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8/12/2019 coco terti

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Design and performance of a coconut dehusker machine

Md.Akhir Hamid11*, Mohd Taufik Ahmad1and Ahmad Ngalim2

Abstract

A mechanized coconut dehusker, designed for industrial scale work load, was fabricated

and tested. The machine relies on a 5.5 Hp petrol engine to power a hydraulic pump that

drives a set of double spike rollers. By rotating in different directions, the rollers were

able to grip the coconut eocarp and split the husks and nuts. The efficiency of themachine was tested for four local coconut varieties! "alayan tall #respectively $%.5 &

and '5& for ripened and matured nut() "atag #'5&() "awa #**&() and +ellow dwaft

#-&(. The machine is capable to dehusks %*/0 nuts1hr or */2 sec1nut. The estimated

cost per machine is 3"2, ..

e! "ords# coconut dehusker, efficiency, coconut varieties

$ntroduction

4oconut is one of important industrial crop in the tropics. The whole tree is very

valuable that can be formed into many products and usages. or eample, the coconut

trunk, leaf, fiber, shell and flesh can be used for building material, broom, cushion,

charcoal and milk respectively. The coconut flesh is delicious and more valuable ascompared to other part of the tree. 6n order to etract the flesh from the shell, the coconut

nut has to be dehusked by using hand tools such as knife, iron blade, iron spear or sharphardwood.

"anually dehusking process re7uires the operator to bring the coconut sharplydown into the blade, twisting to one side, loosen the husk and detaching the fiber from

the shell. This action is repeated several times until the entire fibers are removed. The

work is not only hard and dangerous but re7uires considerable skill, strong wrist and arm.8resently, no commercial mechanical dehusking has been developed. 6n the estate, their

workers are paid for 3" 05. 9 5. for manually dehusking of ' 9 2 nut per

day. :n the average, they are able to dehusk 2 nuts per hour. Therefore, mechanicaldehusking machine is necessary to replace the inefficiency, time consuming and labor

problem of manually dehusking.

Titmus and Hickish #2$%$( attempted to develop mechanical coconut dehusker.

Their work was followed by other researchers. "A3;6 has developed a manuallyoperated portable dehusking device ";/2 by Abdullah H. and


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device was claimed to reduce human physical effort during dehusking and only suitable

for both the "alayan Tall and "awa varieties. However, the device is still eposed to

high risk due to the operator is bending nearer the dehusking blades.

Toh and Tan #2$'( developed an electrical/powered coconut dehusking machine.

Their machine re7uires operator to fed in the coconut into a series of turning husk

removals in the assembly line.

=ukra #2$$5( developed a mobile semi/mechanized pneumatic dehuskingmachine. His machine breaks husks and the broken husks are removed from the shell by

operator. The machine consists of operator seat, coconut platform, hopper, pneumatic

system, blade dehusker and two wheel trailer. 6t is able to dehusk "alayan Tall and

"awa varieties of 25/%5 nuts per hour.

urther improvements of the above machines are necessary to improve their

working rate, efficiency, reduce operational time, safety and functionality. Therefore, a

new version of fully mechanical dehusking machine has been developed. This paper

highlights the design, fabrication and performance of dehusking machine on various

varieties of "alaysian coconuts.

Material and method

"echanical 4oconut ;ehusking "achine was designed and fabricated at

>ngineering ?orkshop, "A3;6 =erdang. >ngineering ;esign 4ode of 8ractices,8hysical 8roperties of 4oconut, technical feasibility and economical viability were

considered in the design and development of the machine. The machine consists of petrol

engine as a power driven, hydraulic tank, hydraulic pump, hydraulic hose, pulley, and

chain, double roller with spike, pressure controller, gear and structural frame. igure 2ashows the 0/; schematic diagram of coconut dehusker

8late 2 and 8late % show the picture of the "anual and "echanical ;ehusking "achine,respectively. The function of the machine is to scrap the coconut skin and then splittingthe husk from the nut. The machine was designed portable that can be operated at indoor

or outdoor. The 5.5 h.p. petrol engine transmits power to a hydraulic pump by hydraulic

transmission line. The pump operates the hydraulic motor that rotates the chain androllers with spikes. The speeds of the rollers are controlled by a lever that can be stoped,

forwarded or reversed. 8ressure gauge is installed to set up the suitable pressure gauge

that can regulate the speed of the rollers.The rollers are vertically inclined and covered with mild steel mesh tunnel. The mild steel

mesh tunnel is acted as a safety guard. A forcing lever to ad@ust the nut in contacted with

the spikes is provided at the middle of the tunnel. ;ehusking process re7uires a coconut

to be dropped from the top feeding into the tunnel with rotating rollers and then droppingdown by gravity. The rotating spikes s7ueeze the husk, detach the husk from the nut and

then pushing the husk at the back of the rollers. The clean nut drops into the bottom

basket. The machine re7uires only one operator to feed the coconut into the machine.Hundreds of coconuts from four different varieties were tested in the mechanical coconut

dehusking machine. This is to study the machine performance in terms of reliability,

durability, functionality, safety, work rate, cost and efficiency. The varieties are "alayanTall, "awa, "atag and +ellow ;warf. Their physical properties such as weight, vertical

%


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#cm(

Table 2.8hysical 8roperties of "atag 4oconuts and Their 8erformance ;uring the

;ehusking Test.

;escriptive

=tatistics

o "in "a "ean arian

ce

=td.

;eviation

=td.

>rror of"ean

?eight #kg( 5% 2.2 2.$ 2.5 .% .25 .%

ertical

4ircumference

#cm(

5% 5%. -'.5 -2.5$ 20.* 0.* .52

Horizontal

4ircumference#cm(

5% 5. -.5 5-.'% 2%.2* 0.5 .'

Horizontal3adius #cm(

5% *.% 2.0 $.5 .0 .5 .'

;ehusking Time#s(

5% 0. %-. *. %.0 .5% .-0

Broken After

;ehusking #no(

$15% / / / / / /

=hell Thickness

#mm(

22 0.0 .5 0.' .25 .0$ .2%

Husk Thickness

#cm(

5% . 0.5' %.$ .2 .- .$

Table 2, %, 0 and are also shows the time taken to dehusk a single coconut. Themean working rates for dehusking of "alayan Tall, "atag, "awa and +ellow ;warf

were found *.*', *., *.'5 and '. second respectively. Again, "alayan Tall and"atag took less time due to their shell are thicker and stronger as compared to "awa and

+ellow ;warf. "oreover, their husks are thinner and softer that easier to be detachedfrom the nut.

Table &. 8hysical 8roperties of "awa 4oconuts and Their 8erformance ;uring the;ehusking Test.

;escriptive

=tatistics

o "in "a "ean arian

ce

=td.

;eviation

=td.

>rror of

"ean

?eight #kg( 5 .'5 2.05 2.2 .2 .2 .2ertical4ircumference

#cm(

5 52. -$.5 -0.- 2.** 0.%' .5

Horizontal

4ircumference

#cm(

5 0. 50. *.*2 -.' %.* .0

Horizontal 5 -.' *%. '.' *-.$ '.** 2.2$


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3adius #cm(

;ehusking

Time#s(

5 %. . *.'5 -*.2 '.%2 2.2%

Broken After

;ehusking #no(

2'15 / / / / / /

=hell Thickness#mm(

2- %.' .0 0.** .% .5 .22

Husk Thickness

#cm(

5% 2.52 '. %.0* .*0 .'- .2%

Table '.8hysical 8roperties of +ellow ;warf 4oconuts and Their 8erformance ;uring

the ;ehusking Test.

;escriptive

=tatistics

o "in "a "ean arian

ce

=td.

;eviation

=td.

>rror of"ean

?eight #kg( 5% .5 2.* .*2 .0 .2' .%ertical

4ircumference

#cm(

5% 2. 55. $.52 '.'% %.$* .2

Horizontal

4ircumference#cm(

5% 0$. $.5 5.% 5.$ %. .0

Horizontal3adius #cm(

5% -.% *.$ *.2$ .25 .0$ .5

;ehuskingTime#s(

5% %%. %%. '. 2%.2* 0.$ .'

Broken After;ehusking #no(

%'15% / / / / / /

=hell Thickness

#mm(

20 2.' 0.% %.5 .25 .0' .22

Husk Thickness

#cm(

% .' 0.5 %.$ .5' .*- .25

The standard error of mean for dehusking of "alayan Tall, "atag, "awa and+ellow were found to be very small. The working rate errors are .*2, .-0, 2.2% and

.' second per nut, respectively. Therefore, the confidence level of mechanical coconut

dehusker performance is high that shows its good reliability and functionality.

The analysis of variance between and within the coconut varieties were evaluated

and tabulated in Table 5. The purpose is to estimate the population mean from sample

mean for the dehusking working rate. The hypothesis set up is population mean betweenand within varieties are same for the working rate. Based on sample variance ratio test at

.5 significance level, there is no difference of working rate between and within

varieties. Therefore, there is insufficient evident to re@ect the hypothesis that the samplemean of working rate are same.

5


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Table (. Analysis of ariance on 4oconut ;ehusking "achine in :peration #ut sec /2(

=ource of

ariation

=um of

=7uare

;egree of

reedom

"ean of

=7uare

4alculated

Tabulated

8/alue

Betweenarieties

%$.$ 0 2-.0- .52 %.-5 .$*

?ithinarieties

-*%-.- %$ 0%.2'

Total -**5.*0 %2%

Table -. shows the efficiency of non/broken nut during the dehusking test.

"alayan Tall, "atag, "awa and +ellow ;warf were tested for 55, 5%, 5 and 5%coconuts. The broken number after dehusking were found , $, 2' and %', respectively.

?ith that the non/broken efficiency were calculated of $0, '0, ** and - &.

Table ). >fficiency of on/Broken ut after ;ehusking #&(

"alayan Tall "atag "awa +ellow ;warf

Total Test

#o(

55 5% 5 5%

Broken #o( $ 2' %'

>fficiency #&( $0 '0 ** -

The consumption of petrol was observed during the dehusking test. The mean fuel

consumption for hydraulic pressure of 05, and - 8=6 were found .5 , .-2 and .*-

liter per hour, respectively. Higher hydraulic pressure gives higher rotational of rollerwith spikes in order to dehusk the coconut more faster. However, the higher hydraulicpressure re7uires more fuel as compared the lower pressure. Hydraulic pressure of 05 8=6

was used through out the coconut dehusking tests. Table *. shows the effect of hydraulic

pressure on fuel consumption during the dehusking tests.

Table .>ffect of Hydraulic 8ressure on uel 4onsumption #liter hr/2(

=tatistics o "in "a "ean ariance =td.

deviation

=td.

>rror ofmean

05 8=6 2% .5% .5- .5 .2 .2 .0 8=6 2% .5$ .-% .-2 .2 .2 .0

- 8=6 2% .*5 .** .*- .5 .2 .%

4omparison between machine and manual dehusking rate were tabulated in Table'. The mean dehusking for machine and manual were found *.*' and 0-.% second to

dehusk a coconut, respectively. 6n addition, the standard error of mean for machine

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dehusking is smaller as compare to manual dehusking. The errors are .*2 and 2.2,

respectively. Therefore, manual dehusking is not reliable and consuming more time.

Table +."anual ;ehusking ersus "achine ;ehusking for "alayan Tall 4oconut #=ec.ut/2(

;escriptive=tatistics o "in "a "ean ariance =td.deviation =td.>rror of

mean

"achine

;ehusking

55 . 0. *.*' %*.-% 5.%- .*2

"anual

;ehusking

2 0% 5 0-.% 2%. 0.* 2.2

The analysis of variance machine and manual dehusking of "alayan Tall

4oconuts were evaluated and tabulated in Table $. The purpose is to estimate thepopulation variance from sample for the dehusking working rate. The hypothesis is

population variance is same for the dehusking working rate. Based on sample varianceratio test at .5 significance level, there is no difference of working rate betweenmachine and manual dehusking. Therefore, there is insufficient evident to re@ect the

hypothesis that the sample variance of working rate are same.

Table . ariance Test between ;ehusking and "anual for "alayan Tall

"achine ;ehusking "anual ;ehusking

"ean *.*' 0-.%

ariance %*.-% 2%.

:bservations 55 2

;egree of reedom 5 $ calculated %.%$

tabulated %.'

Based on the no significance difference of sample variance for the machine and

manual dehusking working rate, the test of any difference in population means wereevaluated in Table 2. By using pool variance to estimate the hypothesis that there is no

difference between population mean of machine and manual dehusking working rate.

Based on the evaluation at .5 significance level, there is sufficient evidence to re@ectthe hypothesis that means there is difference in the sample mean to the estimated

population mean. Therefore, the working rate of machine dehusking rate is more efficient

and higher working rate as compared to manual dehusking. "anual and machinedehusking takes 0-.% and *.*' second to dehusk a coconut, respectively.

*


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Table 1-. "ean Test between ;ehusking and "anual for "alayan Tall

"anual ;ehusking ;ehusking "achine

"ean 0-.% *.*'ariance 2%. %*.-2

:bservations 2 55

;egree of reedom -0

t/ calculated 2-.%-

t/ tabulated %.2

The cost benefit analysis for the mechanical and manual coconut dehusking are

tabulated in Table 22. 6t was found that the working rate for a single dehusking ofmachine and manual are .50 cent nut/2 and .5- cent nut/2, respectively. 6t is

estimated that the payback period for investment of coconut dehusker machine is less

than one year with capacity of dehusking of one million coconuts. The advantages ofcoconut dehusking machine is less dependence on labor, less dehusking time, high

working rate, high efficiency, more reliable, safety to operator, cost/effective, 7uality

product and profitable as compared to manual dehusking.

Table 11. 4ost benefit of "echanical 4oconut ;ehusking "achine

6tem 3" #cost(

A. 4apital 4ost Analysis

4apital cost 2,.

>conomic life span * years=crap value %,.

?ork rate 0 nuts1hour

Annual usage % hours8etrol usage %.* lit1hour

8etrol cost 2.01lit

Cabor cost %.1hour Hydraulic oil cost '.1lit

6nterest rate *&

B. ied 4ost Analysis

;epreciation 22%.'-6nterest %.

3epair D maintenance 5.Total %-%.-1years

ied cost1hour 2.021hour

4. ariable 4ost Analysis

uel 0.5-

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Cabor %.

Cubricant .'

Total1hr 5.-Total operation cost 25.$5

4oconut market price 2.1nut

8rofit cost1hour 0.4oconut field price #none process( .1coconut

Buying price coconuts 2%.

Transportation cost 5.

;. ;ehusking 4ost

"anual dehusking rate .5- 4ent ut/2

"achine ;ehusking rate .50 4ent ut/2

onclusion

"echanical 4oconut dehusker is necessary to replace the manual dehusking

method. "echanical dehusker was found less dependent on labor re7uirement, less timeconsuming during the dehusking, higher working rate, higher efficiency, more reliable,

more safety to operator, cost/effective, high 7uality end product and more profitable as

compared to manual dehusking. 6t was found that time taken to dehusk one coconutranges from * to ' seconds, which varies according the type of coconut variety used. The

optimum efficiency of the machine was $%.5&, which was obtained using "alayan Tall

coconuts while the lowest efficiency was -& using the +ellow ;warf coconuts. or the

cost analysis, it was calculated that the payback period of the machine is less than oneyear, with a production of 2 million coconuts. The dehusking rate of the machine was

.50 sen1coconut while the manual dehusking rate was .5- sen1coconut. 6t was shown

that this machine is efficient, cost/effective, durable and reliable.The dehusker machinewas also found stable, reliable, and durable less maintenance, technically feasible and

economically viable.

Ackno"ledgment

The author would like to thank to 6r. ;r. 3izuwan Eamaruddin and all staff and

individuals whom are direct or indirectly involved in the preparation of this paper.

%eferences

2. Anon. "anual ;ehusking ?orking 3ate at Eelantan, 8erak, Terengganu and

=elangor.

%. Abdullah,H. and


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0. =ukra,A.B.#2$$5( ;esign and performance of mobile machine for dehusking

coconut."A3;6 report no!2*$.

. Titmus, 3.?. and Hickish.#2$%$(. 4oconut husking machine. F.=. 8at.2*%/*0$.

Aug.20.

5. Toh, T.=. and Tan, +.8.#2$'(. FpGs coconut dehusking machine paper presented

at the conference on cocoa Dcoconut progress and outlook. Euala Cumpur.

Appendi/ 1.

2


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0igure 1a. 0;/=chematic diagram of the "echanical;ehusking "achine

late 1. "anual ;ehusking late 2.=ide iew of the "achine

22

petrolengine

Hydraulictank

Hydraulicpump

Galvanizedtrough Main frame

Operation

handle

Spikerollers

Safety frame

Handle


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late & eeding into the "achine late '. ;ehusking in :peration

3emarks!

2. The reference in the article #in yellow( is not listed in the reference list. 8lease

insert into the reference list. Thank you.

%. 8lease send us back as soon as possible but not later than *th;ec %$.

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