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US 7,244,115 B2Granted
Extruder for producing bodies of consolidated particulate material
Assignee3H Inventors ApS
InventorsHerbert Krenchel, Helge Fredslund-Hansen, Henrik Stang
Life of this patent
Estimating the term…
Abstract
Shaped bodies of particulate material are produced by introducing an easily flowable slurry of water and particulate material into a mold with perforated walls and applying a sufficiently high pressure to the slurry in the mold so as to express a sufficient proportion of the liquid to allow physical contact and interengagement between the particles. The extrusion is carried out continuously in an extension process including: (A) introducing the slurry under high pressure, (B) conveying the slurry through a shaping section to (C) a draining and consolidation section with drain holds or slits (3), to leave the extruder through (E) an exit section in the form of a solid body (4).
Claims20
An extruder for extruding shaped bodies formed from a flowable slurry containing particulate material and liquid, the extruder comprising:
- an extruder body having
- (a) an inlet space where the flowable slurry containing particulate material and liquid is supplied under a high hydrostatic pressure,
- (b) first and second walls of which respective opposed first and second surfaces together define an elongate moulding space into which the flowable slurry from the inlet section is introduced under the high hydrostatic pressure, said moulding space having a longitudinal flow axis and a uniform cross section, and
- (c) an extrusion outlet located adjacent a terminal end of the moulding space whose cross-sectional shape is defined by the surfaces of said first and second walls, and whose cross-sectional shape defines a shaped body extruded from the moulding space which shaped body is derived from the flowable slurry containing particulate material and a liquid;
- and
- (d) a friction section over a length of the moulding space between the intermediate portion and the extrusion outlet, said friction section including a friction contact between the shaped body and each of the opposed walls of the moulding space which said friction contact exerts a reaction force, on the shaped body against the high hydrostatic pressure by which the flowable slurry is supplied into the moulding space from said inlet space, said reaction force of said friction contact being sufficient by itself to at least substantially prevent the shaped body from moving alone the opposed walls and out of said extrusion outlet due to the high pressure of said flowable slurry without assistance to the shaped body;
- a means for reducing said reaction force of said friction contact between the shaped body and each of the opposed walls in the friction section so that the shaped body exits from said extrusion outlet;
- and
- a plurality of passages at an intermediate portion of one of said first and second walls upstream from said extrusion outlet and in the molding space, which said passages open through the one of said first and second walls from the moulding space to define dewatering slots for the flowable slurry;
- whereby said reaction force forms in the friction section a non-flowable consolidated material which is extrudable through the outlet as the shaped body, which shaped body is formed when liquid is expelled from the moulding space through the dewatering slots at the intermediate portion.
7 more elements
An extruder for extruding shaped bodies formed from a flowable slurry containing particulate material and liquid, the extruder comprising:
- an extruder body having
- (a) an inlet space where the flowable slurry containing particulate material and liguid is supplied under a high hydrostatic pressure,
- (b) inner and outer walls of which an outer and an inner surface, respectively, are opposed and together define an elongate moulding space into which the flowable slurry from the inlet section is introduced under the high hydrostatic pressure, said moulding space having a longitudinal flow axis and a uniform cross section, and
- (c) an extrusion outlet located adjacent a terminal end of the moulding space whose cross-sectional shape is defined by the surfaces of said and outer walls, and whose cross section shape defines a shaped body extruded from the moulding space which shaped body is derived from the flowable slurry containing particulate material and a liquid;
- and
- (d) a friction section over a length of the moulding space between the intermediate portion and the extrusion outlet, said friction section including a friction contact between the shaped body and each of the opposed walls of the moulding space which said friction contact exerts a reaction force on the shaped body against the high hydrostatic pressure by which the flowable slurry is supplied into the moulding space from said inlet space, said reaction force of said friction contact being sufficient by itself to at least substantially prevent the shaped body from moving along the opposed walls and out of said extrusion outlet due to the high pressure of said flowable slurry without assistance to the shaped body;
- a means for reducing said reaction force of said friction contact between the shaped body and each of the opposed walls in the friction section so that the shaped body exits from said extrusion outlet;
- and
- a plurality of passages at an intermediate portion of one of said inner and outer walls upstream from said extrusion outlet and in the molding space, which said passages open through the one of said inner and outer walls from the moulding space to define dewatering slots for the flowable slurry;
- whereby said reaction force forms in the friction section a non-flowable consolidated material which is extrudable through the outlet as the shaped body, which shaped body is formed when liquid is expelled from the molding space through the dewatering slots at the intermediate portion.
7 more elements
An extruder for extruding shaped bodies formed from a flowable slurry containing particulate material and liquid, the extruder comprising:
- an extruder body having
- (a) an inlet section where the flowable slurry containing particulate material and liquid is supplied under a high hydrostatic pressure,
- (b) a liquid removing section into which the flowable slurry from the inlet section is introduced under the high hydrostatic pressure, said liquid removing section including a means for removing liquid from the flowable slurry to produce a non-flowable consolidated material, and
- (c) a friction section following said liquid removing section in which the non-flowable consolidated material is shaped into a shaped body in a moulding space having an extrusion outlet, said friction section including a friction contact between the shaped body and opposed walls of the moulding space which said friction contact exerts a reaction force on the shaped body against the high hydrostatic pressure by which the flowable slurry is supplied into the liquid removing section from said inlet section, said reaction force of said friction contact being sufficient by itself to at least substantially prevent the shaped body from moving along the opposed walls and out of said extrusion outlet due to the high pressure of said flowable slurry without assistance to the shaped body;
- and
- a means for reducing said reaction force of said friction contact between the shaped body and the opposed walls in the friction section so that the shaped body exits from said extrusion outlet.
3 more elements
Dependencies are inferred from the claim text.