Patent Description:
The distribution and concentration of particles in an environment may be determined for a number of reasons. In the exemplary case of a fire suppression system that deploys an agent to extinguish a fire, the concentration of fire suppression agent in the environment may be determined and used to verify that the fire suppression agent has reached a sufficient concentration or to control the release of additional agent. In other scenarios, the concentration of a particular (hazardous) material in the air may trigger an alert. <CIT> shows an example of a omnidirectional aerosol sampling device having a flow shield and a faired body. The sampler allows for air intake from all directions and leads the sampled air to an analysis device downstream of a tubular member.

The present invention provides a particle concentration measurement sensor according to claim <NUM>.

In addition to one or more of the features described above, or as an alternative, further embodiments may include that the inlet is an omnidirectional orifice extending a full three hundred and sixty degrees around the faired body.

In addition to one or more of the features described above, or as an alternative, further embodiments may include that the passageway has a rotationally axisymmetric bell shaped curve.

In addition to one or more of the features described above, or as an alternative, further embodiments may include that the faired body has a bell shape and is rotationally axisymmetric.

In addition to one or more of the features described above, or as an alternative, further embodiments may include that the flow shield has a bell shape and is rotationally axisymmetric.

In addition to one or more of the features described above, or as an alternative, further embodiments may include that the faired body has a first faired body end and a second faired body end located opposite the first faired body end, and wherein the radially outer surface of the faired body has a first outer diameter proximate or at the first faired body end and the radially outer surface of the faired body has a second outer diameter proximate or at the second faired body end, the second outer diameter being greater than the first outer diameter.

In addition to one or more of the features described above, or as an alternative, further embodiments may include that an outer diameter of the radially outward surface increases exponentially from the first outer diameter to the second outer diameter.

In addition to one or more of the features described above, or as an alternative, further embodiments may include that the flow shield has a first flow shield end and a second flow shield end located opposite the first flow shield end, and wherein the radially inward surface of the flow shield has a first inner diameter proximate or at a first distance away from the first flow shield end and the radially inward surface of the flow shield has a second inner diameter proximate or at the second flow shield end, the second inner diameter being greater than the first inner diameter.

In addition to one or more of the features described above, or as an alternative, further embodiments may include that an inner diameter of the radially inward surface increases exponentially from the first inner diameter to the second inner diameter.

In addition to one or more of the features described above, or as an alternative, further embodiments may include that the tubular body has a first tubular end and a second tubular end located opposite the first tubular end, the faired body being operably connected to the tubular body proximate or at the first tubular end, wherein the faired body has a first faired body end and a second faired body end located opposite the first faired body end, and wherein the first faired body end is located closer to the first tubular end than the second faired body end.

In addition to one or more of the features described above, or as an alternative, further embodiments made include that the flow shield has a first flow shield end and a second flow shield end located opposite the first flow shield end, and wherein the first flow shield end is located closer to the first tubular end than the second flow shield end.

In addition to one or more of the features described above, or as an alternative, further embodiments may include that the tubular body further includes a passageway portion defined by the inner surface, and wherein a transition from the passageway to the passageway portion of the tubular body is configured to turn a particle-laden gas about one hundred and eighty degrees.

In addition to one or more of the features described above, or as an alternative, further embodiments may include that the faired body further include one or more channel guides extending away from the radially outer surface of the faired body and toward the radially inward surface of the flow shield.

In addition to one or more of the features described above, or as an alternative, further embodiments may include that the tubular body further includes a passageway portion defined by the inner surface, and wherein a transition from the passageway to the passageway portion of the tubular body is configured to turn a particle-laden gas about ninety degrees.

In addition to one or more of the features described above, or as an alternative, further embodiments may include that the tubular body has a first tubular end and a second tubular end located opposite the first tubular end, the faired body being operably connected to the tubular body proximate or at the first tubular end, wherein the faired body has a first faired body end and a second faired body end located opposite the first faired body end, and wherein the second faired body end is located closer to the first tubular end than the first faired body end.

In addition to one or more of the features described above, or as an alternative, further embodiments may include that the tubular body has a first tubular end and a second tubular end located opposite the first tubular end, the flow shield being operably connected to the tubular body proximate or at the first tubular end, wherein the flow shield has a first flow shield end and a second flow shield end located opposite the first flow shield end, and wherein the second flow shield end is located closer to the first tubular end than the first flow shield end.

The present invention also provides a method of fabricating a flow control device according to claim <NUM>.

In addition to one or more of the features described above, or as an alternative, further embodiments may include forming a passageway portion within the tubular body to a direct particle-laden gas from the passageway through the one or more openings into the passageway portion and to an inlet of a particle concentration measurement sensor.

In addition to one or more of the features described above, or as an alternative, further embodiments may include that the particle-laden gas includes particles of fire suppression agent suspended in a gas and the particle concentration measurement sensor measures a concentration of the fire suppression agent in the gas.

Fire extinguishing agent concentration measurements of dry chemical agents can be performed by extracting agent laden air into a sensor probe that utilizes light scattering principles. These sensor probes rely on extracting agent laden air at concentrations consistent with the concentration outside the sample inlet. The flow within the room or volume to be protected from a fire threat (i.e., fire threat volume) is turbulent and dynamic. Moreover, during an agent discharge event, the gas velocities in the room or volume can vary from null to tens or even low hundreds of meters per second. Particle slip in this environment makes consistent sampling of agent laden gas a challenge. Particle slip occurs when the particle (in this case a dry chemical agent) has a significantly different velocity than the air surrounding it. Thus, particle slip at the inlet of a concentration sensor can result in over-sampling or under-sampling the dry chemical agent. Particle slip will be greatest in regions where flow acceleration is highest.

Embodiments disclosed herein relate to a fire extinguishing agent sampling probe having an omni-directional flow shield around an omni-directional inlet orifice. Advantageously, the omni-directional flow shield protects the omni-directional flow sample inlet from the dynamic and turbulent flows that exist in the fire threat volume. The omni-directional flow shield helps provide the omni-directional sample inlet orifice with dry chemical agent laden air at concentrations that are representative of the concentrations outside of the omni-directional flow shield.

Further, embodiments disclosed herein relate to a fire extinguishing agent sampling probe having a gentle bell-shaped omnidirectional curve to a passageway portion leading to the omni-directional inlet orifice. When sampling a fire extinguishing agent that is dry chemical mixed in with air through an inlet orifice, particle slip may tend to skew the sampled concentration of the dry chemical. The concentration can be over-sampled or under-sampled depending on the directionality flow relative to the inlet. For example, if the airflow is blowing into an unshielded inlet orifice, the concentration can be over-sampled, but if the airflow is blowing away from an unshielded inlet orifice the concentration can be under-sampled. The embodiments disclosed herein help mitigate this problem by protecting the inlet orifice from the bulk flow and providing flow paths that are subject to gentle acceleration, thus minimizing particle slip.

Referring now to <FIG>, a cross-sectional view of a particle concentration measurement sensor <NUM> with a flow control device <NUM> is illustrated in accordance with an embodiment of the present disclosure.

According to an embodiment, the particle concentration measurement sensor <NUM> is part of a fire suppression system <NUM> and is used to determine the concentration of a fire suppression agent in particle-laden gas <NUM> that is drawn into a housing <NUM> of the particle concentration measurement sensor <NUM> through the flow control device <NUM> at an inlet <NUM>. A vacuum source <NUM> may be coupled at an outlet <NUM> of the housing <NUM> to draw gas through from the inlet <NUM> to the outlet <NUM>. As the cross-sectional view of the particle concentration measurement sensor <NUM> indicates, a first window <NUM> and a second window <NUM> define an interaction region <NUM> within the housing <NUM>.

According to the exemplary embodiment of the particle concentration measurement sensor <NUM> shown in <FIG>, a light source <NUM> provides input light <NUM> via an optical fiber <NUM> to the housing <NUM>. In the interaction region <NUM>, the light <NUM> and the particle-laden gas <NUM> entering the housing <NUM> via the inlet <NUM> interact. This interaction is detected at a detector <NUM> outside the interaction region <NUM>. Specifically, the detector <NUM> measures an intensity of the post-interaction light that corresponds with the particle of interest (e.g., fire suppression agent) in the particle-laden gas <NUM>. A controller <NUM> may map that intensity to a concentration. According to alternate embodiments, the particle concentration measurement sensor <NUM> may include a mirror at the location at which the detector <NUM> is shown in <FIG>. The mirror reflects the result of the light interaction in the interaction region <NUM> back through the second window <NUM> and first window <NUM> toward the light source <NUM>. Thus, the detector <NUM> and controller <NUM> may be located at the same side as the light source <NUM> in the alternate embodiment.

The flow control device <NUM>, according to one or more embodiments, includes features that ensure that the concentration of the particle of interest (e.g., fire suppression agent) in the environment is accurately reflected within the housing <NUM> in the interaction region <NUM>. The flow control device <NUM> includes a tubular body <NUM>, a faired body <NUM>, and a flow shield <NUM>.

The tubular body <NUM> is coaxial to a longitudinal axis <NUM>. The tubular body <NUM> extends linearly along the longitudinal axis <NUM> and is parallel to the longitudinal axis <NUM>. The tubular body <NUM> may be cylindrical in shape with a passageway portion <NUM> formed therein. The tubular body <NUM> may be rotationally axisymmetric around the longitudinal axis <NUM>. The tubular body <NUM> includes a tubular wall <NUM> that includes an inner surface <NUM> and an outer surface <NUM>. The inner surface <NUM> is located radially inward from the outer surface <NUM> as measured relative to the longitudinal axis <NUM>. That inner surface <NUM> defines the passageway portion <NUM>. The tubular body <NUM> includes a first tubular end <NUM> and a second tubular end <NUM> located opposite the first tubular end <NUM>. The tubular body <NUM> is fluidly connected to the housing <NUM> of the particle concentration measurement sensor <NUM> at the second tubular end <NUM>. The tubular body <NUM> includes one or more openings <NUM> (i.e., perforations or entryways) in the tubular wall <NUM>. The openings <NUM> extend from the outer surface <NUM> to the inner surface <NUM> through the tubular wall <NUM>. Advantageously, the openings <NUM> are shielded by the from flow shield <NUM> from a direct airflow shot that may lead to the concentration being over-sampled. The passageway portion <NUM> fluidly connects the openings <NUM> to the inlet <NUM> and then to the interaction region <NUM> within the housing <NUM>.

The faired body <NUM> is operably connected to the tubular body <NUM> proximate or at the first tubular end <NUM>. The faired body <NUM> is located a first distance D1 away from the first tubular end <NUM> as measured along the longitudinal axis <NUM>. The openings <NUM> within the tubular body <NUM> are located between the faired body <NUM> and the first tubular end <NUM>, as illustrated in <FIG>. The faired body <NUM> encircles the tubular wall <NUM>.

The faired body <NUM> may have a bell shape with a channel portion <NUM> formed therein. The faired body <NUM> may be rotationally axisymmetric around the longitudinal axis <NUM>. The faired body <NUM> includes a faired body wall <NUM> that includes a radially inner surface <NUM> and a radially outer surface <NUM>. The radially inner surface <NUM> is located radially inward from the radially outer surface <NUM> as measured relative to the longitudinal axis <NUM>. That radially inner surface <NUM> defines the channel portion <NUM> within the faired body <NUM>. The tubular body <NUM> is configured to fit within the channel portion <NUM>. The outer surface <NUM> of the tubular body <NUM> and the radially inner surface <NUM> of the faired body <NUM> may be in an interference fit or press fit with each other. Alternatively, the tubular body <NUM> could be connected to the faired body <NUM> by an appropriate adhesive such as epoxy, or depending on material the attachment means could also be soldering, welding, brazing, or a similar attachment means known to one of skill in the art. Also alternatively, the tubular body <NUM> and the faired body <NUM> may be one integral piece of material that may have been formed by turning on a lathe from bar stock material or additive manufacturing. The faired body <NUM> includes a first faired body end <NUM> and a second faired body end <NUM> located opposite the first faired body end <NUM>. The first faired body end <NUM> is located closer to the first tubular end <NUM> than the second faired body end <NUM>, as illustrated in <FIG>. The second faired body end <NUM> is located closer to the second tubular end <NUM> than the first faired body end <NUM>, as illustrated in <FIG>.

The radially outer surface <NUM> of the faired body <NUM> may have a first outer diameter OD1 proximate or at the first faired body end <NUM> and the radially outer surface <NUM> of the faired body <NUM> may have a second outer diameter OD2 proximate or at the second faired body end <NUM>. The second outer diameter OD2 is greater than the first outer diameter OD1. An outer diameter of the radially outer surface <NUM> may increase exponentially from the first outer diameter OD1 to the second outer diameter OD2. This exponential increase in a size of the outer diameter size results in the bell shape of the radially outer surface <NUM> of the faired body <NUM>.

The flow shield <NUM> is operably connected to the tubular body <NUM> proximate or at the first tubular end <NUM>. The flow shield <NUM> may be located at the first tubular end <NUM> and may cover the first tubular end <NUM>, as illustrated in <FIG>. The openings <NUM> within the tubular body <NUM> are located between the flow shield <NUM> and the faired body <NUM>, as illustrated in <FIG>. The flow shield <NUM> encircles the faired body <NUM> and the tubular wall <NUM>.

The flow shield <NUM> may have a bell shape with an interior chamber <NUM> formed therein. The openings <NUM> within the tubular body <NUM> are located with the interior chamber <NUM> of the flow shield <NUM>. The flow shield <NUM> may be rotationally axisymmetric around the longitudinal axis <NUM>. The flow shield <NUM> includes a flow shield wall <NUM> that includes a radially inward surface <NUM> and a radially outward surface <NUM>. The radially inward surface <NUM> is located radially inward from the radially outward surface <NUM> as measured relative to the longitudinal axis <NUM>. That radially inward surface <NUM> defines the interior chamber <NUM>. A portion of the tubular body <NUM> is configured to fit within the interior chamber <NUM> and a portion of the faired body <NUM> is configured to fit within the interior chamber <NUM>. The outer surface <NUM> of the tubular body <NUM> proximate the first tubular end <NUM> and a portion of the radially inward surface <NUM> of the flow shield <NUM> may be in an interference fit or press fit. with each other. Alternatively, the outer surface <NUM> of the tubular body <NUM> proximate the first tubular end <NUM> could be connected to a portion of the radially inward surface <NUM> of the flow shield <NUM> by an appropriate adhesive such as epoxy, or depending on material the attachment means could also be soldering, welding, brazing, or a similar attachment means known to one of skill in the art. Also alternatively, the tubular body <NUM> and the flow shield <NUM> may be one integral piece of material that may have been formed by turning on a lathe from bar stock material or additive manufacturing. The flow shield <NUM> includes a first flow shield end <NUM> and a second flow shield end <NUM> located opposite the first flow shield end <NUM>. The first flow shield end <NUM> is located closer to the first tubular end <NUM> than the second flow shield end <NUM>, as illustrated in <FIG>. The second flow shield end <NUM> is located closer to the second tubular end <NUM> than the first flow shield end <NUM>, as illustrated in <FIG>.

The radially outward surface <NUM> of the flow shield <NUM> may have a first inner diameter ID1 proximate or at the first distance D1 away from the first flow shield end <NUM> and the radially outward surface <NUM> of the flow shield <NUM> may have a second inner diameter ID2 proximate or at the second flow shield end <NUM>. The second inner diameter ID2 is greater than the first inner diameter ID1. An inner diameter of the radially outward surface <NUM> may increase exponentially from the first inner diameter ID1 to the second inner diameter ID2. This exponential increase in a size of the inner diameter results in the bell shape of the radially outward surface <NUM> of the flow shield <NUM>.

The radially outer surface <NUM> of the faired body <NUM> and the radially inward surface <NUM> of the flow shield <NUM> are in a facing spaced relationship forming a passageway <NUM> therebetween. The passageway <NUM> is rotationally axisymmetric around the longitudinal axis <NUM>. The passageway <NUM> is also bell shaped as it follows the bell shaped curvatures of the radially outer surface <NUM> of the faired body <NUM> and the radially inward surface <NUM> of the flow shield <NUM>. In an embodiment, the passageway <NUM> has a rotationally axisymmetric bell shaped curve.

An inlet <NUM> extends from the radially outer surface <NUM> of the faired body <NUM> to the radially inward surface <NUM> of the flow shield <NUM>. The passageway <NUM> is fluidly connected to the openings <NUM>. The passageway <NUM> extends from the inlet <NUM> to the openings <NUM>. Particle-laden gas <NUM> is configured to flow into the passageway <NUM> through the inlet <NUM>. The inlet <NUM> is rotationally axisymmetric around the longitudinal axis <NUM>. In other words, the inlet <NUM> is an omnidirectional orifice extending a full three hundred and sixty degrees around the longitudinal axis <NUM> or the faired body <NUM>. Advantageously, this allows the fire suppression agent in particle-laden gas <NUM> to flow into the passageway <NUM> through the inlet <NUM> from three hundred and sixty degrees around the flow control devices <NUM>.

The gentle rotationally axisymmetric bell shaped curve of the passageway <NUM> helps slowly bring the particle-laden gas <NUM> up to the speed of airflow being generated by the vacuum source <NUM> to prevent separation of the fire suppression agent from the surrounding gas that makes up the particle-laden gas <NUM>. Thus, the rotationally axisymmetric bell shaped curve helps minimize the slip velocity of the fire suppression agent where the particulates of the fire suppression agent may begin separating from the surrounding gas that is carrying the particulates.

The particle-laden gas <NUM> then makes a one hundred and eighty degrees turn around the <NUM> the first faired body end <NUM> of the faired body <NUM> to enter the passageway portion <NUM> of the tubular body <NUM> through the openings <NUM>. In other words, a transition from the passageway <NUM> to the passageway portion <NUM> of the tubular body <NUM> is configured to turn the particle-laden gas <NUM> about one hundred and eighty degrees. The particle-laden gas <NUM> is then transported through the passageway portion <NUM> of the tubular body <NUM> to the interaction region <NUM> within the housing <NUM>.

Referring now to <FIG>, with continued reference to <FIG>, an isometric view of aspects of the tubular body <NUM> and the faired body <NUM>, and a cutaway isometric view of the flow shield <NUM> is illustrated in accordance with an embodiment of the present disclosure. As illustrated in <FIG>, the radially outer surface <NUM> of the faired body <NUM> may include one or more channel guides <NUM> extending away from the radially outer surface <NUM> and toward the radially inward surface <NUM> of the flow shield <NUM>. Advantageously, the channel guides <NUM> help to straighten or guide the flow of the particle-laden gas <NUM> within the passageway <NUM> formed between the radially outer surface <NUM> of the faired body <NUM> and the radially inward surface <NUM> of the flow shield <NUM>. Also, the channel guides <NUM> help reduce the amount of the particle-laden gas <NUM> that may enter the passageway <NUM> through the inlet <NUM> and then exit back out of the passageway <NUM> through the inlet <NUM>.

In one embodiment, the channel guides <NUM> may extend partially across the passageway <NUM> and terminate in the passageway <NUM> prior to contacting the radially inward surface <NUM> of the flow shield <NUM>. In another embodiment, the channel guides <NUM> may extend completely across the passageway <NUM> and to contact the radially inward surface <NUM> of the flow shield <NUM>. It is understood that the embodiments disclosed herein are also applicable to faired bodies <NUM> without channel guides <NUM>.

Alternatively, the faired body <NUM> may be attached to the tubular body <NUM> without the tubular body <NUM> extending into the faired body <NUM>. For example, the faired body <NUM> may be directly attached to the first tubular end <NUM> of the tubular body <NUM> by an attachment means including, but not limited to, an adhesive, soldering, brazing, welding, or any other attachment means known to one of skill in the art. Alternatively, the faired body <NUM> may be held in position by vertical screws and/or spacers from the flow shield <NUM>.

The faired body <NUM> is operably connected to the tubular body <NUM> proximate or at the first tubular end <NUM>. The openings <NUM> within the tubular body <NUM> are located between the faired body <NUM> and the flow shield <NUM>, as illustrated in <FIG>. The faired body <NUM> encircles the tubular wall <NUM>.

The faired body <NUM> may have a bell shape with a channel portion <NUM> formed therein. The faired body <NUM> may be rotationally axisymmetric around the longitudinal axis <NUM>. The faired body <NUM> includes a faired body wall <NUM> that includes a radially inner surface <NUM> and a radially outer surface <NUM>. The radially inner surface <NUM> is located radially inward from the radially outer surface <NUM> as measured relative to the longitudinal axis <NUM>. That radially inner surface <NUM> defines the channel portion <NUM> within the faired body <NUM>. The tubular body <NUM> is configured to fit within the channel portion <NUM>. The outer surface <NUM> of the tubular body <NUM> and the radially inner surface <NUM> of the faired body <NUM> may be in an interference fit or press fit with each other. Alternatively, the tubular body <NUM> could be connected to the faired body <NUM> by an appropriate adhesive such as epoxy, or depending on material the attachment means could also be soldering, welding, brazing, or a similar attachment means known to one of skill in the art. Also alternatively, the tubular body <NUM> and the faired body <NUM> may be one integral piece of material that may have been formed by turning on a lathe from bar stock material or additive manufacturing. The faired body <NUM> includes a first faired body end <NUM> and a second faired body end <NUM> located opposite the first faired body end <NUM>. The second faired body end <NUM> is located closer to the first tubular end <NUM> than the first faired body end <NUM>, as illustrated in <FIG>. The first faired body end <NUM> is located closer to the second tubular end <NUM> than the second faired body end <NUM>, as illustrated in <FIG>.

The radially outer surface <NUM> of the faired body <NUM> may have a first outer diameter OD1 proximate or at the first faired body end <NUM> and the radially outer surface <NUM> of the faired body <NUM> may have a second outer diameter OD2 proximate or at the second faired body end <NUM>. The second outer diameter OD2 is greater than the first outer diameter OD1. An outer diameter of the radially outer surface <NUM> may increase exponentially from the first outer diameter OD1 to the second outer diameter OD2. This exponential increase in a size of the outer diameter results in the bell shape of the radially outer surface <NUM> of the faired body <NUM>.

The flow shield <NUM> may have a bell shape with an interior chamber <NUM> formed therein. The openings <NUM> within the tubular body <NUM> are located with the interior chamber <NUM> of the flow shield <NUM>. The flow shield <NUM> may be rotationally axisymmetric around the longitudinal axis <NUM>. The flow shield <NUM> includes a flow shield wall <NUM> that includes a radially inward surface <NUM> and a radially outward surface <NUM>. The radially inward surface <NUM> is located radially inward from the radially outward surface <NUM> as measured relative to the longitudinal axis <NUM>. That radially inward surface <NUM> defines the interior chamber <NUM>. A portion of the tubular body <NUM> is configured to fit within the interior chamber <NUM> and a portion of the faired body <NUM> is configured to fit within the interior chamber <NUM>. The outer surface <NUM> of the tubular body <NUM> proximate the first tubular end <NUM> and a portion of the radially inward surface <NUM> of the flow shield <NUM> may be in an interference fit with each other. Alternatively, the outer surface <NUM> of the tubular body <NUM> proximate the first tubular end <NUM> could be connected to a portion of the radially inward surface <NUM> of the flow shield <NUM> by an appropriate adhesive such as epoxy, or depending on material the attachment means could also be soldering, welding, brazing, or a similar attachment means known to one of skill in the art. Also alternatively, the tubular body <NUM> and the flow shield <NUM> may be one integral piece of material that may have been formed by turning on a lathe from bar stock material or additive manufacturing. The flow shield <NUM> includes a first flow shield end <NUM> and a second flow shield end <NUM> located opposite the first flow shield end <NUM>. The second flow shield end <NUM> is located closer to the first tubular end <NUM> than the first flow shield end <NUM>, as illustrated in <FIG>. The first flow shield end <NUM> is located closer to the second tubular end <NUM> than the second flow shield end <NUM>, as illustrated in <FIG>. The flow shield <NUM> may include a tubular portion <NUM>. The tubular portion <NUM> may run about parallel with the tubular body <NUM>, as illustrated in <FIG>. The tubular portion <NUM> may provide added support for the flow shield <NUM> on the tubular body <NUM>.

The radially outward surface <NUM> of the flow shield <NUM> may have a first inner diameter ID1 proximate or at the second distance D2 away from the first flow shield end <NUM> and the radially outward surface <NUM> of the flow shield <NUM> may have a second inner diameter ID2 proximate or at the second flow shield end <NUM>. The second inner diameter ID2 is greater than the first inner diameter ID1. An inner diameter of the radially outward surface <NUM> may increase exponentially from the first inner diameter ID1 to the second inner diameter ID2. This exponential increase in a size of the inner diameter size results in the bell shape of the radially inward surface <NUM> of the flow shield <NUM>.

The gentle rotationally axisymmetric bell shaped curve of the passageway <NUM> helps slowly bring the particle-laden gas <NUM> up to the speed of airflow being generated by the vacuum source <NUM> to prevent separation of the fire suppression agent from the surrounding gas that makes up the particle-laden gas <NUM>. Thus, the rotationally axisymmetric bell shaped curve helps avoid the slip velocity of the fire suppression agent where the particulates of the fire suppression agent may begin separating from the surrounding gas that is carrying the particulates.

The particle-laden gas <NUM> then makes a ninety degree turn around the <NUM> the first faired body end <NUM> of the faired body <NUM> to enter the passageway portion <NUM> of the tubular body <NUM> through the openings <NUM>. In other words, a transition from the passageway <NUM> to the passageway portion <NUM> of the tubular body <NUM> is configured to turn the particle-laden gas <NUM> about ninety degrees in two different areas. The first area is a transition from the passageway <NUM> through the openings <NUM> and the second area is a transition from the openings <NUM> to the passageway portion <NUM> of the tubular body <NUM>. The particle-laden gas <NUM> is then transported through the passageway portion <NUM> of the tubular body <NUM> to the interaction region <NUM> within the housing <NUM>.

Referring now to <FIG>, with continued reference to <FIG>, an isometric view of the tubular body <NUM> and the faired body <NUM>, and a cutaway isometric view of the flow shield <NUM> is illustrated in accordance with an embodiment of the present disclosure. As illustrated in <FIG>, the radially outer surface <NUM> of the faired body <NUM> may include one or more channel guides <NUM> extending away from the radially outer surface <NUM> and toward the radially inward surface <NUM> of the flow shield <NUM>. Advantageously, the channel guides <NUM> help to straighten or guide the flow of the particle-laden gas <NUM> within the passageway <NUM> formed between the radially outer surface <NUM> of the faired body <NUM> and the radially inward surface <NUM> of the flow shield <NUM>. Also, the channel guides <NUM> help reduce the amount of the particle-laden gas <NUM> that may enter the passageway <NUM> through the inlet <NUM> and then exit back out of the passageway <NUM> through the inlet <NUM>.

Referring now to <FIG>, with continued reference to <FIG>, a flow chart of method <NUM> of fabricating a flow control device <NUM>, <NUM> is illustrated, in accordance with an embodiment of the disclosure.

At block <NUM>, a tubular body <NUM>, <NUM> is formed. The tubular body <NUM>, <NUM> includes a tubular wall <NUM>, <NUM>, an inner surface <NUM>, <NUM>, an outer surface <NUM>, <NUM>, and one or more openings <NUM>, <NUM> extending from the outer surface <NUM>, <NUM> to the inner surface <NUM>, <NUM> through the tubular wall <NUM>, <NUM>.

At block <NUM>, a faired body <NUM>, <NUM> formed. The faired body <NUM>, <NUM> includes a radially inner surface <NUM>, <NUM>, a radially outer surface <NUM>, <NUM>, and a channel portion <NUM>, <NUM> defined by the radially inner surface <NUM>, <NUM> within the faired body <NUM>, <NUM>.

At block <NUM>, a flow shield <NUM>, <NUM> is formed. The flow shield <NUM>, <NUM> includes a radially inward surface <NUM>, <NUM>, a radially outward surface <NUM>, <NUM>, and an interior chamber <NUM>, <NUM> defined by the radially inward surface <NUM>, <NUM> within the flow shield <NUM>, <NUM>.

At block <NUM>, the faired body <NUM>, <NUM> is arranged at least partially within the flow shield <NUM>, <NUM> such that the radially inward surface <NUM>, <NUM> is in a facing spaced relationship with the radially outer surface <NUM>, <NUM> of the faired body <NUM> defining a passageway <NUM>, <NUM> therebetween.

The tubular body <NUM>, <NUM> is arranged at least partially within the channel portion <NUM>, <NUM> such that the passageway <NUM>, <NUM> is fluidly connected to the one or more openings <NUM>, <NUM>.

The method <NUM> may further include that a passageway portion <NUM>, <NUM> is formed within the tubular body <NUM>, <NUM> to direct particle-laden gas <NUM>, <NUM> from the passageway <NUM>, <NUM> through the one or more openings <NUM>, <NUM> into the passageway portion <NUM>, <NUM> and to an inlet <NUM>, <NUM> of a particle concentration measurement sensor <NUM>, <NUM>. The particle-laden gas <NUM>, <NUM> includes particles of fire suppression agent suspended in a gas and the particle concentration measurement sensor <NUM>, <NUM> measures a concentration of the fire suppression agent in the gas.

Technical effects and benefits of the features described herein include a using a omnidirectional inlet to pull in a particle laden gas from three hundred and sixty degrees around the inlet and slowly accelerating the particle-laden gas through a bell shaped passage to a velocity of the vacuum pulling the particle-laden gas to avoid particles of the fire suppression agent separating from the gas.

Claim 1:
A particle concentration measurement sensor (<NUM>, <NUM>) comprising:
a housing (<NUM>, <NUM>) having an inlet (<NUM>, <NUM>) and an outlet (<NUM>, <NUM>);
a vacuum source (<NUM>, <NUM>) coupled at the outlet of the housing to draw gas from the inlet to the outlet; and
a flow control device (<NUM>) comprising:
a tubular body (<NUM>, <NUM>) comprising a tubular wall (<NUM>, <NUM>) with an inner surface (<NUM>, <NUM>), an outer surface (<NUM>, <NUM>), and one or more openings (<NUM>, <NUM>) extending from the outer surface to the inner surface through the tubular wall, wherein the tubular body includes a first tubular end (<NUM>, <NUM>) and a second tubular end (<NUM>, <NUM>) located opposite the first tubular end, wherein the tubular body is fluidly connected to the housing at the second tubular end;
a faired body (<NUM>, <NUM>) encircling the tubular body, the faired body comprising a radially inner surface (<NUM>, <NUM>) and a radially outer surface (<NUM>, <NUM>), wherein the faired body is operably connected to the tubular body proximate or at the first tubular end;
a flow shield (<NUM>, <NUM>) encircling the faired body, the flow shield comprising a radially inward surface (<NUM>, <NUM>) and a radially outward surface (<NUM>, <NUM>), the radially inward surface being in a facing spaced relationship with the radially outer surface of the faired body defining a passageway (<NUM>, <NUM>) therebetween, wherein the flow shield is operably connected to the tubular body proximate or at the first tubular end;
wherein the openings within the tubular body are located between the flow shield and the faired body;
wherein the passageway is fluidly connected to the one or more openings; and
an inlet (<NUM>, <NUM>) defined between the radially inward surface of the flow shield and the radially outer surface of the faired body, wherein the passageway extends from the inlet to the one or more openings.