Date – 1/11/22
INTRODUCTION
sangola village ( splapur ) to Adv.B .P. Misal contacted Vigyan Ashram regarding the problem they were facing to dry vegetables and fruits. He wanted Solar Dryer Multi-Purpose Solar Dryer in which he could dry all types of vegetables and fruits. For this he came to Vigyan Ashram and Prasanth Sir gave him complete information about the dryer. And he told his demand that what kind of dryer he wanted. After this I took the responsibility of doing this project. Prashant sir guided me to complete the project. I sent the solar dryer quotation to the customer and talked to him about the payment. Adv.B.P. Misal asked Vigyan Ashram to make a solar dryer like this. After discussion in DIC, it was decided that since the customer has specific requirement of solar dryer, a flat solar dryer with polycarbonate sheet should be made and dispatched.
Introduction of dryers.
A dryer is a machine or device that is used to remove moisture. Any type of material / object can be dried easily by using a dryer. It is of different types. We can use dryer according to the need.
What is drying
Drying is a process that uses heat to remove water (moisture) from a material. This can be done in a number of ways, when water is removed from a substance, its structure changes. This process makes the material harder and less prone to spoilage. This process eliminates the problem of growth of bacteria, yeast and other moisture-related microorganisms in food products. So that the material does not get spoiled for a long time.
The drying rate depends on the material, the humidity and temperature of the surrounding air. In general, the higher the temperature and the lower the humidity, the faster the drying process. Drying is the process of removing excess water keeping in mind the nutritive value, speed visibility and further use. Through this process, food products like pickles, chillies, amla, fish, fruits and spices can be used for a long time after drying.
Drying Methods:-
The natural drying process is usually done using direct sunlight, that is, the sun’s rays hit the product and remove its moisture through natural air circulation. This method is a slow process and has some disadvantages such as dust contamination, insect infestation, and spoilage due to unpredictable rains. These problems can be eliminated by using the mechanized method of drying.
Solar Dryer:- Solar dryer is good other way of drying and it is environment friendly. Any type of material can be dried quickly in a solar dryer. Solar dryers help to provide more heat than the atmospheric temperature. The air in the solar dryer enters the solar dryer through the process of a natural chamber or from an external source such as a fan and the air is heated to the temperature of the dryer along with the moisture and is expelled through the exhaust fan or chimney. This process continues due to which the material dries up. In operation, these dryers can produce temperatures of 54 to 82 °C, which is useful for most food ingredients drying and pasteurization.
Advantages of solar drying
- Any material can be dried in a short time with high temperature and air movement in the chamber.
- Time Saving |
- Solar dryer keeps food products safe from dust, insects, birds and animals.
- Fast drying.
- Higher drying temperatures.
- Offers airflow and temperature control.
- Food is protected from elements.
- The high temperature prevents insect infestation and the rapid drying rate reduces the risk of spoilage by microorganisms.
- The dryers are also waterproof, so there is no need to move food in rainy weather.
- Dryers can be manufactured from locally available materials at relatively low cost.
- Solar dryers last longer. A typical dryer can last for 15-20 years and will require minimal maintenance.
- It needs a small area.
- There is less risk of damage to food products.
Disadvantages of solar drying:-
• Solar dryer can be used more during sunny days only.
• Solar dryers can be slower to process than dryers that use conventional fuel.
• Generally, solar dryers can be used to dry materials at 40-50oC.
• It can be used only during day time when solar energy is present in sufficient quantity.
• Must have skilled personnel for operation and maintenance.
• Takes longer than modern types of electric dryers.
• A backup heating system is essential for products requiring continuous drying.
• The cost of some dryers is high. Due to which small farmers and needy people cannot buy them.
• Requires large amount of initial investment.
• Requires collaboration cost.
Different types of solar dryers
1. Integrated Solar Dryers: In this type, solar energy collection and drying takes place in a single unit. Some examples of this category include step type dryers, cabinet dryers, rack dryers, tunnel dryers, greenhouse dryers and multi-rack dryers.
2. Distributed Solar Dryers: In this type, solar energy collection and drying takes place in two separate units, namely a flat plate air-heater and a drying chamber. Flat plate heaters can be placed on the roof of a building or on the ground or in a place where the intensity of the sun is high. In flat plate heater the air is heated and with the help of blower the hot air is circulated to the drying chamber of the dryer.
3. Mixed Mode dryer: In this type, the solar energy collection takes place in both the flat plate air heater as well as the drying chamber and drying takes place only in the drying chamber. The exterior of the dryer will also receive solar power; It helps to remove moisture quickly.
Solar tunnel dryer:- Tunnel dryer is a semi-cylindrical tunnel shaped dryer. The frame of the dryer is made of galvanized iron and covered with a 200 micron size ultraviolet (UV) stabilized polyethylene sheet, which retains heat inside the dryer. While the inlets at the rear end of the dryer allow fresh air to enter the dryer, the exhaust fan on its front expels moist air from the product. This type of dryer is used for drying sago, coconut, chilli, amla, onion, vegetables, fruits and other agricultural products.
1. According to Sabudana, the drying time in solar tunnel dryer is 5 hours, while the drying time in open sunlight is 11 hours. Thus, about 55% of the drying time is saved in solar tunnel dryers.
2. It takes 43-45 hours to dry one ton of chilli whereas 70 hours is required for drying in the open sun. Using this dryer for drying Byadgi chillies showed a saving of about 40-60 per cent in drying time.
How does work solar dryer.
Solar dryer receives the energy from sun and it dry the crops vegetable fruit
Solar dryer consists with different main parts
Black material is coated on heating element inside the box to absorb more heat from solar radiation . outer frame of made up of heat insulating material to maintain the temperature .when direct or diffuse solar radiation will incident then it will not exit .
There are holes at upper and lower portion of the box for circulation of air .
First of all we keep the fooding material inside the box and close the roof glass
When solar radiation incident on black coating through transparent glass then heating aliment absorb the heat from solar radiation due to heat moisture of fooding material get vaporized and vapor droplets accumulates on the roof glass
As well as cold air enter from lower portion of the box and that air get heated
Due to hot air fooding material rapidly get dry and heated air exit throught upper hole
Vaporized water droplets also remove with hot air in the atmosphere and placed fooding material like vegetables get dry
The outcome of the discussion:
The relative humidity of the air increases with the increase in its temperature, thus there will be more moisture in the air. This extra moisture will come from the contents of the chamber.
All factors being equal, moist air is less dense than dry air because water has a lower molecular weight than nitrogen and oxygen. So moist air will rise in the chamber and it will leave the chamber because of the design of its roof (slanted roof and an opening at the top).
STEPS:-
· PROCESS FLOW DIAGRAM
· MATERIAL FLOW DIAGRAM
· DESIGN MODELLING
· 3D MODELLING
- BILL OF MATERIAL (BOM)
- PROCUREMENT
- FABRICATION
MATERIAL FLOW DIAGRAM
Polycarbonate sheet
Polycarbonate sheet is a type of plastic that can withstand high temperature and high pressure. Polycarbonate sheet is used for solar dryers because it can withstand the heat from the sun and allow you to dry agricultural products without any electricity or gas.
The polycarbonate sheet for solar dryer is a thin, transparent, and durable material that has excellent light transmission properties.
It is often used in the construction of greenhouses and solar dryers. The polycarbonate sheet for solar dryer also offers protection from UV rays and provides insulation against heat loss.
This material is made from polycarbonates, which are thermoplastic polymers. Polycarbonates are used in many applications that require a durable material that is resistant to heat and UV light. Polycarbonate sheets can be used as a substrate for solar dryers.
Material sheet
Material excel sheet is given below
DESIGN MODELLING
Market survey
Sketches
I measure all the dimensions for all the elements which is used for flat bed dryer.
I started hand sketching drawing of solar flat bed dryer.
ENVELOPE DIMENTIONS
DESIGN MODELLING
3D MODELLING
FABRICATION
Step1- Cutting front and back legs of dryer as per measurement
Then cut L angles for the top and bottom frames
Step2- Holes at all angles for screws
Step3- Make frame by welding
Step4- Cutting the Dryer Bed and Side Parts from Plywood
Step 5 – Painted all the parts of the dryer
Step6- All Parts Assembled Together Like – Front , Back Leg , Steel Frame , Plywood Parts.
Step7- cutting of polycarbonate sheet for door
and make solar dryer doors
FINAL PRODUCT
TRAIL
Date :- 16/11/2022
1st Trial result –
Moringa leaves are used to take the first test
Data from the internet
Water content in Moringa leaves – 85%
Observation after taking the trial
Moringa leaves with the help of solar dryer. Can be dried up to 71%.
| Drying Stuff Name | Total weight | After day stuff weight | Moisture | Dry |
| Moringa | 1kg 500gm | 330gm | 22% | 78% |
| Duration | Inner temperature | Out side temperature | Humidity |
| 10 | 25 | 25 | 45 |
| 11 | 38 | 25 | 38 |
| 12 | 55 | 27 | 39 |
| 1 | 59 | 27 | 32 |
| 2 | 54 | 29 | 31 |
| 3 | 48 | 29 | 31 |
| 4 | 38 | 29 | 32 |
| 5 | 31 | 28 | 33 |
Date:- 17/11/2022 to 18/11/2022
2nd Trial Result
onion are used to take the 2nd test
Moisture content in onion-86%
Observation after taking the trial
Onion can be dried up to 86.50% with the help of solar dryer.
| Drying Stuff Name | Total weight | After day stuff weight | Moisture | Dry |
| Onion | 1kg 699gm | 233gm | 13.71 | 86.28 |
| S.r No. | Duration | Inner temperature | Out Side temperature | Humidity |
| 1 | 10:00 | 27 | 27 | 34% |
| 2 | 11:00 | 40 | 27 | 34% |
| 3 | 12:00 | 43 | 27 | 27% |
| 4 | 1:00 | 46 | 28 | 27% |
| 5 | 2:00 | 44 | 29 | 24% |
| 6 | 3:00 | 45 | 28 | 26% |
| 7 | 4:00 | 38 | 28 | 27% |
| 8 | 5:00 | 28 | 28 | 33% |
Date:- 18/11/2022 to 19/11/2022
3rd Trial Result
Coriander are used to take the 3rd test
Moisture content in coriander-80to86%
Observation after taking the trial
coriander can be dried up to 86.50% with the help of solar dryer.
| Drying Stuff Name | Total weight | After day stuff weight | Moisture | Dry |
| coriander | 2kg | 236 | 13.50 | 86.50 |
| S.r No. | Duration | Inner temperature | Out Side temperature | Humidity |
| 1 | 11 | 26 | 26 | 30 |
| 2 | 12 | 36 | 27 | 27 |
| 3 | 1 | 35 | 28 | 25 |
| 4 | 2 | 34 | 28 | 24 |
| 5 | 3 | 35 | 27 | 27 |
| 6 | 4 | 28 | 27 | 25 |
| 7 | 5 | 25 | 27 | 29 |
Date:- 19/11/2022
4th Trial Result
Betel leaves are used to take the 4th test
Moisture content in Betel leaves-84.97%
Observation after taking the trial
Betel leaves can be dried up to 86% with the help of solar dryer
| Drying Stuff Name | Total weight | After day stuff weight | Moisture | Dry |
| Betal Leaves | 250gm | 35gm | 14 | 86 |
| S.r No. | Duration | Inner temperature | Out side temperature | Humidity |
| 1 | 10:00 | 26 | 26 | 41% |
| 2 | 11:00 | 37 | 25 | 37% |
| 3 | 12:00 | 41 | 26 | 34% |
| 4 | 1:00 | 43 | 27 | 30% |
| 5 | 2:00 | 39 | 27 | 28% |
Date:- 20/11/2022 to 21/11/2022
5th Trail Result:-
Onion are used to take the 5th test
Moisture content in -90%
Observation after taking the trial
Onion can be dried up to 87.45% with the help of solar dryer
| Drying Stuff Name | Total weight | After day stuff weight | Moisture | Dry |
| Onion | 2kg | 251gm | 12.55 | 87.45 |
| S.r No. | Duration | Inner temperature | Out Side temperature | Humidity |
| 1 | 10.00 | 26 | 25 | 41 |
| 2 | 11.00 | 32 | 25 | 34 |
| 3 | 12.00 | 34 | 26 | 31 |
| 4 | 1.00 | 34 | 26 | 27 |
| 5 | 2.00 | 37 | 27 | 25 |
| 6 | 3.00 | 36 | 27 | 26 |
| 7 | 4.00 | 31 | 27 | 26 |
| 8 | 5.00 | 26 | 26 | 30 |
Date:- 20/11/2022 to 21/11/2022
6th Trial result
Moringa are used to take the 6th test
Moisture content in -85%
Observation after taking the trial
Moringa leaves can be dried up to 82.01% with the help of solar dryer
| Drying Stuff Name | Total weight | After day stuff weight | Moisture | Dry |
| Moringa Leaves(2nd time) | 1kg 863gm | 335gm | 17.98 | 82.01 |
| S.r No. | Duration | Inner temperature | Out side temperature | Humidity |
| 1 | 10 | 27 | 22 | 41 |
| 2 | 11 | 34 | 24 | 34 |
| 3 | 12 | 37 | 25 | 31 |
| 4 | 1 | 40 | 26 | 27 |
| 5 | 2 | 41 | 27 | 25 |
| 6 | 3 | 40 | 27 | 26 |
| 7 | 4 | 36 | 26 | 26 |
| 8 | 5 | 26 | 26 | 30 |
Date:- 22/11/2022
7th Trial Result
Puran are used to take the 7th test
remove moisture content in puran – 20%
Observation after taking the trial
Puran can be dried up to 33% with the help of solar dryer
| Drying Stuff Name | Total weight | After day stuff weight | Moisture | Dry |
| Puran | 2kg | 1kg 255gm | 67% | 33% |
| S.r No. | Duration | Inner temperature | Surrounding tem. | Humidity |
| 1 | 10:00 | 23 | 23 | 29 |
| 2 | 11:00 | 42 | 25 | 35 |
| 3 | 12:00 | 36 | 27 | 34 |
| 4 | 1:00 | 41 | 28 | 32 |
| 5 | 2:00 | 40 | 28 | 32 |
| 6 | 3:00 | 39 | 29 | 33 |
| 7 | 4:00 | 34 | 29 | 33 |
| 8 | 5:00 | 25 | 23 | 36 |
Date:- 23/11/2022 to 24/11/2022
8th Trail Result
Awala candy are used to take the 7th test
Data from internet
The moisture content of fresh amla was found to be 82.42% (w.b.)
The moisture content of amla candy also varies due to different types of candy.
Observation after taking the trial
Awala can be dried up to 76.05% with the help of solar dryer
| Drying Stuff Name | Total weight | After day stuff weight | Moisture | Dry |
| Awala candy | 2kg | 479 | 23.65 | 76.05 |
| S.r No. | Duration | Inner temperature | Out Side temperature | Humidity |
| 1 | 10 | 25 | 25 | 36 |
| 2 | 11 | 34 | 27 | 35 |
| 3 | 12 | 34 | 27 | 34 |
| 4 | 1 | 36 | 29 | 30 |
| 5 | 2 | 36 | 29 | 31 |
| 6 | 3 | 36 | 29 | 31 |
| 7 | 4 | 30 | 29 | 32 |
| 8 | 5 | 26 | 26 | 36 |
Name plate design for solar dryer in CorelDraw. And cut it with lager cutter and put it on the dryer.
Date – 24/11/2022
The solar dryer has been safely delivered to Adv.B.P. Misal.
Prashant sir wanted data on different material and different weight of solar dryer. So after the solar dryer was delivered, he told me to collect the data by taking a trial on another dryer.
That’s why I continued with the trials.
9th Trail Result
Green chillis are used to take the 9th test
Data from internet
The moisture content of fresh green chillis was found to be 82 to 90% (w.b.) ( data from internet)
Observation after taking the trial
Awala can be dried up to55.9 % with the help of solar dryer.
| Drying Stuff Name | Total weight | After day stuff weight | Moisture | Dry |
| Chills | 2kg | 882 | 55.9 | 44.1 |
| S.r No. | Duration | Inner temperature | Out side temperature | Humidity |
| 1 | 10 | 26 | 26 | 38 |
| 2 | 11 | 39 | 27 | 36 |
| 3 | 12 | 41 | 27 | 29 |
| 4 | 1 | 44 | 26 | 34 |
| 5 | 2 | 42 | 30 | 35 |
| 6 | 3 | 39 | 24 | 36 |
| 7 | 4 | 35 | 29 | 34 |
| 8 | 5 | 25 | 29 | 35 |
Date – 27/11/2022
10th Trial Result
Puran are used to take the 7th test
remove moisture content in puran – 20%
Observation after taking the trial
puran can be dried up to 40.65% with the help of solar dryer.
| Drying Stuff Name | Total weight | After day stuff weight | Moisture | Dry |
| Puran | 2kg | 1kg 187gm | 59.35% | 40.65% |
| S.r No. | Duration | Inner temperature | Out side temperature | Humidity |
| 1 | 10 | 26 | 26 | 51 |
| 2 | 11 | 35 | 27 | 46 |
| 3 | 12 | 40 | 28 | 44 |
| 4 | 1 | 39 | 29 | 42 |
| 5 | 2 | 40 | 29 | 41 |
| 6 | 3 | 34 | 29 | 44 |
| 7 | 4 | 30 | 29 | 45 |
| 8 | 5 | 27 | 28 | 45 |
Date – 29/11/2022 to 1/12/2022
11th Trail Result.
Sweet Amla candy are used to take the 9th test
Data from internet
The moisture content of fresh amla was found to be 82.42% (w.b.)
The moisture content of amla candy also varies due to different types of candy.
Observation after taking the trial
Awala can be dried up to 42 .05% with the help of solar dryer.
| Drying Stuff Name | Total weight | After day stuff weight | Moisture | Dry |
| Sweet awla candy | 6kg 148 gm | 3kg 785gm | 57.56 | 42.43 |
| S.r No. | Duration | Inner temperature | Out side temperature | Out side temperature (Thermometer) |
| 1 | 10 | 23 | 23 | 20 |
| 2 | 11 | 39 | 26 | 26 |
| 3 | 12 | 42 | 26 | 28 |
| 4 | 1 | 46 | 28 | 26 |
| 5 | 2 | 46 | 28 | 27 |
| 6 | 3 | 45 | 30 | 28 |
| 7 | 4 | 38 | 28 | 27 |
| 8 | 5 | 27 | 27 | 25 |
Date- 2/12/2022 to 4/12/2022
12th Trail Result
Fenugreek are used to take the 9th test
Data from internet
The moisture content of fresh fenugreek chillis was found to be 85 to 90% (w.b.) ( data from internet)
Observation after taking the trial
Fenugreek can be dried up to90 % with the help of solar dryer
| Drying Stuff Name | Total weight | After day stuff weight | Moisture | Dry |
| Fenugreek | 2kg | 200 | 10% | 90% |
| S.r No. | Duration | Inner temperature | Out side temperature | Humidity |
| 1 | 10 | 23 | 32 | 49 |
| 2 | 11 | 30 | 25 | 44 |
| 3 | 12 | 34 | 27 | 39 |
| 4 | 1 | 36 | 28 | 35 |
| 5 | 2 | 38 | 30 | 34 |
| 6 | 3 | 37 | 31 | 33 |
| 7 | 4 | 33 | 30 | 37 |
| 8 | 5 | 24 | 29 | 35 |
Date- 6/12/2022 to 8/12/2022
13th Trail Result
Fenugreek are used to take the 9th test
Data from internet
The moisture content of fresh fenugreek chillis was found to be 85 to 90% (w.b.) ( data from internet)
Observation after taking the trial
Fenugreek can be dried up to88 % with the help of solar dryer.
| Drying Stuff Name | Total weight | After day stuff weight | Moisture | Dry |
| Fenugreek | 2kg | 237 | 12% | 88% |
| S.r No. | Duration | Inner temperature | Out side temperature | Humidity |
| 1 | 10 | 26 | 26 | 46 |
| 2 | 11 | 30 | 27 | 40 |
| 3 | 12 | 35 | 29 | 33 |
| 4 | 1 | 37 | 30 | 30 |
| 5 | 2 | 33 | 31 | 30 |
| 6 | 3 | 32 | 32 | 34 |
| 7 | 4 | 32 | 32 | 37 |
| 8 | 5 | 25 | 25 | 37 |
Trail Data sheet
Dryer Semple
Feedback
Solar dryer got very good feedback from the customers. And the customer wants more solar dryers to be made from Vigyan Ashram.
Conclusion
I learned a lot during this project
Communicated with the customer, took the order and prepared the project according to the demand of the customer.
While completing this dryer, I learned all the tools in the workshop. Learned to make hand & 3D sketch of the product. I learned about the moisture content of the product while taking trials.
