CA1067016A - Moving bed particulate filter - Google Patents
Moving bed particulate filterInfo
- Publication number
- CA1067016A CA1067016A CA263,666A CA263666A CA1067016A CA 1067016 A CA1067016 A CA 1067016A CA 263666 A CA263666 A CA 263666A CA 1067016 A CA1067016 A CA 1067016A
- Authority
- CA
- Canada
- Prior art keywords
- bed
- particulate material
- filtration apparatus
- vessel
- baffle
- 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
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D24/00—Filters comprising loose filtering material, i.e. filtering material without any binder between the individual particles or fibres thereof
- B01D24/46—Regenerating the filtering material in the filter
- B01D24/4668—Regenerating the filtering material in the filter by moving the filtering element
- B01D24/4689—Displacement of the filtering material to a compartment of the filtering device for regeneration
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D24/00—Filters comprising loose filtering material, i.e. filtering material without any binder between the individual particles or fibres thereof
- B01D24/02—Filters comprising loose filtering material, i.e. filtering material without any binder between the individual particles or fibres thereof with the filter bed stationary during the filtration
- B01D24/10—Filters comprising loose filtering material, i.e. filtering material without any binder between the individual particles or fibres thereof with the filter bed stationary during the filtration the filtering material being held in a closed container
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D24/00—Filters comprising loose filtering material, i.e. filtering material without any binder between the individual particles or fibres thereof
- B01D24/46—Regenerating the filtering material in the filter
- B01D24/4631—Counter-current flushing, e.g. by air
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Filtration Of Liquid (AREA)
- Filters For Electric Vacuum Cleaners (AREA)
- Preparation Of Clay, And Manufacture Of Mixtures Containing Clay Or Cement (AREA)
- Auxiliary Methods And Devices For Loading And Unloading (AREA)
Abstract
A B S T R A C T
A filtration apparatus consisting of a filtration vessel which contains a bed of particulate material and whose lower portion is of diminished cross section area leading to an outlet through which particulate material may be withdrawn.
The apparatus is designed to permit the withdrawal of material from the base of the bed thereof and to provide for the supplying of replacement particulate material to the bed in such a manner that the bed has a free inclined upper surface extending downwardly from an opening through which replacement particulate material is fed to the bed. The apparatus is designed to cause the liquid to be filtered to enter the bed through the free inclined upper surface for flow downwardly through the bed to a filtrate outlet formed by a screen which retains the particulate material. The apparatus is characterized by the provision of a baffle disposed within the filtration vessel above the outlet therefrom through which material is withdrawn from the base of the bed.
A filtration apparatus consisting of a filtration vessel which contains a bed of particulate material and whose lower portion is of diminished cross section area leading to an outlet through which particulate material may be withdrawn.
The apparatus is designed to permit the withdrawal of material from the base of the bed thereof and to provide for the supplying of replacement particulate material to the bed in such a manner that the bed has a free inclined upper surface extending downwardly from an opening through which replacement particulate material is fed to the bed. The apparatus is designed to cause the liquid to be filtered to enter the bed through the free inclined upper surface for flow downwardly through the bed to a filtrate outlet formed by a screen which retains the particulate material. The apparatus is characterized by the provision of a baffle disposed within the filtration vessel above the outlet therefrom through which material is withdrawn from the base of the bed.
Description
10670:16 , THIS INVENTION relates to the filtration of llquids and more particularly~ though not exclusively~
to the removal of suspended solids from sewage effluents at tertiary treatment atages.
In our Canadian Patent No. 1~016,872 dated September 6, 1977 we have described filtration apparatus comprising a filtration vessel which contains a bed~of particulate material and whose lower portion is of diminishing cross-sectional area leading to an outlet through which particulate material may be withdrawn, means for withdrawing material from the base of the bed, means for supplying replacement particulate material to the bed in such a manner that the bed has a free inclined upper surface extending downwardly from an opening through which replacement particulate material is fed to the bed, and means for causing the liquid to be filtered to enter the bed through said free inclined upper surface for flow downwardly through the bed to a filtrate outlet formed by a screen which retains the particulate material. Such filtratlon apparatus is hereinafter called "filtration apparatus of the kind referred to".
We have found that with this apparatus the velocity proflle of particulate material moving `` ~067~)i6 downwardly through the vessel is such that the material immediately above the oulet moves more rapidly than surrounding material. With a circular vessel such as that shown in Fig. 2 of the drawings of our Canadian Patent No. 1,016,872 this effect can be advantageous since the central vertical core of the filter bed which becomes polluted more qulckly is withdrawn and replaced at a faster rate than surrounding portions of the bed.
In certain applications, as for example when it is deslred that the pollution penetrates deeply into the filter bed, it would be advantageous to ensure a more even velocity profile of the particulate material moving downwardly through the vessel. An even velocity proflle is particularly advantageous in any event with apparatus of the klnd illustrated in ~ig. 1 of the drawings of our Canadian Patent Nol 1,016,872.
It is an ob~ect of the present invention to provide means which aid in obtaining an even velocity profile for particulate material moving downwardly through the filtration vessel.
According to the present invention, there is provided filtration apparatus of the kind referred to characterised by the provision of baffle means disposed within said filtration vessel above the outlet therefrom through which material is withdrawn from the base of the bed.
:" . .
The invention will be described ~urther with reference to the accompanying drawings, which show, by way of example only, two embodiments of the filtration apparatus of the invention.
.. , .
In the drawings:-Fig. 1 shows a vertical cross-section through a first embodiment of the apparatus of the invention, comprising ;15 ; a filter vessel of rectangular horizontal cross-section;
.,.
and Fig. 2 shows a partially cut-away perspective view of a second embodiment of the apparatus comprising a filter vessel of circular horizontal cross-section.
~06'7016 Referring firstly to Fig. 1, it will be seen that this embodlment o~ the apparatus . of the invention essentially comp.rises a vertically extending filter vessel, generally indicated at 10. The vessel 10 is of substant-. ially rectangular horizontal cross-section, which : reduces at the extreme lower end 11 of the vessel to communicate with a pipe 12, to be referred to ; hereinafter.
.
An inclined baffle plate 13 extends within the vessel 10, between opposite end walls . thereof, and is arranged so that its lower edge 14 i is s.paced from a side wall 15 of the vessel 10.
Its upper edge 16 is likewise spaced from the ~ 15 opposite side wall 17 of the vessel 10 but is `~ ` connected with a vertical plate 18, which extends .upwardly therefrom over the remaining height of the vessel 10. A sand-cleaning chamber 19 is provided above the baffle plate 13 and within a compartment 20 at the top of the vessel 10. The .
: base of the chamber 19 is defined by plates 21 and 22 extending from the opposed edges of an outlet 23 of the chamber 19 to the side wall 15 : of the vessel 10 and the baffle plate 13 respectively.
~ ,
to the removal of suspended solids from sewage effluents at tertiary treatment atages.
In our Canadian Patent No. 1~016,872 dated September 6, 1977 we have described filtration apparatus comprising a filtration vessel which contains a bed~of particulate material and whose lower portion is of diminishing cross-sectional area leading to an outlet through which particulate material may be withdrawn, means for withdrawing material from the base of the bed, means for supplying replacement particulate material to the bed in such a manner that the bed has a free inclined upper surface extending downwardly from an opening through which replacement particulate material is fed to the bed, and means for causing the liquid to be filtered to enter the bed through said free inclined upper surface for flow downwardly through the bed to a filtrate outlet formed by a screen which retains the particulate material. Such filtratlon apparatus is hereinafter called "filtration apparatus of the kind referred to".
We have found that with this apparatus the velocity proflle of particulate material moving `` ~067~)i6 downwardly through the vessel is such that the material immediately above the oulet moves more rapidly than surrounding material. With a circular vessel such as that shown in Fig. 2 of the drawings of our Canadian Patent No. 1,016,872 this effect can be advantageous since the central vertical core of the filter bed which becomes polluted more qulckly is withdrawn and replaced at a faster rate than surrounding portions of the bed.
In certain applications, as for example when it is deslred that the pollution penetrates deeply into the filter bed, it would be advantageous to ensure a more even velocity profile of the particulate material moving downwardly through the vessel. An even velocity proflle is particularly advantageous in any event with apparatus of the klnd illustrated in ~ig. 1 of the drawings of our Canadian Patent Nol 1,016,872.
It is an ob~ect of the present invention to provide means which aid in obtaining an even velocity profile for particulate material moving downwardly through the filtration vessel.
According to the present invention, there is provided filtration apparatus of the kind referred to characterised by the provision of baffle means disposed within said filtration vessel above the outlet therefrom through which material is withdrawn from the base of the bed.
:" . .
The invention will be described ~urther with reference to the accompanying drawings, which show, by way of example only, two embodiments of the filtration apparatus of the invention.
.. , .
In the drawings:-Fig. 1 shows a vertical cross-section through a first embodiment of the apparatus of the invention, comprising ;15 ; a filter vessel of rectangular horizontal cross-section;
.,.
and Fig. 2 shows a partially cut-away perspective view of a second embodiment of the apparatus comprising a filter vessel of circular horizontal cross-section.
~06'7016 Referring firstly to Fig. 1, it will be seen that this embodlment o~ the apparatus . of the invention essentially comp.rises a vertically extending filter vessel, generally indicated at 10. The vessel 10 is of substant-. ially rectangular horizontal cross-section, which : reduces at the extreme lower end 11 of the vessel to communicate with a pipe 12, to be referred to ; hereinafter.
.
An inclined baffle plate 13 extends within the vessel 10, between opposite end walls . thereof, and is arranged so that its lower edge 14 i is s.paced from a side wall 15 of the vessel 10.
Its upper edge 16 is likewise spaced from the ~ 15 opposite side wall 17 of the vessel 10 but is `~ ` connected with a vertical plate 18, which extends .upwardly therefrom over the remaining height of the vessel 10. A sand-cleaning chamber 19 is provided above the baffle plate 13 and within a compartment 20 at the top of the vessel 10. The .
: base of the chamber 19 is defined by plates 21 and 22 extending from the opposed edges of an outlet 23 of the chamber 19 to the side wall 15 : of the vessel 10 and the baffle plate 13 respectively.
~ ,
2~4-C41 106701~;
The vesel 10 contains a bed 24 of particulate filter material, in this example formed by sand, introduced into the vessel 10 via the chamber 19. The sand entering the vessel joins an accumulated reserve 25 above the baffle plate 13 and sand from the bottom of the reserve 25 flows past the lower edge 14 of the baffle plate 13 which causes the bed 24 to have a free inclined upper surface 26.
The sand flows downwardly over the inclined surface 26, with a rolling action, which causes the particles of sand to classify. Smaller particles tend to remain at the top of the slope whilst larger particles roll down the slope.
Particles of sand entering the vessel 10 adjacent the side wall 15 tend to flow vertically down-wards without segregation.
. In use, liquid to be filtered is fed to the apparatus via a feed pipe 27, and enters the vessel 10 by flow over a weir plate 28, and under-neath the baffle plate 13 so as to enter the bed 24 by way of the free inclined surface 26. The li~uid is filtered by passing through the bed 24 214- C41 l after which is passes through a filtrate outlet : in the form of a screen 29 in the side wall 15 . of the vessel 10 and is led away through a pipe . 30~ .
Whilst filtration is taking place, sand is continuously drawn from the base of the .
bed 24 into the pipe 12 and raised to the head of the bed 24 through a pipe 31, using the airlift principle, air being introduced into ~ 10 the pipe 12 by a supply line 32 for this : purpose. .
.
A baffle member 100 in the form of a right conical shell is disposed over the outlet at the base of the vessel communicating with the pipe 12 to prevent plug flow of the particulate fil~er material through said outlet and thus ensuring that the particulate material moves downwardly in the bed at a substantially constant velocity over the whole cross-sectional area o~ .
. 20 the bed in a horizontal plane.
The pipe 31 discharges into the chamber 19. A portion of the water fed to the apparatus by the feed pipe 27 is led from the water side of .
. EF/1392 ~ 7 -the baffle plate 13 by a pipe 33, to the space above the sand reserve 25 over the baffle plate 13, at a position beneath the outlet 23 of the chamber l9 as wash water. This wash water may be controlled by means of a valve 34 and it will be understood that the wash water flows upwardly through the chamber 19 and washes the sand supplied to the chamber 19 by the pipe 31. The wash water, containing any contaminants washed out of the sand, overflows from the chamber 19 into the compartment 20, whence it flows away through a drain pipe 35.
Because of the classifying action described above, the particles of sand in the bed 24 are segregated with coarser particles at the water inlet side, finer particles inwardly therefrom and particles of full size range at the water outlet side. The approximate boundaries between these zones are indicated in the drawings by chain dotted lines.
Because of this se~regation the water being filtered passes generally through the coarser particles initially, then through the finer particles and finally throug~ the mixed particles, which latter remain relatively clean on their passage downwards through the vessel 10. As a result the filtration process is very efficient and the bed 24 does not become rapidly blinded to prevent the free flow of liquid to the screen 29.
:10~7016 If desired, a further baffle 36 may be provided so as to produce a second free inclined 3urface 37 which has the effect of directing a layer of predominantly coarser particles downwardly ~ver the filtrate outlet screen 29.
Referring now to Fig. 2, the apparatus there shown i5 generally similar to that o~ Fig. 1, like parts being indicated by like reference numerals. In this embodiment the filter bed 24 ; 10 is of substantially circular horizontal cross- -section and has a free inclined surface 26 of generally inverted conical form at its centre.
The liquid to be filtered thus flows outwardly through the bed 24 from its centre for collection around the periphery of the filter vessel 10.
The baffle plate 13 of the previously described embodiment is replaced by a right conical shell 38, liquid to be filtered being fed to the interior of the shell 38 by means of a pipe 39.
. .
The sand of ~he bed 24 is re-cycled by being drawn from the base of the bed 24 by means of a plurality of angularly spaced pipes 12 and 31, each discharging into a single sand-cleaning chamber 19, the wash water overflowing the weir 40 to _9 _ 106~016 enter the compartment 20, which is annular, and flowing away through drain pipe 35.
A11 of the pipes 12 are ~ed from a single outlet at the base of the vessel and as before a baffle in the form of a right conical shell lO0 is disposed over the outlet and upwardly spaced therefrom to prevent plug flow towards the outlet.
If the filter bed 24 of either embodiment should become excessively contaminated for any reason, it is of course possible to backwash the same by introducing water at the base of the bed 24 or through the pipes 30.
It will be appreciated that the invention is not limited to the above example only, many variations, such as might readily occur to one skilled in the art, being possible without depart-ing from the scope thereof.
Instead of withdrawing material from the base of the bed continuously, material may be withdrawn intermittently. Similarly the liquid to be filtered may be introduced intermittently.
EF/1392 _ 10 -Material withdrawn need not be washed and recycled if fresh replacement material is supplied to the bed.
Of course, when using a circular vessel, the liquid to be filtered could flow towards the centre of the vessel, the filter bed then having an upright conical upper surface.
It wili be understood that the apparatus disclosed will operate successfully with certain 10 kinds of liquids to be filtered even though using a filter material comprised by particles of suitable identical size, but use of a ~ilter material which will classify in the manner described is, of course, preferred.
.
If desired the filter material may be washed with a portion of the supply of liquid to be filtered after passage thereof through the .
filter bed.
EF/1~92
The vesel 10 contains a bed 24 of particulate filter material, in this example formed by sand, introduced into the vessel 10 via the chamber 19. The sand entering the vessel joins an accumulated reserve 25 above the baffle plate 13 and sand from the bottom of the reserve 25 flows past the lower edge 14 of the baffle plate 13 which causes the bed 24 to have a free inclined upper surface 26.
The sand flows downwardly over the inclined surface 26, with a rolling action, which causes the particles of sand to classify. Smaller particles tend to remain at the top of the slope whilst larger particles roll down the slope.
Particles of sand entering the vessel 10 adjacent the side wall 15 tend to flow vertically down-wards without segregation.
. In use, liquid to be filtered is fed to the apparatus via a feed pipe 27, and enters the vessel 10 by flow over a weir plate 28, and under-neath the baffle plate 13 so as to enter the bed 24 by way of the free inclined surface 26. The li~uid is filtered by passing through the bed 24 214- C41 l after which is passes through a filtrate outlet : in the form of a screen 29 in the side wall 15 . of the vessel 10 and is led away through a pipe . 30~ .
Whilst filtration is taking place, sand is continuously drawn from the base of the .
bed 24 into the pipe 12 and raised to the head of the bed 24 through a pipe 31, using the airlift principle, air being introduced into ~ 10 the pipe 12 by a supply line 32 for this : purpose. .
.
A baffle member 100 in the form of a right conical shell is disposed over the outlet at the base of the vessel communicating with the pipe 12 to prevent plug flow of the particulate fil~er material through said outlet and thus ensuring that the particulate material moves downwardly in the bed at a substantially constant velocity over the whole cross-sectional area o~ .
. 20 the bed in a horizontal plane.
The pipe 31 discharges into the chamber 19. A portion of the water fed to the apparatus by the feed pipe 27 is led from the water side of .
. EF/1392 ~ 7 -the baffle plate 13 by a pipe 33, to the space above the sand reserve 25 over the baffle plate 13, at a position beneath the outlet 23 of the chamber l9 as wash water. This wash water may be controlled by means of a valve 34 and it will be understood that the wash water flows upwardly through the chamber 19 and washes the sand supplied to the chamber 19 by the pipe 31. The wash water, containing any contaminants washed out of the sand, overflows from the chamber 19 into the compartment 20, whence it flows away through a drain pipe 35.
Because of the classifying action described above, the particles of sand in the bed 24 are segregated with coarser particles at the water inlet side, finer particles inwardly therefrom and particles of full size range at the water outlet side. The approximate boundaries between these zones are indicated in the drawings by chain dotted lines.
Because of this se~regation the water being filtered passes generally through the coarser particles initially, then through the finer particles and finally throug~ the mixed particles, which latter remain relatively clean on their passage downwards through the vessel 10. As a result the filtration process is very efficient and the bed 24 does not become rapidly blinded to prevent the free flow of liquid to the screen 29.
:10~7016 If desired, a further baffle 36 may be provided so as to produce a second free inclined 3urface 37 which has the effect of directing a layer of predominantly coarser particles downwardly ~ver the filtrate outlet screen 29.
Referring now to Fig. 2, the apparatus there shown i5 generally similar to that o~ Fig. 1, like parts being indicated by like reference numerals. In this embodiment the filter bed 24 ; 10 is of substantially circular horizontal cross- -section and has a free inclined surface 26 of generally inverted conical form at its centre.
The liquid to be filtered thus flows outwardly through the bed 24 from its centre for collection around the periphery of the filter vessel 10.
The baffle plate 13 of the previously described embodiment is replaced by a right conical shell 38, liquid to be filtered being fed to the interior of the shell 38 by means of a pipe 39.
. .
The sand of ~he bed 24 is re-cycled by being drawn from the base of the bed 24 by means of a plurality of angularly spaced pipes 12 and 31, each discharging into a single sand-cleaning chamber 19, the wash water overflowing the weir 40 to _9 _ 106~016 enter the compartment 20, which is annular, and flowing away through drain pipe 35.
A11 of the pipes 12 are ~ed from a single outlet at the base of the vessel and as before a baffle in the form of a right conical shell lO0 is disposed over the outlet and upwardly spaced therefrom to prevent plug flow towards the outlet.
If the filter bed 24 of either embodiment should become excessively contaminated for any reason, it is of course possible to backwash the same by introducing water at the base of the bed 24 or through the pipes 30.
It will be appreciated that the invention is not limited to the above example only, many variations, such as might readily occur to one skilled in the art, being possible without depart-ing from the scope thereof.
Instead of withdrawing material from the base of the bed continuously, material may be withdrawn intermittently. Similarly the liquid to be filtered may be introduced intermittently.
EF/1392 _ 10 -Material withdrawn need not be washed and recycled if fresh replacement material is supplied to the bed.
Of course, when using a circular vessel, the liquid to be filtered could flow towards the centre of the vessel, the filter bed then having an upright conical upper surface.
It wili be understood that the apparatus disclosed will operate successfully with certain 10 kinds of liquids to be filtered even though using a filter material comprised by particles of suitable identical size, but use of a ~ilter material which will classify in the manner described is, of course, preferred.
.
If desired the filter material may be washed with a portion of the supply of liquid to be filtered after passage thereof through the .
filter bed.
EF/1~92
Claims (12)
1. In a filtration apparatus having a filtration vessel which contains a bed of particulate material and whose lower portion is of diminishing cross-sectional area leading to an outlet through which particulate material may be with-drawn, means for withdrawing material from the base of the bed, means for supplying replacement particulate material to the bed in such a manner that the bed has a free inclined upper surface extending downwardly from an opening through which replacement particulate material is fed to the bed, and means for causing the liquid to be filtered to enter the bed through said free inclined upper surface for flow downwardly through the bed to a filtrate outlet formed by a screen which retains the particulate material, the improvement of;
baffle means disposed within said filtration vessel above said outlet through which material is with-drawn from the base of the bed.
baffle means disposed within said filtration vessel above said outlet through which material is with-drawn from the base of the bed.
2. Filtration apparatus according to claim 1 wherein said baffle means has an upper surface which is upwardly inclined towards its centre.
3. Filtration apparatus according to claim 2 wherein said baffle means is in the form of a right conical shell.
4. Filtration apparatus according to claim 1 wherein said particulate material comprises particles of various sizes.
Filtration apparatus according to claim 4 wherein said particulate material comprises sand.
6. Filtration apparatus according to claim 1 wherein means is provided for washing the material withdrawn from the bed and returning same to the bed to constitute the replacement particulate material.
7. Filtration apparatus according to claim 6 wherein means is provided for washing the material with liquid taken from the supply of liquid to be filtered.
8. Filtration apparatus according to claim 6 wherein means is provided for washing the material with a portion of the liquid which has been filtered.
9, Filtration apparatus according to claim 7 wherein the replacement particulate material is supplied to the bed by way of a chamber, means being provided for leading wash liquid to said chamber.
10. Filtration apparatus according to claim 8 wherein the replacement particulate material is supplied to the bed by way of a chamber, means being provided for leading wash liquid to said chamber.
11. Filtration apparatus according to claim 1 wherein the means for supplying replacement particulate material to said bed includes a baffle having an edge forming a boundary to said opening and past which the material flows, the vessel extending beneath said baffle on both sides of said edge.
12. Filtration apparatus according to claim 11 wherein said vessel is of circular cross-section, said baffle being defined by a right conical shell whose maximum diameter is less than the diameter of the vessel.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB45185/75A GB1497914A (en) | 1975-10-31 | 1975-10-31 | Filters |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1067016A true CA1067016A (en) | 1979-11-27 |
Family
ID=10436223
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA263,666A Expired CA1067016A (en) | 1975-10-31 | 1976-10-19 | Moving bed particulate filter |
Country Status (4)
| Country | Link |
|---|---|
| BE (1) | BE847833R (en) |
| CA (1) | CA1067016A (en) |
| DE (1) | DE2650051A1 (en) |
| GB (1) | GB1497914A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3308287A1 (en) * | 1983-03-09 | 1984-09-13 | Bergwerksverband Gmbh, 4300 Essen | METHOD AND DEVICE FOR FILTERING SOLID-LOADED LIQUIDS |
| DE4013080C1 (en) * | 1990-04-25 | 1991-07-04 | Albrecht 2807 Achim De Fricke | Cleaning particulate filter bed - using appts. having vertical tube with filter chamber and inlet |
-
1975
- 1975-10-31 GB GB45185/75A patent/GB1497914A/en not_active Expired
-
1976
- 1976-10-19 CA CA263,666A patent/CA1067016A/en not_active Expired
- 1976-10-29 BE BE171959A patent/BE847833R/en not_active IP Right Cessation
- 1976-10-30 DE DE19762650051 patent/DE2650051A1/en not_active Ceased
Also Published As
| Publication number | Publication date |
|---|---|
| DE2650051A1 (en) | 1977-05-12 |
| GB1497914A (en) | 1978-01-12 |
| BE847833R (en) | 1977-02-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4060484A (en) | Filters | |
| US4246102A (en) | Method for separating pollutants from liquid | |
| US5454959A (en) | Moving bed filters | |
| US4743382A (en) | Method and apparatus for separating suspended solids from liquids | |
| US4178245A (en) | Filtration method | |
| KR100404716B1 (en) | Method and apparatus for separating non-soluble particles from a liquid | |
| US4891142A (en) | Moving bed filtration apparatus and method | |
| CA2239468A1 (en) | Flotation apparatus and process | |
| US5207905A (en) | Baffle assembly for air and water backwash of a media filter | |
| US4746431A (en) | Device for the collection of water in a granular material bed filter | |
| EP0053115B1 (en) | Liquid filtering apparatus | |
| FI58442B (en) | SAETT OCH ANORDNING FOER FILTRERING AV VAETSKA | |
| US5019278A (en) | Continuous washed sand filter and washer | |
| CA1067016A (en) | Moving bed particulate filter | |
| JP3127470B2 (en) | Sand filtration equipment | |
| US3878096A (en) | Continuous filtration plant | |
| US4246118A (en) | Apparatus for separating solid and liquid | |
| WO1983000637A1 (en) | Filtering apparatus | |
| US4624782A (en) | Filtering apparatus | |
| JPS585085B2 (en) | Upflow moving bed filtration equipment | |
| EP0128234B1 (en) | Sand filtration apparatus | |
| US3305092A (en) | Pressure-fluid actuated skimmer and method | |
| JPS5920334Y2 (en) | Continuous "filtration" device | |
| AU624140B2 (en) | Continuous washed sand filter and washer | |
| JPH0717365Y2 (en) | Continuous sand filter |