Presses – Methods – With separation from material of liquid expressed
Patent
1997-08-08
1999-03-02
Gerrity, Stephen F.
Presses
Methods
With separation from material of liquid expressed
100107, 100112, 100116, 100127, B30B 906
Patent
active
058757074
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
This invention concerns a press for removing water from masses containing materials of organic origin. The invention is suitable for use, for example, for drying sludges resulting from sewage treatment.
TECHNICAL BACKGROUND
Such presses have been used for drying sludges, wherein aqueous sludge is compressed by means of a screw in a cylinder with a perforated mantle. An adjustable gate may be provided at one end of the cylinder in order to create counter-pressure.
Waste which is to be burnt must be made as dry as possible. The dry-matter content even of waste to be composted should be brought to a level of 40-60%. This is often difficult with known equipment and, for example, when treating normal municipal waste it is even impossible to achieve. To raise the dry-matter content to an adequate level, dryer fibrous material, such as dried peat, must usually be added in relatively big quantities as back-up material to sludges.
DESCRIPTION OF THE INVENTION
What is most essential in the invention, is that the mass to be dried is pressed out from a compression chamber provided with a perforated mantle through a piston part which is movable in relation to the chamber.
Using the invention, relatively high dry-matter contents can be achieved without having to use much back-up material. In addition, the final product is compressed into a shape which is advantageous for further treatment.
The movable press part also allows automatic control of the compression pressure, whereby the dry-matter content of the final product can be controlled.
Restarting of the press after an interruption is more reliable than in conventional presses, due to the movable press part. Even partly dried mass is easily put into motion when its static friction is overcome dynamically.
The press is preferably provided with cleaning equipment. This is a particular advantage, especially when e.g. non-homogeneous masses tend to jam the filter openings. The cleaning equipment may be based on the use of brushes or spraying equipment. The cleaning equipment may be movable. In a most advantageous embodiment, the cleaning equipment is movable together with the piston part so that cleaning can be directed to a non-pressurized perforated surface, whereby cleaning is efficient.
Owing to efficient cleaning, smaller filtrate holes and a higher compression pressure may be used than in conventional presses.
In one embodiment, the piston part also rotates during its movement. This helps in the loosening of especially longitudinal particles stuck onto the inner surface of the filtrate mantle. Likewise, the rotational motion helps in the loosening of particles which possibly have remained transversely as blockages in discharge openings of the piston part.
The invention is primarily suitable for use in after-drying of sewage sludge, when the sludge has been predried, for example, in a centrifuge or a filtration band press. Dryer back-up material is mixed with the sludge when required. This may be, for example, fibrous waste or peat. The invention is also suitable, for example, in the forest industry for treating flour waste as such, without predrying with a centrifuge or a filtration band press.
The compressed waste is suitable for utilization, for example, to be burned or composted.
DRAWINGS
In the drawings of the description
FIG. 1 is a side view of one equipment in accordance with the invention; and
FIGS. 2 and 3 are cross-sections of FIG. 1.
EXAMPLE
The press shown in FIG. 1 comprises an feeding part 1, a compression chamber 2 and a piston part 3.
The feeding part 1 has a feeding device, such as a pump or most usually a screw conveyor to move the aqueous mass to be compressed to the inlet end of the compression chamber 2.
The compression chamber 2 is a circular cylinder having a water-permeable but solids-retaining perforated mantle 4. In the chamber, the mass is compressed and water is filtrated out through the holes in the mantle. The perforated mantle is preferably made of wedge-wire mesh.
The piston part 3 has a central rod 5 in
REFERENCES:
patent: 500490 (1893-06-01), Grimm
patent: 594297 (1897-11-01), Strattner
patent: 825957 (1906-07-01), Buckley
patent: 942301 (1909-12-01), Wiselogel
patent: 4211163 (1980-07-01), Brown et al.
patent: 5012731 (1991-05-01), Maisonneuve
Gerrity Stephen F.
Oy SNE Environment Engineering Ltd.
LandOfFree
Dewatering press does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Dewatering press, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Dewatering press will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-413489