Performance Evaluation of an Auger-fer Chipping Machine Adapter for cassava and Yam by B.O Soyoye

Performance Evaluation of an Auger-Fed Chipping Machine Adapted for Cassava and Yam

BY

B. O. Soyoye, O. J. Olukunle, and R. F. Chinze

Agricultural and Environmental Engineering Department Federal University of Technology, Akure Ondo State

[email protected], 08036577499

PRESENTED AT

THE NATIONAL ENGINEERING CONFERENCE AND ANNUAL GENERAL MEETING

“SUNSHINE 2015”“SUNSHINE 2015”1

mailto:[email protected]

INTRODUCTIONRoot and tuber crops are abundant in the rural areas of most developing countries, and are often regarded as a cheap food.

Presently, cassava is one of the most important and widely grown food crops in Nigeria. Nigeria is the single largest producer of yam, accounting for about 71% of total world production (Ezeh, 1992) and FAO, 2005).

Increased production of root crops in Nigeria has brought about the need for the development of appropriate processing technology.

2 NSE Annual Conference: SUNSHINE 2015

JustificationTuber crops, because of their high moisture content, cannot be stored for more than 3 to 4 days to avoid the accumulation of toxic substances that make it unfit for consumption.

Therefore processing has been an integral part of the utilization of tuber crops.

Intr. Cont.Intr. Cont.

The main aim of this study is to evaluate the performance of an auger-fed chipping machine with respect to (i) Machine capacity, (ii) Chipping efficiency and (iii) Chip geometry


Materials and MethodsMaterials and Methods

The chipping machine tested in this work consists of hopper, chipping unit, driving unit and the frame.

The hopper forms the chipping chamber with side inclined at 600 for easy sliding of the tubers into the chipping unit that bears the screw conveyor.

With the exception of the frame, shaft and pulley which are made of mild steel, the machine parts are made of stainless steel to avert acid corrosion and contamination.

Description of the ChipperDescription of the Chipper


Machine TestingMachine Testing

The machine was tested in the Agricultural and Environmental Engineering Departmental workshop of the Federal University of Technology Akure Ondo State Nigeria.

It was tested using a variety of cassava (Manihot esculenta) and yam (Dioscoreae rotundata) respectively with varying machine speeds (Plate 1).

Mats & Mtds Cont.

Mats & Mtds Cont.


Plate 1: Tuber chipping machine at testing stages

Mats & Mtds Cont.

Mats & Mtds Cont.


Mats & Mtds Cont.

Mats & Mtds Cont.Performance EvaluationPerformance Evaluation

The machine was tested with an electric motor at speeds of 318, 368, 418, 468, and 518 rpm in order to evaluate the chipping capacity and efficiency, and the adequacy of the chip geometry.

At each speed, tubers with a total weight of 4 kg were fed into the machine through the feeding hopper. The time taken for the chipping and the weight of the output chips were noted.


Plate 2: Measurement of the chip geometry

Mats & Mtds Cont.

Mats & Mtds Cont.

Plate 3: Well chipped tubers being weighed


)( timechipping theis )( tuber chipped of mass totalis )( tuber theof mass initial theis

)( tuber chipped wellof mass theis )(capacity machine theis

(%) efficiency chipping theis

%100

hrTkgMkgM

kgMhrkgC

C

hrkgTMC

MMC

c

tc

i

wc

m

e

c

tcm

i

wce

The efficiency of the machine was found in accordance with the following definitions (Adejumo et al, 2011)

Performance EvaluationPerformance EvaluationMats & Mtds Cont.

Mats & Mtds Cont.

9

Figure 1: Chipping capacity and chipping time of cassava against motor speed

Motor speed (rpm)

Chi

ppin

g ca

paci

ty (k

gh-1)

Chi

ppin

g tim

e (h

)

Results and DiscussionResults and Discussion


Chi

ppin

g ca

paci

ty (k

gh-1)

Chi

ppin

g tim

e (h

)

Motor speed (rpm)

Figure 2: Chipping capacity and chipping time of yam against motor speed

Results and Discussion Cont.Results and Discussion Cont.


Chi

ppin

g ef

ficie

ncy

(%)

Motor speed (rpm)

Figure 3: Chipping efficiency against motor speed



Chi

p ge

omet

ry (m

m)

Figure 4: Cassava chip geometry against speed

Motor speed (rpm)



Chi

p ge

omet

ry (m

m)

Motor speed (rpm)

Figure 5: Yam chip geometry against speed



ConclusionConclusionThe test results showed that an increase in motor speeds results in a decrease in chipping time and an increase in chipping capacity.

The results also revealed a parabolic curve which indicates that as the motor speeds increase, the chipping efficiency increase and later decrease. Therefore, the choice of motor speed for the machine will be a compromise between chipping capacity and chipping efficiency.

Motor speed also has significant effect on the length of chips, especially at high speeds. The best chips geometry was obtained for both tubers at moderate motor speeds.

The machine has maximum capacities of 153.85 kg h–1and 148.15 kg h–1

for cassava and yam respectively at a speed of 518 rpm. It also has maximum chipping efficiencies of 67.5% and 73.3% for cassava and yam respectively at a speed of 418 rpm. 15 NSE Annual Conference: SUNSHINE 2015


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