Solar Dryer Construction and Use Manual Version

Transcription

1 Brigham Yung University BYU SchlarsArchive All Faculty Publicatins Slar Dryer Cnstructin and Use Manual Versin Jnathan P. Rwe Jnathan K. Russn See next page fr additinal authrs Fllw this and additinal wrks at: Part f the Fd Science Cmmns, and the Nutritin Cmmns Original Publicatin Citatin Department f Nutritin, Dietetics, and Fd Science Brigham Yung University BYU SchlarsArchive Citatin Rwe, Jnathan P.; Russn, Jnathan K.; and Steele, Frst M., "Slar Dryer Cnstructin and Use Manual Versin " (2007). All Faculty Publicatins This Peer-Reviewed Article is brught t yu fr free and pen access by BYU SchlarsArchive. It has been accepted fr inclusin in All Faculty Publicatins by an authrized administratr f BYU SchlarsArchive. Fr mre infrmatin, please cntact schlarsarchive@byu.edu, ellen_amatangel@byu.edu.

2 Authrs Jnathan P. Rwe, Jnathan K. Russn, and Frst M. Steele This peer-reviewed article is available at BYU SchlarsArchive:

3 Slar Dryer Cnstructin and Use Manual Versin Jnathan P. Rwe, Jnathan K. Russn, Frst M Steele Department f Nutritin, Dietetics, and Fd Science Brigham Yung University Prv, Utah, USA Chimney Drying Racks Cllectr

4 Intrductin In less time than it tk t develp this slar dryer and manual, the Pacific Island area has experienced several typhns and trpical depressins fllwed by significant flding and destructin f hmes, prperties and crps. It is in the interest f all peple t becme mre self-reliant in times f need and t have the basic necessities available at a mment s ntice t sustain life until transprtatin, cmmerce, health care, agriculture, water, etc. can be restred t a mre nrmal state. This wrk was dne t enable the peple f the Pacific islands t meet sme f their fd requirements in times f need by enabling them t preserve sme f their indigenus crps fr strage in times f emergency. This manual is develped fr the use f thse interested in drying f fd prducts in the Pacific Island areas. The dryer was develped fr use in the Pacific area, but can easily be adapted fr use in mst any area f the wrld. The angle f the slar panel area t the sun is set fr use in areas clse t the equatr. The angle culd be adjusted relative t the latitude f the area and seasn f the year in which yu wish t dry fd prducts, but little wuld be gained by this minr adjustment and s the angle used in this plan shuld be satisfactry t mst areas f the wrld. In the develpment f this slar dryer, cnsideratin was taken t use nly materials that shuld be readily available in mst island areas. Cst f materials was als cnsidered with the cst f this dryer being apprximately $180-$200 US as purchased in Fiji. Naturally this will vary frm time t time and frm lcatin t lcatin. This value is given nly as an estimate. While every effrt was made t minimize the cst f the dryer, it must be realized that this dryer was develped fr use by grups and therefre is mre cstly than the average family culd affrd, but several families tgether shuld be able t cnstruct a dryer withut significant financial burden. Sme carpentry skills are necessary fr successful cnstructin f the dryer. This manual is develped fr thse with minimal carpentry skills. If there are questins n methds used, please refer t a carpenter. Cmments and feedback regarding this manual, prcedures, and applicatin can be directed via t Dr. Frst Steele at frst_steele@byu.edu

5 Slar Dryer Materials List Quantity Dimensins Descriptin Metric measures 1 *8 x 4 x ¾ Exterir Plywd sheet 2.4m x 1.2m x 19mm 1 **8 x 4 x ¼ Exterir Plywd sheet 2.4m x 1.2m x 6mm 2 8 x 4 x 2 treated pine lumber, dressed 100mm x 50mm 20 8 x 2 x 1 treated pine lumber, dressed 50mm x 25mm 3 3/8 x 6 Dwel 9.5mm x 1.8m 1 liter black exterir paint semiglss 1 kg 1 galvanized jlt head nails ml wd glue 2 pair 4 strap hinges, light duty 100mm 2 cans 10 z flat black spray paint 2 3 gate hk brass r galvanized 1 tube 300 g silicne adhesive and sealant 2 meter 1/8 link galvanized chain 6 meters 3 width 23ga welded ½ mesh galvanized 915mm width 10 meters 20ga galvanized steel wire 1 6 x 2 x 1/8 Clear Pespex (plexiglass) 1.83mx610mmx3mm 1 kg 1 ¼ Wd screws (gib bard screws wrk well) ½ kg 2 Wd screws (gib bard screws wrk well) 7 meters 30 cm width Heavy Grade Aluminum Fil Tls Required Tape rule Pencil Electric circular saw, hand saw may be used as well Electric drill with bits, hand drill may be used as well Hammer Safety glasses Heavy duty scissrs Screwdrivers Wire cutters Nt abslutely necessary, but helpful 4 rubber caster wheels (2 ) munted at the base f the dryer t aid in mvement f the dryer. Lcking casters are recmmended. Table saw Level Carpenter square Prtractr r carpenters triangle *Can use ½ in place f ¾ plywd, but strength and durability will be less **Can use 4mm in place f 6mm, but strength and durability will be less

6 Prcedure fr dryer bdy assembly 1- Assemble all building materials and tls befre beginning. 2- Lay ut dryer pieces n 19 mm exterir plywd accrding t dimensins frm layut plan belw. 2400mm x 1200mm x 19mm exterir ply layut plan drawn t scale 2400 mm 1690 mm Side Panel 2 Back Rf Panel 255mm x 660mm Back Chimney Panel 650mm x 150mm Dr Panel 760mm x 660mm 805 mm 229 mm 782 mm 713 mm 1200 mm 152 mm Side Panel mm Side panel detail measurements (mm) (nt t scale) Side Panel 3- Cut ut nly side panel 1 frm 19mm sheet being careful nt t cut int ther pieces. 4- Flip side panel 1 nt side panel 2 t ensure they are matching mirrr images. Make any necessary adjustments t side panel 2.

7 5- Cut ut side panel 2 frm 19 mm sheet, again be careful nt t cut int remaining pieces. 6- Cut ut dr panel and rf panel and chimney panel frm 19mm sheet. 7- Lay ut dryer pieces n 6mm exterir plywd accrding t Figure 2, ensuring that all pieces fit as described. Figure mm x 1200mm x 6mm exterir ply layut plan -drawn t scale 2400mm Bttm Panel 2083mm x 600mm Frnt Rf Panel 660mm x 255mm 1200mm Frnt Panel 600mm x 805mm Chimney Frnt Panel 650mm x 150mm Chimney Side Panels (2) 550mm x 150mm 8- Cut a 255mm piece f wd ff the end f the 6mm sheet this will later be cut int the frnt rf panel. 9- Cut the remaining 6mm piece exactly in half lengthwise. Frm these pieces the bttm panel, frnt panel, and chimney pieces will be cnstructed. This cut dwn the middle must be exact s the tw pieces are f equal width. 10- Measure and cut the bttm panel fllwed by the frnt panel and then the chimney panels.

8 11- Glue and nail bttm panel t side panels as shwn belw. Bttm panel shuld be flush at the tp leaving apprximately 20mm verhang at the bttm. Bttm panel shuld be flush with crner f side panel Bttm panel shuld verlap end f side panel apprximately 20mm Nail alng edges f base using 1" galvanized nails as shwn apprximately 150mm apart. 12- Cut 10 struts frm 50mm x 25mm pine 561mm in length. 13-Attach struts cnnecting side panels using glue and tw 2 wd screws in lcatins as shwn belw. Side view f side panel shwing strut placement. Frnt panel.. Tw 2" screws at each strut lcatin 50mm x 25mm struts 14- Attach frnt panel as shwn abve using 1¼ wd screws at 200mm spacing. 15- Cut a length f 100mm x 50 mm pine 610mm in length and attach t bttm frnt f dryer using 4-2 screws as shwn belw fr frnt base f dryer.

9 16- With the help f anther, place the dryer bdy against a straight wall s the back f the dryer husing is flush t the wall as shwn. Place each f the 100mm x 50mm pine timbers n each side f the dryer and als flush with the wall as shwn. With a pencil, mark the angles f the dryer n the timber as shwn. Wall 4-2" screws used t attach frnt base t dryer bdy 17- With each f the marked 100mm x 50mm timbers cut the tp ff at the angle marked. D nt cut the bttm angle cmpletely thrugh! Cut the inside f the timber halfway thrugh at the bttm marked angle as shwn belw t a depth f 20mm. Then rip the timber t the tp as shwn, cutting ut the piece shaded t frm the dryer legs. 1-Cut cmpletely thrugh bard n the marked angle at tp. 2-Rip the timber dwn t the bttm mark at a depth f 20 mm 20mm depth

10 18- Attach dryer legs t dryer bdy, resting the dryer n the ntched supprt f the leg. Attach with 2 screws as shwn in next diagram. Tp edge f each rf panel may be beveled t ensure a tighter fit 8-2" screws used t anchr each dryer leg t dryer bdy. Frnt rf panel (6mm) Back rf panel (19mm) Rest dryer bdy n ntch f leg Rear view 19-Attach back rf panel (19mm) t dryer bdy using 6-2 screws as shwn abve. Attach frnt rf panel (6mm) t dryer bdy using 6-1 1/4 screws. Rf panels may be beveled t create a tighter fit, but this is nt necessary. Slar Panel Cnstructin The slar panel may be cnstructed using a variety f materials. Individuals shuld evaluate availability, cst, and durability f materials befre building. In the fllwing descriptin heavy duty aluminum fil is used. This is inexpensive and typically available but nt very durable. One may als cnsider using alternate materials like aluminum sda cans r light gauge aluminum sheeting. 20- Paint the bttm f the slar cllectr area black befre prceeding.

11 21- Drill hles parallel t the bttm panel thrugh the centers f the tw struts shwn belw starting at the center f the strut and drilling ne hle every 115.5mm. This shuld make five hles in each strut. Side view f side panel shwing drilling f struts t supprt slar panel material mm Frnt panel Enlarged view.. Tw 2" screws at each strut lcatin 50mm x 25mm struts t be drilled t supprt slar panel material 22-String wire thrugh the hles as shwn belw: this can be dne using ne length f wire and tightening the wire later n. These wires will supprt the slar panel material. View f slar panel shwing stringing 20 ga steel wire thrugh struts t supprt slar panel material mm 115.5mm

12 23-The material f chice shuld be bent t apprximately 60 s that it frms deep grves apprximately 115mm deep and bent at the tp s as t rest n the wire supprts as shwn belw. End view f bent fil t verlap steel wire 60 angle 20 ga wire supprts End view f slar panel shwing 20 ga steel wire supprting bent slar panel material. 115 mm 24- Care shuld be taken when placing the material n the wires t place small quantities f silicn adhesive t the supprt wires. This will aid in keeping the slar cllectin material firmly in place. 25- Cnstruct a frame t fit ver the tp f the slar panel area. Measure the slar panel area t ensure exact measurements fr yur frame. Use 50mm x 25mm pine laid flat t frm the frame. Frame may use 45 cuts at the crners (preferred) r simply butted tight t each frame piece. Cut a grve (dad) t fit the pespex (plexiglass) apprximately 12mm deep int the inside edge f each frame piece. Nte: If yu d nt have access t a table saw t cut these dads, the plexiglass may be carefully drilled and surface munted t the backside f the frame with small screws and sealed with silicne sealant.

13 Attach tp three sides f frame t base f dryer slar panel. Be careful nt t place screws thrugh the dad f the frame. Leave the frame bttm ff t allw the plexiglass t be slid int the frame. 27- Measure the inside area f the frame and add 20mm t each dimensin. Cut the plexiglass t these dimensins and slide it int the frame. Attach the bttm prtin f the frame t the bttm strut f the dryer slar panel base. Fd Dryer Cabinet Cnstructin 28-Cut the 9.5mm dwels int 60 pieces measuring 60mm each in length. 29-Inside the dryer area, mark the centers fr 2 vertical lines f fifteen hles 49mm n center, in each side f the dryer as shwn belw (ne line 60mm frm the frnt f the dryer and ne line 60mm frm the back f the dryer, making a ttal f fur lines f fifteen marks each). Drill at each mark using a 9.5mm drill bit (3/8 ) t a depth f 18mm. These will be used t insert the small lengths f dwel. The hles shuld be placed s that their centers are 49mm apart. 60mm Inside view f dryer cabinet shwing placement f dwel supprts fr 15 dryer shelves 49mm Frnt Back Bttm dwel hle shuld be aligned with tp f strut. 30-Place a small amunt f glue n the end f each dwel and then using a hammer, gently pund the dwels int each f the hles t a depth f 18mm. These dwels will supprt the shelves fr the dryer.

14 31- Measure the final width f the dryer and d a final cut fr the dr t the back f the dryer. The dr shuld measure near the values f 760mm x 630mm. Attach the dr t the back f the slar dryer cabinet using screws prvided with the 4 strap hinges r with 1 ¼ wd screws as shwn belw. Attach 1/8 galvanized chain t hld dr at a hrizntal psitin when pened as shwn. Attach gate hks t each side f dryer dr t hld dr securely and tightly shut. Dryer Shelf Frame Cnstructin 32-Cnstruct fifteen frames frm 50mm x 25mm pine t fit int the shelf supprt slts in the dryer cabinet. Frames shuld be apprximately 565mm x 400mm. This may be adjusted t fit yur specific dryer, but shelf frames shuld slide freely in and ut f dryer cabinet as shwn. 33- Cnstruct frames similar t the methd described previusly in directive number 25. Dad grves in dryer shelves shuld nly be wide enugh t fit the 23 gauge welded mesh. A single cut with the table saw shuld be adequate width f the dad grve. Cut each grve n the inside edge f each frame piece apprximately 15mm deep. If n table saw is available wire mesh can be simply stapled t the frame.

15 34- Cut fifteen pieces f welded mesh t fit dimensins f frame interir (485mm x 330mm) plus 20mm added t each dimensin t fit int the frame grve (505mm x 350mm). 35-Assemble three sides f each dryer shelf frame using glue and 2 wd screws. Slide welded mesh int each frame and attach final side t cmplete frame. Mesh may be secured in the dad grve with silicne sealant. Ensure frame is square and fits easily int dryer cabinet between shelf supprts as shwn. Dryer shelf frame with galvanized wire mesh in shelf supprt f dryer cabinet.

16 Dryer Chimney Cnstructin 36- Assemble using glue and nails the remaining chimney pieces (ne 19mm thick piece and three 6mm thick pieces) t frm a lng rectangular chimney apprximately 650mm lng and 150mm square. Be sure t have ne end f the chimney flush leaving the ther end with the shrter side panels acrss frm each ther as shwn in the phts. 37- Using sme extra plywd, cnstruct a small rf fr the chimney. This rf shuld extend a little bit ver the sides f the chimney and shuld leave a gap t allw ht air t escape during use as shwn. 38- Mark n the tp f the dryer rf the exact width f the chimney. Nte that the chimney has a frnt (6mm) and back (22mm). Orient the chimney crrectly befre marking and cutting int the rf f the dryer. 39- Cut a hle in the tp f the dryer whse width is the same width as the side t side width f the chimney and whse frnt t back distance is the same as the frnt t back inside distance f the chimney. Cut the frnt and back edges f the chimney s that they are flat. This will ensure that the chimney will have a firm base t rest n. The chimney shuld sit dwn int the dryer rf alng the sides and als be resting n the dryer rf n the frnt and back edges f the chimney. 40- A set f strap hinges may be attached t the back f the chimney which will allw the chimney t fld dwn fr easier transprt. T ensure that the chimney is firm in the upright psitin, tensin lines may be added n the frnt f the dryer as shwn. 41- Paint exterir f dryer with exterir paint t prtect frm the weather. Black paint will help increase temperature f the drying chamber. Dryer is best stred in a prtected area r under a tarp. 42- Bracing may be installed n the leg supprts t ensure greater stability. 43- Wheels may als be installed n the dryer t imprve mbility f the dryer. Dryer is nw cmplete!

17 Slar Drying Use Manual 1. INTRODUCTION Use f a slar dryer is an efficient, simple methd f prducing a shelf-stable fd. This manual cncentrates n the drying f cmplex carbhydrate cntaining fds such as tar, cassava and breadfruit that are predminant in the diets f mst Pacific Islanders. Even thugh these fds are specifically discussed, ther rt crp fds and fruits may be dried using the principles discussed in this manual. Fr fds with a rapid rate f deteriratin, such as cassava, tar, and breadfruit, this methd is especially useful. Thrugh slar drying, these fds can be stred fr lng perids and used in emergency situatins. Fd preparatin, drying, strage, and rehydratin are all key cmpnents f prducing a quality, shelf stable prduct. If dried and stred prperly, these fds shuld last at least ne year. 2. FOOD PREPARATION With all prducts, it is imprtant that the beginning prduct is fresh: use f a pr beginning prduct leads t a pr finished prduct. If pssible, begin sample preparatin within ne r tw days f harvest f the prduct. a. Peeling: Begin fd preparatin by peeling the prduct being dried. Prducts may be peeled in the traditinal r custmary way. Rinsing with water may be necessary during and/r after the peeling prcess t remve excess dirt. b. Slicing: Once the fd has been peeled, slicing can begin. Fr best results, the prducts may need t be sliced different than traditinal methds. The prcess f drying and rehydratin requires specific slicing methds. Tar slices shuld be between 1 / 4 and 3 / 8 (7-10 mm) thick. Fr larger pieces, it is necessary t cut the sliced pieces in halves. Smaller pieces will decrease ttal drying time. Tar befre (right) and after (left) peeling

18 T slice cassava, first cut the cassava int 3-4 (5-8 cm) sectins. These shrter sectins will help the cassava dry quicker. Frm these sectins, cut the cassava s that it is n mre than ½ (13 mm) at its thickest part. Peeled and unpeeled cassava sectins Breadfruit slices shuld be cut apprximately 3 / 8 (1 cm) thick. After slicing, the center (seeded) sectin will need t be cut ut f sme pieces. 3. FOOD DRYING a. Placement n the Drying Rack: After the fd has been sliced, it is nw ready t be put n the drying rack. Place a single layer f slices n the drying rack, with as little cntact between pieces as pssible. With mre surface area expsed t air, the pieces will dry better. b. Rtating Racks within the Slar Dryer: When the pieces have been placed n the drying rack, they are nw ready fr drying in the slar dryer. Open the back f the dryer, and place ne rack in each f the slts built int the dryer. Thrughut the drying prcess, the racks may be rtated t help the prducts dry evenly. c. Rtating the Dryer: Thrughut the drying prcess, it is imprtant t rtate the entire dryer. T create the mst effective drying envirnment, the plexiglass (pespex) face f the dryer shuld be in direct sunlight. This is accmplished by peridically rtating the dryer until the side f the dryer and the shadw frm a cntinuus line. Shadw cast by direct sunlight

19 d. Weather Adjustments: During the drying prcess, adjustments may be needed peridically t adapt t the current weather. Fr example, if it begins t rain, it is best t pull the dryer int a cvered area during the rain. 4. FOOD REMOVAL In rder t btain the best finished prduct, the dried fd must be remved frm the dryer at the prper time. Because this time varies between the fds being dried, general rules must be applied. In the case f rt crps, if the fd is dried t a prper level, it will snap sharply when brken. It will als be distinctly dry and brittle. In additin, if the pieces begin t crack, they shuld be dry enugh t be remved frm the dryer. When drying fruits with higher sugar cntent, a prperly dried prduct will still be sft and leathery with n visible misture. Pieces shuld nt stick t each ther, but spring apart after being pressed tgether. 5. FOOD PACKAGING Once the fd has been dried, it is ready t be packaged and stred. Fllwing several guidelines will increase the quality and shelf-life f the prduct: a. Package: Fr ptimal results, Mylar puches (a fil-plastic laminate) are recmmended. These puches will als require a heat sealer t create an airtight envirnment in the bag. If these packages are nt available at stres, they may be btained thrugh the Church f Jesus Christ f Latter-Day Saints Distributin Services. Alternative methds are available, but these methds will decrease significantly the shelf-life f the prduct. Such methds include using plyethylene plastic (requiring a heat sealer), r Ziplc type sacks. Glass jars with a tight seal may als be used. If using an alternative methd, creating an airtight envirnment is crucial. b. Oxygen Absrbers: Befre sealing the strage package, additin f xygen absrbing packets is strngly recmmended. This packet will absrb whatever xygen may be present, thus reducing the chance f micrbial grwth. Oxygen absrbers may als be rdered thrugh the Church f Jesus Christ f Latter-Day Saints Distributin Services. These absrbers wrk best when cmbined with the Mylar puches, but may als be used with alternative packaging methds. c. Envirnment: The strage envirnment is imprtant in preserving fds, especially thse nt packaged in Mylar. A dark, cl, and dry envirnment is mst suitable fr the preservatin f dried fds. In cntrast, a wet, warm, and/r sunlit area will decrease the shelf-life f the dried prducts. In additin, rdents and pests are capable f chewing thrugh mst types f packages. T remedy this, an envirnment free r resistant t rdents and pests is recmmended.

20 6. REHYDRATION In the case f dried rt crps, befre eating the dried fd, it must be rehydrated (have water added back int the prduct) and cked. Fr best results, sak the dried prduct vernight in water. Once this has been dne, bil the fd until it has the desired texture. After rehydratin, the fd may be prepared in a usual manner. Fruits may be eaten directly in the dehydrated frm. References Scanlin, D. 1997, Indirect, thrugh-pass, slar fd dryer. Hme Pwer. February- March Midilli. A., Kucuk, H., and Yapar, Z., A new mdel fr single-layer drying. Drying Technlgy, 20(7) Vlachs, N.A., Karapantsis, T.D., Baluktsis, A.I., Chassapis, D Design and testing f a new slar tray dryer. Drying Technlgy. 20(6) Sharma, V.K., Calangel, A., and Spagna Experimental investigatin f different slar dryers suitable fr fruit and vegetable drying. Renewable Energy. 6(4)