The invention is related to a method for removing water from sphagnum moss, wherein

- extracted sphagnum moss is fed to feed equipment included in the apparatus,

- sphagnum moss is transferred with the feed equipment for feeding sphagnum moss to a feed screw,

- sphagnum moss fed to the feed screw is fed with the feed screw to a pressing chamber of a press into a smaller volume,

- sphagnum moss in the pressing chamber of the press is compressed into a smaller volume for removing water from sphagnum moss through water removal openings included in the pressing chamber,

- dried sphagnum moss is removed from the press.

The invention is also related to apparatus for removing water from sphagnum moss and a work machine for extracting and drying sphagnum moss .

Sphagnummoss is vegetation living on the surface of natural wetland having a continuous structure composed of several sphagnum moss shoots. An individual sphagnummoss shoot 2 is depicted in Figure la. As shown in Figure lb, sphagnum moss 1 has leaves 3 connected to each other, to the surface and between of which free water or occlusion water 6 adheres. Leaves 3 have hyaline cells 4 connected to each other, the cell walls 7 of which form cavities, inside of which there is capillarily bound water 8, as shown in Figure lc .

Henceforth in this application, the term 'moss' is simply used for sphagnum moss, however, always referring to sphagnum moss. Moss differs significantly from peat, which is composed of partly dead moss and other dead wetland vegetation. In other words, peat means an organic soil type that has grown under extremely wet conditions and is incompletely decomposed as a consequence of slow decomposing of wetland plants. The degree of peat decomposition means the amount of amorphous humus compared to plant cells that have retained their original structure. In peat, hyaline cells are broken and peat has a more fine-grained structure compared to that of netlike moss. Because of the fine-grained structure of peat, the surface area of peat is notably larger than that of moss, which also increases the surface area for the binding of water in peat .

Publication FI 20130321 A represents prior art proposing a method and apparatus for handling moss. The object of the method is to extract moss from wetland and remove at least part of water contained in moss immediately after extraction before transporting moss from wetland. Water removal is desired since, at a lower water content, notably larger amounts of moss can be transported without transporting extraordinary water . Moss extraction is desiredduring the time of unfrozen ground when water removal can be performed without thawing already before transferring moss from wetland to further processing. Due to this, apparatus for removing water from moss must be moderately light in weight in order that it could be moved in natural wetland characterised by a low bearing capacity .

Removal of water from moss is generally quite challenging since, being a netlike structure, moss effectively binds water and restores its original volume at least to some extent after pressing, becoming stuck inside channels, for example.

The apparatus proposed in publication FI 20130321 A for removing water from moss includes a counter spindle screw press arranged on a pallet for removing water. However, a counter spindle screw press is quite heavy and, in practice, not adequately powerful to achieve sufficient dewaterinq efficiency at hiqh production capacities. In addition, the use of a counter spindle screw press heavily qrinds moss, breakinq its natural structure. When the structure of moss breaks, its surface area qrows and water has a larqer surface area to adhere to the surface of moss, which weakens dewatering. The breakage of the natural structure is also harmful in terms of further use of moss, since it is desired that moss is undamaged.

Furthermore, the apparatus according to the publication FI 20130321 A is poorly suitable for moss collection and dewatering, particularly if it is desired to move on the surface of trenchless or otherwise non—dried natural wetland, the bearing capacity of which is extremely low for heavy apparatus.

Prior art also includes various pieces of multistep apparatus for biomass drying where multistep pressing is used. One such apparatus is proposed in publication WO 2009/011906 A1. However, such apparatus is not suitable for moss drying because its breaks the cell structure of biomaterial for removing cell-internal water for drying biomaterial for combustion purposes. Correspondingly, prior art also includes publication DE 2608093, wherein apparatus is proposed for squeezing fruit in order to produce juice. The apparatus of this publication is also unsuitable for drying moss because its breaks the cell structure of biomaterial for removing cell-internal water.

The object of the invention is to provide a method that is more efficient than prior art methods and apparatus for removing water frommoss , with which it is possible to preserve the natural structure of moss better than in prior art methods . The characteristic features of the method according to this invention are set forth in the appended claim 1 and the characteristic features of the apparatus according to this invention are set forth in the appended claim 7. Another object of the invention is to provide a work machine that is better than prior art work machines for extracting and drying moss, with which moss can be efficiently extracted in natural wetlands as well. The characteristic features of the work machine according to the invention are set forth in the appended claim 15.

The object of the method according to the invention can be achieved with a method for removing water from moss, wherein extracted moss in the apparatus is fed to a feed screw using at least one mobile feed wall of a feed trough serving as feed equipment, while simultaneously compressing moss into a smaller volume for removing water on the surface of moss from moss, and moss fed to the feed screw is fed with the feed screw to a pressing chamber of a press into a smaller volume . In the method, moss is additionally compressed in the pressing chamber at a pressure of 10 - 40 bar with a piston included in the press into a volume smaller than that of moss for removing water from moss through water removal openings included in the pressing chamber, from hyaline cells of moss without breaking the structure of hyaline cells, and dried moss is removed from the press.

With the method according to the invention, remarkable amounts of water can be removed from moss by means of multistep dewatering without breaking the cell structure of moss. When dewatering is performed in several steps, the compression pressure and compression time applied in a single step remain moderate enabling water removal while keeping the natural cell structure of moss undamaged. In addition, a low compression pressure allows a relatively light apparatus structure, the method thus being usable in natural wetland. In multistep dewatering, water is removed in several steps, the amount of moss remaining therefore moderate in a single dewatering step. Thus, the distance travelled by water during the removal from moss and out of the apparatus remains short enabling fast dewatering. The short transfer distance preferably means a transfer distance shorter than 400 mm, most preferably shorter than 200 mm. Forced feeding of moss with the feed trough and the feed screw ensures the progression of moss in the apparatus until to the press and prevents sticking caused by the elasticity of moss. In other words, moss is only compressed for removing free water contained inmoss and water mechanically bound inmoss applying such a pressure that the cell structure of moss remains essentially undamaged .

Here, natural wetland means wetland that has not been specifically trenched or otherwise dried for production, the bearing capacity of wetland therefore being very low.

In other words, in the method according to the invention, occlusion water and capillary water of moss are removed in two separate steps . Thus, the quantity of water removed in an individual step remains moderate. Advantageously, using the feed trough, moss arriving to the apparatus at a moisture content of about 92 percent by weight can be dried to a moisture content of about 85 percent by weight, that is, removing about half of the water contained in moss.

In the method, water can be continuously pressed from moss with the press for 10 - 90 seconds, preferably for 30 - 50 seconds. As regards dewatering efficiency, it is important that water has sufficient time to be removed from moss and the pressing chamber due to pressure. In this way, water can be removed from hyaline cells of moss through the cell openings of hyaline cells without breaking the cells.

According to an embodiment, the method uses at least one set of feed screws comprising 2 - 10, preferably 4 - 8 feed screws for feeding moss from the feed trough to presses, the number of which corresponds to that of the feed screws, the presses forming a set of presses for increasing the drying capacity. When using a set of feed screws and a set of presses, the diameters of individual feed screws and presses, and thereby the forces acting on them, remain moderate compared to a situation where an individual larger feed screw and press would be used to achieve the same capacity. For example, by using six presses with a diameter of 310 mm instead of one press with a diameter of 950 mm and with corresponding dewatering areas, it is possible to reduce the need of total power by about 40%. When using feed screws and presses with smaller dimensions, the distance of removing water from moss out of the apparatus remains short, which reduces the time necessary for pressing to achieve the desired percent moisture of moss . In smaller presses, it is also possible to use lighter support structures.

Advantageously, the diameter of the feed screws included in the set of feed screws and that of the presses included in the set of presses is 200 - 400 mm. Thus, forces required for pressing remain moderate, and the same applies to the water removal distance .

According to an alternative embodiment, the method uses one feed screw with a diameter of 800 - 1000 mm for feeding moss from the feed trough to one press with a diameter of 800 - 1000 mm. In this case, for implementation, only one power transmission is needed for the feed screw and another one for the press, which simplifies the design of the apparatus. However, on the other hand, when the feed screw and the press become structurally larger, necessary forces also increase and require notably stronger structures for both the power transmission and the feed screw and the press, which adds to the mass of the apparatus and increases the surface pressure exerted on the ground by the work machine transporting the apparatus .

Advantageously, two parallel drying lines consisting of the feed trough, the set of feed screws and the set of presses are used for drying moss with one piece of extraction equipment feeding moss to the drying lines alternately. This enables achievement of higher capacity as well as the possibility to continuously extract moss with the extraction equipment with one feed trough always ready for receiving moss to be dried.

Advantageously, the drying lines are in opposite operating steps to avoid simultaneous emptying of the presses, which could result in moss dropping from the conveyor . Opposite steps mean the pressing step of the press and the piston return step.

Advantageously, when using two drying lines, moss is continuously fed with the feed equipment at least to one press. In this way, it is easier to achieve a high production capacity.

In the method, moss can be continuously processed on drying lines at 4 - 18 L/s, advantageously 10 - 14 L/s. Thus, the method can provide sufficiently high production capacity in terms of industrially efficient operation.

In the method, the start and stop of the press piston are advantageously ramped to avoid vibrations. In this way, it is possible to avoid high accelerations that are otherwise caused by the pressure applied for moving the pistons, which would cause vibrations to the apparatus and stress the apparatus structure.

Advantageously, the pressing chamber of the press is opened for feeding moss and closed by moving the press piston. Thus, the first closing equipment can be implemented without a separate control.

Advantageously, the method is used to remove water from non-preprocessed moss, that is, moss that has been extracted directly from trenchless wetland. Thus, the method can be used to efficiently recover moss from wetlands without a separate wetland trenching and drying step.

Advantageously, a moisture content of 85 - 75 percent by weight is aimed at for driedmoss with the method according to the invention . Surprisingly, it has been noticed that it is not worthwhile drying moss to a dryness below 75 percent by weight, since in this case moss starts to generate heat during storage and the application properties of moss deteriorate.

Moss is preferably extracted during the time of unfrozen ground. Then, water can be removed frommoss without breaking its structure .

According to an embodiment, in the method, moss in the pressing chamber of the press is compressed and an additional filling of the press is performed at least once before removing moss from the pressing chamber after pressing, wherein the additional filling takes place in successive steps, in which the press piston is returned for opening the pressing chamber and more moss is fed to the pressing chamber. During the compression performed by the press, moss is compressed into a volume notably smaller than that of the initial condition in which it was fed to the pressing chamber of the press. Since each moss removal step takes time, it is more efficient to combine several moss batches fed and compressed in different steps into one removal step . By performing the filling of the press several times before unloading moss, it is possible to unload an adequately large amount of moss from the press at an adequately high dry content .

The object of the apparatus according to the invention canbe achieved with apparatus for removing water from moss including a frame, a feed trough, a feed screw and a press. The feed trough serving as the feed equipment is arranged to receive moss and deliver it further and the feed trough includes at least one mobile feed wall for feeding moss to the feed screw while simultaneously compressing moss into a smaller volume for removing water on the surface of moss from moss. The feed screw comprises a first end and a second end and is arranged in the feed equipment by its first end for feeding moss further to the press into a smaller volume, while the feed equipment is arranged to feed moss to the feed screw. The press includes a pressing chamber provided with water removal openings, connected to the second end of the feed screw, and a piston for compressing moss into a smaller volume at a pressure of 10 - 40 bar for removing water from hyaline cells of moss through the water removal openings without breaking their structure.

In the apparatus according to the invention, several successive dewatering devices are used for removing water; therefore, the volume of an individual step can be fairly small. Thus, the compression pressure applied remains moderate and water removed from moss has a short route to be removed to a free space through the water removal openings. In this way, free water i.e. occlusion water and water bound mechanically in moss i.e. capillary water can be removed from moss through the cell openings of hyaline cells without breaking the structure of hyaline cells. In the apparatus according to the invention, a variable volume feed trough is used for force-feeding moss to the feed screw, which in turn feeds moss to the pressing chamber of the press. In this way, sticking of moss in the apparatus before the press is avoided. An advantage of using a feed screw is that a feed screw allows air to be removed from moss during the transfer. Although a feed screw represents well known prior art and reliable technology, it does not function in moss treatment without force-feeding. Tests have surprisingly shown that when using a feed trough and a feed screw, it is not necessary to break the cell structure of moss during moss drying.

Advantageously, in the method, the feed trough is used to remove occlusion water contained in moss and the press is used to remove capillary water mainly contained in hyaline cells , without breaking hyaline cells. The press can also remove the rest of occlusion water if it still contained in moss when it arrives to the press. The press removes at least part of the capillary water of moss.

Water removal openings may have a diameter ranging between 4 and 15 mm, preferably between 5 and 7 mm. It has been surprisingly noticed that large water removal openings of the size mentioned above can be used in moss drying, since, when generally compressing biomass, the size of water removal openings is notably smaller in order to prevent biomass from being pressed through water removal openings during the pressing. The use of the aforementioned large water removal openings is possible because of the undamaged shoot structure of moss. Due to larger openings, fewer water removal openings are required to achieve a sufficient open surface area, therefore, the apparatus is less costly to manufacture.

The apparatus advantageously includes first closing equipment arranged between the second end of the feed screw and the pressing chamber of the press, for closing the pressing chamber during the compression action of the press. In this way, it is possible to prevent moss from entering the piston rod side of the press after the piston has passed the inlet opening.

The apparatus advantageously includes second closing equipment limiting the pressing chamber for closing the pressing chamber during the compression action enabling removal of moss from the pressing chamber of the press after the compression action using the piston. In the press, the piston compresses moss into a smaller volume against the second closing equipment and finally out of the press after the opening of the second closing equipment.

According to an embodiment, the apparatus includes at least one set of feed screws comprising 2 - 10, preferably 4 - 8 feed screws for feeding moss from the feed trough to presses, the number of which corresponds to that of the feed screws, the presses forming a set of presses for increasing the drying capacity.

According to an alternative embodiment, the apparatus includes only one feed screw for feeding moss from the feed trough to only one press.

According to an alternative embodiment, the apparatus may have varying numbers of feed screws and presses. Thus, for example, more than one feed screw with a smaller diameter can feed moss to a press with a diameter larger than that of the feed screw. Advantageously, however, there is a dedicated feed screw for each press .

The apparatus advantageously includes two parallel drying lines comprising a feed trough, a set of feed screws and a set of presses, arranged to be in opposite operating steps of the sets of presses relative to each other. Thus, the feed troughs and feed screws can feed moss continuously to at least one press that is open in terms of moss feeding. The apparatus can be easily scaled to meet selected capacity needs by placing several pressing lines adjacent to each other thereby increasing the capacity of the apparatus.

The apparatus advantageously includes a frame wherein the sets of presses of the drying lines are arranged at an inclined angle relative to the horizontal plane for guiding the water removed from moss. From the sets of presses placed at an inclined angle, water can be guided in a controlledmanner to the side of the apparatus without rewetting moss.

The apparatus advantageously includes a control unit, which comprises a logic unit for controlling at least the feed trough, feed screw, presses, first closing equipment and second closing equipment. With the control unit, the operation of the apparatus can be automated so that the user does not need to manually operate the presses but only feeds moss to the apparatus.

Advantageously, the second closing equipment is provided with channels for removing water in the plane direction of the second closing equipment from the pressing chamber. In this way, a short route is created for water to exit from moss into a free space.

According to an embodiment, the shell included in the feed screw is perforated for removing the occlusion water of moss also with the feed screw. In this way, it is possible to reduce the amount of occlusion water remaining in moss before the press.

The feed trough may be arranged to create an absolute pressure of 0.5 - 5 bar, preferably 0.8 - 1.2 bar, in moss to be fed against the feed screw . In this way, it is possible to increase the efficiency of free water removal from extracted moss with a low power consumption .

The feed trough is advantageously open at least at the top for feeding moss to the feed trough.

The press advantageously includes a piston rod connected to the piston for moving the piston in the pressing chamber. In this way, the piston movement is simple to implement.

The feed screw and the pressing chamber of the press are preferably connected to each other and separated with the first closing equipment to enable moss transfer from the feed screw to the pressing chamber. The successive placement of the feed screw and the press enables forced feeding of moss over the entire distance from the feed trough to the press, so that moss does not move in any place merely due to gravity or otherwise freely, in which case it would be susceptible to sticking. Without a forced transfer, moss expands strongly becoming stuck in one place in a closed space.

The longitudinal directions of the feed screw and the press as well as those of the feed trough and the feed screw may be at an angle of 45 - 90°, preferably at the right angle, relative to each other. Thus, the outer dimensions of the apparatus remain moderate and it can be arranged on a frame of a forest tractor or a slope machine, for example.

Advantageously, force feeding actions between the feed trough and the feed screw as well as between the feed screw and the press are linear movements. Thus, the force applied in forced feeding efficiently takes moss further and moss will not become stuck, which could happen if forced feeding was to be carried out via a pipe curve, for example.

Advantageously, the press piston is perforated for removing water from moss. This allows water to exit also through the piston, in the case that this is the shortest route for water.

According to an embodiment, the pressing chamber of the press has a round cross-section. Then the pressing chamber is easy to manufacture adequately strong to resist forces generating during the pressing.

According to an alternative embodiment, the pressing chamber of the press has a square cross-section. Thus, the first pressing chamber can be made by assembling flat walls, which facilitates perforation .

The first closing equipment may consist of an extension formed in the press piston in the direction of the piston rod for blocking the feed opening included in the press during the pressing action of the press. In other words, the first closing equipment is then integrated into the piston in which case it does not need a separate control but operates automatically with the piston.

Advantageously, the apparatus includes drive equipment for producing the driving power for the feed trough, feed screw and press .

Advantageously, the apparatus also includes pressure sensors arranged at least together with the press for creating measurement information about the compression pressure; based on the measurement information of the sensors, the control unit is arranged to control at least the press and the actuator included in the second closing equipment. The progress of drying can be determined based on the compression pressure.

Advantageously, all of the channels used in the apparatus in which moss is conveyed in some drying step, including the press, have such cross-sections that the cross-sectional area remains at least equal or increases in the progression direction of moss. Elastic moss gets stuck in a channel narrowing in a wedgelike manner failing to advance well.

According to an embodiment, the feed trough includes a mobile feed wall, which is arranged to transfer moss to feed screws connected on both sides of the feed trough.

The object of the work machine according to the invention can be achieved with a work machine for extracting and drying moss, which includes a work machine frame, a chassis construction connected to the work machine frame for supporting the work machine against the surface of wetland, apparatus for removing water from moss, namely dewatering equipment, as well as a control cabin and a motor connected to the work machine frame. The chassis construction comprises a first crawler track chassis connected to the first frame and a second crawler track chassis connected to the second frame. The control cabin and the motor are arranged in the first frame. The work machine further includes extraction equipment for extracting moss from wetland onto the dewatering equipment, arranged in the second frame. Apparatus according to any of the aforementioned embodiments is arranged in the second frame as water removal apparatus for removing water from moss and for unloading dried moss into a load space external to the work machine.

In a work machine according to the invention, the chassis construction implemented with crawler track chassis guarantees a low surface pressure against the base and thus enables collection of moss from natural wetlands as well. In addition, apparatus according to any of the aforementioned embodiments and extraction equipment arranged in the vicinity of the frame allow the moss extraction and drying to take place with the same work machine immediately in the wetland by unloading dried moss into a separate load space so that dried moss does not increase the total weight of the work machine. The apparatus according to the invention for removing water from moss is more gentle towards moss compared to a prior art counter spindle screw press, for example.

Advantageously, the work machine is frame-steered relative to the centre hinge. In this way, good steerability is achieved.

Advantageously, in a work machine according to the invention, the apparatus includes two parallel drying lines comprising the feed trough, the set of feed screws and the set of presses enabling extraction of moss with extraction equipment alternately to the feed trough of each drying line.

Advantageously, the extraction equipment includes an extraction beam assembly and a grab bucket connected to its end. Alternatively, instead of a grab bucket, a milling machine can also be used, but a grab bucket is the primarily recommended device for extracting moss from wetland, since it keeps the moss structure as undamaged and unbroken as possible.

In this context, water removal from moss means removal of a large amount of water from moss, achieving, for example, a minimum water content of 75% compared to the initial water content of 96% relative to the total mass . In other words, this means that from the initial moss water content of 96% with 24 kg of water per 1 kg of solid moss , a final water content of 75% with 3 kg of water per one kilogramme of solid moss is reached. However, water removal does not in any event mean drying of moss to a completely dry state, which is practically impossible with a mere pressure effect.

Water removal effected with the apparatus and method according to the invention is most preferably a three-step process, wherein the feed trough feeds the feed screw while pressing occlusion water from moss, and the feed screw feeds moss to the press, which presses capillary water from moss. The entirety functions extremely efficiently .

The method and apparatus according to the invention are only meant for removing water from moss, not from peat. In this context, moss means the living layer of wetland on the wetland surface where hyaline cells are undamaged and filled with water when extracting moss . Moss is most preferably sphagnummoss growing with a thickness of 20 - 40 cm on the wetland surface depending on the characteristics of the wetland . After moss drying, hyaline cells are still undamaged, but the capillarily bound water inside the hyaline cells has been mainly replaced with air. The invention is described below in detail by making reference to the appended drawings that illustrate some of the embodiments of the invention, in which

Figure la depicts an individual moss shoot,

Figure lb is a basic complete view of leaves of sphagnum moss,

Figure lc is a basic view of the cell structure of moss before drying,

Figure Id is a basic view of the cell structure of moss dried with the method and apparatus according to the invention,

Figure 2a is an axonometric view of an embodiment of the apparatus according to the invention, shown as a complete whole on a crawler track chassis, Figure 2b is a front view of an embodiment of the apparatus according to the invention, shown as a complete whole on a crawler track chassis,

Figures 3a and 3b are axonometric views in different directions of the apparatus according to the invention, separated,

Figure 4a is a cross-sectional side view of the apparatus according to the invention, while moss is being fed to the feed screw with the feed trough, Figure 4b is a cross-sectional side view of the apparatus according to the invention, while moss is being fed to the press with the feed screw,

Figure 4c is a cross-sectional side view of the apparatus according to the invention, while moss is being compressed in the press,

Figure 4d is a cross-sectional side view of the apparatus according to the invention, while dried moss is being removed from the press,

Figure 5 is a block diagram of the steps of the method according to the invention, Figure 6 is a basic hydraulic diagram of the apparatus according to the invention,

Figure 7a is a side view of an advantageous embodiment of the work machine according to the invention, shown as a complete whole,

Figure 7b is a top view of an advantageous embodiment of the work machine according to the invention, shown as a complete whole,

Figure 8 is a basic view of the control system of the work machine according to the invention.

With the method according to the invention, when drying moss 1, hyaline cells 4 of moss 1 remain undamaged and capillary water 8 contained in them, according to Figure lc, is removed at least partly through the holes in the cell walls 7. This results in a situation according to Figure Id, wherein capillary water contained in undamaged hyaline cells 4 has been replaced, partly or totally, with air 9, which makes the structure spongy and light. Thus, undamaged hyaline cells of moss are again capable of receiving water, if moss is used, for example, as a substrate in the final application .

Figure 2a is an axonometric view of the apparatus 10 according to the invention mounted on a base machine. The apparatus is used to remove water from non-preprocessed moss . Non-preprocessed means that it is not necessary to process moss in any way other than its extraction from wetland and lifting onto the apparatus. The apparatus according to the invention is advantageously moveable in the sense that it can be moved economically with a separate base machine in the same way as other wetland machines equipped with a crawler track chassis or an adequate number of wheels, in wetland that is not trenched or prepared in any other way by drying for production purposes. Then, a boundary condition for the apparatus is the weight, which together with the base machine can be in the range of 20 - 35 tons , in which case it generates, implemented with a crawler track chassis, a surface pressure of 1.2 - 2.4 tons/m ² , preferably less than 2 tons/m ² . The surface pressure produced by the apparatus and the base machine can also be lower than 1.2 tons/m ² depending on the lightness of materials used and the surface area of the crawler track chassis used.

The base machine 200 transporting the apparatus 10 may include, according to Figures 2a and 2b, a second frame 114, which is preferably moved in wetland by means of a chassis construction 100 arranged under the frame 101. For example, the frame 12 can be a conventional welded beam frame or an equivalent structure suitable for the purpose . Advantageously, the chassis construction 100 is a crawler track chassis 102 according to Figures 2a and 2b . As the crawler track chassis, it is possible to use, for example, a crawler track chassis based on crawler track applications of excavators of the manufacturer Ab A. HaggblomOy or other equivalent . Alternatively, instead of a crawler track chassis, for example, several parallel wheels or an equivalent construction implemented with wheels can be used as the chassis construction . The base machine is advantageously self-propelled; that is, it includes a power unit which produces the energy used for moving the apparatus in wetland. Advantageously, the same power unit also produces the energy used for water removal from moss for the apparatus according to the invention. For example, the apparatus according to Figures 2a and 2b can be an implement or equivalent trailed by a tractor.

Figures 3a and 3b illustrate the design of the apparatus 10 according to the invention in more detail. The apparatus 10 includes a frame 12, a feed trough 15 serving as feed equipment 14, a feed screw 16, a press 30 and first closing equipment 26 between the feed screw 16 and the press 30 and second closing equipment 28 related to the press 30 and, advantageously, actuators for operating the aforementioned items. Although the second closing equipment 28 in Figure 3b is shown in the same set of presses 30.1 in different steps, that is, some of the items are closed and others are shut down, for illustrating the two positions of the second closing equipment, all items of the second closing equipment 28 operate simultaneously in practice . With these aforementioned components, water removal from moss can be performed in multiple steps so that the amount of water in moss is reduced in each drying step with the moss volume reducing to approximately a third in each step.

The apparatus according to the invention is advantageously continuously operating, which is achieved in such a way that the apparatus 10 according to the invention preferably has, according to Figures 2a and 2b, two parallel drying lines 42 composed of the feed trough 15, the feed screw 16 and the press 30, operating in different pressing steps and enabling continuous feeding of moss to the press 30 of one drying line 42 while the press 30 of the other drying line 42 is in the pressing step. Advantageously, each drying line also includes one set of feed screws 16.1 comprising 2 - 10, preferably 4 — 8 feed screws 16 for feeding moss 1 from the feed trough 15 to the presses 30, the number of which corresponds to that of the feed screws 16, the presses 30 forming a set of presses 30.1 for increasing the drying capacity.

In the embodiment of the apparatus 10 according to the invention shown in Figures 3a and 3b, the feed equipment 14 consists of the feed trough 15 arranged essentially in the horizontal direction. The feed trough 15 is composed of a bottom 32 and sides 36 connected thereto essentially perpendicularly, which together with the bottom 32 limit a partly limited space 34. The partly limited space 34 is open at the top allowing moss 1 to be fed to the feed trough 15 by dropping from above and open on one side being limited to the set of feed screws 16.1, for feeding moss 1 to the feed screws 16. The bottom 32 of the feed trough 15 is fixedly fastened to the side of the feed screw 16 essentially perpendicularly and at an angle of 5 - 15° relative to the horizontal plane, when the apparatus is on a horizontal surface. Either one or all of the sides 36 of the feed trough 15 is/are arranged on guides for forming a mobile feed wall 18. A mobile feed wall 18 is capable of moving relative to the set of feed screws 16.1 so that its distance relative to the feed screws 16 can be varied for pushing moss against the feed screws 16. The feed trough 15 includes actuators 38 for moving the mobile feed wall or walls 28 along the guides 25. When the mobile feed wall 18 or walls 28 move, the partly limited space is reduced compressing moss 1 against the feed screws 16; thus, water adhered to moss separates from moss and flows along the bottom 32 of the feed trough 15 and out from the second water removal openings 68 preferably included in the mobile feed wall 18. The sides 36 of the feed trough can have a height ranging between 500 - 700 mm, width ranging between 1.0 - 2.0 m and length ranging between 0.8 - 1.2 m.

Generally, in this application, when referring to water removal openings, a round, slot—like or other similar form of opening formed in a closed plane is meant, through which water can be removed from an otherwise closed feed trough or pressing chamber of a press . Water removal openings 56 are advantageously round as in Figures 4a - 4d.

Each feed screw 16 includes, according to Figures 4a - 4d, a shell 48 having a first end 47 and a second end 49, both of which are open for enabling the transfer of moss . In addition, the feed screw 16 includes a shaft and a feed worm 46 arranged therein, which are rotated by a motor 52 via a gear assembly 72. With the gear assembly 72 , the speed of rotation of the feed worm 46 can be adjusted suitable for the feeding of moss 1. Advantageously, the feed screws 16 are arranged to rotate from the centre to the sides relative to their direction of rotation so that the set of feed screws 16.1 spreads moss across the entire width of the feed trough 15. With the feed trough 15, it is possible to remove approximately a third of water contained in extracted moss in this water removal step. Then, the amount of remaining water is approximately 16 kg relative to 1 kg of solid matter of moss.

Advantageously, when using two parallel drying lines, one of the presses remains closed in the pressing step, whereat the feed screw will be stopped and the mobile feed wall of the feed trough will be returned as far as possible from the set of feed screws for a new dose of moss.

In this embodiment, connected to the second end 49 of each feed screw 16, there is a press 30 as shown in Figures 4a - 4d. Advantageously, the feed screw 16 is connected to the pressing chamber 20 of the press 30. The volume of the pressing chamber 20 can be modified for compressing moss 1 with the piston 22 included in the press 30. The piston 22 is advantageously connected to a piston rod 24, which is moved in the press 30 for compressing moss 1. Moss 1 arriving via the feed screw 16 only fills a length of the space in the pressing chamber 20 that equals the diameter of the feed screw. First closing equipment 26 arranged between the press 30 and the second end 49 of the feed screw 16 prevents moss 1 arriving through the feed screw 16 from being conveyed to the piston rod 24 side of the piston 22 when the piston 22 passes by the feed opening 33 of the press 30 while compressing moss 1. Advantageously, the first closing equipment 26 is an extension 62 of the piston 22 closing the feed opening 33 of the press 30 when the piston 22 passes by the feed opening 33.

The pressing chamber 20 of the press 30, as well as the piston 22, are advantageously perforated to form water removal openings 56 in order that the transfer route for water removed from moss 1 is as short as possible. A perforation is advantageously made on both the sides and the bottom of the pressing chamber 20. The piston 22 and the piston rod 24 of the press 30 are arranged to move over the entire span of the pressing chamber 20, in order that the piston 22 can push compressed moss 1 as forced feeding out from the end of the pressing chamber 20 while the second closing equipment 28 opens . The press is preferably hydraulically operated, that is a hydraulic cylinder.

Advantageously, arranged related to the pressing chamber 20 of the press 30, there is also second closing equipment 28, with which the outlet opening 54 included in the press 30 is closed during the pressing and by opening of which it is possible to remove moss 1 from the press 30 through the outlet opening 54. Advantageously, the second closing equipment 28 is provided with water removal channels 44, which form a flow channel for capillary water removed from moss. These water removal channels 44 also comprise a lateral part enabling water removal to the side in the plane direction of the second closing equipment 28. Advantageously, the diameter of the longitudinal parts of the press 30 in the water removal channels 44 is in the range of 4 - 8 mm, whereas the diameter of the transverse parts of the press is in the range of 4 - 12 mm. The longitudinal parts of the press 30 in the water removal channels 44 may have a distribution of 20x20 mm, for example, to achieve a short dewatering distance.

Apparatus according to the invention can be placed on a base machine, which preferably includes, as drive apparatus according to the invention, power transmission equipment for transmitting power to the actuators of the feed trough, motors of the feed screw, the press, and the first closing equipment and the second closing equipment. Advantageously, this power transmission equipment consists of a hydraulic circuit comprising valves and an electric control by means of which actuators of the feed trough, the feed screw motor and the press are operated. The hydraulic circuit is illustrated in more detail in Figure 6 and its operation is described later on.

The operation of the apparatus according to the invention is described below by referring to Figures 4a - 4d and the block diagram of Figure 5. Figures 4a - 4d and this description are mainly focused on the operation of one drying line. Water removal from moss 1 is started by feeding moss 1 to the feed equipment 14 i.e. the feed trough 15, according to step 200 of Figure 5. Moss feeding to the apparatus can be advantageously performed by extracting moss with a grapple from preferably natural wetland, but moss can also be fed pneumatically. The grapple is preferably a perforated grapple that can be used to remove occlusion water from moss when compressing it with the grapple.

The feed trough 15 feeds moss 1 toward the feed screw 16 according to step 202 of Figure 5, whereat moss 1 is compressed against the feed screw 16.1 and water adhered to moss can simultaneously be removed from moss. The sides 36 of the feed trough 15 move along guides 25 shown in Figures 3a and 3b toward the feed screw 16, when the length of the actuator, preferably a hydraulic cylinder, fastened to the sides 36, changes. The feeding speed may be in the range of 0.05 - 0.2 m/s. The task of the feed equipment 14 is to move moss 1 toward the feed screw 16 and remove water and air from moss 1.

In step 200 of Figure 5, the piston 22 of the press 30 has been run as far back as possible as shown in Figure 4a, whereat the first closing equipment 26 preferably integrated in the piston 22 has moved away from the front of the outlet opening 33 of the press 30 allowing moss 1 to move to the pressing chamber 20 of the press 30 according to Figure 4b corresponding to step 204 of Figure 5. Since moss 1 consists of a fibrelike network, moss 1 arriving to the pressing chamber 20 essentially fills a length of the space in the pressing chamber 20 that equals the diameter of the feed screw 16. The pressing chamber 20 may be open for feeding moss 1, for example, for 10 - 15 seconds during which time the feed screw 16 has time to push an adequate amount of moss 1 to the pressing chamber 20. At the end of the feeding step, the feed screw stops.

After the feeding of moss 1, the transfer of the piston 22, or the pressing step, begins, wherein the piston 22 and the piston rod 24 move toward the second closing equipment 28, according to Figure 4c and step 206 of Figure 5. In this step, the second closing equipment 28 is closed, that is, it closes the pressing chamber 20 as a closed space together with the first closing equipment 26. Advantageously, the movements of the piston 22 of the press 30 are ramped in such a way that the movement starts slowly and the movement then accelerates uniformly toward the maximum speed. This avoids vibrations caused by the operation of the press. When the piston 22 of the press 30 moves toward the second closing equipment 28, the first closing equipment 26 provided as an extension of the piston 22, that is, the extension 62 of the piston 22 shown in the embodiment of Figures 4a - 4d, moves along with the piston 22 in front of the feed opening 33 preventing movement of moss 1 from the feed screw 16 to the press 30 as the piston 22 passes by the feed opening 33. Moss 1 in the pressing chamber 20 is pressed against the second closing equipment 28 pushed by the piston 22, whereat the small amount of occlusion water remaining in moss 1 and mainly capillary water are removed from the pressing chamber 20 through the water removal openings 56 on the walls of the pressing chamber 20 and along the water removal channels 44 of the second closing equipment 28. Moss 1 with a length equalling the diameter of the feed screw, or 200 - 300 mm as a way of example, fed in the longitudinal direction of the press 30 is compressed against the second closing equipment 28 during a pressing step of 30 - 45 seconds. The entire movement length of the piston 22 can be, for example, 600 mm, if diameter of the piston is 310 mm and the diameter of the feed opening is 280 mm.

When the measuring equipment , or preferably sensors 80 and 82 (shown in Figure 6) , connected in connection with the press 30 in the hydraulic circuit detects that the pressure in the hydraulic line of the press 30 has exceeded a pre-determined limit value within a selected time, the movement of the piston 22 is slowed down and finally, after exceeding a second limit value, the piston 22 is stopped in step 208. After the pressing step of the press 30, the second closing equipment 28 opens in step 210, whereat moss 1 in the pressing chamber 20 of the press 30 can move out from the press 30 facilitated by the movement of the piston 22, whereat moss 1 drops down onto a transfer conveyor 70 according to Figure 4d and step 214 of Figure 5. After this, the piston 22 of the press 30 returns to its start position according to step 212 of Figure 5 and the cycle described above is repeated.

In Figures 4a - 4d, a vertical guide 58 shown under the second closing equipment 28 is used to guide moss dropping from the press 30 to the transfer conveyor 70. Advantageously, the operation of the guide 58 is connected with the operation of the second closing equipment 28 so that when the second closing equipment 28 opens, the guide 58 is also moved to its vertical position to guide moss dropping from the press 30. When the second closing equipment 28 is closed, the guide 58 is partly on the transfer conveyor 70 preventing access of water dropping through the water removal openings 56 of the press 30 to the transfer conveyor 70 where it could wet the moss, particularly the moss dropped to the transfer conveyor from the press of the parallel drying line. According to Figures 2a and 2b, the transfer conveyor 70 transports dried moss below the set of presses 30.1 to a second transfer conveyor 74, which transports moss further to a load space 130 used related to the apparatus 10, for further transportation, according to Figures 7a and 7b. Alternatively, a conveyor or a sacker may be placed in the vicinity of the apparatus .

Since the press 30 remains closed for about half of the time unable to feed moss 1 with the feed screw 16, the use of two or more parallel drying lines is significant in terms of efficiency. When two drying lines are used, moss can be continuously extracted from wetland, as at least one of the feed troughs is free to receive extracted moss while, at the same time, a sufficiently long pressing time is achieved for water removal.

In the apparatus andmethod according to the invention, water removal from moss takes place at least with the feed trough and the press, but advantageously also with the extraction equipment and the feed screw. A requirement for dewatering is a sufficient external pressure exerted on moss, as well as an adequately large free surface area for water to be removed from moss. In addition, an adequately long time under pressure is also needed in order that water has enough time to be removed from moss. For this reason, the pressing chamber of the press must be correctly dimensioned to keep the dewatering time sufficiently short.

The pressing chamber of the press has preferably a circular cross-section with a diameter of 10 - 20 cm, preferably 13 - 18 cm, when the set of presses is composed of six presses. A press with a circular cross-section is easier to manufacture sufficiently strong compared to a square or rectangular cross-section, where the corners are weak points. The length of the pressing chamber in the travel direction of the piston may be in the range of 250 - 500 mm. In the apparatus according to the invention, the diameter of water removal openings used at least related to the press may be in the range of 4 - 8 mm, preferably 5 - 7 mm. For example, the holes may have a horizontal distribution of 15 - 25 mm and a vertical distribution of 5 - 15 mm thus leaving 10% - 30% of the press shell surface area free for water removal . Advantageously, all of the surfaces of the pressing chamber contactingmoss including the piston are perforated for improving dewatering . A corresponding perforation can also be used on the sides of the feed trough.

In the press, the piston is advantageously coated with a material that reduces friction, such as a plastic material . Advantageously, the piston is surrounded by slip plastic, the purpose of which is to reduce sliding friction against the perforated pressing chamber but also to wipe and clean the holes from moss and other impurities attached to them. Alternatively, it is also possible to clean the holes traditionally with brushes and compressed air, which can be directed from inside to outside of the piston.

The drive speed of the screw can be, for example, 150 - 250 rpm, with a thread pitch of 30 cm. The diameter of the feed screw can be between 30 and 50 cm. In the apparatus according to the invention, a piston press is advantageously used as the press, since it can provide an adequate compression pressure in a controlled way uniformly all over in moss without crushing the cell structure. The compression pressure used by the press may be in a class of 10 - 40 bar, preferably 15 - 35 bar, most preferably 18 - 22 bar.

With the apparatus according to the invention, using the dimensioning proposed above, it is possible to feed moss at over 30 m ³ /h to a single drying line. The capacity of apparatus placed on a single chassis, when using two drying lines, may be as high as 60 m ³ /h, while it can still be used with one power unit and moved on the surface of untreated wetland. The maximum output of the power unit may be in a class of 300 - 600 kW, out of which the maximum output can be used, using several presses, the feed trough and drive units, up to 75% of the application time. Advantageously, the feed trough, feed screw, press and second closing equipment of the apparatus are all fastened to the apparatus' frame with bolts thus being easily removable for maintenance or even replaceable. According to an embodiment, the aforementioned components can be hingedly fastened to the frame on one side so that the apparatus can be partly opened.

The operation of the apparatus according to the invention is controlled based on sensors and measurement information using a control unit 11 of Figure 6 including programmable logics. The control unit 11 advantageously controls the directional valves 86 of the actuator 84 of the feed trough 15, feed screw 16, press 30 and second closing equipment 28 and receives signals from the sensors preferably along a CAN bus . The operation of the apparatus according to the invention is fully automated . Information received from sensors is advantageously used for the control, for example, to ramp the movements of the press piston. Ramped acceleration takes place over a span of approximately 20 - 30 cm. Advantageously, the press is controlled independently. According to Figure 6, all actuators can be used with the output of one hydraulic pump 88. Figure 6 also illustrates how the apparatus advantageously includes two parallel drying lines 42. Hydraulics of the feed trough is not shown in Figure 6, but it is obvious to those skilled in the art that it can also use the output of the hydraulic pump 88. The control unit used can be, for example, a programmable logic control unit via a CAN bus manufactured by Bosch Rexroth, Siemens or IFM. It should be understood that the hydraulic diagram of Figure 6 is only depicted on a very basic level and it lacks possible lines for reducing pressure and for pressure control.

In an embodiment of the apparatus according to the invention, the presses of the drying lines operate alternately when using the apparatus, that is, the drying lines are in opposite steps relative to each other. The control unit of the apparatus according to the invention is programmed in such a way that it schedules the work steps of the different components of the apparatus automatically to achieve the maximum capacity.

According to an embodiment, apparatus according to the invention can also be implemented so that a second press and third closing equipment are provided after the press. In this case, moss drying can be continued after the press to achieve a still higher dry content .

Figures 7a and 7b illustrate an advantageous embodiment of the work machine 101 according to the invention. The work machine includes a work machine frame 110 comprising a first frame 112 and a second frame 114 connected together with a centre hinge 116, and a chassis structure 111 fastened to the work machine frame 110 for supporting the work machine 101 against the surface of wetland. The chassis construction 111 comprises a first crawler track chassis 118 connected to the first frame 112 and a second crawler track chassis 120 connected to the second frame 114. With crawler track chassis, the surface pressure exerted on the wetland by the work machine is very small, and thus it can also be driven without problems on the surface of natural wetland characterised by a very low bearing capacity. The control cabin 104 and the motor 106 are arranged in the first frame 112, whereas the extraction equipment 108 for extracting moss from wetland and the apparatus 10 for removing water from moss, namely dewatering equipment 17, are arranged in the second frame. With such a work machine, it is possible to move on the surface of natural wetland even during the time of unfrozen ground simultaneously extracting moss and drying it immediately on the extraction site . Dried moss is unloaded from the dewatering equipment 17 in the work machine 101 into a separate load space 130, such as a transfer platform or similar, which can be moved from the site with a separate transfer device. In this way, extracted and dried moss does not increase the weight of the work machine, when the load space is arranged separated from the work machine. The dewatering equipment 17 of the work machine according to the invention is any of the embodiments of the apparatus according to the invention for removing water from moss, placed on the second frame 114 of the work machine 101. Advantageously, the extraction equipment includes an extraction beam assembly and a grab bucket at its end.

Hydraulics used in the work machine according to the invention may include a hydraulic system comprising seven blocks and provided with its own hydraulic pumps for operating the first crawler track chassis of the first frame, for operating the second crawler track chassis of the second frame, for operating the loader, for operating frame—steering and other auxiliary devices, for operating the hub motors of the crawler track chassis, for operating the dewatering equipment, and for operating rotating devices, such as for operating the feed or the extraction equipment.

Figure 8 illustrates the design of the control unit 11 in more detail. According to Figure 8, apparatus control may include a control system including several programmable IFM displays/controllers. Of these, controllers 140 of the IFM CR0411 type (programmable control systems for mobile work machines) are arranged to control the press of the dewatering equipment and the second closing equipment. In turn, the aforementioned controllers can be controlled via the user interface of the IFM CR0452 programmable display 142. The aforementioned controllers and display can be connected to the control unit 144 via a CAN bus 146, which may be a programmable graphics display of the IFM CR1201 type for controlling mobile work machines with preferably two joysticks 150 connected thereto via a second CAN bus 148. For example, joysticks can be Danfoss JS1 joysticks for controlling preferably eight IFM CR20521/0 modules 152 for the second crawler track chassis , fuel and coolant sensors, lights and wipers, first crawler track chassis, extraction equipment beam, frame-steering, turning of the dewatering equipment and feed screw. Two separate I/O modules can be provided for controlling the extraction equipment. In this context, as a concept not included in the invention, it is proposed that the feed trough set forth in this application can be used alone for moss dewatering. In this case, the feed trough includes a frame, an essentially vertical perforated plate arranged on the frame comprising water removal openings, guides connected transversely to the perforated plate, a trough assembly comprising sides and a bottom connected to these, the trough assembly being open at the top and supported on guides, as well as actuators between the trough assembly and the perforated plate for moving the trough assembly on the guides toward the perforated plate, for compressing moss against the perforated plate for removing water from moss.