BHEL 600 MW Soot Blower

8/16/2019 BHEL 600 MW Soot Blower

1/279

DIVISION C

BOILER MOUNTINGS

VOLUME C1

SOOT BLOWERS

LIST OF CONTENTS

Location Description Ref. No. / Drg. No

1610 – 1611 JINDAL ANGUL VOLUME-C1 PAGE 1 Of 1

TAB-1

(1-4)

SOOT BLOWERS

LRD IIE Views 1-00-076-60601

Furnace Temp. Probe Views ( FTP IE- AC) 1-00-076-60602

Wall Deslagger Views ( WB IE ) 2-00-076-60990

Soot Blower Arrangement 3-00-076-60354

TAB-2

(5-18)

Soot Blower Operations - Emergency Check List Pub. No. 7515

TAB-3

(19-36)

AC Induction Motor(For Soot Blowers) Pub. No. 7506

TAB-4

(37-63)

Soot Blower - General Instructions Pub. No. 7501

TAB-5

(64-91)

Wall Deslagger -Model WB IE Pub. No. 7503

TAB-6

(92-131)

Furnace Temperature Probe Model FTP IE & IIE Pub. No. 7505

TAB-7

(132-193)

LRD IIE Long Retractable Soot Blower Pub. No. 7514

TAB-8

(194-268)

Methods And Procedures For Installation Soot Blowers Pub. No. 7508

TAB-9

(269)

Soot Blower Arrangement 4-00-076-60871


2/279

TAB - 1


3/279

P

04 06 07 08 03 09

10

05 01 02


4/279

01

CB

B

F

F

SECTION-GG

04

E

E

G G

WALL & SLEEVE SECTION

VIEW-BB

DETAIL-C

D

VIEW-D

A

VIEW-A

SECTION-FF SECTION-EE

02


5/279

1 6 1 0

1 6 1 1 V OL

C 1 T A B

1

3


6/279

1 6 1 0

1 6 1 1 V OL

C 1 T A B

1

4


7/279

TAB - 2


8/279

1

INSTRUCTION MANUAL

SOOT BLOWER OPERATIONSEMERGENCY CHECK LIST

PUB. NO. 7515

Bharat Heavy Electricals Limited

Tiruchirapalli

1610 - 1611 VOL - C1 TAB - 2 - 5


9/279

2

CONTENTS

INTRODUCTION

SOOT BLOWER OPERATION -EMERGENCY CHECK LIST

SOOT BLOWER JAMMING

BLOWER MOTOR OVERLOAD

SOOTBLOWER OVERRUN

STEAM PRESSURE LOW

STEAM TEMPERATURE LOW

STEAM NO FLOW

A. C. CONTROL SUPPLY/ POWER SUPPLY FAILURE

SOOT BLOWER SEQUENCE INTERRUPTION

VALVE MOTOR OVERLOAD

PHILOSOPHY OF JAMMING RELAY PROTECTION AND OVERLOAD RELAY

PROTECTION IN SOOTBLOWER MCC.

1610 - 1611 VOL - C1 TAB - 2 - 6


10/279

3

INTRODUCTION

This manual deals with the emergency actions that are to be carried out when an annunciation

occurs during Sootblower operation. Even though many protections are available in the sootblower

control panel, sometimes it is likely mal-operation can happen. At that time the operating and

maintenance engineers may be in search of correct course of action. We hope this manual will helpthe operating and maintenance engineers to know what safe action they can take to protect the

sootblowers as well as the boiler tubes.

The contents of the manual has been carefully prepared. However, it must be understood that no

amount of written instructions will replace intelligent thinking and alertness on the part of the operator

during an emergency to reason the causes of mal-f unctions and to take ‘immediate remedial actions

demanded by the situation.

Suggestions for the improvement of the manual would be welcome.

1610 - 1611 VOL - C1 TAB - 2 - 7


11/279

4

SOOT BLOWER OPERATION -EMERGENCY CHECK LIST

The control panel is normally supplied with the following audible and visual annunciations.

The above alarms can be actuated during the operation of (a) long retractable soot blower (b) wall

deslagger (c) rotary blower (d), half retractable soot blower and (e) airheater cleaner (retractable).

The possible causes and solutions for each of annunciations for long retractable Soot blowers &

wall deslaggers are described in this manual. For other blowers, the causes and solutions may be

more or less similar to long retractable soot blowers.

S1.

No.Descr ip t ion o f annu nc ia t ion

Type of

annunc ia t i on

1. Sootblower jamm ing audible/visual

2. Sootblower motor overload audible/visual

3. Sootblower overrun audible/visual

4. Steam pressure low audible/visual

5. Steam temperature low audible/visual

6. Steam no flow audible/visual7. A.C. con trol supply failure aud ible/visual

8.Sootblower sequencecompletion.

audible/visual

9. Valve Mo tor overload audible/visual

10. Sequence interruption audible/visual

1610 - 1611 VOL - C1 TAB - 2 - 8


12/279

5

1. SOOT BLOWER JAMMING

This alarm will be actuated when soot blower gets jammed mechanically in the forward direction.

The alarm is given through an instantaneous overload relay which is actuated instantaneously and

will reverse the blower to bring to the home position. The instantaneous overload relay will actuate

the timer which will be set at 2 secs., normally current will be 105 percent of the rated current.

1.1 Long retractable soot blower Probable causes and solutions for jamming

Sl. No. Probable Causes Solution

(i) Lance tube fouling with the boiler

tubes or wall sleeve

During shut down the boiler tubes should be

rectified so that a gap of 100-150 mm is kept

in between the lance tube OD and the boiler

tube OD. Realign any tube obstructing thelance movement.

(ii) Physical obstruction for the travelling

carriage in the housing

Check the blower for proper clearance for the

travelling carriage. This can be checked only

by local operation

(iii) If direction of rotation for traverse

motor is incorrect

Change the power cable loads with power off

and run blower again.

(iv) Failure of reverse limit switch Replace the defective switch

(v) Valve stem jammed/pitted Remove the stem and replace or rectify

(vi) Overtightened gland packing intravelling carriage

Loosen the gland

1.2 Wall Deslagger : Probable Causes and Solutions for Jamming:

(i) Swivel tube fouling with shroud

tube

Position the blower in such a way that the

swivel tube does not foul with the shroud

tube and the perpendicularityto the water

wall is to be maintained.

(ii) Dust accumulation on the guide

rods and the swivel tube

Clean the guide rods and the swivel tube

once in a week. If the accumulation of dust is

severe, and morefrequent provide additional

covers.

(iii) Direction of traverse motor is in-

correct

Change the direction of motor by

changing powerleads.

(iv) Wrong setting of limit switches

LSTS and LSTE

Reset the Cam.

(v) Too much of Gland tightness

on wall blower body.

Loosen the gland nuts to have enough

freeness.

(vi) Valve stem/pitted jammed Remove the item and replace or

rectify.

'Reset'push button on the panel should be pressed to continue the sequentialoperation after

bypassing the faulty blower.

1610 - 1611 VOL - C1 TAB - 2 - 9


13/279

6

2. SOOT BLOWER MOTOR OVERLOAD

This annunciation will come on as soon as the motor gets overloaded the traverse motor will get

stopped. The thermal overload relay is set to act normally when the current exceeds 105 percent of the

rated current. The probable causes and solutions for his are given below :

2.1 Long retractable soot blower - Motor overload- Probable Causes and Solutions :

Sl. No. Causes Solutions

(i) Lance tube fouling with boiler

tubes

Same solution as indicated under

sootblower jamming.

(ii) Overtightened gland packing Do not overtighten the glands. A

slight leakage of steam is allowed.

(iii) Wrong overload relay setting Check the overload relay setting and

set the relay at the correct value.(iv) Dust accumulation over the rails Clear the dust and debris.

(v) Wrong motor installation in

powerpacks.

Check the overload relay setting and

set the relay at the correct value.

(vi) Damaged power/control cables

(Short circuit in any two phases in

M.C.C. or Terminal box)

Check the power cables. It is likely

that cables damage will result in

short-circuiting.

(a) Check the power cable from

MCC. to blower terminal box.

(b) Check the power cable from themotor to terminal box.

(c) Check the terminal box of motor.

(vii) Motor winding fault Refer the motor instructions manual.

2.2 Wall deslagger: (i) Swivel tube fouling with the boiler

tubes

Same solution as indicated under

‘Sootblower jamming’.

(ii) Wrong overload relay setting Do as suggested in 2. 1. (iii)

(iii) Short circuit in the powerloads in

M.C.C. or in terminal box

Do as suggested in 2.1 (vi)

(iv) Motor winding fault Do as suggested in 2.1 (vii)

(v) The rack comes out of pinion Sometimes because of loose screws

of cams the rotary gear box is

likely to come out of pinion. For this

(a) an easy solution would be to put

two rubber washers on guide rods.

(b) Periodically tighten the cam screws.

(vi) Improper meshing of gears Dismantle the gear box and check

the meshing of gears.

Overload relay should be reset in M.C.C. before operating the same blower. After ensuring

the lance of the particular blower is withdrawn to the home position only, the

sequential operation should be continued. Physical checking is a must.

1610 - 1611 VOL - C1 TAB - 2 - 10


14/279

7

3. SOOTBLOWER OVERRUN

The total time for forward and reverse operation of sootblowers is supervised by elapsed timers.

When the blower stays for a longer time than its normal working time the blower overrun annunciation

will come and will stop automatic sequence operation and at the same time retract the blowers to its

initial position. Normally the timer is set in excess by 1 or 2 minutes of blower operating time.

The probable causes and suggested solutions are given below

3.1 Long Retractable Soot blower-Soot blower overrun-Probable causes and solutions


(i) Faulty reverse limit switch If the blower is not withdrawn auto-matically

Immediate action

Allow the steam flow if the blower is located in hot

zone. Send one man for closing the regulating valvemanually. Switch off the power,

Then withdraw the lance manually.

Caution

Do not allow the lance inside the boiler for a longertime with blowing medium.

Later

Check the limit switch contacts, spring, etc. If it isin serviceable condition service and put back the

switch. If it is not possible then replace the switchwith a new one.

(ii) Wrong timer setting Normally the timer is set more than 1 minute thanthe operating time. Check the timer setting and set

correctly.

(iii) Failure of contactor andcontactor reverse (CR) coils

Check the forward and reverse contactor, clean theterminals and' contacts and put back in M.C.C.

(iv) Traverse chain failure due to

the weak link

Immediate action :

(a) Allow the steam flow not more than 5 minutes.

(b) Wrap a chain or rope around the travelling

carriage through a winch. If this takes too muchof time, stop the steam flow. By doing so it is

likely that the lance may get bent. In case of blowers located in low temperature zones, the

steam flow can be cut off just after the jamming hasoccurred

(c) And now stop the steam flow.

(d) Pull out the lance tube.

Later : Replace the damaged chain link,

using connector link.

(v) Traverse Motor shaft breakage Immediate Action :

(a) Cut off power supply.

(b) Allow the steam flow for not more than 5 minutes.

(c) Retract the lance, using the hand crank.Later Assemble a new motor and check the direction of

rotation before the blower is put into operation again.

1610 - 1611 VOL - C1 TAB - 2 - 11


15/279

8


(vi) Burnt out or damaged traverse

Motors.

Immediate Action :

(a) Cut off the power supply.

(b) Allow the steam flow for not more than 5

minutes.

(c) Retract the lance tube using the hand crank,after cutting off steam supply.

Later

Assemble a new motor or repaired one and check

the direction of rotations before the blower is put

into operation again.

(vii) Thermal overload

Relay for traverse

motor blows as a

result of which

the traverse motor

stops.

Immediate Action

(a) Cut oft the power supply.

(b) Allow the steam flow for

not more than 5 minutes.

(c) Retract the lance tube using the hand

crank as suggested in 3.1.(i)

Later

Check why the motor has stalled.

Find out the cause

3.2 Wall Deslagger:

(i) ‘ LSTR ' limit switch fails to

operate or damaged, missing switch

arm.

Immediate Action:

(a) Switch off the power supply.

(b) Using the hand crank, withdraw the swivel

tube. (Hand cranking is possible with steam

on).

(ii) Wrong timer setting Normally the time is set for 120 secs. Check thetimer

setting and set correctly.

(iii) Faulty rotary contactor (CRO) Check the rotary contactor, clean the terminals and

contacts and put back in M.C.C.

(iv) Failure of Traverse motor -shaft

or rotary motor shaft

Immediate Action

(a) Switch off the power supply.

(b) Using the hand crank withdraw the swivel

tube. (Withdrawl of swivel tube by hand cranking

is possible with steam on)

Later :Assemble a new motor and check the direction of

rotation before ,he blower is put into operation again

(v) Burnt Out or damaged motors Immediate Action :

(a) Cut off the power supply.

(b) Retract the swivel tube using the hand crank.

Later :

Assemble new motors and 'check the direction of

rotation before the blower is put into operation again.

Reset push button on the panel should be pressed to continue the sequential operation afterensuring the particular blower is in home position. Physical checking is a must.

1610 - 1611 VOL - C1 TAB - 2 - 12


16/279

9

4. STEAM PRESSURE LOW

This annunciation will come to the operator as soon as the system pressure is lower than the set

value. As soon as the annunciation is received, retract the blower immediately and stop the

sootblowing operation. The probable causes and suggested solutions are as follows:

S1. No. Probable Causes Suggested Solutions

(i) Multiple leaks in the system Stop the sootblower operation.

(a) sootblower valve passing. Later

(b) Sootblower flange leakage. Identify the leakage in the system

(c) Drain valve heavy leakage. and attend the leaks.

(ii) Mal-functioning of pressure reducing Immediate Action:

valve Stop the sootblower operation.

Later :

Attend to this problem. Ref.detailed

instructions for trouble shooting

of pressure reducing valve.

Immediate :

(iii) Hand stop valve partially closed (a) Stop the sootblower operation

(b) Open the valve fully.

(c) Then proceed with SB operation.

(iv) Erratic action of pressure switch or Immediate Action:

damaged pressure switch. Sootblowing can be continued by watching the pressure indicator

available on the panel.

Later :

Attend to pressure switch or

replace with a new one.

CAUTION :

Close the steam supply before

attending the work.

(v) Broken supply line Immediate :

Stop the sootblower operation.Later :

Close the steam supply.

Repair the failed steam piping.

Then proceed with Sootblower

operation.

‘Reset’ push button on the panel should be pressed to continue the sequential operation. Physical

checking is a must wherever necessary.

1610 - 1611 VOL - C1 TAB - 2 - 13


17/279

10

5. STEAM TEMPERATURE LOW

This annunciation is provided so that the operator will be cautioned when the medium temperature

is low. It is likely that low steam temperature will cause condensation which will lead to boiler tube

wastage. This may be due to inadequate ‘warm up’ and poor insulation. The solutions will be

sufficiently warm up the line and ensure sound insulation.

Another cause may be choking in the drain line. The solution would be to remove the condensate

properly.

‘Reset’ push button should be pressed after rectifying the fault to continue the sequential operation

further.

1610 - 1611 VOL - C1 TAB - 2 - 14


18/279


19/279

12

7. A. C. CONTROL SUPPLY/ POWER SUPPLY FAILURE

When the A.C. supply fails during the operation of blowers, an alarm is annunciated. If the sootblowing

operation is proceeding at that time, send a gang for withdrawing the blower back out of the boiler.

Proceed as follows :

7.1 Long Retractable Soot blower

(1) Send one man for closing the manual operated valve.

(2) Send another man with hand crank. After declutching withdraw immediately.

7.2 Wall deslagger

Send a man with a hand crank to withdraw the lance tube. “Reset” button must be pressed in the

control panel before proceeding with the operation after the power is restored.

8. SOOT BLOWER SEQUENCE INTERRUPTION

This annunciation will come to the operator when the blower does not start even after the sequencing

signal is given to the other blower to start. If the blower does not start after 10 secs. even after the

completion of operation of the previous blower then this annunciation will come. The probable

causes and solutions are as follows :

Sl. No. Probable causes Solutions

(i) Motor burnt out or damaged traversing motor

Immediate:

Bypass the blower from sequence operation

Press ' reset ' button and proceed with other

blower operation.

Later :

Check the motor. If possible repair the same

or replace with a new motor.

(ii) Failure of motor starter, broken

wires, motor overload.Immediate:

Bypass the blower from sequence operation

and proceed with other blower operation.Later :

Identify the problem and rectify the system.

(iii) Defective cabling. Immediate:

Bypass the blower from sequence operation.

Press "reset" button and proceed with other

blowers operation.

Later :

Identify the problem and rectify the

system.Press "reset" button in the panel before operation is continued.

1610 - 1611 VOL - C1 TAB - 2 - 16


20/279

13

9. VALVE MOTOR OVERLOAD

This annunciation will come if the main supply valve actuator is overloaded. The probable causes

and solutions are as follows :

Sl. No. Probable causes Solutions

(i) Too much gland overtightening Ensure correct gland packing and

tightness.

(ii) Score marks on stem Check Recondition/ Replace stem if

necessary.

(iii) Non-release of motor brake Remove the brake mechanism and

service.

(iv) Wrong setting of limit switch on the actuator.

Set the limit switches correction asinstructed in 0 & M manual.

(v) Wrong overload relay setting. Check and set overload relay at the

recommended value.

(vi) Excessive torque setting of torque

switches.

Set the torque switches at the

recommended value as per 0 & M

manual No. 7001.

(vii) Jamming of moving components in

the guide ways.

Bypass the whole steam line and

then do servicing, For detailed

repairing procedure refer the relevant

0 & M manuals.

After attending to the fault, press 'reset' button in the panel before the operation

is continued.

1610 - 1611 VOL - C1 TAB - 2 - 17


21/279


22/279

TAB - 3


23/279

INSTRUCTION MANUAL

AC INDUCTION MOTOR

(FOR SOOT BLOWERS)

PUB. NO. 7506


Tiruchirapalli

1610 - 1611 VOL - C1 TAB - 3 - 19


24/279

2

CONTENTS

GENERAL INFORMATION

GENERAL

STORAGE

LOCATION OF MOTORS AND CONTROL APPARATUS

GEAR DRIVES

DRYING OUT

REVERSAL OF ROTATION

INSPECTION AND TESTING5

GENERAL

MECHANICAL

ELECTRICAL

MAINTENANCE PROTECTION OF EXPOSED SURFACE6

GENERAL

INSULATION RESISTANCE

REMOVAL AND REPLACEMENT OF BEARINGSBALL AND ROLLER BEARINGS

LUBRICATION

CONTROLLERS, STARTERS AND RHEOSTATS

SAFETY DEVICES

CHECK CHART

AC MOTOR CHECK CHART

MAINTENANCE SCHEDULE1

LIMITS OF TEMPERATURE RISE

DATA SHEET FOR SOOT BLOWER MOTORS

1610 - 1611 VOL - C1 TAB - 3 - 20


25/279

3

GENERAL INFORMATION

1.1 GENERAL

Where the magnitude of the installation justifies the cost, a set of record plans should be provided

by the installation engineer or contractor, clearly indicating the complete layout of the installation.

There is always the possibility that hair, hands or clothing may be caught in moving parts of

electrical machines, which should thus be so located or guarded as to minimize the risk of such

injuries to those who may come in contact. In the case of equipment subject to the provisions of

the Factories Act such mechanical protection is a statutory requirement.

1.2 STORAGE

If the machine has got to be stored for some time before installation, the same has to be done in

a clean, dry place. If the location is susceptible for vibrations transmitted due to working of

heavy machinery, proximity to rail track, etc. it is desirable to have a resilient pad between the

floor and the machine. Also keep the shaft of the motor locked so that, bearings are not damaged

during storage. However, periodically rotate the shaft free and relock it.

1.3 LOCATION OF MOTORS AND CONTROL APPARATUS

Apparatus shall be so located that all current-carrying parts are adequately ventilated in relation

to the losses to be dissipated in the form of heat.

Note: In no circumstances should the motor be enclosed in a box or other covering hat restricts

or excludes the ventilating air to a significant extent. Such restriction may result in the

burning out of the motor when a sustained load approaching the full value is reached.

The motor and control apparatus shall not be located where it is liable to exposure to water,

corrosive liquid, oil, steam, carbon, copper dust, dirt or other adverse condition or to risk of

mechanical damage, unless it is suitably enclosed to withstand such conditions.

Adequate access shall be provided to all working parts. The possible need for facilities for

removing the equipment at a later date for repairs or maintenance should be considered in relation

to the accessibility of the equipment.

Note: For handling heavy equipment it is often advisable to arrange for the incorporation of a

lifting beam in the structure of the building, the beam being located immediately over

such parts of the equipment as may require attention and being capable of supporting

the maximum weight involved.

The placing of apparatus in situations where inflammable material may be present should be

decided in relation to the fire risk involved, and where it is impracticable to segregate the apparatus

from such material, the use of totally enclosed or pipe ventilated apparatus should be considered.

Where resistors are used which are liable to operate at high temperatures, they should be adequately

spaced away from combustible materials such as wood-work, in order to combat the risk of fire.

Whenever the temperature of the casing of the apparatus is liable to exceed 194 Deg. F (or 90

Deg.C) the casing should be so located or guarded as to prevent accidental contact by persons or

with combustible materials.

1.4 GEAR DRIVES

With gear drives, alignment is equally important. The centre of the pinion shall be in line with

the centre of the spur wheel and the two wheels perfectly parallel, the latter being checked by

means of feeler gauges between the teeth of the respective wheels. The gear wheels shall be fully

meshed both in depth and along their width of face and the check for meshing shall be made allthe way round the driven wheel in case it is out of truth. Should the driven wheel be out of truth

and the meshing adjusted correctly at the lowest point of the driven wheel, the gears would jam

when the high parts engage and probably bend the motor shaft.

1610 - 1611 VOL - C1 TAB - 3 - 21


26/279

4

Bevel or single helical gears will impose an end thrust on the motor shaft, and are not therefore

recommended unless provision is made to take the thrust. Double helical gears may also transmit

an end thrust if the end-play in the bearings of the driven gear is greater than the end-play in the

motor bearings. Where mechanical conditions are severe it is sometimes necessary, particularly

in the case of large motors, to employ an outboard bearing for the motor shaft and in some cases

to mount the driving pinion in two separate bearings and couple it to the motor through a suitable

flexible coupling. A flexible coupling is invariably necessary when a motor is coupled to a self-

contained gear box. It is advisable, when any drives of the above mentioned or similar types areconsidered, that this be specified so that provision can be made to suit the conditions.

Where motors are fitted with ball and roller bearings, care shall be taken to ensure that no axial

strain is imposed on the bearings when the half-couplings are bolted together.

1.5 DRYING OUT

All motors shall be dried out before the full voltage is applied to the terminals, if the insulation

resistance is below one megaohm when the machine is cold. A convenient method of doing this

is to block the motor so that it can not rotate and apply a very low voltage of about 10 percent of

the normal to the stator terminals.

In the case of slip-ring motors, the rotor windings should be short-circuited.

Close supervison is necessary during the process of drying out with this method. The heat

generated in the windings is not easily dissipated and one part of the winding may be exceeedingly

hot before another part has had time to expel the moisture. This may be obviated to some extent

by taking every precaution to exclude draughts from the exposed parts of the windings.

The motor can be placed in oven, if available, but the temperature shall not be allowed to exceed

180 Deg. F (or 82.2 Deg.C). Alternatively, hot air may be blown into the motor but the air should

be clean and dry and at a temperature of not more than 180 Deg.F. If no other means are available,

coke braziers or electric radiators may be placed round the machine. Carbon filament lamps

placed inside the machine can be employed quite satisfactorily, but care shall be taken that thehot bulb is not in contact with any windings. If it is not possible to reach a sufficiently high

temperature the ventilation may be reduced by covering the stator with a tarpaulin.

Whichever of the above methods of drying out is adopted, the heating shall be continuous and

shall be carefully watched to ensure that it does not attain a temperature sufficiently high to

damage the insulation. The maximum safe temperature of the windings measured by thermometer

is 180 Deg. F (or 82.2 Deg.C). At the same time the temperature should not be allowed to fall too

low as otherwise re-absorption of moisture would take place.

The insulation resistance will be found to drop considerably as the motor warms up, will reach

the minimum and then remain constant for sometime depending upon the dampness of the machine

and as the drying proceeds the insulation resistance will gradually rise. The drying out shall becontinued as long as the insulation resistance rises, or until a sufficiently high value has been

reached, i.e. not less than 1 megaohm per 1000 volts at 75 Deg.C.

During the drying out period, readings of temperature and insulation resistance shall be taken

atleast once an hour in order to see how the drying out is progressing. The temperature of the

motor shall be kept as constant as possible, otherwise the insulation resistance readings may be

misleading.

NOTE: The motor should be watched constantly whilst drying out.

1.6 REVERSAL OF ROTATION

Reversal of rotation, if required shall be effected by interchanging two of the three supply leads

connected to the stator switch, breaker or starter.

1610 - 1611 VOL - C1 TAB - 3 - 22


27/279

5

2. INSPECTION AND TESTING

2.1 GENERAL

All electrical equipment shall be inspected and tested by competent persons at regular intervals,

the frequency of such inspection depending on the type of equipment and on the operating

conditions. A record of each inspection and of the result of tests should be kept.

2.2 MECHANICAL

Machines shall be checked for alignment to ensure that undue stresses are not imposed on their

bearings.

Where oil-lubricated bearings are employed care should be taken to see that oil does not penetrate

on to windings or other insulation. In addition clearances shall be kept to reasonably close limits

as too large a clearance may affect correct alingment and may cause fouling of the stator by the

rotor, whilst too small a clearance may disturb running mechanical balance. Oil should be checked

to see that it is clean and up to the right level.

The air gaps in sleeve bearing machines shll be checked before commissioning. This check

should be repeated at periodic intervals.

Mechanical operation of motors control gear and protective devices shall be checked for freedom

from external material, care being taken when commissioning to see that all packing materials

are removed.

In the case of motors and control gear, attention should be paid to all contacts, the contact pressure

and contact area being checked and verified as being proper to the operating conditions involved.

If ball roller bearing motors have been kept idle for periods longer than six months whether new,

spare or stand-by plant, the bearing covers should be removed for inspection of grease. If it is

found that the grease has a skin over the surface, the bearings should be washed out thoroughly

in kerosene, and three drops of fine oil added to the race. The bearing housings should be

repacked with new grease recommended by the makers, care being taken to ensure that the ballsor rollers will not churn in the grease. One of the chief functions of grease is to prevent the entry

of dust to the races, very little being required for lubrication.

2.3 ELECTRICAL

All fixed connections shall be checked for tightness and where heavy currents are involved a

check shall be made to see that contact adequate in area and pressure to prevent undue heating is

effected between all contact surfaces.

Before the equipment is put into service, it shall be tested for insulation resistance and other tests

as may be necessary should be made. Continuity tests shall be carried out, particular attention

being given to the secondary connections of current transformers. Before switching in for thefirst time, protective devices shall be set at their minimum current values and at the minimum

time setting in order to minimise the consequence of any fault condition which may arise.

The rating of fuses shall be checked by inspecting the marking on the cartridge-type fuses or

inspecting the gauge and type of wire in the case of semi-enclosed type-fuses. Where practicable,

the operation of overload, no volt and other types of protective device shall also be checked. The

results of such checking should be related to the ascertained resistance of the earth-fault current

path so as to determine the prospect of the protective device operating in the event of a fault to

earth. Earth leakage protection should be adopted in the following cases:

a. If the ascertained resistance is such as to restrict the fault current to a value below the

operating value of the overload releases.

b. If the margin is too small to ensure reliability in all seasons.

1610 - 1611 VOL - C1 TAB - 3 - 23


28/279

6

c. If, where fuses are used, the resistance is such that sufficiently rapid operation cannot

be ensured, and the earthing conditions cannot be improved.

Protective fuses shall be examined regularly, and, as far as possible tested. Where relays are used

in conjunction with current transformers, the test should preferably stimulate working conditions

by utilizing the injection method whereby current is passed through the relays by the application

of a variable injection voltage from a transformer designed for the purpose.

3. MAINTENANCE PROTECTION OF EXPOSED SURFACE

3.1 GENERAL

Protective paint and varnish shall be maintained in good condition by repainting or revarnishing

when necessary, it being noted that in many instances, such as that of machine windings, spraying

is the only effective means of application of such protection.

MOTOR

Cleaning of Machines

Motor shall be blown out at regular intervals to keep their ventilating passage clear, it being

emphasised that many types of totally enclosed motors required such attention, particularly when

operating in dusty atmosphere.

Moisture, oil, dirt, grease and carbon or metallic dust are the principal causes of breakdown. The

motor should therefore be kept clean and dry; water dropped on the machine will soon cause

trouble, unless the motor has been designed to withstand such conditions. The stator and rotor

windings must be kept free from oil and grease, damp and dirt. Periodic cleaning with dry

compressed air, bellows or a brush, is very necessary.

All motors require to be examined and dismantled from time to time and the frequency of

successive cleanings will depend upon the conditions under which the machine operates. During

periodic cleanings care shall be taken to clear air passages in the stator and rotor of any accumulated

dirt.

Terminals and screw connections shall be kept clean and tight. If they become dirty or corroded,

they shall be disconnected and all contact surfaces made clean and smooth. Bad contact leads to

sparking and ultimate breakdown.

After reassembly, the gaps shall be tested as a precautionary measure by means of a feeler gauge.

If it is found that the air gap measurements of two diametrically opposite points differ by as

much as 25% the machine shall be examined, because the brackets or bearing housings will not

be correctly aligned. Gap measurements shall always follow reassembly, since rubbing between

stator and rotor will cause extensive damage.

3.2 INSULATION RESISTANCEThe insulation resistance of the windings shall be tested periodically during service and where

this is found to drop below 1 megaohm/KV with a minimum of 1 Megohm the motor shall be

dried out and put in service. If weak insulation, resistance becomes a regular feature the windings

shall be given a coat of good insulating varnish after the machine has been dried out. Where the

motor is installed in locations, subject to dampness, chemical fumes, etc., the installation indicator

such as a neon lamp to show the condition of the insulation of the motors is recommended.

3.3 REMOVAL AND REPLACEMENT OF BEARINGS

In small frame motors, the bearings can be removed with a bearing puller. The cartridge type

bearing housing is employed in large frame motors.

After cleaning, the housing should be greased with the specified grade grease and the bearing

replaced by applying even pressure to the outer race. Having ensured that the bearing is square

with the housing, it may be necessary to tap lightly into position.

1610 - 1611 VOL - C1 TAB - 3 - 24


29/279

7

Having ascertained that the outer race beds firmly against the housing shoulder, the whole may

be slipped over the shaft which should be cleaned and oiled.

The bearing may now be forced on to the seating by means of a tube placed over the shaft and

applied to its inner race; this method ensures even pressure and the bearing may be driven home

against its locating shoulder. On no account must the inner race mounted by hitting the outer

race and pressure should not be applied to the outer race during the process. The blows should

be equally distributed all round the inner race and care should be taken to avoid hitting or applying

pressure to the lip of the inner race, in the case of a roller bearing. Otherwise the bearing along

with the bearing housing can be heated in medium oil Shell Tellus – 33 Deg. at a temperature not

exceeding 100 Deg. C for about one hour to enable easy mounting by push fit.

3.4 BALL AND ROLLER BEARINGS

Climatic conditions affect the lubrication and it is necessary to ensure that the bearings do not

run hot. This shall be tested from time to time by placing the hand on the bearing cap. A

moderate warmth to the hand is a ready indication that the bearing is running at its best. Higher

or lower temperatures are not dangerous in themselves but increasing temperature or noise are

sure signs that the bearing needs immediate attention. It may be that the addition of a small

amount of grease will arrest and cure the trouble.

When opening up bearings for inspection and cleaning, all dirt and foreign matter shall be removed

from the neighbourhood of the bearing caps. The caps shall then be removed and the bearings,

caps and housings washed with kerosene, all old grease also being removed in the process and

the parts thoroughly cleaned. If the bearing is in good condition, fresh grease shall be pressed

well between the cage, races, balls and rollers. We recommend Shell Alvania No.3 grease or it’s

equivalent. After packing the bearing, any superfluous grease shall be wiped off. If the bearing

appears dirty or if the grease has become hard and disintegrated the bearing shall be removed

from the shaft, withdrawn from the housings and closely inspected for signs of wear.

3.5 LUBRICATION

It is often assumed that with the substitution of rolling motion for sliding motion in antifriction

bearings, the sources of friction are eliminated and lubrication is of secondary importance. But

this is not correct since sliding friction still occurs at the cage which separates the rolling elements

or between the element themselves if they are not separated.

The smooth and silent running of antifriction bearings depends to a large extent on the high

degree of finish imparted to the tracks and rolling elements, and quite apart from its function of

minimising wear on rubbing surfaces, the lubricant is required to protect these highly finished

working parts. The rolling element bearings require a small amount of lubricant depending upon

the size and type of bearing and generally the lubricating intervals are long. However, lubricant

must always be present in the bearings otherwise their lift may be affected or retarded by injurieswhich could have easily been avoided.

The main functions of lubricant in a bearing are:

i. To provide a separating film between rolling and sliding contacting surfaces, thus pre

venting wear.

ii. To act as a coolant to maintain proper bearing temperature.

iii. To prevent the bearing from being contaminated by dirt and other foreign matter.

iv. To prevent corrosion of bearing surfaces.

When the moving parts of a bearing come in contact with grease, a small quantity of oil adheresto the bearing surfaces. Oil is therfore removed from the grease near the rotating parts. The oil

that is picked up by the bearing is gradually broken down by oxidation, or lost by centrifugal

1610 - 1611 VOL - C1 TAB - 3 - 25


30/279

8

force, and volatalisation. Bleeding of the Grease therefore takes place to continue the supply of

a small quantity of oil, which is usually sufficient for satisfactory operation.

Lithium based Multipurpose Grease conforming to Grade 3 of IS 1002-1956 amended upto date,

is recommended for all Rotating machines fitted with antifriction bearings.

The popular greases are:

Shell Alvania (or Multipurpose) Grease 3

Mobilux Grease No.3

Castrol Shperol. AP3

The safe operating temperature range for the above greases is:

-130F to 2480F (approx. Value)

The quantity of Grease which should be applied to the inside of the bearing when relubricatingis,

D x B

W = —————— x 28.35 Grams

6000

Where D = O.D. of the Bearing in mm

B = Width of the Bearing in mm

W = Weight of grease in gm

Running conditions, especially speed relative to the bearing size determine the permissiblerelubrication frequencies, provided an approved ball bearing grease is used.

Over-lubrication is equally hazardous as under-lubrication. If excess grease is maintained in the

race-track under-pressure, excessive friction develops often resulting in the break-down of the

grease, which in turn affect the life of the bearing considerably.

3.6 CONTROLLERS, STARTERS AND RHEOSTATS

The contact and insulating parts must be kept thoroughly free from dirt and moisture and there

shall be firm metallic connection between fixed and removable contacts when they come together.

The covers shall be removed periodically for inspection.

Fuse contacts and terminals must be examined periodically for cleanliness and tightness. When

a fuse wire or strip has to be renewed, care must be taken that the new is of the correct metal and

size.

TWO PART BEARING HOUSING

BALL BEARING WITHDRAWAL BALL BEARING REPLACEMENT

1610 - 1611 VOL - C1 TAB - 3 - 26


31/279

9

3.7 SAFETY DEVICES

Remote tripping devices and limit switches which are provided for safety reasons but which may

not be called upon to function under normal operating conditions, shall be checked for operation

at regular intervals.

Interlocks designed to prevent unsafe operations shall be checked periodically by a deliberate

attempt being made by a competent person to perform the operations which the interlocks are

designed to prevent.Where an emergency supply is provided, the source of supply and all ancillary apparatus shall be

checked periodically.

3.8 CHECK CHART

A check chart should be kept for assistance in the maintenance of the motor. A recommended

chart is given in Section 4. All reports and test results shall be recorded in a suitable log book.

4. AC MOTOR CHECK CHART

SI.No. Trouble Cause Remedy

01 Hot Bearings - Bent or sprung shaft. Straighten or replace shaft.

General. Excessive belt pull. Decrease belt tension.

Pulley too far away. Move pulley closer to bearing.

Pulley diameter too small. Use larger pulley.

Misalignment. Correct by realignment of drive.

02 Hot Bearings Insufficient grease. Maintain proper quantity of

ball or roller. grease in bearing.

Deterioration of grease or Remove old grease, wash

lubricant contaminated. bearings thoroughly in kerosene

and replace with new grease.

Excess lubricant Reduce quantity of grease.

Bearing should not be more than

1/2 filled.

Heat from hot motor or Protect bearing reducing motor

external source. temperature.

Overloaded bearing. Check alignment, side thrust and end thrust.

Broken ball or Rough Replace bearing; first clean

races. housing thoroughly.

03. Oil leakage from Stream of overflow plug Remove re-cement threads

overflow plugs not tight. replace and tighten.

Cracked or broken Replace the plug.

overflow plug.

Plug cover not tight. Requires cork gasket or if screw

type may be tightened.

1610 - 1611 VOL - C1 TAB - 3 - 27


32/279

10

05 Motor Wet Subject to dripping Wipe motor and dry by

circulating heated air

through motor.. Install drip

or canopy type covers over motor protection.

Drenched condition. Motor should be covered to retain

heat and the rotor position

shifted frequently.

Submerged in flood Dismantle and clean parts.

water. Bake windings in oven at

180°F (82°C) for 24 hours

or until resistance to ground

is sufficient.

06. Motor stalls Wrong application. Change type or size.

Consult manufacturer.

Overloaded motor. Reduce load.

Low motor voltage. See that nameplate voltage is

maintained.

Open circuit. Fuses blown, check overload relay, starter and pushout.

Incorrect control Check control sequence.

resistance of wound Replace broken resistors.

rotor. Repair open circuits.

Mechanical locking in Dismantle and repair.

bearings or at air gap. Clean air gap if choked.

07. Motor connected No supply Voltage. Check Voltage on each phase. but does not start One phase open voltage

too low.

04. Motor dirty Ventilation blocked end Clean motor will run 10° to 30°C

winding filled with fine cooler. Dust may be cement,

dust or lint. sawdust, rock dust , grain dust,

coal dust and the like.Dismantle entire

motor and clean all windings and

parts.Rotor winding clogged. Clean and grind slip rings. Clean and

treat windings with good insulating

varnish.

Bearing and brackets Dust and wash with cleaning solvent.

coated inside.


1610 - 1611 VOL - C1 TAB - 3 - 28


33/279

11

If of slip-ring type, lower

the starting resistance.

Rotor Defective. Look for broken rings.

Poor stator coil Remove end belts, locate

connection. with test lamp.

Mechanical locking in Dismantle and repair.

bearings or at air gap. Clean air gap if choked.

08. Motor runs and Power failure. Check for loose connections

then dies down. to line, to fuses and to control.

(see also SI.No.7).

Overload. Examine overload trips. See

that they are set correctlyto approximately 150 percent

full load current. See

that the dashpots are filled

with correct quantity and

grade of oil.

09 Motor does not Not applied properly. Consult supplier for proper

come upto speed. type.

Voltage too low at Use higher voltage on

motor terminals transformer terminals or

because of line drop. reduce load.

If wound rotor Correct secondary control.

improper control

operation of

secondary resistance.

Starting load too high. Check load or motor which is

supposed to carry at start.

Check that all brushes Check secondary connections

are riding on rings. Leave no loads poorly

connected.

Motor may be over Reduce load or try to start

loaded. uncoupled from load.

Control gear defective. Examine each step of the control

gear for bad contact or open

circuit. Make sure that brushes are

making good contact with thering.

Starting torque of load If of squirrel cage type and

too high. with auto-transformer

starting change to a higher tap.


1610 - 1611 VOL - C1 TAB - 3 - 29


34/279

12

10. Motor takes too Excess loading. Reduce load. If motor is

long to accelerate driving a heavy load or is

starting up a long line of

shafting start more slowly

allowing ample time for

acceleration till it overcomes

the difficulty.

Poor circuit. Check for high resistance.

Defective squirrel Replace with new rotor.

cage rotor.

Applied voltage too Get power company to

low. increase voltage tap.

11 Wrong rotation. Wrong sequence of Reverse connections of

phases. motor or at switchboard.

12. Motor overheats Check for overload. Reduce load.

while running

underload. Wrong blowers or Good ventilation is manifest

airshields, may be when a continuous stream

clogged with dirt and of air leaves the motor. If

prevent proper not,check with manufactuer

ventilation of motor.

Motor may have Check to make sure that allone phase open leads are well connected

Grounded coil. Locate and repair.

Unbalanced terminal Check for faulty leads,

voltage. connections and transformers.

Shorted stator coil. Repair and then check

watt-meter reading.

Faulty connections. Indicate by high resistance.


Broken rotor bars. Look for cracks near the rings. A

new rotor may be required as

repairs are usually temporary.

Open primary circuit. Locate fault with testing device

and repair.

1610 - 1611 VOL - C1 TAB - 3 - 30


35/279

13


High voltage or Check terminals of motor

low voltage with voltmeter.

Rotor rubs stator If not poor machining,

bore replace worn bearings.13. Motor vibrates: Motor misaligned. Realign.

after corrections

have been made. Weak foundations. Strengthen base.

Coupling out of Balance coupling.

balance.

Driven equipment Rebalance driven equipment.

unbalanced.

Defective ball or Replace bearings.

roller bearings.

Bearings not in line. Line up properly.

Balancing weights Rebalance rotor.

shifted.

Wound rotor coils Rebalance rotor.

replaced.

Polyphase motor Check for open circuit.

running single phase.

Excessive end play. Adjust bearing or add washer.

14. Unbalance line Unequal terminal volts. Check leads and connections.

current on

polyphase motors Single phase operation. Check for open contacts.

during normal Poor rotor contacts in Check control devices.

operation. control wound rotor

resistance.

Brushes not in proper See that brushes are

position in wound properly seated and shunts

rotor. in good conditions.

15. Scraping noise Fan rubbing air shield. Remove interference.

Fan striking insulation. Clean the fan.

Loose on bedplate. Tighten holding bolts.

16. Magnetic noise. Air gap not uniform. Check and correct bracketfits bearing.

1610 - 1611 VOL - C1 TAB - 3 - 31


36/279

14


Loose bearings. Correct or renew.

Rotor unbalance. Rebalance.

NOTE : Certain amount of magnetic noise is inherent in some low speed designs and shouls not

cause alarm.

17. Motor sparking Motor may be Reduce the load.

at sliprings. overloaded.

Brushes may not be of Use brushes of the grade

correct quality and recommended.

may be sticking in theholders.

Brush pressure may be Adjust the brush pressure

too light or too much. correctly.

Sliprings may be tough, Clean the sliprings and

dirty or oily. maintain them smooth

glossy and free from oil

and dirt.

Sliprings may be ridged Turn and grind the slipring

or out of truth. in a lathe to a smooth finish

5. MAINTENANCE SCHEDULE

The following Maintenance Schedule is suggested as a guide.

5.1 DAILY MAINTENANCE

a. Examine earth connections and motor leads.

b. Check motor windings for overheating. (Note that the permissible maximum temperature

is above that which can be comfortably felt by hand.)

c. Examine control equipment.

d. In the case of oil ring lubricated machines:

i. Examine bearings to see that oil rings are working.

ii. Note temperature of bearings;

iii. Add oil if necessary;

iv. Check and plays

1610 - 1611 VOL - C1 TAB - 3 - 32


37/279

15

5.2 WEEKLY MAINTENANCE

a. Check belt tension. In cases where this is excessive it should immediately be reduced

and in the case of sleeve bearing machines the air gap between rotor and stator should

be checked.

b. Blow out windings of protected type motors, situated in dusty locations.

c. Examine starting equipment for burnt contacts where motor is started and stopped

frequently.

d. Examine oil in the case of oil ring lubricated bearings for contamination by dust, dirt,

etc. (This can be roughly ascertained on inspection by the colour of the oil).

5.3 MONTHLY MAINTENANCE

a. Overhaul Controllers.

b. Inspect and clean oil circuit breakers.

c. Renew oil in high speed bearings in damp and dusty locations.

d. Wipe brush holders and check bedding of brushes of slipring motors.

e. Check the condition of the grease.

5.4 HALF-YEARLY MAINTENANCE

a. Clean windings of motors subjected to corrosive or other element. Also bake and varnish

if necessary.

b. In the case of slip-ring motors check slip-rings for grooving on unusual wear.

c. Renew grease in ball and roller bearings.

d. Drain all oil bearings, wash with kerosene, flush with lubricating oil and refill with

clean oil.

5.5 ANNUAL MAINTENANCE

a. Check all high speed bearings and renew if necessary.

b. Blow out all windings of motors thoroughly with clean dry air. Make sure that the

pressure is not so high as to damage the insulation.

c. Clean and varnish dirty and oily windings.

d. Overhaul motors subject to severe operating conditions.

e. Renew switch and fuse contacts if badly pitted.

f. Renew oil in starters subjected to damp or corrosive elements.

g. Check insulation resistance to earth and between phases of motor windings, control

gear and wiring.

h. Check resistance of earth connections.

i. Check air gaps.

1610 - 1611 VOL - C1 TAB - 3 - 33


38/279

16

5.6 RECORDS

Maintain a register (as per the specimen shown or enclosed) giving one or more pages for each

machine and record therein all important inspections and maintenance works carried out from

time to time. These records shall show past performance, normal insulation level, gap

measurements, nature of repairs and time between previous repairs and other important information

which would be of help for good performance and maintenance.

6. LIMITS OF TEMPERATURE RISE

Permissible maximum temperature rise for class ‘B’ insulation is

120°C

Ambient Temperature .... .... 65°C

1610 - 1611 VOL - C1 TAB - 3 - 34


39/279

17

DATA SHEET FOR SOOT BLOWER MOTORS

SI.

No.

Description Long Retract Long Retract Wall Blower Wall Blower Rotary Blower

01. Application Long Retract

Rotary

Long Retract

Traverse

Wall Blower

Rotary

Wall Blower

Traverse

Rotary Blower

Motor

02. Frame Size 80 80 71 90 71

03. Flange Type IS 2223 Type C IS 2223 Type C IS 2223 Type C IS 2223 Type C IS 2223 Type C

04. Dimensions(Drg.No)

4--20-201-00303

4--20-201-00303 4--20-201-00303 4--20-201-00303 4--20-201-00303

05. Power in KW 0.45 0.37 0.05 0.56 0.09

06. Rated

Voltage

415 415 415 415 415

07. No. of Phases& Frequency

3∅ 50 HZ 3∅ 50 HZ 3∅ 50 HZ 3∅ 50 HZ 3∅ 50 HZ

08. RPM(Approximate)

1425 1365 1480 1425 1425

09. Duty 30 minutes 15 minutes Continous 30 minutes Continous

10. AmbientTemperature

oC

65 65 65 65 65

11. Enclosure &

Protection

Totally

enclosed non

ventilated IP 55 protection

Totally enclosednon ventilated IP

55 protection


55 protection


55 protection


55 protection

12. Class of

Institution

B B B B B

13. Voltage

Variation %± 10 ± 10 ± 10 ± 10 ± 10

14. Frequency

Variation± 5 ± 5 ± 5 ± 5 ± 5

15. Combined

Voltage &

Frequency

Variation

± 10 ± 10 ± 10 ± 10 ± 10

16. Starting

Torque in

kgm.

1.1 0.46 0.245 1.09 0.29

17. Rated Torque 0.3775 0.264 0.0329 0.382 0.063

1610 - 1611 VOL - C1 TAB - 3 - 35


40/279

18

DATA SHEET FOR SOOT BLOWER MOTORS(CONTD.)

SI.No Description LongRetract

LongRetract

WallBlower

WallBlower

RotaryBlower

18. Breakdown Torquein kgm.

1.06 0.485 0.265 1.12 0.29

19. Full load current in

Amps.(Approximat

e)

1.26 0.86 0.44 1.36 0.64

20. No. of leads 6 6 6 6 6

21. Name Plate Stainlesssteel Stainlesssteel Stainlesssteel Stainless Stainlesssteel

22. Paint Epoxy

grey

Epoxy grey Epoxy grey Epoxy grey Epoxy grey

23. Conduct size in the

Terminal Box

M20 x

1.5

M20 x 1.5 M20 x 1.5 M 20 x 1.5 M20 x 1.5

24. Power Factor &Rated

Load(Approximate)

0.68 0.88 0.34 0.78 0.48

25. Efficiency in RatedLoad

(Approximate)

71% 75% 45% 73.5% 44%

26. Maximum stallingTime

(Approximate)

Hot 20sec cold

35

Hot 40 seccold 75

Hot 35 seccold 65

Hot 30 seccold 55

Hot 35 seccold 65

27. Direction of

Rotation

Reversibl

e

Reversible Reversible Reversible Reversible

28. Other Construction

al Features

Shaft end

with oilseal

Shaft end

with oilseal

Shaft end

with oilseal

Shaft end

with oilseal

Shaft end

with oil seal

29. Weight of Motor in

kg. (Approximate)

13.5 13.5 13.5 13.5 13.5

30. GD2 of Motor in

kg.(Approximate)

0.0073 0.0073 0.0027 0.0112 0.0027

1610 - 1611 VOL - C1 TAB - 3 - 36


41/279

TAB - 4


42/279

INSTRUCTION MANUAL

DESCRIPTION, OPERATION AND

MAINTANENCE

SOOT BLOWER

GENERAL INSTRUCTIONS

PUB.NO.7501


Tiruchirapalli

1610 - 1611 VOL - C1 TAB - 4 - 37


43/279

2

CONTENTS

INTRODUCTION

IMPORTANT INSTRUCTIONS

GENERAL INSTRUCTIONS

PREVENTING PUFFS AND FURNACE EXPLOSIONS DURING SOOT

BLOWING

PROCEDURE FOR SETTING BLOWING PRESSURES FOR SOOT BLOWER

SYSTEMS

SOOT BLOWER CHECK LIST AND RECOMMENDED START-UP

PROCEDURE

SOOT BLOWER MAINTENANCE

RECOMMENDED LUBRICATION CHART FOR SOOT BLOWERS

RECOMMENDED QUANTITY OF LUBRICANTS FOR ONE YEAR

VALVE SEAT GRINDING FOR SOOT BLOWER VALVE HEADS

RECOMMENDED PROCEDURE FOR PACKING INSTALLATION

INSTRUCTIONS FOR STORAGE

1610 - 1611 VOL - C1 TAB - 4 - 38


44/279

3

INTRODUCTION

This general instruction, sets some guidelines in preventing puffs and furnace explosions

during soot blowing and outlines the procedure for setting blowing pressures. A check list for

operation and a recommended procedure for start-up are given for general care and correct

start-up. The section on maintenance gives a detailed glimpse into the maintenance problem.

The lubrication schedule helps the maintenance man to choose the correct lubricant and carry

out the lubrication plans.

No Soot Blower system will operate satisfactorily if it is not properly installed, operated and

maintained. It must be recognised that no amount of written instructions can replace intelligent

thinking and reasoning on the part of the operators, especially when coping with unforeseen

operating conditions. It is the operators’ responsibility to become thoroughly familiar not

only with the equipment but also with all pertinent control equipment.

The instruction contained in this manual is only an outline of the correct procedures for

operation and maintenance. The contents in this manual have been compiled and checked by

experts in this field. Every possible care has been taken to ensure the contents are accurate.

Suggestions for the improvement of the manual are welcome.

If you ever have any query about operation, maintenance or related problems, you are welcome

to write to BHEL without obligation.

IMPORTANT INSTRUCTIONS

DO’S

1. CARELESSNESS IN REPAIRING SOOT BLOWING EQUIPMENT CAN CAUSE

SERIOUS INJURIES. ACCIDENTS CAN BE PREVENTED BY TAKING SIMPLE

PRECAUTIONS.

2. INCREASE FURNACE DRAFT BY APPROPRIATE ADJUSTMENTS OF THEINDUCED DRAFT FAN TO TAKE CARE OF THE INCREASED FLUE GAS

VOLUME DUE TO THE SOOT BLOWING OPERATION. THIS WOULD HELP

TO PURGE COMBUSTIBLE GAS POCKETS.

3. AVOID SOOT BLOWING OPERATION WHEN THE REFRACTORY IS HOT

i.e.IMMEDIATELY AFTER STOPPING OR WHEN THE BOILER IS NOT IN

SERVICE FOR SOME TIME.

4. ALL STEAM LEAKS SHOULD BE ATTENDED TO IMMEDIATELY.

5. AVOID EXCESS BLOWING PRESSURE.

6. MAIN MEDIUM VALVE SHOULD BE CLOSED IMMEDIATELY AFTER THECOMPLETION OF THE SOOT BLOWING OPERATION.

7. FOR LUBRICATION, FOLLOW THE LUBRICATION INSTRUCTIONS

CAREFULLY.

8. RETRACT THE LANCE IMMEDIATELY IN THE EVENT OF FAILURE OF

POWER TO AVOID DAMAGE TO THE LANCE.

9. EVEN IF THE BOILER IN OPERATION DOES NOT REQUIRE SOOT

BLOWING, KEEP THEM OPERATING AT LEAST ONCE IN A WEEK. THIS

WILL HELP IF COAL CHARACTERISTIC CHANGE AT A LATER DATE AND

TO KEEP THE SOOT BLOWERS IN ORDER.10. ALL THE PEEP HOLES SHOULD BE CLOSED AND LOCKED BEFORE WALL

DESLAGERS ARE PUT INTO OPERATION.

1610 - 1611 VOL - C1 TAB - 4 - 39


45/279

4

11. DURING OUTAGES, CHECK THE CLEARANCE BETWEEN THE EDGE OF

THE LANCE TUBE AND THE SUPER HEATER, RE-HEATER TUBES. THERE

SHOULD BE A MIN. GAP OF 100MM.

12. THE SOOT BLOWER LINE MUST BE STEAM BLOWN BEFORE THE

BLOWERS ARE PUT INTO OPERATION AT THE TIME OF COMMISSIONING.

DON’TS1. DO NOT ATTEMPT REPAIRS BEYOND YOUR ABILITIES.

2. DO NOT OPERATE THE BLOWERS WITH WET STEAM.

3. DO NOT EXTEND THE LANCE OF LONG RETRACT WITHOUT BLOWING

MEDIUM WHEN BOILER IS ‘ON’.

4. DO NOT OVERTIGHTEN THE PACKING.

5. DO NOT HAND CRANK THE BLOWERS WHILE THE POWER OR BLOWING

MEDIUM IS ‘ON’.

1. GENERAL INSTRUCTIONS1.1 Ordering Repair Parts

When ordering repair parts, always give the Name, Part No., Drg. No., as found on the parts

lists and Model number as found on the brass name plate.

In the case of bearings and elements, swivel tubes or lances refer to Element Location Drawings

and give the Drawing No. for the specific piece needed. Elements may vary for different

locations.

If you have more than one boiler, give the type, size, rating and location of the boiler or

boilers for which parts are needed, and the order number under which you purchased the

Blowers for which parts are needed.

1.2 A Word of Caution

Carelessness in repairing a blowing equipment can cause serious injuries. Accidents can be

prevented by taking simple precautions.

Always get permission and clearance from the proper authority before starting to repair any

equipment.

Use proper lifting equipment for heavy equipment. Do not attempt repairs beyond your ability.

Before repairing any equipment operated by steam or air, make sure all supply valves have

been closed, tagged or locked and also the electrical connections are cut off. If steam or air supply lines must be energised for purpose of test, use extreme caution.

2. PREVENTING PUFFS AND FURNACE EXPLOSIONS DURING SOOT

BLOWING

Explosions, puffs, or blow backs that occur during or as a result of soot blowing operations

should be reported to and discussed with the boiler manufacturer. It is impossible to establish

a definite procedure to prevent these difficulties because of the variation of fuels and the

design and operations of Steam Generating equipment. The start-up or operating engineers

working in conjunction with design engineers or boiler manufacturing firms are best qualified

to recommend procedures of operation on their particular equipment.

The following recommendations are presented for consideration when it is necessary to establish

operational procedure to prevent these difficulties.

1610 - 1611 VOL - C1 TAB - 4 - 40


46/279

5

(i) Cleaning Cycle

As a guide line we suggest a soot blowing cycle of once in a day to start with may be established.

After watching the performance of the particular coal, oil or any other fuel, with reference to

the deposit formation, the blowing cycle can be altered. It is essential to have a satisfactory

cycle so that the heat recovery surfaces are kept free of deposits at the same time the tube

surfaces are not damaged because of frequent blowing. The life of the soot blower parts will

also proportionally decrease with increased frequency. The Boiler operating personnel canestablish the optimum blowing cycle depending on the actual furnace conditions. It is

impossible to predict the deposit formation since too many factors influence the same.

(ii) When possible, the boiler to be cleaned should be operating at or near the maximum

design load.

When soot blowers are operated at low boiler loads, clouds of soot may be blown into the gas

stream to form explosive mixtures which may be ignited by the heat from furnace walls or by

smoldering soot fires. Soot blower operation at low boiler load, with a resulting colder furnace

may also result in some of the unburned combustibles escaping from the furnace and collecting

in pockets in back passes.Agitation and ignition of these gas pockets will cause puffs or explosions. All tube surfaces

and gas passes, therefore, should be blown with the gas flow at or near maximum to purge the

boiler of these possible explosion causes.

(iii) On oil or pulverised fuel fired boilers, soot blowers should be used with the burners

operating at the highest possible burning rate, maintaining even stable combustion.

Soot blowing schedules should be established to take place during the heaviest load

periods, or the burner firing rates should be increased during soot blowing. Burners

should be checked during soot blowing for stability.

A high burning rate assures a lower oxygen content in flue gases which eliminate the difficulty

as explained in (ii) above.

High and stable burning rates also prevent flames from being blown out by small puffs or

agitation of the gas flow common while soot blowing.

(iv) Before operating soot blowers the furnace drafts should be increased by opening the

boiler outlet damper or by making the appropriate adjustments of the induced draft

fan to take care of the increased flue gas volume due to the soot blowing operation.

Increased furnace draft helps to purge combustible gas pockets explained in (ii) above.

Increased furnace draft improves cleaning by moving soot particles through gas passes rather

than re-depositing them on adjacent surfaces.

(v) Conditions may require the operation of soot blowing equipment with the burners

out of service as when cleaning prior to outages to facilitate inspections.This procedure

is dangerous. If unavoidable, soot blowing operation should not proceed while the

refractory is still hot and there is any possibility of soot fires still smoldering in the

setting. Be sure the boiler is cold and inspect the setting for smoldering soot before

blowing.

(vi) The normal sequence of soot blowing is to follow the gas flow through the boiler.

The first soot blower to be operated should be the nearest to the burners then each

unit in turn along the gas passes to complete the cleaning cycle. This method

thoroughly cleans the entire unit by moving along the passes rather than blowingthem loose and redepositing them on adjacent surfaces. It may be desirable to reverse

this procedure when soot deposits are unusually heavy to avoid plugging and puffs

or explosions in the back passes.

1610 - 1611 VOL - C1 TAB - 4 - 41


47/279

6

Blowers should then be operated in reverse order from rear to front to rear. This procedure

may be desirable during period of low load operation, as when units are banked, or on Marine

installations when ships are put out to sea after time spent in port.

(vii) For operating wall deslaggers,operate the row of wall deslaggers at the highest

elevation first and then follow downwards, so that, heavy slags dislodged and

deposited at lower elevation will be cleared by further soot blowing operation and

fall to the ash hopper due to its weight.

3. PROCEDURE FOR SETTING BLOWING PRESSURES FOR SOOT

BLOWER SYSTEMS

3.1 Introduction

All large, high pressure boilers and many medium and small boilers today employ a pressure

reducing valve in the steam supply to the soot blower system. This requirement, coupled with

the fact that all individual soot blower operating head pressures can be easily adjusted externally

while the units operating, permits adjustment of the blowing pressures without internal orifices

and at the same time permits operation of the system on a relatively low supply pressure.

The reduced supply pressure reduces packing and valve maintenance and makes the system

more flexible for pressure adjustment at later dates without the necessity of installing orifices.

A step by step procedure is outlined to attain this set up.

Use the pressure gauge and the connected fittings issued by us for measuring the blowing

pressure. Connect the pressure gauge fittings as shown in the figure.

3.2 Recommended Blowing Pressures

The suggested blowing pressures are listed out in the blowing pressure table, released in

00,076 erection drawing group separately for each contract.

When these pressures are not shown on the blowing pressure Table BHEL should be contacted

for this information. Request for this information should be complete with blower no. location

and the existing blowing pressure.

3.3 Customer Information

It is a most important step that the customer, the operators and the maintenance personnel

understand that these Recommended Blowing Pressures are based on past experience with

similar fuels, boiler design and firing conditions. The pressures are recommended for trial as

a starting point. Blowing pressures are those that are required to clean can only be determined

after a period of operation and trial settings with adjustment later, if necessary.

3.4 Set High Pressure First

The unit marked for highest blowing pressure on the Blowing pressure table is set up first.

This will usually be a retractable unit in the platen section or in front of the slag screen,

(i) The valve head is designed for high pressure. The valve opening of each blower is

adjusted using the setscrew to the required blowing pressure such that the valve dis

is opened fully or partially without completely compressing the spring (i.e. spring

should not be solid).

(ii) The steam supply is then turned on and the pressure recommended is set on this high

pressure unit from the blowing pressure table by adjusting the supply pressure at the

Pressure Reducing Valve. As an example the blowing pressure on this first unit may be 18 Kg./cm2 and the supply pressure may be as low as 21 or 25 kg/cm2 depending

on line drop.

1610 - 1611 VOL - C1 TAB - 4 - 42


48/279

7

3.5 Set Pressures on Other Models

The next step is to set pressures on one each of the other models in the system – one wall

deslagger, one rotary and one air preheater cleaner if they are employed in the particular

system.

In selecting the one unit of each of these models to be checked, consideration should be given

to the highest blowing pressure used on that particular model as well as the unit farthest fromthe source of steam supply. Line drop will be the only reason for not being able to obtain the

recommended pressures.

Where pressure cannot be set as high as desired because of line drop on these secondary

model settings, it obviously will be necessary to increase the supply pressure through the

Pressure Reducing Valve and reduce the pressure on the individual high pressure unit first set

up.

3.6 Setting Pressure on all Other Units

From the above procedure we have established the minimum header supply pressure to give

the maximum blowing pressure on all of the various soot blower models or types of equipmentused in the system. It is now only necessary to set the other pressure by restricting valve

opening on other units using lesser pressures.

These pressure settings must be made with pressure gauges and the units in actual operation.

Measuring the valve opening or using feeler gauges is not reliable since accumulation of

tolerances in the valve linkage causes a variation in pressure settings.

Normally, no alteration is necessary to the safety valve setting. The seal on safety valves must

not be broken or changes made to these safety settings without specific reasons. Safety valves

are for the protection of the equipment and system in case of Pressure Reducing Valve failure

and their setting does not coincide with this method of pressure setting in any way.

Safety Valve set pressure

Because of the pressure fluctuations occuring in the system when each soot blower valve

head is opened and closed the slow reaction of the Pressure Reducing Valve actuator the

safety vave is likely to pop or chatter depending on the set pressure. The set pressure can be

PRESSURE SETTING ARRANGEMENT

ITEM

NO.

NO. OFF BPS W. DRG. NO DESCRIPTION

01 1 3.20.998.00796 CONDENSING LOOP

02 2 4.20.998.0 1763 PACKING (COPPER)

03 1 4.20.998.01759 CONNECTOR

04 1 V75 141 0250 PR. GAUGE 150 RANGE 0.70 ata

1610 - 1611 VOL - C1 TAB - 4 - 43


49/279

8

increased if the set pressure is not already in the maximum setting. Normally a set pressure

upto 42 Kg./cm2 (g) can be set with a 600 psi rated safety valve.

Do not alter the set pressure if the system is stable.

With the above procedure of setting pressure we have the maximum valve opening possible

on any and all individual soot blower operating heads which reduces valve maintenance. We

have the minimum steam pressure on packing, also reducing maintenance.We have a more flexible system in that, if loads are increased or inferior fuels are used for

shorter periods where higher blowing pressures are required, one single adjustment can be

made at the pressure reducing valve rather than changing and gauging all individual units.

When the emergency is past, the original pressures can be restored again with one adjustment

at the pressure reducing valve.

If there are questions or if difficulties should arise in following this procedure, please contact

us for further advice and counsel.

Do not set pressure reducing valve supplied systems at 600 psi and reduce blowing pressures

with orifices and individual head linkage adjustment.3.7 Blowing Pressures

When new jobs are commissioned or started up, we can , based on past experience with the

type of fuels, firing, boilers and equipment involved, recommend blowing pressures for trial

or starting. An operating period then dictates if pressures and operating frequency should be

changed.

Pressure Adjustment In Long Retract

Observation while the boiler is in operation and inspections at outages are always necessary

to see that cleaning is adequate and that tube damage does not result. In order to evaluateeither cleaning problems or tube erosion and determine corrective steps to be taken, down

steam blowing pressures should be gauged and tabulated along with the operating frequency

of the units.

Pressure, nozzle size, nozzle angle, drainage of condensate and frequency of operation items

that should be reviewed and checked relative to cleaning and erosion conditions. We wish the

customer to feel free to call on our service department for advice and counsel which will be

based on our past experience in this type of work.

3.8 Inspections

Inspections of all tube surfaces at any scheduled outage, are essential to determine tube damageand cleaning. Wall blower inspection is difficult and costly because of the need of scaffolds

or bosunchair, nonetheless inspection is necessary because of the fact that they are hard to see

and check while in operation.

1610 - 1611 VOL - C1 TAB - 4 - 44


50/279

9

We recommend that inspection be made at every scheduled outage of sufficient length to

permit installing a bosunchair or scaffold. We also recommend that inspection be made of all

the tube surfaces at each blower location as soon as the boiler is cool enough to enter and

before any hand cleaning is accomplished. This early inspection gives true picture of the

deposits before they are disturbed and also permits repair during the scheduled outage.

4. SOOT BLOWER CHECK LIST AND RECOMMENDED START-UP

PROCEDURE

4.1 Blowing Medium Supply System

(i) Steam System

(a) Check expansion loops for thermal expansion provision.

(b) Check for slope or pitch for drainage as called for on drawings.

(c) Condensate discharge from trap should be led to atmospheric pressure.

(d) Condensate drain should slope down and away from trap for gravity drain.

(ii) Both Air and Steam Systems

(a) Check provisions for boiler expansion

Expansion loops provided on steam system

Flexible couplings or expansion loops on air system.

(b) Pipe Hangers

Sufficient in number

Properly located to eliminate any pipe strain on soot blower inlet

flange when system is in hot operating position.

(c) Blow down either system completely

On “Candelabrum” or gradually rising header and branch line systems,

it is recommended that all branch lines be blown before inlet

flanges of soot blower operating heads are made up.

On properly designed drain systems having a drain connected to each

operating head, blowing down of construction debris and cleaning

lines can be limited to blow down of drain lines and condensate

reservoir immediately preceding the drain valve.

(d) Drains

All drain lines must be blown down before final welding in of the

drain valve proper.

The thermometer or thermocouple should be checked for goodworking

conditions.

4.2 Suggested Operation Procedure

(i) The frequency of soot blower operation depends on the operting conditions, status

of the boiler and boiler cleanliness. Some things which may indicate the need for

cleaning are; increase in boiler exit gas termperature, decrease in boiler gas flow

(assuming constant boiler load) and visual inspection.

(ii) It is important when starting up a boiler that the soot blowers be used frequently and

soon after lighting off. Inefficient combustion in a boiler being started up may result

1610 - 1611 VOL - C1 TAB - 4 - 45


51/279

10

in abnormal deposits on the tubes. Unless they are removed frequently, furnace

explosions or puffs may result later. It is usually also desirable to use the soot

blowers just before taking a boiler out of service.

(iii) When using the soot blowers for the first time, it is advisable to increase the furnace

draft as much as possible during the blowing cycle. After several blowing cycles, it

will be possible to tell how much the furnace draft shoud be increased for blowing.The furnace draft can be increased by opening the boiler outlet damper wider, in

creasing the induced draft fan speed, or opening the induced draft fan damper wider.

No increase in forced draft is recommended.

(iv) When the soot blowers are not being used, the main steam supply valve should

always be closed tightly and the drain valves opened wide. The motor equipment

for electrically driven blowers is housed in suitable enclosures. For all blowers it is

necessary to make the power and control connections from the motor control centres

and panel to each blower. There is usually a local starting button for each blower as

well as a remote button on the control panel. These buttons are indicated on the

wiring diagrams.(v) Suggested Procedures

(a) Assure that power is available at the proper voltage and frequency as specified on

the application drawings.

(b) Increase the furnace draft as described above.

(c) For steam blowing systems, open all drain valves wide. If traps are used, be sure

isolation valves are open and the by-ass valve is closed.

(d) Open the main steam or air supply valve slowly until it is wide open. With steam

blowing cycle, do not operate any blowers until all the piping has been warmed and

drained. Then, if traps are not used, close the drain valve. The hole in the valve seat

will serve to keep the lines drained. Never blow with wet steam.

(e) Operate the blowers in the numerical sequence shown on the general arrangement

drawing. There is a panel “start” push button for each blower. The buttons may be

included in the automatic sequential operation; they may be individual (buttons for

manual operation) therefore, one button must be used to start each blower. Each

button should be held in about 5 seconds and then released. The blower will start

operating, complete the cycle and this will be indicated in the panel; start the next

blower after this blower operation is over.

Pressure Adjustment wall Deslagger

1610 - 1611 VOL - C1 TAB - 4 - 46


52/279

11

(f) Operate each blower in sequence, each may be operated as many times as necessary

to clean. (Note: Allow a cooling period of 1 hr. before subsequent operaion of the

same blower) NEVER ALLOW A BLOWER TO BLOW UNLESS THE NOZZLE

IS ROTATING.

(g) When the entire blowing cycle is complete, close the main stop valve tightly. Open

the drain valves wide if they are closed.

(h) Adjust the furnace draft to Normal.

(i) Open the power and control circuit.

(j) Be sure all blowers have completely retracted and all heads are fully closed.

5. SOOT BLOWER MAINTENANCE

5.1. Soot blowing, once considered a necessary evil, has become a positive necessity on

modern coal and oil-fired boilers. Fuel costs are rising, and heat value per pound of

fuel seems to be decreasing. Ash, sulphur and low-fusion-temperature slags cause

more trouble with lower Bth. U fuels and demand dependable soot blower operation.

Many cost-conscious engineers are now setting up suitable maintenance programme on soot

blowers, and since peculiarities of each boiler plant usually require a programme tailor-made

for each plant, it is advisable to enlist the aid of the manufa

BHEL 600 MW Soot Blower

Documents