WO2009146504A1

WO2009146504A1 - Heat treatment and disinfection system for fluids

Info

Publication number: WO2009146504A1
Application number: PCT/AU2009/000712
Authority: WO
Inventors: Murray Kenneth Thomas Stewart
Original assignee: Packaged Environmental Solutions (Int.) Pty Ltd
Priority date: 2008-06-06
Filing date: 2009-06-05
Publication date: 2009-12-10

Abstract

A disinfection apparatus (110) for the heat treatment of fluids. The disinfection apparatus (110) features an elongate conduit (112) with a first cell (114) and a second cell (116). The first cell (114) is joined to the second cell (116) by a joint (118) to form the first loop of a serpentine or sinuate elongate conduit (112) which may have similar repeating cells and joints. A heater (124) is attached to a wall of the first cell (114). The heater (124) may be used to heat the fluid within the elongate conduit (112) to a sufficient temperature to disinfect the fluid/s whilst the fluid/s are within the elongate conduit (112). In order to reduce the amount of heating of the fluid/s within elongate conduit (112) a pre-heater (126) in the form of a heat exchanger may be used at the inlet conduit (120) and outlet conduit (122).

Description

HEAT TREATMENT AND DISINFECTION SYSTEM FOR FLUIDS

BACKGROUND OF THE INVENTION

1. Field of the Invention

[0001] The present invention relates to a method and apparatus for heating and disinfecting fluids, and in particular to disinfection using heat treatment. Fluids that the invention may be applied to include sludges and slurries

2. Description of the Art

[0002] It is known that heat disinfection of fluids to destroy or inactivate organisms, bacteria, viruses and pathogens in the fluid/s, may be achieved by heating fluids to a sufficient temperature for a sufficient amount of time. Typically when it is desired to disinfect large or small volumes of fluid this is achieved either by heating the fluid in a holding tank or a metallic tank in a batch process or using other configurations to achieve a continuous flow or "on-demand" process.

[0003] However, current systems for disinfecting fluid tend to be expensive, energy inefficient and may have a short lifecycle due to corrosion of the fluid holding and/or heating components; which may make the supply of large volumes of disinfected fluid an expensive and unreliable process.

[0004] Whilst alternatives have been suggested, these techniques are also typically inefficient. For example, in ensuring sufficient sanitation of sewer water, it is typical to use reverse osmosis which uses membranes that are very costly to operate and run whilst not fully recycling all of the waste water. The lack of recycling results in significant fluid losses in the treatment process.

[0005] Furthermore, when providing facilities in remote areas energy efficiency and fluid conservation in the operation of such systems becomes important, primarily in minimizing both operating and environmental costs.

[0006] Another issue is encountered with ships' ballast water. Ballast water is used to maintain buoyancy and stability for a ship carrying varying amounts of cargo. Ships are required to adjust and cycle their ballast water in the open sea by emptying each of the ballast tanks in turn and replenishing the empty tanks with seawater. This is a complex and time consuming process and incurs significant risks to the safety of the ship. In particular, when a ballast tank is empty this places undue strain on the hull and can lead to hull breaches. In addition, whilst the water is being replenished the ship generally suffers from poor stability in the open sea and may capsize in heavy seas.

[0007] Consequently, ship's often remove or add, all or portions of the ballast water as required when loading and unloading cargo in different harbors. Thus a mechanism is provided for marine organisms, pathogens and other contaminants to travel from one distant port to another via ballast water in freight ships.

[0008] None of these prior art devices provides an entirely satisfactory solution to the provision of disinfected fluids, nor to the ease of construction, fluid conservation and energy savings in the provision of disinfected fluids.

SUMMARY OF THE INVENTION

[0009] The present invention aims to provide an alternative disinfection arrangement which overcomes or ameliorates the disadvantages of the prior art, or at least provides a useful choice.

[0010] In one form, the invention provides a disinfection apparatus for a fluid including a pre-heater for the fluid and an elongate conduit adapted for heating and flow of the fluid within the elongate conduit. Where the elongate conduit is adapted for inducing the mixing of the fluid across the conduit profile so that the fluid is heated to a sufficient temperature to disinfect the fluid.

[0011] Preferably the elongate conduit is in one or more serpentine, looped or sinuate configurations. The elongate conduit may be made up of two or more cells joined together.

[0012] Optionally the cells of the elongate conduit may have transverse cross sections of one or more of square, rectangular, polygonal, angular or circular shape so that the cells are adapted to mixing of the fluid.

[0013] Preferably, the elongate conduit has one or more heaters in thermal communication with the fluid and optionally the heater may be an electrical resistance strip heater. Optionally one or more sleeves or pockets from a wall or surface of the elongate conduit may project or protrude into the elongate conduit, where the sleeve or pocket is adapted to receive the heater.

[0014] Optionally the elongate conduit may have one or more formations adapted to mixing of the fluid.

[0015] Preferably the disinfected fluid from the elongate conduit is used by the pre-heater to heat the fluid to a first temperature. Preferably the sufficient temperature range may be 60° to 100⁰C or more preferably 60° to 8O⁰C.

In a further form the invention provides a method for the continuous disinfection of a fluid, including the steps of: providing a pre-heater for the fluid, supplying the fluid to the pre-heater, heating of the fluid in the pre-heater to a first temperature, providing an elongate conduit, supplying the fluid from the pre-heater to the elongate conduit , heating of the fluid to a second temperature either before or within the elongate conduit and then mixing of the fluid in the elongate conduit to a second temperature Where the second temperature is equal to or above a sufficient temperature for the disinfection of the fluid in order to continuously produce a disinfected fluid and the disinfected fluid from the elongate conduit is used by the pre- heater to heat the fluid to a first temperature. Optionally the heating of the fluid to a second temperature may be provided by: a solar collector means, electrical resistance heating, waste heat exchanger, heating fluid tubes, microwave heating or RF induction heating

[0016] In yet a further form, the invention provides a heat treatment apparatus for a fluid including: a pre-heater for the fluid, an elongate conduit adapted for heating and flow of the fluid within the elongate conduit. Where at least one or more portions of the elongate conduit is adapted for heating the fluid and the elongate conduit is adapted for inducing the mixing of the fluid across the conduit profile so that the fluid is heated to a sufficient temperature to heat treat the fluid.

[0017] In yet another alternate form the invention provides a heat disinfection apparatus for a fluid that may include a pre-heater for the fluid and an elongate conduit which is adapted for flow of the fluid within it. Where, the fluid is heated to a sufficient temperature by any one of various heating means and the elongate conduit may be further adapted for inducing the mixing of the fluid across the conduit profile; so that the fluid is heated to a sufficient temperature to disinfect the fluid. The heating means may include a solar collector means, electrical resistance heating, waste heat exchanger, heating fluid tubes, microwave heating or RF induction heating.

[0018] The invention may further provide a a cylinder-in-cylinder arrangement adapted for flow of the fluid within the cylinder-in-cylinder arrangement. Where the fluid is heated to a sufficient temperature by a heating means and the cylinder-in- cylinder arrangement is adapted for inducing the mixing of the fluid; so that the fluid is heated to a sufficient temperature to disinfect the fluid.

[0019] Further forms of the invention are as set out in the appended claims and as apparent from the description.

DISCLOSURE OF THE INVENTION

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The description is made with reference to the accompanying drawings; of which:

[0021] FIG 1 is a schematic, front elevation view, in part section of a disinfection apparatus in an embodiment of the present invention.

[0022] FIG 2 is a schematic transverse cross-sectional view of an elongate conduit along the line 2-2 in FIG 1.

[0023] FIG 3 is a schematic of a four celled elongate conduit, which with respect to FIG 1 is a partial plan sectional view just below the inlet and outlet conduits in alternate, 100 litre/hour, embodiment of the invention.

[0024] FIG 4 is a front elevation view of the disinfection apparatus along the line 3-3 in FIG 3.

[0025] FIG 5 is an alternate, 1000 litre/hour, embodiment of FIG 3.

[0026] FIG 6 is a schematic of cross-sectional views in plan and side elevation of a ship with an alternate embodiment of the invention.

[0027] FIG 7 is a schematic process diagram of a 4,000 litre/hour waste heat disinfection system. [0028] FIG 8 is a schematic process diagram of an embodiment of a solar heat disinfection system.

[0029] FIG 9 is an alternate embodiment of FIG 8.

[0030] FIG 10 is another alternate embodiment of FIG 8.

[0031] FIG 11 is a schematic representation of a longitudinal axial cross- sectional view along the line of 11-11 of FIG 12 of a cylinder-in-cylinder arrangement for heat disinfection.

[0032] FIG 12 is a partial cut-away perspective view of the cylinder-in- cylinder arrangement of FIG 11.

[0033] FIG 13 is an alternate embodiment of the cylinder-in-cylinder arrangement of FIGS 11 and 12.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0034] FIG 1 schematically shows a disinfection apparatus 110 for the heat treatment of fluids. The view of FIG 1 is a front elevation view, in part section of the disinfection apparatus 110. The word "fluid" or "fluids" in the following detailed description and claims is taken to include one or more of: single phase liquids either singularly or in combinations with other liquids (e.g. water, milk, etc), mixed phases (emulsions, slurries of solids, liquids and jells, aerated liquids and fluidised particulates) as well as complex fluidised applications such as sludges were all the previously mentioned may be present in a heterogenous mixture.

[0035] In FIG 1 a section of an elongate conduit 112 is illustrated for a first cell 114 and a second cell 116 of the elongate conduit 112. Where the first cell 114 is joined to the second cell 116 by joint 118 to form the first loop of a serpentine or sinuate elongate conduit 112 with similar repeating cells and joints, described in detail below with respect to FIGS 3 to 5. The elongate conduit 112 may be a continuous conduit or bolted or welded together to form sections; for example the first cell 114 bolted to the joint 118 and then bolted to the second cell 116. The elongate conduit 112 is preferably of a simple square or rectangular cross section but may be of any other cross-sectional shape and length as is suitable for the construction, fluid flow properties and operation of the disinfection apparatus 110 as described above and below. The conduit may be formed wholly or in part of materials with a high corrosion resistance and durability to heat, for example those materials suitable for the food, medical and marine industries and applications, hi addition the elongate conduit 112 for some applications may be required to operate as a pressure vessel. For example when heating liquid water to well above 100⁰C without the vaporisation of the water. The materials used and the construction techniques employed may be as per a person skilled in the art of pressure vessels.

[0036] Examples of materials which may used to form the elongate conduit 112 maybe 316 alloy stainless steel, marine grade aluminium, plastic, carbon fibre composites, ceramic composites and as may be selected or designed by a person skilled in the art. Aluminium is of particular interest for applications where the unfilled or dry weight of the disinfection apparatus is important as well as the durability.

[0037] The mechanical configuration of the elongate conduit 112 is suited to it being in a compact modular form, which may be extended or reduced in length with ease.

[0038] The elongate conduit 112 has an inlet conduit 120 for providing fluid/s to the elongate conduit 112 in the direction indicated by the arrow along side the inlet conduit 120. The fluid/s pass through the elongate conduit 112 via the first cell 114, the joint 118, the second cell 116 and then exit the elongate conduit 112 thru an outlet conduit 122 in the direction of the arrow alongside the outlet conduit 122.

Heating

[0039] A heater 124 is attached to a wall of the first cell 114. The heater 124 may be used to heat the fluid within the elongate conduit 112 to a sufficient temperature to disinfect the fluid/s whilst the fluid/s are within the elongate conduit 112. Accordingly the elongate conduit 112 may also be termed a disinfection conduit 112 for fluid/s. In FIG 1 the heater 124 illustrated is an electrical resistance strip heater of sufficient power to heat the fluid within the first cell 114 to a sufficient temperature for disinfecting the fluid/s. The heater 124 may be attached to the wall of the elongate conduit 112 and heat the fluid through the wall of the elongate conduit 112. Or the heater 124 may form a portion of the wall of the elongate conduit 112. [0040] In alternate embodiment (not shown) the heater 124 may also be in thermal contact with the second cell 116 so that heating of the fluid in the second cell 116 may occur with the same heater 124. hi yet another embodiment, the second cell 116 may have a separate, additional heater (not shown) attached to it so that independent heating of the fluid in the second cell 116 may be done, hi yet another form the heater 124 may be placed within a sleeve or pocket (not shown) that protrudes into the elongate conduit 112 from either an end or a side wall of the elongate conduit 112.

[0041] Other embodiments of heating the fluid within the elongate conduit 112 may include by way of example: electrical resistance heaters inserted into the elongate conduit 112 (e.g. direct immersion heaters), microwave heating of the fluid or RF induction of electrically conducting fluids within the elongate conduit 112. The heating technique may be designed or selected by a person skilled in the art as appropriate for the fluids that are required to be heated within the elongate conduit 112.

[0042] In yet another embodiment of a heating configuration, parallel or wound heating tubes (not shown) to the elongate conduit 112 may be inserted within the elongate conduit 112 ("tube within tube") or in external thermal contact with the walls of the elongate conduit 112. The heating fluid tubes may contain a circulating heated fluid material which provides the source of heating for the fluid/s within the elongate conduit 112. The heated fluid material may be liquid or gas. For example the heating tubes may be supplied with heated fluid material from a solar hot water heater system (described in detail with respect to FIGS 8 to 10), exhaust gases from an internal combustion engine, or flue gas, . The flow of the heated fluid material in the heating tubes may be co-current or counter current to the flow direction of the fluid/s within the elongate conduit 112.

[0043] Alternatively waste / excess heat from the cooling circuits of various motors, boilers and air-conditioning units may be used to provide the heated fluid material for the heating tubes. The use of such excess heat sources or solar heating may be in replacement or in conjunction with the other heating techniques and configurations described above and below. Pre-heater

[0044] In order to reduce the amount of heating of the fluid/s within elongate conduit 112 a pre-heater 126 in the form of a heat exchanger may be used at the inlet conduit 120 and outlet conduit 122. Relatively cool fluid/s for disinfection enter the pre-heater 126 by a supply pipe 128 as indicated by the arrow alongside it and then exit the pre-heater 126 as a hotter fluid/s via the inlet conduit 120 and thence into the elongate conduit 112. Relatively hot disinfected fluid/s from the elongate conduit 112 enter the pre-heater 126 by the outlet conduit 122 and exit the pre-heater as cooler disinfected fluid through the disinfected fluid pipe 130. The heat exchanger function of the pre-heater 126 enables the hot disinfected fluid from the elongate conduit 112 to be used to pre-heat the fluid/s that are to be disinfected without cross contamination.

[0045] The use of the pre-heater 126 as a heat exchanger in the manner described above allows for improved energy efficiency and speed in the heating and cooling of the fluid/s for disinfection.

[0046] The pre-heater 126 may be a parallel plate heat exchanger such as compact brazed heat exchangers (CBE) of high efficiency manufactured by "Swep International" www.swep.net or any number of heat exchangers that a person skilled in the art may design or select from. An example Swep heat exchanger combination may be two "B8" heat exchangers in series.

[0047] In an alternate embodiment the pre-heater 126 may include or be replaced by a booster heater (not shown) in order to improve the flexibility in operation for the supply of appropriate temperature fluid/s to the elongate conduit 112 and/or the temperature of the disinfected fluid from the disinfected fluid pipe 130.

Insulation

[0048] Optionally, in order to further improve the energy efficiency of the disinfection apparatus 110, the pre-heater 126, the elongate conduit 112 and the associated connections described above and below may be encapsulated in insulation. The insulation 132 may be in the form of insulating material 132 applied to various components as lagging or as a housing 132 for the disinfection apparatus 110. For example 25 mm insulating foam board may be used within the inside of the exterior housing of the disinfection apparatus 110. Fluid Flow

[0049] For a fluid/s to be sufficiently disinfected the whole volume of the fluid/s need to heated to a sufficient temperature for a sufficient time. For example to heat disinfect water to a level suitable for washing and drinking, "potable water", a temperature of 80⁰C for 1 minute may be sufficient depending on the number and type of pathogens present in the water for treatment. However sufficient heat treatment for disinfection, or deactivation of the pathogens, is dependent on all parts of the volume of fluid/s being at the sufficient temperature for the sufficient time. Typically to overcome difficulties in reliably being assured that all parts of the fluid/s have been sufficiently heat treated, the fluid/s are heated for extended periods thus extending processing time and power requirements for the disinfection by heat treatment. The configurations and methods of use for the elongate conduit 112 enable sufficient heat treatment throughout the fluid/s' volume with a consequent reduction in time and energy for disinfection compared with prior systems.

[0050] The preferred use of square or rectangular transverse cross section conduit for the elongate conduit 112 in one or more loops, as described above, promotes mixing of the fluid/s across the cross-section of the elongate conduit 112 and mixing in relation to the position of the heating source, heater 124 or its alternate embodiments. The angular or polygonal cross-sectional shape of the elongate conduit 112 combined with an abrupt change, or discontinuity, in fluid flow direction from one cell 114 to the next cell 116 via the joint 118 does not promote the continuing or formation of laminar flow of the fluid within the elongate conduit 112.

[0051] Laminar flow or "channelling" or plug flow of a fluid in a conduit or a pipe is where the fluid flow vectors are all in the same direction. Typically a well defined and stable fluid boundary layer is also present along the conduit wall for laminar flow. Consequently fluid mixing across the transverse cross-section of the conduit through the fluid volume as a whole is minimal or absent. Accordingly heat transfer from a heater 124 located at the wall of the elongate conduit 112 is dominated by conduction, which is a relatively poor mechanism for bulk heat transfer compared with mixing, hi addition in laminar flow conditions only a thin layer of fluid adjacent the heater 124 may be immediately heated. [0052] A common solution to laminar flow is to adjust the fluid flow velocity and pipe diameter or dimensions so as to promote turbulent fluid flow through a pipe or conduit according to the Reynolds' number criteria. Turbulent flow may be characterised by the presence of shedding vortices, plugs of fluid flowing backwards relative to the bulk flow direction and/or separation of the boundary layer from the pipe or conduit wall. Accordingly well developed turbulent flow may efficiently mix heated portions of fluid that were adjacent to a heater 124 into the bulk volume of the fluid in an elongate conduit 112. However the onset of turbulent flow may be difficult to reliably and completely induce in regular, continuous pipe or conduit configurations that are common in fluid processing plants. The use of the angular cross-section elongate conduit 112 combined with an abrupt change, or discontinuity, in fluid flow from one cell 114 to the next 116 may reliably induce and maintain turbulent flow through the elongate conduit 112. In other terms, flow mixing of the fluid/s through the elongate conduit 112 is promoted and maintained reliably.

[0053] For fluid/s that may be highly heterogenous, reliable flow mixing may be even more difficult to attain unless deliberate configurations and techniques are used to ensure that it occurs. This is particularly in situations where the heterogeneity may be variable during the course of the disinfection process. The use of an angular cross-section of the elongate conduit 112 with a serpentine configuration may improve and promote reliable flow mixing for heat transfer within the bulk fluid/s volume. Accordingly the cross-sectional dimensions of the elongate conduit 112, the respective and comparative lengths of the one or more cells 114, 116 and the one or more joints 118 may be designed to improve and promote reliable flow mixing for a particular fluid/s to be disinfected.

[0054] To further improve the fluid/s flow mixing within the elongate conduit 112, one or more optional formations 134 may be inserted and manipulated within the elongate conduit 112. In the example illustrated in FIG 1 the formations 134 are in the form of vanes 134. The form and placement of these vanes 134 may be such so as to divert portions of the fluid/s flow away from the wall of elongate conduit 112 and into the center of the elongate conduit 112. Other vanes may also divert the fluid/s in a vice-versa fashion. [0055] FIG 2 is a transverse cross-sectional view of the elongate conduit 112 along the line 2-2 in FIG 1. FIG 2 illustrates an example of how the vanes 134 may divert fluid/s flow across the transverse cross-section of the elongate conduit 112. In FIG 2 the elongate conduit 112 cross-section is divided into four outer quarters 210 and four inner quarters 212 by a series of dashed lines 214. Arrows 216, 218 illustrate the movement of fluid/s by the diverting action of the vanes 134 within the elongate conduit 112. Fluid/s streams may be diverted from an outer quarter 210 to an opposing inner quarter 212 as shown by the arrow 216. Similarly fluid/s streams may be diverted from an inner quarter 212 to an opposing outer quarter 210 as shown by the arrow 218. It will be appreciated by a person skilled in the art that the particular configuration of the various fluid/s streams being diverting by the formations 134 or vanes 134 may vary in number of diverted fluid streams and the formations used to divert them. For example many fluid streams may be diverted in a twisted, multi- braided, helical fashion coupled with aspects of turbulent flow such as shedding vortices. However the purpose of mixing of the fluid/s across the cross-section of the elongate conduit 112 so as to improve the heat transfer from the heating source 124 to the bulk fluid/s within the elongate conduit 112 will be the same. In particular that the heat transfer by mixing of the fluid/s across the transverse cross-section of the elongate conduit 112 is reliable and efficient for a range of fluid/s in an application.

[0056] The vanes 134 may, by way of example, be in the form of shaped plates or open meshes. The dimensions of the shaped plates or open meshes being such that mechanical filtering of components of the fluid/s does not occur, hi another embodiment, the shape and location of the vanes 134 within the elongate conduit may be adjustable rather than fixed. For example adjustable vanes 134 may be held and manually adjusted via the use of magnetic clamps acting through the wall of the elongate conduit 112. Additionally the magnetic clamps or other fixing mechanism may be electro-mechanically controlled. The use of such manual or electromechanical control may enable deliberate and tuneable adjustment of the fluid/s flow through the elongate conduit 112 so as to optimise heat transfer for particular fluid/s so that sufficient heat treatment occurs throughout the volume of fluid/s.

[0057] In alternate embodiments the formations 134 may be in the form of ducts (not shown), arrangements of wires, propellers or impellors of various shapes and configurations. In yet another embodiment, the formations 134 may be attached to the wall of a cell 114 where a heater 124 is also attached. In this embodiment the formations 134 may also act as heat transfer extensions or radiating fins for a heater 124. In still yet another example the function of the formations may also be in part at least served by the sleeves or pockets inserted into the elongate conduit 112 which may be used to house the heater 124 as described above.

[0058] The formations 134 may also be arranged in a symmetric and/or asymmetric fashion through the elongate conduit 112. The materials to form the formations 134 may be as designed and selected by a person skilled in the art of mechanical fabrication so that the formations 134 are fit for their purpose as described above. For example stainless steel and marine grade aluminium may be used with inclusions of magnetisable stainless steel so as to allow magnetic coupling and/or clamping.

Peripheral Components

[0059] In the above description peripheral components that may be useful but not essential in the use of the disinfection apparatus 110 may not have been described for clarity purposes as appreciated by a person skilled in the art. For example air and/or vapour bleed off valves and lines (not shown) as required for the priming, online process adjustments and maintenance of the disinfection apparatus 110. Features such as air/vapour bleed off valves/lines and thermostatic (3-way and stop valves) may be designed and installed and used as appropriate by a person skilled in construction and operation of fluid processing systems such as the disinfection apparatus 110.

[0060] Typically air/vapour bleed off ports may be installed at the top of a cell 114, 116 of the elongate conduit 112. Bleed or purge ports may also be installed at the bottom of a cell to enable removal of any settled matter or to allow attachment of a purge.

Control and Monitoring

[0061] In FIG 1 the disinfection apparatus 110 may have a power supply and controller unit 136 associated with it. The power supply and controller unit 136 may be configured as a preset or predetermined power supply and controller. The power supply 136 is set for sufficient power to the heater 124 so that a sufficient temperature with a sufficient flow rate of the fluid/s through the elongate conduit 112 is obtained. Sufficient flow rate may be preset or predetermined by use of a valve 138 or fixed orifice in the supply pipe 128 or by use of a suitable thermostat and relay.

[0062] In such an arrangement the theoretical and/or empirical sufficient time, flow rate and heating for performing disinfection of the fluid/s at a sufficient temperature may be determined. The flow rate is then set to include a safety margin so as to ensure that the fluid/s' time in the elongate conduit 112 is longer than the sufficient time for disinfection within the elongate conduit 112.

[0063] An example application is the heat disinfection of water to a level suitable for washing and drinking, "potable water". A sufficient temperature of 8O⁰C for 1 minute may be a sufficient time depending on the quality of the water supply, as described above. For potable water there is a general inverse relationship between the sufficient temperatures (above an approximate minimum threshold of 6O⁰C) and the sufficient time for heat disinfection, for example at higher sufficient temperatures a lower sufficient time is required for heat disinfection to produce potable water. By way of example the higher sufficient temperature may up to 95⁰C or up to 100⁰C for water as the fluid for disinfection.

[0064] The relatively cool water enters the pre-heater 126 at a set flow rate, set by the valve 138, such that the water is pre-heated to a first temperature of at least 5O⁰C, preferably 6O⁰C, or more preferably within a few degrees of the heated disinfected water exiting the elongate conduit 112 at the outlet conduit 122. The preheated water at a first temperature then enters the elongate conduit 112 to be heated to a second temperature of 80⁰C, or more preferably 85⁰C by the fluid's flow mixing and heating along the elongate conduit 112 as described above and below. The set flow rate being preset or predetermined such that by the time the fluid/s exit the elongate conduit 112, all portions of the fluid/s have been at the sufficient temperature and sufficient time (eg 8O⁰C for 1 minute) for heat disinfection of the fluid/s. How far the second temperature (eg 80° to 85⁰C) is set above the sufficient temperature (eg 8O⁰C) may be dependent on how much and how of the fluid/s flow mixing is employed through the elongate conduit 112, either via the configuration of the elongate conduit 112 and/or by the use of formations 134 within it. Extensive fluid's flow mixing along the elongate conduit 112 may enable the second temperature to be set at the sufficient temperature or only 1 ° or 2⁰C above it.

Programmable and Closed Loop Control

[0065] hi a further embodiment sensors and controllers may be added to the disinfection apparatus 110 and interfaced with a power supply, controller and monitoring unit 136. The use of such an arrangement may enable the disinfection apparatus 110 to have the capability to apply a sufficient temperature for sufficient time to fluid/s in order to obtain heat disinfection in a dynamic and/or preprogrammed manner for a variety of fluid/s applications and/or during the course of on-line processing of a particularly complex heterogenous fluid/s application. Such a capability is also of importance for recorded quality assurance of the disinfected fluid.

[0066] The sensors that may be used, by way of example, may include:

• Temperature: These may be deployed to measure the temperature of the fluid at various points along the length of and transverse cross-section of the elongate conduit 112 so as to determine the whether a sufficient temperature is being reached via heating and fluid flow mixing. Examples of such fluid temperature sensors 140 are shown in FIG 1. Heater temperature sensors 142 may be associated with the heater 124 to aid in the operation of the heater 124 with respect to the power supply and the fluid/s' temperature 140 in the elongate conduit 112.

• Flow Rate: The valve 138 may incorporate a flow meter (not shown) to determine the bulk fluid/s flow rate through the supply pipe 128. Anemometers and/or flow meters may also be deployed (not shown) within the elongate conduit 112 to aid in positioning of the formations 134 and identifying any gas or vapour blocks.

• Fluid/s Level: Fluid level sensors (not shown) within the elongate conduit may be deployed to aid in filling and maintaining the fluid flow through elongate conduit 112 and to monitor for gas or vapour blocks. [0067] The controllers that may be used, by way of example, may include:

• Heater power supply and controller: A single heater 124 may be in use or multiple heaters 124 may be used along and about the elongate conduit 112. Multiple heaters 124 may be used in concert or independently as desired.

• Proportional Flow Control Valves and Pumps: For control of the flow rate of the fluid/s through the elongate conduit 112.

• Formations 134 Control: The position and level of diversion of a formation 134 within the elongate conduit 112 may be controlled.

• Length of the Elongate Conduit 112: The number of cells 114, 116 or loops active for an elongate conduit 112 may be controlled depending on the desired flow rate of disinfected fluid/s. High flow rates may require additional loops of an extended serpentine elongate conduit 112 to be active or added / connected with the elongate conduit 112.

[0068] The sensors and controllers used may be interfaced to a suitably programmed processing system, such as a computer, laptop, palm top, PDA, specialised hardware, programmable logic controller, or as designed or selected by a person skilled in the art of programmable automation and control systems.

[0069] In one example of a programmable controller 136, the controller memory (not shown) can be used to store an LUT (Look Up Table) or algorithm that indicates for given temperature values, the proportional valve 138 setting to be used to attain heat disinfection. The programmable controller 136 uses the signals from the fluid temperature sensors 140 to access the LUT and determine from the LUT the appropriate setting for the proportional valve 138. The appropriate setting for the valve 138 may be set via the relevant, interfaced valve controller (not shown). Additional LUTs or algorithms may also be used to give added operational flexibility, for example where the high flow rate of disinfected fluid/s required may be met by increasing the heating of the heater 124 and/or adjusting the position of the formations 134 and/or the number of loops or cells of the elongate conduit 112 that are active. [0070] As well as ensuring that the fluid/s are sufficiently disinfected the programmable controller 136 may also perform a number of other functions or operating modes. For example these may include:

• System Protection for the various components of the disinfection apparatus 110. Included in this operating mode may be fail safe shut down procedures that prevent the disinfection apparatus 110 from providing fluid/s from disinfected fluid pipe 130 if the heat disinfection cannot be assured. Self diagnosis routines and indicators (visual and audible) may also be included in the system protection function.

• Flash Heating Modes: These are operational modes where very high temperatures over a short duration are applied to fluid/s so that some pathogens do not have the opportunity to adopt a quiescent state, for example for formation of a cyst or spore state which may be more heat resistant. Similarly flash heating modes may be applied to fluid food stuffs, such as milk and juices, so that the required heat disinfection occurs but without denaturing the food. Pasteurisation may be one example of a flash heating application.

• Quality Assurance Recording: Various operating parameters for the fluid/s disinfection processing may be recorded for quality assurance purposes. For example temperature and flow rate through the elongate conduit 112.

Scaling Up Examples

[0071] FIGS 3 to 5 schematically illustrate alternate embodiments of the disinfection apparatus 110 in FIG 1. These alternate embodiments in particular are examples of how the disinfection apparatus 110 may be scaled up in performance in terms of the flow rate and the types of fluid/s that may be disinfected.

100 Litre/Hour Disinfection Apparatus

[0072] FIGS 3 and 4 are respective front elevation and partial plan sectional views of a 100 litre/hour fluid/s disinfection apparatus 310 where some of the features such as the valve 138 and the controller unit 136 have been omitted for clarity purposes. FIG 3 shows a four celled elongate conduit 312 which with respect to the two celled elongate conduit 112 of FIG 1 is a partial plan sectional view just below the inlet and outlet conduits 120, 122. The inlet and outlet conduits 120, 122 are shown superimposed on the four celled elongate conduit 312 so as to illustrate the fluid/s flow directions to and from the elongate conduit 312. The four celled elongate conduit 312 has a first cell 114, joint 118 and second cell 116 as per the two celled elongate conduit 112. hi addition the four celled elongate conduit 312 has a third 314 and fourth 316 cells.

[0073] The third cell 314 may be joined to the second cell 116 by a restricted joint 318 where the restricted joint 318 is located at the top of the third 314 and second cell 116 lengths. The restricted joint 318 is an alternate embodiment to previously described joint 118. The restricted joint 318 has one or more reduced cross- sectional dimensions compared with the joint 118. The reduced cross-sectional area of the restricted joint 318 may be used to further increase fluid/s' flow mixing along the elongate conduit 312. In addition the restricted joint 318 may have some mechanical fabrication advantages when assembling the four celled elongate conduit 312. For example the restricted joint may be in the form of triangle (not shown) with the base of the triangle at the base of the cell 116. Such a triangle aperture restricted joint may be easily fabricated during construction of the elongate conduit 112 by cutting a "V" notch in the bottom of the respective walls of two square walled cells that are to be joined together. The cells are then welded together about the "V" notch with a plate welded across the open ends of the cells at the "V" notch end to form two joined cells of an elongate conduit. In yet another embodiment (not shown) the restricted joint 318 may be substituted with a joint 118 in a similar to that illustrated in FIG 1.

[0074] The third cell 314 may be joined to the fourth cell 316 by a joint 118 as illustrated in FIG 1 or in an alternate embodiment by a restricted joint 318.

[0075] The four celled elongate conduit 312 has on the wall of the first cell 114 a heater 124 as per FIG 1. The four celled elongate conduit 312 may also have a second heater 320 attached to another wall of the first cell 114 as shown in the FIG 3. The second heater 320 may be operated with or independently of the first heater 124, depending on the heat disinfection processing requirements for the fluid/s, as described above. For example the second heater 320 may be used in conjunction with the first heater 124 to supply more heating to the fluid/s' over a larger area of the first cell's 114 walls so that the sufficient temperature within the fluid/s occupying the first cell 114 is attained more quickly and/or efficiently. A third heater 322 may be attached to the second cell 116 as shown in FIG 3. The third heater 322, by way of example, may be used in conjunction with the first and second heaters 124, 320 to boost heating or maintain the sufficient temperature of the fluid/s as they pass through the second cell 116. The third heater 322 when not required may inactive or in a standby state of low power output, hi an alternate embodiment additional heaters may be installed with the third 314 and fourth 316 cells, for example to maintain a sufficient temperature of the fluid/s for heat disinfection within those cells.

[0076] In the embodiment shown in FIG 3 the first, second and third heaters 124, 320, 322 may each be a 700 Watt electric strip element attached to a thermally conductive wall of each of the respective first and second cells 114, 116. Alternate embodiments for the heaters 124, 320, 322 are as per described above.

[0077] FIG 4 is a front elevation view of the disinfection apparatus 310 along the line 4-4 in FIG 3. In FIG 4 the pre-heater 126, supply pipe 128 and disinfected fluid pipe 130 have been omitted for clarity purposes. A first temperature sensor 410 may be located on the second heater 320 to monitor the performance of the second heater 320 in providing a sufficient temperature to the first cell 114. Continuing the potable water example described above, the first temperature sensor may be used to monitor a desired set point of 85⁰C so that the fluid/s in the first cell 114 are heated to the desired second temperature of 85⁰C. A second temperature sensor 412 located within joint 118 may be used to monitor the fluid/s temperature at that point. For example for potable water the second temperature sensor 412 may indicate that the fluid/s temperature is 84⁰C, above the sufficient temperature of 8O⁰C for this example application.

[0078] A third temperature sensor 414 may be attached to the third heater 322 to monitor the desired set point for the third heater 322. For the potable water example the third heater 322 may be set to maintain the temperature of the fluid/s above the sufficient temperature of 8O⁰C for the passage through the second cell 116. For example the third temperature sensor 414 may monitor a desired set point for the third heater 322 of 82⁰C. A fourth temperature sensor 416 may be located within the second cell 116 to monitor the temperature of the fluid/s. The output from the fourth temperature sensor 416 may be used to control the proportional valve 138 or a pump supplying the supply pipe 128. For example for potable water, if the fourth temperature sensor 416 indicates that temperature of the fluid/s is less than the sufficient temperature of 8O⁰C the proportional valve 138 maybe shut so as to stop the flow of fluid/s as the condition for heat disinfection of potable water is not being met.

[0079] Additional temperature sensors (not shown) may be installed with the third 314 and fourth 316 cells to perform as described above. The preferred temperature sensors 410, 412, 414, 416 may be thermocouples of a type suitably chosen by a person skilled in the art for each of their respective applications as described above.

[0080] The basic conduit sections making up the four celled elongate conduit 312 are box or square conduit lengths. In FIG 3 the transverse internal dimension 324 of the square conduit making up the cells 114, 116, 314, 316 may be 40mm. The restricted joint 318 may be a cube conduit section of internal dimensions 326 of 10mm for each side.

[0081] In FIG 4 the joint 118 may be a cube conduit section of internal dimensions 418 of 40mm. Each length 420 of the cells 114, 116, 314, 316 maybe 800mm. In alternate embodiments the length 420 of each of the cells 114, 116, 314, 316 may be individually or collectively made longer or shorter than 800mm. The choice of length being made in the context of the overall design of the disinfection apparatus 110, 310, as described above and below, so that the fluid/s for heat disinfection have a sufficient time at the sufficient temperature for heat disinfection. The use of longer lengths may enable longer dwell times for the fluid/s in a cell at a lower sufficient temperature with consequent energy savings for heating.

[0082] In the example given above for FIGS 3 and 4 the total volume of the second, third and fourth cells 116, 314, 316, including the respective joints 118, 318 is approximately 4 litres. The total dwell time for the fluid/s within the second, third and fourth cells 116, 314, 316 is approximately 2 minutes and 20 seconds. The dwell time amply exceeds the sufficient time of 1 minute required for heat disinfection, where the fluid/s have been heated above the sufficient temperature of 8O⁰C (as described above) by the first cell 114 and remain above 8O⁰C during the fluid/s passage thru the second, third and fourth cells 116, 314, 316. [0083] For the potable water example given above for the 100 1/hr disinfection apparatus 310 the pre-heater 126 may be operating such that for cool water entering the pre-heater 126 may be at approximately 2O⁰C with the disinfected water exiting the pre-heater 126 via the disinfected fluid pipe 130 may be within a temperature range of 19° to 23⁰C. The pre-heated water delivered to the four celled elongate conduit 312 via the inlet conduit 120 may be at a first temperature in the range of 75° to 78⁰C.

[0084] As described above with respect to FIG 1, the 100 litre/hour disinfection apparatus 310 may also optionally include formations 134, installed and used in one or more cells 114, 116, 314, 316 of the four celled elongate conduit 312.

[0085] The overall dimensions of an installed compact 100 litre/hour disinfection apparatus may be by way of example height 1000 mm, width 260 mm and breadth 570 mm.

1,000 Litre/Hour Disinfection Apparatus

[0086] FIG 5 is an alternate embodiment of FIG 3, illustrating a 1,000 litre/hour fluid/s disinfection apparatus 510. This disinfection apparatus 510 features an eight celled elongate conduit 512 with the first and second cells 114, 116, the first, second and third heaters 124, 320, 322 and the joint 118 with restrictive joint 318 in a similar configuration to that for the four celled elongate conduit 312.

[0087] The third cell 514 may have a fourth heater 516 to further augment heating of the fluid/s or maintain the fluid/s at or above the desired sufficient temperature. The fourth cell 518 is joined to the third cell 514 by a joint 118 as described above. The fifth cell 520 is connected to the fourth cell 518 by a joining conduit 522. The sixth cell 524 is connected to the fifth cell by a joint 118, the seventh cell 526 is joined to the sixth cell 524 by a restrictive joint 318 and the final, eighth cell 528 is joined to the seventh cell by a joint 118. The fluid/s may exit the eighth cell and the eight celled elongate conduit 512 via the outlet conduit 122.

[0088] The latter four cells 520, 524, 526, 528 of the eight celled elongate conduit 512 are similar in configuration to the first four cells 114, 116, 514, 518, except for the omission of the four heaters 124, 322, 320, 516. This similarity allows in the preferred embodiment for an eight celled elongate conduit 512 to be readily assembled in a modular fashion by duplicate four celled elongate conduit blocks and connecting them via a joining conduit 522. In an alternate embodiment the fourth cell 518 and the fifth cell 520 may be joined by a joint 118 or a restrictive joint 318. In further scale up embodiments of the eight celled elongate conduit 512, successive, modular four celled elongate conduit blocks may be added with heaters, sensors and controllers as required.

[0089] The latter four cells 520, 524, 526, 528 and the third cell 514 with the fourth heater 516 may also have temperature sensors as described above.

[0090] As per the 100 litre/hour disinfection apparatus 310 the basic conduit sections making up the eight celled elongate conduit 512 are box or square conduit lengths. However the transverse internal dimension 530 of the square conduit making up the cells 114, 116, 514, 518, 520, 524, 526, 528 maybe 75mm. The restricted joints 318 maybe by way of example a cube conduit section of internal dimensions 532 of 20mm for each side. The joint 118 maybe by way of example a cube conduit section of side dimensions 75mm.

[0091] As per FIG 4 each length 420 of the eight cells 114, 116, 514, 518, 520, 524, 526, 528 may be 800mm. In alternate embodiments, as described above, the length 420 of each of the cells may be individually or collectively made longer or shorter than 800mm.

[0092] For this 1,000 litre/hour fluid/s disinfection apparatus 510, as may be applied to a potable water example, the four heaters 124, 320, 322, 516 may each be a 900 Watt electric strip element attached to a thermally conductive wall of each of the respective 114, 116, 514, 518 cells . Alternate embodiments for the four heaters 124, 320, 322, 516 are as per described above. An alternate embodiment of the eight celled elongate conduit 512 may include additional heaters for the later four cells 520, 524, 526, 528 in a similar manner to what has been described above

[0093] The use of 1,000 litre/hour fluid/s disinfection apparatus 510 may be in a similar manner to that described above for the 100 litre/hour fluid/s disinfection apparatus 310 for the potable water example, as will be appreciated by a person skilled in the art of fluid processing systems.

[0094] As described above with respect to FIG 1, the 1,000 litre/hour disinfection apparatus 510 may also optionally include formations 134, installed and used in one or more cells 114, 116, 514, 518, 520, 524, 526, 528 of the eight celled elongate conduit 512.

[0095] A 4,000 litre/hour disinfection apparatus version of an eight celled elongate conduit which utilises waste heat for the heating to a sufficient disinfection temperature is described below with respect to FIG 7

Grey and Black Water Disinfection

[0096] The fluid disinfection apparatus 110, 310, 310 described above may be suitable for disinfecting a wide range of waste fluids or effluent in high volume, hi particular, the system may be suited to disinfecting either "grey" or "black" water / fluids as termed by a person skilled in the art of plumbing for waste water and liquids. Grey fluid generally includes fluid/s from showers, wash basins, dishwashers and washing machines. Black fluid generally includes fluid/s from toilets, domestic septic systems, sewage plants, farms (particularly diary, piggeries and the like), as well as waste water from industry.

[0097] Grey and in particular black fluid/s typically contain large amounts of target species for heat treatment such as faecal coli-forms, bacteria, viruses, other pathogens and other undesirable organisms. Black fluid/s may also include compounds such as oestrogen, pharmaceuticals, nitrates, phosphates, and the like that may be amenable to denaturing, deactivation or otherwise conversion using heat treatment. The use of the disinfection apparatus as described above may enable the more economical and rapid treatment of grey or black fluid/s with the additional benefit of the reduced use of commonly used chemical agents for disinfection, flocculation and the like.

[0098] The process conditions that may be used for the disinfection apparatus may be as per that for potable water described above or as per requirements for quarantine or biohazard facilities. For quarantine requirements, by way of example, the sufficient temperature may be 121⁰C for a sufficient time of 20 minutes.

[0099] The disinfection apparatus described above may be used to treat effluent and water from a variety of sources so that it may be put to use in a variety of applications or to render it safe for re-use or disposal. For example animal/farm effluent may be disinfected for use in irrigation of crops or pasture. Polluted river or dam water with catchment areas contributing grey or black fluidVs may be readily disinfected so that they may be used as a source of potable water. Pollution of water reservoir catchment areas is particularly problematic when large rainfall is experienced. Grey fluid/s may be treated so that they may be used for irrigation, washing, fire fighting reservoirs, etc.

[00100] Another embodiment of the disinfection apparatus may be incorporated into tertiary sewage treatment plants so that the final product from the sewage treatment plant is safe for releasing to rivers or the ocean. The sewage treatment plants may be as large as that for a small city or as small as one servicing a residential unit block or an estate of houses. In addition the concentration of residual sludge from sewage plants and the associated problem of concentration of heavy metals and toxic organic compounds (pesticides and the like) may be eliminated by the use of the disinfection apparatus to suitably heat treat the sludge whilst in a fluid and less concentrated form. The heat treated sludge slurry may then be disposed of in a safer low concentrate form or re-used for economic exploitation, by way of example, for agriculture and horticultural compost and fertilisers. Prior to this method of treatment, incineration, controlled landfill or deep sea dumping of the toxic sludge were more economic treatments.

[00101] It will be appreciated by a person skilled in the art of black fluids treatment, such as sewer water, that some pre and post processing of the fluid may be appropriate in addition to the disinfection apparatus. For example, the black fluid may be pre-treated by a bio digester such as a Zabel A300 bio filters www.2abelzone.com . The black fluid may then undergo further pre-treatment such as filtering to remove larger pieces of debris, before being disinfected using one of the above described embodiments.

[00102] It will also be appreciated that residual post purification, such as filtering or chlorination, may also be provided depending on the intended use of the treated fluid/s.

Ship Ballast Water Treatment

[00103] FIG 6 schematically shows cross-sectional views in plan and side elevation of a ship. In this application and embodiment of the disinfection apparatus 110, 310, 510, the ship 610 includes a hull 612 having a number of ballast tanks 614 interconnected via flow-paths or pipes (not shown) extending between bulkheads 616. This allows flow of ballast water 617 between the respective ballast tanks 614 to provide for equalisation of ballast water 617 in the tanks 614. The ship 610 includes an engine 618 for driving propellers 620.

[00104] A disinfection apparatus 110, 310, 510, as described above and adapted as above, may be installed within the ship 610. The disinfection apparatus may be coupled to the ballast water tanks 614 via an inlet pipe 620 and an outlet pipe 622. A pump (not shown) may also be provided to allow ballast water 617 from the ballast tanks 614 to be pumped through the disinfection apparatus.

[00105] The engines 618 include a cooling water inlet 624 which supplies cooling water to a ship heat exchanger (not shown) that is in thermal contact with the engine 618. The ship heat exchanger is coupled via a connecting line 626 to the disinfection apparatus, to act as a heat source to one or more heaters 124, 320, 322, 516 (not shown) as described above. The waste water from the heaters is then coupled to an engine water cooling outlet 628 to allow the cooling water to be discharged from the ship 610.

[00106] The inlet pipe 620 is coupled to the bottom of the ballast tanks

614 whilst the outlet pipe 622 to the top of the ballast water tanks 614. Thus, ballast water 617 may be removed from the bottom of the ballast water tanks 614 and returned to the top of the ballast water tanks 614 so as to promote stratification of the ballast water 617 in the ballast water tanks 614. The returned disinfected water may be at a higher temperature than the cooler water in the lower parts of the ballast tanks 614 and therefore will tend to remain above the cooler water due to the comparative density differences between the hotter and cooler waters 617 within the ballast tanks 614. This stratification of the water 617 in the ballast tanks 614 ensures that the water 617 cycles through the ballast tanks 614 before being disinfected again; thereby ensuring that all the water 617 in the ballast tanks 614 is disinfected adequately.

[00107] The use of the heat generated by the engine 618 may enable a sufficient temperature to be obtained in the disinfection apparatus. Therefore such an arrangement means that heat disinfection may be achieved using no, or only minimal, additional heating. As a result this provides an efficient mechanism for disinfecting ballast water 617 thereby allowing it to be returned to the sea. Furthermore, as the apparatus includes few moving parts little maintenance is required making the apparatus suitable for long term use.

[00108] In an alternate embodiment the engine cooling system may be in the form of a closed system in which cooling water is re-circulated around a loop as shown by the dotted line 630 which suitably interconnects the cooling water inlet 624 and the cooling water outlet 628 to form a re-circulation loop 630.

[00109] In yet another embodiment a disinfection apparatus may be configured (not shown) such that it may be used to directly treat sea water as it is immediately pumped into or out of the ballast tanks 614. Such a disinfection apparatus may have a very high flow rate performance to cope with the high pumping rates required of ballast water adjustments.

[00110] It will be appreciated that the sufficient temperature used by a ship disinfection apparatus will depend on level of disinfection required for the ballast water 617. For example, if the disinfection apparatus is used to treat ballast water 617 that is only to be discharged in the open sea, a lower temperature, such as 50°C may be used. However for ballast water 617 which is to be discharged or loaded in a harbour, quarantine levels may require up to 121 °C be used as the sufficient temperature. In addition the sufficient temperature and sufficient time may also depend on factors such as the contaminants to be treated and any restrictions on time available for disinfection and the level of external heating available.

4,000 litre/hour Waste Heat Disinfection System.

[00111] FIG 7 is a process diagram for a 4,000 litre/hour disinfection apparatus 710 version of an eight celled elongate conduit 712 which utilises waste heat for the heating. The eight celled elongate conduit 712 of FIG 7 is similar to that described with respect to the 1,000 litre/hour system of FIG 5, however it will be readily appreciated that the length and/or cross-sectional area of each cell of the elongate conduit may be scaled appropriately in order to meet the 4,000 litre/hour throughput capacity. By way of example the internal dimension of the square conduit of the cell could be 150 mm and / or the length of each cell may be 1,400 mm. The controller has been omitted for clarity, but it will be appreciated that an appropriate controller may be used in the manner as previously described with respect to FIG 1.

[00112] The waste heat 710 apparatus features two suitable heat exchangers, the first being a pre-heater 126 and the second as a waste heater 714 to the disinfection temperature desired. The pre-heater 126 is a heat exchanger that may be operated in the same manner has described above with respect to FIGS 1, 3 and 5. That is, hot disinfected fluid 724 from the elongate conduit 712 may be used for the pre-heating of the relatively cool inlet fluid 716 for disinfection.

[00113] The waste heater 714 may be used to further heat the pre-heated fluid 718 to the sufficient temperature for disinfection. The waste heater 714 as a waste heat exchanger obtains from a waste heat source 720 the necessary energy to heat the pre-heated fluid 720 to a hot fluid 722 of sufficient temperature for disinfection. Accordingly heaters for the elongate conduit which have been described above may not be necessary for this elongate conduit 712. The sources of waste heat 720 may be as previously described with respect to FIG 1. In one example the waste heat 720 may be derived from a 2,000 litre/hour 100⁰C water boiler system as either the waste/spent water or flue gas if the boiler is fossil fuel fired. Exhausted fluid from the waste heater 714 may be removed via exhaust / drain 744. The hot fluid 722 then passes into the elongate conduit 712 to be mixed and reside at a sufficient temperature and time until disinfection of the fluid is complete. The hot disinfected fluid 724 may then be passed to the pre-heater 126 as described above. After the pre-heater 126 the relatively cool disinfected fluid 726 exits the waste heat disinfection apparatus 710 for use or collection.

[00114] The elongate conduit 712 may also feature an optional booster heater 728. The waste heat disinfection apparatus 710 may also have fluid pumps 730, a flow meter 732, a strainer 734, non-return check valves 736, pressure indicators/sensors 738, temperature sensors 740 and solenoid valves / flow controllers 742 and associated connections (not shown) that a person skilled in the art may readily appreciate.

[00115] The complete 4,000 litre/hour disinfection apparatus 710 may be housed in a container of base dimensions 1200 mm square by 1500mm high. Remote Use and Disaster or Emergency Relief

[00116] Disinfected potable water is highly sought after in emergency relief, for example following natural disasters or the like, hi order to be of maximum relief, it is necessary for the system to be provided in a manner that is sufficiently portable and efficient to allow the system to be rapidly and easily transported to and set up. Such performance requirements are also sought after in remote area applications for potable water supply.

[00117] An example of a disinfection apparatus 110, 310, 510 which may be used for emergency relief or in a remote area may be one using either two, four or eight cells in an elongate conduit as described above. The physical size and weight of an individual disinfection apparatus being constrained by the level of containerisation required and what mode of transport is to be used. For example parachute air drop with subsequent man or horse hauling may require a lightweight skid mounted pallet for the disinfection apparatus. A disinfection apparatus with an elongate conduit of a lightweight, high strength aluminium alloy may be constructed with a dry (unfilled) weight of less than 20kg.

[00118] Peripheral equipment to be also containerised with the above disinfection apparatus to make the provision of portable water self containerised may include bladder tanks for the storage of untreated and treated water, electrical generators, solar hot water heaters for the heating source and the like. It will be appreciated that further detail for the provision of a portable disinfection apparatus may be designed and/or selected by a person skilled in the art of such portable fluid processing systems and military infrastructure in general.

Solar Self Contained Apparatus

[00119] FIGS 8, 9 and 10 are process diagrams for a number of example configurations of a solar disinfection apparatus 810, 910, 1010. The solar disinfection apparatus may be in a form for ready portable deployment into remote areas and the like as described above.

[00120] The elongate conduit example given in FIGS 8, 9 and 10 may be a two cell 112 or four cell 312 elongate conduit as described with respect to FIGS 1 and 3, however it will be readily appreciated that appropriate adaptions and scale-ups may be made to the elongate conduit used as required for the performance of a particular solar disinfection apparatus. In the manner of FIG 7 the controllers have again been omitted for clarity.

[00121] The solar apparatus features a solar energy collector 812 to collect heat energy as radiation from the sun and supply the collected heat energy to within the solar disinfection apparatus to heat the cool inlet fluid 814 to a sufficient temperature for disinfection. The solar energy collector 812 may be any one of many that a person skilled in the art may design or select from. Preferably the solar collector 812 is of a design that heats a circulating fluid which may then be used to transfer the collected heat energy elsewhere. In the following the configurations shown in FIGS 8 and 9 are described first in the below.

[00122] In FIGS 8 and 9 the pre-heater 126 is also a heat exchanger in the manner described with respect to FIG 7. hi FIG 8 the pre-heated fluid 816 is further heated to the sufficient temperature by the solar heat exchanger 818. The solar heat exchanger 818 may be in a closed loop fluid circuit 820 with the solar collector 812 for the necessary heat/energy transfer. The hot fluid 822 then passes into the elongate conduit 112, 312 to be mixed and reside at a sufficient temperature and time until disinfection of the fluid is complete. The hot disinfected fluid 832 may then be passed to the pre-heater 126 as described above. After the pre-heater 126 the relatively cool disinfected fluid 824 exits the solar apparatus 810 for use or collection.

[00123] In the configuration of FIG 9 the solar closed loop circuit 820 has been re-configured such that it now passes directly into heating tubes within or about the elongate conduit 112, 312 as described previously. Accordingly pre-heated fluid 816 passes into the elongate conduit for heating to the sufficient temperature and then to be mixed and reside at a sufficient temperature and time until disinfection of the fluid is complete. The hot disinfected fluid 832 may then be passed to the pre- heater 126 and exit the solar apparatus 910 as described above for FIG 8.

[00124] In FIG 10 the cool fluid 814 is passed directly to the solar heat exchanger 818 to be heated to a sufficient temperature for disinfection. The hot fluid 822 from the solar heat exchanger 818 is then passed to a heat exchanger 1012 and elongate conduit to be mixed and reside at a sufficient temperature and time until disinfection of the fluid is complete. The use of the heat exchanger 1012 may allow for extra capability in residence / dwell time control for disinfection combined with energy and fluid disinfection throughput efficiencies. For example a smaller elongate conduit may be able to be used since the heat exchanger 1012 may be also used to provide the sufficient time for dwell / residence for disinfection. This configuration may also provide weight advantages. The hot disinfected fluid 832 may exit the solar apparatus 1010 for direct use as a hot, disinfected water source.

[00125] It will be readily appreciated that different configurations shown by way of example in FIGS 8, 9 and 10 may exist in the one apparatus that is constructed; where such a multi-configuration apparatus is able to re-configure its operation as required.

[00126] In the manner of FIG 7 the above solar disinfection apparatus

810, 910, 1010 may also have additional items such as pumps 826, filter 828 and a cleaning agent dosing system 830. It will be readily appreciated however that pumps 826 may be optional if the layout of the solar disinfection apparatus is such that thermo-siphoning is utilised for the respective fluid flow transport. In addition flow control may be obtained by the use of bimetallic element assembly temperature valves operating either in a thermostat (set point) or a continuously variable (proportional control) fashion. In a similar manner it will be readily appreciated that other solar or thermo-electric power sources may be used to supply electrical power to the controllers and the like of the solar disinfection apparatus. Additional controlling may also be required for the solar disinfection apparatus in order to minimise heat loss during the night or on cloudy days.

Other Applications

[00127] It will be appreciated that the embodiments of the disinfection apparatus described above may be applied to any form of fluid disinfection apparatus that utilises heat to provide for disinfection or other deactivation or conversion of components of fluid/s. This may include for example medical applications such as retorting and autoclaving, as well as disinfection systems for the disinfection of milk and the like. As well as disinfection of drinking water obtained from sea water via reverse osmosis, vacuum distillation, etc. Pasteurisation

[00128] It will be appreciated by persons skilled in the art that the disinfection of fluid as described above may also be commonly referred to as pasteurisation. Accordingly, the above described techniques may equally apply to pasteurisation, and in particular to the heat treatment of milk, juices and other liquid like food stuffs.

[00129] In the case of milk disinfection, in many circumstances the milk may be produced on farms that are in remote locations. Due to the inherent delays in transport, it is therefore preferable that the milk is disinfected at the farm to ensure freshness. However, in such remote situations, electricity is often generated using a generator, and hence using electrically driven disinfection and pasteurisation systems places a major load on the generator and results in heavy fuel use.

[00130] By utilising an embodiment (not shown) of the disinfection apparatus 110, 310, 510j excess heat from the electrical generator may be employed to provide or augment the heating to the pre-heater 126 and an elongate conduit 112, 312, 512. This arrangement may used to disinfect or pasteurise the milk, resulting in significant cost savings.

[00131] hi another embodiment (not shown) the excess heat from the tanker motor, picking up the milk from the farm, may be used as a heater source for a portable disinfection apparatus associated with the tanker. The tanker may have two bladder tanks within it to separately provide a feed tank and a treated tank, as described above for the Remote Area / emergency relief embodiment. The form of the portable disinfection apparatus may be in a similar embodiment to that described above with reference to "Remote Use and Disaster or Emergency Relief. For the present embodiment remote farms without the ability to adequately refrigerate or pasteurize milk may supply milk to the tanker described so that the milk may be safely treated en-route to the central processing plant for milk.

Bio or Pathogenic Security of Water Supplies

[00132] Intentional contamination of potable water supplies with pathogens by terrorists is a risk that may be experienced by large buildings or facilities which have a single, accessible entry point for their potable water supply. For example anthrax (gastrointestinal for drinking and pulmonary forms for showers and other fluid aerosols) or pathogens with a high efficacy by the oral route may be readily and discretely injected into a mains water supply to a building or facility.

[00133] An embodiment of the disinfection apparatus installed within a secure region of a large building or facility may be used to treat incoming potable water. For the anthrax example the disinfection apparatus may apply a sufficient temperature of 143⁰C for a sufficient time of 0.9 minute to deactivate anthrax in its various forms.

Pre - Treatment:

[00134] It will be appreciated by a person skilled in the art of fluid/s heat treatment that some pre and post processing of the fluid/s for heat treatment by the disinfection apparatus, as described above, may be appropriate. For example in applications where the fluid/s contains chemical contaminates that are not amenable to heat treatment, pre-treatment of the fluid/s may be required to remove or inactivate these contaminates. Example pre-treatments include ozone, electro-coagulation, ionising radiation, activated charcoal systems or as selected or designed by a person skilled in the art.

OU and Tar Sands

[00135] There are substantial under utilised reserves of oil or tar as semi-solid petroleum or bitumen that have recently been identified as being economic to extract, as petroleum fuel prices continue to rise. In the present process for extraction of semi-solid petroleum, the oil must be separated from a slurry mix of water and sand, where hot water is used as a fluidising agent and then to facilitate the separation of the petroleum oil.

[00136] An embodiment of the disinfection apparatus above may be used for the heating, fluidising or part of the subsequent separation of the petroleum oil. The advantages of the disinfection apparatus described above of: heating, fluid flow mixing, energy efficiency, scale-ability, process reliability and rapid control may be of benefit to the oil and tar sands application area. [00137] An embodiment of the disinfection apparatus may have oil and sand separator units located at opposing joints 118, 318, where the oil separator may be located at an uppermost joint and a sand separator unit may be located at a bottommost joint with respect to the cells being in a vertical orientation. The location of the separator units may enable them to take advantage of intentional stratification of the oil and sand in the oil sand slurry. The mixing within the cells for heating may not be done in the region of the joints of the elongate conduit such that the heated slurry of oil, water and sand stratifies into layers within the joints of the elongate conduit. Separator units may then be used at the joints to harvest the respective layers of the stratified slurry.

[00138] In another application area, an embodiment of the above may be used for the remediation or clean up of beaches where a large oil spill has occurred off shore and washed up onto a beach. Another embodiment may be adapted for use in conjunction with oil skimmers operating across the sea.

Cylinder in Cylinder Arrangement

[00139] An option for providing additional residence / dwell time for disinfection of the hot fluid is a "cylinder-in-cylinder" arrangement of co-axial cylinders. FIG 11 is a longitudinal axial cross-sectional view of a cylinder-in-cylinder arrangement 1110 that is shown in perspective in FIG 12. FIG 12 is a partial cut-away perspective view of the cylinder-in-cylinder arrangement 1110.

[00140] In FIGS 11 and 12 four coaxial cylinders 1112, 1114, 1116,

1118 are shown forming the cylinder-in-cylinder arrangement 1110. Appropriate top 1120 and bottom 1122 end caps are used to appropriately form the cylinder-in- cylinder arrangement for carrying fluids. The passage of the fluids from the tangential feed inlet 1124 into and through the cylinder-in-cylinder arrangement is indicated by the arrows. The cylinder-in-cylinder arrangement features the alternating passage of fluid from the inner of one cylinder to the inner of the next cylinder at opposing ends of each of the respective cylinders, as shown by the arrows in FIGS 11 and 12. The tangential feed 1124 may allow for the development of a "rifling" or helical or spiral style of fluid flow about the cylinders so as to increase mixing and residence / dwell time. After the passage of the fluid through the cylinder-in-cylinder arrangement as indicated the fluid exits via the central cylinder 1118 at outlet 1126.

[00141] The cross-sectional dimensions provided in FIG 11 are by way of example only for a 2,000 litre/hour disinfection system. The length dimension 1128 may be in the range from 0.5 to 1.5 m for a 2,000 litre/hour system, however it may be less or more than this range depending on the desired throughput. It will be readily appreciated that these dimensions may change depending on the size and application area of the cylinder-in-cylinder arrangement. In a similar manner the number of coaxial cylinders may also be less or more than four depending on the application area and the desired throughput for example.

[00142] It will be readily appreciated that heating may be supplied to the cylinder-in-cylinder arrangement in a similar manner as described above for the elongate conduit. In a similar manner formations may also be present in the cylinder- in-cylinder arrangement to aid in mixing the fluid as described previously for the elongate conduit.

[00143] hi FIG 13 electrical heating elements in stainless steel pockets or sleeves 1312 have been inserted into an adaptation of a cylinder-in-cylinder arrangement 1110 as described above with respect to FIGS 11 and 12.

[00144] A number of cylinder-in-cylinder arrangements may be used in a series cascade for particular applications.

[00145] The cylinder-in-cylinder disinfection arrangement may be used in conjunction with the elongate conduit disinfection systems described above or stand-alone.

[00146] Although the invention has been herein shown and described in what is conceived to be the most practical and preferred embodiments, it is recognized that departures can be made within the scope of the invention, which are not to be limited to the details described herein but are to be accorded the full scope of the appended claims so as to embrace any and all equivalent assemblies, devices and apparatus.

[00147] In this specification, the word "comprising" is to be understood in its "open" sense, that is, in the sense of "including", and thus not limited to its "closed" sense, that is the sense of "consisting only of. A corresponding meaning is to be attributed to the corresponding words "comprise, comprised and comprises" where they appear.

[00148] It will further be understood that any reference herein to known prior art does not, unless the contrary indication appears, constitute an admission that such prior art is commonly known by those skilled in the art to which the invention relates.

Claims

1. A disinfection apparatus for a fluid comprising: a preheater for the fluid; an elongate conduit adapted for heating and flow of the fluid within the elongate conduit; where: the elongate conduit is adapted for inducing the mixing of the fluid across the conduit profile; so that the fluid is heated to a sufficient temperature to disinfect the fluid.

2. An apparatus according to claim 1 wherein the elongate conduit is in one or more serpentine, looped or sinuate configurations.

3. An apparatus according to any preceding claim wherein the elongate conduit comprises two or more cells joined together.

4. An apparatus according to claim 3 wherein the cells have transverse cross section of one or more of square, rectangular, polygonal, angular or circular shape

5. An apparatus according to claim 4 wherein the transverse cross section of the cells is adapted to mixing of the fluid.

6. An apparatus according to any preceding claim wherein the elongate conduit has one or more heaters in thermal communication with the fluid.

7. An apparatus according to claim 6 wherein the heater is an electrical resistance strip heater.

8. An apparatus according to claim 6 or 7 wherein one or more sleeves or pockets from a wall of the elongate conduit project into the elongate conduit, where the sleeve or pocket is adapted to receive the heater.

9. An apparatus according to any preceding claim wherein the elongate conduit has one or more formations adapted to mixing of the fluid.

10. An apparatus according to any preceding claim wherein the disinfected fluid from the elongate conduit is used by the pre-heater to heat the fluid to a first temperature.

11. An apparatus according to any preceding claim wherein the sufficient temperature is in the range of 60° to 100⁰C.

12. An apparatus according to any preceding claim wherein the sufficient temperature is in the range of 60° to 8O⁰C.

13. A method for the continuous disinfection of a fluid, including the steps of: providing a pre-heater for the fluid; supplying the fluid to the pre-heater; heating of the fluid in the pre-heater to a first temperature; providing an elongate conduit; supplying the fluid from the pre-heater to the elongate conduit; heating of the fluid to a second temperature either before or within the elongate conduit; and mixing of the fluid in the elongate conduit to a second temperature; wherein: the second temperature is equal to or above a sufficient temperature for the disinfection of the fluid in order to continuously produce a disinfected fluid; and the disinfected fluid from the elongate conduit is used by the pre-heater to heat the fluid to a first temperature.

14. The method of claim 13 where the heating of the fluid to a second temperature is provided by: a solar collector means, electrical resistance heating, waste heat exchanger, heating fluid tubes, microwave heating or RF induction heating.

15. A heat treatment apparatus for a fluid comprising: a preheater for the fluid; an elongate conduit adapted for heating and flow of the fluid within the elongate conduit where: at least one or more portions of the elongate conduit is adapted for heating the fluid; and the elongate conduit is adapted for inducing the mixing of the fluid across the conduit profile; so that the fluid is heated to a sufficient temperature to heat treat the fluid.

16. A disinfection apparatus for a fluid comprising: a preheater for the fluid; an elongate conduit adapted for flow of the fluid within the elongate conduit; where: the fluid is heated to a sufficient temperature by a heating means; and the elongate conduit is adapted for inducing the mixing of the fluid across the conduit profile; so that the fluid is heated to a sufficient temperature to disinfect the fluid.

17. An apparatus according to 16 wherein the heating means includes a solar collector, electrical resistance heating, waste heat exchanger, heating fluid tubes, microwave heating or RF induction heating.

18. An elongate conduit for the disinfection of fluids substantially as described herein.

19. A method for the continuous disinfection of a fluid substantially as described herein.

20. A disinfection apparatus for a fluid comprising: a preheater for the fluid; a cylinder-in-cylinder arrangement adapted for flow of the fluid within the cylinder-in-cylinder arrangement; where: the fluid is heated to a sufficient temperature by a heating means; and the cylinder-in-cylinder arrangement is adapted for inducing the mixing of the fluid; so that the fluid is heated to a sufficient temperature to disinfect the fluid.

21. A cylinder-in-cylinder arrangement for the disinfection of fluids substantially as described herein.