[go: up one dir, main page]

CA1066199A - Rotary pelletizing vacuum filter - Google Patents

Rotary pelletizing vacuum filter

Info

Publication number
CA1066199A
CA1066199A CA231,249A CA231249A CA1066199A CA 1066199 A CA1066199 A CA 1066199A CA 231249 A CA231249 A CA 231249A CA 1066199 A CA1066199 A CA 1066199A
Authority
CA
Canada
Prior art keywords
drum
belt
filter
deflecting roller
lattice
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
Application number
CA231,249A
Other languages
French (fr)
Other versions
CA231249S (en
Inventor
Chatty Rao
Kurt Stalinski
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.)
Kloeckner Humboldt Deutz AG
Original Assignee
Kloeckner Humboldt Deutz 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 Kloeckner Humboldt Deutz AG filed Critical Kloeckner Humboldt Deutz AG
Application granted granted Critical
Publication of CA1066199A publication Critical patent/CA1066199A/en
Expired legal-status Critical Current

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D33/00Filters with filtering elements which move during the filtering operation
    • B01D33/06Filters with filtering elements which move during the filtering operation with rotary cylindrical filtering surfaces, e.g. hollow drums
    • B01D33/073Filters with filtering elements which move during the filtering operation with rotary cylindrical filtering surfaces, e.g. hollow drums arranged for inward flow filtration
    • B01D33/09Filters with filtering elements which move during the filtering operation with rotary cylindrical filtering surfaces, e.g. hollow drums arranged for inward flow filtration with surface cells independently connected to pressure distributors
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D33/00Filters with filtering elements which move during the filtering operation
    • B01D33/70Filters with filtering elements which move during the filtering operation having feed or discharge devices
    • B01D33/76Filters with filtering elements which move during the filtering operation having feed or discharge devices for discharging the filter cake, e.g. chutes

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Manufacture And Refinement Of Metals (AREA)
  • Treatment Of Sludge (AREA)
  • Excavating Of Shafts Or Tunnels (AREA)

Abstract

ABSTRACT OF THE DISCLOSURE

An improved rotary vacuum filter for producing filtration blanks or what may be termed pellets from slurries, especially for example, iron ore slurries. Known rotary filters utilize spiked deflecting rollers to remove iron ore agglomerates from interstices in a lattice-like belt. The use of a spiked deflecting roller necessitates the use of a metal belt which is difficult to produce since the belt must be sufficiently flexible to both pass around the deflecting roller and lie sealingly against the surface of a vacuum drum without permitting entry of outside air. This problem is over-come by the present invention which provides a vacuum filter whereby dehydrated iron ore agglomerates are easily released undamaged from the belt without impairing the suction effect produced by the drum. The rotary vacuum filter according to the present invention comprises a filter drum adapted to rotate about a horizontal axis while partly immersed in a filter trough filled with slurry, the filter drum is provided with a filter lining and a suction area, a forming belt, divided like a lattice, lies against the filter lining over the entire suction area of the drum and is adapted to rotate therewith, the forming belt extends from the drum over a deflecting roller arranged at a distance from the drum, the deflecting roller having a diameter smaller than a diameter of the drum, the belt adapted to be lifted off the said drum at an end of the suction area by means of the deflecting roller and being returned thereto before being immersed in the filter trough, the lattice forming belt having walls made of resiliently flexible material, interstices in the lattice for holding filtration blanks, said interstices being tapered conically towards a surface of the belt lying against the filter drum whereby filtration blanks are removed from the interstices by squeezing action as the belt passes around the deflecting roller.

Description

The invention relates to a rotary vacuum filter for producing filtration blanks or what may be termed pellets from slurries, especially , for example, iron ore slurries.
Many iron ores must be subjected to wet mechanical dressing in order to enrich them by removal of the gangue. The slurry thus produced must then be dehydrated and converted to a grain size suitable fo~ ~he subsequent metallurgical process.
German Patent 1 920 219 and German Patent of Addition 1 925 876 discloses a method in which the two operations of dehydrating and moulding are combined with one another.
Dehydrating of the slurry is preferably carried out in so-called rotary vacuum filters comprising a filter drum rotating about a horizontal axis, the lower part of the said drum being immersed in a filter trough filled with the slurry. The filter drum is provided with a filter lining permeable to water.
A negative pressure produced in the interior of the drum causes the s-lurry to be deposited by suction in a layer on the submerged surface of the drum. This deposit is then removed from the trough by the continuously rotating drum. The rotation of the drum removes still more water from the layer of sludge. The dehydrated ore cake is removed from the surface of the drum by appropriate means before the surface of the drum is again immersed in the iron ore slurry.
Division of the dehydrated filter cake is achieved by arranging a lattice-like belt on the surface of the drum, the interstices of the belt being such as to produce, during the dehydrating process, agglomerates of iron in the form of cubes, or the like. The lattice-like forming belt which rotates with the filter drum, is so arranged that it is lifted from the drum at the end of the suction area by means of a deflecting roller located at a distance from the drum, the forming belt being ~k - 1 - ~p 'I

1~)66~99 returned to the drum before again being immersed in the filter trough.
The surface of the deflecting roller is provided with spikes to expel the iron ore agglomerates from the interstices in the belt. As a result, the spikes must be very accurately matched with the interstices. The use of the spiked roller has necessitated the use of a metal forming belt. However, it is extremely difficult to produce a lattice belt made of metal since the belt must be flexible in order to pass around the spiked roller. Further, a high degree of accuracy is required in order to ensure that the spikes enter the interstices. Another problem is to ensure that the lattice belt lies sealingly against the surface of the drum so that no outside air is drawn into the drum.
The present invention proposes to improve this known vacuum filter so that the dehydrated iron ore agglomerates are easily released undamaged from the lattice belt without impair-ing the suction effect produced within the drum. This is achieved by providing a belt having walls made of resiliently flexible material, the belt having interstices therein which are tapered conically towards the surface of the belt which lies against the filter drum. As a result, the lattice belt lies sealingly against the filter drum over the entire suction area.
Furthermore, since the diameter of the deflecting roller is con-siderably smaller than that of the drum, the said belt is bent so sharply around the deflecting roller that most of the pieces of iron ore are released by the squeezing action and easily fall out of the interstices. The conical design of the inter-stices, which are open at the bottom, prevents the iron ore agglomerates therein from adhering to the filter lining when the belt is lifted from the drum, as well as from falling out on the way to the deflecting roller.
In accordance with a broad aspect of the invention there is provided an apparatus for filtering slurries and for the manufacture of pellets from filter ca~es, said apparatu~
comprising: a filter drum adapted to rotate about its axis while partly immersed in the slurries, the filter drum being provided with a filter lining and a suction area and an endless forming belt, divided like a lattice which lies against the filter lining over the entire suction area of the drum and which is adapted to rotate therewith, the forming belt extends from the drum over a deflecting roller arranged at a distance from the drum whereby the pellets which are separated from the filter cakes are removed from the interstices in the lattice, characterized by the fact that the lattice forming belt has walls made of resiliently flexible material, and that said interstices are tapered conically toward a surface of the belt lying against the filter drum.
In one preferred embodiment of the invention, an additional deflecting roller is arranged in the return path of the belt just above the point of immersion, such that the belt runs approximately horizontally between the two deflecting rollers. The advantage of this is that the belt approaches the surface of the drum at a steeper angle, thus enlarging the suc-tion area.
In case any pieces of iron ore fail to drop out of the interstices when the lattice belt passes around the deflect-ing roller, according to a further embodiment of the invention an auxiliary device for shaking, beating, or blowing such pieces out of the said belt is arranged immediately above the return run of the belt. This auxiliary device may be a blower, or a beating or vibrating device.
The invention will now be described with reference to ~066199 the accompanying drawings which illustrate one embodiment of the present invention.
Figure 1 i~ a ~ide elevation of a diagrammatic re-presentation of the drum filter according to the invention, Figure 2 is an enlarged vertical section of the lattic~

forming belt of Figure 1, taken along the ! line II-II, and Figure 3 is a plan view of the enlarged section of the belt of Figure 2.
' m e drum filter illustrated in Figure 1 consists of a filter drum 1 which rotates about a horizontal axis, the lower part of the said drum being immersed in a filter trough 2 filled with iron ore slurry. This slurry is produced by wet mechanical dressing and is fed continuously from a mixing container 3, 1~66~99 through a feed means 4, into trough 2. The slurry is fed into trough 2 at such a rate that the depth of immersion of the filter drum therein remains constant.
Filter drum 1 is provided with a filter lining 5 which is permeable to water. The slurry in filter trough 2 is drawn through the filter lining 5 by means of a vacuum device arranged within the interior of the drum. As filter drum 1 continues to rotate, the slurry is brought to the desired degree of dryness.
The vacuum device is well known in the art and consists of suction cells 6 arranged closely below filter lining 5, the cells 6 being connected by means of suction lines 7 to a control disc 8 located on the axis of the drum. The control disc 8 rotates against a control head, not shown, which is connected to a suction pump, also not shown. The design of the control head is such that suction is applied only to suction lines 7 in rotational area ~ of the drum. None of the remaining suction lines is connected to the pump.
Arranged on filter lining 5 is a lattice-like divided forming belt 9, the interstices in the belt 9 being tapered conically towards the suction side thereof, that is, towards the side of the belt which lies against the filter drum, as best seen in Figures 2 and 3. The belt 9 is made of a resiliently flexible material and is lifted from filter drum 1 at the end of the suction area by means of a deflecting roller 10 arranged at a distance from filter drum 1. The belt 9 is returned to the drum 1 before being immersed in filter trough 2. The conicity (a-b):c of the interstices tapering towards the suction side of the belt is of the order of 1:10. Although a part of the effective surface area of the filter lining 5 is lost due to the thickening of belt webs 14 towards the suction side of the belt, this loss is compensated for by the fact that the thickness of ~066199 the layer of sludge deposi.ted on drum 1 may be considerably greater than if the sludge were deposited by suction without the use of a lattice belt.
Arranged in the return run of the belt, just above the point of immersion, is an additional deflecting roller 11, by means of which lattice belt 9 is caused to travel approximately horizontally towards drum 1. Also, located beneath deflecting roller 10 is a conveyor belt 12 for carrying away the pieces of iron ore 15 released from lattice belt 9. Most of these pieces are released from the interstices due to the resulting squeezing action as the belt passes around deflecting roller 10 and fall onto conveyor belt 12.
In order to re'ease any iron ore agglomerates 15 remaining in lattice belt 9, as well as to ensure that all of the interstices in the belt are ready to receive the new slurry, it is desirable to arrange between the two deflecting rollers 10, 11 and just above the belt 9, an auxiliary device 13, whlch may be in the form of a blowing, a beating, or a vibrating device.
Any pieces of iron ore thus released also drop onto conveyor belt 12.
If conveyor belt 12 is suitably designed, iron ore blanks lS may be simultaneously burned or sintered in order to provide them with the strength required for the subsequent -metallurgical process.

Claims (4)

The embodiments of the invention in which an exclu-sive property or privilege is claimed are defined as follows:-
1. Apparatus for filtering slurries and for the manufac-ture of pellets from filter cakes, said apparatus comprising:
a filter drum adapted to rotate about its axis while partly immersed in the slurries, the filter drum being provided with a filter lining and a suction area and an endless forming belt, divided like a lattice which lies against the filter lining over the entire suction area of the drum and which is adapted to rotate therewith, the forming belt extends from the drum over a deflecting roller arranged at a distance from the drum whereby the pellets which are separated from the filter cakes are removed from the interstices in the lattice, charac-terized by the fact that the lattice forming belt has walls made of resiliently flexible material, and that said interstices are tapered conically toward a surface of the belt lying against the filter drum.
2. A rotary vacuum filter according to claim 1, wherein the taper of the interstices in the lattice amounts approximate-ly 1:10.
3. A rotary vacuum filter according to claims 1 or 2, wherein an additional deflecting roller is located in a return path of the belt from the deflecting roller to the drum, the location of the additional deflecting roller being such that the lattice forming belt extends substantially horizontally between the two deflecting rollers.
4. A rotary vacuum filter according to claims 1 or 2, wherein an auxiliary device is arranged adjacent and above a return run of the forming belt from the deflecting roller to the drum, the auxialiary device adapted to remove filtration pellets remaining in the interstices after the belt has passed around the deflecting roller.
CA231,249A 1974-08-07 1975-07-10 Rotary pelletizing vacuum filter Expired CA1066199A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE2437991A DE2437991C3 (en) 1974-08-07 1974-08-07 Device for filtering sludge

Publications (1)

Publication Number Publication Date
CA1066199A true CA1066199A (en) 1979-11-13

Family

ID=5922647

Family Applications (1)

Application Number Title Priority Date Filing Date
CA231,249A Expired CA1066199A (en) 1974-08-07 1975-07-10 Rotary pelletizing vacuum filter

Country Status (9)

Country Link
AU (1) AU496922B2 (en)
BR (1) BR7505012A (en)
CA (1) CA1066199A (en)
DE (1) DE2437991C3 (en)
FR (1) FR2281430A1 (en)
GB (1) GB1505698A (en)
NL (1) NL7508273A (en)
NO (1) NO140368C (en)
SE (1) SE401788B (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2651098C2 (en) * 1976-11-09 1982-12-02 Klöckner-Humboldt-Deutz AG, 5000 Köln Device for filtering sludge and for producing shaped bodies
DE2752858C2 (en) * 1977-11-26 1986-02-20 Klöckner-Humboldt-Deutz AG, 5000 Köln Method and device for removing moldings from the lattice-like recesses of a molding belt
CN115444159B (en) * 2022-08-19 2023-06-13 广东中烟工业有限责任公司 Double-layer drum-type efficient directional screening device for tobacco flakes

Also Published As

Publication number Publication date
DE2437991C3 (en) 1978-06-08
FR2281430A1 (en) 1976-03-05
BR7505012A (en) 1976-08-03
SE401788B (en) 1978-05-29
NO140368C (en) 1979-08-22
SE7508792L (en) 1976-02-09
AU496922B2 (en) 1978-11-09
NO140368B (en) 1979-05-14
DE2437991B2 (en) 1977-10-20
NO752751L (en) 1976-02-10
FR2281430B1 (en) 1980-04-18
NL7508273A (en) 1976-02-10
AU8275475A (en) 1977-01-06
GB1505698A (en) 1978-03-30
DE2437991A1 (en) 1976-02-26

Similar Documents

Publication Publication Date Title
US4204855A (en) Apparatus for dewatering granulated-slag slurry
EP0251787B1 (en) Apparatus for thickening pulp and paper stock
US3459122A (en) Apparatus for the continuous extraction of moisture from suspended matter
US4661243A (en) Method and apparatus for treating moist dust and mud in the steel industry
US3200949A (en) Sludge flocculating and filtering apparatus
US4692240A (en) Apparatus and a method for separating one solid component from another solid component in suspension in a liquid
US3774760A (en) Sludge dewatering apparatus and process
US2982411A (en) Moisture separation from granular materials
CA1066199A (en) Rotary pelletizing vacuum filter
US4713181A (en) Method and apparatus for handling sludge
US4136031A (en) Apparatus for the recovery of liquid from a liquid medium containing solids
US3984287A (en) Apparatus for separating organic material from particulate tar sands and coal and agglomeration of the particulate residue
US3244281A (en) Process for separating solids from suspensions
US4419249A (en) Method and apparatus for dewatering a slurry of fine particles
US3531872A (en) Process and apparatus for deliquifying fluent material
US1885334A (en) Process and equipment for forming sheets
US3438503A (en) Rotary vacuum filter
US3469703A (en) Method and apparatus for regenerating the filter cloth of a rotary filter table
RU98121004A (en) WET CRUSHING METHOD AND DEVICE FOR ITS IMPLEMENTATION
US4196078A (en) Process and apparatus for dewatering granulated material, especially granulated blast furnace slag
US2481110A (en) Dewatering process
US2330542A (en) Dewatering of suspended solids
US3782555A (en) Feed distribution means for vacuum filters
US1201014A (en) Classifier and dewaterer.
US3501003A (en) Method for recovering the solid from a clogging slurry,more particularly iron oxide slurries in steelworks