METHOD AND DEVICE FOR DISINTEGRATING COARSE MATERIAL

APPAREIL POUR DESAGREGER DES MATIERES GROSSIERES, ET METHODE CONNEXE

English Abstract

ABSTRACT
Coarse waste e.g. stumps (3, 7, 8), lumber from demolition
etc. is disintegrated in a device comprising at least two
cooperating, essentially parallel screws to (1, 2, 6) in
that the screws have mutually opposite feeding directions
so that they tear the waste into pieces. (Fig 1).

Claims

CLAIMS:
1. A method for producing the disintegration of material,
which method comprises:
rotating at least two generally adjacent, generally paral-
lel co-operating screws, each of said screws having
threads which have disintegrating edges which are active
in the direction of advancement of the thread during
rotation and arranged so that each screw has a direction
of thread advancement which is opposite to that of any
immediately adjacent screw, and;
placing the material to be disintegrated in contact with
the screws whereby the disintegration edges of the threads
grip and cut into the material to be disintegrated, in
opposite directions.
2. The method according to claim 1, wherein the degree
of disintegration is controlled by adjustment of the
distance between the screws.
3. The method according to claim 1 or claim 2, wherein
the material is caused to pass through a plurality of
sets of co-operating screws sequentially, each set in
said sequence having decreasing thread dimensions and
decreasing spaces between adjacent threads.
4. A device for producing the disintegration of material,
comprising:
a frame;
at least two screws rotatable mounted to the frame in
an essentially parallel relationship to one another,
said screws having thread edges adapted for disintegration
of material, which edges are active in the direction
of advancement of the threads when the screws are rotated
in a prescribed direction, and each individual screw
having a direction of thread advancement, when rotated

in its prescribed direction, which is opposite to the
direction of thread advancement of any immediately
adjacent screw when said screw is rotated in its own
prescribed direction, and;
drive means for rotating each screw in its prescribed
direction so that the disintegrating edges of the threads
of immediately adjacent screws advance in mutually
opposite directions.
5. The device according to claim 4 wherein the screws are
arranged in co-operating pairs and are supported in
displacable bearings, the distances between adjacent
bearings being adjustable in a direction perpendicular to
the axes of the screws for the purpose of adjustment of
the distances between the screws whereby the dimensions
of the disintegrated material can be adjusted.
6. The device according to claim 4 wherein the thread
helices of adjacent screws are arranged in the same
direction, and wherein the opposite direction of
advancement of immediately adjacent threads is produced
by rotating the screws in opposite directions of
rotation.
7. The device according to claim 5 wherein the thread
helices of adjacent screws are arranged in the same
direction, and wherein the opposite direction of
advancement of immediately adjacent threads is produced
by rotating the screws in opposite directions of
rotation.

8. The device according to claim 4 wherein the thread
helices of adjacent screws are arranged in the opposite
direction, and wherein the opposite direction of
advancement of any immediately adjacent threads is
produced by rotating the screws in the same directions of
rotation.
9. The device according to claim 5 wherein the thread
helices of adjacent screws are arranged in the opposite
direction, and wherein the opposite direction of
advancement of any immediately adjacent threads is
produced by rotating the screws in the same directions of
rotation.
10. The device according to claim 4 further comprising a
surrounding housing adjacent to the frame, opening at the
top to a funnel, and having a discharge opening at the
bottom.
11. The device according to claim 5 further comprising a
surrounding housing adjacent to the frame, opening at the
top to a funnel, and having a discharge opening at the
bottom.
12. The device according to claim 8 further comprising a
surrounding housing adjacent to the frame, opening at the
top to a funnel and having a discharge opening at the
bottom.

13. The device according to claim 9 further comprising a
surrounding housing adjacent to the frame, opening at the
top to a funnel and having a discharge opening at the
bottom.
14. The device according to claim 4 wherein said screws
have blade-shaped threads which slope in the direction of
feed.
15. The device according to claim 5 wherein said screws
have blade-shaped threads which slope in the direction of
feed.
16. The device according to claim 6 wherein said screws
have blade-shaped threads which slope in the direction of
feed.
17. The device according to claim 7 wherein said screws
have blade-shaped threads which slope in the direction of
feed.
18. The device according to claim 8 wherein said screws
have blade-shaped threads which slope in the direction of
feed.
19. The device according to claim 9 wherein said screws
have blade-shaped threads which slope in the direction of
feed.
20. The device according to claim 10 wherein said screws
have blade-shaped threads which slope in the direction of
feed.

21. The device according to claim 11 wherein said screws
have blade-shaped threads which slope in the direction of
feed.
22. The device according to claim 12 wherein said screws
have blade-shaped threads which slope in the direction of
feed.
23. The device according to claim 13 wherein said screws
have blade-shaped threads which slope in the direction of
feed.
24. The device according to claim 14, 15 or 16 wherein
the edges of the blade-shaped threads are covered with a
wear resistant material.
25. The device according to claim 17, 18 or 19 wherein
the edges of the blade shaped threads are covered with a
wear resistant material.
26. The device according to claim 20, 21 or 22 wherein
the edges of the blade-shaped threads are covered with a
wear resistant material.
27. The device according to claim 23 wherein the edges
of the blade-shaped threads are covered with a wear
resistant material.

Description

1228;~41
A method and device for disintegrating coarse material.
TECHNICAL FIELD
The present invention relates to a method and a device
for disintegrating coarse and voluminous non-friable
material, e.g. stumps, peat and waste from clearing,
demolition and packing etc. to desirable fractions for
e.g. making cellulose, fuel, compost and the like.
PRIOR ART
This type of handling demands large machines with heavy
expenses. The machine types, which already are available
on the market, have heavy consumption of energy and proper-
tionately low production capacity at the same time as they
have a limited capacity to accept and disintegrate very
bulky material.
A large group of machines for this purpose disintegrate
the material by feeding the same toward one or several
constrictions by means of one or several parallel screws.
This is a very energy demanding method because of the
friction in the constriction.
Another group of machines (SE-patent 409 420) have screws
which above a bottom feed the material forwardly toward
stationary dolly knives. A problem herewith is ago. that
the material may stop against the knives. To reduce this
problem it is suggested in the patent to intermittently
and individually reverse the operation of the screws to
feed back the material which possibly have stopped. However,
this does not prevent that these machines have defective
capacity.
A third group of machines for this purpose operate with
propeller like screw members which principally divide the
material in a tangential direction against dollies in form
of counteracting rotors or fixed projections from surround
ding stand walls. Also machines with rapidly rotating
striking members e.g. hammer mills have been used to

1;~2839~1
disintegrate coarse waste, but they have limitations
regarding the dimension of the material supplied thereto.
THE INVENTION
The present invention relates to a method and a device
S for disintegrating coarse material to pieces of desirable
dimension with lowest possible energy consumption and with
as little too fine material as possible.
According to the invention the material is disintegrated
in a way which is defined in claim 1. Accordingly, the
material will not be fed forwardly by the screws but is
torn and crushed between them untilitpasses through the
spaces between the screws. By choosing a suitable dime-
soon of the spaces between the screws, a desirable dime-
soon of the disintegrated material can be obtained. Since
the screws have a comparatively small pitch in proportion
to the diameter of the screw the tangential operating
force is geared up to a many times larger axially operating
force. The axial forces in two cooperating screws counter-
act each other. Accordingly, the material introduced bet-
wren these screws is effected by a counteracting force couple tearing the material in its weakest sections into
pieces. When the material is disintegrated so that it can
fall down through the openings between the screws the
material is finally divided and may be transported away.
The above disintegration effect is obtained along the
whole slot between two cooperating screws, which gives a
large production capacity with a comparative small energy
consumption. The threads on the screws should be blade
shaped and slope in the feeding direction and should be
covered on the edge with a wear resistant material. Counter-
acting feeding directions can be provided either by two
adjacent screws having different directions of rotation or
by screws having opposite threads, i.e. one is right
threaded and the other is left threaded.

1228~41.
The division of the material may also be done in several
steps, whereby it may pass several sets of cooperating
screws with gradually decreasing dimensions and mutual
distance.
The characteristics of the device according to the invent
lion appears by claim 6. The screws should be arranged
essentially horizontally so that the material owing to
the gravitation passes between them. Above the screws a
funnel is located and under them an opening for discharge.
In the latter also a grid and classifying means may be
located.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig 1 shows in principle how material is disintegrated
according to the invention.
Figs 2 and 3 show in vertical and horizontal cross section
a construction according to the invention, Fig 2 showing
a cross section along the line II-II in fig 3 and fig 3
showing a cross section along the line III-III in fig 2.
Fig 4 shows in cross section a preferred shape of the
Jo blade thread.
Figs 5 and 6 show an industrial application of the invent
lion in the form of a mobile construction in which a device
according to the invention is built in.
DETAILED DESCRIPTION OF THE INVENTION
In Fig 1 two right threaded screws 1, 2 are shown with
opposite directions of rotation, which accordingly aim to
feed the stump 3 lying on the screws in opposite directions.
The threads are blade shaped and slope with the outer
edges in the feeding direction. The third screw 6 is left
threaded and cooperate with the middle screw 2 and have
the same direction of rotation as this. sty its direction
of rotation the third screw will also aim to pull in the
stump 7 between the screws. Accordingly the material will
be disintegrated by a combination of cutting, pressing,
tearing and bending movements. The obtained pieces 8 pass
between the screws.

1228341
Figs 2 and 3 show a device according to the invention
located on a stand 11 and comprising a frame 12 with
bearings 13 for four screws 14-17. Of these screws, the
two in the middle 15, 16, are right threaded and the two
S outermost 14, 17 left threaded. The screws are operated
by motors 18 and their direction of rotation have been
indicated by arrows. The threads 19 of the screws are
blade shaped and oblique in the feeding direction as is
shown in Fig 4. The material which is to be disintegrated
is fed in by a funnel 20 and the disintegrated material
falls out through a discharge opening 21.
The blade thread 25 shown in Fig 4 lean toward the axle
26 on which it is fixed and is provided with a wear resistant
edge 27. It is advantageous that the disintegrating
edge 27 on the screw in question is active in the feeding
direction of the screw. In other words the edge 27 should
have a lip or a cutting or shearing portion facing in
the feeding direction of the screw so that the edges on
two adjacent rotating screws are capable to grip hold of
and cut into the material at the same time from two differ
rent directions.
The mobile device shown in Figs 5 and 6 consists of a
tractor 31 with steering 32 in the middle and connected to
a trailer 33. Both are provided with support legs 34, 35, 36.
The trailer is provided with a hoisting crane 37 for loading
the material, which is to be disintegrated into a funnel
38, which leads to a screw device according to the invent
lion. This consists of three screws 39, 40, 41 operated
by hydraulic motors 42. For feeding of these there is a
hydraulic assembly 43. Under the screws there is a grid
44, which allow fine material e.g. soil and sand particles
to pass through during disintegration of stumps. The more
coarse material slides on the grid 44 to a transport
device 45 with which the material may be loaded on another

1;;~;~8341
vehicle or be put up in a stack. The screw 40 in the
middle is located lower than the other two and can if its
feeding direction is chosen right assist in feeding out
the material on the grid 44. The bearing housings 46, 47,
48 for the screws are displayable and can be adjusted for
different degrees of coarseness of the material passing
through.