Air filtration device having subsections lacking fluid communication
A filtering device 10 that includes a housing 12 having a plurality of subsections 32, 34 , and 36 where each subsection contains a filter element 26, 28 , and 30 . An inlet 18 is disposed at a first location on the housing 12 , and an upstream air distribution system is placed in fluid communication with the inlet 18 and with each of the subsections 32, 34 , and 36 . A downstream air distribution system is located in fluid communication with each subsection 32, 34 , and 36 , and an outlet 20 is in fluid communication with the downstream air distribution system. The subsections are fashioned such that each subsection 32, 34 , and 36 is not in fluid communication with each other. Using a filtering device so constructed, airflow through the device may be better managed to enable overall product service life to be increased while minimizing pressure resistance of the total filter.
1. A powered air purifying respirator (PAPR) air filtering device that comprises:
(a) a housing that includes a plurality of subsections, each subsection containing a filter element;
(b) an inlet disposed at a first location on the housing;
(c) an upstream air distribution system in fluid communication with the inlet and with each of the subsections;
(d) a downstream air distribution system located in fluid communication with each subsection; and
(e) an outlet in fluid communication with the downstream air distribution system;
wherein the housing subsections are not in fluid communication with each other,
and wherein the housing is curved along a longitudinal axis such that the housing is configured to be located within a crown space of a helmet.
2. An air filtering device of claim 1 , wherein the subsections exhibit substantially the same airflow velocity.
3. The filter cartridge of claim 1 , wherein one or more of the subsections include a split flow filter.
4. The filtering device of claim 3 , wherein the device is a filter cartridge that is adapted for use in a personal respiratory protection device.
5. A personal respiratory protection device that contains the filter cartridge of claim 4 .
6. The personal respiratory protection device of claim 5 comprising the helmet, the filtering cartridge being located in the crown space of the helmet.
7. A powered air purifying respirator, which comprises the filter cartridge of claim 6 in the crown space of the helmet.
8. The filtering device of claim 1 wherein the upstream and downstream air distribution systems each contain a plenum and a manifold.
9. The filtering device of claim 8 , wherein the plenums, manifolds, and filter elements cause substantially the same airflow velocity through each subsection.
10. The filtering device of claim 1 , wherein the air is delivered to each subsection through a plenum and one or more channels or passageways.
11. The filtering device of claim 10 , wherein the air leaving each subsection travels through one or more channels or passageways.
12. The filtering device of claim 1 , wherein the air entering a subsection is split into two airstreams.
13. The filtering device of claim 12 , wherein the split flow airstream passes through opposing filter elements before exiting the subsection.
14. The filtering device of claim 1 , wherein the airflow velocity in each subsection is within 5% of other subsections from a baseline value.
15. The filtering device of claim 1 , wherein the subsections each contain particulate and/or gaseous filters.
16. The filtering device of claim 1 , wherein each subsection contains a particulate filter element that contains microfibers, and wherein each subsection contains a gaseous filter element that contains active particulate.
17. The filtering device of claim 16 , wherein each subsection contains one or more filter elements that are tilted relative to the airflow entering the subsection.
18. The filtering device of claim 1 , wherein the device comprises 2 to 20 subsections.
19. The filtering device of claim 1 , wherein the device contains 3 to 10 subsections.
20. A powered air purifying respirator (PAPR) air filtering device that comprises:
(a) a housing that contains 3 to 10 subsections, each subsection containing a filter element, at least one of the subsection containing two or more filter elements;
(b) an inlet disposed at a first location on the housing;
(c) an upstream air distribution system in fluid communication with the inlet and with each of the subsections, the upstream air distribution system containing a plenum and a manifold;
(d) a downstream air distribution system located in fluid communication with each subsection; and
(e) an outlet in fluid communication with the downstream air distribution system;
wherein the housing subsections are not in fluid communication with each other,
and wherein the housing is curved along a longitudinal axis such that the housing is configured to be located within a crown space of a helmet.