WO2022087641A1

WO2022087641A1 - Pressure vessel system

Info

Publication number: WO2022087641A1
Application number: PCT/ZA2021/050060
Authority: WO
Inventors: Mitch VAN DEN BOS
Original assignee: Van Den Bos Mitch
Priority date: 2020-10-23
Filing date: 2021-10-22
Publication date: 2022-04-28
Also published as: ZA202307001B

Abstract

A pressure vessel system includes: (i) a vessel (12) that: is, during normal operation conditions, under pressure; and defines a vessel outlet (12b); (ii) a primary conduit (16) that, in use, feeds the vessel (12) with liquid under pressure; (iii) a tank (14) that is ventilated; (iv) a sensor (18) for sensing the volume of liquid in the tank (14); and (v) a first valve (20) that is: associated with the primary conduit (16); and operable by the liquid volume sensor (18) to prevent or restricting liquid flow through the primary conduit (16) when a first predetermined volume of liquid is contained within the tank (14). The tank (14) is in fluid communication with the vessel (12) via a second valve (24) that prevents liquid flow from the vessel (12) to the tank (14), such that, in use, when the first predetermined volume of liquid is contained within the tank (14): (a) the first valve (20) prevents or restricts liquid flow to the vessel (12) via the primary conduit (16); and (b) as liquid is discharged from the vessel (12) via the vessel outlet (12b), the pressure in the vessel (12) reduces and the second valve (24) permits liquid to flow from the tank (14) into the vessel (12).

Description

PRESSURE VESSEL SYSTEM

BACKGROUND

The present invention relates to a pressure vessel system. More specifically, the present invention relates to a system for feeding liquid into a pressure vessel. Even more specifically, the present invention relates to a system for returning water at atmospheric pressure to a pressurised geyser.

Various systems for charging a vessel with a liquid are known. For example:

WO2011/030188 “Water saving system to be used in water heaters for hot water supply” describes a water heating system with a pressurised accumulation reservoir that temporarily stores “cold water” before releasing it back into the system.

CN 102297519 describes an unpressurised reservoir that stores “cold water”, which “cold water” is periodically pumped back to a pressurised geyser. Similar systems are described in CN208871870, GB152,591 “Improvements in and relating to vacuum producing apparatus for vapor heating systems and the like installations, utilizing a vacuum”, GB2, 124,348 “A warm water storage system”, GB2,367,880 “Water system with pressure booster” and US5,564,462 “Water conservation delivery system using temperature-controlled by-pass circuit”.

GB1 ,386,387 “Pressurised liquid heat exchange system with open top feed tank” describes an open-topped feed tank that stores water to be fed into a boiler in a continuous flow water-heating system. A similar system is described in GB2,097,525 “Water heating system”.

US2004/0159353 “Water conservation system” and US2013/0061944 “System and methods for water conservation” describe a hot water system that diverts “cold water” to a secondary chamber of a dual-chamber toilet cistern. A similar system is described in US5,524,666 “Water conservation system”. A drawback of all the above systems is that they are unable to feed a pressure vessel with liquid at a pressure that is lower than the normal operating pressure of the vessel. To return liquid to the pressure vessel, the prior art increases the pressure of the returning liquid, either by elevating the feeder tank or by a pump.

It is an object of the present invention to address this drawback and to provide a system that returns liquid to a pressure vessel at a pressure lower than the normal operating pressure of the vessel.

SUMMARY OF THE INVENTION

According to a preferred embodiment of the invention, there is provided a pressure vessel system that includes: a vessel that: is, during normal operation conditions, under pressure; and defines a vessel outlet; a primary conduit that, in use, feeds the vessel with liquid under pressure; a tank that is ventilated; a sensor for sensing the volume of liquid in the tank; and a first valve that is: associated with the primary conduit; and operable by the liquid volume sensor to prevent or restricting liquid flow through the primary conduit when a first predetermined volume of liquid is contained within the tank; the tank being in fluid communication with the vessel via a second valve that prevents liquid flow from the vessel to the tank, such that, in use, when the first predetermined volume of liquid is contained within the tank: the first valve prevents or restricts liquid flow to the vessel via the primary conduit; and as liquid is discharged from the vessel via the vessel outlet, the pressure in the vessel reduces and the second valve permits liquid to flow from the tank into the vessel.

Typically, the first valve is operable by the liquid volume sensor to permit liquid flow through the primary conduit when a second predetermined volume of liquid is contained within the tank, which second predetermined volume of liquid is less than the first predetermined volume of liquid.

Generally, the first valve is disposed along the primary conduit, spaced operatively upstream of the vessel.

Preferably, the tank is in fluid communication with the vessel via a secondary conduit that extends from the tank to either: the vessel; or the primary conduit, operatively downstream of the first valve.

Typically, the liquid volume sensor is a float disposed on a hinged arm, disposed within the tank.

Generally, the liquid volume sensor and first valve is a mechanical float valve.

Preferably, the second valve is a non-return valve.

Typically, the vessel is a hot water geyser.

Generally, the tank is disposed operatively above the vessel. Preferably, the pressure vessel system further includes: a tertiary conduit that extends from the geyser outlet and defines a tertiary conduit outlet at its terminal end; a third valve that: is disposed along the tertiary conduit; includes a temperature sensor; and is operable by the temperature sensor to prevent water flowing past the third valve to the tertiary conduit outlet until the water temperature determined by the temperature sensor reaches a predetermined temperature; and a return conduit that is associated with the third valve, in use, to divert water flowing along the tertiary conduit that has not reached the predetermined temperature to the tank.

BRIEF DESCRIPTION OF THE DRAWING

The invention will now be described in more detail, by way of example only, with reference to the accompanying drawings in which:

Figure 1 is schematic diagram of the pressure vessel system according to a preferred embodiment of the invention.

DESCRIPTION OF THE INVENTION

With reference to Figure 1 , a pressure vessel system 10 includes a vessel 12 and a tank 14 for charging the vessel 12 with liquid.

The vessel 12 is a closed vessel defining an inlet 12a and an outlet 12b. In use, the vessel 12 contains liquid and is, under normal operating conditions, under pressure (i.e. operates at a pressure above ambient atmospheric pressure). Figure 1 shows the vessel 12 as a geyser for heating water. However, it will be appreciated that the vessel 12 could be any other type of vessel that is, under normal operating conditions, under pressure.

The tank 14 is ventilated, i.e. the tank 14 is “and open top tank”, which pressure is equalised with the ambient atmospheric pressure. The tank 14 is disposed operatively above the vessel 12, typically being supported on a stand 15.

A primary conduit 16 extends to the vessel 12 inlet 12a and feeds the vessel 12 with water under pressure. Typically, the primary conduit 16 charges the vessel 12 with water from a pressurised municipal water line.

A sensor 18 for sensing the volume of water in the tank 14 is disposed within the tank 14. The liquid volume sensor 18 is shown in the form of a float attached to a hinged arm, which float moves in response to a change in the water level in the tank 14. It will be appreciated that, although the liquid volume sensor 18 has been described as determining the water volume with reference to the water level within the tank 14, the liquid volume sensor 18 could determine water volume indirectly through any other means, e.g. by sensing pressure or weight.

A first valve 20 is associated with the primary conduit 16. More specifically, the first valve is disposed along the primary conduit 16, spaced from the vessel 12. Put another way, the first valve 20 is disposed along the primary conduit 16, operatively upstream of the vessel 12 inlet 12a. The first valve 20 is movable between: an open condition, in which the first valve 20 permits water under pressure to flow from the municipal water line along primary conduit 16, to feed the vessel 12; and a closed condition, in which the first valve 20 restricts or (preferably) prevents the flow of water under pressure from the municipal water line along the primary conduit 16 to vessel 12.

Operation of the first valve 20 between the open and closed conditions is controlled by the liquid volume sensor 18. When the liquid volume sensor 18 senses the volume of water within the tank 18 above a first predetermined volume, the liquid volume sensor 18 causes the first valve 20 to move to the closed condition, and when the liquid volume sensor 18 senses the volume of water within the tank 18 below a second predetermined volume (which is less than the first predetermined volume, preferably close to zero), the liquid volume sensor 18 causes the first valve 20 to move to the open condition.

Figure 1 shows the liquid volume sensor 18 and the first valve 20 in the form of a mechanical float valve, similar to the type commonly used within toilet cisterns.

The tank 14 is in fluid communication with the vessel 12, which fluid communication is effected by a secondary conduit 22 that extends from the tank 14 to the primary conduit 16, operatively downstream of the first valve 20. Although the secondary conduit 22 has been described as connecting to the vessel 12 via a portion of the primary conduit 16, it will be appreciated that the secondary conduit 22 may connect to the vessel 12 directly.

A second valve 24 is associated with the secondary conduit 22, and prevents water from flowing from the vessel 12 to the tank 14. Preferably, the second valve 24 is a non-return valve, permitting water flow from the tank 14 to the vessel 12 only. It will be appreciated that, during normal operating conditions of the vessel 12, the second valve 24 prevents water from flowing from the pressurised vessel 12 to the non-pressurised tank 14.

A tertiary conduit 26 extends from the vessel 12 outlet 12b and defines a tertiary conduit outlet 26a at its terminal end. A flow regulator 28 (i.e. tap) is disposed at or near the terminal end of the tertiary conduit 26, to regulate flow of water through the tertiary conduit 26.

A third valve 30 is disposed along the tertiary conduit 26, proximal the flow regulator 28, preferably operatively downstream of the flow regulator. The third valve 30 includes a temperature sensor (not shown), and is operable by the temperature sensor to prevent water flowing past the third valve 30 to the tertiary conduit outlet 26a until the water temperature determined by the temperature sensor reaches a predetermined temperature. Systems using such valves with temperature sensors that divert “cold water” to a holding tank or back to the geyser are described in GB2,427,259 “A water-saving device”, US2012/0118414 “Water saver system” and US4,450,829 “Water saving system”.

A return conduit 32 is associated with the third valve 30, in use, to divert water flowing along the tertiary conduit 26 that has not reached the predetermined temperature to the tank 14.

In use:

• The vessel 12 is charged with water under pressure via the primary conduit 16.

• The vessel 12 heats the water, operating under pressure. • When the flow regulator 30 is opened to enable water flow along the tertiary conduit 26, heated water is discharged from the vessel 12 via the vessel outlet 12b.

• Until the water flowing within the tertiary conduit 26 at the third valve 30 (more specifically, at the temperature sensor) reaches a predetermined temperature, the temperature sensor maintains the third valve 30 in a closed condition, causing water flowing along the tertiary conduit 26 to be diverted into the return conduit 32 and along the return conduit 32 into the tank 14. It will be appreciated that pressure in the system (originating from the vessel 12 under normal operating conditions) enables return flow of water to the elevated tank 14.

• When the water flowing within the tertiary conduit 26 at the third valve 30 reaches the predetermined temperature, the temperature sensor causes the third valve 30 to open, permitting the “hot water” to flow out of the tertiary conduit 26 via the tertiary conduit outlet 26a.

• When the liquid volume sensor 18 senses that the volume of water within the tank 14 is above the first predetermined level, the liquid volume sensor 18 causes the first valve 20 to move towards the closed condition, preventing the vessel 12 from being fed with water under pressure by the primary conduit 16.

• As the heated water is discharged from the vessel 12 (i.e. by opening of the flow regulator 30), the water level in the vessel 12 drops. Since the water within the vessel 12 is not being replaced by water conveyed under pressure by the primary conduit 16, the drop in water level in the vessel 12 causes the pressure in the vessel 12 to reduce.

• The reduction in pressure in the vessel 12 causes water to flow from the tank 14, via the secondary conduit 22, past the second valve 24 into the vessel 12. It will be appreciated that such flow past the second valve 24 is permitted when the pressure operatively downstream of the second valve 24 is less than the pressure operatively upstream of the second valve 24.

• When the liquid volume sensor 18 senses that the water volume in the tank 14 has dropped below a second predetermined level (i.e. the tank 14 is effectively empty of water), the liquid volume sensor 18 causes the first valve 20 to move to the open condition, enabling the primary conduit to continue charging the vessel 12 with water under pressure, and consequently pressurising the vessel 12.

• The second valve 24 prevents backflow of water from the vessel 12 to the tank 14 when the pressure in the vessel 12 exceeds the pressure in the tank 14 (more specifically, when the pressure operatively downstream of the second valve 24 is greater than the pressure operatively upstream of the second valve 24. By returning “cold water” that would otherwise be discharged via the tertiary conduit outlet 26a to the vessel 12, the pressure vessel system 10 saves water that would otherwise be wasted. It will be appreciated that, by varying the water level and, consequently the pressure within the vessel 12 during discharge of water from the vessel 12, the pressure vessel system 10 enables an equalised, non-pressurised tank 14 to charge a vessel 12 that is pressurised under normal operating conditions without the use of a pump and without having to create a significant head of water by significantly elevating the tank 14 above the vessel 12. Furthermore, by not requiring the supply of electricity or pumps, the pressure vessel system 10 may be fitted into existing systems more easily than prior art water return systems.

Claims

1 . A pressure vessel system including: a vessel that: is, during normal operation conditions, under pressure; and defines a vessel outlet; a primary conduit that, in use, feeds the vessel with liquid under pressure; a tank that is ventilated; a sensor for sensing the volume of liquid in the tank; and a first valve that is: associated with the primary conduit; and operable by the liquid volume sensor to prevent or restricting liquid flow through the primary conduit when a first predetermined volume of liquid is contained within the tank; the tank being in fluid communication with the vessel via a second valve that prevents liquid flow from the vessel to the tank, such that, in use, when the first predetermined volume of liquid is contained within the tank: the first valve prevents or restricts liquid flow to the vessel via the primary conduit; and as liquid is discharged from the vessel via the vessel outlet, the pressure in the vessel reduces and the second valve permits liquid to flow from the tank into the vessel.

9

2. The pressure vessel system according to claim 1 , wherein the first valve is operable by the liquid volume sensor to permit liquid flow through the primary conduit when a second predetermined volume of liquid is contained within the tank, which second predetermined volume of liquid is less than the first predetermined volume of liquid.

3. The pressure vessel system according to claim 2, wherein the first valve is disposed along the primary conduit, spaced operatively upstream of the vessel.

4. The pressure vessel system according to claim 3, wherein the tank is in fluid communication with the vessel via a secondary conduit that extends from the tank to either: the vessel; or the primary conduit, operatively downstream of the first valve.

5. The pressure vessel system according to claim 4, wherein the liquid volume sensor is a float disposed on a hinged arm, disposed within the tank.

6. The pressure vessel system according to claim 5, wherein the liquid volume sensor and first valve is a mechanical float valve.

7. The pressure vessel system according to claim 6, wherein the second valve is a nonreturn valve.

8. The pressure vessel system according to claim 7, wherein the vessel is a hot water geyser.

9. The pressure vessel system according to claim 8, wherein the tank is disposed operatively above the vessel.

10. The pressure vessel system according to claim 9, further including: a tertiary conduit that extends from the geyser outlet and defines a tertiary conduit outlet at its terminal end; a third valve that: is disposed along the tertiary conduit; includes a temperature sensor; and is operable by the temperature sensor to prevent water flowing past the third valve to the tertiary conduit outlet until the water temperature determined by the temperature sensor reaches a predetermined temperature; and a return conduit that is associated with the third valve, in use, to divert water flowing along the tertiary conduit that has not reached the predetermined temperature to the tank.

11