Gaseous fuel injector with flame arrester

Abstract

A fuel injector for gaseous fuel is provided. In some embodiments, the fuel injector includes a flame arrestor, and in some embodiments, an orifice is included, the flame arrestor configured to prevent or reduce propagation of flame through the fuel injector from a combustion chamber to an internal component contained within the fuel injector. Reducing or preventing flame propagation from the combustion chamber reduces exposure of fuel injector components to temperature variations, improves fuel injector robustness, and extends operating life.

Description

[0001] Cross-references to related applications

[0002] This application claims priority and benefit on the filing date of U.S. Provisional Application Serial No. 63 / 647,685, filed May 15, 2024, which is incorporated herein by reference. Technical Field

[0003] This disclosure relates generally to a fuel injector for supplying gaseous fuel to an internal combustion engine, and more specifically, to a flame arrester for a fuel injector for gaseous fuel. Background Technology

[0004] Fuel injectors used for gaseous fuel injection are subjected to extreme conditions due to pressure and temperature. When gaseous fuel burns in the combustion chamber of an internal combustion engine, high-temperature combustion gases and flames flow back into the fuel injector. This exposes internal injector components to high temperatures, thereby shortening the fuel injector's lifespan and reducing its robustness. Therefore, there remains a need for the unique devices, systems, and technologies disclosed herein.

[0005] The content of the explanatory implementation plan

[0006] For the purpose of clearly, concisely, and accurately describing the illustrative embodiments of this disclosure, the manner and process of making and using the embodiments, and in order to enable the practice, making, and use of the embodiments, reference will now be made to certain exemplary embodiments, including those shown in the figures, and these exemplary embodiments will be described using specific language. However, it should be understood that this is not intended to limit the scope of the invention, and that the invention includes and protects such changes, modifications, and further applications of the exemplary embodiments as would be conceived by those skilled in the art. Summary of the Invention

[0007] This disclosure includes a fuel injector for a gaseous fuel injection system for an internal combustion engine. The fuel injector includes a flame arrester configured to prevent or reduce the propagation of flame from the combustion chamber through the fuel injector to internal components housed within the fuel injector.

[0008] In some implementations, in addition to a flame arrester, the fuel injector also includes a throttling orifice to reduce the propagation of flame from the combustion chamber through the fuel injector to internal components housed within the fuel injector.

[0009] In one embodiment, a fuel injector for providing gaseous fuel to a combustion chamber is disclosed. The fuel injector includes an elongated injector body defining a longitudinally extending fuel passage therein. The fuel passage extends from a gas inlet end of the injector body to a gas outlet end in a downstream direction. The fuel injector also includes a valve assembly located in the fuel passage. The valve assembly includes at least one valve that selectively opens and closes to control the flow of gaseous fuel through the fuel passage to the combustion chamber. The fuel injector also includes a flame arrestor located in the fuel passage downstream of the valve assembly.

[0010] In certain embodiments, a throttle valve is disposed in the fuel passage that forms a throttle orifice between the gas outlet end and the flame arrestor.

[0011] In one embodiment, an apparatus for reducing the propagation of a flame through a fuel passage to internal components of a fuel injector that provides gaseous fuel to a combustion chamber is disclosed. The apparatus includes a flame arrestor configured to be positioned in the fuel passage downstream of the internal components. The flame arrestor includes a plurality of flow passages configured to allow downstream gaseous fuel flow to pass through the flame arrestor in a downstream direction while restricting the propagation of a flame through the flame arrestor in an upstream direction.

[0012] In certain embodiments, the apparatus also includes a throttle valve having a throttle orifice that forms a flow constriction in the fuel passage downstream of the flame arrestor.

[0013] This summary is neither intended nor should it be construed to identify any key or essential features of the claimed subject matter. Additional embodiments, forms, aspects, features, objects, benefits, advantages, aspects, and the like will become apparent to those skilled in the art from the following description and the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0014] The description herein makes reference to the accompanying drawings, which, together with this description, illustrate exemplary embodiments of the claimed subject matter. The drawings created by are included herewith and constitute a part of this specification. In the drawings, like numerals refer to like parts through several views.

[0015] Figure 1 is a schematic illustration of a fuel injection system.

[0016] Figure 2 is a longitudinal cross-sectional view illustrating an exemplary gaseous fuel injector for an internal combustion engine according to an embodiment of the present disclosure.

[0017] Figure 3 is Figure 2 a perspective view of a flame arrestor of the gaseous fuel injector of DETAILED DESCRIPTION

[0018] Reference is made to Figure 1FIG. 1 shows a fuel injection system 10 including at least one fuel injector 100a, 100b, 100c,... 100n for a respective combustion chamber 14 of an internal combustion engine 12. The at least one fuel injector 100a, 100b, 100c,... 100n is in fluid communication with a fuel source 16 containing gaseous fuel 18 and a fuel tank / regulator 20 and / or a common rail 22 to distribute fuel to the injector 100a, 100b, 100c,... 100n. Although Figure 1 Although a plurality of fuel injectors are schematically shown in FIG. 1, the system 10 can include any number of fuel injectors, including one fuel injector. Pressurized gaseous fuel 18 is supplied from the fuel tank / regulator 20 to each of the fuel injectors 100a, 100b, 100c,... 100n. In the discussion below, the fuel injectors 100a, 100b, 100c,... 100n are described with reference to a fuel injector 100 as shown in FIG. 2. Figure 2 Although a plurality of fuel injectors are schematically shown in FIG. 1, the system 10 can include any number of fuel injectors, including one fuel injector. Pressurized gaseous fuel 18 is supplied from the fuel tank / regulator 20 to each of the fuel injectors 100a, 100b, 100c,... 100n. In the discussion below, the fuel injectors 100a, 100b, 100c,... 100n are described with reference to a fuel injector 100 as shown in FIG. 2.

[0019] In one embodiment, the fuel injector 100 provides gaseous fuel to a combustion chamber 14. The fuel injector 100 includes an elongated injector body 101 defining a longitudinally extending fuel passage 102 therein. The fuel passage 102 extends from a gas inlet end 104 of the injector body 101 to a gas outlet end 106 in a downstream direction. The fuel injector 100 also includes a valve assembly 160 positioned in the fuel passage 102. The valve assembly 160 includes at least one valve 162 that selectively opens and closes to control the flow of gaseous fuel through the fuel passage 102 to the combustion chamber 14. The fuel injector 100 also includes a flame arrestor 210 positioned in the fuel passage 102 downstream of the valve assembly 160.

[0020] In one embodiment, an apparatus 200 for reducing the propagation of a flame through a fuel passage 102 to internal components 110 of a fuel injector 100 that provides gaseous fuel to a combustion chamber 14 is disclosed. The apparatus 200 includes a flame arrestor 210 configured to be positioned in the fuel passage 102 downstream of the internal components 110. The flame arrestor 210 includes a plurality of flow passages 212 configured to allow downstream gaseous fuel flow to pass through the flame arrestor 210 in a downstream direction while limiting the propagation of a flame through the flame arrestor 210 in an upstream direction.

[0021] In certain embodiments, the fuel injector 100 includes a throttle valve 250 in the fuel passage 102 that forms a throttle orifice 252 between the gas outlet end 106 and the flame arrestor 210. In certain embodiments, the apparatus 200 also includes the throttle valve 250 that includes the throttle orifice 252 that forms a flow constriction in the fuel passage 102 from the flame arrestor 210 in a downstream direction.

[0022] Reference is made to Figure 2 The injector body 101 extends longitudinally along a central longitudinal axis A. The injector body 101 includes a fuel passage 102 defined by the injector body 101 from a gas inlet end 104 to a gas outlet end 106. The longitudinally extending fuel passage 102 receives therein a valve assembly 160 and a valve actuator 170 to control the flow of gaseous fuel from the gas inlet end 104 to the gas outlet end 106, and to control the flow of combustion gases from the gas outlet end 106 into the fuel passage 102. In the discussion herein, “proximal” or “proximally” refers to an axial or longitudinal position or upstream direction toward the gas inlet end 104, and “distal” or “distally” refers to an axial or longitudinal position or downstream direction toward the gas outlet end 106.

[0023] The injector body 101 can include multiple portions coupled to one another to form the injector body 101. In the illustrated embodiment, the injector body 101 includes an outlet portion 120 extending from the gas outlet end 106, an inlet portion 124 extending from the gas inlet end 104, and a transition portion 122 connecting the outlet portion 120 and the inlet portion 124. Other embodiments contemplate injector bodies 101 made from a single body portion, two body portions, or more than two body portions.

[0024] The outlet portion 124 includes a flange connector 138 to facilitate mounting of the fuel injector 100 on the engine 12. Other features can also be provided on the injector body 101 to facilitate injector mounting. The inlet portion 124 includes a gas passage 140 for receiving a flow of gaseous fuel into the passage 102 of the injector body 101. The inlet portion 124 can also include a wire harness 141 for receiving wires (not shown) coupled to the valve actuator 170.

[0025] The valve assembly 160 is housed primarily in the injector body 101, such as in the outlet portion 120 and the transition portion 122. In the illustrated embodiment, the valve assembly 160 includes a first valve 162 and a second valve 164 spaced distally from and downstream of the first valve 162. In other embodiments, the valve assembly 160 includes a single valve, or more than two valves. The actuator 170 controls the opening of the gaseous fuel flow valve, designated as the first valve 162. In one embodiment, the actuator 170 is an electronic actuator, such as a solenoid, that is electronically controlled by energizing and de-energizing a magnetic coil to actively and selectively control the opening and closing of the first valve 162 of the valve assembly 160.

[0026] The first valve 162 includes a first plunger 166 that is engaged to the gas inlet end 104 and axially movable toward the gas inlet end by actuation of an actuator 170. In one embodiment, the first plunger 166 is an armature plunger. The plunger guide 148 assists in axially guiding the first plunger 166 in response to actuation of the actuator 170. The first plunger 166 is biased into sealing engagement with a first valve seat 168 by a first valve spring 172. When the first valve 162 is open, the first valve spring 172 is compressed and the first plunger 166 translates axially in a proximal direction.

[0027] The first valve seat 168 includes an outer seat member 178 and an inner seat member 180 that are located in the interior of the outlet portion 120. The inner seat member 180 is located within the outer seat member 178. In the illustrated embodiment, the first valve seat 168 is composed of two separate members, but can also be composed of a single member.

[0028] The second valve 164 includes a second plunger 184 supported in the outlet portion 120 and a second valve seat 186. The second plunger 184 contacts the second valve seat 186 in a closed position of the second valve 164 and moves distally away from the second valve seat 186 to open the second valve 164. In one embodiment, the second valve 164 is arranged to limit exposure of the first valve 162 to combustion temperatures and pressures of combustion gases from the inflow fuel passage 102.

[0029] In response to the introduction of a gaseous flow from the first valve 162, the second valve spring 194 is compressed, which causes the second plunger 184 to displace distally to an open position. In the open position, the head 202 is distally spaced from the seat portion 198 to form a gap or passage for gaseous fuel to flow to the combustion chamber 14.

[0030] Because the second valve 164 is passively controlled by the second valve spring 194 based on whether there is a gaseous fuel flow through the first valve 162, and because the second valve 164 is not actuated by the actuator 170 or not connected to any components of the first valve 162, the axial position of the second valve 164 within the injector body 101 can be optimized to balance the temperature and gas mixture conditions of the first valve 162 and the second valve 164 during operation of the fuel injector 100 according to the expected combustion conditions, combustion parameters, etc. of the fuel.

[0031] The nozzle 118 is engaged to the outlet end 106 of the outlet portion 120. The nozzle 118 can include one or more orifices arranged to divert the gaseous fuel flow in a desired direction or flow pattern into the combustion chamber 14. The nozzle 118 can be configured to optimize combustion of the gaseous fuel based on the combustion conditions of the engine 12. The nozzle 118 is always open to allow gaseous fuel flow out of the fuel passage 102, which also allows combustion gases to enter the fuel passage 102.

[0032] The fuel injector 100 also includes a device 200 for reducing propagation of a flame through the fuel passage 102 to the internal components 110 of the fuel injector 100. For example, the device 200 includes a flame arrestor 210, and in certain embodiments, a restriction valve 250. The flame arrestor 210 is configured to be positioned in the fuel passage 102 downstream of the internal components 110. The flame arrestor 210 includes a plurality of flow passages 212 configured to allow downstream gaseous fuel flow to pass through the flame arrestor 210 in a downstream direction while restricting propagation of a flame through the flame arrestor 210 in an upstream direction. The restriction valve 250, if included, includes a restriction orifice 252 that forms a flow constriction in the fuel passage 102 downstream from the flame arrestor 210 in the downstream direction, and can be optimized for combustion and temperature regulation.

[0033] In one embodiment, the restriction valve 250 includes a cylindrical body 254 extending from an upstream end 256 to a downstream end 258. The restriction orifice 252 includes a central portion 260 defining a constant diameter along an intermediate portion of the length of the cylindrical body 254. The restriction orifice 252 also includes an upstream portion 262 extending from the central portion 260 in an upstream direction, and a downstream portion 264 extending from the central portion 260 in a downstream direction. Each of the upstream portion 262 and the downstream portion 264 includes a diameter that tapers outwardly from the constant diameter central portion 260.

[0034] The flame arrestor 210 includes a body 214 extending between a first or upstream end 216 and an opposite second or downstream end 218. The plurality of flow passages 212 extend through the body 214 and are open at each of the upstream end 216 and the downstream end 218. The body 214 of the flame arrestor 210 also includes an outer surface 220 extending from the upstream end 216 to the downstream end 218. The outer surface 220 engages the inner surface 112 of the injector body 101 defining the fuel passage 102. This maintains the flame arrestor 210 in a desired axial position along the fuel passage 102 and centers the flow passages 212 in the fuel passage 102. The flame arrestor body 214 can be designed to optimize heat transfer away from the flame arrestor and need not be the same length as the passage. The body 214 can be a cylinder, mesh, screen, or other suitable configuration.

[0035] The plurality of flow passages 212 are designed in number and size to allow the desired gaseous fuel flow through the flame arrestor 210 to support the prescribed air-fuel ratio and combustion process in the combustion chamber 14. The plurality of flow passages 212 are also configured to be smaller than the flame front condition. This allows the solid body portion of the flame arrestor 210 between the flow passages 212 to absorb the heat of the flame front generated by combustion in the combustion chamber 14 that travels in the upstream direction through the fuel passage 102. The throttle 250, when provided, restricts the flame and helps to slow the propagation of the flame temperature through the fuel passage 102 before the flame reaches the flame arrestor 210, allowing the flame arrestor 210 to be more effective.

[0036] In one embodiment, the flow passages 212 are circular in cross-section and have a diameter of about 0.5 millimeters. However, other sizes and / or shapes of the flow passages 212 are also contemplated. For example, the flow passages 212 can be configured in any suitable size and shape, and provided in any suitable number, that allows the gaseous fuel flow through the flame arrestor 210 to support combustion in the combustion chamber 14 while reducing or preventing the propagation of a flame to the internal components 110. Reducing or preventing the propagation of a flame from the combustion chamber reduces the exposure of the fuel injector components to temperature variations, improves the robustness of the fuel injector, and extends the working life.

[0037] In one embodiment, the plurality of flow passages 212 of the flame arrestor 210 are arranged to form a plurality of circular patterns 222a, 222b, 222c, 222d, 222e of flow passages 212 arranged concentrically around the upstream end 216 and the downstream end 218 of the flame arrestor 210. In one embodiment, at least two circular patterns of flow passages 212 are provided. In another embodiment, at least three concentric circular patterns of flow passages 212 are provided through the flame arrestor 210. In one embodiment, each of the plurality of concentric circular patterns 222a, 222b, 222c, 222d, 222e of flow passages 212 includes at least five flow passages 212. In one embodiment, the plurality of flow passages 212 of the flame arrestor 210 includes a central flow passage 212a surrounded by the plurality of concentric circular patterns 222a, 222b, 222c, 222d, 222e of flow passages 212.

[0038] In one embodiment, the inner component 110 includes a valve assembly 160. In another embodiment, the valve assembly 160 includes a first valve 162 that controls the flow of gaseous fuel through the fuel passage 102 to the combustion chamber 14 and a second valve 164 that is longitudinally spaced apart from the first valve 162 toward the gas outlet end 106. The second valve 164 is configured to control the flow of combustion gases from the combustion chamber 14 into the fuel passage 102 through the gas outlet end 106. The second valve 164 is biased to a closed position and is moved from the closed position to an open position by the flow of gaseous fuel through the open first valve 162.

[0039] In one embodiment, the flame arrestor 210 is located downstream of the inner member 110. For example, the flame arrestor 210 is located downstream of the second valve 164 of the valve assembly 160. The fuel passage 102 includes a first diameter Dl extending from the flame arrestor 210 in a downstream direction to the gas outlet end 106. When provided, the orifice 252 of the restrictor valve 250 defines a second diameter D2 that is less than the first diameter Dl. The restrictor valve 250 is positioned in the fuel passage 102 such that the first diameter Dl of the fuel passage 102 extends in an upstream direction and in a downstream direction from the orifice 252. The orifice 252 tapers from the second diameter D2 to the first diameter Dl in both the upstream direction and the downstream direction.

[0040] In one embodiment, the flame arrestor 210 is located a first distance from the inner component 110. For example, the flame arrestor 210 is spaced apart from a downstream end of the second valve 164 of the valve assembly 160 by an axial distance LI. The restrictor valve 250, when included, is located a second axial distance L2 from the gas outlet end 106. Additionally, a downstream end 258 of the restrictor valve 250 is located a third distance L3 from the flame arrestor 210. The third distance L3 is greater than the first distance LI and the second distance L2. This arrangement positions the restrictor valve 250 near the outlet end 106 to limit and slow the propagation of a flame into the fuel passage 102. The inner component 110 and the flame arrestor 210 are spaced further from the restrictor valve 250 to create a lower temperature environment and increase the effectiveness of the flame arrestor 210. It is also contemplated in other embodiments that the locations of the flame arrestor 210 and the orifice 252, when included, can be arranged in any length combination between the inner component 110 and the gas outlet end 106 to optimize for combustion requirements.

[0041] During operation of the fuel injector 100, gaseous fuel enters the fuel passage 102 at the gas inlet end 104. The first valve 162 of the valve assembly 160 is held in a closed position by the first valve spring 172, preventing gaseous fuel flow through the fuel passage 102. Additionally, the second valve 164 of the valve assembly 160 is normally closed by the second valve spring 194, such that combustion gases cannot flow into the fuel passage 102 to reach the first valve 162, protecting the first valve 162 from higher combustion temperatures.

[0042] Gaseous fuel is injected by opening the first valve 162 with the actuator 170. This causes a gaseous fuel flow to occur downstream of the first valve 162 and open the second valve 164. The gaseous fuel flow passes through the flame arrestor 210, the restriction valve 250 if included, and then through the nozzle 118 to the combustion chamber 14. The flame produced by combustion in the combustion chamber 14 propagates back into the fuel passage 102 is limited by the restriction orifice 252 of the restriction valve 250 if included. The flame arrestor 210 prevents or reduces the ability of the flame front from reaching the second valve 164, protecting the second valve 164 from high heat conditions.

[0043] A further written description of a number of example embodiments will now be provided. According to one aspect, a fuel injector for providing gaseous fuel to a combustion chamber is provided. The fuel injector includes an elongated injector body defining a longitudinally extending fuel passage therein. The fuel passage extends in a downstream direction from a gas inlet end of the injector body to a gas outlet end. The fuel injector further includes a valve assembly located in the fuel passage. The valve assembly includes at least one valve that selectively opens and closes to control a flow of gaseous fuel through the fuel passage to the combustion chamber. The fuel injector further includes a flame arrestor located downstream of the valve assembly in the fuel passage.

[0044] In one embodiment, the fuel injector further includes a restriction valve in the fuel passage forming a restriction orifice between the gas outlet end and the flame arrestor.

[0045] In one embodiment, the fuel injector includes a nozzle located on the gas outlet end of the injector body. The nozzle is configured to divert a flow of gaseous fuel through the gas outlet end into the combustion chamber.

[0046] In one embodiment, the flame arrestor includes a body extending between a first end and an opposite second end. The flame arrestor further includes a plurality of flow channels extending through the body from the first end to the second end.

[0047] In another embodiment, the injector body includes an inner surface extending around the fuel passage. The body of the flame arrestor includes an outer surface extending from the first end to the second end. The outer surface engages the inner surface of the injector body to maintain the flame arrestor in place in the injector body.

[0048] In yet another embodiment, the plurality of flow passages of the flame arrestor includes a central flow passage surrounded by the plurality of flow passages.

[0049] In one embodiment, the valve assembly includes a first valve that controls the flow of gaseous fuel through the fuel passage to the combustion chamber. The valve assembly also includes a second valve longitudinally spaced apart from the first valve toward the gas outlet end. The second valve is configured to control the flow of combustion gas from the combustion chamber into the fuel passage through the gas outlet end. The flame arrestor is located downstream of the second valve.

[0050] In another embodiment, the second valve is biased to a closed position. The second valve is moved from the closed position to an open position by the flow of gaseous fuel through the first valve.

[0051] In one embodiment, the fuel passage includes a first diameter extending from the flame arrestor in a downstream direction to the gas outlet end. The orifice of the restrictor defines a second diameter that is smaller than the first diameter.

[0052] In another embodiment, the restrictor is positioned in the fuel passage such that the fuel passage extends in an upstream direction and in a downstream direction from the orifice. In yet another embodiment, the orifice tapers from the second diameter to the first diameter in both the upstream direction and the downstream direction.

[0053] In one embodiment, the flame arrestor is located a first distance from the valve assembly and the restrictor is located a second distance from the gas outlet end. The restrictor is also located a third distance from the flame arrestor and the third distance is greater than the first distance and the second distance.

[0054] According to another aspect of the disclosure, an apparatus for reducing the propagation of a flame through a fuel passage to internal components of a fuel injector that provides gaseous fuel to a combustion chamber is provided. The apparatus includes a flame arrestor configured for positioning in the fuel passage of the fuel injector downstream of the internal components. The flame arrestor includes a plurality of flow passages configured to allow a downstream flow of gaseous fuel to pass through the flame arrestor in a downstream direction while restricting the propagation of a flame through the flame arrestor in an upstream direction.

[0055] In one embodiment, the apparatus includes an orifice that forms a flow constriction in the fuel passage in a downstream direction from the flame arrestor. In another embodiment, the restrictor includes a cylindrical body extending from an upstream end to a downstream end. The orifice includes a central portion defining a constant diameter along the cylindrical body.

[0056] In another embodiment, the orifice includes an upstream portion extending from the central portion in an upstream direction and a downstream portion extending from the central portion in a downstream direction. Each of the upstream portion and the downstream portion includes a diameter that tapers outwardly from a constant diameter.

[0057] In one embodiment, the flame arrestor includes a main body extending between an upstream end and an opposite downstream end. A plurality of flow passages extend through the main body and are open at each of the upstream end and the downstream end.

[0058] In another embodiment, the plurality of flow passages of the flame arrestor are arranged to form a pattern arranged about the upstream end and the downstream end of the flame arrestor. In yet another embodiment, the plurality of flow passages of the flame arrestor includes a central flow passage surrounded by the plurality of flow passages.

[0059] While the illustrative embodiments of the disclosure have been shown and described detailed in the drawings and the foregoing description, such drawings and the foregoing description are to be taken as illustrative and not restrictive, and it is understood that only certain example embodiments have been shown and described and that all changes and modifications that come within the spirit of the claimed application are desired to be protected. It is understood that the use of the word "preferably", "preferably", "preferred", or "more preferred" "optimally" "optimum" "desirably", or "desirable", "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "as" "

Claims

1. A fuel injector for providing gaseous fuel to a combustion chamber, the fuel injector comprising: an elongated injector body defining a longitudinally extending fuel passage therein, the fuel passage extending in a downstream direction from a gas inlet end to a gas outlet end of the injector body; a valve assembly in the fuel passage, the valve assembly including at least one valve that selectively opens and closes to control a flow of gaseous fuel through the fuel passage to the combustion chamber; and a flame arrestor in the fuel passage downstream of the valve assembly.

2. The fuel injector of claim 1, further comprising a restriction valve in the fuel passage, the restriction valve forming a restriction orifice between the gas outlet end and the flame arrestor.

3. The fuel injector of claim 1, further comprising a nozzle on the gas outlet end of the injector body, wherein the nozzle is configured to divert a flow of gaseous fuel through the gas outlet end into the combustion chamber.

4. The fuel injector of claim 1, wherein the flame arrestor comprises: a body extending between a first end and an opposite second end; and a plurality of flow passages extending through the body from the first end to the second end.

5. The fuel injector of claim 4, wherein: the injector body includes an inner surface extending around the fuel passage; and the body of the flame arrestor includes an outer surface extending from the first end to the second end, the outer surface engaging the inner surface of the injector body to maintain the flame arrestor in place in the injector body and to optimize heat transfer.

6. The fuel injector of claim 5, wherein the plurality of flow passages of the flame arrestor includes a central flow passage surrounded by the plurality of flow passages.

7. The fuel injector of claim 1, wherein the valve assembly comprises: a first valve that controls a flow of gaseous fuel through the fuel passage to the combustion chamber; and a second valve longitudinally spaced apart from the first valve toward the gas outlet end, the second valve configured to control a flow of combustion gases from the combustion chamber into the fuel passage through the gas outlet end, wherein the flame arrestor is downstream of the second valve.

8. The fuel injector of claim 7, wherein: the second valve is biased to a closed position; and the second valve is moved from the closed position to an open position by the flow of gaseous fuel through the first valve.

9. The fuel injector of claim 2, wherein: the fuel passage includes a first diameter extending from the flame arrestor in the downstream direction to the gas outlet end.

10. The fuel injector of claim 9, wherein: the restriction orifice of the restriction valve defines a second diameter that is smaller than the first diameter. ​ ​ ​ 11. The fuel injector of claim 10, wherein the throttle valve is positioned in the fuel passage such that the fuel passage extends from the throttle orifice in an upstream direction and in the downstream direction.

12. The fuel injector of claim 11, wherein the throttle orifice tapers from the second diameter to the first diameter in both the upstream direction and the downstream direction.

13. The fuel injector of claim 2, wherein: the flame arrestor is located a first distance from the valve assembly; the throttle valve is located a second distance from the gas outlet end; and the throttle valve is located a third distance from the flame arrestor, the third distance being greater than the first distance and the second distance.

14. An apparatus for reducing propagation of a flame through a fuel passage to an internal component of a fuel injector that provides gaseous fuel to a combustion chamber, the apparatus comprising: a flame arrestor configured for positioning in the fuel passage of the fuel injector downstream of the internal component, the flame arrestor including a plurality of flow passages configured to allow downstream gaseous fuel flow to pass through the flame arrestor in a downstream direction while restricting propagation of a flame through the flame arrestor in an upstream direction.

15. The apparatus of claim 14, further comprising: a throttle valve including a throttle orifice that forms a flow constriction in the fuel passage from the flame arrestor in the downstream direction.

16. The apparatus of claim 15, wherein: the throttle valve includes a cylindrical body extending from an upstream end to a downstream end; and the throttle orifice includes a central portion defining a constant diameter along the cylindrical body.

17. The apparatus of claim 16, wherein the throttle orifice includes: an upstream portion extending from the central portion in the upstream direction; a downstream portion extending from the central portion in the downstream direction; and each of the upstream portion and the downstream portion includes a diameter that tapers outwardly from the constant diameter.

18. The apparatus of claim 14, wherein the flame arrestor includes a body extending between an upstream end and an opposite downstream end, and the plurality of flow passages each extend through the body and are open at each of the upstream end and the downstream end.

19. The apparatus of claim 18, wherein the plurality of flow passages of the flame arrestor are arranged to form a pattern arranged concentrically about the upstream end and the downstream end of the flame arrestor.

20. The fuel injector of claim 19, wherein the plurality of flow passages of the flame arrestor include a central flow passage surrounded by the plurality of flow passages. ​

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