Valmet Oy

Outokumpu Oy

Valmet Paper Machinery Inc.

Outotec Oyj

Jorma Punju

Rolf Hindstrom

Bjarne Ekberg

Mika Illi

Ismo Juvonen

Paivi Peltonen

Edward Vroman

David Eveland

Kari Vanttinen

Olli Hognabba

The invention relates to a method for cleaning the filter plates of a suction drier, which suction drier (20) comprises a tank (13) for the slurry to be suction dried, in connection to which tank there rotates one or several filter disks formed of the said filter plates (14), on the surface or surfaces of which filter plates (14) there is collected and dried, owing to the suction flow passing through the filter plates (14), a filter cake, which is scraped or otherwise removed from the surface or surfaces of the filter plates. For the cleaning of the porous structure and surfaces of the said filter plates (14), there is arranged, in the tank (13) of the slurry to be filtered, under the liquid surface (11), mainly in the surface water area, an ultrasonic vibrator or vibrators (10), whereto ultrasonic electric power is fed from an ultrasonic generator (22). The cleaning with the ultrasonic vibrator or vibrators (10) is carried out esentially immediately after scraping.

Method for cleaning the filter plates of a suction drier

Multi-layer ceramic filter

A filtering method in which an object to be filtered and dewatered is brought through a finely porous suction face saturated with liquid, into hydraulic connection with a liquid situated under a negative pressure relative to the object to be dewatered. The filter plate or equivalent and the material to be filtered which adheres to the plate by the liquid suction, are surrounded by a pressure-tight cover. A positive pressure relative to atmospheric pressure is introduced into this cover, by which removal of liquid out of the material to be filtered is intensified. A device for providing such filtration is also provided.

Method and apparatus for pressurized dewatering

A method for manufacturing a microporous plate, a filter plate obtained from the method, and suction drier apparatus utilizing such filter plates. According to the method, a casting mix is introduced into the interior of a gypsum mold whereupon water is absorbed from the casting mix into the gypsum so that a crust remains on the inner surface of the mold. The crust is allowed to develop to an appropriate thickness whereupon the remaining casting mix is drained from the mold. The inner surfaces of the crust are allowed to dry whereupon the interior space defined between opposed crust wall portions is filled with a granular material which preferably has the same composition as the crust material. A filter plate comprises a pair of opposed suction walls defining an interior space between them which is filled with a granular material. The suction drier apparatus includes at least one of the filter plates which is mounted to be moved into and out of a basin or the like in which material to be dewatered is present. In one embodiment, the suction drier apparatus includes several filter plates mounted in a circular array around a rotating shaft. A negative pressure is applied to the suction walls of each plate whereby water or other liquid is suctioned from the material to be dewatered through the suction walls into the interior space within the filter plate and then drawn under the negative pressure out of the plate structure.

Microporous plate and method for manufacturing the same and suction

A method for manufacturing a microporous plate, a filter plate obtained from the method, and suction drier apparatus utilizing such filter plates are disclosed. According to the method, a casting mix is introduced into the interior of a gypsum mold whereupon water is absorbed from the casting mix into the gypsum so that a crust remains on the inner surface of the mold. The crust is allowed to develop to an appropriate thickness whereupon the remaining casting mix is drained from the mold. The inner surfaces of the crust are allowed to dry whereupon the interior space defined between opposed crust wall portions is filled with a granular material which preferably has the same composition as the crust material. A filter plate comprises a pair of opposed suction walls defining an interior space between them which is filled with a granular material. The suction drier apparatus includes at least one of the filter plates which is mounted to be moved into and out of a basin or the like in which material to be dewatered is present. In one embodiment, the suction drier apparatus includes several filter plates mounted in a circular array around a rotating shaft. A negative pressure is applied to the suction walls of each plate whereby water or other liquid is suctioned from the material to be dewatered through the suction walls into the interior space within the filter plate and then drawn under the negative pressure out of the plate structure.

Growing community of inventors

Turku, Finland

Rolf Hindstrom