GB2550107A

GB2550107A - Method and apparatus for treating conduits

Info

Publication number: GB2550107A
Application number: GB1605179.9A
Authority: GB
Inventors: Lee Ian
Original assignee: CAMBRIDGE SCIENT SOLUTIONS Ltd
Current assignee: CAMBRIDGE SCIENT SOLUTIONS Ltd
Priority date: 2016-03-29
Filing date: 2016-03-29
Publication date: 2017-11-15
Anticipated expiration: 2036-03-29
Also published as: GB201605179D0; GB2550107B

Abstract

An apparatus for treating fluid conduits to prevent contamination includes a coil 13 for location around a fluid channel 12, a signal generator 15 connected to the coil 13 and configured to supply a sine wave to the coil 13, set at a frequency between RF and audible bands, wherein the coil 13 is configured to resonate at the frequency of the sinewave such that the magnetic field is increased. The signal generator preferably includes a microprocessor running at an update frequency, preferably in the range 300 800kHz, to create the basis of a sine wave, a driver, an inductor and a large value capacitor. The output sine wave from the signal generator may be at a frequency between 20 and 32kHz, most preferably 26.5kHz and the coil is likewise configured to resonate at a compatible frequency. The apparatus of any preceding claim wherein the coil is in parallel with one or more capacitors. A method of treating a beer line using the apparatus is also disclosed.

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 the deposit 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 fluid. In the case of beer lines, yeast and other contaminants can build up over time within the pipes, which potentially can result in contamination of the beer as microorganism growth is encouraged and/or material which has built up within the line could come loose at any moment and be delivered to a customer for drinking. 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 cost in terms of the equipment and chemicals required, downtime and loss of beer within the lines being cleaned, which must be discarded. UK patent number GB2367106 describes a system for cleaning beer lines, comprising an electro-magnetic coil wrapped around the beer lines, and a signal generator for generating an electric current causing the coil to produce a magnetic field. This system helps to prevent contaminants from being deposited and, therefore, reduces the frequency with which the line needs to be cleaned.

An improvement over the general concepts outlined by GB2367106 is described by WO2013034869. This latter document asserts that there is a strong correlation between the length and location of the coil and its successful operation for cleaning beer lines. However, the coil required by the improved design is incorporated into a plastic tube of at least 1.8 metres in length, which must be incorporated into the beer line, i.e. requiring invasive implementation.

The present invention seeks to improve upon the prior art by increasing the magnetic field in the liquid medium whilst removing any harmonics from the wave form and improving RF interference. The solution should be potentially less invasive such that installation requires less on-site work.

In a broad aspect of the invention, there is provided an apparatus for treating fluid conduits, as claimed in the accompanying claims. According to another aspect of the invention there is provided a method of treating fluid conduits as described in the accompanying claims, to prevent or inhibit contamination thereof.

In a preferred embodiment of the invention there is provided an apparatus for treating fluid conduits to prevent contamination thereof, the apparatus comprising a coil suitable for extending along at least part of the length of a conduit that defines a fluid channel where the coil can be wrapped around the fluid channel. The coil has a length or aggregate length L. A signal generator is connected to the coil and configured to supply a sinewave to the coil, set at a frequency lower than RF, but above the audible band. The coil is designed to resonate at the frequency of the sinewave which increases the Amp-Turns ratio in the coil and, therefore, the magnetic field.

It is envisaged that the proposed invention will significantly increase the magnetic field within the liquid medium, possibly up to 50 to 100 times, compared to like-for-like length of coil according to WO2013034869. The improved system prevents harmonics which are otherwise present in the prior art, hence, a shorter overall length of coil is needed which can be more easily retro-fitted onto existing beer lines.

In a preferred form of the present invention the coil is designed to resonate, with suitable parallel capacitors fitted in the coil housing, at a frequency of 26.5kHz. However, the invention may be effective with a frequency range of 20kHz to 32kHz. The desirable attributes of the invention are achieved by careful design of the coil and adding in ceramic capacitors of the correct value. A perfect parallel resonant circuit appears as an infinite impedance to the driver circuitry which, if perfect, does not supply any current. However, as the resonant circuit is not perfect there are losses, and these losses must be supplied by a Mosfet driver.

Preferably, the coil surrounds a conduit that comprises at least part of a delivery line for a beverage, particularly beer. The coil may be wound around a conduit in situ or wound around/embedded with a conduit during manufacture. According to the invention, the signal generator generates an electric current that passes through the coil to create a magnetic field within the conduit and helps to prevent contaminants within the beer being deposited on an inner surface of the conduit. Preferably, the coil is a fixed length between 100mm and 150mm, most preferably 120mm, tightly wound to fit over a beer line. As mentioned, the coil could be incorporated into a section of the beer line or retro-fitted over an existing beer line to reduce the invasiveness of installation, i.e. no replacement of the tube is required. The coil can be further encased in another sleeve or protective outer layer to prevent damage from external forces.

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

Figure 1 is a schematic illustration of a prior art signal generation system;

Figure 2 is a schematic view of a preferred embodiment of the apparatus according to the invention; and

Figure 3 illustrates a signal generator apparatus for treating conduits according to the present invention.

By way of background to the invention, the creation of a magnetic field in a beer line, according to WO2013034869 can be summarised by Figure 1. Specifically, this circuit design for the signal generator is intended to generate a squarewave using two Mosfets to create a push-pull wave form. This is passed into the coil via a capacitor, which turns the squarewave into a sawtooth-like signal.

In an analogous way to the prior art, the present invention involves installing a coil around a beer line as shown in Figure 2. In general, a fluid conveying conduit comprising a tube 11 providing a flow channel 12 is ultimately part of the fluid delivery apparatus, e.g. beer line. The conduit is typically an elongate, cylindrical tube, although the tube may alternatively be of any suitable shape. Typically, the conduit may have a relatively small diameter in the range of 5mm to 15mm internally. It is preferable that the coil be installed at a location close to the storage/source of the fluid, e.g. beer, because it is observed that contaminant build-up in the line is reduced downstream of the coil, not just at the location of the coil.

To prevent deposition of contaminants on the inner surface of the conduit, an electromagnetic coil 13 is provided. The coil is wrapped around the conduit or embedded within a wall thereof so that it surrounds the fluid carrying channel 12. The coil 13 has a length L and extends axially along the length of the conduit. However, according to the present invention the coil need be of relatively limited length, e.g. 10cm to 15cm, preferably 12cm, so that it can be easily installed on the outside of an existing beer line. The coil 13 could be optionally divided into a number of discreet sections.

The preferred coil is helical, although other suitable electro-magnetic coil-equivalent configurations may be possible. Furthermore, the coil 13 may be formed from any suitable electrically conductive material including, e.g. copper or steel wire. Electrical connections 14 are provided at each end of the coil for connection to a signal generator 15, the operation/components of which are generally illustrated by Figure 3. The signal generator 15 is connected to an electrical power supply 16.

Referring to Figure 3, an electrical signal is generated by the signal generator 15 and delivered to the coil 13 as an input signal. This causes the coil 13 to produce a magnetic field within the fluid carrying channel of the conduit/beer line which in turn reduces contaminant build-up on the inner walls thereof, even downstream of the coil location. The input signal may be pulsed as appropriate or otherwise optimised for implementation of the present invention.

Particularly, a dedicated microprocessor, running at an update frequency of 550kHz, creates the basis of a sinewave at 26.5kHz. At this stage (generally denoted 17) the wave form is purely a series of spaced pulses such that, if fdtered, they would create a sinewave.

The wave form is then passed through a Mosfet driver, and a push-pull pair of Mosfets 18, and fed into an inductor 19. Preferably, a commercial unit constructed according to the invention may have twelve outputs, where two coils 13 share one (of a total six) inductor 19 each. In practice a typical delivery system to which the present invention would be applied has multiple beer lines which each require processing according to the invention. However, there are unlikely to be more than twelve lines in a given establishment. If there are then additional units are required to meet demand.

The inductor 19 effectively filters out the 550kHz update frequency and reconstructs a PWM (Pulse Width Modulation) sinewave, i.e. a recognisable sinewave, albeit one that is purely a DC wave form. This is then passed through a large value capacitor 20 to convert it into an AC wave form and fed to the coil 13.

As mentioned above, the coil 13 is designed to resonate with suitable parallel capacitors 21 fitted in the coil housing, preferably at a frequency of 26.5kHz. This is achieved by careful design of the coil and ceramic capacitors of specific value. A perfect parallel resonant circuit would appear as an infinite impedance to the driver circuitry which, if perfect, does not supply any current. However, as the resonant circuit is not perfect there will be losses which must be supplied by the driver.

Claims

1. An apparatus for treating fluid conduits to prevent contamination thereof, the apparatus comprising: a coil for location around a fluid channel that is defined by a length of conduit; a signal generator connected to the coil and configured to supply a sinewave to the coil, set at a frequency between RF and audible bands; wherein the coil is configured to resonate at the frequency of the sinewave such that the magnetic field is increased.

2. The apparatus of claim 1 wherein the signal generator is comprised of a microprocessor, running at an update frequency to create the basis of a sinewave, a driver, an inductor and a large value capacitor.

3. The apparatus of claim 2 wherein the update frequency is in the range 300 -800kHz, preferably 550kHz.

4. The apparatus of claim 1, 2 or 3 wherein the output sinewave from the signal generator is at a frequency between 20 and 32kHz, preferably 26.5kHz and the coil is likewise configured to resonate at a compatible frequency.

5. The apparatus of any preceding claim wherein the coil is in parallel with one or more capacitors.

6. A method for effecting treatment of a fluid channel which is used for conveying beer and like liquids comprising: applying a coil around such fluid channel; generating a signal to apply to the coil, wherein the signal is a sinewave at a frequency between RF and audible bands; wherein the coil is configured to resonate at the frequency of the sinewave such that the magnetic field is increased.