Ranipet

AXIAL FAN
(TLT DESIGN)

SINGLE STAGE

OPERATION & MAINTENANCE

MANUAL

Prepared by Checked by Approved by

Hitesh Kumar T S Selvaraj M. Desigan

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Ranipet Axial Reaction Fan – Single Stage (TLT)

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Ranipet Axial Reaction Fan – Single Stage (TLT)

4.1 Pre-Commissioning Checks

Before commencing commissioning activity on the Fan, the following points should have been
verified. Some of the check points may not be possible to be verified after completing the
assembly of the Fan. However, the connected agencies should confirm that these have been
ensured during various stages of erection.

Ensure The Following

 The bases of Fan parts are tightened without strain.

 Tightness of all foundation bolts of Fan / motor.
 Tightness of connecting bolts of bearing housing and impeller housing.
 Verticality of impeller housing / horizonitality of shaft within 0.04 mm/m.
 The impeller blades are of the same series, also ensure that the blades are mounted in the
serial order and that the rounded nose of the blades are on the suction side of each
impeller.
 Tightness of blade fixing screws to the required torque values.
 Radial clearance of blade tip with respect to longest blade. Radial clearance of blade root
and impeller hub for both full open and full close positions of blades.
 Axial gaps between rotor and stator parts.
 Match marks on the coupling parts.
 Tightness of coupling bolts of spring shackle coupling.
 Correct setting of coupling gap.
 Alignment of couplings to be within 0.05 mm.
 Correct assembly of links.
 Acid cleaning of all incoming and outgoing oil pipes.
 Gravity inclination of all returns oil pipes.
 The oil tank is adequately filled with correct quality of oil.
 Early commissioning of the oil system to facilitate checks on the impeller.
 Proper connection of inlet and outlet of lube oil piping to the main bearings.
 Proper connection of oil pipes to the hydraulic adjustment device assembly.
 There is no pre-load in hydraulic adjustment device assembly introduced by flexible hoses.
 Linearity of blades position w. r. t . local / control room Indication.
 Fixing of Locking Plate for hydraulic adjustment device
 Proper setting of mechanical stoppers.
 Rotate rotor by hand and ensure free rotation without any mechanical rubbing.
 Removal all transport stiffeners (Yellow painted).
 Calibration of all instruments for Fan, Motor and Lube oil system.
 Proper functioning of interlocks / protections.

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Ranipet Axial Reaction Fan – Single Stage (TLT)

 Proper assembly of all expansion joints.

 No foreign matter is left inside Fan casing.
 No loose pieces are found in the suction side ducting of the Fan.
 Precautions laid down by Motor/Oil system suppliers are complied with.
 Start lube oil pump and allow it to run for about two hours. Clean filters. Check level in
the tank. Ensure proper oil flow. Check the pressures and setting of relief valve.

 Check proper functioning of “Emergency Off” switch.

 Proper direction of rotation of motor.
 Never run the Fan/Motor with out protections / interlocks.

4.2 Start Up and Operation

In this chapter, the starting sequence for the Fan is described as individual equipment. For details
connected with the boiler system, refer Fan panel control diagram provided in the boiler control
and instrumentation manual. Protection interlocks for drive motor shall be as recommended by
the respective supplier.
START SEQUENCE OF THE FAN:

a) Control oil pressure :

Kindly refer Lub Oil Scheme Drawing for your project.
b) Lub oil pressure :
c) Tank oil level > 50%
d) Bearing temp < 95 deg C
e) Impeller blades position : Close
f) Discharge damper/gate : Close
g) Fan Motor : ON

ALARM & TRIP VALUES

When the fan is kept under service, the following values may be applied as reference limit and in
case the values are found exceeding, suitable corrective actions may be carried out to maintain
the following values below alarm limit.

DESCRIPTION ALARM TRIP

Fan Bearing Temperature ≥ 95 deg C ≥ 105 deg C
Fan Bearing Vibration (Vel -rms) For Fans erected on
≥ 4.5 mm/s ≥ 9.0 mm/s
Solid Concrete foundation.
Fan Bearing Vibration (Vel - rms) For Fans erected on
≥ 7.0 mm/S ≥ 14 mm/s
Spring Isolator
Differential Pressure across oil filter
Kindly refer Lub Oil Scheme
Lub Oil Pressure low
Drawing for your project.
Control Oil Pressure low
Oil Level In The Tank low
Refer Logic Diagram For Additional Interlocks.

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Ranipet Axial Reaction Fan – Single Stage (TLT)

STARTING OF THE FAN

 Ensure that all protections and interlocks are functioning properly.
 Start the motor. Check for correct direction of rotation of motor. This fan should rotate in
Anti-clockwise while viewing from motor.
 Test run the motor for 8 hours. If found satisfactory, couple the fan with motor.
 Operate the impeller blades to minimum position (Full close).
 Keep the delivery damper in full close position.
 Start the Fan and note starting time.
 Ensure that the discharge damper/ gate starts open simultaneously with the start of fan
motor.

 Measure static pressure at Fan discharge with blades in minimum position. Ensure at least
+ 20 mm of WC. If not, readjust minimum blade setting for this value.
 Measure the vibration and temperature of the bearing. Record the vibration and bearing
temperature every 15 minutes for first half an hour of run and every 30 minutes for the
subsequent 2 hours of run and every hour till trial run completion.
 Check for any abnormal noise in the Fan.
 Check and record the motor current, voltage, and blade opening position.
 Test run for 8 hours.
Caution: Fan should be trial run in the normal operating condition. Loading the fan
with few man hole doors opened/discharge blocked condition is not
permissible.

CHECKS DURING NORMAL OPERATION OF THE FAN

During continuos operation of the Fan the data should be logged as per the format: “
Operational parameter ”. Apart from the data logged in the format the following additional
information is to be logged at fixed convenient intervals.
 Vibration level
 Oil level in the tank
 Leakage in lub and control oil line
 Differential pressure indication of oil filter.

AERODYNAMIC OPERATING CONDITIONS

This term refers to the range in which the Fan can be run in continuous operation without risk of
damage. Throughout a wide range, the performance of AXIAL Fans can be adopted to site
requirements by adjusting the impeller blades. Operation outside that range, in particular if it
lasts longer can result in damages.
(a) If the inlet volume capacity is too little (i.e. the discharge gate is fully closed) rotating
stall with subsequent stalling will occur. Operation with rotating stall leads to
increased loads acting in some components, in particular the Fan blades.
(b) If the inlet volume capacity is too little the power Input may result in non-permissible
heating of Fans.

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Ranipet Axial Reaction Fan – Single Stage (TLT)

The operating ranges that are Off limits for continuous operation are represented in performance
graph. For operating range permissible for the Fan supplied, refer to operating parameters and
characteristics curves.

MINIMUM POSITION OF AXIAL FAN BLADES

During trial operation, a check should be affected. If the machine is operated with damper/gate
opened fully on the discharge side, the pressure at the diffuser should be at least +20 mm of WC.
This condition can be ensured by the help of a static pressure tapping at the end of diffuser
casing. Adjustments on the minimum position of the blades could then be achieved by individual
blade assembly.

PARALLEL OPERATION OF FD (AXIAL TYPE) FANS

These fans are provided with blade pitch control (flow regulation by actuating the blades) and
outlet damper/gate of open close type. The boiler is provided with Two numbers of FD fans.
CHARACTERISTIC CURVE OF THE AXIAL FAN
Refer the typical Characteristic curve of the fan (Fig - 1). The X – axis is the volume flow
through each fan and the Y – axis is the total pressure rise by the individual fan. The numerical
values (-320), (-280), (-120), (+40), (+80), (+120), (+160) and (+280) etc., are the different blade
angles, which corresponds to different loading of the fan. The stable operating range of the fan is
limited by the characteristic fan line for the maximum pressure / volume on the right side and by
the stall line at the top.

BEHAVIOUR OF FAN

The pressure developed by the fan is just equal to the system demand.

Refer Fig – 1. For a blade angle say (+40) let us assume, the volume flow is “ a ” m3/ sec and the
pressure developed is “ b ” mmWC when the system resistance is say “ m ” .

If the resistance of the system is changed to say “ n ” and the blade angle remain same
(+40), then the volume flow through fan will come down to “ c ” m3/ sec and the pressure
developed will increase to “ d ” mmWC. If this system resistance is close to the stall line, the fan
sheds the load and delivers lower volume and low pressure depending on the characteristic of the
fan, that is, the operation will be nearer to the deepest point of the stall line. Similarly, if the
system resistance is decreased to say “ p ” and the blade angle remain same (+40) , then the
volume flow through fan will increase to “ e ” mm3/ sec and the pressure developed will decrease
to “ f ” mmWC.

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Ranipet Axial Reaction Fan – Single Stage (TLT)

STARTING THE FANS

The control logic recommended (apart from other start permissive parameters) for starting the
fan is with its blade full close position and the discharge damper/gate fully closed. As soon as the
fan reaches its rated speed, the discharge damper/gate should be opened fully. The blades of the
fan can be opened to the required level to suit the system demand.

PARALLEL OPERATION

During the single fan operation, the volume and pressure demanded by the system will be high.
Under this condition, if the second fan is started as per the starting sequence mentioned above, it
is expected that the second fan will handle some amount of flow. Correspondingly, the volume
handled by the first fan, which is operating, reduces. Then pressure developed by the first fan
increases along its characteristic line at the same blade position.
At this point, there is a chance that the second fan will go to unstable zone and as a result, the
second fan will remain unloaded irrespective of its blade position. Therefore in order to bring
equal load on both fans, it is required to follow certain procedure given below.
STARTING A SECOND FAN
One fan (Fan A) is running and another fan (Fan B) is to be started. Even here the sequence of
operation must be such that neither of the two fans runs in the unstable range of the
performance graph. The ranges in which parallel fan (Second Fan) can be started is cross-hatched
as shown in the typical performance characteristic of an axial reaction fan (fig-2).

Refer Fig – 3. Let us assume Fan A runs at point “ A1 ” that is the pressure developed is more
than the deepest point “ S ” of the stall line.

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Ranipet Axial Reaction Fan – Single Stage (TLT)

Fan B is now shut off from the system by means of damper/ gate. Before starting Fan B, the
pressure developed by the Fan A should be brought down to “ A2 ” (Ref fig – 4) that is less the
deepest point “ S ” of the stall line. Then Fan B is started as per the starting sequence. By
opening of blades in Fan B, it will deliver certain volume. As Fan B is sharing certain volume, the
volume handled by the Fan A will be decreased and there will be slight increase in pressure at the
same blade position.
So, close the blade position of Fan A by approximately 5%. As the aim is to make both fan
operating at the same duty point on the performance graph, alternatively open the blades of Fan
B by approximately 5% and close the blades of Fan A by approximately 5%. Continue this operation
step by step, till the duty points like blade position and Motor current are same in both fans.
From this point onwards, increasing / decreasing the load on the fans will be simultaneous and
similar in both fans. If not, the phenomena called “ Loading / Unloading Of Fans ” will occur.

Remember the fan should not be permitted to run on or above stall line of the performance
graph continuously.

If the operating (duty) point of both fans is same in the performance graph, the auto control
system will adjust both fans identically to meet the system demand. To achieve this, the
following Mechanical checks should have been performed and logged prior to commissioning of
the fans.
The actual blade positions are calibrated w.r.t control room reading and are identical in both
fans.
There is no mechanical backlash in the linkages of hydraulic adjustment device – Actuator.

SHUTDOWN OF FAN

 Take the Fan operation to manual from auto operation.

 Set the blades to minimum.
 Stop the Fan.
 Close the discharge damper
 Note the deceleration time of the Fan.
 Stop the lub. oil system after about 2 hours.

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Ranipet Axial Reaction Fan – Single Stage (TLT)

PRESERVATION OF FANS DURING LONG SHUT DOWN

No special preservation is required for a shut down period up to 2 weeks. Since the maximum
effective life of rust preventive oil/anti corrosive agents, when applied, has its own life (3
months), re preservation has to he carried out after 3 months. Paint or spray with a rust
preventive compound/oil on polished or machined outer surfaces.

THE COMPOUND / OIL SHALL CONFIRM TO THE FOLLOWING SPECIFICATIONS

Specific Gravity : 0.850

Flash point : 40o C (MIN)
Film thickness at 25oC : 10 microns
Film description : Thin transparent dry film
Non-volume content : 40 - 48%
Coverage at 25o C : 12 Sq.M / Liter
100% Humidity at 50o C : 30 Days (mm)
Remove the preservative prior to commissioning, using suitable solvent like Kerosene / Alkali
wash / Steam blow / Lubricating oil.

THE FOLLOWING PROCEDURE SHALL BE ADOPTED FOR LONG SHUTDOWNS/STAND STILL PERIOD.

 Rotate the rotor by hand for few revolutions once in two days and set rest at a new position
90 Deg away from the original position. This is done to avoid permanent set of the rotor as
well as pitting of shaft and elements of bearings.

 Blow the rotor with compressed air once in ten days to remove hard deposits on the blades.

 Once in ten days, run the lub oil pump and operate the hydraulic adjustment device from
blades full open to blades full close several times.

 Run the fan once in fifteen days for at least half an hour. After each running, repeat the
above steps.

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 Ranipet Axial Reaction Fan – Single Stage (TLT)

4.3 Vibration and Safe Running of Fan

VIBRATION CHARACTERISTICS

Vibration in the simplest form may be considered as the motion of a part of a machine back and
forth from its position of rest end can be expressed as a simple harmonic motion.

DISPLACEMENT
The total distance of movement of the part is peak to peak displacement or Double Amplitude in
microns.

VELOCITY
The speed at which the part is vibrating in mm/sec.

FREQUENCY

The number of cycles of this movement for a given period of time is the frequency.

Condition of Machine as per Operating

ISO 10816 – 3: 1998: Part 3 instruction
Un
Description Good Satisfy Just Satisfy Alarm Trip
satisfy

Up to Above Up to Above Up to Above Above At

“ V ” rms in mm/s 1.8 1.8 4.5 4.5 11.0 11.0 4.5 9.0
Machine Group “G”

580 rpm 80 80 200 200 400 400 200 400

(Solid concrete)

740 rpm 64 64 160 160 320 320 160 320

Displacement
in microns for 990 rpm 48 48 120 120 240 240 120 240
speed
1480 rpm 32 32 80 80 160 160 80 160

2880 rpm 16 16 40 40 80 80 40 80

“ V ” rms in mm/s 2.8 2.8 7.0 7.0 18.0 18.0 7.0 14.0
Machine Group “T ” (Spring

580 rpm 126 126 320 320 640 640 320 640
Isolator)

740 rpm 100 100 250 250 500 500 250 500
Displacement
in microns for 990 rpm 75 75 188 188 375 375 188 375
speed
1480 rpm 50 50 125 125 250 250 125 250

2880 rpm 25 25 65 65 125 125 65 125

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Ranipet Axial Reaction Fan – Single Stage (TLT)

4.4. Operational Problems Causes and Remedies

Alarm Signals Possible Causes @ Remedy

* Operating point out of the fan * Blades pitch to be reduced

Surge operation performance range
> max
( diff. pressure)

* Cooler is damaged or out of order * Cooler has to be replaced

Bearing
> high * Heater is not switched off * Check control system and temperature sensor
Temperatures
* Bearing damage * Replace the bearing assembly

* High unbalance (blade wear, deposits * Clean or replace the blade set
on blades etc.)
* Fan in stall condition * Blade pitch to be reduced
Vibrations > high * Bearing damage (check for high * Replace the bearing assembly
bearing temp.)
* Fan foundation bolts loose * Tighten the bolts

* Oil pressure is dropped down, because * Replace defect oil hoses or oil pump
Bypass oil pump
of: Leaking oil lines or Defect oil
on pump * Reset the pressure switch
* Set point for switch-over is too low
* Oil leakage at the oil unit or the oil * Repair or replace defect parts
lines (outside)
Oil level < min * Oil leakage inside the fan (bearing * Replace the leaking parts(or the whole
assembly, hydr. adjusting device etc.) rotor)

* Oil cooler does not work properly * Check for cooling water inlet temperature
and
Oil temperature > max * Heater is not switched off cooling water flow rate
* Thermostat is malfunctioning * Check thermostat and temperature sensor
* Replace damaged valve
* Oil pressure is too low * Reset the pressure relief valve
* Oil lines are blocked * Inspect and clean the oil lines and the oil
Lube oil flow < min
filter

* Set point of the relief valve is too low * Reset the relief valve
Control oil * Relieve valve is damaged * Replace defect valve
< min
pressure * Oil leakage * Replace leaking parts
* Damage at the hydr. adjusting device * Replace the hydr. adjusting device

* Set point of the relief valve is too low * Reset the relief valve
Lube oil pressure < min * Relieve valve is damaged * Replace defect valve
* Oil leakage * Replace leaking parts

* Filter is blocked by deposits * Switch-over to the bypass filter; Clean the

Oil filter
> max filter cartridge
( diff. Pressure)

Bearing Temp > max * Bearings are damaged Replace the rotor or the bearing assembly
* Fan was operated under stall * Check the operating conditions (Damper
conditions position, sufficient fan performance)
* Broken blades or other rotor parts * Replace the blade set; Repair other fan
Vibrations > max
parts,
as required

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Ranipet Axial Reaction Fan – Single Stage (TLT)

Other troubles Possible Causes @ Remedy

Blades are moving too slow * Set point of the pressure relief valve is * Increase the pressure set point at
too low the relief valve
* Setting drive is too slow * Repair the setting drive
* Oil lines are leaking * Repair or replace leaking parts
* High friction or blockage inside the * Repair or replace the rotor
impeller
* Hydr. adjusting device is defect (sealings) * Replace the hydr. adjusting device

Hydraulic Adjustment * improper locking of HAD * Check and proper lock

Device * High vibration of setting/actuating shaft * Check locking & run out of hydraulic
adjustment Device
* Heavy Oil Leakage through Leak Line * Replace hydraulic adjustment Device
* Blade are not moving * Check proper I/L & O/L port
connection
Unusual noise, combined * Broken blades/rotor parts * Replace defect parts
with increasing bearing * Damage of the bearings * Replace the bearing assembly
temperatures and/or * Broken coupling spring shackles
vibrations

Metallic particles are found * Damage of the bearings or other parts of *Analyse the particles for the chem.
at the oil filter the bearing assembly/hydr. Adjusting composition; Inspect the bearing
device assembly and hydr. adjusting device for
damages/wear

High hysteresis between * Setting- and/or indication shaft parts are *Replace defect parts ( Pin, lamellas,
blade pitch set point and damaged (pin, lamellas, coupling etc) coupling)
actual blade position

@ Always check first whether the measurement itself is correct (e.g. correct set point, proper
function of the instrument etc.)

For attending the hydraulic Adjustment device and blade bearing assembly, assistance
from the fan manufacturer should be sought since these works calls for the special tools
and skills.

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Ranipet Axial Reaction Fan – Single Stage (TLT)

5.1 Constructional Features

The fan is designed for a Forced Draft application. The unit is mounted on a foundation
block. An electric motor attached outside via an intermediate shaft with couplings
provides the necessary power. To adapt the respective load point with regard to the
corresponding quantity of air, the blades are adjusted hydraulically. A nose fairing
provides favourable flow conditions in front of the impeller. Straightener vanes welded
behind the impeller ensure best possible downstream conditions.
A static pressure increase is achieved through change from kinetic energy of air into static
pressure energy by diffuser. To avoid transmission of vibrations the fan is connected to
adjacent sections via expansion joints on suction and discharge side. These expansion
joints are also able to absorb thermal expansion if necessary. The fan consists of the
following Components.

 Stator consisting of Suction Box, Fan housing, Outlet Guide Vane housing with guide
vanes and Diffuser
 Rotor consisting of shaft, impeller with blades, the blade bearing assemblies,
the Hydraulic impeller blade adjustment system and Main bearings (Anti-friction
bearings).

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Ranipet Axial Reaction Fan – Single Stage (TLT)

5.2 Stator Components

Suction Box, fan housing Outlet Guide Vane housing with guide vanes and diffuser are
welded structural steel fabrications, reinforced by flanges and gussets, resting on the
foundation on supporting feet.

5.2.1 Suction Box

The suction box has been arranged in upstream direction immediately ahead of the fan. It
deflects the flow with low loss by means of its well-designed construction. The suction box
is a welded steel construction consisting of:

 the suction box with the entry opening

 the inlet nozzle
 the intermediate shaft Cover and
The intermediate shaft Cover is hold by radial supports in the inlet nozzle. At the suction
box inlet and at the ring-shaped outlet there are measuring studs for Pressure
measurement. The internal protection cover surrounds the intermediate shaft from its
entry into the suction box until its entry into the nose fairing/Bullet.

5.2.2 Fan Housing with Guide Vanes

The fan housing is designed as a welding construction and Bolted with the outlet guide
vanes housing. Fan Housing and Outlet guide vane housings are horizontally split, in order
to facilitate access of the rotor for dismantling and assembly. The rotor is installed and
screwed in bearing saddle flanges.
Bearing saddle flanges are the integral part of the nose fairing /Bullet. Nose fairing /Bullet
is supported by radian supports in impeller housing. Nose fairing /Bullet facilitates the
smooth entry of air to the impeller. After the impeller a hub part (OGV Core) holds by
guide vanes and surrounding the hydraulic adjustment system. The guide vanes assume the
following duty:

 Axial alignment of the turning Air flow leaving the impeller.

Two radial guide vanes in the lower part of OGV and fan housing are hollow in order to
conduct Supply lines, measuring cables .Suction Box and Fan Housing, Outlet Guide Vane
housing and diffuser are flexibly connected via expansion joints.

5.2.3 Diffuser
The diffuser has been arranged directly behind the fan housing with OGV in downstream
direction. The extension of the flow diameter within the diffuser leads to:

 Delay of the flow speed and

 Increase of the static pressure.
This reduces the flow loss in the subsequent duct parts. The diffuser consists of the
housing and the hub hold by radial support plates that are both provided with a entry
openings. The hub is fixed by tangential plates to avoid torsional vibrations due to induced
flow turbulences. Gauge connections have been attached at the diffuser end to measure
the static pressure.

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Ranipet Axial Reaction Fan – Single Stage (TLT)

5.2.4 Insulation
The insulation has been measured corresponding to the acoustic and thermo technical-
calculations.
Any housing divisions, doors, assembly openings as well as parts to be maintained such as
bandages, expansion joints etc. have been provided with easily removable insulation
adapters (caps with self- locking fasteners).
The insulation at the fan has been placed in such a way to conserve the insulation at the
housing parts in the event of a possible disassembly of the fan rotor. Only the adapters
must be removed from the parts.

5.2.5 Expansion Joints

The expansion joints decouple the exhaust gas channel and the fan and detect movements
in the event of different heat expansion. Any one expansion joint is placed between:

 Suction side exhaust gas channel (transition piece) and suction box
 Between suction box and housing
 Between housing and diffuser
 Between diffuser and air duct channel on discharge side.

5.3 Rotor Components

The rotor assembly consists of a main bearing assembly and one impeller with blades, the
blade bearing assemblies, the hydraulic impeller blade adjustment system. The rotor
converts mechanic energy (kinetic energy) into flow energy. The following drawing shows
the rotor schematically:

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Ranipet Axial Reaction Fan – Single Stage (TLT)

5.3.1 Main Bearing

The main bearing is a part of the rotor and mainly consists of the bearing housing, the fan
shaft (main shaft), axial and radial bearings of various designs and of sealing elements.
The main bearing, a compact unit, is centred and screwed in the lower half of the fan
housing. Thermometers and resistance thermometers monitor the bearing temperature.
These thermometers must be connected to signalling instruments at the site.
Simmer rings as sealing elements are always installed, filled with grease. The oil
circulated through the oil return pipe, which opens into the oil reservoir. The main
bearing is lubricated by oil circulation. For this purpose an oil supply unit is attached
outside the fan.

5.3.2 Impeller
The impeller consists of a weld-in hub, a supporting disk, a solid load ring for taking up
the centrifugal forces, impeller casing and a guide ring. The ribs, the load disk and the
cover plate together, give the impeller a strong stiffness. The drive torque is mainly led
into the load ring and the guide ring.

To absorb the natural and the centrifugal force of the impeller, the load ring is designed
in a very stable manner. Hub and fan shaft are connected by interference fit and secured
with a key. To permit mounting of the impeller on the shaft the hub opening is widened
oil-hydraulically.

5.3.3 Blade

The blades change mechanic energy (kinetic energy) into flow energy. The blades consist
of aluminium alloy. To get an ideal efficiency degree, their surface and other geometry
data (such as impeller profile) have been processed quite exactly. The blades are attached
to the shaft) by means of special bolts.

5.3.4 Blade Shaft Bearing Assy

The blade shaft bearing serves the absorption of the impeller blade centrifugal forces and
the continuous blade adjustment during operation. The blade shaft supports the screwed
blades, the counterweight and the adjusting lever.

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Ranipet Axial Reaction Fan – Single Stage (TLT)

The centrifugal forces of the blades and blade shafts are transferred via axial deep groove
ball bearings into relatively small load ring. The angular contact ball bearing and the blade
shaft bearing bushing absorb transverse forces from adjusting and aerodynamic torques.
Various static and dynamic sealings prevent:
 the emission of lubricants from the interior of the impeller and
 the entry of contaminations into the interior of the impeller.
The deep groove ball thrust bearing is lubricated with oil (oil ring lubrication!). The
angular contact ball bearing is filled with grease. Each blade bearing is sealed off by
means of several seals, in both directions (towards the inside and outside).

5.3.5 Hydraulic Impeller Blade Adjustment System

The blades will be adjusted and kept in position during operation by the hydraulic impeller
blade adjustment system. The adjusting range is indicated in the rotor assembly drawing.
The blades, fixed at the outer end of the shaft, will be adjusted and kept in position by
means of a lever, which is provided with a sliding block and which is located at the inner
end of the shaft. Those levers and sliding blocks are embrace by the adjusting disks.
The adjusting disks are connected with the cylinder of the hydraulic impeller blade
adjustment system via the thrust device. The control of this cylinder is affected via the
control slide valve in the control head.

The pressure oil in the space of the control slide valve can reach the respective side of the
adjusting cylinder via the borings through the respective ducts which are opened by the
control slide valve.
Now the adjusting cylinder is displaced accordingly and the blades are adjusted in the
same way via levers. The oil on the other side of the cylinder returns through ducts which
are also opened by the control slide valve.

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Ranipet Axial Reaction Fan – Single Stage (TLT)

To the same extent as the adjusting cylinder is moved, the return rod will also be moved
(as it is fixed at the adjusting cylinder and arranged in the rotational axis).
Thus the borings, released by the control slide valve, will be shut via gearwheels and gear
racks installed in the control head. Upon reaching the given position the adjusting
procedure is finished.

5.3.6 Adjusting Shafts

The mechanical connection between the hydraulic impeller blade adjustment system and
the respective components outside of the fan housing is attained via an indicator shaft and
a setting shaft. An external actuator effects the hydraulic impeller blade adjustment
system via the setting shaft.
Those parts of the Hydraulic impeller blade adjustment system unit which are arranged in
the guide vane and diffuser cores are accessible through assembly openings.

5.4 Fan Accessories

5.4.1 Spring Shackle Coupling

The fan shaft is connected to the motor shaft by means of Spring Shackle couplings
while the distance between the shaft ends is bridged by an intermediate shaft which is
a part of the coupling assembly. The spring shackle coupling can absorb radial and angular
mismatch up to a certain extend. No lubrication is required for the coupling parts.
Coupling Mounting
Mount the coupling on fan shaft as per the attached annexure-I

5.4.2 Oil Circulation Unit

The oil unit consists of an oil tank, two pumps (one standby), filters, coolers and other
necessary fittings and instruments. A pressure relief valve maintains the pressure in the
system. The lubricating oil is fed through a flow-regulating valve.

5.4.3 Drive Motor

Constant speed synchronous induction motors drive these fans. For installation, operation
and maintenance reference is drawn to the instructions of the respective motor suppliers.

5.4.4 Special Tools, Maintenance Devices

For the maintenance of the fan some special bolts and devices are necessary. To mount
and dismount the impeller from the main shaft, the mounting and dismounting device has
to be used.

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Ranipet Axial Reaction Fan – Single Stage (TLT)

5.5 Minimum General Storage Requirements

Frequency Of
Sl.No. Fan Component Storage Locations
Inspection (d)
1. Suction Box Outdoor (a) Monthly

2. Diffuser Outdoor (a) Monthly

3. Silencer Weather Protected (b) Monthly

4. OGV Assembly Weather Protected (b) Monthly

5. Impeller Housing Weather Protected (b) Monthly

6. Shaft with Brg Assy @ Indoor c) Monthly

7. Impeller and Hydraulic Adjustment Divice @ Indoor (c) Monthly

8. Spring shackle coupling Indoor c) Monthly

9. Machined packers and Shims Indoorc) Monthly

10. Instruments Indoorc) Monthly

11. Lub oil system Indoorc) Monthly

Note:-
a) Above ground, on blocks, exposed to weather.
b) Out door, above ground, on blocks covered With Tarpaulins and vented for air
circulation.

c) Clean and dry warehouse.

d) Inspect the components at the given frequency and re preserve it suitably.

@ Specific attention should be given to ensure that the Shaft with brg assy, Impeller and
hydraulic adjustment device is stored inside the covered shed and preserved properly.
This rotor is assembled in our works in a air conditioned hall.

Procedure for Preservation of Machined Surfaces of Fan Spare Shafts at Site

1. Inspect the machined surfaces of the fan shafts immediately on receipt at site.
2. Clean the machined surfaces, if required, by using kerosene or mineral turpentine.
Exposed rust to be removed by rust removing solution (Phosphoric acid 10%).

3. Re-preserve by applying the following:

a) One coat of TRP 1706 rust preventive fluid.
b) After drying, apply one coat of TRP 1710 and
c) After drying apply one more coat of TRP 1710.
4. Tarpaulin and wooden pieces dis-assembled are not to be used at site.
5. The preserved surfaces shall be wrapped with HDPE (High Density Poly Ethylene)
sheets.
6. Keep the shafts in covered storage.
7. Inspect the machined surfaces every month and re preserve as mentioned above.

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Ranipet Axial Reaction Fan – Single Stage (TLT)

Procedure for Preservation of Anti-Friction Bearings

1. The store room must be free from dust.

2. Ideal ambient temperature should be 20 to 30 deg c.
3. Relative air humidity should not exceed 60%. It may be necessary to
install air dehumidifier in places where relative humidity is high.

4. If the bearing is found to be dry and dirty, it should be thoroughly washed and
cleaned before re-packing.

5. The bearing should be first kept in a vessel filled with kerosene for about half an
hour and then washed to take out the dirt.

6. It should then be cleaned in another vessel with filtered kerosene.

7. The final cleaning is to be done by using petrol of mineral turpentine oil.
8. It should be then allowed to dry completely. Pressuraised air for cleaning or
drying purpose is not recommended. (RUST GARD P214).

9. The washed and dry bearing is to be dipped in anti-corrosive oil.

10. The excess oil should be allowed to escape and bearing should be repacked in a
waterproof sealable plastic bag and put in to the carton again.

Recommended Preservative Components

APPLICATION BRAND NAME

TRP 1706, TRP 1710
Machined surfaces ( Indoor storage )
HDPE (High Density Poly Ethylene) sheets.
Machined surfaces ( Outdoor storage ) TRP

Weldments De-oxy Aluminates

Shaft with bearing assembly Oil ISO VG 68 Equivalent: SERVO PRIME 68

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Ranipet Axial Reaction Fan – Single Stage (TLT)

5.6 Maintenance of Fan

Prior to taking the equipment out of service during a planned maintenance program, the
following checks are to be carried out. These checks are designed to help in scheduling the
maintenance activity and to avoid unforeseen delays in re-commissioning the Fan.
 Record vibration level on all bearings. Such of those bearings whose vibration levels are
beyond the permissible levels of satisfactory operation may be subjected to
vibration/signature analysis to carry out the corrective actions.

 Ensure the availability of operational data such as Vibration level, Bearing temperature,
Motor amperage, blade position etc before stopping the Fan.

 Pay specific attention to any abnormal noise emanating from any of the machine
components like bearings etc.

 Observe for any leakage in the Fan like oil, air at Fan connections etc. Observe for any
erosion of Impeller / casing.

 Availability of operational spares and other materials in connection with the observations
made above.

 After the Fan is stopped the following data may be recorded/ensured for reference
during re commissioning.

 Coupling alignment
 Marking the assembled components by match marks
 Servo motor operating time
 Actuator linearity w.r.t control room indication and actual blade position

Between Planned Shutdown

To ensure the long term proper operation of the fan various maintenance services are
required,
Every 8 operating hours - record the vibration level.

Every 500 operating hours or at least once in three months

Clean the lub oil filter. Clean it before the above mentioned time has elapsed when the
differential pressure contact indicator indicates that the filter is dirty.

Every 2000 operating hours or at least once in every six months –

Test the oil, if water is found, find the cause and eliminate it.

Every 4000 operating hours or at least once in a year

 Retighten all the fixing bolts.
 Check the quality of oil, if required change the oil.
Every 8000 operating hours, or after 2 years
Check Operation the normal inspection and Complete over haul

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Ranipet Axial Reaction Fan – Single Stage (TLT)

Forced Shutdown

If the plant shutdown is owing to other parts, it-may be possible to inspect the Fan. We
recommend the following jobs.

 Check whether there is oil leakage inside the Fan.

 Check impeller blades for wear, if any.
 Check whether all blades are equally set when actuating the hydraulic adjustment device.
 Check whether the hydraulic adjustment device is oil tight.

Planned Shutdown

We recommend to effect overhauls for every 8,000 to 10,000 operating hours or at least
once in two years. This job should be performed under the guidance of the specialist of the
Fan manufacturer.

a) Check on Impellers

 Check Impellers and blades for deposits and rust.

 Clean the impeller.
 Check blade fixing bolts.
 Check Inlet edge of impeller blade, for wear.
 Check for position and fixation of compensating weights.

 Check blade bearings for damages.

 Entirely remove old lubricant in blade bearings and fill new lubricant.
 Replace sealing elements in blade bearings.
 Check lever, slide ring and adjusting disc for wear and inspect jewel bearing
assembly.

b) Effect all checks as described under “ between planned shut down and forced
shut down ”
c) Clean inlet and outlet oil lines.
d) Eliminate oil leakages.
e) Check the clearances of main bearings.
f) Ensure free rotation of fan rotor by hand freely.
g) Replace correct Oil hoses for hydraulic adjustment device if required.

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Ranipet Axial Reaction Fan – Single Stage (TLT)

5.7 Dismantling and Reassembly

BHEL specialists should service fan. Our instructions have only one objective, namely to
keep the Fan ready for operation and to avoid longer standstills. Basic requirements for the
installation and removal of such parts are a clean job and avoidance of any kind of force.

Installation and Removal Of Coupling

Refer Annexure.
Removal of the Fan Housing’s Upper Part

 Remove the sound insulation in the area of the expansion joints and longitudinal
flanges of the housing as well as the suspension eyes.

 Detach the expansion joints on suction and on discharge side and the protection
devices (discharge side: out and inside)

 Remove the connection bolts and the locating pins

 Remove the upper part of the fan housing using the connection bolts for separation.
For this very purpose, the longitudinal flanges of the fan housing’s lower part have
been provided with through holes.

 Move blades into " closed " position

 Suspend the upper part of the fan housing; take care that it is balanced precisely
 Lift the upper part of the fan housing vertically until it can no longer touch the blades
 Put down fan housing’s upper part at a suitable place

Removal of the Rotor Assembly (Drg. No : 0 55 214 00897)

 Remove fan housing’s upper part

 Disconnection of the adjustment and indicating shaft from the hydraulic impeller
blade adjustment system

 Disconnection of the oil pipes, hoses and cables of the temperature probes from the
main bearing assembly

 Disconnection of the oil pipes from the main bearing assembly

 Disconnection of the oil pipes from the hydraulic impeller blade adjustment system
Detach locking device from the hydraulic impeller blade adjustment system

 Disconnect the intermediate shaft from the coupling stop on fan side by removing
the connecting bolts.

 Secure the intermediate shaft in the nose of suction box.

 Remove all the blades to avoid any damage and secure the blades safely.
 Release the connecting screws between the main bearing flanges and the supporting
rings in the lower part of the fan housing
 Suspend the rotor as shown in the enclosed draft

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Ranipet Axial Reaction Fan – Single Stage (TLT)

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Ranipet Axial Reaction Fan – Single Stage (TLT)

Attention:

 In order to avoid damages to the blades, the labyrinth rings and the coating, the rotor
assembly must be removed and suspended securely balanced.

 Re-assemble in reverse order; the connecting bolts should be tightened in accordance

with the prescribed torque (ref. also rotor assembly drawing).

Dismantling and Reassembly of the Hydraulic Impeller Blade Adjustment System

(refer drawing - 0 55 214 00897)

 Disconnect the hydraulic oil pipes from the hydraulic impeller blade adjustment system
 Disconnect the locking device between impeller blade adjustment system and fan
housing

 Disconnect the adjusting and indicating shaft from the hydraulic impeller blade
adjustment system.

 Release the centering bolts (01) and unscrew the connecting bolts (02 & 03)
 Remove the support cover (04) and suspend the adjustment system to a lifting jack
 Unscrew the adjusting disc (06) to HAD connecting bolt (05) and disengage the
hydraulic unit from the guide bushing (07) in the fan shaft.

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Ranipet Axial Reaction Fan – Single Stage (TLT)

 This work can be carried also when the fan housing’s upper part is closed. Access is
given through the two man holes in the diffuser.

 The component can be taken out through the a.m. opening by means of a lifting gear
suspended in the hub of the housing. (Weight of hydr. adjustment system 58 kg).

 Assembly in reverse order.

 The alignment of the hydraulic impeller blade adjustment system effected by means of
the centering screws (1) Aligning accuracy and measuring methods see draft. The torque
for the connecting bolts is shown in the rotor assembly drawings.

Dismantling of the Impeller

 All Connecting Surfaces Must Be Cleaned carefully and make match mark.
 Then, generate an oil pressure p for expansion and increase dis-mounting force F.
 Maintain oil pressure p at possible maximum pressure and pull the impeller out at the
same time.

 Mounting will be carried out acc. to sketch " Mounting of Impeller".

 At the end of the mounting procedure, a built up pressure loading with about 1000 KN.
 Reduce expansion oil pressure “ p ” and only unload the feed shaft once oil pressure “ p
” has dissipated.

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Ranipet Axial Reaction Fan – Single Stage (TLT)

Dismounting of the Impeller

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Ranipet Axial Reaction Fan – Single Stage (TLT)

Mounting of the impeller

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Ranipet Axial Reaction Fan – Single Stage (TLT)

Assembly of the Blade Shaft Bearings (refer drawing - 0 55 214 00897)

The blade shaft bearings are constructed with axial deep groove ball bearings as supporting
bearings and angular ball bearings as thrust bearings and guide bearings. Following the cleaning,
checking, and, if necessary, replacement of parts during inspection, the blade bearings should be
assembled essentially as described below:

Attention: All functional surfaces must be processed, cleaned, molycoted, oiled,

greased, degreased, etc., as shown in the rotor assembly drawing.

Shaft Guide Bushing and Blade Foot Seal

Install the shaft bearing bushing (6) into the neck bearing by bonding.

Support Bearing Unit

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Ranipet Axial Reaction Fan – Single Stage (TLT)

Insert axial deep groove ball bearing (7) into the bearing shell (8) as follows:
 Insert the bearing ring into the bearing shell (8)

 Add the balls, diameter and dimensions per rotor assembly drawing
 Put the bearing ring over the balls

 Mount dynamic seal (9, 10) into the bearing mount (8)
 Put shaft nut (11) over the deep groove axial ball bearing (7)

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Ranipet Axial Reaction Fan – Single Stage (TLT)

 Turn the complete unit by 180° and insert static seals (12)
 Grease O-ring with solid lubricant on Teflon basis

Guide Bearing Unit

 Insert the dynamic seals (13, 14) into the bearing cover and grease slightly
 Fit the O-ring (15) into the bearing cover (16) and grease solid lubricant on Teflon basis
 Fill the guide bearing with grease.
 Press the guide bearing (17) into the support ring (16) and check for correct position as per
rotor assembly drawing

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Ranipet Axial Reaction Fan – Single Stage (TLT)

Bearing Shield
 Static seal (18) and dynamic seal (19, 20) have to be mounted onto the bearing shield (21)
 Grease slightly

Adjusting Lever
 The surface of sliding block shaft should be covered with graphite powder.
 Press sliding block (22) onto the adjusting lever (23)
 Secure sliding block with the snap ring (24)

Shaft
 Coat shaft guide bushing (6) with graphite powder.
 Grease mounting surfaces of counter weight (25) and guide bearing (17) slightly with
"Antiseize ASA16".
 Grease shaft surface (26) and blade fixing bolt thread area in shaft with “Molykote 1000".
 Degrease adjusting lever seat (23)

 Fit key (27) into the shaft groove

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Ranipet Axial Reaction Fan – Single Stage (TLT)

 Set O-ring (28) into the radial groove of the shaft

Mounting of the Blade Shaft Bearing Assembly

 Grease face of guide bearing (17) and bearing cup (8) with "Antiseize ASA 16".
Press bearing shield with seal (18) consisting of O-ring (20) and Teflon labyrinth ring (19)
into the borehole of the guide ring.
 Insert greased and preassembled guide bearing (17) in the appropriate guide ring boring
and assemble with support (16).

 Put preassembled supporting bearing, including seal (12), in the support ring boring and
secure its position with appropriate spacers between support and guide bearing.

 Put counter weight (25) on top of the supporting ring boring (check impeller assembly
drawing for position of the groove).

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Ranipet Axial Reaction Fan – Single Stage (TLT)

Mounting of the Blade Shaft, Support and Guide Bearing Assembly

 Insert the blade shaft (26) into the "support bearing assembly" from above through the
blade shaft bearing bushing (6) until the blade shaft thread rests on the blade shaft nut
thread. Lubricate the blade shaft thread before inserting the blade shaft.

 Lift counter weight (25) and deposit it on two identical supports

 Turn shaft nut (11) several times
 Fasten blade shaft nut (11) until the faces of the bearing pot (8) and the guide bushing (17)
sit on the particular opposite surface .The torque increases suddenly when contact is made.
 The blade shaft nut is secured by a retaining spring (29) and a retaining ring (30)
 It may be necessary to tighten the blade shaft nut a little more in order to cover the
retaining grooves between the blade shaft and the blade shaft nut

 Unscrewing the blade shaft nut too far, i.e., releasing the pretension, may result in a
malfunction of the seals (9,10,12,13 and14)

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Ranipet Axial Reaction Fan – Single Stage (TLT)

Assembly of the Blade and the Adjusting Lever

 Pull the adjusting lever (23) onto blade shaft (26), after degreasing the mounting surfaces
 An appropriate wedge, applied to the provided slot in the adjusting lever, will expand the
boring enough to ease assembly

 The pretreated locking screws (31) and the locking nut (32) are put in loosely into the
adjusting lever. Apply "Antiseize ASA 16" marked. Grease thread and support area of the
blade connection bolt with "Molykote 1000".

 Insert seals (33, 34) in the borehole of the outer impeller casing
 Screw blades (35) onto the blade shaft by means of the blade shaft bolts. For torque
requirements please ref. rotor assembly drawing.

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Ranipet Axial Reaction Fan – Single Stage (TLT)

Attention:
 The position of the blade towards the counter weight must be set acc. to the drawing.
 Put the blades (35) and the adjusting lever (23) into central position; ref. impeller assembly
drawing.
 Generally, the adjusting levers are mounted in direction of rotation of the fan. The adjusting
lever is in central position, too.

 Tighten the safety nut (32) with the torque shown in the impeller assembly drawing; add
the friction torque between safety nut (32) and clamping screw (31) to the torque of the
screw.
Disassembly and Assembly of the Blades

Prior to assembly the threads of the blade bolts should be treated as shown in the rotor
assembly drawing. The assembly is to be permed in the correct order.

 The impeller blades have to be checked for wear.

 Remove the screws connecting the blades and blade shafts and extracts each blade form its fit.
 The quality of the surface permits this
(no rust, no damages) which should he
ensured by visual checks.

 They have been, and will be, tightened

to the correct torque, with a calibrated
torque wrench.

 During the blade mounting process, the

impeller must be secured against
rotation by suitable blocking devices.
 Clean and lubricate fixing surfaces,
shaft bearing bushing, bushing, and
shaft flange, place seal rings on blade
foot, mount blades at the circumference
of the impeller according to their
sequence number, fasten bolts to
prescribed tightening torque, according
to the sequences shown in Figure.
 Screws must be coated with Molykote
and have to be tightened to the
specified torque. Make sure that the
screws are loaded uniformly.
Before assembling the blades, commission
the lube oil system and ensure cleanliness
of the oil lines by oil flushing. (Refer
Commissioning of lube oil system). Connect
oil lines to the hydraulic adjustment device.
Switch off the lub oil pump till all the blades
are mounted.

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Ranipet Axial Reaction Fan – Single Stage (TLT)

The impeller blades are identified by an alphabet series. They are also marked serially.
Example
A1, A2 ........ An
B1, B2 ........ Bn
Ensure that the blades to be mounted belong to the same series. Usually the impeller hub is also
marked serially. However, blades may be mounted on the hub starting from anyone location and
proceeding in the serial order as marked on the blades. They may be assembled proceeding in the
clock-wise or counter clockwise direction.

Ensure that the round nose of the blades is fixed on the suction side.

Assemble the blades. Ensure that the blades are positioned and tightened in identical
position. This is to avoid uneven gap between blades.
Tighten the blade fixing screws. Tighten to the required torque values. At blade full close position,
ensure that the blades are not fouling with each other. There can be minimum gap between blades.

Note: The entire site made oil lines must be acid cleaned and neutralized. Prior to connecting
the flexible oil hoses with the hydraulic adjustment device, the lub oil system must be
thoroughly flushed for at least 8 hours or till no dirt/ sediments are found in the oil
filters. Oil flushing should be done bye passing the fan bearings and hydraulic adjustment
device.

The torques please find in the rotor assembly drawing.

Blade Gap Measurement

Turn the rotor and pre-check the blade

gap in the lower part of the fan
housing.

Place upper part of housing and fasten

nuts hand tight. Check the blade gap
according to the following procedure:

 The blade angle has to be

adjusted to closed position.

 Measure all blade gaps at the

same position “x” to find out
the longest blade. Mark the respective blade accordingly.

 Carry out the blade gap measurement first with the longest blade at each of the positions P
(eight points at the circumference).
 Countercheck the gaps at the horizontal flanges ( 3 and 9)
 Compare with permissible gap acc. to the drawing and prepare records

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Ranipet Axial Reaction Fan – Single Stage (TLT)

Disassembly and Assembly of the Shaft with Bearing Assembly (Drg No: 0 55 214 00897)
 Remove the cap screw (40)
 Remove the bearing cover (41)
 Remove the cap screw (43)
 Remove the bearing cover I (44)
 Remove the impeller side oil ring (45)
 After remove the above components reposition the assembly as coupling side in top on the
stand.
 Remove the cap screw (40)
 Remove the bearing cover (42)
 Remove the cap screw (43)
 Remove the bearing cover II (44)
 Remove the coupling side oil ring (45)
 Use a “ eye ” bolt, slowly pull out shaft from impeller side end to coupling side end (towards
coupling side) including Angular contact Ball bearings and Cylindrical Roller bearing inner
race.
 Remove the angular contact ball bearing (46)
 Remove the outer spacer (47) and inner spacer (48)
 Remove the angular contact ball bearing (49) and inner race of the cylindrical roller bearing
(50).
 Remove the cylindrical Roller bearing outer race (51) from the housing.
 Using a hydraulic pump to admit pressure to the contact areas of the anti-friction bearings.
 For pulling of the bearings, use tools as recommended by the manufacturer. To protect
bearing shoulders, races, cages and the balls or rollers and do not employ any force (do not
use hammer).

 Anti-friction bearings have to be Installed or removed in accordance with the instructions of

the bearing manufactures.

 Remove the protective coatings / old grease by means of liquid solvents like turpentine from
the shaft surface / bearings and related components. Thoroughly clean the bearings and
shaft surfaces. .

 Make sure that the bearings housing bore and shaft diameters are in accordance with the
drawings.

 Ensure the condition of the rolling elements and proper tolerance of the bearings.
 No bearing shall be accepted, if the same is found pitted, rusted or damaged.
 Wipe the bearings with clean cloth.
 Make arrangements to heat the bearing elements in oil bath. The heating container should
be clean. Immerse the bearings completely in oil bath. Take care that the bearing should
not touch the walls as well as the bottom of the container.
 Slowly heat the oil to about 100° centigrade (But never exceed a temperature of 100o
centigrade). Ensure the temperature, and allow sufficient soaking time before mounting.

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Ranipet Axial Reaction Fan – Single Stage (TLT)

 For the bearing radial clearances, refer bearing catalogue/drawing/Fan Technical Data.
 The sealing elements must not be damaged. The bearing clearances indicated also must be
ensured.
 Install the bearing with the shaft in reverse sequence.

Precaution:-
It is required that every possible care to be taken, so that the bearings are mounted
properly. It is of utmost importance that the instructions given here, regarding
mounting of the bearings, are strictly adhered to, in the same sequence, as indicated, to
Avoid Any Future Problems..
Hydraulic Impeller Blade Adjustment System
For inspection, disassembly and assembly, please require a BHEL supervisor or return the entire
hydraulic impeller blade adjustment system with the control head to the factory for overhaul.

Commissioning of Fan after Major Overhaul

Prior to starting the fan after a major overhaul, ensure all checks as mentioned in the chapter
Pre commissioning checks - chapter no 4.1

5.8 Lubrication Instructions

The Lubricating oil for the Fan bearings are supplied by the centralized oil pumps which
supply oil for the hydraulic servomotor also. It must be borne In mind that the quality of oil
flowing to the bearings and its pressure must be maintained as recommended. The flow
control device provided in the oil system (lube oil inlet Fine) is to be covered arid protected.

The oil to be used shall be a turbine quality oil to suit the following specifications:
ISO Viscosity Grade : 68
o
Kinematic Viscosity at 40 C : 64-72 cst
Viscosity index : 95 min
Flash point : 210o C (min)
Pour point : -6o C (max)
Neutralization No - mg KOH/gm : 0.2

The oil must not foam during operation. Foam removing agents containing silicon must not
be utilised. The oil must have good anti-corrosion properties.

Lubricant Filling

Fill the recommended lube oil (through a fine mesh strainer only) up to the required level.
Do not mix lubricants of different grade and make.

Lubricant Check

At first commissioning and after a basic overhaul, the entire oil must be drained after an
operating period of 100 hrs. All dirt should be eliminated from the oil tank. Then fill in again
the oil through the fine mesh strainer.

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 Ranipet Axial Reaction Fan – Single Stage (TLT)

Care of Lubricant

Test the quality of the oil every month and if found unsatisfactory and oil containing
water/dirt the oil should be changed immediately. The maximum permissible limit of
contamination is 100 ppm.

Recommended Lubrication Chart

Obser Qty /
Sl.no Component Lubricant Supplier Location Frequency
vation Fan
Servo prime 68 M/s IOC Once in 2 years
Fan main Bearings
Turbinol 68 M/s HPC or Based on the See
01 and Hydraulic Oil tank Daily
Bharat turbol 68 M/s BPC oil quality note 1
adjustment device
Teresso 68 (Others) see note 2
Mobil Glygoyle During Over
10 Ltr
Blade shaft 30 and Mobil See Inside haul (once in
02 *****
bearing assembly grease 28 / note.3 Rotor 2 years)
1 Kg
Burutox M21 see note 4
Blade shaft During Over
Molykote
bearing bushing See Inside haul (once in
03 microfine ***** 0.5 Kg
and pushrod guide note.3 Rotor 2 years)
graphite powder
bushing see note 4
During Over
Bearing shaft and
Mobil grease 28 See Outside haul (once in
04 indication shaft ***** 0.2 kg
/ Burutox M21 note.3 Rotor 2 years)
see note 4
Blade bolt and Molykote 1000
05 Common 0.5 Kg
other bolt paste

Notes:

1) Oil quantity depends on tank capacity. Levels marked in the oil tank level gauge.

2) The frequency of filling shown is for normal operation. For initial operation follow
lubricating instructions given in this manual.
3) The blade bearing assembly lubricants are presently imported. Development of
indigenous supplier is under study.
4) The lubricants of blade bearing assembly are renewed only during major overhauls of the
Fan (usually once in two years). This has to be done only by trained personnel. BHEL
personnel may be requisitioned for supervision.

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Ranipet Axial Reaction Fan – Single Stage (TLT)

5.9 Recommended List of Spares

We recommend stocking atleast one set of the components per boiler shown in the drawings of
Rotor assembly, Shaft with bearing assembly, and Blade bearing assembly as spare to
meet the O & M requirement apart from having a stock of one assembled set of rotor assembly
to meet emergency requirement.

While ordering spares, kindly quote drawing number, item number, description and quantity
required.

Contact Address For Getting Spares

The Additional General Manager (Spares Business)

Bharat Heavy Electricals Limited,
Boiler Auxiliaries Plant,
Ranipet, Tamil Nadu, Pin Code-632406.

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