Method for efficient filtration of chemical baths
US6267894A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 3, 1998 |
| Grant date | Jul 31, 2001 |
| Priority date | — |
| Expiry date | Dec 3, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S134/902
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A method of filtering a bath (1,31) having a liquid containing particles of varying sizes therein and the recirculation and filtering system. The method and system require providing a recirculation route from the bath outflow and returning to the bath inflow. The route includes a first path communicating with the bath outflow and having serially a first controllable valve (5,9) and a filter having a relatively large pore size. The route also includes a second path communicating with the bath outflow and having serially a second controllable valve (11,15) and a filter having a relatively small pore size. There is a return path from each filter to the bath inflow. The return path from each filter can be a separate path or the paths can be connected at the output end before returning to the bath. The particle count in the recirculation route can be monitored either between the bath outflow and the first and second valves (3), between the bath inflow and each of the filters having large and small pore size (23), or both for controlling operation of the first and second valves. The controllable valves can also be controlled by a time program, bath operation program or the like.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.