JPH09206578A - Agitating mixer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To apply uniform and strong shear on a fluid passing through a flow passage consisting of a clearance to uniformize deposited particles by installing a flow passage resistant plate fitted to supporting bars in a clearance between a cylindrical vessel and a fluid guiding cylinder. SOLUTION: A fluid guiding cylinder 8 is fixed by legs 9 concentrically with a vessel 1 leaving a clearance, and a fluid passes through between the legs 9. In a clearance between the fluid guiding cylinder 8 and the vessel 1, a spiral helical ribbon blade 10 is fitted to supporting bars 7. The supporting bars 7 are provided with a doughnut flow passage resistant body 13 near the upper part of the fluid guiding cylinder 8 so that it may close a quarter to three quarters of the section of the flow passage. In this way, uniform and strong shear force is applied on a fluid passing through the flow passage to deposit particles such as uniform and particulate rubber.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a mixer for stirring and mixing a liquid substance to obtain a uniform product, a polymerization reaction device for polymerizing a low-viscosity substance to obtain a high-viscosity polymer substance, and The present invention relates to a stirring and mixing apparatus used as a phase inversion reactor in a rubber particle precipitation step of high impact polystyrene (HIPS).

[0002]

2. Description of the Related Art Conventionally, many types of agitation mixers have been used. For low-viscosity liquids, propellers, turbines,
Paddles are common, and for viscous liquids, spiral band wings (helical ribbon wings), helical screw wings, and cone-shaped wings are common.

In particular, a high viscosity liquid, which is often handled in a polymer manufacturing process, is more difficult to mix than a low viscosity liquid, and the quality of the product depends on the selection of the agitation mixer, so the shape should be carefully selected. There is a need.

As a stirring and mixing apparatus which can be used in a wide range from low viscosity liquid to high viscosity liquid, there are a helical screw blade and a helical ribbon blade having a fluid guide cylinder (draft tube) in a container.

The helical ribbon impeller with a draft tube has a shape in which the helical ribbon impeller is installed in the gap between the inner wall of the container and the outer wall of the draft tube, and is a high performance stirring and mixing device with extremely high liquid circulation performance.

FIG. 2 shows a conventional stirring and mixing apparatus using a helical ribbon blade with a draft tube. The cylindrical container 1 and the lid 2 of the stirrer are provided with a liquid supply port 3 and a liquid discharge port 4, respectively, and a rotary shaft 5 is inserted concentrically with the container 1 from above. An arm 6 oriented at a right angle, that is, horizontally, is attached to the rotary shaft 5, and a support rod 7 is attached downward from both ends of the arm 6.

Further, a cylindrical fluid guide cylinder (draft tube) 8 is fixed to the container 1 by a plurality of legs 9 so as to be concentric with the container 1 and with a gap from the container 1. Fluid is allowed to pass between the legs 9. A spiral ribbon-shaped helical ribbon blade 10 is installed in the gap between the fluid guide cylinder 8 and the container 1, the helical ribbon blade 10 is attached to the support rod 7, and the helical ribbon blade 10 rotates in the direction of arrow 12. It rotates with the rotating shaft 5.

In both of the conventional stirring and mixing apparatuses of the above-mentioned two examples, in order to improve the circulation performance of the liquid in the tank, obstacles are not provided to the liquid circulation passage as much as possible. However,
For example, in the case of the conventional stirring and mixing device using the helical ribbon blade with the draft tube shown in FIG. 2, the fluid is generated by the rotation of the helical ribbon blade 10 provided between the cylindrical container 1 and the fluid guide tube 8. Since it rises without resistance between the cylindrical container 1 and the fluid guide cylinder 8, there is a drawback that the frequency of shearing the fluid is small in the gap between the helical ribbon blade 10 and the cylindrical container 1 or the fluid guide cylinder 8.

[0009]

In the production of impact-resistant polystyrene (hereinafter abbreviated as HIPS), there is a step of crystallizing rubber dissolved in styrene as fine particles. In order to generate (particle size), it is necessary that the fluid be uniformly sheared. However, as described above, in the conventional stirring and mixing apparatus, the frequency of shearing the fluid when passing through the flow channel is small (only a few percent of the fluid flowing through the flow channel receives a strong shearing force). There is a problem that the deposited rubber particles are not uniform.

The present invention has been made for the purpose of solving the above problems.

[0011]

The stirring and mixing apparatus of the present invention is installed in a cylindrical container, inside the cylindrical container, concentric with the container, and with a gap between the container and the container. The container and the fluid guide tube are formed by a cylindrical fluid guide tube, a rotary shaft that is installed concentrically with the same container, an arm that is mounted substantially at a right angle to the rotary shaft, and a support rod that is mounted on the arm. And a flow path resistance plate which is attached to the support rod and is disposed in the gap between the cylindrical container and the fluid guide cylinder.

As described above, according to the present invention, since the flow path resistance plate is provided in the gap between the cylindrical container and the fluid guide cylinder,
The pressure loss in the flow passage formed by the gap increases, and the flow that flows backward (circulates) through the gap between the helical ribbon blade and the cylindrical container or fluid guide cylinder increases significantly, and as a result, passes through this flow passage. The frequency of shearing is increased in the fluid, and the fluid is uniformly sheared, so that the particle size of the precipitated particles such as rubber becomes uniform.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment of the present invention will be described below with reference to FIG.

A cylindrical container 1 and a lid 2 of the stirring device are provided with a liquid supply port 3 and a liquid discharge port 4, respectively, and a rotary shaft 5 is inserted coaxially with the container 1 from above. An arm 6 oriented at a right angle, that is, horizontally, is attached to the rotating shaft 5, and a support rod 7 is attached downward from both ends of the arm 6.

A cylindrical (draft tube) 8 is fixed to the container 1 by a plurality of legs 9 so as to be concentric with the container 1 and with a gap from the container 1. , Fluid is allowed to pass between the legs. A helical helical ribbon blade 10 is installed in a gap between the fluid guide cylinder 8 and the container 1, and the helical ribbon blade 1 is provided.
0 is attached to the support rod 7, and the helical ribbon wing 1
0 rotates together with the rotary shaft 5 which rotates in the direction of arrow 12.

A doughnut-shaped flow path resistance plate 13 is formed in the support rod 7 near the upper portion of the fluid guide cylinder 8 in the gap between the cylindrical container 1 and the fluid guide cylinder 8 with respect to the cross-sectional area of the flow path. It is provided so as to close the cross-sectional area of 1/4 to 3/4.
The ratio of the cross-sectional area of the flow path resistance plate 13 to the flow path is adjusted by the viscosity of the fluid, the number of revolutions of the helical ribbon blade, the number of turns, or the like.

In this embodiment, when the rotary shaft 5 is rotated by a drive unit (not shown) as shown by an arrow 12, the liquid rises outside the fluid guide cylinder 8 and descends inside.

At this time, since the flow path resistance plate 13 is provided in the flow path formed in the gap between the cylindrical container 1 near the upper part of the fluid guide tube 8 and the fluid guide tube 8, the cylindrical container is formed. 1
When the fluid passes through the fluid guide cylinder 8, a backflow is generated in the gap, so that the fluid is uniformly and strongly sheared, and the particles of rubber or the like precipitated at this time are atomized and made uniform.

[0019]

According to the present invention, as described in the claims, since the flow path resistance plate attached to the support rod is installed in the gap between the cylindrical container and the fluid guide cylinder, the above-mentioned gap is provided. Uniform and strong shearing is applied to the fluid passing through the flow path formed in step (3), and it becomes possible to deposit particles of rubber and the like that are homogeneous and fine.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a first embodiment of the present invention.

FIG. 2 is a vertical sectional view showing a conventional stirring and mixing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylindrical container 2 Lid 3 Supply port 4 Discharge port 5 Rotating shaft 6 Arm 7 Support rod 8 Fluid guide tube 9 Leg 10 Helical ribbon blade 13 Fluid resistance plate

Claims (1)

[Claims] 1. A cylindrical container, a cylindrical fluid guide cylinder provided inside the same container and coaxial with the same container, and a cylindrical fluid guide cylinder provided with a gap between the cylindrical container and the same container, and coaxially with the same container. Rotation axis,
An arm mounted substantially at a right angle to the rotary shaft, a stirring blade inserted in a gap between the container and the fluid guide cylinder by a support rod mounted on the arm, and the cylindrical shape mounted on the support rod. An agitating / mixing device comprising a flow path resistance plate disposed in a gap between the container and the fluid guide cylinder.