Vibration History. Pulp & Bleach Area. ips. Average Amplitude Velocity. Year

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1 Average Amplitude Velocity ips Vibration History Pulp & Bleach Area Year

2 R&E Maintenance Expense Pulp & Bleach Area Dollars / Ton Year

3 Dollars / Ton Average Amplitude Velocity ips R&E Maintenance Expense Vibration History Year

4 Intellectuals solve problems; geniuses prevent them. Albert Einstein

5 What percentage of your machines are the highest HP? medium HP? low HP?

6 Average Maintenance Costs By Machine Size 500 hp hp.... $1x hp / yr $2x / hp / yr $4x / hp / yr 1 hp....

7 Vibration vs. Maintenance Costs 1800 rpm pumps 50 Dollars, Thousands Velocity, ips Machine 0

8 Vibration vs. Maintenance Costs 1800 rpm pumps 50 Dollars, Thousands Velocity, ips Machine < $4, in/sec 0

9 Vibration vs. Maintenance Costs 1800 rpm pumps 50 Dollars, Thousands Velocity, ips Machine < $7, in/sec 0

10 Vibration vs. Maintenance Costs 1800 rpm pumps 50 Dollars, Thousands Velocity, ips < $15,000 Machine 0.08 in/sec

11 Fastest means to determine your own actual costs

12 Maintenance Expense vs Vibration History Machine type Highest Velocity, ips Maintenance Cost, $ Lowest Velocity, ips Maintenance Cost, $ Total Highest Lowest Difference in maintenance costs for 3 machines with highest vibration vs 3 machines with lowest vibration: Difference in 12 month maintenance costs = $

13 Maintenance Expense vs Vibration History Machine type Pump rpm Pump rpm Highest Velocity, ips Maintenance Cost, $ Lowest Velocity, ips Maintenance Cost, $ Fan Total Highest Lowest 5397 Difference in maintenance costs for 3 machines with highest vibration vs 3 machines with lowest vibration: Difference in same period maintenance costs = $ 68,077

14 Simplest, Easiest Procedures to Lower Amplitudes on Existing Plant Machinery Eliminating Foot Frame related Resonance

15 Pk Velocity in In./Sec A-REACTOR BLD. SPRAY MIH MOTOR INBOARD HORIZ. 2x RPM SPECTRUM DISPLAY 12-NOV-90 18:22 PK=.7089 LOAD=90.0 RPM=3594 RPS= x RPM Frequency in Hz

16 Pk Velocity in In./Sec A-REACTOR BLD. SPRAY MIH MOTOR INBOARD HORIZ. 2x RPM SPECTRUM DISPLAY 15-NOV-90 18:32 PK=.1970 LOAD=90.0 RPM=3585 RPS= x RPM Frequency in Hz

17 1.0 Before 0.24 After 0.8 Auto 0.21 scaled

18 Before After Adjusted to same scale Added 2 3 mils of shim under one flange bolt!

19 Electric motor All bolts tight Two bolts loose DISPLACEMENT IN MILS DISPLACEMENT IN MILS

20 100 % Large pulp and paper company s goals for additional production running time 99 Ultimate Target 98 Initial Target 97 Present production Primary production Machines (from company s several mills)

21 100 % Goals for additional production running time Initial Target 250,000 Tons / yr Additional 250,000 Tons / year 365 = 685 tons / day Primary production Machines (from company s several mills)

22 100 % Goals for additional production running time 99 Additional 500,000 Tons / yr Additional 500,000 Tons / year 365 = 1370 tons / day Primary production Machines (from company s several mills)

23 VP Production - major paper company: I can get an additional large papermill - not through the expenses and problems of building one - but by getting only 20 of our present machines to run just a little bit longer each day. How?? Through our new very practical machinery improvement / precision maintenance efforts.

24 Large Aluminum manufacturing facility Machinery 5000 pieces of rotating equipment Maintenance Philosophy Before starting the program: run to failure After: machinery improvement / precision

25 Inches/Second Average Vibration Levels for all Equipment 0 Year 1 Year 6

26 Unscheduled vs Scheduled Maintenance % Scheduled 15 % Unscheduled 85 % Scheduled 91 % 20 0 Year 1 Unscheduled 9 % Year 6

27 Annual Pump Maintenance (Run to Failure) 1,500 Pumps ( Hp) MTBF - 4 Years Average rebuild / replacement cost - $25,000 / pump Total pump maintenance cost - $9,375,000 / year

28 Annual Pump Maintenance Costs: Same 1,500 Pumps ( Hp) First four years $4,687,500 / year Fifth year - present: < $1,000,000

29 Million Pounds per Month Production Increase (through machinery improvement efforts) 30 million pounds per month 60 million pounds per month With no increase in expansion of capital machinery! Year 1 Year 6

30 ISO Balance Standards G 100 Crankshaft -drives of fast diesel engines with six or more cylinders, complete engines of cars, trucks and locomotives G 16 Propeller shafts, carden shafts, parts of crushing machinery, parts of agricultural machinery G 6.3 Parts of process plant machines, paper machinery rolls, fans, fly wheels, pump impellers, electric motor armatures G 2.5 Gas and steam turbines, Turbine driven machines, machine tool drives, motor armatures with special requirements G 1 Tape recorder and phonograph drives, grinding machines, small motor armatures with special requirements

31 Page 225 G 2.5 G 6.3 G 1

32 ISO Rotor Balancing Standards: circa 1956 Shaft centerline orbit around center of mass G 2.5 G 6.3 G 1 API American Petroleum Institute

33 1.1 mils radius = 2.2 mils orbit Converted to inches RPM = approximately 0.22 in /sec Not so good for long production life! RPM 1800

34 centerline orbit radius of 12 mils Total displacement Converted to inches mils! How will this affect the gearmesh? RPM 2000

35 Pitch circles

36 Addendum : Portion of tooth above the pitch circle Addendum Dedendum Dedendum : Portion of tooth below the pitch circle

37 Dedendum Addendum

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39 Addendum Dedendum

40 Addendum Addendum

41 Dedendum Dedendum

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45 Gearmesh frequency 12,498 cpm Excessive barring on paper napkin machine

46 Apply sideband cursor Gearmesh frequency

47 Sideband difference frequency 118 cpm Gearmesh frequency

48 The peak in velocity is only 0.1 ips Gear rpm = cpm (closest data point at 120 cpm)

49 The peak in velocity is only 0.1 ips Gear rpm = cpm But the displacement is 16.6 mils! Indicates a large rotor imbalance

50 The gear was balanced and the barring eliminated

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52 Balancing Narrow and Overhung Rotors If the width of the rotor is less than ¼ of the diameter, then it only requires a single plane balance. False!

53 Usually calls for single plane balance

54 Usually calls for single plane balance

55 Calls for two plane balance

56 If the rotor is overhung (cantilevered), regardless of width, then it most often requires a single plane balance. False!

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58 Vibratory motion of shaft centerline Greatest amplitude at the top

59 Cooling fan what a convenient place for balancing at the top plane False!

60 Couple (rocking motion) pivot point Static imbalance (overhung) creates large couple

61 If Resonant in the rocking mode, bracing usually does not work Instead, use a tuned dynamic absorber (works only on a resonant system)

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66 Develop your own company standards for precision balancing G 1 Parts of process plant machines, paper machinery rolls, fans, fly wheels, pump impellers, electric motor armatures

67 Balancing time, including cleaning the rotor, removing burrs, adding proper key, mounting on balancing machine, adjusting drive unit and positioning end stops. Balance to G 6.3 Time: 1 to 1½ hours Balancing time, from G 6.3 to G 2.5, ½ hour Balancing time, from G 2.5 to G 1 (or API) another ½ hour Total extra time for balancing from G 6.3 to G 1, One hour

68 Total for true precision balance Motor solo test and touchup ½ hour 1 hour Extra for true precision alignment 1 hour Foot related resonance test ½ hour Additional resonance improvement 1 hour Total 4 hours At $100/hour = $400

69 Eccentricity at 200 RPM = 12 mils Vibration amplitude in displacement : 12 x 2 = 24 mils

70 Most common places where alignment goes wrong Actual thermal growth situations

71 From Update International Surveys Typical responses from Supervisors and Managers My plant already has modern alignment instruments (laser and/or reverse indicator). My people have received a good training from: instrument manufacturer alignment seminar specialists internal training staff Update International..etc

72 Responses from those who perform alignment Nobody has ever complained about my work I can get the job done with one indicator, faster than setting up the fixtures. I love using the laser system. I use it all the time. Question: How do you know when to quit? Typical answer: I have a lot of experience. I just know it.

73 Responses on: When do you offset for thermal growth? Almost never When it is a brand new machine, with manufacturer s representative present. Nobody tells me when. I don t believe they re hot enough! It s not my job to figure it out. When in doubt, I ask my supervisor / maintenance planner.

74 Fan (very hot) History: 10 years of vibration amplitudes from 1.0 to 1.5 in / sec Replaced worn bearings, every 4 to 6 months Each shutdown resulted in an outage of half the plant Repeatedly balanced in-place Repeatedly realigned, (including offsets for thermal growth) Thermal growth offsets supplied by fan manufacturer Manufacturer s calculations based on one motor / fan assembly

75 Fan (very hot) Fan (very hot) Actually there were two fans back-to-back

76 notice the exceptionally hot area for each outboard pedestal. Fan (very hot) Fan (very hot)

77 Noise enclosure Hot Steam Turbine A Generator 3000 rpm B History: 4 years of high vibration amplitudes 4 different consultants (with no solutions) thermal offsets estimated for generators internal temperatures (same for each end) no actual temperatures measured consider temperature pedestal A relative to pedestal B

78 Now, what else can magnify these vibrations? Resonance at new operating speed How can we tell ahead of time?

79 ½ HP variable speed vibration shaker Range 0 to 6,000 RPM

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81 Shaker large enough to shake a whole section of a paper machine

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83 Not resonant Not resonant 1 st Resonance Frequency 1 st Resonance Frequency 2 nd Resonance Frequency 2 nd Resonance Frequency 3 rd Resonance Frequency 3 rd Resonance Frequency

84 ON 0.08 Testing for resonance with a shaker using a 10 division modal shape plot A B C D E F G H I

85 First resonance excited by shaker

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91 Dynamic imbalance: Composed of static and couple To counterbalance first resonance whip remove static imbalance To counterbalance second resonance whip remove couple imbalance

92 Notice: no balance weights or holes, no tough point indicated between shaft and bore

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95 This did not start with bad gearteeth. It Finally started magnified with no dynamic by resonance balance with and poor cracks assembly forming fits at the node

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97 Surface speed: feet/minute Number of bars Distance (feet) Bars Ft X Ft Minute = Bars/Minute = Frequency causing the barring First determine what is not causing the problem Often involves a resonance

98 Barring on a roll: number of bars X roll RPM

99 Equal angles Aligned Misaligned Unequal angles

100 Before After alignment

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106 Coupling binding and resonant pipe Lumens Frequency CPM

107 Fans Lumens Frequency CPM

108 Out of balance fans 30 away from resonant headbox Resonated section of headbox above the slice

109 Centri-screen drive motor Lumens Frequency CPM

110 Coupling binding Centri-screen and resonant pipe drive motor Lumens Frequency CPM

111 Headbox Pipe resonant to 2x RPM of pump below

112 Normal

113 Resonant

114 Resonant

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