Integrated O2RU system

An oxygen removal system for removing dissolved oxygen from fuel within a fuel system includes a first housing, a second housing, a membrane filter, a piston assembly, and an outlet cap. The first housing extends along a first axis between a first housing first end and a first housing second end. The second housing is disposed about the first housing. The membrane filter is disposed between the first housing and the second housing. The piston assembly has a piston housing that is disposed about the second housing. The piston assembly is arranged to generate a vacuum to remove a fluid from the membrane filter.

BACKGROUND

Quantities of oxygen may readily dissolve into various liquid media such as a hydrocarbon fuel. In certain applications, the hydrocarbon fuel may be used as a coolant for various systems of a vehicle such as an aircraft engine. The dissolved oxygen within the hydrocarbon fuel may react at elevated temperatures to form free radicals such as coke precursors that may lead to the formation of deposits. These deposits may clog fuel filters, injectors, or other fuel system components.

Accordingly, it is desirable to remove the dissolved oxygen from the hydrocarbon fuel to limit coke formation.

BRIEF DESCRIPTION

Disclosed is an oxygen removal system for removing dissolved oxygen from fuel within a fuel system. The oxygen removal system includes a first housing, a second housing, a membrane filter, a piston assembly, and an outlet cap. The first housing extends along a first axis between a first housing first end and a first housing second end. The first housing defines a plurality of holes that are disposed transverse to the first axis. The second housing is disposed about the first housing. The second housing extends along the first axis between a second housing first end and a second housing second end. The membrane filter is disposed between the first housing and the second housing. The piston assembly has a piston housing that is disposed about the second housing. The piston housing extends along the first axis between a piston housing first end and a piston housing second end. The piston housing second end, the first housing second end, and the second housing second end define a cavity. The piston assembly is arranged to generate a vacuum to remove a fluid from the membrane filter. The outlet cap is disposed within the cavity.

In addition to one or more of the features described herein, the outlet cap is secured to the first housing second end.

In addition to one or more of the features described herein, a fuel filter is received within the first housing and arranged to receive fuel along the first axis and discharge fuel through the plurality of holes.

In addition to one or more of the features described herein, a leakage protection valve is disposed within a valve body that extends towards an end of the membrane filter.

In addition to one or more of the features described herein, an extension member extends along the first axis from the outlet cap through an opening defined by the piston housing second end.

In addition to one or more of the features described herein, the extension member is a hollow member that defines a first fluid outlet.

In addition to one or more of the features described herein, the extension member defines a second fluid outlet that is disposed transverse to the first fluid outlet.

In addition to one or more of the features described herein, the second fluid outlet is fluidly connected to the cavity.

In addition to one or more of the features described herein, a third housing is disposed about the piston housing and the second housing, and extends along the first axis between a third housing first end and a third housing second end.

In addition to one or more of the features described herein, the third housing first end is secured to the second housing first end.

In addition to one or more of the features described herein, the piston housing is movable along the first axis relative to the membrane filter, the second housing, and the third housing.

Also disclosed is an oxygen removal system that includes a first housing, a second housing, a membrane filter, a third housing, and an end cap. The first housing extends between a first housing first end and a first housing second end, the first housing receives a fuel filter. The second housing is disposed about the first housing and extends between a second housing first end and a second housing second end. The membrane filter is disposed between the first housing and the second housing. The third housing is disposed about the second housing and extends between a third housing first end and a third housing second end. The third housing first end has a first flange that extends towards the first housing. The end cap abuts the first flange and extends into at least one of the third housing and the second housing.

In addition to one or more of the features described herein, an outlet cap is disposed opposite the end cap, the outlet cap abuts the first housing second end.

In addition to one or more of the features described herein, the outlet cap is at least partially disposed between the first housing and the second housing.

In addition to one or more of the features described herein, a piston assembly has a piston housing disposed between the second housing and the third housing. The piston housing extends between a piston housing first end and a piston housing second end.

In addition to one or more of the features described herein, the third housing second end has a second flange that extends towards the piston housing.

In addition to one or more of the features described herein, the piston housing is movable between a first position in which the piston housing first end abuts the second housing first end and a second position in which the piston housing first end is spaced apart from the second housing first end.

In addition to one or more of the features described herein, a biasing member extends between the second flange and a piston skirt extending from the piston housing first end towards the third housing.

In addition to one or more of the features described herein, the biasing member biases the piston housing towards the first position.

In addition to one or more of the features described herein, a valve assembly is operatively connected to the end cap and extending towards the membrane filter.

DETAILED DESCRIPTION

A detailed description of one or more embodiments of the disclosed apparatus are presented herein by way of exemplification and not limitation with reference to the Figures.

Referring toFIGS. 1A, 1B, 1C and 2, an oxygen removal system10for removing dissolved oxygen from fuel is shown. The oxygen removal system10is incorporated into a fuel system and is arranged to remove the dissolved oxygen within the fuel to inhibit or reduce the formation of coke or other deposits when the fuel is heated. The removal of the dissolved oxygen may enable the fuel system to operate at a higher temperature and therefore increase overall efficiency of the energy conversion unit, e.g. engine, which incorporates the fuel system having oxygen removal system10.

The oxygen removal system10is an integrated unit that includes a first housing20, a second housing22, a third housing24, a piston assembly26, an outlet cap28, an end cap30, and a valve assembly32. The first housing20, the second housing22, the third housing24, the piston assembly26, the outlet cap28, and the end cap30are disposed concentrically with each other. The integration of the above identified components into a single unit may eliminate plumbing lines that connect the individual elements of the oxygen removal system10as well as to reduce the overall size of the oxygen removal system10.

The first housing20extends along a first axis40between a first housing first end42and a first housing second end44. The first housing first end42is provided with a first inner diameter and the first housing second end44is provided with a second inner diameter that is less than the first inner diameter. An inner surface of the first housing20is configured as a tapered surface having a taper that extends from the first housing first end42towards the first housing second end44.

The first housing20defines a support rib46that extends from the first housing second end44towards the first housing first end42.

The first housing20defines a first plurality of holes50and a second plurality of holes52that are disposed transverse to the first axis40. The first plurality of holes50extend between the first housing first end42and the first housing second end44.

The first housing20may be arranged as a fuel filter housing that receives a fuel filter60. The fuel filter60includes sealing elements that engage the inner surface of the first housing20. The fuel filter60is arranged to receive fuel along the first axis40, turn the fuel, and enable the fuel to exit or be discharged in a direction that is disposed transverse to the first axis40and through the first plurality of holes50of the first housing20towards the second housing22.

The second housing22is disposed about and is spaced apart from the first housing20. The second housing22extends along the first axis40between a second housing first end70and the second housing second end72. The second housing22includes a skirt74that is disposed proximate the second housing first end70and radially extends away from the first axis40towards the third housing24. The skirt74includes a sealing element that slidably engages the third housing24. The second housing second end72is configured as an open end.

A membrane filter80is disposed between the first housing20and the second housing22. The membrane filter80includes a tube bundle or a plurality of hollow tubes88that extend along the first axis40between a first membrane end82and a second membrane end84. The plurality of hollow tubes88are formed into a hollow cylindrical shaped bundle that are supported by potting or an epoxy86at the first membrane end82and at the second membrane end84. The potting or epoxy86adheres the plurality of hollow tubes88together but allows the first membrane end82and the second membrane end84to be open to be subject to the vacuum generated by the piston assembly26.

Referring toFIGS. 1A-1C, the plurality of hollow tubes88are selectively permeable membrane tubes that are disposed within a first flow circuit that is defined between the first housing20and the second housing22. The plurality of hollow tubes are disposed at least partially about a circumference of the first housing20that includes multiple holes that are axially spaced apart along a length of the membrane filter80. The multiple holes ensure a uniform fuel flow through the plurality of hollow tubes88to maximize the efficiency of each tube. Fuel flows radially through the first plurality of holes50of the first housing20and flows over the plurality of hollow tubes88of the membrane filter80. As the fuel passes over the plurality of hollow tubes of the membrane filter80, oxygen is drawn from the fuel through the membrane filter80and into the center of each tube of the plurality of hollow tubes88. A second flow circuit fluidly communicates with an inner channel or center of the tubes of the plurality of hollow tubes88such that a vacuum draws or carries away oxygen that is pulled from the fuel that flows around the plurality of hollow tubes88of the membrane filter80and is within the inner channel of center of a tube of the plurality of hollow tubes88. The center of a tube of the plurality of hollow tubes88is partially isolated from the first flow circuit such that the vacuum does not pass through a wall of a tube of the plurality of hollow tubes88. The fuel flows across or over the plurality of hollow tubes88of the membrane filter80and exits the membrane filter80through the second plurality of holes52of the first housing20and then is turned to flow axially towards an outlet of the oxygen removal system10.

In the embodiment shown inFIG. 1B, the plurality of hollow tubes88may be disposed between the first housing20and the second housing22and may at least partially disposed about a circumference of the first housing20. The support rib46may at least partially define the first plurality of holes50and a plurality of holes87. A first grate89amay be disposed between an opening to the first flow circuit and the plurality of hollow tubes88and a second grate89bmay be disposed between an opening to the second flow circuit and the plurality of hollow tubes88. A divider wall89cmay extend between the first housing20and the second housing22that prevents flow from short circuiting from the inlet to the outlet such that fuel is forced to flow around the entire circumference of the first housing20and through the plurality of hollow tubes88of the membrane filter80.

The flow may pass over an outside surface of a tube of the plurality of hollow tubes88as the flow travels circumferentially, as shown inFIG. 1B, while a flow that passes through the inner channel of a tube of the plurality of hollow tubes88may be drawn out through the second flow circuit.

In the embodiment shown inFIG. 1C, a first wall89dand a second wall89eare disposed between the first housing20and the second housing22to cause flow within the first flow path to move radially outward and inward as the flow flows around the circumference of the first housing20. For example, the first wall89dand the second wall89emay define a labyrinth path such that the first wall89dextends from the first housing20towards but does not reach the second housing22and the second wall89eextends from the second housing22towards but does not reach the first housing20.

An inner grate89fmay overlay one or more inner pass through channels, IC, between each wall pair89d,89e. An outer grate89gmay overlay one or more outer pass through channels, OC, between each wall pair89d,89e. The plurality of hollow tubes88of the membrane filter80may be disposed between the inner grate89fand the outer grate89gsuch that flow is radial through each tube section of the plurality of hollow tubes88.

The flow may travel radially outward through each section of tubes of the plurality of hollow tubes88into the outer pass through channels, OC, where the flow may travel circumferentially to the next section of tubes where the flow travels radially inward to the inner pass through channels, IC.

The third housing24is disposed about the second housing22and the piston assembly26. The third housing24extends along the first axis40between a third housing first end90and a third housing second end92. The third housing24has a first flange94that is disposed proximate the third housing first end90and extends towards the first housing20and the first axis40. The first flange94engages the skirt74of the second housing22. The first flange94facilitate securing the third housing first end90to the second housing first end70. The third housing24has a second flange96that is disposed proximate the third housing second end92and extends towards the first housing20, the piston assembly26, and the first axis40.

The piston assembly26is at least partially disposed about the second housing22and is disposed between the second housing22and the third housing24. The piston assembly26includes a piston housing100. The piston housing100extends along the first axis40between a piston housing first end102and a piston housing second end104.

The piston housing100includes a piston skirt106that is disposed proximate the piston housing first end102and radially extends towards the third housing24. The piston skirt106includes an extension or a spacer108that extends axially towards the skirt74of the second housing22. The combination of the skirt74of the second housing22, the spacer108of the piston skirt106, and the piston skirt106of the piston housing100define a first chamber110. The first chamber110is arranged to receive oxygen that is removed from the fuel by the membrane filter80.

The piston housing second end104defines an opening112that is disposed about the first axis40. The piston housing first end102defines a port114that is fluidly connected to the first chamber110.

A cavity120is defined by the piston housing second end104, the first housing second end44, and the second housing second end72.

A biasing member130extends between the second flange96of the third housing24and the piston skirt106of the piston housing100. The biasing member130is arranged to bias the piston housing100towards a first position in which the piston housing first end102approximately abuts the second housing first end70.

The piston housing100is movable between a first position, as shown inFIG. 1, and a second position, as shown inFIG. 2, relative to the first housing20, the fuel filter60, the second housing22, the membrane filter80, and the third housing24. The spacer108of the piston skirt106of the piston housing100engages the skirt74of the second housing22while the piston housing100is in the first position, and pressurized fuel is not provided to the oxygen removal system10. As pressurized fuel enters the oxygen removal system10, the pressure acting on the piston housing100overcomes the spring force provided by the biasing member130and moves the piston housing100towards the second position. The piston housing first end102is spaced apart from the second housing first end70such that the spacer108of the piston skirt106does not engage the skirt74of the second housing22while the piston housing100is in the second position. As the piston housing100moves towards the second position, a vacuum is created to draw the oxygen from within the tubes of the membrane filter80and is directed towards the cavity120.

The outlet cap28is disposed within the cavity120and is disposed opposite the end cap30. The outlet cap28is at least partially disposed between the first housing20and the second housing22. The outlet cap28abuts and is secured to the first housing second end44. A fastener extends through the outlet cap28and into the support rib46to secure the outlet cap28to the first housing20.

The outlet cap28includes an extension member140that extends along the first axis40from a portion of the outlet cap28through the opening112of the piston housing100. The piston housing100is arranged to ride along or slidably engage the extension member140as the piston housing100moves between the first position and the second position.

The extension member140is configured as a hollow member that defines a first fluid outlet142that extends along the first axis40. The first fluid outlet142is arranged to discharge fuel axially along the first axis40such that the fuel may be delivered to other systems. The extension member140defines a second fluid outlet144that is disposed transverse to the first axis40and is disposed transverse to the first fluid outlet142. The second fluid outlet144is fluidly connected to the cavity120. In at least one embodiment, a cap146is disposed proximate an end of the extension member140. The cap146extends at least partially into the extension member140and includes a portion that is disposed transverse to and abuts an end of the extension member140.

The end cap30is disposed opposite the outlet cap28. The end cap30is disposed proximate the first housing first end42, the second housing first end70, and the third housing first end90. The end cap30abuts the first flange94and is arranged to receive a fastener that extends through the first flange94and into the skirt74of the second housing22to secure the end cap30to the third housing24and the second housing22.

The end cap30defines a fuel inlet150that is disposed about the first axis40. The fuel inlet150is arranged to receive fuel axially along the first axis40such that it enters into the oxygen removal system10.

The end cap30extends into a region that is disposed between the first housing20and the second housing22. The end cap30is arranged to receive the valve assembly32.

The valve assembly32is operatively connected to the end cap30and extends towards the membrane filter80within the region that is disposed between the first housing20and the second housing22.

The valve assembly32includes a first valve160and a second valve162that are disposed within a valve body170that extends through the end cap30and extends into the first flow circuit that is defined between the first housing20and the second housing22such that the valve body170extends towards an end of the membrane filter80. The first valve160and the second valve162are arranged axially along a second axis164that is disposed substantially parallel to the first axis40. The first valve160is configured as a check valve that is fluidly connected to the first chamber110that collects oxygen that is purged from the membrane filter80. As oxygen is removed from the fuel and is collected within the first chamber110, the first valve160may open and vent the removed oxygen to ambient around the second valve162.

The second valve162is fluidly connected to the first valve160. The second valve162is configured as a leakage protection valve. The second valve162allows oxygen to pass through the second valves diametrical clearance, but the second valve162may translate along the second axis164to compress a biasing member166should the first chamber110become pressurized due to fuel entering the first chamber110or the first chamber110exceeding a predetermined pressure. As the biasing member166is compressed, the second valve162moves towards a leakage inhibit position in which the second valve162engages a seal168. The seal168is at least partially received within a valve body170that contains both the first valve160and the second valve162.

The second valve162is in communication with a sensor or a switch180that is in communication with a controller. A message is output for display by the controller, responsive to the second valve162engaging the seal168.