Tuesday, 3 November 2015

Solvent Extraction Plant

Hexane solvent oil extraction - Definition, Glossary, Details - OilgaeSolvent Extraction is a process which involves extracting oil from oil-bearing materials by treating it with a low boiler solvent as opposed to extracting the oils by mechanical pressing methods (such as expellers, hydraulic presses, etc.) The solvent extraction method recovers almost all the oils and leaves behind only 0.5% to 0.7% residual oil in the raw material. In the case of mechanical pressing the residual oil left in the oil cake may be anywhere from 6% to 14%.
The solvent extraction method can be applied directly to any low oil content raw materials. It can also be used to extract pre-pressed oil cakes obtained from high oil content materials. Because of the high percentage of recovered oil, solvent extraction has become the most popular method of extraction of oils and fats. In a nutshell, the extraction process consists of treating the raw material with hexane and recovering the oil by distillation of the resulting solution of oil in hexane called miscella. Evaporation and condensation from the distillation of miscella recovers the hexane absorbed in the material. The hexane thus recovered is reused for extraction. The low boiling point of hexane (67°C / 152°F) and the high solubility of oils and fats in it are the properties exploited in the solvent extraction process

Tuesday, 6 October 2015

Boiler Auto Deashing System

Boiler tube burst

Boiler scale

Boiler scale is caused by impurities being precipitated out of the water directly on heat transfer surfaces or by suspended matter in water settling out on the metal and becoming hard and adherent.

Boiler water gauge glass

Boiler soot blower

Boiler induced fan ID Fan

ID is "Induced Draft" and FD is "Forced Draft." In an induced draft system, the fan is at the exit end of the path of flow, and the system is under negative pressure - that is, the pressure in the flow area is below atmospheric, because the air is being drawn through the fan.

Boiler draft meter

How to destory a boiler - Part 1

William L. Reeves, P.E
President, ESI Inc. of Tennessee
Category: Incidents 
Summary: The following article is a part of the National Board Technical Series. This article was originally published in the Winter 1999 National BoardBULLETIN. (4 printed pages)
This article covers the four most common ways to "destroy a boiler," including fuel explosions, low-water conditions, poor water treatment, and improper warm-up.
The design and construction of power and recovery boilers represent one of the largest capital expenditures in the industrial utilities arena. The operational reliability and availability of these boilers is often critical to the profitability of the facility. Safe operation of these units requires careful attention to many factors. Failure to follow a few well-established practices can, and likely will, result in a catastrophe. The most common ways to "destroy a boiler" include the following: 
Fuel ExplosionsContaminated FeedwaterLow-Water Conditionsmproper Blowdown TechniquesPoor Water TreatmentImproper StorageImproper Warm-upPulling a Vacuum on the BoilerImpact Damage to TubesFlame ImpingementSevere Overfiring
Fuel Explosions
One of the most dangerous situations in the operation of a boiler is that of a fuel explosion in the furnace. The photo above shows the complete devastation of a utility boiler.
Conditions have to be just right for an explosion to occur and when a boiler is properly operated, it is not possible for such an event to take place. The most common causes of a fuel explosion are:
Fuel-rich mixtures - The danger of a fuel-rich mixture is that high concentrations of unburned fuel can build up. When this unburned fuel ignites, it can do so in a very rapid or explosive manner. Fuel-rich mixtures can occur any time that insufficient air is supplied for the amount of fuel being burned. Never add air to a dark smoky furnace. Trip the unit, purge thoroughly, then correct the problem. By adding air with a fire in the unit, you may develop an explosive mixture. While it is dangerous to have too rich a mixture, the reverse is not true. A lean mixture which results in more air than necessary, while not efficient, is not dangerous.
Poor atomization of oil - Just as fuel-rich mixtures could allow accumulation of unburned combustibles, any inventory of a combustible fuel in the furnace can result in an explosion. Boilers are blown up every year as a result of poor atomization of oil which results in incomplete combustion and can lead to unburned oil puddling on the floor of the furnace. To prevent this, the oil tips must be clean, the oil temperature must be correct, the oil viscosity must be in spec, and the atomizing steam (or air) pressure and fuel oil pressure must be properly adjusted.
Improper purge - Many of the explosions occur after a combustion problem which has resulted in a burner trip. Consider the following example: suppose that the oil tip becomes plugged, which disturbs the spray pattern, causing an unstable flame that results in a flame failure. The operator attempts to relight the burner without investigating the cause and during successive attempts to relight the burner, oil is sprayed into the furnace.
The oil on the hot furnace floor begins to volatize and release its combustible gases when the operator initiates another trial for ignition. The pilot then ignites the large inventory of unburned combustible gases in the furnace, which produces the explosion.
This entire scenario can be prevented by:
Investigating the cause of the trip before attempts to relight.
Allowing the furnace to purge thoroughly. This is particularly important if oil has spilled into the furnace. The purge will evacuate the inventory of unburned gases until the concentration is below the explosive limits. Purge, purge, purge!
Low-Water Conditions 
The potential for severe and even catastrophic damage to a boiler as a result of low-water conditions is easy to imagine considering that furnace temperatures exceed 1,800°F, yet the strength of steel drops sharply at temperatures above 800°F. The only thing that allows a boiler to withstand these furnace temperatures is the presence of water in all tubes of the furnace at all times that a fire is present. Low-water conditions will literally melt steel boiler tubes with the result closely resembling a spent birthday candle, as shown above.
Typical industrial boilers are "natural circulation" boilers and do not utilize pumps to circulate water through the tubes. These units rely on the differential density between hot and cold water to provide the circulation. As the water removes heat from the tubes, the water temperature increases and it rises to the boiler steam drum. Eventually, sufficient heat is transferred and steam is generated. Colder feedwater replaces the water that rises, which creates the natural circulation. A typical boiler circulation (as shown below) will illustrate:
Boiler feedwater being introduced into the steam drum.Cooler water sinking through tubes called "downcomers."Water absorbing heat from the tubes, then the heated water rising to the steam drum.
Due to the critical need for water, modern boilers are equipped with automatic low-water trip switches. Some older boilers may not have these relatively inexpensive devices. If your boilers do not have low-water trips, run, don't walk, to the phone and initiate their installation. You have an accident and expensive repairs waiting to happen. The needed repairs can range from retubing to total destruction of the unit if the drums overheat. In the event of low water, the low-water trips will trip the burner (or fuel flow for solid fuel boilers) and shut down the forced draft fan. This shuts down the heat input.
The trips should be installed at a water level that will prevent damage. Normal operating level is generally near the centerline of the steam drum. Low-water trips are generally installed approximately 6" lower, but the manufacturer's drawings usually indicate normal and minimum water levels which vary from unit to unit.
The potential for damage is more critical with solid fuel-fired boilers. A gas/oil boiler has no inventory or bed of fuel. When you trip the burner, for all practical purposes, the heat input immediately stops. With solid fuel units, however, a fairly large mass of bark, coal, etc., is still on the grate and even though starved of air by the loss of the forced draft fan, these units have more "thermal inertia" and will continue to produce some heat.
The control of the boiler drum level is tricky and even the best tuned control systems cannot always prevent a low-water condition. The "water level" in a steam drum is actually a fairly unstable compressible mixture of water and steam bubbles that will shrink and swell with pressure changes and will actually shrink momentarily when more "cold" feedwater is added.
Some common causes of low-water conditions include:
Feedwater pump failureControl valve failureLoss of water to the deaerator or make-up water systemDrum level controller failureDrum level controller inadvertently left in "manual" positionLoss of plant air pressure to the control valve actuatorSafety valve liftingLarge, sudden change in steam load
Unfortunately, an alarming number of boilers equipped with low-water trips are destroyed each year. Common reasons:
Disabled trip circuits - very common - a $39 jumper cable will readily foil the best-made plans (with repairs often exceeding $100,000, this represents an attention-grabbing return on investment for a $39 expenditure!). A typical scenario involves disabling the trips to eliminate nuisance trips due to improperly tuned controls, etc. This is a "band-aid" to cover the real problem and should never be allowed.
Inoperative trip switches - the trip switches should be blown down regularly to remove sludge. These switches are installed in "dead legs" where no circulation occurs. Sludge will eventually plug the piping or the switch itself.
Have you checked your trips today? Nuisance trips should not be a concern with a properly tuned boiler with proper drum internals, so this is not a valid reason to disable low-water trips. Dysfunctional low-water trips should be a "no go" item and should be corrected before the boiler is fired.
Poor Water Treatment
Boiler feedwater is treated to protect it from two basic problems: the buildup of solid deposits on the interior or water side of the tubes, and corrosion.
Prevention of scaling or buildup - The need for proper feedwater treatment is obvious if you will consider the comparison of a boiler and a pot of boiling water on the stove. The boiler is actually an oversized distillery in that the water that enters the boiler is vaporized to steam, leaving the solids behind. Depending on the amount of solids in the water, or hardness, the residue is sometimes visible when a pot containing water is boiled until all water is vaporized.
This same thing occurs inside the boiler and, if left unchecked, can destroy it. Boilers rely on the water to protect the steel boiler tubes from the temperatures in the furnace which greatly exceed the melting point of the tube material. A buildup of deposits inside the tubes will produce an insulating layer which inhibits the ability of the water to remove the heat from the tube. If this continues long enough, the result is localized overheating of the tube and eventual blowout.
In order to prevent the buildup of deposits on the tubes, the level of solids in the boiler feedwater must be reduced to acceptable limits. The higher the operating pressure and temperature of the boiler, the more stringent the requirements for proper feedwater treatment. Refer to the table below for the maximum recommended concentration limits in the water of an operating boiler according to ABMA.
Drum Operating Pressure
(psig)Total Dissolved Solids
(ppm)Total Alkalinity
(ppm)Silica
(ppm Si02)Total Suspended Solids
(ppm)0-3003,50070015015301-4503,0006009010451-6002,500500408601-7501,000200303751-900750150202901-1,00062512581
Unless a power generation turbine is involved, or the water quality is particularly bad, most industrial boilers operate at sufficiently low pressures to enable the use of simple water softeners for feedwater treatment. At higher pressures and when turbines and superheaters are involved, more complex feedwater treatment systems such as reverse osmosis, demineralizer systems, etc., are required to treat the feedwater. A state-of-the-art demineralization system is shown in the photo on the opposite page.
Solids are also removed from the boiler through proper operation of the continuous blowdown system and by the use of intermittent or bottom blowdown on a regular basis. Blowdown flows reduce the solids by dilution.
High conductivity or contamination of the boiler feedwater can create other problems such as drum level instability and foaming. This can result in high or low-water alarms and an increase in the carryover of moisture droplets into the steam header since the moisture separator of the drum cannot handle the resultant carryover.
Prevention of corrosion - The most effective method of controlling corrosion is proper deaeration of the water. The removal of oxygen from the water drastically reduces the potential for corrosion. This is most often accomplished through the use of deaerators. These units typically utilize steam to both preheat the feedwater and remove the oxygen, carbon dioxide, and other gases from the make-up water. Oxygen scavenging chemicals are also commonly injected into the deaerator to provide an additional measure of protection. Additionally, the boiler steam drum, or feedwater, has generally supplied chemicals at a controlled rate for even further protection. A qualified water treatment specialist is invaluable in determining the best method for your plant and your site-specific water requirements.
Preventive measures - In order to prevent problems with poor water treatment, the following are recommended:
Verify that your boiler feedwater is of sufficient high quality for the temperatures and pressures involved. Water quality standards based on operating pressures and temperatures as recommended by ABMA should be followed.
Verify that the water leaving the deaerator is free of oxygen, that the deaerator is operated at the proper pressure, and that the water is at saturation temperature for the pressure.
Verify proper operation of the water treatment systems on a regular basis. Loss of resin from a softener or demineralizer can create problems if the resin escapes into the feedwater. Such resins can melt on the tube surfaces, resulting in overheated tubes, etc.
Never use untreated water in a boiler.
Adjust continuous blowdown to maintain the conductivity of the boiler water within acceptable limits and blow down the mud drum on a regular basis.
It is also important to blow the sludge out of all the dead legs of the low-water trips, water column, etc., on a regular basis to prevent sludge buildup in these areas. The buildup of sludge can disable the low-water trips.
The boiler water side should be inspected on a regular basis. Should any signs of scaling or build up of solids on the tubes be noted, adjustments to the water treatment should be made.
The water side of the deaerator should be inspected on a regular basis for corrosion. This is an important safety issue because a deaerator can rupture from corrosion damage. All the water in the deaerator would immediately flash to steam in the event of a rupture.
Proper treatment of the boiler feedwater is absolutely critical to enable a normal life expectancy of the unit. This is one of the most serious boiler "destroyers."
Improper Warm-up
This is a common problem because management and production often exert extreme pressure on utilities to complete forced or scheduled outages so that production can resume. As soon as the boiler is "capable" of producing steam, they want it.
The improper warm-up of a steam boiler is one of the most severe hardships a boiler must endure. Going through the cycle of start-up, operation, and shutdown for any boiler creates higher equipment stresses and, consequently, much more maintenance-type issues than continuous operation at maximum rated capacity. Any piece of equipment such as a boiler, airplane fuselage, or combustion engine that undergoes an extreme transformation from ambient out of service conditions to operating conditions is subject to fatigue and failure. Good design and the process of making a slow transition between these conditions is essential for prolonging boiler life and reducing the possibility of failure.
A typical boiler is constructed of different types of materials which operate in totally different environments, including:
Drums and headers fabricated of thick metal which contain water and steam,
Tubes fabricated of much thinner metal which contain water and steam,
Refractory materials that are exposed to high furnace temperatures on one side and cooling from water, steam, and air on the other side,
Insulation materials which are specially designed to operate at a much higher temperature on one side than on the other side, and
Thick cast-iron castings such as access doors that are refractory-lined which see the full temperature of the furnace on one side and ambient air cooling on the other side.
By design, all of these materials heat up and cool down at a much different rate. This situation is made much worse when a component is exposed to different temperatures. For example, a steam drum that is operating at normal water level has the bottom half of the drum cooled by water and the top half by air initially and steam eventually. If one starts to fire the boiler from a cold start, the water will heat up very quickly in the drum and the bottom half of the drum will expand much more quickly than the top half which is not in contact with water. Consequently, the bottom of the drum will become longer than the top, causing the drum to warp. This phenomenon called "drum humping" can lead to stress fractures of the generating tubes between the steam and mud drums.
Refractory damage is the most prevalent damage associated with a quick warm-up of a boiler from a cold start. Refractory by design transfers heat very slowly and therefore heats up much more slowly than metal. Also, as the air inside the furnace and refractory cool, moisture is absorbed from the air in the refractory. A gradual warm-up is required to prevent refractory from cracking; this allows adequate time for the moisture to be driven from the refractory. Trapped moisture quickly becomes steam and causes the refractory to spall as the steam escapes.
The standard warm-up curve for a typical boiler does not increase the boiler water temperature over 100°F per hour. It is not unusual for a continuous minimum fire to exceed this maximum warm-up rate. Consequently, the burner must be intermittently fired to ensure that this rate is not exceeded.
Correct planning and education will allow a boiler to be started properly, which will prolong the boiler life and eliminate costly maintenance repairs.
Editor's note: Some ASME Boiler and Pressure Vessel Code requirements may have changed because of advances in material technology and/or actual experience. The reader is cautioned to refer to the latest edition and addenda of the ASME Boiler and Pressure Vessel Code for current requirements.

Monday, 5 October 2015

Clinker at boiler

Clinkers, or slag, are made up of elements and minerals found in coal which are non-combustible. When burnt, they melt and fuse together, forming lumpy ashes.

Tuesday, 29 September 2015

Tiga Insan Yang Saya Kagumi Dalam TOASTMASTERS

Sejak sertai TI April 2013 hingga kini, saya telah menjadi ahli kepada 4 kelab di Sandakan dan Lahad Datu. Menjadi Charter Presiden dan juga Triple Crown pertama sesi 2014-2015. Saya amat kagumi 3 insan yang menyebabkan saya sentiasa bersemangat meneruskan perjalanan dalam Toastmasters tanpa henti. Ibarat kata Area Director Shane Ho, a running Toastmaster.

Tiga insan itu adalah Datuk Hasan Sandukong, Hj Ir Azmer dan Hjh Kasmah. Mereka adalah contoh kepada saya kenapa saya mesti teruskan usaha dalam Toastmasters. Ada ramai lagi ahli yang saya kagumi, namun itu sekadar contoh utama.

Saya amat kagum dengan Datuk Hasan Sandukong kerana beliau sudah berada di kemuncak kerjaya dan hidup beliau. Pernah berkhidmat sebagai Speaker DUN Sabah dan telah berusia, namun beliau nekad terus aktif dalam Toastmasters hingga kini. Mengulang - ulang modul CC hingga kali ke 13 dan kini masih melakukan perkara yang sama! Hadir ke mesyuarat di dua kelab, malah hadir ke banyak program kelab dalam dan luar daerah. Beliau mengajar saya erti usia bukan penghalang dalam melakukan sesuatu terutama dalam BELAJAR. Beliau sebenarnya banyak MENGAJAR saya untuk menjadi lebih hebat!

Insan kedua adalah Hj Ir Azmer Shamsuddin. Insan yang amat sibuk pernah saya temui. Aktif dalam pelbagai bidang mahupun persatuan. Beliau juga berada di tahap tertinggi kerjaya, namun tetap meluangkan masa meneruskan perjalanan dalam Toastmasters. Aktif dalam 2 kelab. Jika dikaji dari segi masa dan sibuk, beliau adalah orang paling layak untuk memberikan alasan terbabit. Namun, masa bukan alasan beliau. Komitmen dan sikap beliau amat menakjubkan. Sikap beliau yang rendah diri menyebabkan hilang rasa sombong dalam diri saya yang tidak punya apa - apa. Jika beliau boleh lakukan, kenapa pula kita yang lebih jual mahal? Adakah kita sudah lebih baik dari beliau?

Insan ketiga adalah Presiden Hjh Kasmah Mukmin. Beliau sangat unik. Beliau sangat hebat. Di usia emas, beliau sanggup menggalas tugasan sebagai presiden kelab. Bukan satu persatuan beliau ikuti, malah 6 persatuan beliau bergiat aktif. Jika usia lebih 60 tahun menjadi alasan, tidak kepada insan ini. Wajahnya sentiasa ceria dengan senyuman. Cekal melayan kareneh pelbagai ahli. Terus tekad dalam Toastmasters.

Ketiga - tiga insan di atas amat saya kagumi. Mereka adalah ikon kepada Toastmasters. Contoh insan bergelar pemimpin yang dilahirkan oleh organisasi bertaraf antarabangsa. Bukan rhetorik malah bukti nyata di depan mata. Perjalanan dan pengembaraan dalam Toastmasters akan membawa semua ahli ke perhentian kejayaan yang tidak pernah anda gambarkan. Ayuh, sertai kami hari ini!

Zulkefli Muhammad, ACS, CL
CHARTER PRESIDEN
TOASTMASTERS BANGSAWAN LAHAD DATU

Saturday, 26 September 2015

Welding

Controlling Your Fear

Triggers
1. New and uknown situations
2. Risk of failure
3. Potential for appearing foolish
4. Possibility of boring the audience

Anxiety Symptoms
1. Increase heart rate
2. Butterflies in the stomach
3. Incontrollable shakes
4. Lightheadedness
5. Dizziness

Managing Anxiety

1. EXPERIENCE
Practice
Rehearse
Deliver a speech before your Toastmasters club
Give presentations anywhere you can

2. VISUALIZATION

3. RELAXITION

CONCLUSION
It is normal to feel nervous
Your audience won't notice
Use methods to exhibit confidence

Successful Conclusions

Criteria
1. Achieve a sense of closure
2. An impact
3. 5-10% of the entire speech time

Use quotation
1. Adds authority
2. Amuses listeners
3. Dramatize your speech

Techniques
1. Tell story or anecdote
Develop quickly
Make it short
Reinforce your message

2. Call for action
Clearly explain what action the audience should take

3. Ask a rhetorical question

4. Refer to the begining remarks

5. Summarize your main points
Repetition reinforces your message

TIPS FOR SUCCESS
1. Memorize your conclusion
2. End on time
3. Refrain from adding new points

CONCLUSION

"GREAT is the art of BEGINING,
but GREATER is the art of ENDING."
(Henry Wadsworth Longfellow)

Friday, 25 September 2015

Begining your speech

Successfull Opening
1. Get the attention
2. Introduce the topic
3. Establish rapport
4. 5-10% of the entire speech time

Opening Tecniques
1. State the importance of your topic
2. Starting STATEMENT!
3. Arouse suspense @ curiosity
4. Tell a STORY @ ANECDOTE
5. Ask a RHETORICAL question
6. Begin with a QUOTATION
It can be
6.1 add authority to a speech
6.2 amuse the audience
6.3 dramatize a speech point

7. Reference the occasion
- audience common interest
8. Humor
9. Audience participation
10. Demonstration
11. A reference to a historical event

AVOID
1. Acknowledging the amount of preparation
2. Avoid being dull and boring
3. Avoid delaying mention of the topic

CONCLUSION

A dynamic begining is essential for a successfull speech!

Speech Introduction

Why it is important?

1. Smooth transition
2. Proper mindset
3. Speaker authority

General Essentials
1. Speaker's name
2. Speech topic
3. Tittle

Toastmasters Essentials
1. Speech assigment
2. Speech objectives
3. Delivery time

Draft the Introduction
1. Approach
2. Length
3. Delivery
4. Clarification

Applying Restraint
1. Don't upstage the speaker
2. Don't reveal speech details
3. Don't suprice the speaker
4. Don't praise the speaker's skills
5. Don't rely on cliches
6. Don't save the speaker's name until last

Speaker's Responsibility
1. Be available to offer speech related information.
2. Inform the introducer of any special considerations.

Lectern Etiquette
1. Speak to the audience
2. Lead the applause
3. Shake hands
4. Leave the lectern
5. Show interest

Introduction are only the begining
1. Speech's ideas
2. Point of entertainment
3. How the speech helped or englightened the audience
4. Words of thanks and appreciation

Iron Phase

Iron - carbon up to 2% -> steels
>2% -> cast iron

Eutectoid point
- 0.8% carbon
- temperature 732 deg C

Austenite
- carbon steel at high temperature.
- Face Center Cubic

Example
18-8 (18% Cr and 8% Ni) -> Stainless Steel

Ferrite
- Body Center Cubic (BCC) can hold very little carbon typically 0.0001% at room temperature (pure iron)

Cementite
- very hard
- consist of 6.7% carbon

Martensite
-

Hypereutectoid
- steels with 0.77% < carbon < 1.7% carbon (high carbon steel)

Objective of TEMPERING

1. Reduce brittleness and increase ductility

2. Remove internal stresses

3. To make sufficiently tough to resist shock and fatique

Wednesday, 23 September 2015

DOSH Inspection

2 jenis
1. Pemeriksaan Pertama
2. Pemeriksaan Ulangan
FMA 1967
STEAM BOILER & UNFIRED PRESSURE VESSEL
Reg 76 Opening out boiler
Reg 78 Notifiable occurances
Reg 79 Repairs
Overhaul boiler dilakukan setiap 15 bulan
Atau
SSI Special Skip Inspection
+3 bulan + 3 bulan (jika diluluskan) untuk maksima 36 bulan.
Pemberitahuan, Perakuan Kelayakan & Pemeriksaan
Kilang dan Jentera, 1970
Pemeriksaan Pertama dilakukan oleh Pemeriksa daripada JKKP
Untuk memastikan dandang termasuk
1. Boiler supports
2. Piping installations
3. Safety and other valves
4. Water columns
5. Gage cocks
6. Peralatan keselamatan memenuhi kehendak undang - undang dan kod rekabentuk.
Reg 14
Peraturan (Pemberitahuan, Perakuan Kelayakan dan Pemeriksaan)
Kilang dan Jentera, 1970
Dilakukan setiap 15 bulan
Bertujuan memastikan dandang tersebut dalam keadaan yang memuaskan dan selamat digunakan.
Pemeriksaan dilakukan secara menyeluruh.
Reg 17
Persediaan untuk pemeriksaan
1. Dandang stim termasuk economiser atau superheater, dikosongkan, disejukkan, dikeringkan dan dibersihkan dalam dan luar.
2. Semua fire bar dan main steam stop valve ditanggalkan
3. Semua tiub, header, sight glass dan fusible plug ditanggalkan.
4. Semua pili, injap ditanggalkan, dicuci dan dibersihkan.
5. Dandang stim diasingkan dari mana - mana dandang stim atau air panas mengikut cara yang ditetapkan.
6. Semua kehendak khas Pemeriksa seperti yang tertulis di dalam pemberitahu pemeriksaan ditepati.

Jenis - jenis kerosakan boiler

1. Furnace rupture
2. Scaling
3. General corrosion
4. Pitting
5. Carcking
6. Bulging
7. Blistering
8. Tube snaking

Prosedur Boiler Maintenance

Persedian sebelum maintenance
-> maklumkan tarikh pemeriksaan dan dapatkan persetujuan dari JKKP.
1. Stop boiler. Buang bahan bakar. Cooling down.
2. Buat insulation boiler.
3. Open man hole boiler.
4. Lakukan boiler pre - inspection.
5. Sekiranya ada defect - > prosedur pembaikan dilakukan.
6. Mulakan mekanikal cleaning pada surface, tube, furnace.
7. Final inspection.
8. DOSH inspection.
9. Box up.
10. Filling boiler with feed water dan HT.
11. Sekiranyan DOSH berikan arahan untuk jalankan HT -> prosedur HT dilakukan.
12. Flushing air boiler untuk buang saki baki kotoran.
13. Start up boiler.
14. Set safety valves.
15. Commissioning and monitoring.
16. Online operation.

Monday, 21 September 2015

Maturity

Pic of technical for a day

Motivation for a day

Impurities in boiler water

Impurities includes
DISSOLVED GASSES
CHEMICAL COMPOUNDS
SUSPENDED SOLIDS
Uncontrolled concentration of these impurities can cause corrosion problems.
1. Hardness
presence of calsium & magnesium. Normally presence in a CARBONATE @ BICARBONATE ->referred to as "carbonate hardness".
Hardness may also combined with sulfated, nitrates or chlorides which is reffered to "noncarbonated hardness"
May deposited as scale.
1.1 Calsium carbonates.
Form a tenacious scale.
Form a weak carbonic acid solution -> corroded the metals in the condensate system and contiminate the condensate with dissolved metals.
1.2 Calsium sulfates
Calsium sulfate scale
Ie gypsum
1.3 Magnesium bicarbonate
Decomposes to form Magnesium Hydroxide and CO2
A sticky sludge @ deposit as scale.
+ silica -> magnesium hydroxide and hydrochloric acid which may be removed as sludge.
1.4 Magnesium Chloride
Very soluble.
+ metal -> magnesium hydroxide and hydrochloric acid.
Corrode the boiler above the water line.
2. Silica
Or silicon dioxide SiO2
Form a hard, glassy coating on the boiler surfaces.
Deposited on turbine blades or piping.
Treatment -> phosphate treatment , external treatment or continious blowdown.
3. Iron and other suspended solids
4. Dissolved gases/oxygen and CO2
5. Alkalinity/causticity
6. PH

Term in boiler water treatment

Sunday, 20 September 2015

Latent Heat

energy released or absorbed, by a body or a thermodynamic system, during a constant-temperature process.
An example is a state of matter change, meaning a phase transition, such as ice melting or water boiling.