Non-consumable respirator training filter

A training filter includes an upper shell having a substantially central hole; a lower shell adjoined to the upper shell; and a plug positioned in the substantially central hole and extending through the lower shell, wherein the plug includes a top wall having a plurality of apertures; a valve adjacent to the top wall and the plurality of apertures; the plug defining a hollow breathing resistance core adjacent to the valve; an angled sidewall flanking the breathing resistance core; and a connection mechanism connected to the plug opposite the top wall. The training filter duplicates the weight, size, shape, and breathing resistance of an actual filter and is reusable and cleanable without a shelf life unlike an actual filter.

BACKGROUND

Technical Field

The embodiments herein generally relate to filters, and more particularly to filters used in respirators.

Description of the Related Art

Respirator users perform a variety of tasks with a respirator in potentially hazardous environments. Operating a respirator incorrectly or knocking the respirator loose in a hazardous environment can be deadly. To prevent mistakes, training in a safe environment while wearing a respirator is helpful, and often required by employers, to understand the performance limitations of wearing a respirator. Some examples include: shouldering and sighting a weapon, operating a vehicle, physical mobility and physical exertion limitations, and maneuvering in confined spaces. These tasks may become harder because respirators can limit the user's field of view, increase breathing resistance, increase head borne weight and neck fatigue, physically interfere with a user's other equipment/environment, or cause other hardships to the user.

In order to provide effective training, the user must typically experience as many realistic conditions as possible, which requires the user to have a filter in place and feel the breathing resistance the filter would provide. All filters have a limitation in their service life, which begins to degrade when exposed to a number of environmental conditions including humidity and ambient particulates. These conditions degrade filter life, performance, or completely consume the filtration capacity, regardless of the training environment's toxicity. Using a consumable filter in a training environment that doesn't require filtration creates a cost and disposal burden which is preferably avoidable.

Currently there are many different types of training oral nasal masks that simulate breathing at high altitudes, or increase breathing resistance. These masks are generally targeted towards physical fitness training. While it might be possible to find a training mask whose breathing resistance is similar to a filter canister and respirator combination, the training masks do not simulate wearing a full face piece respirator with filter canister.

SUMMARY

In view of the foregoing, an embodiment herein provides a training filter comprising an upper shell having a substantially central hole or port; a lower shell adjoined to the upper shell; and a plug positioned in the substantially central hole and extending through the lower shell, wherein the plug comprises: a top wall having a plurality of apertures; a valve adjacent to the top wall and the plurality of apertures; the plug defining a hollow breathing resistance core or chamber adjacent to the valve; an angled sidewall flanking the breathing resistance core adjacent the valve; and a connection mechanism connected to the plug opposite the top wall. The valve may comprise a stem outwardly extending from the top wall of the plug. The connection mechanism may comprise a hole creating a continuous air path from the plurality of apertures through the hollow breathing resistance core and through the connection mechanism. The training filter may further comprise a ballast surrounding the plug. The upper shell and the lower shell may comprise an air pocket surrounding the ballast. The valve may comprise a flapper valve. The valve and the angled sidewall may be configured to alter a breathing resistance through the plug. The plurality of apertures may be arranged in a pattern. The plurality of apertures and the angled sidewall may be configured to match a breathing resistance of a non-training filter. The angled sidewall, the pattern of the plurality of apertures, a predetermined number of the plurality of apertures, and the valve may be configured to alter the breathing resistance of the training filter to match that of an actual respirator filter. The connection mechanism may outwardly protrude from the lower shell and be adapted to connect to a respirator.

Another embodiment provides a reusable training filter comprising a first shell having a hole or port; a second shell adjoined to the first shell; a plug positioned in the hole and extending through the second shell, wherein the plug comprises: a valve seat comprising at least one aperture; a valve adjacent to the valve seat and the at least one aperture; the plug defining a hollow breathing resistance chamber or core adjacent to the valve; an angled upper sidewall flanking the breathing resistance core; and a connector connected to the plug at an end opposite the top wall. The filter further comprises a ballast surrounding the plug, wherein the first shell and the second shell comprise an air pocket surrounding the ballast. The valve may comprise a stem outwardly extending from the valve seat of the plug. The connector may comprise a hole creating a continuous air flow path from the at least one aperture through the hollow breathing resistance core and the connector.

The valve may comprise a flapper valve. The valve and the angled upper sidewall may be configured to alter a breathing resistance through the plug. The at least one aperture may comprise a plurality of apertures arranged in a pattern. The plurality of apertures and the angled upper sidewall may be configured to match a breathing resistance of a non-training filter. The angled upper sidewall, the pattern of the plurality of apertures, and a predetermined number of the plurality of apertures may be configured to alter the breathing resistance to match that of an actual respirator filter. The connector may outwardly protrude from the second shell.

DETAILED DESCRIPTION

The embodiments herein provide a non-consumable respirator training filter. Referring now to the drawings, and more particularly toFIGS. 1 through 9, where similar reference characters denote corresponding features consistently throughout the figures, there are shown preferred embodiments.

There are many different respirator filter canisters that could be simulated with a training filter. The embodiments herein describe using the C2A1 military filter. However, other types of filters could be used in accordance with the embodiments herein.FIGS. 1 through 6illustrate various views of a training filter5in accordance with the embodiments herein. As generally shown inFIG. 1, the filter5comprises an upper (first) shell10adjoined to a lower (second) shell15. The upper shell10comprises a generally tapered upper wall20configured with a substantially centrally positioned inlet port23. As shown inFIG. 2, a series of beveled lips21,22form the periphery of the upper wall20. As shown inFIGS. 5 and 6, a plug25is seated within the inlet port23and extends through the filter5. The plug25includes an upright stem33that forms part of a valve65such that the stem33extends outward from a top30wall of the plug25. The valve65may comprise silicone in one embodiment. The stem33is configured to be positioned substantially central on the top wall or valve seat30(e.g., top wall or upper portion of the plug25). A plurality of apertures35are configured in the top wall or valve seat30of the plug25surrounding the stem33. The valve65is configured as a flapper valve according to an embodiment. The stem33is pulled through a center hole35a(shown inFIG. 7A) in the valve seat30of the plug25to hold the valve65in place. The stem33is dimensioned and configured to allow a user to grab onto and pull the valve33into position. As shown inFIGS. 3 and 4, the lower shell15comprises a lower wall45that is offset and protruding outwards from a surrounding lip40that forms the periphery of the lower shell15. An outwardly protruding connection mechanism50is positioned in a substantially central part of lower wall45, wherein the connection mechanism50includes threads55that are dimensioned and configured to engage a complementary set of threads (not shown) on a respirator (not shown). The connection mechanism50is substantially hollow such that hole60is formed through the entire height of the connection mechanism50and up through the entire height of the lower shell15and a partial height of the upper shell10, as shown inFIGS. 5 and 6.FIGS. 7A through 7Cillustrate isolated views of the plug25. The apertures35of the plug25allow air into a chamber or hollow breathing resistance core63, which is defined by the plug25and positioned below the valve65. The plug25further comprises a flared and tapered lower sidewall72that is adjacent to the connection mechanism50. The lower sidewall72is configured to align with the lower shell15and allows the plug25to retain its position in the filter5.

The plug25has a plurality of features to replicate the breathing resistance of a conventional commercial or military filter the training filter5is used to replace. The plug25further includes an angled sidewall70that flanks the hollow breathing resistance core63. The apertures35, valve65, and sidewall70are collectively adapted and configured to match the breathing resistance of a conventional commercial or military filter. An air path62connects the breathing resistance core63to the hole60of the connection mechanism50. This completes the air flow path from apertures35through the hollow breathing resistance core63and air path62then out of hole60of the connection mechanism50and into a connected respirator (not shown). The valve65is configured to open and close in order to control the flow of air from at least one aperture of the plurality of apertures35through the hollow breathing resistance core63and through the hole60of the connection mechanism50. An air pocket75is configured through the upper shell10and lower shell15and abuts a ballast80that surrounds the plug25such that the ballast80adds weight to the filter5, which is configured to allow the trainer filter5provided by the embodiments herein to replicate the weight of the commercial or military filters.

To ensure that the breathing resistance of the training filter5matches with the conventional C2A1 filter, the pressure downstream of three C2A1 filters was experimentally measured. Pressure was recorded at air flow rates in 20 liter per minute (LPM) increments between 20-120 LPM. The comparison of the training filter5provided by the embodiments herein versus the three C2A1 filters (C2A1-A, C2A1-B, and C2A1-C) is shown inFIG. 8. As indicated inFIG. 8, the resistance of the training filter5is comparable to the conventional filters at various flow rates, which suggests that the training filter5provides similar functionality as actual filters, but without the drawbacks of using actual filters in training scenarios.

The training filter5provided by the embodiments herein can be used for training in place of the conventional C2A1 filters, which saves cost and allows a user to train indefinitely on a single training filter5. Additionally, the training filter5eliminates the carbon bed common in conventional chemical filters. This removes any chance of the user breathing in dislodged carbon. Carbon can shed or become dislodged from impacts or damage to the filter canister during training, and can be a health hazard if ingested or inhaled by the user.

In other embodiments, the density and wall thickness of the upper shell10, lower shell15, plug25, and ballast80can vary and be properly sized to attain the correct weight. Moreover, a different combination and configuration of apertures35, port23, valve33, and sidewall70could be used to match the breathing resistance profile of a filter canister.

FIG. 9compares the measured resistance of a conventional Avon GPCF50 filter with the training filter5provided by the embodiments herein. Resistance measurements were recorded in the same fashion as the measurements presented for the C2A1 filters inFIG. 8. As indicated inFIG. 9, the resistance of the training filter5is comparable to the conventional filter at various flow rates, which suggests that the training filter5can be tuned to replicate other filter resistances and configurations as actual filters, but without the drawbacks of using actual filters in training scenarios.

The embodiments herein reduce filter consumption in training scenarios, which allows a user to become accustomed to wearing a respirator without the costs or risks of using an actual filter. The training filter5provides the same external ornamental shape, weight, and breathing resistance as a filter canister in a training filter housing. The breathing resistance is simulated by a series of apertures35and the valve65, which at various breathing rates match the breathing resistance of an actual filter. Replacing the HEPA filtration media and carbon bed with the plug25having apertures35, valve65, and a hollow breathing resistance core63having tapered walls70allows the training filter5to duplicate the weight, size, shape, and breathing resistance of an actual filter and be reusable and cleanable, without a shelf life, unlike an actual filter.