GB1560969A

GB1560969A - Method and press for rupturing cell walls of green plants

Info

Publication number: GB1560969A
Application number: GB4777877A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1976-11-16
Filing date: 1977-11-16
Publication date: 1980-02-13
Also published as: FR2370442A1; DK140512B; DK140512C; DK513876A

Description

(54) METHOD AND PRESS FOR RUPTURING CELL WALLS OF GREEN PLANTS (71) I, ARNE MOELLER, of 97 Torupvejen, 3390 Hundested, Denmark, of Danish Nationality, do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement: The invention relates to a method for rupturing the cell walls of green plants in order to make a concentrated feed or feeding stuff, and a press for the performance of the method.

Squeezing out liquid from grass and other green crops makes it possible to exploit the crop better, as the liquid phase has a content of proteins which are accessible for animals with only one stomach, such as pigs and poultry. Further the water content of the green mass is considerably reduced which means that it is easier and cheaper to preserve, either by drying or by ensiling.

These facts have been known for some years, and liquid squeezing has been made by direct squeezing of comminuted green crop in a variety of presses. In these processes, however, the power consumption is so high that such techniques have not been used very often.

However, experiments have shown that a more effective and far less power consuming liquid squeeze process may be obtained by dividing the process into two phases, namely fracturing of cell walls and subsequent liquid squeezing.

Thus, professors H. D. Bruhn and R. G.

Koegel of the University of Wisconsin have shown that an effective fracturing of cell walls requiring very little power is obtained by pressing the green crop through an extrusion plate provided with extrusion holes of a diameter of W15 mm. The experimental production was carried out with a press-piston, the bottom piece of which had the form of an extrusion plate. Based on the obtained results a continuously working machine was built at the University of Wisconsin in 1974/75, which machine was based on an ordinary ring matrix press, known from the feed stuffs industry, but having a horizontally placed ring matrix and with extrusion holes. With this technique, followed by a squeezing, liquid squeezing from the green crop has been carried out with a power consumption of only 10^20% of that used by the previously mentioned methods.

Although there are many points of resemblance between this technique for fracturing of cell walls and the technique which is used, e.g. in the feed stuffs industry, -for the compression of food pills (e.g. see French Patent No. 891.152) there is principally and functionally a considerable difference between the techniques.

In a crop compressor dry material is pressed through press holes or press channels, which in the active zone are cylindrical or slightly conical with the smallest opening at the place where the material leaves the press. The press channels have an active press length which is usually 20= 100 mm, depending on the diameter of the hole and the material. By pressing the material through the press channels, compression, frictional heating and cementing together takes place, so that the material keeps the cylindrical form after having left the press.

In the cell wall fracture device newly harvested material with a water content of about 80% is pressed through the especially formed extrusion holes, where the active zone is limited to the narrow edge. Here the cell walls are fractured, as they are exposed to a heavy pressure gradient during the passage of the sectional reduction.

However, the above-mentioned technique with the ring matrix press has a number of disadvantages. Such a ring matrix with conical boring from both sides is difficult -and expensive to produce, and also this solution requires that the green mass follows a complicated and unnatural movement along the internal periphery of the ring matrix. Experiments have been made with a horizontally placed ring matrix but only 255S of the calculated capacity was achieved, mainly because of the unnatural movement of ma terials, involving vertical fall towards the bottom of the matrix, whereafter the squeezing rollers were to bring the material out to the periphery, up along the inner wall of the matrix and out through the extrusion holes.Further attempts have been made to raise the ring matrix to a vertical position, but there were still problems of capacity and operation, probably due to the somewhat unnatural movement of materials necessary to press the material out through the extrusion holes, which are not placed at the lower part of the matrix.

The present invention provides a method of rupturing cell walls of green plants for the production of a concentrated feed stuff, which comprises pressing green plant material against a generally horizontal plate having through-holes by means of one or more squeezing rollers, the plate and the roller(s) being moved relative to each other such that the green plant material is pressed through the holes, the cross-sectional area of each hole in the direction of pressing of the plant material decreasing in a first portion and then increasing in the remaining portion so as to produce a sharp-edged constriction where said first portion meets said remaining portion.

Unusually good economy is obtained, as the effect is used for depressing the green plants into all the holes with equal effect in such a way that the capacity of the horizontal matrix is used to its full extent. A further consequence of the method is the use of simple and robust means. The material follows a natural movement of materials as it falls down on the matrix, whereafter the squeezing rollers press the material through the holes.

A plant press for carrying out the method comprises a horizontal plate having throughholes, and one or more squeezing rollers movable relative to the plate such that green plant material may be pressed through the holes; the cross-sectional area of each hole in the direction of pressing of the plant material decreasing in a first portion and then increasing in the remaining portion of the hole so as to produce a sharp-edged constriction where said first portion meets said remaining portion.

The interior edge of the constriction is necessary to make the required fracturing of cell walls possible, as the lacking counterpressure in the hole during the depression of the plants causes a fracturing of the cell walls, In order to prevent the material from blocking up the hole below the edge, the holes may have an enlarged opening towards- the outlet side.

An embodiment of the invention will now as described with reference to the drawing, in which: Figure 1 shows a press with horizontally placed extrusion plate seen from above, Figure 2 shows the same press seen from the side, and Figure 3 shows a sectional view through a hole.

As shown in Fig. 1 and 2, a horizontally placed disc-shaped extrusion plate 1 has a suitable number of holes 2 placed in concentric circles at a suitable mutual distance apart. Above the extrusion plate one or more squeezing rollers 3 are mounted, which can be rotated around the vertical axis of the extrusion plate and simultaneously be turned around their own axis. On supplying green plants to the horizontal extrusion plate, these are pressed through the holes by means of the squeezing rollers, which causes rupture of the cell walls.

The holes 2 are shaped as shown in Fig.

3. Towards the squeezing rollers each hole has an upper frusto-conical portion with the larger opening upwards, and a lower frustroconical portion with its larger opening towards the underside, in order to build an "hourglass" shaped hole. This results in a sectional restriction along an edge 4.

The upper cone on the inlet side serves partly to supply the material and partly to protect the edge 4 against wear caused by the squeezing rollers, whereas the lower cone on the outlet side allows transport of the material through the plate without compression of the material.

When the green plants are pressed into the holes, the cell walls burst, as they become subjected to a heavy pressure gradient caused by the pressure from the squeezing rollers and the constriction in the holes.

After the rupture of the cell walls the material is then pressed further through the holes and can be collected under the extrusion plate.

By this method a pulp is produced which can then in generally known manner be exposed to liquid squeezing, as the ruptured cell will now easily release its cell liquid.

Instead of rotating the squeezing rollers, the extrusion plate may itself be rotated, provided that squeezing rollers are mounted above the plate for squeezing the green plants through the holes.

WHAT I CLAIM IS: 1. A method of rupturing cell walls of green plants for the production of a concentrated feed stuff, which comprises pressing green plant material against a generally horizontal plate having through-holes by means of one or more squeezing rollers, the plate and the roller(s) being moved relative to each other such that the green plant material is pressed through the holes, the crosssectional area of each hole in the direction of pressing of the plant material decreasing

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. terials, involving vertical fall towards the bottom of the matrix, whereafter the squeezing rollers were to bring the material out to the periphery, up along the inner wall of the matrix and out through the extrusion holes. Further attempts have been made to raise the ring matrix to a vertical position, but there were still problems of capacity and operation, probably due to the somewhat unnatural movement of materials necessary to press the material out through the extrusion holes, which are not placed at the lower part of the matrix. The present invention provides a method of rupturing cell walls of green plants for the production of a concentrated feed stuff, which comprises pressing green plant material against a generally horizontal plate having through-holes by means of one or more squeezing rollers, the plate and the roller(s) being moved relative to each other such that the green plant material is pressed through the holes, the cross-sectional area of each hole in the direction of pressing of the plant material decreasing in a first portion and then increasing in the remaining portion so as to produce a sharp-edged constriction where said first portion meets said remaining portion. Unusually good economy is obtained, as the effect is used for depressing the green plants into all the holes with equal effect in such a way that the capacity of the horizontal matrix is used to its full extent. A further consequence of the method is the use of simple and robust means. The material follows a natural movement of materials as it falls down on the matrix, whereafter the squeezing rollers press the material through the holes. A plant press for carrying out the method comprises a horizontal plate having throughholes, and one or more squeezing rollers movable relative to the plate such that green plant material may be pressed through the holes; the cross-sectional area of each hole in the direction of pressing of the plant material decreasing in a first portion and then increasing in the remaining portion of the hole so as to produce a sharp-edged constriction where said first portion meets said remaining portion. The interior edge of the constriction is necessary to make the required fracturing of cell walls possible, as the lacking counterpressure in the hole during the depression of the plants causes a fracturing of the cell walls, In order to prevent the material from blocking up the hole below the edge, the holes may have an enlarged opening towards- the outlet side. An embodiment of the invention will now as described with reference to the drawing, in which: Figure 1 shows a press with horizontally placed extrusion plate seen from above, Figure 2 shows the same press seen from the side, and Figure 3 shows a sectional view through a hole. As shown in Fig. 1 and 2, a horizontally placed disc-shaped extrusion plate 1 has a suitable number of holes 2 placed in concentric circles at a suitable mutual distance apart. Above the extrusion plate one or more squeezing rollers 3 are mounted, which can be rotated around the vertical axis of the extrusion plate and simultaneously be turned around their own axis. On supplying green plants to the horizontal extrusion plate, these are pressed through the holes by means of the squeezing rollers, which causes rupture of the cell walls. The holes 2 are shaped as shown in Fig. 3. Towards the squeezing rollers each hole has an upper frusto-conical portion with the larger opening upwards, and a lower frustroconical portion with its larger opening towards the underside, in order to build an "hourglass" shaped hole. This results in a sectional restriction along an edge 4. The upper cone on the inlet side serves partly to supply the material and partly to protect the edge 4 against wear caused by the squeezing rollers, whereas the lower cone on the outlet side allows transport of the material through the plate without compression of the material. When the green plants are pressed into the holes, the cell walls burst, as they become subjected to a heavy pressure gradient caused by the pressure from the squeezing rollers and the constriction in the holes. After the rupture of the cell walls the material is then pressed further through the holes and can be collected under the extrusion plate. By this method a pulp is produced which can then in generally known manner be exposed to liquid squeezing, as the ruptured cell will now easily release its cell liquid. Instead of rotating the squeezing rollers, the extrusion plate may itself be rotated, provided that squeezing rollers are mounted above the plate for squeezing the green plants through the holes. WHAT I CLAIM IS:

1. A method of rupturing cell walls of green plants for the production of a concentrated feed stuff, which comprises pressing green plant material against a generally horizontal plate having through-holes by means of one or more squeezing rollers, the plate and the roller(s) being moved relative to each other such that the green plant material is pressed through the holes, the crosssectional area of each hole in the direction of pressing of the plant material decreasing

in a first portion and then increasing in the remaining portion of the hole so as to produce a sharp-edged constriction where said first portion meets said remaining portion.

2. A method of rupturing cell walls of green plants substantially as herein described, with reference to the drawings.

3. A method of producing a liquid feed stuff, which comprises pressing green plant material against a generally horizontal plate having through-holes by means of one or more squeezing rollers, the plate and the roller(s) being moved relative to each other such that the green plant material is pressed through the holes, the cross-sectional area of each hole in the direction of pressing of the plant material decreasing in the first portion and then increasing in the remaining portion of the hole so as to produce sharpedged constriction where said first portion meets said remaining portion and squeezing the pulp produced to release the liquid.

4. A method of producing a liquid feed stuff substantially as herein described with reference to the drawings.

5. A plant press for carrying out the method of Claims 1 or 2 which comprises a horizontal plate having through-holes, and one or more squeezing rollers movable relative to the plate such that green plant material may be pressed through the holes; the cross-sectional area of each hole in the direction of pressing of the plant material decreasing in a first portion and then increasing in the remaining portion of the hole so as to produce a sharp-edged constriction, where said first portion meets said remaining portion.

6. A plant press for carrying out the method of Claim 1 or 2 substantially as described with reference to and as shown in Figure 1 or Figures 1 to 3.