Patent ID: 6429575
Filing Date: 2002-08-06
Classification: B06B

Abstract:
Device for transmitting ultrasoninc energy to a fluid or pasty medium, witha) an alternating current generator, which is designed to provide frequencies between 1 kHz and 100 kHz, b) a magnetostrictive or piezoelectric transducer which can be brought into high frequency longitudinal mechanical oscillations under the alternating current voltage output of a generator, c) a cylindrical-rod shaped wave guide, which can be excited to longitudinal resonant oscillations via the transducer, and d) a tubular shaped hollow chamber resonator acoustically coupled with the wave guide, which converts the longitudinal resonant oscillations in respect to its longitudinal axis into transverse oscillations, of which the oscillation energy can be transmitted into the medium to be treated with ultrasound, whereby e) the hollow chamber resonator is so arranged or designed, that it satisfies the resonance condition with respect to the longitudinal as well also with respect to the transversal self-oscillations of its jacket, wherein the resonator length L, the outer diameter D0 and the thickness &dgr; of the resonator wall (18; 62) are tuned to each other according to the relationships L=ClR2&it;fr&it;n&af;(1-Î”&it;â€ƒ&it;L1+1+Î”&it;â€ƒ&it;L);n=1,2,3,â€¦(1)D0=ClrÏ€&it;â€ƒ&it;fr+(1+Î”&it;â€ƒ&it;D)(3)L&leq;Î´&af;(D0-Î´)&CenterDot;ClR&CenterDot;Ï RD0&it;Ï L&it;CL(5)â€ƒin which ClR represents the sound velocity of the longitudinal ultrasound-oscillations in the material of the hollow chamber resonator (17; 17â€²), which is satisfied by the relationship ClR=E&af;(1-v)Ï R&af;(1+v)&it;(1-2&it;v)(2)â€ƒwherein CL represents the sound velocity in the ultrasound radiation subjected load material, &rgr;R represents the specific weight of the resonator material, &rgr;L represents the specific weight of the load material, E represents the Young's modulus of elasticity, with the Poisson's transverse contraction constant of the resonator-material, and fr represents the resonance frequency of the hollow chamber-resonator (17; 17â€²), wherein the dimensions &Dgr;L and &Dgr;D satisfy the relationships Î”&it;â€ƒ&it;L=a2a2-(1+Î”&it;â€ƒ&it;D)2(4)â€ƒand Î”&it;â€ƒ&it;D=b2-a2c2-1-1(4â€²)â€ƒin which a and b characterize the point of intersection coordinates of two functions a1(y) and a2(y) according to the relationship a1(b)=a2(b)=a, which in implicit form are provided by the relationships â€ƒ&xgr;(a1,Jn)&bgr;(a1)+&mgr;(a1,Nn)(1âˆ’G(a1))âˆ’&mgr;(y,Jn)G(a1)+&mgr;(y,Nn)=0â€ƒâ€ƒ(6/1)q&af;(a2,Jn)&it;Î²&af;(a2)+q&af;(a2,Nn)&it;(1-G&af;(a2))-Îºt&af;(a2)Îºt&af;(a2)&af;[q&af;(y,Jn)&it;G&af;(a2)-1&it;(y,Nn)]=0(6/2)â€ƒ&kgr;t2(x)=kt2âˆ’k2(x)â€ƒâ€ƒ(6/3)&kgr;l2(x)=kl2âˆ’k2(x)â€ƒâ€ƒ(6/4) k2(x)=kl2&kgr;2(x)â€ƒâ€ƒ(6/5) k1,t=2&it;Ï€&it;â€ƒ&it;frClR,t(6/6)Îº2&af;(x)=(1-2&it;v)&it;(b2-x2)-x2(1-2&it;v)&it;(b2-x2)(6/7)Î¾&af;(x,Zn)=zN+1&af;(x)-v2&it;x(n+1)&it;(1-v)&it;Zn&af;(x)(6/8)q&af;(x,Zn)=&dd;Zn+1&af;(x)&dd;x-(n+1)x&CenterDot;Zn+1&af;(x)(6/9)Î¼&af;(x,Zn)=Zn+1&af;(x)+v&af;[&vartheta;&af;(x)-Îº2&af;(x)](1-v)&it;Îº2&af;(x)&CenterDot;&dd;Zn+1&af;(x)&dd;x(6/10)â€ƒwith: &thgr;(x=a1 or a2)=1; &thgr;(x=y)=c2 G&af;(X)=G1&af;(x,Nn)G1&af;(x,Jn)(6/11)â€ƒG1(x,Zn)=&mgr;(x,Jn)[&xgr;(y,Zn)+&xgr;(x,Nn)]âˆ’&xgr;(x,Jn)[&mgr;(x,Zn)+&mgr;(x,Nn)]â€ƒâ€ƒ(6/13) C=ClRCt(6/14)Ct2=E2&it;Ï R&af;(1+v)(6/15)â€ƒare given, wherein Ct represents the sound velocity of the transverse ultrasound wave.