GB2133078A

GB2133078A - Vaporising and supplying LPG

Info

Publication number: GB2133078A
Application number: GB08234201A
Authority: GB
Inventors: Frank Ellis
Original assignee: ORFORD JOHN REGINALD
Current assignee: ORFORD JOHN REGINALD
Priority date: 1982-12-01
Filing date: 1982-12-01
Publication date: 1984-07-18
Also published as: AU2178583A

Abstract

Liquid petroleum gas is supplied to a first chamber (2) from a pipe 1 and passes to a second chamber (12) via a valve (11) controlled by a pressure sensitive actuator (16, 17, 18) to be closed when pressure within the second chamber (12) reaches a predetermined value, a heat exchanger (15) vaporising the liquid fuel and a third chamber (24) receiving the vaporised fuel from the heat exchanger (15) via a valve (26) which opens to allow the vaporised fuel to enter a supply duct (25) to an engine carburettor when the pressure at the end of the said supply duct (25) is below atmospheric. An actuator (29, 30) operated manually or by solenoid enables valve (26) to be opened to supply fuel for starting. A filter 5 is provided in chamber (2) and is covered by a cap (6) which forms a stop valve openable by a solenoid actuator (7). <IMAGE>

Description

SPECIFICATION Fuel supply means This invention relates to liquid petroleum gas (L.P.G.) supply means for internal combustion engines, and in particular to converters for gasifying liquid petroleum gas.

A converter for L.P.G. according to the invention comprises a first chamber containing a filter to receive liquid fuel from a supply, a second chamber having a pressure sensitive valve actuator to close a stop valve between the two said chambers when pressure within the second chamber reaches a predetermined value, a heat exchanger to receive liquid fuel from the second chamber and convert it into gaseous form, and a third chamber to receive the gaseous fuel from the heat exchanger and having an outlet valve which opens to allow the gaseous fuel to enter a supply duct to an engine carburettor when the pressure at the end of the said supply duct is below atmospheric.

In a preferred form of the invention the chambers and the heat exchanger are continuously arranged within a single outer casing. A pressure release valve is provided to allow escape of excess liquid fuel from the first chamber into a drain duct, and a priming device is mounted in the third chamber to open the outlet valve independently of the pressure at the end of the supply duct. The heat exchanger may be in the form of a plurality of tubes through which the fuel passes and which extend through a water jacket.

An embodiment of the invention will now be described with reference to the accompanying drawing wherein.

Figure 1 shows a diagrammatic side view of a converter according to the invention.

Referring to the drawing, a feed pipe 1 from a storage tank of L.P.G. (not shown) leads to a first chamber 2. The chamber 2 is divided into compartments 3, 4 by a liquid-tight partition 5 mounting a filter 6 through which liquid fuel reaches the compartment 4 from the compartment 3. The filter is covered by a cap 6 forming a stop valve which can be opened against a closing spring by energising a solenoid actuator 7 a pressure release safety valve 8 in an end wall of the compartment 3 is pre-set to open when the pressure in the compartment rises above a predetermined value, for example if the filter becomes blocked, to allow excess liquid fuel to escape into a pipe 9 surrounding the feed pipe 1.

The pipe 9 has a drain 10 to vent fuel collecting in the pipe to atmosphere outside the body of the vehicle or enclosure in which the fuel system embodying the converter is mounted. The pipe 9 is attached to the end wall 31 of the chamber 2 by means of a flange 32.

A normally open valve 11 allows liquid fuel from compartment 4 to enter a second chamber 1 2. The second chamber has an intermediate partition 13 spaced from its end walls to support exit ducts 14 which allow passage to fuel from the chamber 12 to a heat exchanger 15. The partition also supports a diaphragm 1 6 backed by a spring 17 and connected by a pivoted linkage 18 to the valve 11.

If the pressure chamber 12 rises above a pre set value the diaphragm is forced back against the pressure of spring 1 7 and actuates the linkage to close the valve 11 and isolate the chamber 12 from the chamber 2. The pre-set value can be altered by adjustment of the spring pressure by a conventional servo adjuster 1 9.

The heater exchanger comprises a plurality of open-ended heat exchange ducts 20 extending through a water jacket 21 having inlet and outlet connections 22, 23 to a supply of water, for example to cooling system of an engine. In order to prevent possible damage to the heat exchanger in the event that the water in the cooling system should freeze, the water jacket may be provided with an expansion chamber in the form of rubber beilows. Danger of freezing arises in the event that the circulation of water through the jacket is interrupted. When this happens vaporization of the liquid fuel causes a drop in the water temperature which may be sufficient to produce freezing.As the fuel passes along the ducts 20, heat from the water jacket produces progressive gasification so that at the downstream ends of the ducts the fuel is converted into the gaseous state for supply to the carburettor of the engine to be powered by the fuel. The gas from the heat exchanger passes into an outlet chamber 24 which is connected by an outlet pipe 25 to the carburettor bore through a spring loaded check valve 26. The valve spring 27 normally holds the valve 26 closed until on an induction stroke of the engine a depression occurs in the carburettor producing suction in the pipe 25 and the chamber 26. The consequent drop in pressure in the chamber 26 causes the valve 26 to open against the spring pressure.Normally with a multi cylinder engine a continuous depression is present in the carburettor bore and thus the valve 26 remains open to provide a passage for the gaseous fuel. If however the depression should fail, the valve 26 closes. This causes a rise in pressure within the heat exchanger and thence in the chamber 1 2 so that the valve 11 closes as previously described, interupting the fuel supply.

In order to allow the carburettor to be primed before starting up the engine, the valve 26 carries a collar 27 engageable by a fork 28 at one end of a pivoted bell-crank lever 29, the other end of the lever being connected to a mechanical or solenoid operated puil rod 30 within a housing extending through the wall of the chamber 24. Movement of the rod 30 thus produces unseating of the valve 26 to allow fuel flow through the converter before the engine is started.

For manufacturing convenience each chamber and the heat exchanger is cylindrical in shape with valve and inlet and outlet orifices in their flat end walls. The respective cylindrical walls are all of the same diameter so that they can be joined together by end flanges or other means in succession to form a single cylindrical body.

In order to meet the danger of fuel leakage between the converter and the carburettor, the outlet pipe is surrounded by a sleeve 33 which is attached to the converter by a flange 34. The sleeve is sealed to the carburettor body at its other end, and, in the same manner as the pipe 9, is vented to the exterior of the vehicle in which the converter is installed.

Claims (Filed on 25-11-83) 1. A converter for liquid petroleum gas (L.P.G.) comprising a first chamber containing a filter to receive liquid petroleum fuel from a supply, a second chamber having a pressure sensitive valve actuator to close a stop valve between the two said chambers when pressure within the second chamber reaches a predetermined value, a heat exchanger to receive liquid fuel from the second chamber and convert it into gaseous form, and a third chamber to receive the gaseous fuel from the heat exchanger and having an outlet valve which opens to allow the gaseous fuel to enter a supply duct to an engine carburettor when the pressure at the end of the said supply duct is below atmospheric.

2. A converter according to claim 1, wherein the first, second and third chambers and the heat exchanger are contiguously arranged within a single outer casing.

3. A converter according to claim 1 or claim 2, including a pressure release valve to allow escape of excess liquid fuel from the first chamber into a drain duct, and a priming device mounted in the third chamber to open the outlet valve independently of the pressure at the end of the supply duct.

4. A converter according to claim 3, wherein the priming device includes a pivotally mounted bell-crank lever engaging at one end with the outlet valve and actuated at the other end mechanically or electromagnetically to displace the outlet valve into an open position against a force biassing the outlet valve towards a closed position.

5. A converter according to any one of claims 1 to 4, wherein the pressure sensitive valve actuator includes a diaphragm displaceable against the force of a spring by excess pressure in the second chamber, to close the stop valve via a pivoted linkage.

6. A converter according to any one of claims 1 to 5, wherein the heat exchanger is in the form of a plurality of tubes through which the fuel passes, and which extend through a water jacket.

7. A converter for liquid petroleum gas, (L.P.G.) substantially as hereinbefore described with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. In order to meet the danger of fuel leakage between the converter and the carburettor, the outlet pipe is surrounded by a sleeve 33 which is attached to the converter by a flange 34. The sleeve is sealed to the carburettor body at its other end, and, in the same manner as the pipe 9, is vented to the exterior of the vehicle in which the converter is installed. Claims (Filed on 25-11-83)

1. A converter for liquid petroleum gas (L.P.G.) comprising a first chamber containing a filter to receive liquid petroleum fuel from a supply, a second chamber having a pressure sensitive valve actuator to close a stop valve between the two said chambers when pressure within the second chamber reaches a predetermined value, a heat exchanger to receive liquid fuel from the second chamber and convert it into gaseous form, and a third chamber to receive the gaseous fuel from the heat exchanger and having an outlet valve which opens to allow the gaseous fuel to enter a supply duct to an engine carburettor when the pressure at the end of the said supply duct is below atmospheric.