RU2372974C1 - Cavitation membrane apparatus - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to separate industrial, agricultural and household suspensions and can be used in various industrial branches. Proposed apparatus comprises carcass with semi-permeable membrane, purifying element fitted inside aforesaid carcass to reciprocate therein. Carcass consists of confuser and two diffusers mounted successively. Last diffuser represents ceramal semi-permeable membrane inclined to previous diffuser at smaller angle. Purifying element arranged at carcass diffuser section represents a number of successive cone-like or dome-like cavitation exciters that increase along flow direction and interconnected vi a springs fastened on push rod arranged to move axially driven by screw gear. Larger base of aforesaid cavitation exciter is directed towards membrane apparatus outlet.

EFFECT: higher efficiency.

2 cl, 5 dwg

Description

The invention relates to the field of separation of suspensions of industrial, agricultural and domestic purposes and can be used in various industries.

Known filter membrane elements in which the decrease in concentration polarization is carried out using a cylindrical sleeve with pockets and cleaning movable inserts [and.with. 1431795, B01D 13/00], a turbulent insert in the form of a chain or a ribbon of flexible elements pivotally attached at one end to a porous frame [a.s. 1502042, B01D 13/00], interconnected by jumpers of bushings having a wing-shaped profile in longitudinal section [a.s. 1505563, В01D 13/00], rotary bushings with blades [a.s. 1367995, В01D 13/00], screw channels of the turbulator [a.s. 521902, B01D 13/00 and A.S. 1430054, B01D 13/00], flat elements in the form of plates with holes [a.s. 152041, B01D 13/00], a cleaning element made in the form of two longitudinal halves of a hyperboloid [as 1465069, B01D 13/00], two hollow rods installed with the possibility of reciprocating motion [a.s. 528011, B01D 13/00].

A disadvantage of the known filter membrane elements is an increase in the concentration polarization level both over time and along their length, which leads to unstable operation and, accordingly, low productivity.

Known membrane apparatus [and.with. 1775145 USSR, MKP B01D 63/16 / Membrane apparatus / N.S. Orlov, A.Sh. Shayakhmetov, A.G. Borodkin, Moscow Institute of Chemical Technology D.I. Mendeleev, publ. November 15, 1992], comprising a housing with a bundle of hollow fibers fixed in two tube sheets, covers with inlet and outlet fittings for solutions, and an ultrasound transducer made in the form of a plate having the shape of a tube sheet and located perpendicular to the channels of the hollow fibers.

A disadvantage of the known membrane apparatus is the limited coverage, because ultrasonic vibrations are quenched at the entrance to the channels of the hollow fibers, which does not provide a uniform decrease in the concentration polarization level along their length, which leads to unstable operation and, accordingly, low productivity of the apparatus.

The closest in technical essence and the achieved effect is a reversible membrane mechanism [Patent 2142330 (Russian Federation), MKI B01D 63/00, 63/16 Reversible membrane apparatus / S.T. Antipov, S.V. Shakhov, Yu.A. Zavyalov , A.N. Ryazanov, A.V. Koltakov, publ. in BI, 1999, No. 34], containing a tubular porous frame with a semipermeable membrane laid on its inner surface on a substrate, and inside the frame there is a cleaning element mounted with the possibility of reciprocating movement and made of elastic material, the end parts of which repeat the configuration of the inner the surface of the fittings, while the middle part of the cleaning element has a recess, the end surface of which is made in the form of a truncated cone, and in longitudinal section s an appearance mirroring boom, wherein the ends on a frame mounted conical spout connected to valves and interconnected pipe.

A drawback of the reverse membrane mechanism is the low force acting on the near-membrane highly concentrated product layer, as well as the insufficient degree of flow turbulization with an increase in the concentration of solids in the solution and an increase in its viscosity, which leads to a decrease in the efficiency of liquid separation, as well as the inability to use the membrane mechanism for emulsification processes, dispersion and homogenization.

An object of the invention is to increase the efficiency of liquid separation by increasing the force acting on the near-membrane highly concentrated product layer, the degree of turbulization of the flow with increasing concentration of solids in the solution and increasing its viscosity, as well as expanding the scope.

The technical task of the invention is achieved by the fact that in a cavitation membrane apparatus containing a frame with a semi-permeable membrane, the cleaning element mounted inside the frame with the possibility of reciprocating movement, new is that the frame is made in the form of consecutive confuser and two diffusers, the latter the diffuser is made in the form of a ceramic-metal semipermeable membrane and has a smaller angle of inclination relative to the previous one, and the cleaning element is located d in the diffuser part of the frame, is a series of successively arranged cavitators or dome-shaped cavitators, increasing in the direction of flow and interconnected by springs, mounted on a rod made with axial movement by means of a helical gear, with the larger base of the cavitators directed towards the exit membrane apparatus, and the diameters of the cavitators are determined from the ratio

,

,

where d _i is the diameter of the i-th cavitator, mm;

L _i - the distance between adjacent cavitators, mm, L _i = L _{i + 1} = ... = L;

α is the angle of the diffuser, deg.

The technical result consists in increasing the efficiency of liquid separation by increasing the force acting on the near-membrane highly concentrated product layer, the degree of turbulization of the flow with increasing concentration of solids in the solution and increasing its viscosity, as well as expanding the scope.

Figure 1 shows a cross section of a cavitation membrane apparatus; figure 2 is a three-dimensional model of a cavitation membrane apparatus; figure 3 is a design diagram for determining the diameter of the cavitator; figure 4 is a design diagram for determining the i-th number of diameters of cavitators, figure 5 is a diagram of the operation of the apparatus.

The cavitation membrane apparatus (FIGS. 1-2) contains a frame 1 made in the form of sequentially placed confuser 2 and two diffusers 3 and 4, the last diffuser made in the form of a ceramic-metal semipermeable membrane and has a smaller angle of inclination relative to the previous one. Inside the frame 1, in its diffuser part, there is a cleaning element 5 made with the possibility of reciprocating movement, which is a series of successively arranged cavitators 6 conical or dome-shaped, increasing with increasing diameter of the diffuser 4 and interconnected by springs 7, fixed on the rod 8, made with the possibility of axial movement by means of a helical gear 9, and the larger base of the cavitators 6 is directed towards the exit from the membranes th unit, wherein the base of the first predetermined diameter cavitator downstream motion of the feed solution. And the diameter of the second cavitator is determined based on the design scheme (figure 3) as follows.

We assume that AC = L.

Express AC from triangle ABC

,

,

from here

Express sun from triangle ABC

The cavitator diameter is determined by the formula

D = d + 2 · BC,

then, substituting the expression for BC taking into account the expression for AB, we obtain

Transforming the last expression, we get

The diameters of all other cavitators (figure 4) are determined from the ratio

,

,

where d _i is the diameter of the i-th cavitator, mm;

L _i - the distance between adjacent cavitators, mm, L _i = L _{i + 1} = ... = L;

α is the angle of the diffuser, deg.

The number of cavitators 6 depends on the physicochemical properties of the initial solutions.

The fastening of the cleaning element 5 on the rod 8 with the ability to move in one direction or another is caused by the need to adjust the operating mode of the device depending on the initial properties of the product (mainly on its structural and rheological characteristics) in the initial period. And the stiffness of the springs 7 provides the necessary distances between the cavitators 6, depending on the liquid pressure and the viscosity properties of the product, varying along the length of the membrane.

A pipe 10 with a flange 11 serves to supply the initial solution, and a pipe 12 with a flange 13 is used to withdraw the concentrate.

The proposed cavitation membrane apparatus operates as follows.

Before starting the operation of the cavitation membrane apparatus using the axial movement of the rod 8, the position of the cleaning element 5 in the form of a block of cavitators 6 is established depending on the initial properties of the product.

The initial solution intended for processing, through the pipe 10 is fed into the cavitation membrane apparatus under operating pressure (for example, 5-10 MPa) and enters the confuser 2, in which its speed increases, and then enters two consecutive diffusers 3 and 4, in which smoothing of pulsating pressures is provided and conditions are created for a smoother flow and flow around cavitators 6. As the solution flows around each cavitator 6, the boundary layer is turbulized I near the surface of the ceramic-metal semipermeable membrane and its breakdown in the middle of the flow with the occurrence of cavitation in the shared solution (Fig. 5) by the formation and collapse of bubbles, providing additional pulsed effects on the membrane layer of the product and contributing to a decrease in the concentration polarization level.

In addition, the bubbles, exerting a force effect due to the energy of their collapse on the high molecular weight particles of the product that have settled and adhered to the membrane surface, as well as particles located at the inlet and inside the capillary, tear them off the surface, after which the particles are carried away with the flow of the separated liquid.

Moreover, with a change in the viscosity of the product, a change in the flow rate and, accordingly, the distance between the cavitators 6, which is automatically controlled by the stiffness of the springs 7 connecting them.

As the solution moves in the apparatus, it separates, part of which passes through the membrane and is discharged out in the form of a filtrate. The output of the concentrate is carried out through the pipe 12.

The proposed cavitation membrane apparatus allows:

- increase the efficiency of liquid separation;

- increase the force acting on the near-membrane highly concentrated product layer;

- increase the degree of turbulization of the stream with an increase in the concentration of solids in the solution and an increase in its viscosity;

- expand the range of use of the apparatus with the aim of its use for the processes of emulsification, dispersion and homogenization.

Claims (2)

1. Cavitation membrane apparatus containing a frame with a semipermeable membrane, a cleaning element mounted inside the frame with the possibility of reciprocating motion, characterized in that the frame is made in the form of consecutive confuser and two diffusers, and the last diffuser is made in the form of a ceramic-metal semipermeable membrane and has a smaller angle of inclination relative to the previous one, and the cleaning element located in the diffuser part of the frame is a row The sequence located cavitators conical or dome-shaped, increasing in the direction of flow and joined together by springs mounted on the rod, adapted to move axially through the helical gear, wherein the larger base cavitators directed towards the outlet of the membrane device. 2. The apparatus according to claim 1, characterized in that the diameters of the cavitators are determined from the ratio

,
where d _i is the diameter of the i-th cavitator, mm;
L _i - the distance between adjacent cavitators, mm, L _i = L _{i + 1} = ... = L;
α is the angle of the diffuser, deg.

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