Ultrasonic Txheem Cov Ntsiab Cai

Tsawg dua li lub suab tsis zoo tib yam, lub zog ntawm ultrasound ua kom zoo, tab sis kuj los ntawm cov khoom siv opaque, no feature tau dav siv ultrasonic kuaj, thickness, kev ntsuas nrug, chaw taws teeb tswj thiab kev siv tshuab ntawm ultrasonic. Ultrasonic ntsuam xyuas yog ib qho technology uas USES ultrasound los nthuav cov duab puab ntawm cov khoom siv opaque. Ntawm qhov kev hloov ntawm ultrasonic acoustic tsom rua kev siv tshuaj tua kab mob, lub ultrasonic ntawm tus qauv kis tau yog ib feem ntawm cov ntaub ntawv (xws li lub peev xwm ntawm kev xav, kev nqus thiab tawg ntawm lub suab tsis), acoustic lens converge on piezoelectric receiver, hluav taws xob input input amplifier, siv kev xa tshuaj tuaj yeem tig opaque qauv duab tso tawm ntawm lub vijtsam. Cov cuab yeej hu ua ultrasonic tsom. Ultrasonic kev siv tshuab tau dav dav siv hauv kev kuaj mob, hauv kev tsim ntawm kev siv tshuab hluav taws xob siv rau kev ntsuam xyuas ntawm cov teev loj hauv kev loj hlob, yog siv los rau kev pom kev sib txawv ntawm cov khoom sib txawv hauv cov cheeb tsam science thiab ciam thaj, thiab lwm yam. Acoustical holography yog ib qho ultrasonic cuam tshuam txoj cai ntawm cov ntaub ntawv thiab cov me nyuam thaij duab ntawm opaque acoustic imaging technology, nws txoj cai thiab kho qhov muag duab yog tib yam, cov ntaub ntawv yog txhais tau txawv (saib daim duab qhia). Nrog tib lub ultrasonic teeb liab qhov kev txhawj xeeb ob transducer muab tso rau hauv ib lub kua, lawv launched ob ntsig txog txoj hlua ntawm ultrasound: ib nqaj los ntawm cov khoom kawm tom qab ua ib nthwv dej, ib pawg ntawm kev yoj. Nthuav nthwv dej thiab kev siv ntim coherent superposition acoustical hologram ua rau ntawm qhov dej, nrog laser beam acoustical hologram, siv lub laser xav txog ntawm lub suab paj nruag acrystical hologram diffraction thiab tau txais tej yam zoo li rov qab, feem ntau nrog rau lub koob yees duab thiab lub TV nyob rau lub sijhawm soj ntsuam .

Lub ntsiab lus ntawm ultrasonic tu

Ultrasonic tu nyhuv, yog ntau tshaj li tib neeg lub rooj sib hais suab yoj hauv cov kua. Thaum cov ultrasonic propagation nyob rau hauv lub detergent, vim lub sonic yog longitudinal yoj, longitudinal yoj los txhawb lub luag hauj lwm ntawm cov xov xwm yuav ua rau cov kua hloov, ua rau muaj ntau lub tshuab nqus npuas, hu ua "cavitation nyhuv". Thaum lub npuas compression blasting, tuaj yeem ua rau muaj zog, yuav ua rau lub teeb ntawm cov khoom nyob rau hauv kaum tsev av tawg, thiab txhim kho tus ntxuav ntxuav cov nyhuv, tshuav ntev ntawm ultrasonic zaus takanami, muaj zog penetrating zog, thiaj li muaj lub keej los yog zais cov txheej txheem ntawm kev tu, muaj peev xwm ua tau zoo ntawm cov dej ntxuav

Ultrasonic tu yog raws li cavitation, uas yog, nyob rau hauv qhov dej huv hauv kev ceev ceev ntawm ntau npuas thiab ceev implosion. Txoj kev poob siab yuav ua rau lub plhaub tawm ntawm sab hauv thiab sab nraud ntawm cov khoom ua haujlwm raus tes rau hauv kev ntxuav tu. Nrog rau kev nce ntawm ultrasonic zaus, tus npawb ntawm cov npuas tsub ntxiv thiab cov kev txaj muag blasting yog tsis muaj zog. Yog li, ultrasound high zaus yog tshwj xeeb tshaj yog tsim los tu tu cov av me me uas tsis muaj qhov tawg ntawm lub workpiece. Tus expansion ntawm cavitation npuas thiab tawg ntho (implosion) npuas yog tsim los ntawm kev siv lub siab (ultrasonic), siv lub suab tsis muaj suab thaj. Txhua lub tsev ultrasonic tu, yog li no, yuav tsum muaj peb theem pib: cheng fang tu dej hauv lub tank, converts hluav taws xob zog rau cov neeg kho tshuab zog ntawm cov hluav taws xob hluav taws xob teeb liab transducer thiab ultrasonic generator.

Transducers thiab cov generators

Qhov tseem ceeb tshaj plaws ntawm ultrasonic tu system yog cov transducer. Muaj ob hom transducer, ib qho yog sib nqus transducer, uas yog tsim los ntawm xee lossis nickel alloy. Ib tug piezoelectric transducer uas ua los ntawm txhuas cov zirconate titanate los yog lwm yam khoom xyaw.

Thaum twg cov khoom piezoelectric tso rau hauv ib qho hluav taws xob ntawm qhov ua hluav taws xob hloov, nws deforms. Qhov no hu ua "piezoelectric effect". Sib nqus transducers, los ntawm kev sib piv, yog ua los ntawm cov ntaub ntawv uas deform hauv kev hloov magnetic teb. Txawm siv hom transducer zoo li cas, qhov tseem ceeb tshaj plaws yog feem ntau qhov kev cuam tshuam ntawm cavitation nyhuv.

Ultrasonic tsis, ib yam li lwm lub suab tsis, yog cov ntsiab lus ntawm qhov siab, ib nthwv dej uas thim tawm thiab nthuav dav (li nram qab no). Yog hais tias lub suab hluav taws xob muaj zog txaus, cov kua raug thawb tawm ntawm cov theem ntawm cov nthwv dej thiab cov npuas tsim. Hauv cov theem qis ntawm yoj, cov npuas tawg los yog implode nyob rau hauv cov dej instantly, ua tau zoo heev nruj quab yuam, tshwj xeeb yog tsim rau tu. Txoj kev no yog hu ua cavitation. Lub suab tsis yawm ntawm compression thiab expansion yog sojntsuam theoretically, qhov tawg ntawm qhov cavitation npuas yuav tsim ntau tshaj 10000 psi siab thiab siab kub ntawm 20000 ° F (11000 ° C), thiab nyob rau hauv lub moj tej tawg yuav tawg sai sai sab nraud tawg. Zog tso tawm los ntawm cavitation npuas yog tsawg heev, tab sis txhua thib ob rau lab tus kab cavitation npuas tawg thaum tib lub sij hawm, cov nyhuv loj yuav muaj zog heev, ua rau muaj kev cuam tshuam ntawm kev sib kis ntawm cov khoom ua haujlwm nto spalling, qhov no yog tag nrho cov yam ntxwv ntawm ultrasonic tu. Yog hais tias lub zog ultrasonic yog loj txaus, cavitation yuav tshwm sim zaws rau hauv kev ntxuav tu, thiaj li ultrasound tuaj yeem ntxuav me me kab thiab qhov. Cavitation kuj txhawb nqa cov tshuaj lom neeg thiab kev nce mus txog qhov xaus ntawm daim nyias nyias. Tab sis tsuas yog nyob rau hauv ib cheeb tsam ntawm lub siab ua kua yog tsawg dua cov roj siab hauv qhov sib tw ntawm cov khoom ua si yuav tsim cov teeb meem cavitation hauv cheeb tsam, yog li cov generated ntawm lub ultrasonic wave amplitude yog loj txaus kom los siav tau tus mob no. Qhov tsawg zog yuav tsum tsim kom muaj cavitation hu ua cavitation critical point. Sib txawv cov kua muaj cavitation ntau qhov tseem ceeb, yog li ultrasonic lub zog yuav tsum tshaj li qhov tseemceeb uas yuav tsum tau ua kom tiav cov nyhuv. Ntawd yog, cavitation npuas tsuas ua tau yog tias lub zog tshaj qhov taw qhia tseem ceeb rau ultrasonic tu.

Qhov tseem ceeb ntawm cov zaus

Lub suab nrov nrov yog tsim los ntawm kev ua haujlwm tsawg tsawg (hauv kev sib tham ntawm tib neeg lub rooj sib hais). Thaum lub sijhawm tsawg dua 20kHz, lub suab nrov ua haujlwm tsis yog tsuas yog siab heev, tab sis yuav tshaj qhov kev nyab xeeb suab txwv uas muaj los ntawm txoj haujlwm kev nyab xeeb thiab kev noj qab haus huv los yog lwm txoj cai. Nyob rau hauv kev siv cov cuab yeej hluav taws xob yuav tsum tau tshem cov av tsis tas xav txog kev puas tsuaj ntawm cov khoom ua haujlwm, ib lub tsev tu ntau dua li ntawm 20kHz txog 30kHz feem ntau xaiv. Qhov kev tu ncua ntawm qhov sib txuam no feem ntau yog siv los ntxuav cov khoom loj, hnyav lossis siab ceev. Lub 20KHz sib nqus transducer thiab 25KHz piezoelectric transducer Cavitation Tus Zog Muaj zog rau 40 kHz frequencies feem ntau siv los ntxuav cov khoom me me, ntau dua qhov ntsej los yog tshem tawm cov tshuaj tiv thaiv me me. High frequencies tseem siv tau rau hauv cov ntawv sau npe ntawm qhov kev puas tsuaj tsis pub nyob rau ntawm cov khoom ua haujlwm. Siv high frequencies pab txoj kev kawm tu ntau yam. Raws li qhov nce, ntau tus cavitation npuas tsub kom ncav lawm, ua ntau qhov siab tsis muaj zog uas tso cai rau lawv nkag rau qhov khoob me me. Yog hais tias lub hwj huam tseem nyob ruaj khov thiab cavitation npuas txo, lub zog tso tawm los ntawm cavitation npuas yuav txo qhov sib npaug, uas ua kom txo tau qhov kev puas tsuaj rau lub workpiece nto. Lwm zoo dua ntawm frequencies yog tias lawv txo qhov sib npaug ciam txheej (Bernoulli nyhuv), cia ultrasound los 'xyuas' kawg feem me me. Qhov teeb meem no zoo ib yam li cov pob zeb me me nyob rau hauv qab ntawm ib txoj dej ntshiab thaum dej nyob hauv dej ntws. Lub tuam txhab muaj ntau yam kev sib tshuam ntawm 40kHz, 80kHz, 120kHz thiab 170kHz. Cov khoom uas muaj lub sij hawm ntawm 350kHz tuaj yeem xaiv thaum tu cov khoom me me. Lub tuam txhab nyuam qhuav pib lub MicroCoustics system rau tej lub sijhawm ntawm ib zaus ntawm 400kHz.