JPS62100287A - Granulation apparatus for immobilized microorganism - Google Patents

Abstract

PURPOSE:To obtain a spherical immobilized microorganism having a uniform diameter, by dripping a mixture solution of a microorganism and an immobilizing agent through nozzles of a special structure into a gelation tank. CONSTITUTION:A mixture solution of a microorganism and an immobilizing agent is dripped from a dripping means 10 into a gelation tank 32 to granulate a gelatinous immobilized microorganism. In the process, the dripping means 10 consists of a hollow rotating body 12, capable of containing the mixture solution therein and having plural nozzles 22 on the outer periphery thereof and a driving mechanism for intermittently rotating the hollow rotating body 12 with a horizontal plane.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a granulation device for immobilized microorganisms, and particularly to a granulation device suitable for producing spherical immobilized microorganisms with uniform diameter.

[Conventional technology]

Immobilized microorganisms are microorganisms that are encircled and immobilized within a polymer gel such as polyacrylamide.

The immobilized microorganisms are used for the purpose of promoting a desired reaction in the object to be treated through the biochemical action of the immobilized microorganisms. For this purpose, it is necessary for the immobilized microorganisms to efficiently contact the material to be treated in the reactor, and from the viewpoint of strength and fluidity, the immobilized microorganisms should be spherical with a uniform diameter. Especially requested.

A liquid phase granulation method is known as a method for producing spherical immobilized microorganisms. In this method, droplets of a mixed solution of microorganisms and a fixative are dropped into a gelling agent solution, and the droplets are gelled and granulated by the action of the gelling agent.

By the way, in this liquid phase granulation method, it is difficult to form uniform spherical droplets with a desired diameter, and as a result, the immobilized microorganisms granulated in the gelling agent solution have a small size. There was a problem that there was wide variation in shape (and it was difficult to mass-produce on an industrial scale).

That is, the immobilized microorganism is required to have a perfect spherical shape with a predetermined uniform diameter selected from a range of 1 to 6 ft depending on its purpose and manner of use. For example, when a liquid mixture of microorganisms and a fixative is allowed to fall naturally from the tip of a nozzle while applying a constant static pressure, droplets that are relatively close to perfect spheres can be formed. However, this method has poor production efficiency, and in order to form droplets with the desired diameter, the nozzle hole diameter must be changed to the optimum size each time, and nozzles of various sizes must be prepared. . Furthermore, since the viscosity and surface tension vary depending on the composition of the liquid mixture, there is no guarantee that droplets of the same diameter can be formed using the same nozzle.

Furthermore, when a rotary nozzle is used to spray droplets by the action of centrifugal force, production efficiency is good, and the diameter of the droplets can be arbitrarily selected by adjusting the rotational speed. However, in this method, a large centrifugal force is required to break up the liquid mixture flowing out from the nozzle tip into droplets, and the droplets are given a large initial velocity force.

For this reason, the droplets are deformed into a flat shape and land in the mepalizing agent solution. Therefore, it is difficult for the immobilized microorganisms produced by the method using a rotating nozzle to maintain a true spherical shape.

[Problem that the invention seeks to solve]

An object of the present invention is to solve the problems of the prior art described above and to provide an apparatus capable of efficiently granulating spherical immobilized microorganisms having a uniform diameter.

[Means for resolving intervening points]

The granulation device for immobilized microorganisms according to the present invention includes a plurality of nozzles attached to the outer periphery of a hollow rotary body that accommodates a mixed liquid as droplet dropping means, and the hollow rotary body is intermittently rotated in a horizontal plane. It is characterized by:

[For production]

When the hollow rotating body is rotated intermittently, a large acceleration is applied to the nozzle tip at the moment of starting and stopping, and the liquid mixture flowing out to the nozzle tip is divided. Since almost no centrifugal force acts on the separated droplets of the mixed liquid, their initial velocity is small. Therefore, the droplet does not deform into a flat shape,
It is dropped into the gelling agent solution below while maintaining its spherical shape.

〔Example〕

An embodiment of the present invention is shown in FIGS. 1 and 2.

10 is a droplet dropping means according to the present invention, and a hollow rotating shaft 14 is attached to the center of the upper part of the hollow rotating body 12.
This rotating shaft 14 is supported by a bearing 16. A mixed liquid supply pipe 18 is inserted into the hollow part 13 of the rotating shaft 14 , and its open end is connected to the hollow part 13 of the hollow rotating body 12 .
has reached.

Further, an injection can 20 for the mixed liquid is provided at the upper end of the supply pipe 18. A plurality of nozzles 22 are attached to the lower part of the hollow rotating body 10 at equal intervals on the outer periphery thereof in a concentric circle. Further, one end of a crank 26 that is rotatable about the bin 24 is connected to a predetermined position of the hollow rotating body 12, and the other end of the crank 26 is connected to a rotating arm 28. This rotary arm 28 is rotated in one direction on a horizontal plane by a motor 30 equipped with a continuously variable transmission mechanism.

A dulling tank 32 is arranged below the hollow rotating body 12, and a gelling agent solution 34 is filled in the tank.

In the above configuration, when the motor 3o is driven, the rotary arm 28 horizontally rotates in one direction, and the crank 26 is operated, thereby causing the hollow rotating body 12 to alternately rotate in forward and reverse directions. In this state, when a mixed solution of microorganisms and fixative is injected into the injection can 20, the mixed solution falls inside the supply W2B,
The hollow part of the hollow rotating body 12 reaches ]3. The liquid mixture that has reached the inside of the hollow portion 13 is subjected to centrifugal force by the 120-time operation of the hollow rotating body, moves toward the outer circumference, and is about to be discharged to the outside from the nozzle 22. At this time, horizontal force is applied to the mixed liquid at the tip of the nozzle 22 by the rotation of the hollow rotating body 120, and the mixed liquid is divided into droplets. This division is mainly performed at the moment when the rotation direction of the hollow rotating body 120 changes.

The details will be explained below with reference to FIGS. 3 and 4.

FIG. 3 shows the forward and reverse rotation of the hollow rotating body 12. In the figure, 34 means a fulcrum at which the crank 26 is connected to the hollow rotating body 12, and 36 is a fulcrum at which the crank 26 is connected to the rotating arm 28.

Corresponding to the rotation locus A of the fulcrum 36, the fulcrum 34 moves within the range of a locus B, and the hollow rotating body 12 rotates.

At this time, the relationship between the rotation angle θ of the fulcrum 36, the rotation angle θ1 of the fulcrum 34, the angular velocity ω1, and the angular acceleration a1 is expressed as
Shown in Figures (a), (b), and (c). As is clear from FIG. 4C), the absolute value of the angular acceleration oL1 is maximum when the rotation angle θ of the fulcrum 360 is 0 (2π) or π.

Therefore, this angular acceleration acts as a horizontal impact force, and the liquid mixture at the tip of the nozzle 22 is divided into droplets.

Since the angular velocity ω1 at this time is approximately 0, as is clear from FIG. 4(b), almost no centrifugal force acts on the droplet. For this reason, the initial velocity of the falling droplet is extremely small, and the droplet falls while maintaining a substantially perfect spherical shape.

As described above, in this embodiment, when the hollow rotary body 12 rotates within a predetermined angle range, the direction of rotation changes; the instantaneous angular velocity a is the maximum, and the angular velocity) fω1 is 0. This method efficiently forms spherical droplets at the timing of .

The droplets from the tip of the nozzle 22 fall into the melting tank 32 below, and become stable immobilized microorganisms that maintain their true spherical shape due to the action of the gelling agent solution 34.

[Example of practical experience]

Experiments were conducted depending on the conditions of the manure.

Microorganisms...activated sludge (microbial concentration 20,000my/
l,) Fixing agent: 0.6% sodium alginate mixture.
・・Microorganism 5096, fixing agent 50% gelling agent solution・
・・2%CaCl2 hollow rotating body Rotation radius・・・・・・
・20 rotation angle... 80 degrees, nozzle length... 51 Experiment 1 Using a 0 Yu 2 snow nozzle, the number of rotations of the rotating arm was 0,3
The pellets of immobilized microorganisms were granulated at 0.500.700 rpm. FIG. 5 shows the relationship between the diameter of the pellet and the number of rotations of the rotary arm, and FIG. 6 shows the relationship between the deformation rate of the pellet. Note that the deformation rate of the pellet was determined by the following formula.

Experiment 2 The number of rotations of the rotating arm was set to 50 Orpm, and the diameter of the nozzle was changed to 1, 1, 5, 2, 2, 51, and pellets of immobilized microorganisms were granulated. FIG. 7 shows the relationship between the diameter of the pellet and the diameter of the nozzle.

Experiment 3 For comparison, a hollow rotating body was rotated continuously and droplets were formed by the action of centrifugal force. The other experimental conditions were actually the same as those in Experiment I. The relationship between the rotation speed of the hollow rotating body and the diameter of the pellet is shown in Figure 8, and the relationship between the deformation rate of the pellet is shown in Figure 9.

In FIGS. 5 to 9, each point indicates an average value in each experiment, and the line widths above and below each point indicate a confidence interval with a confidence rate of 95%.

Comparing FIG. 5 and FIG. 8, it can be seen that as the movable or rotational speed of the hollow rotating body increases, the diameter of the pellet decreases in the same manner, but in the case of FIG. 5 according to the present invention,
It can be seen that when the rotation speed of the rotating arm is constant, the variation in the diameter of the pellet is small.

Moreover, when comparing FIG. 6 and FIG. 9, it is found that
In the case of the figure, it can be seen that the deformation rate of the pellet is within the range of 1.0 to 1.3 regardless of the change in the rotational speed of the rotary arm, and a stable, perfectly spherical pellet can be obtained. On the other hand, in the case of FIG. 9 according to the prior art, it is shown that as the rotational speed of the hollow rotating body increases, the deformation rate increases and the number of flat pellets increases.

From FIG. 7, it can be seen that the smaller the diameter of the nozzle, the smaller the diameter of the pellet, and the smaller its fluctuation.

Therefore, in carrying out this example, the desired diameter with small variations can be achieved by appropriately selecting the rotational speed of the rotating arm and the diameter of the nozzle while taking into consideration the viscosity and surface tension of the mixed liquid. It is possible to granulate perfectly spherical immobilized microorganisms.

In the embodiment described above, the nozzle 22 attached to the hollow rotating body 12 was installed in the vertical direction, but it may be attached in the horizontal direction as shown in FIG. io. Further, as shown in FIG. 11, a conical slope may be provided from the center of the hollow rotating body 12 toward the surrounding nozzles 22 to facilitate uniform movement of the mixed liquid to each nozzle.

The drive mechanism that rotates the hollow rotating body alternately in forward and reverse directions is
The present invention is not limited to the mechanism using the rotary arm and crank, but may be a mechanism in which a motor is directly connected to the hollow rotary body and the hollow rotary body is rotated by electrical control.

Further, the hollow rotating body is not limited to being rotated alternately in the forward and reverse directions, but may be rotated intermittently in one direction, for example, by 45 degrees, using a stepping motor.

〔Effect of the invention〕

According to the present invention, spherical immobilized microorganisms having a uniform diameter can be efficiently (granulated).

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention, FIG. 2 is a side cross-sectional view illustrating a hollow rotating body according to the present invention, FIG. 3 is an explanatory view showing the rotating state of the hollow rotating body, and FIG. Figures (a), (b), and (c) are graphs showing the relationship between the rotation angle θ1, angular velocity ω1, and angular acceleration a1 of the hollow rotating body corresponding to the rotation of the rotary arm, respectively, and Figures 5 to 7 are graphs showing the relationship between 8 and 9 are graphs showing the experimental results when using a continuous rotating body according to the prior art, and FIGS. 10 and 11 are graphs showing the experimental results when using the device according to the present invention. FIG. 3 is a side sectional view showing another structural example of the hollow rotating body according to the invention. 10...Dripping means, 12...Hollow rotating body 18
... Mixed liquid supply pipe, 22 ... Nozzle 26 ... Crank, 28 ... Rotating arm 32 ... Gelling tank, 34 ... Gelling agent solution. Fig. 1 Fig. 2 Fig. 3 2 Fig. 4 Fig. 8 Fig. 9 Zero rotation number (rpm) of one 90 mm in the figure Number of openings of the hollow gypsum body (rprn) Fig. 10 Fig. 11 figure

Claims (1)

[Claims] An apparatus for granulating immobilized microorganisms, comprising a means for dropping a liquid mixture of microorganisms and an immobilizing agent as droplets from a nozzle, and a gelling tank for reacting and gelling the dropped droplets in a gelling agent solution. In the above, the droplet dropping means includes a hollow rotary body having a plurality of nozzles on the outer periphery and capable of accommodating the mixed liquid inside, and a drive mechanism that intermittently rotates the hollow rotary body in a horizontal plane. A granulation device for immobilized microorganisms, characterized in that it is configured as follows.