KR20170137766A - Multistage hood filter - Google Patents

Abstract

The filter assembly includes a housing and a diffuser permanently attached within a central portion of the housing. The baffle assembly is permanently attached to the housing adjacent the diffuser. A removable support structure is installed within the housing on the side of the diffuser opposite the baffle assembly. A removable filter pad is installed between the removable support structure and the diffuser. The removable support structure may be supported on opposite ends by opposing lips of the housing.

Description

Multistage hood filter

The present invention relates generally to filters for use in an exhaust hood, and more particularly to multi-staged filters for use in such hoods.

In a typical restaurant kitchen, a plurality of cooking units are arranged side by side under a normal exhaust hood. The cooking unit may include, for example, a range, a griddle, a fryer, and a broiler. The cooking processes performed in these devices all produce air with various amounts and temperatures of grease, smoke, fumes, moisture, heat, and other particles. The air is drawn into the exhaust hood, where it is filtered. One known filtration system is disclosed in U.S. Patent No. 7,581,539 B2 to Aviles et al., The disclosure of which is incorporated herein by reference.

According to a particular embodiment, the multi-stage oil filtration system is designed to fit completely within the standard 2 inch wide baffle filter channel in the ventilation hood. The system includes a first filter and a second filter operatively disposed in series. The first filter comprises a filter material having an upstream surface and a downstream surface and an external support element abutting the upstream or downstream surface and is configured to be mounted within the upstream side of the second filter. The outer support may be attached to the filter material without any additional support on opposite sides of the filter material. The second filter is configured to be mounted in the ventilation hood and has a perforated air diffuser, a flame barrier, and an upstream opening that retains the first filter in the middle portion of the housing of the system.

The first filter may be disposed on the upstream side or the downstream side of the second filter.

The first filter including a first surface and a second surface opposite the first surface; An outer support structure abutting one of the first surface and the second surface of the filter material; At least one fastening element disposed adjacent a periphery of a side of an external support structure abutting one of the first surface and the second surface, wherein the at least one fastening element retains the filter material substantially in place relative to the external support structure And the outer support structure provides rigidity to the filter material.

BRIEF DESCRIPTION OF THE DRAWINGS For a more complete understanding of the embodiments of the present invention, the needs satisfied thereby, and the objects, features, and advantages thereof, reference is now made to the following detailed description taken in conjunction with the accompanying drawings.
1 is a perspective view of a filter assembly mounted in an exhaust hood on a cooking apparatus, in accordance with an embodiment of the present invention.
2 is a perspective view of a filter assembly lifted by a mounting tool into an opening in an exhaust hood, in accordance with an embodiment of the present invention.
3 is a perspective view of a component of a filter assembly in accordance with an embodiment of the present invention in which the outer support structure is removed and the filter material is folded into the interior of the opening in the second filter;
4 is a front isometric view of a filter assembly, in accordance with an embodiment of the present invention.
5 is a schematic cross-sectional view of a filter assembly, in accordance with an embodiment of the present invention.
6 is a rear isometric view of a filter assembly, in accordance with an embodiment of the present invention.
7 is an enlarged front view of a first filter according to an embodiment of the present invention.
8 is a perspective view of the bottom of the filter assembly, in accordance with an embodiment of the present invention.
9 is an exploded perspective view of a filter assembly, in accordance with an embodiment of the present invention.
10 is an exploded perspective view of a filter assembly, in accordance with an embodiment of the present invention.

Commercial exhaust hoods manufactured to be installed in the United States must conform to certain codes and standards, such as National Fire Protection Associates (NFPA) Standard 96. This standard specifies that all hoods used in commercial cooking establishments installed on cookware that produce effluents other than heat and steam other than grease during the cooking process shall be individually and separately operated in accordance with Underwrites Laboratories (UL) Standard 1046 It is required to include the grease removal device as listed or as a component of the UL 710 listed hood. This standard requires that the degreasing device be capable of preventing flame spreading from the upstream surface of the filter to the downstream region of the filter.

Since the standard exhaust hood has a 2 inch width filter channel for a standard 2 inch thickness baffle filter, another embodiment of a fiber based disposable grease filter is provided within the filter channel for fitting additional disposable grease filters adjacent the baffle filter Due to the absence of space, welding or drilling may be required to modify the exhaust hood and / or existing baffle filters.

An exemplary embodiment of the present invention includes a first filter having a high efficiency oil filtration capability and a second filter disposed downstream of the first filter (with respect to the direction of air flow through the filter and the hood) And a multi-stage oil filtration system designed to fully fit inside the standard 2 inch wide baffle filter channel in the ventilation hood. The first filter comprises a filter material attached to an outer support structure made of a relatively more rigid material. The second filter is preferably effective to prevent diffusion of the flame from the upstream side of the filtration system to the downstream region of the system.

The second filter may be any filter that drains grease out of the filter, and is also preferably an effective flame barrier. One example of a filter for ventilation hood that drains oil into an oil drain and is an effective flame barrier is disclosed in U.S. Patent No. 3,910,782 to Struble et al., The disclosure of which is incorporated herein by reference. Baffle type filter.

It is understood that other grease drains and flame barrier filters are within the spirit and scope of the embodiments of the present invention.

The baffle filter is very effective in preventing the flame from advancing to the downstream side as required by UL standard 1046. However, baffle filters are satisfactory for filtering out grease having a particle size of greater than about 10 micrometers (占 퐉), but less effective for smaller particles. Thus, embodiments of the present invention further include a first disposable or permanent filter positioned upstream of the second filter in the air flow direction, the second filter being separate for the first filter. Furthermore, the baffle filter is difficult to clean and reuse, and therefore it is advantageous to have a disposable filter upstream from the baffle filter.

In certain embodiments, the filter material may include a stabilizing frame, such as, for example, the filter disclosed in US Patent No. 8,277,530 B2 to Alexander et al., The disclosure of which is incorporated herein by reference, Fibers, such as natural, synthetic, and / or hybrid fibers, with or without fibers. In other embodiments, the filter material may be made entirely or partly of wool fibers, such as, for example, but not limited to, filters disclosed in U.S. Patent No. 6,293,983 to More, the disclosure of which is incorporated herein by reference. And is partially manufactured.

Recent changes to the UL 1046 standard now allow testing of so-called "multistage" filters. If the filter assembly can pass the tests mandated by the standard as a whole, then materials that can not pass the standard flame safety requirements separately and can not be passed may be used.

Embodiments of the present invention thus provide a filtration system having both a first filter and a second filter wherein the second filter is a highly effective flame barrier and the first filter is highly effective in trapping particulates. The final combination simplifies the installation procedure and reduces the cost of renewal associated with disposable filter materials, providing excellent performance in both respects.

In some embodiments, the first filter may be formed of a natural, synthetic, and / or hybrid fiber, such as, but not limited to, wool fibers, wood-based viscose fibers, and cellulosic- It is partially fabricated with a metal mesh or fiber. The blend of fibers blends refractory viscose fibers with wool fibers; Carding of the blend into a fibrous web; Needle punching of a fibrous web into a nonwoven blanket; And application of a bonding emulsion to the woolen fibers. Certain embodiments may further include applying a vacuum to the nonwoven blanket and / or passing the nonwoven blanket through the oven at greater than 280 degrees Fahrenheit. In some embodiments, the first filter is made of an organic material, such as a natural organic material. In some embodiments, the second filter is made of an animal-derived organic material such as wool.

Other filter materials are within the scope of the appended claims.

The material of the first filter may be disposed or attached adjacent to an outer support structure made of a relatively more rigid material. Fiber filters are advantageous for their particle filtering capabilities, but their stiffness is similar to the stiffness of a paper towel if there is no inner frame or outer housing interposing a filter material between the two surfaces. The inner frame option results in an expensive manufacturing cost, whereas an openable outer housing interposing a filter material between the two surfaces compresses the filter material to increase air flow resistance and result in less oil capture capability. For this reason, their use is limited despite their filtration characteristics.

By attaching a single surface of the fiber material to one surface of the external support structure, defects caused by lack of rigidity of the fiber material may be corrected. In certain embodiments, the outer support structure may include a fastening element that grips the filter material to hold it in place. In this manner, the material may be provided with its original loft, density, grease trapping capacity, and minimum airflow resistance, while still achieving stiffness for easier installation and removal.

As described above, the first filter may be installed on the upstream side of the second filter in an exhaust hood canopy according to a specific embodiment, as shown in Fig. There are at least two alternative configurations for positioning the first filter with respect to the external support structure. First, the first filter may be positioned such that the filter material is on the downstream side of the external support structure in the airflow direction, similar to those shown in Fig. Second, the first filter may be positioned with the filter material on the upstream side of the outer support structure, similar to those shown in Fig. An additional benefit when the outer support structure is located upstream of the filter material is that the outer support structure can provide a better aesthetic appearance compared to the appearance of the contaminated filter material. Alternatively, when the outer support structure is configured on the downstream side of the filter material, the outer support structure will remain cleaner for a longer period of time resulting in reduced labor and associated cleaning costs.

1, the filter assembly 200 is mounted within the hood 102 above the cooking utensil 100. As shown in FIG. The fryer 101 is shown for illustrative purposes. Alternatively, the cooking utensil may include, for example, a range, a griddle, a fryer, a broiler, and the like.

Figure 2 illustrates the operation of sliding the head 501 of the mounting tool 502 below the upper lip 401 of the filter assembly 200 and moving the filter assembly upwardly into the opening 105 and upper channel 103 in the hood 200 The filter assembly 200 being lifted by manipulation and lying down into the lower channel 104 here.

Figure 3 illustrates the outer support structure 300 being removed from the housing 400 while the filter material 303 is disposed behind the upper lip 401 and lower lip 402 of the second filter 202 Respectively. The filter material 303 is folded to expose the downstream perforated air diffuser 409.

4 shows a front isometric view of the filter assembly 200 and a baseline used to indicate a cross-sectional view as shown in Fig.

Figure 5 illustrates one of the cross-sectional views of the filter assembly 200 referenced in Figure 4 wherein the filter assembly 200 includes the following components: a first filter 201 and a second filter 202 You may. The first filter 201 may comprise an outer support structure 300 and a filter material 303. The second filter 202 may include an intermediate divider tab 408 (optional), a perforated air diffuser 409, and a baffle assembly 404 all encapsulated within the housing 400. The baffle assembly 404 includes a vertical baffle rib 405 of the upstream row and a vertical baffle rib 406 of the downstream row and each rib is offset from the other rib to form an airflow gap 407. Optional vertical bail handles 410 may be added to the housing 400. The filter assembly 200 enters the filter assembly 200 through the first filter 201 and then through the perforated air diffuser 409 and then through the airflow gap 407 provided by the baffle assembly 404 ("P") < / RTI >

Most of the grease may be filtered from the air stream by the filter material 303 in the first filter 201. [ Any residual grease entrained in the through-air may be attached to the vertical baffle ribs 405 of the upstream row and the vertical baffle ribs 406 of the downstream row. The baffle assembly 404 may then function as a channel or gutter and may direct the accumulation of grease to the bottom of the filter assembly 200 under gravity as further described in Figure 8 .

Figure 6 shows a back view of a second filter 202 revealing a baffle filter assembly 404 that includes a vertical rib 405 in the upstream row, a vertical rib 406 in the downstream row, and an airflow opening 407 .

4-6 illustrate that the baffle assembly 404 and the perforated air diffuser 409 are secured within the housing 400 and that the external support structure 300 and the filter material 303 are removed from the housing 400 Lt; / RTI > This allows the filter material to be periodically replaced without the need to remove the entire housing from the kitchen hood. The filter material 303 may be simply disposed relative to the outer support structure 300 and then the outer support structure may be inserted into the housing 400. [ The upper lip 400a and the lower lip 400b of the housing 400 hold the outer support structure 300 in place in the housing 400. [

Gravity will pull the outer support structure 300 away from the diffuser 409 so that the filter material is not compressed between the diffuser 409 and the outer support structure 300 when it is installed in the hood 102 in this manner Will be. This permits an air gap 420 between the filter material 303 and the diffuser 409. This air gap and the lack of compression of the filter material 303 allows the filter material 303 to operate more efficiently to remove greasy particulates from the air. The removable external support structure may also be perforated to permit sufficient air flow therethrough.

FIG. 7 shows a side view of a separate fastening element 301 (not shown) that may be located on any one or more of the sides of the outer support structure 300 and is designed as a velcro or hook for attaching or penetrating directly to the filter material 303 woven or non- In which the filter material 303 is attached to the outer support structure 300 by the use of the filter material 303 as shown in Fig. The fastening elements 301 can be any size or shape and can be attached to the outer support structure 300 using an adhesive, welding, riveting, sewing, threaded engagement or any combination thereof.

Other independent coupling elements 301 are within the scope of the appended claims. For example, in certain embodiments, the filter material may be attached to an external support structure using a latch, a hook and loop fastener, a clamp, an adhesive, a stick tack, a hook, or other similar means.

Figure 8 shows the bottom of the housing 400 of the filter assembly 200, which may include a series of drain holes 411, 412 for the first and second filters, respectively, through which the grease Or may be advanced on the way to a ventilation hood holding a reservoir (not shown).

Figs. 9 and 10 show two configuration options in which the first filter 201 is disposed on the upstream side of the second filter 202. Fig.

9 shows that in the first filter 201, the external support structure 201 is oriented on the downstream side of the filter material 303. Fig. This may be done to filter the air before the filter material 303 is brought into contact with the outer support structure 300 to reduce the need for the outer support structure 300 to be cleaned at night and to provide rigidity to the filter material 303 Still available.

Fig. 10 shows that in the first filter 201, the external support structure 201 is oriented on the upstream side of the filter material 303. Fig. This may be done so that the external support structure 300 maintains the rigidity for the filter material 303 while providing better aesthetics. This configuration is also shown in the embodiment of Figs. 1-5.

According to certain embodiments of the present invention, the components of the filter assembly may be made from stainless steel. For example, a reusable component of a system including a baffle assembly, an air diffuser, a housing, and an external support structure may be made of stainless steel. Filter materials comprising disposable filters may be made from a variety of different materials, including combinations of wool and viscose materials. In certain embodiments, it is advantageous for the wool to comprise more than 50%, in some embodiments more than 75% of the blend of materials of the filter material. For example, wool may account for 60% to 90%, or 70% to 80% of the blend. In this embodiment, the viscose is the only other material in the blend and may occupy the remaining amount of material. In another embodiment, it is more advantageous to include more than 50%, in some cases more than 75%, of the viscose material in the blend. Similarly, viscose may comprise from 60% to 90%, or from 70% to 80% of the blend. In this embodiment, the wool is the only other material in the blend and may occupy the remaining amount of material.

It is advantageous to size the filter assembly to allow it to be inserted into the hood to replace the 2-inch baffle filter. Accordingly, the thickness of the entire filter assembly in the housing and in some embodiments may be in the range of one and a half to two inches thick. In certain embodiments, the total thickness may be in the range of 1.65 "to 1.95" to allow optimal "fit" within the hood. In the particular illustrated embodiment of the present disclosure, a 1.75 "thick assembly is illustrated.

In certain embodiments, the filter assemblies of Figs. 4-6 may be of a square configuration having sides that are within a range of 14 "to 16 ". This will allow multi-stage filters to replace standard baffle filters in standard hoods. In the illustrated embodiment, the side of the filter is approximately 15.5 "long.

To fit within the housing of the filter assembly, the outer support structure is configured to be a square or rectangular configuration that is slightly smaller than the filter assembly. In the illustrated embodiment, the outer support structure is approximately 14.5 "by 15 ". The "short" side corresponds to the side that will engage the upper lip and the lower lip of the housing. In another embodiment, the side of the outer support structure may be 13.5 "to 15.5", and the "short" side is about 1/2 inch shorter than the long side.

Figures 4-6 are generally shown as accumulation. Thus, the baffle filter accounts for more than 50% of the thickness of the filter assembly. In various embodiments, the baffle filter may comprise 55% to 75% of such thickness. The outer support structure and the filter material together comprise less than one third of the thickness. In various embodiments, the outer support structure may comprise from 15% to 40% of the thickness. In certain embodiments, a filter material (e.g., a filter pad) is configured to allow the filter assembly to pierce the outer support structure on at least two sides of the outer support structure, and in some embodiments, May be slightly longer in one dimension than the outer support structure.

According to a particular embodiment, the stiffness provided by the external support structure may be advantageous to more easily handle the filter material during installation and removal of the filter material, thereby shortening the time and effort required for installation and removal.

The first filter may be oriented with external support elements on the upstream or downstream side of the filter material for aesthetic and maintenance purposes benefit.

The external support structure may not require any additional support on opposite sides of the filter material.

The first filter may be attached to the second filter, for example, removably.

The filter material of the first filter may be natural fibers, hybrid fibers, synthetic fibers or any combination thereof.

The second filter element may cooperate to form an opening for the first filter.

The second filter may include a housing, a top lip, a bottom lip, a suspension clip, a flame barrier, a drain hole, an intermediate divider tab, and a perforated air diffuser.

The flame barrier in the second filter may be one or more baffle filters, metal mesh filters, or any other known flame barrier.

The ventilation hood may comprise a track and the second filter may be configured to be inserted and possibly clipped onto the hood and moved along the track by use of a suspension clip of the filter assembly. The first filter may also be configured to be inserted into the hood by being inserted into the second filter and moving along the track.

Claims (7)

A housing,
A diffuser permanently attached within the central portion of the housing,
A baffle assembly permanently attached to the housing adjacent the diffuser,
A removable support structure installed within the housing at a side of the diffuser opposite the baffle assembly,
And a removable filter pad disposed between the removable support structure and the diffuser,
Wherein the removable support structure is supported on opposite ends by opposing lips of the housing. 2. The filter assembly of claim 1, wherein the removable support structure and the removable filter pad are sized to allow an air gap of greater than about 1/4 "between the removable filter pad and the diffuser. The filter assembly of claim 1, wherein the removable filter pad comprises woolen fibers and viscose fibers. 4. The filter assembly of claim 3, wherein the viscose fiber comprises 50 to 95% of the removable filter pad. 4. The filter assembly of claim 3, wherein the woolen fibers comprise 50 to 95% of the removable filter pads. 2. The filter assembly of claim 1, wherein the filter pad, the removable support structure, and the diffuser are laterally spaced from the baffle assembly to permit passage of air through the baffle assembly. 2. The filter assembly of claim 1, wherein the removable support structure comprises a back support having a perforation formed therein.

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