WO2016092579A1

WO2016092579A1 - Method and device for the homogeneous and delimited mixing of fluids

Info

Publication number: WO2016092579A1
Application number: PCT/IT2015/000299
Authority: WO
Inventors: Vito Lavanga; Stefano FARNE'
Original assignee: Vito Lavanga
Priority date: 2014-12-09
Filing date: 2015-12-09
Publication date: 2016-06-16

Abstract

Device and Method for the homogeneous and delimited mixing of fluids, both liquid and gaseous, forming part of a fluid mass in motion or in state of rest. The method comprises: • taking part of the material from said fluid mass; • making a vigorous mixing of the fluid material taken; • reinserting the fluid mixed material into said fluid mass; The device (A, B) comprises: •. a first manifold (1, 10), closed at both ends, on which a first plurality of holes (la, 10a) is made, aligned along a generatrix of said first manifold (1,10); •. a second manifold (2, 20), closed at both ends, on which it is made a second plurality of holes (2a, 20a) aligned along a generatrix of said second manifold (2, 20); • · a pipe (3, 3a) that connects said first manifold (1, 10) with said second manifold ( 2, 20); • · pumping means (4), inserted in said pipe (3, 3a), which cause a movement of a fluid contained in said pipe (3, 3a) by said first manifold (1, 10) towards said second manifold (2, 20);

Description

METHOD AND DEVICE FOR THE HOMOGENEOUS AND DELIMITED MIXING OF FLUIDS

DESCRIPTION

This invention refers to a method and to a device for the implementation 5 of said method, for the homogeneous and delimited mixing of fluids, both liquid and gaseous, forming part of a fluid mass in motion or in state of rest, and to a device for the implementation of said method.

It is strongly felt the need to have systems to mix liquid and/or gaseous phases, in various industrial processes, particularly functional to obtain and/or

10 accelerate the production processes or services such as, but not limited to, fermentation, chemical reactions, homogenization and maintenance in suspension. Existing technologies employ various principles of technical physics and chemistry, using articulated installation structures, by resorting to mechanical actions, generally by propellers or blades, in which they are

15 generated vortical motions that, by setting in motion the fluid mass and in interaction the different components, generate the mixing and the suitable homogenization to allow the biological and/or chemical expected processes, but frustrate much of the action imparted by the pushing mechanism with an evident dissipation of the used energy. The devices currently available remedy

20 to this problem by means of complex geometries of "break-vortexes" and/or distributing the motion mechanism in different points of the fluid mass, increasing the plant costs. In other processes, it is necessary to isolate the mixing space in specific volumes, reducing to a minimum the dispersion in neighbouring zones. Also in this case the problem is solved by the use of

25 complicated and expensive systems to stem harmful effects, as vortical and stationary motions. These problems pervade many sectors such as the municipal wastewater treatment plants, the plants for the anaerobic digestion or the microalgae crops. A combination that is not obtainable with the devices currently available is the mixing and simultaneous thrust of a fluid mass with a

30 homogeneous movement and according to a specific plane. This invention constitutes an innovation with respect to the current state of the art, allowing to overcome these problems in a simple and economical way.

In summary, in the current state it is not possible to mix a delimited part of a fluid mass, without disturbing the surrounding fluid mass.

The object of this invention is to propose a method and a device for the implementation of said method, respectively conform to claims 1 and 4, for the homogeneous and delimited mixing of fluids, both liquid and gaseous.

The method is characterized by:

• taking part of the material from said fluid mass;

• making a vigorous mixing of the fluid material taken;

• reinserting the fluid mixed material into said fluid mass;

said taking and reinsertion causing a flow (D,D1) in said fluid mass.

The device is characterized in that it comprises:

• a first manifold, closed at both ends, on which a first plurality of holes is made, aligned along a generatrix of said first manifold;

• a second manifold, closed at both ends, on which it is made a second plurality of holes aligned along a generatrix of said second manifold;

• a pipe that connects said first manifold with said second manifold;

• pumping means, inserted in said pipe, which cause a movement of a fluid contained in said pipe by said first manifold towards said second manifold;

said first and second manifold being inserted in said fluid mass from which said fluid material is taken and reinserted creating a flow (D,D1) in said fluid mass, said stream (D, D1) being contiguous to said device (A, B).

Other characteristics, such as for example the relative positioning of said first perforated manifold dedicated to the taking and of said second perforated manifold dedicated to the inlet, will be the subject of the dependent claims.

The use of a device according to the invention allows, for example:

• to support the delimited mixing level to hydrolytic portion in the anaerobic digestion;

• to support a gentle excitation to avoid sedimentation phenomena (e.g. microalgae); • in wastewater conditioners where it is necessary to set in motion a delimited zone and to leave stationary the others.

The invention will now be described for illustrative and not limitative purposes, according to a preferred embodiment and with reference to the accompanying drawings, wherein:

- Figure 1 shows a possible embodiment of the device according to the invention;

- Figure 2 shows a variant of the device according to the invention.

With reference to figure 1, with (A) it is indicated a device according to the invention. Said device (A) includes:

• a first manifold (1), preferably tubular, closed at both ends, on which it is made a first plurality of holes (1a) aligned along a generatrix of said first manifold (1);

• a second manifold (2), preferably tubular, closed at both ends, on which it is made a second plurality of holes (2a) aligned along a generatrix of said second manifold (2);

• a pipe (3) which connects the bottom of said first manifold (1) with the upper part of said second manifold (2);

• pumping means (4), inserted in said pipe (3), which cause a movement in the direction indicated by the arrow (F) of a fluid contained in said pipe (3).

When the device (A), according to the invention is submerged in a fluid, liquid or gaseous, said pumping means (4) create a pressure drop inside said first manifold (1) and an overpressure inside said second manifold (2). The consequence is that the fluid, in which the device (A) is submerged, enters the first manifold (1) through the holes (1a), flows through the pipe (3) and exits from the second manifold (2) through the holes (2a).

Positioning said first (1) and second (2) manifold so that said first plurality of holes (1a) is faced to said second plurality of holes (2a), it is obtained a flow indicated by the arrows (D), that comes out from said second manifold (2) and enters said first manifold (1). In practice, it is obtained a kind of fluid thin layer that exits from the second manifold (2) and enters the first manifold (1). By appropriately sizing the passage sections, i.e. the number and the diameter of the holes (1a) and (2a), and the flow rate of the pumping device (4), it is obtained a laminar motion, that does not substantially change the state of motion or the state of rest of the external fluid.

However the motion of said thin layer is such as to cause the suction of other material which then enters the first manifold (1) and undergoes a vigorous mixing, due to the passage through the manifolds (1) and (2), the pipe (3) and the pumping device (4). To increase the effectiveness of the mixing, the passage sections can be dimensioned in such a way as to cause accelerations and slowing down of the flow; furthermore the ducts may be internally corrugated to increase the internal turbulence and, therefore, the effectiveness of the mixing.

In practice, it is obtained the effect of mixing vigorously the fluid thus perturbing in a minimum extent the movement or the state of rest of the fluid itself, by performing the following steps:

• to take a flow of fluid material, using means fitted to carry out said taking without causing disturbances into the fluid which change in a substantial way the movement or the state of rest;

· to make a vigorous mixing of the taken flow;

• to reinsert the mixed material into the fluid material, using means fitted to carry out said reintroduction without causing disturbances in the fluid which change in a substantial way the movement or the state of rest.

This feature makes the device (A) according to the invention, suitable to be inserted into a flow of fluid material that is undergoing a reaction (chemical, biological or other) along a given path. The reaction is favoured by an effective mixing of the fluid materials which constitute the fluid and the device (A), according to the invention is suitable to carry out said vigorously mixing, without substantially changing the comprehensive motion of said fluid. Using multiple devices (A) according to the invention and positioning them in sequence along the flow, it is obtained the effect to get an efficient mixing, and therefore a more rapid completion of the reactions in act, without that the flow of fluid materials is changed in a substantial way, as instead it occurs with the devices of the prior art which carry out the mixing without delimiting the fluid on which they act.

The same device (A) according to the invention is suitable to homogenize locally portions of a fluid mass, without significantly disturb the remaining mass, said mixing occurring on a substantially immobile fluid.

In fig. 2 it is shown a version (B) of the device according to the invention, in which the position of the collectors is reversed, in such a way that the generatrices along which the holes are aligned (10a), on the first manifold (10), and (20a), on the second manifold (20) are opposite to each other. In this case the device (B) according to this version, achieves the effect of causing a homogeneous flow (D1) in the fluid in which it is inserted. Said flow develops in a plane defined by the axis of said manifolds (10, 20) and is oriented according to the direction from the first manifold (10) to the second manifold (20). In the case in which the device (B) is inserted in a pre-existing flow, the flow (D1) is added to said pre-existing flow, whereby there is obtained the effect to increase or reduce the speed of said flow, depending on the mutual orientation of said flows.

The fluid to be mixed enters into the holes (10a) of a first manifold (10), flows along a pipe (3a), the pumping device (4) and is reintroduced into the fluid mass through the outlet holes (20a) of a second manifold (20).

In practice, if the fluid mass is stationary, the device (B) sets it in motion, while if the fluid mass is in motion, the flow (D) is algebraically added to the existing motion of the fluid itself.

In both devices (A) and (B), the described configuration of the connection between the first manifold (1 , 10) and the second manifold (2, 20) through said pipes (3, 3a) is such as to achieve a condition of reverse return, resulting in the uniform distribution of loads and therefore, uniform advancement of the flow (D,

D1).

Both the device (A) that the device (B) can be inserted in the fluid by arranging the manifolds (1 , 2, 10, 20) in horizontal or in vertical or in oblique position, above and below the reaction space, helping to counteract the effects of sedimentation or to accentuate specific processes.

According to a preferred embodiment, not shown, the two branches of the circuit, that is the branch in pressure drop, comprising said first manifold (1 , 10), and the one under pressure, comprising said second manifold (2, 20) may be conveniently used to change the planes of progression of the fluids. This can be simply obtained by suitably positioning the two manifolds (1 , 10) and (2, 20) in such a way that the outgoing flow from the second manifold (2, 20) is not complanate with the flow entering the first manifold (1 , 10). In practice the axis of said first and second manifold (10, 20) are not in the same plane.

According to another embodiment, not shown, said first and second manifold have a curved shape like an open ring.

The invention has been described for illustrative and not limitative purposes, according to some preferred embodiments. The person skilled in the art could be able to find several other embodiments, all falling within the scope of protection of the enclosed claims.

Claims

1. method for the homogeneous and delimited mixing of fluids, both liquid and gaseous, forming part of a fluid mass in motion or in state of rest, characterized by:

· taking part of the material from said fluid mass;

• making a vigorous mixing of the fluid material taken;

• reinserting the fluid mixed material into said fluid mass;

said taking and reinsertion causing a flow (D,D1) in said fluid mass.

2. Method for the homogeneous and delimited mixing of fluids, according to claim 1 , characterized in that said material is taken and reinserted into said fluid mass, using means fitted to carry out said taking and reinsertion without causing disturbances which adversely affect in a substantial way the preexisting movement or state of rest of said fluid mass, said flow (D) being laminar and being directed from said taking means towards said reinsertion means.

3. Method for the homogeneous and delimited mixing of fluids, according to claim 1 , characterized in that said material is taken and reinserted into said fluid mass, using taking and reinsertion means arranged in such a way to cause a flow (D1) which disturbs the state of motion or the state of rest of said fluid mass, algebraically adding to said movement or state of rest of said fluid mass.

4. Device (A, B), for the homogeneous and delimited mixing of fluids, both liquid and gaseous, forming part of a fluid mass in motion or in state of rest, characterized in that it comprises:

• a first manifold (1 , 10), closed at both ends, on which a first plurality of holes (1a, 10a) is made, aligned along a generatrix of said first manifold

(1a, 10a);

• a second manifold (2, 20), closed at both ends, on which it is made a second plurality of holes (2a, 20a) aligned along a generatrix of said second manifold (2, 20);

· a pipe (3, 3a) that connects said first manifold (1 , 10) with said second manifold (2, 20); • pumping means (4), inserted in said pipe (3, 3a), which cause a movement of a fluid contained in said pipe (3, 3a) by said first manifold towards said second manifold (2, 20);

said first (1 , 10) and second (2, 20) manifold being inserted in said fluid mass from which said fluid material is taken and reinserted creating a flow (D,D1) in said fluid mass, said stream (D, D1) being contiguous to said device (A, B).

5. Device (A), for the homogeneous and delimited mixing of fluids, according to claim 4, characterized in that said first manifold (1) and said second manifold (2) are positioned in such a way that said first plurality of holes (1a) is facing said second plurality of holes (2a), so as to obtain a flow, indicated by the arrows (D), that comes out from said second manifold (2) and enters said first manifold (1), obtaining a kind of fluid thin layer that exits from the second manifold (2) and enters the first manifold (1).

6. Device (B), for the homogeneous and delimited mixing of fluids, according to claim 4, characterized in that said first manifold (10) and said second manifold

(2) are positioned in such a way that the generatrices, along which are aligned the holes (10a), on the first manifold (10), and (20a), on the second manifold (20) are opposite to each other in such a way as to cause a homogeneous flow (D1) in the fluid in which it is inserted, said flow developing in a plane defined by the axes of said manifolds (10, 20) and being oriented according to the direction from the first manifold (10) to the second manifold (20).

7. Device (B), for the homogeneous and delimited mixing of fluids, according to claim 4, characterized in that the axis of said first manifold (10) and said second manifold (20) are not in the same plane in such a way that the outgoing flow from the second manifold (20) is not complanate with the flow entering the first manifold (10).

8. Device (A, B), for the homogeneous and delimited mixing of fluids, according to at least one of the claims from 4 to 7, characterized in that said first manifold (1 , 10) and said second manifold (2, 20) are connected between them by said pipe (3, 3a) in such a way as to get a condition of reverse return, in such a way to get the uniform distribution of loads and, therefore, the uniform advancing of the flow (D, D1).

9. Device (A, B), for the homogeneous and delimited mixing of fluids, according to at least one of the claims from 4 to 8, characterized in that said ducts (3, 3a) are internally corrugated to increase the internal turbulence and, therefore, the effectiveness of the mixing.

10. Device (A, B), for the homogeneous and delimited mixing of fluids, according to at least one of claims from 4 to 9, characterized in that said first and second manifold have a curved shape like an open ring.