CALCULATION OF VENTURI NOZZLES DIAMETER FOR NASAL BREATHING EVALUATION DEVICE

Transcription

1 Interntinl Jurnl f Mechnicl Engineering (IJME) ISSN Vl. 2, Issue 4, Se 203, 2-28 IASET CALCULATION OF VENTUI NOZZLES DIAMETE FO NASAL BEATHING EVALUATION DEVICE KNIGAVKO IUII VOLODYMYOVYCH, OLEG GIGOOVITSH AVUNIN 2 & HUSHAM FAOUK ISMAIL 3,2 Dertment f BME, Khrv Ntinl University f di Electrnics, Khriv, Urine 3 Dertment f Bimedicl Technlgy, INAYA Medicl Cllege, Sudi Arbi ABSTACT Nzzles nd Venturi nzzles re devices tht re inserted in circulr crss-sectin cnduit t crete ressure difference f sttic ressure. Bsed n tht ressure difference, flw rte f flwing fluid cn be clculted. Methdlgy results f Venturi nzzle dimeter clculting device t determine the ressure dr/flw rte chrcteristics f the humn nsl irwys re described. The results f ur methd ffer high-stbility erfrmnce nd cmct cnstructin. The stndrd studying nd metrlgicl verifictin inted n ssibility f btining sufficiently relible mesurement results when using flw meter bsed n Venturi nzzle. This methd cn be cnsidered s resect t imrvement infrmtin-mesurement technlgy lterntive cntrl nd technicl dignstics. In cmbintin with cmuter interfce, these devices rvide high level f mbility nd en u entirely new ersectives fr rhinlgicl reserch nd rctice, esecilly in humn hysilgy nd envirnmentl studies. KEYWODS: hinmnmetery, Pneumtchgrhy, Flw Meters, Pressure Sensrs, Venturi Nzzle, Pressure Dr nd Flw te INTODUCTION Three tyes f nzzles re cvered in clcultr: ISA 932 nzzle, lng rdius nzzle nd Venturi nzzle. All three tyes differ frm ech ther bsed n its she. All nzzles hve rdius shed cnvergent inlet with cylindricl thrt nd Venturi nzzle ls hs divergent rt s utlet. Nzzle nd Venturi nzzle clcultr cn be used fr bth liquids nd gses. In medicl lictins the humn resirtry system cn be reresented s n nlg neumtic ctutr, including wer surce device fr ir suctin nd dischrge, nd neumtic system f ir ieline with resistnce n irflw th, thrugh nsl ssges r humn muth. This wer surce includes the ctutr muscles fr the humn lung, which functin s cmressr with cycle in suctin nd in dischrge, s well s the nsl ssge nd rl cvity, which re cnsidered s ielines with resistnces. At resent, medicl devices hve been resented fr nsl brething dignsis[], which re bsed n nlysis f neumtic ir resistnce in crdintes f «flw rte-ressure» (ctul ressure dr) [2], cinciding with hydrulic nlysis nd neumtic resistnce n hydrulics industril nd neumtics by designing nd studying vrius hydrneumtic devices. STATEMENT OF THE POBLEM Venturi devices use differentil ressure t crete vcuum within the device, which llws users t te dvntge f the suctin t mix tw fluids. As ne liquid flws thrugh the Venturi device, higher entry ressure nd lwer exit ressure, cmbined with nrrw int n the injectr tube, crete vcuum. This is nwn s the Venturi effect. A

2 22 Knigv Iurii Vldymyrvych, Oleg Grigrvitsh Avrunin & Hushm Fru Ismil suctin rt n the side f the device ner the vcuum int llws nther liquid t be drwn int the first ne. Once the different ressures, s well s the rte f ir flw, re nwn, the munt f suctin the Venturi device cretes cn be clculted.in rder t cnstruct nd design bse fr lcl dignstic device, the flw rte chrcteristics f humn nsl ssges were reviewed nd the methdlgy f clcultin f such device ws bserved. S in this study we re ble t mesure the dimeter f the Venturi device's utflw hle. And t mesure the dimeter t the nrrwer suctin int, within the device. THE MAIN PAT The nlysis f current flw meter cnstructin nd ressure sensrs tht re used t determine the ressure drflw rte chrcteristics fr ny neumtic resistnce indictes the technicl ssibilities f mdern utmtic rcessing mesuring techniques fr infrmtin receiving, nd the ssibility f using flw meter devices such s the Venturi nzzle s mesuring equiment [3-5]. Figure shws semi-cnstructin digrm f the device used fr determining the flw rte by using Venturi nzzle, s in unit, we cnstructed hle2 dimeter d, hle 3, nd differentil ressure sensr tye PS with nlg utut, which ws used t mesure ressure dr. Tube3 with suly «-» sensrs PS crresnds t dischrge mesuring (vcuum) in the ieline, nd the chnnel «+» llws us t btin the vlue f the ressure dr. Thus, t Clculte the Dimeter f the Venturi Nzzle, it is Necessry t Cllte the Fllwing Dt nd Limittins The mximum flw rte tht is generted by humn insirtin must nt be greter thn макс 8 L/s nd in exirtin rech 4 6 L/s; макс 6 L/s [6]. Accrding t helth stte, ge, nd nsl ssges disese, insirtin cnnt even Using nzzle dimeter less thn the d 7 mm leds t significnt difficulty f tient during insirtin, esecilly t high-intensity mde frequency nd mlitude; Sensrs tht we used t mesure ressure dr must be in full-scle rnge (when reching the mximum flw rte generted by humns), with the timl rnge f u t 2/3 f the mximum scle vlue, in rder t imrve ccurcy f mesurements; When using the Venturi nzzle, ne shuld te int ccunt the irreversibility f this device, which mens tht the flw rte mesurement is ssible nly when the ir flw is in the directin f the «nzzle-diffuser», nd nt vice vers; The mximum ressure develed by the flw f ir ssing thrugh the nzzle shuld nt exceed humn hysilgicl ssibilities (ccurtely, its musculr ssibilities s lungs ctutr fr generting cycle f exnsin nd cntrctin). The lst limittin is bsed n reliminry sttic mesurements f humn ssibilities t crete excessive ressure in the exirtry cycle nd negtive ne (vcuum) in the insirtry cycle, s crried ut in Khriv Ntinl University f di Electrnics. The ressure guge ws used tgether with mn-vcuum meter tye MVM4- УУ2 by Urine Stte Stndrd2405 with dimeter f 60 mm f the scle: Frm 0 t 0.6 ilguss / cm2 nd scle fctr f 0.02 ilguss / cm2 fr excessive ressure mesurement; Frm 0 t «minus» ilguss / cm2 nd scle fctr 0.02 ilguss / cm2 fr dischrge ressure mesurement (vcuum).

3 Clcultin f Venturi Nzzles Dimeter fr Nsl Brething Evlutin Device 23 During the mesurements yield, rubber tube with length f 0.5 m ws ttched t the mnmeter, nd the mnmeter ws instlled verticlly t nse level. Air suctin (insirtin) nd dischrge (exirtin) were crried ut thrugh the muth, when the free end f the tube iced in the muth, becuse the rcess f suctin nd dischrge ws crried ut in clsed sce (lung, lrynx, rl cvity, mnvcuum meter). Accrding t Pscl s lw, ll mesuring ints f excessive ressure r dischrge (vcuum) remin cnstnt. As result, the fllwing mesurements were estblished: The mximum excessive ressure is but 0.5 ilguss / cm2 r ~5 P; The mximum vcuum vlue is but 0.4 ilguss / cm2 r ~40 P. The btined results llw us t me reliminry chice but the mximum vlues f the ressure trnsducer tht is subjected t the limittin ccrding t Item N. 5. This ws cnsidered s cunter fr the ressure generted by the flw meter due t the resistnce f the ir flw in its mst nrrw rt, nd this shuld nt exceed 30% f the vlue generted by humns, which llw us t determine the mximum ressure vlue f the trnsducer t but 5 P in the exirtry cycle (excessive ressure) nd 0 P in the insirtry cycle (dischrge r suctin). Figure : Semi-Cnstructin Scheme Flw Meter, Built n the Princile f Venturi Nzzle The design f the dignsing device cnsidered the flw rte chrcteristics nly fr the ir suctin cycle. T mesure the dimeter f Venturi nzzle, we used the flw rte clculting frmuls [3] 3 d c 4 а - The dischrge cefficient f flw meter used in cnstructin,,l/s, () - Crrectin cefficient, ting int ccunt the exnsin f tmsheric ir in the flw meter, c - Crrectin cefficient, ting int ccunt the lctin f the flw meter, d - Nzzle dimeter, in mm, а - Air density, g / m3 - Pressure dr in ressure sensr PS, with tw mesuring hles, ne f them is fr negtive ressure mesurement (vcuum r dischrge) lcted in the nzzle diffuser nd cnnected t n electricl utlet, nd the secnd is cmmunicted with tmshere, nd mesured in P. The ir density ws determined by the fllwing frmul:

4 24 Knigv Iurii Vldymyrvych, Oleg Grigrvitsh Avrunin & Hushm Fru Ismil P N g g а = = 2 3 T н (273.5 t C ) J К м N м м g К = (273.5 t C ) t C, кg/m3, (2) - Atmsheric ressure, in P, - Atmsheric ressure [mmhg], which is sscited t ressure in [P] equlity 98, 03 = mmhg clumn - Gs cnstnt t tmsheric ressure hving dimensin J N м = g К g К, which ssumes cnstnt fr ll chnges in vlues f tmsheric ressure, equl t the vlue f the gs cnstnt н fr T nrml tmsheric cnditins by Urine Stte Stndrd when ir temerture н = 20 Сnd ressure н = P = (760 mm Hg clumn). frmul: J н 288 g К, (3) T t C -Abslute temerture, mesured in degrees Celsius [ С ] befre testing. Nmintin f crrectin cefficients [3]: fr flw meter used in cnstructin, recmmended cefficient vlue 0f с ; cefficient vlue = cceted t rti f 2 P, nd t 3 4 > 2 P tht is clculted by the н, (4) Where н Tа а а Tн н - The rti f ir density, =.4 dibtic index. vlue, Fr exmle, if the mximum ressure dr = 0 P, nd cefficient were the cceted miniml н (5) Thus, the frmul fr clculting the flw rte hs the fllwing frm: d tc, L/s, (6) Or fter the intermedite clcultins:

5 Clcultin f Venturi Nzzles Dimeter fr Nsl Brething Evlutin Device tc d Frm which we get the frmul fr clculting the dimeter f the nzzle, L/s, (7) d tc (8) Fr rcticl clcultin f nzzle dimeter, we te in dvnce the fllwing rmeters: макс - The mximum erting ressure fr ressure sensr (by ssrt); = - T be cnfirmed by Frmul (5); = The flw rte cefficient vlue, within the recmmendtin rnge by ef. [3], nd which is t be cnfirmed t the finl trils cnstructin; = 760 mm рт. Clumn - re- setting vlue by tmsheric ressure, which shuld be ccunted t ech flw mesurement thrugh the Venturi nzzle; t mesurement. о 20 C - The ir temerture in the mesuring rm, which is ls t be ccunted fr ech flw The btined dt must be cnfirmed when crrying stndrd, including metrlgicl, certifictin, nd must be tested n the instlltin ccrding t the exeriment in Figure 2., which resents rincil neumtic circuit fr devices under studying tye(differentil ressure-flw chrcteristics DPF) nd devices fr creting resistnce nd clibrtin f ir flw mesurement. T crete stble ir flw while urging device tye DPF, wer surce f but 600 wtts is required. Using clibrted (reference) flw meter llws us t ssess the errr generted by the flw meter, nd if necessry, cn crry ut crrectins f the flw cefficient vlues in rder t minimize the errr. Cnstructively, DPF rtus cnsists f flw meter РА DPF bsed n Venturi nzzle, blc ressure sensrs BPS, mdule nlg-digitl cnverter (ADC), nd ersnl cmuter (PC) with USB interfce. In the unit f flw meter РА DPF erfrmed inside cylindricl diffuser with the extensin dimeter directed twrd the surce f ir inte. A flw meter junctin ws fixed t the unit with reverse vlve (V) nd Pressure Mesuring Pint (PMP). Chec resistnce (r set f resistnces), which indicted flw cntrller (FC), ws munted t the utlet hle f the junctin. In the BPS blc, ressure sensrs PS PS4 were relced with electricl terminls nd flexible tubes (ies) fr cmmunictin ressure sensrs with the flw meter РА DPF (PS) nd ressure mesurement ints C nd D in the flw cntrller FC (T2 nd T3). Flexible tube T4 ws used fr simultneus testing (checing) f the ressure sensr PS PS4. The lce fr ressure sensrs mesuring ws the intercnnectin ielines T... T3: PS-T- ressure sensr fr flw meter; PS2-T2- ressure sensr fr mesuring in nshrings;

6 26 Knigv Iurii Vldymyrvych, Oleg Grigrvitsh Avrunin & Hushm Fru Ismil PS3-T3- ressure sensr fr mesuring in vizrd; PS4-T4- ressure sensr fr bresting exirtin hse registrtin. everse vlve (V) serves t limit the excessive ressure t vid sensr dmge t PS PS4. Pressure Mesuring Pints PMP llws us t cnnect the dditinl ressure trnsducer (if necessry). The Device DPF Prvides Simultneus cntrl f the ressure dr nd flw rte in the testing chnnel (trct r flw cntrller); Prcessing btined test results by cnstructing grhic deendence f the ressure dr frm the flw rte nd by clculting the rti f flw t ressure dr nd irflw wer. Determintin f the ir flw ws rvided by mesuring the ressure t the diffuser inlet, by clculting the frmul lining the rmeters f ressure dr nd flw rte in turbulent qudrtic deendence mde, nd by using clibrtin (reference) flw meter РА. T rvide flw rte mesurement in the full rnge f ressure trnsducer PS (t imrve mesurement ccurcy), the DPF device is cmleted with flw meters РА DPF with tw r three nminl vlues f nzzle dimeters. РА DPF flw meter cn be instlled directly n the blc BPS r t sme distnce frm the unit, in rnge length f intercnnecting iing T... T3. frmul: Figure 2: Pneumtic Circuit Digrm Bench Instlltin fr Metrlgicl Certifictin Devices DPF T clculte the ctul (djusted) cefficient vlues, flw rte ws btined frm Equtin (7) using the fllwing 9.38 э ф А tc d э, (9) э - Air flw, mesured by clibrted flw meter, L / s, А d tc -Cefficient, (0)

7 Clcultin f Venturi Nzzles Dimeter fr Nsl Brething Evlutin Device 27 Ech clcultin mde f mesurement ws erfrmed due t ssible mbient temerture chnges tmsheric ressure tc nd, s well s the existence f functinl deendence f crrectin fctr (4), ting int ccunt the exnsin tmsheric ir in the flw meter n ressure dr s well s the reltins f ir density. T ssess the reetbility f the results nd ctul crrectness, we btined (secified) vlues by flw cefficient cnsidering functinl deendence:,l/s, () - Cefficient f rrtinlity between flw rte nd squre rt f the ressure dr d F tc, (2) d nd studied flw meter. F - dimeter f nzzle nd flw cefficient, resectively, which were cnsidered cnstnt fr the The rmeters ; ; и tc re cnsidered cnstnt fr ech test mde. Next, fr ech test mde, the vlue f the cefficient ws clculted using the frmul. (3) By devitin vlues, the stbility f testimny flw meter ws evluted in full rnge f flw mesurement: MAX MAX MIN 00, %. (4) As n Exmle, we Present the esults f Cefficient Clcultin, s Obtined by Testing Full-Scle Mdels f Flw Meters When d = 7 mm = 3.4% in the rnge = L/s; When d = 8 mm = 4.4% in the rnge = L/s; When d = 9 mm = 0.2% in the rnge = L/s. The finl ste in creting the device is cnsidering its stte metrlgicl certifictin, which estblishes the reltive errr f flw rte mesurement.

8 28 Knigv Iurii Vldymyrvych, Oleg Grigrvitsh Avrunin & Hushm Fru Ismil 00%, (5) Where - the flw rte f ir thrugh verifible flw meter РАDPF determined by clculting Frmul (7), l / s, - Air flw, mesured clibrtin (reference) flw meter PA, L / s. CONCLUSIONS A methd fr clculting nzzle dimeter ws designed t determine ressure dr nd flw rte chrcteristics f humn nsl ssges. Stndrd studying nd metrlgicl verifictin inted n the ssibility f btining sufficiently relible mesurement results when using flw meter tht is bsed n Venturi nzzle. The rsect f further wr is cmlex studies f the flw meter s rt f device fr dignsing n erdynmic nsl ssges functin. EFEENCES. W. Bchmnn. Obstructed nsl brething. Bsis investigtin: Histry, Insectin, hinmnmtry, llergy (rf. V. Bhmnn. Difficulty f breth. Bcgrund studies: Histry, Exmintin, hinmnmetry, llergies) с. 2. Authentictin, The Unin f Sviet Scilist eublics Artus fr determining nse ir cnductin. Mrtinens M.L, Bure D.A. Inventrs' certifictes nd tents 8 in Stte Stndrd f Unin f Sviet Scilist eublics rdil ventiltrs nd xil. Methds erdynmic Exeriences. 4. Stte Stndrd f Unin f Sviet Scilist eublics (ISO 567-:2003). Flw rte mesurement nd fluid munt nd gs with using stndrd nrrwing devices. Prt. The rincile f the mesurement methdlgy nd generl requirements. 5. Stte Stndrd f Unin f Sviet Scilist eublics (intergvernmentl stndrd). Flw mesurement nd fluid munt nd gs with using stndrd nrrwing devices. Prt 5. mesurement methdlgy rcedure. 6. E.I Sl, A.B Kiensii,.S Tmshevsii, E.I. nd thers, Sirmetry. Its technicl surt. Prblems nd rsects// «Technicl Electrdynmics» Themtic issue. The rblems f mdern electricl engineering. Prt 3. - Kiev: Urinin Institute f Electrdynmics f NANO, : 9 24, 2008.