WO2013034869A2

WO2013034869A2 - Method and apparatus for treating conduits

Info

Publication number: WO2013034869A2
Application number: PCT/GB2011/001525
Authority: WO
Inventors: Ian Lee
Original assignee: Cambridge Scientific Solutions Limited
Priority date: 2011-09-06
Filing date: 2011-10-24
Publication date: 2013-03-14
Also published as: GB2494417A; GB2494417B; GB201115416D0; EP2753436A2; WO2013034869A3

Abstract

An apparatus for treating fluid conduits to prevent contamination comprises a conduit (2) defining a fluid channel (4) and a coil (6) extending along at least part of the length of the conduit (2) and around the fluid channel (4), said coil having a length or aggregate length L. A signal generator (10) is connected to the coil (6), the signal generator being configured to supply a varying electrical signal to the coil (6) whereby the coil (6) generates a varying magnetic field within the fluid channel (4). The length or aggregate length L of the coil (6) is at least 1.8 metres.

Description

METHOD AND APPARATUS FOR TREATING CONDUITS

The present invention relates to a method and apparatus for treating fluid conduits, and in particular for treating delivery lines for beverages such as beer. More specifically, the invention relates to a method and apparatus for treating fluid conduits using a coil for producing a magnetic field to prevent deposition of contaminants within the conduit.

Fluid conveying conduits such as water pipes, beer lines, and the like are commonly used to transport liquids or fluidised materials from a supply point to a distribution point. For conduits which convey beverages (consumable liquids), regulatory requirements dictate that the liquid is transported with minimum contamination to the liquid.

In the case of beer lines, yeast and other contaminates can build up over time within the pipes, resulting in contamination of the beer. Once contaminants have deposited within a pipe, the pipe must either be cleaned or replaced. Beer lines must therefore be cleaned frequently to remove contaminants. However, cleaning beer lines results in significant costs, in terms of the equipment and chemicals required to clean the lines, down time, and the loss of beer within the lines, which must be discarded when the lines are cleaned.

UK Patent Number GB 2,367,106 describes a system for cleaning beer lines, comprising an electro-magnetic coil wrapped round the beer line, and a signal generator for generating an electric current causing the coil to produce a magnetic field. This system helps to prevent contaminants from depositing on the inner surface of the beer line, and therefore significantly reduces the frequency with which the line needs to be cleaned.

Previously, it was not fully understood how the system described in GB 2,367,106 works or what criteria are required for successful implementation of the system. We have now discovered that there is a strong correlation between the length and location of the coil and its successful operation. According to one aspect of the present invention, there is provided and apparatus for treating fluid conduits, as claimed in the accompanying claims. According to another aspect of the present invention, there is provided a method of treating fluid conduits as described in the accompanying claims, to prevent or inhibit contamination thereof.

In an embodiment of the present invention, there is provided an apparatus for treating fluid conduits to prevent contamination thereof, the apparatus comprising a conduit defining a fluid channel and a coil extending along at least part of the length of the conduit and around the fluid channel, the coil having a length or aggregate length L. A signal generator is connected to the coil, the signal generator being configured to supply a varying electrical signal to the coil, whereby the coil generates a varying magnetic field within the fluid channel. The length or aggregate length L of the coil is at least 1.8 metres.

Advantageously, the length or aggregate length L of the coil is in the range 1.8 to 5.0 metres. In certain circumstances, the length L may be more than 5 metres.

In a preferred embodiment, the conduit comprises at least part of a delivery line for a beverage, and preferably for beer.

Advantageously, the coil extends around a section of a beer delivery line located adjacent a beer supply container. More preferably, the coil extends around a section of a beer delivery line located between a beer supply container and a delivery pump, fob detector or cooler.

In a particularly preferred embodiment, the delivery line has a total length D and the length or aggregate length L of the coil is in the range 3% to 5% of the delivery line length D. The delivery line length D represents the total length from the beer supply container to the delivery tap.

Advantageously, the fluid channel has an internal diameter in the range 5mm to 15mm. The coil is preferably a helical coil.

Advantageously, the signal generator is configured provide a pulsed or varying energy signal to the coil, the signal having a varying frequency, which is preferably higher than audio frequencies. The pulsed or varying energy signal preferably comprises a square waveform having a varying frequency.

According to another preferred aspect of the invention there is provided a method of treating a conduit to prevent contamination thereof, the method comprising providing a conduit having a channel for conveying a fluid, providing a coil that extends along at least part of the length of the conduit and around the fluid channel, said coil having a length or aggregate length L, connecting a signal generator to the coil, and supplying a varying electrical signal to the coil whereby the coil generates a varying magnetic field within the fluid channel, wherein the length or aggregate length L of the coil is at least 1.8 metres.

Advantageously, the conduit comprises at least part of a delivery line for a beverage, preferably for beer.

In an embodiment of the invention, the signal generator generates an electric current that passes through the coil to create a magnetic field within the conduit. This helps to prevent deposition of contaminants on the inner surface of the conduit from fluid conveyed by the conduit.

The conduit may comprise a tube wall, and at least a section of the coil may be encased within the tube wall along at least a section of the length of the tube.

Preferably, the coil is located within the tubular wall of the conduit, between the inner and outer surfaces of the conduit. This provides a cleaning effect that is maximised because the coil is located close to the inner surface and hence to the fluid conveyed within the conduit. In addition, locating the coil within between the inner and outer surfaces of the conduit helps to protect the coil from damage. The tube and the coil may be formed integrally. That is, a section of the tube may be formed about a section of the coil.

The present invention will now be described by way of example with reference to the following illustrative figures, in which:

Figure 1 is a schematic illustration of an apparatus for treating a fluid conduit, according to an embodiment of the invention; Figure 2 illustrates a typical beer dispensing installation, in which an apparatus according to an embodiment of the present invention has been installed for treating beer lines;

Figure 3 is a longitudinal section of a fluid conduit according to a preferred embodiment of the present invention; and

Figure 4 is a cross-sectional view of the conduit of Figure 3.

Referring to Figure 1, a fluid conveying conduit 2 comprises a tube providing a flow channel 4 for liquid to flow through the conduit. The conduit 2 is typically an elongate, cylindrical tube, although the tube may alternatively be of any suitable shape, for example a tube of square cross section. The present invention is applicable to fluid conveying conduits of varying size. Typically, the conduit may have a relatively small diameter in the range 5-15mm. For example, it may be a standard beer line having a diameter of ¼" (6.3mm), 5/16" (7.9mm) or 3/8" (9.5mm), or it may have a larger diameter.

To prevent deposition of contaminants on the inner surface of the conduit 2, an electromagnetic coil 6 is provided. The coil 6 is wrapped around the conduit or embedded within the wall of the conduit so that it surrounds the fluid carrying channel 4 within the conduit 2. The coil 6 has a length L and extends axially along the length of the conduit 2. The coil 6 may extend along the entire length of the conduit 2 or only along a preselected section or sections of the conduit 2. The coil 6 may optionally be divided into a number of discrete sections, where L represents the aggregate length of the coil sections.

The coil 6 shown in the illustrations is a helical coil that extends around the conduit 2 in a helical configuration. Other suitable electro-magnetic coil configurations may alternatively be utilised.

The coil 6 may be formed from any suitable electrically conductive material including, for example, copper or steel wire. Electrical connections 8 are provided at both ends of the coil 6, for connecting the coil to a signal generator 10, which is connected to an electrical power supply 12.

An electrical signal is generated by the signal generator 10 and delivered to the coil 6 as an input signal. This causes the coil 6 to produce a magnetic field within the fluid carrying channel 4 of the conduit 2. The input signal may be a pulsed or varying current input signal, which may be pulsed or varied at varying frequencies. For example, the pulsed or varying current input signal may comprise a square waveform having a ramped frequency (that is, the frequency of the square waveform repeatedly increases from a lower frequency to a higher frequency before falling back to the lower frequency). The input signal provided by the signal generator 1 0 is selected to provide efficient cleaning of the conduit 2. In particular, the input signal causes the coil 2 to produce a magnetic field that prevents or minimises deposition of particulates suspended in the fluid on the inner surface of the fluid channel 4 within the conduit 2.

For application as a beer line, the conduit 2 generally comprises a tube of flexible nylon or urethane or another food-grade polymer. However, it should be understood that the conduit 2 may be formed of any material suitable for the fluid to be conveyed and the environment in which the conduit is to be utilised. The internal diameter of the conduit 2 and the thickness of the wall surrounding the fluid channel 4 may be varied according to the environment and application for which the conduit is intended.

A typical cellar installation for dispensing beer that includes an apparatus according to an embodiment of the invention is illustrated in figure 2. In this example, beer is dispensed from two types of container: a pair of pressurised keg barrels 14 and an unpressurised cask barrel 16. Each of these barrels 14, 16 is connected by a flexible polymeric beer tube 18 (called a "drop line") to a pump 20. The pumps 20 are usually mounted on a wall of the cellar somewhere above the barrels and may typically be gas-operated diaphragm pumps, for example of the type commonly called "flojet" pumps. Downstream of each of the keg barrel pumps 20 is a fob detector 22, which operates to shut off the flow of beer when the barrel is nearly empty to prevent excessive frothing (or "fobbing") of the beer.

After leaving the pumps 20 (and, where provided, the fob detectors 22), the beer flows through a set of beer delivery lines 26 (which may be rigid or flexible) to a cooler 28, and then via a water-cooled bundle 30 of beer delivery lines (commonly called a "python") to a set of dispensing taps 32 at the bar 34.

In this embodiment, the coils 6 are wound around the first section of the beer delivery lin^pc mmnn ci^iK, ft^p flexible beer tubes 18 (the drop lines) that extend from the barrels 14, 16 to the pumps 20. Each coil 6 has a length of at least 1.8 metres, preferably between 1.8m and 5m, and is connected to a signal generator 10 mounted on the wall of the cellar adjacent the pumps 20. We have found that the apparatus is most effective at preventing contamination of the beer lines when the coils 6 have a length of at least 1.8m. We have also found that the apparatus is most effective when the coils 6 are wound around the first part of each beer delivery line, between the barrel 14, 16 and the respective pump 20. Surprisingly, we have found that when the coils 6 are installed as described, they help to prevent contamination of the whole beer delivery system, including the beer delivery pipes 26 and the pipes in the python 30 that are located a considerable distance downstream of the coils.

As previously indicated, the coil 6 may either be wound around the outside of the conduit 2, or it may be embedded within the wall 40 of the conduit as shown in figures 3 and 4. Encasing the coil 6 within the wall 40 of the conduit 2 between the inner surface 42 of the wall 40 and the outer surface 44 allows the coil 6 to be positioned closer to the inner surface 42. It has been found that by locating the coil 6 closer to the inner surface 42, and consequently closer to the fluid within the channel 4, the cleaning effect of the coil 6 is significantly increased. The cleaning effect of the coil 6 may be maximised by locating the coil closer to the inner surface 42 than the outer surface 44, and as close to the inner surface 42 as possible within the constraints of the material from which the conduit 2 is formed.

Encasing the coil 6 within the conduit 2 also helps to protect the coil 6 from damage. The windings of the coil 6 are able to maintain their configuration, even when the conduit 2 is flexed, and movement of the coil 6 relative to the conduit 2 is prevented. In addition, it has been found that the coil 6 provides structural reinforcement for the conduit 2, which helps to prevent crimping or flattening of the conduit 2.

Any suitable signal may be provided to the coil 6 to prevent contamination of the conduit 2. However, it is particularly effective to provide an AC signal that varies between positive and negative values on a continual and constantly repetitive scale. The frequency of the signal provided by the signal generator is preferably higher than audio frequencies (above 20kHz), and more preferably in the range 20kHz to 300GHz. The signal generator 10 may include a free running oscillator emitting a near sawtooth (RAMP) signal. The RAMP signal is fed into a voltage controlled oscillator, which provides a square wave output signal, the frequency of the output signal being dependent on the input signal from the RAMP generator. The output signal is provided to an output transistor via a resistor, and is then provided via a capacitor to the coil 6. This configuration ensures a uniform signal configuration.

It will be appreciated that in further embodiments of the invention various modifications may be made to the specific arrangements described above and shown in the drawings. For example, whilst the conduit is described in terms of a beer line or water pipe, it will be. appreciated it may be a conduit for conveying any fluid or fluidised material (including pumped solid particulate materials).

Claims

1. An apparatus for treating fluid conduits to prevent contamination thereof, the apparatus comprising:

a conduit (2) defining a fluid channel (4);

a coil (6) extending along at least part of the length of the conduit (2) and around the fluid channel (4), said coil having a length or aggregate length L; and

a signal generator (10) connected to the coil (6), the signal generator being configured to supply a varying electrical signal to the coil (6) whereby the coil (6) generates a varying magnetic field within the fluid channel (4);

characterised in that the length or aggregate length L of the coil (6) is at least 1.8 metres.

.

2. The apparatus of claim 1, wherein the length or aggregate length L of the coil (6) is in the range 1.8 to 5.0 metres.

3. The apparatus of claim 1 or claim 2, wherein the conduit (2) comprises at least part of a delivery line for a beverage.

4. The apparatus of claim 3, wherein the conduit (2) comprises at least part of a delivery line for beer.

5. The apparatus of claim 4, wherein the coil extends around a section of a beer delivery line located adjacent a beer supply container.

6. The apparatus of claim 5, wherein the. coil extends around a section of a beer delivery line located between a beer supply container and a delivery pump, fob detector or cooler.

7. The apparatus of any one of claims 3 to 6, wherein the delivery line has a total length D and the length or aggregate length L of the coil (6) is in the range 3% to 5% of the delivery line length D.

8. The apparatus of any preceding claim, wherein the fluid channel (4) has an internal diameter in the range 5mm to 15mm.

9. The apparatus of any preceding claim, wherein the coil (6) is a helical coil.

10. The apparatus of any preceding claim, wherein the signal generator (10) is configured provide a pulsed or varying energy signal to the coil (6), the signal having a varying frequency.

1 1. The apparatus of claim 10, wherein the pulsed or varying energy signal comprises a square waveform having a varying frequency.

12. A method of treating a conduit to prevent contamination thereof, comprising: providing a conduit (2) having a channel (4) for conveying a fluid; providing a coil (6) that extends along at least part of the length of the conduit (2) and around the fluid channel (4), said coil having a length or aggregate length L; and connecting a signal generator (10) to the coil (6) and supplying a varying electrical signal to the coil (6) whereby the coil (6) generates a varying magnetic field within the fluid channel (4); characterised in that the length or aggregate length L of the coil (6) is at least 1.8 metres.

13. The method of claim 12, wherein the conduit (2) comprises at least part of a delivery line for a beverage.

14. The method of claim 13, wherein the conduit (2) comprises at least part of a delivery line for beer.

15. The method of claim 14, wherein the coil extends around a section of a beer delivery line located adjacent a beer supply container.

16. The method of claim 15, wherein the coil extends around a section of a beer delivery line located between a beer supply container and a delivery pump, fob detector or cooler.

17. The method of any one of claims 13 to 16, wherein the delivery line has a total length D and the length or aggregate length L of the coil (6) is in the range 3% to 5% of the delivery line length D.

18. The method of any one of claims 13 to 17, wherein the fluid channel (4) has an internal diameter in the range 5mm to 15mm.

19. The method of any one of claims 13 to 18, wherein the coil (6) is a helical coil.

20. The method of any one of claims 13 to 19, wherein the signal generator (10) provides a pulsed or varying energy signal to the coil (6), the signal having a varying frequency.

21. The method of claim 20, wherein the pulsed or varying energy signal comprises a square waveform having a varying frequency.