VALVE ASSEMBLY FOR AIRCRAFT

CROSS-REFERENCE TO RELATED APPLICATION

|ΘΘ0Ι| This application claims priority from . ^' United States Provisional Application Serial No. 61/928,200, filed January 16, 2014; the disclosure of which is incorporated herein by reference.

BACKGROUND f¾i)4)2| This invention relates in general to aircraft de-icing valve assemblies. More particularly, this invention relates to pneumatic valves used in de-icing systems for de-icing of aircraft surfaces, including wings, struts, stabilisers and engine nacelle,

SUMMARY

10003} This preferred embodiment relates in particular to pneumatic valves for de-icing aircraft surfaces, including, wings, struts, stabilizers, and engine nacelle. This pressure regulating and distribution valve (PRDV) ensures proper inflation pressure levels and evacuation pressure levels are maintained at de-icing boots. One unique feature of the PRDV is that it can regulate both the de-icing boot's inflation pressure and deflation pressure by directly tapping into the engine bleed air compressor. This is an improvement over the prior art where valve manifolds use independently operating pressure regulators and vacuum ejectors to achieve the same result. f ^{ K ⁾ 04| The preferred embodiment combines (! ) the function of reducing the outlet flow to a regulated pressure during the inflation cycle and (2) then reverting to a shutoff / vacuum generating device, ail while utilizing one valve or device. This reduces system weight, complexity of installation, and total part count. Specifically, the PRDV reduces the number of components whil increasing system reliability and. safety assessment values.

0005} Aircraft de-icing systems are known, for preventing or removing ice from aircraft edge surfaces. In an aircraft, de-icing system, pressurized air is regulated and distributed, in a closed environment, to a de-icing boot. Typically, a regulator provides regulated air to an independent control valve. The control valve then distributes the regulated pressurized air to a de-icing boot. Regulated air inflates de-icing boots at aircraft leading edges and removes ice on the leading edges. Alternatively, the regulated air provides a vacuum at de-icing boots to continuously sequence between the inflation and deflation of the de-icing boot. These sequences are provided by control valves which control the distribution and removal of the regulated air in the aircraft de-icing boots. t ⁾ 6| The PRDV is a control valve that, both, regulates and distributes pressurized air to a de-icing boot in an aircraft de-icing system. The PRDV regulates and distributes pressurized air, in a single valve assembly, through use of a piloting normally open electrical solenoid valve. Under alternative configurations, other solenoid valves, such as a direct acting normally open electrical solenoid valve, may be used. The normally open electrical solenoid valve switches between iirflatiou defiation modes. k\ the deflation mode, unregulated supply air pressure is used to de-activate the regulation function of the PRDV and create a vacuum. This allows a vacuum ejector to deflate the de-icing boot in fluid connection with the PRDV. The vacuum function is achieved through a vacuum ejector which utilizes the unregulated engine bleed air supply to de-pressurize the valve, in the alternative, in the inflation mode, when electrically activated, the solenoid valve allows unregulated engine bleed air to pass through a pressure regulator for inflation of the de-icing boot. The net effect of the PR DV is to alternate between periodic inflation/deflation cycl ing of the de-icing boot at set cycle times. 0007| Another embodiment is a valve assembly. The valve assembly includes a valve housing with a primary flow channel an output port, a pressure -regulation device, a fluid acceleration, device, a. secondary flow channel, and an ejector port. The pressure regulation device regulates a pressure of a regulated fluid in the primary flow channel when the valve assembly is in a pressure regulating mode. This regulated fluid is output through the -output, port. When the valve assembly is in a lo pressure operating mode, the pressure regulation device seals off an unregulated pressure portion of the primary flow channel from a low pressure portion of the primary flow channel, in this mode, the fluid acceleration device accelerates unregulated fluid in the unregulated pressure portion of the primary flow channel to create accelerated fluid. The secondary flow channel is located between the fluid accelerated, device and the low pressure portion of the primary flow channel. While in the low pressure operating mode, the accelerated fluid lowers the pressure in the low pressure portion of the primary flow channel via the secondary flow channel to pull low pressure fluid into the low pressure portion of the primary flow channel from the output port. This low pressure fluid flows via the secondary flow channel, from the low pressure portion of the primary flow channel to the ejector port wher it exits the valve assembly and enters the atmosphere. j 09081 Another embodiment is a pressure regulation and distribution valve (PllDV) assembly that operates, in a pressure regulation mode and at other times in a de- icing boot deflation mode. The PRDV assembly includes a housing, a inlet port for receiving an unregulated pressurized air, an outlet port, a primary flow channel, a pressure regulator, a fluid accelerator, a vacuum ejector flow channel, a vacuum ejector secondary flow channel, and a vacuum ejector port. The primary flow ch nnel is within, the housing and extends between the inlet port and the outlet port. The pressure regulator maintains a pressure of a regulated fluid exiting the outlet port when the PRDV assembly is operated in a pressure regulation mode. When operating in the de-icing boot deflation mode, the fluid accelerator accelerates unregulated fluid creating accelerated fluid. The vacuum ejector flow channel has a first end connected to the primary flow channel and a second end connected to the fluid accelerator. The vacuum ejector secondary flow channel is connected, adjacent to both the fluid accelerator and the primary flow channel. While still operating in the de-icing boot deflation mode, the accelerated fluid lowers the pressure of the primary flow channel so that, the primary flow channel draws in low pressure fluid, from the outlet port. The vacuum ejector is connected adjacent the fluid accelerator and the vacuum ejector secondary flow channel. The Sow pressure fluid, travels through the vacuum ejector secondary flow channel and exits the vacuum ejector to the atmosphere. d1M)9| Anothe embodiment is a method of operating a dual mode valve. The method begins by switching the dual mode valve to a pressure regulation mode. Next a regulated fluid with a regulated pressure value is produced from an unregulated fluid received at an inlet port of die dual mode valve. This fluid is then output through at an outlet port of the dual mode valve. The dual mode valve is later switched to a low pressure mode, in this mode, a low pressure is created in the dual mode valve. This low pressure draws a fluid, into the dual mode valve through the outlet port. The fluid drawn into the dual mode valve through the outlet port is then discharged out a vacuum ejector port of the dual mode valve to the atmosphere.

BRIEF DESCRIPTION OF THE DRAWINGS f 00101 Reference is made to the accompanying drawings in which particular embodiments and further benefits of the invention are illustrated as described in more detail in the description below, in which:

|001 1 FIG. 1 is a schematic of a prior art aircraft de-icing system; fOOllJ FIG. 2 is a perspective view of prior art aircraft wing sections with de-icing boots;

|0013| FIG. 3 is a diagrammatic perspective view of one embodiment, of a PRDV;

[0014j FIG. 4 is a cross-sectional view of the PRD ^' V embodiment of FIG. 3, taken through line 4-4;

|O0151 FIG. 5 is a cross-sectional view of the PRDV embodiment of FIG, 3 during the de-icing boot inflation mode, taken through line 5-5; f 00161 FIG. 5a is a cross-sectional, view of the PRDV embodiment of FIG. 3 during the de-icing boot deflation, mode, taken through line 5-5;

{00171 FI - 6 is a cross-sectional view of the PRDV embodiment of FIG. 3, taken through line 6-6;

[ 0181 FIG. 7 is a cross-sectional view of the PRDV embodiment of FIG. 3, taken through line 7-7; £0019J FIG. 8 is an illustration of a P DV during de-icing boot deflation mode; and £0020| FIG. 9 is an illustration of a PRDV daring de-icing boot inflation mode. {00211 FIG. 10 is a flow diagram of a method of operating a dual mode valve.

DETAILED DESCRI ΡΤΊΟΝ

[0022J Referring now to the drawings, FIG. I illustrates a prior art. aircraft, de-icing system .10 which receives pressurized air from a engine air compressor (not shown) or nacelle intake 20. Typically, air pressure produced by an engine air compressor is within a range of approximately 25 psig - 200 psig. However, to utilize the pressurized air tor an aircraft de-icing system 10, air pressure is typically reduced to a range of approximately 18 psig - 21 psig. This range of pressure is only one example range and other embodiments may have different ranges. To accomplish reduction in air pressure, prior ait aircraft de-icing systems 10 utilize pressure reducing valves / regulators 30 and check valves 40. In tire illustrated prior art system, these pressure reducing valves / regulators 30 and check, valves 40 operat independently from a prior art de-icing valve 50. Pressure reducing valves / regulators 30 take air pressure produced by engine air compressor (not shown) or nacelle intake 30 (at 25 psig - 200 psig) reducing the pressure to a working range of approximately 18 psig - 21 psig. Cheek valve 4(3 maintains consistent air pressure and prevents back feed when multiple conduits 60 are utilized, as illustrated in FIG. 1. The prior art de-icing valve 50 then receives pressurized air within a working range of approximately 18 psig - 21 psig which is then distributed to the aircraft edge surfaces, including, wings 70, struts (not shown), stabilisers 80, and. engine nacelle 90. Prior art de-icing valve 50 sequences the distribution of pressurized air to independent de-icing hoot sections 100 across the boot profile. A de-icing boot section 100 is further shown in FIG, 2, as a deflated de-icing boot section i 00(a) and an inflated de-icing boot section 100(b). By way of example, sequences are set at fixed cycle times, between inflation and deflation modes (i.e. one minute). The sequences prevent ice from building up on inflated de-icing boot sections 1 0 by continuously changing the position of de-icing boot section 100 at aircraft edge surfaces. [0O23| Sequencing between inflation and deflation modes is _. typically controlled by prior art de-icing valve 50 i prior art de-icing system 10. in inflation mode, pressurized air is distributed from the de-icing valve to de-icing boot sections 100, as illustrated by inflated de-icing boot section 100(b) in FIG. 2. In deflation mode, pressurized, air is utilized .at the prior art de-icing valve 50 to create a vacuum, removing air from de-icing boot section. 100, as illustrated by deflated de-icing boot section 100(a) in FIG. 2,

[0024 j The preferred embodiment combines (I ) the function of reducing outlet flow to a regulated pressure during the inflation cycle and (2) then reverting to a shutoff / vacuum generating device, all while utilizing one valve or device. This reduces system weight, complexity of installation and total part count. Specifically, the preferred embodiment reduces the number of components while increasing system, reliability and safety assessment values. 0025] Referring now to FIG. 3, _: a pressure regulating and distribution valve assembly 1 10 (PRDV) is illustrated within a housing 120. As further illustrated by F G. -8 and FIG. 9, housing 120 contains a primary flow channel 130, an inlet, port 140, an outlet port 150, a vacuum ejector primary .flow channel 1 0, a vacuum ejector secondary flow channel 1 70, a vacuum ejector 180 (also referred to as a jet pump), a solenoid valve 190, and a pressure regulator 200, FIG. 8 and 9 illustrate flow channel 130 extends from inlet port 1 0 to outlet port 150 wherein inlet port 140 is in fluid communication, via a conduit 60, with engine bleed air compressor 20, Engine bleed air compressor 20 includes nacelle intake or any source of engine bleed air, generally.. Unregulated pressurized air is received from engine bleed air compressor 20 by PRDV 1 10 through, inlet port .140. During de-icing boot inflation, regulated pressurized air is provided to de-icing boot 100 through outlet port 150. Outlet port 150 is in fluid communication via a conduit 60 with de-icing boot 100. During de-icing boot deflation, a vacuum is provided to de- icing boot 100 at outlet port .150 through conduit 60 in fluid communication with said de-icing boot 100.

|09261 Vacuum, ejector primary flow channel 160 exiends through PRDV housing 120 from flow channel 130 to vacuum ejector 180. Vacuum ejector I SO is an opening in the exterior of PRDV housing 120 exposed to the atmosphere. Vacuum ejector primary flow chaiinei 160 contains a vextturi orifice 210. Venturi orifice 210 increases the speed of fluid passing through. Vacuum ejector secondary flow channel 170 is connected to vacuum ejector primary flow channel 160 between venturi, orifice 210 and vacuum ejector I SO. ^' Vacuum ejector secondary flow channel 170 extends .from vacuum ejector primary flow channel 160 and connects to flow channel 130. f 0027J A pressure regulator structure 200 is also located in. PRDV housing Ί 20. Pressure regulator structure 200 comprises a compressing sprin 220, a piston 230, a piston chamber 240., a piston rod 250, and a poppet 260, Piston od 25 is connected to piston 230 on one end and connected to poppet 260 on the other end. Piston 230 is located in piston chamber 240, Piston rod 250 extends poppet 260 into flow channel 130. Compression spring 220 is located to the opposite side of piston 230 as piston rod 250 and poppet 260. Compression spring 220 extends from piston 230 to an exterior wall 270 of housing 120. 0Θ28| Compression spring 220 applies a spring load to piston 230. Spring 220 forces piston 230 away from exterior wall 270 of housing 1 0, When compression spring 220 forces piston 230 a way from exterior wall 270 of housing 120 piston rod 250 and poppet 260 are forced further into flow channel 130, Flow channel ! 30 is configured such that, as piston rod 250 and poppet 260 are forced further into flow channel 130, pressurized air through flow channel 130 increases, proportionately. In the alternative _. , when compression spring 220 depresses, piston rod 250 and poppet 260 depth decreases within flow channel 130 and pressurized air through flow channel 130 decreases, proportionately.

J002 J When compression spring 220 is fully extended, flow channel 130 is open to a maximum flow capacity, hi the alternative, when compression spring 220 is .fully compressed, poppet 260 seals closed flow channel 130, To accompiish this, a seat 280 is formed in flow channel 130, Poppet 260 sets in seat 280 forming the above mentioned seal. Thus,, when flow channel 130 is sealed there is no -pressurized air flowing to outlet port 150 through flow channel 130.

[0030] Piston chamber 240 is located between piston 230 and poppet 260. Piston chamber 240 is movably sealed at piston 230. Additionally, piston, chamber 240 is movabiy sealed from flow channel 130 at piston rod 250. Piston chamber 240 is open to a feedback loop 290, Feedback loo 290 is also open to primary flow channel 130 between poppet 260 and outlet port 150. Feedback loop 290 provides fluid communication between piston chamber 240 and primary flow channel 130. fWKJiJ The regulated pressurized air flow is accomplished by the position of poppet 260 in relation to seat 280 within primary flow channel 130. The position of the poppet 260 is controlled by the spring load of the compression spring 220 which may have a set spring load or be provided with an optional adjustment mechanism, such as a pressure regulator adjustment screw 320, illustrated by FIG. 3 - FIG. 5a. Pressurized air in the primary flow channel 130 enters piston chamber 240 through feedback loop 290 and creates force resistance against piston 230 opposite the force of spring 220 load. Specifically, feedback loop 290 senses downstream pressur and compression spring 220 is sized such that spring load biases pressure regulator structure 200 open at poppet 230 based upon pressure resistance at feedback loop 290. As compression spring 220 depresses, as described above, air pressure through the flow channel 130 decreases, proportionately. Regulated pressurized air exits the outlet port 150 and is distributed to de-icing boot 100 in fluid communication with the PR DV housing 120 at the outlet port 150.

|8632 ^' 1 PRDV housing 120 further includes solenoid valve 190. Such solenoid valve 90 may be of the type manufactured by MAC Valves, inc. Specifically, the MAC

Bullet Valve®, with a 3 -way configuration, is illustrated in the embodiment, as shown by FIG. 8 and FIG. 9. The MAC Bullet Valve® is. herein incorporated by reference. Solenoid valve 1.90 is open to and in fluid communication with vacuum ejecto primary flow channel 160 through a ^' solenoid valve inlet 300. Solenoid valve inlet 300 is connected to vacuum, ejector primary flow channel 160 between How channel 130 and venturi orifice 210. Solenoid valve outlet 310 is open to and in fluid communication with piston chamber 240. Soleiioid valve outlet 310 ts at least 1 :4 larger in ske than feedback loop 290. 0033J In operation, unregulated pressurized air from, an engine bleed air compressor 20 enters PRDV housing 120 through inlet port 140. As illustrated by FIG. 9, pressurized air flows through primary flow channel 130 to poppet 260 which

S regulates the pressurized air flow to the desired pressure (by use of example, 1..8 psig - 21 psig) based upon the position of poppet 260, The deflation mode is accomplished when solenoid valve 1 0 activates to block any pressurized air passing from solenoid valve 1 0 to solenoid valve outlet 31 . This allows the regulating function of P DV 1 10 to operate as described above. f003 J In de-icing boot deflation mode, as illustrated by FIG. 8. a vacuum is created to remove the air from de-icing boot 100. The vacuum deflates and forces de-icing boots 100 asainst the aircraft leadina edae surfaces (i.e. 70. 80. 90, etc.). in deflation mode, unregulated pressurize air flows into flow channel 130, however, flow channel 130 is sealed closed at poppet 260. Solenoid valve 190 receives unregulated pressurized air from primary flow channel 130 through vacuum ejector primary flow channel 160 and solenoid valve inlet 300. Solenoid valve 1 0 allows the unregulated pressurized, air passing through solenoid valve 190 to enter the piston chamber 240 through solenoid valve outlet 310, The unregulated pressurized air forces piston 230 toward exterior wall 270 of housing 120 and forces compression spring 220 fully compressed. As previously discussed, when compression, spring 220 is fully compressed poppet 230 seals flow channel 1.30 closed by creating a seal when seated in flow channel seat 280.

|003S| A vacuum is created at outlet port. 150 when unregulated pressurized air is forced through ejector primary flow channel 160 and venturi orifice 210, therein. Unregulated pressurized air enters venturi orifice 210, Upon exiting venturi orifice 210, the fluid speed increases. The increased fluid speed creates a reduction in pressure in ejector secondary flow channel 170. The reduced pressure creates a vacuum m the sealed portion of flow channel 1.30. between poppet 260 and outlet port 130, The vacuum then reverses air flow at outlet port 150.. Air located in de-icing boot 100, in fluid commmtioarion with the outlet port 150, is forced from de-icing boot 100 into the vacuum. Air then escapes through ejector secondary flow channel .170 and into the atmosphere throug vacuum ejector 180.

|00361 Although air leakage may occur from piston chamber 240 at feedback loop 290, the air leakage is minimal. Flow channel. 130 remains closed and the vacuum is maintained since feedback loop 290 is significantly smaller than solenoid valve outlet 310,

[0037] A boot overpressure relief valve 330 (BQRV), also referred to as dump valve, ma optionally be provided on PRDV housing 120. BQRV 330 pops open nd damps air to the atmosphere upon exceeding a. set pressure, as a safety mechanism. The pressure setting is typically set at a value slightly above the regulated pressurized air- working range (i.e. set at 22 psig for a working range of 18 psig - 21 psig), BQRV 330 may be installed on an air line, independent of the PRDV housing 120, or integral to PRDV housing 120,. as illustrated by FIG. 3 and FIG. 4.

{00381 A boot pressure switch 340 may optionally be provided on PRDV housing 1.20 as a sensing mechanism. Boot pressure switch 340 will latch a fault in the instance PRDV 1 10 is not working. Specifically, an onboard controller reads the switch state, between inflation/deflation modes, and determines if the air pressures in either the PRDV 1 10 or the de-icing boot section 100 are properly timed and in the appropriate mode.

£00391 A cartridge heater 350 may .optionally be provided on PRDV bousing 1.20, in close, proximity of regulator and ejector, to prevent freezing.

{00401 Example methods may be better appreciated with reference to flow diagrams.

While for purposes of simplicity of explanation, the illustrated methodologies are shown and described as a series of blocks, it is to be appreciated that the methodologies are not limited by the order of the blocks, as some blocks can occur in different orders and/or concurrently with other blocks from that shown and described. Moreover, less than all the illustrated blocks may be required to implement an example methodology. Blocks may be combined or separated into multiple components. Furthermore, additional and/or alternative methodologies can employ additional, not illustrated blocks,

{00411 Fig- 1 illustrates a method 1000 of operating a dual mode valve. The method begins., at 1002, by switching the dual mode valve to a pressure regulation mode. A regulated fluid is produced with a regulated pressure value, at 1004, from an unregulated fluid received on an inlet port of the dual mode valve. This can be perfonned as discussed above. The regulated fluid is discharged at an outlet port of the dual mode val ve, at 1006. Later, the dual mode valve is changed to operate in a low pressure mode, at 1008. The pressure within a channel connected to the outlet port, is lowered, at 10 0. This can be dorse by using a venture type of device as discussed above. A fluid is then drawn into the dual mode valve, at 1012, through the outlet port. The fluid drawn into the dual mod valve through the outlet port out is discharged out a vacuum ejector port of the dual mode valve to the atmosphere, at 1014. While this invention has been described with reference to particular embodiments thereof, it shall be understood that such description is by way of illustration, arid not by way of limitation. Accordingly, the scope and content of th invention axe to be defined by the terms of the appended claims.

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