Vertical Boiler

The vertical boiler is a simple type which consists of a firebox at the bottom and a copper barrel with a smoke tube.  It typically is used to drive stationary engines and boats.  Firing is accomplished by alcohol or solid fuel pellets.  More sophisticated versions of the vertical boiler contain many small tubes and are sometimes fired by coal or charcoal.

Package Boiler,Vertical Boiler / 200kg/hr

The furnace of this product is type of water tube penetrating flow, vertical three returns. Burner is on the top location, top burner-burning. Each part of fuel gas continually heat transferring through three returns, decreasing the exhaust gas temperature greatly, reducing the heat loss when preheating boiler at the time of startup and shutdown and to improve thermal efficiency. There are protective device controller, automatic resume contacts with the parts fuction,and dual-exhaust current thermal protection devices, enhancing the security functions.

1. Quickly startup, achieving high temperature and pressure in short time.

2. Nature circle, be able to endure different temperature.

3. Water level, steam pressure etc. many chain protection ways.

4. The structure design is perfect and excellent, covering small installing area.

Inhouse Boilerman Training

Adalah dimaklumkan bahawa kami di AIZ Training Services juga mengadakan inhouse Boilerman Training atau kursus dikilang2 atau dipremis perniagaan anda dengan bayaran yang berpatutan.

Selain kursus boilerman  atau boiler driver, kami juga menyediakan kursus2 Internal Combustion Engine (ICE), Pump Operation and maintenance, Air Compressor Operation and maintenance, Turbine Operation and maintenance dan Maintenance management.

 Bersama peserta2 kursus boilerman diTesac (M) sdn bhd Kuala Trengganu pada 9&10 Mac 2011.

Water Column

Purpose of water column:
When steaming, boiler water is in constant, turbulent, violent motion. If a glass attached direct to the boiler, the water would oscillate up and down so rapidly that an accurate reading would be difficult at best. The construction and placement of a water column averages out these wild gyrations, providing a stable water level allows the gauge glass and other devices to yield accurate reading.

Hydrostatic Test

TUJUAN :

Untuk menguji kekuatan boiler dan fittings

FMA reg. 72

  Setiap boiler berikut mesti melakukan ujian HT:

1.  Boiler baru digunakan

2.  Setelah boiler repair. (eg. Repair crack by welding)

3.  Setiap tidak lebih 7 tahun

4.  Boiler yang tidak dapat diperiksa didalamnya kerana kecil

(tiada access)

5. Boiler yang diubah design. Untuk menentukan semula ASWP

SYARAT: 2 x ASWP (untuk boiler bertekanan<100 psi)

 1.5 x ASWP + 50 psi (untuk boiler bertekanan> 100 psi)

CONTOH : Boiler tekanan ASWP 10 bar

UJIAN   : (1.5 x 10 bar) + 3.4 bar = 18.4 bar (maksimum)

* 1 bar = 14.72 psi,   3.4 bar = 50 psi

Langkah2 HT

1.   Tutup dan blind setiap flange dan measuring instrument

2.   Gag atau blind Safety valves

3.   Isi air ke dalam boiler dan s/htr hingga penuh

    (air keluar ke vent line) – suhu air >= amb. Temp.

 4.Tutup vent valve

5. Teruskan pam air kedalam boiler menggunakan

    high pressure pump

6. Naikkan tekanan boiler secara berperingkat

7. Periksa sekiranya ada kebocoran

8. Sekiranya terdapat kebocoran dipertengahan ujian,

    release tekanan dan ketatkan ditempat kebocoran

9. Teruskan semula ujian setelah kebocoran diatasi

10.Pada 1.5% ASWP hendaklah bertahan selama 20

    minit dan tidak ada sebarang kebocoran

11.Kemudian turunkan tekanan secara berperingkat

Draft

Q. What function does draft play in the combustion of fuel?
A. Draft provides the differential  pressure in a furnace to ensure the flow of the gases. Without draft, stagnation in the burning process would result and the fire or process of combustion would die from lack of air. Draft pushes or pulls air and the resultant flue gas through a boiler and up into the stack. The draft overcome the resistance to flow of the tubes, furnace walls, baffles, dampers and the chimney lining.

Natural  Draft
Natural draft is produced by the chimney into which the boiler exhausts. The cool air admit to the furnace, rushes in to displace the lighter hot gases in the furnace. Thus the hot gases rise (chimney effect), causing the natural draft.

Mechanical Draft
Mechanical draft  is produced artificially by mean of forced or induced draft fans. The chimney is still necessary on mechanical draft installation for venting the produced of combustion high enough not to be offensive to the surroundings.

Boiler Baffles

Q. What is the boiler baffles?
A. The flow of the combustion gas over the banks of boiler tubes is controlled by what a called baffle.

Q. What factors does baffle arrangement depends?
A.           1. Allowable draft (draught) loss
               2. The layout the boiler heating surface and its dimension
               3. Gas out position
               4. Fuel
               5. Fuel burning equipment and operating parameter
               6. Baffles supporting device

Q. What factors should be considered in designing a baffles
A. The baffle design should be such that it
              1.Ensures best distribution of heating surface with respect to gaseous product of combustion
              2. Ensures proper flue gas velocity
              3.Maintain cross flow of flue gas pass the boiler tubes
              4. Deposit flyash and dust where is it accessible for easy removal
              5. Eliminates dead pockets
              6. Avoids high draft (draught) loss

2nd Gred Steam Enginner - Part B

1st/2nd Grade Steam Engineer - Oral examination

1st Grade Steam Engineer - Part B paper 1- Desember 2003

1st Grade Steam Engineer - Part B paper 1- June 2003

Boiler Overhaul

Overhaul boiler dilakukan setiap 15 bulan untuk menyambung CF (Certificate of Fittness) atau + 3 bulan + 3 bulan (if approved) 

Langkah2

1)Turunkan firing, stop boiler operation dan cooling down

2) Buat isolation boiler system

3 Open man hole boiler

4)Lakukan boiler pre-inspection (internal)

5)Sekiranya didapati ada defect seperti crack, mesti repair dahulu

6) Buat mekanikal cleaning pada surface, tube dan furnace

7)Final inspection (internal)

8)DOSH inspection

9)Box-up

10)Filling boiler dengan feed water dan leak check

11)Sekiranya DOSH menghendaki Hydro test, blind semua flange dan ikut procedure HT test

12)Flushing all boiler water apabila selesai

13)Filling boiler dan dosing chemical Ammonia dan Hydrazine

14)Start-up boiler

15)Buat recommissioning dan safeguarding test (PSV, Level switch)

16)On-line operation

WATER HARDNESS

Hardness dipecahkan kepada Carbonate dan non-carbonate hardness
Hardness – Kewujudan Calcium dan Magnesium (dan mungkin iron, aluminium, manganese

CLASSIFICATION	Carbonate hardness	Non-bicarbonate Hardness
Calcium hardness	Calcium Bicarbonate Ca(HCO3)2 Calcium Carbonate CaCO3	Calcium Sulphate CaSO4 Calcium Chloride CaCl2
Magnesium Hardness	Magnesium Bicarbonate Mg(HCO3)2 Magnesium Carbonate MgCO3	Magnesium Sulphate MgSO4 Magnesium Chloride MgCl2

Boiler Explosion

Letupan yang berlaku didalam Furnace
Minor Explosion dipanggil sbg Puff, Flareback or fire blowback.


Biasanya disebabkan oleh:
- pengumpulan gas yang tidak terbakar (unburn fuel) didalam furnace
- Air/fuel ration in a explosive mixture
- Pembakaran yang tak sempurna
- ignition timing failure
- insufficiency purging process
- Fuel supply and control not in proper condition
- Loss of furnace draft


Kerosakan akibat daripada Furnace Explosion
Dinding boiler retak, mengelembong dan runtuh
Tube dan tube plate retak, longgar akibat dari gegaran
kerosakan pada plate baffle
kerosakan teruk seperti boiler explosion, drum sagging dan kerosakan boiler structure


Langkah2 asas bagi mencegah Furnace explosion:
Buat pemeriksaan boiler operasi secara berkala
Sekiranya burner stop tiba-tiba, pastikan fuel supply diberhentikan dan buat pemeriksaan dengan teliti
Pastikan burner dan peralatan yg berkaitan dgn burner sentiasa bersih dan memuaskan(working satisfactory)
Periksa interlock system secara berkala sekiranya boiler mengunakan induce dan force draft fan
Pastikan suhu dan tekanan air preheater, drying air dan fuel air mengikut suhu standard yg diperlukan
Jangan biarkan Pembakaran yg tak seimbang berterusan didalam furnace
Purge furnace dengan sempurna sebelum boiler firing

l

Boiler failure

Reason for boiler Failure	Fire Tube	Water Tube
Mechanical, electrical fault/failure, maintenance testing	35%	19%
Boiler water trouble	17%	36%
Personnel	16%	13%
Corrosion and erosion	11%	9%
Installation and design deficiencies	10%	8%
Defective material	8%	3%
Other reasons- miscellaneous	3%	12%

Entry into the Boiler

1.1. Apply  PTW procedure

2.2. Ventilation and purging for 24 hrs (min 12 hrs)

3.3. Use oxygen analyser before entry

4.4. Carry out a bag of necessary tool

5.5. Enter the boiler with your head first ( vertical boiler: enter with leg first)

6.6. Remember to open top manhole first then follow up with bottom manhole cover (to prevent hot air to hitting you)

Tip to prevent boiler accident

1.Maintenance of boiler logs

l2.Routine check-up/maintenance of boiler control

l3.Avoid installing a combination low water fuel supply cut off and automatic water feeder control unit.

l4.If above combination unit must be used for any reason, its should be backed  up by a separated low water fuel supply cut off

l5.Competent personnel should be assigned the responsibility of servicing and maintaining the control system

6.Cut the maintenance budget should not reduce the maintenance force responsibility for the upkeep of boiler
7.Adequate emergency power should be available to supply the control system when the normal power supply is interrupted.
8.Record should be kept of the testing, calibrating, maintenance and replacement of component

Boiler safety

Historically, boilers were a source of many serious injuries and property destruction due to poorly understood engineering principles. Thin and brittle metal shells can rupture, while poorly welded or riveted seams could open up, leading to a violent eruption of the pressurized steam. Collapsed or dislodged boiler tubes could also spray scalding-hot steam and smoke out of the air intake and firing chute, injuring the firemen who loaded coal into the fire chamber. Extremely large boilers providing hundreds of horsepower to operate factories could demolish entire buildings. 

lA boiler that has a loss of feed water and is permitted to boil dry can be extremely dangerous. If feed water is then sent into the empty boiler, the small cascade of incoming water instantly boils on contact with the superheated metal shell and leads to a violent explosion that cannot be controlled even by safety steam valves. 

Draining of the boiler could also occur if a leak occurred in the steam supply lines that was larger than the make-up water supply could replace.

Steam Trap

A steam trap is a device used to discharge condensate and non condensable gases with a negligible consumption or loss of live steam. Most steam traps are nothing more than automatic valves. They open, close or modulate automatically. 

 

Boiler Tubes Name

Generating Tube/Riser

-Direct tube to the flue gas

-Material normally medium carbon steel

-OD size 2~3 inches and thickness 3.2 ~4.5 mm 

Downcomer tube

-Not direct to the flue gas

-OD > 6 in 

Superheater tube

- To add heat to the steam without raising the pressure of the steam

-Material High Carbon steel

-Generate superheated steam 

lDistributing tube/water injection

-to distribute water into drum – below LWL 

Economizer tube

-To increase temp feed water before it enters to the boiler drum and reduce flue gas temp

-after the last path of flue gas

Flame and Smoke

Flame

-A yellowish orange, rolling flame indicates good combustion.

-An incandescent white flame with jagged edges shows excess air

-A reddish, smoky flame indicates insufficient air

oSmoke

-A light brown haze at the stake usually indicates efficient combustion

-Black smoke at the stake usually indicates insufficient air

-White smoke at the stake  indicates a large amount  of excess air