Patent Application
20050078449
The invention relates to retard a heating or over-heating condition and to provide adequate air flow and, more particularly, to meet the inflammability standards in telecommunications devices.
Telecommunications devices must adhere to certain standards concerning fire security and inflammability. Compliance with these standards is terribly important particularly for public communications. In the case of a fire, telecommunication could be lost over vast geographic areas, which could result in financial loss, public disarray and dissatisfaction with services, and even panic. Therefore, these standards are taken seriously by the industry and all attempts to meet the criteria are taken.
Within a frame 100 of telecommunications devices 102 shown in
Typically, the racks are tested for compliance with the standards by taking measurements while simultaneously raising the heat load. In regards the American market, these requirements are stringently enforced in accordance with the Telcordia GR63 standard, which prescribes Fire Resistance Criteria for Electronic Components. Currently, GR63 requires that all polymeric materials, components, and interconnect wire and cable used within equipment assemblies comply with one of the following criteria:
Practically speaking, inflammable or at least fire resistant materials were used to construct the telecommunications box and components therein.
The conventional wisdom concerning fire within a telecommunications box is to reduce the air flow as much as possible. This arising from the physical principle that air fuels a fire. For this reason, it has been a practice to provide for any openings on the telecommunications box, particularly where the air flow is concerned, such as on the top side, to have means for closing and securing that no air can enter the box. As will be explained, this philosophy is problematic.
Another problem that frustrates the standardized testing is that different telecommunications boxes are differently configured. Under different air flow conditions, the telecommunications box may have different heat dissipation characteristics. For example, when one or more modules are removed from the telecommunications box, the heating dissipation characteristics change. This is shown in
Moreover, the heating dissipation characteristics change in a way that is unexpected. By removing modules, one would expect that less components would decrease heat, and thus reduce the risk or problems of fire. In principle this is true. However, the heat dissipation problems are exacerbated in the case of a module removed, particularly for those adjacent the module experiencing a fire. The reason for this was determined by experiment, during the development of this invention, to be a lack of air flow due to the missing modules. This is because, without the physical profile of the module, there is inadequate air resistance adjacent the missing module. As a result, an adequate air flow cannot be ensured and, thus, adequate cooling cannot be maintained.
This is certainly problematic, because certain customer configurations do not require functional optical networking circuit packs. Since the empty slots provide no resistance to air flow, most of the air passes through this way as a result. The critical components receive less cooling and can overheat causing reduced system life or in some cases system failure.
The present invention offers a manner in which to retard a heating or overheating condition and to provide adequate air flow. There is provided a manner in which to maintain a working temperature environment in an electronics device and, furthermore, to prevent a fire in a telecommunications device or at least to reduce the flames of a fire substantially so that the fire can be brought under control or stopped from spreading. More specifically, the invention provides a manner in which to fulfill the inflammability standards in telecommunications devices.
An object of the present invention is to provide heating dissipation in a telecommunications device.
An object of the present invention is to retard a heating or overheating condition telecommunications device.
An object of the present invention is to provide adequate air flow telecommunications device.
An object of the present invention is to provide a manner in which to maintain a working temperature environment in an electronics device.
An object of the present invention is to provide to prevent a fire in a telecommunications device.
An object of the present invention is to reduce the flames of a fire substantially so that the fire can be brought under control or stopped from spreading.
An object of the present invention is to provide a manner in which to fulfill the inflammability standards in telecommunications devices.
An object of the present invention is to provide a manner in which to fulfill the GR63 standard.
In accordance with these and other objects of the invention, there is provided an apparatus for retarding a fire condition of a telecommunications component mounted on a module to be inserted into a telecommunications box, the module having a planar surface having a first side and a second side generally opposed to the first side. A ventilator provides a cross air flow generally in a direction from the first side to the second side. A first opening in the telecommunications box in an area adjacent of the first side of the planar surface forms a substantial portion of the cross air flow emanating from the first side. A second opening in the telecommunications box arranged in an area adjacent to the second side of the planar surface exhausts the cross flow air, such that the cross flow air substantially retards the fire condition.
A method is provided for retarding a fire condition of a telecommunications component mounted on a planar surface of a module housed in a telecommunications box, the planar surface having a first side and a second side generally opposed to the first side, wherein a ventilator that provides a cross air flow generally in a direction from the first side to the second side. A step of arranging arranges a first opening in the telecommunications box in an area adjacent of the first side of the planar surface in order to form a substantial portion of the cross air flow emanating from the first side. A step of arranging arranges a second opening in the telecommunications box in an area adjacent to the second side of the planar surface in order to exhaust the cross flow air, such that the cross flow air substantially retards the fire condition.
a and 2b illustrate an exemplary embodiment of the invention; and
The invention will now be discussed in reference to
One or more ventilators 208, which may be arranged singularly in several next to each other in a module. In one aspect of the invention, the inventive aspect is to control the ventilator 208 or ventilators in dependence on an air pressure created by the temperature within the box 200.
In one aspect of the invention, the ventilator turns dependent on the measured ambient temperature at a predetermined temperature resistance. This creates the general air flow which tends to cool the electronic components of the telecommunications device. Due to the control of the ventilators in this manner, another advantage is that the operating noise is substantially lowered at e.g. ambient temperature.
One or more ventilators may be arranged in a ventilator drawer 210 situated above in the Figures. A second drawer 212 may be arranged below the elements to be cooled. Of course, the invention is not limited to the arrangement where the ventilator drawers are above and below, but opposite from each other. In another configuration for example the ventilators could be fore and aft, i.e., front and rear, or in another aspect may be diagonally opposed. The result is a cross flow of air that crosses a planar face of a particular module from one side of the module to the opposing side.
In one aspect, the lower module 212 is separated for EMV reasons and because of possibly burning construction units that fall through a perforated sheet metal lying over it. This placement offers an ideal ventilator redundancy in case of failure of a ventilator or with exchange of ventilator drawer. In case of one or more ventilator failure, the invention provides that the still intact or remaining ventilator is switched to full number of revolutions.
The advantage concerning the behavior in case of fire, however, is due to the fact that one or more separate thermal relays, arranged in the environment of the upper ventilator module, the lower ventilator on full can regulate temperatures over approximately 90 C.
The upper ventilators run in the case of fire because of the temperature resistance applied there on full number of revolutions, however in the case of flames directly blazing under it could be already destroyed. The high turning ventilators cause the air flow to rise and the above operating, heated elements there tend to be cooled down.
A test of the invention was conducted in accordance with the GR63 testing parameters, which calls for a pipe with horizontal gas flames to be inserted into the equipment. The influx gas flow is then increased linear up to a maximum value and then decreased to zero. Thereby, only within certain limits flames and developed smoke may the goal of testing be ascertained.
Under these conditions, the flames and smoke existing as energy within the Box is to transferred upward in the best possible manner by the ventilator away from the equipment. Thus, the ignition temperature of the inflammatory construction units even when brought up to the high point of the gas supplied (=largest flame development) after approximately 1 minute is not reached.
In addition, the lower ventilators where run during the test. On maximum permissible engine speed, the ventilators operated correctly since they the are below or outside fire area.
In addition to control of the ventilator, the invention prevents or retards a fire condition of a telecommunications component mounted on a module to be inserted into a telecommunications box by providing for a cross flow of air. As previously mentioned, the preeminent thinking is additional air increases the incendiary effect. However, while this in principle true, it has been found in the invention that the opposite is true, at least for electronic components stored in racks or frames.
For description, let us define the module as having a planar surface 214 having a first side 216 and a second side 218 generally opposed to the first side. Of course, planar does not necessarily mean but that it has a general plane surface. In the invention, the ventilator 208 provides a cross air flow 220 generally in a direction from the first side to the second side.
A first opening 222 in the telecommunications box 200 in an area adjacent the first side of the planar surface. The first opening provides the inlet for a substantial portion of the cross air flow emanating from the first side.
A second opening 224 in the telecommunications box 200 arranged in an area adjacent to the second side of the planar surface in order to exhaust the cross flow air. In the invention, it was found through experimentation that, through the operation of the assisted air provided by the openings, the cross flow air substantially retards the fire condition. Indeed, it was observed that flames inside the telecommunications box were substantially reduced owing to the present invention.
In another aspect of the invention shown in
The present invention simulates the component friction and causes air flow resistance, thereby balancing the cooling air flow towards the functional cards. Through testing, it has been proven that the air flow guide of the present invention reduces critical temperatures by over 7 deg C.
Now with reference to
Openings 304 shown in
The general shape and form of the air flow guide is preferable in the form of a module. That is, it may be generally rectangular with a planar profile. There may also be a front panel 306 and thumb screws 308 for fitting the air flow guide into an existing slot of a telecommunications box.
It shall also be appreciated that the invention need not necessarily require all empty slots to be filled with an air flow guide. It is possible to insert air flow guides in the adjacent empty slots, adjacent that is to a module. However, the testing was performed with all empty slots filled with an air flow guide and the optimum results were achieved.
The invention has been described with respect to particular examples shown in the figures. However, it shall be understood that the invention encompasses more than the particular embodiments shown and that the invention shall not be limited thereby.
A further advantage embodiment of the invention is the separate arrangement and the separate control of the used ventilators. The ventilators, arranged side by side in a slot, are turning as a function of the measured temperature of the environment at a temperature resistor. Therefore the operating noise (e.g. at room temperature) will be decreased. A first ventilator drawer is arranged above, a second ventilator drawer is arranged below the elements to be cooled. The second ventilator drawer is protected by a perforated plate. This is because of electromagnetic compatibility (EMC) and/or protection against falling or burning elements, which could hit the second ventilator.
This arrangement of the ventilators offers a redundancy of the ventilators in case of failure of a ventilator or in case of exchanging of a drawer. In both cases the still working ventilator will work on full speed to compensate the failure of the other or others.
Another advantage embodiment of the invention is that one or more temperature controller arranged in the vicinity of the first ventilator drawer control the ventilators arranged in the second drawer (below the elements to be cooled) to full speed, at a temperature of about 90 degrees of centigrade.
In case of fire the above arranged ventilators are on full speed, but because of the fire normally they will be destroyed. High speed ventilators have the effect that the volume flow and the air flow increase and that the elements in the upper area of the box will be tendentially cooled down.
This application claims priority to the U.S. Provisional application No. 60/505698, filed Sep. 24, 2003 and which is incorporated by reference herein in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 60505698 | Sep 2003 | US |
