Patent Application
20130074697
Dust filtration in networking equipment can be a concern, particularly in new networking environments. Some recent networking equipment deployment practices include decentralization of networking equipment, “outside air cooling” with air side economizers, portable data centers, and even deployment in tents. Many of these recent deployment practices employ networking equipment into dirty environments, which escalates risk of damage due to overheating the networking equipment. Additionally, emerging markets have increased contamination risk due to uncontrolled air quality environments in which the equipment is placed.
Electromagnetic interference (EMI) solutions and high density heat sinks in equipment also add new potential for dust to accumulate in unserviceable areas of networking equipment. Dust fouling impedes cooling solutions, although it may take several years, thus eluding detection in traditional development testing. Increased contamination increases the vulnerability of the equipment and leads to additional maintenance, down time, and costly service in the field.
Existing dust filter technology is not well suited for many networking equipment applications. Most available dust filtration solutions are designed to remove a very high percentage of all particulate matter, including extremely fine particulates. This is despite that most small particulate passes straight through computing equipment with very little effect on cooling efficiency. The primary threat to cooling solutions is from “long fiber” dust, such as cotton or cardboard fibers, for example. Existing filters typically clog rapidly and reduce cooling performance.
In the following detailed description, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. In this regard, directional terminology, such as “top,” “bottom,” “front,” “back,” “leading,” “trailing,” etc., is used with reference to the orientation of the Figure(s) being described. Because components of embodiments can be positioned in a number of different orientations, the directional terminology is used for purposes of illustration and is in no way limiting. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims. It is to be understood that features of the various embodiments described herein may be combined with each other, unless specifically noted otherwise.
Embodiments provide techniques of filtering air for electrical equipment. The air filtration techniques minimize air flow impedance, smooth air flow, and maximize dust collection.
The at least one chassis (e.g. top chassis 14 and bottom chassis 16) is arranged to contain an air stream provided by a cooling subsystem formed by filter assemblies 30 and 130 and optionally at least one fan 84. (see
Filter assemblies 30, 130 are illustrated extended from enclosure 12 in
In one embodiment, a mechanism 46 (such as mechanism 46 illustrated in
When fully assembled, filter assemblies 30, 130 are positioned within enclosure 12 so as to not protrude outside enclosure 12. This increases the usability and functionality as well as the aesthetic appeal of equipment 10. Filter assemblies 30, 130 include filter 50 (such as filter 50 illustrated in
In one embodiment, filter assemblies 30, 130 are configured as tapered plenums. In one embodiment, the size and shape of filter assemblies 30, 130 depends on the geometry of electrical equipment 10 into which filter assemblies 30, 130 are installed, including the width and depth of electrical equipment 10.
First side 36 and second side 38 are generally triangular shaped, tapering from front inlet face 32 toward back 34. Alternatively, first side 36 and second side 38 are rectangularly or otherwise shaped and include a mechanism for securing filters 50 at angle θ with respect to inlet face 32. In one embodiment, filter assemblies 30, 130 create a pressure front which makes the airflow turn as interior channel 60 gets narrower and pressure builds, forcing the air to redirect. Angle θ should be sufficient to let airflow into the inner wedge shaped channel area 60. In one embodiment, angle θ permits the airflow to turn approximately ninety degrees as it passes through filter 50 with respect to inlet face 32. In one embodiment, filter 50 is configured to balance the initial impact, and therefore airflow blockage, over the long term useable life of filter 50.
With reference to
Filters 50 include frame 52 disposed along the perimeter of media 54. In one embodiment, frame 52 is c-shaped with the top and bottom portions extending over the media 54. In one embodiment, frame 52 is configured around media 54 in a manner that minimizes the size of frame 52 while still allowing frame 52 to contain media 54. Media 54 may be attached within frame 52 by any suitable mechanism including friction fit, for example. Generally, frame 54 includes a fastener such as a mechanical fastener, for example, a screw, a rivet or other suitable fastener. Frame 52 provides rigidity and provides a structure for attaching filter 50 within filter assemblies 30, 130. For example, frame 52 can include mounting holes along the perimeter to secure filter 50.
In one embodiment, frame 52 is electrically conducting, thereby providing electrical bonding between media 54 and enclosure 12. In one embodiment, frame 52, which encompasses a perimeter of filter media 54, is a metallic material such as aluminum, although other materials may also be used. In one embodiment, frame 52 is formed of 2 mm thick aluminum, for example. In one embodiment, frame 52 and/or media 54 provide EMI shielding and/or RFI containment. Filter media 54 removes dust and other particulates from air drawn through filter media 54. Filter 50 includes filter media 54 including at least one inner layer 58 and opposing outer layers 56 disposed exterior to inner layers 58. Media 54 is configured as a porous media. In one embodiment, filter media 54 provides RFI containment and/or EMI shielding through a generally electrically conductive coarse substrate. In one embodiment, filter media 54 includes an expanded aluminum layered media.
Filter media 54 is configured of material suitable to trap long fiberous material and allow fine particles to pass through. Filter media 54 material is selected based on several different criteria such as the mesh variety offered, gage of the material (i.e., thickness), layer count, and opening size of the filter assembly within which the filter fits, for example. In one embodiment, inner layers 58 are a thinner gage metallic material than outer layers 56. Outer layers 56 assist with retaining inner layers 58 and provide filter media 54 a level of rigidity. In one embodiment, a thinner gage of at least one inner layer 58 is used to improve air flow and minimize air flow impedance. In one embodiment, either one of or both outer layers 56, and at least one inner layer 58, include a metallic material such as aluminum. Other suitable materials may also be used. Outer layers 56 and inner layers 58 may be made from commercially available material.
Embodiments of media 54 were tested by exposing media 54 to a mixture of airborne fiber and fine particulate matter. A reliability design verification dust chamber replicating one embodiment of field failure mechanism of electrical equipment was created. Initial thermal penalty, dust build up in key areas of the chassis, and “filter fill” thermal penalty were closely monitored throughout the test. A 3/32 inch layered aluminum material embodiment was used and tested. Other material embodiments, such as a honeycomb front panel, polyester fabric media, electrostatic media, metal mesh screen, ⅜ inch layered aluminum, quadrofoam horizontally placed, and quadrafoam diagonally placed, were used and tested. The 3/32 inch layered aluminum embodiment performed significantly better than the other tested material embodiments in testing of both initial impact and “filter fill” thermal impact. With a filter change, the selected media 54 will restore initial thermal performance, while the unfiltered equipment will continue to degrade.
In
With particular regard to
As air exits filter assembly 30 through filter media filter 50 on first surface 40 and/or second surface 42 of filter assembly 30, airflow 70 is reoriented and redirected by the angled filters 50 within filter assembly 30. In one embodiment, airflow 70 is directed both upward and downward toward interface module card cage 80. Airflow 70 is directed between electrical components within interface module card cage 80. In one embodiment, the electrical components are installed in a parallel manner running from the top to the bottom of the interface module card cage 80, thereby allowing airflow 70 to flow between the electrical components. After exiting interface module card cage 80, airflow 70 is redirected to exhaust out back 25 of electrical equipment 10. Alternatively, airflow 70 can continue out any exterior surface of enclosure 12 which enables airflow 70 to be exhausted. In one embodiment, airflow 70 exits through exhaust 82. In one embodiment, a fan 84 assists airflow 70 out of electrical equipment 10. Fan 84 can be used to drive air out of exhaust 82 or pull air through electrical equipment 10 thereby generating a continuous flow of air through electrical equipment 10 as indicated by airflow 70.
With particular reference to
With reference to
Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and/or equivalent implementations may be substituted for the specific embodiments shown and described without departing from the scope of the present invention. This application is intended to cover any adaptations or variations of the specific embodiments discussed herein. Therefore, it is intended that this invention be limited only by the claims and the equivalents thereof.
