Mixing systems
US5972661A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Sep 28, 1998 |
| Grant date | Oct 26, 1999 |
| Priority date | — |
| Expiry date | Sep 28, 2018 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01J2219/00768
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A system for providing improved bulk liquid mixing and effective gas-liquid contacting for mass transfer of the gas to the liquid, especially a non-Newtonian liquid, the viscosity of which decreases when under shearing conditions (shear thinning), in an upright tank. A process, such as fermentation which produces commercial quantities of polysaccharides such as xanthan gum, may be carried out in the tank. An upright draft tube is mounted within the tank and has a lower end spaced from the tank bottom and an upper end spaced below the surface of the liquid in the tank. A plurality of mixing impellers in the draft tube are sufficiently close to each other to establish a field or pattern of agitation to cause shear thinning and upflow throughout the draft tube and which may produce turbulence at the liquid surface. A plurality of radially inwardly projecting, circumferentially spaced baffles extend from the draft tube and are proximate the mixing impellers to prevent swirling of the liquid within the draft tube. Gas may be sparged into the vessel in or adjacent to the lower end of the draft tube. A circulating co-current flow of gas and liquid, with intimate gas-liquid contact, is ind…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.