GB2064814A - Improvements relating to pressure reducers - Google Patents

Abstract

The reducer includes an expansion chamber 10 having a predetermined volume, an inlet orifice 15 of predetermined dimension and an outlet orifice 14 of larger dimension than the inlet orifice, the arrangement being such that the pressure and velocity of gas flowing from the outlet orifice is reduced in proportion to the ratio of the orifice dimensions and chamber volume. <IMAGE>

Description

SPECIFICATION Improvements relating to pressure regulators This invention relates to a pressure regulator for gases and particularly to a pressure regulator for attachment to a gas burner on a cooking appliance for a barbecue.

Regulators known to Applicants, of the diaphragm type for example, involve the use of moving parts and even in their simplest form are comparatively complex.

The object of the present invention is to provide a regulator device which is simple to construct yet effective in operation.

There is provided according to the present invention, a pressure regulator including an expansion chamber for communication with a source of gas at relatively high pressure on the one hand and utilising means using said gas at a relatively low pressure, the connection between said high pressure source and said chamber including an orifice of predetermined dimension allowing flow into said chamber having a predetermined volume and an outlet orifice of larger dimension than said inlet orifice, the arrangement being such that the pressure and velocity of gas flowing from the outlet orifice of the expansion chamber is reduced in proportion to the ratio of the orifice dimensions and chamber volume. In this application the gas could be saturated with liquid.

The invention will be described in greater detail having reference to the accompanying drawings when applied to a regulator for gas obtained from a pressurised bottle which is the method of storage for Liquid Petroleum Gas (L.P.G.) commonly used as a fuel for gas stoves, lights, etc.

In the accompanying drawings: Figure 1 shows a burner and regulator assembly from one side; Figure 2 is a plan view of Figure 1; and Figure 3 is a sectional view of the regulator.

The regulator of the invention includes an expansion chamber 10 having a jet 11 and 12 with an inlet orifice 15 and an outlet orifice 14. The inlet jet 11 is connected to a source of gas preferably L.P.G.

through a standard form of gas valve control 16 used on gas stoves. The outlet jet 12 is connected to a burner 17 mounted within a shroud 18 forming part of the stove.

In one example of the regulator of the invention there is provided an inlet orifice diameter of 0.3 m.m.

and an outlet orifice diameter of 0.6 m.m. connected to an expansion chamber of 19 c.c. Thus with a flow rate from a storage pressure vessel of 1 Ib./hr. of gas at 90 p.s.i. the pressure of gas in the chamber is approximately 22 p.s.i. Thus a pressure regulation in the ratio of approximately 4:1 is obtained. The regulation of the device is approximate only and does not have the accuracy and adaptability of conventional regulators, however, the accuracy of the device is acceptable at bottle pressures in the range of 20 - 150 p.s.i. The pressure regulation is a factor of both orifice dimension and expansion chamber volume.

In application to a stove burner the result achieved is satisfactory and allows use of less stringent tolerances in the manufacture of the burner components. The lower pressure of gas at the burner allows the use of fewer and larger holes in the burner and the size of the holes is not so critical.

The burner includes a primary air port 19 for mixing of air with gas emitting from the jet 12. The burner includes a further expansion chamber 20 which communicates with the burner jets 21 which in use face downwardly into the shroud 18. The chamber 20 and the chamber at the burner jets may be separated by an apertured baffle (not shown) which will assist in even spreading of the gas mixture to all burner jets. The shroud 18 is apertured at 22 to allow secondary air to the burner and ensures complete burning of the gas. The burner top is built to overhang the burner jets 21 and prevents blockage thereof caused by material, such as, cooking debris, falling from above. The flame emanating from the burner is efficient and what is termed a "lazy flame" which can be used to effectively heat a hotplate.

Alternately the arrangement is well suited to an open flame type barbecue having heated rocks mounted above the burner and an open mesh cooking grille optionally in combination with a partial hotplate forming the cooking surface. Cooking fats dripping onto the rocks will produce flames and additional heat which will give the gas fired appliance added realism without affecting the operation ofthe burners.

1. A pressure regulator including an expansion chamber for communication with a source of gas at relatively high pressure on the one hand and utilising means using said gas at a relatively low pressure, the connection between said high pressure source and said chamber including an orifice of predetermined dimension allowing flow into said chamber having a predetermined volume and an outlet orifice of larger dimension than said inlet orifice, the arrangement being such that the pressure and velocity of gas flowing from the outlet orifice of the expansion chamber is reduced in proportion to the ratio of the orifice dimensions and chamber volume.

2. A gas cooking stove when fitted with a pressure regulator as claimed in claim 1 comprising a burner connected to said outlet orifice including a mixing chamber in which gas emitted from the outlet orifice is mixed with air and burner ports directed downwardly from said burner.

3. A cooking stove as claimed in claim 2 wherein the burner is mounted in a shroud forming part of the stove and includes an aperture for admission of air to enhance burning of the gas mixture emitted from the burner ports.

4. A pressure regulator substantially as described when having reference to the accompanying drawings.

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

Claims (5)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Improvements relating to pressure regulators This invention relates to a pressure regulator for gases and particularly to a pressure regulator for attachment to a gas burner on a cooking appliance for a barbecue. Regulators known to Applicants, of the diaphragm type for example, involve the use of moving parts and even in their simplest form are comparatively complex. The object of the present invention is to provide a regulator device which is simple to construct yet effective in operation. There is provided according to the present invention, a pressure regulator including an expansion chamber for communication with a source of gas at relatively high pressure on the one hand and utilising means using said gas at a relatively low pressure, the connection between said high pressure source and said chamber including an orifice of predetermined dimension allowing flow into said chamber having a predetermined volume and an outlet orifice of larger dimension than said inlet orifice, the arrangement being such that the pressure and velocity of gas flowing from the outlet orifice of the expansion chamber is reduced in proportion to the ratio of the orifice dimensions and chamber volume. In this application the gas could be saturated with liquid. The invention will be described in greater detail having reference to the accompanying drawings when applied to a regulator for gas obtained from a pressurised bottle which is the method of storage for Liquid Petroleum Gas (L.P.G.) commonly used as a fuel for gas stoves, lights, etc. In the accompanying drawings: Figure 1 shows a burner and regulator assembly from one side; Figure 2 is a plan view of Figure 1; and Figure 3 is a sectional view of the regulator. The regulator of the invention includes an expansion chamber 10 having a jet 11 and 12 with an inlet orifice 15 and an outlet orifice 14. The inlet jet 11 is connected to a source of gas preferably L.P.G. through a standard form of gas valve control 16 used on gas stoves. The outlet jet 12 is connected to a burner 17 mounted within a shroud 18 forming part of the stove. In one example of the regulator of the invention there is provided an inlet orifice diameter of 0.3 m.m. and an outlet orifice diameter of 0.6 m.m. connected to an expansion chamber of 19 c.c. Thus with a flow rate from a storage pressure vessel of 1 Ib./hr. of gas at 90 p.s.i. the pressure of gas in the chamber is approximately 22 p.s.i. Thus a pressure regulation in the ratio of approximately 4:1 is obtained. The regulation of the device is approximate only and does not have the accuracy and adaptability of conventional regulators, however, the accuracy of the device is acceptable at bottle pressures in the range of 20 - 150 p.s.i. The pressure regulation is a factor of both orifice dimension and expansion chamber volume. In application to a stove burner the result achieved is satisfactory and allows use of less stringent tolerances in the manufacture of the burner components. The lower pressure of gas at the burner allows the use of fewer and larger holes in the burner and the size of the holes is not so critical. The burner includes a primary air port 19 for mixing of air with gas emitting from the jet 12. The burner includes a further expansion chamber 20 which communicates with the burner jets 21 which in use face downwardly into the shroud 18. The chamber 20 and the chamber at the burner jets may be separated by an apertured baffle (not shown) which will assist in even spreading of the gas mixture to all burner jets. The shroud 18 is apertured at 22 to allow secondary air to the burner and ensures complete burning of the gas. The burner top is built to overhang the burner jets 21 and prevents blockage thereof caused by material, such as, cooking debris, falling from above. The flame emanating from the burner is efficient and what is termed a "lazy flame" which can be used to effectively heat a hotplate. Alternately the arrangement is well suited to an open flame type barbecue having heated rocks mounted above the burner and an open mesh cooking grille optionally in combination with a partial hotplate forming the cooking surface. Cooking fats dripping onto the rocks will produce flames and additional heat which will give the gas fired appliance added realism without affecting the operation ofthe burners. CLAIMS

1. A pressure regulator including an expansion chamber for communication with a source of gas at relatively high pressure on the one hand and utilising means using said gas at a relatively low pressure, the connection between said high pressure source and said chamber including an orifice of predetermined dimension allowing flow into said chamber having a predetermined volume and an outlet orifice of larger dimension than said inlet orifice, the arrangement being such that the pressure and velocity of gas flowing from the outlet orifice of the expansion chamber is reduced in proportion to the ratio of the orifice dimensions and chamber volume.

2. A gas cooking stove when fitted with a pressure regulator as claimed in claim 1 comprising a burner connected to said outlet orifice including a mixing chamber in which gas emitted from the outlet orifice is mixed with air and burner ports directed downwardly from said burner.

3. A cooking stove as claimed in claim 2 wherein the burner is mounted in a shroud forming part of the stove and includes an aperture for admission of air to enhance burning of the gas mixture emitted from the burner ports.

4. A pressure regulator substantially as described when having reference to the accompanying drawings.

5. A cooking stove fitted with a regulator as claimed in claim 4.