RU2411074C1 - Combined static mixer-activator - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to static mixer-activator for multiphase systems and can be used to bring about mechanical effects on the structure of said systems or that of individual fluid. Proposed mixer comprises three mixers arranged successively and operating on different principles. First mixer produces kinematic effects, second mixer generates cavitation effects and third mixer separates fluid flow into in minor crossing jets. Combined, said mixers produce active mixing and structure-forming effects by disturbing initial intermolecular interaction.

EFFECT: higher homogeneity of liquid-phase system.

5 cl, 2 dwg

Description

The invention relates to static mixing devices containing several sequentially arranged mixers of a different mode of action and relates to the field of mixing liquid-phase systems, including those being a dispersion medium and a dispersed phase, as well as to the field of directional activation of the properties and recombination of these systems.

The goal is to increase the efficiency of mixing and structuring, as a result of which the molecules and molecular chains acquire such a spatial configuration that provides a more complete oxidation by oxygen.

As a rule, achieving this goal by means of one type of static mixer requires refinement of its design and technological parameters as applied to specific miscible or activated liquid-phase systems, which is often a long and laborious process.

Therefore, the consistent use of several static mixers of various designs located in one direct-flow housing allows you to get a universal static mixer-activator.

There are several common types of static mixers.

These primarily include mixers with screw elements, which are made of a flat thin plate by twisting in the left or right directions (for example: US patents No. 3286992 and No. 3443927; UK patent No. 1413825; ed. Certificate of the USSR No. 504549 and No. 804464). Screw elements may be located on the surface of a tube, shaft, or shaft (for example, US Pat. Nos. 4,049,241 and 3,797,300).

Other widespread are static mixers with intermediate chambers. Mixing in them is carried out by creating a sharp expansion and narrowing of the space inside the cylindrical body, causing a change in the flow velocity and the appearance of enhanced vortex formation associated with separation of the flow from the walls (for example: US patents No. 3404869 and No. 352391; ed. Certificate. Czechoslovakia No. 214380; Auth. Certificate of the USSR No. 103903).

Simple in design, but no less effective is a static mixer, in which the intermediate chambers are separated by disks with several through channels (US patent No. 3582048).

Static mixers are also widely used, in which elements from mutually perpendicular plates oriented along a cylindrical body and constituting a spatial lattice ensure the separation of liquids into separate jets and their movement through complex channels where they are repeatedly crushed (for example: US patent No. 3620106).

In addition to direct use, some types of mixers can be used to activate liquids and solutions. As a rule, a magnet or an electromagnet that creates a magnetic field is built into the design of such an activator mixer (for example, RF patents: No. 2085277; No. 2275956; No. 2224586; No. 2225223). There are activators with magnetic elements that simultaneously carry out magneto-mechanical processing of a single liquid medium.

In addition to these mixers, mixers with corrugated elements, tubular mixers, vortex mixers with teardrop-shaped elements, with turbulent inserts (injection and ejection) were widely used.

The rare principles of the mixers include:

- acoustic resonance (for example, USSR patent No. 909430 and No. 775514);

- a laser beam (for example, RF patent No. 173210);

- cavitation (for example, RF patent No. 2202406);

- transmission of electric current (for example, USSR patent No. 1780822, RF No. 2205681, RF No. 2094106);

- mixing using a venturi (for example, RF patent No. 2093257);

- mixing using a porous insert (for example, RF patent No. 2132724).

The desire to increase the efficiency of small-sized mixers due to the complexity of their designs led to the appearance of many varieties of mixing elements. But such a solution to this problem requires a high-precision and complex manufacturing technology of these elements and especially minimize the existing gaps. Examples are Russian patents No. 2323377, No. 2261755, No. 2080164, No. 2322521.

The technical task of the invention is to use a mechanical effect on liquid-phase systems to obtain a high degree of homogeneity when mixing a dispersion medium and a dispersed phase, and for a separately processed liquid medium, activation and recombination, leading to the breaking of intermolecular bonds due to van der Waals forces , and P-bonds.

To solve this technical problem, it is necessary to carry out a mechanical action with a high specific energy intensity and create a highly developed interfacial surface.

In the case of static mixers, a solution can be obtained by passing flows of mixed liquid-phase systems or a single liquid medium through mixers with various exposure methods that reproduce the complex movement of elementary volumes, accompanied by the distribution of colliding molecules in relative energies.

A similar approach is contained in the patent of the Russian Federation 2266776, relating to the production of waterproof explosives and adopted as a prototype.

Mixing is carried out in an apparatus with successively located mixing zones, called static, kinematic and dynamic. The latter is carried out in a rotary pulsation apparatus, which does not apply to static mixers. Accordingly, the mixer has three sections. In the first section, the flow meets a static obstacle, for example, in the form of partitions inclined at a different angle. In the second section, the rotational component of the flow is amplified by means of blades mounted on the shaft of the rotor-pulsation apparatus and supplying the mixture flow to the gap of the rotating rotor relative to the stator.

The main disadvantages of this solution are:

- the presence of an external energy source as a drive of a rotary pulsation apparatus;

- design complexity;

- increase in size in comparison with low-volume static mixers.

These disadvantages are eliminated in the proposed combined static mixer-activator.

The principles of mixing and activation, incorporated in the proposed mixer-activator, are as follows. In the first section, a complex flow movement occurs, realizing the normal, tangential, relative and Coriolis acceleration components, and at the same time, the corresponding inertia forces (kinematic zone). In the second section, vortex formation and cavitation occur. In the third section, the final crushing of the stream into mini-jets and droplets, the diameter of which is 5 microns or less, is achieved, which ensures a high degree of homogenization.

The scheme of the combined static mixer-activator is presented in figure 1.

In a cylindrical housing 1 having a stepped inner surface, sections I, II, III are located.

Section I is located at the inlet to the activator mixer. There is a mixer in it, consisting of two screw elements 2 and 3. The screw element 2 is adjacent to the cylindrical surface of the housing 1 and has a right-handed or left-handed winding. Inside the screw element 2 is a screw element 3, having respectively a left-side or right-side winding. Between the turns of the screw elements 2 and 3 there is as small a gap as possible. Inside the screw element 3 also with a small gap passes a cylindrical rod 4, made at the same time with a cylindrical insert 5 having a cone 6 from the side opposite to the rod 4.

In the cylindrical insert 5, channels 7 are made, the centers of the inlet openings of which are located in the gap between the turns of the screw elements 2 and 3. The channels 7 can be located along the axis of the housing 1 or at an angle to this axis.

The cylindrical insert 5 refers to section II, which also includes an intermediate chamber 8.

After the intermediate chamber 8, section III follows, inside which a mixing element 9 is installed, composed of intersecting gratings 10 forming a spatial channel system that separates and reconnects the streams, as a result of which the dispersion medium and the dispersed phase are effectively mixed with the multipoint mass transfer at the molecular level. An example of a crossed grid 10 is shown in scheme 2a, b. A characteristic feature of the grill 10 is the presence of teeth bent in different directions so that there are cracks between the teeth and the width of the cracks between the teeth bent to one side would be equal to the width of the teeth bent to the other side, and vice versa.

It is also essential that all the gaps between the nodes of the mixers and the housing 1 are so small that there are shifts between the molecular layers.

The mixer activator operates as follows.

The pump, which is not shown in FIG. 1, mixes the liquid-phase systems to the input of section I and then randomly distributes them to the external and internal screw elements, respectively, 2 and 3. Further movement of the liquid-phase systems distributed in this way is carried out in antiphase, which leads to multiple local quasi-shock processes leading to crushing and mixing of these systems. At the end of section I, a vortex zone is formed in front of the cylindrical insert 5, forming a pseudo-boiling layer.

Next, the mixed liquid-phase systems enter the channels 7, in which the internal pressure increases, compressing the resulting drops. When droplets enter the intermediate chamber 8 of section II, cavitation occurs due to a sharp pressure drop and crushing of large droplets into droplets of smaller diameter. Cone 6 is designed for the directional movement of the resulting flows and eliminates the stagnant zone. In section III, the droplet-containing streams are again divided into small jets, which move along the broken slit-like channels forming a spatial lattice.

As a result, conditions are created for the fragmentation of long molecular chains into shorter ones, and heavy molecular chains are divided into lighter ones. As a result, in addition to mixing, liquid-phase systems are activated, which is expressed, inter alia, in the uniform distribution of heavy and light molecular chains at the outlet of section III.

The passage of the mixed liquid-phase systems through the mixers installed in sections I and III reproduces the dynamic regime in which individual molecules or complexes of colliding molecules are transformed from the initial ith quantum state to all final f states. They can be both insignificant and significant, leading to noticeable changes in the quality of the product. It is also significant that when the flows pass through these mixers, an unstable stationary state can arise, leading to self-oscillations. The pulsating operation of the feed pumps also contributes to this.

Screw elements 2 and 3 can be made in the form of springs with left and right winding. Depending on the density and viscosity of the mixed media, it is advisable to change the winding pitch. In the considered mixer-activator, the regulation is carried out using the end cap 11 located at the inlet to the mixer-activator, which has a thread, and by means of a corresponding thread in the housing 1 can be moved in the axial direction. The second end cover 12 located at the outlet of the treated medium from the mixer-activator may be blind or also mounted on the thread. Furthermore, said lid 12 has a neutral cone-shaped recess for forming an outlet flow.

The assembly of the mixer installed in section III may be a prefabricated of the elements depicted in figa, b or executed according to known patents.

Claims (5)

1. The combined mixer-activator is a direct-flow type for polar and non-polar liquid media, which carries out a mechanical effect on the structure of these liquid media or a single medium and consists of three types of sequentially located mixers, characterized in that the first mixer is configured to perform a kinematic action, resulting in to quasi-shock, the second mixer is configured to implement cavitation, the third mixer is located with the possibility of dividing the total liquid flow into small overlapping jets and together these three kinds of mixers operate as an active function of mixing and structuring function by impairing initial intermolecular interaction due to Van der Waals forces. 2. The activator mixer according to claim 1, characterized in that the first mixer implements the kinematics and dynamics of the complex movement, creating a quasi-shock effect on the liquid medium, and consists of the first and second cylindrical spirals having a mutually opposite direction of winding, and the first spiral is in of the second spiral, a guide rod is installed inside the first spiral with a small gap, having an annular protrusion, on which the first and second spirals are supported by one end side, and the second spiral, which is external in relation the first spiral, inserted in a cylindrical housing with a small clearance possible. 3. The mixer-activator according to claim 1, characterized in that the second mixer consists of the specified guide rod and the intermediate chamber and the specified guide rod has a step-conical configuration and one step is a cylindrical guide with a diameter slightly smaller than the inner diameter of the first spiral, the second stage has a diameter slightly smaller than the inner diameter of the specified case, and the third stage has a cone shape with a base diameter smaller than the diameter of the second stage, and in the second stage Partially beyond the limits of the first step, circumferentially, which is the boundary between said first and second spirals are formed holes intended to create a pressure differential when overflow of the liquid medium from the first mixer to the intermediate chamber. 4. The activator mixer according to claim 1, characterized in that the third plate-type mixer consists of elements in the form of combs with teeth bent in opposite directions to a certain angle and assembled in such a way that together these elements form a three-dimensional lattice with a width offset teeth slots. 5. The mixer-activator according to claim 1, characterized in that the housing has hermetically sealed end caps with fittings, and the internal cavity of the housing is divided into two cylindrical sections, realizing the possibility of setting the first and third mixers with different external diameters, and has annular protrusions, serving as stops for the specified guide rod of the second mixer, and the cover on the side of the first mixer during installation has the possibility of translational movement with subsequent fixing in one of the ways.

Images