DESIGN AND DEVELOPMENT OF A MOTORIZED GINGER RHIZOMES SPLITTING MACHINE

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1 Journal of Applied Agricultural Research 04, 6(): -30 ISSN Agricultural Research Council of Nigeria, 04 DESIGN AND DEVELOPMENT OF A MOTORIZED GINGER RHIZOMES SPLITTING MACHINE *Simonyan, K. J., Eke, A. B., Adama, J. C., Ehiem, J. C., Onwuka, U. N., Okafor yadi, O. C., Iheke, A. R., Nwankwojike, B. N. 3 and D. A. Okpara 4 Agricultural and Bioresources Engineering Department; Agricultural Economics Department; 3Mechanical Engineering Department; 4 Agronomy Department Michael Okpara University of Agriculture, Umudike, P.M.B. 767, Umuahia. Abia State Nigeria *simonyan.kayode@mouau.edu.ng; ABSTRACT A motorized ginger rhizomes splitting machine using sawing principle with serrated blade was designed and developed using locally available materials. The developed ginger rhizomes splitting machine was tested for splitting efficiency (SE), machine capacity (MC), percent dust (PD) and percent injured (PI) using two locally grown ginger rhizomes: Umudike ginger I (UG I) and Umudike ginger II (UG II). Moisture contents of ginger varieties used during the test were 73.64% wb and 77.3% wb for UG I and UG II, respectively. Result obtained from the test showed that average machine capacity of kg/h was obtained with UG I while a higher value of kg/h was obtained for UG II. The average splitting efficiency for UG I and UG II was 7.97% and 6.6%, respectively. The average percent dust was.56% and 4.8%, respectively for UG I and UG II and average percent injured was 5.7% and 7.63% for UG I and UG II, respectively. The machine is recommended for adoption by farmers. Keywords: Ginger, splitting, splitting efficiency, percent dust, percent injured INTRODUCTION Ginger (Zingiber officinale Roscoe) is an economic crop providing foreign exchange earnings to Nigerian farmers. It is a perennial monocotyledon crop grown in the savannah and rain forest zones of Nigeria. Ginger is valued for its essential oils, mainly oleoresin and gingerol, used in pharmaceutical, bakery and soft drink beverage industries as well as culinary and cosmetic preparation. Freshly harvested ginger rhizomes have a moisture content of 80-85% and safe storage moisture of 0 % db (Emehute, 00). Two commercial ginger varieties commonly grown in Nigeria are: Umudike Ginger, (UG ) locally called Tafin giwa (Elephant s foot) having a bold yellow rhizome flesh with stout short internodes. The second is black ginger Umudike Ginger II (UG II) locally called Yatsum Biri (Monkey s finger) because of the very irregular shape of its fingers. Umudike ginger II rhizome flesh is dull grey in colour and it grows taller and has longer internodes than UG. However, UG I variety is more popular than UG II, apparently because the yield is higher. Nevertheless, UG II is more pungent as a result of its higher oleoresin content (Njoku et al., 995). The epidermal cells of ginger rhizomes contain most of the essential oils which give ginger its characteristic aroma, a prime factor in determining its market value (Agarwal et al., 987; Ali et al., 99). Ginger rhizomes

2 Simonyan et al., 04 splitting is longitudinal to enable maximum surface exposure for quick and uniform drying thereby retaining the aroma, flavour and pungency, the qualities requirements in ginger trade. The cutting tool must be sharp to avoid multiple cutting or crushing. Traditionally, ginger splitting is done manually involving holding ginger rhizome with one hand and passing a sharp knife through the rhizome fingers longitudinally cutting it into fairly symmetrical pairs. This operation is tedious, labour intensive, risky and dangerous. It has been reported that this has limited the number of hectares produced (Onwueme, 988) as it takes one-man day of 8 hours to split 0 kg of fresh ginger rhizomes (Babawale, 00). Efforts are being made to develop ginger splitting machines locally with various degrees of success recorded. National Root Crops Research Institute (NRCRI), Umudike developed both manual and motorised ginger splitting machines. The motorised ginger splitting machine consists of two rollers rotating in clockwise and anticlockwise directions inwardly. The rollers are positioned directly under the hopper to facilitate splitting by positioning ginger longitudinally at splitting point. A disc with four knives split ginger rhizomes into uniform thickness as preset. The ginger falls by gravity (Babawale, 00). Guwo et al. (008) developed a motorised ginger splitting machine with a stationary blade, 30 cm long positioned horizontally with an upward pointing knife-edge, 5 cm impeller equispaced across the centre of blades lateral cross-section which permit them to swirl across the blade without being obstructed. The machine was evaluated at three moisture levels, five impeller speed levels to determine its splitting efficiency on two ginger varieties (Tafin giwa and Yatsun biri). Splitting efficiency of the two ginger varieties decreased with increase in impeller speed and decrease in moisture content. Maximum splitting efficiency of the machine was 8.5% for Tafin giwa and 67.95% for Yatsum Biri at 40 rpm and % wb. They, however, did not report the throughput capacity and percent of ginger rhizomes damaged. A manual ginger slicing machine developed by Federal Institute of Industrial Research, Oshodi (FIIRO) (Onu and Okafor, 00) consists of a rotary disc with blades. Throughput capacity of the slicer varied between. kg/hr to 8.85 kg/hr. The slicing efficiency varied between 66±0.9% and 7.4±6.4%. Interestingly they reported an increase in slicing efficiency of 7.4% at a low moisture content of 64%. Simonyan et al. (003) developed a motorised ginger slicer which was able to slice ginger rhizomes longitudinally. They reported an increase in slicing efficiency from 64.6% at % MC (db) to 76.8% at 30% MC (db) and percent damage of 3.% at 30% MC (db) to 35.4% % MC (db) at.8 revolutions per second, respectively. In recognition of the constraints imposed by traditional manual method of splitting ginger which is time consuming and labour intensive, there is need to design and construct a motorised splitting machine. The machine is expected to use a different operational principle from the existing ginger splitting machines and be entirely fabricated locally, easy to operate and cheap to be adopted by small scale farmers. This study was broadly aimed at developing an appropriate motorised ginger rhizomes splitting machine for adoption by farmers. The specific objective is to test the developed motorised ginger rhizomes splitting machine. MATERIALS AND METHODS Design and construction of ginger rhizomes splitting machine was conducted at the Postharvest Technology Laboratory, Agricultural and Bioresources Engineering Department, Michael Okpara University of Agriculture, Umudike, Abia State, Nigeria.

3 Motorized Ginger Rhizomes Splitting machine Design consideration for ginger rhizomes splitting machine D diameter of larger pulley connected to splitting blade shaft 50 mm The following factors were considered in developing the ginger rhizomes splitting machine: N rpm i. Develop a machine that will be able to split ginger rhizomes longitudinally; ii. Minimise the ginger rhizomes losses; iii. Minimise drudgery and risk involved in the splitting process; iv. Develop a ginger rhizomes splitting machine that will be affordable to the generality of farmers; v. Reduce machine components to increase reliability thereby minimise maintenance and repair costs. Design of hopper The hopper is a trapezoid shaped inclined structure. Area of hopper, A h...() Where: a, b are the parallel sides, upper and base, respectively, mm h perpendicular height, mm. Volume of hopper 365 x mm 3...() Splitting Speed N ( a + b) h ( ) mm D N D...(3) Where: N prime mover speed 900 rpm N speed of splitting blade shaft, rpm D diameter of prime mover pulley 60 mm Where: N 3 speed of smaller pulley connected to splitting blade shaft, rpm N N 3 6 rpm N 3D 3 N 4D 4...(4) Where: D3 effective diameter of smaller pulley connected to splitting blade shaft 60 mm D4 effective diameter of larger pulley connected to crankshaft 60 mm N 4 speed of larger pulley connect to crankshaft, rpm N3D N 4 D rpm Splitting disc shaft design The combined shock and fatigue factors were taken into account since the shaft is subjected to combined bending and torsion moment. Figure gives the shear force and bending moment diagrams. For rotating shafts subjected to suddenly applied load with minor shocks only, Khurmi and Gupta (005) gave K m and K t range from.5 to.0 respectively. Assuming K m.5 and K t.5 and σ b 84 MPa and τ 8 Mpa for shafts with allowance for keyways as given by Khurmi and Gupta (005), the equivalent twisting moment is: T [( K M ) + ( K T ) ] e m t...(5) 3

4 Simonyan et al., 04 [(.5 x 8.65) + (.5 x 3) ] Nm And the equivalent bending moment M [ ] ( K M ) + ( K M ) + ( K T ) e m m t...(6) [ ] ( ) + ( ) + (.5 3.0) Where: M e equivalent bending moment, Nm T e equivalent twisting moment, Nm M maximum bending moment, Nm T twisting moment, Nm K m combined shock and fatigue factors for bending K t combined shock and fatigue factors for torsion 4.86 Nm Figure : Shear Force and Bending Moment Diagrams 4

5 Motorized Ginger Rhizomes Splitting machine Key. Crank shaft. Bearing housing 3. Push rod 4. Casing 5. Blade 6. Frame 7. Engine sitting 8. Pulley 9. Hopper Figure : Isometric drawing of ginger rhizomes splitting machine Also T τ 6 d 3 e d s s 6 Te π τ 3 3. mm Assuming a factor of safety of.5. d s.5 x mm π M e σ b d 3 d s 3 M π σ b e 3 3 s 4.5 mm...(7)...(8) Assuming factor of safety of.5. d s.5 x mm. The value of equivalent moment diameter was chosen being of higher value to be able to withstand the shocks and fatigue. Hence a shaft diameter of 5 mm was chosen. The empirical data obtained was used to design the splitting machine. Figure shows the isometric drawing of ginger rhizomes splitting machine. Description of ginger rhizomes splitting machine The motorized ginger splitting machine consists of frame, feeding unit, pressing mechanism, splitting mechanism, power transmission and discharging unit. Figure 3 shows the developed ginger rhizomes splitting machine. 5

6 Simonyan et al., 04 Frame The frame dimensioned 850 mm by 300 mm was constructed with 5 mm by 5 mm angle iron. It is a rectangular shaped structure which positions all the machine components to perform its operation satisfactorily. It also has 360 mm by 80 mm extension of the frame as stand for the prime mover. Feeding unit The hopper is trapezoidal shaped structure with 4 mm base width, 00 mm top width, 30 mm height and 0 mm wide. The hopper is inclined at 34 o based on the angle of repose of ginger to the horizontal to ensure easy movement of ginger rhizomes to the splitting unit under gravity and also to reorient the rhizomes for longitudinal splitting by the splitting blade. Pressing mechanism: comprises crank shaft, connecting rod and piston. Crankshaft: This unit translates rotary motion of the prime mover to reciprocating movement of piston. It has a shaft 5 mm diameter with a ball bearing positioned at centre of the shaft. Connecting rod: this transmits rotary motion of the crankshaft to reciprocating motion of piston. Figure 3: The developed ginger rhizomes splitting machine 6

7 Motorized Ginger Rhizomes Splitting machine Piston This is the main component of the pressing mechanism. The piston reciprocates vertically within the splitting unit housing from top dead centre to bottom dead centre. It opens the inlet space to receive ginger rhizomes from the hopper to splitting unit at bottom dead centre of its inlet stroke. It closes the inlet space, pushing and guiding ginger rhizomes against the rotating splitting blade for splitting, discharging the splits at top dead centre of the pressing stroke. Splitting mechanism The splitting mechanism is powered rotating serrated blade. The splitting blade diameter is 40 mm, constructed from mm thick stainless steel to prevent corrosion and avoid contamination. The splitting blade is serrated at the circumference and is enclosed inside the splitting chamber. Power transmission system The prime mover, (a 5 hp Robin petrol engine was used for the test), was mounted on the stand to help stabilise the machine. Power transmission to the moving parts of splitting machine were by shaft, pulley and belt drive. Discharging unit Discharge unit is an extension of the splitting unit casing. Split ginger rhizomes are discharged under gravity for collection. Principle of operation The developed ginger rhizomes splitting machine operates on the slider crank mechanism based on sawing principle to split ginger rhizomes. The ginger rhizomes fall freely by gravity through splitting chamber reorienting the rhizomes longitudinally for splitting. The piston pushes the ginger rhizomes to rotating serrated blades to be sheared. The splitted ginger rhizomes are discharged to the trough for collection. Experimental procedure Two locally grown ginger rhizome varieties used for the test were obtained from NRCRI out-growers in Kachia, Kaduna State, Nigeria. The ginger rhizomes were sorted into large, medium and small sizes. The motorized ginger rhizomes splitting machine was allowed to run for about two minutes to stabilise before feeding cleaned ginger rhizomes through the hopper manually. A Lutron digital photo tachometer was used to measure the blade shaft speed. A constant speed was used during the test for all samples. The ginger rhizomes were fed singly into the machine. The feeding time and time required for a batch of the splitted ginger rhizomes fed into the machine to be extruded were recorded. The feed rate was calculated in kg/h. There were three replications for each parameter tested. The split ginger rhizomes, unsplitted ginger rhizomes, injured but split rhizomes and Table : Parameters tested from the developed ginger rhizomes splitting machine Parameters UG I UG II I II III Average I II III Average Feed Rate, kg/h Machine Capacity, kg/h Splitting Efficiency, % Percent Dust, % Percent Injured, %

8 Simonyan et al., 04 ginger dust (fine ginger particles due to sawing) as a result of the splitting with serrated blade were collected and their weight determined respectively. The moisture contents of ginger rhizomes used during the test were 73.64% wb and 77.3% wb for UG I and UG II, respectively. Testing of developed ginger rhizomes splitting machine The performance of developed ginger splitting machine was tested as: F R...(9) Where F R is feed rate in kg/h; Q f is mass of ginger rhizomes fed into the machine in kg and t is the time to finish the feeding in hour. M c Q t f Q t...(0) Where M C is machine capacity, Q t is mass of ginger rhizome splitted in kg; t time taken for splitting in hour. W SE s 00 W t...() Where SE is splitting efficiency in percent; W is mass of ginger rhizomes in kg and W s is mass of ginger rhizomes split in kg. Wi PI 00 W...() Where PI is percent injured in percentage; W is mass of ginger rhizome in kg and W i is mass of ginger rhizomes injured in kg. W PD s 00 W...(3) Where PD is percent dust in percentage; Ws is mass of ginger rhizome sawn in form of dust in kg; W is mass of ginger rhizome fed into the machine in kg. RESULTS AND DISCUSSION The results of tests performed on the developed motorized ginger rhizomes splitting machine are presented in Table. The average feed rate obtained for UG I and UG II was 8.33 kg/h and 08 kg/h, respectively. The average feed rate for UG I was higher than UG II. This may be due to UG II being more lignified thereby posing more resistance to cutting. This agrees with the result of Guwo et al. (00). An average machine capacity of kg/h was obtained with UG I while a higher value of kg/h was obtained for UG II. The machine capacity obtained was higher than. kg/h to 8.85 kg/h published by Onu and Okafor (00). The disparity in results obtained by Onu and Okafor may be due to their machine being manually operated while this is motorised. The average splitting efficiency for UG I and UG II was 7.97% and 6.6%, respectively. The splitting efficiency obtained is within the range reported as maximum splitting efficiency by Guwo et al. (008) of 8.5% for Tafin giwa and 67.95% for Yatsum Biri at 40 rpm, and that reported by Onu and Okafor (00) of 84.35% wb 66±0.9% to 7.4±64% while Simonyan et al. (003) reported a slicing efficiency of 64.6% at % MC (db) to 76.8% at 30% MC (db) and percent damage of 3.% at 30% MC (db) to 35.4% % MC (db) at.8 revolution per seconds, respectively. Guwo et al. (008) and Onu and Okafor (00) however, did not report the percent damage which would have given more insight to the effectiveness of the ginger splitting machine. Onu and Okafor (00) also did not report on the variety of ginger used for testing the developed ginger machine. There is similarity in the result obtained with the current machine from the 8

9 Motorized Ginger Rhizomes Splitting machine one reported by Guwo et al. (008), in that, there is disparity between the splitting efficiency obtained from the two varieties. This may be due to the fibrousness of the rhizomes. UG II appears to be more fibrous than UG I The average percent dust was.56% and 4.8%, respectively for UG I and UG II while average percent injured was 5.7% and 7.63% for UG I and UG II, respectively. The percent damage obtained was much lower than 3. to 35.4% published by Simonyan et al. (003). The principle of operation of the two machines are different; while the current machine is based on sawing principle the former by Simonyan et al. (003) was based on pushing the ginger rhizomes against stationary blades which resulted in pounding. The average values of feed rate and splitting efficiency for UG I was higher than UG II because UG I is less fibrous while the average machine capacity, percent dust and percent injured of UG II was higher than UG I; this may be due to UG II is more lignified than UG I. This corroborates the results of Simonyan et al. (03) on the physical properties of ginger that varieties have effect on the design of splitting machine since the sizes and shapes of the ginger rhizomes are different. CONCLUSION AND RECOMMENDATION A motorized ginger rhizome splitting machine was designed, developed and tested. The machine was tested for splitting efficiency, machine capacity, percent dust and percent injured using two locally grown ginger rhizomes UG I and UG II varieties. The average values of feed rate, and splitting efficiency for UG I was higher than UG II (8.33 kg/h and 7.97% and kg/h and 6.6%, respectively) while the average machine capacity, percent dust and percent injured of UG II was higher than UG I (96.33 kg/h, 4.8%, 7.63% and kg/hr,.56%, 5.7%, respectively). The developed ginger rhizomes splitting machine is recommended for adoption by the farmers. ACKNOWLEDEMENT The authors acknowledge Michael Okpara University of Agriculture, Umudike for providing the fund for this research vide EIT /08/ 0. REFERENCES Agarwal, Y. C., Hiran, A. and. Galundra, A. S Ginger Peeling Parameters. Agricultural Mechanization in Asia, Africa and Latin America, 8(): Ali, Y., Jain G. C., Kapdi, S. S., Agarwal, Y. C. and Bhatanager, S. 99. Development of Brush - type Ginger Peeling Machine. Agricultural Mechanization in Asia, Africa and Latin America, (): Babawale, O. O. 00. Mechanical Splitting and Drying of Ginger. Proceedings of Three Training Workshops on Ginger Production, Processing, Utilization and Marketing held at the National Roots Crop Research Institute Umudike. p Emehute, J. K. U. 00. Eds. Proceedings of Three Training Workshops on Ginger Production, Processing, Utilization and Marketing held at the NRCRI, Umudike. 59 pp. Guwo, A. N., Ndirika, V. I. O. and Mohammed, U. S Performance Evaluation of Ginger Splitting Machine. Proceedings of the 8 th International Conference and 9 th Annual General Meeting of the Nigerian Institution of Agricultural Engineers held at FUT Yola. Vol 9:

10 Simonyan et al., 04 Khurmi R. S. and Gupta, J. K.005. Machine Design. Eurasia Publishing House (PVT) India. Njoku, B. O., Mbanoso, E. N. A. and Asumugha, G. N Ginger Production by Conventional and Tissue Culture Techniques. DolfMadi Publishers. Owerri, Imo State. Onu, L. I. and Okafor, G. I. 00. Effect of Physical and Chemical factor Variations on the Efficiency of Mechanical Slicing of Nigerian Ginger (ZingiberOfficinate Rose). Journal of Food Engineering, 56: Onwueme, I. C Towards Increased Production and Export of Ginger in Nigeria. Proceeding of the First National Ginger Workshop held at NRCRI, Umudike. p. 6-. Simonyan, K. J., Jegede, K. M. and Lyocks, S. W. J Development of a Motorised Ginger Slicer. Agricultural Mechanization in Asia, Africa and Latin America, 34(): Simonyan, K. J., Ehiem, J. C., Eke, A. B., Adama, J. C. and Okpara, D. A. 03. Some physical properties of ginger varieties. Journal of Applied Agricultural Research, 5():