ROOTS Dresser Whispair MAX User manual

I ROOTS rfpm4
JYHLTHb~M~
BLOWER
13 /4 -31 /2 inch gear diameter
INSTRUCTIONS
ROTARY LOBE BLOWERS
NUMBERS IN ( ) ARE METRIC EQUIVALENTS
INFORMATION SUMMARY This page
Receiving ... Installing Operating ...
OPERATING CHARACTERISTICS 2
Description ... Control ... Protection
OPERATING L1MITATIONS 3
Pressure
... Temperature Speed
INSTALLATION
3,4
Mounting Piping Driving
LUBRiCATION 5
Oil Fill ... Servicing Greasing
OPERATION 5
Starting
Testing Adjustment
TROUBLE SHOOTING 6
Capacity ... Power Heating
SAFETY PRECAUTIONS
7'
Physical ... Operating General
MAINTENANCE/REPLACEMENTS 7,8
Servicing ... Clearances ... Repairs
PARTS DRAWiNGS
9.11
SALES OFFICES 12
To Get The Most From Your Roots Blower
II Check shipment for damage in transit. After filing
claim
with carrier, notify nearest Roots Sales Office or fac-
tory.
aUnpack shipment carefully and check contents
against Packing List. Notify Sales Office or factory if a
shortage appears.
E:I Store in aclean, dry location if immediate installation
is not to be made. Keep covers on all openings and protect
against weather and corrosion.
IEIRead LIMITATIONS and INSTALLATION sec-
tions in this book and plan the complete installation
accordingly.
BProvide adequate safeguards against accidents to per-
sons working on or near the blower. See PRECAUTIONS.
mInstall correctly, using recommended accessories to
protect blower during regular operation.
Ii Lubricate blower and drivin~ equipment before
operating. See
LUBRICATION.
m Read starting check points under OPERATION, then
operate blower briefly to check for obvious faults. Make
corrections before proceeding with a trial run under nor-
mal operating conditions.
mIn event of trouble during installation or operation of
anew unit, do
not attempt repairs. Notify nearest Sales
Office, or
factory giving all blower nameplate information
and operating conditions.
EUnauthorized attempts at equipment repair may void
Manufacturer's warranty. Units out of warranty may be
repaired or
adjusted by the owner. It is recommended that
such work be limited to the operation described in this
manual, using Factory Parts. Good inspection and
maintenance practices should reduce the need for repairs.
See
Distributor List on last page for parts and service
after warranty period.
NOTE -Information in this manual is correct as of the date of publication. The Manufacturer reserves the right to make design or material changes without
notice, and without obligation to make similar changes on equipment of prior manufacture, •
Bulletin /RB-131-778

The Roots rotary lobe blower is apositive displace-
ment
type unit, whose pumping capacity is determined by
size, operating speed, and
pressure conditions. It employs
two double-lobe impellers mounted on parallel shafts and
rotating in opposite directions within acylinder closed
at
the ends by headplates. As the impellers rotate, air is
drawn into one side
of the cylinder and forced out the
opposite side against the pressure existing there. The
pressure developed, therefore, depends on
the resistance
of the discharge system.
Effective sealing of
the blower inlet area from the
discharge area is accomplished by use of very small
operating clearances. Resulting absence of moving contacts
eliminates
the need for any internal lubrication. Clearances
between
the impellers during rotation are maintained by a
pair of accurately machined timing gears, mounted on
the
two shafts extended outside the air chamber.
The proprietary Whispair blower design provides a
chamber on
the discharge side of the cylinder. From this
chamber two or more slots open back into
the two
alternately closed pocket areas
of the cylinder, shown as A
and B
in Figure 1. These slots, at certain impeller
positions, allow discharge
pressure to bleed into the
normally low pressure pockets. They also provide a jet
action on the impellers in the direction of rotation. Gradual
pressure build-up in the pockets, to alevel almost equal to
the discharge pressure, reduces backflow rate at the
instant of pocket discharge so that pulsing and shock noise
are minimized. This permits operation
at higher speeds
with conservative noise levels, and
in most cases enables
use of asmaller unit
to produce required capacity.
In
Figure 1, flow is left to right from blower inlet to
discharge. The lower impeller is mounted on the driving
shaft, and
rotates counterclockwise. As shown in Position
1, it is delivering ameasured volume (A) into the discharge
pressure chamber.
At the same time, space (B) between
the
upper impeller and cylinder wall is filling with another
and equal volume
at atmospheric or inlet pressure. It is
about
to be sealed off by the clockwise rotation of this
impeller, for delivery
to the dishcarge.
Position 2shows the inlet area sealed, but some
discharge pressure is now
entering space (B) through the
slot passage, as indicated by the small arrows. Force of this
jet gives arotative assist to the impeller, while also build-
ing
pressure in sealed space (B). Rotation continues to
Position 3, where volume (B) is delivered to the discharge
chamber in
the same manner as volume (A) in Position 1.
Because of the almost complete pressure equalization
through
the slot, no sudden shock occurs at this point.
One complete revolution
of the driving shaft
alternately traps four fixed and equal volumes of air (two
by each impeller) and pushes them through
to the
discharge. The pumping capacity of alobe blower operating
at aconstant speed therefore remains relatively independ-
end of reasonable inlet or discharge
pressure variations. To
change capacity, it is necessary to change speed of rotation.
No attempt should ever be made to control capacity by
means of a
throttle valve in the intake or dishcarge piping.
This will not only increase
the power load on the driver,
but can also overload and seriously damage the blower.
Likewise, if apossibility exists
that flow to the blower inlet
may be cut off during normal operation of aprocess,
then
an adequate vacuum relief valve must be installed near the
blower. Apressure type relief valve in the dishcarge line
near
the blower is also strongly recommended for
protection against cut-off
or blocking in this line.
When abelt drive is employed, blower speed can
usually be adjusted
to obtain desired capacity by changing
the diameter of one or both sheaves, or by using a
vari-speed motor pulley.
In adirect coupled arrangement, a
variable speed motor or transmission is required. or excess
air may be blown off
through amanually controlled
unloading valve and silencer. See Figure
3. If returned to
the blower inlet, air must be cooled to lOooF (38°C)
through aby-pass arrangement.
Before making any change in blower capacity, or
operating conditions, contact the
nearest Roots Sales Office
for specific information applying
to your particular blower.
In all cases, operating conditions must be maintained
within
the approved range of pressures, temperatures and
speeds as
stated under LIMITATIONS. Also, the blower
must not be used to handle air containing liquids or solids.
Serious damage to the rotating parts will result.
To permit continued satisfactory. performance, a
blower
must be operated within certain approved limiting
conditions. The manufacturer's
warranty is, of course, also
contingent
on such operation. Maximum limits for
pressure,
temperature and speed are specified here for
various blower sizes when operated under
standard
atmospheric conditions. Do not exceed anyone of these
limits.
Example: The listed maximum allowable temperature
rise (increase in air temperature between inlet and
Position 1 Position 2
Position 3
Figure 1. Air Flow Through AWhispair Blower
2

Table 3 - Maximum Speeds
must be reduced by 2/3 of the difference between
ambient and the actual measured inlet tempera-
ture.
B. Average of inlet plus discharge temperature should
not exceed 250°F. (121°C), except
that frame 1701
is limited
to 145° (63°C) average.
C. Maximum discharge temperature for frame 1701 is
190°F. (88°C).
For J-series frames the maximum is
320°F. (160°C).
SPEED RANGE -Whispair blowers may be operated at
speeds up to the maximums listed here for the various
frame sizes. They may
be direct coupled to 3550 RPM
motors, or to 1750 motors if
pressure/temperature
conditions are within limits. At ,lower speeds, excessive
temperature rise may be the principle consideration.
Roots blowers are internally
treated at the factory to
protect against normal atmospheric corrosion before
installation. Maximum period of protection is one
year
under average conditions, if plugs or seals are not
removed. Protection against chemical or salt water
atmosphere is not provided. Do not remove seals until
ready
to start installation, as protection will be lost by
evaporation.
NOTE - If there is to be an extended period between
installation and startup, the following steps should be taken
to insure corrosion protection:
1. Coat internals of cylinder and gearbox with
Motorstor or equivalent.
Repeat once a year or as
conditions may require. Motorstor is oil soluble and
does not have to
be removed before lubricating. If
desired, Motorstor may be removed from within the
cylinder shortly before startup by spraying afine
mist of petroleum solvent
through the blower while
it is running
at aslow speed with open inlet and
discharge, or
it can remain in the blower if it is not
harmful
to the operation of the connected system.
Motorstor is aproduct of
Daubert Chemical Co.,
2000 Spring Rd., Oak Brook, Ill. 60521.
2. Fill drive end bearing cavities with grease as
specified in lubrication section.
3.
Paint shaft extension and all other exposed
machined surfaces with Nox-Rust X-145 or equiva-
lent.
4. Seal inlet, discharge, and all vent openings with
tape. It is not recommended that the unit be set in
place, piped
to the system, and allowed to remain
idle for
extended periods. If any part is left open to
atmosphere,
the Motorstor vapor will escape and
lose
its effectiveness.
5. Units are not to be subjected to excessive vibration
during storage.
If stored outdoors, provide coverage
such as atarpaulin
or lean-to.
3500
4360
7100
4970
3550
Maximum RPM
Frame Size
1701
1702, 1704, 1707
1702J, 1704J, 1707J
2504J,2506J,2510J
3505J, 3509J, 3514J
Table 2 - Allowable Temperature Rise
TEMPERATURE -Various blower frame sizes are
approved only for installations where the following
temperature limitations can be maintained in service.
A. Maximum
temperature rise (T.R.) in Fahrenheit
degrees (CO) must not exceed listed values when
the inlet is at ambient temperature and not higher
than lOooF (38°C). Ambient is considered as the
general temperature of the space around the
blower. This is not outdoor temperature unless the
blower is installed outdoors.
Note -
If inlet temperature is higher than lOooF.
(38°C),
the above allowable temperature rise values
discharge) for any particular blower may occur well before
the maximum speed or maximum pressure rating is
reached.
Temperature rise then is the limiting condition. In
other words, the operating limit is always to be determined
by
the maximum rating reached first, and it can be anyone
of the three: pressure, temperature or speed.
Be sure to arrange connection or taps for ther-
mometers and mercury type pressure or vacuum gauges
near the inlet and discharge connections of the blower.
These, along with agood tachometer, will enable periodic
checks of operating conditions to
be made easily.
Note -specially ordered blowers with non
standard
construction, or with impeller end clearances greater than
shown in Table 6, will not have the operating limits
specified here. Contact your Roots Sales Office for specific
information.
PRESSURE - On pressure service, the pressure
differential in pounds per square inch, (kPa) between
blower inlet and discharge, must not exceed the figure
listed below for
the specific blower frame size concerned.
Also, in any
system where the blower inlet is at apositive
pressure above atmosphere, the discharge pressure must
never exceed 25 PSI (172 kPa) gauge regardless of blower
size.
On vacuum service, with the discharge going to
atmospheric pressure, the inlet suction or vacuum in inches
of
mercury (kPa) must not be greater than the values listed
for
the specific frame size.
Table 1 - Allowable Pressure Conditions
Max. Differential
Max. Inlet
Frame Size Pressure -
PSI
Vacuum-Ins. Hg.
(kPa) (kPa)
1701 5(34)
N/A
1704 6(41) 8(27)
1702J 10 (69)
14 (47)
1702,2504J,3505J
10 (69)
12 (40)
1704J,2506J,3509J 6(41) 12 (40)
1707,1707J 4(28) 6(20)
2510J 4(28)
8.5 (29)
3514J 4(28) 8(27)
Frame
T. R.
Frame T. R.
Size
F. ° (CO)
Size
F. ° (CO)
1701 90 (50) 2504J 250 (139)
1702 320 (178) 2506J
140 (78)
1704
125 (69) 2510J 90 (50)
1707 60 (33) 3505J HJU
(lU~)
1702J 320 (178) 3509J 135 (75)
1704J
125 (69) 3514J 90 (50)
1707J 60 (33)
3

K-20394
..
DISCHARGE
-~-- UNLOADING VALVE
DISCHARGE SNUBBER
~
ROVIDE CONNECTIONS FOR
THERMOMETERS AND PRESSURE OR
- ~~~~U~N~~?SEcSH~~~~~ TO BLOWER
IPRESSURE RELIEF VALVE
\r ~ CHECK VALVE
~~~':t=6
CROSS
''-,L FLEXIBLE CONNECTORS
i_ ALTERNATE ARRANGEMENT
OF INLET
DRY TYPE
INLET FILTER
[
INLET CLEANER-
SILENCER
INLET
SILENCER -- _
Whispair blowers normally have aflattened bulge on
one side of the cylinder with apipe connection extending
from it, as shown
in Figure 1. These units must be driven
with the correct rotation
to make this connection the
discharge. Figure 2shows the standard drive shaft
locations as viewed from
the drive end, and the correct
counterclockwise direction of rotation. For special con-
struction (drive shaft
at the top or right), correct rotations
would be opposite or clockwise. An arrow near
the shaft
indicates
the rotation to be used. Some few blowers (1701,
1702,1704,1707) do not have cylinder bulge. These may be
operated in either direction, as necessary
to produce
discharge
at the more convenient connection.
Piping should
be accurately squa~ed with the blower,
supported independently, and sized no smaller than
the
connections on the blower. Use only clean, new pipe and
make certain
it is free of scale, cuttings, weld beads, dirt or
any
other foreign material. To guard against damage to
blower, especially when an inlet filter is not used, install a
screen of
16 mesh backed with hardware cloth at or near
the inlet opening. Make provisions to clean the screen of
collected debris
after afew hours operation, and
periodically thereafter. Install an inlet filter in dusty or
sandy locations.
Figure 3shows atypical complete installation of
blower and accessories where quietest operation is wanted.
Note
the absence of throttle or shut-off valves in either
dishcarge or intake piping.
If it is possible for air flow to be
cut off in either
of these lines, make provisions to add a
pressure and/or vacuum relief valve as discussed under
OPERATING CHARACTERISTICS.
Figure 3. AComplete Blower Installation, With
Alternate Inlet Arrangement
In some installations it may be desirable to use only an
inlet silencer-cleaner supported directly from
the blower
connection. This is shown as an
alternate arrangement in
Figure 3. Weight must be kept to aminimum to prevent
blower casing distortion when the inlet is on the side.
Ablower may be driven by direct coupling
to the
driver, or by V-belt to obtain other speeds within the
approved range. Refer to LIMITATIONS before selecting
the drive speed. Also, be sure to arrange for suitable
protective guards as discussed in PRECAUTIONS.
Lubricated couplings
are the preferred type, but
Lovejoy Type Lor similar non-lubricated type may also be
used. Coupling halves
must correctly fit blower and driver
shafts, so
that only light tapping is required to install each
half. The two shafts
must be as accurately aligned as
possible, both horizontally and vertically,
to limit operating
strain on either shaft.
Proper gap between coupling halves
must be established with the motor armature on its
electrical center. This will minimize the chance for end
thrust on the blower shaft.
Figure 2. Rotation and Discharge For Standard
Blower
t0
6. Rotate drive shaft three or four revolutions every
two weeks.
7. Prior to startup, remove flange covers on both inlet
and discharge and inspect internals
to insure
absence of
rust, check all internal clearances. Also,
at this time, remove gear cover and inspect gear
teeth for rust.
Install blower in aprotected indoor location, if
possible. However, an unprotected outdoor installation will
be satisfactory if correct lubrication for expected
temperatures is provided. Just before starting the
installation, remove plugs or covers from inlet and
discharge connections. Inspect for
dirt or foreign objects
inside
the blower, then turn dirve shaft by hand to make
sure that it rotates freely.
Mount blower in alevel position. Use of arigid, solidly
supported, smooth flat plate is recommended. Make
sure
blower feet rest evenly on the plate before fastening down.
Twisting
or cramping the blower in mounting will cause
impeller contact and binding during operation.
On blowers
having
two feet, loosening the the screws (Item 123) into
the headplate flanges should permit adjusting
the feet for
even contact with
the plate. Then fasten both feet to the
plate with screws and lockwashers, and retighten the
headplate screws carefully. On blowers with four feet, this
procedure may not be successful. Shimming
under one or
more feet may then be required
to produce asolid
mounting.
Ablower factory-mounted on abase should not require
the above adjustments. The assembly can become twisted
in shipping, however, and it might be wise to loosen the
foot hold-down screws to check foot contact with the
mounting surface. The base should then be mounted on a
solid foundation or heavy flooring, using shims as necessary
at bolting points to prevent warping the assembly.
Transmission of small operating vibrations to a
supporting
structure in some cases may be objectionable.
Use of vibration isolators,
or vibration absorbing materials,
can be effective in overcoming this problem. To avoid
blower casing distortion,
the treatment used should be
applied under the motor-blower common mounting plate or
base,
rather than directly under the blower feet alone.
Blower feet
are detachable to allow converting aunit
having side connections
to one with top and bottom
connections. Smaller units
(1700 and 2500 series) have only
one foot on each end. These
must be unbolted and
transferred individually to the opposite ends when making
this conversion
.. On larger blowers having four feet, the
two at each end are unbolted and moved 90
0to new
positions on
the same end. Units arranged for flange
mounting directly
to C-Frame electric motors are available
only with side connections.
4

In aV-belt drive, the blower sheave must fit its shaft
accurately, run true, and be mounted not more than 1/ 4 " (7
mm) from bearing housing. A tight or driving fit will force
the blower impeller out of its normal position and cause
internal damage. Aloose fit will probably result in shaft
damage or breaking. The motor sheave must also fit
correctly, and
be properly aligned with the blower sheave.
Failure to accomplish this will result in the blower impeller
being forced
against one of the head plates during
operation, causing serious damage to the blower.
Adjust motor position on its sliding base so that belt
tension is in accordance with the drive manufacturer's
instructions. Avoid excessive belt tension at all times.
Recheck tension
after the first ten hours of operation, and
periodically
thereafter, to avoid slippage and loss of blower
speed.
Check blower after installation, and before applying
power,
by rotating the drive shaft by hand. If it does not
rotate freely, look for uneven mounting, piping strain,
excessive helt tension or coupling misalignment. Do not
operate the blower at this time because there is no oil
supply in
the gear hou.se. Read LUBRICATION section.
The oil change interval will depend on the oil operating
temperature and the type of oil. For agood grade
industrial type non-detergent oil with ablower discharge
temperature of less than 250°F, (121°C) oil change should
be made
every 1,000 operating hours. For blower discharge
temperatures of higher than 250°F (121 DC), more frequent
oil changes will be required.
Shaft bearings at drive end of blower are grease
lubricated. All Whispair Max blowers have pressure type
grease fittings in the bearing housings. Only greases
Table 5 - Oil Sump Capacities
Blower Top and Bottom
Side
Frame Series Connections (liters) Connections (liters)
1700 2-7/8
fl. oz. (.085) 3-1/8 fl. oz. (.092)
2500 8-1/2 fl. oz. (.251) 6-5/8 fl. oz. (.196)
3500
11 fl. oz. (.325) 8-5/8 fl. oz. (.255)
classified as NLGI Group II high temperature greases with
synthetic bases should be used. Among these are Aero
Shell 16 and Mobil Grease 28. Mixing of soap base .and
synthetic base greases destroys the lubricity of both with
resultant failure of the bearings. Drive end bearings must
be greased prior to initial start-up. Aregular greasing
schedule should be maintained per Table 6.
Check gear house oil level every week and add oil if
needed. Do not check or fill
oil while the blower is running.
Blower Size Greasing Interval
]70], 1707, 1707-J 700 operating hours
25]0-J,35]4-J
]704, 1704-J, 2506-J 300 operating hours
3509-J
]702, 1702-J, 2504-J 150
Operating hours
3505-J
Table 6
Before starting the blower for the first time under
power, recheck the installation thoroughly to reduce the
likelihood of troubles. Use the follQwing check list as a
guide, but also consider any other special conditions in your
installation.
1. Be certain no bolts, rags or dirt have been left in the
blower casing.
2. Be certain that inlet piping is free of debris. If an
open outdoor air
intake is used, be sure the opening
is clean and
protected by a strong screen.
3. If installation is not recent, check blower leveling,
drive alignment,
belt tension, and tightness of all
mounting bolts.
4.
Be certain the proper quantity of oil is in the gear
house.
5. Be certain the driving motor is properly lubricated,
and that. it
is connected through suitable electrical
overload devices.
6.
Rotate blower shaft several times by hand to make
sure impellers are free at all points, with no rubbing
or bumping.
7. Check
motor rotation by momentarily pushing the
start button. If not in accordance with arrow on
blower,
reverse the motor connections.
Initial operation should be carried out under "no load"
conditions by opening all valves and
venting the discharge
to atmosphere, if possible.
Then start motor briefly, listen
for unusual noises, and check
the blower coasts freely to a
stop. If
no problem appears, repeat this check and let
Blower with Side Connections
K-203~
OIL DRAIN
-OIL LEVEL HOlE\
Blower with Top/Bottom Connections
\OIL FILL HOLE
\
VENT
Shaft bearings at the gear end of the blower are splash
lubrieated by one or both gears dipping into an oil sump
formed in the headplate. Before starting the blower, fill
this
sump as instructed below:
Figure 4. Gearhouse Oil Filling
1. Remove oil fill plug (item 140, Fig. 6, 7, and 8) from
the gear end headplate. Also remove oil level plug
from the gear cover.
2. Pour oil through fill hole slowly till the oil starts to
run out of oil level hole.
3. After the oil has stopped running out of oil level
hole, replace
the oil fill and level plugs. Apply Per-
matex No. 2 or an equivalent sealant on oil level
plugt.hreads prior to installation.
Recommended
oil grades for various operating
conditions are listed in Table 4. Quantities required to fill
sumps in
the different blower frame sizes for either vertical
or horizontal piping arrangements are listed in Table 5.
Table 4 - Recommended Oil Grades
Ambient Discharge Viscosity Approx.
Temperature Pressure-PSIG
SSU lOO°F. SAE No.
(kPaG) (38°C)
Below
~lOoF (32°C) Below 2.0 (14)
500-700
30
Over gO°F (32°C) Below 2.0 (14)
700-1000
40
Below !lO°F (32°C) Over 2.0
(14)
700-1000
40
Over 90°F (32°C) Over 2.0
(14)
1000-1200 50
.-tt--
5

the motor run alittle longer. If any questions exist,
investigate before proceeding further.
Now operate the unit for about 10 minutes. During this
run feel cylinder and headplates for development of hot
spots that indicate rubbing contacts. Also listen for
knocking sounds (contact between impellers), and watch for
any change or
increase in vibration. At the end of this run,
check the inlet screen near the blower for collected debris.
After above tests are completed and any necessary
corrections made, afinal check run of a least one hour
should be performed under normal operating conditions.
Start unloaded as above, and apply the system pressure
load gradually by closing the discharge atmospheric vent.
Use a mercury manometer connected to the discharge
piping
to see that the pressure rating of the blower in not
exceeded. Also use good thermometers to determine the
temperature rise through the blower. Both figures should
satisfy the conditions listed under LIMITATIONS. Check
the unit frequently during this run. Shut dowl! immediately
if excessive noise or
heating develops and refer to
TROUBLE SHOOTING CHECK LIST.
Assuming all tests are satisfactory, the blower will
now be ready for continuous full load operation. During the
first several days, make periodic checks to determine that
all conditions remain acceptable and steady. These checks
may be particularly important if the blower is part of a
process
system where conditions may vary. At the first
opportunity, stop the blower and clean or remove the inlet
screen. Also recheck leveling, coupling alignment or belt
tension, and mounting bolts for
tightness.
If operation proves that blower capacity is alittle too
high for the actual air requirements, a' small excess may be
blown off through the manual vent valve. It is not good
practice
to use the pressure relief valve as an automatic
vent. Such use may cause. the discharge pressure to become
excessive, and can also result in failure of the valve itself.
If the blower capacity is low, it may be possible to increase
the drive speed. Before attempting this change, contact the
TROUBLE SHOOTING CHECKLlS't
ITEM POSSIBLE CAUSE
1 Speed too low
2
Wrong rotation
3
Obstruction in piping
4
Speed too low
5 Excessive pressure rise
TROUBLE
No AirFlow
Low Capacity
Excessive
Power
Overheating
of Bearings
or Gears
Vibration
6
7
8
9
10
11
12
13
14
15
16
17
18
19
Obstruction in piping
Excessive slip
Speed too high
Pressure too high
Impellers rubbing
Inadequate lubrication
Excessive lubrication
Excessive pressure rise
Coupling misalignment
Excessive belt tension
Misaligmpent
Impellers rubbing
Worn bearings/gears
Unbalanced or rubbing
impellers '
REMEDY
Check by.tachometer and .c01npare with speed shown on
Roots
Order Acknowledgment.
Compare actual rotation with Figure 2. Change driver if
wrong:
Check piping, screen, valves, silencer
to assure an open
flow
path.
See item 1. If belt drive, check for slippage and readjust
tension.
Check inlet vacuum and discharge
pressure, and com-
pare these figures with specified operating conditions
on
Order.
See item 3.
Check inside of casing for
worn or eroded surfaces caus-
ing excessive clearances.
Check
speed and compare with Roots Order.
See item 5.
Inspect outside of cylinder and head plates for high tem-
perature areas, then check for impeller contacts at these
points.
Correct blower mounti~.g, drive alignment.
Check oil
sump level in· gearhouse, and try to inject
grease in drive end bearings.
Check
gear oil level. If incorrect, drain and refill with
clean oil of recommended
grade.
See item 5.
Check carefully. Realign if questionable.
Readjust for correct tension.
Seeitem 14.
See item 10.
Check
gear backlash and condition of bearings, and re-
place as indicated.
Scale or process material may build up on casing and im-
pellers,
or inside impellers. Remove buildcup to restore
original clearances and impeller balance.
6

nearest Roots Sales Office for recommendations based on
actual
requirements and operating pressure/temperature
conditions.
For equipment covered specifically or indirectly in this
instruction book, it is important that all personnel observe
safety precautions to minimize the chances of injury.
Among many considerations, the following should particu-
larly be noted:
•Blower casing and associated piping or accesories may
become hot enough to cause major skin burns on
contact.
• Internal and external rotating parts of the blower and
driving equipment can produce serious physical inju-
ries. Do not reach into any opening in the blower while
it is operating, or while subject to accidental starting.
Cover external moving parts with adequate guards.
• Disconnect power' before doing any work, and avoid
By-passing or rendering inoperative any safety or
protective devices.
• If blower is operated with piping disconnected, place
a
strong coarse screen over the inlet and avoid stand-
ing in the discharge air stream.
• Stay clear of the blast from pressure relief valves and
the suction area of vacuum relief valves. -
•Avoid extended exposure in close proximity to
machinery with high intensity noise levels.
• Use proper care and good procedures in handling,
lifing, installing, operating and maintaining the equip-
ment.
•Casing pressure must not exceed 25 PSI (172 kPa)
gauge. Do not pressurize vented cavities from an exter-
nal source, nor restrict the vents.
•Do not use air blowers on explosive or hazardous gases.
• Other potential hazards to safety may also be
associated with operation of this equipment. All per'
sonnel working in or passing through the area should
be warned by signs and trained to exercise adequate
general safety precautions.
Regular inspection of the blower and its installation,
along with complete checks on operating conditions, will
pay
dividends in added life and usefulness. Particular
attention should be paid to lubrication of timing gears and
hearings in accordance with comments under LUB1tICA-
'fION. Also service the driver per manufacturer's
instructions, and lubricate the coupling or check belt drive _'
tension. By use of thermometers and guages, make sure
that hlower operating temperature and pressure remain
within allowed limits.
When ablower is taken out of service it may require
internal protection against rusting or corrosion. The need
for such
protection must be a matter of judgement based on
existing conditions as well as length of down-time. Under
atmospheric conditions producing- rapid corrosion, the
hlower should be protected immediately. Treatment
7
consists of spraying or flushing the interior with a mixture
of light oil and keroesene. Before restarting, check internal
condition visually and rotate the drive shaft by hand.
Should adjustments or replacements eventually be
needed, these can often be performed locally as described
in this book, after obtaining required parts. Personnel
should have agood background of mechanical experience
and be thoroughly familfar with these instruc:tions. Major
repairs not covered in this book should be reJfrred to the
nearest Sales Office or Distributor.
When ordering parts, give all blower; nameplate
information, plus the Item Numbers and Na~es as taken
from the appropriate assembly drawing in, this book.
Numbers shown in brackets ( ) in the following repair
procedures correspond to Item Numbers in theprawings.
REPLACEMENT OF GEARS
BEARINGS, SEALS, IMPELLERS AND SHAFTS
1. Remove sheave or coupling from blower drive shaft.
2. Drain oil from gear house by removing lower pipe
plug (111).
3. Remove g-ear cover plate (6), being careful not to
damage gasket (11) ..
4. Remove both gear :elamping nuts (102). Lock
impellers by
wedging 'between lobes to prevent
rotation while loosening nuts.
5. Loosen all cap screw,s, (107) and (124) in drive end
headplate. Insert jack.~crews in threaded holes and
01111 headplat~ away from cylinder about 1/4" (7
mm).
H. At gear end, drive both impeller shafts toward
headplate to loosen gears from taper fits, and
remove gears: Avoid;,iiJamaging shaft threads by
using- a soft metal, pl'lstic or wood mallet.
7.
Remove drive end headplate (1) and cylinder (3),
and pull both
impellers (4) and (5) out of the gear
end headplate.
R. Rt'move all bearings (100, 101) from both head-
platt's. They should be easily removable by inserting
afing-er or an expandill,g tool in the shaft hole.
Bt'arings at the gear end can be damaged during
gt'ar removal, and it is advisable that all four
lwarings be replaced when a blower is torn down.
9. Removl' all 'shaft seals (117, 118) from both
.hl'adplates by driving out with awood dowel
insPl'ted through thC'shaft holes from thl' rear.
1O.Install nl'W replaeenlC'nt sl'als in one or both
heanplatl's, as requiren by the design. After
lubricating- the outer I'dlfE\ position seal over its
rl'cess with the -shaft sl'aling- lip facing out as shown
in ,Issembly drawing. The'n prl'ss evenly into plael'
until Ihe
spal faee is even with face of recess.
Lubricate seal lip with light g-rC'ase.
1"1. Assemblp ~war t'nd headplatp (2) to eylinder (3).
, , Make sun' dpwC'1 sleeves (108) are in place in the
two alignnwnl ~oles in flange l'ars, then insert short
S<TPWS in thesp holps and tighten. On 1700 Series
blowers Iht'st", two :scn'ws will be removed when
. gt'ar coVP!' is installed with long serl'Ws.

12. Set this assembly on aflat surface plate, with the
open end of the cylinder up. Insert both impellers,
taper end of shafts first, being careful to avoid
damage
to seal lips. Make sure the longer (driving)
-
shaft is in either the bottom or left hole in relation
to blower feet.
See Figure 2.
13. Assemble drive end headplate (ll to the cylinder
over
its dowel sleeves (l08). Insert and tighten all
cap
screws in both headplates.
FEELER J~
-
-r--WEDGE
~ .. -
HAFT
K-20J97
14. To install bearings correctly in both headplates, first
determine how back clearance "X" shown in the
assembly drawing is to be provided. To do this,
measure the thickness of the bearing and _add
dimension
"X," 1/32" or 1/16" (.08 or .16 mm)
depending on blower size.
Then measure the depth
of the head plate recess. Any difference between
these two figures will be the amount the bearing
face should project beyond the headplate face. If
there is no difference, the bearing should be flush.
Apply alight film of oil on
bearing fits prior to
pressing bearings on shafts.
15.
Press bearings into the headplates as determined
above, using an aligning tool that will pass over the
shaft and push on both inner and outer races at the
same time. This will keep the bearings square with
the headplate. Note that open bearings are used
only in
the gear end headplate. The drive end
requires bearings sealed on one side, with the sealed
face placed on
the outside. Degrease shaft and gear
tapers.
16. Install new driven gear (upper shaft or left shaft
when facing gear end of a standard unit.') Oil shaft
threads lightly and tighten gear clamping nut with a
torque wrench to the value listed in Table 7. Asmall
hardwood ';"edge
between impeller lobe and cylinder
opening will
prevent shaft from turning.
Table 7 - Gear Nut Torque
Frame Series Nut Torque (Kg-m)
1701 (only) 10 lb.-ft. (1.5)
1700
25 lb.-ft. (3.5)
2500
75 lb.-ft. (10)
3500 190 lb.-ft.
(26)
17. Install new driving gear after first positioning
impellers correctly in relation to each
other as
shown in
Figure 5. With both impellers at 45°,
insert along metal feeler gauge between the two
adjacent lobes and clamp it there by pushing small
hardwood wedges
between the back sides of these
lobes and the cylinder openings. Feeler gauge
thickness should be amiddle value
taken from the
last column in Table 8. Now install the gear,
observing tooth match
marks if present, and tighten
the nut lightly.
18. Remove wedges and feeler gauge,
then rotate
impellers to determine lobe clearances at all (four)
8
Figure 5. Wedging of Impellers, Viewed From
Gear End
45° positions. They should be 'approximately equal,
and within
the range listed for the blower size.
Adjust gear position if necessary, then insert the
corrected feeler and wedges and tighten the gear
nut to full torque. Spin the drive shaft by hand to
make
sure there are no gear tight spots or impeller
contacts.
19. Install
gear cover plate (6) with gasket (11). Use the
original special gasket if in good condition, or a
factory replacement, positioning it to match
the
headplate shape. If it is necessary to make a
replacement, be
sure to use material of the original
thickness and
cut it to duplicate the original shape
exactly. This will produce
the oil metering orifice
required between outer and inner sections of the on
sump, without which gears and bearings will run
dry.
20. Replace oil
drain plug (111) and refill gear house
with
proper grade of oil as discussed under
LUBRICATION.
21. Reinstall drive
sheave or coupling half, and remount
blower in correct alignment with driver. Refer to
discussion
under INSTALLATION.
Table 8 - Standard Whispair Blower Clearances -
Inches
(mm)
Frame Impeller End Impeller Tip Impeller Lobes
Size To Headplate To at 45°
Total Both Ends Cylinder see Fig. 5
1701 .002-.005
(.05-.13) .0015-.003(.04-.08 .006-.008(.15-.20)
17021 J .004-.008(.10-.20) .003 -.005(.08-.13 .006-.008(.15-.20)
1704/J .007-.010(.18-.25).003 -.005(.08-.13 .006-.008(.15-.20)
1707/J .007-.01 O( .18-.25) .003 -.005(.08-.13 .006-.008(.15-.20)
2504J .007-.010 (.18-.25) .004
-.006(.10-.15 .008-.010(.20-.25)
2506J .007-.010
(.18-.25) .004 -.006(.10-.15 .008-.010(.20-.25)
2510J .007-.010
(.18-.25) .004 -.006(.10-.15 .008-.010(.20-.25)
3505J ,.005-.009 (.13-.23) .005 -.007(.13-.18
.009-.012(.23-.30)
3509J .007-.010 (.18-.25) .005 -.007(.13-.18 .009-.012(.23-.30)
3514J .007-.010
(.18-.25) .005 -.007(.13-.18 .009-.012(.23-.30)
Note -Clearances listed above are used in assembly at the
factory. They may change in service, but should never be
less
than the minimum values. Only well qualified
personnel should
attempt to measure clearances.

126
124
Imm
3500 MODELS HAVE FOUR FEET
126 124
120
139
139
136
136
137
137
114
113
114
138
123
100
4
104
107 3
135
...J u,
15
4 14
CAPSCREW AND ~
LOCKWASHER BY CUSTOMER
15
117
II
101
/41
7-_
105
133--_
138
III
1700 SERlES~
103 6
NOTE: ITEM NQ 104 NOT
US'ED ON 2500 SERIES.
ITEM NAME ITEM
NAME ITEM NAME
I HEADPLATE D.E.
101
BEARING G.E. 117 SEAL
G.E.
2
HEADPLATE G.E. 102 NUT- STOP
118 SEAL
D.E.
3
CYLINDER 103 SCREW- CAP
120
FITTING - GREASE
4
IMP. & SHAFT - DRIVE
104
NUT (SEE NOTE)
123 SCREW- CAP
5
IMP. & SHAFT - DRIVEN
105 SCREW-CAP 124 SCREW- CAP
6
CCNER- GEAR
106
SCREW- CAP 126
WASHER- FLAT
7
GEAR
107
SCREW- CAP
127 PLUG - EVEI ET
9
NAMEPLATE
108
SLEEVE-DOWEL
133
LABEL-LUBRICATION
II
GASKET - GEAR COVER
110
SCREW - MACHINE
135
WASI-£R -LOCK
14 FOOT - RIGHT HAND III PLUG - PIPE (DRYSEAL)
136 ARROW - ROTATION
15
FOOT -LEFT HAND
113 KEY - SQUARE
137
SCREW - DRIVE
100
BEARING
D.E.
114
COVER - PROTECTIVE
138 LABEL- WHISPAJR
141 BREATHER- OIL
140
PLUG - PIPE (OIL FILLER)
139 BEARING COVER
TYPICAL
3500 SERIES
WHISPAIR MAX BLOWER 847-506-022
Figure 6. Assembly of J-Series Whispair Max Blowers

CAPSCREW AND
LOCKWASHER BY CUSTOMER
114
123
104
135
15
137
/139
,-J
124 126
<~
//
1/
'/
!/
1'0
3
114
138
139
14
Liol 117 15 4
......
o
~
NAME
ITEM NAME ITEM NAME
I
HEADPLATE - D. E. 100 BEARING - D. E.
113 KEY-SQUARE
2 HEADPLATE - G. E. 101 BEARING - G.E. 114 COVER - PROTECTIVE
3 CYLINDER 102
NUT-STOP
117 SEAL - G.E.
4
IMP. & SHAFT - DRIVE 103 SCREW- CAP 118
SEAL -D.E.
5
IMP. & SHAFT - DRIVEN
104 NUT 120
FITTING - GREASE
6 COVER -GEAR 105 SCREW-CAP 123
SCREW-CAP
7
GEAR
138 LABEL- WHISPAIR
124
SCREW-CAP
9 NAMEPLATE 107 SCREW-CAP
126
WASHER-FLAT
II
GASKET-GEAR COVER 108
SLEEVE - DOWEL
127 PLUG -EYELET
14
FOOT - RIGHT HAND
110
SCREW - MACHINE
133
LABEL-LUBRICATION
15 FOOT-LEFT HAND
III
PLUG -PIPE (DRYSEAL)
135 WASHER - LOCK
140 PLUG-PIPE (OIL FILLER) 137 SCREW-DRIVE
f39
BEARING COVER
141
BREATHER - OIL
847-254-022
WHSPAIR MAX BLOWER
Figure 7. Assembly of 1700Series Conventional (162) Whispair Max Blowers

712t:
118 113
129
Imm
Imm
Imm
TYPICAL
3500 SERIES
847-653-023
2500 I,
1700 113
3500
DIMENSION .. X'
130
131
S
108 124
4 126 120
136 a. 137 NOT USED ON 7
108
103
2
6
133
LOCKWASHER
1~--1I4
105
BY CUSTOMER
l
·· '"
CAPSCREW &
6
ITEM NO. I
00 SERlE
ITEM NAME ITEM NAME ITEM NAME
IHEADPLATE-
D. E. 100 BEARING -D.
E.
117
SEAL-G.E.
2HEADPLATE- G.E.
101
BEARING- G.E.
118
SEAL-D.E.
3CYLINDER
102
NUT- STOP 120
FITTING- GREASE
4
IMP. &SHAFT- DRIVE 103
SCREW-CAP
124
SCREW-CAP
5
IMP. &SHAFT- DRIVEN
105
SCREW-CAP
126
WASHER-FLAT
6COVER- GEAR
107
SCREW-CAP
127
PLUG- EYELET
7GEAR
108
SLEEVE -DOWEL
128 COUPLING .
9NAMEPl ATE
110
SCREW- MACHINE 129 KEY- SQ. (MOTOR)
II GASKET· GEAR COVER
III PLUG- PIPE 130 MOTOR
106
SCREW-CAP
113
KEY-SQ. (BLOWER)
131
SCREW-CAP
133 LABEL-LUBRICATION
114
PROTECTIVE PLUG
138
LABEL -WHISPAIR
136 ARROW- ROTATION 137 SCREW-DRIVE
III
110 II
130
114-_--J1
...
...
Figure 8. Assembly of Motor-Mounted Whispair Max Blowers