Description of Invention

The present invention relates to condensers. In particular, the present invention relates to a condenser for use in a desalination process, distillation process, waste fluid separation process/unit or self-irrigating greenhouse.

Condensers that transform vapour to liquid are well known. However, such condensers normally require complex processes having intricate designs which are difficult and expensive to manufacture and maintain. Moreover, such condensers are typically made from materials that are liable to corrosion, heavy and difficult to handle.

Condensers are known in the form of a plurality of tubes in which cold fluid flows within the tubes such that fluid vapour coming into contact with the surface of the tubes condenses thereon. These condensers are easily broken or damaged during installation and use. When such condensers are made of glass, such breakages can produce sharp pieces of glass that are a safety issue.

The disadvantage of such condensers is that not all of the surface area of the condenser is positioned adjacent to the fluid flowing through the tubes, which means that there is a tendency for hot and cold spots to form across the surface of the condenser thereby reducing its efficiency.

A known condenser is in the form of two sheets of plastic, heat sealed together at intervals to form a plurality of tubes with spaces between the tubes. Such condensers require higher pressure of fluid to ensure that the tubes are filled adequately. Moreover, the flimsy nature of the sheets of plastic means that the condenser as a whole is prone to being punctured or damaged such that they are no longer fluid tight.

There is a need for a condenser that can be easily manufactured, stored, installed and maintained at a low cost. There is also a need for a condenser that is not detrimental to the environment. There is a further need for a robust condenser.

It is an object of the present invention to provide a condenser that overcomes or mitigates some or all of the above disadvantages.

For the avoidance of doubt, the following terms are intended to have the definitions as outlined below:

Delivery inlet conduit may be any suitable apparatus that can convey fluid into one or more of the channels of each unit. When there is one or more delivery inlet conduits, the conduits can be connected to a separate or the same fluid supplies.

Outlet conduit may be any suitable apparatus that can convey fluid from one or more of the channels of each unit. When there are one or more outlet conduits, the conduits can be connected to a separate or the same fluid outflow.

A living hinge is a thin flexible bearing that joins two parts together and allowing the two parts to bend along the line of the hinge.

The spacer may be of any shape provided that it achieves the function of spacing two adjacent units from one another and provides an additional fluid pathway for the condensed fluid. The spacer may be made from any suitable material. Preferably the spacer is made from a material that is strong and durable, light, recyclable, fluid and moist resistant, has good chemical resistance, has good biological resistance to contamination, and/or is bio- cleanable.

In a first aspect of the present invention there is provided a condenser comprising at least one unit having a first end and a second end; each unit comprising two opposing walls defining a cavity therebetween and at least one interconnecting wall positioned within the cavity between the two walls to form a plurality of elongate channels; each channel providing an internal passage defining a fluid flow path through the unit from the first end to the second end; an inlet delivery conduit adapted to deliver fluid to at least one end of one or more of the channels at or near the first end of the unit; and an outlet conduit adapted to receive fluid flowing from at least one end of one or more of the channels at or near the second end of the unit.

In a further aspect of the present invention there is provided a condenser consisting essentially of or consisting of at least one unit having a first end and a second end; each unit comprising two opposing walls defining a cavity therebetween and at least one interconnecting wall positioned within the cavity between the two walls to form a plurality of elongate channels; each channel providing an internal passage defining a fluid flow path through the unit from the first end to the second end; an inlet delivery conduit adapted to deliver fluid to at least one end of one or more of the channels at or near the first end of the unit; and an outlet conduit adapted to receive fluid flowing from at least one end of one or more of the channels at or near the second end of the unit.

An advantage provided by condensers embodying the present invention is that the arrangement of the opposing walls and interconnecting wall imparts a structural rigidity to the condenser. Such an arrangement also provides a condenser that can be easily manufactured, installed and maintained at a low cost. The installation and maintenance can be carried out by unskilled labourers.

In an advantageous embodiment, the opposing walls are parallel to one another and the interconnecting walls are straight. The interconnecting walls may be in the form of one or more straight segments joined at one or more points. Such arrangements ensure that substantially all of the surface area of the external surface of each unit is proximate to the fluid flow in a channel during use; thereby the surface area of each unit does not form hot and cold spots during use.

In an alternative advantageous embodiment, the opposing walls are planar and parallel to one another and the interconnecting walls are straight having a transverse cross section in the shape of a parallelogram, trapezium, square, rectangle or triangle. Any shape of cross section is envisaged. Preferably, the opposing walls are parallel to one another and each interconnecting wall is substantially perpendicular to each of the opposing walls forming channels having a traverse cross section in the shape of a square or rectangle. These specific arrangements also ensure that substantially all of the surface area of the external surface of each unit is proximate to the flow of fluid in a channel during use; thereby the surface area of each unit does not form hot and cold spots during use.

In a further embodiment the opposing walls may be non-planar and parallel to one another and the interconnecting walls are straight. Such an arrangement also ensures that substantially all of the surface area of the external surface of each unit is proximate to the fluid flow in a channel during use. The arrangement means that the surface area of each unit does not form hot and cold spots during use.

Alternatively, the traverse cross section of the channels is a different polygonal shape, such as a triangle; or in the shape of a circle or ovoid.

In a preferred embodiment, the external surface of one or both of the planar or non-planar opposing walls is formed so as to be rough and/or to have protrusions and indentations to provide a larger surface area on which vapour may condense. Any shape of structure to provide a rough surface and/or protrusions and indentations on the surface is envisaged. Alternatively, the external surface is smooth. A smooth surface is easier and cheaper to manufacture.

Preferably, the internal surface of the channels is smooth to ensure a substantially uniform temperature along the entire length of the channel and across the walls of the channel.

Advantageously, the opposing walls are thin to ensure that a high differential between the temperature of the external surface and the vapour entering the condenser can be maintained. Advantageously, the opposing walls have a thickness of 0.5 to 5mm. More advantageously, the opposing walls have a thickness of 1 to 3 mm.

Preferably, the opposing walls and interconnecting walls are integral with one another. The walls can be in the form of a single piece or a plurality of components that are fixed to one another. The integral character of the walls imparts a higher structural rigidity to the condenser. Advantageously the opposing walls and/or the interconnecting walls are formed of polypropylene, copolymers of polypropylene or other variants thereof. More advantageously, the opposing walls and/or interconnecting walls are formed of medium density polypropylene.

Polypropylene is a material that has high flexural strength ensuring that the rigid structure is flexible, thereby ensuring that the units are not easily damaged during installation and use. Condenser units formed from polypropylene are strong and durable, light, recyclable, fluid and moist resistant, and have good chemical resistance and biological resistance to contamination. Moreover, polypropylene is a good heat conductor.

Alternatively, the opposing walls and/or interconnecting walls may be formed from any material such as metal or any other rigid plastic. It is envisaged that the opposing walls and/or the interconnecting walls of the condenser may be formed from any material that has the above properties. Preferably, the opposing walls and/or interconnecting walls will be formed from a material having the same advantageous properties of polypropylene. A skilled person will appreciate that the exact material used will depend upon the use of the condenser.

Advantageously, the opposing walls and interconnecting walls are formed by extrusion. Suitable extrusion processes are known in the art and provide a simple and inexpensive means of manufacture.

In an advantageous embodiment, one or more of the units are folded to form folded sections of the unit. More advantageously, each folded section is positioned at an angle of between 1 to 179 degrees to an adjacent folded section. In a preferred embodiment the folded section between the folded sections is a living hinge. Preferably, the folded unit is held in its folded position by a clip.

Preferably, the delivery inlet conduit and/or the outlet conduit are situated at the first end and second end of the unit respectively. In such an arrangement less pressure is required to pass the fluid along the channels during use. Moreover, this arrangement enables a simple connection between the unit and the conduits.

In an alternative embodiment, the delivery inlet conduit and/or the outlet conduit are situated near to the first end and second end of the unit respectively.

In a further embodiment of the invention, each unit or each channel have separate delivery inlet conduits and/or the outlet conduits.

Preferably, the condenser further comprises a releasable fluid tight closure to cover at least a part of the inlet delivery conduit and/or the outlet conduit to prevent the fluid flow into and/or out of, respectively, one or more units during use. This permits individual units to be removed during use of the condenser for repair or replacement. Therefore, the condenser can still function whilst one or more of the units are removed for repair and maintenance. This ensures a high operating efficiency and secures a supply of condensed fluid. Moreover, the cost of replacing one or more units is substantially less than replacing the entire condenser.

Advantageously, the condenser further comprises a releasable fluid tight closure to cover at least a part of the inlet delivery conduit and/or the outlet conduit to prevent the fluid flow into and/or out of, respectively, one or more channels during use. This permits individual channels to be isolated in the event of a blockage.

More advantageously, the condenser further comprises a filter that prevents any unwanted matter from entering and/or leaving the inlet delivery conduit and outlet conduit. This ensures that the channels do not become blocked with unwanted matter thereby ensuring that fluid can flow unimpeded through the channels. More advantageously, the filter is self cleaning.

Preferably, one or more of the units further comprises a releasable end cap to cover the first and/or second end of the unit. The end cap prevents the entry of materials into the unit, thereby preventing damage to the unit when it is removed from the condenser for repair and maintenance.

In a preferred embodiment the condenser comprises a plurality of units. More preferably, the condenser further comprises at least one spacer in which each spacer is positioned between two adjacent units. Such an arrangement ensures that the adjacent units are spaced apart during use to ensure that as large a surface area of the unit as possible is available for condensation to take place. The spacer increases the overall structural rigidity of the condenser. The spacer acts by preventing adjacent units sticking together and reducing the overall available surface area, which also prevents the formation of hot and cold spots on the opposing walls. The spacer can also provide an additional flow path for the condensed vapour during use.

In a preferred embodiment, two or more spaces are positioned between the same adjacent units. Such an arrangement ensures that the units are separated over their entire area from one end to the second end. Preferably, each spacer is fixed to one of the adjacent units or to both of the adjacent units thereby defining a fluid passageway. The overall structural rigidity of the condenser is increased by fixing the spacer to one or both of the adjacent units. Moreover, the fluid passageway provides a simple and efficient means of directing the condensed vapour to an appropriate outflow area.

Advantageously, the spacer has a first and a second end, the first end being elevated with respect to the second end. Such an elevation increases the flow rate of the condensed fluid to the outflow area during use.

In preferred embodiments, the spacer is in a single plane or in step-like arrangement. The spacer may be a planar platform extending between adjacent units or curved to provide and open conduit for the flow of condensed vapour during use.

In a preferred embodiment, an axis running from the one end to the second end of each unit is in a substantially vertical orientation. In such an arrangement, during use, one end of the unit is positioned at the top and the second end is at the bottom such that the fluid can flow upwards and/or downwards through the channels. Preferably, in such an orientation, the units are tall and relatively thin such that less ground space is required to provide the same surface area for condensation to take place.

Advantageously, the units, during use, have a height between 1 to 3m, a width between 2 to 4m and a depth of 50cm to 1.5m.

Alternatively, an axis running from the one end to the second end of each unit is in a substantially horizontal orientation. In an advantageous embodiment, the units are positioned parallel to one another. For example, during use, the vapour enters the condenser and moves into the spaces between the adjacent units and the vapour condenses on the external surfaces of the opposing walls of the adjacent units.

Alternatively, the units are positioned at an angle of between 1 to 179 degrees to an adjacent unit. In an advantageous embodiment the units are spaced apart and, if the axis that runs perpendicular to the direction of the channels were to meet, the angle therebetween would be between 1 to 179 degrees.

In an alternative embodiment a unit is folded to form two or more planar segments. The folded section may be a simple fold of the unit or a living hinge to form a plurality of segments. The segments may be of different sizes and more than one fold may be formed in a single unit. The angle between the segments of each unit is between 1 to 179 degrees. The angle will depend on the intended use of the condenser.

In an advantageous embodiment, the condenser further comprises a frame connected to each unit and/or the inlet conduit and/or the outlet conduit. The frame increases the structural rigidity of the condenser. The frame also enables quick and easy installation of the condenser. The frame further ensures that the units are held in a desired position with respect to one another, which will depend on the intended use of the condenser. More advantageously, the spacers may be attached to the frame.

In a preferred embodiment the condenser further comprises a trough into which the condensed fluid can flow. More preferably, the trough is positioned below the units during use. Advantageously the trough is connected to the frame. The invention further provides a unit of the embodied invention as described above.

The invention further provides a kit comprising a condenser embodied by the invention or a plurality of units of the embodied invention. Advantageously, the kit further comprises a frame, one or more closures, one or more end caps, one or more spacers and/or one or more troughs as described above.

A further aspect of the invention is the use of a condenser, unit or kit of the embodied invention in a desalination process, distillation process, waste fluid separation process/unit or self-irrigation greenhouse.

Figure 1 is a first embodiment of a condenser in accordance with the present invention;

Figures 2A to 2E are transverse cross sections of channels in accordance with alternative embodiments of the present invention;

Figure 3 is an alternative embodiment of a condenser in accordance with the present invention; and

Figure 4 is alternative embodiment of a condenser in accordance with the present invention.

As illustrated in figure 1 , a first embodiment of a condenser (1 ) comprises comprising a plurality of units (2) having a first end (3) and a second end (4); each unit (2) comprising two opposing walls (5) defining a cavity (6) therebetween and at least one interconnecting wall (7) positioned within the cavity (6) between the two walls (5) to form a plurality of elongate channels (8); each channel (8) providing an internal passage defining a fluid flow path through the unit (2) from the first end (3) to the second end (4); an inlet delivery conduit (7) adapted to deliver fluid to at least one end of one or more of the channels (8) at or near the first end (3) of the unit (2); and an outlet conduit (9) adapted to receive fluid flowing from at least one end of one or more of the channels (8) at or near the second end (4) of the unit (2).

As shown in figure 1 , the opposing walls (5) are both planar and parallel to one another; and the interconnecting walls (7) are straight. The interconnecting walls (7) are perpendicular to the opposing walls (5) thereby proving channels (8) that have a traverse cross section in the shape of a square. The channels (8) extend fully from the one end (3) of the unit (2) to the second end (4) of the unit (2). The channels are suitable for a fluid to pass along the channel such that they are conveyed all the way through the unit (2). In this embodiment the fluid is intended to flow from the one end (3) to the second end (4) of the unit (2) in the direction of arrow A.

The plurality of units (2) are positioned parallel to one another. The axis running from the one end (3) to the second end (2) of each unit (2) is in a substantially vertical orientation. The space between adjacent units (2) will depend on the intended use of the condenser (1 ).

In this embodiment, there are two spacers (11 ) positioned between each set of adjacent units (2). The spacers (11 ) are fixed to both of the adjacent units (11 ) and define a planar fluid passageway, thereby providing an additional flow path for the condensed vapour during use. The spacers (11 ) have a first end (13) and second end (14), and the first end (13) is elevated with respect to the second end (14).

The opposing walls (5) and interconnecting walls (3) are an integral polypropylene unit (2) formed by an extrusion process. The size of the channels (8) and thickness of the walls (5, 7) will depend upon the intended use of the condenser (1 ). In this embodiment, a structure commercially know as Correx forms the unit (2).

As illustrated in figure 1 , in use, the delivery input conduit (9) introduces fluid into the channels (8) at one end (3) of each of the units (2). In this embodiment, a single delivery input conduit (9) provides fluid to all of the units (2) and channels (8). The fluid flows from the one end (3) to the second end

(4) through the channels (8) in the direction of arrow A, as shown in figure 1. The fluid exits the channels (8) into the outlet conduit (10). In this embodiment, a single outlet conduit (10) receives fluid from the channels (8) of each of the units (2). Vapour enters the condenser (1 ) in the spaces between the adjacent units (2) in the direction of the arrow B. The temperature of the fluid in the channels (8) is substantially lower than the temperature of the vapour such that the vapour condenses on the external surface of the opposed walls (5). The condensed vapour flows down the surface of the opposed walls

(5) in the direction of arrow C until it reaches a spacer (11 ). The flow path provided by the spacer (11 ) guides the condensed fluid into the trough (12).

Figures 2A to 2E illustrate alternative embodiments of the transverse cross sections of the channels. The units (2) of the alternative embodiments have opposing walls (5) parallel to one another and the interconnecting walls (7) are straight. The embodiments of figures 2A to 2D show units having planar opposing walls; whereas the unit illustrated in figure 2E has non-planar opposing walls (5). Figure 2D illustrates an embodiment in which the interconnecting walls are in the form of two straight segments joined at a point.

As illustrated in figure 3, the opposing walls (5) are both planar and parallel to one another; and the interconnecting walls (7) are straight. The interconnecting walls (7) are perpendicular to the opposing walls (5) thereby providing channels (8) that have a traverse cross section in the shape of a square. The channels (8) extend fully from one end (3) of the unit (2) to the second end (4) of the unit (2). The channels are suitable for a fluid to pass along the channel such that they are conveyed all the way through the unit (2). In this embodiment the fluid is intended to flow from the one end (3) to the second end (4) of the unit (2) in the direction of arrow A.

The units (2) are positioned at an angle a ^° of between 1 to 179 degrees to the adjacent unit. In this embodiment the units do not touch because they are spaced apart. Therefore, the angle a ^° is the angle that would be formed between the axes that run perpendicular to the direction of the channels were to meet, as illustrated by the dotted lines. The space between adjacent units (2) and the angle therebetween will depend on the intended use of the condenser (1 ). It is envisaged that three or more units will be arranged in such a manner.

The opposing walls (5) and interconnecting walls (3) are an integral polypropylene unit (2) formed by an extrusion process. The size of the channels (8) and thickness of the walls (5, 7) will depend upon the intended use of the condenser (1 ). In this embodiment, structures commercially know as Correx form the unit (2).

As illustrated in figure 3, in use, a delivery input conduit (not shown) introduces fluid into the channels (8) at one end (3) of each of the units (2). The fluid flows from the one end (3) to the second end (4) through the channels (8) in the direction of arrow A, as shown in figure 1. The fluid exits the channels (8) into an outlet conduit (not shown). Vapour travelling substantially horizontally enters the condenser (1 ) in the spaces between the adjacent units (2) in the directions of the arrows B. The temperature of the fluid in the channels (8) is substantially lower than the temperature of the vapour such that the vapour condenses on the external surface of the opposed walls (5). The condensed vapour flows down the surface of the opposed walls (5) in the direction of arrow C until it reaches a trough (not shown).

The embodiment shown in figure 4 has two units having planar and parallel opposing walls and straight interconnecting walls (7). The interconnecting walls (7) are perpendicular to the opposing walls (5) thereby proving channels (8) that have a traverse cross section in the shape of a square. The channels (8) extend fully from the one end (3) of the unit (2) to the second end (4) of the unit (2). The channels are suitable for a fluid to pass along the channel such that they are conveyed all the way through the unit (2). In this embodiment the fluid is intended to flow from the one end (3) to the second end (4) of the unit (2) in the direction of arrow A.

Each unit (2) is folded to form two planar segments (15). In this embodiment the unit (2) is folded in half. However, the segments (15) may be of different sizes and more than one fold may be formed in a single unit (2). The folded section (16) between the two segments (15) is a living hinge. However, the folded section (16) could be a simple fold of the unit (2) to form a plurality of segments (15). The angle a ^° between the segments (15) of each unit is between 5 to 175 degrees. The angle will depend on the intended use of the condenser (1 ).

The opposing walls (5) and interconnecting walls (3) are an integral polypropylene unit (2) formed by an extrusion process. The size of the channels (8) and thickness of the walls (5, 7) will depend upon the intended use of the condenser (1 ). In this embodiment, a structure commercially known as Correx forms the unit (2). As illustrated in figure 4, in use, a delivery input conduit (not shown) provides fluid into the channels (8) at one end (3) of each of the units (2). The fluid flows from the one end (3) to the second end (4) through the channels (8) in the direction of arrow A, as shown in figure 1. The fluid exits the channels (8) into an outlet conduit (not shown). Vapour travelling substantially horizontally enters the condenser (1 ) in the spaces between the adjacent units (2) in the direction of the arrows B. The temperature of the fluid in the channels (8) is substantially lower than the temperature of the vapour such that the vapour condenses on the external surface of the opposed walls (5). The condensed vapour flows down the surface of the opposed walls (5) in the direction of arrow C until it reaches a trough (not shown).

The described molecular condensers may be used in a desalination process, distillation process, waste fluid separation process/unit or self-irrigation greenhouse.

When used in this specification and claims, the terms "comprises" and "comprising" and variations thereof mean that the specified features, steps or integers are included. The terms are not to be interpreted to exclude the presence of other features, steps or components.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.