Note: Descriptions are shown in the official language in which they were submitted.
20~10
Process and apparatus for the PreParation of bulk
~materials
The invention relates to a process and an
apparatus for the preparation of bulk materials,
especially in the form of fragmentary fractions and/or
pourable materials which are prepared by comminuting
and/or wet treatment and by subsequent thermal treatment.
DE-A-2,252,259 makes known an apparatus for the
recovery of basic foundry-mould materials, in which the
basic mould material in the form of a mixture of lumps or
individual grains is fed from a comminuting device via a
screen to a metal separator and from there to an anneal-
ing unit. In the annealing unit, the basic mould material
is freed of substances containing carbon and is subse-
quently cooled in an associated cooling device. In afurther device, the cooled basic mould material is
treated and cleaned pneumatically and mechanically in
such a way that the embrittled layer minerals flake off.
The sand regenerated and graded in this way is thereafter
provided for reuse.
The present invention is concerned with the
problem of an economical reuse of bulk materials, such as
occur, for example, in the form of fractions containing
metal and fractions fragmentary because of organic or
chemical binders or else already in the form of pourable
used foundry sands of various sand types.
The object on which the invention is based is to
provide a process for the preparation of bulk materials
in the form of fragmentary fractions and/or pourable
materials and an apparatus, by means of which process and
apparatus the bulk materials can be prepared to assume a
reusable quality of substantially new value.
The object is achieved, by the process according
to the invention, in that the bulk material is fed
largely in free fall to a first washing vessel, is
thereby subjected by a number of nozzles directed into
the interior to a high-pressure liquid medium for the
purpose of detaching the adhering dirt particles and is
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subsequently cleaned and separated in an associated
second washing vessel, and in that the cleaned bulk
material is thereafter dried and guided for thermal
treatment through an externally heated pipeline system
rotatable about its longitudinal axis.
The apparatus according to the invention for
carrying out the process comprises at least one first
washing vessel and a drum-type furnace with a heatable
combustion chamber for the thermal treatment of bulk
materials and is characterised in that the first washing
vessel is assigned a second washing vessel connected to
it, the first washing vessel being equipped in its
interior with a number of nozzles arranged axially and
radially at a distance from one another, and the second
washing vessel being connected, with a drying container
interposed, to a spirally designed pipeline system
arranged in the combustion chamber of the drum-type
furnace, mounted rotatably about its longitudinal axis
and intended for the thermal treatment of the dried bulk
material.
Further features of the invention emerge from the
following description in conjunction with the drawing and
the patent claims.
The invention is described in more detail below
with reference to the drawing. In this:
Figure l shows an apparatus, represented as a flow
diagram, with a cleaning device and with an
associated drum-type furnace for the prepara-
tion of bulk materials,
Figure 2 shows a first exemplary embodiment of the
cleaning device for the apparatus according to
Figure 1, represented on a larger scale and in
a sectional view,
Figure 3 shows a second exemplary embodiment of the
cleaning device for the apparatus according to
Figure l, represented on a larger scale and in
a sectional view, and
Figure 4 shows the cleaning device according to Figure
3, represented in a top view and in section
205~410
-- 3 --
along the line IV-IV.
Figure 1 shows as a flow diagram an apparatus,
designated as a whole by 100, for the preparation of bulk
materials, this apparatus 100 comprising essentially a
diagrammatically represented cleaning device 50 or 150
and a drum-type furnace 220 connected to it via a
feedline 14 or 114.
The drum-type furnace 220 can be assigned either
one cleaning device 50 shown on a larger scale in Figure
2, or the other cleaning device 150 shown on a larger
scale in Figure 3. The cleaning device 50 or 150 is
assigned a transport and conveyor band 1, from which the
so-called bulk material (not shown) is fed in the
direction of the arrows 1' and 1" to a funnel-like
collecting container 2. From a screen 3 movable to and
fro in the direction of the arrow 3' by means (not
shown), the bulk material is fed, approximately by
pouring, to the cleaning device 50 or 150.
The drum-type furnace 220 and the two cleaning
devices 50 and 150 are described in detail below.
The drum-type furnace 220 represented diagram-
matically in Figure 1 comprises essentially a container
221 which is assigned in the front part designed as the
entrance A a burner 231, by means of which the interior
221', designed as a combustion chamber, of the container
221 is heated.
In one exemplary embodiment not shown in any more
detail, the container 221 can be subdivided into
individual heatable zones, as seen in the longitudinal
direction of the drum-type furnace 220. At the same time,
a plurality of burner or heater elements arranged offset
relative to one another are provided on the outer wall of
the container.
At the rear part of the container 221 designed as
an exit B, a first chamber 226, a filter device 222, a
blower 225 and a second chamber 224 are provided.
Furthermore, a grating 223 is arranged between the first
chamber 226 and the second chamber 224. The filter device
222 is connected to the entrance A of the container 221
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via a line 227, with a blower 228 being interposed. The
second chamber 224 is connected to a collecting container
230 via a line 229.
Arranged in the front region of the combustion
chamber 221' of the container 221 is a distributor
element 235 which, for example, is of container-like
design and which is connected to a pipeline system 240
arranged in the container 221. The pipeline system 240
comprises at least one, but preferably a number of
spirally wound pipes 241 which are each connected at one
end to the feedline 14 or to the distributor element 235
and at the exit B to the first chamber 226. The single
spiral pipe 241 or else the complete pipeline system 240
is connected operatively to a diagrammatically repre-
sented drive 242 arranged correspondingly at the entrance
A. The pipeline system 240 is mounted in the combustion
chamber 221' of the container 221 rotatably about an
approximately horizontal longitudinal axis X in the
direction of the arrow Z.
In a preferred exemplary embodiment, the pipeline
system 240 is arranged in the combustion chamber 221' of
the container 221 about a longitudinal axis X' inclined
upwards relative to the longitudinal axis X or about a
longitudinal axis X" inclined downwards relative to the
longitudinal axis X. The angle ~ or ~' formed between the
horizontal axis X and the upwardly inclined or downwardly
inclined longitudinal axis X~ or X" is respectively
approximately of the order of 10 to 30~.
The container 221 is mounted, for example, on two
pedestals 245, 245' arranged at a distance from one
another in the axial direction of the container 221. The
mounting of the container 221 on the two pedestals 245,
245' can also take place in the horizontal plane. When
the container 221 is arranged horizontally, the pipeline
system 240 is arranged in the combustion chamber 221' at
the abovementioned upward inclination ~ or downward
inclination ~'. With a coaxial arrangement of the
pipeline system 240 in the combustion chamber 241', the
container 221 is arranged and mounted correspondingly on
~0~4~10
two pedestals 245, 245' with its longitudinal axis X at
a similar upward or downward inclination.
The pipe cross-section for the individual pipe
241 of the pipe system 240 installed in the drum-type
furnace 220 can be of differing shape. In a way not shown
in more detail, the pipe cross-section of the pipe shaped
to form a spiral can, for example, be circular, square,
rectangular, triangular, polygonol, offset squarely in
parallel or the like. An essential feature of the cross-
sectional shape of the pipe is, however, that theindividual spiral has as large a heat-transmission
surface as possible.
The cleaning device 50 shown in ~igure 2 on a
larger scale and in a sectional view comprises essen-
tially a first washing vessel 30 and a second washingvessel 40 connected to this. The transport and conveyor
band 1 appropriately assigned to the washing vessel 30l
as well as the collecting container 2 and the screen 3
movable to and fro are of a design similar to that of the
exemplary embodiment described withreference to Figure 1.
Arranged on the first washing vessel 30 is a
diagrammatically represented pipeline system 25 which is
connected via a feedline 16 to an appropriately assigned
high-pressure pump 4. In the exemplary embodiment
illustrated, the pipeline system 25 comprises ringlines
21, 22, 23 and 24 which are arran~ed at a distance from
one another in the axial direction of the first washing
vessel 30 and largely surround the outer circumference of
the washing vessel 30 and which are connected to the
high-pressure pump 4 via corresponding bridge lines 17
and 18, 18' and 19, 19' connected to the feedline 16~
In the interior 35 of the first washing vessel 30
there is a plurality of nozzles 21', 22', 23' and 24'
which are arranged circumferentially and axially at a
distance from one another and which are fastened to the
vessel wall 30' in a way not shown in any more detail and
are connected to the individual ringlines 21, 22, 23 and
24 arranged correspondingly on the outer circumference of
the washing vessel 30.
20~441~
Arranged on the first washing vessel 30 at tlle
lower end facing the second washing vessel 40 is a
connecting flange 31 which is provided with an annular
~3roove 31' for the sealing mounting of the second washing
vessel 40.
The second washing vessel 40 fastened to the
first washing vessel 30 by means (not shown) and, for
example, forming a unit with this comprises essentially
a cylindrical body 42 arranged in the annular groove 31'
of the first washing vessel 30 and a flange 41 located on
it. A filter element 43 is arranged in the interior 45 of
the cylindrical body 42 which can be designed, for
example, as a steel jacket or, to reveal its functioning,
as a transparent body. The interior 45 of the cylindrical
body 42 is subdivided by the filter element 43 into a
first chamber 45' for the actual bulk material (not
shown) and into a second chamber 46 for detached washings
47 resting on the bottom of the annular chamber 46. An
essentially funnel-like orifice 44 is provided for
emptying in the lower flange 41.
Furthermore, on the second washing vessel 40, a
line 8 connected to the orifice 44 and arranged sealed
off on the lower flange 41 is connected to a shut-off
valve 9~ The line 8 leads to an appropriately associated
container 6 which is preferably equipped with a screen 7
and which, with a valve 13 interposed, is connected to a
filter press 5 via a return line 12.
The fluid is fed via the return line 12 in the
direction of the arrow 12' by way of the filter press 5
and via a line 15 in the direction of the arrow 15' to
the high-pressure pump 4 again and from there by way of
the pipeline system 25 to the first washing vessel 30
once more.
The cleaned sand (not shown) is fed for thermal
treatment to the drum-type furnace 220 in the direction
of the arrow 14' via the line 14. As shown in Figure 1,
a slide 203 can be arranged in the line 14 between the
container 6 and the drum-type furnace 220 and is
connected operatively to an appropriately controllable
20~41~
piston/cylinder unit 202 for opening and closing.
Moreover, connected to the lower flange 41 of the
second washing vessel 40, with a valve 10 interposed, is
a line 11, via which the washings 47 are fed to the
filter press 5 in the direction of the arrow 10'. The
residual fluid precipitated from the filter press 5 is
likewise fed to the high-pressure pump 4 in the direction
of the arrow 15' by way of the line 15, whilst the
remaining solids are fed via a line 11~ in the direction
of the arrow 11" to an installation (not shown) for
further processing.
Figure 3 shows the washing device 150 on a larger
scale and in a sectional view, and a first washing vessel
130 and a second washing vessel 140 connected to this can
be seen. The transport and conveyor band 1 appropriately
assigned to the washing vessel 130, as well as the
collecting container 2 and the screen 3 movable to and
fro are of a design similar to that of the exemplary
embodiment described with reference to ~igure 1.
Arranged on the first washing vessel 130 is a
diagrammatically represented pipeline system, designated
as a whole by 125, which is connected to a correspon-
dingly associated high-pressure pump 104 via a feedline
116 designed as a bridge line.
As seen in the axial direction of the washing
vessel 130, the pipeline system 125 comprises a plurality
of ringlines 121, 120, 119, 118 and 117 which are
arranged at a distance from one another and surround
approximately half the outer circumference of the vessel
130 and which are connected to the high-pressure pump 104
via the corresponding feedline 116.
In the interior 135 of the washing vessel 130,
appropriately designed high-pressure nozzles are assigned
to each individual ringline 121, 120, 119, 118 and 117.
The high-pressure nozzles forming respective groups are
designated by 121', 120', 119', 118' and 117', the
individual high-pressure nozzles ~eing fastened to the
vessel wall 130' in a way not shown in any more detail.
On the side located opposite the high-pressure nozzle
2~4~0
-- 8 --
groups 121', 120~, 119', 118' and 117', an appropriately
arranged and fastened baffle plate 136 is provided in the
interior 135 of the washing vessel 130. ~ocated on the
first washing vessel 130 at the lower end facing the
second washing vessel 140 is a connecting flange 131
which is provided with an annular groove 131' for the
sealing mounting of the second washing vessel 140.
The second washing vessel 140 fastened to the
first washing vessel 130 by means (not shown) and forming
a unit with this comprises essentially a cylindrical body
142 arranged in the annular groove 131' of the first
washing vessel 130 and a flange 141 located on it. A
filter element 143 is arranged in the interior 145 of the
cylindrical body 142 which, for example, can be designed
as a steel jacket or, to reveal the functioning, as a
transparent body. The interior 145 of the cylindrical
body 142 is subdivided by the filter element 143 into a
first chamber 145' for the actual bulk material (not
shown) and into a second chamber 146 for detached
washings 147. An approximately funnel-like orifice 144 is
provided for emptying in the lower flange 141.
Furthermore, on the second washing vessel 140, a
line 108 arranged sealed off on the lower flange 141 is
connected to a shut-off valve 109. The line 108 leads to
an appropriately associated container 106 which is
preferably equipped with a screen 107 and which, with a
valve 113 interposed, is connected to a filter press 105
via a return line 112. The cleaned sand is fed
essentially to the drum-type furnace 220 (Figure 1) in
the direction of the arrow 114' for thermal treatment by
way of the line 114, whilst the fluid is fed via the line
112 in the direction of the arrow 112' to the filter
press 105 and via a line 115 in the direction of the
arrow 115' to the high-pressure pump 104 and from there
by way of the pipeline system 125 to the first washing
vessel 130 once more.
Furthermore, connected to the lower flange 141 of
the second washing ve~sel 140, with a valve 110 inter-
posed, is a line 111, by way of which the washings 147
2~4~
are fed to the filter press 105 in the direction of the
arrow 110'. The fluid separated by the filter press 105
is fed to the high-pressure pump 104 in the direction of
the arrow 115' via the line 115, whilst the remaining
solids are fed for use in the direction of the arrow 111~
via a line 111' to an installation (not shown) for
further processing.
It may be pointed out, at this juncture, that a
sound transducer 80 or 180 connected operatively to an
ultrasonic device 85 or 185 can be respectively arranged
in the second washing vessel 40 according to Figure 2 and
in the second washing vessel 140 according to Figure 3.
By means of the sound transducers 80 or 180 a permanent
movement of the bulk material is additionally generated
in the washing vessel 40 or 140, thereby ensuring that
the dirt particles are further detached.
Moreover, in an alternative embodiment (not
shown)~ there is the possibility of assigning to the
second washing vessel 40 or 140, instead of to the first
washing vessel 30 or 130, a screen-like collecting
element, on which the bulk material fed from the
container 2 rests and is subjected to the high-pressure
liquid medium for detaching the adhering dirt particles.
The nozzles are directed at an appropriate angle to the
bulk material or to the screen-like collecting element.
Figure 4 shows the washing device 150 represented
in section along the line IV-IV of Figure 3 and in a top
view, and the washing vessel 130 and the pipeline system
125 arranged on it and having a ringline 118 connected to
the feedline 116 can be seen. In the interior 135 can be
seen the baffle plate 136 arranged and fastened on the
inner wall 130' and the high-pressure nozzle group
designated as a whole by 118'. The individual high-
pressure nozzles not designated in any more detail are
arranged at a distance from one another on the vessel
wall 130' in the circumferential direction and are
fastened to this in a way not shown in any more detail.
The essential working steps of the apparatus 100
are described below:
,
20~4~1~
-- 10 --
The so-called bulk material is fed from the
tr~nsport and conveyor band 1 in the direction of the
arrows 1' and 1" to the first washing vessel 30 or 130,
in which the free-falling bulk material is subjected to
a liquid medium, for example a water jet, by means of a
plurality of high-pressure nozzles 21', 22', 23', 24' or
121', 120', 119~, 118', 117' arranged appropriately
distributed.
In a second washins vessel 40 or 140, the dirt
particles or washings are separated from the bulk
material by the filter 43 or 143. With the slide 9 or 109
opened, the bulk material thus cleaned passes into the
container 6 or 106 equipped with a screen 7 or 107 and is
dried correspondingly in this.
For thermal treatment, the bulk material is fed
from the container 6 or 106 by way of the line 14 or 114
to the pipeline system 240 connected operatively to the
distributor element 235.
As a result of the rotational movement, oriented
in the direction of the arrow Z about the longitudinal
axis X or X' or X", of the pipeline system 240 arranged
in the combustion chamber 221', the bulk material is
transported in the direction of the arrow 220' and
optimum heating of the material thereby achieved. The
bulk material conveyed through the pipeline system 240 by
pouring as a result of the rotational movement is guided
into the chamber 226 and is subjected in this to the air-
stream of the blower 225, with the result that the
remaining gases and fine particles are removed from the
sand. The remaining gases and fine particles are fed from
the blower 225 via the filter device 222 and via the
return line 227 in the direction of the arrow 227' for
complete combustion in the combustion chamber 221'.
The cleaned material which has fallen into the
chamber 224 can be fed from there in the direction of the
arrow 229' to a container 230 by way of a line 229 and
thereafter be used as material of largely new value.
