JPH04145936A - Method and device for agitating and mixing liquid - Google Patents

Abstract

PURPOSE:To suppress the generation of bubbles and splashing of a liq. when the liqs. are agitated and mixed by providing an impeller of a specified size in an agitated vessel, rotating the impeller at low speed and agitating the liqs. CONSTITUTION:A large-sized impeller 3 is rotated at low speed to agitate the soln. 2 in an agitated vessel 1. Plural impellers 3 are fixed along a rotating shaft 8 set at the center of the vessel 1. The diameter D1 of the impeller 3 and the inner diameter D0 of the vessel 1 are limited to conform to D1=D0Xalpha (alpha=0.5 to 0.9), and the upper end 3a is allowed to protrude from the maximum liq. level L2. The length H1 of the impeller in the liq. is controlled to >= about 80% of the liq. depth dmax at the maximum liq. level L2. When the liq. surface in the vessel is displaced, a part of the impeller is always above the liq. level, hence the agitating condition is not changed, and the generation of bubbles and splashing of the liq. are minimized when the liqs. are agitated and mixed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a liquid stirring and mixing method and a liquid stirring and mixing apparatus for uniformly stirring and mixing, for example, adding an additive or the like to a liquid.

[Prior Art] In the process of producing photographic emulsions, etc., additives are mixed into a photographic solution by stirring, and this photographic emulsion, etc. is coated on a support using a coating device to produce a photographic light-sensitive material. will be carried out.

In order to mix these solutions uniformly and to keep the stirring and mixing state constant even if the liquid level fluctuates, stirring is used for this stirring and mixing, as described in Japanese Patent Publication No. 45-39590, for example. There is a stirring and mixing device that increases or decreases the rotational speed of the blades depending on the liquid level.

This stirring and mixing apparatus produces a photographic emulsion by placing an aqueous solution of gelatin and an alkali halide in a stirring container, and adding an aqueous silver nitrate solution or the like to the stirring container while stirring with a stirring blade.

In this conventional stirring mixing device, when the liquid level is below the lower liquid level set at the bottom of the stirring container,
The stirring rotational speed of the stirring blade is kept low, and when the silver nitrate aqueous solution is added and reaches the lower liquid level, the stirring rotational speed of the stirring blade is increased from low to medium speed, and the liquid level further rises until the upper liquid level reaches the upper liquid level. When this is reached, the rotational speed of the stirring blade is increased from medium speed to high speed.

[Problems to be Solved by the Invention] However, in such conventional stirring and mixing, the stirring blades were relatively small compared to the stirring vessel, so in order to uniformly stir and mix the aqueous solution, it was necessary to increase the rotation speed. I had to set it higher.

For this reason, when stirring photographic emulsions, etc., there is a risk that a large amount of harmful foam and air bubbles will be generated, and the generation of foam is said to lead to the formation of gore. If a photographic emulsion containing such bubbles and air bubbles is produced, it becomes impossible to form a uniform photosensitive film on a photographic light-sensitive material. The load placed on the defoaming device tended to be large.

Furthermore, since the rotational speed of the stirring blade is high, liquid scattering occurs, and this liquid scattering impairs the manufacturing environment and further promotes the generation of foam and air bubbles.

Furthermore, since the stirring blades were relatively small, when the viscosity of the aqueous solution to be stirred increased, the time required for mixing was extremely long, making it inefficient.

In order to eliminate the above-mentioned drawbacks of conventional stirring and mixing, this invention provides a liquid stirring and mixing method that minimizes the generation of foam and air bubbles during stirring and the scattering of liquid by reducing the rotational speed, and that also enables rapid stirring and mixing. It is an object of the present invention to provide a method and a liquid agitation mixing device.

[Means for Solving the Problems] In order to solve the above problems, the invention of the liquid stirring and mixing method according to claim 1 provides a method for supplying a liquid to a stirring container, and using a part of stirring blades provided in the stirring container. , it is characterized by stirring and mixing the liquid by rotating at a low speed with the liquid constantly above the liquid level in response to the liquid level displacement.

Further, in the liquid stirring and mixing method according to claim 2, the shape of the liquid interface portion of the stirring blade does not change within a range from the lowest liquid level to the highest liquid level.

In addition, the invention of a liquid stirring and mixing device according to claim 3 includes a stirring container containing a liquid whose liquid level changes within a range from a lowest liquid level to a highest liquid level, and a stirring and mixing of the liquid in this stirring container. In the liquid stirring and mixing device, the stirring blade has a blade diameter whose rotational diameter around its rotation axis is approximately 50 to 90% of the inner diameter of the stirring vessel, and the stirring blade has an upper end portion of the stirring blade. protrudes above the highest liquid level, and the length of the stirring blade submerged in the liquid from the highest liquid level is approximately 80% or more of the liquid depth at this highest liquid level. It is characterized by having

Further, in the liquid stirring and mixing device according to claim 3, the shape of the liquid interface portion of the stirring blade does not change within a range from the lowest liquid level to the highest liquid level.

[Function] In the liquid agitation mixing according to the invention according to claim 1 or 3,
A part of the stirring blade provided in the stirring container is rotated at a low speed to stir and mix the liquid in a state in which a part of the stirring blade is always exposed above the liquid level in response to the liquid level displacement. Therefore, even if the liquid level in the stirring container changes, a part of the stirring blade will always remain above the liquid level, and the stirring state will not change at all times. Therefore, the generation of foam and air bubbles and the scattering of liquid during stirring and mixing can be suppressed as much as possible, and moreover, rapid stirring and mixing can be performed.

Further, in the liquid agitation mixer according to claim 2 or 4, the shape of the liquid interface part of the stirring blade does not change within the range from the lowest liquid level to the highest liquid level, and the liquid level displacement The stirring state does not change, and the generation of foam and air bubbles and the scattering of liquid during stirring and mixing are minimized, and rapid stirring and mixing is possible.

[Example 1] Hereinafter, an example of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a side view of the liquid stirring and mixing device of the present invention, and FIG. 2 is a plan view of the liquid stirring and mixing device of the present invention.

In this stirring and mixing device, a photographic gelatin solution 2 is placed in a stirring container 1, and while stirring with a large stirring blade 3, a surfactant or the like is added through a pipe 4 disposed above the stirring container 1. A photographic emulsion is prepared by adding Agent 5. The photographic emulsion in the stirring container 1 is supplied from a pipe 6 to a coating device (not shown), and is coated on a conveyed support to produce a photographic light-sensitive material.

The liquid level 7 of the photographic gelatin solution 2 in the stirring container 1 fluctuates within the range from the lowest liquid level L1 to the highest liquid level L2, and the liquid depth d also changes between d min - d max.

A plurality of large stirring blades 3 are attached along a rotating shaft 8 provided at the center of the stirring container 1. The rotating shaft 8 is rotated by a drive motor 9, and the photographic gelatin in the stirring container 1 is Stir solution 2. The shape of the liquid interface of the stirring blade 3 does not change within the range from the lowest liquid level L1 to the highest liquid level L2.

As shown in FIG. 2, the blade diameter D1, which is the diameter of the stirring blade 3 centered on the rotating shaft 8 of the stirring blade 3, is approximately D1=DOxα (α=05 to 0. 9) is satisfied.

Further, the stirring blade 3 has its upper end 3a at the highest liquid level L2.
The Kel solution 2 protrudes further out of the liquid, and from this highest liquid level L2
The submerged blade length H1, which is the length of the submerged blade, is H1 = 0.95
It is a size that satisfies the relational expression of Xdmax.

Further, a plurality of stirring holes 3b are bored in the stirring blade 3 along the rotating shaft 8. The stirring holes 3b apply shearing force to the entire photographic gelatin solution 2 when the stirring blade 3 rotates to promote mixing, and even if the liquid level changes, it applies a uniform shearing force to the liquid surface to prevent the generation of bubbles. Since these holes are intended to be stable against changes in the liquid level, they are perforated almost uniformly over the entire surface of each stirring blade 3, and the upper part of the stirring hole 3b protrudes from the liquid level.

Next, another embodiment will be described based on FIGS. 3 and 4.

In this embodiment, the rotating shaft 8 of the large stirring blade 3 is eccentric from the center of the stirring container 1. Additionally, a rotating shaft 8 is provided on the inner surface of the stirring container 1, extending from the upper part to the lower part of the stirring container 1.
A baffle plate 31 is protruded parallel to the stirring blade 3 at a position that does not contact the stirring blade 3. The eccentric stirring blade 3 and the baffle plate 31 create an asymmetrical vortex in the flow of the stirred photographic gelatin solution 2, and serve to stir and mix the entire photographic gelatin solution 2 uniformly and quickly.

Next, the results of an experiment of stirring and mixing using the stirring and mixing apparatus according to the present invention will be explained in comparison with the case of a conventional stirring and mixing apparatus.

Experimental Example 1 In this experiment, a stirring vessel 1 with a liquid capacity of 1300 m°C as shown in Figs. The stirring speed is kept constant (N) while changing the liquid volume.
= 150 rpm) for stirring and mixing.

The maximum liquid volume is Vmax=1300mft, and the liquid depth d at this time is d=dmax=1. o, each d=0.7
The mixture was stirred and mixed at each liquid depth stage of 5, 0.50, and 0.25.

In addition, additive 5 is an anionic surfactant (?1A 5%
). The amount of addition was 65 mρ when the liquid depth was d10, and the amount was proportional to the liquid depth during the 7 nights of Iya.

25 minutes after adding additive 5 at each liquid depth stage, the foam volume Va is measured, and after 60 minutes, the presence or absence of globs is determined.
This solution was coated and developed, and evaluated by observing the coated surface with a magnifying glass.

The conventional stirring and mixing device used for comparison uses four paddle blades 41 (blade diameter D2/container inner diameter DO=1/3, Blade length H2/blade diameter D2=115, blade position I/liquid depth dmax=0
．． 9) is used, and the stirring rotation speed is N=78Orpm.
(At liquid depth d=10, the stirring mixing device of this invention,
The mixing time of the conventional stirring mixer is the same. ), the foam volume Va was measured in the same manner as above under the same conditions as above except for stirring, and the presence or absence of sloshing was evaluated.

The results of this experiment are shown in Table 1.

Margin Table 1 Below: In the above table, ◯ indicates that a blunder occurred, and × indicates that a blunder did not occur.

According to the experimental results, in the liquid stirring and mixing apparatus of the present invention, the foam volume Va generated is extremely small and constant even when the liquid volume is changed. Also, there was no occurrence of gore.

On the other hand, in the conventional liquid agitation mixer using turbile blades, as the liquid volume decreased, the generation of foam increased rapidly and the occurrence of globs was also observed.

Experimental Example 2 Next, we will use a liquid stirring and mixing device in which the rotating shaft 9 is eccentric as shown in FIGS. 3 and 4, and a stirring and mixing device in which the rotating shaft 8 is not eccentric as shown in FIGS. 1 and 2. An experiment was conducted to compare the equipment.

In this experiment, a stirring container 1 with a liquid capacity of 13° C. was used, two types of model solutions having viscosities of 250 cP and 1400 cP were placed in the stirring container 1, and the tracer liquid was added to the model solution and mixed by stirring. Table 2 shows the experimental results of the time required for mixing in model solutions of each viscosity.
Shown below. However, at this time, the stirring rotation speed N = 6 Or, p
, m.

Table 2 As is clear from Table 2, the mixing time is shorter when the rotating shaft 8 is eccentric, and when mixing highly viscous solutions, the mixing time is significantly longer than with a liquid agitation mixer that is not eccentric. can be shortened to

[Effects of the Invention] As explained above, in the liquid agitation mixing according to the invention according to claim 1 or 2, a part of the stirring blade provided in the stirring container always protrudes from the liquid surface in response to the liquid surface displacement. In this state, the stirring blade rotates at low speed to mix the liquid, so even if the liquid level in the stirring container changes, a part of the stirring blade is always kept above the liquid level. Since the stirring state does not always change, the generation of foam and air bubbles and the scattering of liquid during stirring and mixing can be suppressed as much as possible, and rapid stirring and mixing is possible.

Further, in the liquid agitation mixing according to claim 2 or 4, the shape of the liquid interface part of the stirring blade does not change within the range from the lowest liquid level to the highest liquid level, so that the liquid level does not displace. The stirring state does not change due to the stirring blade, even when
The generation of foam and air bubbles and the scattering of liquid during agitation and mixing are suppressed to the utmost, and rapid agitation and mixing are possible.

[Brief explanation of drawings]

FIG. 1 is a side view of a liquid stirring and mixing device according to the present invention, in which the stirring blade is not eccentric, FIG. 2 is a plan view of a liquid stirring and mixing device in which the stirring blade is not eccentric, and FIG. FIG. 4 is a side view of a liquid stirring and mixing device with eccentric blades, FIG. 4 is a plan view of a liquid stirring and mixing device of the present invention with eccentric blades, and FIG. 5 is a side view of a conventional liquid stirring and mixing device using turbine blades. FIG. In the figure, 1 is a stirring container, 2 is Kel's solution, 3 is a stirring blade,
3a is the upper end, 3b is the stirring hole, 7 is the liquid level, 8 is the rotating shaft,
31 is a baffle plate, d is the liquid depth, Dl is the blade diameter, Hl is the submerged blade length, Ll is the lowest liquid level, and L2 is the highest liquid level. Figure Figure Figure Figure Figure

Claims (1)

[Claims] 1. Supplying a liquid to a stirring container, and rotating a part of stirring blades provided in the stirring container at a low speed in a state that is always above the liquid surface in response to the displacement of the liquid surface; A liquid stirring and mixing method characterized by stirring and mixing liquids. 2. The liquid stirring and mixing method according to claim 1, wherein the shape of the liquid interface of the stirring blade does not change within the range from the lowest liquid level to the highest liquid level. 3. A liquid stirring and mixing device having a stirring container containing a liquid whose liquid level changes within a range from a lowest liquid level to a highest liquid level, and a stirring blade for stirring and mixing the liquid in this stirring container, the above-mentioned The stirring blade has a blade diameter whose rotational diameter around the rotation axis is approximately 50 to 90% of the inner diameter of the stirring vessel, and the upper end of the stirring blade protrudes above the highest liquid level, and A liquid stirring and mixing device characterized in that the length of the blade submerged in the liquid from the highest liquid level of the stirring blade is approximately 80% or more of the liquid depth at the highest liquid level. 4. The liquid stirring and mixing device according to claim 3, wherein the shape of the liquid interface of the stirring blade does not change within a range from the lowest liquid level to the highest liquid level.