Patent Description:
Data centers are relied upon to store and distribute valuable information across many industries. Industry demands that these data centers remain continuously functional. Downtime can damage the reputation of a data center and result in the loss of customers. The valuable information handled by data centers is primarily stored on magnetic Hard Disk Drives (HDDs). These hardware devices have a known sensitivity to sound. That is, sound pressure can cause vibration induced damage or disruptions to an HDD.

Unfortunately, inert gas fire suppression systems typically used to protect the server rooms that house this type of equipment in a data center, utilize nozzles that can produce sound levels which may have an adverse effect on this noise sensitive hardware. Indeed, some common nozzles generate noise levels in excess of <NUM> dB, which creates an unacceptable risk of lost data and operation time for a data center.

It would therefore be beneficial to provide a nozzle for a fire suppression system that produces lower noise levels than more common nozzles, so that the nozzle can be readily used to protect data centers without risk of lost operation time. <CIT> discloses an arrangement of the prior art.

According to an aspect of the invention, a nozzle assembly for a fire suppression system is provided according to claim <NUM>.

In addition to one or more of the features described above, or as an alternative, in further embodiments the nozzle portion is generally cylindrical in shape.

In addition to one or more of the features described above, or as an alternative, in further embodiments a cross-sectional area of the center body varies over a length of the center body, the length being oriented parallel to a longitudinal axis of the nozzle assembly.

In addition to one or more of the features described above, or as an alternative, in further embodiments the center body has an upstream end and a downstream end, and a diameter of the center body at the upstream end is smaller than a diameter of the center body at the downstream end such that the center body is generally conical in shape.

In addition to one or more of the features described above, or as an alternative, in further embodiments the center body has a hollow interior.

In addition to one or more of the features described above, or as an alternative, in further embodiments the hollow interior of the center body is filled with a sound absorbing material.

In addition to one or more of the features described above, or as an alternative, in further embodiments one or more apertures are formed in a surface of the center body.

In addition to one or more of the features described above, or as an alternative, in further embodiments the center body is formed from a sheet metal.

In addition to one or more of the features described above, or as an alternative, in further embodiments the center body is formed from a mesh material.

In addition to one or more of the features described above, or as an alternative, in further embodiments the at least one perforated filter member is formed from a perforated metal plate.

In addition to one or more of the features described above, or as an alternative, in further embodiments the at least one perforated filter member has about between <NUM>% to <NUM>% open area as defined by a multiplicity of perforations.

In addition to one or more of the features described above, or as an alternative, in further embodiments the at least one perforated filter member includes a plurality of perforated filter members positioned within the interior cavity of the nozzle portion in spaced apart relationship along a central axis thereof.

In addition to one or more of the features described above, or as an alternative, in further embodiments each of the plurality of perforated filter members has the same porosity.

In addition to one or more of the features described above, or as an alternative, in further embodiments each of the plurality of perforated filter members has a different porosity.

In addition to one or more of the features described above, or as an alternative, in further embodiments a porous metal foam insert is positioned downstream from the at least one perforated filter member.

In addition to one or more of the features described above, or as an alternative, in further embodiments the inlet end of the body includes a metering orifice.

In addition to one or more of the features described above, or as an alternative, in further embodiments the flow of fire extinguishing agent is output from the plurality of exit orifices having a generally horizontal orientation.

Referring now to the drawings wherein like reference numerals identify similar structural elements and features of the subject invention, there is illustrated in <FIG> a server room <NUM> located in a data center <NUM>, which houses racks <NUM> containing hard disk drives <NUM>, and a fire suppression system <NUM> for protecting the server room <NUM> in the event of the detection of a hazardous condition such as smoke, excessive heat, or fire. The fire suppression system <NUM> includes a storage tank <NUM> containing an inert gas fire suppressant, such as argon.

The fire suppression system <NUM> further includes one or more low-velocity acoustic noise reduction nozzle assemblies constructed in accordance with an embodiment disclosed herein and designated generally by reference numeral <NUM> for discharging the fire suppressant contained in storage tank <NUM> into the server room <NUM> in the event of a fire.

Referring to <FIG>, various example of the low-velocity acoustic noise reduction nozzle assembly <NUM> are illustrated. As shown, the nozzle assembly <NUM> includes a body <NUM> having an inlet end <NUM> for receiving a flow of fire extinguishing agent from the fire suppression system <NUM> at a particular entrance mass flow of about between <NUM> and <NUM>/s, such as <NUM>/s for example, and inlet pressure of between about <NUM> bar and <NUM> bar ( <NUM> psig and <NUM> psig), such as <NUM> bar ( <NUM> psig ) for example. The body <NUM> of nozzle assembly <NUM> further includes an axially extending nozzle portion <NUM>.

The axially extending nozzle portion <NUM> of the nozzle assembly <NUM> has a outer wall <NUM> and an interior cavity <NUM> that defines a central longitudinal axis extending along line X-X in upstream Us and downstream directions Ds. In the illustrated, example of <FIG>, the outer wall <NUM> of the nozzle portion <NUM> is generally conical in shape such that the cross-sectional area of the interior cavity <NUM> of the nozzle portion <NUM> decreases in the downstream direction. In an embodiment, best shown in <FIG>, the outer wall <NUM> of the nozzle portion <NUM> is generally cylindrical in shape such that the cross-sectional area of the interior cavity <NUM> defined by the outer wall <NUM> of the nozzle portion <NUM> is generally constant over the axial length of the nozzle portion <NUM>.

A plurality of exit orifices <NUM> are formed in the outer wall <NUM> of nozzle portion <NUM> for efficiently vectoring the flow of fire extinguishing agent exiting therefrom and to effectively reduce the acoustic noise level of the nozzle assembly <NUM>. Moreover, the exit orifices <NUM> formed in the outer wall <NUM> of nozzle portion <NUM> help to reduce the overall acoustic signature of the nozzle assembly <NUM>. In an example, such as shown in <FIG> for example, the exit orifices <NUM> defined in the outer wall <NUM> of the nozzle portion <NUM> are oriented at an angle α<NUM> that is perpendicular to the local wall angle of the conical outer wall <NUM> of nozzle portion <NUM> to control fluid vectoring. Alternatively, as shown in <FIG>, the exit orifices <NUM> defined in the outer wall <NUM> of the nozzle portion <NUM> may be oriented at an angle α<NUM> that is perpendicular to the central axis X-X of the nozzle portion <NUM> so as to control fluid vectoring in a different manner. Alternatively, the exit orifices <NUM> can be oriented at other angles ranging from the orientation shown in <FIG> to the orientation shown in <FIG>, so as to control fluid vectoring in another preferred manner, which would depend upon the configuration of the area to be protected by the nozzle assembly <NUM>. By expelling the fire extinguishing agent from the plurality of exit orifices in a generally horizontal direction, perpendicular to the axis X of the nozzle portion <NUM>, the flow may cover a greater area, thereby providing better coverage within the server room <NUM>.

It is also envisioned that the exit orifices <NUM> formed in the outer wall <NUM> of the nozzle portion <NUM> may vary in diameter and/or in number along the central axis X-X of the nozzle portion <NUM>. For example, the upstream exit orifices <NUM> can have a diameter "D" while the downstream exit orifices <NUM> can have a smaller diameter "d" as illustrated in <FIG>, or alternatively, a larger diameter. Although the variations in configurations of the exit orifices <NUM> are discussed with respect to the a nozzle portion <NUM> having a conical outer wall <NUM>, it should be understood that a nozzle portion <NUM> having a cylindrical outer wall <NUM> may similarly include any configuration of the exit orifices <NUM> illustrated and described herein.

Those skilled in the art will readily appreciate that the frequency of the noise generated by the nozzle assembly <NUM> will increase as the exit orifices <NUM> decrease in size. Accordingly, the diameter of the exit orifices <NUM> should be sized so as to minimize the overall acoustic signature of the nozzle assembly <NUM>, while maintaining a preferred coverage volume of about <NUM><NUM>.

Furthermore, the nozzle portion <NUM> is preferably dimensioned to progressively decrease in internal cross-sectional area, and thus the inner diameter is selected to, in combination with the distribution of the plurality of exit orifices <NUM> to provide uniform discharge velocities. The particular uniform discharge velocities provide desired mass flow and dispersal on the one hand while maintaining acceptable sound levels on the other hand. In an embodiment, the nozzle portion <NUM> is configured so that the internal cross-sectional area of the nozzle portion <NUM> taken at any point along the central axis X-X is equal to the total open area of the exit orifices <NUM> formed in the outer wall <NUM> of the nozzle portion <NUM> downstream from that point. Consequently, the static pressure within the interior cavity <NUM> of the nozzle portion <NUM> will be maintained at a level that will ensure that fire extinguishing agent is uniformly fed to all of the exit orifices <NUM> for the entire duration of the discharge, which could range from <NUM> seconds to <NUM> seconds.

This reduction in the cross-sectional area of the nozzle portion <NUM> can be achieved via several different configurations. In examples where the outer wall <NUM> is conical in shape (<FIG>), the slope of the conical outer wall <NUM> may be selected to achieve a cross-sectional area that is equal to the total open area of exit orifices <NUM> located downstream therefrom as described above. However, in embodiments where the outer wall <NUM> is not conical, such as embodiments where the outer wall is cylindrical (<FIG> and <FIG>), a center body <NUM> is positioned within the interior cavity <NUM> of the nozzle portion <NUM> to achieve the desired change in cross-sectional area over the axial length of the nozzle portion <NUM>. The center body <NUM> may be formed from any suitable material, and may be substantially solid, or alternatively, may have a generally hollow interior. The center body <NUM> may be connected to the cylindrical nozzle portion <NUM> via any suitable connection mechanism. For example, the center body <NUM> may be integrally formed with the nozzle portion <NUM>, may be welded to the nozzle portion <NUM>, or may be removably affixed thereto, such as via a threaded connection. As shown, the center body <NUM> is generally conical is shape, with a cross-sectional area of the center body <NUM> increasing in the downstream direction. In an embodiment, an exterior surface of the center body <NUM> is generally rounded or smooth to minimize turbulence and noise generated by contact with the flow of fire extinguishing agent.

Further, in embodiments where the center body <NUM> is generally hollow, an interior of the center body <NUM> may be filled with a sound absorbing material <NUM>, such as packing foam, fiberglass, or another open celled foam for example. In an embodiment, best shown in <FIG>, the surface <NUM> of the center body <NUM> has a plurality of apertures formed therein. For example the center body <NUM> may be formed from a mesh material. However, in other embodiments, the center body <NUM> may be formed from a solid material, such as sheet metal for example, having a plurality of openings or apertures formed therein. In such embodiments, the material selected to form the center body <NUM> is sufficiently rigid to withstand the forces applied thereto by the flow of fire extinguishing agent through the nozzle portion <NUM>.

With continuing reference to <FIG>, the inlet end <NUM> of the body <NUM> of nozzle assembly <NUM> includes a threaded flange <NUM>, which is connectable for operative engagement with a threaded fitting <NUM>. The threaded fitting <NUM> has a conventional NPT format that is adapted to communicate with the fire suppression system <NUM> and includes a metering orifice <NUM>. In an embodiment, an intermediate portion <NUM> of the fitting <NUM> forms a diffuser wherealong the inner diameter (ID) of the fitting <NUM> diverges (expands in transverse cross-sectional area) from upstream to downstream. The diffuser functions to slow velocity, but typically generates turbulence (discussed below). As is discussed below, the velocity reduction is a step in a dispersal method that produces acceptable sound levels.

The nozzle assembly <NUM> may additionally include one or more perforated filter members <NUM> for reducing the entrance velocity of the fire extinguishing agent, in furtherance of acoustic noise level reduction. Moreover, the one or more perforated filter members <NUM> function to lower the pressure of the incoming flow before entering the nozzle portion <NUM>, dropping the inlet pressure by about <NUM> bar ( <NUM> psig ) to a preferred exit pressure to avoid supersonic jet flow. In an embodiment, the preferred exit pressure is about <NUM> bar ( <NUM> psig). As a result of the one or more perforated filter members <NUM> advantageously lowering the velocity and pressure of the incoming flow of fire suppressant, in combination with the exit orifices <NUM> lowering the acoustic signature of the nozzle assembly <NUM>, the nozzle assembly <NUM> has a resulting noise level equal to or less than about <NUM> db. Those skilled in the art will readily appreciate that achieving such a noise level will not cause damage or disruption to the HDDs <NUM> that are located within the server room of a data center <NUM> in the event of a fire.

In the illustrated, example of <FIG>, a perforated filter member <NUM> is positioned within the interior cavity <NUM> of the nozzle portion <NUM>, upstream from the exit orifices <NUM> formed in the outer wall <NUM>. As shown, the at least one perforated filter member <NUM> is supported or otherwise firmly retained within the interior cavity <NUM> of the body <NUM> of nozzle assembly <NUM>, sandwiched between an interior abutment surface <NUM> of the body <NUM> and a leading edge <NUM> of the threaded fitting <NUM>.

While the nozzle assembly <NUM> is illustrated in <FIG> is shown with only one perforated filter member <NUM> positioned within the interior cavity <NUM> of nozzle portion <NUM>, it is envisioned that the nozzle assembly <NUM> could include a plurality of perforated filter members, including two or more than two perforated filter members in spaced apart relationship along the central axis X-X thereof. For example, as best seen in <FIG>, the nozzle assembly <NUM> could have two of spaced apart filter members, including a downstream perforated filter member 50a positioned within the interior cavity <NUM> and an upstream perforated filter member 50b positioned within the threaded fitting <NUM>. In yet another embodiment, illustrated in <FIG>, the nozzle assembly <NUM> can include three spaced apart filter members <NUM> including a first perforated filter member 50a positioned within the interior cavity <NUM>, a second perforated filter member 50b positioned generally centrally within the threaded fitting <NUM>, and a third perforated filter member 50c, positioned directly downstream from the metered orifice <NUM>.

An example of a perforated filter member <NUM> is illustrated in more detail in <FIG>. As shown, the perforated filter member <NUM> may be in the form of a perforated metal plate, such as made from aluminum or a similar light-weight metal having a thickness of about <NUM> ( <NUM>/<NUM> inch). In an embodiment, about <NUM>% to <NUM>% of the surface area of the perforated filter member <NUM> is defined by open space. For example, about <NUM>% of the surface of the perforated filter member is open space formed by a multiplicity of apertures <NUM>.

Furthermore, a porous material, such as a metal foam insert for example, could be associated with an upstream side of one or more of the perforated filter members <NUM> to further reduce the inlet pressure of the fire suppressant. More particularly, in the non-limiting embodiment of <FIG>, a first porous metal foam insert 58a is associated with an upstream side of perforated filter member 50a, a second porous metal foam insert 58b is associated with an upstream side of perforated filter member 50b, and a third porous metal foam insert 58c is associated with an upstream side of perforated filter member 50c. When present in the nozzle assembly <NUM>, the porous metal foam inserts may be about <NUM> ( <NUM> inches ) in thickness. When used alone or in combination, these porous components function to reduce the pressure while evenly distributing the flow throughout the cross-sectional area, and reducing the noise associated with the flow turbulence. When the perforated filter member <NUM>/porous metal foam <NUM> are used just downstream of a metering orifice (<NUM> in <FIG>), they function to effectively reduce the noise associated with supersonic flow by dissipating the shock formed downstream of the metering orifice <NUM>.

While each of the perforated filter members 50a, 50b, and 50c may have the same porosity, embodiments where one or more of the filter members <NUM> has a different porosity is also within the scope of the disclosure. For example, in such an embodiment, the perforated filter members 50a, 50b, and 50c may decrease in porosity in a downstream direction Ds along the axis X-X of the interior cavity <NUM>. Thus, the upstream filter member 50c could be a perforated metal plate having a porosity of about <NUM>% and the downstream filter member 50a could be a perforated metal plate having a porosity of about <NUM>%, so as to gradually or otherwise progressively reduce the fluid pressure of the fire suppression agent in a stepwise or multi-staged manner.

Claim 1:
A nozzle assembly (<NUM>) for a fire suppression system (<NUM>), comprising:
a body (<NUM>) having an inlet end (<NUM>);
a nozzle portion (<NUM>) extending from the body (<NUM>), the nozzle portion (<NUM>) having:
an interior cavity (<NUM>) having an outlet end;
a center body (<NUM>) arranged within the interior cavity (<NUM>) adjacent the outlet end; and
a plurality of exit orifices (<NUM>) are formed in an outer wall (<NUM>) of the nozzle portion (<NUM>), in communication with the interior cavity (<NUM>); and
at least one perforated filter member (<NUM>) positioned upstream from the plurality of exit orifices (<NUM>) formed in the nozzle portion (<NUM>);
wherein the center body (<NUM>) is positioned within the interior cavity (<NUM>) of the nozzle portion (<NUM>) characterized in
that an internal cross-sectional area of the interior cavity (<NUM>) taken at any location along a central axis X-X of the nozzle portion (<NUM>) is equal to a total open area of the plurality of exit orifices (<NUM>) arranged downstream from that location.