Tuesday 30 March 2010

Improvement Project at Loagan Bunut POM 2008-2010

Improvement activity since y2008 - 2010.
  1. Quarters (Manager's Bunglow, Staff & Labour) upkeep, maintenance, landskaping & improvement.
  2. Establish gotong royong culture among labours to maintaning the quarters compound.
  3. Road to quarters and mill access road.
  4. USB % from an average 10% to below 3%. Improve extraction rates of CPO & PK.
  5. OER at average 20% to above 21%.
  6. QMS9001; awareness, delegation & implementation. Maintaining quality certificate since y 2007.
  7. Mill landskaping & upkeep.
  8. Setup Preventive maintenance.
  9. Establish history card - recording for maintenance activity.
  10. Establish Safety Committee to enhance safety awareness together Fire Fighting Squad & First Aid Squad.
  11. Establish safety signage to enhance safety awareness.
  12. Establish KSLB Recreation Club to enhance all welfare activity and improve organization skill among staff & workers.
  13. Increase feed water temperature from 60 degree C to 70 degree C.
  14. Encaurage boilerman to attend boilerman Grade 1.
  15. Reduce workers & staff turnover.
  16. Solving high temperature problem at turbine water coolant.
  17. Increase sundry revenue by selling pk shell.
  18. Reduce diesel comsumption by running boiler extra hours.
  19. Safety - Establish "Permit Kerja Kontraktor" to enhance safety among contractors. (Jun 2008).
  20. Safety - Establish evacaution point - for emergency evacaution assembly. (Jun 2009)
Project basis :-
  1. Double thresher to improve loose fruit recovery at Threshing Station.
  2. Recycling pump at Faculatative Ponds. Enhance effluent treatment. (Oct 2009)
  3. CEMS - DOE Install system for continous emmision monitoring system. (March 2010)
  4. Install chlorination system for water - domestic line.
  5. New units 2 x JESA for staff quarters. (Feb 2008)
  6. Install new P25 screw press. (Sept 2009).
  7. Install Cages Repair Bay for 15 MT cages maintenance.
  8. Install 2nd Fruit Elevator. (March 2010).
  9. Recycling effluent treated water for landskaping. (Mac 2010)
  10. Additional water clarifier outlet at water treatment plant to reduce chemical consumption. (Dec 2009)
  11. Recycling discharge water to reservior water to reduce water consumption. (March 2010)
  12. Mill notice boards to enhance internal communication.
  13. Establish Staff & Workers Monthly Morning Briefing. (Jun 2008)
Pending / Outstanding
  1. Develop a good engineer / assistant manager.
  2. Morning briefing to enhance workers & staff interpersonnal skills & safety awareness.
  3. Staff monthly gotong - royong.
continue...

Friday 26 March 2010

Maintenance of Boiler III

Insulation
  1. Adequate insulation is very improtant. Burning fuel unnecessarily because the insulation isn't maintained is not a wise practice.
  2. Whenever insulation is removed for maintenance or repair, make certain it's put back or replaced. Or, it will waste of energy, it's hazardous because you could be severaly burned.
  3. If the insulation get wet, dry it.
  4. Damaged or compressed insulation should be replaced as part of the annual clean up operation. Where the damage is repeated, take consideration to install better protection of the insulation.
  5. Ruled of thumb -> re-evaluate your insualtion if you can't hold your hand on it.
  6. Don't add insulation at any part of a boiler casing.
  7. The cost to replace the insulation is much low than the energy loss using poor or damage insualtion.

Refractory

  1. Refractory material may exposed to high temperature of a furnace, subject to very caustic or acidic. Some components of fuels produce vanadium, particularly offensive. Breaking off of a layer of the refractory from one quarter to two inches thick, a process call spalling.
  2. Refractory does expand and contract with changes in temperature.
  3. Some of boiler operator repairing every crack that appears, as a result, accelerate the damage.
  4. Rules; any crack that is smaller 2 pensil, where you ca't put a sharpened pencil in up to the yellow paint, sholud be left alone. That expansion cracks will close up as the boiler heats up.
  5. Pluggin larger cracks as much as three quarters of an inch, with hard refractory materials isn't recommended. Use ceramics fibres rated at temperatures as high as 3200 degree F that should used to fill those cracks.
  6. Castable -> is a powder that's mixed with water to form a very dense soupy mixture that can be poured into spaces surrounded by forms.

Packing

Thursday 25 March 2010

Maintenance of boiler II

Ensure to get everything because failing to maintain something can be hazardous.

Cleaning
Lack of cleanliness of the plant indicating of nothing but trouble. Cleaning is part of preventive maintenance program. This include cleaning burners, operating soot blowers and cleaning oil strainers.

Instructions & specifications

  1. Read the manual first and every time before you perform any maintenance unless you know the book by heart.
  2. Prepare checklist that helps you make sure follow the instructions. It is awfull to forget the step and out of sequence with the component failure being a result.
  3. If you don't have the manual, contact the manufacturer to get one.
  4. A checklist can save the time and prevent failure.
  5. You will loss a several days simply because you refused to take a few minutes to look at the instructions.

Example of incidents at Iwo Jima, a Navy aircarft carrier in Oct of 1990, when 10 people were killed because a valve bonnet blew off in a confined engine room. -> use the right material.

Lock-Out, Tag Out

Refer to OSHA.

  1. Hung near the eguipment so it's easliy seen and used.
  2. Each valve is closed or opened and locked the number of the lock is marked on the diagram with non-permanent marker.
  3. All keys for those lock are placed in one box which has lid secured.
  4. To follow confined space procedures.

Lubrication

  1. Second most important element of preventive maintenance.
  2. Sampling of oil - condition of lub oil.
  3. Use of synthetic oils can save cost.
  4. Use wrong oil can result instantaneous breakdown to the equipment.
  5. Keeping an update chart that covers everthing in the plant is important.
  6. Paying attention to proper lubrication schedules can save time in the long run.
  7. Don't over-lubrication or insufficient attention to others machine mainly due to improper schedule, that result unnecessary lubrication.
  8. Suggest to install recording of running hour to determine when lubrication is necessary.
  9. Tracking the service been done in a log book.
  10. Frequency of operation to be consider. The continously running can result constant heating and coolingg of the bearing results in swell and shrinkage of the lubricant & can result in air & moisture mixing with it to degrade the lubricant and rust the bearing.
  11. Require lubricant oil replacement.
  12. Greasing - over greasing result the bearing shaft seals failure - forced them to upset + additional forced around the shaft.
  13. The grease eventually block cooling air flow passes within the equipment. Don't forget to put plug or cap.
  14. Follow the recommendations by manufacturer - volume of greasing.
  15. Use proper grease.
  16. Grease function -> support the loads, speed.
  17. Failure to clean grease fitting before attaching the grease gun. Use a clean free rag to wipe off the fitting. Prevent anything to protect the lubricants. Clean the fitting before attacging the grease gun. Eliminating contamination of greasing.
  18. Mark all grease, lubricant, proper storage.
  19. Oil lubricant - replace of fitler, coolers, control of temperature according the manufacturer's instructions.
  20. Temperature is critical to lubricant system - can break the properties.
  21. Cleanliness is the next important factor because clearances in bearings and gears are so small the the particle of dust can span the clearance to produce damage in the equipment. A little contamination of lubricating system can result in total system failure costing thousand times more than oil.

Maintenance of Boiler I

Function of maintenance.
  1. Operability.
  2. Reliability of equipment & system by limiting or preventing wear, vibration, eriosion, corrosion, oxidation & breakdown. Prevent significant repair cost.
  3. Cost control.

3 Category :-

  1. Breakdown maintenance. Low cost because basically do nothing to prevent a failure.
  2. Preventive maintenance. Regular scgedule. Prevent damage to equipment or systems. Water treatment & lubrication are 2 principle preventive maintenance activities in a boiler plant. Prevent corrosion, scale, friction. Prevent erosion by ensuring velocities do not get too high.
  3. Predictive maintenance. Monitoring, examinations and test to reveal problems. Annual inspections of steam boilers to detecy formation of scale, corrosion, vibration, wear, cracks, overheating & other problems to prevent eventual failure. The best investment in predictive maintenance is the operator's ear. An operator can detect many problems such as change in sound, vibration, temperature (by simply resting a hand on the equipment) that consider investment in test and monitoring equipment. Constant attendance by a boiler plant operator is one investment in predictive maintenance that ensure no suprises major equipments or system failures.

Preventive & predictive maintenance require an expenditure of effort and materials which represent an investment in reliability.

Don't simply won't pay any attention to until they fail, then you'll replace them.

Should represent a cost relative to the potential loss.

Example

1. 1/2 HP feed pump.

2. 2000 HP feep pump.


Between those 2 extreme are all sorts of variations on monitoring and maintenance but most of them rely on the skill and dedication of boilerman, fireman. Each round of the boiler plant you will look and listen to the feed pump, noting its condition, look for signs of vibration or shaft leakage, possibly feel the motor and pump bearing housings to get a sense of their temperature.

All boilerman & fireman must have a sound of maintenance program and proof - documented it in log book for treaceability. A schedule and a record of the work being done is the best evidence that you are doing your job and a failure will not reflect on your performance. If you've done a good job planning and executing the maintenance plan you should't have any failures.

The best place to start the schedule is the manufacturer recommends, operating & maintenance manuals, until you get some track record to find any additional or improvements.

Tuesday 23 March 2010

Goals of Maintenance

ZERO BREAKDOWN

Five counter measures :-

  1. Maintaining well regulated basic conditions (cleaning, lubricating & bolting).
  2. Adhering to proper operating procedures.
  3. Total condition monitoring (performance, mechanical & diagnostic based).
  4. Improving weakness in design.
  5. Improving operation & maintenance skills.

Philosophy of Maintenance

defined as the "upkeep of property". Involves restoration of tolerances trhough a series of intelligent compromises.

Total Productive Maintenace
Combining the practice of preventive maintenance & total quality control & total employee involvement results in an innovative system for equipment maintenance that optimizes effectiveness, eliminates breakdowns & promotes autonomous operator maintenance through day to day activity. The concept known as Total Productive Miantenance (TPM), Seiichi Nakajima.

Life Cycle Cost
Selection of all equipment.

Performance Based Total Productive Maintenance System
Combination of total condition monitoring & the maintenance principles of total productive maintenance.

5 P's for major maintenace for power plant

1. Panic maintenance based on breakdowns
2. Preventive maintenance
3. Performance based maintenance
4. Performance productive maintenance
5. Performance based total productive maintenance (PTPM)

PTPM consists of the following elements :-


  1. To maximize equipment efficiency & time between overhaul.
  2. To maximize equipment effectiveness.
  3. Establishes a through system of PM for the equipment's entire life span.
  4. Impremented by various departments (engineering, operations, maintenance).
  5. Involves every single employee, from top management to workers on the floor.
  6. Based on the promotions of PM through motivation management; autonomous small group activities.
'Total' means ;


  1. Total overall performance effectiveness indicates PTPM's pursuit of maximum plant efficiency & minimum downtime.
  2. Pursuit of economic efficiency @ profitability.
  3. Total maintenance system; Maintenance prevention & maintenance improvement (MP/MI).
  4. Total participation of all employees, autonomous, small group activities.
Down time :

  1. Loss of time due to unnecessary overhauls based only on time intervals.
  2. Equipment failure-from breakdowns.
  3. Loss of time due to spare part unsuitability @ insufficient spares.
  4. Idling & minor stoppages - due to the abnormal operation of sensors or other protective devices.
  5. Reduced output - due to discrepancies between designed & actual operating conditions.

Defect :

  1. Process defects - due to improper process conditions that do not meet machinery design requirements.
  2. Reduced yiled - from machine start up to stable production due to the inability of the machine to operate at proper design conditions.

Ultrasonic evaluation

Ultrasonic testing is used to check for: arcing, tracking, corona discharge and vibration.
In certain instances it is easier to ‘listen’ for problems from a distance when it is difficult to get right next to the equipment in question.
Ultrasound is an effective, low cost means of evaluating the condition of insulation components on high-voltage transmission and distribution equipment.
Initial Equipment Cost: $4300
Training Costs:
Initial Training = 40 hours offsite, fee= $1,500
Recertification = 8 hours, twice per year, offsite

Ultrasound should be used in conjunction with Infrared Imaging when Infrared Imaging is not practical.
Ultrasound can often detect potential insulation faults that do not show up in an infrared survey.
A combination of infrared and ultrasound is often used on high-voltage electrical equipment, particularly enclosed switchgear.
Infrared locates resistive faults (e.g. dirty switch contacts or loose joints)
Ultrasound locates developing insulation faults
Ultrasound instrument can be used on enclosed switchgear that cannot be ‘viewed’ with an infrared instrument. Removing a few bolts allows ultrasound to penetrate into the inside of the gear.

Infrared imaging

A hand held camera is used in a way that enables you to ‘see’ temperature differences. The camera is a lot like a video camera in size and weight.
The hotter the temperature, the more yellow the equipment
Not all temperature differences are indicative of problems
You must be trained to recognize those temperature differences that are significant
Some Infrared Imaging Costs:
Thermal imaging system ~$30,000
Technician training & fluency education

Here is a transformer as seen through a short wave infrared camera.
The yellow coloring does not indicate a problem. It is the reflection of sunlight.
The maintenance technician must be trained to recognize this. Otherwise he will report ‘false’ hot spots that will lead to wasted corrective action.

Here, the same transformer is seen through a long wave infrared camera.
The ‘false’ hot spots seen through the short wave camera do not show up here but maintenance technician must be trained to recognize significant yellow areas.
Maintenance programs that require outdoor surveys are best served by long wave cameras.

Laser alignment

Provides quicker and more accurate means of shaft alignment than dial gauges.
There are many sources of error in dial gauge readings:

sagging indicator brackets
sticking/jumping dial hands
low resolution means rounding losses
play in mechanical linkages
tilted dial indicator leads to offset errors
axial shaft play leads to gap error

Laser alignment tool costs $13,000 - $15,000.
Technician requires one day training about how to use the tool

Vibration analysis

Vibration is measurement of the periodic motion of equipment (I.e. the ‘shaking’). Vibration is measured in units of inches/second (in/sec, IPS).

All equipment vibrates, but if this vibration becomes too severe, it indicates problems. Use vibration levels to prioritize repairs.

Some Rules of Thumb to judge the condition of your equipment:
less than 0.050 IPS Excellent
0.050 - 0.100 IPS Good
0.100 - 0.200 IPS Acceptable
0.200 - 0.400 IPS Unacceptable
greater than 0.400 IPS Failure Likely

The technician takes a simple hand held instrument out each piece of equipment to be tested.
He then attaches a magnetic accelerometer to several specific places and records readings electronically.
These readings are then downloaded to a computer and analyzed with a software program purchased with the hand held instrument.

Costs to set up your own on-site program
Approximately $40,000 for software and hardware
One week training for your technician
Your technician must work on vibration monitoring at least 3 days/month to stay fluent in the technology and analysis

Costs to contract out
Approximately $7,000 per year (depends on number of pieces of equipment and accessibility)

Oil analysis

  • Take periodic samples of oil from equipment & sent out for laboratory analysis.
  • Test condition & wear of components.
  • Will wam of impending problems & reduce chance of premature failures.
  • Will possible point out root causes of failure
  • Costs.

A typical machine condition - vibration trend


Predictive Maintenance

Condition based management :-

  1. Vibration analysis
  2. Oil Analysis
  3. Temperature analysis
  4. Pressure Analysis
  5. Ultrasonic
  6. Wear analysis
  7. Efficiency analysis
  8. Visual analysis

Boiler Audit

Job scope for the boiler audit should include the following items:

MONTHLY SERVICE:
1. Test combustion for five points on the base fuel on which the boiler is operating.
Backup fuel may be the base fuel for at least two of the twelve monthly tests. Necessary
adjustments to improve fuel air ratios should be made, with readings to record efficiency and
other data both before and after the adjustments are made.
2. Test flame failure control.
3. Test low water control cutoff and auxiliary using the slow drain method.
4. Test high pressure cutoff to be done by customer's operator.
5. Test gas pressure switches at high pressure cutoff and at low pressure cutoff.
6. Test combustion air proving switch.
7. Test auxiliary contacts on motor starter.
8. Test atomizing medium proving switch.
9. Test high and low fire proving switches.
10. Test high and low oil temperature.
11. Test low oil pressure switch.
12. Remove pilot assembly, clean and adjust.
13. Complete service report with recommendations.

ANNUAL SERVICE:
1. Open and washout boiler water-side.
2. Brush tubes and/or clean fireside surfaces.
3. Replace all gaskets on water-side and fireside.
4. Repack feed water pumps.
5. Clean strainers.
6. Replace gauge glass of DA or makeup tank.
7. Test float switches on make-up tank.
8. Shop rebuilt and testing of safety relief valves.

400 kW Diesel Generator General Overhoul of March 2010


duration for service : 10 to 14 days.
by Scott & English (Malaysia) Sdn. Bhd.
estimate RM48,000.00 General overhoul by original manufacturer. Running hours at above 12,000 hours.
KTA 19 G4
  • Service & repair radiator
  • Service & test oil cooler
  • Service & repair aftercooler
  • Service & calibrate fuel pump
  • Service & repair starter
  • Service & repair charging alternator
  • Valve seat reseating
  • Valve refacing
  • Replace water cap
  • Polish crankchaft M-Std & C-Std
Parts replace / service
  1. Thermostat (2)
  2. Clamp (2)
  3. Plug expansion (2)
  4. Gasket, Injector (2)
  5. O ring (18)
  6. Plug (48)
  7. Con rod bearing (12)
  8. Plug, EX (12)
  9. Belt, V (1)
  10. Bushing camshaft (7)
  11. Nozzle (6)
  12. Absorber shock (1)
  13. Thermostat (2)
  14. Insert V ext (8)
  15. Insert V intake (12)
  16. Valve guide (24)
  17. Turbo repair kit
  18. Rotator valve (24)
  19. WTR PMP repair kit
  20. Seal
  21. Repair kit
  22. Liner kit (6)
  23. Upper GSK Set
  24. Lower GSK set
  25. Set piston ring (10)
  26. Lube oil
  27. Air housing
  28. Main brg
  29. Chem water coolant (4)
  30. Super filter (2)
  31. LO filter (2)
  32. Water filter
  33. Injector (6) - check ball, screen, orifice, gasket, cap, pin.

Sunday 21 March 2010

Five factors for wining the war; Sun-Tzu

  1. One who knows when he can fight and when he cannot fight, will be victorious.
  2. One who recognizes how to employ large and small numbers will be victorious.
  3. One whose upper & lower ranks have the same desires will be victoroius.
  4. One who fully prepared awaits the unprepared will be victorious.
  5. One whose generals is capable & not interfered with by the rulers will be victorious.

Five generals dangerous during war

The strategy for employing the army, do not rely on their not coming, but depend on us having the means to awaits them. Do not rely on their not attacking, but depend on us having unassailable posotion. Thus generals have 5 dangerous :-

  1. One committed to dying can be slain.
  2. One committed to living can be captured.
  3. One (easily) angered and hasty (to act) can be insulted.
  4. One obsessed with being scruplous and untainted can be shamed.
  5. One who loves the people can be troubled.

Evaluating the condition of a boiler

The operating staff must prepare proper records of all maintenance to ensure that any problems with the boiler are known. Examination methods such as nondestructive testing are then used to evaluate the remaining life of the boiler component in question.

The condition of the steam drum is a critical component to evaluate. There are two types of steam drums:

1. The all-welded design used predominantly in utility boilers, where the operating pressure exceeds 1800 psi.
2. Drums with rolled tubes, such as the two-drum industrial-type boiler


Since the steam drum operates at saturation temperature, the steam/water temperature is less than 700°F (see Table C.1), and therefore, the drum is made of carbon steel and is not subject to significant creep.

Creep is the slow deformation of continuously stressed metal over time, which could lead eventually to a fracture.

Damage to a drum is primarily due to internal metal loss. This can be caused by corrosion and oxidation, which can occur during extended outages if proper precautions are not taken. Damage also can occur from mechanical and thermal stresses on the drum, which concentrate at nozzle and attachment welds. These stresses occur often in boilers that are cycled frequently in an on/off mode of
operation.

The feedwater penetration area has the greatest thermal differential because incoming feedwater can be several hundred degrees below the drum temperature. Steam drums with rolled tubes (e.g., a two-drum boiler) have problems with tube seat leakage, where there is a slight seeping of water through the rolled joint.

Caustic embrittlement can result if the leak is not stopped. In lower drums of industrial-type boilers, large thermal differential or mechanical stresses are not present; however, rolled-tube seat leakage can occur, with similar problems resulting as with the steam drum.


Superheater and reheater tubes are affected by both erosion and corrosion. In addition, the high temperature results in increased stress on the tubes. These factors lead to tube cracks and eventual leaks.


Water-cooled tubes such as the furnace walls, boiler bank, and economizer operate at or below saturation temperature and therefore are not subject to significant creep. Proper water chemistry is important in maintaining tube life, and if necessary, water-side deposits can be cleaned by chemicals when required.

Erosion and corrosion are the primary problems of the tubes, assuming that good water chemistry is practiced. If not, deposits form on the inside of the tubes, and heat transfer is affected, which can result in high metal temperatures and eventual failure of the tube.

These and other components and auxiliaries of the boiler must be examined and maintained properly during planned outages. This is proper operation, which will lead to high plant availability.

Boiler efficiency; ASME test code

The ASME test code has established a procedure to determine the boiler efficiency and the required boiler heat input to achieve the desired boiler output, which is the steam flow at the required pressure and temperature. This procedure requires the calculation of all the losses in a steam-generating unit, which include the following:
Loss due to moisture in the fuel
Loss due to the
water that may be formed during the combustion from the hydrogen contained in the fuel
Loss due to the
moisture in the air that is used for combustion
Loss due to the heat carried up the stack by
flue gas
Loss due to the
incomplete combustion of carbon in the fuel, called unburned carbon loss
Loss due to
radiation of heat, leaks, and other unaccounted-for losses

The boiler

  1. A boiler (or steam generator, as it is commonly called) is a closed vessel in which water, under pressure, is transformed into steam by the application of heat.
  2. Open vessels and those generating steam at atmospheric pressure are not considered to be boilers.
  3. In the furnace, the chemical energy in the fuel is converted into heat, and it is the function of the boiler to transfer this heat to the water in the most efficient manner.
  4. Thus the primary function of a boiler is to generate steam at pressures above atmospheric by the absorption of heat that
    is produced in the combustion of fuel.
  5. With waste-heat boilers, heated gases serve as the heat source, e.g., gases from a gas turbine.
  6. A steam electric power plant is a means for converting the potential chemical energy of fuel into electrical energy.
  7. In its simplest form it consists of a boiler supplying steam to a turbine, and the turbine driving an electric generator.

Ideal Boiler

The ideal boiler includes
1. Simplicity in construction, excellent workmanship, materials conducive to low maintenance cost, high efficiency, and high availability.
2. Design and construction to accommodate expansion and contraction properties of materials.
3. Adequate steam and water space, delivery of clean steam, and good water circulation.
4. A furnace setting conducive to efficient combustion and maximum rate of heat transfer.
5. Responsiveness to sudden demands and upset conditions.
6. Accessibility for cleaning and repair.
7. A factor of safety that meets code requirement.

Oil & Gas Fired Boiler Inspection Schedule

No.

Daily

Weekly

Monthly

½ yearly

Annually

1

Check water level

Check for tight closing of fuel values

Inspect burner

Clean low – water cut offs

Clean fireside surface

2

Blowdown boiler

Check fuel & linkage

Analyze combustion

Check preheater

Check & clean flues

3

Blowdown water column

Check indicating lights & alarms

Check cams

Inspect refractor & insulation

Clean waterside surface

4

Check combustion visually

Check operating & limit controls

Inspect for flue gas leaks

Clean oil pump strainer & filter

Check oil storage tanks

5

Treat water per established program

Check safety & interlock controls

Inspect for hot spots

Clean air cleaner & air/oil separator

Check fluid levels on hydraulic valves

6

Record boiler operating pressure / temperature

Check low – water cut off operation

Review boiler blowdown procedures

Check pump coupling alignment

Check gauge glasses

7

Record feedwater pressure/temperature

Check for leaks, noise, vibration, unusual comditions, etc.

Check combustion air supply

Reset combustion

Remove & recondition safety valves

8

Record oil pressure/ temperature

Check operation of all motors

Check all filter elements

Inspect mercury switches

Check oil pumps

9

Record gas pressure

Check general burner operation

Check fuel systems

Check boiler feed pumps

10

Record atomizing pressure

Check lubricanting oil levels

Check belt drives

Check chemical feed systems

11

Check general boiler/ burner operation

Check flame scanner assembly

Check lubrication requirements

Tighten all electrical terminals

12

Record boiler water supply & return temperature

Check packing glands

Check deaerator & boiler feed system

13

Record makeup water usage

Check gauge glass

Check linkages

14

Check operation of auxiliary equipment


extract from Steam Plant Operation, 8th Edition

Four Types of NDT at Boiler

The most common nondestructive tests used in boiler inspections include the following:

1. Magnetic particle testing (MT)
is used to detect surface and nearsurface flaws by observing any discontinuity that shows in the pattern of iron particles that are applied to the test piece. Because a magnetic field is used on the test piece, these tests are applicable only to ferrous materials. The shape of the test piece also determines whether it can be MT tested.

2. Liquid penetrant testing (PT)
also detects surface cracking in a component, and it's not dependent on the magnetic property of the material or its shape. The PT test detects surface flaws by capillary action of the liquid dye penetrant, and it is only effective where the discontinuity is open to the component surface.

3. Ultrasonic testing (UT)
is used extensively for measurement of the wall thickness of tubes. The loss of material due to corrosion and erosion is a primary cause of failure of pressure parts. In many areas of the boiler where corrosion and erosion are expected, a baseline UT test is conducted. In subsequent tests, these test results are compared with the baseline information, and the life of the component can be projected. Therefore, at planned outages, tubes having a high rate of wear can be replaced, which prevents an unscheduled outage due to tube failure.

4. Radiography or x-ray testing (RT)
is the most important nondestructive test during the field erection of a boiler. It is also used in assessing the condition of pressure parts such as piping. The major disadvantage of radiography is excessive exposure to radioactive rays and the potential harmful effects to personnel. Protective procedures must be used to minimize any potential effect.

Extract from STEAM PLANT OPERATION 8TH EDITION

Saturday 20 March 2010

Pengurusan Sumber Air Di Industri Sawit

Semasa artikel ini ditulis, semua tempat di Malaysia sedang mengalami kesan El Nino/El Nina yang amat teruk. Kemarau yang berpanjangan sejak Mei 2009 sehingga sekarang telah memberi kesan kepada industry sawit serta negara. Keluaran buah sawit dan minyak mula menunjukkan penurunan sejak awal tahun 2010. Banyak tempat di seluruh negara mengalami kemarau yang melampau. Berikut adalah beberapa buah fikiran untuk menanggani masalah ini serta bersedia jika suasana kemarau tidak berubah :-

  1. Kilang Sawit
    1. Operasi memproses buah sawit ; Nisbah yang digunakan adalah 0.39 m3 /FFB (proses), 0.60 m3/FFB (boiler) & 0.30 m3/FFB (domestic-housing). Penjimatan boleh dilakukan di bahagian proses dan boiler dengan mengurangkan penggunaan air di press, bilik minyak dan boiler.
    2. Gunakan sludge untuk dilution dan elakkan atau kurangkan penggunaan air untuk operasi separator serta bilik minyak.
    3. Recycle turbine water coolant untuk kegunaan di bilik minyak.
    4. Melakukan pemeriksaan dan pembaikan terhadap sistem stim seperti pembaikan steam trap secara berkala (bulanan) untuk semua unit di dalam kilang. Baiki segera semua sistem stim yang bocor (paip,valve, tangki & steam trap).
    5. Operasi boiler ; kurangkan blowdown jika paras TDS di bawah parameter yang dibenarkan. Kurang pembaziran stim melalui blow off safety valve, kebocoran paip air dan stim serta kurang backwash softerner jika nilai hardeness <1 ppm.
    6. Baiki segera paip yang bocor di kilang mahupun di perumahan.
    7. Amalkan dry cleaning di kilang. Gunakan fiber untuk mencuci kesan minyak. Fiber adalah medium terbaik untuk mengeringkan minyak. Elakkan penggunaan air berlebihan untuk operasi mencuci kilang. Sapu atau hilangkan kesan minyak sebelum air digunakan.
    8. Atap kilang, disebabkan kilang mempunyai sumber air tetap, tidak ada kilang yang menggunakan sepenuhnya air hujan. Atap kilang yang besar sepatutnya digunakan sepenuhnya. Pasang gutter untuk menuai air hujan. Air tersebut boleh digunakan untuk kerja – kerja mencuci dan menyiram pokok bunga di halaman kilang.
    9. Recycle air effluent. Air effluent mempunyai banyak nutrient yang berguna untuk tumbuhan. Ambil air effluent yang telah dirawat untuk digunakan untuk kerja – kerja mencuci serta menyiram taman, jalan di dalam kilang.
    10. Jika terdapat sumber air berdekatan, preserve sumber air tersebut. Pasangkan pam jika perlu untuk mengambil air dan dipam ke kolam utama.
    11. Bekalkan tangki untuk semua perumahan kilang untuk tujuan penyimpanan air hujan.
    12. Pastikan air yang digunakan kembali semula ke tanah.
  2. Ladang Sawit
    1. Sejak sekian lama, ladang sawit telah menggunakan air hujan untuk kegunaan domestik. Usaha untuk menambahkan kapasiti penyimpanan boleh dilakukan dengan menambah gutter dan tangki sedia ada. Bina tangki yang besar atau tambah jumlah tangki.
    2. Bina tasik buatan atau kolam takungan yang dapat menampung air untuk setahun mengikut jumlah penduduk di ladang tersebut.
    3. Gali telaga. Banyak ladang berada di kawasan rendah serta berpaya. Mustahil jika air tidak ada jika telaga digali. Jika air tersebut tidak sesuai untuk diminum, cara jalan untuk menapis atau merawat. Jika masih tidak dapat diguna untuk minuman, gunakan air tersebut untuk kerja – kerja mencuci, campuran racun dan menyiram benih pokok sawit.


Friday 19 March 2010

Circuit breaker for 3 phase motors


A
Direct starter
Star delta starter
Nominal intensity of circuit breaker
Maximum nominal power – motor with cage -
Maximum nominal power – motor with rings or cage –
125 V220 V380 V500 V125 V220 V380 V500 V
kW
20.150.250.450.60.250.430.751
40.330.5511.30.5511.72.2
60.61.051.82.70.91.552.73.6
101.11.93.34.31.52.64.56
151.52.64.562.3479.2
2023.5683.25.59.512.5
2535.2912471216
354.17.212.5175.81017.523
505.51017228.314.52533
607.513.3233010183141
801017304013.3244154
10013.323405317.7315370
1251832557222396788
1604070924985112
200529012062107141
2256611515271140160
2608114018581160185
3009316021093185210
350107185107225
430132225132
500155155
600186186