Sib piv lub zog ntom ntom rau koj daim ntawv thov-Ib Daim Ntawv Qhia Txog Kev Siv Hluav Taws Xob rau Cartridge rhaub

It's difficult for maintenance engineers when a brand-new single head heating tube (cartridge heater) breaks down too soon, often just weeks after it was put in. In some circumstances, bad manufacturing quality is to blame, but in most cases, the problem is because a specification-watt density, also known as power density or surface loading-was missed.

Watt ceev qhia koj ntau npaum li cas hluav taws xob hluav taws xob (hauv watts) poob ib square feet ntawm lub tshuab cua sov qhov chaw sov. Txhawm rau txheeb xyuas qhov kub npaum li cas lub cylindrical cartridge rhaub tso tawm, koj tuaj yeem siv cov mis:
Watt ceev (W / cm²)=Wattage / (π × Dia (cm) × Heated Length (cm))

los yog nyob rau hauv imperial ntsuas:
Watt ceev (W/in²)=Wattage / (π × Diameter (in) × Heated Length (hauv))

Tus lej no qhia koj tias muaj kev ntxhov siab ntau npaum li cas ntawm lub tshuab cua sov thiab cov khoom sab hauv. When the watt density is higher, the resistance wire and sheath have to work at higher temperatures, which speeds up oxidation, insulation breakdown, and final burnout.

Kev lag luam kev paub qhia tau hais tias rau ntau qhov kev lag luam siv cov tshuab cua sov uas ua haujlwm ntawm qhov kub ntawm qhov kub txog li 600℃(1112℃F), kev txuag watt ceev ntawm 5-7 W / cm² (kwv yees 32-45 W / in²) feem ntau muab qhov zoo tshaj plaws sib npaug ntawm kev ua haujlwm thiab kev ua neej nyob. Tab sis qhov tseem ceeb tshaj plaws uas tau tso cai tuaj yeem sib txawv heev nyob ntawm qhov loj ntawm lub rhaub, qhov kub thiab txias nws khiav ntawm, qhov haum rau siab, thiab thermal conductivity ntawm nruab nrab nyob ib ncig ntawm nws. Hauv cov chaw zoo tshaj plaws nrog cov cua sov ua kom zoo, siab -cov khoom siv hluav taws xob ceev ceev tuaj yeem ncav cuag 100–300 W / in² (15.5–46.5 W / cm²). Txawm li cas los xij, nws ib txwm zoo dua los xaiv lub wattage qis dua rau lub neej ua haujlwm ntev dua.## Vim li cas cov cua sov uas muaj qhov loj dua yog qhov zoo dua ntawm Tswj Watt Density

Lub 25mm loj txoj kab uas hla ib lub taub hau cua sov raj yog ib tug meej yeej nyob rau hauv cov ntaub ntawv no. Piv nrog rau qhov me me - lub taub rhaub dej, nws muaj qhov qis dua watt ceev vim nws muaj qhov loj dua qhov chaw ntawm ib chav tsev ntev.

Siv lub tshuab rhaub 500W, piv txwv li: - Nrog 10mm (kwv yees li 0.394 hauv) txoj kab uas hla thiab 200mm rhuab ntev, watt ntom yuav ntau dua 8-10 W / cm², uas tej zaum yuav siab dhau rau ntau cov pwm los yog chim siv . - Tib 500W lub zog hluav taws xob 2 lub sij hawm sib kis ntau dua. thaj tsam, txo qhov ceev kom txog li 3-5 W / cm², uas yog qis dua qhov kev txwv kev nyab xeeb.

Kev ntxhov siab tsawg txhais tau hais tias qhov txias txias hauv cov xov hlau, muaj feem tsawg dua ntawm cov chaw kub, qeeb oxidation ntawm nickel-chromium kuj hlau, thiab lub neej ua haujlwm ntev dua. Cov kws ua haujlwm qee zaum qhia tag nrho cov watts yam tsis tau xav txog yuav ua li cas lub zog ntawd kis mus rau thaj chaw me me. Qhov no ua rau muaj kev ua tsis tiav thaum ntxov.## Cov Lus Qhia rau Watt Density los ntawm Daim Ntawv Thov

Ntau hom kev tshaj tawm thiab ib puag ncig xav tau qhov sib txawv watt ntom ntom:
- Hlau pwm, tuag, thiab platens (siab thermal conductivity, xws li cov cuab yeej hlau los yog txhuas): Cov khoom no thauj cov cua sov tawm ntawm lub sheath zoo heev, uas tso cai rau ntau dua watt ntom ntom -feem ntau 6–15 W / cm² lossis ntau dua (txog 40–{5}} W / in² nyob ntawm qhov kub thiab haum). Tight bore fits (clearance Tsawg dua lossis sib npaug ntawm 0.05–0.1mm diametral) ua rau kev sib cuag tau zoo dua, uas ua rau muaj kev txwv tsis pub ntau dua . - Yas extrusion cylinders lossis txhaj tshuaj molding chim: Txhawm rau kom cov polymer tsis txhob kub dhau rau hauv ib qho chaw, qhov ntom ntom feem ntau yog nyob ib ncig ntawm 5–8 W / cm² (Heev conductivity): qis dua, feem ntau 2-5 W / cm² lossis tsawg dua. Lub sheath kub nce sai heev vim tias tsis muaj txoj hauv kev kom cua sov khiav. Qhov no tuaj yeem ua rau lub hnab ntim tau sai heev. - Cov kua lossis roj: Nws nyob ntawm seb lawv ntws npaum li cas thiab ceev npaum li cas. Nrog rau kev khiav zoo, qhov loj dua yog qhov xav tau, tab sis cov kua dej tuab yuav tsum tau derated kom cov sheath ntawm carbonising.

Nco ntsoov saib cov duab kos uas cov chaw tsim khoom muab uas qhia qhov siab tshaj plaws tso cai watt ntom tiv thaiv kev ua haujlwm kub thiab qhov haum rau qhov ntev. A looser fit makes the safe watt density drop a lot since the air gap serves as an insulator.## Important Calculation Information: Only Use Heated Length

Ib qho yuam kev feem ntau yog xam cov watt ntom siv lub tshuab rhaub tag nrho ntev es tsis txhob siv qhov ntev ntawm cov cua sov. Feem ntau ib leeg - lub taub hau lub taub hau lub taub hau muaj qhov tsis muaj cua sov "txias" thaj tsam nyob ib puag ncig ntawm cov hlau lead tawm (feem ntau 25–50mm lossis ntau dua) thiab qee zaum ntawm qhov ntxeev los tiv thaiv cov coj lossis ua kom yooj yim rau mount. Kev siv tag nrho ntev ua rau qhov tseeb watt ceev ntawm qhov ua haujlwm zoo saib qis dua li qhov tiag tiag, uas tuaj yeem ua rau muaj kev phom sij txaus ntshai.

Tau txais qhov tseeb rhuab ntev los ntawm tus kws kho mob lossis ntsuas koj tus kheej. Ntawm no, qhov tseeb nres cov qauv tsim uas me dhau thiab ua rau muaj kev ntxhov siab ntau dhau ntawm thaj chaw ua haujlwm.## Cov lus qhia muaj txiaj ntsig zoo rau kev xaiv thiab muab tso rau hauv loj -Diameter Cartridge rhaub

1. Ntxiv cov npoo kev nyab xeeb-Yog tias koj qhov kev suav suav pom tias 800W txaus, xav txog 1000W lub rhaub uas ntev dua me ntsis lossis muaj txoj kab uas hla loj dua, zoo li qhov kev xaiv 25mm. Qhov chaw saum npoo loj dua txo qis watt ceev thaum khaws lossis ua kom sov dua- ua haujlwm tau zoo. Qhov ntau ntawm 10-20% yog qhov zoo tshaj plaws, tab sis cov npoo loj dua yog xav tau rau lub voj voog ua haujlwm uas tsis meej, hloov pauv, lossis kev caij tsheb kauj vab uas tshwm sim ntau heev.

2. Kev sib piv ntawm qhov hluav taws xob yog qhov yuav tsum tau- Lub tshuab cua sov rau 240V tsuas yog ua haujlwm ntawm 120V, uas txhais tau tias nws tsuas yog cua sov ib qho - plaub ntawm lub zog ntsuas. Ntawm qhov tod tes, lub tshuab hluav taws xob 120V ntawm 240V ua rau plaub zaug ntawm watts thiab watt ntom ntom, uas feem ntau ua rau tsis ua haujlwm sai. Nco ntsoov xyuas cov khoom siv hluav taws xob thiab xav txog kev siv dual -voltage architecture yog tias koj xav tau ntau dua.

3. Ua kom haum zoo yog qhov tseem ceeb tshaj plaws -Txawm qhov kev xaiv watt ntom ntom zoo tshaj plaws yuav tsis ua haujlwm yog tias nws tsis raug teeb tsa kom raug. Laum thiab ream lub qhov uas nws haum zoo (feem ntau yog ib tug clearance ntawm 0.001–0.005 "los yog 0.025-0.13mm). Xyuas kom lub rhaub haum snugly tsis muaj zog, thiab ntxuav nws zoo. Tsis txhob siv lubricants uas carbonise. Tsis zoo hu ua zoo conduction rau hauv lub hnab tshos cua, uas ua rau cov insulator ua hauj lwm nyuaj.

4. Xav txog kev caij tsheb kauj vab thiab tswj- kev caij tsheb kauj vab thiab tawm sai sai ua rau lub neej luv dua li kev khiav tsis tu ncua. Sim ua kom lub voj voog ua haujlwm ntawm li 50/50, los yog siv cov kev tswj sib luag (SCRs lossis PID nrog cov khoom siv- xeev relays) kom cov hlau tsis kub dhau.

5. Sheath khoom sib koom ua ke-Siv qis watt ntom ntom nrog siab - zoo sheaths zoo li Incoloy 840 nyob rau hauv cov chaw uas kub los yog me ntsis corrosive. Kev thauj khoom nruab nrab thiab kev ua haujlwm zoo ntawm cov hlau ua ke ua rau cov khoom siv tau ntev dua.## Feem ntau yuam kev thiab Ntev-Lub Sij Hawm Tau Txais

Thaum koj dhau - qhia txog watt ntom ntom kom ua kom cov khoom cua sov sai dua, nws yuav rov qab thiab ua kom lub neej ntawm lub rhaub kom luv li 50-80% lossis ntau dua vim nws hnav sai dua. Ntawm qhov tod tes, kev xaiv kev saib xyuas uas nyiam cov diameters loj dua, xws li 25 hli thaum muaj chav, ua rau muaj qhov kub thiab txias ntau dua, tsis kam lees tsawg dua, tsis muaj sijhawm poob qis, thiab qis dua tag nrho cov tswv cuab, txawm tias tus nqi pib yog siab dua me ntsis.

Nyob rau hauv luv luv, siv lub cartridge rhaub kom tiav tsis tau txhais hais tias tau txais lub hwj chim los yog ceev tshaj plaws. Nws yog hais txog kev sib txuas cov khoom siv hluav taws xob zoo, thaj chaw saum npoo, haum, thiab kev xav tau ntawm daim ntawv thov. 25 hli loj txoj kab uas hla ib lub taub hau cua sov raj uas tsis tshua muaj watt ceev yog feem ntau yog qhov zoo tshaj plaws, feem ntau txhim khu kev qha xaiv rau hnyav- lub luag hauj lwm setups uas muaj teeb meem nrog uneven cua sov los yog luv luv lub neej. Yog tias koj tsis paub meej, mus nrog qhov qis dua, xyuas txhua qhov loj thiab qhov hluav taws xob, thiab saib cov chaw tsim khoom cov ntaub ntawv ua tau zoo. Cov txiaj ntsig yog ntau txhiab ntau teev ntawm kev ua haujlwm, cov txheej txheem zoo ib yam, thiab kev thaj yeeb ntawm lub siab ntawm cov khoom hauv pem teb.

Cov tshuab cua sov ua haujlwm tau txais kev ua haujlwm zoo thiab ua haujlwm ntev uas niaj hnub tsim khoom xav tau los ntawm kev ua watt ntom ntom yog qhov tseem ceeb tshaj plaws tsim qauv tsis yog kev xav tom qab.