GVHD:Nguyn Th Minh TrinhSV :Nguyn nh Khang : L Xun Nht Hiu : * NHM 7

TI: *

NI DUNG:nh ngha p sut, chn khngCc thit b o p sut chn khngng dng trong k thut v i sngTi Liu Tham Kho

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I.p sut1. nh ngha:L lc tc dng vung gc ln mt n v din tch, k hiu l p.

*p=F/S (kG/cm2)

I.P SUT2. n v o p sut

*1 Pa = 1 N/m21 mm Hg = 133.322 N/m21 mm H20 = 9.8 N/m21 bar = 105 N/m21 at = 9.8 x 104 N/m2

*I.P SUT

II.CHN KHNG:

* 1.Lch s chn khng

Democrite- cha ca thuyt nguyn t, cho rng chn khng l khng gian khng cha vt cht, trng rng, hon ton khng c gAristote li ph nhn chn khng, cho rng khng gian cha y ete v tr-cht tinh ty tuyt vi, n c mt mi ni, mi chn.+Nhng t duy nim c tnh trit hc v chn khng. trng rng, h v thng tr t duy ca th gii Rp, La M, Hy Lp b nh khi c s ra i khoa hc thc nghim caGallile(1564-1642),Pascal(1623-1662),Torricelli(1608-1647) th k XVII.

II.CHN KHNG:

* 1.Lch s chn khng

+ ng phng,t lu s dng p sut chn khng trong cha bnh, c th l s dng gic ht +Nhng n nm 1654, sau th nghim caqu cu MagdeburgdoOtto Von Guericketin hnh ti bang Magdeburg, nc c, qu ng, chn khng mi thc s c hiu ng v bt u phc v sn xut .+Ngy nay,l thuyt lng t khng nh rng: Do s ng n canguyn l bt nhm lun c sdao ngkhi lng v nng lng (d rt nh) trong lng chn khng. Ngha l, nhng ht mangnng lngvn tn ti trong chn khng. Chng to ra p sut trong lng chn khng, gi lp sut lng t chn khng.

II.CHN KHNG:

* 2.nh ngha.

nh ngha chn khng c in: Chn khng lkhng giankhng chavt cht. Nh vy chn khng cth tchkhc khng vkhi lng bngkhng (v do nng lng bngkhng). Do khng c vt cht bn trong, chn khng l ni khng cp sut.

nh ngha chn khng trong k thut: khong khng-thi gian c th cmt vt chtthp hoc rt thp, do chn khng l trng thi c p sut nh hn p sut kh quyn trung bnh chun.

II.CHN KHNG:

* 3.Phn loi.

I.Phng php o:o p sut trc tip:L phng php s dng cc chuyn i c i lng vo tng ng vi lc, ng sut cn o. i lng ra c bin i thnh cc tn hiu in.Mch o v ch th cho kt qu o khng thng qua h dn truyn trung gian

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I.Phng php o:o gin tip: L phng php s dng cc phn t n hi, cc h dn truyn, bin lc, ng sut, p sut thnh di chuyn.Cc chuyn i o cc lng di chuyn, t suy ra i lng cn o

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I.Phng php o:

*Trong phm vi chn khng cao v p sut siu cao hin nay ngi ta dng phng php in o lng,gm cc dng c o nh sau:

Chn khng k kiu dn nhit:Da theo mi quan h ca h s dn n nhit ca cht kh vi p sut p sut thp. Nhit dy dn khi cn bng nhit s thay i ty theo h s dn nhit ca kh v dng cu in khng cn bng xc nh in tr dy dn ta s bit c chn khng tng ng

I.Phng php o:

* Chn khng k kiu Ion

Da trn hin tng ion ha. C nhiu cch thc hin vic ion ha nh: + Dng tc dng ca t trng v in trng + S t pht x ca catot c t nng khi c in p trn anot + Dng s phng x

p k kiu p tp sut to ra ng lc c hc trong vt liu st t s to ra s bin i h s dn nhit t ca vt liu .Li dng hiu ng p t ta c th ch to ra c b nhy cm kiu p t

II.Dng c o:Chn khng k Mc leoddng o p sut chn khng.Nguyn l hot ng: da trn nh lut nn p on nhit ca kh l tng.

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*ng VenturiBi tp Tnh vn tc ca nc ti vng c mt ct nh bit chnh ct p l h = 10cm. V tit din ln gp i tit din nh

*Bm ht chn khngGAST (USA):Rotary vane vacuum pump- Bm ht nn chn khng Gast kiu cnh gtng dng: - Dng cho kh th y t - Y hc tr liu - ng gi - Ngh thut ha - Nng h bng chn khng - Ly mu kh - ng gi chn khng - Bm ht chn khng, my ht chn khng Phng th nghim - Bm ht chn khng, my ht chn khng Thc phm v..v

*Bm ht chn khngb) BECKER (GERMANY) :Bm ht chn khng khng du Becker VT4.4 -4.40 Series

ng dng: bm ht chn khng, my ht chn khng trong ngnh bao b, Thc phm, Robotics, trong y t v nhiu ng dng khc. Nhng bm ny cng c lp trong mt s h thng chn khng trung tm cho nhng ng dng c bit, bn cng c th la chn loi kt hp va ht va nn cho mt s ng dng trong ngnh in n phong b

*Bm ht chn khngBm kt hp ht nn chn khng Becker DVT Series

Bm ht chn khng vng nc 2 cp Taiwan GW/GWV Series

Bm ht nn chn khng SV1.50-5.1050 SeriesBm ht chn khng Taiwan model DS-2S

*T Sy Chn Khng XF-050 France EtuvesMy ht chn khng Dz 300A

*Phng php ht chn khng trong iu tr tn thng ty sngPhng php ht chn khng trong xy dng

*Van chn khng dng kh nn VSMR Series (theo nguyn l ca van chn khng Ejector)ng dng: s dng nhiu trong cng nghip dy chuyn t ng ha, trong cc cnh tay robot...thi gian p ng nhanh

*Phu ht chn khng Vmeca - VB SERIES:

Phu ht chn khng Vmeca - VFC SERIES

ng dng: + tm g dn + tm nha + nng hp giy + phim mng mng + hp cc tng v linh kin in tng dng: + nng knh t, knh chn gi + bng hnh ti vi

* Gio trnh o lng nhit Hong Dng Hng http://www.youtube.com http://www.hctechco.com K thut o lng - tp 2 (NXB DHQG) Mt s ti liu ca anh ch kha trc

*Thank you for your attention!