Liquid purification or separation – Filter – Material
Patent
1985-12-03
1987-12-01
Hruskoci, Peter
Liquid purification or separation
Filter
Material
210728, 264118, 264122, 264DIG48, 264DIG69, B01D 3904
Patent
active
047102985
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
This invention relates to an auxiliary for the dewatering of a sludge, a method for the use thereof, and a method for the manufacture thereof.
BACKGROUND OF THE INVENTION
As means of aiding in the dewatering of sludge, the practice of using a high molecular weight flocculant and fibers such as, for example, fibers of pulp or sawdust in their simply mixed manner has been known to the art. This mixed auxiliary is inferior to an inorganic flocculant in terms of water content in the cake formed during the dewatering operation and ease of separation of the cake from the filter cloth. It further has the disadvantage that the use of the mixed auxiliary entails much time and labor, necessitates provision of large facilities for storage and transportation, and fails to manifest a stable effect.
DISCLOSURE OF THE INVENTION
The inventors have made a diligent study in search of a solution to the problem mentioned above and, consequently, completed this invention. Specifically, this invention relates to an auxiliary for the dewatering of sludge which comprises at least one organic fibrous material having the bulk specific gravity thereof increased to at least 0.3 g/cm.sup.3 in density by pressing or by wetting with water, and at least one high molecular weight flocculant, and to a method for dewatering sludge with the auxiliary by the steps of adding the auxiliary to the sludge and adjusting the consequently formed flocs to a diameter not exceeding 1 mm.
Examples of the organic fibrous materials usable in this invention (hereinafter referred to simply as "fiber") include natural fibers (plant fibers, i.e. cellulosic fibers such as pulp, cotton, sawdust, straw and grass peat, and animal fibers such as silk and wool), man-made fibers (i.e. cellulosic fibers such as rayon and acetate), synthetic fibers (such as polyamide, polyester, and acryls), and mixtures thereof. Among these, cellulosic plant fibers (such as paper, sawdust, cotton, straw, pulp, and grass peat) are desirable selections; and plant fibrous materials, in the form of fiber or capable of assuming a fibrous state in water, are more desirable selections. Paper (waste-paper such as, for example, waste-newspapers), particularly crushed paper, proves to be desirable. The crushed paper in a state containing uncrushed fragments of paper (1 to 50 mm in size, for example) not in a predominant proportion can be used as a fiber.
Optionally, the crushed paper may be used in combination with some other organic fibrous materials (hereinafter referred to as "fiber"). The ratio of the crushed paper to the other fiber in this case falls generally in the range of 100:0 to 1:99, preferably in the range of 100:0 to 50:50.
The fiber is usable in various forms such as, for example, powder, fibrous particles represented by chopped filaments (generallY not more than 100 deniers in thickness), fiber piece obtained by bundling a plurality of fibers, treating the produced bundle with a suitable cohesion agent, and cutting the bound bundle in a suitable size, fiber pieces obtained by bundling a plurality of fibers, twisting the produced bundle into a thread-like bundle and cutting the thread-like bundle in a suitable size, cut pieces of woven fabric, non-woven fabric, and knit fabric, and loose fibers obtained by untwisting such fabrics. Although the length of the fiber is not specifically defined, it falls generally in the range of 0.01 to 50 mm, preferably in the range of 0.1 to 30 mm.
As the high molecular weight flocculant, cationic, anionic, and nonionic high molecular weight flocculants are usable. Use of a cationic high molecular weight flocculant proves particularly desirable.
Among the cationic high molecular flocculants suitable for use in this invention are included polymers and copolymers of at least one cationic monomer or a combination thereof with at least one other ethylenically unsaturated monomer.
Concrete examples of the cationic monomer include cationic acrylic monomers such as tertiary nitrogen-containing acrylates, tertiary nitrogen-
REFERENCES:
patent: 3158532 (1964-11-01), Pall et al.
patent: 3194727 (1965-07-01), Adams et al.
patent: 3242073 (1966-03-01), Guebert et al.
patent: 3259570 (1966-07-01), Priesing et al.
patent: 3509021 (1970-04-01), Woodward
patent: 3951792 (1976-04-01), Azorlosa et al.
patent: 4104160 (1978-08-01), Wegmuller et al.
patent: 4152307 (1979-05-01), Shibahara et al.
patent: 4290988 (1981-09-01), Nopper et al.
patent: 4481115 (1984-11-01), Wade et al.
patent: 4488969 (1984-12-01), Hou
patent: 4559143 (1985-12-01), Asada et al.
Kirk-Othmer Encyclopedia of Chemical Technology, 2nd ed., vol. 18, pp. 688-689.
Fujiura Yoji
Hasegawa Yoichi
Noda Kimihiko
Hruskoci Peter
Sanyo Chemical Industries Ltd.
LandOfFree
Auxiliary for dewatering of sludge does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Auxiliary for dewatering of sludge, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Auxiliary for dewatering of sludge will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1929868