WATER-TUBE BOILER

SCOPE : To design, supply, deliver to site, installation, testing, commissioning and guarantee of one (1) unit bi-drum water-tube boiler.

SPECIFICATIONS : The steam boiler shall be 35.000 kg/hr. Water tube Bi-Drum type, designed specifically to burn palm fibre and shells.

Steam Condition at Mains : 22 kg/cm2 gauge,

Saturated Temperature : 219 °C.

Approx. Feed Water Temp at MCR : 70 °C.

Boiler MCR : 35.000 Kg steam/hour at operating pressure.

Boiler Operating Range : 50% to 100% MCR Overload Capacity Range : 110% 0f MCR (short

period) Overall Efficiency : Not less than 75%

Electrical Supply : 415 V+_ 6%, 50 Hz, 3 Phase, 4 wire.

The supply of the steam boiler shall but not be limited to the following.1. Supporting structure2. Steam water drums with internal fittings3. Headers and tubes4. Mountings and fitting5. Spring loaded safety valves for steam drum6. Soot blower system7. Automatic feed water regulation using the latest technology

available in the market c/w high, high-high and low and low-low water alarm. The alarm shall not be resetable until the level is corrected. Indicating lights shall also be installed on boiler front and control panel to indicate the states of alarm.

8. Integral feed water piping from feed water pumps to boiler drum. 9. Integral steam piping from boiler drum to main stop valve and any

equipment within the scope of works.10. All boiler drain piping.11. Integral electrical system from boiler MCC to equitment.12. Reflex and Bi-color water level gauge glasses13. Manual and automatic blowdown valves14. Furnace grate.15. Explosion doors16. Forced, secondary (over fire) and Induced Draugth fans, complete

with automatic and manual draugth control.All fan sizes, capacities static pressures and volumes are to be specified.

17. Fuel feeder fan complete with feeder spouts and adjusment to facilitate efficient fuel spreading across its whole grate surface.

18. Dust collecting system19. Chimney and flue gas ducting

20. Mechanised fuel feeder of pendulum type with anti fire back flash features.

21. All ducts22. All refractories and common red bricks23. All galleries, ladders and railings24. All main, auxiliary and non-return valves25. Water sampling and cooling system26. All gauge and instrumentation complete with one (1) steam/water

flowmeter, steam/water temperature meter, steam pressure meter, draught/temperature meter and smoke density meter for each boiler.

27. Blowdown chamber silencer complete with piping from the boiler.28. Instrument and control panel complete with mimic diagram

indicating state of operation inclusive of necessary field instrument wiring. All indicating lights shall use 24 VAC power supply.

29. Recommended spare parts and tools for maintenance30. Insulation complete for all heated surfaces31. Steam pressure and water flow recorders/meters of 250 mm

circuler type32. Operating manuals33. Chemicals for boiling outs34. Cleaning and painting35. One (1) electric drived and one (1) steam drive feed pump of

proven performance. The pumps shall be sized at least 1,5 times the MCR of the boiler.

36. Computerised DATA LOGGING system for the operation of the boiler with option for future automation.

37. Detailed technical specifications and drawings.38. Fixed mounted pollution monitoring instruments

Boiler Design & ConctructionThe essence of design shall be reliability and efficiency in order to give long continuous servise with high economy and low maintenance cost.

In complying with the requirement of the specification, both with respect to arrangements and detail, design is to conform to the best current practices. Each of the several parts of the plant is to be of maker’s standard design provided that this design is in general accordance with these specifications. Particular attention shall be given to internal and external access in order to facilitate inspection, cleaning and maintenance. The design, dimensions, and materials of all parts are to be such that they will not suffer damage as a result of stress under the most severe service conditions.

Material used in the construction of the boiler ancillaries are to be of the highest quality and selected particularly to meet the duties expected of them.

Steam generation tubes shall be of adeguate sizes and tube ends shall be expanded onto their seating.

All construction shall be to British Standards or equivalent acceptable to the Indonesian authorities, and in accordance with Lloyd’s safety regulations and local authorities regulations. All designs shall be submitted for approval by the local authorities with all necessary drawings and test certificates.

All relevant information and documents shall be copied to the Engineer.

Design Code:

In accordance to BS 1113 and BS 5759 or approved aquivalent standards.

Manifolds For Side & Rear Water walls

Constructed from solid drawn hot finished seamless pipe to BS 3602 G410 and closed at each end with a flat plate of material to BS 1501 - 151 – Gr 430A.

Inspections & Tests

These shall be carried out and certified by Lloyd, Bureau Veritas or other approved authorities.Boiler Mountings & FittingsAll mountings and fittings necessary for the safe and proper operation of plants shall be provided. Each item to be complete with ancillary piping and any other required accessories.

Two water level gauges of Reflex and Bi-colour type located to give easy observation from the boiler floor level. Adequate illumination shall be provided. One remote water level indivator located at the instrument and control panel or at the boiler floor level with adequate illumination shall also be provided.

Safety valves of spring loaded type, for the steam drum, of adequate capacity shall be provided, complete with release piping, supports and silencers as necessary.

Steam soot blowers shall be supplied in adequate numbers and situated such that proper cleaning of the heating surfaces is effected and the operating efficiency of the boiler is maintained at its maximum withhout manual cleaning.

Automatic Feed Water regulation shall be provided to maintain automatically the working water level at all times and at varying load conditions.

Isolating valves shall be provided on the outlet and inlet of the regulator and a by-pass valve is also provided for use when the regulator is out of commission. The regulator shall be individually connected to the steam and electrical Feed Water pumps.

One electric and one steam dived Feed Water pumps of turbine type shall be provided. Capacity of each pump shall be at 150% MCR of boiler rating. Pressure gauges and relief valves shall be provided for each Feed Water Line.

Water level alarms with distrinct audible alarm and coloured indicator lights to signal high and low water levels in the drum. The alarm shall be audible within a 38m distance from the boiler during normal factory operations.

The furnace and grate shall be designed for the efficient combustion of oil palm fibre and shell which are the normal fuel utilised. Self de-ashing facilities shall be incorporated.

Pin-hole grates are not acceptable.

There shall be occasions necessary where firewood and dewatered empty oil palm bunches are used.

Fuel normally used are of the following characterictics: Shell to fibre : up to 25% shell Moisture content in fibre : up to 42% by weight Moisture content in shell : up to 22% by weight.

Induced, forced and secondary draughts shall be provided with draught control arrangements operated automatically and hand controls at the boiler front. Drafts will be sufficient to ensure effective combustion at maximum continius rating and meet environmental regulations in smoke density and emission levels.

Insulation and refractories, of high quality shall be used.

Instrumentation

Instrumentation shall be provided for: Steam drum and lower drum pressure gauge (150mm installed on drum). Steam drum pressure gauge (250mm installed on boiler front). Steam temparature gauge (150mm c/w pocket installed on drum) Flue gas temperature gauge. Furnace draughts Steam flow, water flow and pressure recorders/meters and totaliser (Installed

on panel). Steam, feed water and flue gas temperature recorders/meter (installed on

panel) Smoke density meter, recorder with alrm at Ringleman 2 scale (installed on

panel)All control instrument shall use 4-20mA signal and meant for hooking-up to Central Control Station (by Others). Platform, Ladders, Staircase

All necessary operating floors, access galleries and platforms complete with handrails, stairways and ladders required for the safe and convenient operation and maintenance of the plant.

Blowdown And Drains

Blowdown outlets and water drainage outlets from drums, headers, etc, shall each be provided with two stop valves in series with special handles or key. Automatic blow down valves with TDS besed controllers shall also be provided.

Water Sampling Cooler

Water sampling shall incorporate a stainless steel cooling coil and associated eqipment. The scope shall include the installation of cooling water piping from nearby water supply line.

Chimney

Chimney height shall be designed for an efflux velocity of 8 m/sec and to comply with the Indonesian environmental regulations but shall not be less than 30m

Chimney shall be of self-standing type. Necessary sampling points shall be provided in compliance with local authority’s regulations. Ladder and landing platform shall be provided at the sampling points.

Number plate measuring 450 x 450 mm painted in black shall be provided at the top of the chambers.

Copper strips conductor shall be provided throughout the length of the chimney complete with earthing rods and chambers. Calculation on chimney structural design, efflux and height shall be furnished.

Multicyclone

A multicyclone dust collecting system shall be designed for emission of particles of less than 0.4 gm/Nm3 and to comply with the Indonesian environmental regulations. Dust removal and disposal system shall be incorporate.

A dust handling and disposal system shall incorporate to remove the dust.

Maintenance Tools

Special tools and apparatus shall be provided for the mantenance and repair of the boiler. One set of tube expanders and one set of mechanical tube cleaner shall be included.

Fuel Feeding System

One complete set of automatic fuel feeding system shall be offered with the supply. The feeding system shall be pendulum type with anti fire flash features incorporated with it. The gearbox/geared motor used for the drive system shall have at least 2.0 factor of safety.

The fuel feeding system supplied mush be ensured of effective distribution of the palm fibre grate. Detail design shall be furnished together with the tender.

Cleaning & Painting

After fabrication and before delivery to the site. The boiler and ancillaries are to be well wire-brushed and cleaned, before given one coat of primer. After erection the whole plant including bare pipe surfaces and handrailings are to be wire-brushed and cleaned, after which all parts except surface intended to be lagged are to be given two coats of white colour and quality paint. All paintwork is to be finised in colour according to specifications. All hot surface shall be painted with one coat of primer and two coats of finishes of silicon-based heat resistant paint in accordance with manufactureer’s recommendation.

Drawing & Specifications

Sufficent drawings technical data and specification shall be furnished together with the tender. Schedules of electrical loading, fan sizes, etc. Shall also be provided.

Submission of NDT done on welds and joints are necessary.

Electrical

Motor Control Center ( MCC) of IP44 complete with MCCB, ammeter, voltmeter, starter, veltilation fan and internal light shall be provided. Cables to motors shall be of PVC/SWA/PWA copper type and run on G.I cable trays. All electrical works shall be in accordance with rule and regulation of local authorities, BS and IEC Standard.

Fans

All fans shall be tested and witnessed by the Engineer ini wokshop or at the site for capacity, pressure and mechanical balancing to ensure that these comply with the requirements specified. The test procedures shall conform to BS or equivalent standard. Induced draugth fan blades shall be of heat resistance material and the fan speed shall not be more than 750 rpm. ID fan shall be coupled with fluid coupling to motor.

Fan Damper Controller

Induced draugth fan damper shall be controlled by PID Controller through hydraulic type actuator. Forced draugth fan damper shall be controlled by the same type of controller either through electrical or hydraulic actuator and the damper shall be located at the fan inlet.

Tests on Completion

The manufacturer shall carry out capacity and rating tests to ensure the specifications are complied, before taking over by the Owner.

The boiler unit shall be steamed continuously to its maximum continous rating for a minimum period of three (3) hours operating in conjuction with the turbo alternators.

The capacity test on each boiler unit shall be carried out to achieve a 110% output rating during this period.

Technical data, specifications and relevant literatures shall also be provided for technical evaluation.

Approved Makes

Motor : Elektrim, Crompton, TEFC, 4-pole, Class F, IP 54.Gearboxes : SIEMENS, SEW, BENZLAR-SALAPump : SIHI, TorishimaFan : Airvenco, ABB-Flakt, Phoenix, etc.Steam turbine : COPPUS, etc.

Flanges

DIN PN 40 for for pressure above 3 kg/cm2

DIN PN 16 for for pressure above 3 kg/cm2