GB2437363A

GB2437363A - Apparatus for creating a vortex ring bubble in a fluid

Info

Publication number: GB2437363A
Application number: GB0607678A
Authority: GB
Inventors: Christopher William Starey; Daniel James Rees-Whippey; Stephen Taylor
Original assignee: AC AUTOMATION SERVICES Ltd
Current assignee: AC AUTOMATION SERVICES Ltd
Priority date: 2006-04-18
Filing date: 2006-04-18
Publication date: 2007-10-24
Also published as: GB0607678D0

Abstract

The apparatus comprises a source of pressurised gas e.g a pump 4, an accumulator 3 directly connected to the output of the source of pressurised gas for receiving pressurised gas therefrom, a controlled outlet valve 2 connected to an output of the accumulator to supply pressurised gas into a body, and a vent valve 5 provided between the output of the source of pressurised gas 4 and the accumulator 3 and operable to relieve pressure in the apparatus. This allows continuous operation of the source whilst the outlet valve 2 operates intermittently to produce the bubbles.

Description

APPARATUS

The present invention relates to an apparatus for creating a vortex ring bubble in a fluid. In particular, the present invention relates to an apparatus for creating a vortex ring bubble of air in a liquid. In addition, the present invention also relates to a method of producing vortex ring bubbles using afore-mentioned apparatus.

It is well known to produce bubbles such as gaseous bubbles in fluids such as liquids. In particular, the production of gaseous bubbles in coloured liquids provides an aesthetically pleasing decorative effect which many individuals find relaxing. For example, the popularity of lamps filled with a viscous coloured material through which bubbles were passed on a continuous basis, known as lava lamps, had a strong resurgence as a decorative item for the home in recent years due to the aesthetically pleasing nature of the moving bubbles and the relaxing calming effect of the lamp on an observer. In addition, the use of moving bubbles through liquids, particularly in combination with coloured lights and lighting effects, is popular in the stimulation of children, particularly children with special educational needs or conditions which affect their natural intellectual development.

Bubbles may he produced in many liquids and the use of viscous fluids helps to slow the progression of the bubble or bubbles travelling from the base of the liquid to the surface of the liquid. The bubbles may come in many sizes, dependent on the pressure of the gas and viscosity of the liquid through which the gas is being passed. Typically, the bubbles are spherical in geometric shape. However, bubbles of alternative forms are possible but their production is a skilled process.

The production of vortex ring bubbles (i.e. doughnut-shaped hubbies) of gas in a liquid is particularly difficult, although some divers have been able to produce such hubbies by careful exhalation of air upwards in a controlled manner.

In an automated system, the key to the production of such vortex ring bubbles appears to he the provision of a controlled momentary flow of gas through a nozzle into a body of liquid.

However, although it is possible to control the flow of gas through the nozzle by means of a regulating valve operable to switch the inflow of pressurised gas through a bubble-generating system on and off, as desired, the gas flow through the nozzle into a body of liquid must be accurately controlled. This is typically carried Out by using a supply of gas provided at a constant pressure and the subsequent control of gas flow through the system using a multiple valve arrangement. Such an arrangement where the system operates at a constant pressure is wearing on the components of a system and therefore shortens the life of the components and therefore the useahie life of the bubble-generating system.

There is therefore a need for a device which is operable to reliably produced vortex ring bubbles over a prolonged period of time whilst minimising wear on the components of the system.

Summary of the Invention

The present invention seeks to address the problems of the prior art.

Accordingly, a first aspect of the present invention provides an apparatus for creating a vortex ring bubble in a fluid, the apparatus comprising a source of pressurised gas, an accumulator directly connected to the output of the source of pressurised gas for receiving pressurised gas therefrom, a controlled outlet valve connected to an output of the accumulator to supply pressurised gas into a body, and a vent valve provided between the output of the source of pressurised gas and the accumulator and operable to relieve pressure in the apparatus.

The arrangement described above allows the source of pressurised gas to be provided, for example, by a pump which pumps air into a reservoir, such pump being able to be run continuously, rather than having to be started and stopped to accommodate required pressures through the apparatus. Instead, the source of pressurised gas is constantly available and when not needed through the apparatus, the pressurised gas is then vented from the apparatus by opening the vent valve and relieving pressure in the apparatus.

In this way, the pump may he run continuously, thus avoiding wear and tear on the pump and pump components.

In one embodiment, the apparatus may further comprise an outlet valve having a nozzle through which pressurised gas passes in use, said nozzle provided in contact with the fluid. This allows the nozzle shape and dimensions to be selected to suit the size and dimensions of the vortex ring bubble required.

The nozzle outlet may be of any desired shape, and is preferably substantially circular in cross-section.

The nozzle outlet may be of any desired size, and is preferably in the range of I mm to 8 mm in diameter. In one embodiment, the nozzle outlet is around 4 mm.

The smaller the diameter of the nozzle, the smaller the overall dimensions of the bubble produced and therefore, the lower the visual impact of the bubble on an observer. The larger the diameter of the nozzle, the lower the quality of the bubble produced due to slight fluid flow-back into the nozzle during bubble generation.

However, this phenomenon can be overcome by increasing the pressures through the system during the bubble generation cycle.

The nozzle may protrude into the fluid. For example, the nozzle may protrude at least one millimetre into the fluid, and may protrude up to six millimetres into the fluid. Preferably, the nozzle protrudes between two and four millimetres into the fluid. However, the preferred protrusion distance may vary independence upon the pressure through the system, the timing of valve opening/closing sequences and the specific fluid used within which the bubbles are produced.

In one embodiment, the outlet valve comprises a one-way flow valve preventing flow of liquid from the body of fluid through the outlet valve. In this way, flow of fluid from the body of fluid into the apparatus is prevented should the pressurised gas within the apparatus fall to a level below that of the pressure of the fluid at the nozzle. Thus, the apparatus is protected from flow of liquid into the apparatus and the components of the apparatus are thereby protected from flooding and/or damage caused by undesirable fluid flow through the apparatus.

In one embodiment, the source of pressurised gas comprises a pump means which pumps air into the accumulator under pressure. This is one of the most useful sources of pressurised gas as it avoids the need for a supply tank of pressurised gas to feed the system. In addition, the gas flow is constant and the problems encountered by an emptying pressurised gas tank are avoided. Due to the arrangement of the apparatus, the pump means may be constantly operated to produce pressurised gas, as the gas pressure through the apparatus may be relieved by operation of the vent valve to vent the pressurised gas from the apparatus.

When pressurised gas is required to be diverted through the apparatus, the vent valve may be closed and the gas will then be guided through the apparatus to the nozzle where it is released through the fluid in a controlled manner in order to produce the vortex ring bubbles.

In one embodiment, the gas flow through the apparatus is controlled by means of a plurality of valves, such as solenoid valves or the like, in communication with the pump means. It would be appreciated that any suitable valves known to the skilled person and appropriate for the function may he used as an alternative to solenoid valves. For example, any valve system with a response time of around 20 to 30 ms or less could be used.

The valves may be located between the source of pressurised gas and the nozzle, in order to control the flow of pressurised gas through the apparatus and ensure that the gas reaching the nozzle and released into the body of fluid is of the appropriate pressure and is released in controlled discreet amounts in order to create the vortex ring bubbles.

It will be appreciated that the body of fluid may comprise a liquid. The liquid used may be any suitable liquid for receiving the vortex ring bubbles. For example, the liquid may be water, or water with one or more additives such as glycerol or the like, to increase the viscosity of the liquid and slow the passage of bubbles through the liquid in order that they may be more easily observed and create a more aesthetically pleasing effect.

The liquid may have any suitable viscosity. For example, water may he used, which has a viscosity of 0.89 cp at 25 C. Alternatively, a more viscous liquid such as mineral oil with, for example, a viscosity of 18.59 cp at 40 C may be used.

It is even possible to use liquids of higher viscosity such as silicon-based oils having viscosities of up to 50 cp at 40 C. Increased viscosity will reduce the speed at which bubbles rise through the liquid. Use of liquids of increased viscosities may require adjustment of pressures through the system and timing of the valve sequences during bubble generation.

It is to be understood that the liquid may be coloured using any suitable dye or other colouring means, such that the effect of the passage of bubbles through the liquid is more effective. Alternatively, the fluid used may be clear or may he of any desired colour and a lighting effect may be applied through the liquid in order to create an aesthetically pleasing effect as the bubbles pass through the liquid.

Lighting the liquid may also serve to highlight the bubble or bubbles within the liquid and the passage of the bubble or bubbles through the liquid.

A further aspect of the present invention provides a means of producing a vortex ring bubble in a body of fluid using an apparatus in accordance with a first aspect of the present invention, the method comprising the steps of: i) Providing apparatus in communication with a fluid; ii) Providing pressurised gas at the source; iii) Whilst keeping the controlled outlet valve closed, opening the vent valve so as to vent pressured gas; iv) Whilst keeping the controlled outlet valve closed, closing the vent valve so as to pressurise the gas in the accumulator; v) Whilst keeping the vent valve closed, briefly opening the controlled outlet valve to allow a bubble to form in the fluid; and vi) Immediately closing the vent valve after formation of the bubble and opening the vent valve to vent pressured gas from the source.

When the vent valve is open to vent pressurised gas, the gas may be vented to the atmosphere or to any further reservoir or accumulator or any other suitable container.

Brief Description of the Drawings

An embodiment of the present invention will now be described, by way of example only, and with reference to the accompanying drawings, in which: Figure 1 illustrates a cross-sectional view of a first embodiment of an apparatus according to the present invention with the vent valve in the venting position; Figure 2 shows the embodiment of Figure 1 with the vent valve in a closed position; Figure 3 shows a perspective view of some of the components of the apparatus of Figures 1 and 2; and Figure 4 is a graph showing a four second snapshot of a valve timing system of one embodiment of an apparatus in accordance with the present invention.

Detailed Description of the Invention

Figure 1 shows an apparatus 10 in accordance with the present invention provided with sidewalls 20 in communication with an upper plate 30. A chamber 6 is provided in sealed engagement with upper plate 30, chamber 6 containing a fluid, such as a liquid, in use. Chamber 6 is composed of any suitable transparent or translucent material. Acrylic e.g. PMMA (polymethyl methacrylate) may be used due to its cost, impact resistance and excellent optical properties. Other suitable materials include glass (particularly toughened glass), polycarbonates, high impact-resistant clear polystyrene and the like, which may he used as an alternative to, or in addition to, acrylic.

The majority of the components of the apparatus 10 are contained within the housing. These components comprise a pressurised gas source, in the form of a pump 4. The pump 4 is in direct connection with an accumulator or reservoir 3. In addition, pump 4 is vented to the atmosphere via vent solenoid valve 5.

Pressurised gas from pump 4 is therefore vented to the atmosphere when vent solenoid valve 5 is in the open configuration, as shown in Figure 1.

S

When vent solenoid valve 5 is in the closed position, as shown in Figure 2, pressurised gas from pump 4 is channelled to reservoir 3 where it accumulates and is subsequently fed through apparatus 10 via bubble solenoid valve 2 and one-way valve outlet 1 which is located at nozzle 40. Nozzle 40 is positioned such that it protrudes slightly beyond the surface of upper plate 30 and is the point at which pressurised gas is released into the liquid filled chamber 6. Upper plate 30 is composed of any suitable transparent or translucent material known to the skilled person.

The nozzle 40 protrudes beyond the surface of upper plate 30 by two to four millimetres. This assists in the generation of the vortex ring bubble. The nozzle 40 contains a one-way valve I which ensures that no liquid in chamber 6 can travel through the nozzle towards bubble solenoid valve 2, but instead the liquid is retained within chamber 6, even if the gas pressure through the components within the housing falls below the liquid pressure at the outlet of nozzle 40.

When the vent solenoid valve 5 is closed, air is pumped by pump 4 into reservoir 3 where the air can pressurise due to bubble solenoid valve 2 being in a closed configuration. After a pre-determined pressurisation period, the bubble solenoid valve 2 is opened for a selected finite amount of time, thereby releasing pressurised gas through the one-way valve 1 and out of nozzle 40 into the liquid filled chamber 6. The released gas forms a vortex ring bubble at nozzle 40, which resembles a doughnut shape. The vortex ring bubble then ascends through the liquid in chamber 6. The speed of ascension of the vortex ring bubble though the liquid in chamber 6 is dependent, at least in part, on the viscosity of the liquid within chamber 6. The greater the viscosity of the liquid within chamber 6, the slower the vortex ring bubble will ascend through the liquid in a direction away from upper plate 30. The viscosity of the liquid may be an inherent property of the natural liquid selected to fill the chamber 6. Alternatively, the viscosity of the liquid may be altered by addition of one or more viscous substances, such as glycerol or the like. It will be readily appreciated by the skilled person that any suitable liquid may he selected to fill chamber 6. Alternatively, the liquid may he supplemented by any suitably viscous additive in order to produce a liquid of selected viscosity for use in chamber 6.

Illumination means 8 is provided on the underside of upper plate 30 to chamber 6 (see figures 1 and 2). The illumination means 8 provides illumination through the transparent or translucent upper plate 30 into the liquid filled chamber 6. The illumination means may provide a white light which illuminates the fluid within chamber 6. Alternatively, illumination means 8 may provide a coloured light applied from the underside of plate 30 up through the liquid in chamber 6. The illumination may comprise a coloured lighting effect such that the light colour changes or pulses. However, it will be readily appreciated by the skilled person that illumination means 8 may provide any suitable required lighting effect through the liquid contained in chamber 6. This means that the apparatus may be viewed in a dark environment, where the liquid will be lit from the underside of upper plate and the visibility of the vortex ring bubbles created at nozzle 40 and ascending through the liquid in chamber 6 will be more visible. This creates an aesthetically pleasing and visually stimulating bubble display.

It will be appreciated that the chamber 6 may be of any desired height and that the ascension rate of the bubbles may be selected to suit the environment in which the apparatus 10 is to be located. For example, the location of apparatus 10 in an environment to create a relaxing atmosphere may require that the liquid in chamber 6 is of a reasonably high viscosity. However, the use of the apparatus 10 in an environment for stimulation, for example of children with special needs or to produce an energising effect on observers, may require that the viscosity of the liquid in chamber 6 is reduced such that the bubbles ascend through the chamber at a faster rate.

Figure 3 shows a perspective view of the embodiment previously described with reference to Figures 1 and 2. However, Figure 3 shows various components of the apparatus which are located beneath upper plate 30 in isolation from the rest of the apparatus.

Pump 4 is shown in direct communication with venting solenoid valve 5 and reservoir 3. Reservoir 3 is then connected to outlet nozzle 40 via bubble control solenoid valve 2. Nozzle 40 contains the one-way valve 1. Therefore, in use, when venting solenoid valve 5 is in the open position, air pumped from pump 4 will he vented out through solenoid valve 5 and through venting outlet 60. When venting solenoid valve 5 is closed, all the air from pump 4 is pumped through to reservoir 3 where the air accumulates and becomes pressurised as it cannot travel further through the apparatus due to bubble control solenoid valve 2 being in a closed position. Once an appropriate pressure has been reached, bubble control solenoid valve 2 is opened for a controlled finite amount of time, thus releasing pressurised air up through nozzle 40 and out into the liquid in chamber 6 (not shown in Figure 3).

It will therefore be appreciated that the pump 4 may be continuously operated throughout the use of the apparatus and that the pressure throughout the apparatus is not constant, but instead is constantly varying throughout the apparatus, although at the time when a vortex ring bubble is formed at the outlet of nozzle 40, the pressure through the apparatus is momentarily constant. The varying pressure over time through the apparatus components is beneficial in prolonging the life of the components and minimising wear and tear on the components of the apparatus 10.

In addition, the arrangement of the components of apparatus 10 allows a constant gas supply to he maintained at all times without compromise on the ability of the apparatus 10 to form vortex ring bubbles.

Figure 4 shows a four second snapshot of a valve timing system of one embodiment of an apparatus according to the present invention.

The graph of figure 4 shows a set of valve timing values that could be used to create a vortex bubble given the following conditions: Diameter of outlet valve = 4 mm Protrusion of outlet valve = 3 mm Fluid type = mineral oil Viscosity of fluid = 18.59 cp @ 40 C Room temperature = 17 C Depth of fluid 440 mm Approx. gas pressure at time of release = 5 PSI There are three stages involved with blowing a vortex ring in the system illustrated in figure 4: I. Shown as the palest shading on the chart, and indicated as (i) -The vent solenoid (Chi) is open thus venting the system and reducing the load on the pump. Within the reservoir and throughout the following system the pressure is at atmospheric pressure.

2. Shown as the intermediate shading on the chart, and indicated as (ii) -The vent solenoid (Chi) is closed, thus pressurising the reservoir and the following system due to the bubble solenoid valve (Ch2) being closed.

3. Shown as the darkest shading on the chart, and indicated as (iii) -The venting solenoid (Chi) is still closed and the bubble solenoid (Ch2) is briefly opened (in this case for 36.88 ms) to form a bubble at the outlet.

Following the bubble being blown, the bubble solenoid (Ch2) is closed again and the vent solenoid (Chi) opened to vent the system, thereby protecting the apparatus.

Although aspects of the invention have been described with reference to the embodiment shown in the accompanying drawings, it is to be understood that the invention is not limited to the precise embodiments shown and that various changes and modifications may be effected without further inventive skill and effort.

Claims

CLAIMS

1. Apparatus for creating a vortex ring bubble in a fluid, the apparatus comprising: a source of pressurised gas; an accumulator directly connected to the output of the source of pressurised gas for receiving pressurised gas therefrom; a controlled outlet valve connected to an output of the accumulator to supply pressurised gas into a body; and a vent valve provided between the output of the source of pressurised gas and the accumulator and operable to relieve pressure in the apparatus.

2. Apparatus according to Claim I further comprising an outlet valve having a nozzle through which pressurised gas passes in use, said nozzle provided in contact with the fluid.

3. Apparatus according to Claim 2, wherein the nozzle protrudes into the fluid.

4. Apparatus according to Claim 3, wherein the nozzle protrudes at least I mm into the fluid.

5. Apparatus according to Claim 3 or Claim 4, wherein the nozzle protrudes no more than 6mm into the fluid.

6. Apparatus according to Claim 4 or Claim 5, wherein the nozzle protrudes between two and four mm into the fluid.

7. Apparatus according to any one of Claims I to 6, wherein the outlet valve comprises a one way flow device preventing flow of liquid from the body of fluid through the outlet valve.

8. Apparatus according to any preceding Claim, wherein the source of pressurised gas comprises a pump means.

9. Apparatus according to Claim 8, wherein the gas flow though the apparatus is controlled by means of a plurality of solenoid valves in l() communication with the pump means.

10. Apparatus according to any preceding Claim, wherein the fluid is a liquid.

11. Apparatus according to Claim 10, wherein the liquid has a viscosity of up to 50 cp at 40 C.

12. A method of producing a vortex ring bubble in a body of fluid using the apparatus of any one of Claims 1 to 11, the method comprising the steps of: i) Providing apparatus in communication with a fluid; ii) Providing pressurised gas at the source; iii) Whilst keeping the controlled outlet valve closed, opening the vent valve so as to vent pressured gas; iv) Whilst keeping the controlled outlet valve closed, closing the vent valve so as to pressurise the gas in the accumulator; v) Whilst keeping the vent valve closed, briefly opening the controlled outlet valve to allow a bubble to form in the fluid; and vi) Immediately closing the vent valve after formation of the bubble and opening the vent valve to vent pressured gas from the source. 1-s

13. Apparatus substantially as hereinbefore described and with reference to the accompanying figures.

14. A method substantially as hereinbefore described and with reference to the accompanying figures.