1) rice industry sector of bangladeshreeep.sreda.gov.bd/...parboiling-system-brochure.pdf · with...

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1) Rice Industry Sector of BangladeshRice is the staple food of Bangladesh, the nation grows about 35 Mill MT ofpaddy annually. At present about 95% of the total harvested paddy is processedin rice mills to produce finished edible rice. There are about 50,000 small andmedium-sized mills called 'Chatal' and about 500 automatic rice mills inBangladesh. This is the only industry sector where hundreds of thousands ofrural men and women are employed. Most of the people here prefer parboiledrice due to some of its inherent benefits. Hence about 90% of the total rice isprocessed for parboiling and the remaining 10% is non-parboiled. Again, 70% oftotal parboiled rice is processed in Chatals using inefficient traditional boilers.

In Chatals, parboiling is donemanually in batches using lowpressure steam produced withtraditional boilers made by localskilled technicians and masons.For medium size Chatals, thecapacity ranges from 10-20 MT ofrice/batch. Parboiled rice is thendried in sunshine on openplastered floor (Chatal). Theseboilers are fired by husk and arevery energy inefficient (efficiency only 20-30%), unsafe and polluting as well.Due to low energy efficiency, about 60 to 70% of the produced husk is consumedduring parboiling process. Dried parboiled paddy is later on milled to finishedrice, weighed, bagged and marketed.

Parboiling capacities of these mills depend on the sun drying Chatal area. Fora batch of 15MT paddy a drying floor area of about 1 acre is needed. Smallcapacity mills are less energy efficient compared to those having highercapacity (economy of scale).

2) Processing of Paddy to Get Finished Edible RiceHarvested paddy is processed and milled to get edible rice. After milling ofpaddy, about 68% by weight is rice, 20% husk (outer shell) and 10% bran (thinoily layer covering the inner kernel) are available. Rice bran is the raw materialfor high quality edible oil and husk is a significant source of biomass energy.

Improved Rice Parboiling System

Fig 1: A Typical Chatal


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3) Pre-Milling ProcessThis is a need based processing of rice. Depending on the required kind andquality of final cooked rice, there are mainly two types of pre-processing donewith paddy before milling:- (i) Parboiling process and (ii) Non-parboilingprocess

4) Parboiling ProcessParboiling is the process of partially precooking paddy by using steam beforesubsequent drying and milling. It is a hydrothermal process that may be definedas gelatinization of starch within the rice grain. During parboiling process thestarch and protein molecules expand and fill the internal air space whichcreates strong cohesion between them. Both fissures and cracks present in theendosperm are sealed. After drying it becomes tough enough to withstandmilling stresses that increases the total yield of finished edible rice andminimizes the broken rice quantity.

First of all, paddy is soaked into water for several hours. It is then taken intocylindrical bins and parboiled by passing steam through it for a few minutes.A schematic diagram of manual paddy parboiling system is shown in Fig-2.

Normally steam pressure of 0.5kg/cm2 gauge is sufficient forparboiling. Steam is produced in aboiler by firing husk and/or sawdust. Steam pressure of maximum1.0 kg/cm2 gauge is sufficient fornecessary transportation fromboiler to parboiling point throughpipes. Normally Moisture content inparboiled paddy is up to 35%. Driedparboiled paddy having maximum 14% moisture content is suitable for milling.

In semi-automatic mills, to increase the batch frequency, after partial sundrying the final drying is done with mechanical dryer. In manual processing,parboiling and drying is done in batches. Generally one batch takes on average3 days. In modern automatic mills parboiling and drying is done sequentially ina continuous way using automatic parboiling bins and mechanical dryer byapplying both thermal and electrical energy.

G.L.G.L.

PARBOILING BINS

Fig 2: Paddy Parboiling Process


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5) Benefits of Parboiled RiceParboiled rice has several inherent quality improvements and benefits:-

a. The inner kernel becomes sticky and the internal cracks (if any) aremended. This helps withstand subsequent milling stresses (reducesbreakage) leading to higher yield of finished rice.

b. Micro nutrients from rice bran penetrate into the kernel making it tastyand fortified.

c. Characteristics and longevity of cooked rice depends on the soaking timeand degree of parboiling (single/double boiling etc.).

6) Non-Parboiling ProcessHere, harvested paddy is dried manually on floor under open sunshine (in caseof Chatals) or using mechanical dryer to bring the moisture content down to asuitable level(about 10%) and then milled to produce final finished rice. Lowmoisture content makes the grains hard and cohesive enough to withstandmilling stresses keeping the breakage reduced. But longevity and taste of finalun-parboiled cooked rice is less compared to that of parboiled rice.

7) Milling ProcessPaddy is milled either in simple traditional huller mills or in a series of modernimproved milling equipment like rubber sheller (husker), de-stoner, paddyseparator, polisher, colour sorter etc., depending on the requirement of thequality and yield of the final finished rice.

During milling process, the inner edible kernel is separated out from the outerhull/husk and bran. Husk and bran come out as bye products. Husk is mostlyused as fuel and other specific purposes (like poultry bed spread, briquettingetc.). Separated pure bran (available from modern milling) is very valuable andused as the input for quality edible oil industry. Whereas, Husk and bran mix(output of traditional huller milling machine) is used as animal feed or fuel.

Due to inefficient use in Traditional Boilers, 60-70% of produced husk is usedup for production of steam during parboiling.

Husk is one of the major sources of biomass energy in Bangladesh. But due toinefficient use, huge amount of husk is wastefully burnt up in these traditionalmills. Traditional Boilers create health hazard and pollute the environment


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profusely. Moreover, there is no proper safety equipment installed on it. Thisleads to frequent accidents.

8) Initiatives for Identifying Lapses of 'Traditional

Parboiling' SystemDuring 2003, development of energy efficient parboiling system was initiated inBangladesh by DFID. A unit was designed, fabricated and piloted. But the designwas not sustainable. However, the piloting showed that the overall thermalefficiency of parboiling technology can be improved significantly if the designis technically perfected. It will then have huge potential for mass disseminationin the rice mill clusters.

In this backdrop, GIZ came forward toimprove this technology. At first a team ofrelevant experts from GIZ, Bangladesh RiceResearch Institute and Energy Audit Cell ofMinistry of Power Energy and MineralResources (MPEMR) were involved to studythe efficiency and other status of thetraditional boilers in different major ricemill clusters of the country. The teamidentified the major lapses in the existingboilers and prepared their findings andrecommendations. The outcome of the studyshowed that traditional boilers are veryenergy inefficient (efficiency only 20-30%),unsafe and polluting as well. Required steam pressure is very low (about0.5kg/cm2 only) for the batch operations practiced in Chatals. But due to lowoverall energy efficiency, about 60 to 70% of the produced husk is used upduring parboiling process.

9) Lapses of Traditional Boilers Identified by Expert TeamTraditional boilers are fabricated and constructed by local workshop techniciansand masons. As such the design of boiler vessel and civil constructions aredifferent from place to place. These designs are not done from properengineering view point. The overall thermal efficiencies of these boilers are alsovery low over a range depending on what features are incorporated in its design.Main lapses are briefly narrated below:-

Fig 3: Typical Traditional Boiler


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10) Varied type of boiler vessel geometry A particular geometry of boiler andfurnace had been developed andreplicated in a particular area basedon the knowledge and skill of thelocal technicians. The vesselgeometry are - cylindrical, semi-cylindrical with flat bottom, flat onall sides including bottom etc.Cylindrical configuration has moreheating surface area than the flatbottom type which affects the heat transfer rate into water inside. Overallperformance of these systems depend on the particular type of design andstructure.

a) Cylindrical boiler vessel of thin sheet/ joining multiple oil drums:

Here 6 to 8 or more nos. of usedoil drums of different types arejoined together. These drums arevery thin in thickness and do notlast long. Similarly, Vessels madeof single thin M/S sheets hassame effect. Unwise longer usemay lead to explosion/accidents.Vessel of single thin MS sheet hassame effect. Unwise longer usemay lead to explosion/accidents.

b) Semi-cylindrical vessel with flat bottom:

Here heating takes place under theflat bottom which always remains incontact with water above. Thuspossibility of dry boiling could beavoided. But due to low heatingsurface area, this boiler showsreduced efficiency compared tocylindrical ones.

c) Insufficient boiler length:

The boilers are of different lengths (12-16 feet) which affect the proper/complete combustion of fuel and flame holding time inside the furnace.

Fig 4: Cylindrical Vessel

Fig 5: Joining Oil Drums

Fig 6: Semi-Cylindrical Vessel


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d) Un-insulated boiler shell and steam pipe surfaces:

In all most all cases exposed boiler shell surfaces are not insulated. Thelong steam pipe leading to parboiling bin is also un-insulated. Hence,huge heat energy radiates out reducing the efficiency.

e) No manhole on boiler for regular interior cleaning:

Normally, there is no manhole on the traditional boiler shell for enteringinside for internal cleaning. Only a blow down pipe is not sufficient forcleaning accumulated sticky mud & impurities unless scrubbed manuallyentering inside. Thick deposits hamper heat transfer across shell metalreducing the overall efficiency.

f) Boiler vessel placed deep inside the furnace:

Sometimes boiler vessel is placed deep inside the furnace for increasedheat exchange. When water inside evaporates up and the level dropsdown sufficiently, flame impinges on the upper dry part of the vessel.This causes dry boiling and softens the vessel metal leading to explosion.

g) Absence of any safety instrumentation:

Above all there are no pressure gauge, water level indicator and safetyvalve etc. on these boiler vessel which keeps the possibility of pressurebuild up any time beyond safe limit and causing dry boiling leading toexplosion.

11) Improper furnace geometry (dimension)Normally the boiler shell is placed on an external furnace and the length variesbetween 12 to 16 feet. But the geometry (length, height & depth) is not proper.Lapses observed are as follows:-

a) Inadequate furnace volume and length:In most cases furnace volume (length, depth and height) is insufficientfor proper combustion of fuel(husk), flame development and enoughflame holding time before final exit. Furnace entrance and exit are wideopen. In some cases, live flame leaves out of the furnace at high speedtrailing huge heat energy with it which is lost and creates fire hazard.

b) Improper ash pit depth inside furnace:Husk contains about 20% sand. Hence, after burning, huge volume of ash(sand + un-burnt carbon) gets accumulated inside the furnace pit. Theboiler runs at a stretch for 4-5 hours/batch. In most cases, pit size isnot sufficient. Ash builds up and narrows down the effective furnace


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volume affecting proper combustion and heat transfer. Where ash pit isvery deep, it prevents proper flame establishment and increases thedeposit of partially burnt husk. This increases ultimate huskconsumption. When deposited outside, this partially burnt husk laden ashmay cause fire hazard.

c) Wide open fuel charging door:

Traditional boilers are fired manually by hand/ spoon throwing of huskinside the furnace through wide open door. As such huge heat energyradiate out and get lost. Radiated heat and flash back flame may impingeon operator's body & face causing serious health hazards.

d) Insufficient furnace bed insulation:

The ash pit bed found not sufficiently insulated. Huge heat energy leaksout down the bed to the ground causing inefficiency.

12) Absence of proper height of chimneyIn most cases no/improper chimney is fitted with the boiler. Chimney createsnatural draught which allows fresh air inside for combustion of fuel and drainsout flue gas from the furnace. If short, drought insufficient, fuel does not burncompletely. If high, draught is also high which sweeps away huge heat energy.This reduces overall efficiency. Chimney also help carry over and wide dispersalof fly ash and pollutants keeping the work place and neighborhood clean andpollution free.

13) Absence of flue duct between boiler/furnace and

chimneyIn most cases there is no flue duct between the boiler furnace and the chimney.Flue duct help arrest and settle down fly ashes, black carbon and otherparticulate matters and allow clean flue gas to pass out through the chimney.This helps keep work premises and surroundings clean.

14) GIZ Initiative for Development of Improved Rice

Parboiling SystemGIZ later under took another project to develop an improved but cost effectivesystem which will be more energy efficient, safe and environment friendly aswell. GIZ assigned the previous team again to develop the desired improved


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system keeping in view the lapses observedduring the previous study. This time theteam involved Modern Erection Ltd. (a localboiler fabrication industry) from the verydesign stage.

Approach adopted was to keep the designsimple so that it can easily be replicated bythe local skilled fabrication workshoptechnicians and masons and yet the cost bewithin the affordability of the Chatal owners.Paddy once soaked is to be parboiledquickly to keep up the quality of finishedrice. For this reason emphasis was given onlocal level fabrication for facilitating quick after sales service.

During the period of 2007-2015, the expert team has successfully developed,piloted and perfected an 'Improved Rice Parboiling System (IRPS)' which couldattain overall thermal energy efficiency of 45% and above. The designsimultaneously addresses safety and environmental aspects in a cost effectiveway. It is equipped with necessary meters and appropriate safety equipment.Around 75 units, have been installed till then at different rice mill clusterswhich are in operation satisfactorily and profitably.

Finally, the design has been standardized. At present market price, fabrication/construction, installation and commissioning cost of one unit of IRPS is aboutTk. 4.50 lakh. Though the initial cost is high compared to traditional one, it hasa Payback Period of 2-3 years.

15) Major Components of the

Standardized IRPS DesignKeeping in view the inherent lapses in theTraditional Boilers, the design of theimproved system was developed and fieldtested. The major components of theimproved system are:- a) Boiler Vessel, b)Furnace, c) Flue Gas Duct, d) Chimney e)Different Meters and Safety Equipment, f)Power Husk Blower

Fig 7: IRPS in Operation

Fig 8: Boiler Vessel Internal


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16) Brief Description and Salient Features of Major Components

a) Boiler Vessel:

It is a simple 16'x4' semi-cylindrical shell type vessel cross sectionhaving corrugated flat bottom for increased heating surface. There isprovision for easy manual horizontal cleaning. It has a top manhole tofacilitate internal manual scrubbing and maintenance. The corrugatedhorizontal bottom plate is the only surface heated from bottom andalways water remains on top of it. Hence little scope for any dry boiling.Its outer surface is insulated with glass wool blanket that preventsradiation and convective losses.

Construction materials are mainly 4mm thick MS sheets & Angles, No. 10'Voltic Marine' welding rods andSteel Nut-Bolts. Top plates are rolledout and Bottom corrugated platesare made by bending machine.Fabrication work is mainly weldingand assembly works. These materialare available at Steel markets atBongshal & English road area ofDhaka city and different Divisional and District head quarters.

b) Furnace:

The furnace is a brickwork on which the boiler vessel sits. Its walls areconstructed with lime mortar binder for longer life. It has a front steelclosing door having a small aperture for insertion of muzzle of huskfeeding power blower. The inside of door panels are lined up with mudinsulation. It thus can prevent any radiation loss, flame flash back andhot expose to operator's face and increases the door panel longevity.Bottom is insulated with compact sand and brick soling. Brick walls of15"thickness are sufficient for boiler vessel load and provide satisfactoryinsulation against heatconduction and radiation out.Furnace volume is enough forproper flame built up andeffective heat transfer to vesselwater. The ash pit is spaciousenough, walls being taperedupward, to accumulate ash for afull batch operation. Flue exit is

Fig- 9: Furnace & Flue Duct

Fig- 10: Furnace Internal


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at back end having a wide but less deep opening near the vessel bottom.This help retain most of the ash inside the furnace and prevents possiblefly ash carry over to chimney. Lime and mortar construction is preferredfor longer life. All civil construction like furnace, flue duct and chimneyare simple masonry works. Materials of construction are brick, sand,lime, cement, rods etc. which are locally available. A two-part flush steeldoor having inside mud insulation is fitted at the furnace front. There isa rectangular slit at the middle for inserting blower muzzle.

c) Flue Duct:

A 10'x3'x5' flue duct is constructed betweenthe furnace exit and chimney entrance. Wideand long flue duct slows down the exitingflue gas speed. It help settle down anycarried over ash at the bed bottom andallows a clean flue gas to pass to chimney.Thus it helps in maintaining a pollution andemission free environment around. Duct roofis covered with small 2'x3.5'x3" R.C.C. slabsfor easy lifting for flue exit port openingadjustment and duct cleaning.

d) Chimney:

A 35' tall, 8.0'x8.0' base and tapered top brick work chimney isconstructed at flue duct end. It has a 4'x4' hollow inner space at base.Chimney creates necessary draught continuously which carries away theburnt products of combustion out of furnace and draws in requiredcombustion air for burning of fresh charge of fuel. Lime & mortarmasonry work is preferred. However, for cost control, it can also beconstructed with good quality sticky mud.

e) Different Meters and Safety Equipment:

For proper safety, the boiler vessel isequipped with Steam Pressure Gauge,Water Level Indicator, Dead Weight TypeSafety Valve etc. A pressure of maximum1.0 kg/cm2 is sufficient to flow steam tothe bin and subsequent paddy parboiling.The indication of pressure gauge alertsthe operator to control fuel feeding ratefor maintaining vessel steam pressure

Fig 11: Typical Chimney

Fig 12: Water level


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within the above limit. The safety valve bleeds out steam automaticallyif the pressure exceeds the above limit. This sit in type dead weight foolproof safety valve can be fabricated easily at local workshop.

It is a cylindrical MSsheet cup filled withcement concreteweighing 10 kg andhaving a 0.75'x0.75"diaGI pipe in centre asmandrel. This valve sitsfreely with rubbergasket on a 1'x1" diavertical pipe fitted on the vessel body. The water level indicator is aPyrex glass tube (about 18" long) fitted vertically by the vessel side with0.5" dia pipe pieces and nipples. This always indicates the actual waterlevel inside the vessel. Thus the risk of any dry boiling (if there is nowater inside) can be avoided. All above equipment together cost onlywithin Tk. 8,000/-. All these meters and safety equipment are availablewith the boiler equipment vendors at Alu Bazar and Nawabpur area inDhaka city.

f) Husk Feeding Power Blower:

For a controlled air fuel ratio and fordoing away with the tiresome andhazardous manual fuel (husk) feedinginside furnace, a suitable powerblower is used. The power blowercharges husk smoothly at set rateinto furnace and protect the operatorfrom fire exposure and drudgery.Power blower husk feedermanufactured by M/s BarikEngineering, BISCIC, Naogaon is foundmost convenient. It can also separateout whole paddy or rice, if any, in thehusk before throwing in to thefurnace. Thus it help save huge amount of paddy/rice from wastefulburning.

Fig 13: Steam PressureGauge

Fig 14: Dead Wt. SafetyValve

Fig 15: Husk Blower


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17) Budget for IRPS Fabrication, Construction and

Commissioning

a) Boiler Vessel fabrication with MS Sheet, Angles, Flat Bar, Glass WoolInsulation Steam Pressure Gauge, Water Level Gauge & Dead Weighttype Safety Valve

Tk. 1,45,000/-

Major Components Budget

b) Construction of Furnace, Flue Duct, Chimney and Boiler House TrussShade etc.

Tk. 2,65,000/-

d) Installation and Commissioning Cost Tk. 10,000/-

c) Cost of Husk Feeding Power Blower Tk. 30,000/-

Total Installed Cost Tk.4,50,000/-

18) Comparison between IRPS and Traditional Parboiling

System

1.0 Very Energy Efficient (50% Husk ConsumptionCompared to Traditional Ones)

Very Energy Inefficient (DoubleHusk Consumption)

2.0 Very Clean and Environment Friendly Very Dirty and Environment Polluting

6.0 Completely Closed System - No Heat Radiation to Operator

Wide Open Husk Feeding Port- Huge Radiation To Operator

8.0 Boiler Body Well Insulated - No SignificantHeat Loss

Boiler Body Uninsulated - HugeHeat Loss

10.0 Long Working Life (10-15 Yrs) Short Working Life (2-5 Yrs)

4.0 Explosion Proof-Pressure, Water Gauges &Safety Valve Fitted

Not Fitted With Any Kind OfExplosion Protection Device

3.0 Health Hazard Free For Boiler Operators AndWorkers

Very Hazardous For Boiler OperatorsAnd Workers

5.0 Husk Feeding By Power Blower- Less Drudgery Husk Feeding Manually By Hand-Very Tiresome

7.0 Uniform Fuel (Husk) Feeding And CombustionControl Possible

Manual Fuel Feeding IntermittentAnd Combustion Control Not Possible

9.0 Very Comfortable Work Environment Very Hot and Hazardous WorkEnvironment

11.0 Initial Cost High Compared To Traditional Ones( But Have Payback Within 2 Yrs)

Low Initial Cost (But QuickReplacement Required)

Sl No. Improved Rice Parboiling System Traditional Parboiling System


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19) Modified IRPS for Integrated Paddy Parboiling-cum-

Drying OperationThe design of an IRPS standardized as above is suitable for simple paddyparboiling purpose of 12-15MT in a batch of 4-5 hours. Here, boiler is filled upwith water once to complete the parboiling of whole batch of soaked paddy.Thus there is no need for any automatic feed pump to refill water time to timeunder pressurized condition during operation. Again, the depth of the ash pit issufficient to accumulate the total amount of ash produced during parboiling ofa whole batch of paddy. There is enough time for natural cooling down of theboiler furnace and then the accumulated ash can be removed gradually. Thisnon automation of design has kept the total cost of the system at a minimum.

However, for mechanical drying, the continuous drying time requires about 12-15 hours for the same amount of parboiled paddy produced in a batch. Hence,the boiler is to be in operation continuously for that period. As suchmodification and addition is to be made on both boiler vessel and furnacesystem to make it suitable for continuous operation for at least the abovementioned period at a stretch.

For sun drying, millers have to depend completely on the weather, which is veryunpredictable during monsoon and foggy days. As such, they had to minimizethe frequency of batch operations which puts negative impact on the businessviability.

In mechanical drying, hot drying air is passed through paddy mass falling downfrom top of a tower. The process continues for several pass till the grainmoisture comes down to a desired level.

At present there are two types of hot air generation system for paddy dryeroperation. One type is the traditional inefficient hot flue system. The other mostefficient type is one using steam from imported industrial boiler- mainly usedin Automatic mills. The hot flue system is less costly compared to importedindustrial boiler. But it occupies huge internal covered space. Small and mediumChatal owners cannot afford to install mechanical dryer because of this costlyimported boiler or hot flue based system for hot air production.

On Chatal owners' request, GIZ initiated development of a low cost dryingsolution using IRPS. In this respect, GIZ undertook a pilot project to incorporatenecessary suitable modification/ addition on the already developed IRPS designso that parboiling cum drying can be done sequentially with this new modifiedsystem. For this purpose GIZ assigned Agro-processing department ofBangabandhu Sheikh Mujibur Rahman Agriculture University, Gazipur. The team


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included experts who were involved earlier with IRPS development. The expertssuccessfully developed the desired modified version of boiler vessel andfurnace system. A suitable steam-air heat exchanger was also designed forproducing hot air. Finally all these were installed and coupled with an existingautomatic mechanical paddy dryer in a rice mill at Sherpur district. The systemworked satisfactorily for normal parboiling as well as for drying both parboiledand non-parboiled paddy. The temperature of the generated hot air could beattained between 60-80 oC which is ideal for maintaining the quality of finishedrice.

20) Features of the Modified Boiler Vessel Following features have been incorporated in the modified boiler design:-

a. An automatic water level controller has been installed on the boiler bodythrough a feed pump for continuous operation.

b. Reserve water tank for make-up, hot condensate return tank, heatexchanger and piping system installed. This system works during dryeroperation.

c. Steam goes from boiler to the heatexchanger to generate hot drying airneeded for the drying purpose. Thedryer blower draws in fresh airthrough this heat exchanger. Air getsheated and passes into the dryercolumn for drying paddy.

d. The steam cools down to hotcondensate and returns to condensatetank. An automatic feed pump (1/2 hp) feeds this hot condensate in tothe boiler again.

e. The feed pump starts and stops according to the low and high waterlevel inside boiler.

f. Hot condensate recycles back considerable amount of heat energy withit into the boiler increasing cycle efficiency. Fresh water from reservetank makes up the short fall. Thus boiler operation can continue as longas required.

This automatic feed pump system installation requires an additional Tk.60,000/- over the standard IRPS boiler fabrication cost. All theseequipment are available with the boiler instrument vendors.

Fig 16: Modified Boiler forParboiling - Drying


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21) The Modified Furnace, Flue Duct, Chimney System A major modification in the furnace design has been incorporated. Salientfeatures are mentioned below:-

a. Furnace bed has been elevated above theground level and it slopes down at the back.

b. An ash disposal downward opening doorat the furnace back end has beenincorporated which is operated by anextended metal handle. When opened, theaccumulated ash over it drops down onthe ground.

c. This door remains closed upward when husk feeding blower runs.

d. For quick ash disposal, the husk feeding blower is stopped for a while.The ash disposal door opened downward and ash discharged. Closing upthe bottom door, husk feeding can start again. Thus ash disposal can bedone at regular intervals till the boiler runs and drying operation continues.

e. The hot ash stays on the ground, cools down and later taken out throughanother side door and disposed off. Water may be spread over hot ashfor quick cooling.

The estimated additional cost for this modified installation is about Tk.1,00,000/- over the normal construction cost of furnace, flue duct andchimney.

22) Features of Steam-Air Heat Exchanger for Hot Air

Production:a. The heat exchanger design is for modular

fabrication. Several modules are fastened inseries. This design permits addition/replacement of any module to increase the heatexchanger capacity depending on the systemrequirement.

b. Each module is made with bundle of 0.75" MSpipes in two rows fitted in staggered way withtwo headers. The top header is the steamheader and the bottom header is thecondensate header.

Fig 17: Modified Furnace & BackAsh Discharge port

Fig 18: Steam- Air Heat-Exchanger, Dryer Blower


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c. Live steam enters into the parallel steam headers and passes throughthe tubes downward and gets condensed after heating the fresh crossflow air over the outside of the tubes drawn by dryer blower.

d. The condensate return line is fastened with the condensate headerthrough a float type stream trap which allows condensate to flow outbut not the live steam. This trap ensures the maximum possible heatutilization from steam.

e. The estimated fabrication costof this heat exchanger withplain MS tubes including thecondensate return system isabout Tk.3,50,000/-. Instead ofplain steel tube, finned tubemakes the heat-exchanger'ssize smaller and it canminimize the fabrication costalso. But in this case regularcleaning becomes slightlydifficult.

23) Boiler Fabrication Skill Welding Training for Local

Level W/s WeldersGIZ organized training for two batches of workshop welders from different ricemills clusters at 'Linde Welding Training Centre', Dhaka. This was done in viewof skill development to facilitate quality and safe fabrication of IRPS at locallevel on order basis from millers and providing after sales service withinquickest possible time. Skill masonry training was arranged during actualconstruction at site. In the duration of the program, this skill development wasdone for welders and masons from 12 Chatal clusters of the country.

Fig 19: Make-Up Water Tank


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24) List of Service Providers/ Workshops/ SkilledWelders/ Skilled Masons for Fabrication, Construction andInstallation of IRPS:

01 Ashugonj, B'Baria 1. M/s Nandi Engg. Works,Ashugonj,

Pro: Mr. A. K. Nandi-01712841445

1. Mr. Anjan KumarNandi-01712841445

1. MasonMigrated

03 Kurigram Sadar 1. Md. Isahak Ali01716834646

2. Md.Selim

1. Md. Hakim Ali01774937401

2. Md. RahimBadsha

02 Bhurungamari,Kurigram

1. M/s Bhai Bhai Engg. Workshop, Andherijhar,Bhurungamari,

Pro: Md. Rafiqul Islam01724564458

1. Md. Rafiqul Islam01724564458

1. Md. Idris Ali01724034237

04 Ishwardi, Pabna 1. M/s Sompod Traders,

I. K. Road, Joy Nagar,WAPDA Gate

Pro: Md. Shamsul Alam01780133374

2. M/s Sobhania Engg. Works,

Pro: Md. Sanaullah01714232230

3. M/s Bengal Engg. Works

Boroichhora, Ishwardi,

Pro: Md. Ansarul Islam01711247878

1. Md. Kabir Hossain01732247976

2. Md. Momotaz

3. Md. Sanaullah01714232230

4. Md. Ansarul Islam01711247878

1. Md. DakhilUddin01928107141

2. Md. ZahurulIslam01911540674

Md. Nuruzzaman

06 Mohadevpur,Naogaon

1. M/s Ranjan Gas & ElectricWelding Worshop,Mohadevpur,

Pro: Ranjan Nath Das01712217963

1. Ranjan Nath Das01712217963

1. Md. AbulKalam0171094586001768938220

SlNo.

Name of

Clusters

Name of Service

Providers/ Fabrication

Workshop

Name of Skilled

Welders &

contact no

Name of

skilled

Masons

1. M/s Dablu Engg. Works,

Kurigram Sadar

Pro: Md. Isahak Ali01716834646

05 Joypurhat Sadar 1. Md. Firoz AlamSagor, 01712157890

2. Md. Shafi

3. Md. Sumon

1. Md. MosarrafHossain01739626976

2. Md. Firoz-01736133374

1. M/s Sagor Engg. Works,Thana Road, Joypurhat

Pro: Md. Firoz Alam Sagor:

01712157890

07 Patkelghata, TalaSatkhira

1. Md. Afser AliPar Kumira,Patkelghata,Tala01745704229

2. Zakir Hossain

Md. Alauddin

1. M/s Padda welding Works,Kalibari Road, PatkelghataBazar, Patkelghata, Tala

Pro: Mohadeb Chakrobrty


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08 Sherpur, Bogra 1. M/s Bappi Engg., SheruaBat Tala, Sherpur,Pro: Md. Anowar Hossain01712385070

1. Md. Anowar Hossain01712385070

2. Md. Alamin HossainBappi 01738334710

3. Md. Shahinul Islam01704263323

1. Md. Babul01821613486

2. Md. AminulIslam01739887058

3. AkkasParamanik

4. Md. AbdusSalam

09 Sherpur District 1. M/s Shami Engg. Workshop, Sitalpur, ChikerKhalerMoor, Sherpur Pro: Md. Shamol Talukdar01912567594, 01795208754

2. M/s Alamgir Engg.Workshop, Naohata,Kandirpar Moor, Sherpur

Pro: Md. Alamgir Hossain01716-265997

1. Md. Mohon

2. Md.Jewel

3. Md. Alamgir Hossain01716-265997

4. Md. Abdul Karim01744825833

5. Md. Wasim01912421224

1. Md. Farid0172440910

2. Md. MujiburRahman01980721519

10 Thakurgaon Sadar 1. M/s Anonto Engg. Works,Baliadangi More,Thakurgaon Road,Thakurgaon Pro: Satten Karmokar01712385070

1. Satten Karmokar01712385070

2. Subed Karmokar

SlNo.

Name of

Clusters

Name of Service

Providers/ Fabrication

Workshop

Name of Skilled

Welders &

contact no

Name of

skilled

Masons

1. Md. AbidulIslam01773852795

2. Md. NurulIslam01751249344

3. Md. FaridulIslam01737274296

11 Mahigonj,Rangpur Sadar,Rangpur

1. M/s New Alam MetalWorkshop, College Raoad,Mahigonj, Rangpur

Pro: Md. Alam Haider;Phone: 01731240026

1. Chhoto Miah

2. Sree Shimul Chandra

1. Md. Azhar Mia

12 Gurudashpur,Natore

1. M/s Chalan Bil Engg.Workshop, Chanchkoir BashHata, Gurudashpur,

Pro: Gaur Kormokar

1. Gaur Kormokar

2. Shaheen

3. Shagor

1. Md. Torab Ali


Some Pictures of Progressive Fabrication of IRPS Boiler Vessel

Some Pictures of Installed IRPS at Different Rice Mills Clusters

Renewable Energy and Energy Efficiency Programme

Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH

PO BOX: 6091, Gulshan-1Dhaka-1212, BangladeshPhone: +880-2-55068744-52Fax: +880-2-5506 8753E-mail: [email protected]: www.giz.de/bangladesh

1) rice industry sector of bangladeshreeep.sreda.gov.bd/...parboiling-system-brochure.pdf · with...

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