Description of technology
Rocket Stove Dryer is a device which is especially designed to dry Large Cardamom and also be very useful to dry the fruits, vegetables, ginger, coffee, tea and herbs as well as Non timber forest products by using Biomass as fuel. This dryer basically consists of • Rocket Stove part where fuel wood is fired. The stove part is based on rocket stove design as per Aprovecho Model, • Bed part where the flue gasses coming from the combustion chamber is distributed evenly to all over the drying cabinet through the flue channels covered with a sheet metal which acts as Heat exchanger. • Drying chamber where the drying materials are placed in the trays and air movement is created to remove moisture from the materials placed on the trays. • Double layered Chimney, which create the natural draft to remove the saturated air from the drying camber. The flue gas from the stove goes out from the short internal chimney which provides energy to the long outer chimney for creating the draft. It is very useful for the farmers, cooperatives and small scale fruits and vegetables drying industry. No special expertise and skill is required to operate the dryer. Anybody who is involved in drying business can operate the dryer. This rocket stove dryer do not have any moving part. Therefore, except occasional painting, changing of gaskets and regular cleaning of dryer, it is easy to maintain it. Local farmer, operator can easily maintain it.
Specific Features
Nepal is the largest producer of large cardamom in the world. It is one of the major cash crops in Nepal. Traditionally, cardamom is dried in the traditional bhatti (traditional kiln). The fire is lit down the stone-walled drying chamber whereas the carda
Status of Technology
Commercial Prototype
• The rocket dryer saves 50 percent fuel wood compared to the traditional bhatti and the pink colour of the dried cardamom and the volatile oils are also retained. • Hence the farmers can get mor

Areas of application/Business opportunities
Drying of large cardamom, fruits, vegetable, herbs and tea etc.
Name of the component
Total area required (sqM)
9m2 (only for the dryer)
Materials required for construction
Wooden planks, G.I. Sheet, M.S. plate, Glass wool, Enamel Paint , M.S. mesh, stone or brick , fireproof brick, hinges etc.
N Rs.30000,00
Procedure of Installation
Construction of the Stove part by the mason and dryer part by the carpenter.
Maintenance requirements
No regular maintenance required except the air leakage from the gaskets.
Labor cost
N Rs.10000.00
Fabrication at the site
Total investment
Rs.40,000.0 (Excluding the cost of land)
Name of the organization
Research Centre for Applied Science and Technology(RECAST), Tribhuvan University
Address/Zip code
Kathmandu, Nepal