GAS/LIQUID MIXER VIA DILUTION AND DIVISION

Abstract

Device for mixing a gas into a liquid, implementing a screw structure in a pipe in which the liquid is able to circulate, and also means for injecting the gas at one or more points into the pipe, characterized in that: the first zone encountered by the liquid has a screw portion within which the shaft is a pipe pierced with orifices, the liquid to be treated passing through the space inside the pipe surrounding the shaft, while the gas is distributed inside the shaft and discharges via the orifices into the liquid; the second zone encountered by the liquid situated downstream of the first zone is constituted by a screw portion of which the shaft is devoid of orifices.

Claims

1. A device for mixing a gas into a liquid, having a screw structure in a pipe in which the liquid is able to circulate, and also an injection device for injecting the gas at one or more points into the pipe, wherein: two zones with different actions are implemented in the screw: in a first part of the screw, mixing by dilution in which the gas is progressively distributed into the liquid, followed by a second part of the screw performing mixing by division; and wherein the first zone encountered by the liquid has a screw portion within which the shaft is a pipe pierced with orifices, the liquid to be treated passing through the space inside the pipe surrounding the shaft, while the gas is distributed inside the shaft and discharges via the orifices into the liquid; wherein the second zone encountered by the liquid situated downstream of the first zone, and being in fluid communication therewith, is constituted by a screw portion of which the shaft is devoid of orifices.

2. The device according to claim 1, characterized in that the device is able to be integrated into an existing pipe of an overall installation.

3. The device according to claim 1, characterized in that the device is able to be integrated into a bypass loop of an overall installation with the aid of a pump.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0036] For a further understanding of the nature and objects for the present invention, reference should be made to the following detailed description, taken in conjunction with the accompanying drawings, in which like elements are given the same or analogous reference numbers and wherein:

[0037] FIG. 1 illustrates a partial schematic view of an example of implementation in the sequence of these two zones;

[0038] FIG. 2 illustrates a representative mixing (division) zone.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0039] The above will be explained more clearly with the aid of the appended FIG. 1, which provides a partial schematic view of an example of implementation in the sequence of these two zones (with a zoomed-in view in the right-hand part of the figure, showing the direction of advancement of the fluid in the structure): [0040] A first zone (first zone encountered by the fluid to be treated) is therefore visualized, which first zone has an Archimedes screw portion within which the shaft is a pipe pierced with orifices, the liquid to be treated passes through the space inside the pipe surrounding the shaft, while the gas passes inside the shaft and discharges via the orifices into the liquid surrounding the shaft; As will be explained below, this zone can be referred to as a dilution zone). [0041] This first zone is followed by a second zone, which zone can be referred to as a mixing zone or division zone, as constituted only by the sequence of the blades of a screw (without gas inlet). [0042] Dilution in the first zone, and reference can even be made to progressive dilution since with each revolution of the water in the Archimedes screw the water encounters an orifice through which the gas escapes; the gas is therefore not injected at a single point but at a succession of points. The distribution of the gas into the water is therefore progressive, so as to keep the gas bubbles separated. [0043] Division in the second zone: the idea is to divide the liquid/gas stream in two at each revolution; at each revolution it divides and merges so as to be divided into two again, allowing easy mixing.

[0044] In addition, consideration can be given to the example, illustrated in the appended FIG. 2, of a mixing (division) zone counting, in the example shown, 15 turns, therefore 15 division operations; a given volume of water will thus be divided 15 times.

[0045] The number of orifices and the diameter of the pipe will be chosen according to the dissolution requirement. It is obvious to a person skilled in the art of gases that the more spaced-apart holes there are and the smaller the diameter of the hole, the more formation of small bubbles there is. The size of the bubbles at creation (entry into the liquid) will be at least identical or even partially already dissolved at the exit from the tube. It is therefore necessary to take care over the production of small bubbles, and to promote a high speed, preferentially a turbulent regime, in order to obtain good, forced mixing of the gas with the liquid (speed of the gas of typically 1 to 2 m/s, preferably about 2 m/s).

[0046] The invention then relates to a device for mixing a gas into a liquid, implementing a screw structure in a pipe in which the liquid is able to circulate, and also means for injecting the gas at one or more points into the pipe, it being possible for the screw to be of any type, such as an Archimedes screw or a screw with a central shaft and blades organized on this shaft, characterized in that: [0047] two zones with different actions are implemented in the screw: in a first part, mixing by dilution in which the gas is progressively distributed into the liquid, followed by a second part performing mixing by division; [0048] the first zone encountered by the liquid has a screw portion within which the shaft is a pipe pierced with orifices, the liquid to be treated passing through the space inside the pipe surrounding the shaft, while the gas is distributed inside the shaft and discharges via the orifices into the liquid; [0049] the second zone situated downstream of the first zone and being perfectly adjacent thereto and in fluid communication therewith is constituted by a screw portion of which the shaft is devoid of orifices.

[0050] As has been said, the screw used can be of any type: [0051] Endless screws: used for transporting bulk materials, such as grains, powders, or granules. [0052] Archimedes screws: mainly used for pumping and moving liquids, such as water or viscous liquids. [0053] Metering screws: designed to precisely meter bulk materials or liquids, often used in industrial processes. [0054] Pressure screws: used to apply a controlled pressure to the transported materials in order to compact or expel them.

[0055] Reference herein to one embodiment or an embodiment means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the invention. The appearances of the phrase in one embodiment in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments necessarily mutually exclusive of other embodiments. The same applies to the term implementation.

[0056] As used in this application, the word exemplary is used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as exemplary is not necessarily to be construed as preferred or advantageous over other aspects or designs. Rather, use of the word exemplary is intended to present concepts in a concrete fashion.

[0057] Additionally, the term or is intended to mean an inclusive or rather than an exclusive or. That is, unless specified otherwise, or clear from context, X employs A or B is intended to mean any of the natural inclusive permutations. That is, if X employs A; X employs B; or X employs both A and B, then X employs A or B is satisfied under any of the foregoing instances. In addition, the articles a and an as used in this application and the appended claims should generally be construed to mean one or more unless specified otherwise or clear from context to be directed to a singular form.

[0058] The singular forms a, an and the include plural referents, unless the context clearly dictates otherwise.

[0059] About or around or approximately in the text or in a claim means +10% of the value stated.

[0060] As used herein, room temperature in the text or in a claim means from approximately 20 C. to approximately 30 C.

[0061] The term ambient temperature refers to an environment temperature approximately 20 C. to approximately 30 C.

[0062] Comprising in a claim is an open transitional term which means the subsequently identified claim elements are a nonexclusive listing i.e. anything else may be additionally included and remain within the scope of comprising. Comprising is defined herein as necessarily encompassing the more limited transitional terms consisting essentially of and consisting of; comprising may therefore be replaced by consisting essentially of or consisting of and remain within the expressly defined scope of comprising.

[0063] Ranges may be expressed herein as from about one particular value, and/or to about another particular value. When such a range is expressed, it is to be understood that another embodiment is from the one particular value and/or to the other particular value, along with all combinations within said range. Any and all ranges recited herein are inclusive of their endpoints (i.e., x=1 to 4 or x ranges from 1 to 4 includes x=1, x=4, and x=any number in between), irrespective of whether the term inclusively is used.

[0064] It will be understood that many additional changes in the details, materials, steps, and arrangement of parts, which have been herein described and illustrated in order to explain the nature of the invention, may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims. Thus, the present invention is not intended to be limited to the specific embodiments in the examples given above and/or the attached drawings.

[0065] While embodiments of this invention have been shown and described, modifications thereof may be made by one skilled in the art without departing from the spirit or teaching of this invention. The embodiments described herein are exemplary only and not limiting. Many variations and modifications of the composition and method are possible and within the scope of the invention. Accordingly, the scope of protection is not limited to the embodiments described herein, but is only limited by the claims which follow, the scope of which shall include all equivalents of the subject matter of the claims.