FILTRATION ARRANGEMENTS AND FILTRATION APPARATUS
20240299869 ยท 2024-09-12
Assignee
Inventors
Cpc classification
B01D2201/204
PERFORMING OPERATIONS; TRANSPORTING
B01D33/04
PERFORMING OPERATIONS; TRANSPORTING
B01D33/50
PERFORMING OPERATIONS; TRANSPORTING
B01D33/056
PERFORMING OPERATIONS; TRANSPORTING
International classification
Abstract
A filtration arrangement for a filtration apparatus for filtrating liquid, the filtration arrangement comprising a filtration vessel; a continuous filtering element for removing particles from liquid passing therethrough, the filtering element being arranged to move along a path into the filtration vessel and out from the filtration vessel; and two wheels sealingly engaging the filtering element on opposite sides thereof inside the filtration vessel, where each of the two wheels is rotatable relative to the filtration vessel along with movement of the filtering element. A filtration arrangement comprising a fluid ejecting device, and a filtration apparatus are also provided.
Claims
1. A filtration arrangement for a filtration apparatus for filtrating liquid, the filtration arrangement comprising: a filtration vessel; a continuous filtering element for removing particles from liquid passing therethrough, the filtering element being arranged to move along a path into the filtration vessel and out from the filtration vessel; and two wheels sealingly engaging the filtering element on opposite sides thereof inside the filtration vessel, where each of the two wheels is rotatable relative to the filtration vessel along with movement of the filtering element, wherein the filtration vessel comprises two circular portions, wherein the two wheels are forced into a respective of the circular portions with the filtering element therebetween, and wherein the filtration arrangement further comprises at least one stationary wheel sealing member arranged to seal between the filtering element and a respective of the circular portions.
2. The filtration arrangement according to claim 1, wherein the two wheels are vertically movable relative to the filtration vessel.
3. The filtration arrangement according to claim 1, wherein each wheel comprises at least one seat, and wherein the filtering element is received in the seats.
4-5. (canceled)
6. The filtration arrangement according to claim 3, wherein each stationary wheel sealing member is received in a respective of the seat.
7. The filtration arrangement according to claim 1, wherein the at least one stationary wheel sealing member is made of plastic material.
8. The filtration arrangement according to claim 1, wherein the filtration vessel comprises two cavities laterally outside the respective wheels.
9. The filtration arrangement according to claim 8, further comprising a stationary cavity sealing member in a bottom of each cavity.
10-15. (canceled)
16. A filtration apparatus for filtrating liquid, the filtration apparatus comprising a filtration arrangement according to claim 1.
17. A filtration arrangement for a filtration apparatus for filtrating liquid, the filtration arrangement comprising: a filtration vessel; a continuous filtering element for removing particles from liquid passing therethrough, the filtering element being arranged to move along a path into the filtration vessel and out from the filtration vessel; and two wheels sealingly engaging the filtering element on opposite sides thereof inside the filtration vessel, where each of the two wheels is rotatable relative to the filtration vessel along with movement of the filtering element, wherein the filtration vessel comprises two cavities laterally outside the respective wheels, and wherein the filtration arrangement further comprises a stationary cavity sealing member in a bottom of each cavity.
18. A filtration arrangement for a filtration apparatus for filtrating liquid, the filtration arrangement comprising: a filtration vessel; a continuous filtering element for removing particles from liquid passing therethrough, the filtering element being arranged to move along a path into the filtration vessel and out from the filtration vessel, and the filtering element comprising a filter cloth and a carrier supporting the filter cloth; and a fluid ejecting device configured to provide a varying stream of fluid towards the filter cloth to induce vibrations in the filter cloth.
19. The filtration arrangement according to claim 18, wherein the filtration arrangement is configured to separate the filter cloth from the carrier outside of the filtration vessel.
20. The filtration arrangement according to claim 19, wherein the fluid ejecting device is positioned between the carrier and the filter cloth.
21. The filtration arrangement according to claim 18, wherein the fluid ejecting device comprises at least one fluid ejecting tube arranged to oscillate in a lateral direction with respect to the path.
22. The filtration arrangement according to claim 18, wherein the fluid ejecting device is configured to provide a varying flow of fluid towards the filter cloth.
23. The filtration arrangement according to claim 18, wherein the fluid ejecting device comprises at least one carrier support for supporting the carrier.
24. A filtration apparatus for filtrating liquid, the filtration apparatus comprising a filtration arrangement according to claim 1.
25. A filtration apparatus for filtrating liquid, the filtration apparatus comprising a filtration arrangement according to claim 9.
26. A filtration apparatus for filtrating liquid, the filtration apparatus comprising a filtration arrangement according to claim 10.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0048] Further details, advantages and aspects of the present disclosure will become apparent from the following description taken in conjunction with the drawings, wherein:
[0049]
[0050]
[0051]
[0052]
[0053]
[0054]
[0055]
[0056]
[0057] schematically represents a partial perspective side view of the filtration arrangement;
[0058]
[0059]
DETAILED DESCRIPTION
[0060] In the following, a filtration arrangement comprising two wheels, a filtration arrangement comprising a fluid ejecting device, and a filtration apparatus comprising such filtration arrangement, will be described. The same or similar reference numerals will be used to denote the same or similar structural features.
[0061]
[0062] A filtration volume 22 is delimited by the two wheels 18a, 18b and by the filtering element 16 inside the filtration vessel 14. Water 20 to be filtrated is received in the filtration volume 22. The wheel 18b comprises a seat 24b. The wheel 18a comprises a corresponding seat 24a (
[0063] As shown in
[0064] The filtering element 16 here comprises a continuous filter cloth 28 and a continuous carrier, here exemplified as a carrier belt 30. The carrier belt 30 supports the filter cloth 28. The filter cloth 28 is arranged outside the carrier belt 30. The filter cloth 28 may for example be a Minimesh? RPD HIFLO-S sold by Haver & Boecker, such as RPD HIFLO 5 S, 10 S, 15 S, 20 S, 30 S or 40 S.
[0065] The filter cloth 28 may for example have a pore size of at least 1 ?m and/or less than 50 ?m. The filter cloth 28 may for example have a thickness of 0.20 mm to 0.25 mm. The carrier belt 30 may for example have a thickness of at least 0.20 mm and/or less than 5 mm.
[0066] The filtration arrangement 12 further comprises an electric motor 32. The motor 32 is configured drive the filtering element 16 along the path 26 and is configured to control the speed of the filtering element 16.
[0067] The filtration arrangement 12 of this example further comprises a plurality of rollers. In
[0068] The filtration apparatus 10 further comprises a fluid ejecting device 36. The fluid ejecting device 36 is configured to clean a passive part the filtering element 16, i.e. outside the filtration volume 22, here below the filtration vessel 14. The fluid ejecting device 36 is configured to force filtride or filter cake away from the filtering element 16 by pressurized air. The fluid ejecting device 36 is described in greater detail below.
[0069] The filtration apparatus 10 of this example further comprises an inlet line 38. The inlet line 38 is here exemplified as a vertical pipe for conducting water 20 to be filtrated to the filtration vessel 14.
[0070] The filtration apparatus 10 of this example further comprises an upstream filter 40. The upstream filter 40 has a substantially higher permeability than the filtering element 16 and may therefore be referred to as a coarse filter.
[0071] The filtration apparatus 10 of this example further comprises a collection arrangement 42. As shown in
[0072] The filtration apparatus 10 further comprises a control system 46. The control system 46 comprises a data processing device 48 and a memory 50 having a computer program stored thereon. The computer program comprises program code which, when executed by the data processing device 48 causes the data processing device 48 to perform, or command performance of, various steps as described herein. The control system 46 is for example in signal communication with the motor 32 to control the motor 32.
[0073] The filtration apparatus 10 of this example further comprises an inlet valve 52. The inlet valve 52 is one example of a liquid inlet device according to the present disclosure. By controlling the inlet valve 52, an inlet flow 54 through the inlet line 38 of water 20 to be filtrated can be controlled. The inlet valve 52 is in signal communication with the control system 46. The control system 46 can control an opening degree of the inlet valve 52.
[0074] The filtration apparatus 10 of this example further comprises an outlet line 56. The outlet line 56 is here exemplified as a vertical pipe. The outlet line 56 does however not necessarily need to be vertically oriented. An upstream and geodetically highest end of the outlet line 56 is open to the filtering element 16 inside the filtration vessel 14. A downstream and geodetically lowest end of the outlet line 56 is open to the collection tank 44. Besides the upstream end and the downstream end, the outlet line 56 is closed. The outlet line 56 thus conducts water 20 from the filtration vessel 14 below the filtering element 16 to the collection tank 44. Reference numeral 58 in
[0075] The outlet line 56 may have a vertical extension of one meter to ten meters. A vertical drop of water 20 below the filtering element 16 is thereby provided by the outlet line 56. For this reason, the outlet line 56 may be referred to as a drop pipe. A water drop of five meters in the outlet line 56 may correspond to a differential pressure of 500 mbar over the filtering element 16, and a water drop of eight meters in the outlet line 56 may correspond to a differential pressure of 800 mbar over the filtering element 16.
[0076] The filtration apparatus 10 of this example further comprises an outlet valve 62. The outlet valve 62 is one example of a liquid outlet device according to the present disclosure. One alternative example of a liquid outlet device according to the present disclosure is a liquid pump. By controlling the outlet valve 62, a collection volume liquid flow 64 out from the collection tank 44 through a collection outlet 66 can be controlled. The outlet valve 62 is positioned in a geodetically low region of the collection tank 44. The outlet valve 62 is in signal communication with the control system 46. The control system 46 can control an opening degree of the outlet valve 62.
[0077] The filtration apparatus 10 of this example further comprises a vacuum pump 68. The vacuum pump 68 is one example of a gas outlet device according to the present disclosure. The vacuum pump 68 is arranged in parallel with the outlet valve 62.
[0078] The vacuum pump 68 is configured to suck gases 70 out from the top of the collection tank 44 to thereby evacuate the gases 70. By controlling the vacuum pump 68, a gas flow 72 out from the collection tank 44 can be controlled. The vacuum pump 68 is positioned in, and connected to, a geodetically highest region of the collection tank 44. The vacuum pump 68 is in signal communication with the control system 46. The control system 46 can control a speed of the vacuum pump 68, for example by means of a variable frequency drive.
[0079] The collection tank 44 is positioned downstream of the outlet line 56. As shown in
[0080] The filtration apparatus 10 of this example further comprises an inlet level sensor 74. By means of the inlet level sensor 74, an inlet level of water 20 in the filtration vessel 14 can be monitored. The inlet level sensor 74 is in signal communication with the control system 46.
[0081] The filtration apparatus 10 of this example further comprises an outlet level sensor 76. By means of the outlet level sensor 76, an outlet level 78 of water 20 in the collection tank 44 can be monitored. The outlet level sensor 76 is in signal communication with the control system 46.
[0082] The filtration apparatus 10 of this example further comprises a temperature sensor 80. The temperature sensor 80 of this example is arranged in the collection tank 44. By means of the temperature sensor 80, a temperature of the water 20 in the collection tank 44 can be monitored. The temperature sensor 80 is in signal communication with the control system 46.
[0083] The filtration apparatus 10 of this example further comprises a pressure sensor 82. The pressure sensor 82 is configured to monitor an underpressure of the water 20. The pressure sensor 82 of this example is positioned in the outlet line 56. The pressure sensor 82 is in signal communication with the control system 46.
[0084] Polluted water 20 is conducted through the inlet line 38 to the filtration vessel 14. The inlet flow 54 is controlled by means of the inlet valve 52 based on signals from the inlet level sensor 74. In this way, the inlet level of water 20 in the filtration vessel 14 can be controlled, for example to a constant level. Coarse particles in the water 20 are filtered by the upstream filter 40. Finer particles are filtered by the filter cloth 28. The filtering element 16 may move continuously during filtration, but the filter speed may be controlled.
[0085] As the water 20 moves downstream in the outlet line 56, more room is made available upstream of the water 20 in the outlet line 56 below the filtering element 16. An underpressure is thereby created in the outlet line 56 below the filtering element 16. This underpressure can be measured by the pressure sensor 82. The temperature of the water 20 may for example be 20? C. In this case, the water 20 boils at an underpressure of 0.1 bar. When the underpressure is reduced (to a lower absolute pressure value), the filter flow through the filtering element 16 is increased.
[0086] The difference between the atmospheric, or substantially atmospheric, pressure upstream of the filtering element 16 and the underpressure downstream of the filtering element 16 constitutes a differential pressure over the filtering element 16. By means of the geodetic difference in height of the outlet line 56, the gravity force of the water column in the outlet line 56 pulls the water 20 through the filtering element 16 to establish a differential pressure over the filtering element 16. In this way, a liquid pump for driving the water 20 out from the collection tank 44 can be avoided and the energy efficiency of the filtration apparatus 10 can thereby be improved.
[0087] Although bacteria can survive quite rapid and high pressure increases, bacteria cannot survive rapid pressure decreases. By subjecting the water 20 to a rapid pressure decrease over the filtering element 16, any living organisms in the water 20 will be killed.
[0088] The vacuum pump 68 sucks gases 70 out from the top of the collection tank 44 and discharges the gases 70 to the atmosphere. In this way, the water level in the collection tank 44 can be held constant. The vacuum pump 68 is therefore synchronized with the underpressure in the outlet line 56.
[0089]
[0090] The wheels 18a, 18b sealingly engage the filtering element 16 inside the filtration vessel 14 on opposite sides of the filtering element 16. Since the wheels 18a, 18b are allowed to rotate and move vertically relative to the filtration vessel 14, the wheels 18a, 18b compress the filtering element 16 inside the filtration vessel 14 by gravity and rotate together with the filtering element 16. The wheels 18a, 18b and the filtering element 16 thereby provide a rotatable seal of the filtration volume 22. The wheels 18a, 18b rotate along with the movement of the filtering element 16 along the path 26 inside the filtration vessel 14. Since the tangential speed of each of the wheels 18a, 18b corresponds to the speed on the respective side of the filtering element 16, friction losses between the wheels 18a, 18b and the filtering element 16 are eliminated.
[0091] In
[0092]
[0093] The filter cloth 28 of this example is a metal wire cloth having a three-dimensional pore geometry. The wire cloth comprises warp wires and weft wires crossing each other and interwoven by a weave pattern. The warp wires are formed in at least two different configurations to define warp wires of first and second types. Pores are formed in interstices between sections of two neighboring warp wires and crossing sections of two neighboring weft wires. Due to this three-dimensional pore geometry, the filter cloth 28 has a constant permeability after a certain degree of clogging, for example when subjected to backwashing after each filtration cycle. The filter cloth 28 may for example be of the type Minimesh? RPD HIFLO-S sold by Haver & Boecker, such as RPD HIFLO 5 S, 10 S, 15 S, 20 S, 30 S or 40 S.
[0094]
[0095] In
[0096]
[0097]
[0098] The cavities 94a, 94b are arranged to collect any overspill of water 20 due to splashing. The stationary cavity sealing members 96a, 96b prevent water 20 in the cavities 94a, 94b from joining filtrated water 20 downstream of the filtering element 16. A small flow of water 20 may intentionally be directed to each cavity 94a, 94b to provide some circulation of water 20 in the cavities 94a, 94b in order to prevent water 20 from resting in the cavities 94a, 94b for long time periods.
[0099]
[0100]
[0101] During movement of the filtering element 16, the wheels 18a, 18b rotate and there is no relative movement between the wheels 18a, 18b and the filtering element 16. The filtering element 16 slides on the stationary wheel sealing members 98, 98a, 98b. The stationary wheel sealing members 98, 98a, 98b are made of plastic to further reduce friction losses.
[0102]
[0103]
[0104] The fluid ejecting device 36 is configured to provide a stream of air to the filter cloth 28. The air stream is provided substantially vertically downwards, and outwards with respect to the loop formed by the filter cloth 28. At the same time, the fluid ejecting device 36 supports the carrier belt 30.
[0105]
[0106] The fluid ejecting device 36 further comprises a tube guide 104 for each fluid ejecting tube 102. Each tube guide 104 limits movement of the associated fluid ejecting tube 102 to the lateral direction 86. The fluid ejecting tubes 102 are flexible. The air stream from the fluid ejecting tubes 102 to the filter cloth 28 blow particles out from the filter cloth 28. Besides, when air is supplied to the fluid ejecting tubes 102, the fluid ejecting tubes 102 oscillate in the lateral direction 86. This causes the air stream onto the filter cloth 28 to vary. As a consequence, vibrations are induced in the filter cloth 28. These vibrations provide an additional removal of particles from the filter cloth 28. That is, the filter cloth 28 is both subjected to an air stream to remove particles, and is shaken to remove particles.
[0107] The oscillations of the fluid ejecting tubes 102 also result in that the entire width of the filter cloth 28 will be covered by the air stream. The fluid pipe 100 may be supplied with a constant flow of air. Alternatively, the flow of air may be varied to provide a varying air stream to induce vibrations of the filter cloth 28.
[0108]
[0109] While the present disclosure has been described with reference to exemplary embodiments, it will be appreciated that the present invention is not limited to what has been described above. For example, it will be appreciated that the dimensions of the parts may be varied as needed. Accordingly, it is intended that the present invention may be limited only by the scope of the claims appended hereto.