GB2128661A

GB2128661A - Method for producing dried lump peat

Info

Publication number: GB2128661A
Application number: GB08327341A
Authority: GB
Inventors: Laurri Heikki Ilmari Toivakka
Original assignee: Individual
Current assignee: Individual
Priority date: 1982-10-13
Filing date: 1983-10-12
Publication date: 1984-05-02
Also published as: GB8327341D0; FI75358C; FI75358B; FI823485L; FI823485A0; SE8305585D0; IE832392L; GB2128661B; IE54639B1; SE8305585L

Abstract

A method for producing dried lump peat, wherein peat is detached from a bog and formed into lumps, whereafter the lumps are arranged on the surface of the bog and allowed to dry. The lumps are comparatively large, substantially disc-shaped pieces (1), for instance slices of uniform thickness the sides of which have an elliptical shape, and these lumps are arranged on the bog surface (2) so that their central axes are horizontal. About 5% of the surface area of the lumps will thus be in contact with the bog surface and the rest serves as drying surface on which the sun and wind may act. The drying on the bog surface preferably constitutes an initial drying phase, followed by final drying in a storage heap. <IMAGE>

Description

SPECIFICATION Method for producing dried lump peat The present invention concerns a method for producing dried lump peat wherein peat raw material is detached from the bog, and formed into lumps, whereafter the lumps are arranged on the surface of the bog and are allowed to dry.

The drawback of existing methods for lump peat is their inefficiency. That is they do not fuily utilise the drying capacity of the bog surface.

A method by which peat could be produced at a rate consistent with the total drying capacity of the bog or which could at least approximate to this capacity would afford a substantial improvement compared to existing methods. An object of the invention is to provide such a procedure.

The present invention provides a method for producing dried lump peat, in which peat is detached from a bog and is formed into lumps, after which the lumps are arranged on the bog surface and allowed to dry, characterised in that the lumps which are formed are substantially disc-shaped and they are arranged on the bog surface so that the central axes of the discs are horizontal. The method of the invention ensures that fastest possible drying of the lumps is achieved.

By virtue of the invention the advantage is gained that the peat lumps can be made substantially larger than heretofore. The disc-like lumps may be, for instance, elliptically shaped slices of uniform thickness, with length and breadth of the order of 250 to 300 mm and thickness of the order of 100--1 50 mm. When such lumps are placed standing on edge on the bog surface, about 5% of their surface area will be in contact with the bog surface and the remaining 95% will constitute the drying surface, which is exposed to the drying action of wind and sunlight.

It has been found in preliminary tests that pieces like this can be made to dry out sufficiently without the need to provide holes in them to promote drying.

In the method of the invention, known machines for the production of lump peat can be used. One may contemplate e.g. a screw-type machine, the working depth of which may be up to 1.4 mm. The lumps produced by the machine may be arranged on the bog surface in rows parallel to the travel of the machine, with the lumps lying at a predetermined spacing. The density of lumps may then be such that the quantity of peat being dried is about 700 to 800 m3 per hectare. Since on one bog two or three peat batches per summer can be produced, the production per production period will be about 1 400 to 2400 m3 per hectare, which is substantially more than the production achievable by any procedure known in the art.

A further advantage of the invention is the convenience of collection of the large disc-shaped lumps from the bog after the drying phase. All things considered the labour input per cubic metre of lump peat produced is considerably less than in any procedure known in the art. The lumps collected from the bog are preferably transported into a storage heap, where their drying continues.

In that case, the drying on the bog constitutes the initial drying step, in which a dry matter content of about 4050% is reached, and the ultimate dry matter content of the lumps is not reached until after further drying in the storage heap. The heap is preferably situated on the edge of the bog and may be provided with a roof, with the lumps stored in the heap in a manner enabling air to pass through between the lumps. The drying taking place in the heap is rather slow, and this is an advantage with a view to the quality of the dried peat because in this way the lumps will be very compact, and a high energy content per unit volume of peat is achieved.

The invention is described in more detail in the following with reference being made to the accompanying drawings, wherein: Fig. 1 shows a disc-shaped peat lump formed according to the invention, Fig. 2 shows lumps as in Fig. 1, arranged in rows on the bog surface, and Fig. 3 illustrates graphically the drying of lumps on the bog surface in a particular case by way of example.

In the procedure of the invention, the peat is most appropriately taken up from the bog with a lump peat machine which forms disc-shaped lumps of the peat. One such lump 1 is shown in Fig. 1, consisting of a slice-like body of uniform thickness and having sides with the shape of an ellipse. As taught by the invention, the iumps 1 are arranged on the bog surface in rows, where they are allowed to dry under action of sun and wind. During this phase the lumps are standing on one edge, that is, with the central axes of the lumps horizontal, and thereby only about 5% of their surface area is in contact with the bog surface, the rest serving as free drying surface.

The way in which the lumps 1 are arranged on the bog 2 can be seen in Fig. 2. When the lumps 1 have dried out enough, they are collected from the bog and transported to a heap located e.g. on the edge of the bog, for further drying.

Fig. 3 shows graphically the results of a drying trial in which disc-shaped peat lumps (as in Fig. 1) were used, the ellipsoidal side of the lump having length and breadth (dimensions A and B in the figure) 300 mm and 260 mm, and the thickness of the lump (dimension C in the figure) being 120 mm. The test was run during a period of about two and a half month, in July to September, and Fig 3 shows the moisture contained in the peat (in %) as a function of the drying time, the time being entered as calender dates.The four different graphs -IV in the figure represent the moisture content of the peat as measured at four different points of the lump, graph I representing the topmost quarter of the breadth of the lump (at its height as it is standing on its edge), graph 11 the next lower quarter, graph III the foliowing lower quarter, and graph IV the lowermost quarter of the lump, (i.e., the part of the lump against the bog surface). The figure reveals that in about three weeks the lumps have dried to a moisture content of about 5060%, and it would be advantageous at this point to move the lumps from the bog into a heap. The moisture content of the lumps reduced further in the course of a continued test, but when the aim is to achieve highest possible quality of the lump peat, it is no longer necessarily an advantage to continue the drying on the bog surface any further.

Claims

1. A method for producing dried lump peat, in which peat is detached from a bog and is formed into lumps, after which the lumps are arranged on the bog surface and allowed to dry, characterised in that the lumps which are formed are substantially disc-shaped and they are arranged on the bog surface so that the central axes of the discs are horizontal.

2. A method as claimed in claim 1, wherein the peat is detached from the bog with a lump peat machine and that the lumps are arranged on the bog surface in rows parallel to the travel of the machine.

3. A method as claimed in claim 1 or 2, wherein the lumps are arranged on the bog surface in such a way that 700-800 m3 of peat is dried per hectare.

4. A method as claimed in any of claims 1 to 3, wherein initial drying of the lumps takes place on the bog surface, whereafter the lumps are transported to a storage heap for further drying.

5. A method as claimed in claim 4, wherein the lumps are dried on the bog surface until their dry matter content is at least 40%, whereafter the lumps are transported to the storage heap.

6. A method for producing dried lump peat substantially as herein described with particular reference to the accompanying drawings.

7. Dried lump peat when produced by a method as claimed in any of claims 1 to 6.