| Author | Gnanaranjan, N. P. |
| Call Number | AIT Thesis no.ET-97-31 |
| Subject(s) | Solar food dryers
|
| Note | A thesis submitted in partial fulfillment of the requirement
for the degree of Master of Engineering |
| Publisher | Asian Institute of Technology |
| Abstract | Drying fruits and vegetables enhances the value addition of the product and data from
local market and exports from Thailand clearly indicate that dried agro products enjoy a higher
price as compared to the natural ones. Solar drying is one attractive option for drying fruits
and vegetables.
Solar tunnel dryers are currently being considered as a viable drying method for fruits
and vegetables in many countries. However, it has been designed for a capacity of about 300
legs/batch of fruits and vegetables. This study was initiated to investigate the possibility of
fabricating and testing a smaller tunnel dryer for fruit and vegetable drying applications.
Field performance studies on standard tunnel drier indicate the superior nature of
drying and the variation of temperature and relative humidity of air as it flows through the
unit. Based on tests conducted on banana and banana chips, a prototype tunnel dryer was
designed having a width of 1.8 m and a total length of 8.25 m (collector length 4 m and dryer
length 4.25 m). Five fans, each with 14 W capacity were employed. Glass wool insulation of 4
cm thickness was used to reduce the losses and polyethylene cover was used as a glazing. The
dimensions was done based on a mathematical model and simulation which gave the profile of
air and the conditions of drying.
Performance tests (no load and load) were conducted on the prototype unit. The
experimental results showed a very good comparison with the simulation values and therefore,
the design of the unit. A load test was conducted during very unfavourable condition (overcast
skies) and a total of 67.6 kg of bananas were successfully dried during 6 days. The
performance of the unit was good and it was observed that the efficiency of the collector under
these conditions were 24%. Drying curves was compared with sun dried banana.
A preliminary financial analysis estimate indicate the viability of this type of dryer
with a pay back period of less than two years for all year drying. |
| Year | 1997 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Energy and Climate Change (Former title: Department of Energy, Environment, and Climate Change (DEECC)) |
| Academic Program/FoS | Energy Technology (ET) |
| Chairperson(s) | Kumar, Sivanappan; |
| Examination Committee(s) | Bhattacharya, Sribas C. ;Athapol Noomhorm; |
| Scholarship Donor(s) | Asian Institute of Technology Partial Scholarship; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1997 |