitable while some is deleterious. The also-ran or de vastation brought just about by joggle is non an immediate 1. trembling finally leads to a fatigue failure and this should be of involvement to the operators and up assumeers of works equipment.For the explosive charge use scientist or plus direction practician, these facts about overreach can be translated to intelligent and intercommunicate determinations for indus political campaign workss. With legion different devices, quiver degrees on works e quipment can be detected, measured and recorded. It is possible to analyze the readings cool to find the precondition of an plus and even predict an at hand failure. All revolving or stationary works equipment select acceptable quiver degrees stipulated by criterions much(prenominal) as the International Organization for Standardization ( ISO ) Codes or developed in-house by quiver observe Engineers. A divergence from the acceptable quiver degrees is an indicator of the oncoming of impairment which is unwanted. This cognition gives insight into the literal place of a piece of equipment, eliminates guessing and enables the boot utilize scientist to be after a fitting response to the plus s impairment. Such assure and provision can take to a immense economy in cargon costs, prevent un required downtime, better safety and public presentation for whatsoever plus.Further more(prenominal), quiver monitoring and compend incorporates some mod techniques for the find of the answer cause of stalk instrumentry failures. Using these techniques can int shutdown the difference amidst changeless dislocations and good plus availableness.It is the aim of this macho-many to supply a clear attenuate proposal as to how to work out the trade of the familiar failures of the Yoho High Pressure ( H.P. ) come out scrubber affections by the application of these advanced quiver synopsis techniques and too supply a rule for supervising the status of the spirit to pre-empt apiece impairment that can jump out surprises. This will guarantee a mitigate in present c atomic number 18 costs and relieve the work load of c ar forces whose tweet is trussed up with the financial aid of these affections.Case Study and job DescriptionThe Yoho H.P. g inclineening scrub brush kernels are vertical, turbine, submerged nubs that ravish cured pellucids from the dash scrubbing brush vas to the chief petroleum oil output signal heading on the Yoho offshore o il and brag lay. The piths are submerged in position that receive provender from the H.P. scrubber vas by gravitation. The cured liquid is a mixture of H2O and light petroleum oil. There are terzetto pumps on skid and these pumps are decisive to works operations. angiotensin-converting enzyme pumps runs at a press cutting and an extra pump or the some other(a) two pumps can be put in go, if the demand resurrect due to an increasing degree of liquid in the H.P. jiffy Scrubber. In the event of an outage of all terzetto pumps, the works could lose ingatheringion to the argument of one hundred 1000 poses of rough oil per xxiv hours ( 4100 barrels/hour ) .The pumps were com cast offioned in 2006 at works start-up and hold had legion failures since. They have proven undependable and soon a avower s pumps ( which are portable and of a different design ) , are relied upon to exe skip overe their be. There have been occasions when all three pumps are in a state of disrep air.These pumps approach patternly run swimmingly for a piece and so go noisy, vibrate and eventually neglect. After a pump fails, it is taken out of the hole, sent to the shore-base for see, sent back to the program for reinstallation and so reinstalled. Probes of the legion failure instances reveal that the pump military postures, riser rip drives and bushings have worn out given room for peckerwood drama, impeller maltreat and mechanical varnish failure. founding, fix and rebuild processs have been scrutinized and checked for quality. This has non yielded any dividends nevertheless, as the pumps maintain neglecting after two or three calendar months in service.Fig. 1. overleaf presents a cut-away subdivision of the pumps. The plat is supplied by the harbourrs but is alter as the existent H.P. break Scrubber pump has six impellers, a top column of 11inches distance, two intermediate columns of 30 inches length, a john column of 30 inches length, and a pump bowl asse mbly of 36.25 inches length.The length of the pumps makes it hard for remotion and puzzle up and as much(prenominal) care practicians, works operators and works direction have been invariably distressed by the frequent failure of these pumps.Fig. 1. Gould heart and soul elanl VIC-T ( beginning ITT-Gould Product catalogue, online www.gouldspumps.com/pump_VIC.html Accessed sixth whitethorn 2010 stock ticker SpecificationManufacturer ITT-Gould headland chicane Length 129 InchsHead beam of light Diameter 1 InchSeal Method robotlike Sealing waxDrive 40 HP electric automobile rideDifferential Pressure 200 Pounds per square inchCapacity clxxx Gallons per MinuteRevolutions per minute 3000Impeller 5 Weathervanes, EnclosedFailure and living recitalThe tabular array be number one shows the failures and some care activities performed on the three H.P. flare up Scrubber spunks over a biennial period. The rows 69, 71, 72, 90,91,97,98,102,103 and 110 show times when none of the t hree pumps were operational. The cost of this inaccessibility of the pumps is multiplex. It ranges from the loss of produceion of about one hundred 1000 barrels of rough oil per twenty-four hours, to punishments for non-compliance with environmental ordinances and most significantly, safety.Signal-to-noise ratioDateEVENT/ACTIVITYEQUIPMENT TAGNO. OF PUMPS AVAILABLECOMMENTS/ FINDINGS111-Jan-06HP blink of an eye Scrubber inwardness B Auto Operation jobYP-G-1803A212-Jan-06Trouble-shooting of LSLL-6207 on HP gleam ScrubberYP-G-1803A31-Mar-06PM on HP break open Scrubber middles A and BYP-G-180A/B3A411-Mar-06 marrows Operation StartedYP-G-180A/B /CAEarliest recorded day of the month of petroleum and produced H2O motion with YP installations55-Jun-06Test-run HP flicker Scrubber gist C with quiver group, QIT to find cause of inordinate quiverYP-G-180C3Expecting essence67-Jun-06Investigating cause of inordinate quiver on HP glitter Scrubber affection CYP-G-180C3shiver traced to dam aged Mech. Sealing wax79-Jun-06 removed HP blaze up Scrubber manage C for fixsYP-G-180C2A89-Jun-06Unblocked strainers on HP burn down Scrubber nerves A & A BYP-G-180A/B2A912-Jun-06Rectified hapless murder and noisy operation on HP flame up Scrubber manages A & A BYP-G-180A/B2A1019-Jun-06PM on HP photoflash Scrubber marrow AYP-G-180AAA113-Jul-06 effected position of HP light Scrubber bosom CYP-G-180C3A124-Jul-06Removed HP ostentation Scrubber sum B for fixs in QITYP-G-180B2A1315-Jul-06Remove and dust HP Flare Scrubber eye C suck strainerYP-G-180C2A1412-Aug-06Remove and dismantle HP Flare Scrubber Pump C sucking strainerYP-G-180C2A1524-Aug-06Remove and clean HP Flare Scrubber Pumps A & A C suction strainerYP-G-180A/C2A1627-Aug-06 set up out HP Flare Scrubber Pump A and transferred to incubus bayYP-G-180A1A1730-Aug-06Rigged in HP Flare Scrubber Pump B after QIT fixsYP-G-180B2A182-Sep-06Removed shaft unified on HP Flare Scrubber pump B, removed ride and installed labour from pump angstromYP-G-180A/B2Electricians look intoing mellow-pitched electromotive force on motor193-Sep-06Transfer motor, pump and all associated split from YP-G-180B to G-180AYP-G-180A/B1A204-Sep-06Installed pump caput, motor and shaft hub on HP Flare Scrubber Pump AYP-G-180A1A215-Sep-06Carried out matching runout cheques, impeller overturn ( Reinstallation ) on pump antiophthalmic factorYP-G-180A2A228-Sep-06PM on HP Flare Scrubber Pump CYP-G-180C2A2311-Sep-06Remove and clean HP Flare Scrubber Pump C suction strainerYP-G-180C2A2429-Oct-06Bleed off gas from HP Flare Scrubber Pump C suction and exit lineYP-G-180C2A2512-Nov-06Replacement of Mech. Seal on Pump CYP-G-180C1A2613-Nov-06Removed HP Flare Scrubber Pump C for fixs in QITYP-G-180C1A2728-Nov-06Reinstallation of Pump CYP-G-180C1A282-Dec-06 established facility of HP Flare Scrubber Pump C and test-ran it.YP-G-180C2A2921-Dec-06PM on HP Flare Scrubber Pumps A and CYP-G-180A/C2A306-Feb-07Commenced installing of pu mp BYP-G-180B2A317-Feb-07 move installing of pump BYP-G-180B2Expecting Mech. Sealing wax3224-Apr-07 facility of Mech. Seal on Pump BYP-G-180B2A3325-Apr-07 accurate Mech. Seal Installation of Pump BYP-G-180B3A3428-Apr-07Troubleshoot overload moorage mistaking on Pump BYP-G-180B3A3530-Apr-07Rechecked alliance of Bump BYP-G-180B3A361-whitethorn-07Rectified overload trip on Pump B- cleaned recess strainerYP-G-180B3Discharge line was modify with sand and sludge3714-whitethorn-07Mech. Seal replacing on Pump CYP-G-180C2 make love worn around Mech Seal3815- may-07Rigged out HP Flare Scrubber Pump C for fix at QITYP-G-180C2A3927-whitethorn-07Troubleshoot high quiver on Pump BYP-G-180B2A4030-May-07Removed HP Flare Scrubber Pump B for fixs in QITYP-G-180B1A411-Jun-07Assessed stuffs for stiff valves associated with pumpsYP-G-180A/B /C1A423-Jun-07Reinstallation of Pump CYP-G-180C1A436-Jun-07 effected Pump C InstallationYP-G-180C2A447-Jul-07Reinstallation of Pump BYP-G-180B2A4510-Jul-07Complet ed Pump B InstallationYP-G-180B3A4613-Jul-07Troubleshoot frequent tripping of Pump BYP-G-180B3Electric motor job. This was fixed4721-Jul-07Rigged out HP Flare Scrubber Pump A and transferred to lading bayYP-G-180A2A4822-Jul-07Rigged out HP Flare Scrubber Pump B and installed in A barrelYP-G-180A/B1Pump B becomes Pump A4923-Jul-07Alliance and commissioning of Pump AYP-G-180A2A5026-Jul-07Remove and clean HP Flare Scrubber Pumps A & A C suction strainersYP-G-180A/C2A5110-Aug-07Rigged out HP Flare Scrubber Pump A and transferred to lading bayYP-G-180A1A5217-Aug-07Commenced installing of pump AngstromYP-G-180A1A5318-Aug-07Continued installing of pump AngstromYP-G-180A1A5422-Aug-07Alliance and commissioning of Pump AYP-G-180A2A5511-Sep-07PM on HP Flare Scrubber Pump AYP-G-180A2A5617-Oct-07Removal and resettlement of Pump A to Pump B barrelYP-G-180A/B2Pump A becomes B5721-Oct-07 examine low empty force per unit battlefield on Pump BYP-G-180B2A5822-Oct-07Replacement of Mech. Seal on Pump CYP-G-180C2A5923-Oct-07Rigged out HP Flare Scrubber Pump B and transferred to lading bayYP-G-180B1A6024-Oct-07Rigged out Pump A barrel for bring out fixs by FMSYP-G-180A1A6125-Oct-07Rigged in Pump A barrel after leak fixs by FMSYP-G-180A1A6228-Oct-07Commenced installing of pump AngstromYP-G-180A1A6329-Oct-07Completed installing of pump AngstromYP-G-180A2A6431-Oct-07Remove stiff hub from Pump B motorYP-G-180B2A653-Nov-07Remove Motor to W/Shop to bore and tap wiped out(p) bolts of Motor Fan CoverA2A6629-Dec-07Remove damaged pump C and commenced installing of refurbished pumpYP-G-180C1A6730-Dec-07Rig out Pump C due to miss of keyway on shaftYP-G-180C1A681-Jan-08Transferred bad pump to lading bay for QIT W/ShopA1A698-Jan-08Removed HP Flare Scrubber Pump A for fix in QITYP-G-180A0A709-Jan-08Installed Flare Scrubber Pump AYP-G-180A1A7110-Jan-08Removal of Pump AYP-G-180A0Pump stiff.7212-Jan-08Commenced installing of pump AngstromYP-G-180A0A7313-Jan-08Completed installing of pump Angstr omYP-G-180A1A7427-Jan-08Rigged in Pump B and commissioned sameYP-G-180B2A754-Mar-08PM on HP Flare Scrubber Pumps A & A BYP-G-180A/B2A7613-Apr-08Removal and resettlement of Pump A to Pump C barrelYP-G-180A/C1Pump A barrel leaking petroleum from cut bleed line. Pump A becomes C7714-Apr-08Commenced installing of pump CYP-G-180C1A7815-Apr-08Completed installing of pump CYP-G-180C2A7917-Apr-08Rigged out HP Flare Scrubber Pump B and transferred to lading bayYP-G-180B1A80AAAAA8118-Apr-08Removal of dust from Pump barrelYP-G-180B1A8221-Apr-08Commenced installing of pump BYP-G-180B1A8322-Apr-08Completed installing of pump BYP-G-180B2A849-May-08Commenced set uping out Pump CYP-G-180C1A8510-May-08Completed set uping out Pump CYP-G-180C1A8617-May-08Commenced installing of pump CYP-G-180C1A8718-May-08Completed installing of pump CYP-G-180C2A8820-May-08Rectified failure to refer on Pump BYP-G-180B2A8923-May-08Rigged out HP Flare Scrubber Pump B for QIT fixsYP-G-180B1A9026-May-08Rigged out HP Fla re Scrubber Pump C for QIT fixsYP-G-180C0A9127-May-08Commenced installing of pump BYP-G-180B0A9228-May-08Completed installing of pump BYP-G-180B1A9313-Jun-08Commenced installing of pump CYP-G-180C1A9414-Jun-08Completed installing of pump CYP-G-180C2A9517-Jun-08Rigged out HP Flare Scrubber Pump B for QIT fixsYP-G-180B1A9617-Jun-08Troubleshoot failure to raise on Pump CYP-G-180C1A9718-Jun-08Rigged out HP Flare Scrubber Pump C for QIT fixsYP-G-180C0A9820-Jun-08Commenced installing of pump BYP-G-180B0A9921-Jun-08Completed installing of pump BYP-G-180B1A10022-Jun-08Reconfirmed Pump B allianceYP-G-180B1A10124-Jun-08PM on HP Flare Scrubber Pump BYP-G-180B1A10226-Jun-08Rigged out HP Flare Scrubber Pump B for QIT fixsYP-G-180B0A10330-Jun-08Commenced installing of pump B on freshly designed baseYP-G-180C0FMS welding / design inaccurate. Pump pulled out to C- put1041-Jul-08Completed installing of pump CYP-G-180C1A1055-Jul-08Swapped set B to A PositionYP-G-180A1A10611-Jul-08Investigated unusu al noise on Pump CYP-G-180C1A10722-Jul-08Worked with FMS to measure transition of Pump basesYP-G-180A/B /CAA10826-Jul-08Installed pump AngstromYP-G-180A2A10929-Jul-08Removed pump CYP-G-180C1A11031-Jul-08Commence remotion of Pump AYP-G-180A0AFig.2. Failure and Maintenance Summary for H.P. Flare Scrubber Pumps, YPLiterature followGraham and Nurcombe ( 2003 ) , observed that numerous perpendicular submersible pump failures find oneself instead out of the blue, without due warning and rough economic climes and disputation has become an inducement for equipment operators to want to acquire the best service out of their equipment. This translates to higher life anticipation with works equipment and as much(prenominal) status supervising engineerings such as thrill, Lubricant and Exhaust gas analyses have become really popular to forestall unwanted and un imagened machinery outages. Of the afore-mentioned techniques, palpitation analysis they say, is likely the most of import bec ause of its proved efficaciousness and planetary credence in many industries.In a instance bill of submergible pumps at Saudi Aramco, they highlighted the demand to cognize the status of the pump internals which were submerged in liquid and are normally without status monitoring. ISO codes pronounce that objectives be monitored but this is non straight done for submerged pumps because the bearings are ordinarily unaccessible. Alternatively, ISO allows measures to be taken from the accessible parts of the machine i.e. from the Electric motor and the downside of this is that plentifulness of quiver training gets losing or attenuated. A batch of the misplays associated with perpendicular submergible pumps nevertheless arise from those unaccessible places e.g. cavitation, flow induced quiver etc. , and as such supervising the status of the underwater parts straight provides a valuable beginning of reading for predictive and symptomatic steps that can do large cost nest testicl e for equipment operators.They have developed and tested transducers and quiver monitoring equipment which can be utilize to straight acquire information from the submerged pump parts.It is non plenty merely to supervise the quiver status of these pumps nevertheless. The job at deal is that of the frequent failures of the H.P. Flare Scrubber pumps from the very clip they were commissioned. Installing the submergible quiver monitoring devices would decidedly assist to foretell the failures but would make nil to place the implicit in cause of the frequent failures. So, the failures great power be predicted but would go on often however. The root-cause of these failures demands to be place so that a permanent solution can be developed. Vibration analysis similarly makes this possible.Sinha ( 2008 ) shows that site installing of machines has effects on their quiver and dynamic features, even when they are good designed. He points to the fact that many freshly installed machines vib rate severely and neglect often merely as has been described in the debut and in the care history of the H.P. Flare Scrubber pumps. Hence it is of import to decide any machine installing jobs if equipment availableness is desired. A quiver analysis and dynamic word watch technique known as average(a) Testing can be used to expose the innate frequencys of the machine installing assembly and the in operation(p) amphetamine checked to see if near to any of the native absolute frequencys. operational(a) machines at velocities at or shut to structural immanent oftennesss brings about resonance which is seen as inordinate quiver. This trial makes it possible to place the correct(ip) places on the construction to use stiffening in order to cut down quiver by modifying the structural natural oftennesss. He gave some illustrations were these had been done successfully to suppress frequent machinery failures.DeMatteo ( 2001 ) presents a instance ken of how the quiver analysis methods of Modal Testing and operate Deflection frame have been used to work out the job of inordinate quiver on perpendicular pumps which are similar to the H.P. Flare Scrubber pumps.A parking lot yet enfeebling mistake for these pumps is cavitation. A mentioned earlier, it occurs at the underwater parts of this pump where at that place is no status monitoring as of the present. Cavitation is a phenomenon that takes topographic point in these kinds of pumps when the impact of a smooth ining vapor of the fluid been pumped causes harm to the impellers and other pump internals. Vapour-bubbles can be formed within the wired fluid at low force per unit area pump internals as a consequence or restricted suction, fluctuating liquid degrees of the H.P. Flare Scrubber vas etc. When these bubbles move on to higher force per unit area countries within the pump, they collapse and cause harm to the pump. Wilcoxon Research says that, The prostration of the bubbles is a violent subroutin e that creates an impacting action inside the pump. This impact will depend upon high frequence resonances in the pump construction. For this ground, they advocate the usance of quiver detectors in pumps. Cernetic ( 2009 ) says in the same vena, that quiver signals should be used to observe cavitation at the early phases of development since this phenomenon causes pump harm and a decrease in efficiency.From the foregoing, the instance for forestalling failures is being made and the demand for rail Based Maintenance ( CBM ) emphasised. Prickett and Eavery ( 1991 ) compared preventative care and Breakdown care with CBM. CBM is shown to be cheaper and as such is required for the H.P. Flare Scrubbers if appertain profitableness and equipment availableness are desired.Overview of Proposed Vibration observe and outline Based Solution to patronage FailuresFirst and first, it must be ascertained that the site installing of the three pumps is non doing any quiver jobs. The Vibration analysis techniques of Modal Testing and Operating Deflection Shape are proposed for usage to find the root-cause of the frequent failures. Modal proving on the one manus would demo structural natural frequences, lymph gland points and musical mode forms for the three pumps. The look form is the warp of the construction at any natural frequence. This information would assist to find if operate velocity is perilously close to the structural natural frequences, the dynamic feature of the construction and the points of least or no warp on the construction ( nodes ) where supports or stiffening may be added in order to relieve quiver degrees. The doctor swagger method shall be used to transport this trial out, in situ.The Operating Deflection Shape ( ODS ) on the other manus, would as the name implies show the warp of each pump construction at the operating frequence of 50Hz ( 3000rev ) . In other words, the ODS would demo the consequence of the operating velocity on assorted par ts of the construction and it can be seen if points on the construction vibrate in dress or non. Should parts of a construction non travel in symbolise with the other parts, destructive burden can happen which can give rise to frequent failures.Transporting out these trials as mentioned above would place jobs with the installing. Solving the installing jobs would extinguish the frequent failures. The solution as mentioned earlier, normally involves the application of supports in determine places or the stiffening of bing supports.After the installing jobs are taken attention of, it is proposed that for good mounted quiver detectors are put in topographic point. For the open parts of the pump assembly i.e. the electric motor, it is proposed that two accelerometers be mounted at each of the antifriction bearing lodging countries. The accelerometers would be stud mounted at each bearing lodging at set cants apart. Having these accelerometers installed in add-on to the analysis of the generated signals would do it possible to observe bearing mistakes at their incipient phases, such that something could be done to forestall a more dearly-won harm to the whole pump assembly.As for the submersed parts of the pump, i.e. the journal bearings, the shaft, the impeller/bowl assembly, the Bently Nevada designed submergible propinquity investigations are proposed for usage to supervise the quiver and give diagnostic and prognostic capablenesss for such mistakes as cavitation, impeller harm, weariness shaft cleft, instability etc. , which are the common mistakes of machinery such as these and can merely be detected by submersed detectors. Understanding what goes on in the pump hole is critical to maintaining the pump healthy. For case cavitation can be detected on clip with these investigations, procedure conditions changed and the dependability of the pumps maintained. The quiver information collected by these detectors would be analysed and used to do quality determin ations sing the needed care responses. Analysis techniques would include frequence spectrum analysis, envelope analysis, polar occult plans, orbital cavity hugger-mugger plans etc.This three prong attack is strongly believed to extinguish the frequent failures, cut down the boilers suit care costs and assist in guaranting the handiness of the three H.P. Flare Scrubber Pumps.The techniques shall be expounded in more fact within this study and all the necessary tools and quiver signal bear upon methods shall be specified.In-Situ Modal Testing for the PumpsThis quiver trial is to uncover any jobs with the installing of the pumps which might be responsible for the frequent failures undergo within the past few old ages. In this trial, the natural frequences, manner form and nodes will be determined for each pump construction.An instrumented cock would be used to provide impact or energy to each construction at a known frequence and responses measured. When there is resonance, ref ining would be seen in the response spectrum. A frequency Response routine ( FRF ) is obtained utilizing the force and the response spectra. The response can be represented asFRF= = A + J BWhere A= Real Part, B= unreal Part and arrange =At vibrancy, the exciting frequence from impact cock = Natural Frequency of Pump Structure.A 0, B gives the Mode Shape, and Phase 90AThe computations are performed and graphs displayed by the FFT ( Fast Fourier Transformation ) Analyzer as shown below.Fig. 3. duration sphere and frequence sphere signals. ( extraction M14 Lecture Notes, 2010, disseminated sclerosis Maintenance Engineering and plus Management, University of Manchester )The FRF shows frequence extremums which may or may non be structural natural frequences. However, for the structural natural frequences, the relationships shown supra would all use. The existent portion of the curve ( A ) would go by dint of through zip and the stage would alter by 90A . The fanciful portion of t he FRF gives the manner form.So, the needed equipment for the unmoved average testing of the pump constructions are as followsSome accelerometers positioned along points on a pump construction ( accelerometers can be secured by magnetic agencies )An instrumented cockAn FFT AnalyzerCable connexions for cock and accelerometers to analyserPost Processing Software.The diagram below shows the layout for the trial. The instrumented cock is used to excite the pump construction and the responses taken from the measuring points and analysed to give all the information required i.e. manner form, nodes and natural frequences.Fig.4. Schematic of Vertical Pump Impact TestFig. 5. Impact Test and Modal parametric quantities ( beginning Richardson M.H. ( 1997 ) , Is It a Mode Shape, or an Operating Deflection Shape , Sound and Vibration Magazine, thirtieth Anniversary Issue. )Fig.6. Mode shapes from Imaginary Part of FRF ( beginning Richardson M.H. ( 1997 ) , Is It a Mode Shape, or an Operating Deflection Shape , Sound and Vibration Magazine, 30th Anniversary Issue. )Fig.7. Example of manner form obtained from pump modal proving. ( Beginning Sinha J.K. , ( 2008 ) , Vibration- found diagnosing Techniques Used in nuclear Power Plants An Overview of Experiences , Nuclear Engineering and Design, Elsevier B.V. , Volume 238, Issue 9, pp. 2439-2452.From the attendant manner forms and ascertained natural frequences, penetration can be obtained as to the exact places for stiffening application or mass remotion in order to alter the natural frequences. Experience has shown that resonance in these kind of instances is due to the intimacy of the operating velocity ( runing frequence or 1x ) or multiples thereof, to one or more structural natural frequences. For the pump described in fig.7. above, the job was resolved welding a thick home base to the stool in order to stiffen it and by put ining extra u-bolts on the discharge line.Operating Deflection ShapeThe Operating Deflection Shape ( ODS ) merely shows how much the pump construction is traveling at a suspect frequence ( most significantly, the normal runing velocity ) and how much difference there is in stage between different points of the pump construction as it operates.The set-up is merely as was used for the average testing. The difference nevertheless, is that the instrumented cock is non used to excite the construction. Alternatively the machine would be run at its normal operating velocity and quiver informations collected from the accelerometers is fed to the multi-channel analyser. The end product from the analyser is so fed into the computing machine which would hold installed medical specialist package for ODS show. The show would demo the existent quiver form of the construction. It would be clearly seen, if the pump construction is flexing, if parts are traveling out of stage with one another etc. It would be seen if any status exists which contributes to frequent failures.Fig.8. Example of Software Animation of ODS FRF informations. ( Beginning Richardson M.H. ( 1997 ) , Is It a Mode Shape, or an Operating Deflection Shape , Sound and Vibration Magazine, 30th Anniversary Issue. )It is proposed that both Modal Testing and ODS analysis be carried out by contractors who are specializers in the country of survey and have a proved path record of success.Proposed Permanently Mounted Vibration-based Condition Monitoring dodgingFig.9. Set-up of Proposed Permanently mounted quiver monitoring system for the H.P. Flare Scrubber Pumps ( Influenced by Fig.5. , Graham K.M. and Nurcombe B. , ( 2003 ) , Vertical Water Pumps- What s occurrent Down The Hole , eye socket Magazine, 1Q 2003, pp. 4-9 )Fig. 10. Orthogonally mounted propinquity investigations on-line useable from hypertext transfer protocol //zone.ni.com/reference/en-XX/ servicing/372416A-01/svtconcepts/obt_tbs_shctln/ Accessed 6th May 2010 The proposed for good mounted quiver monitoring and analysis system for each pump would hold the followersFour Bently Nevada 330400 Accelerometers mounted as shown on the diagramFour 3300XL 8mm submerged Proximity Probes mounted in Custom accouterments ( two each for two different journal places along shaft length )A Bently Nevada 1900/65 General Condition Equipment MonitorA tacho-sensor for shaft place mention ( from any reputable manufacturer- Bently Nevada, SKF, Endevco )and,A laptop computer with the Bently Nevada System 1 version 6.5 Diagnostic package installed for the analysis of information collected by any of the proctors.The accelerometers would be used to mensurate the quiver degrees of the anti-friction bearings on the pumps electric motors while the submersed propinquity investigations would mensurate shaft quiver, within the impeller shell and intermediate columns. All the transducer information would be collected by the 1900/65 proctor for each equipment. The proctors are designed for uninterrupted monitoring and readouts from them ca n be checked from clip to clip by dedicated forces or works operators.Besides, these proctors have the capableness of being fasten into bing works control systems such that quiver warning degrees and danger saltation for each pump can be announced in control suites via hearable dismaies or visible radiations when these degrees are breached. Additionally, there is the capableness to tack trips and closures in the instance of high quiver degrees occasioned by mistakes such as cavitation. The proctors can be installed near to the equipment in sheltered enclosures, utilizing a dead overseas telegram tally. The System 1 package is capable of advanced quiver analysis through the usage of shows such as annunciate Plots, Spectral shows, wintry privy plans, Envelope analysis, etc. It is besides capable of informations acquisition and computer storage which makes swerving possible. Detailed specifications for the assorted equipment are supplied in the appendix.Signal Conditioning and ProcessingAs is good known, the end product from the accelerometers and propinquity investigations are linear and clip sphere signals. These have to be converted to digital end products and frequence sphere signatures for mistake analyse to be carried out. This is achieved by the Fast Fourier Transformation ( FFT ) algorithm. Analyzing the frequences shown in a spectrum is substantive for understanding implicit in machinery mistakes, as certain mistakes have trenchant frequence features. For case, pump revolving velocity would be shown in the frequence spectrum and mistakes on the shaft could be presented as multiples of revolving frequence. The Bently Nevada 1900/65 proctor and System 1 package facilitate this.Fig. 11. Time sphere and frequence sphere signals. ( Beginning M04 Lecture Notes, 2010, MSc Maintenance Engineering and Asset Management, University of Manchester )The quiver measuring devices have been chosen carefully to understate the noise and unwanted preventive to m easuring signals. The Bently Nevada 1900/65 has the capableness for low base on balls filtering and high base on balls filtering and these can be configured to accommodate exploiter demands. This helps to extinguish the aliasing consequence and other instrument related noise. ( See product specification sheet in appendix for inside informations ) .There is besides the capableness for envelope analysis by the usage of criterion or compound demodulation. This is supported by proctor and analysis package and is in particular usable for the early sensing of mistakes on the electric motor anti-friction bearings.Diagnosis Software Display Plots and UsesThe following show some of the show plots that can be generated by the diagnostic package reckonPerformance mapRotor stator profileRotor formHydro air disseminatePhasorHistogramOctaveCasacade/Full CasacadeCurrent ratesBar graph forge train diagramAlarm/System event list way / Multivariable tendencyTabular listTime base ( with option for principle of superpositionof service line informations )Orbit / Time base ( with option forsuperposition of baseline informations )Orbit ( with option for superposition ofbaseline informations ) lie with mean total lineSpectrum / Full spectrum ( with optionfor superposition of baseline informations )Ten vs. YWaterfall / Full waterfallPolar/Acceptance partOf the list above, accents would be placed on the Bode, Polar, Orbit, Shaft mean centreline and Waterfall out of sight plans. These mystical plans can be used during normal and transeunt machine conditions to expose the normally experient mistakes.The Bode unfathomable plan is really utile in placing the critical velocity ( natural frequence ) of a machine, as it shows the quiver behavior of the said machine during start-up or shut-down ( transeunt conditions ) .Fig. 12. Bode Plot Example. Online acquirable from hypertext transfer protocol //zone.ni.com/reference/en-XX/help/372416A-01/svtconcepts/bode_polar_plots/ Access ed 6th May 2010 The polar secret plan gives the bountifulness of 1X ( machine RPM or runing frequence ) and its stage difference from the mention place. The amplitude and stage behaviors can be interpreted to existent equipment wellness or defect.Fig. 13. Polar Plot illustration online Available from hypertext transfer protocol //zone.ni.com/reference/en-XX/help/372416A-01/svtconcepts/bode_polar_plots/ Accessed 6th May 2010 The Orbit secret plan hints out how the shaft is revolving within the bearing. This tells how much clearance exists between shaft and bearing wall. This information is priceless as it can be used to find bearing load alterations and the oncoming of bearing wear.Fig. 14. Orbit Plot illustration online Available from hypertext transfer protocol //zone.ni.com/reference/en-XX/help/372416A-01/svtconcepts/obt_tbs_shctln/ Accessed 6th May 2010 The Shaft centreline secret plan is used in much the same manner as the orbit secret plan in that it can be used to state how much wear has happened within a bearing. The secret plan checks the concentricity or eccentricity of shaft running within a diary bearing, as the name implies.Fig. 15. Shaft Centerline secret plan illustration online Available from hypertext transfer protocol //zone.ni.com/reference/en-XX/help/372416A-01/svtconcepts/obt_tbs_shctln/ Accessed 6th May 2010 The Waterfall secret plan is utile during the transeunt machine operations. It shows how frequency constituents such as 1X, 2X, 3X etc alteration with clip or any other variable. The information obtained can be used to do good judgements as to existent machine conditions.Fig. 16. Waterfall plot illustration online Available from hypertext transfer protocol //integratedpro.com/content/ ? p=1114 Accessed 6th May 2010 Diagnosis chartMistakeSteady province singularityTransient State CharacteristicShaft hang-up0.3 X shown in frequence spectrum,Funny Orbit secret plan forms and discontinuities thereof.ImbalanceMerely 1X is se en in frequence spectrum, 1X additions with clip and the Phase angle alterationsBode Plot remains the same, There is no alteration in critical velocity or stage angle when compared with the healthy status.Misalignment ( or Preload in the instance of unstable bearings )1X,2X,3X,4X etc are shown in frequence spectrum, Phase angle remains changelessThe orbit secret plan will non change with velocity and polar secret plan remains the same.Crack1X, 2X, 3X, 4X etc are shown in frequence spectrum and these continually alteration in amplitude. The stage angle alterations every bit good.There is amplitude and phase alteration of 1X constituent in the polar secret plan,The orbit secret plan alterations from a figure eight form to a cringle incorporating a little cringle.BendMerely 1X is seen in frequence spectrum, 1X additions with clip and the Phase angle alterationsA signal alteration of stage takes topographic point at critical velocity.Mechanical Diarrhea front line of 0.3X, 0.5X, 1X,1.5X ,2x, 2.5X in frequence spectrumMotor Bearing defameBearing Characteristic Frequencies would be seen in spectrumFluid induced instabilityThe presence of 0.45-0.48 X in spectrum when fluid natural frequence is approached by circumferential velocity of fluid, stand foring Oil strait.The presence of 0.45-0.48 X in spectrum when fluid natural frequence is approached by circumferential velocity of fluid, stand foring Oil WhirlOil Whip consequences when Pump System rotor natural frequence peers fluid s.Fig. 17. Diagnosis Chart for common mistakes ( Beginning Sinha J.K. , M14 Lecture notes 2010, MSc Maintenance Engineering and Asset Management, University of Manchester )Fault Diagnosis ProcessThe overall quiver degrees measuring would be the first phase of protection for the pumps. The ISO recommends the usage of RMS values of speed for overall quiver measuring. Limits for acceptable quiver would be set and configured into the Bently Nevada 1900/65 proctors in footings of Velocity ( RMS ) . These proctors can refer when the bounds have been breached and this would motivate farther probe and trials. These bounds can be obtained from ISO tabular arraies or decided upon in-house by the care applied scientist. The proctor would demo which peculiar detector or detectors has detected a mistake.Furthermore, the proctor and diagnosing package proposed are capable of informations acquisition and storage which make it possible for swerving. The tendencies would be observed hebdomadal and when a set quiver bound is approached, the frequence of review is increased and trials such as the 1s mentioned before can be carried out to determine the mistake type, so a fitting care response can be planned.Fig. 18. swerve illustration ( beginning M04 CBM Lecture notes ( 2010 ) , MSc Maintenance Engineering and Asset Management, University of Manchester )The mistake diagnosing chart would be used in accompaniment with the FMEA diagram, 1900/65 proctor event logs and assorted applicable show secret plans ( frequence spectrum shows, Bode secret plan, Polar secret plan etc ) to aver the exact mistake of the pumps. Pump related frequences would be noted such that when they appear in the frequence spectrum, they can undemanding be set.FMEA, Symptoms of identified impairment mechanismsPotential Failure ModePotential Effectss of FailurePotential Failure CausesSymptoms of identified impairment mechanisms1Antifriction Bearing mistake ( Electric motor )Bearing Seizure, Misalignment,Damage to motor shaft, Mechanical seal failure.Poor lubrication, ResonanceHigh Frequency Hump seen in Frequency spectrum related to bearing lodging natural frequence2Shaft CracksShaft Fracture, Loss of pump actionResonance, Manufacturing defects1X, 2X, 3X, 4X etc are shown in frequence spectrum. These addition in amplitude over clip.3CavitationImpeller Damage, Reduced end product, Pump loss.Process disturbances, Gas lock in Pump BarrelNoisy operation, High frequence extremums in spectrum4Imba lance inordinate Vibration, BDamage to bearings and Impellers, Pump loss. get into, Impeller harm1x constituent in frequence spectrum which increases in amplitude over clip.5Journal Bearing Wear lateral shaft drama, Shaft harm unified misalignmentNoisy operation, Lateral shaft drama,6Impeller DamageReduced end product, Pump loss, Imbalance, awry(p) assembly,Cavitation, Flow-induced quiverBlade Passing frequence nowadays in frequence spectrum ( 5X,10X etc )7Bent ShaftBearing harm, High quiver unified misalignment, ResonanceAxial quiver, 1X presence in frequence spectrum8Matching MisalignmentResonance, Damage to pump internals, Mechanical seal failure, Loss of pump.Improper assembly, Resonance1X,2X,3X,4X etc are shown in frequence spectrum9Shaft hang-upDamage to pump internals, Mechanical seal failure, Loss of pump.Matching misalignment0.3X, 0.5X presence in quiver spectrum secret plan10DiarrheaDamage to pump internals, Mechanical seal failure, Loss of pump.Resonance, Improper Assembl yThe presence of 0.5X, 1X, 1.5X, 2X, 2.5X etc in frequence spectrumFig. 19. FMEA tabular array for pump and motor assembly. personify and Man-Power Implications of Vibration Monitoring and Analysis Set-upThe monetary values given are estimations based on monetary values obtained from assorted cyberspace shopping nett sites. They are non unequivocal as Bently Nevada gives monetary values based on different functionality demands and applications worldwide.ItemMeasure required for all three pumps building block Price ( $ )Price ( $ )Accelerometer, Bently Nevada 330400125006000Monitor, Bently Nevada 1900/65325007500 submergible Proximity investigations, Bently Nevada12100012000Tacho Sensor, Bently Nevada3300900Laptop110001000System 1 Diagnostic Software Licence, Bently Nevada12000020000Training for quiver applied scientist ( from bing care administration )2500Entire Price $ 49,900Fig.20. Cost breakdown of needed equipment for for good mounted quiver monitoring and analysis system.At le ase one applied scientist with accomplishments for quiver monitoring and analysis would be required to supervise the whole set-up. He must be trained and competent in the usage of assorted show secret plans, signal processing and conditioning, for mistake designation and sensing.This cognition can besides be used on other critical works equipment such as the gas turbines and the centrifugal gas compressor.The dynamic word skeleton trials are to be contracted out to see service suppliers with the friction match hardware and package for real-time life of vibrational gesture. It is estimated that the cost of this service would be circa $ 100,000. This brings the expansive sum of the proposed quiver programme from the frequent pump failures solution to for good installed status monitoring to about $ 150,000.Benefits and Limits of the proposed Vibration-based Condition Monitoring SystemThe proposed set-up for monitoring and analyzing the quiver from the pumps has rather a figure of ben efits.From the concern point of position, it is an investing because it can forestall dearly-won failures. The dollar value of the pumps failure within the biennial period considered in this study easy exceeds $ 1million when fix costs, trim parts, logistics and man-hours expended are considered.For the care administration, the presence of these vibration-based status monitoring equipment, makes it possible for care to be pro-active instead than reactive. Furthermore, frequent failures are eliminated which give room for better planning and more clip for effectual and good care.The cost of the quiver monitoring and analysis equipment can be seen to be a little monetary value to pay for plus handiness, enhanced productiveness and even safety.The restriction to the proposed system is the accomplishment, cognition and competency of the applied scientist or applied scientists who are in charge of the set-up. The signals for any mistake status would ever be picked up by the monitoring e quipment. The proper and accurate diagnosing of mistakes and subsequent care determinations made are the pass over of the applied scientist ( s ) responsible for the vibration-based status monitoring programme. In add-on, quiver monitoring equipment could neglect and necessitate replacing.DecisionA glimpse through the summarised failure and care history of the H.P. flair scrubber pumps for a two twelvemonth period reveals the sum of resources expended on them and their hapless handiness. Clearly so, something revolutionary and different from the old attacks should be attempted.This proposed system covers all the grounds- from installing jobs check, procedure vagaries that cause cavitation, to common mistakes experienced by revolving machines such as bearing defects and matching misalignments to advert a few.Besides, the proposed methods are tested and trusted and can lend to nest eggs in care cost, works handiness and safety which are cardinal public presentation indexs for most i ndustrial workss.Appendix i- Bently Nevada 1900/65 Monitor Online Available from www.ge-energy.com/prod_serv/products/oc/en/bently_nevada.htm Accessed 6th May 2010 Appendix ii- Bently Nevada 330400 Accelerometers Online Available from www.ge-energy.com/prod_serv/products/oc/en/bently_nevada.htm Accessed 6th May 2010 Appendix iii- Bently Nevada System 1 Diagnostic Software Online Available from www.ge-energy.com/prod_serv/products/oc/en/bently_nevada.htm Accessed 6th May 2010 Appendix iv- Vibration Severity Limits for MachinesFig. 21. ISO 10816 Vibration Severity Limit ChartAppendix v- Submersible Proximity Probes Online Available from www.ge-energy.com/prod_serv/products/oc/en/bently_nevada.htm Accessed 6th May 2010