Patent Publication Number: US-2020298036-A1

Title: Aircraft fire suppression system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. provisional patent application Ser. No. 62/581,118 filed Nov. 3, 2017, the entire contents of which are incorporated by reference herein. 
    
    
     TECHNICAL FIELD 
     The application relates generally to aircraft and, more particularly, to fire suppression systems used in aircraft. 
     BACKGROUND 
     Aircraft have fire suppression systems configured to extinguish fire that might occur in different zones, such as engine compartments, an auxiliary power unit compartment, and pressurized or unpressurized cargo compartments. An example of such fire suppression systems includes several reservoirs each being connected to all of the compartments for redundancy purposes. Such fire suppression systems can be complex and/or heavy. 
     SUMMARY 
     In an aspect, there is provided an aircraft comprising: a fuselage defining a cabin and a baggage bay; engine compartments for receiving engines; an auxiliary power unit compartment for receiving an auxiliary power unit; and a fire suppression system including first and second reservoirs containing a fire suppressant, the first and second reservoirs each connected to all of the engine compartments for distribution of the fire suppressant to the engine compartments, the first reservoir connected to only one of the auxiliary power unit compartment and baggage bay for distribution of the fire suppressant thereto, the second reservoir connected to only the other of the auxiliary power unit compartment and baggage bay for distribution of the fire suppressant thereto. 
     In an embodiment, the baggage bay is connected to the second reservoir through a restrictor configured for lowering a pressure of the fire suppressant circulating therethrough. 
     In an embodiment, the baggage bay is accessible from within the cabin and configured to be pressurized during flight. 
     In an embodiment, a volume of the baggage bay is at least 200 cubic feet. 
     In an embodiment, the fire suppression system further comprising first and second fittings, each of the first and second fitting having a first inlet connected to the first reservoir, a second inlet connected to the second reservoir, and an outlet connected to a respective one of the engine compartments. 
     In an embodiment, the first and second reservoirs each have a first outlet connected to one of the engine compartments, a second outlet connected to another of the engine compartments, and a third outlet, the third outlet of the first reservoir connected to the auxiliary power unit compartment, the third outlet of the second reservoir connected to the baggage bay. 
     In an embodiment, the aircraft further comprises a pressure-relief valve having an inlet connected to the baggage bay and an outlet connected to a region outside the baggage bay, the pressure-relief valve having an opened configuration and a closed configuration, the pressure-relief valve defining a fluid flow communication between the baggage bay and the region in the opened configuration and blocking the fluid flow communication between the baggage bay and the region in the closed configuration. 
     In an embodiment, the baggage bay is fluidly connected to the second reservoir through spaced apart nozzles in fluid communication with the baggage bay. 
     In another aspect, there is provided a fire suppression system for an aircraft, comprising: first, second, third, and fourth fire zones, an air pressure in the first and the second fire zones less than an air pressure in the fourth fire zone; first and second reservoirs each containing a fire suppressant and each having a first outlet fluidly connected to the first fire zone, a second outlet fluidly connected to the second fire zone, and a third outlet, the third outlet of the first reservoir fluidly connected to the third fire zone, the third outlet of the second reservoir fluidly connected to the fourth fire zone; wherein the third fire zone is fluidly separated from the second reservoir and the fourth fire zone is fluidly separated from the first reservoir. 
     In an embodiment, the fourth fire zone is connected to the third outlet of the second reservoir through a restrictor configured for lowering a pressure of the fire suppressant circulating therethrough. 
     In an embodiment, the fire suppression system further comprises a first fitting and a second fitting, the first and second fittings each having a first inlet connected to the first reservoir, a second inlet connected to the second reservoir, and an outlet connected to a respective one of the first and second fire zones. 
     In an embodiment, the fourth fire zone is connected to the third outlet of the second reservoir through spaced apart nozzles in fluid communication with the fourth fire zone. 
     In an embodiment, the fire suppression system further comprises a pressure-relief valve having an inlet connected to the fourth fire zone and an outlet connected to a region around the fourth fire zone, the pressure-relief valve having an opened configuration and a closed configuration, the pressure-relief valve allowing fluid flow communication between the fourth fire zone and the region through the pressure-relief valve in the opened configuration and blocking fluid flow communication therebetween in the closed configuration. 
     In an embodiment, a volume of the fourth fire zone is at least 200 cubic feet. 
     In an embodiment, the fourth fire zone is accessible from within a cabin of the aircraft and configured to be pressurized during flight. 
     In yet another aspect, there is provided a method of connecting a fire suppression system of an aircraft having engine compartments, an auxiliary power unit compartment and a baggage bay, the method comprising: fluidly connecting each of the engine compartments to first and second reservoirs of fire suppressant; fluidly connecting the auxiliary power unit compartment to the first reservoir without fluidly connecting the auxiliary power unit compartment to the second reservoir; and fluidly connecting the baggage bay to the second reservoir without fluidly connecting the baggage bay to the first reservoir, 
     In an embodiment, the first and second reservoirs have each first, second, and third outlets, wherein the method further comprises: connecting one of the engine compartments to the first outlets of the first and second reservoirs; connecting another one of the engine compartments to the second outlets of the first and second reservoirs; connecting the auxiliary power unit compartment to the third outlet of the first reservoir; and connecting the baggage bay to the third outlet of the second reservoir. 
     In an embodiment, fluidly connecting the baggage bay to the second reservoir includes fluidly connecting the baggage bay to the second reservoir via a restrictor for lowering a pressure of the fire suppressant circulating from the second reservoir to the baggage bay. 
     In an embodiment, fluidly connecting the baggage bay with the second reservoir includes connecting the second reservoir with nozzles in fluid communication with the baggage bay. 
     In an embodiment, the method further comprises providing a selective fluid communication between a region around the baggage bay for limiting a pressure increase in the baggage bay when the second reservoir circulates the fire suppressant to the baggage bay. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       For a better understanding of the present disclosure, as well as other aspects and further features thereof, reference is made to the following description which is to be used in conjunction with the accompanying drawings, where: 
         FIG. 1  is a schematic tridimensional view of an aircraft; 
         FIG. 2  is a schematic top view of a fire suppression system of the aircraft of  FIG. 1  in accordance with a particular embodiment; 
         FIG. 3  is a schematic tridimensional view of a panel of a baggage bay of the aircraft of  FIG. 1 , in accordance with a particular embodiment; 
         FIG. 4  is a schematic cross-sectional view of a nozzle of the fire suppression system of  FIG. 2  configured to be affixed to the panel of  FIG. 3 , in accordance with a particular embodiment; and 
         FIG. 5  is a schematic view of a fire suppression system of the aircraft of  FIG. 1  in accordance with another particular embodiment. 
     
    
    
     In the drawings, embodiments are illustrated by way of example. It is to be expressly understood that the description and drawings are only for purposes of illustration and as an aid to understanding. They are not intended to be a definition of the limits of the disclosure. 
     DETAILED DESCRIPTION 
     Referring to the drawings and more particularly to  FIG. 1 , an aircraft is shown at  1 , and is generally described to illustrate some components for reference purposes in the present disclosure. The aircraft  1  has a fuselage  2  defining a cabin  2   a  for receiving passengers. The fuselage  2  has a fore end at which a cockpit is located, and an aft end supporting a tail assembly, with the cabin  2   a  generally located between the cockpit and the tail assembly. The tail assembly comprises a vertical stabilizer  3  with a rudder, and horizontal stabilizers  4  with elevators. The tail assembly has a fuselage-mounted tail, but other configurations may also be used for the aircraft  1 , such as cruciform T-tail, etc. Wings  5  project laterally from the fuselage. The aircraft  1  has engines  6  mounted to the fuselage  2  in the depicted embodiment, although for other aircraft they can be supported by the wings  5 . An auxiliary power unit  10  is located at the aft end of the aircraft  1 . The aircraft  1  is shown as a jet-engine aircraft, but may also be a propeller aircraft. It is also understood that although  FIG. 1  shows a business aircraft, the aircraft  1  may alternately be any other type of aircraft, including, but not limited to, a commercial aircraft or a private aircraft. The aircraft further includes a baggage bay  30 , which in a particular embodiment is located within the cabin  2   a  and accessible by the passengers from the cabin  2   a  during flight. 
     Referring now to  FIG. 2 , the aircraft  1  further includes a fire suppression system  20  configured for extinguishing a fire that may occur in different fire zones of the aircraft  1 , i.e. zones including components susceptible of starting a fire and for which fire suppression must be provided, for example to comply with regulations. In the embodiment shown, the fire zones include a first engine compartment  24  receiving one of the two main engines  6 , a second engine compartment  26  receiving the other of the two main engines  6 , an auxiliary power unit compartment  28  receiving the auxiliary power unit (APU)  10 , and the baggage bay  30  within the cabin  2   a . In the embodiment shown, the engine compartments  24 ,  26  are defined by nacelles disposed around the main engines  6 , and connected to the fuselage  2 ; it is understood that the aircraft may have more than two main engines and that accordingly more than two engine compartments may be provided. In the embodiment shown, the APU compartment  28  is located within a rear section of the fuselage  2  of the aircraft  1  and is separated from a remainder of the fuselage by a bulkhead  32   a . The baggage bay  30  may be located anywhere within the cabin  2   a  and is separated from a remainder of the cabin by bulkhead(s)  32   b ,  32   c.    
     The fire suppression system  20  includes first and second reservoirs  34  and  36  each containing a fire suppressant, which may be halon  1301  or any other suitable fire suppressant. Each reservoir  34 ,  36  is fluidly connected to both of the engine compartments  24 ,  26  for distribution of the fire suppressant to the engine compartments  24 ,  26 . In a particular embodiment having each of the engine compartments  24 ,  26  connected to both of reservoirs  34 ,  36  provides a redundancy to the fire suppression system  20 : if the first reservoir  34  cannot provide the required fire suppressant or was already discharged, the second reservoir  36  is used instead or in addition, and vice-versa. In the embodiment shown, each of the reservoirs  34 ,  36  contains the fire suppressant at a pressure to facilitate the discharge of the fire suppressant. A non-limiting example of pressures for the fire suppressant in the reservoirs  34 ,  36  is at least 200 psi. 
     Regulations and/or certification standards apply to the fire suppression requirements for a given fire zone. For example, the applicable regulations for baggage bays allow some baggage bays to use only a hand-held fire extinguisher H to achieve fire suppression. The regulations may require that baggage bays which rely only on a hand-held fire extinguisher H have a particular configuration, or satisfy a “reach requirement” (i.e, the reach of a crew member when fighting a fire from a door of the baggage bay). If the baggage bay does not have the prescribed configuration or reach requirement, then it may require additional fire suppression measures. Similarly, the regulations may require that baggage bays which rely only on a hand-held fire extinguisher H have a maximum volume. If the volume of the baggage bay exceeds the prescribed maximum volume, then it may require additional fire suppression measures. 
     In a particular embodiment of the fire suppression system  20  disclosed herein, the baggage bay  30  has a particular configuration, or has a particular volume, which exceeds the regulatory requirements. Therefore, it might be required that the baggage bay  30  have additional fire suppression means, such as for example, a connection of the baggage bay  30  to its own dedicated reservoir of fire suppressant. For example, in a particular embodiment, the maximum acceptable volume for which a crew member is able to extinguish a fire using only a hand-held fire extinguisher H by standing in the opening  30   a  of the baggage bay  30  is defined by the applicable regulations to be  200  cubic feet. Accordingly, in this example, the baggage bay  30  has a volume of more than the maximum volume defined in the applicable regulations, and thus would require an additional means of fire suppression. However, and as explained in greater detail below, the fire suppression system  20  allows this more voluminous baggage bay  30  to avoid having its own dedicated reservoir of fire suppressant. 
     In a particular embodiment, the fire suppression system  20  is modified from an existing system where both reservoirs  34 ,  36  are connected to the engine compartments  24 ,  26  and to the APU compartment  28 , and where the baggage bay  30  has a volume exceeding the maximum volume for which the use of a hand-held fire extinguisher H is sufficient and is accordingly fed by a dedicated fire suppressant reservoir fluidly connected to the baggage bay  30 . It has been found that one of the redundancies of providing the fire suppressant to the APU compartment  28  can be omitted, and that one of the reservoirs  34 ,  36  can instead be used to distribute the fire suppressant to the baggage bay  30 . Accordingly, the fire suppression system  20  may result in the omission of the dedicated fire suppression reservoir for the baggage bay  30 , which may allow for a reduction in weight, production time and/or cost for the fire suppression system  20 . 
     In the embodiment shown, the first reservoir  34  is thus connected with the APU compartment  28  for distribution of the fire suppressant thereto, and the second reservoir  36  is connected with the baggage bay  30  for distribution of the fire suppressant thereto. As such, each reservoir  34 ,  36  is fluidly connected to only a respective one of the APU compartment  28  and the baggage bay  30 . In the embodiment of  FIG. 2 , the fire zone defined by the APU compartment  28  is fluidly separated from the second reservoir  36 , and the fire zone defined by the baggage bay  30  is fluidly separated from the first reservoir  34 . There is no conduit fluidly connecting the APU compartment  28  to the second reservoir  36 , no conduit fluidly connecting the baggage bay  30  to the first reservoir  34 , and fluid communication through the reservoirs  34 ,  36  is prevented by the pressure within the reservoirs  34 ,  36  and/or the configuration of their outlets. 
     In a particular embodiment, having the baggage bay  30  connected to one of the reservoirs  34 ,  36  allows for an increase in the volume of the baggage bay  30  beyond the maximum volume for which the use of a hand-held fire extinguisher H is sufficient, without requiring a dedicated reservoir of fire suppressant for the increased-volume baggage bay  30 . In the embodiment shown, the volume of the baggage bay  30  is greater than 200 cubic feet. 
     In the embodiment shown, the first reservoir  34  has a first outlet  34   a  connected to the first engine compartment  24 , a second outlet  34   b  connected to the second engine compartment  26 , and a third outlet  34   c  connected to the APU compartment  28 . 
     The second reservoir  36  has a first outlet  36   a  connected to the first engine compartment  24 , a second outlet  36   b  connected to the second engine compartment  26 , and a third outlet  36   c  connected to the baggage bay  30 . Each of the outlets  34   a - c ,  36   a - c  is normally closed, and operable when distribution of fire suppressant is required. For example, in a particular embodiment, a pyrotechnic capsule, or squib is provided in each outlet  34   a - c ,  36   a - c , which, once detonated, opens the outlet and allows the fire suppressant to exit the reservoirs  34 ,  36 . The outlets  34   a - c ,  36   a - c  are configured to prevent flow into the respective reservoir therethrough. 
     In the embodiment shown, the system  20  further includes a first fitting  50  and a second fitting  52  for connecting the reservoirs  34 ,  36  to the engine compartments  24 ,  26 , which may be for example T-shaped. Each fitting  50 ,  52  has two inlets  50   a ,  52   a  fluidly communicating with an outlet  50   b ,  52   b . One inlet  50   a  of the first fitting  50  is fluidly connected to the first outlet  34   a  of the first reservoir  34  and the other inlet  50   a  of the first fitting  50  is fluidly connected to the first outlet  36   a  of the second reservoir  36 . The outlet  50   b  of the first fittings  50  is fluidly connected to the first engine compartment  24 . One inlet  52   a  of the second fitting  52  is fluidly connected to the second outlet  34   b  of the first reservoir  34  and the other inlet  52   a  of the second fitting  52  is fluidly connected to the second outlet  36   b  of the second reservoir  36 . The outlet  52   b  of the second fitting  52  is fluidly connected to the second engine compartment  26 . Suitable conduits  54  configured for receiving the fire suppressant are used to connect the outlets  34   a ,  34   b ,  36   a ,  36   b  of the reservoirs  34 ,  36  to the fittings  50 ,  52 , and to connect the fittings  50 ,  52  to the engine compartments  24 ,  26 . Another suitable conduit  55  is used to connect the third outlet  34   c  of the first reservoir  34  directly with the APU compartment  28 . 
     Still referring to the embodiment of  FIG. 2 , the air pressure in the engine compartments  24 ,  26  is less than that in the baggage bay  30 . For example, the air pressure within the engine compartments  24 ,  26  may correspond to the outside air pressure of an environment E around the aircraft  1 . The baggage bay  30 , in contrast, is pressurized so as to be accessible from the cabin during flight. Both reservoirs  34 ,  36  are sized and configured to provide fire suppressant to both engine compartments  24 ,  26 . Stated differently, both reservoirs  24 ,  26  are sized to discharge a given quantity of fire suppressant in a given period of time dependent on the volume and flow characteristics of the engine compartments  24 ,  26 . The pressure in one of the reservoirs  34  corresponds to that in the other reservoir  36 , i.e. the pressure in both reservoirs  34 ,  36  is similar or the same. Since the reservoirs  34 ,  36  are sized for both engine compartments  24 ,  26 , the discharge pressure and/or the given quantity of fire suppressant from the reservoirs  34 ,  36  may be too high for the baggage bay  30 . Therefore, the system  20  further includes a restrictor  40  configured for lowering a discharge pressure of the fire suppressant being delivered to the baggage bay  30 . This helps to “slow down” the fire suppressant supplied to the baggage bay  30 . The baggage bay  30  is thus connected to the third outlet  36   c  of the second reservoir  36  through the restrictor  40 . The restrictor  40  is positioned so that the engine compartments  34 ,  36  are fed independently/separately from the restrictor  40 , i.e. the restrictor  40  does not affect the pressure of the fire suppressant being delivered to the engine compartments  34 ,  36 . In a particular embodiment, the APU compartment  28  is not pressurized, and accordingly no restrictor is provided between the first reservoir  34  and the APU compartment  28 . 
     Referring to  FIGS. 2-4 , the system  20  further comprises two nozzles  42  for delivering the fire suppressant to the baggage bay  30 . A panel  60  ( FIG. 3 ) defining a roof or ceiling of the baggage bay  30  has two apertures  62  defined therethrough, each sealingly receiving one of the nozzles  42  extending therethrough. The nozzles  42  are spaced apart from each other so as to allow distribution of the fire suppressant within the baggage bay  30 . Suitable conduits  44  ( FIG. 2 ) connect the third outlet  36   c  of the second reservoir  36  to the nozzles  42  via the restrictor  40 . Referring particularly to  FIG. 4 , in the embodiment shown, the nozzles  42  are L-shaped. An exit flow axis A of each of the nozzles  42  is oriented away from the panel  30  and toward a floor of the baggage bay  30 . The exit flow axis A is oriented substantially perpendicularly or normal to a surface of the panel  30  at the location of the corresponding nozzle  42 . Other configurations are possible, including, but not limited to, configurations including a single nozzle or more than two nozzles, or other types of discharge features such as tubes. 
     The fire suppressant increases in volume when it exits the reservoirs  34 ,  36 . Therefore, a pressure inside the baggage bay  30  increases upon releasing the fire suppressant. Referring back to  FIG. 2 , in the embodiment shown, the system  20  further includes a pressure-relief valve  46  for releasing pressure from the baggage bay  30 . The pressure-relief valve  46  has an inlet  46   a  connected to the baggage bay  30  and an outlet  46   b  connected to a region outside the baggage bay  30 , such as the environment E around the aircraft  1 . In an alternative embodiment, the outlet  46   b  is connects the baggage bay  30  to the underfloor during normal aircraft operation to allow for ventilation of the accessible baggage bay  30 . The pressure-relief valve  46  has an opened configuration and a closed configuration. The pressure-relief valve  46  allows fluid flow communication between the baggage bay  30  and the region E outside the baggage bay  30  through the pressure-relief valve  46  in the opened configuration to limit the pressure differential of the baggage bay  30  with respect to adjacent compartments. The pressure-relief valve  46  blocks fluid flow communication therebetween in the closed configuration. During normal operation of the aircraft  1 , the pressure-relief valve  46  is in the closed configuration. The opening of the pressure-relief valve  46  is coordinated with the release of the fire suppressant from the reservoir  36  into the baggage bay  30  so as to limit the pressure increase within the baggage bay  30  to an acceptable level. 
     In an embodiment, the pressure-relief valve  46  is part of a Baggage Bay Shut-Off Valve (referred to as “BBSOV”). Air enters the baggage bay  30  via the BBSOV through an inlet port of the BBSOV from the normal aircraft air distribution. An outlet port of the BBSOV fluidly connects the baggage bay  30  to an underfloor to allow for ventilation of the baggage bay  30 . The inlet port of the BBSOV is closed following smoke detection to cut the air flow into the baggage bay  30 . The outlet port of the BBSOV is kept open during a period following the discharge of fire suppressant to limit the pressure differential of the baggage bay  30  with respect to adjacent compartments. Limiting the pressure differential may also help to protect liners in the baggage bay  30 , and may also prevent existing decompression blow-out features from inadvertently activating. 
     In a particular embodiment, the discharge time of the second reservoir  36  and the time before opening the pressure-relief valve  46  are adjusted so that the pressure increase caused by the discharge of the fire suppressant in the baggage bay  30  is at most 0.2 PSI (i.e. pressure of at most 0.2 PSID). Therefore, in a particular embodiment, the restrictor  40  allows for time for discharging the fire suppressant in the baggage bay  30  to be higher than the time for discharging the fire suppressant in the engine compartments  24 ,  26 . In a particular embodiment, the discharge time for the baggage bay  30  is selected so that the initial concentration of the fire suppressant in the baggage bay  30  is at least 5% following the discharge of the fire suppressant and is maintained to at least 3% for two minutes thereafter. After the two minutes, and if required, the crew member extinguishes the fire with the hand held extinguisher H, which may be disposed proximate to the baggage bay opening  30   a . Other values for the discharge time and the concentration of fire suppressant are also possible. 
     In a particular embodiment, the system  20  may allow for a reduction of parts, costs, and/or weight because the fire suppression system  20  does not require a dedicated reservoir for the baggage bay  30 . Hence, in-service maintenance inspection of the aircraft  1  may be reduced because there is one less reservoir to inspect compared to other aircraft having a dedicated reservoir of fire suppressant for the baggage bay. Furthermore, in a particular embodiment, having one less reservoir allows for a reduction of the fire suppressant contained within the aircraft  1 . In a particular embodiment, this may be environmentally beneficial because the fire suppressant may be detrimental for the environment. 
     Referring now to  FIG. 5 , a fire suppression system  120  in accordance with another particular embodiment is shown, where elements similar to that of the fire suppression system  20  are identified by the same reference numerals and will not be further described herein. In this embodiment, the fittings are omitted. The first outlets  34   a ,  36   a  of the compartments  34 ,  36  are each directly connected to the first engine compartment  24  and the second outlets  34   b ,  36   b  of the compartments  34 ,  36  are each directly connected to the second engine compartment  26 , via suitable conduits  154   a . Other configurations are also possible. 
     In a particular embodiment and in use, the fire suppressant system  20  is connected by fluidly connecting each of the engine compartments  24 ,  26  to both reservoirs  34 ,  36  of fire suppressant. The APU compartment  28  is fluidly connected only to the first reservoir  34 , i.e. fluidly connected to the first reservoir  34  without being fluidly connected to the second reservoir  36 . The baggage bay  30  is fluidly connected only to the second reservoir  36 , i.e. fluidly connected to the second reservoir  36  without being connected to the first reservoir  34 . In other words, the system  20  is connected such that no fluid communication occurs between the APU compartment  28  and the second reservoir  36 , and between the baggage by  30  and the first reservoir  34 . 
     In the embodiment shown, connecting the fire suppressant system  20  further includes connecting the first engine compartment  24  to the first outlets  34   a ,  36   a  of the reservoirs  34 ,  36 , and connecting the second engine compartment  26  to the second outlets  34   b ,  36   b  of the reservoirs  34 ,  36 . The APU compartment  28  is connected to the third outlet  34   c  of the first reservoir  34  and the baggage bay  30  is connected to the third outlet  36   c  of the second reservoir  36 . 
     In the embodiment shown, the second reservoir  36  is connected to the baggage bay  30  via the restrictor  40  such that fluid communication between the baggage bay  30  and the second reservoir  36  is performed through the restrictor  40  to lower the pressure of the fire suppressant circulating therethrough. 
     In the embodiment shown, connecting the baggage bay  30  with the second reservoir  36  further comprises connecting the second reservoir  36  with the nozzles  42  in fluid communication with the baggage bay  30  to disperse the fire suppressant within the baggage bay  30 . 
     In the embodiment shown, a selective fluid communication between the baggage bay  30  and a region outside the baggage bay is provided for limiting a pressure increase in the baggage bay  30  when the second reservoir  36  injects the fire suppressant in the baggage bay  30 . In the embodiment shown, the pressure-relief valve  46  is used for that purpose. 
     The above description is meant to be exemplary only, and one skilled in the art will recognize that changes may be made to the embodiments described without departing from the scope of the disclosure. Modifications which fall within the scope of the disclosure will be apparent to those skilled in the art, in light of a review of this disclosure, and such modifications are intended to fall within the appended claims.