US3361259A - Method of dewatering of coal slurries - Google Patents

Method of dewatering of coal slurries Download PDF

Info

Publication number
US3361259A
US3361259A US363120A US36312064A US3361259A US 3361259 A US3361259 A US 3361259A US 363120 A US363120 A US 363120A US 36312064 A US36312064 A US 36312064A US 3361259 A US3361259 A US 3361259A
Authority
US
United States
Prior art keywords
steam
filter
coal
dewatering
filter cake
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US363120A
Other languages
English (en)
Inventor
Gathen Rudolf Ludwig Von Der
Preisinger Ferdinand
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Harpener Bergbau AG
Original Assignee
Harpener Bergbau AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Harpener Bergbau AG filed Critical Harpener Bergbau AG
Application granted granted Critical
Publication of US3361259A publication Critical patent/US3361259A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D35/00—Filtering devices having features not specifically covered by groups B01D24/00 - B01D33/00, or for applications not specifically covered by groups B01D24/00 - B01D33/00; Auxiliary devices for filtration; Filter housing constructions
    • B01D35/18—Heating or cooling the filters
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D33/00—Filters with filtering elements which move during the filtering operation
    • B01D33/06—Filters with filtering elements which move during the filtering operation with rotary cylindrical filtering surfaces, e.g. hollow drums
    • B01D33/073—Filters with filtering elements which move during the filtering operation with rotary cylindrical filtering surfaces, e.g. hollow drums arranged for inward flow filtration
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D33/00—Filters with filtering elements which move during the filtering operation
    • B01D33/15—Filters with filtering elements which move during the filtering operation with rotary plane filtering surfaces
    • B01D33/21—Filters with filtering elements which move during the filtering operation with rotary plane filtering surfaces with hollow filtering discs transversely mounted on a hollow rotary shaft
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D33/00—Filters with filtering elements which move during the filtering operation
    • B01D33/58—Handling the filter cake in the filter for purposes other than for regenerating the filter cake remaining on the filtering element
    • B01D33/62—Handling the filter cake in the filter for purposes other than for regenerating the filter cake remaining on the filtering element for drying
    • B01D33/66—Handling the filter cake in the filter for purposes other than for regenerating the filter cake remaining on the filtering element for drying by gases or by heating
    • B01D33/663—Handling the filter cake in the filter for purposes other than for regenerating the filter cake remaining on the filtering element for drying by gases or by heating by direct contact with a fluid
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2201/00—Details relating to filtering apparatus
    • B01D2201/28—Position of the filtering element
    • B01D2201/282—Filtering elements with a horizontal rotation or symmetry axis

Definitions

  • the present invention relates to a method of reducing the water content of coal slurries which are obtained in large amounts in the upgrading of coal.
  • the steam consumption in connection with this previous method is 68 kilograms per metric ton of filter cake, meaning that a filter would require about 1000 cubic meters of steam per hour, and sealing of the hood would be practically impossible.
  • the vacuum in the filter drum is capable of drawing in only a certain amount of water and air, the excessive steam would escape at the feeder and delivery sides.
  • heating of the filter cake to temperatures of C. to C. could not be prevented, these temperatures being so high that, according to coke-oven plant specialists, the surface of the filter cake experiences modifications which are disadvantageous when the dewatered sludge is to be processed into coking coal.
  • the present invention seeks to provide a method and apparatus for dewatering coal and other flotation slurries such that the residual or final water content is minimized, and can be as little as 12%.
  • dewatering of coal slurries by means of vacuum drums or vacuum discfilters and treatment of the filter cake with steam may be accomplished simply when the steam is brought into contact with a preliminarily dewatered filter cake and the treatment is carried out at superheated steam temperatures of C. to C., whereby the steam pressure is regulated such that the condensation point of the steam which penetrates the preliminarily dewatered filter cake is immediately adjacent the filter itself. That is, the steam will condense after passing through the filter cake and immediately before it passes through the filter element itself.
  • the operating conditions may be optimized whereby the steam consumption is on the order of about 14 to 20 kilograms per metric ton and the filter cake is heated to only about 40 C. to 50 C.
  • the proper location of the condensation point within the filter cake, that is, immediately adjacent the actual filter, may be determined by determining the liquid content of the filter cake at the exit side. Shifting of the condensation point may be accomplished by varying the steam pressure or the temperature Within the limits prescribed herein.
  • the admission pressure of the steam is between about 1.2 and 1.5 atmospheres (i.e., 1.2 and 1.5 times absolute atmospheric pressure), and the steam pressure within the filter cake is between 0.6 and 0.9 atmosphere. At such pressures, sealing may be omitted, the steam being admitted via a hood which is turned upside down over a portion of the filter emerging from the sludge.
  • the success of the proccess is believed due to the fact that the sludge, drawn in by the filter vacuum at the feeder side, is preliminarily dewater-ed from between about 32% and 30% to about 27% to 25% water by Weight in a preliminary dewatering zone which is not subject to the steam, whereby mainly the micro-capillary water is drained from the micro-capillaries of the filter cake, The preliminarily dewatered filter cake is then brought into the steam treatment zone by virtue of rotating the filter drum or filter discs.
  • the superheated steam now prenetrates the microcapillaries of the preliminarily dewatered filter cake and eventually starts to condense in the third of the filter cake immediately adjacent the filter itself whereby the degree of superheat and the steam pressure are reduced gradually.
  • the condensation point in accordance with the teachings of the subject invention, is at or close to the interface of the filter cake-vacuum zone, the completely condensed steam is drained off as water by virtue of the vacuum.
  • a hood having an inlet for the steam is erected upon the filter apparatus such that a portion of the drum which is external with respect to the filter sludge is not within the action zone of te steam and defines the aforesaid preliminary dewatering zone, the spacing between the filter and the hood being, for example, about centimeters.
  • the preliminary dewatering zone may be provided by arranging the hood and the steam inlet above the circular filter in an off-center position such as by a structure where the hood and inlet are arranged off-set at a certain distance in the direction of rotation of the drum or disc.
  • the first third of the rotating filter which emerges from the sludge is beyond the action range of the steam, this first third constituting the preliminary dewatering zone men tioned above.
  • the steam hood extends between the individual discs of disc-type filter apparatus, thereby forming steam distribution chambers, the front walls of the hood being spaced from and surrounding the individual discs provided with perforations for the passage of steam.
  • the perforations are provided in the front wall only over a section thereof, this section being arranged ofi-center with respect to the hood in the direction of the device which scrapes the mud off the filter.
  • the steam distribution chambers are provided respectively with separate inlets for the steam.
  • the invention has also been found to be of reat advantage in dehydrating organic residues which are obtained in emulsion form, for example, in processing crude oil and crude oil products and in connection with the various methods for processing refuse such as garbage and rubbish.
  • the volumetric relationships are essentially the same, and essentially the same interrelationships are valid for the progression of the condensation front and, hence, for the selection of the appropriate temperature and presvsures of the steam.
  • the filter devices suitable for coal sludge are also applicable to other flotation concentrates.
  • FIGURE 1 is an illustration of drum filter apparatus utilized in accordance with the present invention.
  • FIG. 2 is a side or plan view schematically illustrating a disc filter apparatus utilized in accordance with the present invention
  • FIG. 3 is a front View of the disc filter apparatus shown in FIG. 2;
  • FIGS. 4 and 5 are graphs illustrating the water content of the filter cake as a function of the steam temperature and steam pressure, respectively.
  • the filter mud or sludge constituting a suspension of coal mud is contained within container 1 of the drum filter apparatus, the drum 2 being rotatable about a shaft 3.
  • the drum 2 is of cylindrical configuration, the outer cylindrical peripheral wall 2A constituting the actual filter element.
  • an underpressure of, for example, 0.5 atmosphere, the underpressure being produced by the creation of a vacuum in shaft 3 by means of a pump or the like, not shown.
  • the steam hood 4 is set up above the container 1, the hood having an inlet 5 for the steam.
  • the drum 2 rotates in the direction of arrow A.
  • the vacuum within the drum 2 causes a layer 6 of coal mud to adhere to the filter surface or wall 2A. Water is drained from this layer 6 of coal mud by virtue of the partial vacuum within the interior of the drum 2 while rotational motion of the drum is in progress.
  • the mud layer 6 is separated from the filter at the other side thereof by means of a scraper 7 or the like.
  • the steam hood 4 is arranged above the drum such that the distance thereof from the container 1 is somewhat greater at the right side shown in FIG. 1 at which the filter with the mud layer 6 thereon emerges then at the left side at which the layer is scraped off by scraper 7.
  • the inlet 5 for the steam is arranged in an off-center position. That is, it is shifted with respect to a vertical line extending through the center of the shaft 3 a certain distance in the direction of drum rotation whereby, in operation, the preliminary dewatering zone, identified by the are E, is formed wherein the mud is preliminarily dewatered under the influence of the vacuum only prior to introducing it into the steam action zone or are C for further removal of water.
  • a special seal between the hood 4 and filter 2 is not required. That is, slip gaskets or the like, not shown, are sufficient in order to prevent the steam from escaping and annoying operating personnel.
  • FIG. 2 there is illustrated disc filter apparatus in accordance with the invention.
  • the container 10 in this case is filled with the sludge; however instead of using a drum as in FIG. 1, a plurality of disc assemblies 8 are provided, only two of such disc assemblies being shown in FIG. 3 for the purpose of clarity.
  • the disc assemblies rotate about a hollow shaft 9 in the direction of arrow 11 shown in FIG. 2; and a parfial vacuum is produced by extraction through the hollow shaft 9.
  • the actual filter elements are constituted by the side walls 8A of the individual disc assemblies 8 on which the filter cakes 12 are deposited in operation.
  • a hood 13 has walls 14A extending between the individual discs, thereby forming steam distribution chambers 14 which are equipped, respectively, with inlets 15 for the steam.
  • the steam is permitted to come into contact with the filter cake by the steam passing through perforations 16 provided in sections of the hood walls 14A, said sections being defined by the are C in FIG. 2 and displaced in the direction of the mud cake scraper 17.
  • a preliminary dewatering zone B where the sludge is dewatered under the effect of the vacuum only
  • a steam action zone C where both the vacuum and steam act upon the sludge.
  • the steam temperature in degrees centrigrade is plotted against the weight percentage of water in the resulting filter cake.
  • steam pressure was in the range of 1.2 and 1.5 atmospheres.
  • curve E it will be appreciated that the water content in the filter cake reaches a minimum at a steam temperature of about 120 C. and 135 C. (248 F. and 275 F.) where the weight percentage of the water in the filter cake is between about 12% and 12.5%. Beneath a temperature of about 120 C. and above a temperature of about 135 C., the water content of the filter cake increases sharply.
  • FIG. 5 the steam pressure in atmospheres is plotted against the weight percentage of water in the filter cake.
  • the temperature of the steam utilized to derive the data of FIG. 5 was in the range between 120 C. and 135 C., the optimum conditions shown by the graph of FIG. 4.
  • the curve F reveals a minimum water content in the sludge at steam pressures between 1.2 and 1.5 atmospheres (about 17.6 and 22 psi). Accordingly, a 12% dewaterization may be achieved at the indicated temperature and pressure ranges. This is an unexpected result, particularly when it is considered that the minimum dewaterization occurs between critical limits of pressure and temperature.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Solid Fuels And Fuel-Associated Substances (AREA)
  • Treatment Of Sludge (AREA)
US363120A 1963-05-16 1964-04-28 Method of dewatering of coal slurries Expired - Lifetime US3361259A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DEH49191A DE1177572B (de) 1963-05-16 1963-05-16 Verfahren und Vorrichtung zum Entwaessern von Kohlenschlaemmen

Publications (1)

Publication Number Publication Date
US3361259A true US3361259A (en) 1968-01-02

Family

ID=7156961

Family Applications (1)

Application Number Title Priority Date Filing Date
US363120A Expired - Lifetime US3361259A (en) 1963-05-16 1964-04-28 Method of dewatering of coal slurries

Country Status (5)

Country Link
US (1) US3361259A (Direct)
BE (1) BE647428A (Direct)
DE (1) DE1177572B (Direct)
GB (1) GB1044642A (Direct)
NL (1) NL6404021A (Direct)

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3592341A (en) * 1970-01-05 1971-07-13 Envirotech Corp Method and apparatus for steam drying filter cake
US3698556A (en) * 1970-10-30 1972-10-17 Envirotech Corp Apparatus for steam drying filter cake
US4107028A (en) * 1977-01-27 1978-08-15 Envirotech Corporation Treatment of iron concentrate slurry to improve filtration
US4115265A (en) * 1975-12-24 1978-09-19 Klockner-Humboldt-Deutz Aktiengesellschaft Method and apparatus for dehydrating suspension
US4134835A (en) * 1977-03-31 1979-01-16 Envirotech Corporation Steam injection assembly for disc filter
US4293411A (en) * 1978-10-05 1981-10-06 Envirotech Corporation Steam seal for disc filter
US4338201A (en) * 1979-08-15 1982-07-06 Fabcon Continuous separation system
EP0596857A1 (de) * 1992-11-06 1994-05-11 Andritz-Patentverwaltungs-Gesellschaft m.b.H. Verfahren und Anlage zur Trennung von Feststoff-Flüssigkeit-Mischungen
WO1994025140A1 (en) * 1993-05-05 1994-11-10 Harry Nilsson Rotating filter
US5379902A (en) * 1993-11-09 1995-01-10 The United States Of America As Represented By The United States Department Of Energy Method for simultaneous use of a single additive for coal flotation, dewatering, and reconstitution
US5413703A (en) * 1987-10-22 1995-05-09 Greenwald, Sr.; Edward H. Method and apparatus for dewatering
US5795484A (en) * 1987-10-22 1998-08-18 Greenwald, Sr.; Edward H. Method and apparatus for dewatering
US6190566B1 (en) 1998-06-23 2001-02-20 Steven N. Kolber Treatment of waste produced by farm animals raised under confined conditions
WO2002082888A1 (de) * 2001-04-14 2002-10-24 Sächsisches Textilforschungsinstitut e.V. Textile bewässerungsmatte
US8871099B1 (en) * 2011-10-18 2014-10-28 Nu-Coal LLC Coal slurry dewatering arrangement
US11000791B2 (en) * 2019-03-06 2021-05-11 Veolia Water Solutions & Technologies Support Rotary disc filter having backwash guides

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1943763C3 (de) * 1969-08-28 1979-12-20 Schenck, Hermann, Prof. Dr.-Ing. Dr.-Ing.E.H., 5100 Aachen Verfahren und Vorrichtung für die Herstellung von Gleichstückkoks
NO140878C (no) * 1975-08-21 1979-12-05 Myrens Verksted As Fremgangsmaate for filtrering av finkornede faste produkter fra en vaeskesuspensjon og toerking av de frafiltrerte produkter, samt innretning for bruk ved gjennomfoering av fremgangsmaaten
AT380226B (de) * 1983-03-17 1986-04-25 Voest Alpine Ag Verfahren zum entwaessern von schlaemmen und/oder organischen stoffen
DE3629805C2 (de) * 1986-09-02 1996-03-21 Reinhard Dr Ing Bott Verfahren zum Bilden und Entfeuchten eines aus Feststoffpartikeln aufgebauten porösen Filterkuchens und Vorrichtung zur Durchführung des Verfahrens
DE4123144C1 (Direct) * 1991-07-12 1992-11-19 Werner Prof. Dr.-Ing. 6740 Landau De Stahl
US6409929B2 (en) 1992-11-11 2002-06-25 Bokela Ingenieurgesellschaft Fur Mechanische Verfahrenstechnik Mbh Steam drying of rotary filter cakes without crack formation
DE4238087C3 (de) * 1992-11-11 1997-12-04 Bokela Ing Gmbh Verfahren zur mechanischen Entfeuchtung eines Filterkuchens und Vorrichtung zur Durchführung des Verfahrens
DE10050733B4 (de) * 2000-04-10 2009-05-14 BOKELA Ingenieurgesellschaft für mechanische Verfahrenstechnik mbH Vorrichtung und Verfahren zur Entfeuchtung eines Filterkuchens

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1336444A (en) * 1917-08-29 1920-04-13 United Filters Corp Method of and apparatus for filtration
US2500056A (en) * 1945-12-20 1950-03-07 Standard Oil Dev Co Method and apparatus for solventcleaning finely divided solids
US3245538A (en) * 1962-12-31 1966-04-12 United States Steel Corp Heating-unit arrangement for vacuum-disc filter

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1336444A (en) * 1917-08-29 1920-04-13 United Filters Corp Method of and apparatus for filtration
US2500056A (en) * 1945-12-20 1950-03-07 Standard Oil Dev Co Method and apparatus for solventcleaning finely divided solids
US3245538A (en) * 1962-12-31 1966-04-12 United States Steel Corp Heating-unit arrangement for vacuum-disc filter

Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3592341A (en) * 1970-01-05 1971-07-13 Envirotech Corp Method and apparatus for steam drying filter cake
US3698556A (en) * 1970-10-30 1972-10-17 Envirotech Corp Apparatus for steam drying filter cake
US4115265A (en) * 1975-12-24 1978-09-19 Klockner-Humboldt-Deutz Aktiengesellschaft Method and apparatus for dehydrating suspension
US4107028A (en) * 1977-01-27 1978-08-15 Envirotech Corporation Treatment of iron concentrate slurry to improve filtration
US4134835A (en) * 1977-03-31 1979-01-16 Envirotech Corporation Steam injection assembly for disc filter
US4293411A (en) * 1978-10-05 1981-10-06 Envirotech Corporation Steam seal for disc filter
US4338201A (en) * 1979-08-15 1982-07-06 Fabcon Continuous separation system
US5795484A (en) * 1987-10-22 1998-08-18 Greenwald, Sr.; Edward H. Method and apparatus for dewatering
US5413703A (en) * 1987-10-22 1995-05-09 Greenwald, Sr.; Edward H. Method and apparatus for dewatering
AU666227B2 (en) * 1992-11-06 1996-02-01 Andritz-Patentverwaltungs-Gmbh Process and installation for the separation of solid-liquid-mixtures
EP0596857A1 (de) * 1992-11-06 1994-05-11 Andritz-Patentverwaltungs-Gesellschaft m.b.H. Verfahren und Anlage zur Trennung von Feststoff-Flüssigkeit-Mischungen
WO1994025140A1 (en) * 1993-05-05 1994-11-10 Harry Nilsson Rotating filter
AU675321B2 (en) * 1993-05-05 1997-01-30 Harry Nilsson Rotating filter
US5379902A (en) * 1993-11-09 1995-01-10 The United States Of America As Represented By The United States Department Of Energy Method for simultaneous use of a single additive for coal flotation, dewatering, and reconstitution
US6190566B1 (en) 1998-06-23 2001-02-20 Steven N. Kolber Treatment of waste produced by farm animals raised under confined conditions
WO2002082888A1 (de) * 2001-04-14 2002-10-24 Sächsisches Textilforschungsinstitut e.V. Textile bewässerungsmatte
US8871099B1 (en) * 2011-10-18 2014-10-28 Nu-Coal LLC Coal slurry dewatering arrangement
US11000791B2 (en) * 2019-03-06 2021-05-11 Veolia Water Solutions & Technologies Support Rotary disc filter having backwash guides

Also Published As

Publication number Publication date
DE1177572B (de) 1964-09-10
GB1044642A (en) 1966-10-05
BE647428A (Direct) 1964-08-17
NL6404021A (Direct) 1964-11-17

Similar Documents

Publication Publication Date Title
US3361259A (en) Method of dewatering of coal slurries
US3188751A (en) Method of producing building aggregate utilizing sludge residue from paper de-inking process
JPS60222125A (ja) 除ダスト装置から湿潤ダスト及び鉱泥を処理する方法及び装置
US3909410A (en) Process for treating sewage sludge
US4214377A (en) Mechanical dewatering process
US3480542A (en) Method and apparatus for the purification of waste water
US2956944A (en) Process for filtering tar
GB1098543A (en) Method of filtering liquid from solid particles
US2044214A (en) Sulphur refining process
US3257309A (en) Manufacture of petroleum coke
US2431677A (en) Process for the recovery of oil from shales
US2277718A (en) Sludge treatment
US2921010A (en) Treatment of bituminous sands
US2070286A (en) Method of treating distillery slop
US539055A (en) Apparatus
US2499412A (en) Filtering method and apparatus
US2553387A (en) Filtering apparatus
US4196078A (en) Process and apparatus for dewatering granulated material, especially granulated blast furnace slag
US3783128A (en) Process for recovering forest product plant wastes
US1721858A (en) Extraction
US1930247A (en) Method of treating clay
US2850511A (en) Solvent extraction of oils from vegetable matter
US2236800A (en) Method of treating distillery wastes
US2690019A (en) Solvent recovery process
GB992138A (en) Improvements in or relating to filters