IDEA experience in combustion improvements in large scale cooking and rural industries.

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1 IDEA experience in combustion improvements in large scale cooking and rural industries. R.M.Amerasekera Executive Director Integrated Development Associatio (IDEA)

2 IDEA experience in combustion improvements in large scale cooking and rural industries. Hotels and Restaurants Hospitals Domestic Income generating activities Curd Making Treacle making Sweetmeat Large scale food preparation Brick Clamps Bakeries

3 Basic improvement in institutional stoves is the introduction of features such as grate, baffle, chimney, sturdy construction, better insulation for improved combustion efficiency, ease of operation, less time consumption improved cooking hygiene Less firewood consumption The stove dimension basically depends on the pot size which guides the grate size and primary air considerations

4 In general standardised and portable designs are not favoured since cooking tasks differ from place to place due to the varying nature and size of the tasks. Institutional stoves are mostly heavy mass stoves. Prior to designing, a deep insight of the nature and requirements of the cooking task is required which calls for tailor made solutions and a good rapport with the users. Popularising institutional stoves require dissemination of stove designing technology through training of artisans.

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6 Reported Firewood savings 39% Time savings 42% Availability of more hot water for the patients

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8 Reported Fuel Savings: 37% Time Savings: 40%

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11 Making Curd Traditionally

12 Using improved stove Milk: 12 lts Traditional Stove: Firewood: 2.5 Kg Time: 50 Mts Improved Stove: Firewood : 1.6kg Time: 31 Mts No fly ash contamination. Other biomass could be used Chimney, Bricks and Mud, Iron Grate

13 24 kg of Paddy Biomass Weight Time Wood Weight Time BEFORE AFTER 12.5 kg 155 mts 8.5kg 145mts 6.5kg 55mts 4.5kg 50mts

14 Cost savings/week Fuel Firewood LPG Kerosene Before- Rs After- Rs

15 High firewood consumption Low quality bricks High breakage

16 Clay improvements: Only clay with moderate sand % is suitable Mix clay with 20-30% of rice husk/sawdust Keep the mixture at least for 2 days to dry Make the bricks using the moulds. Dry the unfired bricks for at least 3 days. Stacking and firing improvements. Method of stacking bricks modified Additional Firing channels are provided The interlayer gaps are filled with rice husk Firing methods are changed

17 Fuel Used Firing with rice husk only. Firing with firewood. Additional channels used Firing with fire wood and rice husk Stacking depends on the method of firing Major disadvantage Ash management and disposal Advantages Low cost of production Better quality of bricks Less or no firewood used Less clay used Light weight bricks with high porosity Less labour intensive due to better drying, easy demoulding, less tending of fire and easy handling Less breakage

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19 Improved brick clamps Transporting rice husk Mixing clay with husk

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21 Improved Kiln with additional channels for combustion

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25 Study tour of brick makers

26 Modifications A hopper to feed the rice husk and blower powered with a 1.5 hp motor or with a hand tractor. Additional opening is made opposite the normal opening or on the side. Two chimneys 16 ft tall are provided above the two openings Cost USD 800. Subsidy provided: USD 250

27 After modifications use firewood as usual for the first firing. Bring up the temperature to C. Remove all ash. Bake the bread at around C. After the baking is over remove the bread and allow it to cool to around 200 C. Blow a little bit of rice husk into the chamber. Close it. Leave it overnight. To start the oven next day ignite the rice husk settled on the oven floor with a little dry biomass. When it ignites blow the rice husk using the motor/blower or a hand tractor. When the temperature rise to 350 o C stop blowing. Remove the ash and the oven is ready for baking again.

28 Blower powered by kerosene water pump engine Blower powered by a hand tractor

29 Ash disposal? Fly ash is an environmental and health hazard. Partly carbonised(black) ash could be used as fertiliser. Water is poured on the hot ash before it cools down and forms white ash.

30 20 bakeries converted BEFORE - FIREWOOD Rs % Rs % Rs % After - Electricity Rice husk - No cost < Rs 25 80% Rs % Rs %

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