Patent Application
20150096641
The application relates generally to flow regulators and more particularly to adjustable fluid devices capable of controlling the flow of fluid through a body.
Conventional “needle type” adjustable orifices adjust the flow by partially and adjustably obstructing an orifice through which the fluid passes, producing a small adjustable gap. However, these “needle type” adjustable orifices are prone to blockage, have a high risk for contamination and may require a filter in some applications. Furthermore, this flow control system is typically complex and costly. Conventional “fixed” orifice control systems require replacement of the orifice with a different diameter orifice to adjust the flow passing through the system. This type of control system is less complex and has lower costs, and reduces the risk of blockage as any debris can freely flow through the orifice and exit the system. However, conventional “fixed” orifice control systems require part replacement to achieve flow adjustment and require the user to keep a number of orifices of different sizes on hand.
Accordingly, there is a need for flow regulators designed to overcome the shortcomings of the conventional adjustable orifice systems.
In one aspect, there is provided a flow regulating device used in a fluid system, comprising: an orifice body defining a longitudinal axis and having a central bore extending axially therethrough between first and second ends of the orifice body, the fluid system in fluid communication with the bore at the second end, the first end having a plurality of circumferentially spaced-apart radially-flexible fingers extending axially from the first end, the fingers having ends adjacent the first end cooperating to define a flow-controlling orifice area in the bore, the fingers configured to reduce an orifice area in response to force applied radially inwardly adjacent the first end; a housing cooperatively receiving the orifice body and configured to apply an increasing radial inward force on the fingers when the orifice body is moved axially relative the housing; and an adjusting apparatus for adjusting the relative axial position of the housing and the orifice body.
In another aspect, there is provided a flow regulating device used in a fluid system, comprising: an orifice body defining a longitudinal axis and having a central bore extending axially therethrough between first and second ends of the orifice body, the orifice body having a conical end section coaxial with the bore at the first end and having a plurality of circumferentially spaced apart through-slits extending axially from the first end and radially through the body so as to define radially-moveable fingers at the first end; a housing defining a cavity extending between one and another ends of the housing and receiving the orifice body, the cavity including a conical section at said one end of the housing configured to cooperate with the orifice body first end, the housing conical section configured to radially compress the fingers when the orifice body is moved in the cavity relative the housing, the fingers defining an adjustable transverse cross section of a flow passageway extending through the orifice body and housing, the flow passageway having first and second openings in fluid communication with the fluid system; and an adjusting apparatus for adjusting radial compression of the housing to the fingers of the orifice body to adjustably restrict said cross section of the flow passageway.
In a further aspect, there is provided a flow regulating system used in a fluid system, comprising: a first flow passageway defining first and second openings of the system located at respective opposed ends of the first flow passageway; a second flow passageway in fluid communication with and extending from the first flow passageway to a distal end of the second flow passageway, the distal end forming a third opening of the system; a fluid flow entering the first flow passageway through the first opening, a first portion of the fluid flow passing through the first flow passageway to the second opening, a second portion of the fluid flow passing through part of the first flow passageway and through the second flow passageway to the third opening; the first flow passageway including a bore extending through an orifice body, the orifice body extending through a cavity of a housing and having a truncated conical end section with a plurality of circumferentially spaced apart axial slits in fluid communication with the bore, the truncated conical end section of the orifice body being radially compressible in a truncated conical section of the cavity, the bore and spaces in the respective slits in combination defining a cross section of the first flow passageway; and an adjusting apparatus for adjusting radial compression of the housing to the truncated conical end section of the orifice body to change an area defined by said cross section of the first flow passageway to cause changes of pressure drop of the fluid flow over the first flow passageway, thereby resulting in corresponding pressure changes of the second portion of the fluid flow at the third opening.
Reference is now made to the accompanying figures in which:
It will be noted that throughout the appended drawings, like features will be identified by like reference numerals.
Referring to
With respect to the longitudinal axis 34, the cylindrical extension 38 may be provided with a plurality of circumferentially spaced apart through-slits 48 (see
A housing 50 which may be substantially cylindrical. The inner wall of the housing 50 may define a cavity 52 for receiving the orifice body 32. The cavity 52 may extend through the housing 50 in the longitudinal direction and may include a truncated conical section 54 positioned between a large cylindrical section 56 and a small cylindrical section 58 of the cavity 52, such that the large cylindrical section 56 and the small cylindrical section 58 extend towards opposed ends of the housing 50. A fitting 60 may be incorporated with the small cylindrical section 58 of the cavity 52, to form one of the opposed ends of the housing 50 for connecting with another part (not shown) of the fluid system 28 of the engine.
A threading engagement 62 may be provided between the cylindrical sections 36, 56 of the orifice body 32 and the inner wall of the housing 50 for adjusting an axial position of the orifice body 32 relative to the housing 50, resulting in the truncated conical end section 40 of the orifice body 32 being radially compressed in the truncated conical section 54 of the cavity 52 by the inner wall of the housing 50. However, the threading engagement 62 may be replaced by any other suitable movement apparatus such as mechanical, electronic or pneumatic devices.
According to one embodiment the large cylindrical section 56 of the cavity 52 may have an opening 63 defined at one of the opposed ends thereof, to allow the end 44 of the orifice body 32 to extend axially outwardly therefrom. The small cylindrical section 58 of the cavity 52 may define an opening 64 at the other of the opposed ends thereof. The opening 64 thus also forms an opening of the fitting 60 of the housing 50. The orifice body 32 may be provided with at least one flat surface 66 extending tangentially with respect to the longitudinal axis 34. For example, the at least one flat surface 66 may be formed as a part of a hexahedral end section (not numbered) of the orifice body 32 located at the end 44 for working with a hand tool to rotate the orifice body 32 about the longitudinal axis 34.
The bore 46 of the orifice body 32 and part of the cavity 52, for example the small cylindrical section 58 of the cavity 52, therefore form a flow passageway 68 extending through the orifice body 32 and the housing 50, defining a first opening formed by the opening 64 at the end of the fitting 60, and a second opening at the end 44 of the orifice body 32. The flow passageway 68 may include a cross section 42a (see
Depending on the application, the materials of the orifice body 32 and the housing 50 may be selected to have different thermal expansion coefficients as a means of thermal adjustment. For this alternative design, the flow regulating device 30 can not only be adjusted manually by adjusting the axial position of the orifice body 32 relative to the housing 50, but can also be automatically adjusted by housing temperature changes which result in diameter changes of the cavity 52 of the housing 50 and the orifice body 32 based on their respective thermal expansion coefficients, which is referred to as a “passive flow control system”. For example, the housing 50 may be made of aluminium and the orifice body 32 may be made of stainless steel. When the temperature of the housing 50 decreases, the aluminium housing 50 will shrink more than the stainless steel orifice body 32 and therefore the cross section 42a of the flow passageway 68 at the flattened first end 42 of the orifice body 32 will reduce (without adjusting an axial position of the orifice body 32 relative to the housing 50) to constrict fluid flow. Depending on the application, this thermal adjustment may be advantageous if the system is designed based on thermal changes and can be self-regulating.
Referring to
The second end 44 of the orifice body 32 may be received within the cavity 52 of the housing 50 instead of extending axially outwardly from the opening 63 of the housing 50 as shown in
Optionally, the flow regulating device 30′ may further include, for example a three-way connector 70 having an internal passage 72 with an inlet 74, a first outlet 76 and a second outlet 78. The connector 70 may be attached to the housing 50 to allow the fitting 60 to be inserted into the first outlet 76 of the connector 70, to thereby communicate the internal passage 72 with the cavity 52 of the housing 50 through the first outlet 76 and the opening 64 which is also the first opening of the flow passageway 68. When the flow regulating device 30′ is installed in one of the fluid systems 28 of the engine shown in
The three-way connector 70 according to this embodiment may have a T-shaped configuration, having a first part 72a of the internal passage 72 and a second part 72b of the internal passage 72, the first and second parts 72a, 72b being perpendicular to each other. The first part 72a of the internal passage may extend from the inlet 74 to the first outlet 76 and may be substantially coaxial with respect to the flow passageway 68, thereby forming part of, or an extension of the flow passageway 68. The second part 72b of the internal passage may be in fluid communication with and extend from the extended flow passageway 68 (the first part 72a of the internal passage 70) to a distal end (not numbered) of the second part 72b of the internal passage 70. The second outlet 78 of the connector 70 is formed at the distal end of the second part 72b.
In this embodiment, the pressure drop can be achieved in either direction. For example, fluid may enter the device 30′ from inlet 74 or from opening 63, and a pressure change at the second outlet 78 can be observed when the cross-section 42a of the flow passageway is adjusted.
The described embodiments of the flow regulating device allow pre-adjustment of the flow and pressure of the fluid systems in gas turbine engines while minimizing potential contamination in the fluid systems. Additional parts beyond basic hand tools may not be required for adjustment of the flow regulating device. The described embodiments of the flow regulating device may reduce complexity as compared to conventional adjustable orifice systems, and thus may reduce overall cost.
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 described subject matter. For example, the housing for containing the orifice body may be a stand-alone part or may be a truncated conical section of the cavity and may be integrated into any device, such a casing or housing of another engine component, thereby eliminating the orifice housing part and reducing overall part count. The truncated conical section described in the above embodiments need not be truncated, nor conical. Besides conical shapes, other progressively-reducing area shapes (e.g. trapezoids) may be used. Alternately, any suitable flexible configuration which reduces bore area in response to radial inward force from the housing, as a function of relative position between housing and orifice body, is within the scope of the present disclosure. Furthermore, as previously noted, the present apparatus may be applicable in any suitable fluid system, and not just the gas turbine example provided. Modifications which fall within the scope of the described subject matter 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.
