WO2009118458A1

WO2009118458A1 - Method for peat production and base and equipment for use in peat production

Info

Publication number: WO2009118458A1
Application number: PCT/FI2009/050235
Authority: WO
Inventors: Ilkka Ilmavirta; Juha Korpi; Kari Mutka; Matti Suoaro
Original assignee: Vapo Oy
Priority date: 2008-03-28
Filing date: 2009-03-27
Publication date: 2009-10-01
Also published as: RU2010144077A; CA2718178A1; EP2257611A1

Abstract

The invention relates to a method for peat production. In the method, peat blocks (15) with a high moisture content are cut mechanically from a bog (10) from a selected lifting groove (12). The cut peat blocks (15) are placed to dry on self-support ing bases (14). After drying, when the moisture content of the peat blocks (15) is at a chosen level, the peat blocks (15) are collected from the bases (14). The peat blocks (15) are placed on the bases (14) mechanically and the bases (14) are handled mechanically, at least when placing the peat blocks (15) on the bases (14). The invention also relates to a base and equipment for use in peat production.

Description

METHOD FOR PEAT PRODUCTION AND BASE AND EQUIPMENT FOR USE IN PEAT PRODUCTION

The present invention relates to a method for peat production, in which method peat blocks with a high moisture content are cut mechanically from a bog from a selected lifting groove, the cut peat blocks are placed to dry on self-supporting bases, and - after drying, when the moisture content of the peat blocks is at a chosen level, the peat blocks are collected from the bases.

The invention also relates to a base and equipment for use in peat production.

In all peat production, the slow drying of peat creates an obvious bottleneck. The reason for the slow natural drying is the structure specific to peat, which binds water. The challenge for all methods is to overcome this specific feature of peat.

Large amounts of good-quality horticultural peat are produced in the Baltic states, using the so-called block-peat method. The lifting of peat blocks, i.e. large peat sods from a bog is mechanized and a machine lifts the peat blocks onto the edge of the lifting groove. As drying progresses, the peat blocks are turned one or more at a time by hand and stacked, possibly on top of each other. Horticultural peat is delivered to customers in sod form. Some typical sizes for peat blocks have been 15 x 15 x 40 cm³ (STEBA) , 18 x 30 x 50 cm³, and 20 x 30 x 45 cm³ (excavator) .

Several peat lifting machines, particularly horticultural peat lifting machines, are known. In the STEBA method, the peat is cut continuously as several blocks at a time, which are turned by a conveyor onto the edge of the lifting groove. Special buckets have also been made for excavators, by means of which peat blocks of specified dimensions can be cut from a bog. These methods demand a considerable amount of manual labour during drying, as the peat blocks are turned and stacked by hand. It can be estimated that each peat block must be handled manually three times before being transferred to a stack.

Finnish patent number 56853 discloses a peat production method, in which the peat is cut from the bog when it is frozen and the peat sods or blocks are placed on plastic to dry.

Finnish parent number 75356 also discloses a peat production method, in which frozen peat blocks are cut from a bog and dried in a vertical position, or, for example, in a stockpile.

Swiss patent number 224710 discloses a self-support base movable by hand, on which peat blocks can be placed to dry.

The aforementioned known peat-production methods, particularly in horticultural peat production, achieve a modest annual production. In practice, only one harvest is achieved each year. In addition, the loss is often great. In the worst case, only about 60 % of the peat blocks lifted reach the store or customer. Other bottlenecks in production are the several manual work stages and the rapid increase in labour costs, as well as the difficulty in recruiting labour.

The invention is intended to create a new type of method for producing horticultural peat, which is substantially more efficient that known methods. In addition, the invention is intended to create a new type of base for use in producing horticultural peat, by means of which not only drying will be accelerated, but also the handling and storing of peat blocks will be improved. The invention is also intended to create a new type of equipment for use in producing horticultural peat, by means of which peat production will be accelerated and simplified. The characteristic features of the method according to the present invention are stated in the accompanying Claim 1. Correspondingly, the characteristic features of the base according to the invention are stated in the accompanying Claim 13. The characteristic features of the equipment according to the invention are stated in the accompanying Claim 18. In the method according to the invention, there are fewer work stages than previously, which reduces the need for labour and improves the quality of the end product. In particular, the use of bases to handle the peat blocks provides several advantages and permits the rationalization and mechanization of production, also during drying. Thus, there is a substantial reduction in the share of manual work. In addition, the peat blocks dry evenly while at the same time re-wetting of the peat blocks is avoided. Thus, several harvests of peat can be produced each year, irrespective of weather conditions. If necessary, drying can be further accelerated, which will multiply the number of harvests available in a year. The equipment is also versatile and efficient.

In the following, the invention is described in detail with reference to the accompanying drawings depicting some embodiments of the invention, in which

Figure 1 shows the lifting stage of a first embodiment of the method according to the invention, when lifting the first harvest, Figure 2 shows the lifting stage of the third harvest of the method of Figure 1, Figure 3 shows an end view of the lifting stage of

Figure 2,

Figure 4 shows a first embodiment of the base according to the invention,

Figure 5 shows the lifting stage of a second embodi- ment of the method according to the invention, when lifting the first harvest, Figure 6a shows a second embodiment of the base according to the invention, Figure βb shows one block group according to the invention, Figure 7a shows a variation of the base of Figure 6a, Figure 7b shows a third embodiment of the base according to the invention,

Figure 8a shows a side view of the equipment according to the invention, in one stage of the method,

Figure 8b shows the equipment of Figure 8a, seen at an angle from above from the rear, Figure 9a shows a side view of the equipment according to the invention, in the second stage of the method,

Figure 9b shows the equipment of Figure 9a, seen at an angle from above from the rear,

Figure 10a shows a fourth embodiment of the base according to the invention, Figure 10b shows schematically the placing of the peat blocks on the base,

Figure 10c show a special embodiment of a peat block.

Figure 1 shows a cross-section of a strip formed on a prepared bog 10. The production of horticultural peat is illustrated as the lifting of the first harvest from the prepared bog 10, in which the strip is delimited by ditches 11. There may be a special vehicle track 13 on the strip. Using a known machine, the horticultural peat is lifted from a lifting groove 12 running parallel to the ditch. The lifting of the peat takes place starting from the side of the ditch 11, in such a way that the free side of the ditch gradually moves transversely over the entire strip, until the whole layer has been lifted.

Second, third, and fourth lifting locations are also drawn schematically in Figure 1. Thus the second harvest is also lifted from the same lifting groove, but in this embodiment the third harvest is lifted from a different lifting groove. After the entire layer has been lifted, the strip is made good if necessary and the lifting of peat is recommenced. In making good, a milling machine, for example, is used.

Figures 1 - 3 do not show the lifting machine operating in the lifting groove 12. It can be either specially designed for this work, or else of some known type, for example, an excavator equipped with a special cutter bucket. Despite the preparation of the bog, the peat being lifted is wet, typically with a moisture content of 90 %. It is then advantageous to detach it by cutting, so that the peat block will remain intact. In this example, the original weight of the peat blocks is 10 kg and their moisture content 91 %. The peat blocks are lifted onto special self-supporting bases. The term self-supporting base means that the base will withstand the weight of the blocks, holding them in the desired position. The self-supporting base can also be handled while the peat blocks are on it. In addition, it is essential that the peat blocks are separated from each other at regular intervals, in order to ensure ventilation and thus drying. In this case, a group of ten peat blocks 15, together with bases 14 forms a drying group 16. In this example, the weight of the peat blocks of each drying group 16 of Figures 1 - 3 totals 100 kg.

The bases 14 are available on the strip and they are placed either mechanically or manually next to the lifting groove 12 in transverse rows (Figures 1 - 3) . The bases are, for example, of corrugated plate metal with relatively deep corrugations and are sufficiently strong to withstand being handled later when filled with peat blocks. The depth of the corrugation is 20 - 70 mm, preferably 30 - 50 mm. Thanks to the corrugation, possible rainwater will run off without being absorbed by the peat blocks. There are preferably holes halfway up the web of the corrugation of the bases, through which rainwater raised by rubbish blocking the groove can drain away (not shown) . A mesh, grille, or other perforated base can also be used as a base. In other words, the base is open in such a way that water can flow off and evaporate from underneath too. This is important in terms of drying, as a significant portion of the water evapo- rates from underneath.

In Figure 1, the lifting machine has lifted during each advance of the lifting groove 12 the peat blocks 15 onto the bases 14 (Figure 4), for forming six block groups 16. In this case, the lifting machine has been envisaged as lifting two harvests from the same lifting groove 12, when the full depth of the lifting groove is reached. In terms of the invention, this is not essential, instead the size of the peat blocks and the progress of the lifting for each harvest are planned optimally for multiple harvesting. Thus double advance of four layers each would produce an octuple stack. Figure 2 shows the stages of Figure 1 when lifting a third harvest while Figure 3 shows a top view of the lifting stages of Figure 2.

Despite their large size, the peat blocks dry relatively rapidly on the bases 14. One dimension against the base should be less than 20 cm (generally 10 - 15 cam) . Depending on weather conditions, the peat blocks will dry to a moisture content of 65 - 80 % in 1 - 4 weeks. In this example, their weight will then have dropped to 3 kg at a moisture content of 70 %. The peat sods will now withstand loading without breaking, so that they can be stacked on top of each other. The stage following drying is drawn in Figures 1 - 3, i.e. the drying groups 16 are lifted on their bases 14 onto the stack 17, or else this can be envisaged as having being collected from the previous harvest. Usually, both production stages are in operation simultaneously. A special cover plate, or some transparent light protection, for example, a plastic film (not shown) , is preferably placed on top of the peat blocks on the topmost base. Alternatively, the partly dried peat blocks are stacked directly on top of each other in a crosswise arrangement without intermediate bases, but preferably on top of a bottom base, and are covered with a cover or other rain protection on top. In this way, the number of bases required is reduced, though the drying time is somewhat longer. In the same way, a special stacking machine is preferably created for the handling of the blocks, in order to reduce manual labour.

The peat blocks are generally placed longitudinally on the bases, transversely to the grooves, because a vertical position is generally too unstable. As such, in a vertical position the contact surface with the base would be smallest, but the position easily becomes unstable. It is particularly important for the peat blocks 15 to be placed apart from each other on the bases 14, which is clearly shown in Figure 4. On the other hand, it is also important that there is not a large surface area of the peat blocks 15 against the base 14.

The bases 14 with peat blocks 15, i.e. the block groups 16 are protected from rain in the stack 17. Stacking can take place either by hand or preferably mechanically, for example, using the front loader of a tractor. Drying continues in the stack quite effectively through the effect of the wind, because the peat blocks are separate from each other and only a small surface area of each block is in contact with the corrugated plate. The peat blocks under the topmost plate continue to dry. If the topmost layer does not have rain protection, its peat blocks will easily dry again with the aid of direct solar radiation and the wind, after they have become wet.

Once drying has continued in the stack 17 for 1 - 4 weeks, depending on weather conditions, the peat blocks will have dried in this example to a moisture content of about 40 %. At the same time, the weight will have dropped to one-and-a-half kilograms, from an original weight of ten kilograms. The peat blocks that have dried to the target moisture content are taken away. The stacks can be transported away from the strip, or, for example, an entire stack can be toppled onto a platform and the bases taken away. Only a limited number of bases will be 5 required, as they are circulated in production.

Figure 4 shows in detail a stack formed of drying groups 16. The block groups have already been formed in an earlier stage. Ventilation gaps 18, with a width of about 3 - 15 cm, prefera- 10 bly about 5 - 7 cm, are left between the peat blocks 15. This, together with the small downward-facing dimension and the water-penetrable base, is quite central to rapid drying.

The size of the peat blocks and the bases can vary to a consid- 15 erable extent within the scope of the inventive idea. Instead of a steel corrugated plate, the base can be a plastic or wooden plate. Instead of a corrugated plate, some other kind of plate, in which there is otherwise an essentially open surface, can be used. Such plates are, for example, a perforated plate, 20 a mesh plate, or a grille formed of bars, or similar. Sufficient ventilation from underneath is an important factor in the drying of a peat block.

The aim is to keep the surface area of the peat blocks against

25 the base as small as possible, without, however, endangering stability. Generally, the peat blocks are detached by cutting in such a way that at least one dimension is equal to, or less than 20 cm. The dimension against the case should be 10 - 20 cm, preferably 10 - 15 cm. The peat blocks are set on the base

30 separately from each other, in such a way that the gap between adjacent blocks is 3 - 15 cm, preferably 5 - 7 cm, in order to make drying more efficient.

Once the moisture content of the peat blocks is typically 65 -

35 80 %, the bases with the peat-block group can be advantageously stacked on top of each other. Except for the uncovered topmost base in the stack, the bases with the peat blocks are protected from rain. Wetting of the topmost peat blocks can be prevented by covering the stacks. In addition, the bases prevent water rising from the bog by capillary action, thus eliminating the greatest factor preventing drying in the traditional production of peat. Generally, 2 - 10 bases, preferably 4 - 7 bases are stacked on top of each other. Drying continues quite effectively through the effect of the wind to the target moisture content, which is generally 30 - 50 %. The peat blocks under the topmost plate continue to dry. By means of the method according to the invention, several, typically from four to six harvests each year can be obtained. The weather risk is also substantially reduced, as rainy periods will not spoil the entire harvest.

By means of the method according to the invention, horticultural peat can be produced with a low waste percentage. Figure 5 shows a second embodiment of the invention. First of all, peat blocks 15, which are set to dry on self-supporting bases 14, are cut mechanically from a bog 10 from a selected lifting groove 12. According to the invention, the peat blocks 15 are placed on the bases 14 mechanically and the bases 14 are handled mechanically, at least when placing the peat blocks 15 on the bases 14. The peat production will then be mechanical, from the cutting of the peat blocks to placing them for drying. The peat blocks 15 are preferably placed to dry on the bases 14 as block groups 16, in such a way that, in each block group 16, the peat blocks 15 are set apart from each other on a single plane on the base 14. Thus, the peat blocks remain securely in place, the drying in a stack being nevertheless rapid. Figure 5 shows schematically the lifting machine 19 and the bases 14 according to the invention.

By arranging certain new properties in the machine, the manual handling of the peat blocks can be avoided entirely, or at least for the most part. In this lifting machine, there are a conveyor 20 for the bases 14, so that the peat blocks cut from the bog are placed directly on the base mechanically. In addition, the bases are handled mechanically, so that the handling of the peat blocks is rapid. The block groups 16 are also covered essentially immediately after placing on the bases 14. Thus, the peat blocks are protected from rain and the peat blocks can even be cut from the bog while it rains. On the other hand, excessive drying of the surface of the topmost peat blocks is avoided, as the peat blocks are protected under the cover from the rays of the sun. An excessively dry outer sur- face would prevent, or at least slow the egress of water from inside the peat block. The cover also prevents dew from forming on the surface of the peat blocks. Thanks to the cover, the peat blocks will also dry during rainy periods, as the peat blocks do not become wet under the cover and evaporation takes place between periods of rain.

Figure 6a shows a second embodiment of the base according to the invention. The base has multiple layers, so that the stacks are formed without separate operations. In other words, several bases 14 are arranged in several layers 21 on top of each other in order to form stacks 17 and the peat blocks 15 are dried in the stack 17 up to the target moisture content. After drying, when the moisture content of the peat blocks is at the selected level, the peat blocks are collected from the bases. In the example shown, the lifting machine 19 moves slowly towards the right, at the same time cutting a large sod of peat from the bog 10, which is then turned onto the transverse conveyor 22. During the transfer, the peat sod is divided, for example, into five peat blocks, which are pushed onto a base 10 on the con- veyor 20 of the lifting machine. At the same time, the peat blocks are moved slightly, to create gaps. Once the base has been filled, it is lowered onto the bog and a new empty base is moved to the position of the transverse conveyor. Thus, the cutting of the peat blocks forms a continuous loop of mechani- cal work stages. In addition, a single handling brings the peat blocks at one time to drying and storage condition. In both methods, a self-supporting base 14, on which the peat blocks that are mechanically cut from the bog 10 are set to dry, is used in the production of horticultural peat. According to the invention, each base 14 includes one or more gripping points 26, 27, 32, for handling the bases 14 mechanically and for setting the peat blocks 15 mechanically onto the base 14. The cut peat blocks 15 are preferably placed to form block groups 16, in each of which there are peat blocks 15 separate from each other on one plane. Thus, the block groups remain in their defined positions and the bases and the peat blocks set on them can be handled mechanically. At the same time, it is unnecessary to move and turn the individual peat blocks, which reduces overall waste as the peat blocks remain as intact as possible .

In Figure 6a, the base 14 includes a support frame 23, in which there are support structures 24 for more than one base 14. The support frame is manufactured from steel profiles, so that it will withstand the base being moved and the weight of the wet peat blocks. Instead of, or as well as steel, other materials too can be used. In this case too, corrugated plates are used, the depth of the corrugation of which is 20 - 70 mm, preferably 30 - 50 mm. In Figure 6a, there are four layers in the support frame 23 while in Figure 7a there are five layers. Generally, the support frame 23 includes support structures 24 for 2 - 8, preferably 4 - 7 bases 14. The larger the peat blocks that are cut, the fewer the layers that are used.

According to the invention, the peat blocks are covered as soon as possible after cutting. Thus, the support frame 23 includes a cover 25, which is arranged to cover essentially the entire base 14. The peat blocks are then covered immediately and will remain dry. On the other hand, the smaller the cover the better the air circulation between the peat blocks. At the same time, the mechanical handling of the base remains as simple as possible. The support frame 23 preferably also include gripping points 26 for handling the support frame mechanically. The lifting machine can grip directly the support frame 23, to which a lifting eye 27 can also be fitted as a gripping point. In addition, the ends of the steel profiles of the lower edge of the support frame 23 can be left open, to form functional gripping points. In that case, fork-lift truck prongs 28 can be pushed into the steel profiles, for the handling and transportation of the base 14 (Figure 7a) .

In the embodiment of Figure 6a, the corrugated plate is about one square metre in size. About 100 peat blocks, weighing a total of about 600 kilograms when cut from the bog, can then be placed on the four layers. Figure 6b shows a block group 16 formed on the corrugated plate from peat blocks 15, in which the size of each peat block 15 is 15 x 15 x 25 cm³. The use of a 1500-mm high support frame, in which the base size is 800 x 1200 mm, is also planned.

Figure 7b shows a third embodiment of the base according to the invention, in which the support structures 24 of the support frame 23 cover the surface area of more than one base 14. In this case, the support frame is formed as an elongated covered set of shelves, onto which the peat blocks are lifted mechanically to dry. As production progresses, the set of shelves can be moved, for example, by being pulled on top of runners. The embodiments of the method and base according to the invention can also be combined. Simple corrugated plates, which are mechanically lifted onto the support structures, or a set of shelves according to Figure 7b, can be used as the bases. On the other hand, the bases according to Figures 6a can be stored in a long set of shelves. The base itself can then be without a cover, which will simply its construction and facilitate its handling.

The equipment for peat production according to the invention is shown in greater detail in Figures 8a - 9b. The equipment is preferably arranged as a single independent device arranged to move on a bog. The device includes elements 29 for cutting peat blocks 15 from a selected groove in a bog 10 with a large moisture content typically of about 90 %. In practice, a large sod is first cut from the bog and divided by the device into peat blocks. By means of suitable dimensioning, even an individual sod can be transferred as such, or equipped with dividing grooves, onto a base. The device further includes means 30 for placing the peat blocks 15 on self-supporting bases 14. The bases 14 too are preferably handled using the same means. In that case, each base 14 is positioned for placing the peat blocks 15 on the bases 14.

In Figure 8a, a first support frame 23 on the left-hand side is carried by a positioning lift 31, the lowest base 14 being ready to receive peat blocks. During the next work stroke of the device, the next base is lowered slightly to receive peat blocks. The support frames 23 are moved to the positioning lift

31 by means of a conveyor 20, using which the support frames 23 are also picked up from the bog 10. For the conveyor 20, there are lifting trunnions 32 in the support frame, from which the support frame 23 hangs freely until the positioning lift.

The support frame 23 slides from the conveyor 16 to the posi- tioning lift 31, on which the support frame 23 is supported in precisely the correct position relative to the device. Thus, the position and movement of the device do not affect the placing of the peat blocks on the base and the various work movements can be automated and staged related to each other, in order to achieve essentially uninterrupted peat production. In this case, the positioning lift 31 is formed of two lifts on top of each other. Thus, the work movement of an individual lift remains advantageously short and, for example, when the lower lift is lowering a support frame onto the bog, the next support frame can be already held by the upper lift. In addition, several support frames can be picked onto the conveyor. In other words, the means 30 include a conveyor arrangement 20 and 31 for picking a base 14 from the bog 10, for positioning the base 14 relative to the device for placing the peat blocks 15, and for lowering the base 14 filled with peat blocks 15 back onto the bog 10. Thus, according to the invention, when placing peat blocks on one base, the next base is taken to be positioned. In addition, the bases are handled mechanically, starting from their positioning right to the removal of the peat blocks from the bases. Thus, the share of manual work remains at a minimum, making peat production substantially more efficient .

In fact, in the method according to the invention, a single set of co-ordinates is defined, in which the lifting of the peat is performed and into which the base is positioned. The device also operates within the same set of co-ordinates, thus permitting the mechanical handling of the peat blocks and bases according to the invention. In the embodiment shown, a single multi-purpose device is used. On the other hand, two separate devices can be used, as long as they are adapted to the same set of co-ordinates, for example, by docking. In that case, the first device of the two joined together can be used, for example, only to lift the peat blocks, which are then placed on the bases using the second machine. In other words, the position and attitude of the peat blocks are the whole time predefined and known .

Figure 10a shows an enlargement of the base of Figure 8a. In this case, the support frame 23 is formed from two tubular frames 33, which are connected by five plate structures 34 forming the bases. The four lowest of these are preferably perforated or mesh plates, the uppermost being solid, thus forming a protective cover. On the centre line of the structure between the tubular frames 33 there is, in addition, a connect- ing bar 35, the parts of which protruding beyond the tubular frames 33 form the lifting trunnions 32 referred to above. The simple and constructionally clear base is well suited to me^¬ chanical handling. In addition, it is sturdy and cheap to manufacture. Also, the flat and smooth base permits a peat block to be placed mechanically on the base. In Figure 10b are five peat blocks placed a distance apart on a single mesh plate. Figure 10c shows a special application of a peat block, which is a single unified piece. In order to achieve rapid drying, in this case the thickness of the peat block is less than 100 mm. The other dimensions of the peat block could be, in this case, for example, 800 x 1100 cm. Thus, rapid and even drying will be achieved from the upper and lower surfaces of the peat block. When producing thin peat blocks, a support frame is used, in which there are more bases than in the above description. The storage and transportation of the slab-like peat block would be inefficient. Therefore, when forming the peat block grooves 36 or cuts, at the positions of which the peat block will divide into smaller parts after drying, or at the latest when being handled, are formed in either one, or both of the flat surfaces.

The target moisture content of a peat block is typically about 50 %. Depending on the intended use, the target moisture content can vary between 40 % and 55 %. The question is thus of mean moisture content. In practice, the surface part of a peat block is considerably drier than the internal part. In other words, peat is often uneven in terms of moisture content. The dry surface part also shrinks, hindering the drying of the internal part. Thus, the drying of a peat block becomes slower the drier it becomes. However, there is a demand for largish peat blocks and sufficiently large peat blocks will remain standing independently, as described above. However, during the simulation of the invention and in other tests it has been surprisingly observed that, by reducing one dimension of a peat block, the drying time can be further reduced. Thus, according to the invention, the peat block is cut, in such a way that the smallest dimension of the block is 3 - 10 cm, preferably 4 - 6 cm. There are then, as it were, two opposing surface parts in the peat block, both of which dry thoroughly rapidly. Thus, the wetter internal part does not form, so that the peat block also has, in addition, an even moisture content throughout. By adjusting the lifting machine, or more generally the equipment, even very thin peat blocks can be lifted. If the smallest dimension remains less than 10 cm, the probability of the block remaining standing diminishes. Thus, in a block group, in addition to, or instead of this smallest dimension, some other larger dimension of the peat block is set against the base. A peat block that is placed fully on its flat side on the base will take up space unnecessarily and the drying of the other side will be slowed. Indeed, it is advantageous to support thin peat blocks on slanting supports, or on perforated planes, when only a small part of the peat block will touch the base. It has been observed in tests that a peat block a few centimetres thick dries to the target moisture content already in a few days. On average, a thin peat block could be produced in, for example, a cycle of about a week. In that case, a single 20- metre-wide strip could produce a thickness of about 30 cm during a single summer. By taking the production conditions and quality of the peat into account, the peat yield can be optimized by altering the dimensions of the peat block. In other words, a great many large peat blocks can be lifted, but their drying will be slow. On the other hand, thin peat blocks dry rapidly, but their lifting is slower and fewer blocks will fit into the support frame. Productivity can be further increased by reducing the initial moisture content from 90 %, for example, by ditching. A reduction of even five percent in the initial moisture content will double the yield. If necessary, the lifting device is altered in such a way as to permit the lifting of peat blocks that are drier than usual.

By means of the method according to the invention, the peat blocks are loaded directly on a covered frame. Several layers of peat blocks are loaded on a well-ventilated base, with the blocks set apart from each other. Being then exposed to the wind, the peat blocks dry considerably faster without being turned and without being touched by hand. After drying, the bases are also emptied of the dried peat blocks mechanically. In every stage, the bases are also handled mechanically. On a covered base, peat blocks can be dried all year round protected from rain, the bases thus being partly also a store. Several harvests can be obtained in year, because the wetting of the peat blocks can be avoided. By means of the method, the quality of a peat block improves and waste is reduced. By further reducing one dimension of a peat block, the drying time can be shortened still more. In that case, several tens of harvests can be obtained in a year. The base and equipment according to the invention can also be applied to the production of fuel peat.

Claims

1. Method for peat production,, in which method

- peat blocks (15) with a high moisture content are cut mechanically from a bog (10) from a selected a lifting groove (12) , the cut peat blocks (15) are placed to dry on self-supporting bases (14), and

- after drying, when the moisture content of the peat blocks (15) is at a chosen level, the peat blocks (15) are collected from the bases (14) , characterized in that the peat blocks (15) are placed on the bases (14) mechanically and the bases (14) are handled mechanically, at least when placing the peat blocks (15) on the bases (14) .

2. Method according to Claim 1, characterized in that each base

(14) is positioned, in order for the peat blocks (15) to be placed on the bases (14) .

3. Method according to Claim 2, characterized in that, when placing peat blocks (15) on one base (14), the next base (14) is taken for positioning.

4. Method according to Claim 2 or 3, characterized in that the bases (14) are handled mechanically, starting from their positioning and terminating with the removal of the peat blocks

(15) from the bases (14).

5. Method according to any of Claims 1 - 4, characterized in that the peat blocks (15) are placed mechanically on the bases (14) to form block groups (16), in which, in each block group (16) , there are peat blocks (15) set apart from each other on a single place on the base (14) .

6. Method according to Claims 1 - 4, characterized in that peat blocks (15) are cut from the bog (10) , each one of which fills one base (14 ) .

5 7. Method according to any of Claims 1 - 6, characterized in that the peat blocks (15) are covered essentially immediately after being placed on the bases (14) .

8. Method according to any of Claims 1 - 7, characterized in 10 that the bases (14) are arranged in several layers (21) on top of each other, in order to form stacks (17) and the peat blocks (15) are dried in a stack (17) until the target moisture content is reached.

15 9. Method according to any of Claims 1 - 8, characterized in that the peat blocks (15) are detached by cutting, in such a way that at least one dimension of the peat block (15) is equal to, or less than 20 cm.

20 10. Method according to Claim 9, characterized in that the small dimension of a peat block (15) is 10 - 20 cm and, in a block group (16), this smallest dimension is set against the base (14 ' ) .

25 11. Method according to Claim 9, characterized in that the smallest dimension of a peat block (15) is 3 - 10 cam, preferably 4 - 6 cm and, in a block group (16), in addition to, or instead of this smallest dimension, some other larger dimension of the peat block (15) is set against the base (14') .

30

12. Method according to any of Claims 1 - 11, characterized in that the peat blocks (15) are placed on a base (14) apart from each other, in such a way that the gap between adjacent peat blocks (15) is 3 - 15 cm, preferably 5 - 7 cm.

35

13. Base for use in peat production, which is self-supporting and on which peat blocks (15) that are mechanically cut from a bog (10) are intended to be placed to dry, characterized in that each base (14) includes one or more gripping points (26,

5 27, 32), both for handling the bases (14) mechanically and for placing the peat blocks (15) mechanically on the base (14) .

14. Base according to Claim 13, characterized in that the base (14) is mainly formed of a corrugated plate, or of a plate, in

10 which there is an otherwise open surface.

15. Base according to Claim 13 or 14, characterized in that the base (14) includes a support frame (23) , in which there are support structures (24) for more than one base (14) .

15

16. Base according to Claim 15, characterized in that the support frame (23) includes support structures (24) for 2 - 8, preferably 4 - 7 bases (14) .

20 17. Base according to Claim 15 or 16, characterized in that the support frame (23) includes a cover (25) , which is arranged to cover substantially the entire base (14) .

18. Equipment for producing peat, which equipment includes 25 elements (29) for cutting peat blocks (15) with a high moisture content, from a lifting groove (12) selected from a bog (10) , characterized in that the equipment further includes means (30) , both for handling the bases (14) , and for placing the peat blocks (15) on self-supporting bases (14) . 30

19. Equipment according to Claim 18, characterized in that the means (30) include a conveyor arrangement (20, 31) for picking up a base (14) from the bog (10), for positioning the base (14) relative to the equipment, for placing the peat blocks (15),

35 and for lowering the base (14) filled with peat blocks (15) back onto the bog (10) .

20. Equipment according to Claim 18 or 19, characterized in that the equipment is arranged to form a single device arranged to move independently on the bog.