GB704633A - Electro-acoustic device - Google Patents

Abstract

<PICT:0704633/III/1> <PICT:0704633/III/2> <PICT:0704633/III/3> <PICT:0704633/III/4> <PICT:0704633/III/5> <PICT:0704633/III/6> Continuously flowing liquids are treated by acoustic energy which is concentrated in a treatment head located at the focal region of a focused ultrasonic transducer (see Group XXXIX). The applications referred to in the Specification include emulsifying two liquids which may be either premixed or introduced into the treatment head through separate passages, sterilization or agglomeration of a single liquid or a liquid dispersion and the dispersion of particles such as copper powder in a liquid of high or low viscosity. As shown in Fig. 1, the liquid to be treated is circulated through a pipe 94 which communicates with a cylindrical member 86 threaded into a treatment head 23, the outer end of the cylinder being closed by a threaded plug 88 which supports a concentrically positioned outlet pipe 89. This pipe has a flared inner end which is positioned at the focal region and is adjustably clamped by a cap and gasket 91, 92. An auxiliary pipe 96 is provided for introducing a second liquid. An acoustic transmission wall 25 partitions the treatment head from a transducer which is contained in a housing 19. In a second embodiment, Fig. 14, a treatment head 111 which is separated from the transducer by a diaphragm 112 comprises inlet and outlet ducts 116, 117 and an auxiliary duct 118. A curved upper wall 114 is manufactured of suitable thickness to act as a reflector of the acoustic energy. Other forms of treatment head may be used in conjunction with a diaphragm. In one arrangement, Fig. 5 (not shown), the upper wall is flat and has a corrugated interior surface crosswise to the flow of liquid to be treated so as to provide a longer treatment path and a scattering of the reflected acoustic energy. An alternative treatment head. Fig. 6, comprises a flat upper wall and inlet and outlet ducts 123, 126 terminating in flared portions 124, 127 which distribute the flow of material over a group of thin baffle discs 128, 129, 130. These discs may be made of stainless steel and provide four separate treatment areas for liquids which do not require violent cavitation. In two further arrangements, Figs. 8 and 10, the diaphragm 112 is omitted and a small diaphragm 134, 143 is secured against a raised ledge on the interior surface of the upper wall. In Fig. 8, vertical inlet and outlet ducts 136, 137 communicate by a spiral groove while in Fig. 10 concentric inlet and outlet pipes 144, 146 are provided together with an auxiliary duct 148. Another form of treatment head, Fig. 11, comprises an inlet pipe 153 <PICT:0704633/III/7> and an outlet pipe 154 which has a constricted throat 156 and terminates in a flared member 157. A diaphragm 1121 which is clamped by the head has a similarly flared central portion. A further device, Fig. 12, is arranged so that the liquid to be treated constitutes an acoustic transmission liquid for conveying to the focal region the acoustic energy generated by transducer elements 15, 16, 17. The device comprises a housing 1911 which includes an integral duct member 162 having a narrow throat portion 161 at the focal region. The liquid may circulate in either direction between the duct 162 and a fitting 163 in a base 1111. Auxiliary ducts 164, 166 are aranged adjacent to the throat portion.ALSO:A continuously flowing liquid is sterilized by acoustic energy radiated by an ultrasonic transducer, (see Group XXXIX), and concentrated at a focal region.