JPH0516896B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an apparatus for mixing powder and granular materials under pressure and heat.

(Prior Art) Apparatuses for stirring, mixing, and drying powder and granular materials can be roughly divided into two types: a rotating container type and a fixed container mixing type.

Figure 2 shows a V-type mixer 1 as a representative of the container rotating type.
This is a method in which material is charged through two charging ports 2 at the top and discharged through an intersecting conical section 3, but this method is difficult to apply to materials that are sticky or soften and melt when heated. , fixed container mixed type is often used.

Fig. 3 shows a so-called Nauta type mixer, in which a screw 4 installed inside the container 1 mixes powder and granules while rotating and revolving; however, heating means (e.g. It is also possible to use it in a mixer that is provided with a jacket (through which high-temperature heat transfer oil flows) and maintained in a pressurized state. However, it is difficult to seal the two shafts of rotation and revolution, making it impossible to operate under high pressure. In addition, in the figure, 5 is a discharge port.

Fig. 4 shows a fountain mixer with a screw 4 installed in the center of the container 1, but when used for heating and mixing using the wall heating method, heat transfer is poor for materials that stick to the inner wall surface, and the mixer is too large to be applied. There are drawbacks to becoming

(Problems to be Solved by the Invention) The inventors investigated an apparatus for impregnating expanded styrene pellets with a solvent while mixing the pellets, and found that the conventional method had poor mixing performance and was difficult to absorb the solvent. Because it uses a method of dripping in a liquid state, it also has a wetting distribution of the solvent.
Uniform mixing and solvent impregnation could not be obtained.

As mentioned above, in a device that impregnates the granules with a solvent while mixing them, the important thing is to uniformly impregnate the granules with the solvent, without causing the granules to adhere to the wall surface, and The purpose of this project is to develop a highly efficient mixing device that does not create stagnation in the container and evenly impregnates the granules with solvent.

(Means for Solving the Problems) The present invention provides stirring by installing a ribbon-type stirring blade having a cone angle substantially the same as that of the conical vertical fixed container at the center of the interior of the conical vertical fixed container. This makes it possible to prevent leaks from the shaft, making it easy to maintain high pressure, and the movement of pellets ascends the peripheral wall surface and descends through the center of the interior, allowing efficient heat exchange.
Furthermore, it is characterized by eliminating adhesion to walls and stagnation.

A device that mixes powder and granular materials under pressure and heat.The main body has a vertical conical shape, and the upper and lower ends are supported by shafts, and the stirring shaft is capable of vertical sliding adjustment. The present invention provides a mixing device characterized by being provided with a ribbon-shaped stirring blade having a cone angle substantially the same as the cone angle of the main body.

The present invention can be advantageously applied as a mixing device and a heating device for powder and granular materials.

(Example) Hereinafter, one embodiment of the present invention will be described in detail with reference to FIG. FIG. 1 shows an example in which the present invention is applied to a device for mixing and solvent impregnating pellets for expanded styrene. In Fig. 1, 1 is a vertical conical mixing body, 2 is a stirring shaft, and to this is fixed a ribbon-shaped stirring blade 3 having a cone angle that is almost the same as that of the main body. ing. Note that it is preferable that the stirring shaft 2 is provided so as to be able to slide up and down. 4 is a jacket through which a heating medium flows, and has an inlet nozzle 5 and an outlet nozzle 6. Reference numeral 7 designates a charging port for raw material pellets, and 8 designates a product discharge valve, which has a mechanism in which a valve body 9 is driven by an air cylinder 11. Also, a metal bellow 1 is installed to prevent leakage from the valve 12.
It is sealed with 0. 13 is a pellet extraction valve, 1
Reference numeral 4 indicates a supply port connected to a solvent supply source (not shown), and reference numerals 15 and 18 indicate a sealing mechanism 16 and a pedestal supporting a stirring electric motor 17.

(Operation) Raw material pellets are charged into the mixer 1 through the charging port 7. In the mixer 1, a heating medium is heated in advance to a predetermined temperature by flowing it from an inlet nozzle 5 to an outlet nozzle 6, and the stirring blade 3 is also rotated by an electric motor 17 at a predetermined rotation speed.

The discharge valve 8 is also kept in a closed state, and after the raw materials have been input, the charging port 7 is closed, and after the temperature of the pellets has risen, a solvent is supplied and the pellets are stirred and mixed for a predetermined period of time to impregnate the pellets with the solvent.

After the impregnation with the solvent is completed, the product discharge valve 8 at the lower part is opened to collect the product into a tank (not shown) outside the system.

(Effects) The effects of arranging the ribbon-shaped stirring blades in the vertical conical mixing tank are: (1) It is possible to prevent the raw materials from adhering to the heating wall surface, and the heat transfer coefficient is improved.

(2) The raw material flows up the wall surface and descends down the center, and the cross-sectional area increases as it goes up, promoting particle mixing in the radial direction, which is different from the conventional V
The heat transfer coefficient is dramatically higher than that of a type mixer.

(3) There are no sluggish areas in the tank,
There is no variation in product quality.

(4) The conical shape makes it easy to discharge the product;
When processing multiple types of raw materials, no contamination occurs between different types of products.

(5) By moving up and down with the stirring shaft, the distance between the ribbon blade and the wall surface can be easily adjusted.

Therefore, even highly adhesive materials can be treated, expanding the field of application.

(6) Compared to a V-type mixer, there is no need to support the entire weight with a shaft, so it can accommodate larger sizes.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing one embodiment of the device of the present invention, and FIGS. 2 to 4 are schematic diagrams showing various conventional mixing devices. 1... Mixer main body, 2... Stirring shaft, 3...
Ribbon-shaped stirring blade, 4...jacket, 7...
Charging port, 8... product discharge valve, 17... electric motor for stirring.

Claims (1)

[Claims] 1. A device for mixing powder and granular materials under pressure and heating, the main body of which is a rigid conical shape, with shaft support near the upper end and lower end, and a stirring shaft that can be slid up and down and inside the main body. A mixing device comprising a ribbon-shaped stirring blade having a cone angle substantially the same as the cone angle of the main body.