- The document discusses the design, construction, and working of a solar lumber dryer. It aims to provide a controlled drying method for lumber using solar energy as an alternative to open-air drying or expensive high-temperature dryers. - Key aspects covered include classifications of solar dryers, materials commonly dried, advantages over traditional drying methods like reduced costs, defects, and drying times. Calculations are presented on moisture content reduction during drying and heat requirements. - Applications mentioned include drying wood, agricultural crops, herbs, spices and more wherever hot air is needed for controlled drying. In conclusion, solar drying is found to be effective and cheaper than normal sun drying for tropical regions.

2. Delivered by Mr. Ashwin S. Ghonmode Mr. Sachin Gayakawad Mr. Anup Jose Mr. Sachit Rawale Mr. Gopal Malu Mr. Saurabh Singh Mr. Kalim Khan Mr. Shishir Damke Mr. Srinivas Rebbawar Guided by Prof. N.R. Gandlewar Department of Mechanical Engg. R.C.E.R.T. Chandrapur

3. Abstract Introduction Classification of Solar Dryers Solar lumber drying technology Design & Construction Working of Solar lumber dryer Analysis & Calculation Advantages and disadvantages Applications Conclusion

4. Abstract - Mr. SRINIWAS REBBAWAR

5. The production of high quality lumber from hardwood requires a gentle and controlled drying to a low wood moisture content. While ambient air drying depends on the weather conditions, conventional high temperature dryers cause high investments and energy costs.

6. The investigations showed that investments, drying costs and energy consumption could be reduced by 50 % compared to conventional high-temperature drying systems. At the same time the quality of the timber was improved considerably .

7. Introduction - Mr. SRINIWAS REBBAWAR

8. Solar energy is a very large inexhaustible source of energy. The power from the Sun intercepted by the earth is approx. 1.8 x 10^11. The daily averages solar energy incident in the country varies from 5 to 7 KWh/Sq.meter

9. In India the traditional open sun drying is mostly utilized in rural areas , which incorporates problems like , - inadequate drying - fungal attacks , insects & birds etc attacks. - other weathering effects etc. - Hence application of solar dryers is incorporated to reduce or minimize the difficulties mentioned above.

10. What is wood drying? Wood drying is a process to come out moisture from the wood. It also deals with: To reduce moisture level Make the wood lighter Painting on the wood more beautiful Work on the wood will be more easy

11. For lumber, the reasons can be briefly summarized as below, To allow the lumber to shrink before it is used as a product. There is an increase in most strength properties of lumber after it has been dried. Drying minimizes the development of mould, stain and decay. Drying improves lumber finishing characteristics properties such as the electrical resistance and thermal insulation behavior are enhanced by drying.

12. Classification of Solar Lumber Dryer’s - Mr. ANUP JOSE

13. Depending upon how the product is heated by solar radiation, solar dryers are generally classified into three types, Direct type. Indirect type. Mixed mode type.

14. As per the method used for moving air over the product, solar dryers are classified as, Passive dryers ( Natural convection ) Active dryers ( Forced convection )

15. Basically a solar timber dryer is a structure that makes use of trapped solar energy to increase the temperature of the circulating air for drying. The greenhouse type. The external collector type.

18. Hardwood Softwood Dhavada. Mooi. Garadi. Bhera. Chichva. Babul. Subabul. Sagvaan.( Teak wood) Bija. ( Bija wood ) Katiyen Shiven. ( Sisum ) Mofa. Chandan

20. In the sixties and seventies with the increasing demand of dried wood for furniture production and escalating cost of energy. Solar drying of wood has considerable interest in the tropical region where sunshine is available throughout the year. Woods and agricultural products are dried to stop the growth of mould or fungi and to extend their shelf life.

21. The result obtained indicated that, Solar drying is faster than air drying, Wood can be dried to reduce moisture content lower than that achievable by air drying. Drying defects are remarkably lower than with air drying The initial cost of a solar kiln is lower than a conventional kiln of the same volume capacity, The drying costs are lower compared to conventional kiln drying.

22. - Mr SHISHIR DAMKE & - Mr SACHIN GAYAKWADE

23. Mr - KALIM KHAN

24. The Solar lumber dryer works on the principle of ‘ Green House Effect.’ The solar dryer captures a part of the solar radiation and uses it to dry the lumber. The solar radiation passes through the glazing and a portion of the available heat is absorbed by the absorber plate. The absorber plate in turn heats the air space within.

25. Some air is admitted and vented in the process through the floor slots, the necessary amount depending on the moisture content in the dryer. The purpose of venting is to keep the relative humidity of the air in the dryer as low as possible while maintaining a high dry-bulb temperature.

26. Calculation & Analysis Mr. Ashwin S. Ghonmode & Mr. Saurabh Singh

27. %MC = wet weight – 1 x 100 oven dry weight

28. For Day 1:- % MC = 7.568 - 7.370 * 100 = 2.68 % 7.370 For Day 2:- % MC = 7.330 – 6.959 * 100 = 5.33 % 6.959 For Day 3:- % MC = 6.953 – 6.503 * 100 = 6.91 % 6.503

29. Calculation for one kg of wood 1.Mass of water to be evaporated M w = W*(M i -M f )/(100-M f ) where , W = wt. of teak lumber (for1 kg) Initial moisture = M i Final moisture = M f

30. 2. Heat required to evaporate Mw = M w *L (L = Latent heat) 3. Area required for Drying timber = Mw*L / It* efficiency

31. For proper analysis a specific time period is chosen. Readings i.e. different temperatures for different time periods are noted. The analysis done can be shown up by the graphs obtained.

32. Time Temp.

33. Time Temperature

34. Time Temperature

35. Days Weight Loss

36. MR . SACHIT RAWALE

37. Time can be faster up. Wood produced are evenly dry. Wood can be produced in large amounts. Wood damage can be controlled. Drying quality is substantially better than air drying. The system has low operating costs (solar energy, less fuel required for additional heating), and less skill is required. The drying cost are lower.

38. Solar kilns depend on weather conditions (affected by rain, cloudy days), resulting in less controllability by the operator, and less predictable outcomes. Experimentally solar timber drying is time consuming and costly exercise.

39. Application Of Solar drying MR . GOPAL MALU

40. Seasoning of wood and timber. Agricultural crop drying. Food processing industry for dehydration of fruits, potatoes, onion, and other vegetables. Textile industries for drying of textile materials.

41. Spices Drying: Chillies, Coriander, Pepper, Turmeric, etc, Fruits Dehydration: Mango, Sapota, Grapes, Banana, Papaya, Amla, etc. Vegetables Dehydration: Carrot, Beetroot, potato, Bitter guard, Bell pepper,etc.,

42. Herbs Drying: Tulsi, Aloevera, Neem, Sweet Neem, etc., Medicinal plants Drying. Dal Drying. Cashew Drying. Paddy Drying. Mushroom Drying

43. Tea leaves Drying. Coffee Beans Drying. Marine Foods ( Fish ) Drying. Leather Drying. Tobacco Drying. Ceramic Drying. Chemical Drying

44. Screen print Drying. Fabric drying. And many more applications Wherever hot air is required

45. After detailed examination & proper evaluation it is observed that , the solar dryer achieves higher drying rates than normal sun drying. Hence we can conclude for tropical areas (like Chandrapur) solar drying is one of the best , cheap & effective option for the purpose of drying lumber.