2. A
Final Project Presentation
Presented to,
Department of Food Packaging
Engineering,
Sir Choturam College Of Agricultural Engineering and
Technology Lodga,
Affiliated to,
Vasantrao Naik Marathwada Krishi Vidyapeeth, Parbhani
In Partial fulfillment of the requirements for the degree of
Bachelor of Technology
In
Agricultural Engineering
3. Presented by,
Miss Horke Savitra Laxman (2019AELD011)
Miss Jangmwar Alka Vyankat (2019AELD013)
Guided by,
Prof. Handibag A.D.
Assistant Professor,
Department of Food Packaging
4. Project Title
“Assessment of To Remove the Moisture Content From
the Fruits Gradient and Weight Products Using With
the Help of Solar Dryer”
5. Drying
Preserving fruits, vegetables, grains, and meat has been
practiced in many parts of the world for thousands of years.
Methods of preservation include: canning, freezing, pickling,
curing (smoking or salting), and drying.
Food spoilage is caused by the action of olds, yeasts, bacteria,
and enzymes.
The drying process removes enough moisture from food to
greatly decrease these destructive effects.
6. Moisture content
It is the amount or quantity of moisture (water) present in the
product.
Water content can be directly measured using a known
volume of the material, and a drying oven. Volumetric water
content, θ, is calculated using:
m wet – m dry
θ = --------------------
ρw X Vb
where
mwet and mdry are the masses of the sample before and after
drying in the oven; ρw is the density of water; and Vb is the
volume of the sample before drying the sample.
7. It is expressed in terms of wet basis or dry basis
The moisture content on wet basis means the mass of water per unit
mass of the moist specimen
Whereas the moisture content on dry basis means the mass of water per
unit mass of the sample's dry weight
The moisture content of fresh foods ranges from 20% to 90%.
The moisture content of rice must be reduced from 24% to 14% of the
total weight. Therefore, drying 1,000 kg of rice requires the removal of
100 kg of water
If food is properly dried, no moisture will be visible when it is cut.
8. Process of Drying
In the process of drying, heat is necessary to evaporate moisture from the
product and a flow of air is needed to carry away the evaporated
moisture.
There are two basic mechanisms involved in the drying process; the
migration of moisture from the interior of product to the surface, and the
evaporation of moisture from the surface to the surrounding air.
The rate of drying is determined by the moisture content and the
temperature of the grain and the temperature, the (relative) humidity and
the velocity of the air in contact with the grain.
9. Open Sun-Drying
The common approach to drying fruits, vegetables and grains in
many tropical countries is to spread them on mats or cloth just on
the front porch.
This can be seen in many places in India.
In cities, they dry on the terrace floor...what is more, often times
the grains are spread on the asphalt roads or sand to dry.
One can see chillies and grains dried this way. This is sun-drying.
10. Disadvantages of Open Sun-Drying
It takes more drying time as the temperature of air is
ambient.
The product may be accumulated with dust during drying
process.
It may be attacked by domestic animals.
The dried product is often of poor quality as a result of grit
and dirt.
The product is often unhygienic as a result of
microorganisms and insects such as flies.
Finally it may result in fetching of lower price to the dried
product.
11. Solar Dryer
It is a device which uses solar energy
for drying of products.
Solar Drier Components
• A solar collector that heats the air
• A drying chamber in which product
is dried and
• Some type of airflow system
Airflow
Drying
chamber
Solar collector
12. Drying Methods
• Direct type or natural circulation/convection drying
• In-Direct type or Forced circulation/convection drying
Based on methods there are essentially two types of
dryers:
1 Box/cabinet type -direct
2 Box type-indirect
13. In direct type Box, it is having single box which carries an absorber [say,
a black metal sheet or black paper] and a tray for keeping products, with
preferably holes in it or a net or matting----kept above the absorber.
The sunlight falls directly on the products through the transparent
cover.
Direct type dryer
High Capacity Multi Rack Type Dryer
15. In the indirect type box, it has two boxes---one collector box
with window and absorber as given above and another box called
drying chamber with racks to keep the products.
An auxiliary unit like blower and heaters are used.
The drying box is kept at a higher level to provide natural
convection or forced convection .
The two boxes are connected by an insulated duct or pipe.
You can add a chimney to the box---- to provide a faster flow of
hot air.
Passive dryers are without a fan or blower...just the natural
convection to push the air out.
Active dryers have an exhaust fan or blower to aid flow of air.
A major advantage is that the absorber box can be a large
with more area exposed to sunlight and we can control the
temperature of the product.
Indirect type dryer
17. Solar Tunnel Drying
For large scale drying, a tunnel type of dryer is used....the products
items are kept in trays and passed through a tunnel which is covered
with glass or plastic sheeting.
Line diagram of solar tunnel dryer
18.
19. A view of existing system of
grapes drying in and around
Bijapur district
20. Pretreatment:
Fresh fruits
Washed in fresh water
Fumigation for 3 hours with
Sulphur fumes (3 g / kg)
Dipping for 3 minutes in the solution of
1.5 l of Keno oil + 2.5 kg of Potassium carbonate
in 100 l of water for 1000 kg of grapes
Drying
The above solution sprayed during drying
alternate days upto 7th day
Storage
The project is under progress.
