JPH0135224Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to the improvement of a stirring and mixing device for stirring and mixing substances in various states such as high viscosity fluids, slurry-like substances, and powders. Polymerization reactors for obtaining polymers by addition polymerization of polymerizable organic compounds and for producing polycondensation polymers such as polyacids and polyesters, and equipment for removing solvents and monomers from polymers. The purpose is to provide a stirring and mixing device that is suitable for combined production.

In general, equipment such as polymerization reaction equipment that processes various substances such as high viscosity fluids, slurry-like substances, and powders is required to be able to perform a sufficient mixing action and have a high heat transfer rate. It is desirable to have an anti-adhesion mechanism for processing. It is said that an effective and reliable way to meet these demands is to incorporate a self-cleaning mechanism with a good mixing effect into the device itself. For this reason, a method using, for example, a screw-like agitating body has been conventionally known.

However, all conventional devices of this type employ a special mechanism to have a self-cleaning effect, making them difficult to manufacture; capacity is too small.

○D There were drawbacks such as not being able to obtain a sufficient mixing effect.

In order to eliminate such drawbacks, the applicant of the present invention previously proposed in Japanese Patent Application No. 47-59211 a stirring and mixing device consisting of a container, a rotating shaft, and a stirring body, and
A plurality of rotating shafts are connected to the drive unit in the container so as to rotate in parallel, in the same rotational direction, and at the same rotational angular velocity, and the stirring body is arranged to rotate coaxially with each of the rotating shafts, and In a cross section perpendicular to the axis, they are combined with a slight gap or in slight contact with each other, and the center of the stirring body and the axis of the rotation axis do not coincide in the cross section perpendicular to the rotation axis, The center of the stirrer should be arranged in the same direction and the same distance from the axis of the rotating shaft, and the container should have a cross-sectional area that is equal to or slightly larger than the outermost trajectory of the stirrer. I suggested that. For example, as shown in FIGS. 1a to 1b, two tubes are installed at both ends of a cylindrical container 1, which has a jacket 2 having inlets and outlets 4 and 3 for the heat medium and inlets and outlets 6 and 5 for the material to be treated. Rotating shafts 7, 8
The structure is such that they are supported and accommodated by bearings 9, 10 and 11, 12, respectively. Inside container 1,
Stirring bodies 13 and 14 are connected and fixed to a plurality of disk-shaped stirring plates by rotating shafts 7 and 8, respectively, in a state in which the stirring bodies 13 and 14 penetrate in a skewer-like manner in the thickness direction of the plates. Also,
The rotating shafts 7 and 8 are coupled to a drive unit (not shown) so as to rotate in the same direction and at the same rotational angular velocity.

The stirring bodies 13 and 14 are shown in FIG.
, - Figures 2a to 2b, which are cross-sectional views in the direction of the arrows.
As shown, a plurality of thick-walled disc-shaped stirring plates 13a, 13b, 13c...: 14 are attached to the rotating shafts 7, 8.
a, 14b, 14c, ... are arranged in series in the surface thickness direction with their eccentric positions shifted, and each stirring plate 13a, 14a: 13b, 14b: 13
c, 14c: ..., etc. are provided so that they are in light contact with each other or with a slight gap between them, but usually each stirring plate is a disk having a diameter equal to the distance OP between the centers of the rotating shafts 7 and 8. and each stirring plate 13a,
When 14a: 13b, 14b:... rotate in the same direction and at the same rotational angular velocity around the axis OP,
They are constructed so that they do not interfere with each other's movements. Furthermore, the centers A ₁ and B ₁ of the stirring bodies 13 and 14:
A ₂ , B ₂ :... do not coincide with the axes O and P of the rotating shafts 7 and 8, and A ₁ , B ₁ : A ₂ , B ₂ :... are all in the same direction and at the same distance from O and P. They are arranged and connected so that they are eccentrically spaced apart. Therefore, the left and right stirring plates 13a, 14a: 13 that are close to each other
b, 14b: 13c, 14c: The gap between the peripheral edge of the rotating body and the container moves in the direction (rightward in FIG. 1). In this way, the stirring body itself forms an intermittent screw, and a strong processing material feeding action is generated. In addition, the inner wall of the container 1 is configured to have a shape similar to or similar to the outermost trajectory of the stirring bodies 13 and 14 as shown in FIGS. 2a and 2b, and the inner wall surface of the container is cleaned by the rotational movement of the stirring bodies. ing.

However, in the stirring/mixing device proposed in Japanese Patent Application No. 47-59211, the wall thickness of the disc-shaped stirring plate constituting the stirring body is uniform, so adjacent stirring plates are centered around the rotation axis. However, the peripheral end surfaces of the same stirring plates are aligned at the same distance.
Therefore, as shown in FIG. 3, the liquid (or solid) in the container is pushed away by the rotational force of each stirring plate (for example, 13b), but the displaced liquid 15 (or solid) is transferred to each stirring plate. There was a strong tendency for the treated substances to mix back in the longitudinal direction of the rotating shaft. Furthermore, when processing solids or slurry containing solids, the solids enter between the peripheral edge of the stirring plate and the inner wall of the container, resulting in the disadvantage that the stirring power must be increased.

The present invention was developed to eliminate such drawbacks in conventional stirring and mixing devices.When the stirring plate rotates, the liquid (or solid) in the container is pushed back and forth at the peripheral edge of the stirring plate, and the liquid (or solid) is separated in the longitudinal direction of the device. It is an object of the present invention to provide a stirring and mixing device that does not cause a back-mixing phenomenon or prevent solids from entering between the peripheral edge of a stirring plate and the inner wall of a container.

The stirring and mixing device of the present invention for achieving this purpose includes a plurality of rotating shafts arranged parallel to each other and rotating in the same direction and at the same rotational speed, and each rotating shaft is provided with a plurality of rotating shafts so as to rotate together with the rotating shaft. and perpendicular to the rotating shaft, a plurality of stirring plates are connected in series in the surface thickness direction, and the stirring plates are combined with a shape such that there is a slight gap or they are lightly in contact with each other in a cross section perpendicular to the rotating shaft, And in a cross section perpendicular to the rotating shaft, the center of each stirring plate does not coincide with the axis of the rotating shaft, but the center of each stirring plate is spaced in the same direction and by the same distance from the axis of the rotating shaft. A stirring and mixing device comprising a stirring body configured as above, and a stirring and mixing processing container that houses the rotating shaft and the stirring body and has a cross-sectional portion equal to or slightly larger than the outermost trajectory of the stirring body, the stirring and mixing device comprising: Each of the stirring plates constituting the body is characterized by being constructed of a thick plate whose circumferential edge plate thickness gradually decreases toward the circumferential edge in a cross section perpendicular to the rotation axis.

An embodiment of the present invention will be described below based on the drawings.

FIGS. 4a and 4b are a partial sectional view of the stirring and mixing device of the embodiment and a sectional view taken along the arrow - in FIG. 4a, where 1 is a cylindrical container, 2 is a jacket, 3, 4 is an inlet/outlet for the heating medium, 5, 6 is an inlet/outlet for the substance to be treated, 7, 8 is a rotating shaft inserted parallel to each other in the container 1, 9, 10, 11, 12 is a rotating shaft bearing, 13', 14' is Stirring body, 13'a, 13'b,
13'c, ... and 14'a, 14'b, 14'c,
... is a disc-shaped stirring plate constituting the stirring bodies 13', 14'.

Inside the container 1, a plurality of disc-shaped stirring plates 1
3'a, 13'b, 13'c,...14'a, 14'b,
14'c, . . . are connected and fixed in a skewer-like manner in series in the plate thickness direction with their eccentric positions shifted.

Further, stirring plates 13'a, 14'a, :13'b,
14'b: 13'c, 14'c:... are, for example, disc-shaped stirring plates 1 as shown in FIGS.
Not only are the stirring plates 13'a, 14'a, 13'b, 14'b, .
The peripheral end plate thickness of b, . . . gradually decreases from a position centered on the axis of the rotating shaft 7. moreover,
As shown in FIGS. 7 and 8, each stirring plate 13'a, _{13'b , .} , B ₂ : are all eccentrically displaced from O and P by the same distance in the same direction, and are connected to each other. Therefore, the left and right stirring plates 13'a, 14'a close to each other: 1
3'b, 14'b: 13'c, 14'c: ... direction (the gap between the peripheral edge of the rotating body (stirring body) and the container moves toward the right in FIG. 4).

Moreover, each stirring plate 13'a, 1 of the stirring body
4'a: 13'b, 14'b, :... has a structure in which the thickness of the peripheral end plates gradually decreases toward the periphery, so that the material to be treated is deposited at a position near the container wall as shown in Figure 9. It is only extruded in one direction and there is little risk of back mixing.

Next, in order to compare the performance of the stirring and mixing device according to the present invention and the stirring and mixing device of the conventional structure, the stirring plate was 30 circular plates with a diameter of 80 mm and a plate thickness of 20 mm are connected in series with the rotating shafts 7 and 8 with an effective axis length of 600 mm with the eccentric distance of 20 mm, with the plate surfaces perpendicular to each other, and inserted into the container. Using the stored material, the rotating shaft is rotated at 180 rpm, and the container contains carboxyl cellulose (hereinafter referred to as "CMC").
An experiment was conducted in which an aqueous solution (2000CP) was continuously introduced and discharged. The liquid supplied into the device is instantaneous.
Switch to CMC solution containing Nacl, outlet 5 of the device
The electrical conductivity was measured using a platinum electrode installed in the sample, and the residence time distribution, that is, the degree of back-mixing, was measured. As a result of the measurement, a characteristic curve a shown in FIG. 10 was obtained. However, in Figure 10, the horizontal axis represents the residence time to average residence time ratio of the feed liquid, and the vertical axis represents the NaCl concentration Co of the feed liquid.
The ratio (C/Co) of the NaCl concentration C of the liquid at the device outlet to that of the liquid is shown. It can be seen from the characteristic curve a in FIG. 10 that the NaCl concentration C at the outlet increases with time.

Moreover, it is closer to the extrusion flow (curve c) than the complete mixing flow (curve b). In addition, when 17% by weight of sand particles of 32 mesh or less were mixed into the feed liquid,
The stirring power was 1.7 times that of the case without mixing.

In addition, as the stirring plate of the above device, a circular plate with the above dimensions (diameter 80 mm, plate thickness 20 mm) is shaped such that the circular end face is gradually reduced in thickness at the peripheral edge as shown in Figure 5.
30 sheets, with the board surface perpendicular to the rotating shaft with an effective axis length of 600 mm.
Then, the C/Co is connected in series in a skewer shape in a shape displaced from each other at an eccentric distance of 20 mm with respect to the axis in a container, and under the same conditions as in the case of the conventional device.
As a result of the measurement, results such as curve d in FIG. 10 were obtained, and it can be seen that the influence of back mixing is clearly reduced. Additionally, 32 mesh sand particles were added to the feed solution.
The stirring power when 17% by weight was mixed was only 1.2 times that when it was not mixed, and almost no entrapment was observed between the peripheral edge of the stirring plate and the inner wall surface of the container.

Similar results can be obtained by using not only a disk-shaped stirring plate but also other shapes of stirring plates such as a cut-out circular stirring plate or an elliptical stirring plate.

As is clear from the above description, the stirring and mixing device according to the present invention has the advantages obtained by the invention of Japanese Patent Application No. 47-59211, as well as the reverse effects of the processed material caused by the stirring plate. It is possible to eliminate the occurrence of mixing phenomena and the phenomenon that solid substances enter between the inner wall of the container and the tip of the stirring plate, and has the advantage of ensuring sufficient mixing of the treated substances and smooth operation of the apparatus.

[Brief explanation of the drawing]

Fig. 1a is a partially cross-sectional side view of a conventional stirring and mixing device, Fig. 1b is a view taken in the - arrow direction of Fig. 1a, and Fig. 2a is a sectional view taken in the - arrow direction of Fig. 1a; Figure b is a sectional view taken in the direction of the - arrow in Figure 1 a, Figure 3 is a diagram of the state of stirring of the treated substance generated between the stirring plate and the inner wall surface of the container in a conventional stirring and mixing device, and Figure 4 a is a diagram of the present invention implemented. Partial cross-sectional side view of the example stirring and mixing device, FIG. 4b
is a view in the - arrow direction of Fig. 4a, Fig. 5 is an explanatory view of the main part showing the mounting state of the stirring plate in the stirring and mixing device of the embodiment of the present invention, and Fig. 6 is a view of the stirring in the stirring and mixing device of the embodiment of the invention. An explanatory diagram showing the eccentric mounting state of the plate with respect to the rotating shaft, FIGS. 7 and 8 are sectional views taken along the arrows - and - , respectively, in FIG. Diagram of the state of stirring of the treated substance occurring between the stirring plate in the device and the inner wall surface of the container, No. 10
The figure is a characteristic curve diagram showing temporal changes in the NaCl concentration at the inlet and outlet of the apparatus for the Nacl-containing carboxyl cellulose aqueous solution treated by the apparatus of the example. In the drawings, 1...container, 2...jacket, 3,
4... Heat medium inlet/outlet, 5, 6... Treated substance inlet/outlet, 7, 8... Rotating shaft, 13, 14, 13', 1
4'... Stirring body, {13a, 13b, 13c, 14
a, 14b, 14c}... Conventional stirring plate, {1
3'a, 13'b, 13'c, 14'a, 14'b,
14'c}...Stirring plate of Example.

Claims (1)

[Scope of utility model registration request] A plurality of rotating shafts are arranged parallel to each other and rotate in the same direction and at the same rotational speed, and a plurality of stirring plates are installed on each rotating shaft so as to rotate together with the rotating shaft and perpendicular to the rotating shaft in the surface thickness direction. The stirring plates are connected in series to each other, and the stirring plates are combined in such a shape that there is a slight gap or light contact in the cross section perpendicular to the rotation axis, and the center of each stirring plate is connected in the cross section perpendicular to the rotation axis. A stirring body configured such that the center of each stirring plate is separated from the axis of the rotating shaft by the same direction and the same distance without coinciding with the axis of the rotating shaft, and the rotating shaft and the stirring body are A stirring and mixing device that is housed in a stirring and mixing processing container having a cross section equal to or slightly larger than the outermost locus of the stirring body, wherein each stirring plate constituting the stirring body is arranged perpendicular to the rotation axis. A stirring and mixing device characterized in that it is constituted by a thick plate whose circumferential edge plate thickness gradually decreases toward the circumferential edge in cross section.