LIQUID FILTRATION DEVICE COMPRISING AN ULTRASOUND EMISSION MODULE

Abstract

A device for filtering liquids, including a filtration module and an ultrasound emission module, where the ultrasound emission module is fixed distant from the filtration module using a fixing means, and the ultrasound emission module is equipped coaxially along its axis with a weight or is equipped perpendicular to its axis with at least one weight, the filtration module and the ultrasound module equipped with its at least one weight going into resonance via the fixing means when the ultrasound emission module emits ultrasound.

Claims

1. A liquid filtration device, comprising: a filtration module; and an ultrasound emission module; wherein the ultrasound emission module is fixed distant from the filtration module using a fixing means, and the ultrasound emission module is equipped coaxially along its axis with a weight or is equipped perpendicular to its axis with at least one weight, wherein the filtration module and the ultrasound module equipped with its at least one weight going into resonance via the fixing means when the ultrasound emission module emits ultrasound.

2. The filtration device according to claim 1, wherein the filtration module is tubular shaped along a first axis.

3. The filtration device according to claim 2, wherein the ultrasound emission module equipped coaxially along its axis with said weight extends along a second axis substantially parallel to the first axis.

4. The filtration device according to claim 2, wherein the ultrasound emission module equipped coaxially along its axis with said weight extends along a second axis, the first axis and the second axis forming an angle of 0 to 15 degrees.

5. The filtration device according to claim 2, wherein the ultrasound emission extends along a second axis, said at least one weight extends along a third axis perpendicular to said second axis, and the first axis and the third axis forming an angle of 0 to 15 degrees.

6. The filtration device according to claim 1, wherein the fixing means is a flange which surrounds the filtration module and makes it possible to fix, distant from the filtration module, the ultrasound emission module equipped with said weight or said at least one weight.

7. The filtration device according to claim 1, wherein the fixing means comprises a chemical and/or physical fixing means.

8. The filtration device according to claim 1, wherein the fixing means is fixed to the filtration module by welding.

9. The filtration device according to claim 1, wherein said ultrasound emission module is fixed to the fixing means by a stud, an anchoring pin or one or more screws.

10. The filtration device according to claim 3, wherein the fixing means forms a bridge between the filtration module and the ultrasound emission module equipped with its weight, the bridge forming an angle of between 90 and 105 degrees relative to the first axis and/or to the second axis.

11. The filtration device according to claim 5, wherein the fixing means forms a bridge between the filtration module and the ultrasound emission module equipped with its weight, the bridge forming an angle of between 90 and 105 degrees relative to the first axis and/or to the third axis.

12. The filtration device according to claim 1, wherein the ultrasound emission module is equipped perpendicular to its axis with two opposite weights arranged on either side of the axis of the ultrasound emission module.

13. The filtration device according to claim 1, wherein the filtration module comprises a filter chosen from among a ceramic filter, a hollow fiber polymeric membrane, a ceramic membrane.

14. The device according to claim 1, wherein the filtration module, the fixing means and the ultrasound emission module equipped with its weight form a single piece.

Description

BRIEF 10

[0116] FIG. 1 is a cross-sectional view of a filtration module.

[0117] FIG. 2 is a perspective view of one embodiment of a filtration device (D).

[0118] FIGS. 3A and 3B are schematic representations in perspective of one embodiment of a fixing means (MF), from two angles of view.

[0119] FIG. 4 is a perspective view of one embodiment of a filtration device (D) comprising the fixing means (MF) of FIGS. 3A and 3B.

[0120] FIG. 5 is a perspective view of another fixing means (MF) fixed to the filtration module.

[0121] FIG. 6 is a side view of a filtration device (D) of FIG. 2.

[0122] FIGS. 7A and 7B are two schematic views of a filtration module according to the invention during the implementation showing the propagation of the ultrasound along the filtration column.

[0123] FIGS. 8A and 8B are two schematic views in perspective of a section of filtration modules comprising a ceramic membrane (MC).

[0124] FIG. 9 is a diagram representing the permeation flow as a function of time, of the application or not of ultrasound and of their powers. In the diagram, the ordinate corresponds to the permeation flow in liters per hour per square meter (L.Math.h.sup.−1.Math.m.sup.−2) and the abscissa the time in minutes (min).

[0125] FIG. 10 is a diagram representing the permeation flow as a function of time, of the application or not of ultrasound and of the transmembrane pressure. In the diagram, the ordinate corresponds to the permeation flow in liters per hour per square meter (L.Math.h.sup.−1.Math.m.sup.−2) and the abscissa the time in minutes (min).

[0126] FIG. 11 is a diagram representing the permeation flow as a function of time, of the application or not of ultrasound and of the emission mode of the ultrasound: continuous (dark gray stripes) or pulsed (light gray stripe at around 130-140 min and 160-170 min). In the diagram, the ordinate corresponds to the permeation flow in liters per hour per square meter (L.Math.h.sup.−1.Math.m.sup.−2) and the abscissa the time in minutes (min).

[0127] FIG. 12 is a histogram representing the rate of retention without ultrasound (NO US), or with ultrasound (V1.0 and V2.0 are 2 versions of studied ultrasound modules).

[0128] FIG. 13 is a front view of one embodiment of a filtration device (D) comprising two weights (P1, P2) arranged along a third axis (A3) perpendicular to the second axis (A2) of the ultrasound emission module (US).

EXAMPLES

Example 1: Example of a Liquid Filtration Device (D) According to the Invention

[0129] An example of a filtration device according to the invention is shown in the appended FIG. 2. In this figure, a tubular filtration module (F) extends along a first axis (A1). A bar corresponding to a fixing means (MF) is fixed to the filtration module (F) in the middle of the length of the tubular module along axis A1.

[0130] A tubular shaped ultrasound emission module (US) is connected coaxially along its axis with a conical shaped weight (P) by a connection element (EL).

[0131] The ultrasound emission module (US), coaxially connected to the conical shaped weight (P) by a connection element (EL), extends along a second axis (A2). As shown in FIG. 2, the connection element (EL) enables the ultrasound emission module and the weight to be connected. The connection element is connected with the bar constituting the fixing means (MF) in the middle of the length, along the axis (A2), of the assembly formed by the ultrasound emission module and the weight. As shown in this figure, the fixing means (MF forms a perpendicular bridge (X) between the filtration module and ultrasound emission module coaxially connected to the weight, and the angle formed by the axes A1 and A2 here is equal to 0 degrees.

[0132] The ultrasound emission module is 35 kHz.

[0133] The filtration module is a Tami Industries monocanal module type filtration column. FIG. 1 shows a diagram of the filtration column when it rests on the ground, comprising the input (O2) and output (O1) of the liquid situated at the upper and lower ends of the filtration column.

Example 2: Example of Devices for Implementing the Invention

[0134] An example of a filtration device according to the invention is shown in the appended FIG. 4. In this figure, a tubular filtration module (F), namely a Tami Industries monocanal module, extends along a first axis A1. The filtration column comprises an input (O2) for the liquid to be filtered and an output (O1) for the filtered liquid. The fixing means (MF) here is a fixing flange that surrounds the filtration module (F) halfway along the length of the tubular module along the axis (A1). The tubular shaped ultrasound emission module (US), namely a 35 kHz emitter, is coaxially connected at its axis (A2) with a conical shaped weight (P). As shown in this figure, the weight comprises an orifice complementary of a part of the ultrasound admission module enabling the housing and direct fixing of the ultrasound emission module (US) with the weight (P). As shown in the figure, the fixing flange (MF) makes it possible to connect, in the form of a bridge, the filtration column (F) with the weight in particular. The length of the bridge formed by the flange is 5 cm. Furthermore, the bridge formed is a perpendicular bridge between the filtration module and the ultrasound emission module coaxially connected to the weight, and the angle formed by the axes (A1) and (A2) here is equal to 0 degrees.

[0135] FIG. 3A shows the surface of the flange facing the weight and comprising an orifice (Dl) into which the connecting element (EL) of the weight is screwed for the mechanical fixing thereof. FIG. 3B shows the fixing flange representing an orifice (C1) wherein, after installation, surrounds the filtration column, the diameter of the orifice C1 being identical to the diameter of the tubular filtration column (F).

[0136] FIG. 6 is a schematic representation along the axis formed by the bridge (X) of an example of filtration device comprising in the foreground the ultrasound emitter (US) connected to the weight (P), and in the background the filtration column (F).

[0137] FIG. 5 is another example of the design of the fixing means (MF) between the filtration column (F) and the ultrasound emission module and/or the weight. The fixing means (MF) here is a solid steel tube comprising a central orifice along the longitudinal axis complementary with a threaded rod enabling a mechanical fixing of the ultrasound emission module and/or the weight. The fixing means (MF) is fixed onto the column (F) by chemical fixing, i.e, by welding of the tube onto the column. The angle formed by the longitudinal axis of the fixing means and the longitudinal axis of the column is equal to 90 degrees.

Example 3: Filtration of a Liquid with an Exemplary Device According to the Invention

[0138] In this example, the filtration device (D) corresponds to the one in FIG. 2 comprising in particular a tubular filtration module F, namely a membrane module capable of filtering volumes of more than 10 liters of cellulose nanocrystal solutions and a monocanal ceramic filtration module 60 cm long. The filtration module used is shown in FIG. 8A representing in perspective a section of a filtration module comprising a ceramic membrane (MC), the ultrasound emitted and the direction of flow of the liquid to be filtered. In the present example, as shown in FIG. 8A, the direction of permeation, or direction of flow of the liquid to be filtered, is from the interior of the ceramic membrane (MC) to the exterior. In another embodiment, a filtration module may be used as shown in FIG. 8B representing in perspective a section of a filtration module comprising a ceramic membrane (MC), the ultrasound emitted and the direction of flow of the liquid to be filtered, wherein the direction of permeation or direction of flow of the liquid may be from the exterior of the ceramic membrane (MC) to the interior.

[0139] The filtration module has been placed in controlled vibration (continuous or pulsed mode) a commercial module at two frequencies 25 and 35 kHz via the coupling with the fixing means shown in FIG. 3 or shown in FIG. 5, the ultrasound emission module (US) was tubular in shape coaxially connected to the substantially conical/frustoconical shaped weight (P) as shown in FIG. 2.

[0140] The emission of the ultrasound therefore allowed the filtration module to be placed under controlled vibration as shown in FIG. 7, representing and illustrating the vibration of the filtration module under the effect of ultrasound. As shown in FIGS. 7A and B, during application of ultrasound at a frequency of 35 kHz, a vibration amplitude of 60% was obtained, advantageously enabling a 23% increase of permeation flow.

[0141] Moreover, an evaluation of the filtration and comparative tests with an exemplary device according to the invention were carried out. The devices used correspond to those mentioned above.

[0142] The filtration was carried out at a temperature of 18±2° C., the frequency of the ultrasound applied was 35 kHz, the incoming flow rate Qv was 70 liters per hour (L.Math.h.sup.−1).

[0143] The solution used for the filtration comprising a concentration of cellulose nanocrystals equal to 0.7 wt. % relative to the total weight of the solution.

[0144] The evaluation of the filtration was carried out by measuring the permeation flow. To do this, the weight of the permeate was acquired over time with a Kern PCB 2000 scale, which transmits the data to a computer via the control of an acquisition software made it possible to determine the permeation flow rate in kg/hr and then in L/hr.

[0145] Using the following equation, the permeation/permeate flow J was determined:

[00001]$J=\frac{Q_p}{S}$ [0146] J: flow of permeate (L.Math.h.sup.−1.Math.m.sup.−2) [0147] Q.sub.p: Permeate volume flow rate (L.Math.h.sup.−1) [0148] S: membrane surface area (m.sup.2)

[0149] FIG. 9 is a diagram representing the permeation flow (L.Math.h.sup.−1.Math.m.sup.−2) as a function of time as a function of the application or not of ultrasound and the applied power. The transmembrane pressure was 0.6×10.sup.5 Pa. The ultrasound powers applied were respectively 0.2, 0.3 or 0.5 W.Math.cm.sup.−2. The ultrasound, when applied, was continuous emission. As represented in this figure, during application of ultrasound, irrespective of the applied power, the permeation flow increases during application of ultrasound. The greatest increase appears for the highest power.

[0150] FIG. 10 is a diagram representing the permeation flow (L.Math.h.sup.−1.Math.m.sup.−2) as a function of time as a function of the application or not of ultrasound and the applied power. The transmembrane pressures were 0.6×10.sup.5 Pa, 0.9×10.sup.5 Pa or 1.2×10.sup.5 Pa. The ultrasound power applied was 0.5 W.Math.cm.sup.−2. The ultrasound, when applied, was continuous emission. In this figure, the stair-step curve represents the change in pressure during the experiment. The curve in bold represents the change of the permeation flow. Without ultrasound, the flow appears to stabilize around 16-17 L/h/m.sup.2 irrespective of the transmembrane pressure applied. As shown in this figure, during application of ultrasound, irrespective of the transmembrane pressure applied, the permeation flow increases during application of ultrasound. As demonstrated in this figure, the use of an exemplary device according to the invention advantageously makes it possible to increase the membrane permeation flow.

[0151] FIG. 11 is a diagram showing the permeation flow (L.Math.h.sup.−1.Math.m.sup.2) as a function of time, of the application or not of ultrasound and of the emission mode of the ultrasound: continuous (dark gray stripes) or pulsed (light gray stripe at around 130-140 min and 160-170 min). During application in pulsed mode, the ultrasound was emitted according to the following cycle: 20 seconds of ultrasound then 5 seconds off. The transmembrane pressure was 0.6×10.sup.5 Pa. The ultrasound power applied was 0.5 W.Math.cm.sup.−2. The curve represents the change of the permeation flow. As represented in this figure, during application of ultrasound, irrespective of the mode, the permeation flow increases during application of ultrasound.

[0152] Furthermore, a study of the possible effect of the ultrasound on the membrane was carried out in order to determine if the application of ultrasound was likely to alter the properties of the membranes. Two exemplary devices according to the invention were tested, differing by the fixing means MF, either a flange that surrounds the filtration module at the middle of the length of the tubular module along the axis A1 (FIG. 4) or the fixing means MF fixed on the column by chemical fixing, namely by welding of the tube onto the column (FIG. 5). Thus, the determination of the retention rate of cellulose nanocrystals present in the solution according to the following formula:

[00002]$\mathrm{TR}=\left(1-\frac{C_{\mathrm{per}}}{C_{\mathrm{alim}}}\right)*100$

where C.sub.per corresponds to the concentration of cellulose nanocrystals at the output of the filtration module and C.sub.alim to the initial concentration cellulose nanocrystals.

[0153] FIG. 12 is a histogram representing the retention rate obtained by exemplary devices according to the invention without the emission of ultrasound (NO US), or with emission of ultrasound with exemplary devices according to the invention comprising the fixing means MF, namely a flange shown in FIG. 3 (V1.0) or the fixing means MF shown in FIG. 5 (V2.0).

[0154] As shown in the figure, the application of ultrasound has no significant effect on the retention rate of the membrane, confirming that its selective structure or layer is not altered and/or modified by the ultrasound.

[0155] This example therefore clearly shows that the device advantageously makes it possible to significantly increase the filtration module filtration efficiency, for example of cellulose nanocrystals, and advantageously without modifying the structure thereof.

[0156] Furthermore, this example demonstrates that the device has improved filtration properties and capacities relative to known devices, advantageously makes it possible to be able to reduce the surface area of filter membranes and/or the number thereof, for example by at least 25%, while preserving the same filtration efficacy and/or an identical efficiency and/or efficacy and/or stable and homogeneous filtration efficiency over time.

Example 4: Another Example of a Liquid Filtration Device (D) According to the Invention

[0157] Another exemplary design of a filtration device (D) according to the invention is shown in FIG. 13.

[0158] In this figure, a tubular filtration module (F) extends along a first axis (A1). The filtration module (F) here is a 7-membrane Kleansep (registered trademark) commercial module (Novasep, length 1178 mm, diameter 80). The filtration column comprises an input (O2) for the liquid to be filtered and an output (O1) for the filtered liquid. A bar corresponding to a fixing means (MF) is fixed to the filtration module in the middle of the length of the tubular module along axis A1. The ultrasound emission module (US) is connected, perpendicular to its axis (A2), with two opposite frustoconical weights (P1) and (P2) by a connection element (EL) which here is generally in the shape of a cross or a star with four branches distributed 90 degrees of angle apart. Each of the two weights (P1, P2) has a diameter of 13 cm and a height of 12.5 cm. The weight of each of the weights is 3 kg. The weights (P1) and (P2) are extended and are aligned along a third axis (A3).

[0159] As shown in FIG. 13, the connection element (EL) makes it possible to connect the ultrasound emission module (US), the set of two weights (P1 and P2) and the fixing means (MF).

[0160] The connection element (EL) is connected with the corresponding bar to the fixing means (MF).

[0161] Along the second axis (A2), the ultrasound emission module (US) and the fixing means (MF) are arranged axially on either side of the connection element (EL) and the two opposite weights (P1 and P2).

[0162] The weights (P1) and (P2) aligned along the third axis (A3) are arranged axially opposite on either side of the second axis (A2).

[0163] As shown in this figure, the fixing means (MF) forms a bridge between the filtration module (F) and the weights, and the angle formed by the axes (A1) and (A3) here is equal to 0 degrees.

[0164] The fixing means (MF) is fixed onto the filtration module by welding of the fixing means (MF) to the surface of the filtration module (F).

[0165] By way of nonlimiting example, the “cross shaped” connection element is for example produced from a single piece by machining or smelting and it comprises two perpendicular bores allowing the mounting and fixing, for one extending along the axis (A2), of the ultrasound emission module (US) and of the fixing means (MF), and for the other extending along the axis (A3) of two weights (P1 and P2).

[0166] The ultrasound emission module is 20 kHz with a maximum power of 1500 W.

[0167] The filtration module is the 7-membrane Kleansep (registered trademark) commercial module (Novasep, length 1178 mm, 80 mm diameter), comprising micro and ultrafiltration membranes BX, diameter 25 mm.

LISTS OF REFERENCES

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