WO2023220787A1

WO2023220787A1 - "seaweed harvester"

Info

Publication number: WO2023220787A1
Application number: PCT/AU2023/050427
Authority: WO
Inventors: Ray Henderson; John ROWBOTTOM; Phil CASSIDY; Shane MCHUGH
Original assignee: Sea Forest Limited
Priority date: 2022-05-20
Filing date: 2023-05-19
Publication date: 2023-11-23

Abstract

A harvesting device (10, 110) for harvesting biomass (12) growing on a substrate material (14), comprises a main pipe (16, 116) extending between a main inlet (18, 118) and a first outlet (20, 120), a branch pipe (22, 122) branching from the main pipe (16, 116) at a position between the main inlet (18, 118) and the first outlet (20, 120). The branch pipe (22, 122) opens into the main pipe (16, 116) at a branch pipe inlet (24, 124) and extends from the main pipe (16, 116) to a second outlet (26, 126).

Description

"Seaweed Harvester "

Technical Field

[0001] The present disclosure relates to a harvesting device for harvesting a biomass present on a substrate material, to a system including the harvesting device for harvesting the biomass, and to a method of harvesting the biomass.

Background

[0002] Methane is a greenhouse gas whose presence in the atmosphere is considered to contribute to global warming. The red seaweed, Asparagopsis, has been shown to reduce the production of methane in sheep and cattle when included in their feed at low doses (for example, 0.1 - 2 %). The efficacy of Asparagopsis is largely dependent on its content of bioactive secondary metabolites, particularly bromoform. There is, therefore, a large and increasing global demand for Asparagopsis.

[0003] Asparagopsis is currently harvested by hand. Thus the harvesting is inefficient and slow and the volumes harvested by each individual are low and limited by an individual’s capacity to harvest. In addition, the integrity of the seaweed, especially the viability of the bioactive compounds contained within the cells of the seaweed, is degraded due to bruising of the plants by hand harvesting practices and extended exposure time to air. Hand harvesting also does not allow for sufficient or selective volumes of biomass with viable growth potential to remain on the substrate on which the Asparagopsis has been grown after harvesting. This is because the Asparagopsis biomass is exposed to air for too long during the harvesting process, the plants become damaged and bruised and, in some instances, are removed completely from the substrate.

[0004] Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present disclosure as it existed before the priority date of each of the appended claims. Summary

[0005] According to the present disclosure, there is provided a harvesting device for harvesting biomass growing on a substrate material, comprising: a main pipe extending between a main inlet and a first outlet; a branch pipe branching from the main pipe at a position between the main inlet and the first outlet, the branch pipe opening into the main pipe at a branch pipe inlet and extending from the main pipe to a second outlet.

[0006] The main pipe has a longitudinal axis. The branch pipe inlet has a width in a direction substantially transverse to the longitudinal axis of the main pipe and a length in a direction substantially parallel to the longitudinal axis of the main pipe. The width of the branch pipe inlet may be greater than the length of the branch pipe inlet.

[0007] The branch pipe inlet may be in the shape of an ellipse. In that case, an axis of the ellipse may lie in the width direction and the minor axis of the ellipse may lie in the longitudinal direction. In other words, the main axis of the ellipse may correspond to the width of the branch pipe inlet and the minor axis of the ellipse may correspond to the length of the branch pipe inlet.

[0008] The branch pipe inlet may be in the shape of a circle and have a constant diameter.

[0009] The main pipe may include a first section in the form of a main section and a second section in the form of an outlet section. The first section (the main section) may be directly or indirectly connected to the second section (the outlet section). The outlet section may terminate in the first outlet. The main pipe may also include a third section in the form of an inlet section. The third section (the inlet section) may be directly connected to the first section. Therefore, when the main pipe includes the first section, the second section, and the third section, the main pipe may be arranged between the third section and the second section. The diameter of the main section may be substantially constant along the length of the main section. The diameter of the outlet section may decrease toward the first outlet. The outlet section may be tapered with the wide end toward the main section and the narrow end toward the first outlet. The inlet section may extend from the first inlet to the main section. The diameter of the inlet section at the first inlet may be greater than the diameter of the main section. The inlet section may be tapered with the wide end being at the main inlet and the narrow end being proximate the main section. The inlet section may be in the shape of a truncated cone. The inlet section may be funnel shaped. The inlet section may be bell shaped. The outlet section may be funnel shaped with the narrow end of the funnel forming the first outlet and the wide end of the funnel being proximate the main section. The average diameter of the outlet section may be less than the average diameter of the inlet section. The average diameter of the inlet section may be greater than the average diameter of the main section.

[0010] The main inlet may have a diameter greater than a diameter of the main pipe at the branch pipe inlet. The first outlet may have a diameter which is smaller than the diameter of the main pipe at the branch pipe inlet.

[0011] The main pipe includes a tapered section downstream of the branch pipe inlet, and a narrow end of the tapered section terminates in the first outlet.

[0012] The branch pipe may be connected to the main section of the main pipe.

[0013] In normal use, typically, the substrate material travels through the harvesting device in a direction from the main inlet to the first outlet. In other words, the substrate material travels through the main inlet through the main section and out of the harvesting device through the first outlet.

[0014] At least one guide element may be positioned within the main pipe and be configured to guide the substrate material received in the main inlet to the first outlet such that the substrate material does not enter the branch pipe.

[0015] The harvesting device may have a plurality of guide elements spaced at intervals such that the biomass separated from the substrate material can pass between the guide elements and into the branch pipe. The at least one guide element may include a guide plate located in the vicinity of the main inlet. The guide plate may be configured to direct fluid flowing into the main pipe toward a wall of the main pipe opposite the branch pipe inlet.

[0016] An internal diameter of the main inlet may be greater than an internal diameter of the first outlet. An internal diameter of the main pipe may decrease gradually toward the first outlet. The main pipe may include a tapered section in which the main pipe narrows or tapers gradually toward the first outlet.

[0017] The branch pipe may narrow to a constriction having an internal diameter which is less than an internal dimeter of the branch pipe at the branch pipe inlet and an internal diameter of the branch pipe at the second outlet. The constriction may generate a venturi effect or a venturi-like effect in the flow of fluid in the branch pipe.

[0018] The biomass may be an organism including, for example, aquatic plants, seaweeds, algae such as red algae (for example, Asparagopsis), and the like. The fluid may be water (for example, salt water or fresh water).

[0019] The substrate material may be a cable or a rope configured for attachment of the biomass.

[0020] Also disclosed herein is a harvesting system, comprising: a harvesting device as described above, a pump having a pump inlet connected directly or indirectly to the second outlet of the harvesting device and configured to draw fluid and the biomass separated from the substrate material from the branch pipe.

[0021] The harvesting device may be connected to the second outlet by a hose.

[0022] The harvesting system may include a mounting bracket for mounting the pump to a harvesting vessel. The harvesting device may also be mountable on the mounting bracket such that the pump and harvesting device are fixed relative to each other. Alternatively or additionally, the harvesting device may be fixed to the pump and thereby the pump and harvesting device may be fixed relative to each other. The bracket may be configured to allow the pump and the harvesting device to move relative to the harvesting vessel such that movement of the pump and harvesting device relative to substrate material and/or the fluid is less than movement of the harvesting vessel relative to the substrate material.

[0023] The mounting bracket may be configured to hold the pump and/or the harvesting device at a position completely submerged below water level. Positioning the pump completely submerged below water level may also position the harvesting device completely submerged below water level. [0024] The pump may be arranged on the vessel away from the harvesting device. The harvesting device may be connected to the pump via a hose or pipe. The pump may be arranged on a deck of the vessel. The harvesting system may include a mounting bracket for mounting the harvesting device independently of the pump. Such a mounting bracket may suspended the harvesting device below the surface of the water.

[0025] The harvesting system may include a hauler which pulls the substrate material through the main pipe of the harvesting device.

[0026] The harvesting system may include a controller which controls the operation of the hauler and the pump in order to adjust the rate of travel of the substrate material through the main pipe relative to a flow rate of the fluid through the main pipe and/or through the branch pipe.

[0027] The harvesting system may include a collection unit in which the biomass drawn through the pump is collected, wherein the biomass is maintained within the fluid from when the biomass enters the main pipe to when the biomass is collected in the collection unit.

[0028] Disclosed herein is a harvesting method for harvesting biomass in an aquatic environment. The method includes drawing a substrate material to which the biomass is attached through a first pipe having a main inlet and a first outlet, the first pipe being connected to a branch pipe having a branch pipe outlet; drawing fluid from the branch pipe outlet to cause a flow of the fluid into the main pipe and into the branch pipe, and regulating the flow of the fluid such that the biomass separates from the substrate material and flows with the fluid into the branch pipe.

[0029] The method may include connecting a pump directly or indirectly to the outlet of the branch pipe to draw the fluid from the branch pipe. The method may include connecting the pump to the outlet of the branch pipe via a hose or pipe. This may allow the harvesting device to be positioned away from the pump and the harvesting vessel. It may allow harvesting to be carried out closer to where the substrate material is deployed while the biomass is growing. [0030] The method may include generating a venturi effect or a venturi-like effect in a flow of the fluid in the branch pipe to assist in harvesting the biomass.

[0031] The method may include transferring the biomass separated from the substrate material into a collection unit with at least a portion of the fluid.

[0032] The harvesting method may include maintaining the biomass in the fluid during the harvesting process to avoid exposure of the biomass to air.

[0033] Throughout this specification the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

Brief Description of Drawings

[0034] Figure 1 is schematic side sectional view of a harvesting device according to a first embodiment of the present disclosure.

[0035] Figure 2 is a schematic cross-sectional view of the harvesting device along the line indicated by the arrows II-II in Figure 1.

[0036] Figure 3 is a schematic view of an end of the harvesting device shown in Figure 1 and shows an outlet end of the harvesting device.

[0037] Figure 4 is a schematic view of another end of the harvesting device shown in Figure 1 and shows an inlet end of the harvesting device.

[0038] Figure 5 is a schematic perspective view of a harvesting device according to a second embodiment of the present disclosure.

[0039] Figure 6 is a plan view of the harvesting device shown in Figure 5.

[0040] Figure 7 is a front view of the harvesting device shown in Figure 5.

[0041] Figure 8 is side view of the harvesting device shown in Figure 5.

[0042] Figure 9 is a cross-sectional view of the harvesting device along the line indicated by the arrows IX-IX in Figure 7. [0043] Figure 10 is a schematic diagram of a harvesting system including a harvesting device according to an embodiment of the present disclosure.

[0044] Figure 11 is a schematic diagram of a mounting bracket with a pump mounted thereon.

Description of Embodiments

[0045] With reference to Figures 1 to 6, reference number 10 generally designates a harvesting device in accordance with an embodiment of the present disclosure. The harvesting device 10 is for harvesting biomass 12 which is adhered to a substrate material 14 (represented by a broken line in Figure 1). The harvesting device 10 includes a main pipe 16 extending between a main inlet 18 (see Figure 4) and a first outlet 20 (see Figure 3). The harvesting device 10 also includes a branch pipe 22 which branches from the main pipe 16 at a position between the main inlet 18 and the first outlet 20. The branch pipe 22 opens into the main pipe 16 at a branch pipe inlet 24 and extends from the main pipe 16 to a second outlet 26. In this first embodiment, the harvesting device 10 includes at least one guide element 28 positioned within the main pipe 16. The guide elements 28 are configured to guide the substrate material 14 received into the main pipe 16 through the main inlet 18 to the first outlet 20 such that the substrate material 14 does not enter the branch pipe 22.

[0046] The substrate material 14 is a material suitable for forming a framework upon which an organism or living material may live and grow or a material to which an organism may become attached. Non-limiting examples of such organisms include, for example, aquatic plants, seaweeds, algae, such as red algae (for example, Asparagopsis), and the like. In the case of seaweeds and alga, the substrate material may be suitable for the attachment of holdfasts. The substrate material 14 may be in the form of a rope or cable. In the present disclosure, the organisms or living material present on the substrate material 14 are referred to generally as “biomass”. In addition, while the biomass which is on the substrate material may have been alive and growing on the substrate material at some time, it will be appreciated that the biomass may not be alive at the time of harvesting. In addition, while the term organism has been used broadly above, it will be appreciated that only a portion of an organism may be present on the substrate material. It will be appreciated from this disclosure that the harvesting device 10 is suitable for harvesting seaweed or algae grown on the substrate material 14 in an aquatic environment.

[0047] As can be seen from Figures 1 and 2, in the embodiment shown, some of the guide elements 28 are in the form of rods or bars 30 which extend across the interior 32 of the main pipe 16. The rods 30 are spaced at intervals. In this embodiment, the rods 30 lie along a center line across the main pipe 16. In addition, in the embodiment shown, one of the guide elements is in the form of a guide plate 36. As can be seen for example in Figure 1, the guide plate 36 is located in the vicinity of the main inlet 18. The guide plate 36 is located in the main pipe 16 at a position between the main inlet 18 and the branch pipe inlet 24. The guide elements 28 are arranged to guide the substrate material 14 which has entered the main pipe 16 via the main inlet 18 through the main pipe 16 to the first outlet 20 and to avoid the substrate material 14 from being drawn into the branch pipe 22. While the guide elements 28 are configured and arranged to reduce the likelihood that the substrate material 14 will be drawing into the branch pipe 22, it will be appreciated that guide elements 28 are configured to allow other materials such as fluids and biomass (for example, biomass separated from the substrate material) to pass between or around the guide elements 28.

[0048] The guide plate 36 is configured to guide the substrate material 14 as it enters the main pipe 16 via the main inlet 18 toward a side of the main pipe 16 away from branch pipe inlet 24. In the embodiment shown in Figure 1, the guide plate 36 is arranged on three rods 30 which in the absence of the guide plate 36 would together with the other rods 30 function as guide elements 28. Thus, in another embodiment (not illustrated), the guide plate 36 is omitted and the rods 30 guide the substrate material 14 through the main pipe 16. It will be appreciated that, when present, the guide plate 36 assists with the process of guiding the leading end of substrate material 14 through the main pipe 16 when it is first threaded through the main pipe 16 as part of the harvesting process discussed in more detail below. It will be appreciated that this threading process is still possible without the guide plate 36. The guide plate 36 also acts to direct fluid flowing into the main pipe 16 toward a wall 34 of the main pipe 16 opposite the branch pipe inlet 24. [0049] With reference to Figure 1, an internal diameter of the main inlet 18 is greater than an internal diameter of the first outlet 20. In addition, as can be seen in Figure 1, in this embodiment, the main pipe 16 includes a main section 19 and a tapered section (or outlet section) 17 where the main pipe 16 narrows or tapers gradually toward the first outlet 20. In the tapered section 17, the internal diameter of the main pipe 16 narrows or decreases gradually toward the first outlet 20. In this embodiment, the narrowing of main pipe 16 in the tapered section 17 occurs in the area of the main pipe 16 downstream of the branch pipe inlet 24. In addition, in this embodiment, the guide elements 28 are not present in this narrowing section of the main pipe 16. In this embodiment, in the main section 19 of the main pipe 16, the internal diameter of the main pipe 16 remains substantially the same along the length of the main section 19. In an alternative embodiment, the internal diameter of the main section 19 may vary and, for example, the internal diameter may decrease slightly from the main inlet 18 to the tapered section 17.

[0050] In this disclosure, except where otherwise indicated, the terms “downstream” and “upstream” are used with respect to a direction of movement of the substrate material 14 through the main pipe 16 of the harvesting device 10 where the substrate material 14 enters the harvesting device 10 through the main inlet 18 and exits the harvesting device 16 via the first outlet 20.

[0051] With reference to Figure 1, the branch pipe 22 narrows to a constriction or neck 38 having an internal diameter which is less than an internal dimeter of the branch pipe 22 at the branch pipe inlet 24 and an internal diameter of the branch pipe 22 at the second outlet 26 such that a venturi effect is generated in the flow of fluid in the branch pipe 22. This is discussed in more detail below.

[0052] By way of an example, in one embodiment, a length of the main pipe 16 from the main inlet 18 to the first outlet 20 may be 510 mm. An internal diameter of the main pipe 16 at the main inlet 18 may be 145 mm. An internal diameter of the main pipe 16 at the first outlet 20 may be 100 mm. The internal diameter of the main pipe 16 may decrease gradually from 160 mm from the first outlet 20 to the first outlet 20. In this region, the internal diameter of the main pipe 16 may decrease gradually from 145 mm to 100 mm. The length of the branch pipe 22 from the branch pipe inlet 24 to the second outlet 26 may be 330 mm. The constriction or neck 38 may be 160 mm from the second outlet 26. The internal diameter of the branch pipe 22 where it is connected to the main pipe 16 may be 140 mm and the internal diameter of the branch pipe 22 at the second outlet may be 140 mm. The internal diameter of the branch pipe 22 at the constriction or neck may be 100 mm. The branch pipe at the branch pipe inlet 24 has an internal diameter which is similar to and slightly smaller than the internal diameter of the main inlet 18. The guide bars 30 may be evenly spaced along the interior of the main pipe 16. For example, with reference to the dimensions given above, the guide bars 30 may be spaced at intervals of 50 mm (centre to centre). However, it is possible for the guide bars to be space at different intervals. In addition, the interval between the end of the guide plate 36 and the first guide bar 30 (the “first” guide bar being closest to the main inlet 18) may be different to the interval between the guide bars 30. For example, with reference to the example given above, the interval between the guide plate 36 and the first guide bar 30 may be, for example, 60 mm. This may assist in vacuuming the biomass from the substrate material 14 where the flow of fluid toward the branch pipe 22 may be stronger.

[0053] The harvesting device 10 may be metal or plastic. In an example, the harvesting device is made from a steel and may be made from a stainless steel selected in light of the environment in which the harvesting device will be used. Such environments may include fresh water aquatic environments, brackish water environments, or saltwater marine environments. The harvesting device may be made from a 2 mm stainless steel sheet. The guide bars 30 may be compatible 12 mm diameter stainless steel rods.

[0054] Figures 5 to 9 illustrate a second embodiment of a harvesting device 110 according to the present disclosure. Components of the second embodiment which are the same, similar, or correspond to components of the first embodiment have been given the same reference number preceded by a “1”. A full description of those components may be omitted below and in that case the reader is referred to the description above. In some instances, different reference numbers have been used.

[0055] With reference to Figures 5 to 9, reference number 110 generally designates a harvesting device in accordance with a second embodiment of the present disclosure. The harvesting device 110 is for harvesting biomass 12 which is adhered to a substrate material 14 (represented by the solid line in Figure 9). The harvesting device 110 includes a main pipe 116 extending between a main inlet 118 (see Figure 8) and a first outlet 120 (see Figures 8 and 9). The harvesting device 110 also includes a branch pipe 122 which branches from the main pipe 116 at a position between the main inlet 118 and the first outlet 120. The branch pipe 122 opens into the main pipe 116 at a branch pipe inlet 124 and extends from the main pipe 116 to a second outlet 126. Unlike the first embodiment, in this second embodiment, the harvesting device 110 does not include guide elements within the main pipe 116. However, in an alternative embodiment (not illustrated) a harvesting device 110 may include one or more guide elements such as those discussed with respect to the first embodiment.

[0056] As discussed above, the substrate material 14 is a material suitable for forming a framework upon which an organism or living material may live and grow or a material to which an organism may become attached. In normal operation, the substrate material 14 is drawn into the main inlet 118 through the harvesting device 110 and out the first outlet (hence the use of the terms “inlet” and “outlet” refers to the passage of the substrate 14 through the harvesting device 110.

[0057] With reference to Figures 7 and 9, the main pipe 116 has a truncated cone- shaped inlet section (also referred to herein as a “third section”) 140, a main section (also referred to herein as a “first section”) 119 and a truncated cone-shaped tapered section (or outlet section - also referred to herein as a second section) 117. As will be appreciated from a comparison of Figures 1 and 8, the main section 119 and the tapered section (outlet section) 117 are similar to the main section 19 and the tapered section 17 of the harvesting device 10 of the first embodiment. The internal diameter of the main inlet 118 is greater than an internal diameter of the first outlet 120. The internal diameter of the main inlet 118 is also greater than the internal diameter of the main section 119. The inlet section 140 is funnel shaped as discussed in more detail below.

[0058] In addition, as can be seen in Figure 8, in this embodiment, the main pipe 116 narrows or tapers gradually toward the first outlet 120. In the tapered section 117, the internal diameter of the main pipe 116 narrows or decreases gradually toward the first outlet 20. In this embodiment, the narrowing of main pipe 116 in the tapered section 117 occurs in the area of the main pipe 116 downstream of the branch pipe inlet 124.

[0059] As with the first embodiment, with respect to this second embodiment, except where otherwise indicated, the terms “downstream” and “upstream” are used with respect to a direction of movement of the substrate material 14 through the main pipe 116 of the harvesting device 110 where the substrate material 14 enters the harvesting device 110 through the main inlet 118 and exits the harvesting device 116 via the first outlet 20.

[0060] With reference to Figure 5 to 9, in this embodiment, the branch pipe inlet 124 has the shape of an ellipse. In Figure 7, an outline of the branch pipe inlet 124 is illustrated with dashed lines to illustrate the shape of the branch pipe inlet (it will be appreciated that the branch pipe inlet 124 cannot actually be seen in this view). The main axis of the ellipse (along the line LD-LD in Figure 7) is transverse with respect to the longitudinal axis (LA-LA (LD-LD) in Figure 7) of the main pipe 116. As a result, the main axis of the ellipse is also transverse to the direction of travel of the substrate 14 through the harvesting device 110 (see Figure 9) during the normal harvesting operation described in more detail below. This is in contrast to the branch pipe inlet 24 of the first embodiment in which the branch pipe inlet 24 is more circular (see Figure 2).

[0061] The shape of the branch pipe inlet 124 is not limited to an ellipse. There are advantages associated with the branch pipe inlet 124 being wider (having a larger dimension for the major axis in the case of an ellipse) in the lateral (circumferentially) or transverse direction (for example, along the line LD-LD in Figure 7) with respect to the longitudinal axis (LA-LA in Figure 7 and Figure 8) of the main pipe 116 than in the longitudinal direction (LD-LD in Figure 7) (having a smaller dimension for the minor axis in the case of an ellipse) with respect to the longitudinal axis of the main pipe 116. For the sake of completeness, the longitudinal direction (LD) is a direction parallel to the longitudinal axis (illustrated in Figures 7 and 8 by the line LA (LD) -LA (LD)). By being wider in the lateral direction, the suction of water and biomass into the branch pipe 122 through the branch pipe inlet 124 is distributed to a greater extend across the width of the main pipe 116. By being narrower in the longitudinal direction LD, the likelihood of the substrate 14 itself being drawing into the branch pipe 122 is reduced. In the present embodiment, the ellipse shape of the branch pipe inlet 124 may be achieved by applying pressure to the end 142 of the pipe which is to be used to form the branch pipe 122 during manufacture such that the reduction in length (corresponding to the minor axis of the ellipse) of the branch pipe inlet 124 (in a direction corresponding to the longitudinal axis of the main pipe 118 after manufacture) is accompanied by an increase in the width (corresponding the major axis of the ellipse) of the branch pipe 124 in the lateral or transverse direction (transverse or lateral with respect to the longitudinal axis of the main pipe). As indicated above, shapes other than an ellipse are possible for the shape of the branch pipe inlet 124 and shapes in which the lateral dimension (with respect to the longitudinal axis of the main pipe 116) of the branch pipe inlet 124 is greater than the longitudinal dimension (with respect to the longitudinal axis of the main pipe 116) of the branch pipe inlet 124 may provide the above mentioned advantages.

[0062] By way of a non-limiting example with respect to this second embodiment, in one example, a length of the main pipe 116 from the main inlet 118 to the first outlet 120 may be 1320 mm. An internal diameter of the main pipe 116 at the main inlet 118 may be 570 mm. An internal diameter of the main section 119 of the main pipe 116 may be 224 mm. The length of the inlet section 140 may be 420 mm. The length of the tapered section (the outlet section) 117 may be 300 mm. The length of the main section 119 (the porting have the same internal diameter) between the inlet section 140 and the tapered section 117 may be 600 mm. Therefore, in the tapered section 117, the internal diameter of the main pipe 16 may decrease gradually from 224 mm to 70 mm. The length of the branch pipe 122 from the branch pipe inlet 124 to the second outlet 126 may be approximately 410 mm when measured along the longest portion of the branch pipe 122 (that is, the length indicated roughly by the line “LI” in Figure 9). Unlike the first embodiment, there is no constriction or neck in this second embodiment.

[0063] The diameter of the branch pipe 122 at the second outlet 126 may be for example 150 mm. In contrast, the length of the minor axis of the ellipse that forms the branch pipe inlet 124 may be for example 100 mm. The second outlet 126 is configured for connection to a hose or a pipe such as by a cam lock female fitting or by other suitable connection methods. In contrast to the branch pipe inlet 124, as the second outlet 126 is configured for connection to hose or a pipe, the second outlet has a shape suitable for mating with the end of the hose or pipe and, in this embodiment, the second outlet 126 is circular in shape as can be seen in Figure 7.

[0064] The harvesting device 110 may be metal or plastic or a combination thereof, for example, see the materials discussed above with respect to the first embodiment. In an example of the second embodiment, the harvesting device 110 is made from a high density polyethylene (HDPE). HDPE has the advantage of being corrosion resistant. The thickness of the high density polyethylene may be 15 mm. It will be appreciated that the harvesting device 10 of the first embodiment may also be manufactured from high density polyethylene.

[0065] In this embodiment, the inlet section 140 has a truncated-cone shape or a funnel shape. The edge or rim 144 of the inlet opening 118 is rounded and curved. The curved surface of the edge 144 of the inlet opening 118 reduces the likelihood (for example, compared with a straight edge) of the substrate 14 catching on the opening 118 and also reduces the likelihood that the biomass 12 adhered to the substrate 14 is damaged or removed from the substrate 14 as the substrate 14 with the biomass 12 enters the harvesting device 110. The wider opening of the entrance section 140 also acts to guide for the substrate 14 with the biomass 12 into the main section 119 of the main pipe 116.

[0066] In this embodiment, the branch pipe 122 extends at an angle A (see Figure 9) to the main pipe 116 giving the harvesting device 110 a more y-shaped (i.e., lower case “y” shape) appearance when viewed from the side (see Figures 8 and 9 - in which the “y” shape profile is reversed). It will be appreciated that the branch pipe 122 angled in this way facilitates the connection of a hose or pipe which is in turn connected to a pump located on the deck, for example, of the vessel and reduces the likelihood (compared for example with a branch pipe 22 which extends at right angles from the harvesting device) that the hose or pipe may bend or kink. [0067] The harvesting device 110 includes a cleat 146 to assist in moving and positioning the harvesting device 110.

[0068] With reference to Figure 10, reference number 200 generally designates a harvesting system in accordance with an embodiment of the present disclosure. Figure 10 is a simple schematic diagram and shows various components of the harvesting system 200. The harvesting system 200 includes the harvesting device 10 of the first embodiment described above. However, the harvesting system 100 may include the harvesting device 110 of the second embodiment as discussed in more detail below.

[0069] As shown in Figure 10, the harvesting system 200 also includes a pump 202. The second outlet 26 of the harvesting device 10 is configured for connection to the pump inlet 204 (see Figure 11) either directly or indirectly. In the case of an indirect connection, the harvesting device 10 may be connected to the pump inlet 204 via a hose or pipe (not shown in the drawings). The pump 202 has a pump outlet 206 which is connected to a discharge (or delivery) pipe 208 through which fluid, biomass 12, and other material which has been drawn into the pump 202 from the harvesting device 10 through the pump inlet 204 is discharged. The delivery pipe 208 discharges or delivers the fluid, biomass 12, and other material into a first container in the form of a collection container 210 which is arranged within a larger second container in the form of a holding container 212. The collection container 210 has a mesh or net like structure configured to allow at least some of the fluid to leave the collection container 210 while keeping the biomass within the collection container 210. In this way, the collection container 210 functions as a concentration vessel in which the biomass accumulates. As the collection container 210 is maintained within the larger holding container 212 which holds the fluid, it is possible maintain the biomass 12 within the fluid with which it was harvested and reduce the likelihood of exposure to air.

[0070] The harvesting system 100 also includes a hauler 214. The leading end of the substrate material 14 can be engaged with the hauler 214 in order for the substrate material 14 to be pulled through the main pipe 16 of the harvesting device 10. The hauler 214 may be in the form of winch and the substrate material 14 may be wound up and collected by the winch. However, the hauler 214 may be configured to pull the substrate material 14 through the harvesting device 10 and then re-deploy the substrate material 14 back into the aquatic environment. In that case, any biomass 12 remaining on the substrate material 14 after harvesting may grow and produce another crop of biomass 12 to be harvested in the future. In addition, new biomass 12 may become attached naturally to the substrate material 14 or it may be positioned manually onto the substrate material 12 in order to produce the next crop of biomass 12.

[0071] The harvesting system 200 may also include a mounting bracket 216 (not shown in Figure 10) as shown schematically in Figure 11 for mounting the pump 202 on a harvesting vessel (not illustrated). When the harvesting device 10 is connected directly to the pump 202, the harvesting device 10 may also be mountable on the mounting bracket 216 such that the pump 202 and harvesting device 10 are fixed relative to each other. Alternatively or additionally, the harvesting device may be fixed to the pump 202 during harvesting. Preferably, the mounting bracket 216 is configured such that the pump 202 and the harvesting device 10 are completely submerged in the fluid (e.g., sea water) during harvesting. This has the advantage of reducing exposure of the biomass 12 to air during the harvesting process.

[0072] The mounting bracket 216 may be configured to buffer the pump 202 and the harvesting device 10 such that not all movement of the harvesting vessel is transmitted to the pump 202 and the harvesting device 10. For example, the mounting bracket 216 may be mounted to the harvesting vessel at or toward a first end 218 and the pump 202 and the harvesting device 10 may be mounted to the mounting bracket 216 at or toward a second end 220 with respect to the position at which the mounting bracket 216 is mounted on the harvesting vessel. The first end 218 may be mounted so that it can pivot at its connection point to the harvesting vessel and the second end 220 may be a free end such that the free end 220, the pump 202 and the harvesting device 10 are submerged and supported within the fluid. Configuring the mounting bracket 216 in this way allows for the harvesting vessel and the pump 202 with the harvesting device 10 to move relative to each other. Therefore, movements of the pump 202 and the harvesting device 10 relative to the surrounding fluid during harvesting due to movement of the harvesting vessel can be reduced. This reduces the likelihood that movement of the harvesting vessel will impact the movement of the substrate material 14 into and through the harvesting device 10 and reduce damage to the biomass or the biomass breaking loose from the substrate material 14 before it is harvested.

[0073] The hauler 214 may also be mounted on the harvesting vessel.

[0074] The harvesting system may also include a controller 222 which controls the operation of the hauler 214 and the pump 202 in order to adjust the rate of travel of the substrate material 14 through the main pipe 16 relative to the flow rate of the fluid through the main pipe 16 and the branch pipe 22. The controller 222 may be configured for wired or wireless connection to the pump 202 and the hauler 214.

[0075] In the embodiment shown in Figure 10, during harvesting, the substrate material 14 travels into the harvesting device via the main inlet 18 through the main pipe 16 and out of the first outlet 20. The path of the biomass 12 during harvesting is indicated by the dotted line. The dotted line illustrates the biomass 12 being adhered to the substrate 14 before the substrate 14 enters the harvesting device 10 and illustrates the biomass 12 being separated from the substrate 14 within the harvesting device 10. As is explained above, some of the biomass 12 may not be removed from the substrate material 14 as the substrate material 14 passes through the harvesting device 10 and therefore some of the biomass 12 may remain attached to the substrate material 14 and travel with the substrate material 14 out of the first outlet 20 of the main pipe 16.

[0076] As illustrated schematically in Figure 10, the substrate material 14 together with the biomass 12 (see item (4) in Figure 10) is drawn into the harvesting device 10 by the hauler 214 in the direction indicated by arrow S. The substrate material 14 passes through the main pipe 16 from the main inlet 18 to the first outlet 20.

[0077] During harvesting, the pump 202 is also operating and draws fluid into the pump 10 through the harvesting device 10. In order to harvest the biomass 12 attached to the substrate material 14, the pump 202 is operated at a level sufficient for the biomass to be pulled (or vacuumed) from the substrate material 14. As explained above, the separate biomass flows together with the fluid into the branch pipe 22 through the pump 202 and into the concentration vessel 210.

[0078] As explained above, the harvesting device 10 is configured in such a way as to guide the substrate material 12 through the harvesting device 10 and reduce the likelihood the substrate material 12 will be pulled into the branch pipe 22 or the pump 202 or to cause blockages within the harvesting device 10. The harvesting device 10 is also configured to assist with the vacuum efficiencies which pull the biomass 12 from the substrate material 14. Preferably, the majority of the suction occurs within the main pipe 16 in the vicinity of the branch pipe inlet 24. In addition, a secondary suction effect in the form of a venturi or venturi like effect further increases the vacuum efficiencies in the neck 38 of the branch pipe 22 where the branch pipe 22 narrows and then widens. In that regard, as described above, in the embodiment shown in Figure 1, the main inlet 18 has an internal diameter which is larger than the first outlet 20. In addition, the main pipe 16 narrows or tapers toward the first outlet 20. The internal diameter of the branch pipe 22 at the branch pipe inlet 24 is similar to but slightly smaller than the internal diameter of the main pipe 16 at the main inlet 18. It will be appreciated therefore that under the influence of the pump 202 more fluid will enter the harvesting device 10 via the main inlet 18. The fluid will be drawn into the branch pipe 22 at the branch pipe inlet 24. It will also be appreciated that the vacuuming of biomass 12 from the substrate material 14 within the harvesting device 10 will occur even when the constriction 38 in the branch pipe 22 is not present and that any venturi or venturilike effects which are produced by the constriction 38 in the branch pipe 22 are additional to the vacuuming effects which occur when the constriction is not present. In that regard, the harvesting device 110 does not include a constriction.

[0079] The harvesting device 10 has a generally T-shape structure when viewed from the side (for example as shown in Figure 1). As can be seen from Figure 1, the longitudinal axis of the branch pipe 22 is substantially perpendicular to the longitudinal axis of the main pipe 16. This shape may have advantages, for example, when connecting the second outlet 26 on the branch pipe 22 to the pump inlet 204. However, the harvesting device 10 is not limited to this particular configuration and other shapes are possible, for example, the branch pipe 22 may extend at an angle to the main pipe 16 giving the harvesting device 10 a more y-shaped (i.e., lower case “y” shape) appearance when viewed from the side (see, for example, the second embodiment). In addition, the branch pipe 22 may be curved. It will be appreciated that the passage of the substrate material 14 through a straight pipe is likely to be smoother than it would be through a bent or curved pipe and therefore there are advantages to the main pipe 16 being substantially straight.

[0080] The pump 202 is preferably a variable speed hydraulic pump. By controlling the speed of the pump 202, a user may also control the amount of biomass 12 which is removed from the substrate material 14. A higher speed will remove a greater amount of biomass 12 and a lower speed will remove less biomass 12. If the substrate material 14 is to be redeployed in order for a further crop of biomass 12 to grow, then lower speed can be selected in order to leave suitable amount of biomass on the substrate material 14 to support the production of a further crop. The pump 102 is also operated at a level to remove the biomass 12 from the substrate material 14 such that the integrity of individual organisms or plants within the biomass 12 to be preserved as much as possible.

[0081] In addition to the operation of the pump 202, the speed with which the substrate material 14 is pulled through the harvesting device 10 is also controlled such that the vacuuming effects of the pump 202 are effective at removing the biomass 12 from the substrate material 14. If the pump 202 is operated at lower speeds, then the rate at which the substrate material 14 is drawn through the harvester may be reduced in order to remove sufficient biomass 12 at the pump’s lower speed. It will be appreciated that the movement of the substrate 14 through the harvesting device is primarily controlled by the hauler 114 and independent of the suction produced by the pump 202.

[0082] The pump 202 may be, for example, an Aqua-Life fish pump (for example, models BP25 to BP100) or similar types of pumps. Such “fish” pumps are configured to reduce damage or injury to the organisms which pass through the pump unit. Therefore, when used with the harvesting device 10, they assist with maintaining the integrity of the harvested biomass 12 and also assist in maintaining the biomass 12 within the fluid and reducing exposure of the biomass 12 to air.

[0083] The substrate material 14 may be for example a rope or a cable suitable for the attachment of the attachment and growth of the organisms which form the biomass.

The substrate material 14 may be for example a rope made from plastics (e.g. polyester, nylon, dyneema, polypropylene, polyethylene, blends of these polymers, and the like). The diameter of the rope or cable may be, for example, from 12 mm to 80 mm, or greater. The ropes or cables may comprise fine threads and have a looped structure to encourage the attachment and growth of the organisms forming the biomass 12. Examples of such ropes or cables are ropes suitable for growing mussels in the marine environment. It will be appreciated that the size of the substrate material 14 and the size of the harvesting device 10 will selected so as to be compatible. A harvesting device 10 have the dimensions specified above by way of example may not be suitable for use with a substrate material 14 having a diameter of 80 mm. Therefore, a larger harvesting device 10 may be selected where the biomass has been grown on a substrate material 14 having larger diameter. In that regard, the size of the harvesting device 10 itself is not limited and will be established based on the conditions under which the biomass 12 has grown and in which the biomass 12 is being harvested.

[0084] Using the example of the red algae Asparagopsis grown in a marine environment, 50 g to 2 kg of wet weight of Asparagopsis may be present per linear meter of rope (substrate material). Depending on the size of the harvesting device 10, the operating speed of the pump 202, and the rate at which the substrate material 14 is drawn through the harvesting device 10, between 80% and 98% of the Asparagopsis present on the substrate material may be harvested, for example. The speed of the substrate material 14 through the harvesting device 10 may be, for example, in a range from 200 m/hr to 6000 m/hr, a range of 400 m/hr to 4000 m/hr, and in a range of from 700 m/hr to 1500 m/hr. For example, a preferable speed may be 1000 m/hr. The pump 202 may be operated at speeds of, for example, 40 L/min to 660 L/min. The weight of the biomass 12 collected by the harvesting system 100 may be from 4t/hr to 55 t/hr. For example, with a rope carrying 500g of biomass per linear meter and a harvesting rate of 1000 m/hr, it would be possible to harvest approximately 0.5 t/hr of biomass. With a rope carrying 1 kg of biomass per linear meter and a harvesting rate of 6000 m/hr, it would be possible to harvest 6t/hr of biomass. The dimensions, speeds, weights, rates, etc., mentioned here are examples only and they are not intended to limit the scope of this disclosure. [0085] As will already be apparent from the above discussion, in order to harvest the biomass 12 (for example, Asparagopsis) which has grown on the substrate material 14, the various components of the harvesting system 200 are assembled for operation. The second outlet 26 of the harvesting device 10 is connected directly or indirectly to the pump inlet 204. In addition, in one embodiment, the harvesting device 10 is directly connected to the pump 202 and the pump 202 and the harvesting device 10 are mounted on a harvesting vessel by means of a mounting bracket 216. In this case, the pump 202 mounted in the mounting bracket 216 may be lowered over the side of a harvesting vessel and the mounting bracket 216 fitted to the harvesting vessel so that the pump 202 is suspended and submerged within the water and thereafter the harvesting device 10 may be fitted to the pump 202. In addition, a leading end of the substrate material 14 is passed or threaded through the main pipe 16 of the harvesting device 10 and then attached directly or indirectly to the hauler 214 which is typically located on the harvesting vessel. A first end of the pump discharge pipe 208 is fitted to the pump outlet 206 and a second end of the discharge pipe 208 is positioned in order to discharge the contents discharged from the pump 202 into a collection container 210 which is also typically located on board the harvesting vessel. The order of these steps is not particularly limited. In addition, other steps not specified here may be carried out. For example, cleaning, maintenance and testing may be carried out prior to harvesting beginning. In that regard, the discharge pipe 208 may not be positioned to discharge the biomass into the collection container 210 until an appropriate stage of setting up or harvesting.

[0086] During the harvesting process, the substrate material 14 to which the biomass 12 is attached is drawn through the main pipe 16 of the harvesting device 10. Fluid is drawn from the branch pipe outlet (the second outlet 26) by the pump 202 to cause a flow of the fluid into the main pipe 16 from around the harvesting device and into then into the branch pipe 22. Typically, the operation of the pump 202 and the hauler 214 is coordinated and their respective speeds are adjusted for optimum speed, efficacy and efficiency of the harvesting based on the particular circumstances, for example, the amount of biomass 12 on the substrate material 14 prior to harvesting and the amount of biomass 12 the user wishes to remain on the substrate material 14 after harvesting (which will produce the next crop). The coordination of the operation of the pump 202 and the hauler 214 may be controlled by the controller 222 discussed above. In addition, the flow of the fluid is regulated such that the biomass 12 is separated from the substrate material 14 and flows with the fluid into the branch pipe 22. This process may include generating a venturi effect or a venturi-like effect in the flow of the fluid in the branch pipe 22 to assist in harvesting the biomass 12. The venturi effect or venturi-like effect may be generated due to the presence of a constriction or neck in the branch pipe 22. The biomass 12 which has been separated from the substrate material 14 is collected in a collection container or unit 210 together with at least a portion of the fluid also drawn into the pump 202 with the biomass 12. Preferably, the biomass 12 is maintained in the fluid during the harvesting process to avoid exposure of the biomass to air. In that regard, using the example of Asparagopsis grown in a marine environment, the Asparagopsis is harvested from the substrate material 14 within the harvesting device 10 and travels together with the water (the fluid) which has been drawn into the harvesting device 10 by the pump 202. The Asparagopsis is maintained within the water as it travels from the harvesting device 10 through the pump 202 and the discharge pipe 208 into the collection container 210. As a result, the Asparagopsis is maintained within the water from when it enters the main pipe 16 to when the it is collected in the collection container 210 and thereby contact with air can be reduced or avoided.

[0087] As discussed above, the harvesting system 200 may include the harvesting device 110 of the second embodiment. In addition, as discussed above, the second outlet 26 of the harvesting device 10 or the second outlet 126 of the harvesting device 110 may be configured for connection to the pump inlet 204 (see, for example, Figure 11) either directly or indirectly. Using the harvesting device 110 as an example, the harvesting device 110 may be connected to the pump inlet 204 via a hose or pipe (not shown in the drawings). In that case, the harvesting device 110 may be suspended in the water (for example, below the water surface) adjacent the vessel and may be attached directly to the frame 218 rather than being attached to a pump attached in turn to the frame 218 as described above. In this alternative arrangement, the harvesting device 110 may be suspended from the side of a vessel with the main inlet 118 directed down and the first outlet 120 directed upward such that the longitudinal axis LA of the harvesting device 110 is arranged substantially vertically. The pump 202 is arranged on the deck of the vessel and the hose or pipe (not shown) connects the pump 202 with the second outlet 126 of the harvesting device 110.

[0088] With reference to Figure 9, the substrate 14 is pulled through the harvesting device 110 by the hauler 214 which is also located on the vessel.

[0089] In this disclosure the term fluid has been used to refer to the medium within which the biomass is present during the harvesting process. Fluid may include the water within which the biomass has been growing before harvesting and may be fresh water or salt water depending on the aquatic environment. In addition, the fluid may include other materials found in such environments such as sands or silts. The fluid may include a mixture or a slurry of such materials.

[0090] It will be appreciated from the above disclosure that the harvesting device provides an alternative to hand harvesting of biomass of organisms including seaweeds such as Asparagopsis grown on a substrate material. As a result, the harvesting device, the harvesting system, and harvesting method allow for the harvesting of increased volumes of biomass in an efficient manner compared with hand harvesting. In addition, adopting strategies which maintain the biomass within the fluid (for example, water) within which the biomass 12 has grown during the harvesting process can reduce the amount of time the biomass is exposed to air and any damage or deterioration which results therefrom. Such practices also assist in preserving the integrity of the plant and protecting the bioactive compounds contained within the cells of the plant, such as those found within the cells of the Asparagopsis plant which are considered an important ingredient as a feed supplement for sheep and cattle.

[0091] While the above disclosure has been made with a particular focus on Asparagopsis and on harvesting living Asparagopsis, it will be appreciated that the device, system and method disclosed herein may be suitable for other applications and for the harvesting of other organisms grown on a substrate material. It is not intended that the device, system and method disclosed herein be limited to the harvesting of live Asparagopsis. [0092] It will be appreciated from the above description that features of the first embodiment can be incorporated in the second embodiment and vice versa and the description of each embodiment is not intended to limit the present disclosure. By way of non-limiting examples, the guide elements described in the first embodiment may be incorporated into the second embodiment. In addition, the branch pipe of the second embodiment may be arranged such that the harvesting device 110 has a T-shaped profile. In addition, the inlet section of the second embodiment may be incorporated into the harvesting device 10 of the first embodiment. Furthermore, the arrangement in which the branch pipe inlet is wider than it is longer as described in the second embodiment may be adopted in the harvesting device 10 of the first embodiment.

[0093] It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the above-described embodiments, without departing from the broad general scope of the present disclosure. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

Claims

CLAIMS:

1. A harvesting device for harvesting biomass growing on a substrate material, comprising: a main pipe extending between a main inlet and a first outlet; a branch pipe branching from the main pipe at a position between the main inlet and the first outlet, the branch pipe opening into the main pipe at a branch pipe inlet and extending from the main pipe to a second outlet.

2. A harvesting device according to claim 1, wherein the main pipe has a longitudinal axis and the branch pipe inlet has a width in a direction substantially transverse to the longitudinal axis and a length in a direction substantially parallel to the longitudinal axis, and wherein the width of the branch pipe inlet is greater than length of the branch pipe inlet.

3. A harvesting device according to claim 1 or claim 2, wherein the branch pipe inlet is in the shape of an ellipse.

4. A harvesting device according to any one of claims 1 to 3, wherein a diameter of the main inlet is greater than a diameter of the main pipe at the branch pipe inlet.

5. A harvesting device according to any one of claims 1 to 4, wherein the main pipe includes a funnel shaped inlet section.

6. A harvesting device according to any one of claims 1 to 5, wherein at least one guide element is positioned within the main pipe and configured to guide the substrate material received in the main inlet to the first outlet such that the substrate material does not enter the branch pipe.

7. A harvesting device according to claim 6, comprising: a plurality of guide elements spaced at intervals such that the biomass separated from the substrate material can pass between the guide elements and into the branch pipe.

8. A harvesting device according to any one of the preceding claims, wherein an internal diameter of the main inlet is greater than an internal diameter of the first outlet.

9. A harvesting device according to any one of the preceding claims, wherein an internal diameter of the main pipe decreases gradually toward the first outlet.

10. A harvesting device according to any one of the preceding claims, wherein the branch pipe narrows to a constriction having an internal diameter which is less than an internal dimeter of the branch pipe at the branch pipe inlet and an internal diameter of the branch pipe at the second outlet.

11. A harvesting device according to any one of the preceding claims, wherein the biomass is red algae.

12. A harvesting device according to any one of the preceding claims, wherein the biomass is Asparagopsis.

13. A harvesting device according to any one of the preceding claims, wherein the substrate material is a cable configured for attachment of the biomass.

14. A harvesting system, comprising: the harvesting device according to any one of claims 1 to 13; and a pump having a pump inlet connected directly or indirectly to the second outlet of the harvesting device and configured to draw fluid and the biomass separated from the substrate material from the branch pipe.

15. A harvesting system according to claim 14, comprising: a mounting bracket for mounting the pump and/or the harvesting device to a harvesting vessel.

16. A harvesting system according to claim 15, wherein the harvesting device is mountable on the mounting bracket such that the pump and harvesting device are fixed relative to each other and move relative to the harvesting vessel such that movement of the pump and harvesting device relative to substrate material is less than movement of the harvesting vessel relative to the substrate material.

17. A harvesting system according to claim 15 or 16, wherein the mounting bracket is configured to hold the harvesting device at a position completely submerged below water level.

18. A harvesting system according to any one of claims 14 to 17, comprising: a hauler which pulls the substrate material through the main pipe of the harvesting device.

19. A harvesting system according to claim 18, comprising: a controller which controls the operation of the hauler and the pump in order to adjust the rate of travel of the substrate material through the main pipe relative to a flow rate of the fluid through the main pipe.

20. A harvesting system according to any one of claims 14 to 19, further comprising: a collection unit in which the biomass drawn through the pump is collected, wherein the biomass is maintained within the fluid from when the biomass enters the main pipe to when the biomass is collected in the collection unit.

21. A harvesting method for harvesting biomass in an aquatic environment, the method including: drawing a substrate material to which the biomass is attached through a first pipe having a main inlet and a first outlet, the first pipe being connected to a branch pipe having a branch pipe outlet, drawing fluid from the branch pipe outlet to cause a flow of the fluid into the main pipe and into the branch pipe, and regulating the flow of the fluid such that the biomass separates from the substrate material and flows with the fluid into the branch pipe.

22. A harvesting method according to claim 21, comprising: connecting a pump directly or indirectly to the outlet of the branch pipe to draw the fluid from the branch pipe.

23. A harvesting method according to any one of claims 21 to 22, comprising transferring the biomass separated from the substrate material into a collection unit with at least a portion of the fluid.

24. A harvesting method according to any one of claims 21 to 23, comprising: maintaining the biomass in the fluid during the harvesting process to avoid exposure of the biomass to air.