This document presents a design for a mixed mode solar crop dryer. It begins with an introduction to solar dryers and their benefits over traditional drying methods. The aim is to calculate moisture reduction from drying and develop a solar drying system. There are two main types of solar drying systems - passive and active. A mixed mode dryer was designed using direct solar heating and a heat exchanger. It works as a solar dryer on sunny days and a hybrid system on cloudy days by recycling 65% of drying air. The dryer construction uses inexpensive, locally available materials like a solar collector, drying cabinets and trays. The experimental setup and working principle are described. Advantages include efficient heating, portability and no operational costs

1. TECHNOLOGICAL UNIVERSITY (PANG LONG)
Department Of Mechanical Engineering
DESIGN OF MIXED MODE SOLAR CROP
DRYER
(Title Defense)
Supervised
By
Daw Zar Zar Thinn
Presented by
Mg Thein Zan Maung
VI Mech - 4

2. Outlines Of Presentation
 Introduction of Solar Dryer
 Aim and Objectives
 Types of drying systems
 Types of solar dryer
 Working principle of Mixed Mode
 Advantages and disadvantages

3. Introduction Of Solar Dryer
Solar thermal energy is in alternative source of energy for
drying fruits, vegetables, grains and other kinds of material.
Drying removes water and thus prevents fermentation or the
grown of molds. Most agricultural and marine products require
drying to preserve the quality of the final product. Traditional
method of direct sun drying results in low-quality products.

4. 20XX Pitch Deck 4
AIM AND
OBJECTIVES
Aim
⦁ To calculate the reduction of moisture content
from drying
Objectives
⦁ To develop a solar dryer system for crop drying
⦁ To identify agricultural products suitable for
solar dryers

5. Types Of Drying System
Solar energy drying systems are classified according to their
heating modes and the way the solar heat is utilized.
Two major types of system-
• Passive solar-energy drying systems [conventionally termed
natural-circulation solar drying systems]
• Active solar-energy drying systems [most types of which are
often termed mixed mode (or) hybrid solar dryer)].

6. ⦁ Integral-type (Direct solar dryers),
⦁ Distributed-type (Indirect solar dryers) and
⦁ Hybrid solar dryers or mixed-mode solar
dryer
 Three Types of Solar Dryers are shown in
(Fig-1.1)
Three Types of Solar Dryers

7. Fig-1.1

8. WORKING PRINCIPLE OF MIXED MOD
• A hybrid solar dryer was designed and
constructed using direct solar energy and a
heat exchanger.
• The dryer was operated during normal sunny
days as a solar dryer, and during cloudy day
as a hybrid solar dryer.
• The efficiency of the solar dryer was raised
by recycling about 65% of the drying air in
the solar dryer and exhausting a small
amount of it outside the dryer.

9. THE DRYING
PROCESS
(1) Cold dry air enters the drying
chamber through the air inlet
(2) The solar rays enter the cabinet
through the transparent cover material
where they are converted into heat
energy
(3) Gradually, the heated moist air
goes up and leaves the drying
chamber through the air outlet at the
high end of the dryer.

10. The materials used for the construction of
mixed-mode solar dryer were inexpensive and
easily obtainable in the local market.
Figures show the essential features of the
dryer consisting of the solar collector (air
heater)
, drying cabinets, and drying trays.
20XX Pitch Deck 10
Construction of mixed-mode solar dryer

11. THE EXPERIMENTAL
SETUP
Solar collector setup

12. The drying cabinet Drying trays
Continues

13. Advantages Of Mix Mode Solar Dryer
• Efficient Heating Device: These dryers work in any sunny or
cloudy area
• Portable: Most of these devices are compact in size and light
weight
• Operational Costs: It also involves zero operational costs
• Temperature Control: It is also quite easy to control the
temperature as it included adjustable venting features.

14. Disadvantages of Mix Mode Solar Dryer
• Over Heating may occur if regular attention is
not paid
• We can't get the accurate amount of sun rays
and heat.

15. FUTURE PLAN
• To generate and evaluate the concepts of the
hybrid dryer by benchmarking the prototype of
this dissertation
• To collect data from Meterological Department

16. THANK YOU FOR YOUR
ATTENTION