| 摘要 |
<p>1,227,444. Jet pumps. CONDENSEURS DEIAS. May 17, 1968 [May 30, 1967], No.23482/68. Heading F1E. An aspirator, e.g. with steam as the inducing fluid for de-gassing molten metals in a vessel connected to the aspirator, comprises an expansion tube 8 in an aspiration chamber 3, and a convergent divergent diffuser 7 having a divergent section comprising a first portion 7b of axial length 0À2 to 0.3 times the minimum diameter D of the diffuser, a second portion 7c of axial length 8 to 10 times D and either cylindrical or of small divergence of the order of 1 degree, and a third portion 7d. In the embodiment shown, expansion tube 8 has a first section 8a having a divergence angle less than 10 degrees, and a second section 8b having a divergence angle between 20 degrees and 60 degrees. Section 8a is effective when starting aspiration, and section 8b is effective to prevent turbulence when the pressure in chamber 3 is very low. In Fig. 2 (not shown), section 8b of expansion tube 8 is omitted.</p> |
