Process and device for the separation of substances dissolved in the washing water used in processing bath of a photographic film
US5607592A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 14, 1995 |
| Grant date | Mar 4, 1997 |
| Priority date | — |
| Expiry date | Jun 14, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C7/44
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
The present invention concerns a process and a device for the separation of substances dissolved in the washing waters used in a processing bath for a photographic film. The photographic film, after passing through the processing bath, is caused to pass successively through at least two washing tanks, the process consisting of causing the waste water from the washing baths to circulate through a nanofiltration membrane device, the permeate from the said nanofiltration device being recirculated to the washing tank or tanks other than the last of the tanks in which the film passes, the last of the tanks being fed with clean water from an auxiliary source.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.