Liquid fuel reformer apparatus

Abstract

liquid fuel reformer apparatus includes a reactor tube having at a first end and injector for introducing droplets of liquid fuel and an inlet for introducing an air flow, and at a second end an outlet for discharging a reformate fuel stream. A reforming catalyst for converting the liquid fuel to the reformate fuel stream is disposed within the reactor tube, and at least one regulator member is disposed between the first end of the tube and the catalyst. At least a portion of the regulator member is permeable to the liquid fuel and to air flow.

Description

TECHNICAL FIELD

The present invention relates to a reformer apparatus for catalytically converting liquid fuels to a blend of gases containing hydrogen and carbon monoxide as major components. More particularly, the present invention relates to a liquid fuel reformer apparatus that includes a regulator member whose effect is to facilitate the vaporization and reforming of liquid fuel introduced into the apparatus.

BACKGROUND OF THE INVENTION

Fuels on board vehicles, for example, hydrocarbon mixtures such as gasoline or diesel fuel, military fuels such as JP8 or the like, or other fuels such as kerosene, biodiesel, alcohol or oxygenated fuels, generally include components of relatively low volatility. The combustion of liquid droplets of such fuels prior to their vaporization typically results in the formation of soot and coke as undesirable byproducts.

The use of a catalytic reformer to convert a liquid fuel into a gaseous fuel stream containing hydrogen and carbon monoxide as major components is known. However the injected liquid fuel is prone to be deposited on the walls of the reformer chamber, forming puddles that are difficult to vaporize or combust. This situation, which is especially likely to occur during cold start operation, results in the production of residues that present a challenge to the control of air:fuel ratios and are adverse to reliable long term operation of the reformer.

Increased volatilization and more complete combustion and/or reforming of the liquid fuel injected into a reformer reactor chamber would be highly desirable. These beneficial results are provided by the apparatus of the present invention.

SUMMARY OF THE INVENTION

The present invention is directed to a liquid fuel reformer apparatus that comprises a reactor tube having at a first end an injector for introducing droplets of liquid fuel and an inlet for introducing an air flow, and at a second end an outlet for discharging a reformate fuel stream. A reforming catalyst for converting the liquid fuel to the reformate fuel stream is disposed within the reactor tube, and at least one regulator member is disposed between the first end of the tube and the catalyst. At least a portion of the regulator member is permeable to liquid fuel and to air and vapor flow.

The liquid fuel reformer apparatus of the present invention can be applied to any liquid fuels commonly found on board vehicles, including, for example, hydrocarbon mixtures such as gasoline or diesel fuel, military fuels such as JP8 or the like, and other fuels such as kerosene, biodiesel, alcohol or oxygenated fuels.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring now to the drawings, which are intended to be exemplary, not limiting:

FIG. 1 schematically depicts, in accordance with the present invention, a liquid fuel reformer apparatus that includes a regulator member for facilitating the vaporization and reforming of liquid fuel introduced into the apparatus.

FIGS. 2, 3, and 4 are schematic plan views of variants of the regulator member included in the reformer apparatus of the present invention.

FIG. 5 is a perspective view of a further variant of the regulator member included in the reformer apparatus of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

As already noted, when a liquid fuel that contains low volatility components is introduced into a reformer apparatus, there is a tendency for fuel droplets impinging on the reformer wall interior surface to agglomerate, forming puddles that resist vaporization and reforming. The reformer apparatus of the present invention, with its included regulator member, facilitates the reforming reaction by, for example, reducing the droplet size of the introduced fuel, diverting the fuel droplets from the reactor wall, increasing the flow velocity of the introduced air in the vicinity of the injected fuel, and improving the mixing of fuel and air.

Referring to FIG. 1, a liquid fuel reformer apparatus 10 comprises a reactor chamber that is preferably a cylindrical tube 11 having an interior wall surface 12, a first end 13, and a second end 14. An injector 15 for introducing liquid fuel F and an inlet 16 for receiving an air flow A are located at first end 13, and an outlet 17 for discharging a reformate fuel stream F is located at second end 14.

Disposed within reactor tube 11 is a reforming catalyst 18 for converting fuel and air to reformate fuel stream R, and a regulator member 19 that facilitates the vaporization and reforming of liquid fuel F is disposed between first end 13 and catalyst 18. Although only a single regulator member 19 is depicted in FIG. 1, it is to be understood that a plurality of such members can be included in reactor tube 11.

FIG. 2 schematically depicts regulator member 219, which is one variant of the regulator member 19 generically represented in FIG. 1. Regulator member 219 comprises a mesh 220, preferably knitted or woven from metal and preferably with openings of about 40-400 μm.

Also shown in FIG. 2 is an annular pattern P, formed on mesh 220 by the spray cone of fuel droplets D (depicted in FIG. 1) produced by injector 15. The dimensions of annular pattern P depend on the characteristics of injector 15, the characteristics of the flow field in front of mesh 220, and the distance between injector 15 and regulator member 19 (219). This distance can be varied as appropriate, but it is desirable that droplets D are intercepted by mesh 220 prior to striking interior wall surface 12 of tube 11. Passage of droplets D through mesh 220 is expected to result in a scattered pattern of droplets of reduced size, with a consequent benefit of improved volatilization and increased reactivity with air.

FIG. 3 schematically depicts regulator member 319, a further variant of the regulator member 19 generically represented in FIG. 1. Regulator member 319 comprises a mesh 320, similar to mesh 220 of FIG. 2, but further includes a second centered circular portion 321 that is impermeable to liquid fuel droplets and to air flow. Passage of droplets D through mesh 320 is expected to result in a scattered pattern of droplets of reduced size; in addition, the constriction provided by impermeable portion 321 would result in increased velocity of the air flow accompanying the fuel through mesh 320.

Still another variant of the regulator member 19 generically represented in FIG. 1 is regulator member 419, schematically depicted in FIG. 4. Similar to regulator member 319 depicted in FIG. 3, regulator member 419 comprises a mesh 420 and a centered circular portion 421 that is impermeable to liquid fuel droplets and to air flow, and it also includes a peripheral circular portion 422 that also is impermeable to fuel droplets and air. It is desirable that the regulator members 319 and 419 both be configured so that the annular pattern P of fuel droplets D produced by injector 15, as shown in FIG.1, be formed on mesh 320 and mesh 420, respectively.

Both of regulator members 319 and 419 would be expected to provide a significant increase in the velocity of the air passing through them, resulting in an enhanced fuel-air mixing rate. In addition, the surfaces of impermeable portions 320 and 420-421 of regulator members 319 and 419, respectively, that face catalyst 18 can be adapted to absorb thermal radiation from the catalyst, providing an efficient heat source for promoting the fuel-air reaction. If desired, any of the variants of regulator member 19 can also be adapted for external electrical heating, which is preferably applied to those portions that are permeable to fuel and air.

FIG. 5 is a perspective view of regulator member 519, a further variant of the regulator member 19 generically represented in FIG. 1. Regulator member 519 is characterized by a honeycomb structure 520 that comprises a plurality of individual cells 521. Compared to the variants 219, 319, and 419 that include a mesh portion, the honeycomb structure of regulator member 519 is characterized by a somewhat greater but still limited thickness, just sufficient to direct the path of the fuel droplets D so as to prevent them from directly impacting wall surface 12.

Although FIG. 5 depicts regulator member 519 as having a fully open honeycomb structure, it can be configured to include portions impermeable to fuel and air, similar to the impermeable portions of members 319 and 419.

While the invention has been described by reference to various specific embodiments, it should be understood that numerous changes may be made within the spirit and scope of the inventive concepts described. Accordingly, it is intended that the invention not be limited to the described embodiments, but will have full scope defined by the language of the following claims.

Claims

1. A liquid fuel reformer apparatus comprising:

a reactor tube having at a first end an injector for introducing liquid fuel and an inlet for introducing an air flow, and at a second end an outlet for discharging a reformate fuel stream;

a reforming catalyst disposed within said reactor tube for converting said liquid fuel to said reformate fuel stream; and

at least one regulator member disposed between said first end and said catalyst, at least a portion of said regulator member being permeable to said liquid fuel and said air flow.

2. The liquid fuel reformer apparatus of claim 1 wherein said regulator member comprises a metal mesh.

3. The liquid fuel reformer apparatus of claim 1 wherein said regulator member comprises a first portion permeable to said liquid fuel and said air flow and a second portion impermeable to said liquid fuel and said air flow, said regulator member operating to reduce the size of liquid fuel droplets and to increase the velocity of air flow passing through said first portion.

4. The liquid fuel reformer apparatus of claim 3 wherein said second portion comprises a centered circular portion of said regulator member.

5. The liquid fuel reformer apparatus of claim 4 wherein said second portion further comprises a peripheral circular portion of said regulator member.

6. The liquid fuel reformer apparatus of claim 3 wherein said regulator member comprises a first surface proximate said catalyst and a second surface distal said catalyst, said first surface being adapted to absorb thermal radiation from said catalyst.

7. The liquid fuel reformer apparatus of claim 1 wherein said regulator member comprises a honeycomb structure.

8. The liquid fuel reformer apparatus of claim 1 wherein said regulator member is adapted for externally applied electrical heating.