DE19823839A1 - Fine gas bubbles released into water through rotating ceramic, plastic or metal - Google Patents

Abstract

Water treatment basin mixes and disperses two or more phases, especially by the introduction of gas into liquids and suspensions. The assembly has a body (1, 1a, 1b) incorporating a mass of pores into which a first gas phase is introduced and distributed. The pored body (1, 1a, 1b) is rotated essentially about a vertical axis, allowing the first phase to emerge from the pores as tiny bubbles. The first phase is finely distributed within the second esp. liquid phase. The rotating body (1, 1a, 1b) is a porous ceramic, porous metal or plastic body.

Description

The invention relates to a method and an apparatus for Mixing and dispersing at least two phases, in particular for gassing liquids or suspensions, e.g. B. Sewage sludge.

DE 42 18 027 A1 describes a device for mixing and Dispersing a liquid and gaseous phase known the one hyperboloidal agitator attached to a shaft has body. The shaft can be designed as a hollow shaft be, by means of which on the hyperboloid surface tissue is sucked into the liquid phase. - The known device does not produce a particularly homogeneous one Entry of air into the liquid phase. In the case of use When a fabric is formed, the air escapes where the pressure is the lowest, d. H. near the wave. In the the gas bubbles introduced are then relative large. Even when introducing the air below the hyperbolide area and a distribution using the hyperboloid stirrer Shear ribs are seen particularly at high volume flows no satisfactory homogeneous gas dispersion in the liquid phase reached.

DE 40 18 780 C2 describes a device for production known from emulsion paints. This device is suitable but not for the introduction of gas into a liquid or a suspension.

DE 35 16 133 C2 is a hollow stirrer for gassing one Liquid reveals the gas according to the jet suction principle  automatically sucked in and distributed in the liquid. The be Known hollow stirrer only works from a certain speed. It is not suitable for gassing suspensions, especially of sewage sludge. Again, there is no sufficient ho mogeneous dispersion of the gaseous phase in the liquid phase se reached.

From the brochure "Suprafilt" of the Gesellschaft für Umwelttech nik mbH, 74676 Bietigheim, are stationary longitudinal plate fans ter and fumigation cylinder known, which at the bottom of a Clarification basins are filed or fastened. To achieve ei A homogeneous dispersion is a multitude of such membranes plate diffuser required. Their maintenance is complex and difficult.

The object of the present invention is to overcome the disadvantages of Eliminate prior art. In particular, a ver drive, which is a homogeneous mixture and Allows dispersion of at least two phases. Furthermore should a device can be provided with which simple and an inexpensive way of mixing and dispersion at least two phases is possible.

This object is solved by the features of claims 1 and 11. Appropriate configurations result from the features of claims 2 to 10 and 12 to 25. To achieve the object, a method for mixing and dispersing at least two phases, in particular for gassing liquids or suspensions, is provided, wherein

• a) a first phase is fed into a porous body and therein is distributed  
• b) the porous body in a second phase about an axis ro is so that
• c) the first phase emerges radially from the porous body and is finely distributed in the second phase.

This enables a homogeneous mixture and dispersion of the in the second phase.

The axis is preferably a substantially vertical one Axis. This enables an even entry of the first Phase into the second phase.

The first phase can be a gas or a first Act liquid. The second phase is advantageous a gas, a second liquid, an emulsion or suspensions sion. This can be, for example, waste water act suspensions resulting from cleaning.

According to a design feature, the porous body can and another phase are fed, with the wide re phase can be the second phase or a third phase. The first and the further phase can advantageously in Pores are mixed. The aforementioned design Features are especially for performing chemical reaks interesting, where a fast and as high as possible mogeneous mixture of two phases and their entry in one of the both or another phase is required.

The second phase is expediently circulated. Thereby is a further homogenization of the mixture or dispersi on causes.

The porous body can be cylindrical or frustoconical a peripheral surface and an upper and lower base  be formed, the peripheral surface with such Circumferential speed is rotating that out of the pores body emerging first phase in the form of fine droplets or Gas bubbles is dispersed in the second phase. The first Phase expediently occurs evenly over the entire Circumferential surface. The peripheral speed is before preferably 4 to 7 m / s. It depends on the average pore size of the porous body and the pressure with which the first, if necessary another phase is brought into the second phase. The bigger The greater the peripheral speed, the greater the speed the emerging first phase acting shear forces. Of the The diameter of the droplets or gas bubbles usually increases with increasing peripheral speed. He also takes with decreasing pore size and falling volume flow.

To solve the problem is also a device for Mi and dispersing at least two phases, in particular for gassing liquids or suspensions, wherein a means for supplying at least a first phase into a porous body and a means for rotating the pores are provided around an axis in a second phase, so that the first phase emerges radially from the pore body and is finely divided in the second phase. - This allows a particularly homogeneous and fine distribution of the first in the second phase. The maintenance effort of the invention Device is compared to conventional static loading reduced gas: In case the device is used to fumigate activated sludge, the porous body must only be hoisted out of the pool. That to the end Exchange of static fumigators required draining of the pelvis not applicable. Because of the device according to the invention Aimable improved mixture and dispersion can be a second phase receiving reaction space with smaller size than previously run.  

The axis is expediently a vertical axis. That he enables an even entry of the first phase into the second phase.

According to a design feature, the pore body is cylin drisch or frustoconical with a peripheral surface and egg ner formed upper and lower base, being egg have a coaxial cylindrical or conical opening can. The frustoconical formation of the porous body and / or the conical design of the opening serve for Compensation of the pending over the height of the porous body hydrostatic pressure drop.

The means for feeding can be coaxial with the porous body orderly pipe. The means for rotating is advantageous one with the upper and / or lower base connected shaft.

At least one of its upper base area can be on the pore body partially covering first connection element and / or a at least partially covering its lower base second connector may be attached. The first and / or second connection element are advantageously in the form of a Rotational hyperbolids trained. The porous body can be between be held the connecting elements. The aforementioned Features result in a compact and fluidic opti lubricated construction.

The first and / or second connection element can on their the outside facing the second phase radially or obliquely running ribs or webs to circulate the second phase exhibit. The ribs or webs can be straight or curved be trained. This will result in further homogenization the mixture or dispersion achieved.  

The shaft is advantageously on the first connection element appropriate. It can be designed as a hollow shaft. In the In this case, the first phase can pass through the hollow shaft to the pores body are fed.

The tube is expediently designed as a standpipe which the second connection element is rotatably supported. Which he The first phase can also pass through the tube to the first porous body be fed by.

In the breakthrough, another design feature a distributor connected to the pipe and / or the hollow shaft Element with radial openings pointing towards the pore body Chen be included. If the first through the hollow shaft Phase and through the tube another phase the porous body are supplied, the distributor element serves at the same time Preparation of a premix. An intimate and homogeneous Wed The first and further phases are created during the passage achieved by the porous body.

The porous body can expediently be a porous ceramic, a porous metal, a porous quartz stone, a metal or Plastic foam, a made of metal or plastic braid or knitted fabric. When performing chemi shear reactions can also be catalytic in the porous body Material added or the pore body from a cataly be made table material.

According to a further embodiment, the porous body can be in the loading rich in circumferential area with a vegetation or Microorganism-inhibiting layer, for. B. a copper or lacquer containing silver. Likewise can the material forming the porous body with an additive or a doping, which a vegetation with  Plants or a stock with microorganisms of the same hem men.

Exemplary embodiments of the invention are described below the drawing explained in more detail. Show here:

Fig. 1 is a schematic cross-sectional view of a first agitating member,

Fig. 2 is a schematic cross-sectional view through a first mixing and dispersing with a second agitating member,

Fig. 3 is a cross-sectional view along the section line BB in Fig. 2,

Fig. 4 is a schematic cross-sectional view of a third stirring element and

Fig. 5 is a perspective view of a second mixing and dispersing device.

In Fig. 1, a cylindrical pore body 1 has a lower GU, an upper base GO and a peripheral surface UF. A coaxial breakthrough 2 is also leads out cylindrically. The upper base surface GO is covered by a first ring-shaped base plate 3 , which is part of a first connection element 4 . The first connection element 4 also has a first hyperboloid surface 5 . Ribs or webs (not shown here) can be attached to this. A two-th annular base plate 6 covers the lower base surface GU. It is received on a carrier plate 7 , which in turn is supported on a flange 8 of a breakthrough 2 by gripping distributor element 9 . The distributor element 9 has a coaxial recess 10 , from which distributor openings 11 extend in the radial direction. A hollow shaft 12 is fastened in the recess 10 in a coaxial arrangement with the porous body 1 .

Fig. 2 shows a schematic cross-sectional view through a mixing and dispersing. In a container 13, the hollow shaft is rotatably supported on a container lid 12 fourteenth The hollow shaft 12 penetrates the container lid 14 ; it is connected to a drive device (not shown here). A standpipe 15 passes through a container bottom 16 . It is held by a mounting element 17 received on the container bottom 16 fastening. A second surface connected to the lower base GU connecting element 18 is rotatably received on the free end of the standpipe 15 .

The flow path of a first phase is indicated by arrow P1. The first phase is introduced through the standpipe 15 into the porous body 1 . It emerges from its circumferential surface UF.

An inlet 19 is provided in the container lid 14 and an outlet 20 is provided in the container bottom 16 .

FIG. 3 shows a cross-sectional view along the section line BB in FIG. 2. The hollow shaft 12 is rotatably held in a bearing 21 which is fastened in a receptacle 22 . The receptacle 22 has an angular channel 23 opening onto an outer surface MF of the hollow shaft 12 with a mouth M. O-ring seals 24 are attached above and below the mouth M. In the area of the mouth M, the mantle surface MF has first hollow shaft openings 25 . The hollow shaft 12 is connected to a double distributor element 26 . The Dop pelverteilerelement 26 has in a of the Hyperbolidflä surface 5 and the base plate 3 enclosed first space R1 he first distributor openings 27 . The first space R1 is connected via an annular gap RS to an annular space RR, which is formed between the double distributor element 26 and the opening 2 . The standpipe 15 also opens out on the side opposite the hollow shaft 12 into the double distribution element 26 . Second distributor openings 28 connect the annular space RR to the interior of the standpipe 15 . There is no direct connection between the standpipe 15 and the hollow shaft 12 within the double distributor element 26 . The phases introduced thereby only meet in the annulus RR.

A by a second hyperboloid surface 29 and the second base plate 6 enclosed second space R2 of the second connection element 18 may be filled with air. The buoyancy caused thereby partially carries the second stirring element.

In the third stirring element shown in Fig. 4, the Po renkkörper 1 is in turn received between the first 4 and the second connecting element 18 . In the first connection element 4 , a shaft 30 is fixed, which is oriented coaxially to the axis of the pore body 1 . On the standpipe 15 , similar to the second stirring element shown in FIG. 3, the second connecting element 18 is rotatably mounted. The free end of the standpipe 15 opens into a further distributor element 31 , which is provided with distributor openings 11 .

In Fig. 5, a fifth stirring element is shown in perspective view. Here, a first 1 a and a second Po renkkörper 1 b are added to a vertically standing multi-channel hollow shaft 12 a. A first chamber (not shown here) of the multi-channel hollow shaft 12 a is connected to the first pore body 1 a. A second channel (not shown here) within the multi-channel hollow shaft 12 a is connected to the second pore body 1 b.

The function of the device is as follows:

The stirring element plunges into a basin filled with a second phase, e.g. B. a clarifier filled with activated sludge. The shaft 30 or hollow shaft 12 is rotatably supported on a bridge spanning the clarifier. The Po body 1 is rotated by the shaft 30 or hollow shaft 12 . Air is z. B. pumped through the hollow shaft 12 . From there it reaches the porous body 1 via the distributor element 9 and the distributor openings 11 . The air bubbles emerging are sheared off on the peripheral surface UF and finely distributed in the second phase.

To stabilize the stirring element, it is possible to additionally store the pore body 1 between the connecting elements 4 , 18 on a standpipe 15 . Due to the hyper bolid-like design of the connection elements, a flow-technically particularly favorable profile is generated. The profile enables a particularly low-friction rotary movement. In addition, in the case of the attachment of ribs or webs on the hyperboloid surfaces 5 , 29, a uniform circulation of the two-th phase is made possible.

The device according to the invention is also suitable for carrying out chemical reactions in which a particularly homogeneous mixture of at least two phases is important. For example, it is possible to supply a first liquid through the hollow shaft 12 and a second liquid through the standpipe 15 to a double distributor element 26 . The first and the second liquid are then mixed in the annulus RR. This mixture is further homogenized as it passes through the porous body 1 . The homogenized mixture exits radially on the circumferential surface UF and enters another liquid or gaseous phase.

With the device shown in FIG. 5, it is possible to evenly gas liquids or suspensions, in particular, taken up in deep and slim containers. The use of a multi-channel hollow shaft 12 a enables each of the porous bodies 1 a, 1 b to be subjected to a predetermined pressure. A hydrostatic pressure drop in the tank can be compensated for.

The peripheral surface UF of the porous body 1 does not necessarily have to be round. It can also have a rough surface or be shaped in the form of a polygon. In this case, the first phase is sucked into the second phase when the stirring element rotates in a liquid second phase according to the jet suction principle. In this case, a pump or a compressor for supplying the first phase can be dispensed with.

Reference list

1

,

1

a,

1

bPore body

2nd

coaxial breakthrough

3rd

first base plate

4th

first connection element

5

first hyperboloid surface

6

second base plate

7

Carrier plate

8th

flange

9

Distribution element

10th

Recess

11

Distribution breakthroughs

12th

Hollow shaft

12th

Multi-channel hollow shaft

13

container

14

Container lid

15

Standpipe

16

Tank bottom

17th

Fastener

18th

second connection element

19th

Intake

20th

procedure

21

camp

22

admission

23

Angular channel

24th

O-ring seal

25th

first hollow shaft breakthroughs

26

Double distributor element

27

first distribution breakthroughs

28

second distribution breakthroughs

29

second hyperboloid surface

30th

wave

31

further distributor element
GO upper footprint
GU Lower footprint
UF circumferential area
M mouth
RS ring gap
First room
R2 second room
RR ring space
MF jacket surface
P1 Current direction of the first phase
P3 Current direction of the third phase

Claims (25)

1. Process for mixing and dispersing at least two phases, in particular for gassing liquids or suspensions, wherein

• a) at least one first phase is fed to a pore body ( 1 , 1 a, 1 b) and distributed therein,
• b) the porous body ( 1 , 1 a, 1 b) is rotated in a second phase about an axis, so that
• c) the first phase radially emerges from the porous body ( 1 , 1 a, 1 b) and is finely distributed in the second phase.

2. The method according to claim 1, wherein the axis is a we major vertical axis. 3. The method according to any one of the preceding claims, wherein the first phase is a gas or liquid. 4. The method according to any one of the preceding claims, wherein the second phase a gas, a second liquid, a Is emulsion or suspension. 5. The method according to any one of the preceding claims, wherein the porous body ( 1 , 1 a, 1 b), the first and a further phase are supplied. 6. The method according to any one of the preceding claims, wherein the further phase the second phase or a third phase se is.   7. The method according to any one of the preceding claims, wherein the first and the further phase in the pore body ( 1 , 1 a, 1 b) are mixed. 8. The method according to any one of the preceding claims, wherein the second phase is circulated. 9. The method according to any one of the preceding claims, wherein the pore body ( 1 , 1 a, 1 b) is cylindrical or truncated cone-shaped with a peripheral surface (UF) and an upper (GO) and lower base surface (GU), and the peripheral surface (UF) is rotated at such a speed that the first phase emerging from the porous body ( 1 , 1 a, 1 b) is dispersed in the form of fine droplets or gas bubbles in the second phase. 10. The method according to any one of the preceding claims, wherein the peripheral speed is 4 to 7 m / s. 11. Device for mixing and dispersing at least two phases, in particular for gassing liquids or suspensions, wherein a means for supplying at least a first phase ( 12 , 15 ) in a pore body ( 1 , 1 a, 1 b) and an agent ( 12 , 12 a) are provided for rotating the pore body ( 1 , 1 a, 1 b) about an axis in a second phase, so that the first phase radially emerges from the pore body ( 1 , 1 a, 1 b) and into in the second phase. 12. The apparatus of claim 11, wherein the axis is an in essential vertical axis. 13. The apparatus of claim 11 or 12, wherein the pore body ( 1 , 1 a, 1 b) is cylindrical or frustoconical in shape with a peripheral surface (UF) and an upper (GO) and lower base surface (GU). 14. Device according to one of claims 11 to 13, wherein the pore body ( 1 , 1 a, 1 b) has a coaxial zylindri's or conical opening ( 2 ). 15. Device according to one of claims 11 to 14, wherein the means for supplying a coaxially to the porous body ( 1 , 1 a, 1 b) is arranged tube ( 15 ). 16. Device according to one of claims 11 to 15, wherein the means for rotating is a shaft ( 12 , 12 a) connected to the upper (GO) and / or lower base surface (GU). 17. The device according to one of claims 11 to 16, wherein on the pore body ( 1 , 1 a, 1 b) is attached to its upper base (GO) at least partially covering the first connecting element ( 4 ). 18. Device according to one of claims 11 to 17, wherein on the pore body ( 1 , 1 a, 1 b) has a lower base surface (GU) at least partially covering second connection element ( 18 ) is attached. 19. Device according to one of claims 11 to 18, wherein the first ( 4 ) and / or second connection element ( 18 ) is / are in the form of a rotational hyperbolide. 20. Device according to one of claims 11 to 19, wherein the first ( 4 ) and / or second connection element ( 18 ) on its outer side facing the second phase have radially or obliquely running ribs or webs for circulating the second phase. 21. Device according to one of claims 11 to 20, wherein the shaft is attached to the first connection element ( 4 ). 22. Device according to one of claims 11 to 21, wherein the shaft is a hollow shaft ( 12 ). 23. The device according to one of claims 11 to 22, wherein the tube is a standpipe ( 15 ) on which the second connection element ( 18 ) is rotatably supported. 24. Device according to one of claims 11 to 23, wherein in the opening ( 2 ) with the pipe and / or the shaft connected ver distributor element ( 9 , 26 , 31 ) with radial to the pore body ( 1 , 1 a, 1 b) facing Breakthroughs ( 11 , 27 , 28 ) is added. 25. Device according to one of claims 11 to 24, wherein the pore body ( 1 , 1 a, 1 b) is a porous ceramic, a po röses metal, a metal or plastic foam, a braid or Ge made of metal or plastic.