WO2005001588A1

WO2005001588A1 - Apparatus for regulating fluid flow

Info

Publication number: WO2005001588A1
Application number: PCT/GB2004/002658
Authority: WO
Inventors: Paul Antony Collins; Martyn Ray Collins
Original assignee: Plexus Development And Research Limited
Priority date: 2003-06-24
Filing date: 2004-06-22
Publication date: 2005-01-06
Also published as: GB0314648D0; GB2403267A

Abstract

Apparatus for regulating fluid flow includes a first component (40) and a second component (22). The first component (40) has a substantially polygonal cross-section and provides a plurality of edges extending in a longitudinal direction of the first component. The second component (22) has a substantially circular cross-section and co-operates with the first component (40) to provide a chamber between the edges of the first component and the second component. An inlet (34) is provided for a fluid flowing into the chamber and an outlet (25) is provided for the fluid flowing out of the chamber. The outlet (25) is at a location remote from the inlet (34).

Description

APPARATUS FOR REGULATING FLUID FLOW

This invention relates to an apparatus for regulating flow of a fluid. The invention may be used, for example, for regulating the flow of fluid (gaseous and liquid) fuels to be supplied to internal combustion engines, such as liquified petroleum gas, compressed natural gas, liquified natural gas and hydrogen gas .

Various systems have been proposed which purport to improve the performance and safety of fuels by vaporising and regulating fluid fuels and by regulating the pressure of gaseous fuels. It ls^'A-nown, for example, to employ diaphragms of elastomeric material, such as rubber, or springs to control vaporisation and pressure and to employ water or other fluid to impart heat to the system so as to aid vaporisation. However, there is a risk that ice will build up in the system and cause a blockage, or that the system will become blocked due to sludge arising from the vaporisation process, or that a valve will stick leaving the regulator ineffective.

It is therefore an object of the present invention to provide an apparatus for regulating fluid flow which overcomes or at least ameliorates the disadvantages explained above. According to one aspect of the present invention there is provided an apparatus for regulating fluid flow, the apparatus comprising:

a first component (having a substantially polygonal cross- section and providing a plurality of edges extending in a longitudinal direction of the first component;

a second component having a substantially circular cross- section and co-operating with the first component to provide a chamber between the edges of the first component and the second component;

an inlet for a fluid into the chamber; and

and outlet for the fluid from the chamber, the outlet being at a location remote from the inlet.

The first component may comprise a member having a polygonal cross-section and the second component may comprise a member having a substantially cylindrical bore, the first component being provided at least partly within the substantially cylindrical bore of the second component. The longitudinal edges of the first component may be chamfered. The first component may be of substantially square cross- section.

The first component and the second component may be provided with co-operating tapered surfaces in the region of the outlet for controlling the pressure of fluid exiting from the outlet. The first component may be movable longitudinally relative to the second component for adjusting the pressure of fluid exiting from the outlet. Locking means may be provided for locking the first component in position relative to the second component. Cover means may be provided to cover the locking means .

An annular chamber may be provided having an inlet and an outlet, the outlet of the annular chamber communicating with the inlet of the chamber formed between the edges of the first component and the second component. The outlet may have a diameter substantially less than the diameter of the inlet. The inlet may be at an angle transverse to the axial direction of the annular chamber and the outlet may be at an angle transverse to the axial direction of the annular chamber. The inlet and the outlet of the annular chamber may be at angles transverse to each other. Means may be provided for controlling the flow rate of fluid exiting the regulator. The flow control means may comprises a plunger operated by a stepper motor.

Heating means, such as electrical heating means, may be provided for heating the fluid in the regulator.

For a better understanding of the present invention and to show more clearly how it may be carried into effect reference will now be made, by way of example, to the accompanying drawings in which:

Figure 1 is a perspective view, partly cut away, of one embodiment of a regulator according to the present invention for regulating fluid flow;

Figure 2 is a cross-sectional view of the regulator shown in Figure 1;

Figure 3 is a cross-sectional view of a barrel member for use in the regulator shown in Figures 1 and 2; and

Figure 4 is a side elevational view of a pressure regulating pin for use in the regulator shown in Figures 1 and 2. The regulator shown in the drawings comprises a generally cylindrical body 2 made, for example, of aluminium or aluminium alloy. A generally cylindrical axially-extending recess 4 is formed in one end of the body and an axial bore 6, of substantially smaller diameter than the recess 4 extends to the other end of the body where the bore forms an outlet 8. The recess 4 is closed by a circular plate 10 which is secured to the end face of the body 2 by suitable fasteners 12 and sealed by means of two concentric O-rings 11A and 11B. A further bore 14 extends radially from the cylindrical surface of the body 2 to the recess 4 and forms an inlet 16 at the surface of the body.

The recess 4 is of stepped configuration with an inner portion 18 being of smaller diameter than an outer portion 20. The inner portion of the bore is smooth, while the outer portion is threaded along at least a part of its axial extent.

Provided within the inner portion 18 of the recess 4 is a barrel member 22. The barrel member is shown in more detail in Figure 3. The barrel member 22 may be made, for example, of brass and is generally cylindrical in shape with an axial cylindrical bore 24 which in the region of that part of the barrel member remote from the closure plate 10 tapers to a smaller diameter, the small diameter portion providing an outlet 25 from the barrel member 22. The cylindrical outer surface of the barrel member 22 is formed with a recess 26 intermediate the ends thereof. This configuration gives rise to a radially protruding flange 28 at each axial end of the barrel member 22 with a recess 26 of substantially even depth between the flanges.

Each flange is itself formed with a circumferential recess to accommodate an 0-ring 30 to seal between the barrel member 22 and the internal surface of the recess 4 thereby forming a hollow cylindrical (annular) chamber 32 between the barrel member 22 and the internal surface of the recess 4, which chamber communicates with the inlet 16 by way of the radial bore 14.

Positioned substantially mid-way along the axial length of the chamber 32 and extending diametrically through the barrel member 22 in a direction transverse (or generally perpendicular) to the axis of the inlet bore 14 is a bore 34 of a diameter which is small relative to the diameter of the inlet bore. That is, the inlet bore 14 is transverse to the axis of the chamber 32 and the outlet bores 34 are also transverse to the axial direction of the chamber 32. Moreover, the inlet bore 14 is transverse to the outlet bores 34. By way of example, in one embodiment the inlet bore 14 may have a diameter of about 5 mm whereas the transverse bore 34 may have a diameter of 1 mm. The transverse bore 34 intersects the axial bore 24 of the barrel member 22 and therefore provides two communicating passages between the chamber 32 and the axial bore 24.

A cylindrical member 36, or plug, is externally threaded and engages with the threads provided on the internal surface of the outer portion 20 of the recess 4. The cylindrical member 36 is provided with an internally threaded bore 38. A pressure regulating pin 40 is externally threaded at one end and is received in the bore 38. The pressure regulating pin 40 is shown in more detail in Figure 4. A lock nut 42 is threaded onto a protruding outermost end of the pin 40 in order to be able to secure the pin in a desired position relative to the cylindrical member 36.

The pressure regulating pin 40 is made, for example, from stainless steel and is formed with a smooth cylindrical portion 44. The smooth cylindrical portion 44 is sealed with the internal surface of the axial bore 24 formed through the barrel member 22 by means of an O-ring seal 46 which is provided in a recess formed in the bore 24.

That end region of the pressure regulating pin 40 remote from the closure plate 10 has a transverse dimension less than the diameter of the bore 24 so as to form a chamber 48 between the pin 40 and the bore 24. The tip of the pressure regulating pin 40 tapers substantially to a point and co-operates with the tapered end of the barrel member 22.

The externally threaded portion of the pressure regulating pin 40 is rotatable to move the tapered tip of the pin longitudinally towards or away from the tapered end of the barrel member 22 so as to adjust the spacing between the tapered end of the barrel member and the tapered tip of the pin. In practice, the spacing is set at the time the regulator is manufactured and the pin 40 is locked in position relative to the barrel member 22 by means of the lock nut 42 and the regulator is subsequently sealed with the closure plate 10.

The end region of the regulating pin 40 remote from the closure plate 10 has a non-circular cross-section in a plane transverse to the axial direction. More specifically, the end region of the regulating pin 40 is angular or polygonal in cross-section, for example square as in the illustrated embodiment. The angular points of intersection of the sides of the polygon may be chamfered if desired as shown, for example, in Figure 4. Thus the angular, polygonal configuration gives rise to a plurality of angular edges which extend in the axial (longitudinal) direction of the regulating pin 40. The diametral bores 34 open into the chamber formed between the end region of the pressure regulating pin 40 and the internal surface of the axial bore 24. The function of the end region of the pressure regulating pin 40 will be explained in more detail hereinafter.

Extending radially into the body 2 at a point between the end of the recess 4 and the outlet 8 is a sleeve 50, for example of brass. The sleeve 50 is of hollow cylindrical configuration having an axial bore with the closed end of the cylinder positioned close to the axis of the body 2. The sleeve 50 intersects the bore 6 which leads to the outlet 8 and is formed with a bore 52 which extends transverse to the axial direction of the sleeve and which is of substantially the same diameter as the bore 6 and is positioned within the body 2 such that the bores 6 and 52 are coaxial.

Slidably mounted within the axial bore of the sleeve 50 is a plunger 54, for example of brass. The plunger 54 is axially connected to a stepper motor 56 for moving the plunger axially so as to determine the area of the flow path through the bore 52 and thereby to control the flow rate of fluid through the bore 52 and thus to the outlet 8. A further recess is formed in that end of the body 2 which includes the outlet 8 and an electrical heater 58 is provided in the further recess for heating the body and therefore the fluid passing therethrough. The electrical heater may be supplied with electricity from an alternator or other electrical supply and may be controlled by a temperature sensor located on or in the body 2 or downstream thereof.

In use of the regulator shown in the drawings, a flow of fluid enters the regulator by way of the inlet 16 from a suitable reservoir (not shown) and exits by way of the outlet 8 to an internal combustion engine (not shown) . The fluid may be, for example, a liquid or a gaseous fuel to be supplied to an internal combustion engine. Thus, the fuel may be, for example, liquified petroleum gas, compressed natural gas, liquified natural gas, hydrogen gas or even a hydrocarbon fuel such as petrol or diesel fuel. The fluid may be at a pressure up to about 300 bar or more.

Fuel flowing into the regulator through the inlet 16 enters the hollow cylindrical chamber 32 where it follows a generally circular flow path around the axis of the chamber. Should it be necessary to heat the incoming fluid in order to assist in vaporising the fluid, the heating takes place within chamber 32 employing heat provided to - li the body 2 by the electrical heater 58. The electrical heater 58 eliminates the risk of ice forming within the regulator due to vaporisation and due to low ambient temperatures. The electrical heater eliminates the need for a supply of hot water and makes it simpler to install the regulator with a consequent reduction in installation time. However, if desired a hot water system can be provided in place of the electrical heater.

Fluid leaves the chamber 32 by way of the two small diameter diametral bores 34 which control the pressure of the fluid downstream of the bores. The fluid enters the chamber formed between the end region of the pressure regulating pin 40 and the internal surface of the axial bore 24. The angular, polygonal configuration of the pin 40 slows the flow of fluid in the chamber and assists with further vaporisation of the fluid, if required. Effectively, the angular, polygonal configuration of the pressure regulating pin 40 within the cylindrical bore 24 creates a plurality of pressure reduction chambers around the pin 40, one between each face of the pin and the internal surface of the bore 24.

Fluid leaves the chamber between the pin 40 and the internal surface of the axial bore 24 by way of a gap between the tapered tip of the pin 40 and the tapered end of the barrel member 22. The tapered configuration assists in the accurate adjustment of the gap and consequently assists in the accurate determination of the pressure regulation as required for the system. The pressure regulation is determined for each particular system and is pre-set during manufacture of the regulator.

The flow rate of fluid leaving the regulator is determined by the relative position of the plunger 54 in the sleeve 50. The relative position of the plunger 54 is controlled by stepper motor 56 which receives a signal from a computer (not shown) connected to the internal combustion engine so as to control the flow rate of fluid to the internal combustion engine.

It should be noted that the provision of the sleeve 50, stepper motor 56 and plunger 54 is optional and is not required for some applications. Further, the use of a plunger arrangement in a fluid flow regulator for internal combustion engines is well known and the plunger arrangement as illustrated may be replaced by a number of equivalent conventional flow regulating means.

Thus the present invention provides a fluid flow regulator and a method of regulating flow of a fluid which does not require any moving parts, such as diaphragms or springs to control flow rate or pressure. In particular, the hollow cylindrical chamber 32 eliminates the need for a conventional diaphragm while the pressure regulating pin 40 eliminates the need for a conventional spring and valve arrangement .

Claims

1. Apparatus for regulating fluid flow characterised by:

a first component (40) having a substantially polygonal cross-section and providing a plurality of edges extending in a longitudinal direction of the first component;

a second component (22) having a substantially circular cross-section and co-operating with the first component (40) to provide a chamber between the edges of the first component and the second component;

an inlet (34) for a fluid into the chamber; and

and outlet (25) for the fluid from the chamber, the outlet being at a location remote from the inlet.

2. An apparatus as claimed in claim 1, characterised in that the first component (40) comprises a member having a polygonal cross-section and the second component (22) comprises a member having a substantially cylindrical bore

(24), the first component being provided at least partly within the substantially cylindrical bore of the second component.

3. An apparatus as claimed in claim 2, characterised in that the longitudinal edges of the first component (40) are chamfered.

. An apparatus as claimed in any preceding claim, characterised in that the first component (40) is of substantially square cross-section.

5. An apparatus as claimed in any preceding claim, characterised in that the first component (40) and the second component (22) are provided with co-operating tapered surfaces in the region of the outlet (25) for controlling the pressure of fluid exiting from the outlet.

6. An apparatus as claimed in claim 5, characterised in that the first component (40) is movable longitudinally relative to the second component (22) for adjusting the pressure of fluid exiting from the outlet (25) .

7. An apparatus as claimed in claim 6, characterised in that locking means (42) is provided for locking the first component (40) in position relative to the second component (22) .

8. An apparatus as claimed in claim 7, characterised in that cover means (10) is provided to cover the locking means (42) .

9. An apparatus as claimed in any preceding claim, characterised in that an annular chamber (32) is provided having an inlet (14) and an outlet (34), the outlet of the annular chamber communicating with the inlet of the chamber formed between the edges of the first component (40) and the second component (22) .

10. An apparatus as claimed in claim 9, characterised in that the outlet (34) has a diameter substantially less than the diameter of the inlet (14).

11. An apparatus as claimed in claim 9 or 10, characterised in that the inlet (14) is at an angle transverse to the axial direction of the annular chamber (32) and the outlet (34) is at an angle transverse to the axial direction of the annular chamber.

12. An apparatus as claimed in claim 11, characterised in that the inlet (14) and the outlet (34) of the annular chamber (32) are at angles transverse to each other.

13. An apparatus as claimed in any preceding claim, characterised in that means (54, 56) is provided for controlling the flow rate of fluid exiting the regulator.

14. An apparatus as claimed in claim 13, characterised in that the flow control means comprises a plunger (54) operated by a stepper motor (56) .

15. An apparatus as claimed in any preceding claim, characterised in that heating means (58) is provided for heating the fluid in the regulator.

16. An apparatus as claimed in claim 15, characterised in that the heating means (58) comprises electrical heating means.