Filtering medium for air filter, filter pack, air filter unit, and method for producing filtering medium for air filter
US10265654B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 20, 2015 |
| Grant date | Apr 23, 2019 |
| Priority date | — |
| Expiry date | May 15, 2036 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01D2275/305
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A filtering medium includes first and second porous membranes mainly composed of fluororesin, and a plurality of air permeable supports to support the first and second membranes. The second membrane is disposed downstream of the first membrane. When air containing polyalphaolefin particles with a count median diameter of 0.25 μm is continuously passed through at a flow rate of 5.3 cm/sec and pressure loss is increased by 250 Pa, the first membrane has a dust retention amount larger than the second membrane. The filtering medium has a pressure loss of less than 200 Pa when air is passed through at a flow rate of 5.3 cm/sec. A collecting efficiency of NaCl particles with a particle diameter of 0.3 μm is 99.97% or more when air containing the NaCl particles is passed through at a flow rate of 5.3 cm/sec. The dust retention amount is 25 g/m2 or more.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.