Engineering Manual.pdf
description
Transcript of Engineering Manual.pdf
1PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Performance Specifications
2PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Performance Specifications
3PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Performance Specifications
3
4PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Performance Specifications
Given: Airflow = 30,000 SCFM (@70° F and density = 0.075 lb/ft^3)Air temperature from process = 200° FDischarge temperature from RTO = 400° FFD fan pressure required = 20 in-H2O
#1. Forced Draft Fan: Specify fan performance of 37,500 ACFM, 20 in-H2O (-1 in-H2O @ Inlet), 200° F, 0.060 lb/ft^3
Effect of Fan Location in System (F.D. Fans vs. I.D. Fans)
Process200°F 200°F
-1 in-H2O +19 in-H2O 0 in-H2O
400°F 400°FHeat
RTO Stack
54321
RFD Fan
Fan ∆P = 20 in-H2O RTO ∆P = 14.5 in-H2O
#2. Induced Draft Fan: Specify fan performance of 50,562 ACFM, 14.8 in-H2O(-14.8 in-H2O @ Inlet), 400° F, 0.0445 lb/ft^3
Process200°F 200°F
-1 in-H2O-1 in-H2O 0 in-H2O
400°F400°F
Heat
RTO
5321
RID Fan
Fan ∆P =14.8 in-H2O
RTO ∆P =14.0 in-H2O
Stack
400°F
4
Q P(gage) Density T(°F)1. 37500 -1 0.060 2002. 35714 +19 0.063 2003. 46875 +14.5 0.048 4004. 48913 +0 0.046 4005. 48913 +0 0.046 400
HP(req’d) = [(37500)(20)] /[(6362)(0.75)] = 157 HP
Q P(gage) Density T(°F)1. 37500 -1 0.060 2002. 37500 -1 0.060 2003. 48913 -0.8 0.046 4004. 50562 -14.8 0.0445 4005. 48913 0 0.046 400
HP(req’d) = [(50562)(14.8)] /[(6362)(0.75)] = 157 HP
NOTE: A higher-volume, lower-pressure fan is required.
Fan Performance Requirements
Fan Inquiry Form
Attach gas composition and/or molecular weight if available.
Fan Type: ■■ Radial Blade ■■ Radial Tip ■■ Other ■■ BC ■■ AF ■■ FC ■■ OptionalSpecify ________________________________________________________________________________
Arrangement No. ___________________________________ Optional__________________________________________Rotation __________________________________________ Discharge ________________________________________
Inlets: ■■ Singles ■■ Double ■■ Optional Desired Noise Limit ________ dBA @_______________Ft.Inlet Boxes: ■■ Yes ■■ No ■■ OptionalDrive: ■■ Direct Coupled ■■ V-Belt Drive ■■ VFD ■■ Other __________________________________________Motor By: ■■ R I ■■ Others
Maximum Motor HP_____________________Preferred Speed __________Type _________Volts _______Phase ____________Cycle_____________________________
Accessories Yes (Y), No (N) or Optional (O)■■ Access Door ■■ Roller/Ball Bearings Special Requirements■■ Drain ■■ Casing ■■ Inlet Box ■■ Sleeveoil Bearings ■■ Air Perf. Test■■ Inlet Screen ■■ Split Housing ■■ Mech. Run Test■■ Flanged Inlet ■■ Blade Wear Protection ■■ Overspeed Test■■ Flanged Outlet ■■ Scroll Liners ■■ Sound Test■■ Drive Guard ■■ Side Liners ■■ Certified Matl. Test Reports■■ Heat Flinger ■■ Silencer ■■ Certified Welding■■ Shaft Seal Type __________ ■■ Circulating Oil System ■■ API 673■■ Insulation Clips ■■ Turning Gear ■■ Special Coatings■■ Insulated Housing ■■ Spray Nozzles Wheel ___________________■■ Radial Inlet Damper ■■ Special Paint, Coating Casing___________________■■ Louvered Inlet Damper ■■ Spring Isolation Base ■■ Spark Resistant■■ Outlet Damper ■■ Bearing Temp. Detectors AMCA-A, B or C _____■■ Independent Bearing Pedestals ■■ Bearing Vibration Detectors ■■ Pressure Test■■ Pedestal Sole Plates■■ Separate Damper, Size ______________________________________________________________________________
Special Requirements, Comments or Sketch: Attach Separate Sheet
Rep. Office ________________________________________ By ______________________ Date ____________________
Customer _________________________________________ Date Quotation Req.___________________________________Street ________________________________________City __________________________________________ State ____________________ ZIP _____________________Telephone _____________________________________ Fax ________________________________________________Attention ______________________________________
Reference or Project ________________________________Number of Fans Required ____________________________Description of Service ______________________________________________________________________________________
________________________________________________________________________________________________________________________________________________________________________________________________________
Max. Mechanical Design Temp ________ (Deg. F)
■■ Clean Air ■■ Dust/Moisture-Laden ■■ Abrasive ■■ Severe Abrasive ■■ Corrosive
Materials of Construction: Wheel_______________________ Casing______________________________________________Type of Dust or Gas ________________________________. _______________________________________________#/HRAltitude _______________________________Ft. Above S.L. Ambient Temp. Range _________to _________F
CONDITION INLET VOLUMEACFM OR SCFM
FAN SP,IN. WG
INLET SP,IN. WG
INLET TEMP.,DEGREES F.
INLET DENSITYLB/FT3
5PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Performance Specifications
6PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Application Information
Radial Blade• Static efficiency to 75%• High tip speed capabilities• Reasonable running
clearance• Best for erosive or sticky
particulate
Backward Inclined• Static efficiency to 80%• Low to medium tip speed
capabilities
Radial Tip• Static efficiency to 75%• Medium to high tip speed
capabilities• Running clearance tighter
than radial blade but notas critical as backwardinclined and airfoil
• Good for high particulateairstream
Airfoil• Static efficiency to 87%• Medium to high tip speed
capabilities• Relatively tight running
clearances
Backward Curved• Medium to high tip speed
capabilities• High efficiency to 83%• Clean or dirty airstreams• Solid one-piece blade design
Paddlewheel• Open design/no shroud• 60-65% static efficiency• Inexpensive design• Good for high temperature
or highly erosiveapplications
• Medium to high pressure
Forward Curved(Sirrocco)• Smallest diameter wheel
for a given pressurerequirement
• High volume capability• 55-65% static efficiency• Often used for high
temperatures
Axial Flow• High volume, low pressure• 35-50% static efficiency• High temperature furnace
recirc. applications• Reversing flow capability• Airflow parallel to shaft axis
7PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Application Information
8PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Selection Information
Development of Fan Performance CurveReprinted from Publication 210 with the express written permission of the Air Movement and Control Association, Inc., 30 W. University Drive, Arlington Heights, IL 60004-1893.
A
SP
A
BC
D
E
E
D
CB
F
F
BHP
SP
CFM
Test duct orifice plates from shut-off to wide open for points A, B, C etc.
Typical Outlet Duct Test Setup
Notes
1. Dotted lines on fan inlet indicate an inlet bell and one equivalent duct diameter which may be used for inlet duct simulation. The duct friction shall not be considered.
2. Dotted lines on the outlet indicate a diffuser cone which may be used toapproach more nearly free delivery.
9PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Selection Information
10PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Selection Information
11PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Selection Information
12PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Selection Information
13PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Selection Information
14PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Selection Information
15PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Selection Information
16PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Selection Information
17PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Selection Information
Single Point OperationThe actual operating point will be determined by the intersection of the system resistance curve and the fan
performance curve. The fan must be selected correctly to exactly meet the design requirement.
System resistance curve
Fan performance curve
SP = 40"
BHP = 1257
Es = 0.75 (75%)
Es
BHP
THOUSANDS CFM
SP
STA
TIC
PR
ES
SU
RE
-IN
CH
ES
H2O
BH
PS
TAT
IC E
FF
ICIE
NC
Y, %
50
40
30
20
10
2000
1000
80
40
50 100 150 200 250
BHP = CFM x SP6362 x Es
(neglecting compressibility)
Fan Selection Considerations• Efficiency• Stability• Sound• Size• Speed
18PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Selection Information
ACFM x SP x Kp
6362 x static efficiency
ACFM = actual cubic feet per minute
SP = static pressure
Kp = compressibility factor
6362 = conversion constant
Static efficiency = , or
Fan HP =
ACFM x SP x Kp
6362 x Fan HP
Fan HP(input)
ACFM x SP x K p
6362
=Air H
P
(output)
19PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Selection Information
20PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Selection Information
21PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Selection Information
Regulation by Radial Inlet Damperor Inlet Box Damper (Parallel Damper)
Inlet damper control offers several advantages compared to outlet dampering. Because the air is prespun in the same angular direction as the fanwheel rotation, the energy required to operate the fan is significantlyreduced. Also, the multiple vanes just upstream of the fanwheel inlet provide a controlled presentation of air to thefanwheel that provides smooth control over a wide range of operation. With this system, there is, in fact, a new fanperformance curve for every damper position. See the example below:
22PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Selection Information
23PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Selection Information
24PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Selection Information
Example: (Fans with geometric similarity)
100" diameter wheel x 10" tip width100,000 CFM @ 20" SP @ 70° F @ 393 BHP
What is performance at 90-1/2" diameter wheel x 9.05" tip width?
CFM2 = (90.5/100)3 (100,000) = 74,122 CFM
SP2 = (90.5/100)2 (20) = 16.3 in. H2O
BHP2 = (90.5/100)5 (393) = 239 HP
Volume: CFM2 = (Size2 / Size1)3 (CFM1)
Static Pressure: SP2 = (Size2 / Size1)2 (SP1)
Horsepower: BHP2 = (Size2 / Size1)5 (BHP1)
Sound Power: LW2 = LW1 + 70 log (Size2 / Size1)
Size Change Fan Law
The Size Change Fan Laws make it easy to determine the performance for a larger size fan based on the knownperformance of an existing fan or a laboratory model fan. This requires that the fans be geometrically similar. Notehowever that Robinson has developed modified versions of this fan law that allow accurate prediction of tipped-out(slightly larger diameter) and de-tipped (slightly smaller diameter) fan rotors. This is sometimes a very cost-effectivemeans of accomplishing in-field modifications to increase performance or decrease horsepower consumption.
Example: (Fans to be tipped out or de-tipped)
CFMMod = (Dia2/Dia1)2 (CFMorig)
SPMod = (Dia2/Dia1)2 (SPorig)
BHPMod = (Dia2/Dia1)4 (BHPorig)
Example: 100" diameter wheel x 10" tip width100,000 CFM @ 20" SP @ 70° F @ 393 BHP
What is performance with a 5% tipout to 105'' diameter?
CFMMod = (105/100)2 (100,000) = 110,250 CFM
SPMod = (105/100)2 (20) = 22.05 in. H2O
BHPMod = (105/100)4 (393) = 478 HP
Note: Effect on sound pressure is greater due to decreased cut-off clearance.
25PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Selection Information
26PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Selection Information
27PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Selection Information
28PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Selection Information
29PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Selection Information
30PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Selection Information
31PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Selection Information
32PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Selection Information
33PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Selection Information
34PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Selection Information
35PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Selection Information
36PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Selection Information
37PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Selection Information
38PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Selection Information
39PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Selection Information
Erosion
Erosion is a major problem on some induced draft fans. High dust loading combined with high inlet velocities canresult in dangerous shutdowns. Hard surface wear liners can help. But reducing the fan inlet velocity by specifying alower speed, larger diameter fan can result in reduced wear and extended fan wheel life.
The kinetic energy (KE) of the particles decreases with the square of the velocity.
Erosion can also be reduced by reducing the particulate flow rate (lbs./hour) or by reducing the averageparticle size.
1. Reducing the particulate flow rate (lbs./hour).
2. Reducing the average particle size.
3. Reducing the particle velocity and the gas velocity at the fan inlet.
Note that changing from a single inlet fan design to a double inlet design is a very effective means of decreasing thefan inlet velocity.
Note: The presence of particulate matter in the gas stream affects the average density at the fan inlet and therefore themotor power requirement as is shown on page 1.
40PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Selection Information
(Note: Over 180 different materials tested to date)
41PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Mechanical Design
42PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Mechanical Design
43PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Mechanical Design
44PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Mechanical Design
45PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Mechanical Design
Comparative Advantages of Oil and Grease
Advantages of Grease1. Maintenance work is ordinarily reduced since thereare no oil levels to maintain.2. Grease in proper quantity is more easily confined to the housing. Design of enclosures can therefore be simplified.3. Freedom from leakage is readily accomplished infood, textile, chemical industries and where contami-nation of products must be avoided.4. Grease improves the efficiency of labyrinth enclo-sures and offers a better protection for the bearing.5. Bearing can be installed in a high velocity gas stream.
Advantages of Oil1. Oil is easier to drain and refill. This may be more desirable for applications requiring shortlubricating intervals.2. The correct amount of lubricant is more easily controlled.3. Oil lends itself more readily to the lubrication of allparts of a machine.4. Oil lends itself to applications with highertemperatures.5. The bearing friction and temperature rise are usuallymore favorable.
46PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Mechanical Design
47PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Mechanical Design
48PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Mechanical Design
49PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Mechanical Design
Sleeve-Type Bearings• No moving parts• No metal-to-metal contact/infinite fatigue life• Babbitted surfaces• Split design for easy maintenance• Shaft-mounted thrust collar (fixed bearings)• Infinite axial expansion capability (for shaft)• External cooling (water, air, circulating oil)• Auxiliary dust seals available
Note: These bearings are generally used for large diameter fans. They have higher load and speed capabilitiesthan rolling element bearings.
Fan Bearing Comparison
Standard SphericalItem of Ball Bearing Roller Bearing Dodge Sleeve
Comparison (Deep Groove) (SAF Housing) Bearing
1. Calculated Life 40,000 / 80,000hrs. 80,000 hrs. Infinite2. Radial Load Capability Low Medium Very Large3. Axial Load Capability Low Medium Very Large4. Cooling Capability Limited Limited Very High
water cooling No No Yesair cooling No No Yes
5. Circulating Oil No Yes Yesmax. flow rate N/A Limited Very High
6. Static Oil Lube No Yes Yes (5-7/16" brg. = (5-7/16" brg.
.6 liters) XC = 2.95 L / RT = 4.49 L)
ring oiled No No Yes7. Grease Lubrication Yes Yes No8. Thermal Analysis Yes Yes Yes9. Dynamic Stiffness Medium High Medium (oil film)
10. Dynamic Damping Minimal Minimal Good11. Shaft Tolerances Nominal Nominal Nominal
+0.000 / -0.0005 +0.000 / -0.005 +0.000 / -0.00212. Shaft Surface 32 32 3213. Shaft Specialties None None XC – None
RT – groove/collar14. Self-Aligning Yes Yes (brg.) Yes (liner to housing)15. Axial Expansion 3/16" – 3/8" Std = 3/8" Unlimited16. Split Housing No Yes Yes17. Split Bearing No No Yes18. Field Replacement Easy Easy Easy
(Outboard)19. Field Replacement Difficult Difficult Fairly Easy
(Inboard) (Must remove coupling (Must remove coupling (Loosen coupling, jackand move motor before and move motor before up shaft about 1/4",
removing/installing bearing) removing/installing bearing) slide old bearing out)20. Spare Parts Worldwide Worldwide USA only21. Availability Stock Stock Stock22. Axial Length Shortest Medium Longest
(affects shaft sizing)23. Price Low Low High
50PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Mechanical Design
51PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Mechanical Design
52PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Mechanical Design
53PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Mechanical Design
D = shaft dia. (in.)I = πD4
(in.4)64
E = Shaft modulus of elasticity (lbs./in.2)W = fanwheel weight (lbs.)A, B, L = distance (in.)y = shaft deflection (in.)Ncr = critical speed (rpm)
y = WL3
48EI
54PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Mechanical Design
55PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Mechanical Design
56PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Mechanical Design
Fanwheel DesignFatigue LifeASME fatigue life curves are used for both high-cycle and low-cycle fatigue calculations. The following is an examplefor ASTM A514 material.
Ab
sorb
ed E
ner
gy
ft.-
lbs.
Str
ess
(psi
)
Impact ToughnessCrack propagation rate is a function of the toughness of the material. This can be quantified by Charpy V-Notchtesting. Materials with low impact toughness are more glasslike or brittle.
The impact toughness varies as a function of temperature for many materials. There is a history of rapid, unexpected failures of fan rotors during cold weather start-up or operation that has been related to low materialimpact toughness. Therefore, Robinson recommends using materials that have an adequate impact toughness at the lowest expected operating temperature. The graph below shows that thermal stress relief of welded A514material has a detrimental effect on the impact toughness. Therefore, thermal stress relief of A514 fanwheels is not a recommended practice. Other materials, of course, may not react to thermal stress relief in this way.
107
106
105
104
10 102 103 104 105 106
57PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Mechanical Design
58PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Mechanical Design
59PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Mechanical Design
60PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Mechanical Design
61PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Mechanical Design
62PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Mechanical Design
Shaft Seals:These are designed to minimize leakage of dangerous gases from the process, or to exclude atmospheric air fromthe process itself. Several seal designs are available with varying sealing effectiveness. (See section on shaft sealdetails).
63PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Mechanical Design
64PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Mechanical Design
65PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Mechanical Design
Shaft may be chrome-plated or ceramic-coated
under packing area.
Shaft may be chrome-plated or ceramic-coated
under packing area.
66PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Mechanical Design
Shaft may be chrome-plated or ceramic-coated
under carbon.
Shaft may be chrome-plated or ceramic-coated
under carbon.
67PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Mechanical Design
68PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Mechanical Design
69PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Mechanical Design
70PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Mechanical Design
71PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Mechanical Design
72PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Mechanical Design
73PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Mechanical Design
In addition to the sound level, the duration of exposure toa particular noise level is also an important local noiseconcern. The table below outlines OSHA’s permissiblenoise exposure limits.
Duration per day, hours Sound level dBA
8 ..................................................................906 ..................................................................924 ..................................................................953 ..................................................................972 ................................................................1001-1/2 ..........................................................1021 ................................................................1051/2 ..............................................................1101/4 or less ..................................................115
When the daily noise exposure is composed of two or more periods ofnoise amounts of different levels, their combined affect should beconsidered, rather than the individual effect of each. If the sum of thefollowing fractions — C1/T1 + C2/T2… Cn/Tn — exceeds unity, then themixed exposure should be considered to exceed the limit value. Cnindicates the total time of exposure at a specified noise level, and Tnindicates the total time of exposure permitted at that level.
Federal Register, Vol. 34, No. 96, May 20, 1959, pp. 7849.
For a ducted inlet/ducted outlet fan in a free field:
LpTOTAL = 10 log (10 + 10 + 10 + 10 )Lpd
10
Lpe
10Lpf
10Lpm
10
LpTOTAL = 10 log (10 + 10 + 10 + 10 )8310
8810
8110
8510
For example:
LpTOTAL = 91.04dB
74PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Mechanical Design
75PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Mechanical Design
76PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Mechanical Design
time (seconds)delta RPM = change in speed (rev./min.)available torque = (motor torque capability) - (fan torque
requirement) at all speeds from zero to normal operating speed (ft.-lb.)
WR2 = fan rotor rotational moment of inertia (lb.-ft.2)
77PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Mechanical Design
78PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Mechanical Design
79PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Mechanical Design
80PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Fabrication & Quality Control
81PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Fabrication & Quality Control
82PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Fabrication & Quality Control
83PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Fabrication & Quality Control
84PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Fabrication & Quality Control
85PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Fabrication & Quality Control
86PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Fabrication & Quality Control
Notes:1. The numerical value after the letter G is equal
to the product of ePER(2πf) expressed in millimeters per second.
G = ePER (2πf), or ePER =
UPER = max residual unbalance for a particular rotor.
UPER = ePER x m = Gm2πf
Example: Rotor weight, (m) = 1000 lbs; Rotor Dia = 75 inch;Maximum operating frequency = 1200 rpm ÷ 60 s/min = 20 cyc/s;Balance to grade G2.5 = 2.5mm/sec.
ePER = = = 0.02 mm
0.02 mm ÷ 25.4 mm/in = .0008 in
UPER = ePER x m = (0.0008 in)(1000 lb) = 0.8 lb-in
0.8 lb in x 16 oz/lb = 12.8 oz-in
Shaft* vibration in free space =
G2πf
G2π (20)
( )2.5mm/sec25.4mm/in = 0.10
insec
*Note: Bearing vibration will be considerably lower thanshaft vibration.
G(2πf)
(peak velocity)
87PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Fabrication & Quality Control
88PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Fabrication & Quality Control
89PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Fabrication & Quality Control
Safety Relief
Safety Relief
PlantAir/H2O
PlantAir/H2O
Pressure Test Procedure for Fan Casings(When no leakage rate is included in the specifications)1. Blind flange with rubber gasket over all inlet and outlet openings.2. Fans with a peak operating static pressure from 0 in-H2O to 138 in-H2O to be pressure tested with compressed
air. Fans with peak operating static pressures over 138 in-H2O to be pressure tested with water.3. Attach plant air line or water line to casing drain or other entry point as follows:
4. Use U-tube water gauge or a 0-5 psi pressure gauge for pressure of 0 to 50 in-H2O. Use 0-5 psi pressure gauge for pressures above 50 in-H2O.
5. Pressurize casing to highest operating static pressure of the fan. (Examine all operating conditions, including 70° F, and use the highest pressure.)
6. Close inlet valve.7. All welds are to be bubble tested with leak detection solution. Repair all weld leaks and begin retesting.8. On the Pressure Test Log Sheet (See page 90), record pressure once every 60 seconds for 15 minutes.9. If average leak rate is less than 2.0 in-H2O per minute, then the unit is satisfactory. If the average leak rate
exceeds 2.0 in-H2O per minute, inspect the area of the shaft seal, inlet/outlet flanges and casing split gaskets first for major leaks.
10. Continue to repair leaks and rerun pressure test until the required leak rate is achieved.
90PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Fabrication & Quality Control
Pressure Test Log Sheet
Factory Order # Serial # Test Date
Size and Description
Assembly Drawing #
Shaft Seal Material Gasket Material
Highest Operating Static Pressure of Fan (all operating conditions, including 70° F) in.-H2O
Test Pressure (max.) in.-H2O
Casing Welded: Inside ■■ Outside ■■ Both Sides ■■
91PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Fabrication & Quality Control
92PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Fabrication & Quality Control
93PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Installation Information
94PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Installation Information
95PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Installation Information
96PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Troubleshooting
97PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Troubleshooting
98PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Troubleshooting
99PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Troubleshooting
100PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Troubleshooting
101PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Troubleshooting
102PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Engineering Publications
Engineering Publications1. Gutzwiller, H.L., Robinson Industries, Inc. “Balance
and Vibration Considerations for Fans,” AMCATechnical Seminar, Los Angeles, California,November 1-3, 1995.
Abstract: For years, we have reviewedspecifications from users of industrial fans thatshow a misunderstanding between the terms“balance” and “vibration.” While the two termsare related, they have independent definitions;and it is important for both users andmanufacturers to clearly understand thedifferences. The Air Moving and ControlAssociation (AMCA) has formed a committee todraft a standard #204 entitled “Balance Qualityand Vibration Levels for Fans.” Other standardsexist for defining balance and vibrationrequirements for the general rotating equipment.However, this committee is to address thespecial consideration for fan equipment inparticular. The purpose of the standard is to“define appropriate fan balance quality andoperating vibration levels to those who specify,manufacture, use and maintain fan equipment.”
2. Banyay, H.D., Robinson Industries, Inc. “MaximizingFan Reliability in Kilns, Dryers and Burners,”Ceramic Industry, Vol. 146, No. 4, April 1996,pages 5-15.
Abstract: The purpose of this paper is todiscuss the proper application of bearings on hotgas fans. The gas temperature for these canrange up to 1300° F or more. The fans typicallyare V-belt driven (AMCA arrangement #1 or #9)and range up to 100 HP.
3. Gutzwiller, H.L., and Banyay, H.D., RobinsonIndustries, Inc., and Ball, W.D., John ZinkCompany. “Marine Vapour Recovery SystemBlowers,” Fans for Hazardous Applications,Seminar by the Fluid Machinery Committee ofthe Institution of the Mechanical Engineers,London, England, October 4, 1994.
Abstract: This paper describes the design andapplication of high-pressure blowers used toexhaust combustible hydrocarbon vapors fromseagoing tankers. Important considerationsinclude stable operation over a wide flow range,spark-resistant and gas-tight construction,minimal noise, resistance to salt-spray corrosion,and ease of maintenance.
4. Grupp, David, Robinson Industries, Inc. “NaturalFrequency of a High Temperature Plug Unit andWall in a Furnace Application,” EngineeringPaper 2566-94-A1, AMCA EngineeringConference, St. Petersburg Beach, Florida,February 20-22, 1994.
Abstract: Critical speed is a well-known designparameter in the fan industry. Most commonly,critical speed is related only to the fan rotor andshaft assembly. Often the effects of the bearings,support structure, foundation and soil areneglected as properties of the system. In mostcases, the stiffness of each of these properties isso high that their effect is indeed negligible.However, when the effects of these propertiesbecome significant, the fan engineer must becareful to design for the system critical speed.The following paper will present a fan applicationproblem in which the stiffness of a wall in afurnace structure resulted in a unique systemcritical resonance at the operating speed of fivehigh temperature axial flow fan assemblies.
5. Gutzwiller, H.L., and Banyay, H.D., RobinsonIndustries, Inc., and Cohen, S.N., FullerCompany. “Cement Plant Preheater Fan Build-up Control,” IEEE Conference, Tarpon Springs,Florida, May 22, 1990.
Abstract: In recent years, greater demands withregard to throughput and efficient utilization ofheat in the kiln due to process design changeshave placed greater demands on the kiln-induced draft fan. These fans have beendesigned with ever-increasing volume and staticpressure requirements, as well as higherprocess gas temperatures. This, of course,means larger fan rotors operating at very high tipspeeds. Along with these design changes, theproblem of build-up on the impeller has alsoincreased markedly … But why must someplants battle this problem routinely while othershave no significant ID fan build-up at all? Whatcauses kiln ID fan build-up problems? How can itbe stopped?
103PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
Engineering Publications
104PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
105PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
106PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
107PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
108PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
109PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000
110PROPRIETARY information of ROBINSON INDUSTRIES, INC.Do NOT copy or distribute.
Jan. 2000