PENANGANAN IKAN DI KAPAL.docx

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PENANGANAN IKAN DI KAPAL

Thursday, November 07, 2013

Thursday, November 07, 2013 Penanganan Hasil PerikananPenanganan Hasil Perikanan,,Pengolahan Hasil PerikananPengolahan Hasil Perikanan No commentsNo comments

Produk perikanan merupakan salah satu enis pangan yang perlu mendapat perhatian terkait dengan keamanan

pangan! "engingat di satu sisi, #ndonesia merupakan negara maritim terbesar di $sia Tenggara sehingga sektor

perika

perikanan nan memegamemegang ng peranaperanan n pentinpenting g dalam perekonomiadalam perekonomian n nasionnasional! al! TTererutama dalam utama dalam penyepenyediaan diaan lapanglapanganan

kera, sumber pendapatan nelayan dan sumber devisa negara! %elain itu, produk perikanan uga merupakan

sumber protein he&ani yang dibutuhkan oleh manusia! Namun di sisi lain, produk perikanan dapat menadi

media perantara bagi bakteri patogen dan parasit yang dapat mengin'eksi manusia!

Penanganan ikan di atas kapal adalah segala upaya terhadap hasil tangkapan di kapal mulai dari tindakan a&al

sampai dengan penyimpanan yang bertuuan menaga mutu ikan sesuai dengan standar yang diinginkan! "utu

ikan tidak dapat diperbaiki tetapi hanya dapat dipertahankan! (erusakan atau penurunan mutu ikan dapat teradi

segera setelah ikan mengalami kematian, peristi&a ini teradi karena mekanisme pertahanan normal ikan terhenti

setelah ikan mengalami kematian! $dapun penyebab kerusakan ikan adalah bakteri, ensim dan reaksi kimia

yang terdapat didalam tubuh ikan maupun lingkungan dimana ikan berada! )ntuk menaga mutu ikan hasil

tangkapan, maka perlu penanganan yang baik seak ikan diangkat dari alat tangkap, selama penyimpanan, dan

pem

pembonbongkagkaranrannyanya, , sehsehingingga ga ikan ikan dapdapat at samsampai pai dikdikonsonsumen dengan umen dengan mutmutu u yanyang g baibaik k dan dan amaaman n untuntukuk

dikonsumsi!

PENANGANAN IKAN DIATAS DEK

*antai geladak dan setiap alat yang

*antai geladak dan setiap alat yang di pakai dalam penanganan ikan segar harus di bedi pakai dalam penanganan ikan segar harus di bersihkan sebelum di pakai!rsihkan sebelum di pakai!

%et

%etelaelah h dindinaikkaikkan an ke ke kapkapal, al, ikika a keakeadaadaan n memmemungungkinkinkan kan ikaikan n segsegera era disdisianiangi gi +di+dikelkeluaruarkan kan isi isi perperut ut dandan

insangnya kemudian dicuci bersih dengan air laut! )mumnya penyiangan hanya di lakukan terhadap ikan-ikan

yang berukuran besar. ikan-ikan kecil seperti lemuru dan kembung tidak praktis untuk di siangi di kapal!

Pencucian dilakukan dengan menggunakan air laut! %isa-sisa darah dan sisa-sisa isi perut dihilangkan, demikian

pula lendir-lendir yang ada! %elanutnya ika keadaan memungkinkan, ikan disortir menurut enis dan ukurannya

dan masing-ma

dan masing-masing disimpan sing disimpan di palka secara terpisah, baik didalam peti-pedi palka secara terpisah, baik didalam peti-peti maupun menggunati maupun menggunakan rak kan rak yangyang

terpisah!

Pencucian Ikan

Pencucian Ikan Hasil TangkapanHasil Tangkapan

%elama bekera di geladak, ikan perlu di lindungi dari sinar matahari dan huan, misalnya dengan memasang

tenda! #kan yang bertumpuk banyak karena menunggu disiangi dapat di tutup dengan terpal basah! /eladak

harus di cuci bersih setelah pekeraan pencucican ikan selesai sebelum hasil tangkapan yang lain dinaikkan ke

kapal!

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PENYIMPANAN DI PALKA

Palkah untuk menyimpan ikan segar harus dibersihkan sebelum dimasuki ikan! Pekeraan mengangkut ikan ke

dalam palka harus dilakukan dengan hati-hati agar tidak melukai ikan. melemparkan atau menuangkan ikan

kedalam palkah atau menginak ikan adalah praktek yang tidak baik!

Penyusunan ikan di palka dapat dilakukan dengan  cara, yaitu dengan menimbun +bulking, dengan bersusun

lap

lapis is menmengguggunakanakan n rak rak   sekasekat t datdatar ar +sh+shel'el'vinving, g, dendengan gan menmengguggunakanakan n petpeti-pi-peti eti +bo+boinging, , dan dan dendengangan

merendam ikan di dalam air dingin!

Penampang Palka Pada Kapal Ikan Penampang Palka Pada Kapal Ikan

A. Menimbun Ikan di Palka (

A. Menimbun Ikan di Palka (Bulking Bulking ))

a

ang dimaksud dengan menimbun ng dimaksud dengan menimbun ialah menumpuk ikan di lantai ialah menumpuk ikan di lantai palka tanpa menggunakan penyekat datar ataupalka tanpa menggunakan penyekat datar atau

peti! 4ara ini pada umumnya dilakukan dikapal ikan yang kecil dan palkanya rendah! 5asar palka terlebih dahulu

dilapisi es setebal 61 cm +atau lebih tebal ika dinding palka tidak diisolasi! #kan ditumpuk di atas lapisan es itu

setebal 10-12 cm. di atasnya diberi lapisan es lagi, kemudian lapisan ikan. demikian seterusnya sampai tingginya

cukup. lapisan paling atas adalah lapisan es!

Tinggi timbunan ikan sebaiknya tidak melebihi 80 cm! Penimbuanan yang lebih tinggi lagi dapat merusak ikan

pada lapisan yang di ba&ah, karena menerima tekanan yang cukup besar! 9iasanya setiap 1 ton ikan yang

disimpan di palka dengan cara peni

disimpan di palka dengan cara penimbunan memerlukan ruang palka yang bermbunan memerlukan ruang palka yang bervolume volume 2- 2, m32- 2, m3

Penyimpanan Ikan Dalam Palka Dengan Cara

Penyimpanan Ikan Dalam Palka Dengan Cara MenimbunMenimbun B. Menyimpan Beruun Lapi (

B. Menyimpan Beruun Lapi (Shelfing Shelfing ))

4ara penyimpanan ini umumnya di lakukan di kapal ikan yang palkanya cukup besar dengan tinggi palka :10

cm! Palka disiapkan dengan konstruksi khusus; di lengkapi dengan rak-rak vertikal dan horisontal yang hidup

+dapat di lepas! %ekat-sekat vertikal berarak 1 meter atau kurang, sedangkan sekat-sekat horisontal berarak

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20-3 cm! 9iasanya rak-rak itu disusun membuur, di sisi kiri dan kanan, sedang ditengah-tengahnya dipakai

seb

sebagaagai i lorlorongong! ! #ka#kan n disdisusuusun n di di ataatas s rakrak-ra-rak k horhorisoisontantal l dendengan gan disdiselielimutmuti i es! es! #ka#kan n yanyang g besbesar ar di di susususunn

membuur!

Pemakaian rak-rak di palka ini dapat menghasilkan ikan yang lebih baik karena ikan tidak terlalu banyak

menerima tekanan, tetapi diperlukan penanganan yang lebih banyak dan di perlukan ruangan yang lebih besar!

Tiap 1 ton

Tiap 1 ton ikan memerlukan ruang palkah 3-, ikan memerlukan ruang palkah 3-, m3 m3 tergantung dari ukuran ikan!tergantung dari ukuran ikan!

!. Menyimpan Ikan Di Palka Den"an Pe#i (

!. Menyimpan Ikan Di Palka Den"an Pe#i (Boxing Boxing ))

Peti untuk menyimpan ikan di kapal umumnya dibuat dari kayu atau plastik yang dirancang dengan ukuran yang

disesuaikan dengan kemampuan manusia setempat, yaitu 20-30 kg! )kuran yang labih besar dirancang untuk

diangkut oleh 2 orang! Peti dari plastik lebih mudah dibersihkan! Peti kayu hendaknya dibuat dari papan yang

diserut halus dan dengan sudut-sudut yang mudah di bersihkan!

Cool Box

Cool Box_{Yang Ditempatkan di Kapal}_{Yang Ditempatkan di Kapal}

#kan di susun di dalam peti dengan di campur dan di selimuti es! (arena peti-peti itu akan di tumpuk di palka,

maka pengisian ikan es tidak boleh melebihi permukaan peti agar ikan tidak tertekan peti diatasnya! 5engan

cara penyimpanan ini, tiap 1 ton ikan memerlukan ruang palka 2, - 3 m3!

D. Merendam Ikan Dalam Air Din"in

Palka ikan dibangun berupa tangki-tangki khusus untuk menampung air laut yang di dinginkan! #kan direndam di

dal

dalam am tantangkigki-ta-tangki ngki tertersebsebut ut samsampai pai saasaat t dibdibongongkar kar di di pelpelabuabuhanhan! ! <ik<ika a dildilakuakukan kan dendengan gan baibaik, k, carcara a iniini

menghasilkan ikan dengan mutu yang lebih baik. pendinginan berlangsung lebih cepat, ikan tidak menerima

tekanan! #kan-ikan besar seperti tuna dan ikan-ikan kecil seperti lemuru dan kembung dapat diperlakukan

dengan cara ini!

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$ir laut

$ir laut didinginkan dengan didinginkan dengan mesin pendingin mesin pendingin yang sudah yang sudah mulai dialankan mulai dialankan seak kapal seak kapal meninggalkan pelabuhanmeninggalkan pelabuhan

menuu daerah penangkapan, dengan maksud agar air sudah cukup dingin pada &aktu hasil tangkapan pertama

dinaikkan! %ering kali tangki-tangki diisi dengan seumlah es sebelum kapal meninggalkan pelabuhan!

Description: Description:

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OPTIMASI PENGGANTIAN FLUIDA KERJA FREON-22

DENGAN HIDROKARON PADA SISTEM PENDINGIN RUANG

MUAT

MUAT KAPALIKAN

KAPALIKAN !STUDI

!STUDI KASUS

KASUS KM"

KM" MINA

MINA JA#A

JA#A

�

KAPAL

IKAN $%2GT&

Optimasi penggantian fluida kerja (refrigeran !re"n#$$ pada sistem pendingin ruang muat kapal ikan dilakukan untuk

pemili%an te

pemili%an ter%adap rer%adap refrigeran %ifrigeran %idr"karb"n dr"karb"n berkenaberkenaan dengaan dengan usa%a unn usa%a untuk mengtuk mengurangi damurangi dampak kerupak kerusakan lingsakan lingkungan ykungan yangang

diakibatkan penggunaan refrigeran %al"carb"n (&#$$' Penelitian ini dilakukan dengan analisa term"dinamika se%ingga

ditemukan secara teknis ba%a refrigeran %idr"karb"n murni &#$)* (dan dengan %idr"karb"n campuran MC#$$ dan HC&#

$$ memiliki sifat teknis yang lebi% baik ditentukan dengan k"efisien prestasi (COP yang lebi% tinggi yaitu sekitar +,**

$$ memiliki sifat teknis yang lebi% baik ditentukan dengan k"efisien prestasi (COP yang lebi% tinggi yaitu sekitar +,** ��

+,$- lebi% baik dari &#$$ yaitu $,*) , analisa secara ek"n"mi di per"le% %asil ba%a penggantian dengan refrigeran

%idr"karb"n dapat meng%emat sekitar .*/ jumla% refrigeran yang digunakan sekaligus juga dapat memperpanjang umur

k"mpres"r dikarenakan pengurangan kegiatan kerja lebi%0paksa pada k"mpres"r' Penelitian ini juga tela% dilakukan analisa

ter%adap sifat flammability (kemampuan terbakar refrigeran Hidr"karb"n dimana pr"sedur kerja dan standar penggunaan

refrigeran ini %arus dilakukan "le% pi%ak yang berk"mpeten dan berpengalaman' Hasil dari penelitian ini disarankan untuk

dijadikan acuan sebagai ba%an pertimbangan dalam penggantian0penggunaan refrigeran %idr"karb"n pada sistem pendingin

ruang muat kapal ikan ataupun ruang muat kapal#kapal lainnya

1.

1. IrIr. . AlaAlam Bm Baheaheraramsymsyah, ah, M.SM.Scc 2.

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$i"ure %&

$i"ure %& Proposed layout and 'lo& plan 'or Proposed layout and 'lo& plan 'or =00 kgh medium and small shrimp=00 kgh medium and small shrimp processing plant

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$i"ure %'

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ale  * + *,, ale  * + *,,

$i"ure

%-$i"ure %- Proposed layout and 'lo& plan 'or Proposed layout and 'lo& plan 'or 2 tday hand-peeling shrimp processing2 tday hand-peeling shrimp processing plant

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$i"ure &,

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$i"ure &*

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$i"ure &

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Sourource:ce:OOAAII

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dallam am dadagiging ng iikan kan tterersebusebutt, , didimmanana a papada da suhu suhu kamkamar ar baktbaktereri i dadan n mmiikrkroooorrganganiismsme e dadapapat t beberrkemkembanbangbgbiiakak

de dennggaanncceeppaatt..OOlleehhkkaarreennaaiittuuppaarraanneellaayyaannsseellaalluummeemmbbaawwaaeessuunnttuukkddiigguunnaakkaannmmeennddiinnggiinnkkaanniikkaanntteerrsseebbuutt ag agaarrtteettaappsseeggaarrppaalliinnggttiiddaakkhhaassiillttaannggkkaappaanntteerrsseebbuuttmmaassiihhbbaagguussddaannsseeggaarrssaammppaaiikkeeTTPPII((TTeemmppaatt P PeelleellaannggaannIIkkaann))uunnttuukkddiijjuuaall..CCaarraaiinniikkaaddaannggkkaallaattiiddaakkeeffeekkttiiffddaanneeﬁﬁssiiaannkkaarreennaauunnttuukkmmeemmbbaawwaaeessddiibbuuttuuhhkkaann w

waktaktu u yanyang g llamama a ((12 12 jjamam) ) sehisehingngga ga es es cepcepat at mmenencaicairr. . salsalah ah satsatu u cacarra a uuntntuk uk mmemempeperrttahahanankan kan mmututu u ddanan

kese keseggaarraanniikkaannddaappaattddiillaakkuukkaannddeennggaannmmeenneerraappkkaanntteekknnoollooggiirreeffrriiggeerraassiiyyaaiittuuddeennggaannmmeennuurruunnkkaannssuuhhuuiikkaann sece seceppaattmmuunnggkkiinnaaggaarraakkttiiﬁﬁttaassbbaakktteerriippeemmbbuussuukkddaappaatttteerrhhaammbbaatt..DDaannaattaassddaassaarriittuullaahhppeennuulliissmmeennggaammbbiill j juudduul l ttuuggaas s ““PPeerraannccaannggaan n SSiisstteem m PPeennddiinnggiin n IIkkaan n PPaadda a KKaappaal l NNeellaayyaan n DDeennggaan n KKaappaassiittaas s 2 2 TToonn” ” yyaanng g ddiigguunnaakkaann un unttuukkmmeennddiinnggiinnkkaanniikkaannhhaassiillttaannggkkaappaann..AAddaappuunnttuujjuuaannppeerreennccaannaaaanniinniiaaddaallaahhuunnttuukkmmeennddaappaattkkaannddeessaaiinn da darriirreeffrriiggeerraattoorryyaannggbbeerrbbeennttuukkbbooxxuunnttuukkmmeennddiinnggiinnkkaanniikkaannhhaassiillttaannggkkaappaannddaannuunnttuukkmmeennggeettaahhuuiiddiimmeennssii kom komppoonneennmmeessiinnrreeffrriiggeerraattoorryyaannggbbeerrbbeennttuukkbbooxxppeennddiinnggiinnddeennggaannkkaappaassiittaass22ttoonn..DDaallaammPPeerraannccaannggaannSSiisstteemm P PeennddiinnggiinnIIkkaannPPaaddaaKKaappaallNNeellaayyaannDDeennggaannKKaappaassiittaass22TToonnddeennggaannddaattaasseebbaaggaaiibbeerriikkuutt::SSiissttiimmrreeffrriiggeerraassii ad adaallaahhVVaappoorrCCoommpprreessssiioonnRReeffrriiggeerraattiioonnSSiisstteemm..,,DDaattaarruuaannggppeennddiinnggiinnuunnttuukkppaannjjaanngg==22mm,,lleebbaarr==11,,55mm,, t

tiinnggggii==11mm,,tteemmppeerraattuurrlluuaarrrruuaannggaann2277°°CC,,tteemmppeerraattuurrddaallaammrruuaannggaann--22°°CC, , babahan han rruauangangan n = = bbahahan an ddiindindingng

A Alluummiinniiuummddiitteemmppeellppeennyyeekkaatt,,bbaahhaannppeellaappiisskkaayyuukkeerraassddaannﬁﬁbbeerrggllaassss,,AAlluummiinniiuummddiitteemmppeellppeennyyeekkaatt,, r reeffrriiggeerraannttyyaannggddiigguunnaakkaannaaddaallaahhRR--2222,,ddiimmaannaaddaattaakkoommpprreessoorraaddaallaahh::jjeenniisskkoommpprreessoorrttoorraakk,,bbeebbaann pe pennddiinnggiinnaann==7700,,777766kkWW,,ddaayyaakkoommpprreessoorr==11,,6688kkWW..JJeenniissKKoonnddeennssoorrttaabbuunnggbbeerrppeennddiinnggiinnaaiirr,,ssuussuunnaannppiippaa ho horriizzoonnttaall,,bbaahhaannppiippaatteemmbbaaggaattiippee--KK,,ddiiaammeetteerrlluuaarrppiippaa==00,,00009955mm,,ddiiaammeetteerrddaallaammppiippaa==00,,00007788mmtteebbaall pi pippaa==00,,0000008899mm,,jjuummllaahhppiippaa4422,,ppaannjjaannggppiippaa22,,4499mm,,lluuaassppeerrmmuukkaaaannppaannaass==33,,1122mm22..UUnnttuukkeevvaappoorraattoorrjjeenniiss eva evappoorraattoorrkkeerriinnggSSuussuunnaannppiippaa,,ssttaaggggeerreedd((zziigg--zzaagg)),,bbaahhaannppiippaatteemmbbaaggaattiippee--KK,,ddiiaammeetteerrlluuaarrppiippaa== 0, 0,00009955,,ddiiaammiiaammeetteerrddaallaammppiippaa==00,,00007788mm,,tteebbaallppiippaa==00,,0000008899mm,,jjuummbbllaahhppiippaa4422,,ppaannjjaannggppiippaa==1111,,1111mm,, l luuaassppeerrmmuukkaaaannppaannaass==1133,,9922mm22,,uunnttuukkkkaattuuppeekkssppaannssiiyyaannggddiigguunnaakkaannaaddaallaahhkkaattuupptteerrmmoossttaattiiss..

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@e'rigeration is a process &hereby heat is removed and reected, and this can be @e'rigeration is a process &hereby heat is removed and reected, and this can be achieved by any o' the 'ollo&ing methods;

achieved by any o' the 'ollo&ing methods; Aapour compression Aapour compression Aapour absorption Aapour absorption $ir cycle $ir cycle Thermoelectric Thermoelectric

The most &idely used is the vapour compressions system and only in eceptional The most &idely used is the vapour compressions system and only in eceptional circumstances &ould another method be contemplated in a

circumstances &ould another method be contemplated in a modern 'ish processingmodern 'ish processing installation! Bven applications &hich apparently do not use this method, such as chilling installation! Bven applications &hich apparently do not use this method, such as chilling &ith ice or 'ree?ing &ith

&ith ice or 'ree?ing &ith a cryogenic liCuid, are indirect uses o' the vapour compressiona cryogenic liCuid, are indirect uses o' the vapour compression system, since such a system &ould have been used to make the ice or

system, since such a system &ould have been used to make the ice or liCui'y the gas!liCui'y the gas! Aa

Aapour absorption is still pour absorption is still used in some domestic re'rigerators and used in some domestic re'rigerators and there has been athere has been a revival o' interest in this

revival o' interest in this system 'or some commercial applications since it can besystem 'or some commercial applications since it can be operated 'rom a &aste

operated 'rom a &aste heat source! The absorption system does not reCuire heat source! The absorption system does not reCuire mechanicalmechanical po&er, there

po&er, there'ore, there is no reCuirement 'or an 'ore, there is no reCuirement 'or an electrical supply o' direct drive engine!electrical supply o' direct drive engine! The only reCuirement is an input o' heat, t

The only reCuirement is an input o' heat, there'ore, this type o' re'rigeration system mayhere'ore, this type o' re'rigeration system may be considered 'or limited applications in situations &here a heat source is cheaper or be considered 'or limited applications in situations &here a heat source is cheaper or more readily available than an electrical or mechanical drive!

more readily available than an electrical or mechanical drive! The air cycle system is inherently sa'e and is

The air cycle system is inherently sa'e and is no& almost eclusively used 'or cabinno& almost eclusively used 'or cabin cooling in aircra't!

cooling in aircra't!

The thermoelectric cooling system is con'ined to use &ith applications &hich reCuire very The thermoelectric cooling system is con'ined to use &ith applications &hich reCuire very small re'rigeration e''ects, such as

small re'rigeration e''ects, such as instrument cooling and laboratory use!instrument cooling and laboratory use!

Dther methods have been used, but they either have not been suitable 'or commercial Dther methods have been used, but they either have not been suitable 'or commercial operations or have no& become obsolete 'or a variety o' other reasons!

operations or have no& become obsolete 'or a variety o' other reasons!

4ryogenic re'rigeration, as mentioned above, is an indirect application o' the vapour 4ryogenic re'rigeration, as mentioned above, is an indirect application o' the vapour compression system and liCuid nitrogen and liCui'ied

compression system and liCuid nitrogen and liCui'ied or solid carbon dioide or solid carbon dioide cryogeniccryogenic systems have a limited application in 'ish processing!

systems have a limited application in 'ish processing! $ high

$ high purity 'luorocarbon re'rpurity 'luorocarbon re'rigerant, @12, is also used igerant, @12, is also used in immersion or spray cooin immersion or spray coolingling systems, but again there is only a l

systems, but again there is only a limited use in the 'ishing industry!imited use in the 'ishing industry!

3.1.1.2 Refrigerants:

$lthough there are a &

$lthough there are a &ide range o' re'rigerants avide range o' re'rigerants available, many have pailable, many have properties &hichroperties &hich suit them 'or special purpose applications only! The re'rigerants listed in Table 12 are suit them 'or special purpose applications only! The re'rigerants listed in Table 12 are those commonly used in the

those commonly used in the 'ish industry! and a number o' secondary re'rigerants, such'ish industry! and a number o' secondary re'rigerants, such as ethyl alcohol, methyl alcohol, glycol solutions and saltsugar solutions, have also a as ethyl alcohol, methyl alcohol, glycol solutions and saltsugar solutions, have also a limited use!

(14)

The choice o' re'rigerant is usually based on technical reCuirements, but other The choice o' re'rigerant is usually based on technical reCuirements, but other considerations, such as sa'ety, high costs or import controls, may

considerations, such as sa'ety, high costs or import controls, may result in a result in a compromisecompromise choice being made!

choice being made!

Table *

Table * @e'rigerants @e'rigerants

D

Deeii""nnaa##ii//nn !!00eemmiiaal l nnaammee TTrraadde e nnaammee

P

Prriimmaarryy @@1122 55iicchhlloorrooddii''lluuoorroommeetthhaannee >>rreeoon n 1122, , $$rrccttoon n 1122, , ##cceeoon n 1122

@

@2222 44hhlloorrooddii''lluuoorroommeetthhaannee >>rreeoon n 2222, , $$rrccttoon n 2222, , ##cceeoon n 2222

@02

@02 $?eo$?eotroptrope oe o' @22 ' @22 and and @1@111 +4hloropenta'luoroethane +4hloropenta'luoroethane

>reon 02, $rcton 02, #ceon 02 >reon 02, $rcton 02, #ceon 02

@7

@71717 $n$nhydhydrourous s ammammononiaia

%econdar %econdar yy

4alcium chloride brine 4alcium chloride brine

%odium chloride brine %odium chloride brine

T

Trriicchhlloorrooeetthhyylleennee TTrriikklloonneeE E $$

+Triklone is a trade mark o' #NBD% +Triklone is a trade mark o' #NBD% 4hlor *imited

4hlor *imited

The cost o' re'rigerants depends on the unit Cuantity +si?e o' c

The cost o' re'rigerants depends on the unit Cuantity +si?e o' c ylinder and the Cuantityylinder and the Cuantity +&eight ordered! The costs listed in

+&eight ordered! The costs listed in TTaable 13 are ble 13 are 1F=3 )( values 'or 1F=3 )( values 'or the Cuantities andthe Cuantities and unit containers speci'ied! #nitial costs may also include an additional deposit 'or the unit containers speci'ied! #nitial costs may also include an additional deposit 'or the re'rigerant containers!

re'rigerant containers!

"any o' the physical properties o' a re'rigerant are important to

"any o' the physical properties o' a re'rigerant are important to the design engineer andthe design engineer and this in'ormation is no& readily available in

this in'ormation is no& readily available in suppliers catalogues and in tet books! Dnlysuppliers catalogues and in tet books! Dnly some o' their attributes and likely applications are, there'ore, given in

some o' their attributes and likely applications are, there'ore, given in the 'ollo&ingthe 'ollo&ing notes!

notes! i!

i! @e'@e'rigrigeraerant 12 hnt 12 has a ras a relaelativtively lely lo& lao& latentent heat heat valt value aue and thnd this is ais is an adn advanvantagtage ine in small machines since the higher 'lo& rates reCuired allo& 'or

small machines since the higher 'lo& rates reCuired allo& 'or better control! @12better control! @12 is usable do&n to lo&er temperatures, but belo& -2F!=G4 negative pressures &ill is usable do&n to lo&er temperatures, but belo& -2F!=G4 negative pressures &ill prevail on the lo& pressure side o' the

prevail on the lo& pressure side o' the system &ith potential problems resultingsystem &ith potential problems resulting 'rom leaks o' air and moisture! @12 is completely miscible &ith oil at all likely 'rom leaks o' air and moisture! @12 is completely miscible &ith oil at all likely operating temperatures, there'ore, oil return systems are

operating temperatures, there'ore, oil return systems are relativelyrelatively uncomplicated!

(15)

$i"ure

-$i"ure - 9asic mechanical re'rigeration system 9asic mechanical re'rigeration system

@e'rigeration is there'ore a continuous process &ith the re'rigerant changing 'rom liCuid @e'rigeration is there'ore a continuous process &ith the re'rigerant changing 'rom liCuid to gas, to liCuid, as

to gas, to liCuid, as heat is added and lost!heat is added and lost!

>our basic systems using mechanical re'rigeration are used 'or 'ish 'ree?ing and cold >our basic systems using mechanical re'rigeration are used 'or 'ish 'ree?ing and cold storage, and these are sho&n

storage, and these are sho&n diagrammatically in >igures 10, 11, 12 and 13, &ith diagrammatically in >igures 10, 11, 12 and 13, &ith notesnotes on the type o' application &here they are likel

on the type o' application &here they are likely to be used!y to be used! i!

i! 5ry e5ry eppansansion sion sysystemtem; )se; )sed in ad in all the ll the smasmall insll instatallatllationions ans and in ind in instastallallatiotionsns &here there are not likely to

&here there are not likely to be problems &ith re'rigeration distribution or thebe problems &ith re'rigeration distribution or the temperature 'luctuations induced by the cycling o'

temperature 'luctuations induced by the cycling o' the thermostatic epansionthe thermostatic epansion valve!

valve!

$i"ure *,

(16)

ii!

ii! >lo>loodeoded sysd system &tem &ith naith naturtural ciral circulculatiation; Thon; The 'loe 'loodeoded sysd system gtem giveives a betts a better heer heatat trans'er than the dry epansion system since there is more liCuid present in trans'er than the dry epansion system since there is more liCuid present in thethe cooler! $

cooler! $ 'looded system also 'looded system also ensures better re'rigerant distribution, ensures better re'rigerant distribution, there'ore,there'ore, they are appropriate &hen there are a number o' parallel circuits 'or

they are appropriate &hen there are a number o' parallel circuits 'or thethe re'rigerant 'lo&!

re'rigerant 'lo&!

The reservoir in a natural circulation system is situated above the coolers, The reservoir in a natural circulation system is situated above the coolers, there'ore, it is not suitable 'or

there'ore, it is not suitable 'or &idely separated multiple units!&idely separated multiple units! The most appropriate application likely in 'ish 'ree?ing is &ith

The most appropriate application likely in 'ish 'ree?ing is &ith hori?ontal platehori?ontal plate 'ree?ers &hich are single units &ith a

'ree?ers &hich are single units &ith a number o' parallel circuits 'ormed by thenumber o' parallel circuits 'ormed by the 'ree?er plates!

'ree?er plates!

$i"ure **

$i"ure ** 5iagram o' 5iagram o' natural convection 'looded re'rigeration systemnatural convection 'looded re'rigeration system iii

iii!! >lo>loodeoded sysd system &tem &ith puith pump cimp circurculatlation; Puion; Pump cimp circurculatlation aion allo&llo&s a 'loos a 'looded sded sysystemtem to be used &ith its

to be used &ith its advantage in good heat trans'er and re'rigerant distribution, inadvantage in good heat trans'er and re'rigerant distribution, in a multiple unit system &ith the

a multiple unit system &ith the lo&-temperature liCuid reservoir situated, i'lo&-temperature liCuid reservoir situated, i' necessary

necessary, a&ay 'rom the , a&ay 'rom the immediate vicinity o' immediate vicinity o' the coolers!the coolers! $n eample o' this kind o

$n eample o' this kind o' application is a numb' application is a number o' vertical plate 'ree?er uer o' vertical plate 'ree?er unitsnits supplied 'rom a common liCuid receiver sited in a

supplied 'rom a common liCuid receiver sited in a separate engine room!separate engine room!

$i"ure *

(17)

iv

iv!! %ec%econdondary reary re'ri'rigergerant syant systestem; Thim; This has als has all the advl the advantantageages o' a pumps o' a pump-ci-circurculatlateded 'looded system &ithout the need to have a pipe&ork and cooler system suitable 'looded system &ithout the need to have a pipe&ork and cooler system suitable 'or the higher

'or the higher re'rigerant pressures! The system &ould there'ore be appropriatere'rigerant pressures! The system &ould there'ore be appropriate &hen there is a high potential 'or

&hen there is a high potential 'or leaks such as on a 'ishing vessel! The primaryleaks such as on a 'ishing vessel! The primary re'rigerant is con'ined to

re'rigerant is con'ined to the condenser unit and heat the condenser unit and heat echanger onlyechanger only, and this, and this may be located in a separate engine room!

may be located in a separate engine room! $ sec

$ secondary system aondary system also avoids the potenlso avoids the potential problems that may restial problems that may result 'romult 'rom having a large charge o' a volatile re'rigerant in

having a large charge o' a volatile re'rigerant in a &orking space such as aa &orking space such as a 'actory 'loor or in a

'actory 'loor or in a cold store +>igure 13!cold store +>igure 13!

$i"ure *1

$i"ure *1 5iagram o' 5iagram o' secondary re'rigeration systemsecondary re'rigeration system

3.1.2.5 Refrigeration, instrumentation and controls:

#n order to regulate the 'lo&

#n order to regulate the 'lo& o' re'rigerant, maintain design operating conditions ando' re'rigerant, maintain design operating conditions and allo& eCuipment to be

allo& eCuipment to be operated sa'ely and economically, a number o' controls are usedoperated sa'ely and economically, a number o' controls are used &ith re'rigeration systems!

&ith re'rigeration systems!

The compleity o' a control system usually relates to the si?e

The compleity o' a control system usually relates to the si?e o' the plant, ranging 'romo' the plant, ranging 'rom no more than a capillary throttling device to

no more than a capillary throttling device to regulate re'rigerant 'lo& in a small hermeticregulate re'rigerant 'lo& in a small hermetic system to comple, computer-based control systems 'or the

system to comple, computer-based control systems 'or the more recently installedmore recently installed large, multiple unit systems!

large, multiple unit systems!

%ome o' the controls used 'or the si?e

%ome o' the controls used 'or the si?e o' plant more likely in o' plant more likely in the 'ishing industry arethe 'ishing industry are listed belo&! $

listed belo&! $ brie' indication is brie' indication is given o' the given o' the reCuirement! 'unction! &hether spares arereCuirement! 'unction! &hether spares are advisable and the likely cost!

advisable and the likely cost! ii!! PPrreessssuurre e ggaauuggeess

Pressure gauges are used to i

Pressure gauges are used to indicate plant-operating conditions and they are there'orendicate plant-operating conditions and they are there'ore use'ul 'or routine inspections and, also, &hen 'ault-'inding! /auges are normally

use'ul 'or routine inspections and, also, &hen 'ault-'inding! /auges are normally

positioned at the compressor to indicate pressures on the high and lo& pressure sides o' positioned at the compressor to indicate pressures on the high and lo& pressure sides o' the system &ith additional

the system &ith additional gauges, as necessarygauges, as necessary, to indicate the , to indicate the intermediate pressure inintermediate pressure in a t&o-stage system and the

(18)

additional gauge may be used in a larger system to indicate the

additional gauge may be used in a larger system to indicate the pressure at thepressure at the evaporator and, also, the pump delivery

evaporator and, also, the pump delivery pressure &hen a secondary re'rigerant is pressure &hen a secondary re'rigerant is used!used! To

To cover all these reCuirements, three di''erent pressure ranges may cover all these reCuirements, three di''erent pressure ranges may be reCuired, andbe reCuired, and although they are not essential 'or the plant operation, spares should be available since although they are not essential 'or the plant operation, spares should be available since a reliable gauge &ould

a reliable gauge &ould help to reduce both help to reduce both operational and maintenance costs!operational and maintenance costs! The cost o' gauges &ill vary bet&een )%

The cost o' gauges &ill vary bet&een )%  and )% 2! and )% 2! iiii!! TTeemmppeerraattuurre e ggaauuggeess

*ike pressure gauges, temperature gauges, or pocket thermometers, are used to *ike pressure gauges, temperature gauges, or pocket thermometers, are used to monitor plant-operating conditions and to assist &ith

monitor plant-operating conditions and to assist &ith 'ault-'inding! Thermometers used'ault-'inding! Thermometers used &ith the re'rigeration compressor are used to monitor temperatures at the same

&ith the re'rigeration compressor are used to monitor temperatures at the same positions as the re'rigerant pressure gauges since

positions as the re'rigerant pressure gauges since both readings are normally reCuiredboth readings are normally reCuired to assess the plant-operating condition!

to assess the plant-operating condition! $dditional temperature g

$dditional temperature gauges are also heauges are also help'ul to measure cooling &lp'ul to measure cooling &ater temperature,ater temperature, the temperature o' a secondary re'rigerant or the temperature o' a lo& pressure, primary the temperature o' a secondary re'rigerant or the temperature o' a lo& pressure, primary re'rigerant, liCuid

re'rigerant, liCuid reservoirreservoir!!

5ial gauges are also used to monitor the t

5ial gauges are also used to monitor the temperature in air-blast 'ree?ers, but 'or coldemperature in air-blast 'ree?ers, but 'or cold stores a recording thermometer is advisable since this in'ormation is o'ten reCuired 'or stores a recording thermometer is advisable since this in'ormation is o'ten reCuired 'or checking later!

checking later!

5ial thermometers cost bet&een )% 1 and )% 2! 5ial thermometers cost bet&een )% 1 and )% 2! %team thermometers cost bet&een )% 3 and )% =! %team thermometers cost bet&een )% 3 and )% =! 4ircular chart recorders cost about )% 30!

4ircular chart recorders cost about )% 30! $t least t&o temperature ra

$t least t&o temperature ranges are reCuired nges are reCuired to cover all these reCuto cover all these reCuirements, and theirements, and the availability o' spares is not normally critical

availability o' spares is not normally critical since thermometers can usually besince thermometers can usually be interchanged &ithout breaking into the system, or

interchanged &ithout breaking into the system, or a hand-held thermometer, used in ana hand-held thermometer, used in an appropriate &ay, can be substituted!

(19)

$i"ure

*-$i"ure *- Pressure and Pressure and temperature measurementemperature measurementt iiiiii!! @@ee''rriiggeerraannt 't 'lloo&&

4ontrol o' re'rigerant 'lo& is

4ontrol o' re'rigerant 'lo& is probably the most important control to be eerci?ed in aprobably the most important control to be eerci?ed in a re'rigeration system! The 'ollo&ing are 'our eamples o' control likely to be used; re'rigeration system! The 'ollo&ing are 'our eamples o' control likely to be used;

a!

a! Hand epHand epansioansion valve; $ n valve; $ valve &hivalve &hich accurch accurately conately controls the 'lo& o' re'rigtrols the 'lo& o' re'rigeranerant tot to eactly match the re'rigeration load! Hand epansion &ould only be used &hen eactly match the re'rigeration load! Hand epansion &ould only be used &hen the re'rigeration load is constant or the inertia o'

the re'rigeration load is constant or the inertia o' the system means that changesthe system means that changes &ould only be small and progress slo&ly. a l

&ould only be small and progress slo&ly. a large cold store &ith constantarge cold store &ith constant attendance is the type o' application suited to this method!

attendance is the type o' application suited to this method! Hand epansion valves are o'ten 'itted in parallel &ith other

Hand epansion valves are o'ten 'itted in parallel &ith other control devices socontrol devices so that they can be manually operated in the case o' a

that they can be manually operated in the case o' a 'ailure! 4ost )% 30-80,'ailure! 4ost )% 30-80, depending on si?e!

depending on si?e! b!

b! TherThermostamostatic epatic epansion vansion valve; Thlve; This is an automis is an automatic devatic device &hich giice &hich gives aves a modulated control o' re'rigerant 'lo& and it is

modulated control o' re'rigerant 'lo& and it is the most &idely used method &ith athe most &idely used method &ith a variety o' individual designs to

variety o' individual designs to suit particular reCuirements! The valve sensessuit particular reCuirements! The valve senses pressure and temperature at the evaporator and

pressure and temperature at the evaporator and uses the in'ormation to supplyuses the in'ormation to supply only su''icient liCuid re'rigerant to

only su''icient liCuid re'rigerant to match the evaporatorIs reCuirement!match the evaporatorIs reCuirement! Thermostatic epansion valve

Thermostatic epansion valves +tev are made in s +tev are made in a &ide range o' si?es anda &ide range o' si?es and models and the 'ollo&ing list &ill,

models and the 'ollo&ing list &ill, there'ore, only give an approimate indication o' there'ore, only give an approimate indication o' the likely cost!

the likely cost! )% 1 'or tev

)% 1 'or tev &ith capacity o' 1000 kcalh&ith capacity o' 1000 kcalh )% 0 'or tev &ith capacity o' F 000 kcalh )% 0 'or tev &ith capacity o' F 000 kcalh )% 13 'or tev &ith

)% 13 'or tev &ith capacity o' F0 000 kcalhcapacity o' F0 000 kcalh )% 10 'or tev &ith

)% 10 'or tev &ith capacity o' 18 000 kcalhcapacity o' 18 000 kcalh $ spa

$ spare valve should al&ayre valve should al&ays be available, but the inss be available, but the installation o' a hand eptallation o' a hand epansion by-ansion by-pass can be used 'or a short time

pass can be used 'or a short time in an emergencyin an emergency!! c!

c! *o& sid*o& side level coe level controntrol; This cal; This can be a mechn be a mechanicaanical or electrl or electrical devical device &hicice &hich ish is used to control the level o' l

used to control the level o' liCuid in the lo& pressure receiver o' a iCuid in the lo& pressure receiver o' a 'looded primary'looded primary re'rigerant system or the primary re'rigerant level in the

re'rigerant system or the primary re'rigerant level in the heat echanger o' aheat echanger o' a secondary re'rigeration system!

secondary re'rigeration system! The level control is essential to the

The level control is essential to the operation o' the system, there'ore, a spareoperation o' the system, there'ore, a spare should be available or, depending on the type

should be available or, depending on the type used, spares 'or the moreused, spares 'or the more vulnerable parts should be held!

vulnerable parts should be held! 4ost )% 200-30!4ost )% 200-30! d!

d! High preHigh pressurssure level coe level controntrol; This is a mel; This is a mechanchanical or eleical or electricactrical device &l device &hich ishich is designed to maintain a

designed to maintain a constant level in a constant level in a high-pressure liCuid receiver! #n ahigh-pressure liCuid receiver! #n a correctly charged 'looded system this &ill ensure the correct level o' re'rigerant i correctly charged 'looded system this &ill ensure the correct level o' re'rigerant i nn the lo&-pressure receiver or heat

the lo&-pressure receiver or heat echangerechanger! This type o' control ! This type o' control also ensuresalso ensures that the condenser is al&ays empty o' liCuid re'rigerant and thereby operates at that the condenser is al&ays empty o' liCuid re'rigerant and thereby operates at its design

(20)

iivv!! %%aa''eetty y ddeevviicceess

%a'ety devices come into t&o categories; those 'or protecting the eCuipment and those %a'ety devices come into t&o categories; those 'or protecting the eCuipment and those 'or the environment! "ost small units operate &ithout sa'ety devices since replacement 'or the environment! "ost small units operate &ithout sa'ety devices since replacement costs are lo&

costs are lo& and irreparable damage less likely! $and irreparable damage less likely! $lso, &ith lso, &ith smaller units, simplicity ismaller units, simplicity iss al&ays desirable! *arger units, ho&ever, 'rom about 20 hp

al&ays desirable! *arger units, ho&ever, 'rom about 20 hp and up&ards, &ould have oneand up&ards, &ould have one or more o' the 'ollo&ing devices;

or more o' the 'ollo&ing devices; a!

a! High preHigh pressurssure cut-oue cut-out; This limt; This limits the presits the pressure in the cosure in the condenndenser and otser and other parther partss o' the high pressure side o' this

o' the high pressure side o' this system thus avoiding the possibility o' damagesystem thus avoiding the possibility o' damage and overheating o' the re'rigerant oil! 4ost )%

and overheating o' the re'rigerant oil! 4ost )% 1-7!1-7! b!

b! *o& pres*o& pressure cutsure cut-out; T-out; This limithis limits the minimus the minimum pressm pressure at &hicure at &hich the evapoh the evaporatorrator and other parts o' the lo& pressure side o'

and other parts o' the lo& pressure side o' the system operate! *o& pressuresthe system operate! *o& pressures can be damaging to the machine and also give rise to

can be damaging to the machine and also give rise to ecessive leakage into theecessive leakage into the system &hen the pressure is

system &hen the pressure is unnecessarunnecessarily operated belo& atmospheric! 4ostily operated belo& atmospheric! 4ost )% 1-7!

)% 1-7! c!

c! Dil presDil pressure cusure cut-outt-out; This en; This ensuresures that the cos that the comprempressor is nossor is not operat operated i' 'or somted i' 'or somee reason lubricating oil is not being circulated at the

reason lubricating oil is not being circulated at the reCuired rate! 4ost )% 0-7!reCuired rate! 4ost )% 0-7! d!

d! "otor ov"otor overloaerload; This ded; This device can pvice can protecrotect both the drivt both the drive motor and the motor and the re'rigee re'rigeratiorationn eCuipment i' there is

eCuipment i' there is an ecessively high load on an ecessively high load on the compressor, a blockage orthe compressor, a blockage or ceasure!

ceasure!

vv!! 44aappaacciitty y ccoonnttrrooll

4apacity control o' a re'rigeration system can be achieved in many &ays and the 4apacity control o' a re'rigeration system can be achieved in many &ays and the 'ollo&ing list gives some o' the

'ollo&ing list gives some o' the methods likely to be used in 'ish methods likely to be used in 'ish 'ree?ing and cold'ree?ing and cold storage;

storage;

D''-loading o' cylinders in a multicylinder compressor ! D''-loading o' cylinders in a multicylinder compressor ! 9y-passing 'rom de 1 i very

9y-passing 'rom de 1 i very to suction at the compressorto suction at the compressor Dno''-cycling o' the compressor by either

Dno''-cycling o' the compressor by either a temperature or pressure-sensing device,a temperature or pressure-sensing device, %peed control o' the drive motor either by

%peed control o' the drive motor either by electrical or mechanical means ,electrical or mechanical means , $ Cu

$ Cuali'ied person should bali'ied person should be consulted on &e consulted on &hether this reCuiremenhether this reCuirement is necessary and ot is necessary and onn the choice o'

(21)

$i"ure ,

$i"ure , 9atch air-blast 'ree?er &ith 9atch air-blast 'ree?er &ith side loading and unloadingside loading and unloading

$i"ure *

(22)

$i"ure 

$i"ure  9atch-continuous air-blast 'ree?er &ith cross'lo& air circulation 9atch-continuous air-blast 'ree?er &ith cross'lo& air circulation This allo&s the produce to be Cuickly loaded into the

This allo&s the produce to be Cuickly loaded into the 'ree?er rather than have delays'ree?er rather than have delays &hile &aiting 'or 'ull

&hile &aiting 'or 'ull loads! The number o' trolleys and the loading interval are selectedloads! The number o' trolleys and the loading interval are selected to ensure that &hen the 'ree?er is 'ull

to ensure that &hen the 'ree?er is 'ully loaded a ne& trolley &ill y loaded a ne& trolley &ill be echanged &ith onebe echanged &ith one &hich has been in 'or the necessary 'ree?ing time and, therea'ter, a one out and one in &hich has been in 'or the necessary 'ree?ing time and, therea'ter, a one out and one in system is operated! This loading arrangement also ensures that

system is operated! This loading arrangement also ensures that the re'rigerationthe re'rigeration demand is more uni'ormly spread than &ould be the case 'or a

demand is more uni'ormly spread than &ould be the case 'or a batch 'ree?er +>igure 23!batch 'ree?er +>igure 23! $ ba

$ batch-continuous 'reetch-continuous 'ree?er layout and air'lo& arr?er layout and air'lo& arrangement should bangement should be designed toe designed to ensure that a ne& load o' &arm

ensure that a ne& load o' &arm 'ish is not placed upstream o' a 'ish is not placed upstream o' a partially 'ro?en load!partially 'ro?en load! iiii!! TTrroolllleyeys, s, papalllleetsts, s, shheelvlveess

Trolley

Trolleys are more mobile but s are more mobile but take up more space on the 'actory 'loor! Pallet loads can betake up more space on the 'actory 'loor! Pallet loads can be moved directly 'rom the 'ree?er to a

moved directly 'rom the 'ree?er to a cold store 'or temporary storage &ithout the need 'or cold store 'or temporary storage &ithout the need 'or taking epensive eCuipment out o' service!

taking epensive eCuipment out o' service!

>ied shelves &ithin the 'ree?er are not recommended since the 'ree?er door must be >ied shelves &ithin the 'ree?er are not recommended since the 'ree?er door must be le't open during loading! This may take a considerable time and result in

le't open during loading! This may take a considerable time and result in an unnecessaryan unnecessary high ingress o' heat and &ater vapour &ith the

high ingress o' heat and &ater vapour &ith the air entering the 'ree?er! Jith a 'ied shel'air entering the 'ree?er! Jith a 'ied shel' arrangement some o' the air-blast 'ree?erIs versatility &ill also be l

arrangement some o' the air-blast 'ree?erIs versatility &ill also be l ost!ost! iiiii!i! #n#n-l-linine or se or spipiraral col contntininuouous 'us 'reree?e?ererss

%piral 'ree?ers are designed to reduce the 'loor space reCuirement o' the 'ree?er but %piral 'ree?ers are designed to reduce the 'loor space reCuirement o' the 'ree?er but they, i

they, in turn, reCuire a higher roo' n turn, reCuire a higher roo' clearance and in some cases this may be eCuallyclearance and in some cases this may be eCually critical! %piral 'ree?ers also tend to

critical! %piral 'ree?ers also tend to distort the shape o' some products due to thedistort the shape o' some products due to the curvature o' the belt path! #n l

curvature o' the belt path! #n line 'ree?ers have been built &ith a multi-belt ine 'ree?ers have been built &ith a multi-belt operation inoperation in order to reduce the 'loor space +>igure 28! Trans'er o' partially 'ro?en 'ish 'rom one belt order to reduce the 'loor space +>igure 28! Trans'er o' partially 'ro?en 'ish 'rom one belt to another! ho&ever

to another! ho&ever, may be di''icult , may be di''icult and result in and result in breakage or distortion o' the breakage or distortion o' the product!product! This trans'er, ho&ever

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'ree?er &ith some products by ensuring that the &et product does not adhere to the 'ree?er &ith some products by ensuring that the &et product does not adhere to the 'irst'irst belt +>igure 27!

belt +>igure 27!

$i"ure 1

$i"ure 1 The e''ect on temperature and re'rigeration capacity &hen The e''ect on temperature and re'rigeration capacity &hen loading a batch air-loading a batch air-blast 'ree?er

blast 'ree?er

$i"ure 2

$i"ure 2 4ontinuous belt air-blast 'ree?er &ith cross'lo& air 4ontinuous belt air-blast 'ree?er &ith cross'lo& air circulation+also constructedcirculation+also constructed &ith countercurrent series 'lo& air circulation

(24)

$i"ure 3

$i"ure 3 4ontinuous air-blast 'ree?er &ith the belt 4ontinuous air-blast 'ree?er &ith the belt arranged in a spiralarranged in a spiral

$i"ure %

(25)

$i"ure &

$i"ure & %emi-'luidi?ed 'lo& 'ree?er &ith %emi-'luidi?ed 'lo& 'ree?er &ith double beltdouble belt

1..2 4er#ial pla#e 5ree6er

3.2.4.1 General:

The vertical plate 'ree?er +AP> is ideally

The vertical plate 'ree?er +AP> is ideally suited 'or bulk 'ree?ing o' 'ish! and suited 'or bulk 'ree?ing o' 'ish! and althoughalthough originally designed 'or 'ree?ing 'ish at sea! it

originally designed 'or 'ree?ing 'ish at sea! it is no& also used etensively on land mainlyis no& also used etensively on land mainly 'or 'ree?ing seasonal 'ish &hich are 'ro?en in bulk 'or

(26)

$i"ure 1&

$i"ure 1& T&enty-station vertical plate 'ree?er &ith top T&enty-station vertical plate 'ree?er &ith top unloading arrangementunloading arrangement

The product is loaded into spaces 'ormed by re'rigerated plates &hich 'orm the stations The product is loaded into spaces 'ormed by re'rigerated plates &hich 'orm the stations o' a vertical plate 'ree?er unit! The plates are

o' a vertical plate 'ree?er unit! The plates are hydraulically closed thereby slightlyhydraulically closed thereby slightly compacting the product to a preset block thickness and also improving the contact compacting the product to a preset block thickness and also improving the contact bet&een the 'ish and the plate sur'aces!

bet&een the 'ish and the plate sur'aces! $'ter 'ree?ing, the cold re'r

$'ter 'ree?ing, the cold re'rigerant is turned o'' aigerant is turned o'' and a hot re'rigerant supnd a hot re'rigerant supply is circulatedply is circulated through the plates to de'rost them and break the bond bet&een the plates and the

through the plates to de'rost them and break the bond bet&een the plates and the product! This de'rost procedure only takes a

product! This de'rost procedure only takes a 'e& minutes and, &hen 'e& minutes and, &hen complete, thecomplete, the hydraulic system is operated to open the plates and raise the blocks to

hydraulic system is operated to open the plates and raise the blocks to the top o' thethe top o' the 'ree?er ready 'or removal!

'ree?er ready 'or removal!

%ince the product is 'ro?en into a

%ince the product is 'ro?en into a symmetrical block, it is ideally suited symmetrical block, it is ideally suited 'or palleti?ing to'or palleti?ing to give good utili?ation o'

give good utili?ation o' cold storage space! The product can be cold storage space! The product can be 'ro?en un&rapped and'ro?en un&rapped and stored &ithout packaging or 'ro?en in paper or plastic bags &hich are inserted bet&een stored &ithout packaging or 'ro?en in paper or plastic bags &hich are inserted bet&een the plates be'ore loading the 'ish! )n&rapped products may, ho&ever, be gla?ed or the plates be'ore loading the 'ish! )n&rapped products may, ho&ever, be gla?ed or inserted into cartons a'ter '

inserted into cartons a'ter 'ree?ing!ree?ing!

3.2.4.2 ree!er si!e:

The si?e o' a AP>

The si?e o' a AP> unit depends on the plate si?e, plate spacing and the number o'unit depends on the plate si?e, plate spacing and the number o' stations!

stations! $ plate &

$ plate &idely used has dimenidely used has dimensions o' 1 120  = sions o' 1 120  = mm &hich produces 'umm &hich produces 'ull-si?ed blocksll-si?ed blocks measuring 1 080  20 mm! Dther plate

measuring 1 080  20 mm! Dther plate si?es available 'rom the same manu'acturersi?es available 'rom the same manu'acturer give block dimensions o' 1 1=0  F0 mm

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ho&ever

ho&ever, be available 'rom , be available 'rom other manu'acturers! The provision o' a non-standard plateother manu'acturers! The provision o' a non-standard plate si?e &ill be epensive since this may reCuire a

si?e &ill be epensive since this may reCuire a special die to etrude the plate sections!special die to etrude the plate sections! The standard block thicknesses produ

The standard block thicknesses produced in AP> are ced in AP> are 0 mm, 7 mm and 100 mm, 0 mm, 7 mm and 100 mm, andand by means o' special adaptors it is possible to

by means o' special adaptors it is possible to have more than one standard spacing inhave more than one standard spacing in the same unit!

the same unit!

$ny number o' station

$ny number o' stations can be supplied us can be supplied up to a limit o' about 30, bup to a limit o' about 30, but manu'acturers &illt manu'acturers &ill normally only supply 'ive or si

normally only supply 'ive or si standard si?es! %pecial reCuirements, such as small unitsstandard si?es! %pecial reCuirements, such as small units 'or 'ree?ing trials

'or 'ree?ing trials or laboratory use, can, or laboratory use, can, ho&everho&ever, be made on , be made on reCuest!reCuest!

Jhen selecting the number o' stations per 'ree?er unit, account should be taken o' the Jhen selecting the number o' stations per 'ree?er unit, account should be taken o' the likely pattern o' 'ish supplies! )nit

likely pattern o' 'ish supplies! )nit si?es should be selected so that they are likely to si?es should be selected so that they are likely to bebe completely 'illed during each cycle, thus avoiding the possibility o' 'ree?ing partial loads completely 'illed during each cycle, thus avoiding the possibility o' 'ree?ing partial loads or having 'ree?ers &aiting 'or 'urther supplies to complete a l

or having 'ree?ers &aiting 'or 'urther supplies to complete a l oad!oad!

Dverall dimensions and &eights 'or a 'ull standard range is given in Table 33! Dverall dimensions and &eights 'or a 'ull standard range is given in Table 33!

Table 11

Table 11 Aertical plate 'ree?ers 5imensions and shipping data +uncrated Aertical plate 'ree?ers 5imensions and shipping data +uncrated

PENGERTIAN REFRIGERASI

Ap

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Pen,in(in

Refrigerasi adalah

Refrigerasi adalah produkproduksi si aau pengusahaaaau pengusahaan n dan dan pemelpemeliharaiharaan an ingkingka a suhu darisuhu dari

suau !ahan aau ruangan pada ingka yang le!ih rendah dari pada suhu lingkungan

aau amos"ir sekiarnya dengan cara penarikan aau penyerapan panas dari !ahan aau

ruangan erse!u.

#e"rigrasi dapa dikaakan $uga se!agai se!agai proses pemindahan panas dari suau

!ahan aau ruangan ke !ahan aau ruangan lainnya %Ilyas, 1&&'(, sedangkan menuru

)ara

)arano no %1&*+( pendingina%1&*+( pendinginan n aau re"rigeraaau re"rigerasi si adalaadalah h suau proses suau proses penyepenyeraparapan n panaspanas

pada suau !enda

pada suau !enda dimandimana a proseproses s ini er$adi karena proses ini er$adi karena proses penguapenguapan !ahan pan !ahan pendinpendingingin

%re"rigeran(.

(28)

M

Meennuurruu  AAririssmmuunnaannddaar r ddaan n SSaaiio o %%22++( ( rre"e"ririggereraassi i aaddaallaah h uussaahha a uunnuukk

memper

memperahanahankan kan suhu rendah suhu rendah yaiyaiu u suau proses suau proses mendimendinginkanginkan n udara sehingga dapaudara sehingga dapa

mencapai emperaur dan kelem!a!an yang sesuai dengan kondisi yang dipersyarakan

erhadap kondisi udara dari suau ruangan erenu, "akor suhu dan emperaur sanga

!erperan dalam memelihara dan memperahankan

!erperan dalam memelihara dan memperahankan nilai kesegaran ikan.nilai kesegaran ikan.

Refrigrasi memanfaatkan sifat-sifat panas (thermal) dari bahan refrigerant selagi bahan

itu berubah keadaan dari bentuk cairan menjadi bentuk gas atau uap da sebaliknya dari

gas kembali menjadi cairan (Ilyas, 1993)

PRINSIP DASAR REFRIGRASI MEKANIK PRINSIP DASAR REFRIGRASI MEKANIK 1

1 Gambaran Umum Refrigerasi Mekanik Gambaran Umum Refrigerasi Mekanik

!rinsip dasar dari refrigerasi mekanik adalah pr"ses penyerapan panas dari dalam suatu

ruangan berinsulasi tertutup kedap lalu memindahkan serta mengenyahkan panas keluar

dari ruangan tersebut

!r"ses merefrigerasi ruangan tersebut perlu tenaga atau energi #nergi yang paling

c"c"k untuk refrigerasi adalah tenaga listrik yaitu untuk menggerakkan k"mpres"r pada

unit refrigerasi (Ilyas, 1993 )

$

$ Proses Proses ang !erlangsung Dalam ang !erlangsung Dalam Sis"em RefrigerasiSis"em Refrigerasi

%al

%alam am susuatu atu sissistem tem rerefrifrigragrasi si memekankanik, ik, beberlarlangngsunsung g bebbeberaerapa pa prpr"se"ses s &si&sik k yanyangg

sederhana 'ika ditinjau dari segi term"dinamika, seluruh pr"ses perubahan itu terlibat

tenaga panas, yang dikel"mp"kkan atas panas laten penguapan, panas sensibel, panas

laten pengembunan dan lain sebagainya

en

enuruurut t "f"fyan yan IlyIlyas as (19(199393), ), suasuatu tu siksiklus lus rerefrifrigragrasi si secsecara ara berberuruurutan tan bebera*ra*al al dardarii

pemampatan, melalui pengembunan (k"ndensasi), pengaturan pemuaian dan berakhir

pada penguapan (e+ap"rasi)

Sa"u siklus refrigrasi kom#resi ua# adalah sebagai beriku"$